X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/4a3eedf9ecc9bbe3f3a5c6ce5e53ad199d639d32..b226f5e54a60dc81db17b1260381d7dbfea3cdf1:/bsd/netinet/tcp_input.c diff --git a/bsd/netinet/tcp_input.c b/bsd/netinet/tcp_input.c index 302ab9431..c18f014e1 100644 --- a/bsd/netinet/tcp_input.c +++ b/bsd/netinet/tcp_input.c @@ -1,8 +1,8 @@ /* - * Copyright (c) 2000-2007 Apple Inc. All rights reserved. + * Copyright (c) 2000-2017 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ - * + * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in @@ -11,10 +11,10 @@ * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. - * + * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. - * + * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, @@ -22,7 +22,7 @@ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. - * + * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* @@ -78,21 +78,30 @@ #include #include #include - +#include +#if !CONFIG_EMBEDDED +#include +#endif +#include #include /* before tcp_seq.h, for tcp_random18() */ +#include + #include #include #include +#include +#include #include #include #include -#include /* for ICMP_BANDLIM */ +#include /* for ICMP_BANDLIM */ #include #include /* for ICMP_BANDLIM */ #include #include +#include #if INET6 #include #include @@ -101,10 +110,14 @@ #include #endif #include +#include #include #include #include #include +#include +#include +#include #if INET6 #include #endif @@ -128,127 +141,233 @@ struct tcphdr tcp_savetcp; #endif /* CONFIG_MACF_NET || CONFIG_MACF_SOCKET */ #include +#include +#if MPTCP +#include +#include +#include +#endif /* MPTCP */ -#ifndef __APPLE__ -MALLOC_DEFINE(M_TSEGQ, "tseg_qent", "TCP segment queue entry"); -#endif +#include #define DBG_LAYER_BEG NETDBG_CODE(DBG_NETTCP, 0) #define DBG_LAYER_END NETDBG_CODE(DBG_NETTCP, 2) #define DBG_FNC_TCP_INPUT NETDBG_CODE(DBG_NETTCP, (3 << 8)) #define DBG_FNC_TCP_NEWCONN NETDBG_CODE(DBG_NETTCP, (7 << 8)) -static int tcprexmtthresh = 2; -tcp_cc tcp_ccgen; - -#if IPSEC -extern int ipsec_bypass; -#endif +#define TCP_RTT_HISTORY_EXPIRE_TIME (60 * TCP_RETRANSHZ) +#define TCP_RECV_THROTTLE_WIN (5 * TCP_RETRANSHZ) +#define TCP_STRETCHACK_ENABLE_PKTCNT 2000 struct tcpstat tcpstat; static int log_in_vain = 0; -SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_in_vain, CTLFLAG_RW, - &log_in_vain, 0, "Log all incoming TCP connections"); +SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_in_vain, + CTLFLAG_RW | CTLFLAG_LOCKED, &log_in_vain, 0, + "Log all incoming TCP connections"); static int blackhole = 0; -SYSCTL_INT(_net_inet_tcp, OID_AUTO, blackhole, CTLFLAG_RW, - &blackhole, 0, "Do not send RST when dropping refused connections"); +SYSCTL_INT(_net_inet_tcp, OID_AUTO, blackhole, + CTLFLAG_RW | CTLFLAG_LOCKED, &blackhole, 0, + "Do not send RST when dropping refused connections"); -int tcp_delack_enabled = 3; -SYSCTL_INT(_net_inet_tcp, OID_AUTO, delayed_ack, CTLFLAG_RW, - &tcp_delack_enabled, 0, +SYSCTL_SKMEM_TCP_INT(OID_AUTO, delayed_ack, + CTLFLAG_RW | CTLFLAG_LOCKED, int, tcp_delack_enabled, 3, "Delay ACK to try and piggyback it onto a data packet"); -int tcp_lq_overflow = 1; -SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcp_lq_overflow, CTLFLAG_RW, - &tcp_lq_overflow, 0, +SYSCTL_SKMEM_TCP_INT(OID_AUTO, tcp_lq_overflow, + CTLFLAG_RW | CTLFLAG_LOCKED, int, tcp_lq_overflow, 1, "Listen Queue Overflow"); +SYSCTL_SKMEM_TCP_INT(OID_AUTO, recvbg, CTLFLAG_RW | CTLFLAG_LOCKED, + int, tcp_recv_bg, 0, "Receive background"); + #if TCP_DROP_SYNFIN -static int drop_synfin = 1; -SYSCTL_INT(_net_inet_tcp, OID_AUTO, drop_synfin, CTLFLAG_RW, - &drop_synfin, 0, "Drop TCP packets with SYN+FIN set"); +SYSCTL_SKMEM_TCP_INT(OID_AUTO, drop_synfin, + CTLFLAG_RW | CTLFLAG_LOCKED, static int, drop_synfin, 1, + "Drop TCP packets with SYN+FIN set"); #endif SYSCTL_NODE(_net_inet_tcp, OID_AUTO, reass, CTLFLAG_RW|CTLFLAG_LOCKED, 0, "TCP Segment Reassembly Queue"); -__private_extern__ int tcp_reass_maxseg = 0; -SYSCTL_INT(_net_inet_tcp_reass, OID_AUTO, maxsegments, CTLFLAG_RW, - &tcp_reass_maxseg, 0, - "Global maximum number of TCP Segments in Reassembly Queue"); - -__private_extern__ int tcp_reass_qsize = 0; -SYSCTL_INT(_net_inet_tcp_reass, OID_AUTO, cursegments, CTLFLAG_RD, - &tcp_reass_qsize, 0, - "Global number of TCP Segments currently in Reassembly Queue"); - static int tcp_reass_overflows = 0; -SYSCTL_INT(_net_inet_tcp_reass, OID_AUTO, overflows, CTLFLAG_RD, - &tcp_reass_overflows, 0, +SYSCTL_INT(_net_inet_tcp_reass, OID_AUTO, overflows, + CTLFLAG_RD | CTLFLAG_LOCKED, &tcp_reass_overflows, 0, "Global number of TCP Segment Reassembly Queue Overflows"); -__private_extern__ int slowlink_wsize = 8192; -SYSCTL_INT(_net_inet_tcp, OID_AUTO, slowlink_wsize, CTLFLAG_RW, - &slowlink_wsize, 0, "Maximum advertised window size for slowlink"); +SYSCTL_SKMEM_TCP_INT(OID_AUTO, slowlink_wsize, CTLFLAG_RW | CTLFLAG_LOCKED, + __private_extern__ int, slowlink_wsize, 8192, + "Maximum advertised window size for slowlink"); + +SYSCTL_SKMEM_TCP_INT(OID_AUTO, maxseg_unacked, + CTLFLAG_RW | CTLFLAG_LOCKED, int, maxseg_unacked, 8, + "Maximum number of outstanding segments left unacked"); -static int maxseg_unacked = 8; -SYSCTL_INT(_net_inet_tcp, OID_AUTO, maxseg_unacked, CTLFLAG_RW, - &maxseg_unacked, 0, "Maximum number of outstanding segments left unacked"); +SYSCTL_SKMEM_TCP_INT(OID_AUTO, rfc3465, CTLFLAG_RW | CTLFLAG_LOCKED, + int, tcp_do_rfc3465, 1, ""); + +SYSCTL_SKMEM_TCP_INT(OID_AUTO, rfc3465_lim2, + CTLFLAG_RW | CTLFLAG_LOCKED, int, tcp_do_rfc3465_lim2, 1, + "Appropriate bytes counting w/ L=2*SMSS"); + +int rtt_samples_per_slot = 20; + +int tcp_acc_iaj_high_thresh = ACC_IAJ_HIGH_THRESH; +u_int32_t tcp_autorcvbuf_inc_shift = 3; +SYSCTL_SKMEM_TCP_INT(OID_AUTO, recv_allowed_iaj, + CTLFLAG_RW | CTLFLAG_LOCKED, int, tcp_allowed_iaj, ALLOWED_IAJ, + "Allowed inter-packet arrival jiter"); +#if (DEVELOPMENT || DEBUG) +SYSCTL_INT(_net_inet_tcp, OID_AUTO, acc_iaj_high_thresh, + CTLFLAG_RW | CTLFLAG_LOCKED, &tcp_acc_iaj_high_thresh, 0, + "Used in calculating maximum accumulated IAJ"); + +SYSCTL_INT(_net_inet_tcp, OID_AUTO, autorcvbufincshift, + CTLFLAG_RW | CTLFLAG_LOCKED, &tcp_autorcvbuf_inc_shift, 0, + "Shift for increment in receive socket buffer size"); +#endif /* (DEVELOPMENT || DEBUG) */ + +SYSCTL_SKMEM_TCP_INT(OID_AUTO, doautorcvbuf, + CTLFLAG_RW | CTLFLAG_LOCKED, u_int32_t, tcp_do_autorcvbuf, 1, + "Enable automatic socket buffer tuning"); + +SYSCTL_SKMEM_TCP_INT(OID_AUTO, autorcvbufmax, + CTLFLAG_RW | CTLFLAG_LOCKED, u_int32_t, tcp_autorcvbuf_max, 512 * 1024, + "Maximum receive socket buffer size"); + +#if CONFIG_EMBEDDED +int sw_lro = 1; +#else +int sw_lro = 0; +#endif /* !CONFIG_EMBEDDED */ +SYSCTL_INT(_net_inet_tcp, OID_AUTO, lro, CTLFLAG_RW | CTLFLAG_LOCKED, + &sw_lro, 0, "Used to coalesce TCP packets"); + +int lrodebug = 0; +SYSCTL_INT(_net_inet_tcp, OID_AUTO, lrodbg, + CTLFLAG_RW | CTLFLAG_LOCKED, &lrodebug, 0, + "Used to debug SW LRO"); + +int lro_start = 4; +SYSCTL_INT(_net_inet_tcp, OID_AUTO, lro_startcnt, + CTLFLAG_RW | CTLFLAG_LOCKED, &lro_start, 0, + "Segments for starting LRO computed as power of 2"); + +int limited_txmt = 1; +int early_rexmt = 1; +int sack_ackadv = 1; +int tcp_dsack_enable = 1; + +#if (DEVELOPMENT || DEBUG) +SYSCTL_INT(_net_inet_tcp, OID_AUTO, limited_transmit, + CTLFLAG_RW | CTLFLAG_LOCKED, &limited_txmt, 0, + "Enable limited transmit"); + +SYSCTL_INT(_net_inet_tcp, OID_AUTO, early_rexmt, + CTLFLAG_RW | CTLFLAG_LOCKED, &early_rexmt, 0, + "Enable Early Retransmit"); + +SYSCTL_INT(_net_inet_tcp, OID_AUTO, sack_ackadv, + CTLFLAG_RW | CTLFLAG_LOCKED, &sack_ackadv, 0, + "Use SACK with cumulative ack advancement as a dupack"); + +SYSCTL_INT(_net_inet_tcp, OID_AUTO, dsack_enable, + CTLFLAG_RW | CTLFLAG_LOCKED, &tcp_dsack_enable, 0, + "use DSACK TCP option to report duplicate segments"); + +#endif /* (DEVELOPMENT || DEBUG) */ +int tcp_disable_access_to_stats = 1; +SYSCTL_INT(_net_inet_tcp, OID_AUTO, disable_access_to_stats, + CTLFLAG_RW | CTLFLAG_LOCKED, &tcp_disable_access_to_stats, 0, + "Disable access to tcpstat"); + +SYSCTL_SKMEM_TCP_INT(OID_AUTO, challengeack_limit, + CTLFLAG_RW | CTLFLAG_LOCKED, uint32_t, tcp_challengeack_limit, 10, + "Maximum number of challenge ACKs per connection per second"); + +SYSCTL_SKMEM_TCP_INT(OID_AUTO, do_rfc5961, + CTLFLAG_RW | CTLFLAG_LOCKED, static int, tcp_do_rfc5961, 1, + "Enable/Disable full RFC 5961 compliance"); -static int tcp_do_rfc3465 = 1; -SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3465, CTLFLAG_RW, - &tcp_do_rfc3465, 0, ""); extern int tcp_TCPTV_MIN; +extern int tcp_acc_iaj_high; +extern int tcp_acc_iaj_react_limit; -u_long tcp_now; +int tcprexmtthresh = 3; + +u_int32_t tcp_now; +struct timeval tcp_uptime; /* uptime when tcp_now was last updated */ +lck_spin_t *tcp_uptime_lock; /* Used to sychronize updates to tcp_now */ struct inpcbhead tcb; #define tcb6 tcb /* for KAME src sync over BSD*'s */ struct inpcbinfo tcbinfo; -static void tcp_dooptions(struct tcpcb *, - u_char *, int, struct tcphdr *, struct tcpopt *); -static void tcp_pulloutofband(struct socket *, - struct tcphdr *, struct mbuf *, int); -static int tcp_reass(struct tcpcb *, struct tcphdr *, int *, - struct mbuf *); -static void tcp_xmit_timer(struct tcpcb *, int); +static void tcp_dooptions(struct tcpcb *, u_char *, int, struct tcphdr *, + struct tcpopt *); +static void tcp_finalize_options(struct tcpcb *, struct tcpopt *, unsigned int); +static void tcp_pulloutofband(struct socket *, + struct tcphdr *, struct mbuf *, int); +static int tcp_reass(struct tcpcb *, struct tcphdr *, int *, struct mbuf *, + struct ifnet *); +static void tcp_xmit_timer(struct tcpcb *, int, u_int32_t, tcp_seq); static inline unsigned int tcp_maxmtu(struct rtentry *); -#if INET6 -static inline unsigned int tcp_maxmtu6(struct rtentry *); -#endif +static inline int tcp_stretch_ack_enable(struct tcpcb *tp, int thflags); +static inline void tcp_adaptive_rwtimo_check(struct tcpcb *, int); + +#if TRAFFIC_MGT +static inline void update_iaj_state(struct tcpcb *tp, uint32_t tlen, + int reset_size); +void compute_iaj(struct tcpcb *tp, int nlropkts, int lro_delay_factor); +static void compute_iaj_meat(struct tcpcb *tp, uint32_t cur_iaj); +#endif /* TRAFFIC_MGT */ -/* Neighbor Discovery, Neighbor Unreachability Detection Upper layer hint. */ #if INET6 -#define ND6_HINT(tp) \ -do { \ - if ((tp) && (tp)->t_inpcb && \ - ((tp)->t_inpcb->inp_vflag & INP_IPV6) != 0 && \ - (tp)->t_inpcb->in6p_route.ro_rt) \ - nd6_nud_hint((tp)->t_inpcb->in6p_route.ro_rt, NULL, 0); \ -} while (0) -#else -#define ND6_HINT(tp) +static inline unsigned int tcp_maxmtu6(struct rtentry *); #endif -extern u_long *delack_bitmask; +unsigned int get_maxmtu(struct rtentry *); + +static void tcp_sbrcv_grow(struct tcpcb *tp, struct sockbuf *sb, + struct tcpopt *to, u_int32_t tlen, u_int32_t rcvbuf_max); +void tcp_sbrcv_trim(struct tcpcb *tp, struct sockbuf *sb); +static void tcp_sbsnd_trim(struct sockbuf *sbsnd); +static inline void tcp_sbrcv_tstmp_check(struct tcpcb *tp); +static inline void tcp_sbrcv_reserve(struct tcpcb *tp, struct sockbuf *sb, + u_int32_t newsize, u_int32_t idealsize, u_int32_t rcvbuf_max); +static void tcp_bad_rexmt_restore_state(struct tcpcb *tp, struct tcphdr *th); +static void tcp_compute_rtt(struct tcpcb *tp, struct tcpopt *to, + struct tcphdr *th); +static void tcp_early_rexmt_check(struct tcpcb *tp, struct tcphdr *th); +static void tcp_bad_rexmt_check(struct tcpcb *tp, struct tcphdr *th, + struct tcpopt *to); +/* + * Constants used for resizing receive socket buffer + * when timestamps are not supported + */ +#define TCPTV_RCVNOTS_QUANTUM 100 +#define TCP_RCVNOTS_BYTELEVEL 204800 -extern void add_to_time_wait(struct tcpcb *); -extern void postevent(struct socket *, struct sockbuf *, int); +/* + * Constants used for limiting early retransmits + * to 10 per minute. + */ +#define TCP_EARLY_REXMT_WIN (60 * TCP_RETRANSHZ) /* 60 seconds */ +#define TCP_EARLY_REXMT_LIMIT 10 -extern void ipfwsyslog( int level, const char *format,...); -extern int ChkAddressOK( __uint32_t dstaddr, __uint32_t srcaddr ); +extern void ipfwsyslog( int level, const char *format,...); extern int fw_verbose; -__private_extern__ int tcp_sockthreshold; -__private_extern__ int tcp_win_scale; #if IPFIREWALL +extern void ipfw_stealth_stats_incr_tcp(void); + #define log_in_vain_log( a ) { \ if ( (log_in_vain == 3 ) && (fw_verbose == 2)) { /* Apple logging, log to ipfw.log */ \ ipfwsyslog a ; \ + } else if ( (log_in_vain == 4 ) && (fw_verbose == 2)) { \ + ipfw_stealth_stats_incr_tcp(); \ } \ else log a ; \ } @@ -256,52 +375,279 @@ __private_extern__ int tcp_win_scale; #define log_in_vain_log( a ) { log a; } #endif +int tcp_rcvunackwin = TCPTV_UNACKWIN; +int tcp_maxrcvidle = TCPTV_MAXRCVIDLE; +SYSCTL_SKMEM_TCP_INT(OID_AUTO, rcvsspktcnt, CTLFLAG_RW | CTLFLAG_LOCKED, + int, tcp_rcvsspktcnt, TCP_RCV_SS_PKTCOUNT, "packets to be seen before receiver stretches acks"); -/* - * Indicate whether this ack should be delayed. - * We can delay the ack if: - * - delayed acks are enabled (set to 1) and - * - our last ack wasn't a 0-sized window. We never want to delay - * the ack that opens up a 0-sized window. - * - delayed acks are enabled (set to 2, "more compatible") and - * - our last ack wasn't a 0-sized window. - * - if the peer hasn't sent us a TH_PUSH data packet (this solves 3649245) - * - the peer hasn't sent us a TH_PUSH data packet, if he did, take this as a clue that we - * need to ACK with no delay. This helps higher level protocols who won't send - * us more data even if the window is open because their last "segment" hasn't been ACKed - * - delayed acks are enabled (set to 3, "streaming detection") and - * - if we receive more than "maxseg_unacked" full packets per second on this socket - * - if we don't have more than "maxseg_unacked" delayed so far - * - if those criteria aren't met, acts like "2". Allowing faster acking while browsing for example. - * - */ -#define DELAY_ACK(tp) \ - (((tcp_delack_enabled == 1) && ((tp->t_flags & TF_RXWIN0SENT) == 0)) || \ - (((tcp_delack_enabled == 2) && (tp->t_flags & TF_RXWIN0SENT) == 0) && \ - ((thflags & TH_PUSH) == 0) && ((tp->t_flags & TF_DELACK) == 0)) || \ - (((tcp_delack_enabled == 3) && (tp->t_flags & TF_RXWIN0SENT) == 0) && \ - (tp->t_rcvtime == 0) && ((thflags & TH_PUSH) == 0) && \ - (((tp->t_unacksegs == 0)) || \ - ((tp->rcv_byps > (maxseg_unacked * tp->t_maxseg)) && (tp->t_unacksegs < maxseg_unacked))))) +#define DELAY_ACK(tp, th) \ + (CC_ALGO(tp)->delay_ack != NULL && CC_ALGO(tp)->delay_ack(tp, th)) static int tcp_dropdropablreq(struct socket *head); static void tcp_newreno_partial_ack(struct tcpcb *tp, struct tcphdr *th); +static void update_base_rtt(struct tcpcb *tp, uint32_t rtt); +void tcp_set_background_cc(struct socket *so); +void tcp_set_foreground_cc(struct socket *so); +static void tcp_set_new_cc(struct socket *so, uint16_t cc_index); +static void tcp_bwmeas_check(struct tcpcb *tp); + +#if TRAFFIC_MGT +void +reset_acc_iaj(struct tcpcb *tp) +{ + tp->acc_iaj = 0; + CLEAR_IAJ_STATE(tp); +} + +static inline void +update_iaj_state(struct tcpcb *tp, uint32_t size, int rst_size) +{ + if (rst_size > 0) + tp->iaj_size = 0; + if (tp->iaj_size == 0 || size >= tp->iaj_size) { + tp->iaj_size = size; + tp->iaj_rcv_ts = tcp_now; + tp->iaj_small_pkt = 0; + } +} + +/* For every 32 bit unsigned integer(v), this function will find the + * largest integer n such that (n*n <= v). This takes at most 16 iterations + * irrespective of the value of v and does not involve multiplications. + */ +static inline int +isqrt(unsigned int val) +{ + unsigned int sqrt_cache[11] = {0, 1, 4, 9, 16, 25, 36, 49, 64, 81, 100}; + unsigned int temp, g=0, b=0x8000, bshft=15; + if ( val <= 100) { + for (g = 0; g <= 10; ++g) { + if (sqrt_cache[g] > val) { + g--; + break; + } else if (sqrt_cache[g] == val) { + break; + } + } + } else { + do { + temp = (((g << 1) + b) << (bshft--)); + if (val >= temp) { + g += b; + val -= temp; + } + b >>= 1; + } while ( b > 0 && val > 0); + } + return(g); +} + +/* +* With LRO, roughly estimate the inter arrival time between +* each sub coalesced packet as an average. Count the delay +* cur_iaj to be the delay between the last packet received +* and the first packet of the LRO stream. Due to round off errors +* cur_iaj may be the same as lro_delay_factor. Averaging has +* round off errors too. lro_delay_factor may be close to 0 +* in steady state leading to lower values fed to compute_iaj_meat. +*/ +void +compute_iaj(struct tcpcb *tp, int nlropkts, int lro_delay_factor) +{ + uint32_t cur_iaj = tcp_now - tp->iaj_rcv_ts; + uint32_t timediff = 0; + + if (cur_iaj >= lro_delay_factor) { + cur_iaj = cur_iaj - lro_delay_factor; + } + + compute_iaj_meat(tp, cur_iaj); + + if (nlropkts <= 1) + return; + + nlropkts--; + + timediff = lro_delay_factor/nlropkts; + + while (nlropkts > 0) + { + compute_iaj_meat(tp, timediff); + nlropkts--; + } +} + +static +void compute_iaj_meat(struct tcpcb *tp, uint32_t cur_iaj) +{ + /* When accumulated IAJ reaches MAX_ACC_IAJ in milliseconds, + * throttle the receive window to a minimum of MIN_IAJ_WIN packets + */ +#define MAX_ACC_IAJ (tcp_acc_iaj_high_thresh + tcp_acc_iaj_react_limit) +#define IAJ_DIV_SHIFT 4 +#define IAJ_ROUNDUP_CONST (1 << (IAJ_DIV_SHIFT - 1)) + + uint32_t allowed_iaj, acc_iaj = 0; + + uint32_t mean, temp; + int32_t cur_iaj_dev; + + cur_iaj_dev = (cur_iaj - tp->avg_iaj); + + /* Allow a jitter of "allowed_iaj" milliseconds. Some connections + * may have a constant jitter more than that. We detect this by + * using standard deviation. + */ + allowed_iaj = tp->avg_iaj + tp->std_dev_iaj; + if (allowed_iaj < tcp_allowed_iaj) + allowed_iaj = tcp_allowed_iaj; + + /* Initially when the connection starts, the senders congestion + * window is small. During this period we avoid throttling a + * connection because we do not have a good starting point for + * allowed_iaj. IAJ_IGNORE_PKTCNT is used to quietly gloss over + * the first few packets. + */ + if (tp->iaj_pktcnt > IAJ_IGNORE_PKTCNT) { + if ( cur_iaj <= allowed_iaj ) { + if (tp->acc_iaj >= 2) + acc_iaj = tp->acc_iaj - 2; + else + acc_iaj = 0; + + } else { + acc_iaj = tp->acc_iaj + (cur_iaj - allowed_iaj); + } + + if (acc_iaj > MAX_ACC_IAJ) + acc_iaj = MAX_ACC_IAJ; + tp->acc_iaj = acc_iaj; + } + + /* Compute weighted average where the history has a weight of + * 15 out of 16 and the current value has a weight of 1 out of 16. + * This will make the short-term measurements have more weight. + * + * The addition of 8 will help to round-up the value + * instead of round-down + */ + tp->avg_iaj = (((tp->avg_iaj << IAJ_DIV_SHIFT) - tp->avg_iaj) + + cur_iaj + IAJ_ROUNDUP_CONST) >> IAJ_DIV_SHIFT; + + /* Compute Root-mean-square of deviation where mean is a weighted + * average as described above. + */ + temp = tp->std_dev_iaj * tp->std_dev_iaj; + mean = (((temp << IAJ_DIV_SHIFT) - temp) + + (cur_iaj_dev * cur_iaj_dev) + + IAJ_ROUNDUP_CONST) >> IAJ_DIV_SHIFT; + + tp->std_dev_iaj = isqrt(mean); + + DTRACE_TCP3(iaj, struct tcpcb *, tp, uint32_t, cur_iaj, + uint32_t, allowed_iaj); + + return; +} +#endif /* TRAFFIC_MGT */ + +/* + * Perform rate limit check per connection per second + * tp->t_challengeack_last is the last_time diff was greater than 1sec + * tp->t_challengeack_count is the number of ACKs sent (within 1sec) + * Return TRUE if we shouldn't send the ACK due to rate limitation + * Return FALSE if it is still ok to send challenge ACK + */ +static boolean_t +tcp_is_ack_ratelimited(struct tcpcb *tp) +{ + boolean_t ret = TRUE; + uint32_t now = tcp_now; + int32_t diff = 0; + + diff = timer_diff(now, 0, tp->t_challengeack_last, 0); + /* If it is first time or diff > 1000ms, + * update the challengeack_last and reset the + * current count of ACKs + */ + if (tp->t_challengeack_last == 0 || diff >= 1000) { + tp->t_challengeack_last = now; + tp->t_challengeack_count = 0; + ret = FALSE; + } else if (tp->t_challengeack_count < tcp_challengeack_limit) { + ret = FALSE; + } + + /* Careful about wrap-around */ + if (ret == FALSE && (tp->t_challengeack_count + 1 > 0)) + tp->t_challengeack_count++; + return (ret); +} + +/* Check if enough amount of data has been acknowledged since + * bw measurement was started + */ +static void +tcp_bwmeas_check(struct tcpcb *tp) +{ + int32_t bw_meas_bytes; + uint32_t bw, bytes, elapsed_time; + + if (SEQ_LEQ(tp->snd_una, tp->t_bwmeas->bw_start)) + return; + + bw_meas_bytes = tp->snd_una - tp->t_bwmeas->bw_start; + if ((tp->t_flagsext & TF_BWMEAS_INPROGRESS) && + bw_meas_bytes >= (int32_t)(tp->t_bwmeas->bw_size)) { + bytes = bw_meas_bytes; + elapsed_time = tcp_now - tp->t_bwmeas->bw_ts; + if (elapsed_time > 0) { + bw = bytes / elapsed_time; + if ( bw > 0) { + if (tp->t_bwmeas->bw_sndbw > 0) { + tp->t_bwmeas->bw_sndbw = + (((tp->t_bwmeas->bw_sndbw << 3) + - tp->t_bwmeas->bw_sndbw) + + bw) >> 3; + } else { + tp->t_bwmeas->bw_sndbw = bw; + } + + /* Store the maximum value */ + if (tp->t_bwmeas->bw_sndbw_max == 0) { + tp->t_bwmeas->bw_sndbw_max = + tp->t_bwmeas->bw_sndbw; + } else { + tp->t_bwmeas->bw_sndbw_max = + max(tp->t_bwmeas->bw_sndbw, + tp->t_bwmeas->bw_sndbw_max); + } + } + } + tp->t_flagsext &= ~(TF_BWMEAS_INPROGRESS); + } +} static int -tcp_reass(tp, th, tlenp, m) - register struct tcpcb *tp; - register struct tcphdr *th; - int *tlenp; - struct mbuf *m; +tcp_reass(struct tcpcb *tp, struct tcphdr *th, int *tlenp, struct mbuf *m, + struct ifnet *ifp) { struct tseg_qent *q; struct tseg_qent *p = NULL; struct tseg_qent *nq; struct tseg_qent *te = NULL; - struct socket *so = tp->t_inpcb->inp_socket; - int flags; + struct inpcb *inp = tp->t_inpcb; + struct socket *so = inp->inp_socket; + int flags = 0; int dowakeup = 0; + struct mbuf *oodata = NULL; + int copy_oodata = 0; + u_int16_t qlimit; + boolean_t cell = IFNET_IS_CELLULAR(ifp); + boolean_t wifi = (!cell && IFNET_IS_WIFI(ifp)); + boolean_t wired = (!wifi && IFNET_IS_WIRED(ifp)); + boolean_t dsack_set = FALSE; /* * Call with th==0 after become established to @@ -310,6 +656,18 @@ tcp_reass(tp, th, tlenp, m) if (th == NULL) goto present; + /* + * If the reassembly queue already has entries or if we are going + * to add a new one, then the connection has reached a loss state. + * Reset the stretch-ack algorithm at this point. + */ + tcp_reset_stretch_ack(tp); + +#if TRAFFIC_MGT + if (tp->acc_iaj > 0) + reset_acc_iaj(tp); +#endif /* TRAFFIC_MGT */ + /* * Limit the number of segments in the reassembly queue to prevent * holding on to too many segments (and thus running out of mbufs). @@ -317,8 +675,10 @@ tcp_reass(tp, th, tlenp, m) * queue. Always keep one global queue entry spare to be able to * process the missing segment. */ + qlimit = min(max(100, so->so_rcv.sb_hiwat >> 10), + (TCP_AUTORCVBUF_MAX(ifp) >> 10)); if (th->th_seq != tp->rcv_nxt && - tcp_reass_qsize + 1 >= tcp_reass_maxseg) { + (tp->t_reassqlen + 1) >= qlimit) { tcp_reass_overflows++; tcpstat.tcps_rcvmemdrop++; m_freem(m); @@ -327,14 +687,13 @@ tcp_reass(tp, th, tlenp, m) } /* Allocate a new queue entry. If we can't, just drop the pkt. XXX */ - MALLOC(te, struct tseg_qent *, sizeof (struct tseg_qent), M_TSEGQ, - M_NOWAIT); + te = (struct tseg_qent *) zalloc(tcp_reass_zone); if (te == NULL) { tcpstat.tcps_rcvmemdrop++; m_freem(m); return (0); } - tcp_reass_qsize++; + tp->t_reassqlen++; /* * Find a segment which begins after this one does. @@ -351,40 +710,98 @@ tcp_reass(tp, th, tlenp, m) * segment. If it provides all of our data, drop us. */ if (p != NULL) { - register int i; + int i; /* conversion to int (in i) handles seq wraparound */ i = p->tqe_th->th_seq + p->tqe_len - th->th_seq; if (i > 0) { + if (TCP_DSACK_ENABLED(tp) && i > 1) { + /* + * Note duplicate data sequnce numbers + * to report in DSACK option + */ + tp->t_dsack_lseq = th->th_seq; + tp->t_dsack_rseq = th->th_seq + + min(i, *tlenp); + + /* + * Report only the first part of partial/ + * non-contiguous duplicate sequence space + */ + dsack_set = TRUE; + } if (i >= *tlenp) { tcpstat.tcps_rcvduppack++; tcpstat.tcps_rcvdupbyte += *tlenp; + if (nstat_collect) { + nstat_route_rx(inp->inp_route.ro_rt, + 1, *tlenp, + NSTAT_RX_FLAG_DUPLICATE); + INP_ADD_STAT(inp, cell, wifi, wired, + rxpackets, 1); + INP_ADD_STAT(inp, cell, wifi, wired, + rxbytes, *tlenp); + tp->t_stat.rxduplicatebytes += *tlenp; + inp_set_activity_bitmap(inp); + } m_freem(m); - FREE(te, M_TSEGQ); - tcp_reass_qsize--; + zfree(tcp_reass_zone, te); + te = NULL; + tp->t_reassqlen--; /* * Try to present any queued data * at the left window edge to the user. * This is needed after the 3-WHS * completes. */ - goto present; /* ??? */ + goto present; } m_adj(m, i); *tlenp -= i; th->th_seq += i; } } + tp->t_rcvoopack++; tcpstat.tcps_rcvoopack++; tcpstat.tcps_rcvoobyte += *tlenp; + if (nstat_collect) { + nstat_route_rx(inp->inp_route.ro_rt, 1, *tlenp, + NSTAT_RX_FLAG_OUT_OF_ORDER); + INP_ADD_STAT(inp, cell, wifi, wired, rxpackets, 1); + INP_ADD_STAT(inp, cell, wifi, wired, rxbytes, *tlenp); + tp->t_stat.rxoutoforderbytes += *tlenp; + inp_set_activity_bitmap(inp); + } /* * While we overlap succeeding segments trim them or, * if they are completely covered, dequeue them. */ while (q) { - register int i = (th->th_seq + *tlenp) - q->tqe_th->th_seq; + int i = (th->th_seq + *tlenp) - q->tqe_th->th_seq; if (i <= 0) break; + + /* + * Report only the first part of partial/non-contiguous + * duplicate segment in dsack option. The variable + * dsack_set will be true if a previous entry has some of + * the duplicate sequence space. + */ + if (TCP_DSACK_ENABLED(tp) && i > 1 && !dsack_set) { + if (tp->t_dsack_lseq == 0) { + tp->t_dsack_lseq = q->tqe_th->th_seq; + tp->t_dsack_rseq = + tp->t_dsack_lseq + min(i, q->tqe_len); + } else { + /* + * this segment overlaps data in multple + * entries in the reassembly queue, move + * the right sequence number further. + */ + tp->t_dsack_rseq = + tp->t_dsack_rseq + min(i, q->tqe_len); + } + } if (i < q->tqe_len) { q->tqe_th->th_seq += i; q->tqe_len -= i; @@ -395,8 +812,8 @@ tcp_reass(tp, th, tlenp, m) nq = LIST_NEXT(q, tqe_q); LIST_REMOVE(q, tqe_q); m_freem(q->tqe_m); - FREE(q, M_TSEGQ); - tcp_reass_qsize--; + zfree(tcp_reass_zone, q); + tp->t_reassqlen--; q = nq; } @@ -411,6 +828,15 @@ tcp_reass(tp, th, tlenp, m) LIST_INSERT_AFTER(p, te, tqe_q); } + /* + * New out-of-order data exists, and is pointed to by + * queue entry te. Set copy_oodata to 1 so out-of-order data + * can be copied off to sockbuf after in-order data + * is copied off. + */ + if (!(so->so_state & SS_CANTRCVMORE)) + copy_oodata = 1; + present: /* * Present data to user, advancing rcv_nxt through @@ -419,72 +845,182 @@ present: if (!TCPS_HAVEESTABLISHED(tp->t_state)) return (0); q = LIST_FIRST(&tp->t_segq); - if (!q || q->tqe_th->th_seq != tp->rcv_nxt) + if (!q || q->tqe_th->th_seq != tp->rcv_nxt) { + /* Stop using LRO once out of order packets arrive */ + if (tp->t_flagsext & TF_LRO_OFFLOADED) { + tcp_lro_remove_state(inp->inp_laddr, inp->inp_faddr, + th->th_dport, th->th_sport); + tp->t_flagsext &= ~TF_LRO_OFFLOADED; + } + + /* + * continue processing if out-of-order data + * can be delivered + */ + if (q && (so->so_flags & SOF_ENABLE_MSGS)) + goto msg_unordered_delivery; + return (0); + } + + /* + * If there is already another thread doing reassembly for this + * connection, it is better to let it finish the job -- + * (radar 16316196) + */ + if (tp->t_flagsext & TF_REASS_INPROG) + return (0); + + tp->t_flagsext |= TF_REASS_INPROG; + /* lost packet was recovered, so ooo data can be returned */ + tcpstat.tcps_recovered_pkts++; + do { tp->rcv_nxt += q->tqe_len; flags = q->tqe_th->th_flags & TH_FIN; - nq = LIST_NEXT(q, tqe_q); LIST_REMOVE(q, tqe_q); - if (so->so_state & SS_CANTRCVMORE) + if (so->so_state & SS_CANTRCVMORE) { m_freem(q->tqe_m); - else { - if (sbappendstream(&so->so_rcv, q->tqe_m)) + } else { + so_recv_data_stat(so, q->tqe_m, 0); /* XXXX */ + if (so->so_flags & SOF_ENABLE_MSGS) { + /* + * Append the inorder data as a message to the + * receive socket buffer. Also check to see if + * the data we are about to deliver is the same + * data that we wanted to pass up to the user + * out of order. If so, reset copy_oodata -- + * the received data filled a gap, and + * is now in order! + */ + if (q == te) + copy_oodata = 0; + } + if (sbappendstream_rcvdemux(so, q->tqe_m, + q->tqe_th->th_seq - (tp->irs + 1), 0)) dowakeup = 1; + if (tp->t_flagsext & TF_LRO_OFFLOADED) { + tcp_update_lro_seq(tp->rcv_nxt, + inp->inp_laddr, inp->inp_faddr, + th->th_dport, th->th_sport); + } } - FREE(q, M_TSEGQ); - tcp_reass_qsize--; - q = nq; + zfree(tcp_reass_zone, q); + tp->t_reassqlen--; + q = LIST_FIRST(&tp->t_segq); } while (q && q->tqe_th->th_seq == tp->rcv_nxt); - ND6_HINT(tp); + tp->t_flagsext &= ~TF_REASS_INPROG; #if INET6 - if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { - + if ((inp->inp_vflag & INP_IPV6) != 0) { + KERNEL_DEBUG(DBG_LAYER_BEG, - ((tp->t_inpcb->inp_fport << 16) | tp->t_inpcb->inp_lport), - (((tp->t_inpcb->in6p_laddr.s6_addr16[0] & 0xffff) << 16) | - (tp->t_inpcb->in6p_faddr.s6_addr16[0] & 0xffff)), + ((inp->inp_fport << 16) | inp->inp_lport), + (((inp->in6p_laddr.s6_addr16[0] & 0xffff) << 16) | + (inp->in6p_faddr.s6_addr16[0] & 0xffff)), 0,0,0); } else #endif { KERNEL_DEBUG(DBG_LAYER_BEG, - ((tp->t_inpcb->inp_fport << 16) | tp->t_inpcb->inp_lport), - (((tp->t_inpcb->inp_laddr.s_addr & 0xffff) << 16) | - (tp->t_inpcb->inp_faddr.s_addr & 0xffff)), + ((inp->inp_fport << 16) | inp->inp_lport), + (((inp->inp_laddr.s_addr & 0xffff) << 16) | + (inp->inp_faddr.s_addr & 0xffff)), 0,0,0); } + +msg_unordered_delivery: + /* Deliver out-of-order data as a message */ + if (te && (so->so_flags & SOF_ENABLE_MSGS) && copy_oodata && te->tqe_len) { + /* + * make a copy of the mbuf to be delivered up to + * the user, and add it to the sockbuf + */ + oodata = m_copym(te->tqe_m, 0, M_COPYALL, M_DONTWAIT); + if (oodata != NULL) { + if (sbappendmsgstream_rcv(&so->so_rcv, oodata, + te->tqe_th->th_seq - (tp->irs + 1), 1)) { + dowakeup = 1; + tcpstat.tcps_msg_unopkts++; + } else { + tcpstat.tcps_msg_unoappendfail++; + } + } + } + if (dowakeup) sorwakeup(so); /* done with socket lock held */ return (flags); - } /* - * Reduce congestion window. + * Reduce congestion window -- used when ECN is seen or when a tail loss + * probe recovers the last packet. */ static void tcp_reduce_congestion_window( struct tcpcb *tp) { - u_int win; - - win = min(tp->snd_wnd, tp->snd_cwnd) / - 2 / tp->t_maxseg; - if (win < 2) - win = 2; - tp->snd_ssthresh = win * tp->t_maxseg; + /* + * If the current tcp cc module has + * defined a hook for tasks to run + * before entering FR, call it + */ + if (CC_ALGO(tp)->pre_fr != NULL) + CC_ALGO(tp)->pre_fr(tp); ENTER_FASTRECOVERY(tp); - tp->snd_recover = tp->snd_max; + if (tp->t_flags & TF_SENTFIN) + tp->snd_recover = tp->snd_max - 1; + else + tp->snd_recover = tp->snd_max; tp->t_timer[TCPT_REXMT] = 0; + tp->t_timer[TCPT_PTO] = 0; tp->t_rtttime = 0; - tp->ecn_flags |= TE_SENDCWR; - tp->snd_cwnd = tp->snd_ssthresh + - tp->t_maxseg * tcprexmtthresh; + if (tp->t_flagsext & TF_CWND_NONVALIDATED) { + tcp_cc_adjust_nonvalidated_cwnd(tp); + } else { + tp->snd_cwnd = tp->snd_ssthresh + + tp->t_maxseg * tcprexmtthresh; + } +} + +/* + * This function is called upon reception of data on a socket. It's purpose is + * to handle the adaptive keepalive timers that monitor whether the connection + * is making progress. First the adaptive read-timer, second the TFO probe-timer. + * + * The application wants to get an event if there is a stall during read. + * Set the initial keepalive timeout to be equal to twice RTO. + * + * If the outgoing interface is in marginal conditions, we need to + * enable read probes for that too. + */ +static inline void +tcp_adaptive_rwtimo_check(struct tcpcb *tp, int tlen) +{ + struct ifnet *outifp = tp->t_inpcb->inp_last_outifp; + + if ((tp->t_adaptive_rtimo > 0 || + (outifp != NULL && + (outifp->if_eflags & IFEF_PROBE_CONNECTIVITY))) + && tlen > 0 && + tp->t_state == TCPS_ESTABLISHED) { + tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp, + (TCP_REXMTVAL(tp) << 1)); + tp->t_flagsext |= TF_DETECT_READSTALL; + tp->t_rtimo_probes = 0; + } } +inline void +tcp_keepalive_reset(struct tcpcb *tp) +{ + tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp, + TCP_CONN_KEEPIDLE(tp)); + tp->t_flagsext &= ~(TF_DETECT_READSTALL); + tp->t_rtimo_probes = 0; +} /* * TCP input routine, follows pages 65-76 of the @@ -492,49 +1028,845 @@ tcp_reduce_congestion_window( */ #if INET6 int -tcp6_input(mp, offp) - struct mbuf **mp; - int *offp; +tcp6_input(struct mbuf **mp, int *offp, int proto) { - register struct mbuf *m = *mp; - struct in6_ifaddr *ia6; +#pragma unused(proto) + struct mbuf *m = *mp; + uint32_t ia6_flags; + struct ifnet *ifp = m->m_pkthdr.rcvif; IP6_EXTHDR_CHECK(m, *offp, sizeof(struct tcphdr), return IPPROTO_DONE); + /* Expect 32-bit aligned data pointer on strict-align platforms */ + MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m); + /* * draft-itojun-ipv6-tcp-to-anycast * better place to put this in? */ - ia6 = ip6_getdstifaddr(m); - if (ia6 && (ia6->ia6_flags & IN6_IFF_ANYCAST)) { - struct ip6_hdr *ip6; + if (ip6_getdstifaddr_info(m, NULL, &ia6_flags) == 0) { + if (ia6_flags & IN6_IFF_ANYCAST) { + struct ip6_hdr *ip6; + + ip6 = mtod(m, struct ip6_hdr *); + icmp6_error(m, ICMP6_DST_UNREACH, + ICMP6_DST_UNREACH_ADDR, + (caddr_t)&ip6->ip6_dst - (caddr_t)ip6); + + IF_TCP_STATINC(ifp, icmp6unreach); + + return (IPPROTO_DONE); + } + } + + tcp_input(m, *offp); + return (IPPROTO_DONE); +} +#endif + +/* Depending on the usage of mbuf space in the system, this function + * will return true or false. This is used to determine if a socket + * buffer can take more memory from the system for auto-tuning or not. + */ +u_int8_t +tcp_cansbgrow(struct sockbuf *sb) +{ + /* Calculate the host level space limit in terms of MSIZE buffers. + * We can use a maximum of half of the available mbuf space for + * socket buffers. + */ + u_int32_t mblim = ((nmbclusters >> 1) << (MCLSHIFT - MSIZESHIFT)); + + /* Calculate per sb limit in terms of bytes. We optimize this limit + * for upto 16 socket buffers. + */ + + u_int32_t sbspacelim = ((nmbclusters >> 4) << MCLSHIFT); + + if ((total_sbmb_cnt < mblim) && + (sb->sb_hiwat < sbspacelim)) { + return(1); + } else { + OSIncrementAtomic64(&sbmb_limreached); + } + return(0); +} + +static void +tcp_sbrcv_reserve(struct tcpcb *tp, struct sockbuf *sbrcv, + u_int32_t newsize, u_int32_t idealsize, u_int32_t rcvbuf_max) +{ + /* newsize should not exceed max */ + newsize = min(newsize, rcvbuf_max); + + /* The receive window scale negotiated at the + * beginning of the connection will also set a + * limit on the socket buffer size + */ + newsize = min(newsize, TCP_MAXWIN << tp->rcv_scale); + + /* Set new socket buffer size */ + if (newsize > sbrcv->sb_hiwat && + (sbreserve(sbrcv, newsize) == 1)) { + sbrcv->sb_idealsize = min(max(sbrcv->sb_idealsize, + (idealsize != 0) ? idealsize : newsize), rcvbuf_max); + + /* Again check the limit set by the advertised + * window scale + */ + sbrcv->sb_idealsize = min(sbrcv->sb_idealsize, + TCP_MAXWIN << tp->rcv_scale); + } +} + +/* + * This function is used to grow a receive socket buffer. It + * will take into account system-level memory usage and the + * bandwidth available on the link to make a decision. + */ +static void +tcp_sbrcv_grow(struct tcpcb *tp, struct sockbuf *sbrcv, + struct tcpopt *to, u_int32_t pktlen, u_int32_t rcvbuf_max) +{ + struct socket *so = sbrcv->sb_so; + + /* + * Do not grow the receive socket buffer if + * - auto resizing is disabled, globally or on this socket + * - the high water mark already reached the maximum + * - the stream is in background and receive side is being + * throttled + * - if there are segments in reassembly queue indicating loss, + * do not need to increase recv window during recovery as more + * data is not going to be sent. A duplicate ack sent during + * recovery should not change the receive window + */ + if (tcp_do_autorcvbuf == 0 || + (sbrcv->sb_flags & SB_AUTOSIZE) == 0 || + tcp_cansbgrow(sbrcv) == 0 || + sbrcv->sb_hiwat >= rcvbuf_max || + (tp->t_flagsext & TF_RECV_THROTTLE) || + (so->so_flags1 & SOF1_EXTEND_BK_IDLE_WANTED) || + !LIST_EMPTY(&tp->t_segq)) { + /* Can not resize the socket buffer, just return */ + goto out; + } + + if (TSTMP_GT(tcp_now, + tp->rfbuf_ts + TCPTV_RCVBUFIDLE)) { + /* If there has been an idle period in the + * connection, just restart the measurement + */ + goto out; + } + + if (!TSTMP_SUPPORTED(tp)) { + /* + * Timestamp option is not supported on this connection. + * If the connection reached a state to indicate that + * the receive socket buffer needs to grow, increase + * the high water mark. + */ + if (TSTMP_GEQ(tcp_now, + tp->rfbuf_ts + TCPTV_RCVNOTS_QUANTUM)) { + if (tp->rfbuf_cnt >= TCP_RCVNOTS_BYTELEVEL) { + tcp_sbrcv_reserve(tp, sbrcv, + tcp_autorcvbuf_max, 0, + tcp_autorcvbuf_max); + } + goto out; + } else { + tp->rfbuf_cnt += pktlen; + return; + } + } else if (to->to_tsecr != 0) { + /* + * If the timestamp shows that one RTT has + * completed, we can stop counting the + * bytes. Here we consider increasing + * the socket buffer if the bandwidth measured in + * last rtt, is more than half of sb_hiwat, this will + * help to scale the buffer according to the bandwidth + * on the link. + */ + if (TSTMP_GEQ(to->to_tsecr, tp->rfbuf_ts)) { + if (tp->rfbuf_cnt > (sbrcv->sb_hiwat - + (sbrcv->sb_hiwat >> 1))) { + int32_t rcvbuf_inc, min_incr; + /* + * Increment the receive window by a + * multiple of maximum sized segments. + * This will prevent a connection from + * sending smaller segments on wire if it + * is limited by the receive window. + * + * Set the ideal size based on current + * bandwidth measurements. We set the + * ideal size on receive socket buffer to + * be twice the bandwidth delay product. + */ + rcvbuf_inc = (tp->rfbuf_cnt << 1) + - sbrcv->sb_hiwat; + + /* + * Make the increment equal to 8 segments + * at least + */ + min_incr = tp->t_maxseg << tcp_autorcvbuf_inc_shift; + if (rcvbuf_inc < min_incr) + rcvbuf_inc = min_incr; + + rcvbuf_inc = + (rcvbuf_inc / tp->t_maxseg) * tp->t_maxseg; + tcp_sbrcv_reserve(tp, sbrcv, + sbrcv->sb_hiwat + rcvbuf_inc, + (tp->rfbuf_cnt * 2), rcvbuf_max); + } + /* Measure instantaneous receive bandwidth */ + if (tp->t_bwmeas != NULL && tp->rfbuf_cnt > 0 && + TSTMP_GT(tcp_now, tp->rfbuf_ts)) { + u_int32_t rcv_bw; + rcv_bw = tp->rfbuf_cnt / + (int)(tcp_now - tp->rfbuf_ts); + if (tp->t_bwmeas->bw_rcvbw_max == 0) { + tp->t_bwmeas->bw_rcvbw_max = rcv_bw; + } else { + tp->t_bwmeas->bw_rcvbw_max = max( + tp->t_bwmeas->bw_rcvbw_max, rcv_bw); + } + } + goto out; + } else { + tp->rfbuf_cnt += pktlen; + return; + } + } +out: + /* Restart the measurement */ + tp->rfbuf_ts = 0; + tp->rfbuf_cnt = 0; + return; +} + +/* This function will trim the excess space added to the socket buffer + * to help a slow-reading app. The ideal-size of a socket buffer depends + * on the link bandwidth or it is set by an application and we aim to + * reach that size. + */ +void +tcp_sbrcv_trim(struct tcpcb *tp, struct sockbuf *sbrcv) +{ + if (tcp_do_autorcvbuf == 1 && sbrcv->sb_idealsize > 0 && + sbrcv->sb_hiwat > sbrcv->sb_idealsize) { + int32_t trim; + /* compute the difference between ideal and current sizes */ + u_int32_t diff = sbrcv->sb_hiwat - sbrcv->sb_idealsize; + + /* Compute the maximum advertised window for + * this connection. + */ + u_int32_t advwin = tp->rcv_adv - tp->rcv_nxt; + + /* How much can we trim the receive socket buffer? + * 1. it can not be trimmed beyond the max rcv win advertised + * 2. if possible, leave 1/16 of bandwidth*delay to + * avoid closing the win completely + */ + u_int32_t leave = max(advwin, (sbrcv->sb_idealsize >> 4)); + + /* Sometimes leave can be zero, in that case leave at least + * a few segments worth of space. + */ + if (leave == 0) + leave = tp->t_maxseg << tcp_autorcvbuf_inc_shift; + + trim = sbrcv->sb_hiwat - (sbrcv->sb_cc + leave); + trim = imin(trim, (int32_t)diff); + + if (trim > 0) + sbreserve(sbrcv, (sbrcv->sb_hiwat - trim)); + } +} + +/* We may need to trim the send socket buffer size for two reasons: + * 1. if the rtt seen on the connection is climbing up, we do not + * want to fill the buffers any more. + * 2. if the congestion win on the socket backed off, there is no need + * to hold more mbufs for that connection than what the cwnd will allow. + */ +void +tcp_sbsnd_trim(struct sockbuf *sbsnd) +{ + if (tcp_do_autosendbuf == 1 && + ((sbsnd->sb_flags & (SB_AUTOSIZE | SB_TRIM)) == + (SB_AUTOSIZE | SB_TRIM)) && + (sbsnd->sb_idealsize > 0) && + (sbsnd->sb_hiwat > sbsnd->sb_idealsize)) { + u_int32_t trim = 0; + if (sbsnd->sb_cc <= sbsnd->sb_idealsize) { + trim = sbsnd->sb_hiwat - sbsnd->sb_idealsize; + } else { + trim = sbsnd->sb_hiwat - sbsnd->sb_cc; + } + sbreserve(sbsnd, (sbsnd->sb_hiwat - trim)); + } + if (sbsnd->sb_hiwat <= sbsnd->sb_idealsize) + sbsnd->sb_flags &= ~(SB_TRIM); +} + +/* + * If timestamp option was not negotiated on this connection + * and this connection is on the receiving side of a stream + * then we can not measure the delay on the link accurately. + * Instead of enabling automatic receive socket buffer + * resizing, just give more space to the receive socket buffer. + */ +static inline void +tcp_sbrcv_tstmp_check(struct tcpcb *tp) +{ + struct socket *so = tp->t_inpcb->inp_socket; + u_int32_t newsize = 2 * tcp_recvspace; + struct sockbuf *sbrcv = &so->so_rcv; + + if ((tp->t_flags & (TF_REQ_TSTMP | TF_RCVD_TSTMP)) != + (TF_REQ_TSTMP | TF_RCVD_TSTMP) && + (sbrcv->sb_flags & SB_AUTOSIZE) != 0) { + tcp_sbrcv_reserve(tp, sbrcv, newsize, 0, newsize); + } +} + +/* A receiver will evaluate the flow of packets on a connection + * to see if it can reduce ack traffic. The receiver will start + * stretching acks if all of the following conditions are met: + * 1. tcp_delack_enabled is set to 3 + * 2. If the bytes received in the last 100ms is greater than a threshold + * defined by maxseg_unacked + * 3. If the connection has not been idle for tcp_maxrcvidle period. + * 4. If the connection has seen enough packets to let the slow-start + * finish after connection establishment or after some packet loss. + * + * The receiver will stop stretching acks if there is congestion/reordering + * as indicated by packets on reassembly queue or an ECN. If the delayed-ack + * timer fires while stretching acks, it means that the packet flow has gone + * below the threshold defined by maxseg_unacked and the receiver will stop + * stretching acks. The receiver gets no indication when slow-start is completed + * or when the connection reaches an idle state. That is why we use + * tcp_rcvsspktcnt to cover slow-start and tcp_maxrcvidle to identify idle + * state. + */ +static inline int +tcp_stretch_ack_enable(struct tcpcb *tp, int thflags) +{ + if (tp->rcv_by_unackwin >= (maxseg_unacked * tp->t_maxseg) && + TSTMP_GEQ(tp->rcv_unackwin, tcp_now)) + tp->t_flags |= TF_STREAMING_ON; + else + tp->t_flags &= ~TF_STREAMING_ON; + + /* If there has been an idle time, reset streaming detection */ + if (TSTMP_GT(tcp_now, tp->rcv_unackwin + tcp_maxrcvidle)) + tp->t_flags &= ~TF_STREAMING_ON; + + /* + * If there are flags other than TH_ACK set, reset streaming + * detection + */ + if (thflags & ~TH_ACK) + tp->t_flags &= ~TF_STREAMING_ON; + + if (tp->t_flagsext & TF_DISABLE_STRETCHACK) { + if (tp->rcv_nostrack_pkts >= TCP_STRETCHACK_ENABLE_PKTCNT) { + tp->t_flagsext &= ~TF_DISABLE_STRETCHACK; + tp->rcv_nostrack_pkts = 0; + tp->rcv_nostrack_ts = 0; + } else { + tp->rcv_nostrack_pkts++; + } + } + + if (!(tp->t_flagsext & (TF_NOSTRETCHACK|TF_DISABLE_STRETCHACK)) && + (tp->t_flags & TF_STREAMING_ON) && + (!(tp->t_flagsext & TF_RCVUNACK_WAITSS) || + (tp->rcv_waitforss >= tcp_rcvsspktcnt))) { + return(1); + } + + return(0); +} + +/* + * Reset the state related to stretch-ack algorithm. This will make + * the receiver generate an ack every other packet. The receiver + * will start re-evaluating the rate at which packets come to decide + * if it can benefit by lowering the ack traffic. + */ +void +tcp_reset_stretch_ack(struct tcpcb *tp) +{ + tp->t_flags &= ~(TF_STRETCHACK|TF_STREAMING_ON); + tp->rcv_by_unackwin = 0; + tp->rcv_unackwin = tcp_now + tcp_rcvunackwin; + + /* + * When there is packet loss or packet re-ordering or CWR due to + * ECN, the sender's congestion window is reduced. In these states, + * generate an ack for every other packet for some time to allow + * the sender's congestion window to grow. + */ + tp->t_flagsext |= TF_RCVUNACK_WAITSS; + tp->rcv_waitforss = 0; +} + +/* + * The last packet was a retransmission, check if this ack + * indicates that the retransmission was spurious. + * + * If the connection supports timestamps, we could use it to + * detect if the last retransmit was not needed. Otherwise, + * we check if the ACK arrived within RTT/2 window, then it + * was a mistake to do the retransmit in the first place. + * + * This function will return 1 if it is a spurious retransmit, + * 0 otherwise. + */ +int +tcp_detect_bad_rexmt(struct tcpcb *tp, struct tcphdr *th, + struct tcpopt *to, u_int32_t rxtime) +{ + int32_t tdiff, bad_rexmt_win; + bad_rexmt_win = (tp->t_srtt >> (TCP_RTT_SHIFT + 1)); + + /* If the ack has ECN CE bit, then cwnd has to be adjusted */ + if (TCP_ECN_ENABLED(tp) && (th->th_flags & TH_ECE)) + return (0); + if (TSTMP_SUPPORTED(tp)) { + if (rxtime > 0 && (to->to_flags & TOF_TS) + && to->to_tsecr != 0 + && TSTMP_LT(to->to_tsecr, rxtime)) + return (1); + } else { + if ((tp->t_rxtshift == 1 + || (tp->t_flagsext & TF_SENT_TLPROBE)) + && rxtime > 0) { + tdiff = (int32_t)(tcp_now - rxtime); + if (tdiff < bad_rexmt_win) + return(1); + } + } + return(0); +} + + +/* + * Restore congestion window state if a spurious timeout + * was detected. + */ +static void +tcp_bad_rexmt_restore_state(struct tcpcb *tp, struct tcphdr *th) +{ + if (TSTMP_SUPPORTED(tp)) { + u_int32_t fsize, acked; + fsize = tp->snd_max - th->th_ack; + acked = BYTES_ACKED(th, tp); + + /* + * Implement bad retransmit recovery as + * described in RFC 4015. + */ + tp->snd_ssthresh = tp->snd_ssthresh_prev; + + /* Initialize cwnd to the initial window */ + if (CC_ALGO(tp)->cwnd_init != NULL) + CC_ALGO(tp)->cwnd_init(tp); + + tp->snd_cwnd = fsize + min(acked, tp->snd_cwnd); + + } else { + tp->snd_cwnd = tp->snd_cwnd_prev; + tp->snd_ssthresh = tp->snd_ssthresh_prev; + if (tp->t_flags & TF_WASFRECOVERY) + ENTER_FASTRECOVERY(tp); + + /* Do not use the loss flight size in this case */ + tp->t_lossflightsize = 0; + } + tp->snd_cwnd = max(tp->snd_cwnd, TCP_CC_CWND_INIT_BYTES); + tp->snd_recover = tp->snd_recover_prev; + tp->snd_nxt = tp->snd_max; + + /* Fix send socket buffer to reflect the change in cwnd */ + tcp_bad_rexmt_fix_sndbuf(tp); + + /* + * This RTT might reflect the extra delay induced + * by the network. Skip using this sample for RTO + * calculation and mark the connection so we can + * recompute RTT when the next eligible sample is + * found. + */ + tp->t_flagsext |= TF_RECOMPUTE_RTT; + tp->t_badrexmt_time = tcp_now; + tp->t_rtttime = 0; +} + +/* + * If the previous packet was sent in retransmission timer, and it was + * not needed, then restore the congestion window to the state before that + * transmission. + * + * If the last packet was sent in tail loss probe timeout, check if that + * recovered the last packet. If so, that will indicate a real loss and + * the congestion window needs to be lowered. + */ +static void +tcp_bad_rexmt_check(struct tcpcb *tp, struct tcphdr *th, struct tcpopt *to) +{ + if (tp->t_rxtshift > 0 && + tcp_detect_bad_rexmt(tp, th, to, tp->t_rxtstart)) { + ++tcpstat.tcps_sndrexmitbad; + tcp_bad_rexmt_restore_state(tp, th); + tcp_ccdbg_trace(tp, th, TCP_CC_BAD_REXMT_RECOVERY); + } else if ((tp->t_flagsext & TF_SENT_TLPROBE) + && tp->t_tlphighrxt > 0 + && SEQ_GEQ(th->th_ack, tp->t_tlphighrxt) + && !tcp_detect_bad_rexmt(tp, th, to, tp->t_tlpstart)) { + /* + * check DSACK information also to make sure that + * the TLP was indeed needed + */ + if (tcp_rxtseg_dsack_for_tlp(tp)) { + /* + * received a DSACK to indicate that TLP was + * not needed + */ + tcp_rxtseg_clean(tp); + goto out; + } + + /* + * The tail loss probe recovered the last packet and + * we need to adjust the congestion window to take + * this loss into account. + */ + ++tcpstat.tcps_tlp_recoverlastpkt; + if (!IN_FASTRECOVERY(tp)) { + tcp_reduce_congestion_window(tp); + EXIT_FASTRECOVERY(tp); + } + tcp_ccdbg_trace(tp, th, TCP_CC_TLP_RECOVER_LASTPACKET); + } else if (tcp_rxtseg_detect_bad_rexmt(tp, th->th_ack)) { + /* + * All of the retransmitted segments were duplicated, this + * can be an indication of bad fast retransmit. + */ + tcpstat.tcps_dsack_badrexmt++; + tcp_bad_rexmt_restore_state(tp, th); + tcp_ccdbg_trace(tp, th, TCP_CC_DSACK_BAD_REXMT); + tcp_rxtseg_clean(tp); + } +out: + tp->t_flagsext &= ~(TF_SENT_TLPROBE); + tp->t_tlphighrxt = 0; + tp->t_tlpstart = 0; + + /* + * check if the latest ack was for a segment sent during PMTU + * blackhole detection. If the timestamp on the ack is before + * PMTU blackhole detection, then revert the size of the max + * segment to previous size. + */ + if (tp->t_rxtshift > 0 && (tp->t_flags & TF_BLACKHOLE) && + tp->t_pmtud_start_ts > 0 && TSTMP_SUPPORTED(tp)) { + if ((to->to_flags & TOF_TS) && to->to_tsecr != 0 + && TSTMP_LT(to->to_tsecr, tp->t_pmtud_start_ts)) { + tcp_pmtud_revert_segment_size(tp); + } + } + if (tp->t_pmtud_start_ts > 0) + tp->t_pmtud_start_ts = 0; +} + +/* + * Check if early retransmit can be attempted according to RFC 5827. + * + * If packet reordering is detected on a connection, fast recovery will + * be delayed until it is clear that the packet was lost and not reordered. + * But reordering detection is done only when SACK is enabled. + * + * On connections that do not support SACK, there is a limit on the number + * of early retransmits that can be done per minute. This limit is needed + * to make sure that too many packets are not retransmitted when there is + * packet reordering. + */ +static void +tcp_early_rexmt_check (struct tcpcb *tp, struct tcphdr *th) +{ + u_int32_t obytes, snd_off; + int32_t snd_len; + struct socket *so = tp->t_inpcb->inp_socket; + + if (early_rexmt && (SACK_ENABLED(tp) || + tp->t_early_rexmt_count < TCP_EARLY_REXMT_LIMIT) && + SEQ_GT(tp->snd_max, tp->snd_una) && + (tp->t_dupacks == 1 || + (SACK_ENABLED(tp) && + !TAILQ_EMPTY(&tp->snd_holes)))) { + /* + * If there are only a few outstanding + * segments on the connection, we might need + * to lower the retransmit threshold. This + * will allow us to do Early Retransmit as + * described in RFC 5827. + */ + if (SACK_ENABLED(tp) && + !TAILQ_EMPTY(&tp->snd_holes)) { + obytes = (tp->snd_max - tp->snd_fack) + + tp->sackhint.sack_bytes_rexmit; + } else { + obytes = (tp->snd_max - tp->snd_una); + } + + /* + * In order to lower retransmit threshold the + * following two conditions must be met. + * 1. the amount of outstanding data is less + * than 4*SMSS bytes + * 2. there is no unsent data ready for + * transmission or the advertised window + * will limit sending new segments. + */ + snd_off = tp->snd_max - tp->snd_una; + snd_len = min(so->so_snd.sb_cc, tp->snd_wnd) - snd_off; + if (obytes < (tp->t_maxseg << 2) && + snd_len <= 0) { + u_int32_t osegs; + + osegs = obytes / tp->t_maxseg; + if ((osegs * tp->t_maxseg) < obytes) + osegs++; + + /* + * Since the connection might have already + * received some dupacks, we add them to + * to the outstanding segments count to get + * the correct retransmit threshold. + * + * By checking for early retransmit after + * receiving some duplicate acks when SACK + * is supported, the connection will + * enter fast recovery even if multiple + * segments are lost in the same window. + */ + osegs += tp->t_dupacks; + if (osegs < 4) { + tp->t_rexmtthresh = + ((osegs - 1) > 1) ? (osegs - 1) : 1; + tp->t_rexmtthresh = + min(tp->t_rexmtthresh, tcprexmtthresh); + tp->t_rexmtthresh = + max(tp->t_rexmtthresh, tp->t_dupacks); + + if (tp->t_early_rexmt_count == 0) + tp->t_early_rexmt_win = tcp_now; + + if (tp->t_flagsext & TF_SENT_TLPROBE) { + tcpstat.tcps_tlp_recovery++; + tcp_ccdbg_trace(tp, th, + TCP_CC_TLP_RECOVERY); + } else { + tcpstat.tcps_early_rexmt++; + tp->t_early_rexmt_count++; + tcp_ccdbg_trace(tp, th, + TCP_CC_EARLY_RETRANSMIT); + } + } + } + } + + /* + * If we ever sent a TLP probe, the acknowledgement will trigger + * early retransmit because the value of snd_fack will be close + * to snd_max. This will take care of adjustments to the + * congestion window. So we can reset TF_SENT_PROBE flag. + */ + tp->t_flagsext &= ~(TF_SENT_TLPROBE); + tp->t_tlphighrxt = 0; + tp->t_tlpstart = 0; +} + +static boolean_t +tcp_tfo_syn(struct tcpcb *tp, struct tcpopt *to) +{ + u_char out[CCAES_BLOCK_SIZE]; + unsigned char len; + + if (!(to->to_flags & (TOF_TFO | TOF_TFOREQ)) || + !(tcp_fastopen & TCP_FASTOPEN_SERVER)) + return (FALSE); + + if ((to->to_flags & TOF_TFOREQ)) { + tp->t_tfo_flags |= TFO_F_OFFER_COOKIE; + + tp->t_tfo_stats |= TFO_S_COOKIEREQ_RECV; + tcpstat.tcps_tfo_cookie_req_rcv++; + return (FALSE); + } + + /* Ok, then it must be an offered cookie. We need to check that ... */ + tcp_tfo_gen_cookie(tp->t_inpcb, out, sizeof(out)); + + len = *to->to_tfo - TCPOLEN_FASTOPEN_REQ; + to->to_tfo++; + if (memcmp(out, to->to_tfo, len)) { + /* Cookies are different! Let's return and offer a new cookie */ + tp->t_tfo_flags |= TFO_F_OFFER_COOKIE; + + tp->t_tfo_stats |= TFO_S_COOKIE_INVALID; + tcpstat.tcps_tfo_cookie_invalid++; + return (FALSE); + } + + if (OSIncrementAtomic(&tcp_tfo_halfcnt) >= tcp_tfo_backlog) { + /* Need to decrement again as we just increased it... */ + OSDecrementAtomic(&tcp_tfo_halfcnt); + return (FALSE); + } + + tp->t_tfo_flags |= TFO_F_COOKIE_VALID; + + tp->t_tfo_stats |= TFO_S_SYNDATA_RCV; + tcpstat.tcps_tfo_syn_data_rcv++; + + return (TRUE); +} + +static void +tcp_tfo_synack(struct tcpcb *tp, struct tcpopt *to) +{ + if (to->to_flags & TOF_TFO) { + unsigned char len = *to->to_tfo - TCPOLEN_FASTOPEN_REQ; + + /* + * If this happens, things have gone terribly wrong. len should + * have been checked in tcp_dooptions. + */ + VERIFY(len <= TFO_COOKIE_LEN_MAX); + + to->to_tfo++; + + tcp_cache_set_cookie(tp, to->to_tfo, len); + tcp_heuristic_tfo_success(tp); + + tp->t_tfo_stats |= TFO_S_COOKIE_RCV; + tcpstat.tcps_tfo_cookie_rcv++; + if (tp->t_tfo_flags & TFO_F_COOKIE_SENT) { + tcpstat.tcps_tfo_cookie_wrong++; + tp->t_tfo_stats |= TFO_S_COOKIE_WRONG; + } + } else { + /* + * Thus, no cookie in the response, but we either asked for one + * or sent SYN+DATA. Now, we need to check whether we had to + * rexmit the SYN. If that's the case, it's better to start + * backing of TFO-cookie requests. + */ + if (tp->t_tfo_flags & TFO_F_SYN_LOSS) { + tp->t_tfo_stats |= TFO_S_SYN_LOSS; + tcpstat.tcps_tfo_syn_loss++; + + tcp_heuristic_tfo_loss(tp); + } else { + if (tp->t_tfo_flags & TFO_F_COOKIE_REQ) { + tp->t_tfo_stats |= TFO_S_NO_COOKIE_RCV; + tcpstat.tcps_tfo_no_cookie_rcv++; + } + + tcp_heuristic_tfo_success(tp); + } + } +} + +static void +tcp_tfo_rcv_probe(struct tcpcb *tp, int tlen) +{ + if (tlen != 0) + return; + + tp->t_tfo_probe_state = TFO_PROBE_PROBING; + + /* + * We send the probe out rather quickly (after one RTO). It does not + * really hurt that much, it's only one additional segment on the wire. + */ + tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp, (TCP_REXMTVAL(tp))); +} + +static void +tcp_tfo_rcv_data(struct tcpcb *tp) +{ + /* Transition from PROBING to NONE as data has been received */ + if (tp->t_tfo_probe_state >= TFO_PROBE_PROBING) + tp->t_tfo_probe_state = TFO_PROBE_NONE; +} + +static void +tcp_tfo_rcv_ack(struct tcpcb *tp, struct tcphdr *th) +{ + if (tp->t_tfo_probe_state == TFO_PROBE_PROBING && + tp->t_tfo_probes > 0) { + if (th->th_seq == tp->rcv_nxt) { + /* No hole, so stop probing */ + tp->t_tfo_probe_state = TFO_PROBE_NONE; + } else if (SEQ_GT(th->th_seq, tp->rcv_nxt)) { + /* There is a hole! Wait a bit for data... */ + tp->t_tfo_probe_state = TFO_PROBE_WAIT_DATA; + tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp, + TCP_REXMTVAL(tp)); + } + } +} + +/* + * Update snd_wnd information. + */ +static inline bool +tcp_update_window(struct tcpcb *tp, int thflags, struct tcphdr * th, + u_int32_t tiwin, int tlen) +{ + /* Don't look at the window if there is no ACK flag */ + if ((thflags & TH_ACK) && + (SEQ_LT(tp->snd_wl1, th->th_seq) || + (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) || + (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) { + /* keep track of pure window updates */ + if (tlen == 0 && + tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd) + tcpstat.tcps_rcvwinupd++; + tp->snd_wnd = tiwin; + tp->snd_wl1 = th->th_seq; + tp->snd_wl2 = th->th_ack; + if (tp->snd_wnd > tp->max_sndwnd) + tp->max_sndwnd = tp->snd_wnd; - ip6 = mtod(m, struct ip6_hdr *); - icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR, - (caddr_t)&ip6->ip6_dst - (caddr_t)ip6); - return IPPROTO_DONE; + if (tp->t_inpcb->inp_socket->so_flags & SOF_MP_SUBFLOW) + mptcp_update_window_wakeup(tp); + return (true); } - - tcp_input(m, *offp); - return IPPROTO_DONE; + return (false); } -#endif void -tcp_input(m, off0) - struct mbuf *m; - int off0; +tcp_input(struct mbuf *m, int off0) { - register struct tcphdr *th; - register struct ip *ip = NULL; - register struct ipovly *ipov; - register struct inpcb *inp; + struct tcphdr *th; + struct ip *ip = NULL; + struct inpcb *inp; u_char *optp = NULL; int optlen = 0; - int len, tlen, off; + int tlen, off; int drop_hdrlen; - register struct tcpcb *tp = 0; - register int thflags; + struct tcpcb *tp = 0; + int thflags; struct socket *so = 0; int todrop, acked, ourfinisacked, needoutput = 0; struct in_addr laddr; @@ -542,33 +1874,61 @@ tcp_input(m, off0) struct in6_addr laddr6; #endif int dropsocket = 0; - int iss = 0; - int nosock = 0; - u_long tiwin; + int iss = 0, nosock = 0; + u_int32_t tiwin, sack_bytes_acked = 0; struct tcpopt to; /* options in this segment */ - struct sockaddr_in *next_hop = NULL; #if TCPDEBUG short ostate = 0; #endif +#if IPFIREWALL + struct sockaddr_in *next_hop = NULL; struct m_tag *fwd_tag; +#endif /* IPFIREWALL */ u_char ip_ecn = IPTOS_ECN_NOTECT; + unsigned int ifscope; + uint8_t isconnected, isdisconnected; + struct ifnet *ifp = m->m_pkthdr.rcvif; + int pktf_sw_lro_pkt = (m->m_pkthdr.pkt_flags & PKTF_SW_LRO_PKT) ? 1 : 0; + int nlropkts = (pktf_sw_lro_pkt == 1) ? m->m_pkthdr.lro_npkts : 1; + int turnoff_lro = 0, win; +#if MPTCP + struct mptcb *mp_tp = NULL; +#endif /* MPTCP */ + boolean_t cell = IFNET_IS_CELLULAR(ifp); + boolean_t wifi = (!cell && IFNET_IS_WIFI(ifp)); + boolean_t wired = (!wifi && IFNET_IS_WIRED(ifp)); + boolean_t recvd_dsack = FALSE; + struct tcp_respond_args tra; + +#define TCP_INC_VAR(stat, npkts) do { \ + stat += npkts; \ +} while (0) + TCP_INC_VAR(tcpstat.tcps_rcvtotal, nlropkts); +#if IPFIREWALL /* Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain. */ - fwd_tag = m_tag_locate(m, KERNEL_MODULE_TAG_ID, KERNEL_TAG_TYPE_IPFORWARD, NULL); + if (!SLIST_EMPTY(&m->m_pkthdr.tags)) { + fwd_tag = m_tag_locate(m, KERNEL_MODULE_TAG_ID, + KERNEL_TAG_TYPE_IPFORWARD, NULL); + } else { + fwd_tag = NULL; + } if (fwd_tag != NULL) { - struct ip_fwd_tag *ipfwd_tag = (struct ip_fwd_tag *)(fwd_tag+1); - + struct ip_fwd_tag *ipfwd_tag = + (struct ip_fwd_tag *)(fwd_tag+1); + next_hop = ipfwd_tag->next_hop; m_tag_delete(m, fwd_tag); } - +#endif /* IPFIREWALL */ + #if INET6 struct ip6_hdr *ip6 = NULL; int isipv6; #endif /* INET6 */ int rstreason; /* For badport_bandlim accounting purposes */ struct proc *proc0=current_proc(); - + KERNEL_DEBUG(DBG_FNC_TCP_INPUT | DBG_FUNC_START,0,0,0,0,0); #if INET6 @@ -576,20 +1936,21 @@ tcp_input(m, off0) #endif bzero((char *)&to, sizeof(to)); - tcpstat.tcps_rcvtotal++; - - - #if INET6 if (isipv6) { + /* + * Expect 32-bit aligned data pointer on + * strict-align platforms + */ + MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m); + /* IP6_EXTHDR_CHECK() is already done at tcp6_input() */ ip6 = mtod(m, struct ip6_hdr *); tlen = sizeof(*ip6) + ntohs(ip6->ip6_plen) - off0; - if (in6_cksum(m, IPPROTO_TCP, off0, tlen)) { - tcpstat.tcps_rcvbadsum++; + th = (struct tcphdr *)(void *)((caddr_t)ip6 + off0); + + if (tcp_input_checksum(AF_INET6, m, th, off0, tlen)) goto dropnosock; - } - th = (struct tcphdr *)((caddr_t)ip6 + off0); KERNEL_DEBUG(DBG_LAYER_BEG, ((th->th_dport << 16) | th->th_sport), (((ip6->ip6_src.s6_addr16[0]) << 16) | (ip6->ip6_dst.s6_addr16[0])), @@ -604,8 +1965,14 @@ tcp_input(m, off0) */ if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) { /* XXX stat */ + IF_TCP_STATINC(ifp, unspecv6); goto dropnosock; } + DTRACE_TCP5(receive, struct mbuf *, m, struct inpcb *, NULL, + struct ip6_hdr *, ip6, struct tcpcb *, NULL, + struct tcphdr *, th); + + ip_ecn = (ntohl(ip6->ip6_flow) >> 20) & IPTOS_ECN_MASK; } else #endif /* INET6 */ { @@ -614,11 +1981,8 @@ tcp_input(m, off0) * Note: IP leaves IP header in first mbuf. */ if (off0 > sizeof (struct ip)) { - ip_stripoptions(m, (struct mbuf *)0); + ip_stripoptions(m); off0 = sizeof(struct ip); - if (m->m_pkthdr.csum_flags & CSUM_TCP_SUM16) - m->m_pkthdr.csum_flags = 0; /* invalidate hwcksuming */ - } if (m->m_len < sizeof (struct tcpiphdr)) { if ((m = m_pullup(m, sizeof (struct tcpiphdr))) == 0) { @@ -626,81 +1990,40 @@ tcp_input(m, off0) return; } } + + /* Expect 32-bit aligned data pointer on strict-align platforms */ + MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m); + ip = mtod(m, struct ip *); - ipov = (struct ipovly *)ip; - th = (struct tcphdr *)((caddr_t)ip + off0); + th = (struct tcphdr *)(void *)((caddr_t)ip + off0); tlen = ip->ip_len; - KERNEL_DEBUG(DBG_LAYER_BEG, ((th->th_dport << 16) | th->th_sport), - (((ip->ip_src.s_addr & 0xffff) << 16) | (ip->ip_dst.s_addr & 0xffff)), - th->th_seq, th->th_ack, th->th_win); - - if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) { - if (m->m_pkthdr.csum_flags & CSUM_TCP_SUM16) { - u_short pseudo; - char b[9]; - *(uint32_t*)&b[0] = *(uint32_t*)&ipov->ih_x1[0]; - *(uint32_t*)&b[4] = *(uint32_t*)&ipov->ih_x1[4]; - *(uint8_t*)&b[8] = *(uint8_t*)&ipov->ih_x1[8]; - - bzero(ipov->ih_x1, sizeof(ipov->ih_x1)); - ipov->ih_len = (u_short)tlen; - HTONS(ipov->ih_len); - pseudo = in_cksum(m, sizeof (struct ip)); - - *(uint32_t*)&ipov->ih_x1[0] = *(uint32_t*)&b[0]; - *(uint32_t*)&ipov->ih_x1[4] = *(uint32_t*)&b[4]; - *(uint8_t*)&ipov->ih_x1[8] = *(uint8_t*)&b[8]; - - th->th_sum = in_addword(pseudo, (m->m_pkthdr.csum_data & 0xFFFF)); - } else { - if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR) - th->th_sum = m->m_pkthdr.csum_data; - else - th->th_sum = in_pseudo(ip->ip_src.s_addr, - ip->ip_dst.s_addr, htonl(m->m_pkthdr.csum_data + - ip->ip_len + IPPROTO_TCP)); - } - th->th_sum ^= 0xffff; - } else { - char b[9]; - /* - * Checksum extended TCP header and data. - */ - *(uint32_t*)&b[0] = *(uint32_t*)&ipov->ih_x1[0]; - *(uint32_t*)&b[4] = *(uint32_t*)&ipov->ih_x1[4]; - *(uint8_t*)&b[8] = *(uint8_t*)&ipov->ih_x1[8]; - - len = sizeof (struct ip) + tlen; - bzero(ipov->ih_x1, sizeof(ipov->ih_x1)); - ipov->ih_len = (u_short)tlen; - HTONS(ipov->ih_len); - th->th_sum = in_cksum(m, len); - - *(uint32_t*)&ipov->ih_x1[0] = *(uint32_t*)&b[0]; - *(uint32_t*)&ipov->ih_x1[4] = *(uint32_t*)&b[4]; - *(uint8_t*)&ipov->ih_x1[8] = *(uint8_t*)&b[8]; - - tcp_in_cksum_stats(len); - } - if (th->th_sum) { - tcpstat.tcps_rcvbadsum++; + if (tcp_input_checksum(AF_INET, m, th, off0, tlen)) goto dropnosock; - } + #if INET6 /* Re-initialization for later version check */ ip->ip_v = IPVERSION; #endif ip_ecn = (ip->ip_tos & IPTOS_ECN_MASK); + + DTRACE_TCP5(receive, struct mbuf *, m, struct inpcb *, NULL, + struct ip *, ip, struct tcpcb *, NULL, struct tcphdr *, th); + + KERNEL_DEBUG(DBG_LAYER_BEG, ((th->th_dport << 16) | th->th_sport), + (((ip->ip_src.s_addr & 0xffff) << 16) | (ip->ip_dst.s_addr & 0xffff)), + th->th_seq, th->th_ack, th->th_win); + } /* * Check that TCP offset makes sense, - * pull out TCP options and adjust length. XXX + * pull out TCP options and adjust length. */ off = th->th_off << 2; if (off < sizeof (struct tcphdr) || off > tlen) { tcpstat.tcps_rcvbadoff++; + IF_TCP_STATINC(ifp, badformat); goto dropnosock; } tlen -= off; /* tlen is used instead of ti->ti_len */ @@ -709,7 +2032,7 @@ tcp_input(m, off0) if (isipv6) { IP6_EXTHDR_CHECK(m, off0, off, return); ip6 = mtod(m, struct ip6_hdr *); - th = (struct tcphdr *)((caddr_t)ip6 + off0); + th = (struct tcphdr *)(void *)((caddr_t)ip6 + off0); } else #endif /* INET6 */ { @@ -719,13 +2042,12 @@ tcp_input(m, off0) return; } ip = mtod(m, struct ip *); - ipov = (struct ipovly *)ip; - th = (struct tcphdr *)((caddr_t)ip + off0); + th = (struct tcphdr *)(void *)((caddr_t)ip + off0); } } optlen = off - sizeof (struct tcphdr); optp = (u_char *)(th + 1); - /* + /* * Do quick retrieval of timestamp options ("options * prediction?"). If timestamp is the only option and it's * formatted as recommended in RFC 1323 appendix A, we @@ -735,11 +2057,11 @@ tcp_input(m, off0) if ((optlen == TCPOLEN_TSTAMP_APPA || (optlen > TCPOLEN_TSTAMP_APPA && optp[TCPOLEN_TSTAMP_APPA] == TCPOPT_EOL)) && - *(u_int32_t *)optp == htonl(TCPOPT_TSTAMP_HDR) && + *(u_int32_t *)(void *)optp == htonl(TCPOPT_TSTAMP_HDR) && (th->th_flags & TH_SYN) == 0) { to.to_flags |= TOF_TS; - to.to_tsval = ntohl(*(u_int32_t *)(optp + 4)); - to.to_tsecr = ntohl(*(u_int32_t *)(optp + 8)); + to.to_tsval = ntohl(*(u_int32_t *)(void *)(optp + 4)); + to.to_tsecr = ntohl(*(u_int32_t *)(void *)(optp + 8)); optp = NULL; /* we've parsed the options */ } } @@ -753,18 +2075,12 @@ tcp_input(m, off0) * * This is a violation of the TCP specification. */ - if (drop_synfin && (thflags & (TH_SYN|TH_FIN)) == (TH_SYN|TH_FIN)) + if (drop_synfin && (thflags & (TH_SYN|TH_FIN)) == (TH_SYN|TH_FIN)) { + IF_TCP_STATINC(ifp, synfin); goto dropnosock; + } #endif - /* - * Convert TCP protocol specific fields to host format. - */ - NTOHL(th->th_seq); - NTOHL(th->th_ack); - NTOHS(th->th_win); - NTOHS(th->th_urp); - /* * Delay dropping TCP, IP headers, IPv6 ext headers, and TCP options, * until after ip6_savecontrol() is called and before other functions @@ -775,10 +2091,42 @@ tcp_input(m, off0) */ drop_hdrlen = off0 + off; + /* Since this is an entry point for input processing of tcp packets, we + * can update the tcp clock here. + */ + calculate_tcp_clock(); + + /* + * Record the interface where this segment arrived on; this does not + * affect normal data output (for non-detached TCP) as it provides a + * hint about which route and interface to use for sending in the + * absence of a PCB, when scoped routing (and thus source interface + * selection) are enabled. + */ + if ((m->m_pkthdr.pkt_flags & PKTF_LOOP) || m->m_pkthdr.rcvif == NULL) + ifscope = IFSCOPE_NONE; + else + ifscope = m->m_pkthdr.rcvif->if_index; + + /* + * Convert TCP protocol specific fields to host format. + */ + +#if BYTE_ORDER != BIG_ENDIAN + NTOHL(th->th_seq); + NTOHL(th->th_ack); + NTOHS(th->th_win); + NTOHS(th->th_urp); +#endif + /* * Locate pcb for segment. */ findpcb: + + isconnected = FALSE; + isdisconnected = FALSE; + #if IPFIREWALL_FORWARD if (next_hop != NULL #if INET6 @@ -787,12 +2135,12 @@ findpcb: ) { /* * Diverted. Pretend to be the destination. - * already got one like this? + * already got one like this? */ inp = in_pcblookup_hash(&tcbinfo, ip->ip_src, th->th_sport, ip->ip_dst, th->th_dport, 0, m->m_pkthdr.rcvif); if (!inp) { - /* + /* * No, then it's new. Try find the ambushing socket */ if (!next_hop->sin_port) { @@ -821,22 +2169,14 @@ findpcb: ip->ip_dst, th->th_dport, 1, m->m_pkthdr.rcvif); } -#if IPSEC - if (ipsec_bypass == 0) { -#if INET6 - if (isipv6) { - if (inp != NULL && ipsec6_in_reject_so(m, inp->inp_socket)) { - IPSEC_STAT_INCREMENT(ipsec6stat.in_polvio); - goto dropnosock; - } - } else -#endif /* INET6 */ - if (inp != NULL && ipsec4_in_reject_so(m, inp->inp_socket)) { - IPSEC_STAT_INCREMENT(ipsecstat.in_polvio); - goto dropnosock; - } - } -#endif /*IPSEC*/ + /* + * Use the interface scope information from the PCB for outbound + * segments. If the PCB isn't present and if scoped routing is + * enabled, tcp_respond will use the scope of the interface where + * the segment arrived on. + */ + if (inp != NULL && (inp->inp_flags & INP_BOUND_IF)) + ifscope = inp->inp_boundifp->if_index; /* * If the state is CLOSED (i.e., TCB does not exist) then @@ -878,7 +2218,8 @@ findpcb: ntohs(th->th_sport), thflags); break; case 3: - if ((thflags & TH_SYN) && + case 4: + if ((thflags & TH_SYN) && !(thflags & TH_ACK) && !(m->m_flags & (M_BCAST | M_MCAST)) && #if INET6 ((isipv6 && !IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &ip6->ip6_src)) || @@ -897,8 +2238,9 @@ findpcb: break; } } - if (blackhole) { + if (blackhole) { if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type != IFT_LOOP) + switch (blackhole) { case 1: if (thflags & TH_SYN) @@ -911,42 +2253,73 @@ findpcb: } } rstreason = BANDLIM_RST_CLOSEDPORT; + IF_TCP_STATINC(ifp, noconnnolist); goto dropwithresetnosock; } so = inp->inp_socket; if (so == NULL) { - if (in_pcb_checkstate(inp, WNT_RELEASE, 1) == WNT_STOPUSING) - inp = NULL; // pretend we didn't find it + /* This case shouldn't happen as the socket shouldn't be null + * if inp_state isn't set to INPCB_STATE_DEAD + * But just in case, we pretend we didn't find the socket if we hit this case + * as this isn't cause for a panic (the socket might be leaked however)... + */ + inp = NULL; #if TEMPDEBUG - printf("tcp_input: no more socket for inp=%x\n", inp); + printf("tcp_input: no more socket for inp=%x. This shouldn't happen\n", inp); #endif goto dropnosock; } -#ifdef __APPLE__ - /* - * Bogus state when listening port owned by SharedIP with loopback as the - * only configured interface: BlueBox does not filters loopback - */ - if (so == &tcbinfo.nat_dummy_socket) - goto drop; - -#endif - tcp_lock(so, 1, 2); + socket_lock(so, 1); if (in_pcb_checkstate(inp, WNT_RELEASE, 1) == WNT_STOPUSING) { - tcp_unlock(so, 1, 2); - inp = NULL; // pretend we didn't find it + socket_unlock(so, 1); + inp = NULL; // pretend we didn't find it goto dropnosock; } +#if NECP + if (so->so_state & SS_ISCONNECTED) { + // Connected TCP sockets have a fully-bound local and remote, + // so the policy check doesn't need to override addresses + if (!necp_socket_is_allowed_to_send_recv(inp, NULL, NULL, NULL)) { + IF_TCP_STATINC(ifp, badformat); + goto drop; + } + } else { +#if INET6 + if (isipv6) { + if (!necp_socket_is_allowed_to_send_recv_v6(inp, + th->th_dport, th->th_sport, &ip6->ip6_dst, + &ip6->ip6_src, ifp, NULL, NULL, NULL)) { + IF_TCP_STATINC(ifp, badformat); + goto drop; + } + } else +#endif + { + if (!necp_socket_is_allowed_to_send_recv_v4(inp, + th->th_dport, th->th_sport, &ip->ip_dst, &ip->ip_src, + ifp, NULL, NULL, NULL)) { + IF_TCP_STATINC(ifp, badformat); + goto drop; + } + } + } +#endif /* NECP */ + tp = intotcpcb(inp); if (tp == 0) { rstreason = BANDLIM_RST_CLOSEDPORT; + IF_TCP_STATINC(ifp, noconnlist); goto dropwithreset; } if (tp->t_state == TCPS_CLOSED) goto drop; + /* If none of the FIN|SYN|RST|ACK flag is set, drop */ + if (tcp_do_rfc5961 && (thflags & TH_ACCEPT) == 0) + goto drop; + /* Unscale the window into a 32-bit value. */ if ((thflags & TH_SYN) == 0) tiwin = th->th_win << tp->snd_scale; @@ -958,6 +2331,11 @@ findpcb: goto drop; #endif + /* Avoid processing packets while closing a listen socket */ + if (tp->t_state == TCPS_LISTEN && + (so->so_options & SO_ACCEPTCONN) == 0) + goto drop; + if (so->so_options & (SO_DEBUG|SO_ACCEPTCONN)) { #if TCPDEBUG if (so->so_options & SO_DEBUG) { @@ -973,35 +2351,88 @@ findpcb: } #endif if (so->so_options & SO_ACCEPTCONN) { - register struct tcpcb *tp0 = tp; + struct tcpcb *tp0 = tp; struct socket *so2; struct socket *oso; struct sockaddr_storage from; #if INET6 struct inpcb *oinp = sotoinpcb(so); #endif /* INET6 */ - int ogencnt = so->so_gencnt; + struct ifnet *head_ifscope; + unsigned int head_nocell, head_recvanyif, + head_noexpensive, head_awdl_unrestricted, + head_intcoproc_allowed; + + /* Get listener's bound-to-interface, if any */ + head_ifscope = (inp->inp_flags & INP_BOUND_IF) ? + inp->inp_boundifp : NULL; + /* Get listener's no-cellular information, if any */ + head_nocell = INP_NO_CELLULAR(inp); + /* Get listener's recv-any-interface, if any */ + head_recvanyif = (inp->inp_flags & INP_RECV_ANYIF); + /* Get listener's no-expensive information, if any */ + head_noexpensive = INP_NO_EXPENSIVE(inp); + head_awdl_unrestricted = INP_AWDL_UNRESTRICTED(inp); + head_intcoproc_allowed = INP_INTCOPROC_ALLOWED(inp); -#if !IPSEC /* - * Current IPsec implementation makes incorrect IPsec - * cache if this check is done here. - * So delay this until duplicated socket is created. + * If the state is LISTEN then ignore segment if it contains an RST. + * If the segment contains an ACK then it is bad and send a RST. + * If it does not contain a SYN then it is not interesting; drop it. + * If it is from this socket, drop it, it must be forged. */ if ((thflags & (TH_RST|TH_ACK|TH_SYN)) != TH_SYN) { - /* - * Note: dropwithreset makes sure we don't - * send a RST in response to a RST. - */ + IF_TCP_STATINC(ifp, listbadsyn); + + if (thflags & TH_RST) { + goto drop; + } if (thflags & TH_ACK) { + tp = NULL; tcpstat.tcps_badsyn++; rstreason = BANDLIM_RST_OPENPORT; goto dropwithreset; } + + /* We come here if there is no SYN set */ + tcpstat.tcps_badsyn++; goto drop; } -#endif KERNEL_DEBUG(DBG_FNC_TCP_NEWCONN | DBG_FUNC_START,0,0,0,0,0); + if (th->th_dport == th->th_sport) { +#if INET6 + if (isipv6) { + if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, + &ip6->ip6_src)) + goto drop; + } else +#endif /* INET6 */ + if (ip->ip_dst.s_addr == ip->ip_src.s_addr) + goto drop; + } + /* + * RFC1122 4.2.3.10, p. 104: discard bcast/mcast SYN + * in_broadcast() should never return true on a received + * packet with M_BCAST not set. + * + * Packets with a multicast source address should also + * be discarded. + */ + if (m->m_flags & (M_BCAST|M_MCAST)) + goto drop; +#if INET6 + if (isipv6) { + if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || + IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) + goto drop; + } else +#endif + if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) || + IN_MULTICAST(ntohl(ip->ip_src.s_addr)) || + ip->ip_src.s_addr == htonl(INADDR_BROADCAST) || + in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) + goto drop; + #if INET6 /* @@ -1016,32 +2447,20 @@ findpcb: * for the exchange. * * If we do not forbid deprecated addresses, we accept - * the SYN packet. RFC2462 does not suggest dropping - * SYN in this case. - * If we decipher RFC2462 5.5.4, it says like this: - * 1. use of deprecated addr with existing - * communication is okay - "SHOULD continue to be - * used" - * 2. use of it with new communication: - * (2a) "SHOULD NOT be used if alternate address - * with sufficient scope is available" - * (2b) nothing mentioned otherwise. - * Here we fall into (2b) case as we have no choice in - * our source address selection - we must obey the peer. - * - * The wording in RFC2462 is confusing, and there are - * multiple description text for deprecated address - * handling - worse, they are not exactly the same. - * I believe 5.5.4 is the best one, so we follow 5.5.4. + * the SYN packet. RFC 4862 forbids dropping SYN in + * this case. */ if (isipv6 && !ip6_use_deprecated) { - struct in6_ifaddr *ia6; - - if ((ia6 = ip6_getdstifaddr(m)) && - (ia6->ia6_flags & IN6_IFF_DEPRECATED)) { - tp = NULL; - rstreason = BANDLIM_RST_OPENPORT; - goto dropwithreset; + uint32_t ia6_flags; + + if (ip6_getdstifaddr_info(m, NULL, + &ia6_flags) == 0) { + if (ia6_flags & IN6_IFF_DEPRECATED) { + tp = NULL; + rstreason = BANDLIM_RST_OPENPORT; + IF_TCP_STATINC(ifp, deprecate6); + goto dropwithreset; + } } } #endif @@ -1049,7 +2468,7 @@ findpcb: #if INET6 if (isipv6) { struct sockaddr_in6 *sin6 = (struct sockaddr_in6*)&from; - + sin6->sin6_len = sizeof(*sin6); sin6->sin6_family = AF_INET6; sin6->sin6_port = th->th_sport; @@ -1061,7 +2480,7 @@ findpcb: #endif { struct sockaddr_in *sin = (struct sockaddr_in*)&from; - + sin->sin_len = sizeof(*sin); sin->sin_family = AF_INET; sin->sin_port = th->th_sport; @@ -1079,24 +2498,20 @@ findpcb: else so2 = sonewconn(so, 0, NULL); } - if (!so2) + if (!so2) goto drop; } - /* - * Make sure listening socket did not get closed during socket allocation, - * not only this is incorrect but it is know to cause panic - */ - if (so->so_gencnt != ogencnt) - goto drop; + + /* Point "inp" and "tp" in tandem to new socket */ + inp = (struct inpcb *)so2->so_pcb; + tp = intotcpcb(inp); oso = so; - tcp_unlock(so, 0, 0); /* Unlock but keep a reference on listener for now */ + socket_unlock(so, 0); /* Unlock but keep a reference on listener for now */ so = so2; - tcp_lock(so, 1, 0); + socket_lock(so, 1); /* - * This is ugly, but .... - * * Mark socket as temporary until we're * committed to keeping it. The code at * ``drop'' and ``dropwithreset'' check the @@ -1104,9 +2519,40 @@ findpcb: * socket created here should be discarded. * We mark the socket as discardable until * we're committed to it below in TCPS_LISTEN. + * There are some error conditions in which we + * have to drop the temporary socket. */ dropsocket++; - inp = (struct inpcb *)so->so_pcb; + /* + * Inherit INP_BOUND_IF from listener; testing if + * head_ifscope is non-NULL is sufficient, since it + * can only be set to a non-zero value earlier if + * the listener has such a flag set. + */ + if (head_ifscope != NULL) { + inp->inp_flags |= INP_BOUND_IF; + inp->inp_boundifp = head_ifscope; + } else { + inp->inp_flags &= ~INP_BOUND_IF; + } + /* + * Inherit restrictions from listener. + */ + if (head_nocell) + inp_set_nocellular(inp); + if (head_noexpensive) + inp_set_noexpensive(inp); + if (head_awdl_unrestricted) + inp_set_awdl_unrestricted(inp); + if (head_intcoproc_allowed) + inp_set_intcoproc_allowed(inp); + /* + * Inherit {IN,IN6}_RECV_ANYIF from listener. + */ + if (head_recvanyif) + inp->inp_flags |= INP_RECV_ANYIF; + else + inp->inp_flags &= ~INP_RECV_ANYIF; #if INET6 if (isipv6) inp->in6p_laddr = ip6->ip6_dst; @@ -1114,7 +2560,7 @@ findpcb: inp->inp_vflag &= ~INP_IPV6; inp->inp_vflag |= INP_IPV4; #endif /* INET6 */ - inp->inp_laddr = ip->ip_dst; + inp->inp_laddr = ip->ip_dst; #if INET6 } #endif /* INET6 */ @@ -1129,61 +2575,40 @@ findpcb: inp->in6p_laddr = in6addr_any; else #endif /* INET6 */ - inp->inp_laddr.s_addr = INADDR_ANY; + inp->inp_laddr.s_addr = INADDR_ANY; inp->inp_lport = 0; - tcp_lock(oso, 0, 0); /* release ref on parent */ - tcp_unlock(oso, 1, 0); - goto drop; - } -#if IPSEC - /* - * To avoid creating incorrectly cached IPsec - * association, this is need to be done here. - * - * Subject: (KAME-snap 748) - * From: Wayne Knowles - * ftp://ftp.kame.net/pub/mail-list/snap-users/748 - */ - if ((thflags & (TH_RST|TH_ACK|TH_SYN)) != TH_SYN) { - /* - * Note: dropwithreset makes sure we don't - * send a RST in response to a RST. - */ - tcp_lock(oso, 0, 0); /* release ref on parent */ - tcp_unlock(oso, 1, 0); - if (thflags & TH_ACK) { - tcpstat.tcps_badsyn++; - rstreason = BANDLIM_RST_OPENPORT; - goto dropwithreset; - } + socket_lock(oso, 0); /* release ref on parent */ + socket_unlock(oso, 1); goto drop; } -#endif #if INET6 if (isipv6) { - /* - * Inherit socket options from the listening - * socket. - * Note that in6p_inputopts are not (even - * should not be) copied, since it stores + /* + * Inherit socket options from the listening + * socket. + * Note that in6p_inputopts are not (even + * should not be) copied, since it stores * previously received options and is used to - * detect if each new option is different than - * the previous one and hence should be passed - * to a user. - * If we copied in6p_inputopts, a user would - * not be able to receive options just after - * calling the accept system call. - */ + * detect if each new option is different than + * the previous one and hence should be passed + * to a user. + * If we copied in6p_inputopts, a user would + * not be able to receive options just after + * calling the accept system call. + */ inp->inp_flags |= oinp->inp_flags & INP_CONTROLOPTS; - if (oinp->in6p_outputopts) - inp->in6p_outputopts = - ip6_copypktopts(oinp->in6p_outputopts, - M_NOWAIT); + if (oinp->in6p_outputopts) + inp->in6p_outputopts = + ip6_copypktopts(oinp->in6p_outputopts, + M_NOWAIT); } else #endif /* INET6 */ - inp->inp_options = ip_srcroute(); - tcp_lock(oso, 0, 0); + { + inp->inp_options = ip_srcroute(); + inp->inp_ip_tos = oinp->inp_ip_tos; + } + socket_lock(oso, 0); #if IPSEC /* copy old policy into new socket's */ if (sotoinpcb(oso)->inp_sp) @@ -1196,177 +2621,255 @@ findpcb: printf("tcp_input: could not copy policy\n"); } #endif - tcp_unlock(oso, 1, 0); /* now drop the reference on the listener */ - tp = intotcpcb(inp); + /* inherit states from the listener */ + DTRACE_TCP4(state__change, void, NULL, struct inpcb *, inp, + struct tcpcb *, tp, int32_t, TCPS_LISTEN); tp->t_state = TCPS_LISTEN; tp->t_flags |= tp0->t_flags & (TF_NOPUSH|TF_NOOPT|TF_NODELAY); + tp->t_flagsext |= (tp0->t_flagsext & (TF_RXTFINDROP|TF_NOTIMEWAIT|TF_FASTOPEN)); + tp->t_keepinit = tp0->t_keepinit; + tp->t_keepcnt = tp0->t_keepcnt; + tp->t_keepintvl = tp0->t_keepintvl; + tp->t_adaptive_wtimo = tp0->t_adaptive_wtimo; + tp->t_adaptive_rtimo = tp0->t_adaptive_rtimo; tp->t_inpcb->inp_ip_ttl = tp0->t_inpcb->inp_ip_ttl; - /* Compute proper scaling value from buffer space */ - if (inp->inp_pcbinfo->ipi_count < tcp_sockthreshold) { - tp->request_r_scale = max(tcp_win_scale, tp->request_r_scale); - so->so_rcv.sb_hiwat = lmin(TCP_MAXWIN << tp->request_r_scale, (sb_max / (MSIZE+MCLBYTES)) * MCLBYTES); - } - else { - while (tp->request_r_scale < TCP_MAX_WINSHIFT && - TCP_MAXWIN << tp->request_r_scale < - so->so_rcv.sb_hiwat) - tp->request_r_scale++; - } + if ((so->so_flags & SOF_NOTSENT_LOWAT) != 0) + tp->t_notsent_lowat = tp0->t_notsent_lowat; + tp->t_inpcb->inp_flags2 |= + tp0->t_inpcb->inp_flags2 & INP2_KEEPALIVE_OFFLOAD; + + /* now drop the reference on the listener */ + socket_unlock(oso, 1); + + tcp_set_max_rwinscale(tp, so, ifp); KERNEL_DEBUG(DBG_FNC_TCP_NEWCONN | DBG_FUNC_END,0,0,0,0,0); } } + socket_lock_assert_owned(so); -#if 1 - lck_mtx_assert(((struct inpcb *)so->so_pcb)->inpcb_mtx, LCK_MTX_ASSERT_OWNED); -#endif - /* - * Radar 3529618 - * This is the second part of the MSS DoS prevention code (after - * minmss on the sending side) and it deals with too many too small - * tcp packets in a too short timeframe (1 second). - * - * For every full second we count the number of received packets - * and bytes. If we get a lot of packets per second for this connection - * (tcp_minmssoverload) we take a closer look at it and compute the - * average packet size for the past second. If that is less than - * tcp_minmss we get too many packets with very small payload which - * is not good and burdens our system (and every packet generates - * a wakeup to the process connected to our socket). We can reasonable - * expect this to be small packet DoS attack to exhaust our CPU - * cycles. - * - * Care has to be taken for the minimum packet overload value. This - * value defines the minimum number of packets per second before we - * start to worry. This must not be too low to avoid killing for - * example interactive connections with many small packets like - * telnet or SSH. - * - * Setting either tcp_minmssoverload or tcp_minmss to "0" disables - * this check. - * - * Account for packet if payload packet, skip over ACK, etc. - * - * The packet per second count is done all the time and is also used - * by "DELAY_ACK" to detect streaming situations. - * - */ if (tp->t_state == TCPS_ESTABLISHED && tlen > 0) { - if (tp->rcv_reset > tcp_now) { - tp->rcv_pps++; - tp->rcv_byps += tlen + off; - if (tp->rcv_byps > tp->rcv_maxbyps) - tp->rcv_maxbyps = tp->rcv_byps; /* - * Setting either tcp_minmssoverload or tcp_minmss to "0" disables - * the check. - */ - if (tcp_minmss && tcp_minmssoverload && tp->rcv_pps > tcp_minmssoverload) { - if ((tp->rcv_byps / tp->rcv_pps) < tcp_minmss) { - char ipstrbuf[MAX_IPv6_STR_LEN]; - printf("too many small tcp packets from " - "%s:%u, av. %lubyte/packet, " - "dropping connection\n", -#if INET6 - isipv6 ? - inet_ntop(AF_INET6, &inp->in6p_faddr, ipstrbuf, - sizeof(ipstrbuf)) : -#endif - inet_ntop(AF_INET, &inp->inp_faddr, ipstrbuf, - sizeof(ipstrbuf)), - inp->inp_fport, - tp->rcv_byps / tp->rcv_pps); - tp = tcp_drop(tp, ECONNRESET); -/* tcpstat.tcps_minmssdrops++; */ - goto drop; - } - } + * Evaluate the rate of arrival of packets to see if the + * receiver can reduce the ack traffic. The algorithm to + * stretch acks will be enabled if the connection meets + * certain criteria defined in tcp_stretch_ack_enable function. + */ + if ((tp->t_flagsext & TF_RCVUNACK_WAITSS) != 0) { + TCP_INC_VAR(tp->rcv_waitforss, nlropkts); + } + if (tcp_stretch_ack_enable(tp, thflags)) { + tp->t_flags |= TF_STRETCHACK; + tp->t_flagsext &= ~(TF_RCVUNACK_WAITSS); + tp->rcv_waitforss = 0; } else { - tp->rcv_reset = tcp_now + TCP_RETRANSHZ; - tp->rcv_pps = 1; - tp->rcv_byps = tlen + off; + tp->t_flags &= ~(TF_STRETCHACK); + } + if (TSTMP_GT(tp->rcv_unackwin, tcp_now)) { + tp->rcv_by_unackwin += (tlen + off); + } else { + tp->rcv_unackwin = tcp_now + tcp_rcvunackwin; + tp->rcv_by_unackwin = tlen + off; } } - -#if TRAFFIC_MGT - if (so->so_traffic_mgt_flags & TRAFFIC_MGT_SO_BACKGROUND) { - tcpstat.tcps_bg_rcvtotal++; - - /* Take snapshots of pkts recv; - * tcpcb should have been initialized to 0 when allocated, - * so if 0 then this is the first time we're doing this - */ - if (!tp->tot_recv_snapshot) { - tp->tot_recv_snapshot = tcpstat.tcps_rcvtotal; - } - if (!tp->bg_recv_snapshot) { - tp->bg_recv_snapshot = tcpstat.tcps_bg_rcvtotal; - } - } -#endif /* TRAFFIC_MGT */ /* - Explicit Congestion Notification - Flag that we need to send ECT if - + The IP Congestion experienced flag was set. - + Socket is in established state - + We negotiated ECN in the TCP setup - + This isn't a pure ack (tlen > 0) - + The data is in the valid window - - TE_SENDECE will be cleared when we receive a packet with TH_CWR set. + * Keep track of how many bytes were received in the LRO packet + */ + if ((pktf_sw_lro_pkt) && (nlropkts > 2)) { + tp->t_lropktlen += tlen; + } + /* + * Explicit Congestion Notification - Flag that we need to send ECT if + * + The IP Congestion experienced flag was set. + * + Socket is in established state + * + We negotiated ECN in the TCP setup + * + This isn't a pure ack (tlen > 0) + * + The data is in the valid window + * + * TE_SENDECE will be cleared when we receive a packet with TH_CWR set. */ if (ip_ecn == IPTOS_ECN_CE && tp->t_state == TCPS_ESTABLISHED && - (tp->ecn_flags & (TE_SETUPSENT | TE_SETUPRECEIVED)) == - (TE_SETUPSENT | TE_SETUPRECEIVED) && tlen > 0 && - SEQ_GEQ(th->th_seq, tp->last_ack_sent) && - SEQ_LT(th->th_seq, tp->last_ack_sent + tp->rcv_wnd)) { + TCP_ECN_ENABLED(tp) && tlen > 0 && + SEQ_GEQ(th->th_seq, tp->last_ack_sent) && + SEQ_LT(th->th_seq, tp->last_ack_sent + tp->rcv_wnd)) { + tp->t_ecn_recv_ce++; + tcpstat.tcps_ecn_recv_ce++; + INP_INC_IFNET_STAT(inp, ecn_recv_ce); + /* Mark this connection as it received CE from network */ + tp->ecn_flags |= TE_RECV_ECN_CE; tp->ecn_flags |= TE_SENDECE; } - + /* - Clear TE_SENDECE if TH_CWR is set. This is harmless, so we don't - bother doing extensive checks for state and whatnot. + * Clear TE_SENDECE if TH_CWR is set. This is harmless, so we don't + * bother doing extensive checks for state and whatnot. */ - if ((thflags & TH_CWR) == TH_CWR) { + if (thflags & TH_CWR) { tp->ecn_flags &= ~TE_SENDECE; + tp->t_ecn_recv_cwr++; + } + + /* + * If we received an explicit notification of congestion in + * ip tos ecn bits or by the CWR bit in TCP header flags, reset + * the ack-strteching state. We need to handle ECN notification if + * an ECN setup SYN was sent even once. + */ + if (tp->t_state == TCPS_ESTABLISHED + && (tp->ecn_flags & TE_SETUPSENT) + && (ip_ecn == IPTOS_ECN_CE || (thflags & TH_CWR))) { + tcp_reset_stretch_ack(tp); + CLEAR_IAJ_STATE(tp); } - + + if (ip_ecn == IPTOS_ECN_CE && tp->t_state == TCPS_ESTABLISHED && + !TCP_ECN_ENABLED(tp) && !(tp->ecn_flags & TE_CEHEURI_SET)) { + tcpstat.tcps_ecn_fallback_ce++; + tcp_heuristic_ecn_aggressive(tp); + tp->ecn_flags |= TE_CEHEURI_SET; + } + + if (tp->t_state == TCPS_ESTABLISHED && TCP_ECN_ENABLED(tp) && + ip_ecn == IPTOS_ECN_CE && !(tp->ecn_flags & TE_CEHEURI_SET)) { + if (inp->inp_stat->rxpackets < ECN_MIN_CE_PROBES) { + tp->t_ecn_recv_ce_pkt++; + } else if (tp->t_ecn_recv_ce_pkt > ECN_MAX_CE_RATIO) { + tcpstat.tcps_ecn_fallback_ce++; + tcp_heuristic_ecn_aggressive(tp); + tp->ecn_flags |= TE_CEHEURI_SET; + INP_INC_IFNET_STAT(inp,ecn_fallback_ce); + } else { + /* We tracked the first ECN_MIN_CE_PROBES segments, we + * now know that the path is good. + */ + tp->ecn_flags |= TE_CEHEURI_SET; + } + } + + /* + * Try to determine if we are receiving a packet after a long time. + * Use our own approximation of idletime to roughly measure remote + * end's idle time. Since slowstart is used after an idle period + * we want to avoid doing LRO if the remote end is not up to date + * on initial window support and starts with 1 or 2 packets as its IW. + */ + if (sw_lro && (tp->t_flagsext & TF_LRO_OFFLOADED) && + ((tcp_now - tp->t_rcvtime) >= (TCP_IDLETIMEOUT(tp)))) { + turnoff_lro = 1; + } + + /* Update rcvtime as a new segment was received on the connection */ + tp->t_rcvtime = tcp_now; + /* * Segment received on connection. * Reset idle time and keep-alive timer. */ - tp->t_rcvtime = 0; - if (TCPS_HAVEESTABLISHED(tp->t_state)) - tp->t_timer[TCPT_KEEP] = TCP_KEEPIDLE(tp); + if (TCPS_HAVEESTABLISHED(tp->t_state)) { + tcp_keepalive_reset(tp); + + if (tp->t_mpsub) + mptcp_reset_keepalive(tp); + } /* * Process options if not in LISTEN state, * else do it below (after getting remote address). */ - if (tp->t_state != TCPS_LISTEN && optp) + if (tp->t_state != TCPS_LISTEN && optp) { tcp_dooptions(tp, optp, optlen, th, &to); - + } +#if MPTCP + if (tp->t_state != TCPS_LISTEN && (so->so_flags & SOF_MP_SUBFLOW) && + mptcp_input_preproc(tp, m, th, drop_hdrlen) != 0) { + tp->t_flags |= TF_ACKNOW; + (void) tcp_output(tp); + tcp_check_timer_state(tp); + socket_unlock(so, 1); + KERNEL_DEBUG(DBG_FNC_TCP_INPUT | + DBG_FUNC_END,0,0,0,0,0); + return; + } +#endif /* MPTCP */ if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) { - if (to.to_flags & TOF_SCALE) { - tp->t_flags |= TF_RCVD_SCALE; - tp->requested_s_scale = to.to_requested_s_scale; - tp->snd_wnd = th->th_win << tp->snd_scale; - tiwin = tp->snd_wnd; + if (!(thflags & TH_ACK) || + (SEQ_GT(th->th_ack, tp->iss) && + SEQ_LEQ(th->th_ack, tp->snd_max))) + tcp_finalize_options(tp, &to, ifscope); + } + +#if TRAFFIC_MGT + /* + * Compute inter-packet arrival jitter. According to RFC 3550, + * inter-packet arrival jitter is defined as the difference in + * packet spacing at the receiver compared to the sender for a + * pair of packets. When two packets of maximum segment size come + * one after the other with consecutive sequence numbers, we + * consider them as packets sent together at the sender and use + * them as a pair to compute inter-packet arrival jitter. This + * metric indicates the delay induced by the network components due + * to queuing in edge/access routers. + */ + if (tp->t_state == TCPS_ESTABLISHED && + (thflags & (TH_SYN|TH_FIN|TH_RST|TH_URG|TH_ACK|TH_ECE|TH_PUSH)) == TH_ACK && + ((tp->t_flags & (TF_NEEDSYN|TF_NEEDFIN)) == 0) && + ((to.to_flags & TOF_TS) == 0 || + TSTMP_GEQ(to.to_tsval, tp->ts_recent)) && + th->th_seq == tp->rcv_nxt && LIST_EMPTY(&tp->t_segq)) { + int seg_size = tlen; + if (tp->iaj_pktcnt <= IAJ_IGNORE_PKTCNT) { + TCP_INC_VAR(tp->iaj_pktcnt, nlropkts); } - if (to.to_flags & TOF_TS) { - tp->t_flags |= TF_RCVD_TSTMP; - tp->ts_recent = to.to_tsval; - tp->ts_recent_age = tcp_now; + + if (m->m_pkthdr.pkt_flags & PKTF_SW_LRO_PKT) { + seg_size = m->m_pkthdr.lro_pktlen; } - if (to.to_flags & TOF_MSS) - tcp_mss(tp, to.to_mss); - if (tp->sack_enable) { - if (!(to.to_flags & TOF_SACK)) - tp->sack_enable = 0; - else - tp->t_flags |= TF_SACK_PERMIT; + if ( tp->iaj_size == 0 || seg_size > tp->iaj_size || + (seg_size == tp->iaj_size && tp->iaj_rcv_ts == 0)) { + /* + * State related to inter-arrival jitter is + * uninitialized or we are trying to find a good + * first packet to start computing the metric + */ + update_iaj_state(tp, seg_size, 0); + } else { + if (seg_size == tp->iaj_size) { + /* + * Compute inter-arrival jitter taking + * this packet as the second packet + */ + if (pktf_sw_lro_pkt) + compute_iaj(tp, nlropkts, + m->m_pkthdr.lro_elapsed); + else + compute_iaj(tp, 1, 0); + } + if (seg_size < tp->iaj_size) { + /* + * There is a smaller packet in the stream. + * Some times the maximum size supported + * on a path can change if there is a new + * link with smaller MTU. The receiver will + * not know about this change. If there + * are too many packets smaller than + * iaj_size, we try to learn the iaj_size + * again. + */ + TCP_INC_VAR(tp->iaj_small_pkt, nlropkts); + if (tp->iaj_small_pkt > RESET_IAJ_SIZE_THRESH) { + update_iaj_state(tp, seg_size, 1); + } else { + CLEAR_IAJ_STATE(tp); + } + } else { + update_iaj_state(tp, seg_size, 0); + } } + } else { + CLEAR_IAJ_STATE(tp); } +#endif /* TRAFFIC_MGT */ /* * Header prediction: check for the two common cases @@ -1386,7 +2889,7 @@ findpcb: * be TH_NEEDSYN. */ if (tp->t_state == TCPS_ESTABLISHED && - (thflags & (TH_SYN|TH_FIN|TH_RST|TH_URG|TH_ACK|TH_ECE)) == TH_ACK && + (thflags & (TH_SYN|TH_FIN|TH_RST|TH_URG|TH_ACK|TH_ECE|TH_CWR)) == TH_ACK && ((tp->t_flags & (TF_NEEDSYN|TF_NEEDFIN)) == 0) && ((to.to_flags & TOF_TS) == 0 || TSTMP_GEQ(to.to_tsval, tp->ts_recent)) && @@ -1410,71 +2913,61 @@ findpcb: if (SEQ_GT(th->th_ack, tp->snd_una) && SEQ_LEQ(th->th_ack, tp->snd_max) && tp->snd_cwnd >= tp->snd_ssthresh && - ((!tcp_do_newreno && !tp->sack_enable && - tp->t_dupacks < tcprexmtthresh) || - ((tcp_do_newreno || tp->sack_enable) && - !IN_FASTRECOVERY(tp) && to.to_nsacks == 0 && - TAILQ_EMPTY(&tp->snd_holes)))) { + (!IN_FASTRECOVERY(tp) && + ((!(SACK_ENABLED(tp)) && + tp->t_dupacks < tp->t_rexmtthresh) || + (SACK_ENABLED(tp) && to.to_nsacks == 0 && + TAILQ_EMPTY(&tp->snd_holes))))) { /* * this is a pure ack for outstanding data. */ ++tcpstat.tcps_predack; - /* - * "bad retransmit" recovery - */ - if (tp->t_rxtshift == 1 && - tcp_now < tp->t_badrxtwin) { - ++tcpstat.tcps_sndrexmitbad; - tp->snd_cwnd = tp->snd_cwnd_prev; - tp->snd_ssthresh = - tp->snd_ssthresh_prev; - tp->snd_recover = tp->snd_recover_prev; - if (tp->t_flags & TF_WASFRECOVERY) - ENTER_FASTRECOVERY(tp); - tp->snd_nxt = tp->snd_max; - tp->t_badrxtwin = 0; - } - /* - * Recalculate the transmit timer / rtt. - * - * Some boxes send broken timestamp replies - * during the SYN+ACK phase, ignore - * timestamps of 0 or we could calculate a - * huge RTT and blow up the retransmit timer. - */ - if (((to.to_flags & TOF_TS) != 0) && (to.to_tsecr != 0)) { /* Makes sure we already have a TS */ - if (!tp->t_rttlow || - tp->t_rttlow > tcp_now - to.to_tsecr) - tp->t_rttlow = tcp_now - to.to_tsecr; - tcp_xmit_timer(tp, - tcp_now - to.to_tsecr); - } else if (tp->t_rtttime && - SEQ_GT(th->th_ack, tp->t_rtseq)) { - if (!tp->t_rttlow || - tp->t_rttlow > tcp_now - tp->t_rtttime) - tp->t_rttlow = tcp_now - tp->t_rtttime; - tcp_xmit_timer(tp, tp->t_rtttime); - } - acked = th->th_ack - tp->snd_una; + + tcp_bad_rexmt_check(tp, th, &to); + + /* Recalculate the RTT */ + tcp_compute_rtt(tp, &to, th); + + VERIFY(SEQ_GEQ(th->th_ack, tp->snd_una)); + acked = BYTES_ACKED(th, tp); tcpstat.tcps_rcvackpack++; tcpstat.tcps_rcvackbyte += acked; + /* - * Grow the congestion window, if the - * connection is cwnd bound. + * Handle an ack that is in sequence during + * congestion avoidance phase. The + * calculations in this function + * assume that snd_una is not updated yet. */ + if (CC_ALGO(tp)->congestion_avd != NULL) + CC_ALGO(tp)->congestion_avd(tp, th); + tcp_ccdbg_trace(tp, th, TCP_CC_INSEQ_ACK_RCVD); sbdrop(&so->so_snd, acked); + if (so->so_flags & SOF_ENABLE_MSGS) { + VERIFY(acked <= so->so_msg_state->msg_serial_bytes); + so->so_msg_state->msg_serial_bytes -= acked; + } + tcp_sbsnd_trim(&so->so_snd); + if (SEQ_GT(tp->snd_una, tp->snd_recover) && SEQ_LEQ(th->th_ack, tp->snd_recover)) tp->snd_recover = th->th_ack - 1; tp->snd_una = th->th_ack; + + TCP_RESET_REXMT_STATE(tp); + /* * pull snd_wl2 up to prevent seq wrap relative * to th_ack. */ tp->snd_wl2 = th->th_ack; - tp->t_dupacks = 0; + + if (tp->t_dupacks > 0) { + tp->t_dupacks = 0; + tp->t_rexmtthresh = tcprexmtthresh; + } + m_freem(m); - ND6_HINT(tp); /* some progress has been done */ /* * If all outstanding data are acked, stop @@ -1485,17 +2978,35 @@ findpcb: * are ready to send, let tcp_output * decide between more output or persist. */ - if (tp->snd_una == tp->snd_max) + if (tp->snd_una == tp->snd_max) { tp->t_timer[TCPT_REXMT] = 0; - else if (tp->t_timer[TCPT_PERSIST] == 0) - tp->t_timer[TCPT_REXMT] = tp->t_rxtcur; + tp->t_timer[TCPT_PTO] = 0; + } else if (tp->t_timer[TCPT_PERSIST] == 0) { + tp->t_timer[TCPT_REXMT] = + OFFSET_FROM_START(tp, + tp->t_rxtcur); + } + if (!SLIST_EMPTY(&tp->t_rxt_segments) && + !TCP_DSACK_SEQ_IN_WINDOW(tp, + tp->t_dsack_lastuna, tp->snd_una)) + tcp_rxtseg_clean(tp); + + if ((tp->t_flagsext & TF_MEASURESNDBW) != 0 && + tp->t_bwmeas != NULL) + tcp_bwmeas_check(tp); sowwakeup(so); /* has to be done with socket lock held */ + if (!SLIST_EMPTY(&tp->t_notify_ack)) + tcp_notify_acknowledgement(tp, so); + if ((so->so_snd.sb_cc) || (tp->t_flags & TF_ACKNOW)) { - tp->t_unacksegs = 0; (void) tcp_output(tp); } - tcp_unlock(so, 1, 0); + + tcp_tfo_rcv_ack(tp, th); + + tcp_check_timer_state(tp); + socket_unlock(so, 1); KERNEL_DEBUG(DBG_FNC_TCP_INPUT | DBG_FUNC_END,0,0,0,0,0); return; } @@ -1507,8 +3018,33 @@ findpcb: * with nothing on the reassembly queue and * we have enough buffer space to take it. */ + + /* + * If this is a connection in steady state, start + * coalescing packets belonging to this flow. + */ + if (turnoff_lro) { + tcp_lro_remove_state(tp->t_inpcb->inp_laddr, + tp->t_inpcb->inp_faddr, + tp->t_inpcb->inp_lport, + tp->t_inpcb->inp_fport); + tp->t_flagsext &= ~TF_LRO_OFFLOADED; + tp->t_idleat = tp->rcv_nxt; + } else if (sw_lro && !pktf_sw_lro_pkt && !isipv6 && + (so->so_flags & SOF_USELRO) && + !IFNET_IS_CELLULAR(m->m_pkthdr.rcvif) && + (m->m_pkthdr.rcvif->if_type != IFT_LOOP) && + ((th->th_seq - tp->irs) > + (tp->t_maxseg << lro_start)) && + ((tp->t_idleat == 0) || ((th->th_seq - + tp->t_idleat) > (tp->t_maxseg << lro_start)))) { + tp->t_flagsext |= TF_LRO_OFFLOADED; + tcp_start_coalescing(ip, th, tlen); + tp->t_idleat = 0; + } + /* Clean receiver SACK report if present */ - if (tp->sack_enable && tp->rcv_numsacks) + if (SACK_ENABLED(tp) && tp->rcv_numsacks) tcp_clean_sackreport(tp); ++tcpstat.tcps_preddat; tp->rcv_nxt += tlen; @@ -1522,37 +3058,78 @@ findpcb: * rcv_nxt. */ tp->rcv_up = tp->rcv_nxt; - tcpstat.tcps_rcvpack++; + TCP_INC_VAR(tcpstat.tcps_rcvpack, nlropkts); tcpstat.tcps_rcvbyte += tlen; - ND6_HINT(tp); /* some progress has been done */ + if (nstat_collect) { + if (m->m_pkthdr.pkt_flags & PKTF_SW_LRO_PKT) { + INP_ADD_STAT(inp, cell, wifi, wired, + rxpackets, m->m_pkthdr.lro_npkts); + } else { + INP_ADD_STAT(inp, cell, wifi, wired, + rxpackets, 1); + } + INP_ADD_STAT(inp, cell, wifi, wired,rxbytes, + tlen); + inp_set_activity_bitmap(inp); + } + + /* + * Calculate the RTT on the receiver only if the + * connection is in streaming mode and the last + * packet was not an end-of-write + */ + if (tp->t_flags & TF_STREAMING_ON) + tcp_compute_rtt(tp, &to, th); + + tcp_sbrcv_grow(tp, &so->so_rcv, &to, tlen, + TCP_AUTORCVBUF_MAX(ifp)); + /* * Add data to socket buffer. */ + so_recv_data_stat(so, m, 0); m_adj(m, drop_hdrlen); /* delayed header drop */ - if (sbappendstream(&so->so_rcv, m)) + + /* + * If message delivery (SOF_ENABLE_MSGS) is enabled on + * this socket, deliver the packet received as an + * in-order message with sequence number attached to it. + */ + if (sbappendstream_rcvdemux(so, m, + th->th_seq - (tp->irs + 1), 0)) { sorwakeup(so); + } #if INET6 if (isipv6) { KERNEL_DEBUG(DBG_LAYER_END, ((th->th_dport << 16) | th->th_sport), (((ip6->ip6_src.s6_addr16[0]) << 16) | (ip6->ip6_dst.s6_addr16[0])), - th->th_seq, th->th_ack, th->th_win); + th->th_seq, th->th_ack, th->th_win); } else -#endif +#endif { KERNEL_DEBUG(DBG_LAYER_END, ((th->th_dport << 16) | th->th_sport), (((ip->ip_src.s_addr & 0xffff) << 16) | (ip->ip_dst.s_addr & 0xffff)), - th->th_seq, th->th_ack, th->th_win); + th->th_seq, th->th_ack, th->th_win); } - if (DELAY_ACK(tp)) { - tp->t_flags |= TF_DELACK; - tp->t_unacksegs++; + TCP_INC_VAR(tp->t_unacksegs, nlropkts); + if (DELAY_ACK(tp, th)) { + if ((tp->t_flags & TF_DELACK) == 0) { + tp->t_flags |= TF_DELACK; + tp->t_timer[TCPT_DELACK] = OFFSET_FROM_START(tp, tcp_delack); + } } else { - tp->t_unacksegs = 0; tp->t_flags |= TF_ACKNOW; tcp_output(tp); } - tcp_unlock(so, 1, 0); + + tcp_adaptive_rwtimo_check(tp, tlen); + + if (tlen > 0) + tcp_tfo_rcv_data(tp); + + tcp_check_timer_state(tp); + socket_unlock(so, 1); KERNEL_DEBUG(DBG_FNC_TCP_INPUT | DBG_FUNC_END,0,0,0,0,0); return; } @@ -1564,13 +3141,8 @@ findpcb: * Receive window is amount of space in rcv queue, * but not less than advertised window. */ -#if 1 - lck_mtx_assert(((struct inpcb *)so->so_pcb)->inpcb_mtx, LCK_MTX_ASSERT_OWNED); -#endif - { int win; - + socket_lock_assert_owned(so); win = tcp_sbspace(tp); - if (win < 0) win = 0; else { /* clip rcv window to 4K for modems */ @@ -1578,17 +3150,25 @@ findpcb: win = min(win, slowlink_wsize); } tp->rcv_wnd = imax(win, (int)(tp->rcv_adv - tp->rcv_nxt)); +#if MPTCP + /* + * Ensure that the subflow receive window isn't greater + * than the connection level receive window. + */ + if ((tp->t_mpflags & TMPF_MPTCP_TRUE) && + (mp_tp = tptomptp(tp))) { + mpte_lock_assert_held(mp_tp->mpt_mpte); + if (tp->rcv_wnd > mp_tp->mpt_rcvwnd) { + tp->rcv_wnd = imax(mp_tp->mpt_rcvwnd, (int)(tp->rcv_adv - tp->rcv_nxt)); + tcpstat.tcps_mp_reducedwin++; + } } +#endif /* MPTCP */ switch (tp->t_state) { /* - * If the state is LISTEN then ignore segment if it contains an RST. - * If the segment contains an ACK then it is bad and send a RST. - * If it does not contain a SYN then it is not interesting; drop it. - * If it is from this socket, drop it, it must be forged. - * Don't bother responding if the destination was a broadcast. - * Otherwise initialize tp->rcv_nxt, and tp->irs, select an initial + * Initialize tp->rcv_nxt, and tp->irs, select an initial * tp->iss, and send a segment: * * Also initialize tp->snd_nxt to tp->iss+1 and tp->snd_una to tp->iss. @@ -1597,55 +3177,12 @@ findpcb: * segment in this state. */ case TCPS_LISTEN: { - register struct sockaddr_in *sin; + struct sockaddr_in *sin; #if INET6 - register struct sockaddr_in6 *sin6; + struct sockaddr_in6 *sin6; #endif -#if 1 - lck_mtx_assert(((struct inpcb *)so->so_pcb)->inpcb_mtx, LCK_MTX_ASSERT_OWNED); -#endif - if (thflags & TH_RST) - goto drop; - if (thflags & TH_ACK) { - rstreason = BANDLIM_RST_OPENPORT; - goto dropwithreset; - } - if ((thflags & TH_SYN) == 0) - goto drop; - if (th->th_dport == th->th_sport) { -#if INET6 - if (isipv6) { - if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, - &ip6->ip6_src)) - goto drop; - } else -#endif /* INET6 */ - if (ip->ip_dst.s_addr == ip->ip_src.s_addr) - goto drop; - } - /* - * RFC1122 4.2.3.10, p. 104: discard bcast/mcast SYN - * in_broadcast() should never return true on a received - * packet with M_BCAST not set. - * - * Packets with a multicast source address should also - * be discarded. - */ - if (m->m_flags & (M_BCAST|M_MCAST)) - goto drop; -#if INET6 - if (isipv6) { - if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || - IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) - goto drop; - } else -#endif - if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) || - IN_MULTICAST(ntohl(ip->ip_src.s_addr)) || - ip->ip_src.s_addr == htonl(INADDR_BROADCAST) || - in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) - goto drop; + socket_lock_assert_owned(so); #if INET6 if (isipv6) { MALLOC(sin6, struct sockaddr_in6 *, sizeof *sin6, @@ -1670,11 +3207,9 @@ findpcb: } else #endif { -#if 0 - lck_mtx_assert(((struct inpcb *)so->so_pcb)->inpcb_mtx, LCK_MTX_ASSERT_OWNED); -#endif + socket_lock_assert_owned(so); MALLOC(sin, struct sockaddr_in *, sizeof *sin, M_SONAME, - M_NOWAIT); + M_NOWAIT); if (sin == NULL) goto drop; sin->sin_family = AF_INET; @@ -1685,7 +3220,8 @@ findpcb: laddr = inp->inp_laddr; if (inp->inp_laddr.s_addr == INADDR_ANY) inp->inp_laddr = ip->ip_dst; - if (in_pcbconnect(inp, (struct sockaddr *)sin, proc0)) { + if (in_pcbconnect(inp, (struct sockaddr *)sin, proc0, + IFSCOPE_NONE, NULL)) { inp->inp_laddr = laddr; FREE(sin, M_SONAME); goto drop; @@ -1694,14 +3230,11 @@ findpcb: } tcp_dooptions(tp, optp, optlen, th, &to); + tcp_finalize_options(tp, &to, ifscope); + + if (tfo_enabled(tp) && tcp_tfo_syn(tp, &to)) + isconnected = TRUE; - if (tp->sack_enable) { - if (!(to.to_flags & TOF_SACK)) - tp->sack_enable = 0; - else - tp->t_flags |= TF_SACK_PERMIT; - } - if (iss) tp->iss = iss; else { @@ -1717,30 +3250,62 @@ findpcb: * initialize CCsend and CCrecv. */ tp->snd_wnd = tiwin; /* initial send-window */ + tp->max_sndwnd = tp->snd_wnd; tp->t_flags |= TF_ACKNOW; tp->t_unacksegs = 0; + DTRACE_TCP4(state__change, void, NULL, struct inpcb *, inp, + struct tcpcb *, tp, int32_t, TCPS_SYN_RECEIVED); tp->t_state = TCPS_SYN_RECEIVED; - tp->t_timer[TCPT_KEEP] = tcp_keepinit; + tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp, + TCP_CONN_KEEPINIT(tp)); dropsocket = 0; /* committed to socket */ + + if (inp->inp_flowhash == 0) + inp->inp_flowhash = inp_calc_flowhash(inp); +#if INET6 + /* update flowinfo - RFC 6437 */ + if (inp->inp_flow == 0 && + inp->in6p_flags & IN6P_AUTOFLOWLABEL) { + inp->inp_flow &= ~IPV6_FLOWLABEL_MASK; + inp->inp_flow |= + (htonl(inp->inp_flowhash) & IPV6_FLOWLABEL_MASK); + } +#endif /* INET6 */ + + /* reset the incomp processing flag */ + so->so_flags &= ~(SOF_INCOMP_INPROGRESS); tcpstat.tcps_accepts++; if ((thflags & (TH_ECE | TH_CWR)) == (TH_ECE | TH_CWR)) { /* ECN-setup SYN */ tp->ecn_flags |= (TE_SETUPRECEIVED | TE_SENDIPECT); } + goto trimthenstep6; } /* - * If the state is SYN_RECEIVED: - * if seg contains an ACK, but not for our SYN/ACK, send a RST. + * If the state is SYN_RECEIVED and the seg contains an ACK, + * but not for our SYN/ACK, send a RST. */ case TCPS_SYN_RECEIVED: if ((thflags & TH_ACK) && (SEQ_LEQ(th->th_ack, tp->snd_una) || SEQ_GT(th->th_ack, tp->snd_max))) { rstreason = BANDLIM_RST_OPENPORT; + IF_TCP_STATINC(ifp, ooopacket); goto dropwithreset; } + + /* + * In SYN_RECEIVED state, if we recv some SYNS with + * window scale and others without, window scaling should + * be disabled. Otherwise the window advertised will be + * lower if we assume scaling and the other end does not. + */ + if ((thflags & TH_SYN) && + (tp->irs == th->th_seq) && + !(to.to_flags & TOF_SCALE)) + tp->t_flags &= ~TF_RCVD_SCALE; break; /* @@ -1760,10 +3325,29 @@ findpcb: (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) { rstreason = BANDLIM_UNLIMITED; + IF_TCP_STATINC(ifp, ooopacket); goto dropwithreset; } if (thflags & TH_RST) { if ((thflags & TH_ACK) != 0) { + if (tfo_enabled(tp)) + tcp_heuristic_tfo_rst(tp); + if ((tp->ecn_flags & (TE_SETUPSENT | TE_RCVD_SYN_RST)) == TE_SETUPSENT) { + /* + * On local connections, send + * non-ECN syn one time before + * dropping the connection + */ + if (tp->t_flags & TF_LOCAL) { + tp->ecn_flags |= TE_RCVD_SYN_RST; + goto drop; + } else { + tcp_heuristic_ecn_synrst(tp); + } + } + soevent(so, + (SO_FILT_HINT_LOCKED | + SO_FILT_HINT_CONNRESET)); tp = tcp_drop(tp, ECONNREFUSED); postevent(so, 0, EV_RESET); } @@ -1772,45 +3356,88 @@ findpcb: if ((thflags & TH_SYN) == 0) goto drop; tp->snd_wnd = th->th_win; /* initial send window */ + tp->max_sndwnd = tp->snd_wnd; tp->irs = th->th_seq; tcp_rcvseqinit(tp); if (thflags & TH_ACK) { tcpstat.tcps_connects++; - + if ((thflags & (TH_ECE | TH_CWR)) == (TH_ECE)) { /* ECN-setup SYN-ACK */ tp->ecn_flags |= TE_SETUPRECEIVED; - } - else { + if (TCP_ECN_ENABLED(tp)) { + tcp_heuristic_ecn_success(tp); + tcpstat.tcps_ecn_client_success++; + } + } else { + if (tp->ecn_flags & TE_SETUPSENT && + tp->t_rxtshift == 0) { + tcp_heuristic_ecn_success(tp); + tcpstat.tcps_ecn_not_supported++; + } + if (tp->ecn_flags & TE_SETUPSENT && + tp->t_rxtshift > 0) + tcp_heuristic_ecn_loss(tp); + /* non-ECN-setup SYN-ACK */ tp->ecn_flags &= ~TE_SENDIPECT; } - + #if CONFIG_MACF_NET && CONFIG_MACF_SOCKET /* XXXMAC: recursive lock: SOCK_LOCK(so); */ mac_socketpeer_label_associate_mbuf(m, so); /* XXXMAC: SOCK_UNLOCK(so); */ #endif /* Do window scaling on this connection? */ - if ((tp->t_flags & (TF_RCVD_SCALE|TF_REQ_SCALE)) == - (TF_RCVD_SCALE|TF_REQ_SCALE)) { + if (TCP_WINDOW_SCALE_ENABLED(tp)) { tp->snd_scale = tp->requested_s_scale; tp->rcv_scale = tp->request_r_scale; } - tp->rcv_adv += tp->rcv_wnd; + + tp->rcv_adv += min(tp->rcv_wnd, TCP_MAXWIN << tp->rcv_scale); tp->snd_una++; /* SYN is acked */ + if (SEQ_LT(tp->snd_nxt, tp->snd_una)) + tp->snd_nxt = tp->snd_una; + + /* + * We have sent more in the SYN than what is being + * acked. (e.g., TFO) + * We should restart the sending from what the receiver + * has acknowledged immediately. + */ + if (SEQ_GT(tp->snd_nxt, th->th_ack)) { + /* + * rdar://problem/33214601 + * There is a middlebox that acks all but one + * byte and still drops the data. + */ + if ((tp->t_tfo_stats & TFO_S_SYN_DATA_SENT) && + tp->snd_max == th->th_ack + 1 && + tp->snd_max > tp->snd_una + 1) { + tcp_heuristic_tfo_middlebox(tp); + + so->so_error = ENODATA; + + tp->t_tfo_stats |= TFO_S_ONE_BYTE_PROXY; + } + + tp->snd_max = tp->snd_nxt = th->th_ack; + } + /* * If there's data, delay ACK; if there's also a FIN * ACKNOW will be turned on later. */ - if (DELAY_ACK(tp) && tlen != 0) { - tp->t_flags |= TF_DELACK; - tp->t_unacksegs++; + TCP_INC_VAR(tp->t_unacksegs, nlropkts); + if (DELAY_ACK(tp, th) && tlen != 0 ) { + if ((tp->t_flags & TF_DELACK) == 0) { + tp->t_flags |= TF_DELACK; + tp->t_timer[TCPT_DELACK] = OFFSET_FROM_START(tp, tcp_delack); + } } else { tp->t_flags |= TF_ACKNOW; - tp->t_unacksegs = 0; } /* * Received in SYN_SENT[*] state. @@ -1818,32 +3445,82 @@ findpcb: * SYN_SENT --> ESTABLISHED * SYN_SENT* --> FIN_WAIT_1 */ - tp->t_starttime = 0; + tp->t_starttime = tcp_now; + tcp_sbrcv_tstmp_check(tp); if (tp->t_flags & TF_NEEDFIN) { + DTRACE_TCP4(state__change, void, NULL, + struct inpcb *, inp, + struct tcpcb *, tp, int32_t, + TCPS_FIN_WAIT_1); tp->t_state = TCPS_FIN_WAIT_1; tp->t_flags &= ~TF_NEEDFIN; thflags &= ~TH_SYN; } else { + DTRACE_TCP4(state__change, void, NULL, + struct inpcb *, inp, struct tcpcb *, + tp, int32_t, TCPS_ESTABLISHED); tp->t_state = TCPS_ESTABLISHED; - tp->t_timer[TCPT_KEEP] = TCP_KEEPIDLE(tp); + tp->t_timer[TCPT_KEEP] = + OFFSET_FROM_START(tp, + TCP_CONN_KEEPIDLE(tp)); + if (nstat_collect) + nstat_route_connect_success( + inp->inp_route.ro_rt); + /* + * The SYN is acknowledged but una is not + * updated yet. So pass the value of + * ack to compute sndbytes correctly + */ + inp_count_sndbytes(inp, th->th_ack); } - /* soisconnected may lead to socket_unlock in case of upcalls, - * make sure this is done when everything is setup. +#if MPTCP + /* + * Do not send the connect notification for additional + * subflows until ACK for 3-way handshake arrives. */ - soisconnected(so); + if ((!(tp->t_mpflags & TMPF_MPTCP_TRUE)) && + (tp->t_mpflags & TMPF_SENT_JOIN)) { + isconnected = FALSE; + } else +#endif /* MPTCP */ + isconnected = TRUE; + + if ((tp->t_tfo_flags & (TFO_F_COOKIE_REQ | TFO_F_COOKIE_SENT)) || + (tp->t_tfo_stats & TFO_S_SYN_DATA_SENT)) { + tcp_tfo_synack(tp, &to); + + if ((tp->t_tfo_stats & TFO_S_SYN_DATA_SENT) && + SEQ_LT(tp->snd_una, th->th_ack)) { + tp->t_tfo_stats |= TFO_S_SYN_DATA_ACKED; + tcpstat.tcps_tfo_syn_data_acked++; +#if MPTCP + if (so->so_flags & SOF_MP_SUBFLOW) + so->so_flags1 |= SOF1_TFO_REWIND; +#endif + tcp_tfo_rcv_probe(tp, tlen); + } + } } else { - /* - * Received initial SYN in SYN-SENT[*] state => simul- - * taneous open. If segment contains CC option and there is - * a cached CC, apply TAO test; if it succeeds, connection is - * half-synchronized. Otherwise, do 3-way handshake: - * SYN-SENT -> SYN-RECEIVED - * SYN-SENT* -> SYN-RECEIVED* - */ + /* + * Received initial SYN in SYN-SENT[*] state => simul- + * taneous open. If segment contains CC option and there is + * a cached CC, apply TAO test; if it succeeds, connection is + * half-synchronized. Otherwise, do 3-way handshake: + * SYN-SENT -> SYN-RECEIVED + * SYN-SENT* -> SYN-RECEIVED* + */ tp->t_flags |= TF_ACKNOW; tp->t_timer[TCPT_REXMT] = 0; + DTRACE_TCP4(state__change, void, NULL, struct inpcb *, inp, + struct tcpcb *, tp, int32_t, TCPS_SYN_RECEIVED); tp->t_state = TCPS_SYN_RECEIVED; + /* + * During simultaneous open, TFO should not be used. + * So, we disable it here, to prevent that data gets + * sent on the SYN/ACK. + */ + tcp_disable_tfo(tp); } trimthenstep6: @@ -1887,11 +3564,20 @@ trimthenstep6: /* Received a SYN while connection is already established. * This is a "half open connection and other anomalies" described * in RFC793 page 34, send an ACK so the remote reset the connection - * or recovers by adjusting its sequence numberering + * or recovers by adjusting its sequence numbering. Sending an ACK is + * in accordance with RFC 5961 Section 4.2 */ case TCPS_ESTABLISHED: - if (thflags & TH_SYN) - goto dropafterack; + if (thflags & TH_SYN) { + /* Drop the packet silently if we have reached the limit */ + if (tcp_do_rfc5961 && tcp_is_ack_ratelimited(tp)) { + goto drop; + } else { + /* Send challenge ACK */ + tcpstat.tcps_synchallenge++; + goto dropafterack; + } + } break; } @@ -1929,6 +3615,11 @@ trimthenstep6: * only accepting RSTs where the sequence number is equal to * last_ack_sent. In all other states (the states in which a * RST is more likely), the more permissive check is used. + * RFC 5961 Section 3.2: if the RST bit is set, sequence # is + * within the receive window and last_ack_sent == seq, + * then reset the connection. Otherwise if the seq doesn't + * match last_ack_sent, TCP must send challenge ACK. Perform + * rate limitation when sending the challenge ACK. * If we have multiple segments in flight, the intial reset * segment sequence numbers will be to the left of last_ack_sent, * but they will eventually catch up. @@ -1966,49 +3657,72 @@ trimthenstep6: if (thflags & TH_RST) { if ((SEQ_GEQ(th->th_seq, tp->last_ack_sent) && SEQ_LT(th->th_seq, tp->last_ack_sent + tp->rcv_wnd)) || - (tp->rcv_wnd == 0 && - ((tp->last_ack_sent == th->th_seq) || ((tp->last_ack_sent -1) == th->th_seq)))) { - switch (tp->t_state) { + (tp->rcv_wnd == 0 && + ((tp->last_ack_sent == th->th_seq) || + ((tp->last_ack_sent -1) == th->th_seq)))) { + if (tcp_do_rfc5961 == 0 || tp->last_ack_sent == th->th_seq) { + switch (tp->t_state) { + + case TCPS_SYN_RECEIVED: + IF_TCP_STATINC(ifp, rstinsynrcv); + so->so_error = ECONNREFUSED; + goto close; + + case TCPS_ESTABLISHED: + if (tcp_do_rfc5961 == 0 && tp->last_ack_sent != th->th_seq) { + tcpstat.tcps_badrst++; + goto drop; + } + if (TCP_ECN_ENABLED(tp) && + tp->snd_una == tp->iss + 1 && + SEQ_GT(tp->snd_max, tp->snd_una)) { + /* + * If the first data packet on an + * ECN connection, receives a RST + * increment the heuristic + */ + tcp_heuristic_ecn_droprst(tp); + } + case TCPS_FIN_WAIT_1: + case TCPS_CLOSE_WAIT: + /* + Drop through ... + */ + case TCPS_FIN_WAIT_2: + so->so_error = ECONNRESET; + close: + postevent(so, 0, EV_RESET); + soevent(so, + (SO_FILT_HINT_LOCKED | + SO_FILT_HINT_CONNRESET)); + + tcpstat.tcps_drops++; + tp = tcp_close(tp); + break; - case TCPS_SYN_RECEIVED: - so->so_error = ECONNREFUSED; - goto close; + case TCPS_CLOSING: + case TCPS_LAST_ACK: + tp = tcp_close(tp); + break; - case TCPS_ESTABLISHED: - if (tp->last_ack_sent != th->th_seq) { - tcpstat.tcps_badrst++; + case TCPS_TIME_WAIT: + break; + } + } else if (tcp_do_rfc5961) { + tcpstat.tcps_badrst++; + /* Drop if we have reached the ACK limit */ + if (tcp_is_ack_ratelimited(tp)) { goto drop; + } else { + /* Send challenge ACK */ + tcpstat.tcps_rstchallenge++; + goto dropafterack; } - case TCPS_FIN_WAIT_1: - case TCPS_CLOSE_WAIT: - /* - Drop through ... - */ - case TCPS_FIN_WAIT_2: - so->so_error = ECONNRESET; - close: - postevent(so, 0, EV_RESET); - tp->t_state = TCPS_CLOSED; - tcpstat.tcps_drops++; - tp = tcp_close(tp); - break; - - case TCPS_CLOSING: - case TCPS_LAST_ACK: - tp = tcp_close(tp); - break; - - case TCPS_TIME_WAIT: - break; } } goto drop; } -#if 0 - lck_mtx_assert(((struct inpcb *)so->so_pcb)->inpcb_mtx, LCK_MTX_ASSERT_OWNED); -#endif - /* * RFC 1323 PAWS: If we have a timestamp reply on this segment * and it's less than ts_recent, drop it. @@ -2033,8 +3747,35 @@ trimthenstep6: } else { tcpstat.tcps_rcvduppack++; tcpstat.tcps_rcvdupbyte += tlen; + tp->t_pawsdrop++; tcpstat.tcps_pawsdrop++; - if (tlen) + + /* + * PAWS-drop when ECN is being used? That indicates + * that ECT-marked packets take a different path, with + * different congestion-characteristics. + * + * Only fallback when we did send less than 2GB as PAWS + * really has no reason to kick in earlier. + */ + if (TCP_ECN_ENABLED(tp) && + inp->inp_stat->rxbytes < 2147483648) { + INP_INC_IFNET_STAT(inp, ecn_fallback_reorder); + tcpstat.tcps_ecn_fallback_reorder++; + tcp_heuristic_ecn_aggressive(tp); + } + + if (nstat_collect) { + nstat_route_rx(tp->t_inpcb->inp_route.ro_rt, + 1, tlen, NSTAT_RX_FLAG_DUPLICATE); + INP_ADD_STAT(inp, cell, wifi, wired, + rxpackets, 1); + INP_ADD_STAT(inp, cell, wifi, wired, + rxbytes, tlen); + tp->t_stat.rxduplicatebytes += tlen; + inp_set_activity_bitmap(inp); + } + if (tlen > 0) goto dropafterack; goto drop; } @@ -2049,12 +3790,20 @@ trimthenstep6: */ if (tp->t_state == TCPS_SYN_RECEIVED && SEQ_LT(th->th_seq, tp->irs)) { rstreason = BANDLIM_RST_OPENPORT; + IF_TCP_STATINC(ifp, dospacket); goto dropwithreset; } + /* + * Check if there is old data at the beginning of the window + * i.e. the sequence number is before rcv_nxt + */ todrop = tp->rcv_nxt - th->th_seq; if (todrop > 0) { + boolean_t is_syn_set = FALSE; + if (thflags & TH_SYN) { + is_syn_set = TRUE; thflags &= ~TH_SYN; th->th_seq++; if (th->th_urp > 1) @@ -2065,6 +3814,8 @@ trimthenstep6: } /* * Following if statement from Stevens, vol. 2, p. 960. + * The amount of duplicate data is greater than or equal + * to the size of the segment - entire segment is duplicate */ if (todrop > tlen || (todrop == tlen && (thflags & TH_FIN) == 0)) { @@ -2078,9 +3829,24 @@ trimthenstep6: /* * Send an ACK to resynchronize and drop any data. * But keep on processing for RST or ACK. + * + * If the SYN bit was originally set, then only send + * an ACK if we are not rate-limiting this connection. */ - tp->t_flags |= TF_ACKNOW; - tp->t_unacksegs = 0; + if (tcp_do_rfc5961 && is_syn_set) { + if (!tcp_is_ack_ratelimited(tp)) { + tcpstat.tcps_synchallenge++; + tp->t_flags |= TF_ACKNOW; + } + } else { + tp->t_flags |= TF_ACKNOW; + } + + if (todrop == 1) { + /* This could be a keepalive */ + soevent(so, SO_FILT_HINT_LOCKED | + SO_FILT_HINT_KEEPALIVE); + } todrop = tlen; tcpstat.tcps_rcvduppack++; tcpstat.tcps_rcvdupbyte += todrop; @@ -2088,6 +3854,24 @@ trimthenstep6: tcpstat.tcps_rcvpartduppack++; tcpstat.tcps_rcvpartdupbyte += todrop; } + + if (TCP_DSACK_ENABLED(tp) && todrop > 1) { + /* + * Note the duplicate data sequence space so that + * it can be reported in DSACK option. + */ + tp->t_dsack_lseq = th->th_seq; + tp->t_dsack_rseq = th->th_seq + todrop; + tp->t_flags |= TF_ACKNOW; + } + if (nstat_collect) { + nstat_route_rx(tp->t_inpcb->inp_route.ro_rt, 1, + todrop, NSTAT_RX_FLAG_DUPLICATE); + INP_ADD_STAT(inp, cell, wifi, wired, rxpackets, 1); + INP_ADD_STAT(inp, cell, wifi, wired, rxbytes, todrop); + tp->t_stat.rxduplicatebytes += todrop; + inp_set_activity_bitmap(inp); + } drop_hdrlen += todrop; /* drop from the top afterwards */ th->th_seq += todrop; tlen -= todrop; @@ -2100,15 +3884,35 @@ trimthenstep6: } /* - * If new data are received on a connection after the - * user processes are gone, then RST the other end. + * If new data are received on a connection after the user + * processes are gone, then RST the other end. + * Send also a RST when we received a data segment after we've + * sent our FIN when the socket is defunct. + * Note that an MPTCP subflow socket would have SS_NOFDREF set + * by default. So, if it's an MPTCP-subflow we rather check the + * MPTCP-level's socket state for SS_NOFDREF. */ - if ((so->so_state & SS_NOFDREF) && - tp->t_state > TCPS_CLOSE_WAIT && tlen) { - tp = tcp_close(tp); - tcpstat.tcps_rcvafterclose++; - rstreason = BANDLIM_UNLIMITED; - goto dropwithreset; + if (tlen) { + boolean_t close_it = FALSE; + + if (!(so->so_flags & SOF_MP_SUBFLOW) && (so->so_state & SS_NOFDREF) && + tp->t_state > TCPS_CLOSE_WAIT) + close_it = TRUE; + + if ((so->so_flags & SOF_MP_SUBFLOW) && (mptetoso(tptomptp(tp)->mpt_mpte)->so_state & SS_NOFDREF) && + tp->t_state > TCPS_CLOSE_WAIT) + close_it = TRUE; + + if ((so->so_flags & SOF_DEFUNCT) && tp->t_state > TCPS_FIN_WAIT_1) + close_it = TRUE; + + if (close_it) { + tp = tcp_close(tp); + tcpstat.tcps_rcvafterclose++; + rstreason = BANDLIM_UNLIMITED; + IF_TCP_STATINC(ifp, cleanup); + goto dropwithreset; + } } /* @@ -2131,7 +3935,7 @@ trimthenstep6: SEQ_GT(th->th_seq, tp->rcv_nxt)) { iss = tcp_new_isn(tp); tp = tcp_close(tp); - tcp_unlock(so, 1, 0); + socket_unlock(so, 1); goto findpcb; } /* @@ -2143,7 +3947,6 @@ trimthenstep6: */ if (tp->rcv_wnd == 0 && th->th_seq == tp->rcv_nxt) { tp->t_flags |= TF_ACKNOW; - tp->t_unacksegs = 0; tcpstat.tcps_rcvwinprobe++; } else goto dropafterack; @@ -2157,14 +3960,14 @@ trimthenstep6: /* * If last ACK falls within this segment's sequence numbers, * record its timestamp. - * NOTE: + * NOTE: * 1) That the test incorporates suggestions from the latest * proposal of the tcplw@cray.com list (Braden 1993/04/26). * 2) That updating only on newer timestamps interferes with * our earlier PAWS tests, so this check should be solely * predicated on the sequence space of this segment. - * 3) That we modify the segment boundary check to be - * Last.ACK.Sent <= SEG.SEQ + SEG.Len + * 3) That we modify the segment boundary check to be + * Last.ACK.Sent <= SEG.SEQ + SEG.Len * instead of RFC1323's * Last.ACK.Sent < SEG.SEQ + SEG.Len, * This modified check allows us to overcome RFC1323's @@ -2181,14 +3984,31 @@ trimthenstep6: } /* - * If a SYN is in the window, then this is an + * Stevens: If a SYN is in the window, then this is an * error and we send an RST and drop the connection. + * + * RFC 5961 Section 4.2 + * Send challenge ACK for any SYN in synchronized state + * Perform rate limitation in doing so. */ if (thflags & TH_SYN) { - tp = tcp_drop(tp, ECONNRESET); - rstreason = BANDLIM_UNLIMITED; - postevent(so, 0, EV_RESET); - goto dropwithreset; + if (tcp_do_rfc5961) { + tcpstat.tcps_badsyn++; + /* Drop if we have reached ACK limit */ + if (tcp_is_ack_ratelimited(tp)) { + goto drop; + } else { + /* Send challenge ACK */ + tcpstat.tcps_synchallenge++; + goto dropafterack; + } + } else { + tp = tcp_drop(tp, ECONNRESET); + rstreason = BANDLIM_UNLIMITED; + postevent(so, 0, EV_RESET); + IF_TCP_STATINC(ifp, synwindow); + goto dropwithreset; + } } /* @@ -2198,9 +4018,34 @@ trimthenstep6: */ if ((thflags & TH_ACK) == 0) { if (tp->t_state == TCPS_SYN_RECEIVED || - (tp->t_flags & TF_NEEDSYN)) + (tp->t_flags & TF_NEEDSYN)) { + if ((tfo_enabled(tp))) { + /* + * So, we received a valid segment while in + * SYN-RECEIVED (TF_NEEDSYN is actually never + * set, so this is dead code). + * As this cannot be an RST (see that if a bit + * higher), and it does not have the ACK-flag + * set, we want to retransmit the SYN/ACK. + * Thus, we have to reset snd_nxt to snd_una to + * trigger the going back to sending of the + * SYN/ACK. This is more consistent with the + * behavior of tcp_output(), which expects + * to send the segment that is pointed to by + * snd_nxt. + */ + tp->snd_nxt = tp->snd_una; + + /* + * We need to make absolutely sure that we are + * going to reply upon a duplicate SYN-segment. + */ + if (th->th_flags & TH_SYN) + needoutput = 1; + } + goto step6; - else if (tp->t_flags & TF_ACKNOW) + } else if (tp->t_flags & TF_ACKNOW) goto dropafterack; else goto drop; @@ -2209,6 +4054,7 @@ trimthenstep6: /* * Ack processing. */ + switch (tp->t_state) { /* @@ -2221,23 +4067,42 @@ trimthenstep6: tcpstat.tcps_connects++; /* Do window scaling? */ - if ((tp->t_flags & (TF_RCVD_SCALE|TF_REQ_SCALE)) == - (TF_RCVD_SCALE|TF_REQ_SCALE)) { + if (TCP_WINDOW_SCALE_ENABLED(tp)) { tp->snd_scale = tp->requested_s_scale; tp->rcv_scale = tp->request_r_scale; + tp->snd_wnd = th->th_win << tp->snd_scale; + tp->max_sndwnd = tp->snd_wnd; + tiwin = tp->snd_wnd; } /* * Make transitions: * SYN-RECEIVED -> ESTABLISHED * SYN-RECEIVED* -> FIN-WAIT-1 */ - tp->t_starttime = 0; + tp->t_starttime = tcp_now; + tcp_sbrcv_tstmp_check(tp); if (tp->t_flags & TF_NEEDFIN) { + DTRACE_TCP4(state__change, void, NULL, + struct inpcb *, inp, + struct tcpcb *, tp, int32_t, TCPS_FIN_WAIT_1); tp->t_state = TCPS_FIN_WAIT_1; tp->t_flags &= ~TF_NEEDFIN; } else { + DTRACE_TCP4(state__change, void, NULL, + struct inpcb *, inp, + struct tcpcb *, tp, int32_t, TCPS_ESTABLISHED); tp->t_state = TCPS_ESTABLISHED; - tp->t_timer[TCPT_KEEP] = TCP_KEEPIDLE(tp); + tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp, + TCP_CONN_KEEPIDLE(tp)); + if (nstat_collect) + nstat_route_connect_success( + tp->t_inpcb->inp_route.ro_rt); + /* + * The SYN is acknowledged but una is not updated + * yet. So pass the value of ack to compute + * sndbytes correctly + */ + inp_count_sndbytes(inp, th->th_ack); } /* * If segment contains data or ACK, will call tcp_reass() @@ -2245,15 +4110,69 @@ trimthenstep6: */ if (tlen == 0 && (thflags & TH_FIN) == 0) (void) tcp_reass(tp, (struct tcphdr *)0, &tlen, - (struct mbuf *)0); + NULL, ifp); tp->snd_wl1 = th->th_seq - 1; - /* FALLTHROUGH */ +#if MPTCP + /* + * Do not send the connect notification for additional subflows + * until ACK for 3-way handshake arrives. + */ + if ((!(tp->t_mpflags & TMPF_MPTCP_TRUE)) && + (tp->t_mpflags & TMPF_SENT_JOIN)) { + isconnected = FALSE; + } else +#endif /* MPTCP */ + isconnected = TRUE; + if ((tp->t_tfo_flags & TFO_F_COOKIE_VALID)) { + /* Done this when receiving the SYN */ + isconnected = FALSE; - /* soisconnected may lead to socket_unlock in case of upcalls, - * make sure this is done when everything is setup. + OSDecrementAtomic(&tcp_tfo_halfcnt); + + /* Panic if something has gone terribly wrong. */ + VERIFY(tcp_tfo_halfcnt >= 0); + + tp->t_tfo_flags &= ~TFO_F_COOKIE_VALID; + } + + /* + * In case there is data in the send-queue (e.g., TFO is being + * used, or connectx+data has been done), then if we would + * "FALLTHROUGH", we would handle this ACK as if data has been + * acknowledged. But, we have to prevent this. And this + * can be prevented by increasing snd_una by 1, so that the + * SYN is not considered as data (snd_una++ is actually also + * done in SYN_SENT-state as part of the regular TCP stack). + * + * In case there is data on this ack as well, the data will be + * handled by the label "dodata" right after step6. */ - soisconnected(so); + if (so->so_snd.sb_cc) { + tp->snd_una++; /* SYN is acked */ + if (SEQ_LT(tp->snd_nxt, tp->snd_una)) + tp->snd_nxt = tp->snd_una; + + /* + * No duplicate-ACK handling is needed. So, we + * directly advance to processing the ACK (aka, + * updating the RTT estimation,...) + * + * But, we first need to handle eventual SACKs, + * because TFO will start sending data with the + * SYN/ACK, so it might be that the client + * includes a SACK with its ACK. + */ + if (SACK_ENABLED(tp) && + (to.to_nsacks > 0 || + !TAILQ_EMPTY(&tp->snd_holes))) + tcp_sack_doack(tp, &to, th, + &sack_bytes_acked); + + goto process_ACK; + } + + /* FALLTHROUGH */ /* * In ESTABLISHED state: drop duplicate ACKs; ACK out of range @@ -2272,21 +4191,143 @@ trimthenstep6: case TCPS_TIME_WAIT: if (SEQ_GT(th->th_ack, tp->snd_max)) { tcpstat.tcps_rcvacktoomuch++; - goto dropafterack; + if (tcp_do_rfc5961 && tcp_is_ack_ratelimited(tp)) { + goto drop; + } else { + goto dropafterack; + } + } + if (tcp_do_rfc5961 && SEQ_LT(th->th_ack, tp->snd_una - tp->max_sndwnd)) { + if (tcp_is_ack_ratelimited(tp)) { + goto drop; + } else { + goto dropafterack; + } + } + if (SACK_ENABLED(tp) && to.to_nsacks > 0) { + recvd_dsack = tcp_sack_process_dsack(tp, &to, th); + /* + * If DSACK is received and this packet has no + * other SACK information, it can be dropped. + * We do not want to treat it as a duplicate ack. + */ + if (recvd_dsack && + SEQ_LEQ(th->th_ack, tp->snd_una) && + to.to_nsacks == 0) { + tcp_bad_rexmt_check(tp, th, &to); + goto drop; + } } - if (tp->sack_enable && + + if (SACK_ENABLED(tp) && (to.to_nsacks > 0 || !TAILQ_EMPTY(&tp->snd_holes))) - tcp_sack_doack(tp, &to, th->th_ack); + tcp_sack_doack(tp, &to, th, &sack_bytes_acked); + +#if MPTCP + if (tp->t_mpuna && SEQ_GEQ(th->th_ack, tp->t_mpuna)) { + if (tp->t_mpflags & TMPF_PREESTABLISHED) { + /* MP TCP establishment succeeded */ + tp->t_mpuna = 0; + if (tp->t_mpflags & TMPF_JOINED_FLOW) { + if (tp->t_mpflags & TMPF_SENT_JOIN) { + tp->t_mpflags &= + ~TMPF_PREESTABLISHED; + tp->t_mpflags |= + TMPF_MPTCP_TRUE; + mptcplog((LOG_DEBUG, "MPTCP " + "Sockets: %s \n",__func__), + MPTCP_SOCKET_DBG, + MPTCP_LOGLVL_LOG); + + tp->t_timer[TCPT_JACK_RXMT] = 0; + tp->t_mprxtshift = 0; + isconnected = TRUE; + } else { + isconnected = FALSE; + } + } else { + isconnected = TRUE; + } + } + } +#endif /* MPTCP */ + + tcp_tfo_rcv_ack(tp, th); + + /* + * If we have outstanding data (other than + * a window probe), this is a completely + * duplicate ack and the ack is the biggest we've seen. + * + * Need to accommodate a change in window on duplicate acks + * to allow operating systems that update window during + * recovery with SACK + */ if (SEQ_LEQ(th->th_ack, tp->snd_una)) { - if (tlen == 0 && tiwin == tp->snd_wnd) { + if (tlen == 0 && (tiwin == tp->snd_wnd || + (to.to_nsacks > 0 && sack_bytes_acked > 0))) { + /* + * If both ends send FIN at the same time, + * then the ack will be a duplicate ack + * but we have to process the FIN. Check + * for this condition and process the FIN + * instead of the dupack + */ + if ((thflags & TH_FIN) && + !TCPS_HAVERCVDFIN(tp->t_state)) + break; +process_dupack: +#if MPTCP + /* + * MPTCP options that are ignored must + * not be treated as duplicate ACKs. + */ + if (to.to_flags & TOF_MPTCP) { + goto drop; + } + + if ((isconnected) && (tp->t_mpflags & TMPF_JOINED_FLOW)) { + mptcplog((LOG_DEBUG, "MPTCP " + "Sockets: bypass ack recovery\n"), + MPTCP_SOCKET_DBG, + MPTCP_LOGLVL_VERBOSE); + break; + } +#endif /* MPTCP */ + /* + * If a duplicate acknowledgement was seen + * after ECN, it indicates packet loss in + * addition to ECN. Reset INRECOVERY flag + * so that we can process partial acks + * correctly + */ + if (tp->ecn_flags & TE_INRECOVERY) + tp->ecn_flags &= ~TE_INRECOVERY; + tcpstat.tcps_rcvdupack++; + ++tp->t_dupacks; + + /* + * Check if we need to reset the limit on + * early retransmit + */ + if (tp->t_early_rexmt_count > 0 && + TSTMP_GEQ(tcp_now, + (tp->t_early_rexmt_win + + TCP_EARLY_REXMT_WIN))) + tp->t_early_rexmt_count = 0; + /* - * If we have outstanding data (other than - * a window probe), this is a completely - * duplicate ack (ie, window info didn't - * change), the ack is the biggest we've - * seen and we've seen exactly our rexmt - * threshhold of them, assume a packet + * Is early retransmit needed? We check for + * this when the connection is waiting for + * duplicate acks to enter fast recovery. + */ + if (!IN_FASTRECOVERY(tp)) + tcp_early_rexmt_check(tp, th); + + /* + * If we've seen exactly rexmt threshold + * of duplicate acks, assume a packet * has been dropped and retransmit it. * Kludge snd_nxt & the congestion * window so we send only this one @@ -2305,18 +4346,38 @@ trimthenstep6: * network. */ if (tp->t_timer[TCPT_REXMT] == 0 || - th->th_ack != tp->snd_una) + (th->th_ack != tp->snd_una + && sack_bytes_acked == 0)) { tp->t_dupacks = 0; - else if (++tp->t_dupacks > tcprexmtthresh || - ((tcp_do_newreno || tp->sack_enable) && - IN_FASTRECOVERY(tp))) { - if (tp->sack_enable && IN_FASTRECOVERY(tp)) { + tp->t_rexmtthresh = tcprexmtthresh; + } else if (tp->t_dupacks > tp->t_rexmtthresh || + IN_FASTRECOVERY(tp)) { + + /* + * If this connection was seeing packet + * reordering, then recovery might be + * delayed to disambiguate between + * reordering and loss + */ + if (SACK_ENABLED(tp) && !IN_FASTRECOVERY(tp) && + (tp->t_flagsext & + (TF_PKTS_REORDERED|TF_DELAY_RECOVERY)) == + (TF_PKTS_REORDERED|TF_DELAY_RECOVERY)) { + /* + * Since the SACK information is already + * updated, this ACK will be dropped + */ + break; + } + + if (SACK_ENABLED(tp) + && IN_FASTRECOVERY(tp)) { int awnd; - + /* * Compute the amount of data in flight first. - * We can inject new data into the pipe iff - * we have less than 1/2 the original window's + * We can inject new data into the pipe iff + * we have less than 1/2 the original window's * worth of data in flight. */ awnd = (tp->snd_nxt - tp->snd_fack) + @@ -2326,14 +4387,22 @@ trimthenstep6: if (tp->snd_cwnd > tp->snd_ssthresh) tp->snd_cwnd = tp->snd_ssthresh; } - } else + } else { tp->snd_cwnd += tp->t_maxseg; - tp->t_unacksegs = 0; + } + + /* Process any window updates */ + if (tiwin > tp->snd_wnd) + tcp_update_window(tp, thflags, + th, tiwin, tlen); + tcp_ccdbg_trace(tp, th, + TCP_CC_IN_FASTRECOVERY); + (void) tcp_output(tp); + goto drop; - } else if (tp->t_dupacks == tcprexmtthresh) { + } else if (tp->t_dupacks == tp->t_rexmtthresh) { tcp_seq onxt = tp->snd_nxt; - u_int win; /* * If we're doing sack, check to @@ -2342,88 +4411,183 @@ trimthenstep6: * check to see if we're in newreno * recovery. */ - if (tp->sack_enable) { + if (SACK_ENABLED(tp)) { if (IN_FASTRECOVERY(tp)) { tp->t_dupacks = 0; break; + } else if (tp->t_flagsext & TF_DELAY_RECOVERY) { + break; } - } else if (tcp_do_newreno) { + } else { if (SEQ_LEQ(th->th_ack, tp->snd_recover)) { tp->t_dupacks = 0; break; } } - win = min(tp->snd_wnd, tp->snd_cwnd) / - 2 / tp->t_maxseg; - if (win < 2) - win = 2; - tp->snd_ssthresh = win * tp->t_maxseg; + if (tp->t_flags & TF_SENTFIN) + tp->snd_recover = tp->snd_max - 1; + else + tp->snd_recover = tp->snd_max; + tp->t_timer[TCPT_PTO] = 0; + tp->t_rtttime = 0; + + /* + * If the connection has seen pkt + * reordering, delay recovery until + * it is clear that the packet + * was lost. + */ + if (SACK_ENABLED(tp) && + (tp->t_flagsext & + (TF_PKTS_REORDERED|TF_DELAY_RECOVERY)) + == TF_PKTS_REORDERED && + !IN_FASTRECOVERY(tp) && + tp->t_reorderwin > 0 && + (tp->t_state == TCPS_ESTABLISHED || + tp->t_state == TCPS_FIN_WAIT_1)) { + tp->t_timer[TCPT_DELAYFR] = + OFFSET_FROM_START(tp, + tp->t_reorderwin); + tp->t_flagsext |= TF_DELAY_RECOVERY; + tcpstat.tcps_delay_recovery++; + tcp_ccdbg_trace(tp, th, + TCP_CC_DELAY_FASTRECOVERY); + break; + } + + tcp_rexmt_save_state(tp); + /* + * If the current tcp cc module has + * defined a hook for tasks to run + * before entering FR, call it + */ + if (CC_ALGO(tp)->pre_fr != NULL) + CC_ALGO(tp)->pre_fr(tp); ENTER_FASTRECOVERY(tp); - tp->snd_recover = tp->snd_max; tp->t_timer[TCPT_REXMT] = 0; - tp->t_rtttime = 0; - tp->ecn_flags |= TE_SENDCWR; - if (tp->sack_enable) { + if (TCP_ECN_ENABLED(tp)) + tp->ecn_flags |= TE_SENDCWR; + + if (SACK_ENABLED(tp)) { tcpstat.tcps_sack_recovery_episode++; + tp->t_sack_recovery_episode++; tp->sack_newdata = tp->snd_nxt; tp->snd_cwnd = tp->t_maxseg; - tp->t_unacksegs = 0; + tp->t_flagsext &= + ~TF_CWND_NONVALIDATED; + + /* Process any window updates */ + if (tiwin > tp->snd_wnd) + tcp_update_window( + tp, thflags, + th, tiwin, tlen); + + tcp_ccdbg_trace(tp, th, + TCP_CC_ENTER_FASTRECOVERY); (void) tcp_output(tp); goto drop; } tp->snd_nxt = th->th_ack; tp->snd_cwnd = tp->t_maxseg; - tp->t_unacksegs = 0; + + /* Process any window updates */ + if (tiwin > tp->snd_wnd) + tcp_update_window(tp, + thflags, + th, tiwin, tlen); + (void) tcp_output(tp); - tp->snd_cwnd = tp->snd_ssthresh + - tp->t_maxseg * tp->t_dupacks; + if (tp->t_flagsext & TF_CWND_NONVALIDATED) { + tcp_cc_adjust_nonvalidated_cwnd(tp); + } else { + tp->snd_cwnd = tp->snd_ssthresh + + tp->t_maxseg * tp->t_dupacks; + } if (SEQ_GT(onxt, tp->snd_nxt)) tp->snd_nxt = onxt; + + tcp_ccdbg_trace(tp, th, + TCP_CC_ENTER_FASTRECOVERY); goto drop; + } else if (limited_txmt && + ALLOW_LIMITED_TRANSMIT(tp) && + (!(SACK_ENABLED(tp)) || sack_bytes_acked > 0) && + (so->so_snd.sb_cc - (tp->snd_max - tp->snd_una)) > 0) { + u_int32_t incr = (tp->t_maxseg * tp->t_dupacks); + + /* Use Limited Transmit algorithm on the first two + * duplicate acks when there is new data to transmit + */ + tp->snd_cwnd += incr; + tcpstat.tcps_limited_txt++; + (void) tcp_output(tp); + + tcp_ccdbg_trace(tp, th, TCP_CC_LIMITED_TRANSMIT); + + /* Reset snd_cwnd back to normal */ + tp->snd_cwnd -= incr; } - } else - tp->t_dupacks = 0; + } break; } /* * If the congestion window was inflated to account * for the other side's cached packets, retract it. */ - if (tcp_do_newreno || tp->sack_enable) { - if (IN_FASTRECOVERY(tp)) { - if (SEQ_LT(th->th_ack, tp->snd_recover)) { - if (tp->sack_enable) - tcp_sack_partialack(tp, th); - else - tcp_newreno_partial_ack(tp, th); - } else { - /* - * Out of fast recovery. - * Window inflation should have left us - * with approximately snd_ssthresh - * outstanding data. - * But in case we would be inclined to - * send a burst, better to do it via - * the slow start mechanism. - */ - if (SEQ_GT(th->th_ack + - tp->snd_ssthresh, - tp->snd_max)) - tp->snd_cwnd = tp->snd_max - - th->th_ack + - tp->t_maxseg; - else - tp->snd_cwnd = tp->snd_ssthresh; - } + if (IN_FASTRECOVERY(tp)) { + if (SEQ_LT(th->th_ack, tp->snd_recover)) { + /* + * If we received an ECE and entered + * recovery, the subsequent ACKs should + * not be treated as partial acks. + */ + if (tp->ecn_flags & TE_INRECOVERY) + goto process_ACK; + + if (SACK_ENABLED(tp)) + tcp_sack_partialack(tp, th); + else + tcp_newreno_partial_ack(tp, th); + tcp_ccdbg_trace(tp, th, TCP_CC_PARTIAL_ACK); + } else { + EXIT_FASTRECOVERY(tp); + if (CC_ALGO(tp)->post_fr != NULL) + CC_ALGO(tp)->post_fr(tp, th); + tp->t_pipeack = 0; + tcp_clear_pipeack_state(tp); + tcp_ccdbg_trace(tp, th, + TCP_CC_EXIT_FASTRECOVERY); + } + } else if ((tp->t_flagsext & + (TF_PKTS_REORDERED|TF_DELAY_RECOVERY)) + == (TF_PKTS_REORDERED|TF_DELAY_RECOVERY)) { + /* + * If the ack acknowledges upto snd_recover or if + * it acknowledges all the snd holes, exit + * recovery and cancel the timer. Otherwise, + * this is a partial ack. Wait for recovery timer + * to enter recovery. The snd_holes have already + * been updated. + */ + if (SEQ_GEQ(th->th_ack, tp->snd_recover) || + TAILQ_EMPTY(&tp->snd_holes)) { + tp->t_timer[TCPT_DELAYFR] = 0; + tp->t_flagsext &= ~TF_DELAY_RECOVERY; + EXIT_FASTRECOVERY(tp); + tcp_ccdbg_trace(tp, th, + TCP_CC_EXIT_FASTRECOVERY); } } else { - if (tp->t_dupacks >= tcprexmtthresh && - tp->snd_cwnd > tp->snd_ssthresh) - tp->snd_cwnd = tp->snd_ssthresh; + /* + * We were not in fast recovery. Reset the + * duplicate ack counter. + */ + tp->t_dupacks = 0; + tp->t_rexmtthresh = tcprexmtthresh; } - tp->t_dupacks = 0; - tp->t_bytes_acked = 0; + + /* * If we reach this point, ACK is not a duplicate, * i.e., it ACKs something we sent. @@ -2439,60 +4603,30 @@ trimthenstep6: tp->t_flags &= ~TF_NEEDSYN; tp->snd_una++; /* Do window scaling? */ - if ((tp->t_flags & (TF_RCVD_SCALE|TF_REQ_SCALE)) == - (TF_RCVD_SCALE|TF_REQ_SCALE)) { + if (TCP_WINDOW_SCALE_ENABLED(tp)) { tp->snd_scale = tp->requested_s_scale; tp->rcv_scale = tp->request_r_scale; } } process_ACK: - acked = th->th_ack - tp->snd_una; + VERIFY(SEQ_GEQ(th->th_ack, tp->snd_una)); + acked = BYTES_ACKED(th, tp); tcpstat.tcps_rcvackpack++; tcpstat.tcps_rcvackbyte += acked; /* - * If we just performed our first retransmit, and the ACK - * arrives within our recovery window, then it was a mistake - * to do the retransmit in the first place. Recover our - * original cwnd and ssthresh, and proceed to transmit where - * we left off. - */ - if (tp->t_rxtshift == 1 && tcp_now < tp->t_badrxtwin) { - ++tcpstat.tcps_sndrexmitbad; - tp->snd_cwnd = tp->snd_cwnd_prev; - tp->snd_ssthresh = tp->snd_ssthresh_prev; - tp->snd_recover = tp->snd_recover_prev; - if (tp->t_flags & TF_WASFRECOVERY) - ENTER_FASTRECOVERY(tp); - tp->snd_nxt = tp->snd_max; - tp->t_badrxtwin = 0; /* XXX probably not required */ - } - - /* - * If we have a timestamp reply, update smoothed - * round trip time. If no timestamp is present but - * transmit timer is running and timed sequence - * number was acked, update smoothed round trip time. - * Since we now have an rtt measurement, cancel the - * timer backoff (cf., Phil Karn's retransmit alg.). - * Recompute the initial retransmit timer. - * Also makes sure we have a valid time stamp in hand + * If the last packet was a retransmit, make sure + * it was not spurious. * - * Some boxes send broken timestamp replies - * during the SYN+ACK phase, ignore - * timestamps of 0 or we could calculate a - * huge RTT and blow up the retransmit timer. + * This will also take care of congestion window + * adjustment if a last packet was recovered due to a + * tail loss probe. */ - if (((to.to_flags & TOF_TS) != 0) && (to.to_tsecr != 0)) { - if (!tp->t_rttlow || tp->t_rttlow > tcp_now - to.to_tsecr) - tp->t_rttlow = tcp_now - to.to_tsecr; - tcp_xmit_timer(tp, tcp_now - to.to_tsecr); - } else if (tp->t_rtttime && SEQ_GT(th->th_ack, tp->t_rtseq)) { - if (!tp->t_rttlow || tp->t_rttlow > tcp_now - tp->t_rtttime) - tp->t_rttlow = tcp_now - tp->t_rtttime; - tcp_xmit_timer(tp, tp->t_rtttime); - } + tcp_bad_rexmt_check(tp, th, &to); + + /* Recalculate the RTT */ + tcp_compute_rtt(tp, &to, th); /* * If all outstanding data is acked, stop retransmit @@ -2500,123 +4634,125 @@ process_ACK: * If there is more data to be acked, restart retransmit * timer, using current (possibly backed-off) value. */ + TCP_RESET_REXMT_STATE(tp); + TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp), + tp->t_rttmin, TCPTV_REXMTMAX, + TCP_ADD_REXMTSLOP(tp)); if (th->th_ack == tp->snd_max) { tp->t_timer[TCPT_REXMT] = 0; + tp->t_timer[TCPT_PTO] = 0; needoutput = 1; } else if (tp->t_timer[TCPT_PERSIST] == 0) - tp->t_timer[TCPT_REXMT] = tp->t_rxtcur; + tp->t_timer[TCPT_REXMT] = OFFSET_FROM_START(tp, + tp->t_rxtcur); /* - * If no data (only SYN) was ACK'd, - * skip rest of ACK processing. + * If no data (only SYN) was ACK'd, skip rest of ACK + * processing. */ if (acked == 0) goto step6; /* - * When new data is acked, open the congestion window. + * When outgoing data has been acked (except the SYN+data), we + * mark this connection as "sending good" for TFO. + */ + if ((tp->t_tfo_stats & TFO_S_SYN_DATA_SENT) && + !(tp->t_tfo_flags & TFO_F_NO_SNDPROBING) && + !(th->th_flags & TH_SYN)) + tp->t_tfo_flags |= TFO_F_NO_SNDPROBING; + + /* + * If TH_ECE is received, make sure that ECN is enabled + * on that connection and we have sent ECT on data packets. */ - if ((thflags & TH_ECE) != 0 && - (tp->ecn_flags & TE_SETUPSENT) != 0) { + if ((thflags & TH_ECE) != 0 && TCP_ECN_ENABLED(tp) && + (tp->ecn_flags & TE_SENDIPECT)) { /* - * Reduce the congestion window if we haven't done so. + * Reduce the congestion window if we haven't + * done so. */ - if (!(tp->sack_enable && IN_FASTRECOVERY(tp)) && - !(tcp_do_newreno && SEQ_LEQ(th->th_ack, tp->snd_recover))) { + if (!IN_FASTRECOVERY(tp)) { tcp_reduce_congestion_window(tp); - } - } else if ((!tcp_do_newreno && !tp->sack_enable) || - !IN_FASTRECOVERY(tp)) { - /* - * RFC 3465 - Appropriate Byte Counting. - * - * If the window is currently less than ssthresh, - * open the window by the number of bytes ACKed by - * the last ACK, however clamp the window increase - * to an upper limit "L". - * - * In congestion avoidance phase, open the window by - * one segment each time "bytes_acked" grows to be - * greater than or equal to the congestion window. - */ - - register u_int cw = tp->snd_cwnd; - register u_int incr = tp->t_maxseg; - - if ((acked > incr) && tcp_do_rfc3465) { - if (cw >= tp->snd_ssthresh) { - tp->t_bytes_acked += acked; - if (tp->t_bytes_acked >= cw) { - /* Time to increase the window. */ - tp->t_bytes_acked -= cw; - } else { - /* No need to increase yet. */ - incr = 0; - } - } else { - /* - * If the user explicitly enables RFC3465 - * use 2*SMSS for the "L" param. Otherwise - * use the more conservative 1*SMSS. - * - * (See RFC 3465 2.3 Choosing the Limit) - */ - u_int abc_lim; - - abc_lim = (tcp_do_rfc3465 == 0) ? - incr : incr * 2; - incr = lmin(acked, abc_lim); - } - } - else { + tp->ecn_flags |= (TE_INRECOVERY|TE_SENDCWR); /* - * If the window gives us less than ssthresh packets - * in flight, open exponentially (segsz per packet). - * Otherwise open linearly: segsz per window - * (segsz^2 / cwnd per packet). + * Also note that the connection received + * ECE atleast once */ - - if (cw >= tp->snd_ssthresh) { - incr = incr * incr / cw; - } + tp->ecn_flags |= TE_RECV_ECN_ECE; + INP_INC_IFNET_STAT(inp, ecn_recv_ece); + tcpstat.tcps_ecn_recv_ece++; + tcp_ccdbg_trace(tp, th, TCP_CC_ECN_RCVD); } + } - - tp->snd_cwnd = min(cw+incr, TCP_MAXWIN<snd_scale); + /* + * When new data is acked, open the congestion window. + * The specifics of how this is achieved are up to the + * congestion control algorithm in use for this connection. + * + * The calculations in this function assume that snd_una is + * not updated yet. + */ + if (!IN_FASTRECOVERY(tp)) { + if (CC_ALGO(tp)->ack_rcvd != NULL) + CC_ALGO(tp)->ack_rcvd(tp, th); + tcp_ccdbg_trace(tp, th, TCP_CC_ACK_RCVD); } if (acked > so->so_snd.sb_cc) { tp->snd_wnd -= so->so_snd.sb_cc; sbdrop(&so->so_snd, (int)so->so_snd.sb_cc); + if (so->so_flags & SOF_ENABLE_MSGS) { + so->so_msg_state->msg_serial_bytes -= + (int)so->so_snd.sb_cc; + } ourfinisacked = 1; } else { sbdrop(&so->so_snd, acked); + if (so->so_flags & SOF_ENABLE_MSGS) { + so->so_msg_state->msg_serial_bytes -= + acked; + } + tcp_sbsnd_trim(&so->so_snd); tp->snd_wnd -= acked; ourfinisacked = 0; } /* detect una wraparound */ - if ((tcp_do_newreno || tp->sack_enable) && - !IN_FASTRECOVERY(tp) && + if ( !IN_FASTRECOVERY(tp) && SEQ_GT(tp->snd_una, tp->snd_recover) && SEQ_LEQ(th->th_ack, tp->snd_recover)) tp->snd_recover = th->th_ack - 1; - if ((tcp_do_newreno || tp->sack_enable) && - IN_FASTRECOVERY(tp) && + + if (IN_FASTRECOVERY(tp) && SEQ_GEQ(th->th_ack, tp->snd_recover)) EXIT_FASTRECOVERY(tp); + tp->snd_una = th->th_ack; - if (tp->sack_enable) { + + if (SACK_ENABLED(tp)) { if (SEQ_GT(tp->snd_una, tp->snd_recover)) tp->snd_recover = tp->snd_una; } if (SEQ_LT(tp->snd_nxt, tp->snd_una)) tp->snd_nxt = tp->snd_una; - + if (!SLIST_EMPTY(&tp->t_rxt_segments) && + !TCP_DSACK_SEQ_IN_WINDOW(tp, tp->t_dsack_lastuna, + tp->snd_una)) + tcp_rxtseg_clean(tp); + if ((tp->t_flagsext & TF_MEASURESNDBW) != 0 && + tp->t_bwmeas != NULL) + tcp_bwmeas_check(tp); + /* - * sowwakeup must happen after snd_una, et al. are updated so that - * the sequence numbers are in sync with so_snd + * sowwakeup must happen after snd_una, et al. are + * updated so that the sequence numbers are in sync with + * so_snd */ sowwakeup(so); + if (!SLIST_EMPTY(&tp->t_notify_ack)) + tcp_notify_acknowledgement(tp, so); + switch (tp->t_state) { /* @@ -2629,17 +4765,24 @@ process_ACK: /* * If we can't receive any more * data, then closing user can proceed. - * Starting the timer is contrary to the + * Starting the TCPT_2MSL timer is contrary to the * specification, but if we don't get a FIN * we'll hang forever. */ if (so->so_state & SS_CANTRCVMORE) { - tp->t_timer[TCPT_2MSL] = tcp_maxidle; - add_to_time_wait(tp); - soisdisconnected(so); + tp->t_timer[TCPT_2MSL] = OFFSET_FROM_START(tp, + TCP_CONN_MAXIDLE(tp)); + isconnected = FALSE; + isdisconnected = TRUE; } + DTRACE_TCP4(state__change, void, NULL, + struct inpcb *, inp, + struct tcpcb *, tp, + int32_t, TCPS_FIN_WAIT_2); tp->t_state = TCPS_FIN_WAIT_2; - goto drop; + /* fall through and make sure we also recognize + * data ACKed with the FIN + */ } break; @@ -2651,17 +4794,19 @@ process_ACK: */ case TCPS_CLOSING: if (ourfinisacked) { + DTRACE_TCP4(state__change, void, NULL, + struct inpcb *, inp, + struct tcpcb *, tp, + int32_t, TCPS_TIME_WAIT); tp->t_state = TCPS_TIME_WAIT; tcp_canceltimers(tp); - /* Shorten TIME_WAIT [RFC-1644, p.28] */ - if (tp->cc_recv != 0 && - tp->t_starttime < (u_long)tcp_msl) - tp->t_timer[TCPT_2MSL] = - tp->t_rxtcur * TCPTV_TWTRUNC; - else - tp->t_timer[TCPT_2MSL] = 2 * tcp_msl; - add_to_time_wait(tp); - soisdisconnected(so); + if (tp->t_flagsext & TF_NOTIMEWAIT) { + tp->t_flags |= TF_CLOSING; + } else { + add_to_time_wait(tp, 2 * tcp_msl); + } + isconnected = FALSE; + isdisconnected = TRUE; } break; @@ -2684,32 +4829,37 @@ process_ACK: * it and restart the finack timer. */ case TCPS_TIME_WAIT: - tp->t_timer[TCPT_2MSL] = 2 * tcp_msl; - add_to_time_wait(tp); + add_to_time_wait(tp, 2 * tcp_msl); goto dropafterack; } + + /* + * If there is a SACK option on the ACK and we + * haven't seen any duplicate acks before, count + * it as a duplicate ack even if the cumulative + * ack is advanced. If the receiver delayed an + * ack and detected loss afterwards, then the ack + * will advance cumulative ack and will also have + * a SACK option. So counting it as one duplicate + * ack is ok. + */ + if (sack_ackadv == 1 && + tp->t_state == TCPS_ESTABLISHED && + SACK_ENABLED(tp) && sack_bytes_acked > 0 && + to.to_nsacks > 0 && tp->t_dupacks == 0 && + SEQ_LEQ(th->th_ack, tp->snd_una) && tlen == 0 && + !(tp->t_flagsext & TF_PKTS_REORDERED)) { + tcpstat.tcps_sack_ackadv++; + goto process_dupack; + } } step6: /* * Update window information. - * Don't look at window if no ACK: TAC's send garbage on first SYN. */ - if ((thflags & TH_ACK) && - (SEQ_LT(tp->snd_wl1, th->th_seq) || - (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) || - (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) { - /* keep track of pure window updates */ - if (tlen == 0 && - tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd) - tcpstat.tcps_rcvwinupd++; - tp->snd_wnd = tiwin; - tp->snd_wl1 = th->th_seq; - tp->snd_wl2 = th->th_ack; - if (tp->snd_wnd > tp->max_sndwnd) - tp->max_sndwnd = tp->snd_wnd; + if (tcp_update_window(tp, thflags, th, tiwin, tlen)) needoutput = 1; - } /* * Process segments with URG. @@ -2758,14 +4908,14 @@ step6: * but if two URG's are pending at once, some out-of-band * data may creep in... ick. */ - if (th->th_urp <= (u_long)tlen + if (th->th_urp <= (u_int32_t)tlen #if SO_OOBINLINE && (so->so_options & SO_OOBINLINE) == 0 #endif ) tcp_pulloutofband(so, th, m, drop_hdrlen); /* hdr drop is delayed */ - } else + } else { /* * If no out of band data is expected, * pull receive urgent pointer along @@ -2773,7 +4923,26 @@ step6: */ if (SEQ_GT(tp->rcv_nxt, tp->rcv_up)) tp->rcv_up = tp->rcv_nxt; -dodata: /* XXX */ + } +dodata: + + /* Set socket's connect or disconnect state correcly before doing data. + * The following might unlock the socket if there is an upcall or a socket + * filter. + */ + if (isconnected) { + soisconnected(so); + } else if (isdisconnected) { + soisdisconnected(so); + } + + /* Let's check the state of pcb just to make sure that it did not get closed + * when we unlocked above + */ + if (inp->inp_state == INPCB_STATE_DEAD) { + /* Just drop the packet that we are processing and return */ + goto drop; + } /* * Process the segment text, merging it into the TCP sequencing queue, @@ -2782,9 +4951,15 @@ dodata: /* XXX */ * is presented to the user (this happens in tcp_usrreq.c, * case PRU_RCVD). If a FIN has already been received on this * connection then we just ignore the text. + * + * If we are in SYN-received state and got a valid TFO cookie, we want + * to process the data. */ - if ((tlen || (thflags&TH_FIN)) && - TCPS_HAVERCVDFIN(tp->t_state) == 0) { + if ((tlen || (thflags & TH_FIN)) && + TCPS_HAVERCVDFIN(tp->t_state) == 0 && + (TCPS_HAVEESTABLISHED(tp->t_state) || + (tp->t_state == TCPS_SYN_RECEIVED && + (tp->t_tfo_flags & TFO_F_COOKIE_VALID)))) { tcp_seq save_start = th->th_seq; tcp_seq save_end = th->th_seq + tlen; m_adj(m, drop_hdrlen); /* delayed header drop */ @@ -2800,60 +4975,94 @@ dodata: /* XXX */ * immediately when segments are out of order (so * fast retransmit can work). */ - if (th->th_seq == tp->rcv_nxt && - LIST_EMPTY(&tp->t_segq) && - TCPS_HAVEESTABLISHED(tp->t_state)) { - if (DELAY_ACK(tp) && ((tp->t_flags & TF_ACKNOW) == 0)) { - tp->t_flags |= TF_DELACK; - tp->t_unacksegs++; - } + if (th->th_seq == tp->rcv_nxt && LIST_EMPTY(&tp->t_segq)) { + TCP_INC_VAR(tp->t_unacksegs, nlropkts); + /* + * Calculate the RTT on the receiver only if the + * connection is in streaming mode and the last + * packet was not an end-of-write + */ + if (tp->t_flags & TF_STREAMING_ON) + tcp_compute_rtt(tp, &to, th); + + if (DELAY_ACK(tp, th) && + ((tp->t_flags & TF_ACKNOW) == 0) ) { + if ((tp->t_flags & TF_DELACK) == 0) { + tp->t_flags |= TF_DELACK; + tp->t_timer[TCPT_DELACK] = + OFFSET_FROM_START(tp, tcp_delack); + } + } else { - tp->t_unacksegs = 0; tp->t_flags |= TF_ACKNOW; } tp->rcv_nxt += tlen; thflags = th->th_flags & TH_FIN; - tcpstat.tcps_rcvpack++; + TCP_INC_VAR(tcpstat.tcps_rcvpack, nlropkts); tcpstat.tcps_rcvbyte += tlen; - ND6_HINT(tp); - if (sbappendstream(&so->so_rcv, m)) + if (nstat_collect) { + if (m->m_pkthdr.pkt_flags & PKTF_SW_LRO_PKT) { + INP_ADD_STAT(inp, cell, wifi, wired, + rxpackets, m->m_pkthdr.lro_npkts); + } else { + INP_ADD_STAT(inp, cell, wifi, wired, + rxpackets, 1); + } + INP_ADD_STAT(inp, cell, wifi, wired, + rxbytes, tlen); + inp_set_activity_bitmap(inp); + } + tcp_sbrcv_grow(tp, &so->so_rcv, &to, tlen, + TCP_AUTORCVBUF_MAX(ifp)); + so_recv_data_stat(so, m, drop_hdrlen); + + if (sbappendstream_rcvdemux(so, m, + th->th_seq - (tp->irs + 1), 0)) { sorwakeup(so); + } } else { - thflags = tcp_reass(tp, th, &tlen, m); + thflags = tcp_reass(tp, th, &tlen, m, ifp); tp->t_flags |= TF_ACKNOW; - tp->t_unacksegs = 0; } - if (tlen > 0 && tp->sack_enable) + if ((tlen > 0 || (th->th_flags & TH_FIN)) && SACK_ENABLED(tp)) { + if (th->th_flags & TH_FIN) + save_end++; tcp_update_sack_list(tp, save_start, save_end); + } + + tcp_adaptive_rwtimo_check(tp, tlen); + + if (tlen > 0) + tcp_tfo_rcv_data(tp); - if (tp->t_flags & TF_DELACK) + if (tp->t_flags & TF_DELACK) { #if INET6 if (isipv6) { KERNEL_DEBUG(DBG_LAYER_END, ((th->th_dport << 16) | th->th_sport), (((ip6->ip6_src.s6_addr16[0]) << 16) | (ip6->ip6_dst.s6_addr16[0])), - th->th_seq, th->th_ack, th->th_win); + th->th_seq, th->th_ack, th->th_win); } else #endif { KERNEL_DEBUG(DBG_LAYER_END, ((th->th_dport << 16) | th->th_sport), (((ip->ip_src.s_addr & 0xffff) << 16) | (ip->ip_dst.s_addr & 0xffff)), - th->th_seq, th->th_ack, th->th_win); + th->th_seq, th->th_ack, th->th_win); } - + } - /* - * Note the amount of data that peer has sent into - * our window, in order to estimate the sender's - * buffer size. - */ - len = (u_int)(so->so_rcv.sb_hiwat - (tp->rcv_adv - tp->rcv_nxt)); - if (len > so->so_rcv.sb_maxused) - so->so_rcv.sb_maxused = len; } else { - m_freem(m); + if ((so->so_flags & SOF_MP_SUBFLOW) && tlen == 0 && + (m->m_pkthdr.pkt_flags & PKTF_MPTCP_DFIN) && + (m->m_pkthdr.pkt_flags & PKTF_MPTCP)) { + m_adj(m, drop_hdrlen); /* delayed header drop */ + mptcp_input(tptomptp(tp)->mpt_mpte, m); + tp->t_flags |= TF_ACKNOW; + } else { + m_freem(m); + } thflags &= ~TH_FIN; } @@ -2866,21 +5075,20 @@ dodata: /* XXX */ socantrcvmore(so); postevent(so, 0, EV_FIN); /* - * If connection is half-synchronized - * (ie NEEDSYN flag on) then delay ACK, * If connection is half-synchronized * (ie NEEDSYN flag on) then delay ACK, * so it may be piggybacked when SYN is sent. * Otherwise, since we received a FIN then no * more input can be expected, send ACK now. */ - if (DELAY_ACK(tp) && (tp->t_flags & TF_NEEDSYN)) { - tp->t_flags |= TF_DELACK; - tp->t_unacksegs++; - } - else { + TCP_INC_VAR(tp->t_unacksegs, nlropkts); + if (DELAY_ACK(tp, th) && (tp->t_flags & TF_NEEDSYN)) { + if ((tp->t_flags & TF_DELACK) == 0) { + tp->t_flags |= TF_DELACK; + tp->t_timer[TCPT_DELACK] = OFFSET_FROM_START(tp, tcp_delack); + } + } else { tp->t_flags |= TF_ACKNOW; - tp->t_unacksegs = 0; } tp->rcv_nxt++; } @@ -2891,8 +5099,10 @@ dodata: /* XXX */ * enter the CLOSE_WAIT state. */ case TCPS_SYN_RECEIVED: - tp->t_starttime = 0; + tp->t_starttime = tcp_now; case TCPS_ESTABLISHED: + DTRACE_TCP4(state__change, void, NULL, struct inpcb *, inp, + struct tcpcb *, tp, int32_t, TCPS_CLOSE_WAIT); tp->t_state = TCPS_CLOSE_WAIT; break; @@ -2901,6 +5111,8 @@ dodata: /* XXX */ * enter the CLOSING state. */ case TCPS_FIN_WAIT_1: + DTRACE_TCP4(state__change, void, NULL, struct inpcb *, inp, + struct tcpcb *, tp, int32_t, TCPS_CLOSING); tp->t_state = TCPS_CLOSING; break; @@ -2910,21 +5122,18 @@ dodata: /* XXX */ * standard timers. */ case TCPS_FIN_WAIT_2: + DTRACE_TCP4(state__change, void, NULL, + struct inpcb *, inp, + struct tcpcb *, tp, + int32_t, TCPS_TIME_WAIT); tp->t_state = TCPS_TIME_WAIT; tcp_canceltimers(tp); - /* Shorten TIME_WAIT [RFC-1644, p.28] */ - if (tp->cc_recv != 0 && - tp->t_starttime < (u_long)tcp_msl) { - tp->t_timer[TCPT_2MSL] = - tp->t_rxtcur * TCPTV_TWTRUNC; - /* For transaction client, force ACK now. */ - tp->t_flags |= TF_ACKNOW; - tp->t_unacksegs = 0; + tp->t_flags |= TF_ACKNOW; + if (tp->t_flagsext & TF_NOTIMEWAIT) { + tp->t_flags |= TF_CLOSING; + } else { + add_to_time_wait(tp, 2 * tcp_msl); } - else - tp->t_timer[TCPT_2MSL] = 2 * tcp_msl; - - add_to_time_wait(tp); soisdisconnected(so); break; @@ -2932,8 +5141,7 @@ dodata: /* XXX */ * In TIME_WAIT state restart the 2 MSL time_wait timer. */ case TCPS_TIME_WAIT: - tp->t_timer[TCPT_2MSL] = 2 * tcp_msl; - add_to_time_wait(tp); + add_to_time_wait(tp, 2 * tcp_msl); break; } } @@ -2947,10 +5155,13 @@ dodata: /* XXX */ * Return any desired output. */ if (needoutput || (tp->t_flags & TF_ACKNOW)) { - tp->t_unacksegs = 0; (void) tcp_output(tp); } - tcp_unlock(so, 1, 0); + + tcp_check_timer_state(tp); + + + socket_unlock(so, 1); KERNEL_DEBUG(DBG_FNC_TCP_INPUT | DBG_FUNC_END,0,0,0,0,0); return; @@ -2974,6 +5185,7 @@ dropafterack: (SEQ_GT(tp->snd_una, th->th_ack) || SEQ_GT(th->th_ack, tp->snd_max)) ) { rstreason = BANDLIM_RST_OPENPORT; + IF_TCP_STATINC(ifp, dospacket); goto dropwithreset; } #if TCPDEBUG @@ -2983,9 +5195,10 @@ dropafterack: #endif m_freem(m); tp->t_flags |= TF_ACKNOW; - tp->t_unacksegs = 0; (void) tcp_output(tp); - tcp_unlock(so, 1, 0); + + /* Don't need to check timer state as we should have done it during tcp_output */ + socket_unlock(so, 1); KERNEL_DEBUG(DBG_FNC_TCP_INPUT | DBG_FUNC_END,0,0,0,0,0); return; dropwithresetnosock: @@ -3012,7 +5225,7 @@ dropwithreset: goto drop; /* IPv6 anycast check is done at tcp6_input() */ - /* + /* * Perform bandwidth limiting. */ #if ICMP_BANDLIM @@ -3025,25 +5238,28 @@ dropwithreset: tcp_trace(TA_DROP, ostate, tp, (void *)tcp_saveipgen, &tcp_savetcp, 0); #endif + bzero(&tra, sizeof(tra)); + tra.ifscope = ifscope; + tra.awdl_unrestricted = 1; + tra.intcoproc_allowed = 1; if (thflags & TH_ACK) /* mtod() below is safe as long as hdr dropping is delayed */ tcp_respond(tp, mtod(m, void *), th, m, (tcp_seq)0, th->th_ack, - TH_RST, m->m_pkthdr.rcvif); + TH_RST, &tra); else { if (thflags & TH_SYN) tlen++; /* mtod() below is safe as long as hdr dropping is delayed */ tcp_respond(tp, mtod(m, void *), th, m, th->th_seq+tlen, - (tcp_seq)0, TH_RST|TH_ACK, m->m_pkthdr.rcvif); + (tcp_seq)0, TH_RST|TH_ACK, &tra); } /* destroy temporarily created socket */ if (dropsocket) { - (void) soabort(so); - tcp_unlock(so, 1, 0); + (void) soabort(so); + socket_unlock(so, 1); + } else if ((inp != NULL) && (nosock == 0)) { + socket_unlock(so, 1); } - else - if ((inp != NULL) && (nosock == 0)) - tcp_unlock(so, 1, 0); KERNEL_DEBUG(DBG_FNC_TCP_INPUT | DBG_FUNC_END,0,0,0,0,0); return; dropnosock: @@ -3060,26 +5276,22 @@ drop: m_freem(m); /* destroy temporarily created socket */ if (dropsocket) { - (void) soabort(so); - tcp_unlock(so, 1, 0); + (void) soabort(so); + socket_unlock(so, 1); + } + else if (nosock == 0) { + socket_unlock(so, 1); } - else - if (nosock == 0) - tcp_unlock(so, 1, 0); KERNEL_DEBUG(DBG_FNC_TCP_INPUT | DBG_FUNC_END,0,0,0,0,0); return; } -static void -tcp_dooptions(tp, cp, cnt, th, to) /* * Parse TCP options and place in tcpopt. */ - struct tcpcb *tp; - u_char *cp; - int cnt; - struct tcphdr *th; - struct tcpopt *to; +static void +tcp_dooptions(struct tcpcb *tp, u_char *cp, int cnt, struct tcphdr *th, + struct tcpopt *to) { u_short mss = 0; int opt, optlen; @@ -3109,6 +5321,8 @@ tcp_dooptions(tp, cp, cnt, th, to) continue; bcopy((char *) cp + 2, (char *) &mss, sizeof(mss)); NTOHS(mss); + to->to_mss = mss; + to->to_flags |= TOF_MSS; break; case TCPOPT_WINDOW: @@ -3116,8 +5330,8 @@ tcp_dooptions(tp, cp, cnt, th, to) continue; if (!(th->th_flags & TH_SYN)) continue; - tp->t_flags |= TF_RCVD_SCALE; - tp->requested_s_scale = min(cp[2], TCP_MAX_WINSHIFT); + to->to_flags |= TOF_SCALE; + to->to_requested_s_scale = min(cp[2], TCP_MAX_WINSHIFT); break; case TCPOPT_TIMESTAMP: @@ -3130,16 +5344,10 @@ tcp_dooptions(tp, cp, cnt, th, to) bcopy((char *)cp + 6, (char *)&to->to_tsecr, sizeof(to->to_tsecr)); NTOHL(to->to_tsecr); - - /* - * A timestamp received in a SYN makes - * it ok to send timestamp requests and replies. - */ - if (th->th_flags & TH_SYN) { - tp->t_flags |= TF_RCVD_TSTMP; - tp->ts_recent = to->to_tsval; - tp->ts_recent_age = tcp_now; - } + /* Re-enable sending Timestamps if we received them */ + if (!(tp->t_flags & TF_REQ_TSTMP) && + tcp_do_rfc1323 == 1) + tp->t_flags |= TF_REQ_TSTMP; break; case TCPOPT_SACK_PERMITTED: if (!tcp_do_sack || @@ -3156,10 +5364,60 @@ tcp_dooptions(tp, cp, cnt, th, to) tcpstat.tcps_sack_rcv_blocks++; break; + case TCPOPT_FASTOPEN: + if (optlen == TCPOLEN_FASTOPEN_REQ) { + if (tp->t_state != TCPS_LISTEN) + continue; + + to->to_flags |= TOF_TFOREQ; + } else { + if (optlen < TCPOLEN_FASTOPEN_REQ || + (optlen - TCPOLEN_FASTOPEN_REQ) > TFO_COOKIE_LEN_MAX || + (optlen - TCPOLEN_FASTOPEN_REQ) < TFO_COOKIE_LEN_MIN) + continue; + if (tp->t_state != TCPS_LISTEN && + tp->t_state != TCPS_SYN_SENT) + continue; + + to->to_flags |= TOF_TFO; + to->to_tfo = cp + 1; + } + + break; +#if MPTCP + case TCPOPT_MULTIPATH: + tcp_do_mptcp_options(tp, cp, th, to, optlen); + break; +#endif /* MPTCP */ } } - if (th->th_flags & TH_SYN) - tcp_mss(tp, mss); /* sets t_maxseg */ +} + +static void +tcp_finalize_options(struct tcpcb *tp, struct tcpopt *to, unsigned int ifscope) +{ + if (to->to_flags & TOF_TS) { + tp->t_flags |= TF_RCVD_TSTMP; + tp->ts_recent = to->to_tsval; + tp->ts_recent_age = tcp_now; + + } + if (to->to_flags & TOF_MSS) + tcp_mss(tp, to->to_mss, ifscope); + if (SACK_ENABLED(tp)) { + if (!(to->to_flags & TOF_SACK)) + tp->t_flagsext &= ~(TF_SACK_ENABLE); + else + tp->t_flags |= TF_SACK_PERMIT; + } + if (to->to_flags & TOF_SCALE) { + tp->t_flags |= TF_RCVD_SCALE; + tp->requested_s_scale = to->to_requested_s_scale; + + /* Re-enable window scaling, if the option is received */ + if (tp->request_r_scale > 0) + tp->t_flags |= TF_REQ_SCALE; + } } /* @@ -3167,13 +5425,11 @@ tcp_dooptions(tp, cp, cnt, th, to) * it doesn't appear in the user's data queue. * It is still reflected in the segment length for * sequencing purposes. + * + * @param off delayed to be droped hdrlen */ static void -tcp_pulloutofband(so, th, m, off) - struct socket *so; - struct tcphdr *th; - register struct mbuf *m; - int off; /* delayed to be droped hdrlen */ +tcp_pulloutofband(struct socket *so, struct tcphdr *th, struct mbuf *m, int off) { int cnt = off + th->th_urp - 1; @@ -3190,36 +5446,215 @@ tcp_pulloutofband(so, th, m, off) m->m_pkthdr.len--; return; } - cnt -= m->m_len; - m = m->m_next; - if (m == 0) - break; + cnt -= m->m_len; + m = m->m_next; + if (m == 0) + break; + } + panic("tcp_pulloutofband"); +} + +uint32_t +get_base_rtt(struct tcpcb *tp) +{ + struct rtentry *rt = tp->t_inpcb->inp_route.ro_rt; + return ((rt == NULL) ? 0 : rt->rtt_min); +} + +/* Each value of RTT base represents the minimum RTT seen in a minute. + * We keep upto N_RTT_BASE minutes worth of history. + */ +void +update_base_rtt(struct tcpcb *tp, uint32_t rtt) +{ + u_int32_t base_rtt, i; + struct rtentry *rt; + + if ((rt = tp->t_inpcb->inp_route.ro_rt) == NULL) + return; + if (rt->rtt_expire_ts == 0) { + RT_LOCK_SPIN(rt); + if (rt->rtt_expire_ts != 0) { + RT_UNLOCK(rt); + goto update; + } + rt->rtt_expire_ts = tcp_now; + rt->rtt_index = 0; + rt->rtt_hist[0] = rtt; + rt->rtt_min = rtt; + RT_UNLOCK(rt); + return; + } +update: +#if TRAFFIC_MGT + /* + * If the recv side is being throttled, check if the + * current RTT is closer to the base RTT seen in + * first (recent) two slots. If so, unthrottle the stream. + */ + if ((tp->t_flagsext & TF_RECV_THROTTLE) && + (int)(tcp_now - tp->t_recv_throttle_ts) >= TCP_RECV_THROTTLE_WIN) { + base_rtt = rt->rtt_min; + if (tp->t_rttcur <= (base_rtt + target_qdelay)) { + tp->t_flagsext &= ~TF_RECV_THROTTLE; + tp->t_recv_throttle_ts = 0; + } + } +#endif /* TRAFFIC_MGT */ + if ((int)(tcp_now - rt->rtt_expire_ts) >= + TCP_RTT_HISTORY_EXPIRE_TIME) { + RT_LOCK_SPIN(rt); + /* check the condition again to avoid race */ + if ((int)(tcp_now - rt->rtt_expire_ts) >= + TCP_RTT_HISTORY_EXPIRE_TIME) { + rt->rtt_index++; + if (rt->rtt_index >= NRTT_HIST) + rt->rtt_index = 0; + rt->rtt_hist[rt->rtt_index] = rtt; + rt->rtt_expire_ts = tcp_now; + } else { + rt->rtt_hist[rt->rtt_index] = + min(rt->rtt_hist[rt->rtt_index], rtt); + } + /* forget the old value and update minimum */ + rt->rtt_min = 0; + for (i = 0; i < NRTT_HIST; ++i) { + if (rt->rtt_hist[i] != 0 && + (rt->rtt_min == 0 || + rt->rtt_hist[i] < rt->rtt_min)) + rt->rtt_min = rt->rtt_hist[i]; + } + RT_UNLOCK(rt); + } else { + rt->rtt_hist[rt->rtt_index] = + min(rt->rtt_hist[rt->rtt_index], rtt); + if (rt->rtt_min == 0) + rt->rtt_min = rtt; + else + rt->rtt_min = min(rt->rtt_min, rtt); + } +} + +/* + * If we have a timestamp reply, update smoothed RTT. If no timestamp is + * present but transmit timer is running and timed sequence number was + * acked, update smoothed RTT. + * + * If timestamps are supported, a receiver can update RTT even if + * there is no outstanding data. + * + * Some boxes send broken timestamp replies during the SYN+ACK phase, + * ignore timestamps of 0or we could calculate a huge RTT and blow up + * the retransmit timer. + */ +static void +tcp_compute_rtt(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th) +{ + int rtt = 0; + VERIFY(to != NULL && th != NULL); + if (tp->t_rtttime != 0 && SEQ_GT(th->th_ack, tp->t_rtseq)) { + u_int32_t pipe_ack_val; + rtt = tcp_now - tp->t_rtttime; + /* + * Compute pipe ack -- the amount of data acknowledged + * in the last RTT + */ + if (SEQ_GT(th->th_ack, tp->t_pipeack_lastuna)) { + pipe_ack_val = th->th_ack - tp->t_pipeack_lastuna; + /* Update the sample */ + tp->t_pipeack_sample[tp->t_pipeack_ind++] = + pipe_ack_val; + tp->t_pipeack_ind %= TCP_PIPEACK_SAMPLE_COUNT; + + /* Compute the max of the pipeack samples */ + pipe_ack_val = tcp_get_max_pipeack(tp); + tp->t_pipeack = (pipe_ack_val > + TCP_CC_CWND_INIT_BYTES) ? + pipe_ack_val : 0; + } + /* start another measurement */ + tp->t_rtttime = 0; + } + if (((to->to_flags & TOF_TS) != 0) && + (to->to_tsecr != 0) && + TSTMP_GEQ(tcp_now, to->to_tsecr)) { + tcp_xmit_timer(tp, (tcp_now - to->to_tsecr), + to->to_tsecr, th->th_ack); + } else if (rtt > 0) { + tcp_xmit_timer(tp, rtt, 0, th->th_ack); } - panic("tcp_pulloutofband"); } /* - * Collect new round-trip time estimate - * and update averages and current timeout. + * Collect new round-trip time estimate and update averages and + * current timeout. */ static void -tcp_xmit_timer(tp, rtt) - register struct tcpcb *tp; - int rtt; +tcp_xmit_timer(struct tcpcb *tp, int rtt, + u_int32_t tsecr, tcp_seq th_ack) { - register int delta; + int delta; + + /* + * On AWDL interface, the initial RTT measurement on SYN + * can be wrong due to peer caching. Avoid the first RTT + * measurement as it might skew up the RTO. + * + */ + if (tp->t_inpcb->inp_last_outifp != NULL && + (tp->t_inpcb->inp_last_outifp->if_eflags & IFEF_AWDL) && + th_ack == tp->iss + 1) + return; + + if (tp->t_flagsext & TF_RECOMPUTE_RTT) { + if (SEQ_GT(th_ack, tp->snd_una) && + SEQ_LEQ(th_ack, tp->snd_max) && + (tsecr == 0 || + TSTMP_GEQ(tsecr, tp->t_badrexmt_time))) { + /* + * We received a new ACk after a + * spurious timeout. Adapt retransmission + * timer as described in rfc 4015. + */ + tp->t_flagsext &= ~(TF_RECOMPUTE_RTT); + tp->t_badrexmt_time = 0; + tp->t_srtt = max(tp->t_srtt_prev, rtt); + tp->t_srtt = tp->t_srtt << TCP_RTT_SHIFT; + tp->t_rttvar = max(tp->t_rttvar_prev, (rtt >> 1)); + tp->t_rttvar = tp->t_rttvar << TCP_RTTVAR_SHIFT; + + if (tp->t_rttbest > (tp->t_srtt + tp->t_rttvar)) + tp->t_rttbest = tp->t_srtt + tp->t_rttvar; + + goto compute_rto; + } else { + return; + } + } tcpstat.tcps_rttupdated++; tp->t_rttupdated++; + + if (rtt > 0) { + tp->t_rttcur = rtt; + update_base_rtt(tp, rtt); + } + if (tp->t_srtt != 0) { /* * srtt is stored as fixed point with 5 bits after the - * binary point (i.e., scaled by 8). The following magic + * binary point (i.e., scaled by 32). The following magic * is equivalent to the smoothing algorithm in rfc793 with * an alpha of .875 (srtt = rtt/8 + srtt*7/8 in fixed - * point). Adjust rtt to origin 0. + * point). + * + * Freebsd adjusts rtt to origin 0 by subtracting 1 + * from the provided rtt value. This was required because + * of the way t_rtttime was initiailised to 1 before. + * Since we changed t_rtttime to be based on + * tcp_now, this extra adjustment is not needed. */ - delta = ((rtt - 1) << TCP_DELTA_SHIFT) + delta = (rtt << TCP_DELTA_SHIFT) - (tp->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT)); if ((tp->t_srtt += delta) <= 0) @@ -3240,8 +5675,9 @@ tcp_xmit_timer(tp, rtt) delta -= tp->t_rttvar >> (TCP_RTTVAR_SHIFT - TCP_DELTA_SHIFT); if ((tp->t_rttvar += delta) <= 0) tp->t_rttvar = 1; - if (tp->t_rttbest > tp->t_srtt + tp->t_rttvar) - tp->t_rttbest = tp->t_srtt + tp->t_rttvar; + if (tp->t_rttbest == 0 || + tp->t_rttbest > (tp->t_srtt + tp->t_rttvar)) + tp->t_rttbest = tp->t_srtt + tp->t_rttvar; } else { /* * No rtt measurement yet - use the unsmoothed rtt. @@ -3250,10 +5686,11 @@ tcp_xmit_timer(tp, rtt) */ tp->t_srtt = rtt << TCP_RTT_SHIFT; tp->t_rttvar = rtt << (TCP_RTTVAR_SHIFT - 1); - tp->t_rttbest = tp->t_srtt + tp->t_rttvar; } - tp->t_rtttime = 0; - tp->t_rxtshift = 0; + +compute_rto: + nstat_route_rtt(tp->t_inpcb->inp_route.ro_rt, tp->t_srtt, + tp->t_rttvar); /* * the retransmit should happen at rtt + 4 * rttvar. @@ -3267,7 +5704,8 @@ tcp_xmit_timer(tp, rtt) * the minimum feasible timer (which is 2 ticks). */ TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp), - max(tp->t_rttmin, rtt + 2), TCPTV_REXMTMAX); + max(tp->t_rttmin, rtt + 2), TCPTV_REXMTMAX, + TCP_ADD_REXMTSLOP(tp)); /* * We received an ack for a packet that wasn't retransmitted; @@ -3283,11 +5721,22 @@ static inline unsigned int tcp_maxmtu(struct rtentry *rt) { unsigned int maxmtu; + int interface_mtu = 0; + + RT_LOCK_ASSERT_HELD(rt); + interface_mtu = rt->rt_ifp->if_mtu; + + if (rt_key(rt)->sa_family == AF_INET && + INTF_ADJUST_MTU_FOR_CLAT46(rt->rt_ifp)) { + interface_mtu = IN6_LINKMTU(rt->rt_ifp); + /* Further adjust the size for CLAT46 expansion */ + interface_mtu -= CLAT46_HDR_EXPANSION_OVERHD; + } if (rt->rt_rmx.rmx_mtu == 0) - maxmtu = rt->rt_ifp->if_mtu; + maxmtu = interface_mtu; else - maxmtu = MIN(rt->rt_rmx.rmx_mtu, rt->rt_ifp->if_mtu); + maxmtu = MIN(rt->rt_rmx.rmx_mtu, interface_mtu); return (maxmtu); } @@ -3297,16 +5746,44 @@ static inline unsigned int tcp_maxmtu6(struct rtentry *rt) { unsigned int maxmtu; + struct nd_ifinfo *ndi = NULL; + RT_LOCK_ASSERT_HELD(rt); + if ((ndi = ND_IFINFO(rt->rt_ifp)) != NULL && !ndi->initialized) + ndi = NULL; + if (ndi != NULL) + lck_mtx_lock(&ndi->lock); if (rt->rt_rmx.rmx_mtu == 0) maxmtu = IN6_LINKMTU(rt->rt_ifp); else maxmtu = MIN(rt->rt_rmx.rmx_mtu, IN6_LINKMTU(rt->rt_ifp)); + if (ndi != NULL) + lck_mtx_unlock(&ndi->lock); return (maxmtu); } #endif +unsigned int +get_maxmtu(struct rtentry *rt) +{ + unsigned int maxmtu = 0; + + RT_LOCK_ASSERT_NOTHELD(rt); + + RT_LOCK(rt); + + if (rt_key(rt)->sa_family == AF_INET6) { + maxmtu = tcp_maxmtu6(rt); + } else { + maxmtu = tcp_maxmtu(rt); + } + + RT_UNLOCK(rt); + + return (maxmtu); +} + /* * Determine a reasonable value for maxseg size. * If the route is known, check route for mtu. @@ -3318,9 +5795,9 @@ tcp_maxmtu6(struct rtentry *rt) * size (usually 512 or the default IP max size, but no more than the mtu * of the interface), as we can't discover anything about intervening * gateways or networks. We also initialize the congestion/slow start - * window to be a single segment if the destination isn't local. - * While looking at the routing entry, we also initialize other path-dependent - * parameters from pre-set or cached values in the routing entry. + * window. While looking at the routing entry, we also initialize + * other path-dependent parameters from pre-set or cached values + * in the routing entry. * * Also take into account the space needed for options that we * send regularly. Make maxseg shorter by that amount to assure @@ -3333,19 +5810,17 @@ tcp_maxmtu6(struct rtentry *rt) * */ void -tcp_mss(tp, offer) - struct tcpcb *tp; - int offer; +tcp_mss(struct tcpcb *tp, int offer, unsigned int input_ifscope) { - register struct rtentry *rt; + struct rtentry *rt; struct ifnet *ifp; - register int rtt, mss; - u_long bufsize; + int rtt, mss; + u_int32_t bufsize; struct inpcb *inp; struct socket *so; struct rmxp_tao *taop; int origoffer = offer; - u_long sb_max_corrected; + u_int32_t sb_max_corrected; int isnetlocal = 0; #if INET6 int isipv6; @@ -3360,38 +5835,35 @@ tcp_mss(tp, offer) #else #define min_protoh (sizeof (struct tcpiphdr)) #endif - lck_mtx_lock(rt_mtx); + #if INET6 if (isipv6) { - rt = tcp_rtlookup6(inp); - if (rt && (IN6_IS_ADDR_LOOPBACK(&inp->in6p_faddr) || IN6_IS_ADDR_LINKLOCAL(&inp->in6p_faddr) || rt->rt_gateway->sa_family == AF_LINK)) - isnetlocal = TRUE; + rt = tcp_rtlookup6(inp, input_ifscope); } else #endif /* INET6 */ { - rt = tcp_rtlookup(inp); - if (rt && (rt->rt_gateway->sa_family == AF_LINK || - rt->rt_ifp->if_flags & IFF_LOOPBACK)) - isnetlocal = TRUE; + rt = tcp_rtlookup(inp, input_ifscope); } + isnetlocal = (tp->t_flags & TF_LOCAL); + if (rt == NULL) { tp->t_maxopd = tp->t_maxseg = #if INET6 isipv6 ? tcp_v6mssdflt : #endif /* INET6 */ tcp_mssdflt; - lck_mtx_unlock(rt_mtx); return; } ifp = rt->rt_ifp; /* * Slower link window correction: - * If a value is specificied for slowlink_wsize use it for PPP links - * believed to be on a serial modem (speed <128Kbps). Excludes 9600bps as - * it is the default value adversized by pseudo-devices over ppp. + * If a value is specificied for slowlink_wsize use it for + * PPP links believed to be on a serial modem (speed <128Kbps). + * Excludes 9600bps as it is the default value adversized + * by pseudo-devices over ppp. */ - if (ifp->if_type == IFT_PPP && slowlink_wsize > 0 && + if (ifp->if_type == IFT_PPP && slowlink_wsize > 0 && ifp->if_baudrate > 9600 && ifp->if_baudrate <= 128000) { tp->t_flags |= TF_SLOWLINK; } @@ -3435,38 +5907,23 @@ tcp_mss(tp, offer) * or rttvar. Convert from the route-table units * to scaled multiples of the slow timeout timer. */ - if (tp->t_srtt == 0 && (rtt = rt->rt_rmx.rmx_rtt)) { - /* - * XXX the lock bit for RTT indicates that the value - * is also a minimum value; this is subject to time. - */ - if (rt->rt_rmx.rmx_locks & RTV_RTT) - tp->t_rttmin = rtt / (RTM_RTTUNIT / TCP_RETRANSHZ); - else - tp->t_rttmin = isnetlocal ? tcp_TCPTV_MIN : TCP_RETRANSHZ; - tp->t_srtt = rtt / (RTM_RTTUNIT / (TCP_RETRANSHZ * TCP_RTT_SCALE)); - tcpstat.tcps_usedrtt++; - if (rt->rt_rmx.rmx_rttvar) { - tp->t_rttvar = rt->rt_rmx.rmx_rttvar / - (RTM_RTTUNIT / (TCP_RETRANSHZ * TCP_RTTVAR_SCALE)); - tcpstat.tcps_usedrttvar++; - } else { - /* default variation is +- 1 rtt */ - tp->t_rttvar = - tp->t_srtt * TCP_RTTVAR_SCALE / TCP_RTT_SCALE; - } - TCPT_RANGESET(tp->t_rxtcur, - ((tp->t_srtt >> 2) + tp->t_rttvar) >> 1, - tp->t_rttmin, TCPTV_REXMTMAX); + if (tp->t_srtt == 0 && (rtt = rt->rt_rmx.rmx_rtt) != 0) { + tcp_getrt_rtt(tp, rt); + } else { + tp->t_rttmin = isnetlocal ? tcp_TCPTV_MIN : TCPTV_REXMTMIN; } - else - tp->t_rttmin = isnetlocal ? tcp_TCPTV_MIN : TCP_RETRANSHZ; #if INET6 mss = (isipv6 ? tcp_maxmtu6(rt) : tcp_maxmtu(rt)); #else mss = tcp_maxmtu(rt); #endif + +#if NECP + // At this point, the mss is just the MTU. Adjust if necessary. + mss = necp_socket_get_effective_mtu(inp, mss); +#endif /* NECP */ + mss -= min_protoh; if (rt->rt_rmx.rmx_mtu == 0) { @@ -3498,6 +5955,10 @@ tcp_mss(tp, offer) (origoffer == -1 || (tp->t_flags & TF_RCVD_TSTMP) == TF_RCVD_TSTMP)) mss -= TCPOLEN_TSTAMP_APPA; + +#if MPTCP + mss -= mptcp_adj_mss(tp, FALSE); +#endif /* MPTCP */ tp->t_maxseg = mss; /* @@ -3528,6 +5989,14 @@ tcp_mss(tp, offer) } tp->t_maxseg = mss; + ASSERT(tp->t_maxseg); + + /* + * Update MSS using recommendation from link status report. This is + * temporary + */ + tcp_update_mss_locked(so, ifp); + #if RTV_RPIPE bufsize = rt->rt_rmx.rmx_recvpipe; if (bufsize < so->so_rcv.sb_hiwat) @@ -3540,34 +6009,39 @@ tcp_mss(tp, offer) (void)sbreserve(&so->so_rcv, bufsize); } - /* - * Set the slow-start flight size depending on whether this - * is a local network or not. - */ - if (isnetlocal) - tp->snd_cwnd = mss * ss_fltsz_local; - else - tp->snd_cwnd = mss * ss_fltsz; + set_tcp_stream_priority(so); if (rt->rt_rmx.rmx_ssthresh) { /* * There's some sort of gateway or interface * buffer limit on the path. Use this to set - * the slow start threshhold, but set the - * threshold to no less than 2*mss. + * slow-start threshold, but set the threshold to + * no less than 2*mss. */ tp->snd_ssthresh = max(2 * mss, rt->rt_rmx.rmx_ssthresh); tcpstat.tcps_usedssthresh++; + } else { + tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; } - lck_mtx_unlock(rt_mtx); + + /* + * Set the slow-start flight size depending on whether this + * is a local network or not. + */ + if (CC_ALGO(tp)->cwnd_init != NULL) + CC_ALGO(tp)->cwnd_init(tp); + + tcp_ccdbg_trace(tp, NULL, TCP_CC_CWND_INIT); + + /* Route locked during lookup above */ + RT_UNLOCK(rt); } /* * Determine the MSS option to send on an outgoing SYN. */ int -tcp_mssopt(tp) - struct tcpcb *tp; +tcp_mssopt(struct tcpcb *tp) { struct rtentry *rt; int mss; @@ -3583,15 +6057,14 @@ tcp_mssopt(tp) #else #define min_protoh (sizeof (struct tcpiphdr)) #endif - lck_mtx_lock(rt_mtx); + #if INET6 if (isipv6) - rt = tcp_rtlookup6(tp->t_inpcb); + rt = tcp_rtlookup6(tp->t_inpcb, IFSCOPE_NONE); else #endif /* INET6 */ - rt = tcp_rtlookup(tp->t_inpcb); + rt = tcp_rtlookup(tp->t_inpcb, IFSCOPE_NONE); if (rt == NULL) { - lck_mtx_unlock(rt_mtx); return ( #if INET6 isipv6 ? tcp_v6mssdflt : @@ -3604,7 +6077,7 @@ tcp_mssopt(tp) * believed to be on a serial modem (speed <128Kbps). Excludes 9600bps as * it is the default value adversized by pseudo-devices over ppp. */ - if (rt->rt_ifp->if_type == IFT_PPP && slowlink_wsize > 0 && + if (rt->rt_ifp->if_type == IFT_PPP && slowlink_wsize > 0 && rt->rt_ifp->if_baudrate > 9600 && rt->rt_ifp->if_baudrate <= 128000) { tp->t_flags |= TF_SLOWLINK; } @@ -3614,34 +6087,39 @@ tcp_mssopt(tp) #else mss = tcp_maxmtu(rt); #endif - lck_mtx_unlock(rt_mtx); + /* Route locked during lookup above */ + RT_UNLOCK(rt); + +#if NECP + // At this point, the mss is just the MTU. Adjust if necessary. + mss = necp_socket_get_effective_mtu(tp->t_inpcb, mss); +#endif /* NECP */ + return (mss - min_protoh); } /* * On a partial ack arrives, force the retransmission of the * next unacknowledged segment. Do not clear tp->t_dupacks. - * By setting snd_nxt to ti_ack, this forces retransmission timer to + * By setting snd_nxt to th_ack, this forces retransmission timer to * be started again. */ static void -tcp_newreno_partial_ack(tp, th) - struct tcpcb *tp; - struct tcphdr *th; +tcp_newreno_partial_ack(struct tcpcb *tp, struct tcphdr *th) { tcp_seq onxt = tp->snd_nxt; - u_long ocwnd = tp->snd_cwnd; + u_int32_t ocwnd = tp->snd_cwnd; tp->t_timer[TCPT_REXMT] = 0; + tp->t_timer[TCPT_PTO] = 0; tp->t_rtttime = 0; tp->snd_nxt = th->th_ack; /* * Set snd_cwnd to one segment beyond acknowledged offset - * (tp->snd_una has not yet been updated when this function + * (tp->snd_una has not yet been updated when this function * is called) */ - tp->snd_cwnd = tp->t_maxseg + (th->th_ack - tp->snd_una); + tp->snd_cwnd = tp->t_maxseg + BYTES_ACKED(th, tp); tp->t_flags |= TF_ACKNOW; - tp->t_unacksegs = 0; (void) tcp_output(tp); tp->snd_cwnd = ocwnd; if (SEQ_GT(onxt, tp->snd_nxt)) @@ -3650,12 +6128,11 @@ tcp_newreno_partial_ack(tp, th) * Partial window deflation. Relies on fact that tp->snd_una * not updated yet. */ - if (tp->snd_cwnd > th->th_ack - tp->snd_una) - tp->snd_cwnd -= th->th_ack - tp->snd_una; + if (tp->snd_cwnd > BYTES_ACKED(th, tp)) + tp->snd_cwnd -= BYTES_ACKED(th, tp); else tp->snd_cwnd = 0; tp->snd_cwnd += tp->t_maxseg; - } /* @@ -3672,29 +6149,63 @@ tcp_dropdropablreq(struct socket *head) { struct socket *so, *sonext; unsigned int i, j, qlen; - static int rnd; - static struct timeval old_runtime; + static u_int32_t rnd = 0; + static u_int64_t old_runtime; static unsigned int cur_cnt, old_cnt; - struct timeval tv; + u_int64_t now_sec; struct inpcb *inp = NULL; struct tcpcb *tp; if ((head->so_options & SO_ACCEPTCONN) == 0) - return 0; + return (0); + + if (TAILQ_EMPTY(&head->so_incomp)) + return (0); + + so_acquire_accept_list(head, NULL); + socket_unlock(head, 0); + + /* + * Check if there is any socket in the incomp queue + * that is closed because of a reset from the peer and is + * waiting to be garbage collected. If so, pick that as + * the victim + */ + TAILQ_FOREACH_SAFE(so, &head->so_incomp, so_list, sonext) { + inp = sotoinpcb(so); + tp = intotcpcb(inp); + if (tp != NULL && tp->t_state == TCPS_CLOSED && + so->so_head != NULL && + (so->so_state & (SS_INCOMP|SS_CANTSENDMORE|SS_CANTRCVMORE)) == + (SS_INCOMP|SS_CANTSENDMORE|SS_CANTRCVMORE)) { + /* + * The listen socket is already locked but we + * can lock this socket here without lock ordering + * issues because it is in the incomp queue and + * is not visible to others. + */ + if (socket_try_lock(so)) { + so->so_usecount++; + goto found_victim; + } else { + continue; + } + } + } so = TAILQ_FIRST(&head->so_incomp); - if (!so) - return 0; - microtime(&tv); - if ((i = (tv.tv_sec - old_runtime.tv_sec)) != 0) { - old_runtime = tv; + now_sec = net_uptime(); + if ((i = (now_sec - old_runtime)) != 0) { + old_runtime = now_sec; old_cnt = cur_cnt / i; cur_cnt = 0; } - - + qlen = head->so_incqlen; + if (rnd == 0) + rnd = RandomULong(); + if (++cur_cnt > qlen || old_cnt > qlen) { rnd = (314159 * rnd + 66329) & 0xffff; j = ((qlen + 1) * rnd) >> 16; @@ -3705,68 +6216,227 @@ tcp_dropdropablreq(struct socket *head) /* Find a connection that is not already closing (or being served) */ while (so) { inp = (struct inpcb *)so->so_pcb; - + sonext = TAILQ_NEXT(so, so_list); if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) != WNT_STOPUSING) { - /* Avoid the issue of a socket being accepted by one input thread - * and being dropped by another input thread. - * If we can't get a hold on this mutex, then grab the next socket in line. + /* + * Avoid the issue of a socket being accepted + * by one input thread and being dropped by + * another input thread. If we can't get a hold + * on this mutex, then grab the next socket in + * line. */ - if (lck_mtx_try_lock(inp->inpcb_mtx)) { + if (socket_try_lock(so)) { so->so_usecount++; - if ((so->so_usecount == 2) && so->so_state & SS_INCOMP) + if ((so->so_usecount == 2) && + (so->so_state & SS_INCOMP) && + !(so->so_flags & SOF_INCOMP_INPROGRESS)) { break; - else {/* don't use if beeing accepted or used in any other way */ + } else { + /* + * don't use if being accepted or + * used in any other way + */ in_pcb_checkstate(inp, WNT_RELEASE, 1); - tcp_unlock(so, 1, 0); + socket_unlock(so, 1); } + } else { + /* + * do not try to lock the inp in + * in_pcb_checkstate because the lock + * is already held in some other thread. + * Only drop the inp_wntcnt reference. + */ + in_pcb_checkstate(inp, WNT_RELEASE, 1); } } so = sonext; - } - if (!so) - return 0; - - TAILQ_REMOVE(&head->so_incomp, so, so_list); - tcp_unlock(head, 0, 0); + if (so == NULL) { + socket_lock(head, 0); + so_release_accept_list(head); + return (0); + } /* Makes sure socket is still in the right state to be discarded */ if (in_pcb_checkstate(inp, WNT_RELEASE, 1) == WNT_STOPUSING) { - tcp_unlock(so, 1, 0); - tcp_lock(head, 0, 0); - return 0; + socket_unlock(so, 1); + socket_lock(head, 0); + so_release_accept_list(head); + return (0); } +found_victim: if (so->so_usecount != 2 || !(so->so_state & SS_INCOMP)) { - /* do not discard: that socket is beeing accepted */ - tcp_unlock(so, 1, 0); - tcp_lock(head, 0, 0); - return 0; + /* do not discard: that socket is being accepted */ + socket_unlock(so, 1); + socket_lock(head, 0); + so_release_accept_list(head); + return (0); } + socket_lock(head, 0); + TAILQ_REMOVE(&head->so_incomp, so, so_list); + head->so_incqlen--; + head->so_qlen--; + so->so_state &= ~SS_INCOMP; + so->so_flags |= SOF_OVERFLOW; so->so_head = NULL; + so_release_accept_list(head); + socket_unlock(head, 0); - /* - * We do not want to lose track of the PCB right away in case we receive - * more segments from the peer - */ + socket_lock_assert_owned(so); tp = sototcpcb(so); - so->so_flags |= SOF_OVERFLOW; - tp->t_state = TCPS_TIME_WAIT; - (void) tcp_close(tp); - tp->t_unacksegs = 0; + + tcp_close(tp); + if (inp->inp_wantcnt > 0 && inp->inp_wantcnt != WNT_STOPUSING) { + /* + * Some one has a wantcnt on this pcb. Since WNT_ACQUIRE + * doesn't require a lock, it could have happened while + * we are holding the lock. This pcb will have to + * be garbage collected later. + * Release the reference held for so_incomp queue + */ + VERIFY(so->so_usecount > 0); + so->so_usecount--; + socket_unlock(so, 1); + } else { + /* + * Unlock this socket and leave the reference on. + * We need to acquire the pcbinfo lock in order to + * fully dispose it off + */ + socket_unlock(so, 0); + + lck_rw_lock_exclusive(tcbinfo.ipi_lock); + + socket_lock(so, 0); + /* Release the reference held for so_incomp queue */ + VERIFY(so->so_usecount > 0); + so->so_usecount--; + + if (so->so_usecount != 1 || + (inp->inp_wantcnt > 0 && + inp->inp_wantcnt != WNT_STOPUSING)) { + /* + * There is an extra wantcount or usecount + * that must have been added when the socket + * was unlocked. This socket will have to be + * garbage collected later + */ + socket_unlock(so, 1); + } else { + /* Drop the reference held for this function */ + VERIFY(so->so_usecount > 0); + so->so_usecount--; + + in_pcbdispose(inp); + } + lck_rw_done(tcbinfo.ipi_lock); + } tcpstat.tcps_drops++; - tcp_canceltimers(tp); - add_to_time_wait(tp); - - tcp_unlock(so, 1, 0); - tcp_lock(head, 0, 0); - head->so_incqlen--; - head->so_qlen--; - return 1; + + socket_lock(head, 0); + return(1); +} + +/* Set background congestion control on a socket */ +void +tcp_set_background_cc(struct socket *so) +{ + tcp_set_new_cc(so, TCP_CC_ALGO_BACKGROUND_INDEX); +} + +/* Set foreground congestion control on a socket */ +void +tcp_set_foreground_cc(struct socket *so) +{ + if (tcp_use_newreno) + tcp_set_new_cc(so, TCP_CC_ALGO_NEWRENO_INDEX); + else + tcp_set_new_cc(so, TCP_CC_ALGO_CUBIC_INDEX); +} + +static void +tcp_set_new_cc(struct socket *so, uint16_t cc_index) +{ + struct inpcb *inp = sotoinpcb(so); + struct tcpcb *tp = intotcpcb(inp); + u_char old_cc_index = 0; + if (tp->tcp_cc_index != cc_index) { + + old_cc_index = tp->tcp_cc_index; + + if (CC_ALGO(tp)->cleanup != NULL) + CC_ALGO(tp)->cleanup(tp); + tp->tcp_cc_index = cc_index; + + tcp_cc_allocate_state(tp); + + if (CC_ALGO(tp)->switch_to != NULL) + CC_ALGO(tp)->switch_to(tp, old_cc_index); + + tcp_ccdbg_trace(tp, NULL, TCP_CC_CHANGE_ALGO); + } +} + +void +tcp_set_recv_bg(struct socket *so) +{ + if (!IS_TCP_RECV_BG(so)) + so->so_flags1 |= SOF1_TRAFFIC_MGT_TCP_RECVBG; + + /* Unset Large Receive Offload on background sockets */ + so_set_lro(so, SO_TC_BK); +} + +void +tcp_clear_recv_bg(struct socket *so) +{ + if (IS_TCP_RECV_BG(so)) + so->so_flags1 &= ~(SOF1_TRAFFIC_MGT_TCP_RECVBG); + + /* + * Set/unset use of Large Receive Offload depending on + * the traffic class + */ + so_set_lro(so, so->so_traffic_class); +} + +void +inp_fc_unthrottle_tcp(struct inpcb *inp) +{ + struct tcpcb *tp = inp->inp_ppcb; + /* + * Back off the slow-start threshold and enter + * congestion avoidance phase + */ + if (CC_ALGO(tp)->pre_fr != NULL) + CC_ALGO(tp)->pre_fr(tp); + + tp->snd_cwnd = tp->snd_ssthresh; + tp->t_flagsext &= ~TF_CWND_NONVALIDATED; + /* + * Restart counting for ABC as we changed the + * congestion window just now. + */ + tp->t_bytes_acked = 0; + + /* Reset retransmit shift as we know that the reason + * for delay in sending a packet is due to flow + * control on the outgoing interface. There is no need + * to backoff retransmit timer. + */ + TCP_RESET_REXMT_STATE(tp); + + /* + * Start the output stream again. Since we are + * not retransmitting data, do not reset the + * retransmit timer or rtt calculation. + */ + tcp_output(tp); } static int @@ -3775,19 +6445,253 @@ tcp_getstat SYSCTL_HANDLER_ARGS #pragma unused(oidp, arg1, arg2) int error; + struct tcpstat *stat; + stat = &tcpstat; +#if !CONFIG_EMBEDDED + proc_t caller = PROC_NULL; + proc_t caller_parent = PROC_NULL; + char command_name[MAXCOMLEN + 1] = ""; + char parent_name[MAXCOMLEN + 1] = ""; + struct tcpstat zero_stat; + if ((caller = proc_self()) != PROC_NULL) { + /* get process name */ + strlcpy(command_name, caller->p_comm, sizeof(command_name)); + + /* get parent process name if possible */ + if ((caller_parent = proc_find(caller->p_ppid)) != PROC_NULL) { + strlcpy(parent_name, caller_parent->p_comm, + sizeof(parent_name)); + proc_rele(caller_parent); + } + + if ((escape_str(command_name, strlen(command_name) + 1, + sizeof(command_name)) == 0) && + (escape_str(parent_name, strlen(parent_name) + 1, + sizeof(parent_name)) == 0)) { + kern_asl_msg(LOG_DEBUG, "messagetracer", + 5, + "com.apple.message.domain", + "com.apple.kernel.tcpstat", /* 1 */ + "com.apple.message.signature", + "tcpstat", /* 2 */ + "com.apple.message.signature2", command_name, /* 3 */ + "com.apple.message.signature3", parent_name, /* 4 */ + "com.apple.message.summarize", "YES", /* 5 */ + NULL); + } + } + if (caller != PROC_NULL) + proc_rele(caller); + if (tcp_disable_access_to_stats && + !kauth_cred_issuser(kauth_cred_get())) { + bzero(&zero_stat, sizeof(zero_stat)); + stat = &zero_stat; + } + +#endif /* !CONFIG_EMBEDDED */ if (req->oldptr == 0) { req->oldlen= (size_t)sizeof(struct tcpstat); } - error = SYSCTL_OUT(req, &tcpstat, MIN(sizeof (tcpstat), req->oldlen)); + error = SYSCTL_OUT(req, stat, MIN(sizeof (tcpstat), req->oldlen)); return (error); } -SYSCTL_PROC(_net_inet_tcp, TCPCTL_STATS, stats, CTLFLAG_RD, 0, 0, - tcp_getstat, "S,tcpstat", "TCP statistics (struct tcpstat, netinet/tcp_var.h)"); +/* + * Checksum extended TCP header and data. + */ +int +tcp_input_checksum(int af, struct mbuf *m, struct tcphdr *th, int off, int tlen) +{ + struct ifnet *ifp = m->m_pkthdr.rcvif; + + switch (af) { + case AF_INET: { + struct ip *ip = mtod(m, struct ip *); + struct ipovly *ipov = (struct ipovly *)ip; + + if (m->m_pkthdr.pkt_flags & PKTF_SW_LRO_DID_CSUM) + return (0); + + /* ip_stripoptions() must have been called before we get here */ + ASSERT((ip->ip_hl << 2) == sizeof (*ip)); + + if ((hwcksum_rx || (ifp->if_flags & IFF_LOOPBACK) || + (m->m_pkthdr.pkt_flags & PKTF_LOOP)) && + (m->m_pkthdr.csum_flags & CSUM_DATA_VALID)) { + if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR) { + th->th_sum = m->m_pkthdr.csum_rx_val; + } else { + uint32_t sum = m->m_pkthdr.csum_rx_val; + uint32_t start = m->m_pkthdr.csum_rx_start; + int32_t trailer = (m_pktlen(m) - (off + tlen)); + + /* + * Perform 1's complement adjustment of octets + * that got included/excluded in the hardware- + * calculated checksum value. Ignore cases + * where the value already includes the entire + * IP header span, as the sum for those octets + * would already be 0 by the time we get here; + * IP has already performed its header checksum + * checks. If we do need to adjust, restore + * the original fields in the IP header when + * computing the adjustment value. Also take + * care of any trailing bytes and subtract out + * their partial sum. + */ + ASSERT(trailer >= 0); + if ((m->m_pkthdr.csum_flags & CSUM_PARTIAL) && + ((start != 0 && start != off) || trailer)) { + uint32_t swbytes = (uint32_t)trailer; + + if (start < off) { + ip->ip_len += sizeof (*ip); +#if BYTE_ORDER != BIG_ENDIAN + HTONS(ip->ip_len); + HTONS(ip->ip_off); +#endif /* BYTE_ORDER != BIG_ENDIAN */ + } + /* callee folds in sum */ + sum = m_adj_sum16(m, start, off, + tlen, sum); + if (off > start) + swbytes += (off - start); + else + swbytes += (start - off); + + if (start < off) { +#if BYTE_ORDER != BIG_ENDIAN + NTOHS(ip->ip_off); + NTOHS(ip->ip_len); +#endif /* BYTE_ORDER != BIG_ENDIAN */ + ip->ip_len -= sizeof (*ip); + } + + if (swbytes != 0) + tcp_in_cksum_stats(swbytes); + if (trailer != 0) + m_adj(m, -trailer); + } + + /* callee folds in sum */ + th->th_sum = in_pseudo(ip->ip_src.s_addr, + ip->ip_dst.s_addr, + sum + htonl(tlen + IPPROTO_TCP)); + } + th->th_sum ^= 0xffff; + } else { + uint16_t ip_sum; + int len; + char b[9]; + + bcopy(ipov->ih_x1, b, sizeof (ipov->ih_x1)); + bzero(ipov->ih_x1, sizeof (ipov->ih_x1)); + ip_sum = ipov->ih_len; + ipov->ih_len = (u_short)tlen; +#if BYTE_ORDER != BIG_ENDIAN + HTONS(ipov->ih_len); +#endif + len = sizeof (struct ip) + tlen; + th->th_sum = in_cksum(m, len); + bcopy(b, ipov->ih_x1, sizeof (ipov->ih_x1)); + ipov->ih_len = ip_sum; + + tcp_in_cksum_stats(len); + } + break; + } +#if INET6 + case AF_INET6: { + struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); + + if (m->m_pkthdr.pkt_flags & PKTF_SW_LRO_DID_CSUM) + return (0); + + if ((hwcksum_rx || (ifp->if_flags & IFF_LOOPBACK) || + (m->m_pkthdr.pkt_flags & PKTF_LOOP)) && + (m->m_pkthdr.csum_flags & CSUM_DATA_VALID)) { + if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR) { + th->th_sum = m->m_pkthdr.csum_rx_val; + } else { + uint32_t sum = m->m_pkthdr.csum_rx_val; + uint32_t start = m->m_pkthdr.csum_rx_start; + int32_t trailer = (m_pktlen(m) - (off + tlen)); + + /* + * Perform 1's complement adjustment of octets + * that got included/excluded in the hardware- + * calculated checksum value. Also take care + * of any trailing bytes and subtract out their + * partial sum. + */ + ASSERT(trailer >= 0); + if ((m->m_pkthdr.csum_flags & CSUM_PARTIAL) && + (start != off || trailer != 0)) { + uint16_t s = 0, d = 0; + uint32_t swbytes = (uint32_t)trailer; + + if (IN6_IS_SCOPE_EMBED(&ip6->ip6_src)) { + s = ip6->ip6_src.s6_addr16[1]; + ip6->ip6_src.s6_addr16[1] = 0 ; + } + if (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst)) { + d = ip6->ip6_dst.s6_addr16[1]; + ip6->ip6_dst.s6_addr16[1] = 0; + } + + /* callee folds in sum */ + sum = m_adj_sum16(m, start, off, + tlen, sum); + if (off > start) + swbytes += (off - start); + else + swbytes += (start - off); + + if (IN6_IS_SCOPE_EMBED(&ip6->ip6_src)) + ip6->ip6_src.s6_addr16[1] = s; + if (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst)) + ip6->ip6_dst.s6_addr16[1] = d; + + if (swbytes != 0) + tcp_in6_cksum_stats(swbytes); + if (trailer != 0) + m_adj(m, -trailer); + } + + th->th_sum = in6_pseudo( + &ip6->ip6_src, &ip6->ip6_dst, + sum + htonl(tlen + IPPROTO_TCP)); + } + th->th_sum ^= 0xffff; + } else { + tcp_in6_cksum_stats(tlen); + th->th_sum = in6_cksum(m, IPPROTO_TCP, off, tlen); + } + break; + } +#endif /* INET6 */ + default: + VERIFY(0); + /* NOTREACHED */ + } + + if (th->th_sum != 0) { + tcpstat.tcps_rcvbadsum++; + IF_TCP_STATINC(ifp, badformat); + return (-1); + } + + return (0); +} + + +SYSCTL_PROC(_net_inet_tcp, TCPCTL_STATS, stats, + CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED, 0, 0, tcp_getstat, + "S,tcpstat", "TCP statistics (struct tcpstat, netinet/tcp_var.h)"); static int sysctl_rexmtthresh SYSCTL_HANDLER_ARGS @@ -3802,7 +6706,7 @@ sysctl_rexmtthresh SYSCTL_HANDLER_ARGS /* * Constrain the number of duplicate ACKs - * to consider for TCP fast retransmit + * to consider for TCP fast retransmit * to either 2 or 3 */ @@ -3814,5 +6718,6 @@ sysctl_rexmtthresh SYSCTL_HANDLER_ARGS return (0); } -SYSCTL_PROC(_net_inet_tcp, OID_AUTO, rexmt_thresh, CTLTYPE_INT|CTLFLAG_RW, - &tcprexmtthresh, 0, &sysctl_rexmtthresh, "I", "Duplicate ACK Threshold for Fast Retransmit"); +SYSCTL_PROC(_net_inet_tcp, OID_AUTO, rexmt_thresh, CTLTYPE_INT | CTLFLAG_RW | + CTLFLAG_LOCKED, &tcprexmtthresh, 0, &sysctl_rexmtthresh, "I", + "Duplicate ACK Threshold for Fast Retransmit");