/*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2008 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* @(#)tcp_input.c 8.12 (Berkeley) 5/24/95
* $FreeBSD: src/sys/netinet/tcp_input.c,v 1.107.2.16 2001/08/22 00:59:12 silby Exp $
*/
-
+/*
+ * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
+ * support for mandatory and extensible security protections. This notice
+ * is included in support of clause 2.2 (b) of the Apple Public License,
+ * Version 2.0.
+ */
#include <sys/param.h>
#include <sys/systm.h>
#include <kern/cpu_number.h> /* before tcp_seq.h, for tcp_random18() */
+#include <machine/endian.h>
+
#include <net/if.h>
#include <net/if_types.h>
#include <net/route.h>
#include <netkey/key.h>
#endif /*IPSEC*/
+#if CONFIG_MACF_NET || CONFIG_MACF_SOCKET
+#include <security/mac_framework.h>
+#endif /* CONFIG_MACF_NET || CONFIG_MACF_SOCKET */
+
#include <sys/kdebug.h>
#ifndef __APPLE__
#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 = 3;
+static int tcprexmtthresh = 2;
tcp_cc tcp_ccgen;
-extern int apple_hwcksum_rx;
#if IPSEC
extern int ipsec_bypass;
-extern lck_mtx_t *sadb_mutex;
#endif
struct tcpstat tcpstat;
&drop_synfin, 0, "Drop TCP packets with SYN+FIN set");
#endif
-SYSCTL_NODE(_net_inet_tcp, OID_AUTO, reass, CTLFLAG_RW, 0,
+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, OID_AUTO, slowlink_wsize, CTLFLAG_RW,
&slowlink_wsize, 0, "Maximum advertised window size for slowlink");
+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");
+
+static int tcp_do_rfc3465 = 1;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3465, CTLFLAG_RW,
+ &tcp_do_rfc3465, 0, "");
+
+static int tcp_do_rfc3465_lim2 = 1;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3465_lim2, CTLFLAG_RW,
+ &tcp_do_rfc3465_lim2, 0, "Appropriate bytes counting w/ L=2*SMSS");
+
+#if CONFIG_IFEF_NOWINDOWSCALE
+int tcp_obey_ifef_nowindowscale = 0;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, obey_ifef_nowindowscale, CTLFLAG_RW,
+ &tcp_obey_ifef_nowindowscale, 0, "");
+#endif
+
+extern int tcp_TCPTV_MIN;
+
+u_int32_t tcp_now;
-u_long 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 *);
+ u_char *, int, struct tcphdr *, 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 *);
static void tcp_xmit_timer(struct tcpcb *, int);
+static inline unsigned int tcp_maxmtu(struct rtentry *);
+#if INET6
+static inline unsigned int tcp_maxmtu6(struct rtentry *);
+#endif
/* Neighbor Discovery, Neighbor Unreachability Detection Upper layer hint. */
#if INET6
#define ND6_HINT(tp)
#endif
-extern u_long *delack_bitmask;
+extern u_int32_t *delack_bitmask;
+
+extern void add_to_time_wait(struct tcpcb *);
+extern void postevent(struct socket *, struct sockbuf *, int);
-extern void ipfwsyslog( int level, char *format,...);
+extern void ipfwsyslog( int level, const char *format,...);
extern int ChkAddressOK( __uint32_t dstaddr, __uint32_t srcaddr );
extern int fw_verbose;
+__private_extern__ int tcp_sockthreshold;
+__private_extern__ int tcp_win_scale;
+#if IPFIREWALL
#define log_in_vain_log( a ) { \
if ( (log_in_vain == 3 ) && (fw_verbose == 2)) { /* Apple logging, log to ipfw.log */ \
ipfwsyslog a ; \
} \
else log a ; \
}
+#else
+#define log_in_vain_log( a ) { log a; }
+#endif
+
/*
* Indicate whether this ack should be delayed.
* 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 4 full packets per second on this socket, we're streaming acts as "1".
- * - if we don't meet that criteria, acts like "2". Allowing faster acking while browsing for example.
+ * - 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 == 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) && (tp->rcv_byps > (4* tp->t_maxseg))) || (((thflags & TH_PUSH) == 0) && ((tp->t_flags & TF_DELACK) == 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)))))
-static int tcpdropdropablreq(struct socket *head);
+static int tcp_dropdropablreq(struct socket *head);
static void tcp_newreno_partial_ack(struct tcpcb *tp, struct tcphdr *th);
tcp_reass_overflows++;
tcpstat.tcps_rcvmemdrop++;
m_freem(m);
+ *tlenp = 0;
return (0);
}
if (so->so_state & SS_CANTRCVMORE)
m_freem(q->tqe_m);
else {
- if (sbappend(&so->so_rcv, q->tqe_m))
+ if (sbappendstream(&so->so_rcv, q->tqe_m))
dowakeup = 1;
}
FREE(q, M_TSEGQ);
}
+/*
+ * Reduce congestion window.
+ */
+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;
+ ENTER_FASTRECOVERY(tp);
+ tp->snd_recover = tp->snd_max;
+ tp->t_timer[TCPT_REXMT] = 0;
+ tp->t_rtttime = 0;
+ tp->ecn_flags |= TE_SENDCWR;
+ tp->snd_cwnd = tp->snd_ssthresh +
+ tp->t_maxseg * tcprexmtthresh;
+}
+
/*
* TCP input routine, follows pages 65-76 of the
int dropsocket = 0;
int iss = 0;
int nosock = 0;
- u_long tiwin;
+ u_int32_t tiwin;
struct tcpopt to; /* options in this segment */
- struct rmxp_tao *taop; /* pointer to our TAO cache entry */
- struct rmxp_tao tao_noncached; /* in case there's no cached entry */
struct sockaddr_in *next_hop = NULL;
#if TCPDEBUG
short ostate = 0;
#endif
struct m_tag *fwd_tag;
+ u_char ip_ecn = IPTOS_ECN_NOTECT;
+ unsigned int ifscope;
+
+ /*
+ * 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_flags & M_PKTHDR) && m->m_pkthdr.rcvif != NULL)
+ ifscope = m->m_pkthdr.rcvif->if_index;
+ else
+ ifscope = IFSCOPE_NONE;
/* 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);
th->th_seq, th->th_ack, th->th_win);
if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
- if (apple_hwcksum_rx && (m->m_pkthdr.csum_flags & CSUM_TCP_SUM16)) {
+ 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];
bzero(ipov->ih_x1, sizeof(ipov->ih_x1));
ipov->ih_len = (u_short)tlen;
+
+#if BYTE_ORDER != BIG_ENDIAN
HTONS(ipov->ih_len);
+#endif
+
pseudo = in_cksum(m, sizeof (struct ip));
*(uint32_t*)&ipov->ih_x1[0] = *(uint32_t*)&b[0];
len = sizeof (struct ip) + tlen;
bzero(ipov->ih_x1, sizeof(ipov->ih_x1));
ipov->ih_len = (u_short)tlen;
+
+#if BYTE_ORDER != BIG_ENDIAN
HTONS(ipov->ih_len);
+#endif
+
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++;
/* Re-initialization for later version check */
ip->ip_v = IPVERSION;
#endif
+ ip_ecn = (ip->ip_tos & IPTOS_ECN_MASK);
}
/*
th = (struct tcphdr *)((caddr_t)ip6 + off0);
} else
#endif /* INET6 */
- {
- if (m->m_len < sizeof(struct ip) + off) {
- if ((m = m_pullup(m, sizeof (struct ip) + off)) == 0) {
- tcpstat.tcps_rcvshort++;
- return;
+ {
+ if (m->m_len < sizeof(struct ip) + off) {
+ if ((m = m_pullup(m, sizeof (struct ip) + off)) == 0) {
+ tcpstat.tcps_rcvshort++;
+ return;
+ }
+ ip = mtod(m, struct ip *);
+ ipov = (struct ipovly *)ip;
+ th = (struct tcphdr *)((caddr_t)ip + off0);
}
- ip = mtod(m, struct ip *);
- ipov = (struct ipovly *)ip;
- th = (struct tcphdr *)((caddr_t)ip + off0);
}
- }
optlen = off - sizeof (struct tcphdr);
optp = (u_char *)(th + 1);
/*
* tcp_dooptions(), etc.
*/
if ((optlen == TCPOLEN_TSTAMP_APPA ||
- (optlen > TCPOLEN_TSTAMP_APPA &&
+ (optlen > TCPOLEN_TSTAMP_APPA &&
optp[TCPOLEN_TSTAMP_APPA] == TCPOPT_EOL)) &&
- *(u_int32_t *)optp == htonl(TCPOPT_TSTAMP_HDR) &&
- (th->th_flags & TH_SYN) == 0) {
+ *(u_int32_t *)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));
/*
* 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
/*
* Delay dropping TCP, IP headers, IPv6 ext headers, and TCP options,
#if IPFIREWALL_FORWARD
if (next_hop != NULL
#if INET6
- && isipv6 == NULL /* IPv6 support is not yet */
+ && isipv6 == 0 /* IPv6 support is not yet */
#endif /* INET6 */
) {
/*
ip->ip_dst, th->th_dport, 1, m->m_pkthdr.rcvif);
}
+ /*
+ * 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_boundif;
#if IPSEC
if (ipsec_bypass == 0) {
- lck_mtx_lock(sadb_mutex);
#if INET6
if (isipv6) {
if (inp != NULL && ipsec6_in_reject_so(m, inp->inp_socket)) {
- ipsec6stat.in_polvio++;
- lck_mtx_unlock(sadb_mutex);
+ IPSEC_STAT_INCREMENT(ipsec6stat.in_polvio);
+ if (in_pcb_checkstate(inp, WNT_RELEASE, 0) == WNT_STOPUSING)
+ inp = NULL; // pretend we didn't find it
goto dropnosock;
}
} else
#endif /* INET6 */
if (inp != NULL && ipsec4_in_reject_so(m, inp->inp_socket)) {
- ipsecstat.in_polvio++;
- lck_mtx_unlock(sadb_mutex);
+ IPSEC_STAT_INCREMENT(ipsecstat.in_polvio);
+ if (in_pcb_checkstate(inp, WNT_RELEASE, 0) == WNT_STOPUSING)
+ inp = NULL; // pretend we didn't find it
goto dropnosock;
}
- lck_mtx_unlock(sadb_mutex);
}
#endif /*IPSEC*/
}
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);
+ tcp_lock(so, 1, (void *)2);
if (in_pcb_checkstate(inp, WNT_RELEASE, 1) == WNT_STOPUSING) {
- tcp_unlock(so, 1, 2);
+ tcp_unlock(so, 1, (void *)2);
inp = NULL; // pretend we didn't find it
goto dropnosock;
}
else
tiwin = th->th_win;
+#if CONFIG_MACF_NET
+ if (mac_inpcb_check_deliver(inp, m, AF_INET, SOCK_STREAM))
+ goto drop;
+#endif
+
+ /* Radar 7377561: 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) {
#if INET6
struct inpcb *oinp = sotoinpcb(so);
#endif /* INET6 */
- int ogencnt = so->so_gencnt;
+ unsigned int head_ifscope;
+
+ /* Get listener's bound-to-interface, if any */
+ head_ifscope = (inp->inp_flags & INP_BOUND_IF) ?
+ inp->inp_boundif : IFSCOPE_NONE;
-#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 (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
/*
}
#endif
if (so->so_filt) {
+#if INET6
if (isipv6) {
struct sockaddr_in6 *sin6 = (struct sockaddr_in6*)&from;
sin6->sin6_flowinfo = 0;
sin6->sin6_addr = ip6->ip6_src;
sin6->sin6_scope_id = 0;
- } else {
+ }
+ else
+#endif
+ {
struct sockaddr_in *sin = (struct sockaddr_in*)&from;
sin->sin_len = sizeof(*sin);
}
if (so2 == 0) {
tcpstat.tcps_listendrop++;
- if (tcpdropdropablreq(so)) {
+ if (tcp_dropdropablreq(so)) {
if (so->so_filt)
so2 = sonewconn(so, 0, (struct sockaddr*)&from);
else
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 */
so = so2;
tcp_lock(so, 1, 0);
/*
- * This is ugly, but ....
- *
* Mark socket as temporary until we're
* committed to keeping it. The code at
* ``drop'' and ``dropwithreset'' check the
* 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-zero is sufficient, since it
+ * can only be set to a non-zero value earlier if
+ * the listener has such a flag set.
+ */
+#if INET6
+ if (head_ifscope != IFSCOPE_NONE && !isipv6) {
+#else
+ if (head_ifscope != IFSCOPE_NONE) {
+#endif /* INET6 */
+ inp->inp_flags |= INP_BOUND_IF;
+ inp->inp_boundif = head_ifscope;
+ }
#if INET6
if (isipv6)
inp->in6p_laddr = ip6->ip6_dst;
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 */
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 <w.knowles@niwa.cri.nz>
- * 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;
- }
- goto drop;
- }
-#endif
#if INET6
if (isipv6) {
/*
if (sotoinpcb(oso)->inp_sp)
{
int error = 0;
- lck_mtx_lock(sadb_mutex);
/* Is it a security hole here to silently fail to copy the policy? */
if (inp->inp_sp != NULL)
error = ipsec_init_policy(so, &inp->inp_sp);
if (error != 0 || ipsec_copy_policy(sotoinpcb(oso)->inp_sp, inp->inp_sp))
printf("tcp_input: could not copy policy\n");
- lck_mtx_unlock(sadb_mutex);
}
#endif
- tcp_unlock(oso, 1, 0); /* now drop the reference on the listener */
- tp = intotcpcb(inp);
+ /* inherit states from the listener */
tp->t_state = TCPS_LISTEN;
tp->t_flags |= tp0->t_flags & (TF_NOPUSH|TF_NOOPT|TF_NODELAY);
+ tp->t_keepinit = tp0->t_keepinit;
tp->t_inpcb->inp_ip_ttl = tp0->t_inpcb->inp_ip_ttl;
+
+ /* now drop the reference on the listener */
+ tcp_unlock(oso, 1, 0);
+
/* Compute proper scaling value from buffer space */
- while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
- TCP_MAXWIN << tp->request_r_scale <
- so->so_rcv.sb_hiwat)
- tp->request_r_scale++;
+ 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 = imin(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++;
+ }
KERNEL_DEBUG(DBG_FNC_TCP_NEWCONN | DBG_FUNC_END,0,0,0,0,0);
}
}
-
#if 1
lck_mtx_assert(((struct inpcb *)so->so_pcb)->inpcb_mtx, LCK_MTX_ASSERT_OWNED);
#endif
* 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.
*
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 ((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, "
+ "%s:%u, av. %ubyte/packet, "
"dropping connection\n",
-#ifdef INET6
+#if INET6
isipv6 ?
inet_ntop(AF_INET6, &inp->in6p_faddr, ipstrbuf,
sizeof(ipstrbuf)) :
}
}
} else {
- tp->rcv_reset = tcp_now + PR_SLOWHZ;
+ tp->rcv_reset = tcp_now + TCP_RETRANSHZ;
tp->rcv_pps = 1;
tp->rcv_byps = tlen + off;
}
}
+#if TRAFFIC_MGT
+ if (so->so_traffic_mgt_flags & TRAFFIC_MGT_SO_BG_REGULATE) {
+ 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.
+ */
+ 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)) {
+ 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.
+ */
+ if ((thflags & TH_CWR) == TH_CWR) {
+ tp->ecn_flags &= ~TE_SENDECE;
+ }
+
/*
* Segment received on connection.
* Reset idle time and keep-alive timer.
* else do it below (after getting remote address).
*/
if (tp->t_state != TCPS_LISTEN && optp)
- tcp_dooptions(tp, optp, optlen, th, &to);
+ tcp_dooptions(tp, optp, optlen, th, &to, ifscope);
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 (to.to_flags & TOF_TS) {
tp->t_flags |= TF_RCVD_TSTMP;
tp->ts_recent_age = tcp_now;
}
if (to.to_flags & TOF_MSS)
- tcp_mss(tp, to.to_mss);
+ tcp_mss(tp, to.to_mss, ifscope);
if (tp->sack_enable) {
if (!(to.to_flags & TOF_SACK))
tp->sack_enable = 0;
* be TH_NEEDSYN.
*/
if (tp->t_state == TCPS_ESTABLISHED &&
- (thflags & (TH_SYN|TH_FIN|TH_RST|TH_URG|TH_ACK)) == TH_ACK &&
+ (thflags & (TH_SYN|TH_FIN|TH_RST|TH_URG|TH_ACK|TH_ECE)) == TH_ACK &&
((tp->t_flags & (TF_NEEDSYN|TF_NEEDFIN)) == 0) &&
((to.to_flags & TOF_TS) == 0 ||
TSTMP_GEQ(to.to_tsval, tp->ts_recent)) &&
tp->ts_recent = to.to_tsval;
}
+ /* Force acknowledgment if we received a FIN */
+
+ if (thflags & TH_FIN)
+ tp->t_flags |= TF_ACKNOW;
+
if (tlen == 0) {
if (SEQ_GT(th->th_ack, tp->snd_una) &&
SEQ_LEQ(th->th_ack, tp->snd_max) &&
- tp->snd_cwnd >= tp->snd_wnd &&
+ tp->snd_cwnd >= tp->snd_ssthresh &&
((!tcp_do_newreno && !tp->sack_enable &&
tp->t_dupacks < tcprexmtthresh) ||
((tcp_do_newreno || tp->sack_enable) &&
* "bad retransmit" recovery
*/
if (tp->t_rxtshift == 1 &&
- tcp_now < tp->t_badrxtwin) {
+ tcp_now < tp->t_badrxtwin) {
+ ++tcpstat.tcps_sndrexmitbad;
tp->snd_cwnd = tp->snd_cwnd_prev;
tp->snd_ssthresh =
tp->snd_ssthresh_prev;
tp->snd_nxt = tp->snd_max;
tp->t_badrxtwin = 0;
}
- if (((to.to_flags & TOF_TS) != 0) && (to.to_tsecr != 0)) /* Makes sure we already have a TS */
+ /*
+ * 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 + 1);
- else if (tp->t_rtttime &&
- SEQ_GT(th->th_ack, tp->t_rtseq))
+ 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;
tcpstat.tcps_rcvackpack++;
tcpstat.tcps_rcvackbyte += acked;
+ /*
+ * Grow the congestion window, if the
+ * connection is cwnd bound.
+ */
+ if (tp->snd_cwnd < tp->snd_wnd) {
+ tp->t_bytes_acked += acked;
+ if (tp->t_bytes_acked > tp->snd_cwnd) {
+ tp->t_bytes_acked -= tp->snd_cwnd;
+ tp->snd_cwnd += tp->t_maxseg;
+ }
+ }
sbdrop(&so->so_snd, acked);
if (SEQ_GT(tp->snd_una, tp->snd_recover) &&
SEQ_LEQ(th->th_ack, tp->snd_recover))
tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
sowwakeup(so); /* has to be done with socket lock held */
- if ((so->so_snd.sb_cc) || (tp->t_flags & TF_ACKNOW))
+ if ((so->so_snd.sb_cc) || (tp->t_flags & TF_ACKNOW)) {
+ tp->t_unacksegs = 0;
(void) tcp_output(tp);
+ }
tcp_unlock(so, 1, 0);
KERNEL_DEBUG(DBG_FNC_TCP_INPUT | DBG_FUNC_END,0,0,0,0,0);
return;
}
} else if (th->th_ack == tp->snd_una &&
LIST_EMPTY(&tp->t_segq) &&
- tlen <= sbspace(&so->so_rcv)) {
+ tlen <= tcp_sbspace(tp)) {
/*
* this is a pure, in-sequence data packet
* with nothing on the reassembly queue and
* Add data to socket buffer.
*/
m_adj(m, drop_hdrlen); /* delayed header drop */
- if (sbappend(&so->so_rcv, m))
+ if (sbappendstream(&so->so_rcv, m))
sorwakeup(so);
#if INET6
if (isipv6) {
th->th_seq, th->th_ack, th->th_win);
}
if (DELAY_ACK(tp)) {
- tp->t_flags |= TF_DELACK;
+ tp->t_flags |= TF_DELACK;
+ tp->t_unacksegs++;
} else {
+ tp->t_unacksegs = 0;
tp->t_flags |= TF_ACKNOW;
tcp_output(tp);
}
#endif
{ int win;
- win = sbspace(&so->so_rcv);
+ win = tcp_sbspace(tp);
+
if (win < 0)
win = 0;
else { /* clip rcv window to 4K for modems */
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:
* <SEQ=ISS><ACK=RCV_NXT><CTL=SYN,ACK>
* Also initialize tp->snd_nxt to tp->iss+1 and tp->snd_una to tp->iss.
#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;
#if INET6
if (isipv6) {
MALLOC(sin6, struct sockaddr_in6 *, sizeof *sin6,
} else
#endif
{
-#if 1
+#if 0
lck_mtx_assert(((struct inpcb *)so->so_pcb)->inpcb_mtx, LCK_MTX_ASSERT_OWNED);
#endif
MALLOC(sin, struct sockaddr_in *, sizeof *sin, M_SONAME,
FREE(sin, M_SONAME);
}
- tcp_dooptions(tp, optp, optlen, th, &to);
+ tcp_dooptions(tp, optp, optlen, th, &to, ifscope);
if (tp->sack_enable) {
if (!(to.to_flags & TOF_SACK))
*/
tp->snd_wnd = tiwin; /* initial send-window */
tp->t_flags |= TF_ACKNOW;
+ tp->t_unacksegs = 0;
tp->t_state = TCPS_SYN_RECEIVED;
- tp->t_timer[TCPT_KEEP] = tcp_keepinit;
+ tp->t_timer[TCPT_KEEP] = tp->t_keepinit ? tp->t_keepinit : tcp_keepinit;
dropsocket = 0; /* committed to socket */
tcpstat.tcps_accepts++;
+ if ((thflags & (TH_ECE | TH_CWR)) == (TH_ECE | TH_CWR)) {
+ /* ECN-setup SYN */
+ tp->ecn_flags |= (TE_SETUPRECEIVED | TE_SENDIPECT);
+ }
+#if CONFIG_IFEF_NOWINDOWSCALE
+ if (tcp_obey_ifef_nowindowscale && m->m_pkthdr.rcvif != NULL &&
+ (m->m_pkthdr.rcvif->if_eflags & IFEF_NOWINDOWSCALE)) {
+ /* Window scaling is not enabled on this interface */
+ tp->t_flags &= ~TF_REQ_SCALE;
+ }
+#endif
goto trimthenstep6;
}
goto dropwithreset;
}
if (thflags & TH_RST) {
- if (thflags & TH_ACK) {
+ if ((thflags & TH_ACK) != 0) {
tp = tcp_drop(tp, ECONNREFUSED);
postevent(so, 0, EV_RESET);
- }
+ }
goto drop;
}
if ((thflags & TH_SYN) == 0)
tcp_rcvseqinit(tp);
if (thflags & TH_ACK) {
tcpstat.tcps_connects++;
- soisconnected(so);
+
+ if ((thflags & (TH_ECE | TH_CWR)) == (TH_ECE)) {
+ /* ECN-setup SYN-ACK */
+ tp->ecn_flags |= TE_SETUPRECEIVED;
+ }
+ else {
+ /* 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 (DELAY_ACK(tp) && tlen != 0) {
tp->t_flags |= TF_DELACK;
+ tp->t_unacksegs++;
}
else {
tp->t_flags |= TF_ACKNOW;
+ tp->t_unacksegs = 0;
}
/*
* Received <SYN,ACK> in SYN_SENT[*] state.
tp->t_state = TCPS_ESTABLISHED;
tp->t_timer[TCPT_KEEP] = TCP_KEEPIDLE(tp);
}
+ /* soisconnected may lead to socket_unlock in case of upcalls,
+ * make sure this is done when everything is setup.
+ */
+ soisconnected(so);
} else {
/*
* Received initial SYN in SYN-SENT[*] state => simul-
* TIME_WAIT STATE:
* Drop the segment - see Stevens, vol. 2, p. 964 and
* RFC 1337.
+ *
+ * Radar 4803931: Allows for the case where we ACKed the FIN but
+ * there is already a RST in flight from the peer.
+ * In that case, accept the RST for non-established
+ * state if it's one off from last_ack_sent.
+
*/
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->rcv_wnd == 0 &&
+ ((tp->last_ack_sent == th->th_seq) || ((tp->last_ack_sent -1) == th->th_seq)))) {
switch (tp->t_state) {
case TCPS_SYN_RECEIVED:
case TCPS_ESTABLISHED:
if (tp->last_ack_sent != th->th_seq) {
+ tcpstat.tcps_badrst++;
goto drop;
}
case TCPS_FIN_WAIT_1:
goto drop;
}
-#if 1
+#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.
* But keep on processing for RST or ACK.
*/
tp->t_flags |= TF_ACKNOW;
+ tp->t_unacksegs = 0;
todrop = tlen;
tcpstat.tcps_rcvduppack++;
tcpstat.tcps_rcvdupbyte += todrop;
*/
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;
if (tp->t_state == TCPS_SYN_RECEIVED ||
(tp->t_flags & TF_NEEDSYN))
goto step6;
+ else if (tp->t_flags & TF_ACKNOW)
+ goto dropafterack;
else
goto drop;
}
case TCPS_SYN_RECEIVED:
tcpstat.tcps_connects++;
- soisconnected(so);
/* Do window scaling? */
if ((tp->t_flags & (TF_RCVD_SCALE|TF_REQ_SCALE)) ==
* later; if not, do so now to pass queued data to user.
*/
if (tlen == 0 && (thflags & TH_FIN) == 0)
- (void) tcp_reass(tp, (struct tcphdr *)0, 0,
+ (void) tcp_reass(tp, (struct tcphdr *)0, &tlen,
(struct mbuf *)0);
tp->snd_wl1 = th->th_seq - 1;
+
/* FALLTHROUGH */
+ /* soisconnected may lead to socket_unlock in case of upcalls,
+ * make sure this is done when everything is setup.
+ */
+ soisconnected(so);
+
/*
* In ESTABLISHED state: drop duplicate ACKs; ACK out of range
* ACKs. If the ack is in the range
else if (++tp->t_dupacks > tcprexmtthresh ||
((tcp_do_newreno || tp->sack_enable) &&
IN_FASTRECOVERY(tp))) {
- if (tp->sack_enable && IN_FASTRECOVERY(tp)) {
+ if (tp->sack_enable && IN_FASTRECOVERY(tp)) {
int awnd;
/*
}
} else
tp->snd_cwnd += tp->t_maxseg;
+ tp->t_unacksegs = 0;
(void) tcp_output(tp);
goto drop;
} else if (tp->t_dupacks == tcprexmtthresh) {
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) {
tcpstat.tcps_sack_recovery_episode++;
tp->sack_newdata = tp->snd_nxt;
tp->snd_cwnd = tp->t_maxseg;
+ tp->t_unacksegs = 0;
(void) tcp_output(tp);
goto drop;
}
tp->snd_nxt = th->th_ack;
tp->snd_cwnd = tp->t_maxseg;
+ tp->t_unacksegs = 0;
(void) tcp_output(tp);
tp->snd_cwnd = tp->snd_ssthresh +
tp->t_maxseg * tp->t_dupacks;
* 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 (!IN_FASTRECOVERY(tp)) {
+ /*
+ * We were not in fast recovery. Reset the duplicate ack
+ * counter.
+ */
+ tp->t_dupacks = 0;
+ }
+ /*
+ * If the congestion window was inflated to account
+ * for the other side's cached packets, retract it.
+ */
+ else {
+ if (tcp_do_newreno || tp->sack_enable) {
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;
+ tcp_newreno_partial_ack(tp, th);
+ }
+ else {
+ if (tcp_do_newreno) {
+ int32_t ss = tp->snd_max - th->th_ack;
+
+ /*
+ * Complete ack. Inflate the congestion window to
+ * ssthresh and exit fast recovery.
+ *
+ * Window inflation should have left us with approx.
+ * 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 (ss < tp->snd_ssthresh)
+ tp->snd_cwnd = ss + tp->t_maxseg;
+ else
+ tp->snd_cwnd = tp->snd_ssthresh;
+ }
+ else {
+ /*
+ * Clamp the congestion window to the crossover point
+ * and exit fast recovery.
+ */
+ if (tp->snd_cwnd > tp->snd_ssthresh)
+ tp->snd_cwnd = tp->snd_ssthresh;
+ }
+
+ EXIT_FASTRECOVERY(tp);
+ tp->t_dupacks = 0;
+ tp->t_bytes_acked = 0;
}
}
- } else {
- if (tp->t_dupacks >= tcprexmtthresh &&
- tp->snd_cwnd > tp->snd_ssthresh)
- tp->snd_cwnd = tp->snd_ssthresh;
+ else {
+ /*
+ * Clamp the congestion window to the crossover point
+ * and exit fast recovery in non-newreno and non-SACK case.
+ */
+ if (tp->snd_cwnd > tp->snd_ssthresh)
+ tp->snd_cwnd = tp->snd_ssthresh;
+ EXIT_FASTRECOVERY(tp);
+ tp->t_dupacks = 0;
+ tp->t_bytes_acked = 0;
+ }
}
- tp->t_dupacks = 0;
+
+
/*
* If we reach this point, ACK is not a duplicate,
* i.e., it ACKs something we sent.
* 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;
* timer backoff (cf., Phil Karn's retransmit alg.).
* Recompute the initial retransmit timer.
* Also makes sure we have a valid time stamp in hand
+ *
+ * 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))
- tcp_xmit_timer(tp, tcp_now - to.to_tsecr + 1);
- else if (tp->t_rtttime && SEQ_GT(th->th_ack, tp->t_rtseq))
+ 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);
+ }
/*
* If all outstanding data is acked, stop retransmit
/*
* When new data is acked, open the congestion window.
- * If the window gives us less than ssthresh packets
- * in flight, open exponentially (maxseg per packet).
- * Otherwise open linearly: maxseg per window
- * (maxseg^2 / cwnd per packet).
*/
- if ((!tcp_do_newreno && !tp->sack_enable) ||
+ if ((thflags & TH_ECE) != 0 &&
+ (tp->ecn_flags & TE_SETUPSENT) != 0) {
+ /*
+ * 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))) {
+ 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 (cw > tp->snd_ssthresh)
- incr = incr * incr / cw;
+
+ if (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_lim2 &&
+ tp->snd_nxt == tp->snd_max) ? incr * 2 : incr;
+
+ incr = lmin(acked, abc_lim);
+ }
+ }
+ else {
+ /*
+ * 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).
+ */
+
+ if (cw >= tp->snd_ssthresh) {
+ incr = max((incr * incr / cw), 1);
+ }
+ }
+
+
tp->snd_cwnd = min(cw+incr, TCP_MAXWIN<<tp->snd_scale);
}
if (acked > so->so_snd.sb_cc) {
tp->snd_wnd -= acked;
ourfinisacked = 0;
}
- sowwakeup(so);
/* detect una wraparound */
if ((tcp_do_newreno || tp->sack_enable) &&
!IN_FASTRECOVERY(tp) &&
}
if (SEQ_LT(tp->snd_nxt, tp->snd_una))
tp->snd_nxt = tp->snd_una;
+
+ /*
+ * sowwakeup must happen after snd_una, et al. are updated so that
+ * the sequence numbers are in sync with so_snd
+ */
+ sowwakeup(so);
switch (tp->t_state) {
* we'll hang forever.
*/
if (so->so_state & SS_CANTRCVMORE) {
- soisdisconnected(so);
tp->t_timer[TCPT_2MSL] = tcp_maxidle;
+ add_to_time_wait(tp);
+ soisdisconnected(so);
}
- add_to_time_wait(tp);
tp->t_state = TCPS_FIN_WAIT_2;
- goto drop;
+ /* fall through and make sure we also recognize data ACKed with the FIN */
}
+ tp->t_flags |= TF_ACKNOW;
break;
/*
tcp_canceltimers(tp);
/* Shorten TIME_WAIT [RFC-1644, p.28] */
if (tp->cc_recv != 0 &&
- tp->t_starttime < tcp_msl)
+ tp->t_starttime < (u_int32_t)tcp_msl)
tp->t_timer[TCPT_2MSL] =
tp->t_rxtcur * TCPTV_TWTRUNC;
else
add_to_time_wait(tp);
soisdisconnected(so);
}
+ tp->t_flags |= TF_ACKNOW;
break;
/*
* 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
* case PRU_RCVD). If a FIN has already been received on this
* connection then we just ignore the text.
*/
- if ((tlen || (thflags&TH_FIN)) &&
+ if ((tlen || (thflags & TH_FIN)) &&
TCPS_HAVERCVDFIN(tp->t_state) == 0) {
tcp_seq save_start = th->th_seq;
tcp_seq save_end = th->th_seq + tlen;
TCPS_HAVEESTABLISHED(tp->t_state)) {
if (DELAY_ACK(tp) && ((tp->t_flags & TF_ACKNOW) == 0)) {
tp->t_flags |= TF_DELACK;
+ tp->t_unacksegs++;
}
else {
+ tp->t_unacksegs = 0;
tp->t_flags |= TF_ACKNOW;
}
tp->rcv_nxt += tlen;
tcpstat.tcps_rcvpack++;
tcpstat.tcps_rcvbyte += tlen;
ND6_HINT(tp);
- if (sbappend(&so->so_rcv, m))
+ if (sbappendstream(&so->so_rcv, m))
sorwakeup(so);
} else {
thflags = tcp_reass(tp, th, &tlen, m);
tp->t_flags |= TF_ACKNOW;
+ tp->t_unacksegs = 0;
}
if (tlen > 0 && tp->sack_enable)
* our window, in order to estimate the sender's
* buffer size.
*/
- len = so->so_rcv.sb_hiwat - (tp->rcv_adv - tp->rcv_nxt);
+ 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);
thflags &= ~TH_FIN;
*/
if (DELAY_ACK(tp) && (tp->t_flags & TF_NEEDSYN)) {
tp->t_flags |= TF_DELACK;
+ tp->t_unacksegs++;
}
else {
tp->t_flags |= TF_ACKNOW;
+ tp->t_unacksegs = 0;
}
tp->rcv_nxt++;
}
tcp_canceltimers(tp);
/* Shorten TIME_WAIT [RFC-1644, p.28] */
if (tp->cc_recv != 0 &&
- tp->t_starttime < tcp_msl) {
+ tp->t_starttime < (u_int32_t)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;
}
else
tp->t_timer[TCPT_2MSL] = 2 * tcp_msl;
/*
* Return any desired output.
*/
- if (needoutput || (tp->t_flags & TF_ACKNOW))
+ if (needoutput || (tp->t_flags & TF_ACKNOW)) {
+ tp->t_unacksegs = 0;
(void) tcp_output(tp);
+ }
tcp_unlock(so, 1, 0);
KERNEL_DEBUG(DBG_FNC_TCP_INPUT | DBG_FUNC_END,0,0,0,0,0);
return;
#endif
m_freem(m);
tp->t_flags |= TF_ACKNOW;
+ tp->t_unacksegs = 0;
(void) tcp_output(tp);
tcp_unlock(so, 1, 0);
KERNEL_DEBUG(DBG_FNC_TCP_INPUT | DBG_FUNC_END,0,0,0,0,0);
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);
+ TH_RST, ifscope);
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);
+ (tcp_seq)0, TH_RST|TH_ACK, ifscope);
}
/* destroy temporarily created socket */
if (dropsocket) {
}
static void
-tcp_dooptions(tp, cp, cnt, th, to)
+tcp_dooptions(tp, cp, cnt, th, to, input_ifscope)
/*
* Parse TCP options and place in tcpopt.
*/
int cnt;
struct tcphdr *th;
struct tcpopt *to;
+ unsigned int input_ifscope;
{
u_short mss = 0;
int opt, optlen;
if (!(th->th_flags & TH_SYN))
continue;
bcopy((char *) cp + 2, (char *) &mss, sizeof(mss));
+
+#if BYTE_ORDER != BIG_ENDIAN
NTOHS(mss);
+#endif
+
break;
case TCPOPT_WINDOW:
to->to_flags |= TOF_TS;
bcopy((char *)cp + 2,
(char *)&to->to_tsval, sizeof(to->to_tsval));
+
+#if BYTE_ORDER != BIG_ENDIAN
NTOHL(to->to_tsval);
+#endif
+
bcopy((char *)cp + 6,
(char *)&to->to_tsecr, sizeof(to->to_tsecr));
+
+#if BYTE_ORDER != BIG_ENDIAN
NTOHL(to->to_tsecr);
+#endif
/*
* A timestamp received in a SYN makes
}
}
if (th->th_flags & TH_SYN)
- tcp_mss(tp, mss); /* sets t_maxseg */
+ tcp_mss(tp, mss, input_ifscope); /* sets t_maxseg */
}
/*
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;
} else {
/*
* No rtt measurement yet - use the unsmoothed 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;
tp->t_softerror = 0;
}
+static inline unsigned int
+tcp_maxmtu(struct rtentry *rt)
+{
+ unsigned int maxmtu;
+
+ RT_LOCK_ASSERT_HELD(rt);
+ if (rt->rt_rmx.rmx_mtu == 0)
+ maxmtu = rt->rt_ifp->if_mtu;
+ else
+ maxmtu = MIN(rt->rt_rmx.rmx_mtu, rt->rt_ifp->if_mtu);
+
+ return (maxmtu);
+}
+
+#if INET6
+static inline unsigned int
+tcp_maxmtu6(struct rtentry *rt)
+{
+ unsigned int maxmtu;
+
+ RT_LOCK_ASSERT_HELD(rt);
+ lck_rw_lock_shared(nd_if_rwlock);
+ 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));
+ lck_rw_done(nd_if_rwlock);
+
+ return (maxmtu);
+}
+#endif
+
/*
* Determine a reasonable value for maxseg size.
* If the route is known, check route for mtu.
* NOTE that this routine is only called when we process an incoming
* segment, for outgoing segments only tcp_mssopt is called.
*
- * In case of T/TCP, we call this routine during implicit connection
- * setup as well (offer = -1), to initialize maxseg from the cached
- * MSS of our peer.
*/
void
-tcp_mss(tp, offer)
+tcp_mss(tp, offer, input_ifscope)
struct tcpcb *tp;
int offer;
+ unsigned int input_ifscope;
{
register struct rtentry *rt;
struct ifnet *ifp;
register int rtt, mss;
- u_long bufsize;
+ u_int32_t bufsize;
struct inpcb *inp;
struct socket *so;
struct rmxp_tao *taop;
int origoffer = offer;
+ u_int32_t sb_max_corrected;
+ int isnetlocal = 0;
#if INET6
int isipv6;
int min_protoh;
#else
#define min_protoh (sizeof (struct tcpiphdr))
#endif
+
#if INET6
- if (isipv6)
+ if (isipv6) {
rt = tcp_rtlookup6(inp);
+ if (rt != NULL &&
+ (IN6_IS_ADDR_LOOPBACK(&inp->in6p_faddr) ||
+ IN6_IS_ADDR_LINKLOCAL(&inp->in6p_faddr) ||
+ rt->rt_gateway->sa_family == AF_LINK))
+ isnetlocal = TRUE;
+ }
else
#endif /* INET6 */
- rt = tcp_rtlookup(inp);
+ {
+ rt = tcp_rtlookup(inp, input_ifscope);
+ if (rt != NULL &&
+ (rt->rt_gateway->sa_family == AF_LINK ||
+ rt->rt_ifp->if_flags & IFF_LOOPBACK))
+ isnetlocal = TRUE;
+ }
if (rt == NULL) {
tp->t_maxopd = tp->t_maxseg =
#if INET6
* is also a minimum value; this is subject to time.
*/
if (rt->rt_rmx.rmx_locks & RTV_RTT)
- tp->t_rttmin = rtt / (RTM_RTTUNIT / PR_SLOWHZ);
- tp->t_srtt = rtt / (RTM_RTTUNIT / (PR_SLOWHZ * TCP_RTT_SCALE));
+ 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 / (PR_SLOWHZ * TCP_RTTVAR_SCALE));
+ (RTM_RTTUNIT / (TCP_RETRANSHZ * TCP_RTTVAR_SCALE));
tcpstat.tcps_usedrttvar++;
} else {
/* default variation is +- 1 rtt */
((tp->t_srtt >> 2) + tp->t_rttvar) >> 1,
tp->t_rttmin, TCPTV_REXMTMAX);
}
- /*
- * if there's an mtu associated with the route, use it
- * else, use the link mtu.
- */
- if (rt->rt_rmx.rmx_mtu)
- mss = rt->rt_rmx.rmx_mtu - min_protoh;
else
- {
- mss =
-#if INET6
- (isipv6 ? nd_ifinfo[rt->rt_ifp->if_index].linkmtu :
-#endif
- ifp->if_mtu
+ 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
- - min_protoh;
+ mss -= min_protoh;
+
+ if (rt->rt_rmx.rmx_mtu == 0) {
#if INET6
if (isipv6) {
- if (!in6_localaddr(&inp->in6p_faddr))
+ if (!isnetlocal)
mss = min(mss, tcp_v6mssdflt);
} else
#endif /* INET6 */
- if (!in_localaddr(inp->inp_faddr))
+ if (!isnetlocal)
mss = min(mss, tcp_mssdflt);
}
+
mss = min(mss, offer);
/*
* maxopd stores the maximum length of data AND options
mss -= TCPOLEN_TSTAMP_APPA;
tp->t_maxseg = mss;
+ /*
+ * Calculate corrected value for sb_max; ensure to upgrade the
+ * numerator for large sb_max values else it will overflow.
+ */
+ sb_max_corrected = (sb_max * (u_int64_t)MCLBYTES) / (MSIZE + MCLBYTES);
+
/*
* If there's a pipesize (ie loopback), change the socket
* buffer to that size only if it's bigger than the current
if (bufsize < mss)
mss = bufsize;
else {
- bufsize = roundup(bufsize, mss);
- if (bufsize > sb_max)
- bufsize = sb_max;
+ bufsize = (((bufsize + (u_int64_t)mss - 1) / (u_int64_t)mss) * (u_int64_t)mss);
+ if (bufsize > sb_max_corrected)
+ bufsize = sb_max_corrected;
(void)sbreserve(&so->so_snd, bufsize);
}
tp->t_maxseg = mss;
#endif
bufsize = so->so_rcv.sb_hiwat;
if (bufsize > mss) {
- bufsize = roundup(bufsize, mss);
- if (bufsize > sb_max)
- bufsize = sb_max;
+ bufsize = (((bufsize + (u_int64_t)mss - 1) / (u_int64_t)mss) * (u_int64_t)mss);
+ if (bufsize > sb_max_corrected)
+ bufsize = sb_max_corrected;
(void)sbreserve(&so->so_rcv, bufsize);
}
* Set the slow-start flight size depending on whether this
* is a local network or not.
*/
- if (
-#if INET6
- (isipv6 && in6_localaddr(&inp->in6p_faddr)) ||
- (!isipv6 &&
-#endif
- in_localaddr(inp->inp_faddr)
-#if INET6
- )
-#endif
- )
+ if (isnetlocal)
tp->snd_cwnd = mss * ss_fltsz_local;
else
tp->snd_cwnd = mss * ss_fltsz;
*/
tp->snd_ssthresh = max(2 * mss, rt->rt_rmx.rmx_ssthresh);
tcpstat.tcps_usedssthresh++;
+ } else {
+ tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
}
+
+ /* Route locked during lookup above */
+ RT_UNLOCK(rt);
}
/*
#else
#define min_protoh (sizeof (struct tcpiphdr))
#endif
+
#if INET6
if (isipv6)
rt = tcp_rtlookup6(tp->t_inpcb);
else
#endif /* INET6 */
- rt = tcp_rtlookup(tp->t_inpcb);
- if (rt == NULL)
- return
+ rt = tcp_rtlookup(tp->t_inpcb, IFSCOPE_NONE);
+ if (rt == NULL) {
+ return (
#if INET6
isipv6 ? tcp_v6mssdflt :
#endif /* INET6 */
- tcp_mssdflt;
+ tcp_mssdflt);
+ }
/*
* Slower link window correction:
* If a value is specificied for slowlink_wsize use it for PPP links
tp->t_flags |= TF_SLOWLINK;
}
- if (rt->rt_rmx.rmx_mtu)
- mss = rt->rt_rmx.rmx_mtu;
- else {
- mss =
-#if INET6
- (isipv6 ? nd_ifinfo[rt->rt_ifp->if_index].linkmtu :
-#endif
- rt->rt_ifp->if_mtu
#if INET6
- );
+ mss = (isipv6 ? tcp_maxmtu6(rt) : tcp_maxmtu(rt));
+#else
+ mss = tcp_maxmtu(rt);
#endif
- }
+ /* Route locked during lookup above */
+ RT_UNLOCK(rt);
return (mss - min_protoh);
}
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_rtttime = 0;
tp->snd_nxt = th->th_ack;
*/
tp->snd_cwnd = tp->t_maxseg + (th->th_ack - tp->snd_una);
tp->t_flags |= TF_ACKNOW;
+ tp->t_unacksegs = 0;
(void) tcp_output(tp);
tp->snd_cwnd = ocwnd;
if (SEQ_GT(onxt, tp->snd_nxt))
* Partial window deflation. Relies on fact that tp->snd_una
* not updated yet.
*/
- tp->snd_cwnd -= (th->th_ack - tp->snd_una - tp->t_maxseg);
+ if (tp->snd_cwnd > th->th_ack - tp->snd_una)
+ tp->snd_cwnd -= th->th_ack - tp->snd_una;
+ else
+ tp->snd_cwnd = 0;
+ tp->snd_cwnd += tp->t_maxseg;
+
}
/*
* The listening TCP socket "head" must be locked
*/
static int
-tcpdropdropablreq(struct socket *head)
+tcp_dropdropablreq(struct socket *head)
{
- struct socket *so;
+ struct socket *so, *sonext;
unsigned int i, j, qlen;
static int rnd;
static struct timeval old_runtime;
struct timeval tv;
struct inpcb *inp = NULL;
struct tcpcb *tp;
-
+
+ if ((head->so_options & SO_ACCEPTCONN) == 0)
+ return 0;
+
+ 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;
cur_cnt = 0;
}
- so = TAILQ_FIRST(&head->so_incomp);
- if (!so)
- return 0;
qlen = head->so_incqlen;
if (++cur_cnt > qlen || old_cnt > qlen) {
while (j-- && so)
so = TAILQ_NEXT(so, so_list);
}
- /* Find a connection that is not already closing */
+ /* Find a connection that is not already closing (or being served) */
while (so) {
inp = (struct inpcb *)so->so_pcb;
- if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) != WNT_STOPUSING)
- break;
+ 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.
+ */
+ if (lck_mtx_try_lock(inp->inpcb_mtx)) {
+ so->so_usecount++;
+ if ((so->so_usecount == 2) && so->so_state & SS_INCOMP)
+ break;
+ else {/* don't use if beeing accepted or used in any other way */
+ in_pcb_checkstate(inp, WNT_RELEASE, 1);
+ tcp_unlock(so, 1, 0);
+ }
+ }
+ 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;
- so = TAILQ_NEXT(so, so_list);
}
if (!so)
return 0;
-
- head->so_incqlen--;
- head->so_qlen--;
+
TAILQ_REMOVE(&head->so_incomp, so, so_list);
tcp_unlock(head, 0, 0);
- /* Let's remove this connection from the incomplete list */
- tcp_lock(so, 1, 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;
}
-
+
+ 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;
+ }
+
so->so_head = NULL;
- so->so_usecount--; /* No more held by so_head */
/*
* We do not want to lose track of the PCB right away in case we receive
* more segments from the peer
*/
tp = sototcpcb(so);
- tp->t_flags |= TF_LQ_OVERFLOW;
- tp->t_state = TCPS_CLOSED;
- (void) tcp_output(tp);
+ so->so_flags |= SOF_OVERFLOW;
+ tp->t_state = TCPS_TIME_WAIT;
+ (void) tcp_close(tp);
+ tp->t_unacksegs = 0;
tcpstat.tcps_drops++;
- soisdisconnected(so);
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;
-
}
static int
tcp_getstat SYSCTL_HANDLER_ARGS
{
+#pragma unused(oidp, arg1, arg2)
int error;
req->oldlen= (size_t)sizeof(struct tcpstat);
}
- error = SYSCTL_OUT(req, &tcpstat, (size_t) req->oldlen);
+ error = SYSCTL_OUT(req, &tcpstat, 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)");
+static int
+sysctl_rexmtthresh SYSCTL_HANDLER_ARGS
+{
+#pragma unused(arg1, arg2)
+
+ int error, val = tcprexmtthresh;
+
+ error = sysctl_handle_int(oidp, &val, 0, req);
+ if (error || !req->newptr)
+ return (error);
+
+ /*
+ * Constrain the number of duplicate ACKs
+ * to consider for TCP fast retransmit
+ * to either 2 or 3
+ */
+
+ if (val < 2 || val > 3)
+ return (EINVAL);
+
+ tcprexmtthresh = val;
+
+ 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");
projects / apple / xnu.git / blobdiff