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Introduce a syncache, which enables FreeBSD to withstand a SYN flood

Browse Source 
DoS in an improved fashion over the existing code.

Reviewed by: silby  (in a previous iteration)
Sponsored by: DARPA, NAI Labs
This commit is contained in:
Jonathan Lemon 2001-11-22 04:50:44 +00:00
parent 60a31b3ae1
commit be2ac88c59
13 changed files with 1924 additions and 1080 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
sys/conf/files
View File

@ -1091,6 +1091,7 @@ netinet/tcp_debug.c optional tcpdebug
netinet/tcp_input.c optional inet
netinet/tcp_output.c optional inet
netinet/tcp_subr.c optional inet
netinet/tcp_syncache.c optional inet
netinet/tcp_timer.c optional inet
netinet/tcp_usrreq.c optional inet
netinet/udp_usrreq.c optional inet

2
sys/net/route.h
View File

@ -139,7 +139,7 @@ struct ortentry {
#define RTF_DYNAMIC 0x10 /* created dynamically (by redirect) */
#define RTF_MODIFIED 0x20 /* modified dynamically (by redirect) */
#define RTF_DONE 0x40 /* message confirmed */
#define RTF_DELCLONE 0x80 /* delete cloned route */
/* 0x80 unused, was RTF_DELCLONE */
#define RTF_CLONING 0x100 /* generate new routes on use */
#define RTF_XRESOLVE 0x200 /* external daemon resolves name */
#define RTF_LLINFO 0x400 /* generated by link layer (e.g. ARP) */

19
sys/netinet/in_pcb.c
View File

@ -555,7 +555,6 @@ in_pcbdetach(inp)
{
struct socket *so = inp->inp_socket;
struct inpcbinfo *ipi = inp->inp_pcbinfo;
struct rtentry *rt = inp->inp_route.ro_rt;
#ifdef IPSEC
ipsec4_delete_pcbpolicy(inp);
@ -566,22 +565,8 @@ in_pcbdetach(inp)
sotryfree(so);
if (inp->inp_options)
(void)m_free(inp->inp_options);
if (rt) {
/*
* route deletion requires reference count to be <= zero
*/
if ((rt->rt_flags & RTF_DELCLONE) &&
(rt->rt_flags & RTF_WASCLONED) &&
(rt->rt_refcnt <= 1)) {
rt->rt_refcnt--;
rt->rt_flags &= ~RTF_UP;
rtrequest(RTM_DELETE, rt_key(rt),
rt->rt_gateway, rt_mask(rt),
rt->rt_flags, (struct rtentry **)0);
}
else
rtfree(rt);
}
if (inp->inp_route.ro_rt)
rtfree(inp->inp_route.ro_rt);
ip_freemoptions(inp->inp_moptions);
inp->inp_vflag = 0;
zfree(ipi->ipi_zone, inp);

89
sys/netinet/in_pcb.h
View File

@ -39,7 +39,6 @@
#include <sys/queue.h>
#include <netinet6/ipsec.h> /* for IPSEC */
#define in6pcb inpcb /* for KAME src sync over BSD*'s */
@ -66,6 +65,58 @@ struct in_addr_4in6 {
struct in_addr ia46_addr4;
};
/*
* NOTE: ipv6 addrs should be 64-bit aligned, per RFC 2553.
* in_conninfo has some extra padding to accomplish this.
*/
struct in_endpoints {
u_int16_t ie_fport; /* foreign port */
u_int16_t ie_lport; /* local port */
/* protocol dependent part, local and foreign addr */
union {
/* foreign host table entry */
struct in_addr_4in6 ie46_foreign;
struct in6_addr ie6_foreign;
} ie_dependfaddr;
union {
/* local host table entry */
struct in_addr_4in6 ie46_local;
struct in6_addr ie6_local;
} ie_dependladdr;
#define ie_faddr ie_dependfaddr.ie46_foreign.ia46_addr4
#define ie_laddr ie_dependladdr.ie46_local.ia46_addr4
#define ie6_faddr ie_dependfaddr.ie6_foreign
#define ie6_laddr ie_dependladdr.ie6_local
};
/*
* XXX
* At some point struct route should possibly change to:
* struct rtentry *rt
* struct in_endpoints *ie;
*/
struct in_conninfo {
u_int8_t inc_flags;
u_int8_t inc_len;
u_int16_t inc_pad; /* XXX alignment for in_endpoints */
/* protocol dependent part; cached route */
struct in_endpoints inc_ie;
union {
/* placeholder for routing entry */
struct route inc4_route;
struct route_in6 inc6_route;
} inc_dependroute;
};
#define inc_isipv6 inc_flags /* temp compatability */
#define inc_fport inc_ie.ie_fport
#define inc_lport inc_ie.ie_lport
#define inc_faddr inc_ie.ie_faddr
#define inc_laddr inc_ie.ie_laddr
#define inc_route inc_dependroute.inc4_route
#define inc6_faddr inc_ie.ie6_faddr
#define inc6_laddr inc_ie.ie6_laddr
#define inc6_route inc_dependroute.inc6_route
/*
* NB: the zone allocator is type-stable EXCEPT FOR THE FIRST TWO LONGS
* of the structure. Therefore, it is important that the members in
@ -76,22 +127,11 @@ struct icmp6_filter;
struct inpcb {
LIST_ENTRY(inpcb) inp_hash; /* hash list */
u_short inp_fport; /* foreign port */
u_short inp_lport; /* local port */
LIST_ENTRY(inpcb) inp_list; /* list for all PCBs of this proto */
u_int32_t inp_flow;
/* protocol dependent part, local and foreign addr */
union {
/* foreign host table entry */
struct in_addr_4in6 inp46_foreign;
struct in6_addr inp6_foreign;
} inp_dependfaddr;
union {
/* local host table entry */
struct in_addr_4in6 inp46_local;
struct in6_addr inp6_local;
} inp_dependladdr;
/* local and foreign ports, local and foreign addr */
struct in_conninfo inp_inc;
caddr_t inp_ppcb; /* pointer to per-protocol pcb */
struct inpcbinfo *inp_pcbinfo; /* PCB list info */
@ -99,13 +139,6 @@ struct inpcb {
/* list for this PCB's local port */
int inp_flags; /* generic IP/datagram flags */
/* protocol dependent part; cached route */
union {
/* placeholder for routing entry */
struct route inp4_route;
struct route_in6 inp6_route;
} inp_dependroute;
struct inpcbpolicy *inp_sp; /* for IPSEC */
u_char inp_vflag;
#define INP_IPV4 0x1
@ -119,9 +152,11 @@ struct inpcb {
struct mbuf *inp4_options; /* IP options */
struct ip_moptions *inp4_moptions; /* IP multicast options */
} inp_depend4;
#define inp_faddr inp_dependfaddr.inp46_foreign.ia46_addr4
#define inp_laddr inp_dependladdr.inp46_local.ia46_addr4
#define inp_route inp_dependroute.inp4_route
#define inp_fport inp_inc.inc_fport
#define inp_lport inp_inc.inc_lport
#define inp_faddr inp_inc.inc_faddr
#define inp_laddr inp_inc.inc_laddr
#define inp_route inp_inc.inc_route
#define inp_ip_tos inp_depend4.inp4_ip_tos
#define inp_options inp_depend4.inp4_options
#define inp_moptions inp_depend4.inp4_moptions
@ -143,9 +178,9 @@ struct inpcb {
LIST_ENTRY(inpcb) inp_portlist;
struct inpcbport *inp_phd; /* head of this list */
inp_gen_t inp_gencnt; /* generation count of this instance */
#define in6p_faddr inp_dependfaddr.inp6_foreign
#define in6p_laddr inp_dependladdr.inp6_local
#define in6p_route inp_dependroute.inp6_route
#define in6p_faddr inp_inc.inc6_faddr
#define in6p_laddr inp_inc.inc6_laddr
#define in6p_route inp_inc.inc6_route
#define in6p_ip6_hlim inp_depend6.inp6_hlim
#define in6p_hops inp_depend6.inp6_hops /* default hop limit */
#define in6p_ip6_nxt inp_ip_p

743
sys/netinet/tcp_input.c
View File

@ -120,11 +120,6 @@ 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");
int tcp_lq_overflow = 1;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcp_lq_overflow, CTLFLAG_RW,
&tcp_lq_overflow, 0,
"Listen Queue Overflow");
#ifdef TCP_DROP_SYNFIN
static int drop_synfin = 0;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, drop_synfin, CTLFLAG_RW,
@ -135,10 +130,9 @@ 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_dooptions __P((struct tcpopt *, u_char *, int, int));
static void tcp_pulloutofband __P((struct socket *,
struct tcphdr *, struct mbuf *, int));
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));
@ -344,11 +338,6 @@ tcp_input(m, off0)
register int thflags;
struct socket *so = 0;
int todrop, acked, ourfinisacked, needoutput = 0;
struct in_addr laddr;
#ifdef INET6
struct in6_addr laddr6;
#endif
int dropsocket = 0;
int iss = 0;
u_long tiwin;
struct tcpopt to; /* options in this segment */
@ -643,6 +632,7 @@ tcp_input(m, off0)
so = inp->inp_socket;
if (so->so_options & (SO_DEBUG|SO_ACCEPTCONN)) {
struct in_conninfo inc;
#ifdef TCPDEBUG
if (so->so_options & SO_DEBUG) {
ostate = tp->t_state;
@ -656,212 +646,232 @@ tcp_input(m, off0)
tcp_savetcp = *th;
}
#endif
if (so->so_options & SO_ACCEPTCONN) {
register struct tcpcb *tp0 = tp;
struct socket *so2;
#ifdef IPSEC
struct socket *oso;
#endif
/* skip if this isn't a listen socket */
if ((so->so_options & SO_ACCEPTCONN) == 0)
goto after_listen;
#ifdef INET6
struct inpcb *oinp = sotoinpcb(so);
#endif /* INET6 */
inc.inc_isipv6 = isipv6;
if (isipv6) {
inc.inc6_faddr = ip6->ip6_src;
inc.inc6_laddr = ip6->ip6_dst;
inc.inc6_route.ro_rt = NULL; /* XXX */
#ifndef IPSEC
/*
* Current IPsec implementation makes incorrect IPsec
* cache if this check is done here.
* So delay this until duplicated socket is created.
*/
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_ACK) {
} else
#endif /* INET6 */
{
inc.inc_faddr = ip->ip_src;
inc.inc_laddr = ip->ip_dst;
inc.inc_route.ro_rt = NULL; /* XXX */
}
inc.inc_fport = th->th_sport;
inc.inc_lport = th->th_dport;
/*
* If the state is LISTEN then ignore segment if it contains
* a 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 the state is SYN_RECEIVED (syncache) and seg contains
* an ACK, but not for our SYN/ACK, send a RST. If the seg
* contains a RST, check the sequence number to see if it
* is a valid reset segment.
*/
if ((thflags & (TH_RST|TH_ACK|TH_SYN)) != TH_SYN) {
if ((thflags & (TH_RST|TH_ACK|TH_SYN)) == TH_ACK) {
if (!syncache_expand(&inc, th, &so, m)) {
/*
* No syncache entry, or ACK was not
* for our SYN/ACK. Send a RST.
*/
tcpstat.tcps_badsyn++;
rstreason = BANDLIM_RST_OPENPORT;
goto dropwithreset;
}
if (so == NULL)
/*
* Could not complete 3-way handshake,
* connection is being closed down, and
* syncache will free mbuf.
*/
return;
/*
* Socket is created in state SYN_RECEIVED.
* Continue processing segment.
*/
inp = sotoinpcb(so);
tp = intotcpcb(inp);
/*
* This is what would have happened in
* tcp_ouput() when the SYN,ACK was sent.
*/
tp->snd_up = tp->snd_una;
tp->snd_max = tp->snd_nxt = tp->iss + 1;
tp->last_ack_sent = tp->rcv_nxt;
/*
* XXX possible bug - it doesn't appear that tp->snd_wnd is unscaled
* until the _second_ ACK is received:
* rcv SYN (set wscale opts) --> send SYN/ACK, set snd_wnd = window.
* rcv ACK, calculate tiwin --> process SYN_RECEIVED, determine wscale,
* move to ESTAB, set snd_wnd to tiwin.
*/
tp->snd_wnd = tiwin; /* unscaled */
goto after_listen;
}
if (thflags & TH_RST) {
syncache_chkrst(&inc, th);
goto drop;
}
#endif
if (thflags & TH_ACK) {
syncache_badack(&inc);
tcpstat.tcps_badsyn++;
rstreason = BANDLIM_RST_OPENPORT;
goto dropwithreset;
}
goto drop;
}
/*
* Segment's flags are (SYN) or (SYN|FIN).
*/
#ifdef INET6
/*
* If deprecated address is forbidden,
* we do not accept SYN to deprecated interface
* address to prevent any new inbound connection from
* getting established.
* When we do not accept SYN, we send a TCP RST,
* with deprecated source address (instead of dropping
* it). We compromise it as it is much better for peer
* to send a RST, and RST will be the final packet
* for the exchange.
*
* If we do not forbid deprecated addresses, we accept
* the SYN packet. RFC2462 does not suggest dropping
* SYN in this case.
* If we decipher RFC2462 5.5.4, it says like this:
* 1. use of deprecated addr with existing
* communication is okay - "SHOULD continue to be
* used"
* 2. use of it with new communication:
* (2a) "SHOULD NOT be used if alternate address
* with sufficient scope is available"
* (2b) nothing mentioned otherwise.
* Here we fall into (2b) case as we have no choice in
* our source address selection - we must obey the peer.
*
* The wording in RFC2462 is confusing, and there are
* multiple description text for deprecated address
* handling - worse, they are not exactly the same.
* I believe 5.5.4 is the best one, so we follow 5.5.4.
*/
if (isipv6 && !ip6_use_deprecated) {
struct in6_ifaddr *ia6;
/*
* If deprecated address is forbidden,
* we do not accept SYN to deprecated interface
* address to prevent any new inbound connection from
* getting established.
* When we do not accept SYN, we send a TCP RST,
* with deprecated source address (instead of dropping
* it). We compromise it as it is much better for peer
* to send a RST, and RST will be the final packet
* for the exchange.
*
* If we do not forbid deprecated addresses, we accept
* the SYN packet. RFC2462 does not suggest dropping
* SYN in this case.
* If we decipher RFC2462 5.5.4, it says like this:
* 1. use of deprecated addr with existing
* communication is okay - "SHOULD continue to be
* used"
* 2. use of it with new communication:
* (2a) "SHOULD NOT be used if alternate address
* with sufficient scope is available"
* (2b) nothing mentioned otherwise.
* Here we fall into (2b) case as we have no choice in
* our source address selection - we must obey the peer.
*
* The wording in RFC2462 is confusing, and there are
* multiple description text for deprecated address
* handling - worse, they are not exactly the same.
* I believe 5.5.4 is the best one, so we follow 5.5.4.
*/
if (isipv6 && !ip6_use_deprecated) {
struct in6_ifaddr *ia6;
if ((ia6 = ip6_getdstifaddr(m)) &&
(ia6->ia6_flags & IN6_IFF_DEPRECATED)) {
tp = NULL;
rstreason = BANDLIM_RST_OPENPORT;
goto dropwithreset;
}
}
#endif
so2 = sonewconn(so, 0);
if (so2 == 0) {
/*
* If we were unable to create a new socket
* for this SYN, we call sodropablereq to
* see if there are any other sockets we
* can kick out of the listen queue. If
* so, we'll silently drop the socket
* sodropablereq told us to drop and
* create a new one.
*
* If sodropablereq returns 0, we'll
* simply drop the incoming SYN, as we
* can not allocate a socket for it.
*/
tcpstat.tcps_listendrop++;
so2 = sodropablereq(so);
if (so2) {
if (tcp_lq_overflow)
sototcpcb(so2)->t_flags |=
TF_LQ_OVERFLOW;
tcp_close(sototcpcb(so2));
so2 = sonewconn(so, 0);
}
if (!so2)
goto drop;
}
#ifdef IPSEC
oso = so;
#endif
so = so2;
/*
* This is ugly, but ....
*
* Mark socket as temporary until we're
* committed to keeping it. The code at
* ``drop'' and ``dropwithreset'' check the
* flag dropsocket to see if the temporary
* socket created here should be discarded.
* We mark the socket as discardable until
* we're committed to it below in TCPS_LISTEN.
*/
dropsocket++;
inp = (struct inpcb *)so->so_pcb;
#ifdef INET6
if (isipv6)
inp->in6p_laddr = ip6->ip6_dst;
else {
inp->inp_vflag &= ~INP_IPV6;
inp->inp_vflag |= INP_IPV4;
#endif /* INET6 */
inp->inp_laddr = ip->ip_dst;
#ifdef INET6
}
#endif /* INET6 */
inp->inp_lport = th->th_dport;
if (in_pcbinshash(inp) != 0) {
/*
* Undo the assignments above if we failed to
* put the PCB on the hash lists.
*/
#ifdef INET6
if (isipv6)
inp->in6p_laddr = in6addr_any;
else
#endif /* INET6 */
inp->inp_laddr.s_addr = INADDR_ANY;
inp->inp_lport = 0;
goto drop;
}
#ifdef 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.
*/
if (thflags & TH_ACK) {
tcpstat.tcps_badsyn++;
rstreason = BANDLIM_RST_OPENPORT;
goto dropwithreset;
}
goto drop;
if ((ia6 = ip6_getdstifaddr(m)) &&
(ia6->ia6_flags & IN6_IFF_DEPRECATED)) {
tp = NULL;
rstreason = BANDLIM_RST_OPENPORT;
goto dropwithreset;
}
}
#endif
/*
* If it is from this socket, drop it, it must be forged.
* Don't bother responding if the destination was a broadcast.
*/
if (th->th_dport == th->th_sport) {
#ifdef INET6
if (isipv6) {
/*
* Inherit socket options from the listening
* socket.
* Note that in6p_inputopts are not (even
* should not be) copied, since it stores
* previously received options and is used to
* detect if each new option is different than
* the previous one and hence should be passed
* to a user.
* If we copied in6p_inputopts, a user would
* not be able to receive options just after
* calling the accept system call.
*/
inp->inp_flags |=
oinp->inp_flags & INP_CONTROLOPTS;
if (oinp->in6p_outputopts)
inp->in6p_outputopts =
ip6_copypktopts(oinp->in6p_outputopts,
M_NOWAIT);
if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
&ip6->ip6_src))
goto drop;
} else
#endif /* INET6 */
inp->inp_options = ip_srcroute();
#ifdef IPSEC
/* copy old policy into new socket's */
if (ipsec_copy_policy(sotoinpcb(oso)->inp_sp,
inp->inp_sp))
printf("tcp_input: could not copy policy\n");
#endif
tp = intotcpcb(inp);
tp->t_state = TCPS_LISTEN;
tp->t_flags |= tp0->t_flags & (TF_NOPUSH|TF_NOOPT);
/* 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 (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;
#ifdef 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))
goto drop;
/*
* SYN appears to be valid; create compressed TCP state
* for syncache, or perform t/tcp connection.
*/
if (so->so_qlen <= so->so_qlimit) {
tcp_dooptions(&to, optp, optlen, 1);
if (!syncache_add(&inc, &to, th, &so, m))
goto drop;
if (so == NULL)
/*
* Entry added to syncache, mbuf used to
* send SYN,ACK packet.
*/
return;
/*
* Segment passed TAO tests.
*/
inp = sotoinpcb(so);
tp = intotcpcb(inp);
tp->snd_wnd = tiwin;
tp->t_starttime = ticks;
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 (DELAY_ACK(tp) && ((thflags & TH_FIN) ||
(tlen != 0 &&
#ifdef INET6
((isipv6 && in6_localaddr(&inp->in6p_faddr))
||
(!isipv6 &&
#endif
in_localaddr(inp->inp_faddr)
#ifdef INET6
))
#endif
))) {
callout_reset(tp->tt_delack, tcp_delacktime,
tcp_timer_delack, tp);
tp->t_flags |= TF_NEEDSYN;
} else
tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN);
tcpstat.tcps_connects++;
soisconnected(so);
goto trimthenstep6;
}
goto drop;
}
after_listen:
/* XXX temp debugging */
/* should not happen - syncache should pick up these connections */
if (tp->t_state == TCPS_LISTEN)
panic("tcp_input: TCPS_LISTEN");
/*
* Segment received on connection.
@ -872,11 +882,25 @@ tcp_input(m, off0)
callout_reset(tp->tt_keep, tcp_keepidle, tcp_timer_keep, tp);
/*
* Process options if not in LISTEN state,
* else do it below (after getting remote address).
* Process options.
* XXX this is tradtitional behavior, may need to be cleaned up.
*/
if (tp->t_state != TCPS_LISTEN)
tcp_dooptions(tp, optp, optlen, th, &to);
tcp_dooptions(&to, optp, optlen, thflags & TH_SYN);
if (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 = ticks;
}
if (to.to_flags & (TOF_CC|TOF_CCNEW))
tp->t_flags |= TF_RCVD_CC;
if (to.to_flags & TOF_MSS)
tcp_mss(tp, to.to_mss);
}
/*
* Header prediction: check for the two common cases
@ -898,7 +922,7 @@ tcp_input(m, off0)
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:
@ -906,7 +930,7 @@ tcp_input(m, off0)
* 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)) &&
((to.to_flags & 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) {
@ -917,7 +941,7 @@ tcp_input(m, off0)
* 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 = ticks;
tp->ts_recent = to.to_tsval;
@ -943,7 +967,7 @@ tcp_input(m, off0)
tp->snd_nxt = tp->snd_max;
tp->t_badrxtwin = 0;
}
if ((to.to_flag & TOF_TS) != 0)
if ((to.to_flags & TOF_TS) != 0)
tcp_xmit_timer(tp,
ticks - to.to_tsecr + 1);
else if (tp->t_rtttime &&
@ -1024,209 +1048,6 @@ tcp_input(m, off0)
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
* 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.
* Fill in remote peer address fields if not previously specified.
* Enter SYN_RECEIVED state, and process any other fields of this
* segment in this state.
*/
case TCPS_LISTEN: {
register struct sockaddr_in *sin;
#ifdef INET6
register struct sockaddr_in6 *sin6;
#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) {
#ifdef 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;
#ifdef 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))
goto drop;
#ifdef INET6
if (isipv6) {
MALLOC(sin6, struct sockaddr_in6 *, sizeof *sin6,
M_SONAME, M_NOWAIT | M_ZERO);
if (sin6 == NULL)
goto drop;
sin6->sin6_family = AF_INET6;
sin6->sin6_len = sizeof(*sin6);
sin6->sin6_addr = ip6->ip6_src;
sin6->sin6_port = th->th_sport;
laddr6 = inp->in6p_laddr;
if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
inp->in6p_laddr = ip6->ip6_dst;
if (in6_pcbconnect(inp, (struct sockaddr *)sin6,
thread0)) {
inp->in6p_laddr = laddr6;
FREE(sin6, M_SONAME);
goto drop;
}
FREE(sin6, M_SONAME);
} else
#endif
{
MALLOC(sin, struct sockaddr_in *, sizeof *sin, M_SONAME,
M_NOWAIT);
if (sin == NULL)
goto drop;
sin->sin_family = AF_INET;
sin->sin_len = sizeof(*sin);
sin->sin_addr = ip->ip_src;
sin->sin_port = th->th_sport;
bzero((caddr_t)sin->sin_zero, sizeof(sin->sin_zero));
laddr = inp->inp_laddr;
if (inp->inp_laddr.s_addr == INADDR_ANY)
inp->inp_laddr = ip->ip_dst;
if (in_pcbconnect(inp, (struct sockaddr *)sin, thread0)) {
inp->inp_laddr = laddr;
FREE(sin, M_SONAME);
goto drop;
}
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 (iss)
tp->iss = iss;
else {
tp->iss = tcp_new_isn(tp);
}
tp->irs = th->th_seq;
tcp_sendseqinit(tp);
tcp_rcvseqinit(tp);
/*
* Initialization of the tcpcb for transaction;
* set SND.WND = SEG.WND,
* 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_starttime = ticks;
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 (DELAY_ACK(tp) && ((thflags & TH_FIN) ||
(tlen != 0 &&
#ifdef INET6
((isipv6 && in6_localaddr(&inp->in6p_faddr))
||
(!isipv6 &&
#endif
in_localaddr(inp->inp_faddr)
#ifdef INET6
))
#endif
))) {
callout_reset(tp->tt_delack, tcp_delacktime,
tcp_timer_delack, tp);
tp->t_flags |= 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);
callout_reset(tp->tt_keep, tcp_keepinit,
tcp_timer_keep, tp);
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;
callout_reset(tp->tt_keep, tcp_keepinit, tcp_timer_keep, tp);
dropsocket = 0; /* committed to socket */
tcpstat.tcps_accepts++;
goto trimthenstep6;
}
/*
* If the state is SYN_RECEIVED:
* if seg contains an ACK, but not for our SYN/ACK, send a RST.
@ -1253,7 +1074,7 @@ tcp_input(m, off0)
* continue processing rest of data/controls, beginning with URG
*/
case TCPS_SYN_SENT:
if ((taop = tcp_gettaocache(inp)) == NULL) {
if ((taop = tcp_gettaocache(&inp->inp_inc)) == NULL) {
taop = &tao_noncached;
bzero(taop, sizeof(*taop));
}
@ -1297,7 +1118,7 @@ tcp_input(m, off0)
* 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 (to.to_flags & TOF_CCECHO) {
if (tp->cc_send != to.to_ccecho) {
if (taop->tao_ccsent != 0)
goto drop;
@ -1359,7 +1180,7 @@ tcp_input(m, off0)
*/
tp->t_flags |= TF_ACKNOW;
callout_stop(tp->tt_rexmt);
if (to.to_flag & TOF_CC) {
if (to.to_flags & TOF_CC) {
if (taop->tao_cc != 0 &&
CC_GT(to.to_cc, taop->tao_cc)) {
/*
@ -1434,7 +1255,7 @@ tcp_input(m, off0)
case TCPS_CLOSING:
case TCPS_TIME_WAIT:
if ((thflags & TH_SYN) &&
(to.to_flag & TOF_CC) && tp->cc_recv != 0) {
(to.to_flags & TOF_CC) && tp->cc_recv != 0) {
if (tp->t_state == TCPS_TIME_WAIT &&
(ticks - tp->t_starttime) > tcp_msl) {
rstreason = BANDLIM_UNLIMITED;
@ -1542,7 +1363,7 @@ tcp_input(m, off0)
* 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. */
@ -1574,7 +1395,7 @@ tcp_input(m, off0)
* 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))
((to.to_flags & TOF_CC) == 0 || tp->cc_recv != to.to_cc))
goto dropafterack;
/*
@ -1694,7 +1515,7 @@ tcp_input(m, off0)
* 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 = ticks;
tp->ts_recent = to.to_tsval;
@ -1748,7 +1569,7 @@ tcp_input(m, off0)
* update cache.CC if it was undefined, pass any queued
* data to the user, and advance state appropriately.
*/
if ((taop = tcp_gettaocache(inp)) != NULL &&
if ((taop = tcp_gettaocache(&inp->inp_inc)) != NULL &&
taop->tao_cc == 0)
taop->tao_cc = tp->cc_recv;
@ -1940,7 +1761,7 @@ tcp_input(m, off0)
* timer backoff (cf., Phil Karn's retransmit alg.).
* Recompute the initial retransmit timer.
*/
if (to.to_flag & TOF_TS)
if (to.to_flags & TOF_TS)
tcp_xmit_timer(tp, ticks - to.to_tsecr + 1);
else if (tp->t_rtttime && SEQ_GT(th->th_ack, tp->t_rtseq))
tcp_xmit_timer(tp, ticks - tp->t_rtttime);
@ -2371,9 +2192,6 @@ tcp_input(m, off0)
tcp_respond(tp, mtod(m, void *), th, m, th->th_seq+tlen,
(tcp_seq)0, TH_RST|TH_ACK);
}
/* destroy temporarily created socket */
if (dropsocket)
(void) soabort(so);
return;
drop:
@ -2386,23 +2204,21 @@ tcp_input(m, off0)
&tcp_savetcp, 0);
#endif
m_freem(m);
/* destroy temporarily created socket */
if (dropsocket)
(void) soabort(so);
return;
}
/*
* Parse TCP options and place in tcpopt.
*/
static void
tcp_dooptions(tp, cp, cnt, th, to)
struct tcpcb *tp;
tcp_dooptions(to, cp, cnt, is_syn)
struct tcpopt *to;
u_char *cp;
int cnt;
struct tcphdr *th;
struct tcpopt *to;
{
u_short mss = 0;
int opt, optlen;
to->to_flags = 0;
for (; cnt > 0; cnt -= optlen, cp += optlen) {
opt = cp[0];
if (opt == TCPOPT_EOL)
@ -2417,92 +2233,67 @@ tcp_dooptions(tp, cp, cnt, th, to)
break;
}
switch (opt) {
default:
continue;
case TCPOPT_MAXSEG:
if (optlen != TCPOLEN_MAXSEG)
continue;
if (!(th->th_flags & TH_SYN))
if (!is_syn)
continue;
bcopy((char *) cp + 2, (char *) &mss, sizeof(mss));
NTOHS(mss);
to->to_flags |= TOF_MSS;
bcopy((char *)cp + 2,
(char *)&to->to_mss, sizeof(to->to_mss));
NTOHS(to->to_mss);
break;
case TCPOPT_WINDOW:
if (optlen != TCPOLEN_WINDOW)
continue;
if (!(th->th_flags & TH_SYN))
if (! is_syn)
continue;
tp->t_flags |= TF_RCVD_SCALE;
tp->requested_s_scale = min(cp[2], TCP_MAX_WINSHIFT);
to->to_flags |= TOF_SCALE;
to->to_requested_s_scale = min(cp[2], TCP_MAX_WINSHIFT);
break;
case TCPOPT_TIMESTAMP:
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);
bcopy((char *)cp + 6,
(char *)&to->to_tsecr, sizeof(to->to_tsecr));
NTOHL(to->to_tsecr);
/*
* A timestamp received in a SYN makes
* it ok to send timestamp requests and replies.
*/
if (th->th_flags & TH_SYN) {
tp->t_flags |= TF_RCVD_TSTMP;
tp->ts_recent = to->to_tsval;
tp->ts_recent_age = ticks;
}
break;
case TCPOPT_CC:
if (optlen != TCPOLEN_CC)
continue;
to->to_flag |= TOF_CC;
to->to_flags |= 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))
if (!is_syn)
continue;
to->to_flag |= TOF_CCNEW;
to->to_flags |= 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;
break;
case TCPOPT_CCECHO:
if (optlen != TCPOLEN_CC)
continue;
if (!(th->th_flags & TH_SYN))
if (!is_syn)
continue;
to->to_flag |= TOF_CCECHO;
to->to_flags |= TOF_CCECHO;
bcopy((char *)cp + 2,
(char *)&to->to_ccecho, sizeof(to->to_ccecho));
NTOHL(to->to_ccecho);
break;
default:
continue;
}
}
if (th->th_flags & TH_SYN)
tcp_mss(tp, mss); /* sets t_maxseg */
}
/*
@ -2675,10 +2466,10 @@ tcp_mss(tp, offer)
#endif
#ifdef INET6
if (isipv6)
rt = tcp_rtlookup6(inp);
rt = tcp_rtlookup6(&inp->inp_inc);
else
#endif
rt = tcp_rtlookup(inp);
rt = tcp_rtlookup(&inp->inp_inc);
if (rt == NULL) {
tp->t_maxopd = tp->t_maxseg =
#ifdef INET6
@ -2884,10 +2675,10 @@ tcp_mssopt(tp)
#endif
#ifdef INET6
if (isipv6)
rt = tcp_rtlookup6(tp->t_inpcb);
rt = tcp_rtlookup6(&tp->t_inpcb->inp_inc);
else
#endif /* INET6 */
rt = tcp_rtlookup(tp->t_inpcb);
rt = tcp_rtlookup(&tp->t_inpcb->inp_inc);
if (rt == NULL)
return
#ifdef INET6

2
sys/netinet/tcp_output.c
View File

@ -216,7 +216,7 @@ tcp_output(tp)
len = (long)ulmin(so->so_snd.sb_cc, win) - off;
if ((taop = tcp_gettaocache(tp->t_inpcb)) == NULL) {
if ((taop = tcp_gettaocache(&tp->t_inpcb->inp_inc)) == NULL) {
taop = &tao_noncached;
bzero(taop, sizeof(*taop));
}

743
sys/netinet/tcp_reass.c
View File

@ -120,11 +120,6 @@ 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");
int tcp_lq_overflow = 1;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcp_lq_overflow, CTLFLAG_RW,
&tcp_lq_overflow, 0,
"Listen Queue Overflow");
#ifdef TCP_DROP_SYNFIN
static int drop_synfin = 0;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, drop_synfin, CTLFLAG_RW,
@ -135,10 +130,9 @@ 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_dooptions __P((struct tcpopt *, u_char *, int, int));
static void tcp_pulloutofband __P((struct socket *,
struct tcphdr *, struct mbuf *, int));
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));
@ -344,11 +338,6 @@ tcp_input(m, off0)
register int thflags;
struct socket *so = 0;
int todrop, acked, ourfinisacked, needoutput = 0;
struct in_addr laddr;
#ifdef INET6
struct in6_addr laddr6;
#endif
int dropsocket = 0;
int iss = 0;
u_long tiwin;
struct tcpopt to; /* options in this segment */
@ -643,6 +632,7 @@ tcp_input(m, off0)
so = inp->inp_socket;
if (so->so_options & (SO_DEBUG|SO_ACCEPTCONN)) {
struct in_conninfo inc;
#ifdef TCPDEBUG
if (so->so_options & SO_DEBUG) {
ostate = tp->t_state;
@ -656,212 +646,232 @@ tcp_input(m, off0)
tcp_savetcp = *th;
}
#endif
if (so->so_options & SO_ACCEPTCONN) {
register struct tcpcb *tp0 = tp;
struct socket *so2;
#ifdef IPSEC
struct socket *oso;
#endif
/* skip if this isn't a listen socket */
if ((so->so_options & SO_ACCEPTCONN) == 0)
goto after_listen;
#ifdef INET6
struct inpcb *oinp = sotoinpcb(so);
#endif /* INET6 */
inc.inc_isipv6 = isipv6;
if (isipv6) {
inc.inc6_faddr = ip6->ip6_src;
inc.inc6_laddr = ip6->ip6_dst;
inc.inc6_route.ro_rt = NULL; /* XXX */
#ifndef IPSEC
/*
* Current IPsec implementation makes incorrect IPsec
* cache if this check is done here.
* So delay this until duplicated socket is created.
*/
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_ACK) {
} else
#endif /* INET6 */
{
inc.inc_faddr = ip->ip_src;
inc.inc_laddr = ip->ip_dst;
inc.inc_route.ro_rt = NULL; /* XXX */
}
inc.inc_fport = th->th_sport;
inc.inc_lport = th->th_dport;
/*
* If the state is LISTEN then ignore segment if it contains
* a 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 the state is SYN_RECEIVED (syncache) and seg contains
* an ACK, but not for our SYN/ACK, send a RST. If the seg
* contains a RST, check the sequence number to see if it
* is a valid reset segment.
*/
if ((thflags & (TH_RST|TH_ACK|TH_SYN)) != TH_SYN) {
if ((thflags & (TH_RST|TH_ACK|TH_SYN)) == TH_ACK) {
if (!syncache_expand(&inc, th, &so, m)) {
/*
* No syncache entry, or ACK was not
* for our SYN/ACK. Send a RST.
*/
tcpstat.tcps_badsyn++;
rstreason = BANDLIM_RST_OPENPORT;
goto dropwithreset;
}
if (so == NULL)
/*
* Could not complete 3-way handshake,
* connection is being closed down, and
* syncache will free mbuf.
*/
return;
/*
* Socket is created in state SYN_RECEIVED.
* Continue processing segment.
*/
inp = sotoinpcb(so);
tp = intotcpcb(inp);
/*
* This is what would have happened in
* tcp_ouput() when the SYN,ACK was sent.
*/
tp->snd_up = tp->snd_una;
tp->snd_max = tp->snd_nxt = tp->iss + 1;
tp->last_ack_sent = tp->rcv_nxt;
/*
* XXX possible bug - it doesn't appear that tp->snd_wnd is unscaled
* until the _second_ ACK is received:
* rcv SYN (set wscale opts) --> send SYN/ACK, set snd_wnd = window.
* rcv ACK, calculate tiwin --> process SYN_RECEIVED, determine wscale,
* move to ESTAB, set snd_wnd to tiwin.
*/
tp->snd_wnd = tiwin; /* unscaled */
goto after_listen;
}
if (thflags & TH_RST) {
syncache_chkrst(&inc, th);
goto drop;
}
#endif
if (thflags & TH_ACK) {
syncache_badack(&inc);
tcpstat.tcps_badsyn++;
rstreason = BANDLIM_RST_OPENPORT;
goto dropwithreset;
}
goto drop;
}
/*
* Segment's flags are (SYN) or (SYN|FIN).
*/
#ifdef INET6
/*
* If deprecated address is forbidden,
* we do not accept SYN to deprecated interface
* address to prevent any new inbound connection from
* getting established.
* When we do not accept SYN, we send a TCP RST,
* with deprecated source address (instead of dropping
* it). We compromise it as it is much better for peer
* to send a RST, and RST will be the final packet
* for the exchange.
*
* If we do not forbid deprecated addresses, we accept
* the SYN packet. RFC2462 does not suggest dropping
* SYN in this case.
* If we decipher RFC2462 5.5.4, it says like this:
* 1. use of deprecated addr with existing
* communication is okay - "SHOULD continue to be
* used"
* 2. use of it with new communication:
* (2a) "SHOULD NOT be used if alternate address
* with sufficient scope is available"
* (2b) nothing mentioned otherwise.
* Here we fall into (2b) case as we have no choice in
* our source address selection - we must obey the peer.
*
* The wording in RFC2462 is confusing, and there are
* multiple description text for deprecated address
* handling - worse, they are not exactly the same.
* I believe 5.5.4 is the best one, so we follow 5.5.4.
*/
if (isipv6 && !ip6_use_deprecated) {
struct in6_ifaddr *ia6;
/*
* If deprecated address is forbidden,
* we do not accept SYN to deprecated interface
* address to prevent any new inbound connection from
* getting established.
* When we do not accept SYN, we send a TCP RST,
* with deprecated source address (instead of dropping
* it). We compromise it as it is much better for peer
* to send a RST, and RST will be the final packet
* for the exchange.
*
* If we do not forbid deprecated addresses, we accept
* the SYN packet. RFC2462 does not suggest dropping
* SYN in this case.
* If we decipher RFC2462 5.5.4, it says like this:
* 1. use of deprecated addr with existing
* communication is okay - "SHOULD continue to be
* used"
* 2. use of it with new communication:
* (2a) "SHOULD NOT be used if alternate address
* with sufficient scope is available"
* (2b) nothing mentioned otherwise.
* Here we fall into (2b) case as we have no choice in
* our source address selection - we must obey the peer.
*
* The wording in RFC2462 is confusing, and there are
* multiple description text for deprecated address
* handling - worse, they are not exactly the same.
* I believe 5.5.4 is the best one, so we follow 5.5.4.
*/
if (isipv6 && !ip6_use_deprecated) {
struct in6_ifaddr *ia6;
if ((ia6 = ip6_getdstifaddr(m)) &&
(ia6->ia6_flags & IN6_IFF_DEPRECATED)) {
tp = NULL;
rstreason = BANDLIM_RST_OPENPORT;
goto dropwithreset;
}
}
#endif
so2 = sonewconn(so, 0);
if (so2 == 0) {
/*
* If we were unable to create a new socket
* for this SYN, we call sodropablereq to
* see if there are any other sockets we
* can kick out of the listen queue. If
* so, we'll silently drop the socket
* sodropablereq told us to drop and
* create a new one.
*
* If sodropablereq returns 0, we'll
* simply drop the incoming SYN, as we
* can not allocate a socket for it.
*/
tcpstat.tcps_listendrop++;
so2 = sodropablereq(so);
if (so2) {
if (tcp_lq_overflow)
sototcpcb(so2)->t_flags |=
TF_LQ_OVERFLOW;
tcp_close(sototcpcb(so2));
so2 = sonewconn(so, 0);
}
if (!so2)
goto drop;
}
#ifdef IPSEC
oso = so;
#endif
so = so2;
/*
* This is ugly, but ....
*
* Mark socket as temporary until we're
* committed to keeping it. The code at
* ``drop'' and ``dropwithreset'' check the
* flag dropsocket to see if the temporary
* socket created here should be discarded.
* We mark the socket as discardable until
* we're committed to it below in TCPS_LISTEN.
*/
dropsocket++;
inp = (struct inpcb *)so->so_pcb;
#ifdef INET6
if (isipv6)
inp->in6p_laddr = ip6->ip6_dst;
else {
inp->inp_vflag &= ~INP_IPV6;
inp->inp_vflag |= INP_IPV4;
#endif /* INET6 */
inp->inp_laddr = ip->ip_dst;
#ifdef INET6
}
#endif /* INET6 */
inp->inp_lport = th->th_dport;
if (in_pcbinshash(inp) != 0) {
/*
* Undo the assignments above if we failed to
* put the PCB on the hash lists.
*/
#ifdef INET6
if (isipv6)
inp->in6p_laddr = in6addr_any;
else
#endif /* INET6 */
inp->inp_laddr.s_addr = INADDR_ANY;
inp->inp_lport = 0;
goto drop;
}
#ifdef 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.
*/
if (thflags & TH_ACK) {
tcpstat.tcps_badsyn++;
rstreason = BANDLIM_RST_OPENPORT;
goto dropwithreset;
}
goto drop;
if ((ia6 = ip6_getdstifaddr(m)) &&
(ia6->ia6_flags & IN6_IFF_DEPRECATED)) {
tp = NULL;
rstreason = BANDLIM_RST_OPENPORT;
goto dropwithreset;
}
}
#endif
/*
* If it is from this socket, drop it, it must be forged.
* Don't bother responding if the destination was a broadcast.
*/
if (th->th_dport == th->th_sport) {
#ifdef INET6
if (isipv6) {
/*
* Inherit socket options from the listening
* socket.
* Note that in6p_inputopts are not (even
* should not be) copied, since it stores
* previously received options and is used to
* detect if each new option is different than
* the previous one and hence should be passed
* to a user.
* If we copied in6p_inputopts, a user would
* not be able to receive options just after
* calling the accept system call.
*/
inp->inp_flags |=
oinp->inp_flags & INP_CONTROLOPTS;
if (oinp->in6p_outputopts)
inp->in6p_outputopts =
ip6_copypktopts(oinp->in6p_outputopts,
M_NOWAIT);
if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
&ip6->ip6_src))
goto drop;
} else
#endif /* INET6 */
inp->inp_options = ip_srcroute();
#ifdef IPSEC
/* copy old policy into new socket's */
if (ipsec_copy_policy(sotoinpcb(oso)->inp_sp,
inp->inp_sp))
printf("tcp_input: could not copy policy\n");
#endif
tp = intotcpcb(inp);
tp->t_state = TCPS_LISTEN;
tp->t_flags |= tp0->t_flags & (TF_NOPUSH|TF_NOOPT);
/* 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 (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;
#ifdef 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))
goto drop;
/*
* SYN appears to be valid; create compressed TCP state
* for syncache, or perform t/tcp connection.
*/
if (so->so_qlen <= so->so_qlimit) {
tcp_dooptions(&to, optp, optlen, 1);
if (!syncache_add(&inc, &to, th, &so, m))
goto drop;
if (so == NULL)
/*
* Entry added to syncache, mbuf used to
* send SYN,ACK packet.
*/
return;
/*
* Segment passed TAO tests.
*/
inp = sotoinpcb(so);
tp = intotcpcb(inp);
tp->snd_wnd = tiwin;
tp->t_starttime = ticks;
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 (DELAY_ACK(tp) && ((thflags & TH_FIN) ||
(tlen != 0 &&
#ifdef INET6
((isipv6 && in6_localaddr(&inp->in6p_faddr))
||
(!isipv6 &&
#endif
in_localaddr(inp->inp_faddr)
#ifdef INET6
))
#endif
))) {
callout_reset(tp->tt_delack, tcp_delacktime,
tcp_timer_delack, tp);
tp->t_flags |= TF_NEEDSYN;
} else
tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN);
tcpstat.tcps_connects++;
soisconnected(so);
goto trimthenstep6;
}
goto drop;
}
after_listen:
/* XXX temp debugging */
/* should not happen - syncache should pick up these connections */
if (tp->t_state == TCPS_LISTEN)
panic("tcp_input: TCPS_LISTEN");
/*
* Segment received on connection.
@ -872,11 +882,25 @@ tcp_input(m, off0)
callout_reset(tp->tt_keep, tcp_keepidle, tcp_timer_keep, tp);
/*
* Process options if not in LISTEN state,
* else do it below (after getting remote address).
* Process options.
* XXX this is tradtitional behavior, may need to be cleaned up.
*/
if (tp->t_state != TCPS_LISTEN)
tcp_dooptions(tp, optp, optlen, th, &to);
tcp_dooptions(&to, optp, optlen, thflags & TH_SYN);
if (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 = ticks;
}
if (to.to_flags & (TOF_CC|TOF_CCNEW))
tp->t_flags |= TF_RCVD_CC;
if (to.to_flags & TOF_MSS)
tcp_mss(tp, to.to_mss);
}
/*
* Header prediction: check for the two common cases
@ -898,7 +922,7 @@ tcp_input(m, off0)
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:
@ -906,7 +930,7 @@ tcp_input(m, off0)
* 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)) &&
((to.to_flags & 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) {
@ -917,7 +941,7 @@ tcp_input(m, off0)
* 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 = ticks;
tp->ts_recent = to.to_tsval;
@ -943,7 +967,7 @@ tcp_input(m, off0)
tp->snd_nxt = tp->snd_max;
tp->t_badrxtwin = 0;
}
if ((to.to_flag & TOF_TS) != 0)
if ((to.to_flags & TOF_TS) != 0)
tcp_xmit_timer(tp,
ticks - to.to_tsecr + 1);
else if (tp->t_rtttime &&
@ -1024,209 +1048,6 @@ tcp_input(m, off0)
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
* 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.
* Fill in remote peer address fields if not previously specified.
* Enter SYN_RECEIVED state, and process any other fields of this
* segment in this state.
*/
case TCPS_LISTEN: {
register struct sockaddr_in *sin;
#ifdef INET6
register struct sockaddr_in6 *sin6;
#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) {
#ifdef 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;
#ifdef 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))
goto drop;
#ifdef INET6
if (isipv6) {
MALLOC(sin6, struct sockaddr_in6 *, sizeof *sin6,
M_SONAME, M_NOWAIT | M_ZERO);
if (sin6 == NULL)
goto drop;
sin6->sin6_family = AF_INET6;
sin6->sin6_len = sizeof(*sin6);
sin6->sin6_addr = ip6->ip6_src;
sin6->sin6_port = th->th_sport;
laddr6 = inp->in6p_laddr;
if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
inp->in6p_laddr = ip6->ip6_dst;
if (in6_pcbconnect(inp, (struct sockaddr *)sin6,
thread0)) {
inp->in6p_laddr = laddr6;
FREE(sin6, M_SONAME);
goto drop;
}
FREE(sin6, M_SONAME);
} else
#endif
{
MALLOC(sin, struct sockaddr_in *, sizeof *sin, M_SONAME,
M_NOWAIT);
if (sin == NULL)
goto drop;
sin->sin_family = AF_INET;
sin->sin_len = sizeof(*sin);
sin->sin_addr = ip->ip_src;
sin->sin_port = th->th_sport;
bzero((caddr_t)sin->sin_zero, sizeof(sin->sin_zero));
laddr = inp->inp_laddr;
if (inp->inp_laddr.s_addr == INADDR_ANY)
inp->inp_laddr = ip->ip_dst;
if (in_pcbconnect(inp, (struct sockaddr *)sin, thread0)) {
inp->inp_laddr = laddr;
FREE(sin, M_SONAME);
goto drop;
}
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 (iss)
tp->iss = iss;
else {
tp->iss = tcp_new_isn(tp);
}
tp->irs = th->th_seq;
tcp_sendseqinit(tp);
tcp_rcvseqinit(tp);
/*
* Initialization of the tcpcb for transaction;
* set SND.WND = SEG.WND,
* 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_starttime = ticks;
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 (DELAY_ACK(tp) && ((thflags & TH_FIN) ||
(tlen != 0 &&
#ifdef INET6
((isipv6 && in6_localaddr(&inp->in6p_faddr))
||
(!isipv6 &&
#endif
in_localaddr(inp->inp_faddr)
#ifdef INET6
))
#endif
))) {
callout_reset(tp->tt_delack, tcp_delacktime,
tcp_timer_delack, tp);
tp->t_flags |= 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);
callout_reset(tp->tt_keep, tcp_keepinit,
tcp_timer_keep, tp);
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;
callout_reset(tp->tt_keep, tcp_keepinit, tcp_timer_keep, tp);
dropsocket = 0; /* committed to socket */
tcpstat.tcps_accepts++;
goto trimthenstep6;
}
/*
* If the state is SYN_RECEIVED:
* if seg contains an ACK, but not for our SYN/ACK, send a RST.
@ -1253,7 +1074,7 @@ tcp_input(m, off0)
* continue processing rest of data/controls, beginning with URG
*/
case TCPS_SYN_SENT:
if ((taop = tcp_gettaocache(inp)) == NULL) {
if ((taop = tcp_gettaocache(&inp->inp_inc)) == NULL) {
taop = &tao_noncached;
bzero(taop, sizeof(*taop));
}
@ -1297,7 +1118,7 @@ tcp_input(m, off0)
* 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 (to.to_flags & TOF_CCECHO) {
if (tp->cc_send != to.to_ccecho) {
if (taop->tao_ccsent != 0)
goto drop;
@ -1359,7 +1180,7 @@ tcp_input(m, off0)
*/
tp->t_flags |= TF_ACKNOW;
callout_stop(tp->tt_rexmt);
if (to.to_flag & TOF_CC) {
if (to.to_flags & TOF_CC) {
if (taop->tao_cc != 0 &&
CC_GT(to.to_cc, taop->tao_cc)) {
/*
@ -1434,7 +1255,7 @@ tcp_input(m, off0)
case TCPS_CLOSING:
case TCPS_TIME_WAIT:
if ((thflags & TH_SYN) &&
(to.to_flag & TOF_CC) && tp->cc_recv != 0) {
(to.to_flags & TOF_CC) && tp->cc_recv != 0) {
if (tp->t_state == TCPS_TIME_WAIT &&
(ticks - tp->t_starttime) > tcp_msl) {
rstreason = BANDLIM_UNLIMITED;
@ -1542,7 +1363,7 @@ tcp_input(m, off0)
* 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. */
@ -1574,7 +1395,7 @@ tcp_input(m, off0)
* 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))
((to.to_flags & TOF_CC) == 0 || tp->cc_recv != to.to_cc))
goto dropafterack;
/*
@ -1694,7 +1515,7 @@ tcp_input(m, off0)
* 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 = ticks;
tp->ts_recent = to.to_tsval;
@ -1748,7 +1569,7 @@ tcp_input(m, off0)
* update cache.CC if it was undefined, pass any queued
* data to the user, and advance state appropriately.
*/
if ((taop = tcp_gettaocache(inp)) != NULL &&
if ((taop = tcp_gettaocache(&inp->inp_inc)) != NULL &&
taop->tao_cc == 0)
taop->tao_cc = tp->cc_recv;
@ -1940,7 +1761,7 @@ tcp_input(m, off0)
* timer backoff (cf., Phil Karn's retransmit alg.).
* Recompute the initial retransmit timer.
*/
if (to.to_flag & TOF_TS)
if (to.to_flags & TOF_TS)
tcp_xmit_timer(tp, ticks - to.to_tsecr + 1);
else if (tp->t_rtttime && SEQ_GT(th->th_ack, tp->t_rtseq))
tcp_xmit_timer(tp, ticks - tp->t_rtttime);
@ -2371,9 +2192,6 @@ tcp_input(m, off0)
tcp_respond(tp, mtod(m, void *), th, m, th->th_seq+tlen,
(tcp_seq)0, TH_RST|TH_ACK);
}
/* destroy temporarily created socket */
if (dropsocket)
(void) soabort(so);
return;
drop:
@ -2386,23 +2204,21 @@ tcp_input(m, off0)
&tcp_savetcp, 0);
#endif
m_freem(m);
/* destroy temporarily created socket */
if (dropsocket)
(void) soabort(so);
return;
}
/*
* Parse TCP options and place in tcpopt.
*/
static void
tcp_dooptions(tp, cp, cnt, th, to)
struct tcpcb *tp;
tcp_dooptions(to, cp, cnt, is_syn)
struct tcpopt *to;
u_char *cp;
int cnt;
struct tcphdr *th;
struct tcpopt *to;
{
u_short mss = 0;
int opt, optlen;
to->to_flags = 0;
for (; cnt > 0; cnt -= optlen, cp += optlen) {
opt = cp[0];
if (opt == TCPOPT_EOL)
@ -2417,92 +2233,67 @@ tcp_dooptions(tp, cp, cnt, th, to)
break;
}
switch (opt) {
default:
continue;
case TCPOPT_MAXSEG:
if (optlen != TCPOLEN_MAXSEG)
continue;
if (!(th->th_flags & TH_SYN))
if (!is_syn)
continue;
bcopy((char *) cp + 2, (char *) &mss, sizeof(mss));
NTOHS(mss);
to->to_flags |= TOF_MSS;
bcopy((char *)cp + 2,
(char *)&to->to_mss, sizeof(to->to_mss));
NTOHS(to->to_mss);
break;
case TCPOPT_WINDOW:
if (optlen != TCPOLEN_WINDOW)
continue;
if (!(th->th_flags & TH_SYN))
if (! is_syn)
continue;
tp->t_flags |= TF_RCVD_SCALE;
tp->requested_s_scale = min(cp[2], TCP_MAX_WINSHIFT);
to->to_flags |= TOF_SCALE;
to->to_requested_s_scale = min(cp[2], TCP_MAX_WINSHIFT);
break;
case TCPOPT_TIMESTAMP:
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);
bcopy((char *)cp + 6,
(char *)&to->to_tsecr, sizeof(to->to_tsecr));
NTOHL(to->to_tsecr);
/*
* A timestamp received in a SYN makes
* it ok to send timestamp requests and replies.
*/
if (th->th_flags & TH_SYN) {
tp->t_flags |= TF_RCVD_TSTMP;
tp->ts_recent = to->to_tsval;
tp->ts_recent_age = ticks;
}
break;
case TCPOPT_CC:
if (optlen != TCPOLEN_CC)
continue;
to->to_flag |= TOF_CC;
to->to_flags |= 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))
if (!is_syn)
continue;
to->to_flag |= TOF_CCNEW;
to->to_flags |= 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;
break;
case TCPOPT_CCECHO:
if (optlen != TCPOLEN_CC)
continue;
if (!(th->th_flags & TH_SYN))
if (!is_syn)
continue;
to->to_flag |= TOF_CCECHO;
to->to_flags |= TOF_CCECHO;
bcopy((char *)cp + 2,
(char *)&to->to_ccecho, sizeof(to->to_ccecho));
NTOHL(to->to_ccecho);
break;
default:
continue;
}
}
if (th->th_flags & TH_SYN)
tcp_mss(tp, mss); /* sets t_maxseg */
}
/*
@ -2675,10 +2466,10 @@ tcp_mss(tp, offer)
#endif
#ifdef INET6
if (isipv6)
rt = tcp_rtlookup6(inp);
rt = tcp_rtlookup6(&inp->inp_inc);
else
#endif
rt = tcp_rtlookup(inp);
rt = tcp_rtlookup(&inp->inp_inc);
if (rt == NULL) {
tp->t_maxopd = tp->t_maxseg =
#ifdef INET6
@ -2884,10 +2675,10 @@ tcp_mssopt(tp)
#endif
#ifdef INET6
if (isipv6)
rt = tcp_rtlookup6(tp->t_inpcb);
rt = tcp_rtlookup6(&tp->t_inpcb->inp_inc);
else
#endif /* INET6 */
rt = tcp_rtlookup(tp->t_inpcb);
rt = tcp_rtlookup(&tp->t_inpcb->inp_inc);
if (rt == NULL)
return
#ifdef INET6

78
sys/netinet/tcp_subr.c
View File

@ -117,11 +117,11 @@ SYSCTL_INT(_net_inet_tcp, TCPCTL_RTTDFLT, rttdflt, CTLFLAG_RW,
&tcp_rttdflt , 0, "Default maximum TCP Round Trip Time");
#endif
static int tcp_do_rfc1323 = 1;
int tcp_do_rfc1323 = 1;
SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW,
&tcp_do_rfc1323 , 0, "Enable rfc1323 (high performance TCP) extensions");
static int tcp_do_rfc1644 = 0;
int tcp_do_rfc1644 = 0;
SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1644, rfc1644, CTLFLAG_RW,
&tcp_do_rfc1644 , 0, "Enable rfc1644 (TTCP) extensions");
@ -224,6 +224,8 @@ tcp_init()
if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
panic("tcp_init");
#undef TCP_MINPROTOHDR
syncache_init();
}
/*
@ -710,18 +712,6 @@ tcp_close(tp)
tcpstat.tcps_cachedssthresh++;
}
}
rt = inp->inp_route.ro_rt;
if (rt) {
/*
* mark route for deletion if no information is
* cached.
*/
if ((tp->t_flags & TF_LQ_OVERFLOW) &&
((rt->rt_rmx.rmx_locks & RTV_RTT) == 0)){
if (rt->rt_rmx.rmx_rtt == 0)
rt->rt_flags |= RTF_DELCLONE;
}
}
no_valid_rt:
/* free the reassembly queue, if any */
while((q = LIST_FIRST(&tp->t_segq)) != NULL) {
@ -1047,6 +1037,17 @@ tcp_ctlinput(cmd, sa, vip)
if (SEQ_GEQ(icmp_seq, tp->snd_una) &&
SEQ_LT(icmp_seq, tp->snd_max))
(*notify)(inp, inetctlerrmap[cmd]);
} else {
struct in_conninfo inc;
inc.inc_fport = th->th_dport;
inc.inc_lport = th->th_sport;
inc.inc_faddr = faddr;
inc.inc_laddr = ip->ip_src;
#ifdef INET6
inc.inc_isipv6 = 0;
#endif
syncache_unreach(&inc, th);
}
splx(s);
} else
@ -1099,6 +1100,7 @@ tcp6_ctlinput(cmd, sa, d)
}
if (ip6) {
struct in_conninfo inc;
/*
* XXX: We assume that when IPV6 is non NULL,
* M and OFF are valid.
@ -1114,6 +1116,13 @@ tcp6_ctlinput(cmd, sa, d)
in6_pcbnotify(&tcb, sa, th.th_dport,
(struct sockaddr *)ip6cp->ip6c_src,
th.th_sport, cmd, notify);
inc.inc_fport = th.th_dport;
inc.inc_lport = th.th_sport;
inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
inc.inc_isipv6 = 1;
syncache_unreach(&inc, &th);
} else
in6_pcbnotify(&tcb, sa, 0, (struct sockaddr *)sa6_src,
0, cmd, notify);
@ -1271,10 +1280,10 @@ tcp_mtudisc(inp, errno)
if (tp) {
#ifdef INET6
if (isipv6)
rt = tcp_rtlookup6(inp);
rt = tcp_rtlookup6(&inp->inp_inc);
else
#endif /* INET6 */
rt = tcp_rtlookup(inp);
rt = tcp_rtlookup(&inp->inp_inc);
if (!rt || !rt->rt_rmx.rmx_mtu) {
tp->t_maxopd = tp->t_maxseg =
#ifdef INET6
@ -1351,21 +1360,21 @@ tcp_mtudisc(inp, errno)
* to get the interface MTU.
*/
struct rtentry *
tcp_rtlookup(inp)
struct inpcb *inp;
tcp_rtlookup(inc)
struct in_conninfo *inc;
{
struct route *ro;
struct rtentry *rt;
ro = &inp->inp_route;
ro = &inc->inc_route;
rt = ro->ro_rt;
if (rt == NULL || !(rt->rt_flags & RTF_UP)) {
/* No route yet, so try to acquire one */
if (inp->inp_faddr.s_addr != INADDR_ANY) {
if (inc->inc_faddr.s_addr != INADDR_ANY) {
ro->ro_dst.sa_family = AF_INET;
ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
((struct sockaddr_in *) &ro->ro_dst)->sin_addr =
inp->inp_faddr;
inc->inc_faddr;
rtalloc(ro);
rt = ro->ro_rt;
}
@ -1375,23 +1384,20 @@ tcp_rtlookup(inp)
#ifdef INET6
struct rtentry *
tcp_rtlookup6(inp)
struct inpcb *inp;
tcp_rtlookup6(inc)
struct in_conninfo *inc;
{
struct route_in6 *ro6;
struct rtentry *rt;
ro6 = &inp->in6p_route;
ro6 = &inc->inc6_route;
rt = ro6->ro_rt;
if (rt == NULL || !(rt->rt_flags & RTF_UP)) {
/* No route yet, so try to acquire one */
if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
struct sockaddr_in6 *dst6;
dst6 = (struct sockaddr_in6 *)&ro6->ro_dst;
dst6->sin6_family = AF_INET6;
dst6->sin6_len = sizeof(*dst6);
dst6->sin6_addr = inp->in6p_faddr;
if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
ro6->ro_dst.sin6_family = AF_INET6;
ro6->ro_dst.sin6_len = sizeof(struct sockaddr_in6);
ro6->ro_dst.sin6_addr = inc->inc6_faddr;
rtalloc((struct route *)ro6);
rt = ro6->ro_rt;
}
@ -1450,17 +1456,17 @@ ipsec_hdrsiz_tcp(tp)
* the route metrics.
*/
struct rmxp_tao *
tcp_gettaocache(inp)
struct inpcb *inp;
tcp_gettaocache(inc)
struct in_conninfo *inc;
{
struct rtentry *rt;
#ifdef INET6
if ((inp->inp_vflag & INP_IPV6) != 0)
rt = tcp_rtlookup6(inp);
if (inc->inc_isipv6)
rt = tcp_rtlookup6(inc);
else
#endif /* INET6 */
rt = tcp_rtlookup(inp);
rt = tcp_rtlookup(inc);
/* Make sure this is a host route and is up. */
if (rt == NULL ||

1161
sys/netinet/tcp_syncache.c Normal file
View File

File diff suppressed because it is too large Load Diff

78
sys/netinet/tcp_timewait.c
View File

@ -117,11 +117,11 @@ SYSCTL_INT(_net_inet_tcp, TCPCTL_RTTDFLT, rttdflt, CTLFLAG_RW,
&tcp_rttdflt , 0, "Default maximum TCP Round Trip Time");
#endif
static int tcp_do_rfc1323 = 1;
int tcp_do_rfc1323 = 1;
SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW,
&tcp_do_rfc1323 , 0, "Enable rfc1323 (high performance TCP) extensions");
static int tcp_do_rfc1644 = 0;
int tcp_do_rfc1644 = 0;
SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1644, rfc1644, CTLFLAG_RW,
&tcp_do_rfc1644 , 0, "Enable rfc1644 (TTCP) extensions");
@ -224,6 +224,8 @@ tcp_init()
if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
panic("tcp_init");
#undef TCP_MINPROTOHDR
syncache_init();
}
/*
@ -710,18 +712,6 @@ tcp_close(tp)
tcpstat.tcps_cachedssthresh++;
}
}
rt = inp->inp_route.ro_rt;
if (rt) {
/*
* mark route for deletion if no information is
* cached.
*/
if ((tp->t_flags & TF_LQ_OVERFLOW) &&
((rt->rt_rmx.rmx_locks & RTV_RTT) == 0)){
if (rt->rt_rmx.rmx_rtt == 0)
rt->rt_flags |= RTF_DELCLONE;
}
}
no_valid_rt:
/* free the reassembly queue, if any */
while((q = LIST_FIRST(&tp->t_segq)) != NULL) {
@ -1047,6 +1037,17 @@ tcp_ctlinput(cmd, sa, vip)
if (SEQ_GEQ(icmp_seq, tp->snd_una) &&
SEQ_LT(icmp_seq, tp->snd_max))
(*notify)(inp, inetctlerrmap[cmd]);
} else {
struct in_conninfo inc;
inc.inc_fport = th->th_dport;
inc.inc_lport = th->th_sport;
inc.inc_faddr = faddr;
inc.inc_laddr = ip->ip_src;
#ifdef INET6
inc.inc_isipv6 = 0;
#endif
syncache_unreach(&inc, th);
}
splx(s);
} else
@ -1099,6 +1100,7 @@ tcp6_ctlinput(cmd, sa, d)
}
if (ip6) {
struct in_conninfo inc;
/*
* XXX: We assume that when IPV6 is non NULL,
* M and OFF are valid.
@ -1114,6 +1116,13 @@ tcp6_ctlinput(cmd, sa, d)
in6_pcbnotify(&tcb, sa, th.th_dport,
(struct sockaddr *)ip6cp->ip6c_src,
th.th_sport, cmd, notify);
inc.inc_fport = th.th_dport;
inc.inc_lport = th.th_sport;
inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
inc.inc_isipv6 = 1;
syncache_unreach(&inc, &th);
} else
in6_pcbnotify(&tcb, sa, 0, (struct sockaddr *)sa6_src,
0, cmd, notify);
@ -1271,10 +1280,10 @@ tcp_mtudisc(inp, errno)
if (tp) {
#ifdef INET6
if (isipv6)
rt = tcp_rtlookup6(inp);
rt = tcp_rtlookup6(&inp->inp_inc);
else
#endif /* INET6 */
rt = tcp_rtlookup(inp);
rt = tcp_rtlookup(&inp->inp_inc);
if (!rt || !rt->rt_rmx.rmx_mtu) {
tp->t_maxopd = tp->t_maxseg =
#ifdef INET6
@ -1351,21 +1360,21 @@ tcp_mtudisc(inp, errno)
* to get the interface MTU.
*/
struct rtentry *
tcp_rtlookup(inp)
struct inpcb *inp;
tcp_rtlookup(inc)
struct in_conninfo *inc;
{
struct route *ro;
struct rtentry *rt;
ro = &inp->inp_route;
ro = &inc->inc_route;
rt = ro->ro_rt;
if (rt == NULL || !(rt->rt_flags & RTF_UP)) {
/* No route yet, so try to acquire one */
if (inp->inp_faddr.s_addr != INADDR_ANY) {
if (inc->inc_faddr.s_addr != INADDR_ANY) {
ro->ro_dst.sa_family = AF_INET;
ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
((struct sockaddr_in *) &ro->ro_dst)->sin_addr =
inp->inp_faddr;
inc->inc_faddr;
rtalloc(ro);
rt = ro->ro_rt;
}
@ -1375,23 +1384,20 @@ tcp_rtlookup(inp)
#ifdef INET6
struct rtentry *
tcp_rtlookup6(inp)
struct inpcb *inp;
tcp_rtlookup6(inc)
struct in_conninfo *inc;
{
struct route_in6 *ro6;
struct rtentry *rt;
ro6 = &inp->in6p_route;
ro6 = &inc->inc6_route;
rt = ro6->ro_rt;
if (rt == NULL || !(rt->rt_flags & RTF_UP)) {
/* No route yet, so try to acquire one */
if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
struct sockaddr_in6 *dst6;
dst6 = (struct sockaddr_in6 *)&ro6->ro_dst;
dst6->sin6_family = AF_INET6;
dst6->sin6_len = sizeof(*dst6);
dst6->sin6_addr = inp->in6p_faddr;
if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
ro6->ro_dst.sin6_family = AF_INET6;
ro6->ro_dst.sin6_len = sizeof(struct sockaddr_in6);
ro6->ro_dst.sin6_addr = inc->inc6_faddr;
rtalloc((struct route *)ro6);
rt = ro6->ro_rt;
}
@ -1450,17 +1456,17 @@ ipsec_hdrsiz_tcp(tp)
* the route metrics.
*/
struct rmxp_tao *
tcp_gettaocache(inp)
struct inpcb *inp;
tcp_gettaocache(inc)
struct in_conninfo *inc;
{
struct rtentry *rt;
#ifdef INET6
if ((inp->inp_vflag & INP_IPV6) != 0)
rt = tcp_rtlookup6(inp);
if (inc->inc_isipv6)
rt = tcp_rtlookup6(inc);
else
#endif /* INET6 */
rt = tcp_rtlookup(inp);
rt = tcp_rtlookup(inc);
/* Make sure this is a host route and is up. */
if (rt == NULL ||

4
sys/netinet/tcp_usrreq.c
View File

@ -765,7 +765,7 @@ tcp_connect(tp, nam, td)
* Generate a CC value for this connection and
* check whether CC or CCnew should be used.
*/
if ((taop = tcp_gettaocache(tp->t_inpcb)) == NULL) {
if ((taop = tcp_gettaocache(&tp->t_inpcb->inp_inc)) == NULL) {
taop = &tao_noncached;
bzero(taop, sizeof(*taop));
}
@ -851,7 +851,7 @@ tcp6_connect(tp, nam, td)
* Generate a CC value for this connection and
* check whether CC or CCnew should be used.
*/
if ((taop = tcp_gettaocache(tp->t_inpcb)) == NULL) {
if ((taop = tcp_gettaocache(&tp->t_inpcb->inp_inc)) == NULL) {
taop = &tao_noncached;
bzero(taop, sizeof(*taop));
}

82
sys/netinet/tcp_var.h
View File

@ -36,9 +36,14 @@
#ifndef _NETINET_TCP_VAR_H_
#define _NETINET_TCP_VAR_H_
#include <netinet/in_pcb.h> /* needed for in_conninfo, inp_gen_t */
/*
* Kernel variables for tcp.
*/
extern int tcp_do_rfc1323;
extern int tcp_do_rfc1644;
/* TCP segment queue entry */
struct tseg_qent {
@ -171,17 +176,56 @@ struct tcpcb {
* to tcp_dooptions.
*/
struct tcpopt {
u_long to_flag; /* which options are present */
u_long to_flags; /* which options are present */
#define TOF_TS 0x0001 /* timestamp */
#define TOF_CC 0x0002 /* CC and CCnew are exclusive */
#define TOF_CCNEW 0x0004
#define TOF_CCECHO 0x0008
u_long to_tsval;
u_long to_tsecr;
tcp_cc to_cc; /* holds CC or CCnew */
tcp_cc to_ccecho;
#define TOF_MSS 0x0010
#define TOF_SCALE 0x0020
u_int32_t to_tsval;
u_int32_t to_tsecr;
tcp_cc to_cc; /* holds CC or CCnew */
tcp_cc to_ccecho;
u_int16_t to_mss;
u_int8_t to_requested_s_scale;
u_int8_t to_pad;
};
struct syncache {
inp_gen_t sc_inp_gencnt; /* pointer check */
struct tcpcb *sc_tp; /* tcb for listening socket */
struct mbuf *sc_ipopts; /* source route */
struct in_conninfo sc_inc; /* addresses */
#define sc_route sc_inc.inc_route
#define sc_route6 sc_inc.inc6_route
u_int32_t sc_tsrecent;
tcp_cc sc_cc_send; /* holds CC or CCnew */
tcp_cc sc_cc_recv;
tcp_seq sc_irs; /* seq from peer */
tcp_seq sc_iss; /* our ISS */
u_long sc_rxttime; /* retransmit time */
u_int16_t sc_rxtslot; /* retransmit counter */
u_int16_t sc_peer_mss; /* peer's MSS */
u_int16_t sc_wnd; /* advertised window */
u_int8_t sc_requested_s_scale:4,
sc_request_r_scale:4;
u_int8_t sc_flags;
#define SCF_NOOPT 0x01 /* no TCP options */
#define SCF_WINSCALE 0x02 /* negotiated window scaling */
#define SCF_TIMESTAMP 0x04 /* negotiated timestamps */
#define SCF_CC 0x08 /* negotiated CC */
#define SCF_UNREACH 0x10 /* icmp unreachable received */
#define SCF_KEEPROUTE 0x20 /* keep cloned route */
TAILQ_ENTRY(syncache) sc_hash;
TAILQ_ENTRY(syncache) sc_timerq;
};
struct syncache_head {
TAILQ_HEAD(, syncache) sch_bucket;
u_int sch_length;
};
/*
* The TAO cache entry which is stored in the protocol family specific
* portion of the route metrics.
@ -306,6 +350,22 @@ struct tcpstat {
u_long tcps_badsyn; /* bogus SYN, e.g. premature ACK */
u_long tcps_mturesent; /* resends due to MTU discovery */
u_long tcps_listendrop; /* listen queue overflows */
u_long tcps_sc_added; /* entry added to syncache */
u_long tcps_sc_retransmitted; /* syncache entry was retransmitted */
u_long tcps_sc_dupsyn; /* duplicate SYN packet */
u_long tcps_sc_dropped; /* could not reply to packet */
u_long tcps_sc_completed; /* successful extraction of entry */
u_long tcps_sc_bucketoverflow; /* syncache per-bucket limit hit */
u_long tcps_sc_cacheoverflow; /* syncache cache limit hit */
u_long tcps_sc_reset; /* RST removed entry from syncache */
u_long tcps_sc_stale; /* timed out or listen socket gone */
u_long tcps_sc_aborted; /* syncache entry aborted */
u_long tcps_sc_badack; /* removed due to bad ACK */
u_long tcps_sc_unreach; /* ICMP unreachable received */
u_long tcps_sc_zonefail; /* zalloc() failed */
u_long tcps_sc_sendcookie; /* SYN cookie sent */
u_long tcps_sc_recvcookie; /* SYN cookie received */
};
/*
@ -383,7 +443,7 @@ struct tcpcb *
void tcp_drain __P((void));
void tcp_fasttimo __P((void));
struct rmxp_tao *
tcp_gettaocache __P((struct inpcb *));
tcp_gettaocache __P((struct in_conninfo *));
void tcp_init __P((void));
void tcp_input __P((struct mbuf *, int));
void tcp_mss __P((struct tcpcb *, int));
@ -397,7 +457,7 @@ void tcp_quench __P((struct inpcb *, int));
void tcp_respond __P((struct tcpcb *, void *,
struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, int));
struct rtentry *
tcp_rtlookup __P((struct inpcb *));
tcp_rtlookup __P((struct in_conninfo *));
void tcp_setpersist __P((struct tcpcb *));
void tcp_slowtimo __P((void));
struct tcptemp *
@ -407,6 +467,14 @@ struct tcpcb *
tcp_timers __P((struct tcpcb *, int));
void tcp_trace __P((int, int, struct tcpcb *, void *, struct tcphdr *,
int));
void syncache_init(void);
void syncache_unreach(struct in_conninfo *, struct tcphdr *);
int syncache_expand(struct in_conninfo *, struct tcphdr *,
struct socket **, struct mbuf *);
int syncache_add(struct in_conninfo *, struct tcpopt *,
struct tcphdr *, struct socket **, struct mbuf *);
void syncache_chkrst(struct in_conninfo *, struct tcphdr *);
void syncache_badack(struct in_conninfo *);
extern struct pr_usrreqs tcp_usrreqs;
extern u_long tcp_sendspace;

2
sys/netinet6/tcp6_var.h
View File

@ -79,7 +79,7 @@ struct ip6_hdr;
void tcp6_ctlinput __P((int, struct sockaddr *, void *));
void tcp6_init __P((void));
int tcp6_input __P((struct mbuf **, int *, int));
struct rtentry *tcp_rtlookup6 __P((struct inpcb *));
struct rtentry *tcp_rtlookup6(struct in_conninfo *);
extern struct pr_usrreqs tcp6_usrreqs;