/*
* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
*
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License"). You may not use this file except in compliance with the
- * License. Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * 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
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * 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.
*
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * 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,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * 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_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/*
* Copyright (c) 1982, 1986, 1988, 1990, 1993, 1994, 1995
#include <kern/cpu_number.h> /* before tcp_seq.h, for tcp_random18() */
#include <net/if.h>
+#include <net/if_types.h>
#include <net/route.h>
#include <netinet/in.h>
#if IPSEC
extern int ipsec_bypass;
+extern lck_mtx_t *sadb_mutex;
#endif
struct tcpstat tcpstat;
-SYSCTL_STRUCT(_net_inet_tcp, TCPCTL_STATS, stats, CTLFLAG_RD,
- &tcpstat , tcpstat, "TCP statistics (struct tcpstat, netinet/tcp_var.h)");
static int log_in_vain = 0;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_in_vain, CTLFLAG_RW,
SYSCTL_INT(_net_inet_tcp, OID_AUTO, blackhole, CTLFLAG_RW,
&blackhole, 0, "Do not send RST when dropping refused connections");
-int tcp_delack_enabled = 1;
+int tcp_delack_enabled = 3;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, delayed_ack, CTLFLAG_RW,
&tcp_delack_enabled, 0,
"Delay ACK to try and piggyback it onto a data packet");
"Listen Queue Overflow");
#if TCP_DROP_SYNFIN
-static int drop_synfin = 0;
+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");
#endif
+SYSCTL_NODE(_net_inet_tcp, OID_AUTO, reass, CTLFLAG_RW, 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,
+ "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");
+
+
u_long tcp_now;
struct inpcbhead tcb;
#define tcb6 tcb /* for KAME src sync over BSD*'s */
struct inpcbinfo tcbinfo;
-static void tcp_dooptions __P((struct tcpcb *,
- u_char *, int, struct tcphdr *, struct tcpopt *));
-static void tcp_pulloutofband __P((struct socket *,
- struct tcphdr *, struct mbuf *, int));
-static int tcp_reass __P((struct tcpcb *, struct tcphdr *, int *,
- struct mbuf *));
-static void tcp_xmit_timer __P((struct tcpcb *, int));
-static int tcp_newreno __P((struct tcpcb *, struct tcphdr *));
+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);
/* Neighbor Discovery, Neighbor Unreachability Detection Upper layer hint. */
#if INET6
extern u_long *delack_bitmask;
+extern void ipfwsyslog( int level, char *format,...);
+extern int ChkAddressOK( __uint32_t dstaddr, __uint32_t srcaddr );
+extern int fw_verbose;
+
+#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 ; \
+}
+
/*
- * Indicate whether this ack should be delayed. We can delay the ack if
- * - delayed acks are enabled and
- * - there is no delayed ack timer in progress and
+ * 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.
+ * 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 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.
+ *
*/
#define DELAY_ACK(tp) \
- (tcp_delack_enabled && !callout_pending(tp->tt_delack) && \
- (tp->t_flags & TF_RXWIN0SENT) == 0)
+ (((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) && (tp->rcv_byps > (4* tp->t_maxseg))) || (((thflags & TH_PUSH) == 0) && ((tp->t_flags & TF_DELACK) == 0)))))
+
+
+static int tcpdropdropablreq(struct socket *head);
+static void tcp_newreno_partial_ack(struct tcpcb *tp, struct tcphdr *th);
static int
struct tseg_qent *q;
struct tseg_qent *p = NULL;
struct tseg_qent *nq;
- struct tseg_qent *te;
+ struct tseg_qent *te = NULL;
struct socket *so = tp->t_inpcb->inp_socket;
int flags;
+ int dowakeup = 0;
/*
* Call with th==0 after become established to
* force pre-ESTABLISHED data up to user socket.
*/
- if (th == 0)
+ if (th == NULL)
goto present;
+ /*
+ * Limit the number of segments in the reassembly queue to prevent
+ * holding on to too many segments (and thus running out of mbufs).
+ * Make sure to let the missing segment through which caused this
+ * queue. Always keep one global queue entry spare to be able to
+ * process the missing segment.
+ */
+ if (th->th_seq != tp->rcv_nxt &&
+ tcp_reass_qsize + 1 >= tcp_reass_maxseg) {
+ tcp_reass_overflows++;
+ tcpstat.tcps_rcvmemdrop++;
+ m_freem(m);
+ return (0);
+ }
+
/* 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);
m_freem(m);
return (0);
}
+ tcp_reass_qsize++;
/*
* Find a segment which begins after this one does.
tcpstat.tcps_rcvdupbyte += *tlenp;
m_freem(m);
FREE(te, M_TSEGQ);
+ tcp_reass_qsize--;
/*
* Try to present any queued data
* at the left window edge to the user.
LIST_REMOVE(q, tqe_q);
m_freem(q->tqe_m);
FREE(q, M_TSEGQ);
+ tcp_reass_qsize--;
q = nq;
}
LIST_REMOVE(q, tqe_q);
if (so->so_state & SS_CANTRCVMORE)
m_freem(q->tqe_m);
- else
- sbappend(&so->so_rcv, q->tqe_m);
+ else {
+ if (sbappend(&so->so_rcv, q->tqe_m))
+ dowakeup = 1;
+ }
FREE(q, M_TSEGQ);
+ tcp_reass_qsize--;
q = nq;
} while (q && q->tqe_th->th_seq == tp->rcv_nxt);
ND6_HINT(tp);
(((tp->t_inpcb->inp_laddr.s_addr & 0xffff) << 16) |
(tp->t_inpcb->inp_faddr.s_addr & 0xffff)),
0,0,0);
- }
- sorwakeup(so);
+ }
+ if (dowakeup)
+ sorwakeup(so); /* done with socket lock held */
return (flags);
}
*/
#if INET6
int
-tcp6_input(mp, offp, proto)
+tcp6_input(mp, offp)
struct mbuf **mp;
- int *offp, proto;
+ int *offp;
{
register struct mbuf *m = *mp;
struct in6_ifaddr *ia6;
- IP6_EXTHDR_CHECK(m, *offp, sizeof(struct tcphdr), IPPROTO_DONE);
+ IP6_EXTHDR_CHECK(m, *offp, sizeof(struct tcphdr), return IPPROTO_DONE);
/*
* draft-itojun-ipv6-tcp-to-anycast
#endif
int dropsocket = 0;
int iss = 0;
+ int nosock = 0;
u_long 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;
+
+ /* 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 (fwd_tag != NULL) {
+ 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);
+ }
+
#if INET6
struct ip6_hdr *ip6 = NULL;
int isipv6;
tlen = sizeof(*ip6) + ntohs(ip6->ip6_plen) - off0;
if (in6_cksum(m, IPPROTO_TCP, off0, tlen)) {
tcpstat.tcps_rcvbadsum++;
- goto drop;
+ goto dropnosock;
}
th = (struct tcphdr *)((caddr_t)ip6 + off0);
*/
if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) {
/* XXX stat */
- goto drop;
+ goto dropnosock;
}
} else
#endif /* INET6 */
- {
+ {
/*
* Get IP and TCP header together in first mbuf.
* Note: IP leaves IP header in first mbuf.
if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
if (apple_hwcksum_rx && (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 ^= 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];
}
if (th->th_sum) {
tcpstat.tcps_rcvbadsum++;
- goto drop;
+ goto dropnosock;
}
#if INET6
/* Re-initialization for later version check */
ip->ip_v = IPVERSION;
#endif
- }
+ }
/*
* Check that TCP offset makes sense,
off = th->th_off << 2;
if (off < sizeof (struct tcphdr) || off > tlen) {
tcpstat.tcps_rcvbadoff++;
- goto drop;
+ goto dropnosock;
}
tlen -= off; /* tlen is used instead of ti->ti_len */
if (off > sizeof (struct tcphdr)) {
#if INET6
if (isipv6) {
- IP6_EXTHDR_CHECK(m, off0, off, );
+ IP6_EXTHDR_CHECK(m, off0, off, return);
ip6 = mtod(m, struct ip6_hdr *);
th = (struct tcphdr *)((caddr_t)ip6 + off0);
} else
optp[TCPOLEN_TSTAMP_APPA] == TCPOPT_EOL)) &&
*(u_int32_t *)optp == htonl(TCPOPT_TSTAMP_HDR) &&
(th->th_flags & TH_SYN) == 0) {
- to.to_flag |= TOF_TS;
+ to.to_flags |= TOF_TS;
to.to_tsval = ntohl(*(u_int32_t *)(optp + 4));
to.to_tsecr = ntohl(*(u_int32_t *)(optp + 8));
optp = NULL; /* we've parsed the options */
* both the SYN and FIN bits set. This prevents e.g. nmap from
* identifying the TCP/IP stack.
*
- * This is incompatible with RFC1644 extensions (T/TCP).
+ * This is a violation of the TCP specification.
*/
if (drop_synfin && (thflags & (TH_SYN|TH_FIN)) == (TH_SYN|TH_FIN))
- goto drop;
+ goto dropnosock;
#endif
/*
NTOHS(th->th_urp);
/*
- * Delay droping TCP, IP headers, IPv6 ext headers, and TCP options,
+ * Delay dropping TCP, IP headers, IPv6 ext headers, and TCP options,
* until after ip6_savecontrol() is called and before other functions
* which don't want those proto headers.
* Because ip6_savecontrol() is going to parse the mbuf to
*/
findpcb:
#if IPFIREWALL_FORWARD
- if (ip_fw_fwd_addr != NULL
+ if (next_hop != NULL
#if INET6
&& isipv6 == NULL /* IPv6 support is not yet */
#endif /* INET6 */
/*
* No, then it's new. Try find the ambushing socket
*/
- if (!ip_fw_fwd_addr->sin_port) {
+ if (!next_hop->sin_port) {
inp = in_pcblookup_hash(&tcbinfo, ip->ip_src,
- th->th_sport, ip_fw_fwd_addr->sin_addr,
+ th->th_sport, next_hop->sin_addr,
th->th_dport, 1, m->m_pkthdr.rcvif);
} else {
inp = in_pcblookup_hash(&tcbinfo,
ip->ip_src, th->th_sport,
- ip_fw_fwd_addr->sin_addr,
- ntohs(ip_fw_fwd_addr->sin_port), 1,
+ next_hop->sin_addr,
+ ntohs(next_hop->sin_port), 1,
m->m_pkthdr.rcvif);
}
}
- ip_fw_fwd_addr = NULL;
} else
#endif /* IPFIREWALL_FORWARD */
{
}
#if IPSEC
+ if (ipsec_bypass == 0) {
+ lck_mtx_lock(sadb_mutex);
#if INET6
- if (isipv6) {
- if (ipsec_bypass == 0 && inp != NULL && ipsec6_in_reject_so(m, inp->inp_socket)) {
- ipsec6stat.in_polvio++;
- goto drop;
- }
- } else
+ if (isipv6) {
+ if (inp != NULL && ipsec6_in_reject_so(m, inp->inp_socket)) {
+ ipsec6stat.in_polvio++;
+ lck_mtx_unlock(sadb_mutex);
+ goto dropnosock;
+ }
+ } else
#endif /* INET6 */
- if (ipsec_bypass == 0 && inp != NULL && ipsec4_in_reject_so(m, inp->inp_socket)) {
- ipsecstat.in_polvio++;
- goto drop;
+ if (inp != NULL && ipsec4_in_reject_so(m, inp->inp_socket)) {
+ ipsecstat.in_polvio++;
+ lck_mtx_unlock(sadb_mutex);
+ goto dropnosock;
+ }
+ lck_mtx_unlock(sadb_mutex);
}
#endif /*IPSEC*/
if (inp == NULL) {
if (log_in_vain) {
#if INET6
- char dbuf[INET6_ADDRSTRLEN], sbuf[INET6_ADDRSTRLEN];
+ char dbuf[MAX_IPv6_STR_LEN], sbuf[MAX_IPv6_STR_LEN];
#else /* INET6 */
- char dbuf[4*sizeof "123"], sbuf[4*sizeof "123"];
+ char dbuf[MAX_IPv4_STR_LEN], sbuf[MAX_IPv4_STR_LEN];
#endif /* INET6 */
#if INET6
if (isipv6) {
- strcpy(dbuf, ip6_sprintf(&ip6->ip6_dst));
- strcpy(sbuf, ip6_sprintf(&ip6->ip6_src));
+ inet_ntop(AF_INET6, &ip6->ip6_dst, dbuf, sizeof(dbuf));
+ inet_ntop(AF_INET6, &ip6->ip6_src, sbuf, sizeof(sbuf));
} else
#endif
- {
- strcpy(dbuf, inet_ntoa(ip->ip_dst));
- strcpy(sbuf, inet_ntoa(ip->ip_src));
- }
+ {
+ inet_ntop(AF_INET, &ip->ip_dst, dbuf, sizeof(dbuf));
+ inet_ntop(AF_INET, &ip->ip_src, sbuf, sizeof(sbuf));
+ }
switch (log_in_vain) {
case 1:
if(thflags & TH_SYN)
log(LOG_INFO,
- "Connection attempt to TCP %s:%d from %s:%d\n",
- dbuf, ntohs(th->th_dport),
- sbuf,
- ntohs(th->th_sport));
+ "Connection attempt to TCP %s:%d from %s:%d\n",
+ dbuf, ntohs(th->th_dport),
+ sbuf,
+ ntohs(th->th_sport));
break;
case 2:
log(LOG_INFO,
- "Connection attempt to TCP %s:%d from %s:%d flags:0x%x\n",
- dbuf, ntohs(th->th_dport), sbuf,
- ntohs(th->th_sport), thflags);
+ "Connection attempt to TCP %s:%d from %s:%d flags:0x%x\n",
+ dbuf, ntohs(th->th_dport), sbuf,
+ ntohs(th->th_sport), thflags);
+ break;
+ case 3:
+ if ((thflags & TH_SYN) &&
+ !(m->m_flags & (M_BCAST | M_MCAST)) &&
+#if INET6
+ ((isipv6 && !IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &ip6->ip6_src)) ||
+ (!isipv6 && ip->ip_dst.s_addr != ip->ip_src.s_addr))
+#else
+ ip->ip_dst.s_addr != ip->ip_src.s_addr
+#endif
+ )
+ log_in_vain_log((LOG_INFO,
+ "Stealth Mode connection attempt to TCP %s:%d from %s:%d\n",
+ dbuf, ntohs(th->th_dport),
+ sbuf,
+ ntohs(th->th_sport)));
break;
default:
break;
}
}
if (blackhole) {
- switch (blackhole) {
- case 1:
- if (thflags & TH_SYN)
- goto drop;
- break;
- case 2:
- goto drop;
- default:
- goto drop;
- }
+ if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type != IFT_LOOP)
+ switch (blackhole) {
+ case 1:
+ if (thflags & TH_SYN)
+ goto dropnosock;
+ break;
+ case 2:
+ goto dropnosock;
+ default:
+ goto dropnosock;
+ }
}
rstreason = BANDLIM_RST_CLOSEDPORT;
- goto dropwithreset;
+ goto dropwithresetnosock;
}
- tp = intotcpcb(inp);
- if (tp == 0) {
- rstreason = BANDLIM_RST_CLOSEDPORT;
- goto dropwithreset;
+ 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
+#if TEMPDEBUG
+ printf("tcp_input: no more socket for inp=%x\n", inp);
+#endif
+ goto dropnosock;
}
- if (tp->t_state == TCPS_CLOSED)
- goto drop;
#ifdef __APPLE__
/*
* Bogus state when listening port owned by SharedIP with loopback as the
* only configured interface: BlueBox does not filters loopback
*/
- if (tp->t_state == TCP_NSTATES)
+ if (so == &tcbinfo.nat_dummy_socket)
goto drop;
+
#endif
+ tcp_lock(so, 1, 2);
+ if (in_pcb_checkstate(inp, WNT_RELEASE, 1) == WNT_STOPUSING) {
+ tcp_unlock(so, 1, 2);
+ inp = NULL; // pretend we didn't find it
+ goto dropnosock;
+ }
+
+ tp = intotcpcb(inp);
+ if (tp == 0) {
+ rstreason = BANDLIM_RST_CLOSEDPORT;
+ goto dropwithreset;
+ }
+ if (tp->t_state == TCPS_CLOSED)
+ goto drop;
/* Unscale the window into a 32-bit value. */
if ((thflags & TH_SYN) == 0)
else
tiwin = th->th_win;
- so = inp->inp_socket;
if (so->so_options & (SO_DEBUG|SO_ACCEPTCONN)) {
#if TCPDEBUG
if (so->so_options & SO_DEBUG) {
}
#endif
if (so->so_options & SO_ACCEPTCONN) {
- register struct tcpcb *tp0 = tp;
+ register struct tcpcb *tp0 = tp;
struct socket *so2;
-#if IPSEC
struct socket *oso;
-#endif
+ struct sockaddr_storage from;
#if INET6
struct inpcb *oinp = sotoinpcb(so);
#endif /* INET6 */
+ int ogencnt = so->so_gencnt;
#if !IPSEC
/*
}
}
#endif
-
- so2 = sonewconn(so, 0);
+ if (so->so_filt) {
+ 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;
+ sin6->sin6_flowinfo = 0;
+ sin6->sin6_addr = ip6->ip6_src;
+ sin6->sin6_scope_id = 0;
+ } else {
+ struct sockaddr_in *sin = (struct sockaddr_in*)&from;
+
+ sin->sin_len = sizeof(*sin);
+ sin->sin_family = AF_INET;
+ sin->sin_port = th->th_sport;
+ sin->sin_addr = ip->ip_src;
+ }
+ so2 = sonewconn(so, 0, (struct sockaddr*)&from);
+ } else {
+ so2 = sonewconn(so, 0, NULL);
+ }
if (so2 == 0) {
tcpstat.tcps_listendrop++;
- so2 = sodropablereq(so);
- if (so2) {
- if (tcp_lq_overflow)
- sototcpcb(so2)->t_flags |=
- TF_LQ_OVERFLOW;
- tcp_drop(sototcpcb(so2), ETIMEDOUT);
- so2 = sonewconn(so, 0);
+ if (tcpdropdropablreq(so)) {
+ if (so->so_filt)
+ so2 = sonewconn(so, 0, (struct sockaddr*)&from);
+ else
+ so2 = sonewconn(so, 0, NULL);
}
- if (!so2)
+ if (!so2)
goto drop;
}
-#if IPSEC
+ /*
+ * 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;
+
oso = so;
-#endif
+ 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 ....
*
}
#endif /* INET6 */
inp->inp_lport = th->th_dport;
- if (in_pcbinshash(inp) != 0) {
+ if (in_pcbinshash(inp, 0) != 0) {
/*
* Undo the assignments above if we failed to
* put the PCB on the hash lists.
#endif /* INET6 */
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
* 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;
} else
#endif /* INET6 */
inp->inp_options = ip_srcroute();
+ tcp_lock(oso, 0, 0);
#if IPSEC
/* copy old policy into new socket's */
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);
tp->t_state = TCPS_LISTEN;
tp->t_flags |= tp0->t_flags & (TF_NOPUSH|TF_NOOPT|TF_NODELAY);
-
+ tp->t_inpcb->inp_ip_ttl = tp0->t_inpcb->inp_ip_ttl;
/* Compute proper scaling value from buffer space */
while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
TCP_MAXWIN << tp->request_r_scale <
}
}
+#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.
+ *
+ *
+ * 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;
+ /*
+ * 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",
+#ifdef 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;
+ }
+ }
+ } else {
+ tp->rcv_reset = tcp_now + PR_SLOWHZ;
+ tp->rcv_pps = 1;
+ tp->rcv_byps = tlen + off;
+ }
+ }
+
/*
* 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->t_timer[TCPT_KEEP] = TCP_KEEPIDLE(tp);
/*
* Process options if not in LISTEN state,
if (tp->t_state != TCPS_LISTEN && optp)
tcp_dooptions(tp, optp, optlen, th, &to);
+
+ 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;
+ }
+ 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);
+ if (tp->sack_enable) {
+ if (!(to.to_flags & TOF_SACK))
+ tp->sack_enable = 0;
+ else
+ tp->t_flags |= TF_SACK_PERMIT;
+ }
+ }
+
/*
* Header prediction: check for the two common cases
* of a uni-directional data xfer. If the packet has
if (tp->t_state == TCPS_ESTABLISHED &&
(thflags & (TH_SYN|TH_FIN|TH_RST|TH_URG|TH_ACK)) == TH_ACK &&
((tp->t_flags & (TF_NEEDSYN|TF_NEEDFIN)) == 0) &&
- ((to.to_flag & TOF_TS) == 0 ||
+ ((to.to_flags & TOF_TS) == 0 ||
TSTMP_GEQ(to.to_tsval, tp->ts_recent)) &&
- /*
- * Using the CC option is compulsory if once started:
- * the segment is OK if no T/TCP was negotiated or
- * if the segment has a CC option equal to CCrecv
- */
- ((tp->t_flags & (TF_REQ_CC|TF_RCVD_CC)) != (TF_REQ_CC|TF_RCVD_CC) ||
- ((to.to_flag & TOF_CC) != 0 && to.to_cc == tp->cc_recv)) &&
th->th_seq == tp->rcv_nxt &&
tiwin && tiwin == tp->snd_wnd &&
tp->snd_nxt == tp->snd_max) {
* NOTE that the test is modified according to the latest
* proposal of the tcplw@cray.com list (Braden 1993/04/26).
*/
- if ((to.to_flag & TOF_TS) != 0 &&
+ if ((to.to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
tp->ts_recent_age = tcp_now;
tp->ts_recent = to.to_tsval;
if (SEQ_GT(th->th_ack, tp->snd_una) &&
SEQ_LEQ(th->th_ack, tp->snd_max) &&
tp->snd_cwnd >= tp->snd_wnd &&
- tp->t_dupacks < tcprexmtthresh) {
+ ((!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)))) {
/*
* this is a pure ack for outstanding data.
*/
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;
}
- if (((to.to_flag & TOF_TS) != 0) && (to.to_tsecr != 0)) /* Makes sure we already have a TS */
+ if (((to.to_flags & TOF_TS) != 0) && (to.to_tsecr != 0)) /* Makes sure we already have a TS */
tcp_xmit_timer(tp,
tcp_now - to.to_tsecr + 1);
else if (tp->t_rtttime &&
tcpstat.tcps_rcvackpack++;
tcpstat.tcps_rcvackbyte += acked;
sbdrop(&so->so_snd, acked);
+ 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;
+ /*
+ * pull snd_wl2 up to prevent seq wrap relative
+ * to th_ack.
+ */
+ tp->snd_wl2 = th->th_ack;
+ tp->t_dupacks = 0;
m_freem(m);
ND6_HINT(tp); /* some progress has been done */
else if (tp->t_timer[TCPT_PERSIST] == 0)
tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
- if (so->so_snd.sb_cc)
+ sowwakeup(so); /* has to be done with socket lock held */
+ if ((so->so_snd.sb_cc) || (tp->t_flags & TF_ACKNOW))
(void) tcp_output(tp);
- sowwakeup(so);
+ tcp_unlock(so, 1, 0);
KERNEL_DEBUG(DBG_FNC_TCP_INPUT | DBG_FUNC_END,0,0,0,0,0);
return;
}
* with nothing on the reassembly queue and
* we have enough buffer space to take it.
*/
+ /* Clean receiver SACK report if present */
+ if (tp->sack_enable && tp->rcv_numsacks)
+ tcp_clean_sackreport(tp);
++tcpstat.tcps_preddat;
tp->rcv_nxt += tlen;
+ /*
+ * Pull snd_wl1 up to prevent seq wrap relative to
+ * th_seq.
+ */
+ tp->snd_wl1 = th->th_seq;
+ /*
+ * Pull rcv_up up to prevent seq wrap relative to
+ * rcv_nxt.
+ */
+ tp->rcv_up = tp->rcv_nxt;
tcpstat.tcps_rcvpack++;
tcpstat.tcps_rcvbyte += tlen;
ND6_HINT(tp); /* some progress has been done */
* Add data to socket buffer.
*/
m_adj(m, drop_hdrlen); /* delayed header drop */
- sbappend(&so->so_rcv, m);
+ if (sbappend(&so->so_rcv, m))
+ sorwakeup(so);
#if INET6
if (isipv6) {
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);
}
- if (tcp_delack_enabled) {
- TCP_DELACK_BITSET(tp->t_inpcb->hash_element);
+ if (DELAY_ACK(tp)) {
tp->t_flags |= TF_DELACK;
} else {
tp->t_flags |= TF_ACKNOW;
tcp_output(tp);
}
- sorwakeup(so);
+ tcp_unlock(so, 1, 0);
KERNEL_DEBUG(DBG_FNC_TCP_INPUT | DBG_FUNC_END,0,0,0,0,0);
return;
}
* 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;
win = sbspace(&so->so_rcv);
if (win < 0)
win = 0;
+ else { /* clip rcv window to 4K for modems */
+ if (tp->t_flags & TF_SLOWLINK && slowlink_wsize > 0)
+ win = min(win, slowlink_wsize);
+ }
tp->rcv_wnd = imax(win, (int)(tp->rcv_adv - tp->rcv_nxt));
}
register struct sockaddr_in6 *sin6;
#endif
- if (thflags & TH_RST)
+#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;
} else
#endif
{
+#if 1
+ lck_mtx_assert(((struct inpcb *)so->so_pcb)->inpcb_mtx, LCK_MTX_ASSERT_OWNED);
+#endif
MALLOC(sin, struct sockaddr_in *, sizeof *sin, M_SONAME,
M_NOWAIT);
if (sin == NULL)
}
FREE(sin, M_SONAME);
}
- if ((taop = tcp_gettaocache(inp)) == NULL) {
- taop = &tao_noncached;
- bzero(taop, sizeof(*taop));
- }
+
tcp_dooptions(tp, optp, optlen, th, &to);
+
+ 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 {
* initialize CCsend and CCrecv.
*/
tp->snd_wnd = tiwin; /* initial send-window */
- tp->cc_send = CC_INC(tcp_ccgen);
- tp->cc_recv = to.to_cc;
- /*
- * Perform TAO test on incoming CC (SEG.CC) option, if any.
- * - compare SEG.CC against cached CC from the same host,
- * if any.
- * - if SEG.CC > chached value, SYN must be new and is accepted
- * immediately: save new CC in the cache, mark the socket
- * connected, enter ESTABLISHED state, turn on flag to
- * send a SYN in the next segment.
- * A virtual advertised window is set in rcv_adv to
- * initialize SWS prevention. Then enter normal segment
- * processing: drop SYN, process data and FIN.
- * - otherwise do a normal 3-way handshake.
- */
- if ((to.to_flag & TOF_CC) != 0) {
- if (((tp->t_flags & TF_NOPUSH) != 0) &&
- taop->tao_cc != 0 && CC_GT(to.to_cc, taop->tao_cc)) {
-
- taop->tao_cc = to.to_cc;
-
- tp->t_state = TCPS_ESTABLISHED;
-
- /*
- * If there is a FIN, or if there is data and the
- * connection is local, then delay SYN,ACK(SYN) in
- * the hope of piggy-backing it on a response
- * segment. Otherwise must send ACK now in case
- * the other side is slow starting.
- */
- if (tcp_delack_enabled && ((thflags & TH_FIN) ||
- (tlen != 0 &&
-#if INET6
- (isipv6 && in6_localaddr(&inp->in6p_faddr))
- ||
- (!isipv6 &&
-#endif /* INET6 */
- in_localaddr(inp->inp_faddr)
-#if INET6
- )
-#endif /* INET6 */
- ))) {
- TCP_DELACK_BITSET(tp->t_inpcb->hash_element);
- tp->t_flags |= (TF_DELACK | TF_NEEDSYN);
- }
- else
- tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN);
-
- /*
- * Limit the `virtual advertised window' to TCP_MAXWIN
- * here. Even if we requested window scaling, it will
- * become effective only later when our SYN is acked.
- */
- tp->rcv_adv += min(tp->rcv_wnd, TCP_MAXWIN);
- tcpstat.tcps_connects++;
- soisconnected(so);
- tp->t_timer[TCPT_KEEP] = tcp_keepinit;
- dropsocket = 0; /* committed to socket */
- tcpstat.tcps_accepts++;
- goto trimthenstep6;
- }
- /* else do standard 3-way handshake */
- } else {
- /*
- * No CC option, but maybe CC.NEW:
- * invalidate cached value.
- */
- taop->tao_cc = 0;
- }
- /*
- * TAO test failed or there was no CC option,
- * do a standard 3-way handshake.
- */
tp->t_flags |= TF_ACKNOW;
tp->t_state = TCPS_SYN_RECEIVED;
tp->t_timer[TCPT_KEEP] = tcp_keepinit;
* continue processing rest of data/controls, beginning with URG
*/
case TCPS_SYN_SENT:
- if ((taop = tcp_gettaocache(inp)) == NULL) {
- taop = &tao_noncached;
- bzero(taop, sizeof(*taop));
- }
-
if ((thflags & TH_ACK) &&
(SEQ_LEQ(th->th_ack, tp->iss) ||
SEQ_GT(th->th_ack, tp->snd_max))) {
- /*
- * If we have a cached CCsent for the remote host,
- * hence we haven't just crashed and restarted,
- * do not send a RST. This may be a retransmission
- * from the other side after our earlier ACK was lost.
- * Our new SYN, when it arrives, will serve as the
- * needed ACK.
- */
- if (taop->tao_ccsent != 0)
- goto drop;
- else {
- rstreason = BANDLIM_UNLIMITED;
- goto dropwithreset;
- }
+ rstreason = BANDLIM_UNLIMITED;
+ goto dropwithreset;
}
if (thflags & TH_RST) {
if (thflags & TH_ACK) {
if ((thflags & TH_SYN) == 0)
goto drop;
tp->snd_wnd = th->th_win; /* initial send window */
- tp->cc_recv = to.to_cc; /* foreign CC */
tp->irs = th->th_seq;
tcp_rcvseqinit(tp);
if (thflags & TH_ACK) {
- /*
- * Our SYN was acked. If segment contains CC.ECHO
- * option, check it to make sure this segment really
- * matches our SYN. If not, just drop it as old
- * duplicate, but send an RST if we're still playing
- * by the old rules. If no CC.ECHO option, make sure
- * we don't get fooled into using T/TCP.
- */
- if (to.to_flag & TOF_CCECHO) {
- if (tp->cc_send != to.to_ccecho) {
- if (taop->tao_ccsent != 0)
- goto drop;
- else {
- rstreason = BANDLIM_UNLIMITED;
- goto dropwithreset;
- }
- }
- } else
- tp->t_flags &= ~TF_RCVD_CC;
tcpstat.tcps_connects++;
soisconnected(so);
/* Do window scaling on this connection? */
tp->snd_scale = tp->requested_s_scale;
tp->rcv_scale = tp->request_r_scale;
}
- /* Segment is acceptable, update cache if undefined. */
- if (taop->tao_ccsent == 0)
- taop->tao_ccsent = to.to_ccecho;
-
tp->rcv_adv += tp->rcv_wnd;
tp->snd_una++; /* SYN is acked */
/*
* If there's data, delay ACK; if there's also a FIN
* ACKNOW will be turned on later.
*/
- if (tcp_delack_enabled && tlen != 0) {
- TCP_DELACK_BITSET(tp->t_inpcb->hash_element);
+ if (DELAY_ACK(tp) && tlen != 0) {
tp->t_flags |= TF_DELACK;
}
- else
+ else {
tp->t_flags |= TF_ACKNOW;
+ }
/*
* Received <SYN,ACK> in SYN_SENT[*] state.
* Transitions:
* SYN_SENT --> ESTABLISHED
* SYN_SENT* --> FIN_WAIT_1
*/
+ tp->t_starttime = 0;
if (tp->t_flags & TF_NEEDFIN) {
tp->t_state = TCPS_FIN_WAIT_1;
tp->t_flags &= ~TF_NEEDFIN;
thflags &= ~TH_SYN;
} else {
tp->t_state = TCPS_ESTABLISHED;
- tp->t_timer[TCPT_KEEP] = tcp_keepidle;
+ tp->t_timer[TCPT_KEEP] = TCP_KEEPIDLE(tp);
}
} else {
/*
* half-synchronized. Otherwise, do 3-way handshake:
* SYN-SENT -> SYN-RECEIVED
* SYN-SENT* -> SYN-RECEIVED*
- * If there was no CC option, clear cached CC value.
*/
tp->t_flags |= TF_ACKNOW;
tp->t_timer[TCPT_REXMT] = 0;
- if (to.to_flag & TOF_CC) {
- if (taop->tao_cc != 0 &&
- CC_GT(to.to_cc, taop->tao_cc)) {
- /*
- * update cache and make transition:
- * SYN-SENT -> ESTABLISHED*
- * SYN-SENT* -> FIN-WAIT-1*
- */
- taop->tao_cc = to.to_cc;
- if (tp->t_flags & TF_NEEDFIN) {
- tp->t_state = TCPS_FIN_WAIT_1;
- tp->t_flags &= ~TF_NEEDFIN;
- } else {
- tp->t_state = TCPS_ESTABLISHED;
- tp->t_timer[TCPT_KEEP] = tcp_keepidle;
- }
- tp->t_flags |= TF_NEEDSYN;
- } else
- tp->t_state = TCPS_SYN_RECEIVED;
- } else {
- /* CC.NEW or no option => invalidate cache */
- taop->tao_cc = 0;
- tp->t_state = TCPS_SYN_RECEIVED;
- }
+ tp->t_state = TCPS_SYN_RECEIVED;
+
}
trimthenstep6:
goto step6;
/*
* If the state is LAST_ACK or CLOSING or TIME_WAIT:
- * if segment contains a SYN and CC [not CC.NEW] option:
- * if state == TIME_WAIT and connection duration > MSL,
- * drop packet and send RST;
- *
- * if SEG.CC > CCrecv then is new SYN, and can implicitly
- * ack the FIN (and data) in retransmission queue.
- * Complete close and delete TCPCB. Then reprocess
- * segment, hoping to find new TCPCB in LISTEN state;
+ * do normal processing.
*
- * else must be old SYN; drop it.
- * else do normal processing.
+ * NB: Leftover from RFC1644 T/TCP. Cases to be reused later.
*/
case TCPS_LAST_ACK:
case TCPS_CLOSING:
case TCPS_TIME_WAIT:
- if ((thflags & TH_SYN) &&
- (to.to_flag & TOF_CC) && tp->cc_recv != 0) {
- if (tp->t_state == TCPS_TIME_WAIT &&
- tp->t_starttime > tcp_msl) {
- rstreason = BANDLIM_UNLIMITED;
- goto dropwithreset;
- }
- if (CC_GT(to.to_cc, tp->cc_recv)) {
- tp = tcp_close(tp);
- goto findpcb;
- }
- else
- goto drop;
- }
break; /* continue normal processing */
+
+ /* 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
+ */
+ case TCPS_ESTABLISHED:
+ if (thflags & TH_SYN)
+ goto dropafterack;
+ break;
}
/*
* echo of our outgoing acknowlegement numbers, but some hosts
* send a reset with the sequence number at the rightmost edge
* of our receive window, and we have to handle this case.
+ * Note 2: Paul Watson's paper "Slipping in the Window" has shown
+ * that brute force RST attacks are possible. To combat this,
+ * we use a much stricter check while in the ESTABLISHED state,
+ * 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.
* 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.
* SYN_RECEIVED STATE:
* If passive open, return to LISTEN state.
* If active open, inform user that connection was refused.
- * ESTABLISHED, FIN_WAIT_1, FIN_WAIT2, CLOSE_WAIT STATES:
+ * ESTABLISHED, FIN_WAIT_1, FIN_WAIT_2, CLOSE_WAIT STATES:
* Inform user that connection was reset, and close tcb.
* CLOSING, LAST_ACK STATES:
* Close the tcb.
* TIME_WAIT STATE:
* Drop the segment - see Stevens, vol. 2, p. 964 and
* RFC 1337.
+ *
+ * Radar 4776325: 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)) {
+ 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) {
case TCPS_SYN_RECEIVED:
goto close;
case TCPS_ESTABLISHED:
+ if (tp->last_ack_sent != th->th_seq) {
+ goto drop;
+ }
case TCPS_FIN_WAIT_1:
case TCPS_CLOSE_WAIT:
/*
goto drop;
}
+#if 1
+ 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.
*/
- if ((to.to_flag & TOF_TS) != 0 && tp->ts_recent &&
+ if ((to.to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to.to_tsval, tp->ts_recent)) {
/* Check to see if ts_recent is over 24 days old. */
tcpstat.tcps_rcvduppack++;
tcpstat.tcps_rcvdupbyte += tlen;
tcpstat.tcps_pawsdrop++;
- goto dropafterack;
+ if (tlen)
+ goto dropafterack;
+ goto drop;
}
}
- /*
- * T/TCP mechanism
- * If T/TCP was negotiated and the segment doesn't have CC,
- * or if its CC is wrong then drop the segment.
- * RST segments do not have to comply with this.
- */
- if ((tp->t_flags & (TF_REQ_CC|TF_RCVD_CC)) == (TF_REQ_CC|TF_RCVD_CC) &&
- ((to.to_flag & TOF_CC) == 0 || tp->cc_recv != to.to_cc))
- goto dropafterack;
-
/*
* In the SYN-RECEIVED state, validate that the packet belongs to
* this connection before trimming the data to fit the receive
SEQ_GT(th->th_seq, tp->rcv_nxt)) {
iss = tcp_new_isn(tp);
tp = tcp_close(tp);
+ tcp_unlock(so, 1, 0);
goto findpcb;
}
/*
/*
* If last ACK falls within this segment's sequence numbers,
* record its timestamp.
- * NOTE that the test is modified according to the latest
- * proposal of the tcplw@cray.com list (Braden 1993/04/26).
+ * 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
+ * instead of RFC1323's
+ * Last.ACK.Sent < SEG.SEQ + SEG.Len,
+ * This modified check allows us to overcome RFC1323's
+ * limitations as described in Stevens TCP/IP Illustrated
+ * Vol. 2 p.869. In such cases, we can still calculate the
+ * RTT correctly when RCV.NXT == Last.ACK.Sent.
*/
- if ((to.to_flag & TOF_TS) != 0 &&
- SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
+ if ((to.to_flags & TOF_TS) != 0 &&
+ SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
+ SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
+ ((thflags & (TH_SYN|TH_FIN)) != 0))) {
tp->ts_recent_age = tcp_now;
tp->ts_recent = to.to_tsval;
}
tp->snd_scale = tp->requested_s_scale;
tp->rcv_scale = tp->request_r_scale;
}
- /*
- * Upon successful completion of 3-way handshake,
- * update cache.CC if it was undefined, pass any queued
- * data to the user, and advance state appropriately.
- */
- if ((taop = tcp_gettaocache(inp)) != NULL &&
- taop->tao_cc == 0)
- taop->tao_cc = tp->cc_recv;
-
/*
* Make transitions:
* SYN-RECEIVED -> ESTABLISHED
* SYN-RECEIVED* -> FIN-WAIT-1
*/
+ tp->t_starttime = 0;
if (tp->t_flags & TF_NEEDFIN) {
tp->t_state = TCPS_FIN_WAIT_1;
tp->t_flags &= ~TF_NEEDFIN;
} else {
tp->t_state = TCPS_ESTABLISHED;
- tp->t_timer[TCPT_KEEP] = tcp_keepidle;
+ tp->t_timer[TCPT_KEEP] = TCP_KEEPIDLE(tp);
}
/*
* If segment contains data or ACK, will call tcp_reass()
(void) tcp_reass(tp, (struct tcphdr *)0, 0,
(struct mbuf *)0);
tp->snd_wl1 = th->th_seq - 1;
- /* fall into ... */
+ /* FALLTHROUGH */
/*
* In ESTABLISHED state: drop duplicate ACKs; ACK out of range
case TCPS_CLOSING:
case TCPS_LAST_ACK:
case TCPS_TIME_WAIT:
-
+ if (SEQ_GT(th->th_ack, tp->snd_max)) {
+ tcpstat.tcps_rcvacktoomuch++;
+ goto dropafterack;
+ }
+ if (tp->sack_enable &&
+ (to.to_nsacks > 0 || !TAILQ_EMPTY(&tp->snd_holes)))
+ tcp_sack_doack(tp, &to, th->th_ack);
if (SEQ_LEQ(th->th_ack, tp->snd_una)) {
if (tlen == 0 && tiwin == tp->snd_wnd) {
tcpstat.tcps_rcvdupack++;
if (tp->t_timer[TCPT_REXMT] == 0 ||
th->th_ack != tp->snd_una)
tp->t_dupacks = 0;
- else if (++tp->t_dupacks == tcprexmtthresh) {
- tcp_seq onxt = tp->snd_nxt;
- u_int win =
- min(tp->snd_wnd, tp->snd_cwnd) / 2 /
- tp->t_maxseg;
- if (tcp_do_newreno && SEQ_LT(th->th_ack,
- tp->snd_recover)) {
- /* False retransmit, should not
- * cut window
+ else if (++tp->t_dupacks > tcprexmtthresh ||
+ ((tcp_do_newreno || tp->sack_enable) &&
+ IN_FASTRECOVERY(tp))) {
+ if (tp->sack_enable && 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
+ * worth of data in flight.
*/
+ awnd = (tp->snd_nxt - tp->snd_fack) +
+ tp->sackhint.sack_bytes_rexmit;
+ if (awnd < tp->snd_ssthresh) {
+ tp->snd_cwnd += tp->t_maxseg;
+ if (tp->snd_cwnd > tp->snd_ssthresh)
+ tp->snd_cwnd = tp->snd_ssthresh;
+ }
+ } else
tp->snd_cwnd += tp->t_maxseg;
- tp->t_dupacks = 0;
- (void) tcp_output(tp);
- goto drop;
+ (void) tcp_output(tp);
+ goto drop;
+ } else if (tp->t_dupacks == tcprexmtthresh) {
+ tcp_seq onxt = tp->snd_nxt;
+ u_int win;
+
+ /*
+ * If we're doing sack, check to
+ * see if we're already in sack
+ * recovery. If we're not doing sack,
+ * check to see if we're in newreno
+ * recovery.
+ */
+ if (tp->sack_enable) {
+ if (IN_FASTRECOVERY(tp)) {
+ tp->t_dupacks = 0;
+ break;
+ }
+ } else if (tcp_do_newreno) {
+ 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;
+ ENTER_FASTRECOVERY(tp);
tp->snd_recover = tp->snd_max;
tp->t_timer[TCPT_REXMT] = 0;
tp->t_rtttime = 0;
+ if (tp->sack_enable) {
+ tcpstat.tcps_sack_recovery_episode++;
+ tp->sack_newdata = tp->snd_nxt;
+ tp->snd_cwnd = tp->t_maxseg;
+ (void) tcp_output(tp);
+ goto drop;
+ }
tp->snd_nxt = th->th_ack;
tp->snd_cwnd = tp->t_maxseg;
(void) tcp_output(tp);
tp->snd_cwnd = tp->snd_ssthresh +
- tp->t_maxseg * tp->t_dupacks;
+ tp->t_maxseg * tp->t_dupacks;
if (SEQ_GT(onxt, tp->snd_nxt))
tp->snd_nxt = onxt;
goto drop;
- } else if (tp->t_dupacks > tcprexmtthresh) {
- tp->snd_cwnd += tp->t_maxseg;
- (void) tcp_output(tp);
- goto drop;
}
} else
tp->t_dupacks = 0;
* If the congestion window was inflated to account
* for the other side's cached packets, retract it.
*/
- if (tcp_do_newreno == 0) {
- if (tp->t_dupacks >= tcprexmtthresh &&
- tp->snd_cwnd > tp->snd_ssthresh)
- tp->snd_cwnd = tp->snd_ssthresh;
- tp->t_dupacks = 0;
- } else if (tp->t_dupacks >= tcprexmtthresh &&
- !tcp_newreno(tp, th)) {
- /*
- * 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 (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;
- tp->t_dupacks = 0;
- }
-
- if (tp->t_dupacks < tcprexmtthresh)
- tp->t_dupacks = 0;
-
- if (SEQ_GT(th->th_ack, tp->snd_max)) {
- tcpstat.tcps_rcvacktoomuch++;
- goto dropafterack;
+ 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;
+ }
+ }
+ } else {
+ if (tp->t_dupacks >= tcprexmtthresh &&
+ tp->snd_cwnd > tp->snd_ssthresh)
+ tp->snd_cwnd = tp->snd_ssthresh;
}
+ tp->t_dupacks = 0;
/*
- * If we reach this point, ACK is not a duplicate,
+ * If we reach this point, ACK is not a duplicate,
* i.e., it ACKs something we sent.
*/
if (tp->t_flags & TF_NEEDSYN) {
if (tp->t_rxtshift == 1 && tcp_now < tp->t_badrxtwin) {
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 */
}
* Recompute the initial retransmit timer.
* Also makes sure we have a valid time stamp in hand
*/
- if (((to.to_flag & TOF_TS) != 0) && (to.to_tsecr != 0))
+ 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))
tcp_xmit_timer(tp, tp->t_rtttime);
* Otherwise open linearly: maxseg per window
* (maxseg^2 / cwnd per packet).
*/
- {
- register u_int cw = tp->snd_cwnd;
- register u_int incr = tp->t_maxseg;
-
- if (cw > tp->snd_ssthresh)
- incr = incr * incr / cw;
- /*
- * If t_dupacks != 0 here, it indicates that we are still
- * in NewReno fast recovery mode, so we leave the congestion
- * window alone.
- */
- if (tcp_do_newreno == 0 || tp->t_dupacks == 0)
- tp->snd_cwnd = min(cw + incr,TCP_MAXWIN<<tp->snd_scale);
+ if ((!tcp_do_newreno && !tp->sack_enable) ||
+ !IN_FASTRECOVERY(tp)) {
+ register u_int cw = tp->snd_cwnd;
+ register u_int incr = tp->t_maxseg;
+ if (cw > tp->snd_ssthresh)
+ incr = incr * incr / cw;
+ tp->snd_cwnd = min(cw+incr, TCP_MAXWIN<<tp->snd_scale);
}
if (acked > so->so_snd.sb_cc) {
tp->snd_wnd -= so->so_snd.sb_cc;
ourfinisacked = 0;
}
sowwakeup(so);
+ /* detect una wraparound */
+ if ((tcp_do_newreno || tp->sack_enable) &&
+ !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) &&
+ SEQ_GEQ(th->th_ack, tp->snd_recover))
+ EXIT_FASTRECOVERY(tp);
tp->snd_una = th->th_ack;
+ if (tp->sack_enable) {
+ 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;
}
add_to_time_wait(tp);
tp->t_state = TCPS_FIN_WAIT_2;
+ goto drop;
}
break;
*/
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;
m_adj(m, drop_hdrlen); /* delayed header drop */
/*
- * Insert segment which inludes th into reassembly queue of tcp with
- * control block tp. Return TH_FIN if reassembly now includes
- * a segment with FIN. This handle the common case inline (segment
- * is the next to be received on an established connection, and the
- * queue is empty), avoiding linkage into and removal from the queue
- * and repetition of various conversions.
- * Set DELACK for segments received in order, but ack immediately
- * when segments are out of order (so fast retransmit can work).
+ * Insert segment which includes th into TCP reassembly queue
+ * with control block tp. Set thflags to whether reassembly now
+ * includes a segment with FIN. This handles the common case
+ * inline (segment is the next to be received on an established
+ * connection, and the queue is empty), avoiding linkage into
+ * and removal from the queue and repetition of various
+ * conversions.
+ * Set DELACK for segments received in order, but ack
+ * 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)) {
-#ifdef __APPLE__
- if (tcp_delack_enabled) {
- TCP_DELACK_BITSET(tp->t_inpcb->hash_element);
+ if (DELAY_ACK(tp) && ((tp->t_flags & TF_ACKNOW) == 0)) {
tp->t_flags |= TF_DELACK;
}
-#else
- if (DELAY_ACK(tp))
- callout_reset(tp->tt_delack, tcp_delacktime,
- tcp_timer_delack, tp);
-#endif
- else
+ else {
tp->t_flags |= TF_ACKNOW;
+ }
tp->rcv_nxt += tlen;
thflags = th->th_flags & TH_FIN;
tcpstat.tcps_rcvpack++;
tcpstat.tcps_rcvbyte += tlen;
ND6_HINT(tp);
- sbappend(&so->so_rcv, m);
- sorwakeup(so);
+ if (sbappend(&so->so_rcv, m))
+ sorwakeup(so);
} else {
thflags = tcp_reass(tp, th, &tlen, m);
tp->t_flags |= TF_ACKNOW;
}
+ if (tlen > 0 && tp->sack_enable)
+ tcp_update_sack_list(tp, save_start, save_end);
+
if (tp->t_flags & TF_DELACK)
{
#if INET6
/*
* 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 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 (tcp_delack_enabled && (tp->t_flags & TF_NEEDSYN)) {
- TCP_DELACK_BITSET(tp->t_inpcb->hash_element);
+ if (DELAY_ACK(tp) && (tp->t_flags & TF_NEEDSYN)) {
tp->t_flags |= TF_DELACK;
}
- else
+ else {
tp->t_flags |= TF_ACKNOW;
+ }
tp->rcv_nxt++;
}
switch (tp->t_state) {
* enter the CLOSE_WAIT state.
*/
case TCPS_SYN_RECEIVED:
- /*FALLTHROUGH*/
+ tp->t_starttime = 0;
case TCPS_ESTABLISHED:
tp->t_state = TCPS_CLOSE_WAIT;
break;
*/
if (needoutput || (tp->t_flags & TF_ACKNOW))
(void) tcp_output(tp);
+ tcp_unlock(so, 1, 0);
KERNEL_DEBUG(DBG_FNC_TCP_INPUT | DBG_FUNC_END,0,0,0,0,0);
return;
m_freem(m);
tp->t_flags |= TF_ACKNOW;
(void) tcp_output(tp);
+ tcp_unlock(so, 1, 0);
KERNEL_DEBUG(DBG_FNC_TCP_INPUT | DBG_FUNC_END,0,0,0,0,0);
return;
-
+dropwithresetnosock:
+ nosock = 1;
dropwithreset:
/*
* Generate a RST, dropping incoming segment.
(tcp_seq)0, TH_RST|TH_ACK);
}
/* destroy temporarily created socket */
- if (dropsocket)
- (void) soabort(so);
+ if (dropsocket) {
+ (void) soabort(so);
+ tcp_unlock(so, 1, 0);
+ }
+ 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:
+ nosock = 1;
drop:
/*
* Drop space held by incoming segment and return.
#endif
m_freem(m);
/* destroy temporarily created socket */
- if (dropsocket)
- (void) soabort(so);
+ if (dropsocket) {
+ (void) soabort(so);
+ tcp_unlock(so, 1, 0);
+ }
+ 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;
case TCPOPT_TIMESTAMP:
if (optlen != TCPOLEN_TIMESTAMP)
continue;
- to->to_flag |= TOF_TS;
+ to->to_flags |= TOF_TS;
bcopy((char *)cp + 2,
(char *)&to->to_tsval, sizeof(to->to_tsval));
NTOHL(to->to_tsval);
tp->ts_recent_age = tcp_now;
}
break;
- case TCPOPT_CC:
- if (optlen != TCPOLEN_CC)
+ case TCPOPT_SACK_PERMITTED:
+ if (!tcp_do_sack ||
+ optlen != TCPOLEN_SACK_PERMITTED)
continue;
- to->to_flag |= TOF_CC;
- bcopy((char *)cp + 2,
- (char *)&to->to_cc, sizeof(to->to_cc));
- NTOHL(to->to_cc);
- /*
- * A CC or CC.new option received in a SYN makes
- * it ok to send CC in subsequent segments.
- */
if (th->th_flags & TH_SYN)
- tp->t_flags |= TF_RCVD_CC;
- break;
- case TCPOPT_CCNEW:
- if (optlen != TCPOLEN_CC)
- continue;
- if (!(th->th_flags & TH_SYN))
- continue;
- to->to_flag |= TOF_CCNEW;
- bcopy((char *)cp + 2,
- (char *)&to->to_cc, sizeof(to->to_cc));
- NTOHL(to->to_cc);
- /*
- * A CC or CC.new option received in a SYN makes
- * it ok to send CC in subsequent segments.
- */
- tp->t_flags |= TF_RCVD_CC;
+ to->to_flags |= TOF_SACK;
break;
- case TCPOPT_CCECHO:
- if (optlen != TCPOLEN_CC)
- continue;
- if (!(th->th_flags & TH_SYN))
+ case TCPOPT_SACK:
+ if (optlen <= 2 || (optlen - 2) % TCPOLEN_SACK != 0)
continue;
- to->to_flag |= TOF_CCECHO;
- bcopy((char *)cp + 2,
- (char *)&to->to_ccecho, sizeof(to->to_ccecho));
- NTOHL(to->to_ccecho);
+ to->to_nsacks = (optlen - 2) / TCPOLEN_SACK;
+ to->to_sacks = cp + 2;
+ tcpstat.tcps_sack_rcv_blocks++;
+
break;
}
}
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 (ifp->if_type == IFT_PPP && slowlink_wsize > 0 &&
+ ifp->if_baudrate > 9600 && ifp->if_baudrate <= 128000) {
+ tp->t_flags |= TF_SLOWLINK;
+ }
so = inp->inp_socket;
taop = rmx_taop(rt->rt_rmx);
isipv6 ? tcp_v6mssdflt :
#endif /* INET6 */
tcp_mssdflt;
- else
+ else {
+ /*
+ * Prevent DoS attack with too small MSS. Round up
+ * to at least minmss.
+ */
+ offer = max(offer, tcp_minmss);
/*
* Sanity check: make sure that maxopd will be large
* enough to allow some data on segments even is the
* funny things may happen in tcp_output.
*/
offer = max(offer, 64);
+ }
taop->tao_mssopt = offer;
/*
tp->t_maxopd = mss;
/*
- * In case of T/TCP, origoffer==-1 indicates, that no segments
- * were received yet. In this case we just guess, otherwise
- * we do the same as before T/TCP.
+ * origoffer==-1 indicates, that no segments were received yet.
+ * In this case we just guess.
*/
- if ((tp->t_flags & (TF_REQ_TSTMP|TF_NOOPT)) == TF_REQ_TSTMP &&
+ if ((tp->t_flags & (TF_REQ_TSTMP|TF_NOOPT)) == TF_REQ_TSTMP &&
(origoffer == -1 ||
(tp->t_flags & TF_RCVD_TSTMP) == TF_RCVD_TSTMP))
mss -= TCPOLEN_TSTAMP_APPA;
- if ((tp->t_flags & (TF_REQ_CC|TF_NOOPT)) == TF_REQ_CC &&
- (origoffer == -1 ||
- (tp->t_flags & TF_RCVD_CC) == TF_RCVD_CC))
- mss -= TCPOLEN_CC_APPA;
+ tp->t_maxseg = mss;
-#if (MCLBYTES & (MCLBYTES - 1)) == 0
- if (mss > MCLBYTES)
- mss &= ~(MCLBYTES-1);
-#else
- if (mss > MCLBYTES)
- mss = mss / MCLBYTES * MCLBYTES;
-#endif
/*
- * If there's a pipesize, change the socket buffer
- * to that size. Make the socket buffers an integral
+ * If there's a pipesize (ie loopback), change the socket
+ * buffer to that size only if it's bigger than the current
+ * sockbuf size. Make the socket buffers an integral
* number of mss units; if the mss is larger than
* the socket buffer, decrease the mss.
*/
#if RTV_SPIPE
- if ((bufsize = rt->rt_rmx.rmx_sendpipe) == 0)
+ bufsize = rt->rt_rmx.rmx_sendpipe;
+ if (bufsize < so->so_snd.sb_hiwat)
#endif
bufsize = so->so_snd.sb_hiwat;
if (bufsize < mss)
tp->t_maxseg = mss;
#if RTV_RPIPE
- if ((bufsize = rt->rt_rmx.rmx_recvpipe) == 0)
+ bufsize = rt->rt_rmx.rmx_recvpipe;
+ if (bufsize < so->so_rcv.sb_hiwat)
#endif
bufsize = so->so_rcv.sb_hiwat;
if (bufsize > mss) {
struct tcpcb *tp;
{
struct rtentry *rt;
+ int mss;
#if INET6
int isipv6;
int min_protoh;
isipv6 ? tcp_v6mssdflt :
#endif /* INET6 */
tcp_mssdflt;
+ /*
+ * 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 (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;
+ }
- return rt->rt_ifp->if_mtu - min_protoh;
+ 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
+ );
+#endif
+ }
+ return (mss - min_protoh);
}
-
/*
- * Checks for partial ack. If partial ack arrives, force the retransmission
- * of the next unacknowledged segment, do not clear tp->t_dupacks, and return
- * 1. By setting snd_nxt to ti_ack, this forces retransmission timer to
- * be started again. If the ack advances at least to tp->snd_recover, return 0.
+ * 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
+ * be started again.
*/
-static int
-tcp_newreno(tp, th)
+static void
+tcp_newreno_partial_ack(tp, th)
struct tcpcb *tp;
struct tcphdr *th;
{
- if (SEQ_LT(th->th_ack, tp->snd_recover)) {
tcp_seq onxt = tp->snd_nxt;
u_long ocwnd = tp->snd_cwnd;
-#ifdef __APPLE__
tp->t_timer[TCPT_REXMT] = 0;
-#else
- callout_stop(tp->tt_rexmt);
-#endif
tp->t_rtttime = 0;
tp->snd_nxt = th->th_ack;
/*
* is called)
*/
tp->snd_cwnd = tp->t_maxseg + (th->th_ack - tp->snd_una);
+ tp->t_flags |= TF_ACKNOW;
(void) tcp_output(tp);
tp->snd_cwnd = ocwnd;
if (SEQ_GT(onxt, tp->snd_nxt))
* not updated yet.
*/
tp->snd_cwnd -= (th->th_ack - tp->snd_una - tp->t_maxseg);
- return (1);
+}
+
+/*
+ * Drop a random TCP connection that hasn't been serviced yet and
+ * is eligible for discard. There is a one in qlen chance that
+ * we will return a null, saying that there are no dropable
+ * requests. In this case, the protocol specific code should drop
+ * the new request. This insures fairness.
+ *
+ * The listening TCP socket "head" must be locked
+ */
+static int
+tcpdropdropablreq(struct socket *head)
+{
+ struct socket *so;
+ unsigned int i, j, qlen;
+ static int rnd;
+ static struct timeval old_runtime;
+ static unsigned int cur_cnt, old_cnt;
+ struct timeval tv;
+ struct inpcb *inp = NULL;
+ struct tcpcb *tp;
+
+ microtime(&tv);
+ if ((i = (tv.tv_sec - old_runtime.tv_sec)) != 0) {
+ old_runtime = tv;
+ old_cnt = cur_cnt / i;
+ cur_cnt = 0;
+ }
+
+ so = TAILQ_FIRST(&head->so_incomp);
+ if (!so)
+ return 0;
+
+ qlen = head->so_incqlen;
+ if (++cur_cnt > qlen || old_cnt > qlen) {
+ rnd = (314159 * rnd + 66329) & 0xffff;
+ j = ((qlen + 1) * rnd) >> 16;
+
+ while (j-- && so)
+ so = TAILQ_NEXT(so, so_list);
+ }
+ /* Find a connection that is not already closing */
+ while (so) {
+ inp = (struct inpcb *)so->so_pcb;
+
+ if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) != WNT_STOPUSING)
+ break;
+
+ 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);
+
+ if (in_pcb_checkstate(inp, WNT_RELEASE, 1) == WNT_STOPUSING) {
+ tcp_unlock(so, 1, 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);
+ tcpstat.tcps_drops++;
+ soisdisconnected(so);
+ tcp_canceltimers(tp);
+ add_to_time_wait(tp);
+
+ tcp_unlock(so, 1, 0);
+ tcp_lock(head, 0, 0);
+
+ return 1;
+
+}
+
+static int
+tcp_getstat SYSCTL_HANDLER_ARGS
+{
+
+ int error;
+
+ if (req->oldptr == 0) {
+ req->oldlen= (size_t)sizeof(struct tcpstat);
}
- return (0);
+
+ error = SYSCTL_OUT(req, &tcpstat, (size_t) 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)");
+
+
projects / apple / xnu.git / blobdiff