diff options
Diffstat (limited to 'sys/netinet/tcp_input.c')
| -rw-r--r-- | sys/netinet/tcp_input.c | 731 |
1 files changed, 261 insertions, 470 deletions
diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c index 7ab594e..6740ebe 100644 --- a/sys/netinet/tcp_input.c +++ b/sys/netinet/tcp_input.c @@ -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 @@ findpcb: 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 @@ findpcb: 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 ((ia6 = ip6_getdstifaddr(m)) && - (ia6->ia6_flags & IN6_IFF_DEPRECATED)) { - tp = NULL; - rstreason = BANDLIM_RST_OPENPORT; - goto dropwithreset; - } - } -#endif + /* + * 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; - 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; + if ((ia6 = ip6_getdstifaddr(m)) && + (ia6->ia6_flags & IN6_IFF_DEPRECATED)) { + tp = NULL; + rstreason = BANDLIM_RST_OPENPORT; + goto dropwithreset; } -#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; + /* + * 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) - inp->in6p_laddr = ip6->ip6_dst; - else { - inp->inp_vflag &= ~INP_IPV6; - inp->inp_vflag |= INP_IPV4; + if (isipv6) { + if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, + &ip6->ip6_src)) + goto drop; + } else #endif /* INET6 */ - inp->inp_laddr = ip->ip_dst; + 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 - } -#endif /* INET6 */ - inp->inp_lport = th->th_dport; - if (in_pcbinshash(inp) != 0) { + 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) /* - * Undo the assignments above if we failed to - * put the PCB on the hash lists. + * Entry added to syncache, mbuf used to + * send SYN,ACK packet. */ -#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 + return; /* - * 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 + * Segment passed TAO tests. */ - 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; - } + 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 - 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); - } 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++; + ))) { + 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 @@ findpcb: 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 @@ findpcb: 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 @@ findpcb: * 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 @@ findpcb: * 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 @@ findpcb: 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 && @@ -1025,209 +1049,6 @@ findpcb: 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 @@ findpcb: * 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 @@ findpcb: * 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 @@ findpcb: */ 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 @@ trimthenstep6: 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 @@ trimthenstep6: * 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 @@ trimthenstep6: * 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 @@ trimthenstep6: * 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 @@ trimthenstep6: * 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 @@ process_ACK: * 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 @@ dropwithreset: 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 @@ drop: &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 |
