/* * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 * $FreeBSD$ */ #include "opt_compat.h" #include "opt_inet6.h" #include "opt_ipsec.h" #include "opt_tcpdebug.h" #include #include #include #include #include #include #include #include #ifdef INET6 #include #endif #include #include #include #include #include #include #include #define _IP_VHL #include #include #include #ifdef INET6 #include #endif #include #ifdef INET6 #include #endif #include #include #ifdef INET6 #include #endif #include #include #include #include #include #ifdef INET6 #include #endif #include #ifdef TCPDEBUG #include #endif #include #ifdef IPSEC #include #endif /*IPSEC*/ #include int tcp_mssdflt = TCP_MSS; SYSCTL_INT(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, CTLFLAG_RW, &tcp_mssdflt , 0, "Default TCP Maximum Segment Size"); #ifdef INET6 int tcp_v6mssdflt = TCP6_MSS; SYSCTL_INT(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, CTLFLAG_RW, &tcp_v6mssdflt , 0, "Default TCP Maximum Segment Size for IPv6"); #endif #if 0 static int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ; 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; 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; SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1644, rfc1644, CTLFLAG_RW, &tcp_do_rfc1644 , 0, "Enable rfc1644 (TTCP) extensions"); static int tcp_tcbhashsize = 0; SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RD, &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable"); static int do_tcpdrain = 1; SYSCTL_INT(_debug, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, "Enable non Net3 compliant tcp_drain"); SYSCTL_INT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_RD, &tcbinfo.ipi_count, 0, "Number of active PCBs"); static void tcp_cleartaocache __P((void)); static void tcp_notify __P((struct inpcb *, int)); /* * Target size of TCP PCB hash tables. Must be a power of two. * * Note that this can be overridden by the kernel environment * variable net.inet.tcp.tcbhashsize */ #ifndef TCBHASHSIZE #define TCBHASHSIZE 512 #endif /* * This is the actual shape of what we allocate using the zone * allocator. Doing it this way allows us to protect both structures * using the same generation count, and also eliminates the overhead * of allocating tcpcbs separately. By hiding the structure here, * we avoid changing most of the rest of the code (although it needs * to be changed, eventually, for greater efficiency). */ #define ALIGNMENT 32 #define ALIGNM1 (ALIGNMENT - 1) struct inp_tp { union { struct inpcb inp; char align[(sizeof(struct inpcb) + ALIGNM1) & ~ALIGNM1]; } inp_tp_u; struct tcpcb tcb; struct callout inp_tp_rexmt, inp_tp_persist, inp_tp_keep, inp_tp_2msl; struct callout inp_tp_delack; }; #undef ALIGNMENT #undef ALIGNM1 /* * Tcp initialization */ void tcp_init() { int hashsize; tcp_iss = random(); /* wrong, but better than a constant */ tcp_ccgen = 1; tcp_cleartaocache(); tcp_delacktime = TCPTV_DELACK; tcp_keepinit = TCPTV_KEEP_INIT; tcp_keepidle = TCPTV_KEEP_IDLE; tcp_keepintvl = TCPTV_KEEPINTVL; tcp_maxpersistidle = TCPTV_KEEP_IDLE; tcp_msl = TCPTV_MSL; LIST_INIT(&tcb); tcbinfo.listhead = &tcb; TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", TCBHASHSIZE, hashsize); if (!powerof2(hashsize)) { printf("WARNING: TCB hash size not a power of 2\n"); hashsize = 512; /* safe default */ } tcp_tcbhashsize = hashsize; tcbinfo.hashbase = hashinit(hashsize, M_PCB, &tcbinfo.hashmask); tcbinfo.porthashbase = hashinit(hashsize, M_PCB, &tcbinfo.porthashmask); tcbinfo.ipi_zone = zinit("tcpcb", sizeof(struct inp_tp), maxsockets, ZONE_INTERRUPT, 0); #ifdef INET6 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) #else /* INET6 */ #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) #endif /* INET6 */ if (max_protohdr < TCP_MINPROTOHDR) max_protohdr = TCP_MINPROTOHDR; if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) panic("tcp_init"); #undef TCP_MINPROTOHDR } /* * Create template to be used to send tcp packets on a connection. * Call after host entry created, allocates an mbuf and fills * in a skeletal tcp/ip header, minimizing the amount of work * necessary when the connection is used. */ struct tcptemp * tcp_template(tp) struct tcpcb *tp; { register struct inpcb *inp = tp->t_inpcb; register struct mbuf *m; register struct tcptemp *n; if ((n = tp->t_template) == 0) { m = m_get(M_DONTWAIT, MT_HEADER); if (m == NULL) return (0); m->m_len = sizeof (struct tcptemp); n = mtod(m, struct tcptemp *); } #ifdef INET6 if ((inp->inp_vflag & INP_IPV6) != 0) { register struct ip6_hdr *ip6; ip6 = (struct ip6_hdr *)n->tt_ipgen; ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | (inp->in6p_flowinfo & IPV6_FLOWINFO_MASK); ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | (IPV6_VERSION & IPV6_VERSION_MASK); ip6->ip6_nxt = IPPROTO_TCP; ip6->ip6_plen = sizeof(struct tcphdr); ip6->ip6_src = inp->in6p_laddr; ip6->ip6_dst = inp->in6p_faddr; n->tt_t.th_sum = 0; } else #endif { struct ip *ip = (struct ip *)n->tt_ipgen; bzero(ip, sizeof(struct ip)); /* XXX overkill? */ ip->ip_vhl = IP_VHL_BORING; ip->ip_p = IPPROTO_TCP; ip->ip_src = inp->inp_laddr; ip->ip_dst = inp->inp_faddr; n->tt_t.th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) + IPPROTO_TCP)); } n->tt_t.th_sport = inp->inp_lport; n->tt_t.th_dport = inp->inp_fport; n->tt_t.th_seq = 0; n->tt_t.th_ack = 0; n->tt_t.th_x2 = 0; n->tt_t.th_off = 5; n->tt_t.th_flags = 0; n->tt_t.th_win = 0; n->tt_t.th_urp = 0; return (n); } /* * Send a single message to the TCP at address specified by * the given TCP/IP header. If m == 0, then we make a copy * of the tcpiphdr at ti and send directly to the addressed host. * This is used to force keep alive messages out using the TCP * template for a connection tp->t_template. If flags are given * then we send a message back to the TCP which originated the * segment ti, and discard the mbuf containing it and any other * attached mbufs. * * In any case the ack and sequence number of the transmitted * segment are as specified by the parameters. * * NOTE: If m != NULL, then ti must point to *inside* the mbuf. */ void tcp_respond(tp, ipgen, th, m, ack, seq, flags) struct tcpcb *tp; void *ipgen; register struct tcphdr *th; register struct mbuf *m; tcp_seq ack, seq; int flags; { register int tlen; int win = 0; struct route *ro = 0; struct route sro; struct ip *ip; struct tcphdr *nth; #ifdef INET6 struct route_in6 *ro6 = 0; struct route_in6 sro6; struct ip6_hdr *ip6; int isipv6; #endif /* INET6 */ int ipflags = 0; #ifdef INET6 isipv6 = IP_VHL_V(((struct ip *)ipgen)->ip_vhl) == 6; ip6 = ipgen; #endif /* INET6 */ ip = ipgen; if (tp) { if (!(flags & TH_RST)) { win = sbspace(&tp->t_inpcb->inp_socket->so_rcv); if (win > (long)TCP_MAXWIN << tp->rcv_scale) win = (long)TCP_MAXWIN << tp->rcv_scale; } #ifdef INET6 if (isipv6) ro6 = &tp->t_inpcb->in6p_route; else #endif /* INET6 */ ro = &tp->t_inpcb->inp_route; } else { #ifdef INET6 if (isipv6) { ro6 = &sro6; bzero(ro6, sizeof *ro6); } else #endif /* INET6 */ { ro = &sro; bzero(ro, sizeof *ro); } } if (m == 0) { m = m_gethdr(M_DONTWAIT, MT_HEADER); if (m == NULL) return; #ifdef TCP_COMPAT_42 tlen = 1; #else tlen = 0; #endif m->m_data += max_linkhdr; #ifdef INET6 if (isipv6) { bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(struct ip6_hdr)); ip6 = mtod(m, struct ip6_hdr *); nth = (struct tcphdr *)(ip6 + 1); } else #endif /* INET6 */ { bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); ip = mtod(m, struct ip *); nth = (struct tcphdr *)(ip + 1); } bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); flags = TH_ACK; } else { m_freem(m->m_next); m->m_next = 0; m->m_data = (caddr_t)ipgen; /* m_len is set later */ tlen = 0; #define xchg(a,b,type) { type t; t=a; a=b; b=t; } #ifdef INET6 if (isipv6) { xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); nth = (struct tcphdr *)(ip6 + 1); } else #endif /* INET6 */ { xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, n_long); nth = (struct tcphdr *)(ip + 1); } if (th != nth) { /* * this is usually a case when an extension header * exists between the IPv6 header and the * TCP header. */ nth->th_sport = th->th_sport; nth->th_dport = th->th_dport; } xchg(nth->th_dport, nth->th_sport, n_short); #undef xchg } #ifdef INET6 if (isipv6) { ip6->ip6_plen = htons((u_short)(sizeof (struct tcphdr) + tlen)); tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr); } else #endif { tlen += sizeof (struct tcpiphdr); ip->ip_len = tlen; ip->ip_ttl = ip_defttl; } m->m_len = tlen; m->m_pkthdr.len = tlen; m->m_pkthdr.rcvif = (struct ifnet *) 0; nth->th_seq = htonl(seq); nth->th_ack = htonl(ack); nth->th_x2 = 0; nth->th_off = sizeof (struct tcphdr) >> 2; nth->th_flags = flags; if (tp) nth->th_win = htons((u_short) (win >> tp->rcv_scale)); else nth->th_win = htons((u_short)win); nth->th_urp = 0; #ifdef INET6 if (isipv6) { nth->th_sum = 0; nth->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(struct ip6_hdr), tlen - sizeof(struct ip6_hdr)); ip6->ip6_hlim = in6_selecthlim(tp ? tp->t_inpcb : NULL, ro6 && ro6->ro_rt ? ro6->ro_rt->rt_ifp : NULL); } else #endif /* INET6 */ { nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); m->m_pkthdr.csum_flags = CSUM_TCP; m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); } #ifdef TCPDEBUG if (tp == NULL || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)) tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); #endif #ifdef IPSEC if (tp != NULL) { m->m_pkthdr.rcvif = (struct ifnet *)tp->t_inpcb->inp_socket; ipflags |= #ifdef INET6 isipv6 ? IPV6_SOCKINMRCVIF : #endif IP_SOCKINMRCVIF; } #endif #ifdef INET6 if (isipv6) { (void)ip6_output(m, NULL, ro6, ipflags, NULL, NULL); if (ro6 == &sro6 && ro6->ro_rt) { RTFREE(ro6->ro_rt); ro6->ro_rt = NULL; } } else #endif /* INET6 */ { (void) ip_output(m, NULL, ro, ipflags, NULL); if (ro == &sro && ro->ro_rt) { RTFREE(ro->ro_rt); ro->ro_rt = NULL; } } } /* * Create a new TCP control block, making an * empty reassembly queue and hooking it to the argument * protocol control block. The `inp' parameter must have * come from the zone allocator set up in tcp_init(). */ struct tcpcb * tcp_newtcpcb(inp) struct inpcb *inp; { struct inp_tp *it; register struct tcpcb *tp; #ifdef INET6 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; #endif /* INET6 */ it = (struct inp_tp *)inp; tp = &it->tcb; bzero((char *) tp, sizeof(struct tcpcb)); LIST_INIT(&tp->t_segq); tp->t_maxseg = tp->t_maxopd = #ifdef INET6 isipv6 ? tcp_v6mssdflt : #endif /* INET6 */ tcp_mssdflt; /* Set up our timeouts. */ callout_init(tp->tt_rexmt = &it->inp_tp_rexmt); callout_init(tp->tt_persist = &it->inp_tp_persist); callout_init(tp->tt_keep = &it->inp_tp_keep); callout_init(tp->tt_2msl = &it->inp_tp_2msl); callout_init(tp->tt_delack = &it->inp_tp_delack); if (tcp_do_rfc1323) tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); if (tcp_do_rfc1644) tp->t_flags |= TF_REQ_CC; tp->t_inpcb = inp; /* XXX */ /* * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives * reasonable initial retransmit time. */ tp->t_srtt = TCPTV_SRTTBASE; tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; tp->t_rttmin = TCPTV_MIN; tp->t_rxtcur = TCPTV_RTOBASE; tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; tp->t_rcvtime = ticks; /* * IPv4 TTL initialization is necessary for an IPv6 socket as well, * because the socket may be bound to an IPv6 wildcard address, * which may match an IPv4-mapped IPv6 address. */ inp->inp_ip_ttl = ip_defttl; inp->inp_ppcb = (caddr_t)tp; return (tp); /* XXX */ } /* * Drop a TCP connection, reporting * the specified error. If connection is synchronized, * then send a RST to peer. */ struct tcpcb * tcp_drop(tp, errno) register struct tcpcb *tp; int errno; { struct socket *so = tp->t_inpcb->inp_socket; if (TCPS_HAVERCVDSYN(tp->t_state)) { tp->t_state = TCPS_CLOSED; (void) tcp_output(tp); tcpstat.tcps_drops++; } else tcpstat.tcps_conndrops++; if (errno == ETIMEDOUT && tp->t_softerror) errno = tp->t_softerror; so->so_error = errno; return (tcp_close(tp)); } /* * Close a TCP control block: * discard all space held by the tcp * discard internet protocol block * wake up any sleepers */ struct tcpcb * tcp_close(tp) register struct tcpcb *tp; { register struct tseg_qent *q; struct inpcb *inp = tp->t_inpcb; struct socket *so = inp->inp_socket; #ifdef INET6 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; #endif /* INET6 */ register struct rtentry *rt; int dosavessthresh; /* * Make sure that all of our timers are stopped before we * delete the PCB. */ callout_stop(tp->tt_rexmt); callout_stop(tp->tt_persist); callout_stop(tp->tt_keep); callout_stop(tp->tt_2msl); callout_stop(tp->tt_delack); /* * If we got enough samples through the srtt filter, * save the rtt and rttvar in the routing entry. * 'Enough' is arbitrarily defined as the 16 samples. * 16 samples is enough for the srtt filter to converge * to within 5% of the correct value; fewer samples and * we could save a very bogus rtt. * * Don't update the default route's characteristics and don't * update anything that the user "locked". */ if (tp->t_rttupdated >= 16) { register u_long i = 0; #ifdef INET6 if (isipv6) { struct sockaddr_in6 *sin6; if ((rt = inp->in6p_route.ro_rt) == NULL) goto no_valid_rt; sin6 = (struct sockaddr_in6 *)rt_key(rt); if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) goto no_valid_rt; } else #endif /* INET6 */ if ((rt = inp->inp_route.ro_rt) == NULL || ((struct sockaddr_in *)rt_key(rt))->sin_addr.s_addr == INADDR_ANY) goto no_valid_rt; if ((rt->rt_rmx.rmx_locks & RTV_RTT) == 0) { i = tp->t_srtt * (RTM_RTTUNIT / (hz * TCP_RTT_SCALE)); if (rt->rt_rmx.rmx_rtt && i) /* * filter this update to half the old & half * the new values, converting scale. * See route.h and tcp_var.h for a * description of the scaling constants. */ rt->rt_rmx.rmx_rtt = (rt->rt_rmx.rmx_rtt + i) / 2; else rt->rt_rmx.rmx_rtt = i; tcpstat.tcps_cachedrtt++; } if ((rt->rt_rmx.rmx_locks & RTV_RTTVAR) == 0) { i = tp->t_rttvar * (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE)); if (rt->rt_rmx.rmx_rttvar && i) rt->rt_rmx.rmx_rttvar = (rt->rt_rmx.rmx_rttvar + i) / 2; else rt->rt_rmx.rmx_rttvar = i; tcpstat.tcps_cachedrttvar++; } /* * The old comment here said: * update the pipelimit (ssthresh) if it has been updated * already or if a pipesize was specified & the threshhold * got below half the pipesize. I.e., wait for bad news * before we start updating, then update on both good * and bad news. * * But we want to save the ssthresh even if no pipesize is * specified explicitly in the route, because such * connections still have an implicit pipesize specified * by the global tcp_sendspace. In the absence of a reliable * way to calculate the pipesize, it will have to do. */ i = tp->snd_ssthresh; if (rt->rt_rmx.rmx_sendpipe != 0) dosavessthresh = (i < rt->rt_rmx.rmx_sendpipe / 2); else dosavessthresh = (i < so->so_snd.sb_hiwat / 2); if (((rt->rt_rmx.rmx_locks & RTV_SSTHRESH) == 0 && i != 0 && rt->rt_rmx.rmx_ssthresh != 0) || dosavessthresh) { /* * convert the limit from user data bytes to * packets then to packet data bytes. */ i = (i + tp->t_maxseg / 2) / tp->t_maxseg; if (i < 2) i = 2; i *= (u_long)(tp->t_maxseg + #ifdef INET6 (isipv6 ? sizeof (struct ip6_hdr) + sizeof (struct tcphdr) : #endif sizeof (struct tcpiphdr) #ifdef INET6 ) #endif ); if (rt->rt_rmx.rmx_ssthresh) rt->rt_rmx.rmx_ssthresh = (rt->rt_rmx.rmx_ssthresh + i) / 2; else rt->rt_rmx.rmx_ssthresh = i; tcpstat.tcps_cachedssthresh++; } } no_valid_rt: /* free the reassembly queue, if any */ while((q = LIST_FIRST(&tp->t_segq)) != NULL) { LIST_REMOVE(q, tqe_q); m_freem(q->tqe_m); FREE(q, M_TSEGQ); } if (tp->t_template) (void) m_free(dtom(tp->t_template)); inp->inp_ppcb = NULL; soisdisconnected(so); #ifdef INET6 if (INP_CHECK_SOCKAF(so, AF_INET6)) in6_pcbdetach(inp); else #endif /* INET6 */ in_pcbdetach(inp); tcpstat.tcps_closed++; return ((struct tcpcb *)0); } void tcp_drain() { if (do_tcpdrain) { struct inpcb *inpb; struct tcpcb *tcpb; struct tseg_qent *te; /* * Walk the tcpbs, if existing, and flush the reassembly queue, * if there is one... * XXX: The "Net/3" implementation doesn't imply that the TCP * reassembly queue should be flushed, but in a situation * where we're really low on mbufs, this is potentially * usefull. */ for (inpb = tcbinfo.listhead->lh_first; inpb; inpb = inpb->inp_list.le_next) { if ((tcpb = intotcpcb(inpb))) { while ((te = LIST_FIRST(&tcpb->t_segq)) != NULL) { LIST_REMOVE(te, tqe_q); m_freem(te->tqe_m); FREE(te, M_TSEGQ); } } } } } /* * Notify a tcp user of an asynchronous error; * store error as soft error, but wake up user * (for now, won't do anything until can select for soft error). */ static void tcp_notify(inp, error) struct inpcb *inp; int error; { register struct tcpcb *tp = (struct tcpcb *)inp->inp_ppcb; register struct socket *so = inp->inp_socket; /* * Ignore some errors if we are hooked up. * If connection hasn't completed, has retransmitted several times, * and receives a second error, give up now. This is better * than waiting a long time to establish a connection that * can never complete. */ if (tp->t_state == TCPS_ESTABLISHED && (error == EHOSTUNREACH || error == ENETUNREACH || error == EHOSTDOWN)) { return; } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && tp->t_softerror) so->so_error = error; else tp->t_softerror = error; wakeup((caddr_t) &so->so_timeo); sorwakeup(so); sowwakeup(so); } static int tcp_pcblist(SYSCTL_HANDLER_ARGS) { int error, i, n, s; struct inpcb *inp, **inp_list; inp_gen_t gencnt; struct xinpgen xig; /* * The process of preparing the TCB list is too time-consuming and * resource-intensive to repeat twice on every request. */ if (req->oldptr == 0) { n = tcbinfo.ipi_count; req->oldidx = 2 * (sizeof xig) + (n + n/8) * sizeof(struct xtcpcb); return 0; } if (req->newptr != 0) return EPERM; /* * OK, now we're committed to doing something. */ s = splnet(); gencnt = tcbinfo.ipi_gencnt; n = tcbinfo.ipi_count; splx(s); xig.xig_len = sizeof xig; xig.xig_count = n; xig.xig_gen = gencnt; xig.xig_sogen = so_gencnt; error = SYSCTL_OUT(req, &xig, sizeof xig); if (error) return error; inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); if (inp_list == 0) return ENOMEM; s = splnet(); for (inp = tcbinfo.listhead->lh_first, i = 0; inp && i < n; inp = inp->inp_list.le_next) { if (inp->inp_gencnt <= gencnt && !prison_xinpcb(req->p, inp)) inp_list[i++] = inp; } splx(s); n = i; error = 0; for (i = 0; i < n; i++) { inp = inp_list[i]; if (inp->inp_gencnt <= gencnt) { struct xtcpcb xt; caddr_t inp_ppcb; xt.xt_len = sizeof xt; /* XXX should avoid extra copy */ bcopy(inp, &xt.xt_inp, sizeof *inp); inp_ppcb = inp->inp_ppcb; if (inp_ppcb != NULL) bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); else bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); if (inp->inp_socket) sotoxsocket(inp->inp_socket, &xt.xt_socket); error = SYSCTL_OUT(req, &xt, sizeof xt); } } if (!error) { /* * Give the user an updated idea of our state. * If the generation differs from what we told * her before, she knows that something happened * while we were processing this request, and it * might be necessary to retry. */ s = splnet(); xig.xig_gen = tcbinfo.ipi_gencnt; xig.xig_sogen = so_gencnt; xig.xig_count = tcbinfo.ipi_count; splx(s); error = SYSCTL_OUT(req, &xig, sizeof xig); } free(inp_list, M_TEMP); return error; } SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0, tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); static int tcp_getcred(SYSCTL_HANDLER_ARGS) { struct sockaddr_in addrs[2]; struct inpcb *inp; int error, s; error = suser(req->p); if (error) return (error); error = SYSCTL_IN(req, addrs, sizeof(addrs)); if (error) return (error); s = splnet(); inp = in_pcblookup_hash(&tcbinfo, addrs[1].sin_addr, addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL); if (inp == NULL || inp->inp_socket == NULL) { error = ENOENT; goto out; } error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred)); out: splx(s); return (error); } SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0, 0, tcp_getcred, "S,ucred", "Get the ucred of a TCP connection"); #ifdef INET6 static int tcp6_getcred(SYSCTL_HANDLER_ARGS) { struct sockaddr_in6 addrs[2]; struct inpcb *inp; int error, s, mapped = 0; error = suser(req->p); if (error) return (error); error = SYSCTL_IN(req, addrs, sizeof(addrs)); if (error) return (error); if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) mapped = 1; else return (EINVAL); } s = splnet(); if (mapped == 1) inp = in_pcblookup_hash(&tcbinfo, *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], addrs[1].sin6_port, *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], addrs[0].sin6_port, 0, NULL); else inp = in6_pcblookup_hash(&tcbinfo, &addrs[1].sin6_addr, addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port, 0, NULL); if (inp == NULL || inp->inp_socket == NULL) { error = ENOENT; goto out; } error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred)); out: splx(s); return (error); } SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0, 0, tcp6_getcred, "S,ucred", "Get the ucred of a TCP6 connection"); #endif void tcp_ctlinput(cmd, sa, vip) int cmd; struct sockaddr *sa; void *vip; { register struct ip *ip = vip; register struct tcphdr *th; void (*notify) __P((struct inpcb *, int)) = tcp_notify; if (cmd == PRC_QUENCH) notify = tcp_quench; else if (cmd == PRC_MSGSIZE) notify = tcp_mtudisc; else if (!PRC_IS_REDIRECT(cmd) && ((unsigned)cmd > PRC_NCMDS || inetctlerrmap[cmd] == 0)) return; if (ip) { th = (struct tcphdr *)((caddr_t)ip + (IP_VHL_HL(ip->ip_vhl) << 2)); in_pcbnotify(&tcb, sa, th->th_dport, ip->ip_src, th->th_sport, cmd, notify); } else in_pcbnotify(&tcb, sa, 0, zeroin_addr, 0, cmd, notify); } #ifdef INET6 void tcp6_ctlinput(cmd, sa, d) int cmd; struct sockaddr *sa; void *d; { register struct tcphdr *thp; struct tcphdr th; void (*notify) __P((struct inpcb *, int)) = tcp_notify; struct sockaddr_in6 sa6; struct ip6_hdr *ip6; struct mbuf *m; int off; if (sa->sa_family != AF_INET6 || sa->sa_len != sizeof(struct sockaddr_in6)) return; if (cmd == PRC_QUENCH) notify = tcp_quench; else if (cmd == PRC_MSGSIZE) notify = tcp_mtudisc; else if (!PRC_IS_REDIRECT(cmd) && ((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) return; /* if the parameter is from icmp6, decode it. */ if (d != NULL) { struct ip6ctlparam *ip6cp = (struct ip6ctlparam *)d; m = ip6cp->ip6c_m; ip6 = ip6cp->ip6c_ip6; off = ip6cp->ip6c_off; } else { m = NULL; ip6 = NULL; } /* * Translate addresses into internal form. * Sa check if it is AF_INET6 is done at the top of this funciton. */ sa6 = *(struct sockaddr_in6 *)sa; if (IN6_IS_ADDR_LINKLOCAL(&sa6.sin6_addr) != 0 && m != NULL && m->m_pkthdr.rcvif != NULL) sa6.sin6_addr.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index); if (ip6) { /* * XXX: We assume that when IPV6 is non NULL, * M and OFF are valid. */ struct in6_addr s; /* translate addresses into internal form */ memcpy(&s, &ip6->ip6_src, sizeof(s)); if (IN6_IS_ADDR_LINKLOCAL(&s) != 0 && m != NULL && m->m_pkthdr.rcvif != NULL) s.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index); if (m->m_len < off + sizeof(*thp)) { /* * this should be rare case * because now MINCLSIZE is "(MHLEN + 1)", * so we compromise on this copy... */ m_copydata(m, off, sizeof(th), (caddr_t)&th); thp = &th; } else thp = (struct tcphdr *)(mtod(m, caddr_t) + off); in6_pcbnotify(&tcb, (struct sockaddr *)&sa6, thp->th_dport, &s, thp->th_sport, cmd, notify); } else in6_pcbnotify(&tcb, (struct sockaddr *)&sa6, 0, &zeroin6_addr, 0, cmd, notify); } #endif /* INET6 */ /* * When a source quench is received, close congestion window * to one segment. We will gradually open it again as we proceed. */ void tcp_quench(inp, errno) struct inpcb *inp; int errno; { struct tcpcb *tp = intotcpcb(inp); if (tp) tp->snd_cwnd = tp->t_maxseg; } /* * When `need fragmentation' ICMP is received, update our idea of the MSS * based on the new value in the route. Also nudge TCP to send something, * since we know the packet we just sent was dropped. * This duplicates some code in the tcp_mss() function in tcp_input.c. */ void tcp_mtudisc(inp, errno) struct inpcb *inp; int errno; { struct tcpcb *tp = intotcpcb(inp); struct rtentry *rt; struct rmxp_tao *taop; struct socket *so = inp->inp_socket; int offered; int mss; #ifdef INET6 int isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0; #endif /* INET6 */ if (tp) { #ifdef INET6 if (isipv6) rt = tcp_rtlookup6(inp); else #endif /* INET6 */ rt = tcp_rtlookup(inp); if (!rt || !rt->rt_rmx.rmx_mtu) { tp->t_maxopd = tp->t_maxseg = #ifdef INET6 isipv6 ? tcp_v6mssdflt : #endif /* INET6 */ tcp_mssdflt; return; } taop = rmx_taop(rt->rt_rmx); offered = taop->tao_mssopt; mss = rt->rt_rmx.rmx_mtu - #ifdef INET6 (isipv6 ? sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : #endif /* INET6 */ sizeof(struct tcpiphdr) #ifdef INET6 ) #endif /* INET6 */ ; if (offered) mss = min(mss, offered); /* * XXX - The above conditional probably violates the TCP * spec. The problem is that, since we don't know the * other end's MSS, we are supposed to use a conservative * default. But, if we do that, then MTU discovery will * never actually take place, because the conservative * default is much less than the MTUs typically seen * on the Internet today. For the moment, we'll sweep * this under the carpet. * * The conservative default might not actually be a problem * if the only case this occurs is when sending an initial * SYN with options and data to a host we've never talked * to before. Then, they will reply with an MSS value which * will get recorded and the new parameters should get * recomputed. For Further Study. */ if (tp->t_maxopd <= mss) return; tp->t_maxopd = mss; if ((tp->t_flags & (TF_REQ_TSTMP|TF_NOOPT)) == TF_REQ_TSTMP && (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 && (tp->t_flags & TF_RCVD_CC) == TF_RCVD_CC) mss -= TCPOLEN_CC_APPA; #if (MCLBYTES & (MCLBYTES - 1)) == 0 if (mss > MCLBYTES) mss &= ~(MCLBYTES-1); #else if (mss > MCLBYTES) mss = mss / MCLBYTES * MCLBYTES; #endif if (so->so_snd.sb_hiwat < mss) mss = so->so_snd.sb_hiwat; tp->t_maxseg = mss; tcpstat.tcps_mturesent++; tp->t_rtttime = 0; tp->snd_nxt = tp->snd_una; tcp_output(tp); } } /* * Look-up the routing entry to the peer of this inpcb. If no route * is found and it cannot be allocated the return NULL. This routine * is called by TCP routines that access the rmx structure and by tcp_mss * to get the interface MTU. */ struct rtentry * tcp_rtlookup(inp) struct inpcb *inp; { struct route *ro; struct rtentry *rt; ro = &inp->inp_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) { ro->ro_dst.sa_family = AF_INET; ro->ro_dst.sa_len = sizeof(ro->ro_dst); ((struct sockaddr_in *) &ro->ro_dst)->sin_addr = inp->inp_faddr; rtalloc(ro); rt = ro->ro_rt; } } return rt; } #ifdef INET6 struct rtentry * tcp_rtlookup6(inp) struct inpcb *inp; { struct route_in6 *ro6; struct rtentry *rt; ro6 = &inp->in6p_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)) { ro6->ro_dst.sin6_family = AF_INET6; ro6->ro_dst.sin6_len = sizeof(ro6->ro_dst); ro6->ro_dst.sin6_addr = inp->in6p_faddr; rtalloc((struct route *)ro6); rt = ro6->ro_rt; } } return rt; } #endif /* INET6 */ #ifdef IPSEC /* compute ESP/AH header size for TCP, including outer IP header. */ size_t ipsec_hdrsiz_tcp(tp) struct tcpcb *tp; { struct inpcb *inp; struct mbuf *m; size_t hdrsiz; struct ip *ip; #ifdef INET6 struct ip6_hdr *ip6; #endif /* INET6 */ struct tcphdr *th; if (!tp || !tp->t_template || !(inp = tp->t_inpcb)) return 0; MGETHDR(m, M_DONTWAIT, MT_DATA); if (!m) return 0; #ifdef INET6 if ((inp->inp_vflag & INP_IPV6) != 0) { ip6 = mtod(m, struct ip6_hdr *); th = (struct tcphdr *)(ip6 + 1); m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr); bcopy((caddr_t)tp->t_template->tt_ipgen, (caddr_t)ip6, sizeof(struct ip6_hdr)); bcopy((caddr_t)&tp->t_template->tt_t, (caddr_t)th, sizeof(struct tcphdr)); hdrsiz = ipsec6_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); } else #endif /* INET6 */ { ip = mtod(m, struct ip *); th = (struct tcphdr *)(ip + 1); m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); bcopy((caddr_t)tp->t_template->tt_ipgen, (caddr_t)ip, sizeof(struct ip)); bcopy((caddr_t)&tp->t_template->tt_t, (caddr_t)th, sizeof(struct tcphdr)); hdrsiz = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); } m_free(m); return hdrsiz; } #endif /*IPSEC*/ /* * Return a pointer to the cached information about the remote host. * The cached information is stored in the protocol specific part of * the route metrics. */ struct rmxp_tao * tcp_gettaocache(inp) struct inpcb *inp; { struct rtentry *rt; #ifdef INET6 if ((inp->inp_vflag & INP_IPV6) != 0) rt = tcp_rtlookup6(inp); else #endif /* INET6 */ rt = tcp_rtlookup(inp); /* Make sure this is a host route and is up. */ if (rt == NULL || (rt->rt_flags & (RTF_UP|RTF_HOST)) != (RTF_UP|RTF_HOST)) return NULL; return rmx_taop(rt->rt_rmx); } /* * Clear all the TAO cache entries, called from tcp_init. * * XXX * This routine is just an empty one, because we assume that the routing * routing tables are initialized at the same time when TCP, so there is * nothing in the cache left over. */ static void tcp_cleartaocache() { }