/* * Copyright (c) 1987, 1989, 1992, 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. * 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. * * @(#)if_sl.c 8.6 (Berkeley) 2/1/94 * $FreeBSD$ */ /* * Serial Line interface * * Rick Adams * Center for Seismic Studies * 1300 N 17th Street, Suite 1450 * Arlington, Virginia 22209 * (703)276-7900 * rick@seismo.ARPA * seismo!rick * * Pounded on heavily by Chris Torek (chris@mimsy.umd.edu, umcp-cs!chris). * N.B.: this belongs in netinet, not net, the way it stands now. * Should have a link-layer type designation, but wouldn't be * backwards-compatible. * * Converted to 4.3BSD Beta by Chris Torek. * Other changes made at Berkeley, based in part on code by Kirk Smith. * W. Jolitz added slip abort. * * Hacked almost beyond recognition by Van Jacobson (van@helios.ee.lbl.gov). * Added priority queuing for "interactive" traffic; hooks for TCP * header compression; ICMP filtering (at 2400 baud, some cretin * pinging you can use up all your bandwidth). Made low clist behavior * more robust and slightly less likely to hang serial line. * Sped up a bunch of things. * * Note that splimp() is used throughout to block both (tty) input * interrupts and network activity; thus, splimp must be >= spltty. */ #include "opt_inet.h" #include "opt_slip.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if INET #include #include #include #include #else #error "Huh? Slip without inet?" #endif #include #include #include #include static MALLOC_DEFINE(M_SL, "sl", "SLIP Interface"); /* * SLRMAX is a hard limit on input packet size. To simplify the code * and improve performance, we require that packets fit in an mbuf * cluster, and if we get a compressed packet, there's enough extra * room to expand the header into a max length tcp/ip header (128 * bytes). So, SLRMAX can be at most * MCLBYTES - 128 * * SLMTU is the default transmit MTU. The transmit MTU should be kept * small enough so that interactive use doesn't suffer, but large * enough to provide good performance. 552 is a good choice for SLMTU * because it is high enough to not fragment TCP packets being routed * through this host. Packet fragmentation is bad with SLIP because * fragment headers aren't compressed. The previous assumptions about * the best MTU value don't really hold when using modern modems with * BTLZ data compression because the modem buffers play a much larger * role in interactive performance than the MTU. The MTU can be changed * at any time to suit the specific environment with ifconfig(8), and * its maximum value is defined as SLTMAX. SLTMAX must not be so large * that it would overflow the stack if BPF is configured (XXX; if_ppp.c * handles this better). * * SLIP_HIWAT is the amount of data that will be queued 'downstream' * of us (i.e., in clists waiting to be picked up by the tty output * interrupt). If we queue a lot of data downstream, it's immune to * our t.o.s. queuing. * E.g., if SLIP_HIWAT is 1024, the interactive traffic in mixed * telnet/ftp will see a 1 sec wait, independent of the mtu (the * wait is dependent on the ftp window size but that's typically * 1k - 4k). So, we want SLIP_HIWAT just big enough to amortize * the cost (in idle time on the wire) of the tty driver running * off the end of its clists & having to call back slstart for a * new packet. For a tty interface with any buffering at all, this * cost will be zero. Even with a totally brain dead interface (like * the one on a typical workstation), the cost will be <= 1 character * time. So, setting SLIP_HIWAT to ~100 guarantees that we'll lose * at most 1% while maintaining good interactive response. */ #define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN) #define SLRMAX (MCLBYTES - BUFOFFSET) #define SLBUFSIZE (SLRMAX + BUFOFFSET) #ifndef SLMTU #define SLMTU 552 /* default MTU */ #endif #define SLTMAX 1500 /* maximum MTU */ #define SLIP_HIWAT roundup(50,CBSIZE) #define CLISTRESERVE 1024 /* Can't let clists get too low */ /* * SLIP ABORT ESCAPE MECHANISM: * (inspired by HAYES modem escape arrangement) * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape } * within window time signals a "soft" exit from slip mode by remote end * if the IFF_DEBUG flag is on. */ #define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/ #define ABT_IDLE 1 /* in seconds - idle before an escape */ #define ABT_COUNT 3 /* count of escapes for abort */ #define ABT_WINDOW (ABT_COUNT*2+2) /* in seconds - time to count */ static LIST_HEAD(sl_list, sl_softc) sl_list; #define FRAME_END 0xc0 /* Frame End */ #define FRAME_ESCAPE 0xdb /* Frame Esc */ #define TRANS_FRAME_END 0xdc /* transposed frame end */ #define TRANS_FRAME_ESCAPE 0xdd /* transposed frame esc */ static int slisstatic(int); static void slmarkstatic(int); static struct sl_softc *slcreate(void); static void sldestroy(struct sl_softc *sc); static struct mbuf *sl_btom(struct sl_softc *, int); static timeout_t sl_keepalive; static timeout_t sl_outfill; static l_close_t slclose; static l_rint_t slinput; static l_ioctl_t sltioctl; static int slioctl(struct ifnet *, u_long, caddr_t); static int slopen(dev_t, struct tty *); static int sloutput(struct ifnet *, struct mbuf *, struct sockaddr *, struct rtentry *); static int slstart(struct tty *); static struct linesw slipdisc = { slopen, slclose, l_noread, l_nowrite, sltioctl, slinput, slstart, ttymodem, FRAME_END }; /* * Called from boot code to establish sl interfaces. */ static int sl_modevent(module_t mod, int type, void *data) { switch (type) { case MOD_LOAD: ldisc_register(SLIPDISC, &slipdisc); LIST_INIT(&sl_list); break; case MOD_UNLOAD: ldisc_deregister(SLIPDISC); printf("if_sl module unload - not possible for this module type\n"); return EINVAL; } return 0; } static moduledata_t sl_mod = { "if_sl", sl_modevent, 0 }; DECLARE_MODULE(if_sl, sl_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); static int *st_unit_list; static size_t st_unit_max = 0; static int slisunitfree(int unit) { struct sl_softc *nc; LIST_FOREACH(nc, &sl_list, sl_next) { if (nc->sc_if.if_dunit == unit) return (0); } return (1); } static int slisstatic(unit) int unit; { size_t i; for (i = 0; i < st_unit_max; i++) if (st_unit_list[i] == unit) return 1; return 0; } static void slmarkstatic(unit) int unit; { int *t; if (slisstatic(unit)) return; MALLOC(t, int *, sizeof(int) * (st_unit_max+1), M_SL, M_NOWAIT); if (t == NULL) return; if (st_unit_list) { bcopy(st_unit_list, t, sizeof(int) * st_unit_max); free(st_unit_list, M_SL); } st_unit_list = t; st_unit_list[st_unit_max] = unit; st_unit_max++; } static struct sl_softc * slcreate() { struct sl_softc *sc; int unit; struct mbuf *m; MALLOC(sc, struct sl_softc *, sizeof(*sc), M_SL, M_WAITOK | M_ZERO); m = m_gethdr(M_TRYWAIT, MT_DATA); if (m != NULL) { MCLGET(m, M_TRYWAIT); if ((m->m_flags & M_EXT) == 0) { m_free(m); m = NULL; } } if (m == NULL) { printf("sl: can't allocate buffer\n"); free(sc, M_SL); return (NULL); } sc->sc_ep = mtod(m, u_char *) + SLBUFSIZE; sc->sc_mbuf = m; sc->sc_buf = sc->sc_ep - SLRMAX; sc->sc_mp = sc->sc_buf; sl_compress_init(&sc->sc_comp, -1); sc->sc_if.if_softc = sc; sc->sc_if.if_mtu = SLMTU; sc->sc_if.if_flags = #ifdef SLIP_IFF_OPTS SLIP_IFF_OPTS; #else IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST; #endif sc->sc_if.if_type = IFT_SLIP; sc->sc_if.if_ioctl = slioctl; sc->sc_if.if_output = sloutput; sc->sc_if.if_snd.ifq_maxlen = 50; sc->sc_fastq.ifq_maxlen = 32; sc->sc_if.if_linkmib = sc; sc->sc_if.if_linkmiblen = sizeof *sc; mtx_init(&sc->sc_fastq.ifq_mtx, "sl_fastq", NULL, MTX_DEF); /* * Find a suitable unit number. */ for (unit=0; ; unit++) { if (slisstatic(unit)) continue; if (!slisunitfree(unit)) continue; break; } if_initname(&sc->sc_if, "sl", unit); LIST_INSERT_HEAD(&sl_list, sc, sl_next); if_attach(&sc->sc_if); bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN); return sc; } /* * Line specific open routine. * Attach the given tty to the first available sl unit. */ /* ARGSUSED */ static int slopen(dev, tp) dev_t dev; register struct tty *tp; { register struct sl_softc *sc; int s, error; error = suser(curthread); if (error) return (error); if (tp->t_line == SLIPDISC) return (0); if ((sc = slcreate()) == NULL) return (ENOBUFS); tp->t_sc = (caddr_t)sc; sc->sc_ttyp = tp; sc->sc_if.if_baudrate = tp->t_ospeed; ttyflush(tp, FREAD | FWRITE); tp->t_line = SLIPDISC; /* * We don't use t_canq or t_rawq, so reduce their * cblock resources to 0. Reserve enough cblocks * for t_outq to guarantee that we can fit a full * packet if the SLIP_HIWAT check allows slstart() * to loop. Use the same value for the cblock * limit since the reserved blocks should always * be enough. Reserving cblocks probably makes * the CLISTRESERVE check unnecessary and wasteful. */ clist_alloc_cblocks(&tp->t_canq, 0, 0); clist_alloc_cblocks(&tp->t_outq, SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1, SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1); clist_alloc_cblocks(&tp->t_rawq, 0, 0); s = splnet(); if_up(&sc->sc_if); splx(s); return (0); } static void sldestroy(struct sl_softc *sc) { bpfdetach(&sc->sc_if); if_detach(&sc->sc_if); LIST_REMOVE(sc, sl_next); m_free(sc->sc_mbuf); mtx_destroy(&sc->sc_fastq.ifq_mtx); if (sc->bpfbuf) free(sc->bpfbuf, M_SL); free(sc, M_SL); } /* * Line specific close routine. * Detach the tty from the sl unit. */ static int slclose(tp,flag) struct tty *tp; int flag; { register struct sl_softc *sc; int s; ttyflush(tp, FREAD | FWRITE); /* * XXX the placement of the following spl is misleading. tty * interrupts must be blocked across line discipline switches * and throughout closes to avoid races. */ s = splimp(); /* actually, max(spltty, splnet) */ clist_free_cblocks(&tp->t_outq); tp->t_line = 0; sc = (struct sl_softc *)tp->t_sc; if (sc != NULL) { if (sc->sc_outfill) { sc->sc_outfill = 0; untimeout(sl_outfill, sc, sc->sc_ofhandle); } if (sc->sc_keepalive) { sc->sc_keepalive = 0; untimeout(sl_keepalive, sc, sc->sc_kahandle); } if_down(&sc->sc_if); sc->sc_ttyp = NULL; tp->t_sc = NULL; sldestroy(sc); } splx(s); return 0; } /* * Line specific (tty) ioctl routine. * Provide a way to get the sl unit number. */ /* ARGSUSED */ static int sltioctl(tp, cmd, data, flag, td) struct tty *tp; u_long cmd; caddr_t data; int flag; struct thread *td; { struct sl_softc *sc = (struct sl_softc *)tp->t_sc; int s, unit, wasup; s = splimp(); switch (cmd) { case SLIOCGUNIT: *(int *)data = sc->sc_if.if_dunit; break; case SLIOCSUNIT: unit = *(u_int *)data; if (unit < 0) { splx(s); return (ENXIO); } if (sc->sc_if.if_dunit != unit) { if (!slisunitfree(unit)) { splx(s); return (ENXIO); } wasup = sc->sc_if.if_flags & IFF_UP; bpfdetach(&sc->sc_if); if_detach(&sc->sc_if); LIST_REMOVE(sc, sl_next); if_initname(&sc->sc_if, "sl", unit); LIST_INSERT_HEAD(&sl_list, sc, sl_next); if_attach(&sc->sc_if); bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN); if (wasup) if_up(&sc->sc_if); else if_down(&sc->sc_if); clist_alloc_cblocks(&tp->t_outq, SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1, SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1); } slmarkstatic(unit); break; case SLIOCSKEEPAL: sc->sc_keepalive = *(u_int *)data * hz; if (sc->sc_keepalive) { sc->sc_flags |= SC_KEEPALIVE; sc->sc_kahandle = timeout(sl_keepalive, sc, sc->sc_keepalive); } else { if ((sc->sc_flags & SC_KEEPALIVE) != 0) { untimeout(sl_keepalive, sc, sc->sc_kahandle); sc->sc_flags &= ~SC_KEEPALIVE; } } break; case SLIOCGKEEPAL: *(int *)data = sc->sc_keepalive / hz; break; case SLIOCSOUTFILL: sc->sc_outfill = *(u_int *)data * hz; if (sc->sc_outfill) { sc->sc_flags |= SC_OUTWAIT; sc->sc_ofhandle = timeout(sl_outfill, sc, sc->sc_outfill); } else { if ((sc->sc_flags & SC_OUTWAIT) != 0) { untimeout(sl_outfill, sc, sc->sc_ofhandle); sc->sc_flags &= ~SC_OUTWAIT; } } break; case SLIOCGOUTFILL: *(int *)data = sc->sc_outfill / hz; break; default: splx(s); return (ENOIOCTL); } splx(s); return (0); } /* * Queue a packet. Start transmission if not active. * Compression happens in slstart; if we do it here, IP TOS * will cause us to not compress "background" packets, because * ordering gets trashed. It can be done for all packets in slstart. */ static int sloutput(ifp, m, dst, rtp) struct ifnet *ifp; register struct mbuf *m; struct sockaddr *dst; struct rtentry *rtp; { register struct sl_softc *sc = ifp->if_softc; register struct ip *ip; register struct ifqueue *ifq; int s; /* * `Cannot happen' (see slioctl). Someday we will extend * the line protocol to support other address families. */ if (dst->sa_family != AF_INET) { if_printf(ifp, "af%d not supported\n", dst->sa_family); m_freem(m); sc->sc_if.if_noproto++; return (EAFNOSUPPORT); } if (sc->sc_ttyp == NULL || !(ifp->if_flags & IFF_UP)) { m_freem(m); return (ENETDOWN); } if ((sc->sc_ttyp->t_state & TS_CONNECTED) == 0) { m_freem(m); return (EHOSTUNREACH); } ifq = &sc->sc_if.if_snd; ip = mtod(m, struct ip *); if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) { m_freem(m); return (ENETRESET); /* XXX ? */ } if (ip->ip_tos & IPTOS_LOWDELAY) ifq = &sc->sc_fastq; if (! IF_HANDOFF(ifq, m, NULL)) { sc->sc_if.if_oerrors++; return (ENOBUFS); } s = splimp(); if (sc->sc_ttyp->t_outq.c_cc == 0) slstart(sc->sc_ttyp); splx(s); return (0); } /* * Start output on interface. Get another datagram * to send from the interface queue and map it to * the interface before starting output. */ static int slstart(tp) register struct tty *tp; { register struct sl_softc *sc = (struct sl_softc *)tp->t_sc; register struct mbuf *m; register u_char *cp; register struct ip *ip; int s; register int len = 0; for (;;) { /* * Call output process whether or not there is more in the * output queue. We are being called in lieu of ttstart * and must do what it would. */ (*tp->t_oproc)(tp); if (tp->t_outq.c_cc != 0) { if (sc != NULL) sc->sc_flags &= ~SC_OUTWAIT; if (tp->t_outq.c_cc > SLIP_HIWAT) return 0; } /* * This happens briefly when the line shuts down. */ if (sc == NULL) return 0; /* * Get a packet and send it to the interface. */ s = splimp(); IF_DEQUEUE(&sc->sc_fastq, m); if (m) sc->sc_if.if_omcasts++; /* XXX */ else IF_DEQUEUE(&sc->sc_if.if_snd, m); splx(s); if (m == NULL) return 0; /* * We do the header compression here rather than in sloutput * because the packets will be out of order if we are using TOS * queueing, and the connection id compression will get * munged when this happens. */ if (sc->sc_if.if_bpf) { /* * We need to save the TCP/IP header before it's * compressed. To avoid complicated code, we just * copy the entire packet into a stack buffer (since * this is a serial line, packets should be short * and/or the copy should be negligible cost compared * to the packet transmission time). */ register struct mbuf *m1 = m; register u_char *cp; if (sc->bpfbuf == NULL) MALLOC(sc->bpfbuf, u_char *, SLTMAX + SLIP_HDRLEN, M_SL, M_NOWAIT); if (sc->bpfbuf) { cp = sc->bpfbuf + SLIP_HDRLEN; len = 0; do { register int mlen = m1->m_len; bcopy(mtod(m1, caddr_t), cp, mlen); cp += mlen; len += mlen; } while ((m1 = m1->m_next) != NULL); } } ip = mtod(m, struct ip *); if (ip->ip_v == IPVERSION && ip->ip_p == IPPROTO_TCP) { if (sc->sc_if.if_flags & SC_COMPRESS) *mtod(m, u_char *) |= sl_compress_tcp(m, ip, &sc->sc_comp, 1); } if (sc->sc_if.if_bpf && sc->bpfbuf) { /* * Put the SLIP pseudo-"link header" in place. The * compressed header is now at the beginning of the * mbuf. */ sc->bpfbuf[SLX_DIR] = SLIPDIR_OUT; bcopy(mtod(m, caddr_t), &sc->bpfbuf[SLX_CHDR], CHDR_LEN); BPF_TAP(&sc->sc_if, sc->bpfbuf, len + SLIP_HDRLEN); } /* * If system is getting low on clists, just flush our * output queue (if the stuff was important, it'll get * retransmitted). Note that SLTMAX is used instead of * the current if_mtu setting because connections that * have already been established still use the original * (possibly larger) mss. */ if (cfreecount < CLISTRESERVE + SLTMAX) { m_freem(m); sc->sc_if.if_collisions++; continue; } sc->sc_flags &= ~SC_OUTWAIT; /* * The extra FRAME_END will start up a new packet, and thus * will flush any accumulated garbage. We do this whenever * the line may have been idle for some time. */ if (tp->t_outq.c_cc == 0) { ++sc->sc_if.if_obytes; (void) putc(FRAME_END, &tp->t_outq); } while (m) { register u_char *ep; cp = mtod(m, u_char *); ep = cp + m->m_len; while (cp < ep) { /* * Find out how many bytes in the string we can * handle without doing something special. */ register u_char *bp = cp; while (cp < ep) { switch (*cp++) { case FRAME_ESCAPE: case FRAME_END: --cp; goto out; } } out: if (cp > bp) { /* * Put n characters at once * into the tty output queue. */ if (b_to_q((char *)bp, cp - bp, &tp->t_outq)) break; sc->sc_if.if_obytes += cp - bp; } /* * If there are characters left in the mbuf, * the first one must be special.. * Put it out in a different form. */ if (cp < ep) { if (putc(FRAME_ESCAPE, &tp->t_outq)) break; if (putc(*cp++ == FRAME_ESCAPE ? TRANS_FRAME_ESCAPE : TRANS_FRAME_END, &tp->t_outq)) { (void) unputc(&tp->t_outq); break; } sc->sc_if.if_obytes += 2; } } m = m_free(m); } if (putc(FRAME_END, &tp->t_outq)) { /* * Not enough room. Remove a char to make room * and end the packet normally. * If you get many collisions (more than one or two * a day) you probably do not have enough clists * and you should increase "nclist" in param.c. */ (void) unputc(&tp->t_outq); (void) putc(FRAME_END, &tp->t_outq); sc->sc_if.if_collisions++; } else { ++sc->sc_if.if_obytes; sc->sc_if.if_opackets++; } } return 0; } /* * Copy data buffer to mbuf chain; add ifnet pointer. */ static struct mbuf * sl_btom(sc, len) register struct sl_softc *sc; register int len; { struct mbuf *m, *newm; MGETHDR(m, M_DONTWAIT, MT_DATA); if (m == NULL) return (NULL); /* * If we have more than MHLEN bytes, it's cheaper to * queue the cluster we just filled & allocate a new one * for the input buffer. Otherwise, fill the mbuf we * allocated above. Note that code in the input routine * guarantees that packet will fit in a cluster. */ if (len >= MHLEN) { MCLGET(m, M_DONTWAIT); if ((m->m_flags & M_EXT) == 0) { /* * we couldn't get a cluster - if memory's this * low, it's time to start dropping packets. */ (void) m_free(m); return (NULL); } /* Swap the new and old clusters */ newm = m; m = sc->sc_mbuf; sc->sc_mbuf = newm; sc->sc_ep = mtod(newm, u_char *) + SLBUFSIZE; m->m_data = (caddr_t)sc->sc_buf; } else bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len); m->m_len = len; m->m_pkthdr.len = len; m->m_pkthdr.rcvif = &sc->sc_if; return (m); } /* * tty interface receiver interrupt. */ static int slinput(c, tp) register int c; register struct tty *tp; { register struct sl_softc *sc; register struct mbuf *m; register int len; u_char chdr[CHDR_LEN]; tk_nin++; sc = (struct sl_softc *)tp->t_sc; if (sc == NULL) return 0; if (c & TTY_ERRORMASK || (tp->t_state & TS_CONNECTED) == 0) { sc->sc_flags |= SC_ERROR; return 0; } c &= TTY_CHARMASK; ++sc->sc_if.if_ibytes; if (sc->sc_if.if_flags & IFF_DEBUG) { if (c == ABT_ESC) { /* * If we have a previous abort, see whether * this one is within the time limit. */ if (sc->sc_abortcount && time_second >= sc->sc_starttime + ABT_WINDOW) sc->sc_abortcount = 0; /* * If we see an abort after "idle" time, count it; * record when the first abort escape arrived. */ if (time_second >= sc->sc_lasttime + ABT_IDLE) { if (++sc->sc_abortcount == 1) sc->sc_starttime = time_second; if (sc->sc_abortcount >= ABT_COUNT) { slclose(tp,0); return 0; } } } else sc->sc_abortcount = 0; sc->sc_lasttime = time_second; } switch (c) { case TRANS_FRAME_ESCAPE: if (sc->sc_escape) c = FRAME_ESCAPE; break; case TRANS_FRAME_END: if (sc->sc_escape) c = FRAME_END; break; case FRAME_ESCAPE: sc->sc_escape = 1; return 0; case FRAME_END: sc->sc_flags &= ~SC_KEEPALIVE; if(sc->sc_flags & SC_ERROR) { sc->sc_flags &= ~SC_ERROR; goto newpack; } len = sc->sc_mp - sc->sc_buf; if (len < 3) /* less than min length packet - ignore */ goto newpack; if (sc->sc_if.if_bpf) { /* * Save the compressed header, so we * can tack it on later. Note that we * will end up copying garbage in some * cases but this is okay. We remember * where the buffer started so we can * compute the new header length. */ bcopy(sc->sc_buf, chdr, CHDR_LEN); } if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) { if (c & 0x80) c = TYPE_COMPRESSED_TCP; else if (c == TYPE_UNCOMPRESSED_TCP) *sc->sc_buf &= 0x4f; /* XXX */ /* * We've got something that's not an IP packet. * If compression is enabled, try to decompress it. * Otherwise, if `auto-enable' compression is on and * it's a reasonable packet, decompress it and then * enable compression. Otherwise, drop it. */ if (sc->sc_if.if_flags & SC_COMPRESS) { len = sl_uncompress_tcp(&sc->sc_buf, len, (u_int)c, &sc->sc_comp); if (len <= 0) goto error; } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) && c == TYPE_UNCOMPRESSED_TCP && len >= 40) { len = sl_uncompress_tcp(&sc->sc_buf, len, (u_int)c, &sc->sc_comp); if (len <= 0) goto error; sc->sc_if.if_flags |= SC_COMPRESS; } else goto error; } if (sc->sc_if.if_bpf) { /* * Put the SLIP pseudo-"link header" in place. * We couldn't do this any earlier since * decompression probably moved the buffer * pointer. Then, invoke BPF. */ register u_char *hp = sc->sc_buf - SLIP_HDRLEN; hp[SLX_DIR] = SLIPDIR_IN; bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN); BPF_TAP(&sc->sc_if, hp, len + SLIP_HDRLEN); } m = sl_btom(sc, len); if (m == NULL) goto error; sc->sc_if.if_ipackets++; if ((sc->sc_if.if_flags & IFF_UP) == 0) { m_freem(m); goto newpack; } if (! netisr_queue(NETISR_IP, m)) { sc->sc_if.if_ierrors++; sc->sc_if.if_iqdrops++; } goto newpack; } if (sc->sc_mp < sc->sc_ep) { *sc->sc_mp++ = c; sc->sc_escape = 0; return 0; } /* can't put lower; would miss an extra frame */ sc->sc_flags |= SC_ERROR; error: sc->sc_if.if_ierrors++; newpack: sc->sc_mp = sc->sc_buf = sc->sc_ep - SLRMAX; sc->sc_escape = 0; return 0; } /* * Process an ioctl request. */ static int slioctl(ifp, cmd, data) register struct ifnet *ifp; u_long cmd; caddr_t data; { register struct ifaddr *ifa = (struct ifaddr *)data; register struct ifreq *ifr = (struct ifreq *)data; register int s, error = 0; struct sl_softc *sc = ifp->if_softc; s = splimp(); switch (cmd) { case SIOCSIFFLAGS: /* * if.c will set the interface up even if we * don't want it to. */ if (sc->sc_ttyp == NULL) { ifp->if_flags &= ~IFF_UP; } break; case SIOCSIFADDR: /* * This is "historical" - set the interface up when * setting the address. */ if (ifa->ifa_addr->sa_family == AF_INET) { if (sc->sc_ttyp != NULL) ifp->if_flags |= IFF_UP; } else { error = EAFNOSUPPORT; } break; case SIOCSIFDSTADDR: if (ifa->ifa_addr->sa_family != AF_INET) error = EAFNOSUPPORT; break; case SIOCADDMULTI: case SIOCDELMULTI: break; case SIOCSIFMTU: /* * Set the interface MTU. */ if (ifr->ifr_mtu > SLTMAX) error = EINVAL; else { struct tty *tp; ifp->if_mtu = ifr->ifr_mtu; tp = sc->sc_ttyp; if (tp != NULL) clist_alloc_cblocks(&tp->t_outq, SLIP_HIWAT + 2 * ifp->if_mtu + 1, SLIP_HIWAT + 2 * ifp->if_mtu + 1); } break; default: error = EINVAL; } splx(s); return (error); } static void sl_keepalive(chan) void *chan; { struct sl_softc *sc = chan; if (sc->sc_keepalive) { if (sc->sc_flags & SC_KEEPALIVE) { if (sc->sc_ttyp->t_pgrp != NULL) { PGRP_LOCK(sc->sc_ttyp->t_pgrp); pgsignal (sc->sc_ttyp->t_pgrp, SIGURG, 1); PGRP_UNLOCK(sc->sc_ttyp->t_pgrp); } } else sc->sc_flags |= SC_KEEPALIVE; sc->sc_kahandle = timeout(sl_keepalive, sc, sc->sc_keepalive); } else { sc->sc_flags &= ~SC_KEEPALIVE; } } static void sl_outfill(chan) void *chan; { struct sl_softc *sc = chan; register struct tty *tp = sc->sc_ttyp; int s; if (sc->sc_outfill && tp != NULL) { if (sc->sc_flags & SC_OUTWAIT) { s = splimp (); ++sc->sc_if.if_obytes; (void) putc(FRAME_END, &tp->t_outq); (*tp->t_oproc)(tp); splx (s); } else sc->sc_flags |= SC_OUTWAIT; sc->sc_ofhandle = timeout(sl_outfill, sc, sc->sc_outfill); } else { sc->sc_flags &= ~SC_OUTWAIT; } }