/* $OpenBSD: spp_usrreq.c,v 1.10 2001/06/25 01:50:18 fgsch Exp $ */ /* $NetBSD: spp_usrreq.c,v 1.9 1996/02/13 22:14:13 christos Exp $ */ /* * Copyright (c) 1984, 1985, 1986, 1987, 1993 * 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. * * @(#)spp_usrreq.c 8.1 (Berkeley) 6/10/93 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * SP protocol implementation. */ void spp_init() { spp_iss = 1; /* WRONG !! should fish it out of TODR */ } struct spidp spp_savesi; int traceallspps = 0; extern int sppconsdebug; int spp_hardnosed; int spp_use_delack = 0; u_short spp_newchecks[50]; /*ARGSUSED*/ void #if __STDC__ spp_input(struct mbuf *m, ...) #else spp_input(m, va_alist) struct mbuf *m; va_dcl #endif { register struct nspcb *nsp; register struct sppcb *cb; register struct spidp *si = mtod(m, struct spidp *); register struct socket *so; short ostate = 0; int dropsocket = 0; va_list ap; va_start(ap, m); nsp = va_arg(ap, struct nspcb *); va_end(ap); sppstat.spps_rcvtotal++; if (nsp == 0) { panic("No nspcb in spp_input"); return; } cb = nstosppcb(nsp); if (cb == 0) goto bad; if (m->m_len < sizeof(*si)) { if ((m = m_pullup(m, sizeof(*si))) == 0) { sppstat.spps_rcvshort++; return; } si = mtod(m, struct spidp *); } si->si_seq = ntohs(si->si_seq); si->si_ack = ntohs(si->si_ack); si->si_alo = ntohs(si->si_alo); so = nsp->nsp_socket; if (so->so_options & SO_DEBUG || traceallspps) { ostate = cb->s_state; spp_savesi = *si; } if (so->so_options & SO_ACCEPTCONN) { struct sppcb *ocb = cb; so = sonewconn(so, 0); if (so == 0) { goto drop; } /* * 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++; nsp = (struct nspcb *)so->so_pcb; nsp->nsp_laddr = si->si_dna; cb = nstosppcb(nsp); cb->s_mtu = ocb->s_mtu; /* preserve sockopts */ cb->s_flags = ocb->s_flags; /* preserve sockopts */ cb->s_flags2 = ocb->s_flags2; /* preserve sockopts */ cb->s_state = TCPS_LISTEN; } /* * Packet received on connection. * reset idle time and keep-alive timer; */ cb->s_idle = 0; cb->s_timer[SPPT_KEEP] = SPPTV_KEEP; switch (cb->s_state) { case TCPS_LISTEN:{ struct mbuf *am; register struct sockaddr_ns *sns; struct ns_addr laddr; /* * If somebody here was carying on a conversation * and went away, and his pen pal thinks he can * still talk, we get the misdirected packet. */ if (spp_hardnosed && (si->si_did != 0 || si->si_seq != 0)) { spp_istat.gonawy++; goto dropwithreset; } am = m_get(M_DONTWAIT, MT_SONAME); if (am == NULL) goto drop; am->m_len = sizeof (struct sockaddr_ns); sns = mtod(am, struct sockaddr_ns *); sns->sns_len = sizeof(*sns); sns->sns_family = AF_NS; sns->sns_addr = si->si_sna; laddr = nsp->nsp_laddr; if (ns_nullhost(laddr)) nsp->nsp_laddr = si->si_dna; if (ns_pcbconnect(nsp, am)) { nsp->nsp_laddr = laddr; (void) m_free(am); spp_istat.noconn++; goto drop; } (void) m_free(am); spp_template(cb); dropsocket = 0; /* committed to socket */ cb->s_did = si->si_sid; cb->s_rack = si->si_ack; cb->s_ralo = si->si_alo; #define THREEWAYSHAKE #ifdef THREEWAYSHAKE cb->s_state = TCPS_SYN_RECEIVED; cb->s_force = 1 + SPPT_KEEP; sppstat.spps_accepts++; cb->s_timer[SPPT_KEEP] = SPPTV_KEEP; } break; /* * This state means that we have heard a response * to our acceptance of their connection * It is probably logically unnecessary in this * implementation. */ case TCPS_SYN_RECEIVED: { if (si->si_did!=cb->s_sid) { spp_istat.wrncon++; goto drop; } #endif nsp->nsp_fport = si->si_sport; cb->s_timer[SPPT_REXMT] = 0; cb->s_timer[SPPT_KEEP] = SPPTV_KEEP; soisconnected(so); cb->s_state = TCPS_ESTABLISHED; sppstat.spps_accepts++; } break; /* * This state means that we have gotten a response * to our attempt to establish a connection. * We fill in the data from the other side, * telling us which port to respond to, instead of the well- * known one we might have sent to in the first place. * We also require that this is a response to our * connection id. */ case TCPS_SYN_SENT: if (si->si_did!=cb->s_sid) { spp_istat.notme++; goto drop; } sppstat.spps_connects++; cb->s_did = si->si_sid; cb->s_rack = si->si_ack; cb->s_ralo = si->si_alo; cb->s_dport = nsp->nsp_fport = si->si_sport; cb->s_timer[SPPT_REXMT] = 0; cb->s_flags |= SF_ACKNOW; soisconnected(so); cb->s_state = TCPS_ESTABLISHED; /* Use roundtrip time of connection request for initial rtt */ if (cb->s_rtt) { cb->s_srtt = cb->s_rtt << 3; cb->s_rttvar = cb->s_rtt << 1; SPPT_RANGESET(cb->s_rxtcur, ((cb->s_srtt >> 2) + cb->s_rttvar) >> 1, SPPTV_MIN, SPPTV_REXMTMAX); cb->s_rtt = 0; } } if (so->so_options & SO_DEBUG || traceallspps) spp_trace(SA_INPUT, (u_char)ostate, cb, &spp_savesi, 0); m->m_len -= sizeof (struct idp); m->m_pkthdr.len -= sizeof (struct idp); m->m_data += sizeof (struct idp); if (spp_reass(cb, si)) { (void) m_freem(m); } if (cb->s_force || (cb->s_flags & (SF_ACKNOW|SF_WIN|SF_RXT))) (void) spp_output(NULL, cb); cb->s_flags &= ~(SF_WIN|SF_RXT); return; dropwithreset: if (dropsocket) (void) soabort(so); si->si_seq = ntohs(si->si_seq); si->si_ack = ntohs(si->si_ack); si->si_alo = ntohs(si->si_alo); ns_error(dtom(si), NS_ERR_NOSOCK, 0); if (cb->s_nspcb->nsp_socket->so_options & SO_DEBUG || traceallspps) spp_trace(SA_DROP, (u_char)ostate, cb, &spp_savesi, 0); return; drop: bad: if (cb == 0 || cb->s_nspcb->nsp_socket->so_options & SO_DEBUG || traceallspps) spp_trace(SA_DROP, (u_char)ostate, cb, &spp_savesi, 0); m_freem(m); } int spprexmtthresh = 3; /* * This is structurally similar to the tcp reassembly routine * but its function is somewhat different: It merely queues * packets up, and suppresses duplicates. */ int spp_reass(cb, si) register struct sppcb *cb; register struct spidp *si; { register struct spidp_q *q; register struct mbuf *m; register struct socket *so = cb->s_nspcb->nsp_socket; char packetp = cb->s_flags & SF_HI; int incr; char wakeup = 0; if (si == SI(0)) goto present; /* * Update our news from them. */ if (si->si_cc & SP_SA) cb->s_flags |= (spp_use_delack ? SF_DELACK : SF_ACKNOW); if (SSEQ_GT(si->si_alo, cb->s_ralo)) cb->s_flags |= SF_WIN; if (SSEQ_LEQ(si->si_ack, cb->s_rack)) { if ((si->si_cc & SP_SP) && cb->s_rack != (cb->s_smax + 1)) { sppstat.spps_rcvdupack++; /* * If this is a completely duplicate ack * and other conditions hold, we assume * a packet has been dropped and retransmit * it exactly as in tcp_input(). */ if (si->si_ack != cb->s_rack || si->si_alo != cb->s_ralo) cb->s_dupacks = 0; else if (++cb->s_dupacks == spprexmtthresh) { u_short onxt = cb->s_snxt; int cwnd = cb->s_cwnd; cb->s_snxt = si->si_ack; cb->s_cwnd = CUNIT; cb->s_force = 1 + SPPT_REXMT; (void) spp_output(NULL, cb); cb->s_timer[SPPT_REXMT] = cb->s_rxtcur; cb->s_rtt = 0; if (cwnd >= 4 * CUNIT) cb->s_cwnd = cwnd / 2; if (SSEQ_GT(onxt, cb->s_snxt)) cb->s_snxt = onxt; return (1); } } else cb->s_dupacks = 0; goto update_window; } cb->s_dupacks = 0; /* * If our correspondent acknowledges data we haven't sent * TCP would drop the packet after acking. We'll be a little * more permissive */ if (SSEQ_GT(si->si_ack, (cb->s_smax + 1))) { sppstat.spps_rcvacktoomuch++; si->si_ack = cb->s_smax + 1; } sppstat.spps_rcvackpack++; /* * If transmit timer is running and timed sequence * number was acked, update smoothed round trip time. * See discussion of algorithm in tcp_input.c */ if (cb->s_rtt && SSEQ_GT(si->si_ack, cb->s_rtseq)) { sppstat.spps_rttupdated++; if (cb->s_srtt != 0) { register short delta; delta = cb->s_rtt - (cb->s_srtt >> 3); if ((cb->s_srtt += delta) <= 0) cb->s_srtt = 1; if (delta < 0) delta = -delta; delta -= (cb->s_rttvar >> 2); if ((cb->s_rttvar += delta) <= 0) cb->s_rttvar = 1; } else { /* * No rtt measurement yet */ cb->s_srtt = cb->s_rtt << 3; cb->s_rttvar = cb->s_rtt << 1; } cb->s_rtt = 0; cb->s_rxtshift = 0; SPPT_RANGESET(cb->s_rxtcur, ((cb->s_srtt >> 2) + cb->s_rttvar) >> 1, SPPTV_MIN, SPPTV_REXMTMAX); } /* * If all outstanding data is acked, stop retransmit * timer and remember to restart (more output or persist). * If there is more data to be acked, restart retransmit * timer, using current (possibly backed-off) value; */ if (si->si_ack == cb->s_smax + 1) { cb->s_timer[SPPT_REXMT] = 0; cb->s_flags |= SF_RXT; } else if (cb->s_timer[SPPT_PERSIST] == 0) cb->s_timer[SPPT_REXMT] = cb->s_rxtcur; /* * When new data is acked, open the congestion window. * If the window gives us less than ssthresh packets * in flight, open exponentially (maxseg at a time). * Otherwise open linearly (maxseg^2 / cwnd at a time). */ incr = CUNIT; if (cb->s_cwnd > cb->s_ssthresh) incr = max(incr * incr / cb->s_cwnd, 1); cb->s_cwnd = min(cb->s_cwnd + incr, cb->s_cwmx); /* * Trim Acked data from output queue. */ while ((m = so->so_snd.sb_mb) != NULL) { if (SSEQ_LT((mtod(m, struct spidp *))->si_seq, si->si_ack)) sbdroprecord(&so->so_snd); else break; } sowwakeup(so); cb->s_rack = si->si_ack; update_window: if (SSEQ_LT(cb->s_snxt, cb->s_rack)) cb->s_snxt = cb->s_rack; if (SSEQ_LT(cb->s_swl1, si->si_seq) || (cb->s_swl1 == si->si_seq && (SSEQ_LT(cb->s_swl2, si->si_ack) || (cb->s_swl2 == si->si_ack && SSEQ_LT(cb->s_ralo, si->si_alo))))) { /* keep track of pure window updates */ if ((si->si_cc & SP_SP) && cb->s_swl2 == si->si_ack && SSEQ_LT(cb->s_ralo, si->si_alo)) { sppstat.spps_rcvwinupd++; sppstat.spps_rcvdupack--; } cb->s_ralo = si->si_alo; cb->s_swl1 = si->si_seq; cb->s_swl2 = si->si_ack; cb->s_swnd = (1 + si->si_alo - si->si_ack); if (cb->s_swnd > cb->s_smxw) cb->s_smxw = cb->s_swnd; cb->s_flags |= SF_WIN; } /* * If this packet number is higher than that which * we have allocated refuse it, unless urgent */ if (SSEQ_GT(si->si_seq, cb->s_alo)) { if (si->si_cc & SP_SP) { sppstat.spps_rcvwinprobe++; return (1); } else sppstat.spps_rcvpackafterwin++; if (si->si_cc & SP_OB) { if (SSEQ_GT(si->si_seq, cb->s_alo + 60)) { ns_error(dtom(si), NS_ERR_FULLUP, 0); return (0); } /* else queue this packet; */ } else { /*register struct socket *so = cb->s_nspcb->nsp_socket; if (so->so_state && SS_NOFDREF) { ns_error(dtom(si), NS_ERR_NOSOCK, 0); (void)spp_close(cb); } else would crash system*/ spp_istat.notyet++; ns_error(dtom(si), NS_ERR_FULLUP, 0); return (0); } } /* * If this is a system packet, we don't need to * queue it up, and won't update acknowledge # */ if (si->si_cc & SP_SP) { return (1); } /* * We have already seen this packet, so drop. */ if (SSEQ_LT(si->si_seq, cb->s_ack)) { spp_istat.bdreas++; sppstat.spps_rcvduppack++; if (si->si_seq == cb->s_ack - 1) spp_istat.lstdup++; return (1); } /* * Loop through all packets queued up to insert in * appropriate sequence. */ for (q = cb->s_q.si_next; q!=&cb->s_q; q = q->si_next) { if (si->si_seq == SI(q)->si_seq) { sppstat.spps_rcvduppack++; return (1); } if (SSEQ_LT(si->si_seq, SI(q)->si_seq)) { sppstat.spps_rcvoopack++; break; } } insque(si, q->si_prev); /* * If this packet is urgent, inform process */ if (si->si_cc & SP_OB) { cb->s_iobc = ((char *)si)[1 + sizeof(*si)]; sohasoutofband(so); cb->s_oobflags |= SF_IOOB; } present: #define SPINC sizeof(struct sphdr) /* * Loop through all packets queued up to update acknowledge * number, and present all acknowledged data to user; * If in packet interface mode, show packet headers. */ for (q = cb->s_q.si_next; q!=&cb->s_q; q = q->si_next) { if (SI(q)->si_seq == cb->s_ack) { cb->s_ack++; m = dtom(q); if (SI(q)->si_cc & SP_OB) { cb->s_oobflags &= ~SF_IOOB; if (so->so_rcv.sb_cc) so->so_oobmark = so->so_rcv.sb_cc; else so->so_state |= SS_RCVATMARK; } q = q->si_prev; remque(q->si_next); wakeup = 1; sppstat.spps_rcvpack++; #ifdef SF_NEWCALL if (cb->s_flags2 & SF_NEWCALL) { struct sphdr *sp = mtod(m, struct sphdr *); u_char dt = sp->sp_dt; spp_newchecks[4]++; if (dt != cb->s_rhdr.sp_dt) { struct mbuf *mm = m_getclr(M_DONTWAIT, MT_CONTROL); spp_newchecks[0]++; if (mm != NULL) { u_short *s = mtod(mm, u_short *); cb->s_rhdr.sp_dt = dt; mm->m_len = 5; /*XXX*/ s[0] = 5; s[1] = 1; *(u_char *)(&s[2]) = dt; sbappend(&so->so_rcv, mm); } } if (sp->sp_cc & SP_OB) { MCHTYPE(m, MT_OOBDATA); spp_newchecks[1]++; so->so_oobmark = 0; so->so_state &= ~SS_RCVATMARK; } if (packetp == 0) { m->m_data += SPINC; m->m_len -= SPINC; m->m_pkthdr.len -= SPINC; } if ((sp->sp_cc & SP_EM) || packetp) { sbappendrecord(&so->so_rcv, m); spp_newchecks[9]++; } else sbappend(&so->so_rcv, m); } else #endif if (packetp) { sbappendrecord(&so->so_rcv, m); } else { cb->s_rhdr = *mtod(m, struct sphdr *); m->m_data += SPINC; m->m_len -= SPINC; m->m_pkthdr.len -= SPINC; sbappend(&so->so_rcv, m); } } else break; } if (wakeup) sorwakeup(so); return (0); } void * spp_ctlinput(cmd, sa, arg) int cmd; struct sockaddr *sa; void *arg; { struct ns_addr *na; extern u_char nsctlerrmap[]; struct ns_errp *errp = NULL; struct nspcb *nsp; struct sockaddr_ns *sns; int type; if (cmd < 0 || cmd > PRC_NCMDS) return NULL; type = NS_ERR_UNREACH_HOST; switch (cmd) { case PRC_ROUTEDEAD: return NULL; case PRC_IFDOWN: case PRC_HOSTDEAD: case PRC_HOSTUNREACH: sns = arg; if (sns == NULL || sns->sns_family != AF_NS) return NULL; na = &sns->sns_addr; break; case PRC_REDIRECT_NET: case PRC_REDIRECT_HOST: case PRC_REDIRECT_TOSNET: case PRC_REDIRECT_TOSHOST: /* * PRC_IS_REDIRECT: Call ns_rtchange to flush the route, so * that the next time we attempt output we try a new one * XXX: Is this the right way? ns_rtchange has a comment * that needs to be fixed. */ sns = (struct sockaddr_ns *) sa; if (sns->sns_family != AF_NS) return NULL; na = &sns->sns_addr; ns_pcbnotify(na, (int)nsctlerrmap[cmd], ns_rtchange, (long) 0); return NULL; default: errp = arg; na = &errp->ns_err_idp.idp_dna; type = errp->ns_err_num; type = ntohs((u_short)type); break; } switch (type) { case NS_ERR_UNREACH_HOST: ns_pcbnotify(na, (int)nsctlerrmap[cmd], spp_abort, (long) 0); break; case NS_ERR_TOO_BIG: case NS_ERR_NOSOCK: nsp = ns_pcblookup(na, errp->ns_err_idp.idp_sna.x_port, NS_WILDCARD); if (nsp) { if(nsp->nsp_pcb) (void) spp_drop((struct sppcb *)nsp->nsp_pcb, (int)nsctlerrmap[cmd]); else (void) idp_drop(nsp, (int)nsctlerrmap[cmd]); } break; case NS_ERR_FULLUP: ns_pcbnotify(na, 0, spp_quench, (long) 0); } return NULL; } /* * When a source quench is received, close congestion window * to one packet. We will gradually open it again as we proceed. */ void spp_quench(nsp) struct nspcb *nsp; { struct sppcb *cb = nstosppcb(nsp); if (cb) cb->s_cwnd = CUNIT; } #ifdef notdef int spp_fixmtu(nsp) register struct nspcb *nsp; { register struct sppcb *cb = (struct sppcb *)(nsp->nsp_pcb); register struct mbuf *m; register struct spidp *si; struct ns_errp *ep; struct sockbuf *sb; int badseq, len; struct mbuf *firstbad, *m0; if (cb) { /* * The notification that we have sent * too much is bad news -- we will * have to go through queued up so far * splitting ones which are too big and * reassigning sequence numbers and checksums. * we should then retransmit all packets from * one above the offending packet to the last one * we had sent (or our allocation) * then the offending one so that the any queued * data at our destination will be discarded. */ ep = (struct ns_errp *)nsp->nsp_notify_param; sb = &nsp->nsp_socket->so_snd; cb->s_mtu = ep->ns_err_param; badseq = SI(&ep->ns_err_idp)->si_seq; for (m = sb->sb_mb; m; m = m->m_act) { si = mtod(m, struct spidp *); if (si->si_seq == badseq) break; } if (m == 0) return; firstbad = m; /*for (;;) {*/ /* calculate length */ for (m0 = m, len = 0; m ; m = m->m_next) len += m->m_len; if (len > cb->s_mtu) { } /* FINISH THIS } */ } } #endif int #if __STDC__ spp_output(struct mbuf *m0, ...) #else spp_output(m0, va_alist) struct mbuf *m0; va_dcl #endif { register struct sppcb *cb = NULL; struct socket *so; register struct mbuf *m; register struct spidp *si = (struct spidp *) 0; register struct sockbuf *sb; int len = 0, win, rcv_win; short span, off, recordp = 0; u_short alo; int error = 0, sendalot; #ifdef notdef int idle; #endif struct mbuf *mprev = NULL; extern int idpcksum; va_list ap; va_start(ap, m0); cb = va_arg(ap, struct sppcb *); va_end(ap); so = cb->s_nspcb->nsp_socket; sb = &so->so_snd; if (m0) { int mtu = cb->s_mtu; int datalen; /* * Make sure that packet isn't too big. */ for (m = m0; m ; m = m->m_next) { mprev = m; len += m->m_len; if (m->m_flags & M_EOR) recordp = 1; } datalen = (cb->s_flags & SF_HO) ? len - sizeof (struct sphdr) : len; if (datalen > mtu) { if (cb->s_flags & SF_PI) { m_freem(m0); return (EMSGSIZE); } else { int oldEM = cb->s_cc & SP_EM; cb->s_cc &= ~SP_EM; while (len > mtu) { /* * Here we are only being called * from usrreq(), so it is OK to * block. */ m = m_copym(m0, 0, mtu, M_WAIT); if (cb->s_flags & SF_NEWCALL) { struct mbuf *mm = m; spp_newchecks[7]++; while (mm) { mm->m_flags &= ~M_EOR; mm = mm->m_next; } } error = spp_output(m, cb); if (error) { cb->s_cc |= oldEM; m_freem(m0); return(error); } m_adj(m0, mtu); len -= mtu; } cb->s_cc |= oldEM; } } /* * Force length even, by adding a "garbage byte" if * necessary. */ if (len & 1) { m = mprev; if (M_TRAILINGSPACE(m) >= 1) m->m_len++; else { struct mbuf *m1 = m_get(M_DONTWAIT, MT_DATA); if (m1 == 0) { m_freem(m0); return (ENOBUFS); } m1->m_len = 1; *(mtod(m1, u_char *)) = 0; m->m_next = m1; } } m = m_gethdr(M_DONTWAIT, MT_HEADER); if (m == 0) { m_freem(m0); return (ENOBUFS); } /* * Fill in mbuf with extended SP header * and addresses and length put into network format. */ M_COPY_HDR(m, m0); MH_ALIGN(m, sizeof (struct spidp)); m->m_len = sizeof (struct spidp); m->m_next = m0; si = mtod(m, struct spidp *); si->si_i = *cb->s_idp; si->si_s = cb->s_shdr; if ((cb->s_flags & SF_PI) && (cb->s_flags & SF_HO)) { register struct sphdr *sh; if (m0->m_len < sizeof (*sh)) { if((m0 = m_pullup(m0, sizeof(*sh))) == NULL) { (void) m_free(m); m_freem(m0); return (EINVAL); } m->m_next = m0; } sh = mtod(m0, struct sphdr *); si->si_dt = sh->sp_dt; si->si_cc |= sh->sp_cc & SP_EM; m0->m_len -= sizeof (*sh); m0->m_data += sizeof (*sh); len -= sizeof (*sh); } len += sizeof(*si); if ((cb->s_flags2 & SF_NEWCALL) && recordp) { si->si_cc |= SP_EM; spp_newchecks[8]++; } if (cb->s_oobflags & SF_SOOB) { /* * Per jqj@cornell: * make sure OB packets convey exactly 1 byte. * If the packet is 1 byte or larger, we * have already guaranted there to be at least * one garbage byte for the checksum, and * extra bytes shouldn't hurt! */ if (len > sizeof(*si)) { si->si_cc |= SP_OB; len = (1 + sizeof(*si)); } } si->si_len = htons((u_short)len); m->m_pkthdr.len = ((len - 1) | 1) + 1; /* * queue stuff up for output */ sbappendrecord(sb, m); cb->s_seq++; } #ifdef notdef idle = (cb->s_smax == (cb->s_rack - 1)); #endif again: sendalot = 0; off = cb->s_snxt - cb->s_rack; win = min(cb->s_swnd, (cb->s_cwnd/CUNIT)); /* * If in persist timeout with window of 0, send a probe. * Otherwise, if window is small but nonzero * and timer expired, send what we can and go into * transmit state. */ if (cb->s_force == 1 + SPPT_PERSIST) { if (win != 0) { cb->s_timer[SPPT_PERSIST] = 0; cb->s_rxtshift = 0; } } span = cb->s_seq - cb->s_rack; len = min(span, win) - off; if (len < 0) { /* * Window shrank after we went into it. * If window shrank to 0, cancel pending * restransmission and pull s_snxt back * to (closed) window. We will enter persist * state below. If the widndow didn't close completely, * just wait for an ACK. */ len = 0; if (win == 0) { cb->s_timer[SPPT_REXMT] = 0; cb->s_snxt = cb->s_rack; } } if (len > 1) sendalot = 1; rcv_win = sbspace(&so->so_rcv); /* * Send if we owe peer an ACK. */ if (cb->s_oobflags & SF_SOOB) { /* * must transmit this out of band packet */ cb->s_oobflags &= ~ SF_SOOB; sendalot = 1; sppstat.spps_sndurg++; goto found; } if (cb->s_flags & SF_ACKNOW) goto send; if (cb->s_state < TCPS_ESTABLISHED) goto send; /* * Silly window can't happen in spp. * Code from tcp deleted. */ if (len) goto send; /* * Compare available window to amount of window * known to peer (as advertised window less * next expected input.) If the difference is at least two * packets or at least 35% of the mximum possible window, * then want to send a window update to peer. */ if (rcv_win > 0) { u_short delta = 1 + cb->s_alo - cb->s_ack; int adv = rcv_win - (delta * cb->s_mtu); if ((so->so_rcv.sb_cc == 0 && adv >= (2 * cb->s_mtu)) || (100 * adv / so->so_rcv.sb_hiwat >= 35)) { sppstat.spps_sndwinup++; cb->s_flags |= SF_ACKNOW; goto send; } } /* * Many comments from tcp_output.c are appropriate here * including . . . * If send window is too small, there is data to transmit, and no * retransmit or persist is pending, then go to persist state. * If nothing happens soon, send when timer expires: * if window is nonzero, transmit what we can, * otherwise send a probe. */ if (so->so_snd.sb_cc && cb->s_timer[SPPT_REXMT] == 0 && cb->s_timer[SPPT_PERSIST] == 0) { cb->s_rxtshift = 0; spp_setpersist(cb); } /* * No reason to send a packet, just return. */ cb->s_outx = 1; return (0); send: /* * Find requested packet. */ si = 0; if (len > 0) { cb->s_want = cb->s_snxt; for (m = sb->sb_mb; m; m = m->m_act) { si = mtod(m, struct spidp *); if (SSEQ_LEQ(cb->s_snxt, si->si_seq)) break; } found: if (si) { if (si->si_seq == cb->s_snxt) cb->s_snxt++; else sppstat.spps_sndvoid++, si = 0; } } /* * update window */ if (rcv_win < 0) rcv_win = 0; alo = cb->s_ack - 1 + (rcv_win / ((short)cb->s_mtu)); if (SSEQ_LT(alo, cb->s_alo)) alo = cb->s_alo; if (si) { /* * must make a copy of this packet for * idp_output to monkey with */ m = m_copy(dtom(si), 0, (int)M_COPYALL); if (m == NULL) { return (ENOBUFS); } si = mtod(m, struct spidp *); if (SSEQ_LT(si->si_seq, cb->s_smax)) sppstat.spps_sndrexmitpack++; else sppstat.spps_sndpack++; } else if (cb->s_force || cb->s_flags & SF_ACKNOW) { /* * Must send an acknowledgement or a probe */ if (cb->s_force) sppstat.spps_sndprobe++; if (cb->s_flags & SF_ACKNOW) sppstat.spps_sndacks++; m = m_gethdr(M_DONTWAIT, MT_HEADER); if (m == 0) return (ENOBUFS); /* * Fill in mbuf with extended SP header * and addresses and length put into network format. */ MH_ALIGN(m, sizeof (struct spidp)); m->m_len = sizeof (*si); m->m_pkthdr.len = sizeof (*si); si = mtod(m, struct spidp *); si->si_i = *cb->s_idp; si->si_s = cb->s_shdr; si->si_seq = cb->s_smax + 1; si->si_len = htons(sizeof (*si)); si->si_cc |= SP_SP; } else { cb->s_outx = 3; if (so->so_options & SO_DEBUG || traceallspps) spp_trace(SA_OUTPUT, cb->s_state, cb, si, 0); return (0); } /* * Stuff checksum and output datagram. */ if ((si->si_cc & SP_SP) == 0) { if (cb->s_force != (1 + SPPT_PERSIST) || cb->s_timer[SPPT_PERSIST] == 0) { /* * If this is a new packet and we are not currently * timing anything, time this one. */ if (SSEQ_LT(cb->s_smax, si->si_seq)) { cb->s_smax = si->si_seq; if (cb->s_rtt == 0) { sppstat.spps_segstimed++; cb->s_rtseq = si->si_seq; cb->s_rtt = 1; } } /* * Set rexmt timer if not currently set, * Initial value for retransmit timer is smoothed * round-trip time + 2 * round-trip time variance. * Initialize shift counter which is used for backoff * of retransmit time. */ if (cb->s_timer[SPPT_REXMT] == 0 && cb->s_snxt != cb->s_rack) { cb->s_timer[SPPT_REXMT] = cb->s_rxtcur; if (cb->s_timer[SPPT_PERSIST]) { cb->s_timer[SPPT_PERSIST] = 0; cb->s_rxtshift = 0; } } } else if (SSEQ_LT(cb->s_smax, si->si_seq)) { cb->s_smax = si->si_seq; } } else if (cb->s_state < TCPS_ESTABLISHED) { if (cb->s_rtt == 0) cb->s_rtt = 1; /* Time initial handshake */ if (cb->s_timer[SPPT_REXMT] == 0) cb->s_timer[SPPT_REXMT] = cb->s_rxtcur; } { /* * Do not request acks when we ack their data packets or * when we do a gratuitous window update. */ if (((si->si_cc & SP_SP) == 0) || cb->s_force) si->si_cc |= SP_SA; si->si_seq = htons(si->si_seq); si->si_alo = htons(alo); si->si_ack = htons(cb->s_ack); if (idpcksum) { si->si_sum = 0; len = ntohs(si->si_len); if (len & 1) len++; si->si_sum = ns_cksum(m, len); } else si->si_sum = 0xffff; cb->s_outx = 4; if (so->so_options & SO_DEBUG || traceallspps) spp_trace(SA_OUTPUT, cb->s_state, cb, si, 0); if (so->so_options & SO_DONTROUTE) error = ns_output(m, (struct route *)0, NS_ROUTETOIF); else error = ns_output(m, &cb->s_nspcb->nsp_route, 0); } if (error) { return (error); } sppstat.spps_sndtotal++; /* * Data sent (as far as we can tell). * If this advertises a larger window than any other segment, * then remember the size of the advertized window. * Any pending ACK has now been sent. */ cb->s_force = 0; cb->s_flags &= ~(SF_ACKNOW|SF_DELACK); if (SSEQ_GT(alo, cb->s_alo)) cb->s_alo = alo; if (sendalot) goto again; cb->s_outx = 5; return (0); } int spp_do_persist_panics = 0; void spp_setpersist(cb) register struct sppcb *cb; { register int t = ((cb->s_srtt >> 2) + cb->s_rttvar) >> 1; extern int spp_backoff[]; if (cb->s_timer[SPPT_REXMT] && spp_do_persist_panics) panic("spp_output REXMT"); /* * Start/restart persistance timer. */ SPPT_RANGESET(cb->s_timer[SPPT_PERSIST], t*spp_backoff[cb->s_rxtshift], SPPTV_PERSMIN, SPPTV_PERSMAX); if (cb->s_rxtshift < SPP_MAXRXTSHIFT) cb->s_rxtshift++; } /*ARGSUSED*/ int spp_ctloutput(req, so, level, name, value) int req; struct socket *so; int name, level; struct mbuf **value; { register struct mbuf *m; struct nspcb *nsp = sotonspcb(so); register struct sppcb *cb; int mask, error = 0; if (level != NSPROTO_SPP) { /* This will have to be changed when we do more general stacking of protocols */ return (idp_ctloutput(req, so, level, name, value)); } if (nsp == NULL) { error = EINVAL; goto release; } else cb = nstosppcb(nsp); switch (req) { case PRCO_GETOPT: if (value == NULL) return (EINVAL); m = m_get(M_DONTWAIT, MT_DATA); if (m == NULL) return (ENOBUFS); switch (name) { case SO_HEADERS_ON_INPUT: mask = SF_HI; goto get_flags; case SO_HEADERS_ON_OUTPUT: mask = SF_HO; get_flags: m->m_len = sizeof(short); *mtod(m, short *) = cb->s_flags & mask; break; case SO_MTU: m->m_len = sizeof(u_short); *mtod(m, short *) = cb->s_mtu; break; case SO_LAST_HEADER: m->m_len = sizeof(struct sphdr); *mtod(m, struct sphdr *) = cb->s_rhdr; break; case SO_DEFAULT_HEADERS: m->m_len = sizeof(struct spidp); *mtod(m, struct sphdr *) = cb->s_shdr; break; default: error = EINVAL; } *value = m; break; case PRCO_SETOPT: if (value == 0 || *value == 0) { error = EINVAL; break; } switch (name) { int *ok; case SO_HEADERS_ON_INPUT: mask = SF_HI; goto set_head; case SO_HEADERS_ON_OUTPUT: mask = SF_HO; set_head: if (cb->s_flags & SF_PI) { ok = mtod(*value, int *); if (*ok) cb->s_flags |= mask; else cb->s_flags &= ~mask; } else error = EINVAL; break; case SO_MTU: cb->s_mtu = *(mtod(*value, u_short *)); break; #ifdef SF_NEWCALL case SO_NEWCALL: ok = mtod(*value, int *); if (*ok) { cb->s_flags2 |= SF_NEWCALL; spp_newchecks[5]++; } else { cb->s_flags2 &= ~SF_NEWCALL; spp_newchecks[6]++; } break; #endif case SO_DEFAULT_HEADERS: { register struct sphdr *sp = mtod(*value, struct sphdr *); cb->s_dt = sp->sp_dt; cb->s_cc = sp->sp_cc & SP_EM; } break; default: error = EINVAL; } m_freem(*value); break; } release: return (error); } /*ARGSUSED*/ int spp_usrreq(so, req, m, nam, controlp) struct socket *so; int req; struct mbuf *m, *nam, *controlp; { struct nspcb *nsp = sotonspcb(so); register struct sppcb *cb = NULL; int s = splsoftnet(); int error = 0, ostate; register struct sockbuf *sb; if (req == PRU_CONTROL) return (ns_control(so, (long)m, (caddr_t)nam, (struct ifnet *)controlp)); if (nsp == NULL) { if (req != PRU_ATTACH) { error = EINVAL; goto release; } } else cb = nstosppcb(nsp); ostate = cb ? cb->s_state : 0; switch (req) { case PRU_ATTACH: if (nsp != NULL) { error = EISCONN; break; } error = ns_pcballoc(so, &nspcb); if (error) break; if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { error = soreserve(so, (u_long) 3072, (u_long) 3072); if (error) break; } nsp = sotonspcb(so); sb = &so->so_snd; cb = malloc(sizeof(*cb), M_PCB, M_NOWAIT); if (cb == 0) { error = ENOBUFS; break; } bzero((caddr_t)cb, sizeof(*cb)); cb->s_idp = malloc(sizeof(*cb->s_idp), M_PCB, M_NOWAIT); if (cb->s_idp == 0) { free(cb, M_PCB); error = ENOBUFS; break; } bzero((caddr_t)cb->s_idp, sizeof(*cb->s_idp)); cb->s_state = TCPS_LISTEN; cb->s_smax = -1; cb->s_swl1 = -1; cb->s_q.si_next = cb->s_q.si_prev = &cb->s_q; cb->s_nspcb = nsp; cb->s_mtu = 576 - sizeof (struct spidp); cb->s_cwnd = sbspace(sb) * CUNIT / cb->s_mtu; cb->s_ssthresh = cb->s_cwnd; cb->s_cwmx = sbspace(sb) * CUNIT / (2 * sizeof (struct spidp)); /* Above is recomputed when connecting to account for changed buffering or mtu's */ cb->s_rtt = SPPTV_SRTTBASE; cb->s_rttvar = SPPTV_SRTTDFLT << 2; SPPT_RANGESET(cb->s_rxtcur, ((SPPTV_SRTTBASE >> 2) + (SPPTV_SRTTDFLT << 2)) >> 1, SPPTV_MIN, SPPTV_REXMTMAX); nsp->nsp_pcb = (caddr_t) cb; break; case PRU_DETACH: if (nsp == NULL) { error = ENOTCONN; break; } if (cb->s_state > TCPS_LISTEN) cb = spp_disconnect(cb); else cb = spp_close(cb); break; case PRU_BIND: error = ns_pcbbind(nsp, nam); break; case PRU_LISTEN: if (nsp->nsp_lport == 0) error = ns_pcbbind(nsp, (struct mbuf *)0); if (error == 0) cb->s_state = TCPS_LISTEN; break; /* * Initiate connection to peer. * Enter SYN_SENT state, and mark socket as connecting. * Start keep-alive timer, setup prototype header, * Send initial system packet requesting connection. */ case PRU_CONNECT: if (nsp->nsp_lport == 0) { error = ns_pcbbind(nsp, (struct mbuf *)0); if (error) break; } error = ns_pcbconnect(nsp, nam); if (error) break; soisconnecting(so); sppstat.spps_connattempt++; cb->s_state = TCPS_SYN_SENT; cb->s_did = 0; spp_template(cb); cb->s_timer[SPPT_KEEP] = SPPTV_KEEP; cb->s_force = 1 + SPPTV_KEEP; /* * Other party is required to respond to * the port I send from, but he is not * required to answer from where I am sending to, * so allow wildcarding. * original port I am sending to is still saved in * cb->s_dport. */ nsp->nsp_fport = 0; error = spp_output(NULL, cb); break; case PRU_CONNECT2: error = EOPNOTSUPP; break; /* * We may decide later to implement connection closing * handshaking at the spp level optionally. * here is the hook to do it: */ case PRU_DISCONNECT: cb = spp_disconnect(cb); break; /* * Accept a connection. Essentially all the work is * done at higher levels; just return the address * of the peer, storing through addr. */ case PRU_ACCEPT: { struct sockaddr_ns *sns = mtod(nam, struct sockaddr_ns *); nam->m_len = sizeof (struct sockaddr_ns); sns->sns_family = AF_NS; sns->sns_addr = nsp->nsp_faddr; break; } case PRU_SHUTDOWN: if (so->so_state & SS_CANTSENDMORE) break; socantsendmore(so); cb = spp_usrclosed(cb); if (cb) error = spp_output(NULL, cb); break; /* * After a receive, possibly send acknowledgment * updating allocation. */ case PRU_RCVD: cb->s_flags |= SF_RVD; (void) spp_output(NULL, cb); cb->s_flags &= ~SF_RVD; break; case PRU_ABORT: (void) spp_drop(cb, ECONNABORTED); break; case PRU_SENSE: case PRU_CONTROL: m = NULL; error = EOPNOTSUPP; break; case PRU_RCVOOB: if ((cb->s_oobflags & SF_IOOB) || so->so_oobmark || (so->so_state & SS_RCVATMARK)) { m->m_len = 1; *mtod(m, caddr_t) = cb->s_iobc; break; } error = EINVAL; break; case PRU_SENDOOB: if (sbspace(&so->so_snd) < -512) { error = ENOBUFS; break; } cb->s_oobflags |= SF_SOOB; /* fall into */ case PRU_SEND: if (controlp) { u_short *p = mtod(controlp, u_short *); spp_newchecks[2]++; if ((p[0] == 5) && p[1] == 1) { /* XXXX, for testing */ cb->s_shdr.sp_dt = *(u_char *)(&p[2]); spp_newchecks[3]++; } m_freem(controlp); } controlp = NULL; error = spp_output(m, cb); m = NULL; break; case PRU_SOCKADDR: ns_setsockaddr(nsp, nam); break; case PRU_PEERADDR: ns_setpeeraddr(nsp, nam); break; case PRU_SLOWTIMO: cb = spp_timers(cb, (long)nam); req |= ((long)nam) << 8; break; case PRU_FASTTIMO: case PRU_PROTORCV: case PRU_PROTOSEND: error = EOPNOTSUPP; break; default: panic("sp_usrreq"); } if (cb && (so->so_options & SO_DEBUG || traceallspps)) spp_trace(SA_USER, (u_char)ostate, cb, (struct spidp *)0, req); release: if (controlp != NULL) m_freem(controlp); if (m != NULL) m_freem(m); splx(s); return (error); } int spp_usrreq_sp(so, req, m, nam, controlp) struct socket *so; int req; struct mbuf *m, *nam, *controlp; { int error = spp_usrreq(so, req, m, nam, controlp); if (req == PRU_ATTACH && error == 0) { struct nspcb *nsp = sotonspcb(so); ((struct sppcb *)nsp->nsp_pcb)->s_flags |= (SF_HI | SF_HO | SF_PI); } return (error); } /* * Create template to be used to send spp packets on a connection. * Called after host entry created, fills * in a skeletal spp header (choosing connection id), * minimizing the amount of work necessary when the connection is used. */ void spp_template(cb) register struct sppcb *cb; { register struct nspcb *nsp = cb->s_nspcb; register struct idp *idp = cb->s_idp; register struct sockbuf *sb = &(nsp->nsp_socket->so_snd); idp->idp_pt = NSPROTO_SPP; idp->idp_sna = nsp->nsp_laddr; idp->idp_dna = nsp->nsp_faddr; cb->s_sid = htons(spp_iss); spp_iss += SPP_ISSINCR/2; cb->s_alo = 1; cb->s_cwnd = (sbspace(sb) * CUNIT) / cb->s_mtu; cb->s_ssthresh = cb->s_cwnd; /* Try to expand fast to full complement of large packets */ cb->s_cwmx = (sbspace(sb) * CUNIT) / (2 * sizeof(struct spidp)); cb->s_cwmx = max(cb->s_cwmx, cb->s_cwnd); /* But allow for lots of little packets as well */ } /* * Close a SPIP control block: * discard spp control block itself * discard ns protocol control block * wake up any sleepers */ struct sppcb * spp_close(cb) register struct sppcb *cb; { register struct spidp_q *s; struct nspcb *nsp = cb->s_nspcb; struct socket *so = nsp->nsp_socket; register struct mbuf *m; s = cb->s_q.si_next; while (s != &(cb->s_q)) { s = s->si_next; m = dtom(s->si_prev); remque(s->si_prev); m_freem(m); } free(cb->s_idp, M_PCB); free(cb, M_PCB); nsp->nsp_pcb = 0; soisdisconnected(so); ns_pcbdetach(nsp); sppstat.spps_closed++; return ((struct sppcb *)0); } /* * Someday we may do level 3 handshaking * to close a connection or send a xerox style error. * For now, just close. */ struct sppcb * spp_usrclosed(cb) register struct sppcb *cb; { return (spp_close(cb)); } struct sppcb * spp_disconnect(cb) register struct sppcb *cb; { return (spp_close(cb)); } /* * Drop connection, reporting * the specified error. */ struct sppcb * spp_drop(cb, errno) register struct sppcb *cb; int errno; { struct socket *so = cb->s_nspcb->nsp_socket; /* * someday, in the xerox world * we will generate error protocol packets * announcing that the socket has gone away. */ if (TCPS_HAVERCVDSYN(cb->s_state)) { sppstat.spps_drops++; cb->s_state = TCPS_CLOSED; /*(void) tcp_output(cb);*/ } else sppstat.spps_conndrops++; so->so_error = errno; return (spp_close(cb)); } void spp_abort(nsp) struct nspcb *nsp; { (void) spp_close((struct sppcb *)nsp->nsp_pcb); } int spp_backoff[SPP_MAXRXTSHIFT+1] = { 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 }; /* * Fast timeout routine for processing delayed acks */ void spp_fasttimo() { register struct nspcb *nsp; register struct sppcb *cb; int s = splsoftnet(); nsp = nspcb.nsp_next; if (nsp) for (; nsp != &nspcb; nsp = nsp->nsp_next) if ((cb = (struct sppcb *)nsp->nsp_pcb) && (cb->s_flags & SF_DELACK)) { cb->s_flags &= ~SF_DELACK; cb->s_flags |= SF_ACKNOW; sppstat.spps_delack++; (void) spp_output(NULL, cb); } splx(s); } /* * spp protocol timeout routine called every 500 ms. * Updates the timers in all active pcb's and * causes finite state machine actions if timers expire. */ void spp_slowtimo() { register struct nspcb *ip, *ipnxt; register struct sppcb *cb; int s = splsoftnet(); register long i; /* * Search through tcb's and update active timers. */ ip = nspcb.nsp_next; if (ip == 0) { splx(s); return; } while (ip != &nspcb) { cb = nstosppcb(ip); ipnxt = ip->nsp_next; if (cb == 0) goto tpgone; for (i = 0; i < SPPT_NTIMERS; i++) { if (cb->s_timer[i] && --cb->s_timer[i] == 0) { (void) spp_usrreq(cb->s_nspcb->nsp_socket, PRU_SLOWTIMO, (struct mbuf *)0, (struct mbuf *)i, (struct mbuf *)0); if (ipnxt->nsp_prev != ip) goto tpgone; } } cb->s_idle++; if (cb->s_rtt) cb->s_rtt++; tpgone: ip = ipnxt; } spp_iss += SPP_ISSINCR/PR_SLOWHZ; /* increment iss */ splx(s); } /* * SPP timer processing. */ struct sppcb * spp_timers(cb, timer) register struct sppcb *cb; long timer; { long rexmt; int win; cb->s_force = 1 + timer; switch (timer) { /* * 2 MSL timeout in shutdown went off. TCP deletes connection * control block. */ case SPPT_2MSL: printf("spp: SPPT_2MSL went off for no reason\n"); cb->s_timer[timer] = 0; break; /* * Retransmission timer went off. Message has not * been acked within retransmit interval. Back off * to a longer retransmit interval and retransmit one packet. */ case SPPT_REXMT: if (++cb->s_rxtshift > SPP_MAXRXTSHIFT) { cb->s_rxtshift = SPP_MAXRXTSHIFT; sppstat.spps_timeoutdrop++; cb = spp_drop(cb, ETIMEDOUT); break; } sppstat.spps_rexmttimeo++; rexmt = ((cb->s_srtt >> 2) + cb->s_rttvar) >> 1; rexmt *= spp_backoff[cb->s_rxtshift]; SPPT_RANGESET(cb->s_rxtcur, rexmt, SPPTV_MIN, SPPTV_REXMTMAX); cb->s_timer[SPPT_REXMT] = cb->s_rxtcur; /* * If we have backed off fairly far, our srtt * estimate is probably bogus. Clobber it * so we'll take the next rtt measurement as our srtt; * move the current srtt into rttvar to keep the current * retransmit times until then. */ if (cb->s_rxtshift > SPP_MAXRXTSHIFT / 4 ) { cb->s_rttvar += (cb->s_srtt >> 2); cb->s_srtt = 0; } cb->s_snxt = cb->s_rack; /* * If timing a packet, stop the timer. */ cb->s_rtt = 0; /* * See very long discussion in tcp_timer.c about congestion * window and sstrhesh */ win = min(cb->s_swnd, (cb->s_cwnd/CUNIT)) / 2; if (win < 2) win = 2; cb->s_cwnd = CUNIT; cb->s_ssthresh = win * CUNIT; (void) spp_output(NULL, cb); break; /* * Persistance timer into zero window. * Force a probe to be sent. */ case SPPT_PERSIST: sppstat.spps_persisttimeo++; spp_setpersist(cb); (void) spp_output(NULL, cb); break; /* * Keep-alive timer went off; send something * or drop connection if idle for too long. */ case SPPT_KEEP: sppstat.spps_keeptimeo++; if (cb->s_state < TCPS_ESTABLISHED) goto dropit; if (cb->s_nspcb->nsp_socket->so_options & SO_KEEPALIVE) { if (cb->s_idle >= SPPTV_MAXIDLE) goto dropit; sppstat.spps_keepprobe++; (void) spp_output(NULL, cb); } else cb->s_idle = 0; cb->s_timer[SPPT_KEEP] = SPPTV_KEEP; break; dropit: sppstat.spps_keepdrops++; cb = spp_drop(cb, ETIMEDOUT); break; } return (cb); } #ifndef lint int SppcbSize = sizeof (struct sppcb); int NspcbSize = sizeof (struct nspcb); #endif /* lint */