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Diffstat (limited to 'sys/net/if_sl.c')
| -rw-r--r-- | sys/net/if_sl.c | 1040 |
1 files changed, 1040 insertions, 0 deletions
diff --git a/sys/net/if_sl.c b/sys/net/if_sl.c new file mode 100644 index 0000000..456f827 --- /dev/null +++ b/sys/net/if_sl.c @@ -0,0 +1,1040 @@ +/* + * 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. + * 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. + * + * @(#)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 "sl.h" +#if NSL > 0 + +#include "opt_inet.h" +#if !defined(ACTUALLY_LKM_NOT_KERNEL) && !defined(KLD_MODULE) +#include "opt_slip.h" +#endif +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/proc.h> +#include <sys/malloc.h> +#include <sys/mbuf.h> +#include <sys/dkstat.h> +#include <sys/socket.h> +#include <sys/sockio.h> +#include <sys/fcntl.h> +#include <sys/signalvar.h> +#include <sys/tty.h> +#include <sys/clist.h> +#include <sys/kernel.h> +#include <sys/conf.h> + +#include <net/if.h> +#include <net/if_types.h> +#include <net/netisr.h> + +#if INET +#include <netinet/in.h> +#include <netinet/in_systm.h> +#include <netinet/in_var.h> +#include <netinet/ip.h> +#else +#error "Huh? Slip without inet?" +#endif + +#include <net/slcompress.h> +#include <net/if_slvar.h> +#include <net/slip.h> + +#include <net/bpf.h> + +static void slattach __P((void *)); +PSEUDO_SET(slattach, if_sl); + +/* + * 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 struct sl_softc sl_softc[NSL]; + +#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 slinit __P((struct sl_softc *)); +static struct mbuf *sl_btom __P((struct sl_softc *, int)); +static timeout_t sl_keepalive; +static timeout_t sl_outfill; +static int slclose __P((struct tty *,int)); +static int slinput __P((int, struct tty *)); +static int slioctl __P((struct ifnet *, u_long, caddr_t)); +static int sltioctl __P((struct tty *, u_long, caddr_t, int, struct proc *)); +static int slopen __P((dev_t, struct tty *)); +static int sloutput __P((struct ifnet *, + struct mbuf *, struct sockaddr *, struct rtentry *)); +static int slstart __P((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 void +slattach(dummy) + void *dummy; +{ + register struct sl_softc *sc; + register int i = 0; + + linesw[SLIPDISC] = slipdisc; + + for (sc = sl_softc; i < NSL; sc++) { + sc->sc_if.if_name = "sl"; + sc->sc_if.if_unit = i++; + 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; + if_attach(&sc->sc_if); + bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN); + } +} + +static int +slinit(sc) + register struct sl_softc *sc; +{ + register caddr_t p; + + if (sc->sc_ep == (u_char *) 0) { + MCLALLOC(p, M_WAIT); + if (p) + sc->sc_ep = (u_char *)p + SLBUFSIZE; + else { + printf("sl%ld: can't allocate buffer\n", + (long)(sc - sl_softc)); + return (0); + } + } + sc->sc_buf = sc->sc_ep - SLRMAX; + sc->sc_mp = sc->sc_buf; + sl_compress_init(&sc->sc_comp, -1); + return (1); +} + +/* + * 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; +{ + struct proc *p = curproc; /* XXX */ + register struct sl_softc *sc; + register int nsl; + int s, error; + + error = suser(p); + if (error) + return (error); + + if (tp->t_line == SLIPDISC) + return (0); + + for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++) + if (sc->sc_ttyp == NULL && !(sc->sc_flags & SC_STATIC)) { + if (slinit(sc) == 0) + 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); + } + return (ENXIO); +} + +/* + * 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_flags &= SC_STATIC; + sc->sc_ttyp = NULL; + tp->t_sc = NULL; + MCLFREE((caddr_t)(sc->sc_ep - SLBUFSIZE)); + sc->sc_ep = 0; + sc->sc_mp = 0; + sc->sc_buf = 0; + } + 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, p) + struct tty *tp; + u_long cmd; + caddr_t data; + int flag; + struct proc *p; +{ + struct sl_softc *sc = (struct sl_softc *)tp->t_sc, *nc, *tmpnc; + int s, nsl; + + s = splimp(); + switch (cmd) { + case SLIOCGUNIT: + *(int *)data = sc->sc_if.if_unit; + break; + + case SLIOCSUNIT: + if (sc->sc_if.if_unit != *(u_int *)data) { + for (nsl = NSL, nc = sl_softc; --nsl >= 0; nc++) { + if ( nc->sc_if.if_unit == *(u_int *)data + && nc->sc_ttyp == NULL + ) { + tmpnc = malloc(sizeof *tmpnc, M_TEMP, + M_NOWAIT); + if (tmpnc == NULL) { + splx(s); + return (ENOMEM); + } + *tmpnc = *nc; + *nc = *sc; + nc->sc_if = tmpnc->sc_if; + tmpnc->sc_if = sc->sc_if; + *sc = *tmpnc; + free(tmpnc, M_TEMP); + if (sc->sc_if.if_flags & IFF_UP) { + if_down(&sc->sc_if); + if (!(nc->sc_if.if_flags & IFF_UP)) + if_up(&nc->sc_if); + } else if (nc->sc_if.if_flags & IFF_UP) + if_down(&nc->sc_if); + sc->sc_flags &= ~SC_STATIC; + sc->sc_flags |= (nc->sc_flags & SC_STATIC); + tp->t_sc = sc = nc; + clist_alloc_cblocks(&tp->t_outq, + SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1, + SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1); + goto slfound; + } + } + splx(s); + return (ENXIO); + } + slfound: + sc->sc_flags |= SC_STATIC; + 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 = &sl_softc[ifp->if_unit]; + 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) { + printf("sl%d: af%d not supported\n", sc->sc_if.if_unit, + 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; + s = splimp(); + if (IF_QFULL(ifq)) { + IF_DROP(ifq); + m_freem(m); + splx(s); + sc->sc_if.if_oerrors++; + return (ENOBUFS); + } + IF_ENQUEUE(ifq, m); + 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; + struct mbuf *m2; + u_char bpfbuf[SLTMAX + SLIP_HDRLEN]; + 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 = 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) { + /* + * Put the SLIP pseudo-"link header" in place. The + * compressed header is now at the beginning of the + * mbuf. + */ + bpfbuf[SLX_DIR] = SLIPDIR_OUT; + bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR], CHDR_LEN); + bpf_tap(&sc->sc_if, 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; + } + } + MFREE(m, m2); + m = m2; + } + + 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; +{ + register struct mbuf *m; + + 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); + } + sc->sc_ep = mtod(m, u_char *) + SLBUFSIZE; + m->m_data = (caddr_t)sc->sc_buf; + m->m_ext.ext_buf = (caddr_t)((intptr_t)sc->sc_buf &~ MCLOFSET); + } 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; + int s; + 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; + } + + s = splimp(); + if (IF_QFULL(&ipintrq)) { + IF_DROP(&ipintrq); + sc->sc_if.if_ierrors++; + sc->sc_if.if_iqdrops++; + m_freem(m); + } else { + IF_ENQUEUE(&ipintrq, m); + schednetisr(NETISR_IP); + } + splx(s); + 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; + + s = splimp(); + + switch (cmd) { + + case SIOCSIFFLAGS: + /* + * if.c will set the interface up even if we + * don't want it to. + */ + if (sl_softc[ifp->if_unit].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 (sl_softc[ifp->if_unit].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 = sl_softc[ifp->if_unit].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) + pgsignal (sc->sc_ttyp->t_pgrp, SIGURG, 1); + 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; + } +} + +#endif |
