freebsd-dev/sys/net/if_sl.c
Bruce Evans 267513a942 Obtained from: partly from ancient patches by ache and me via 1.1.5
Remove nullmodem().

It may be useful to have a null modem routine, but nullmodem()
wasn't one.  nullmodem() was identical to ttymodem() except it
didn't implement MDMBUF (carrier) flow control, didn't do any
wakeups for off to on carrier transitions, and didn't flush the
i/o queues for on to off carrier transitions (flushing has the side
effect of waking up readers and writers) although it did generate
SIGHUPs.  The wakeups must normally be done even if nullmodem() is
null in case something is sleeping waiting for a carrier transition.
In any case, the wakeups should be harmless.  They may cause bogus
results for select(), but select() is already bogus for nonstandard
line disciplines.
1995-07-29 13:40:13 +00:00

1025 lines
25 KiB
C

/*
* 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
* $Id: if_sl.c,v 1.26 1995/07/07 01:13:49 davidg Exp $
*/
/*
* 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 "bpfilter.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/mbuf.h>
#include <sys/buf.h>
#include <sys/dkstat.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/file.h>
#include <sys/signalvar.h>
#include <sys/tty.h>
#include <sys/clist.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <machine/cpu.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/route.h>
#if INET
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#else
Huh? Slip without inet?
#endif
#include <net/slcompress.h>
#include <net/if_slvar.h>
#include <net/slip.h>
#if NBPFILTER > 0
#include <sys/time.h>
#include <net/bpf.h>
#endif
/*
* 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.
*/
#if NBPFILTER > 0
#define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN)
#else
#define BUFOFFSET (128+sizeof(struct ifnet **))
#endif
#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 */
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;
#define ttyerrio ((int (*) __P((struct tty *, struct uio *, int)))enodev)
static struct linesw slipdisc =
{ slopen, slclose, ttyerrio, ttyerrio, sltioctl,
slinput, slstart, ttymodem };
/*
* Called from boot code to establish sl interfaces.
*/
void
slattach()
{
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_next = NULL;
sc->sc_if.if_unit = i++;
sc->sc_if.if_mtu = SLMTU;
sc->sc_if.if_flags =
IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST;
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;
if_attach(&sc->sc_if);
#if NBPFILTER > 0
bpfattach(&sc->sc_bpf, &sc->sc_if, DLT_SLIP, SLIP_HDRLEN);
#endif
}
}
PSEUDO_SET(slattach, if_sl);
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%d: can't allocate buffer\n", sc - sl_softc);
return (0);
}
}
sc->sc_buf = sc->sc_ep - SLRMAX;
sc->sc_mp = sc->sc_buf;
sl_compress_init(&sc->sc_comp);
return (1);
}
/*
* Line specific open routine.
* Attach the given tty to the first available sl unit.
*/
/* ARGSUSED */
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->p_ucred, &p->p_acflag);
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) {
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,
sc->sc_if.if_mtu + SLIP_HIWAT,
sc->sc_if.if_mtu + SLIP_HIWAT);
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.
*/
int
slclose(tp,flag)
struct tty *tp;
int flag;
{
register struct sl_softc *sc;
int s;
if (ttywflush(tp))
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);
}
if (sc->sc_keepalive) {
sc->sc_keepalive = 0;
untimeout(sl_keepalive, sc);
}
if_down(&sc->sc_if);
sc->sc_flags = 0;
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 */
int
sltioctl(tp, cmd, data, flag, p)
struct tty *tp;
int cmd;
caddr_t data;
int flag;
struct proc *p;
{
struct sl_softc *sc = (struct sl_softc *)tp->t_sc;
int s;
s = splimp();
switch (cmd) {
case SLIOCGUNIT:
*(int *)data = sc->sc_if.if_unit;
break;
case SLIOCSUNIT:
sc->sc_if.if_unit = *(u_int *)data;
break;
case SLIOCSKEEPAL:
sc->sc_keepalive = *(u_int *)data * hz;
if (sc->sc_keepalive) {
sc->sc_flags |= SC_KEEPALIVE;
timeout(sl_keepalive, sc, sc->sc_keepalive);
} else {
sc->sc_flags &= ~SC_KEEPALIVE;
untimeout(sl_keepalive, sc);
}
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;
timeout(sl_outfill, sc, sc->sc_outfill);
} else {
sc->sc_flags &= ~SC_OUTWAIT;
untimeout(sl_outfill, sc);
}
break;
case SLIOCGOUTFILL:
*(int *)data = sc->sc_outfill / hz;
break;
default:
splx(s);
return (-1);
}
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.
*/
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_CARR_ON) == 0 &&
(sc->sc_ttyp->t_cflag & CLOCAL) == 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);
sc->sc_if.if_lastchange = time;
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.
*/
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;
#if NBPFILTER > 0
u_char bpfbuf[SLTMAX + SLIP_HDRLEN];
register int len = 0;
#endif
for (;;) {
/*
* If there is more in the output queue, just send it now.
* We are being called in lieu of ttstart and must do what
* it would.
*/
if (tp->t_outq.c_cc != 0) {
if (sc != NULL)
sc->sc_flags &= ~SC_OUTWAIT;
(*tp->t_oproc)(tp);
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;
sc->sc_flags &= ~SC_OUTWAIT;
/*
* 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 NBPFILTER > 0
if (sc->sc_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);
}
#endif
if ((ip = mtod(m, struct 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 NBPFILTER > 0
if (sc->sc_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_bpf, bpfbuf, len + SLIP_HDRLEN);
}
#endif
sc->sc_if.if_lastchange = time;
/*
* 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;
}
/*
* 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)((int)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.
*/
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;
#if NBPFILTER > 0
u_char chdr[CHDR_LEN];
#endif
tk_nin++;
sc = (struct sl_softc *)tp->t_sc;
if (sc == NULL)
return 0;
if (c & TTY_ERRORMASK || ((tp->t_state & TS_CARR_ON) == 0 &&
(tp->t_cflag & CLOCAL) == 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.tv_sec >= 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.tv_sec >= sc->sc_lasttime + ABT_IDLE) {
if (++sc->sc_abortcount == 1)
sc->sc_starttime = time.tv_sec;
if (sc->sc_abortcount >= ABT_COUNT) {
slclose(tp,0);
return 0;
}
}
} else
sc->sc_abortcount = 0;
sc->sc_lasttime = time.tv_sec;
}
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 NBPFILTER > 0
if (sc->sc_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);
}
#endif
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 NBPFILTER > 0
if (sc->sc_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_bpf, hp, len + SLIP_HDRLEN);
}
#endif
m = sl_btom(sc, len);
if (m == NULL)
goto error;
sc->sc_if.if_ipackets++;
sc->sc_if.if_lastchange = time;
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.
*/
int
slioctl(ifp, cmd, data)
register struct ifnet *ifp;
int 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)
if_up(ifp);
} else {
error = EAFNOSUPPORT;
}
break;
case SIOCSIFDSTADDR:
if (ifa->ifa_addr->sa_family != AF_INET)
error = EAFNOSUPPORT;
break;
case SIOCADDMULTI:
case SIOCDELMULTI:
if (ifr == 0) {
error = EAFNOSUPPORT; /* XXX */
break;
}
switch (ifr->ifr_addr.sa_family) {
#ifdef INET
case AF_INET:
break;
#endif
default:
error = EAFNOSUPPORT;
break;
}
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,
ifp->if_mtu + SLIP_HIWAT,
ifp->if_mtu + SLIP_HIWAT);
}
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;
timeout(sl_keepalive, sc, sc->sc_keepalive);
} else {
sc->sc_flags &= ~SC_KEEPALIVE;
untimeout(sl_keepalive, sc);
}
}
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;
timeout(sl_outfill, sc, sc->sc_outfill);
} else {
sc->sc_flags &= ~SC_OUTWAIT;
untimeout(sl_outfill, sc);
}
}
#endif