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/*
* 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: src/sys/net/if_sl.c,v 1.70.2.4 2000/03/01 13:13:10 ru 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 "opt_inet.h"
#include "opt_inet6.h"
#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>
#if NBPFILTER > 0
#include <net/bpf.h>
#endif
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.
*/
#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 */
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 =
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;
IFQ_SET_MAXLEN(&sc->sc_if.if_snd, 50);
sc->sc_fastq.ifq_maxlen = 32;
sc->sc_if.if_linkmib = sc;
sc->sc_if.if_linkmiblen = sizeof *sc;
IFQ_SET_READY(&sc->sc_if.if_snd);
if_attach(&sc->sc_if);
#if NBPFILTER > 0
bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN);
#endif
}
}
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, -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->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 && !(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);
sl_compress_init(&sc->sc_comp, -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, error;
ALTQ_DECL(struct altq_pktattr pktattr;)
IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
/*
* `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);
}
ip = mtod(m, struct ip *);
if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) {
m_freem(m);
return (ENETRESET); /* XXX ? */
}
s = splimp();
if ((ip->ip_tos & IPTOS_LOWDELAY)
#ifdef ALTQ
&& !ALTQ_IS_ENABLED(&sc->sc_if.if_snd)
#endif
) {
ifq = &sc->sc_fastq;
if (IF_QFULL(ifq)) {
IF_DROP(ifq);
m_freem(m);
error = ENOBUFS;
} else {
IF_ENQUEUE(ifq, m);
error = 0;
}
} else {
IFQ_ENQUEUE(&sc->sc_if.if_snd, m, &pktattr, error);
}
if (error) {
splx(s);
sc->sc_if.if_oerrors++;
return (error);
}
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;
#if NBPFILTER > 0
u_char bpfbuf[SLTMAX + SLIP_HDRLEN];
register int len = 0;
#endif
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
IFQ_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 NBPFILTER > 0
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);
}
#endif
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 NBPFILTER > 0
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);
}
#endif
/*
* 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;
#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_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 NBPFILTER > 0
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);
}
#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_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);
}
#endif
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