NetBSD/sys/net/if_sl.c

1076 lines
25 KiB
C

/* $NetBSD: if_sl.c,v 1.72 2001/01/17 00:30:51 thorpej Exp $ */
/*
* 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 8.9 (Berkeley) 1/9/95
*/
/*
* 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.
*/
#include "sl.h"
#if NSL > 0
#include "opt_inet.h"
#include "bpfilter.h"
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/malloc.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/conf.h>
#include <sys/tty.h>
#include <sys/kernel.h>
#if __NetBSD__
#include <sys/systm.h>
#endif
#include <machine/cpu.h>
#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
#include <machine/intr.h>
#endif
#include <net/if.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/route.h>
#ifdef INET
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#else
#error 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
/*
* SLMAX 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, SLMAX can be at most
* MCLBYTES - 128
*
* SLMTU is a hard limit on output packet size. To insure good
* interactive response, SLMTU wants to be the smallest size that
* amortizes the header cost. (Remember that even with
* type-of-service queuing, we have to wait for any in-progress
* packet to finish. I.e., we wait, on the average, 1/2 * mtu /
* cps, where cps is the line speed in characters per second.
* E.g., 533ms wait for a 1024 byte MTU on a 9600 baud line. The
* average compressed header size is 6-8 bytes so any MTU > 90
* bytes will give us 90% of the line bandwidth. A 100ms wait is
* tolerable (500ms is not), so want an MTU around 296. (Since TCP
* will send 256 byte segments (to allow for 40 byte headers), the
* typical packet size on the wire will be around 260 bytes). In
* 4.3tahoe+ systems, we can set an MTU in a route so we do that &
* leave the interface MTU relatively high (so we don't IP fragment
* when acting as a gateway to someone using a stupid MTU).
*
* Similar considerations apply to SLIP_HIWAT: It's 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 SLMAX (MCLBYTES - BUFOFFSET)
#define SLBUFSIZE (SLMAX + BUFOFFSET)
#ifndef SLMTU
#define SLMTU 296
#endif
#if (SLMTU < 3)
#error SLMTU way too small.
#endif
#define SLIP_HIWAT roundup(50,CBSIZE)
#ifndef __NetBSD__ /* XXX - cgd */
#define CLISTRESERVE 1024 /* Can't let clists get too low */
#endif /* !__NetBSD__ */
/*
* 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 */
#ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
void slnetisr(void);
#endif
void slintr(void *);
static int slinit __P((struct sl_softc *));
static struct mbuf *sl_btom __P((struct sl_softc *, int));
/*
* Called from boot code to establish sl interfaces.
*/
void
slattach()
{
struct sl_softc *sc;
int i = 0;
for (sc = sl_softc; i < NSL; sc++) {
sc->sc_unit = i; /* XXX */
sprintf(sc->sc_if.if_xname, "sl%d", i++);
sc->sc_if.if_softc = sc;
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_dlt = DLT_SLIP;
sc->sc_fastq.ifq_maxlen = 32;
IFQ_SET_READY(&sc->sc_if.if_snd);
if_attach(&sc->sc_if);
if_alloc_sadl(&sc->sc_if);
#if NBPFILTER > 0
bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN);
#endif
}
}
static int
slinit(sc)
struct sl_softc *sc;
{
if (sc->sc_mbuf == NULL) {
MGETHDR(sc->sc_mbuf, M_WAIT, MT_DATA);
MCLGET(sc->sc_mbuf, M_WAIT);
}
sc->sc_ep = (u_char *) sc->sc_mbuf->m_ext.ext_buf +
sc->sc_mbuf->m_ext.ext_size;
sc->sc_mp = sc->sc_pktstart = (u_char *) sc->sc_mbuf->m_ext.ext_buf +
BUFOFFSET;
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;
struct tty *tp;
{
struct proc *p = curproc; /* XXX */
struct sl_softc *sc;
int nsl;
int error;
int s;
if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
return (error);
if (tp->t_linesw && (tp->t_linesw->l_no == SLIPDISC))
return (0);
for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++)
if (sc->sc_ttyp == NULL) {
#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
sc->sc_si = softintr_establish(IPL_SOFTNET,
slintr, sc);
if (sc->sc_si == NULL)
return (ENOMEM);
#endif
if (slinit(sc) == 0) {
#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
softintr_disestablish(sc->sc_si);
#endif
return (ENOBUFS);
}
tp->t_sc = (caddr_t)sc;
sc->sc_ttyp = tp;
sc->sc_if.if_baudrate = tp->t_ospeed;
s = spltty();
tp->t_state |= TS_ISOPEN | TS_XCLUDE;
splx(s);
ttyflush(tp, FREAD | FWRITE);
#ifdef __NetBSD__
/*
* make sure tty output queue is large enough
* to hold a full-sized packet (including frame
* end, and a possible extra frame end). full-sized
* packet occupies a max of 2*SLMAX bytes (because
* of possible escapes), and add two on for frame
* ends.
*/
s = spltty();
if (tp->t_outq.c_cn < 2*SLMAX+2) {
sc->sc_oldbufsize = tp->t_outq.c_cn;
sc->sc_oldbufquot = tp->t_outq.c_cq != 0;
clfree(&tp->t_outq);
error = clalloc(&tp->t_outq, 2*SLMAX+2, 0);
if (error) {
splx(s);
#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
softintr_disestablish(sc->sc_si);
#endif
return(error);
}
} else
sc->sc_oldbufsize = sc->sc_oldbufquot = 0;
splx(s);
#endif /* __NetBSD__ */
return (0);
}
return (ENXIO);
}
/*
* Line specific close routine.
* Detach the tty from the sl unit.
*/
void
slclose(tp)
struct tty *tp;
{
struct sl_softc *sc;
int s;
ttywflush(tp);
sc = tp->t_sc;
if (sc != NULL) {
#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
softintr_disestablish(sc->sc_si);
#endif
s = splnet();
if_down(&sc->sc_if);
IF_PURGE(&sc->sc_fastq);
splx(s);
s = spltty();
tp->t_linesw = linesw[0]; /* default line disc. */
tp->t_state = 0;
sc->sc_ttyp = NULL;
tp->t_sc = NULL;
m_freem(sc->sc_mbuf);
sc->sc_mbuf = NULL;
sc->sc_ep = sc->sc_mp = sc->sc_pktstart = NULL;
IF_PURGE(&sc->sc_inq);
/*
* If necessary, install a new outq buffer of the
* appropriate size.
*/
if (sc->sc_oldbufsize != 0) {
clfree(&tp->t_outq);
clalloc(&tp->t_outq, sc->sc_oldbufsize,
sc->sc_oldbufquot);
}
splx(s);
}
}
/*
* Line specific (tty) ioctl routine.
* Provide a way to get the sl unit number.
*/
/* ARGSUSED */
int
sltioctl(tp, cmd, data, flag)
struct tty *tp;
u_long cmd;
caddr_t data;
int flag;
{
struct sl_softc *sc = (struct sl_softc *)tp->t_sc;
switch (cmd) {
case SLIOCGUNIT:
*(int *)data = sc->sc_unit; /* XXX */
break;
default:
return (-1);
}
return (0);
}
/*
* Queue a packet. Start transmission if not active.
* Compression happens in slintr(); 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 slintr().
*/
int
sloutput(ifp, m, dst, rtp)
struct ifnet *ifp;
struct mbuf *m;
struct sockaddr *dst;
struct rtentry *rtp;
{
struct sl_softc *sc = ifp->if_softc;
struct ip *ip;
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("%s: af%d not supported\n", sc->sc_if.if_xname,
dst->sa_family);
m_freem(m);
sc->sc_if.if_noproto++;
return (EAFNOSUPPORT);
}
if (sc->sc_ttyp == NULL) {
m_freem(m);
return (ENETDOWN); /* sort of */
}
if ((sc->sc_ttyp->t_state & TS_CARR_ON) == 0 &&
(sc->sc_ttyp->t_cflag & CLOCAL) == 0) {
m_freem(m);
printf("%s: no carrier and not local\n", sc->sc_if.if_xname);
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 = spltty();
if (sc->sc_oqlen && sc->sc_ttyp->t_outq.c_cc == sc->sc_oqlen) {
struct timeval tv;
/* if output's been stalled for too long, and restart */
timersub(&time, &sc->sc_if.if_lastchange, &tv);
if (tv.tv_sec > 0) {
sc->sc_otimeout++;
slstart(sc->sc_ttyp);
}
}
splx(s);
s = splnet();
if ((ip->ip_tos & IPTOS_LOWDELAY) != 0
#ifdef ALTQ
&& ALTQ_IS_ENABLED(&ifp->if_snd) == 0
#endif
) {
if (IF_QFULL(&sc->sc_fastq)) {
IF_DROP(&sc->sc_fastq);
m_freem(m);
error = ENOBUFS;
} else {
IF_ENQUEUE(&sc->sc_fastq, m);
error = 0;
}
} else
IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
if (error) {
splx(s);
ifp->if_oerrors++;
return (error);
}
sc->sc_if.if_lastchange = time;
splx(s);
s = spltty();
if ((sc->sc_oqlen = 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.
*/
void
slstart(tp)
struct tty *tp;
{
struct sl_softc *sc = tp->t_sc;
/*
* 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) {
(*tp->t_oproc)(tp);
if (tp->t_outq.c_cc > SLIP_HIWAT)
return;
}
/*
* This happens briefly when the line shuts down.
*/
if (sc == NULL)
return;
#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
softintr_schedule(sc->sc_si);
#else
{
int s = splimp();
schednetisr(NETISR_SLIP);
splx(s);
}
#endif
}
/*
* Copy data buffer to mbuf chain; add ifnet pointer.
*/
static struct mbuf *
sl_btom(sc, len)
struct sl_softc *sc;
int len;
{
struct mbuf *m;
MGETHDR(m, M_DONTWAIT, MT_DATA);
if (m == NULL)
return (NULL);
/*
* Allocate a new input buffer and swap.
*/
m = sc->sc_mbuf;
MGETHDR(sc->sc_mbuf, M_DONTWAIT, MT_DATA);
if (sc->sc_mbuf == NULL) {
sc->sc_mbuf = m;
return (NULL);
}
MCLGET(sc->sc_mbuf, M_DONTWAIT);
if ((sc->sc_mbuf->m_flags & M_EXT) == 0) {
m_freem(sc->sc_mbuf);
sc->sc_mbuf = m;
return (NULL);
}
sc->sc_ep = (u_char *) sc->sc_mbuf->m_ext.ext_buf +
sc->sc_mbuf->m_ext.ext_size;
m->m_data = sc->sc_pktstart;
m->m_pkthdr.len = m->m_len = len;
m->m_pkthdr.rcvif = &sc->sc_if;
return (m);
}
/*
* tty interface receiver interrupt.
*/
void
slinput(c, tp)
int c;
struct tty *tp;
{
struct sl_softc *sc;
struct mbuf *m;
int len;
tk_nin++;
sc = (struct sl_softc *)tp->t_sc;
if (sc == NULL)
return;
if ((c & TTY_ERRORMASK) || ((tp->t_state & TS_CARR_ON) == 0 &&
(tp->t_cflag & CLOCAL) == 0)) {
sc->sc_flags |= SC_ERROR;
return;
}
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);
return;
}
}
} 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;
case FRAME_END:
if(sc->sc_flags & SC_ERROR) {
sc->sc_flags &= ~SC_ERROR;
goto newpack;
}
len = sc->sc_mp - sc->sc_pktstart;
if (len < 3)
/* less than min length packet - ignore */
goto newpack;
m = sl_btom(sc, len);
if (m == NULL)
goto error;
IF_ENQUEUE(&sc->sc_inq, m);
#ifdef __HAVE_GENERIC_SOFT_INTERRUPTS
softintr_schedule(sc->sc_si);
#else
{
int s = splimp();
schednetisr(NETISR_SLIP);
splx(s);
}
#endif
goto newpack;
}
if (sc->sc_mp < sc->sc_ep) {
*sc->sc_mp++ = c;
sc->sc_escape = 0;
return;
}
/* 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_pktstart = (u_char *) sc->sc_mbuf->m_ext.ext_buf +
BUFOFFSET;
sc->sc_escape = 0;
}
#ifndef __HAVE_GENERIC_SOFT_INTERRUPTS
void
slnetisr(void)
{
struct sl_softc *sc;
int i;
for (i = 0; i < NSL; i++) {
sc = &sl_softc[i];
if (sc->sc_ttyp == NULL)
continue;
slintr(sc);
}
}
#endif
void
slintr(void *arg)
{
struct sl_softc *sc = arg;
struct tty *tp = sc->sc_ttyp;
struct mbuf *m;
int s, len;
u_char *pktstart, c;
#if NBPFILTER > 0
u_char chdr[CHDR_LEN];
#endif
KASSERT(tp != NULL);
/*
* Output processing loop.
*/
for (;;) {
struct ip *ip;
struct mbuf *m2;
#if NBPFILTER > 0
struct mbuf *bpf_m;
#endif
/*
* Do not remove the packet from the queue if it
* doesn't look like it will fit into the current
* serial output queue. With a packet full of
* escapes, this could be as bad as MTU*2+2.
*/
s = spltty();
if (tp->t_outq.c_cn - tp->t_outq.c_cc <
2*sc->sc_if.if_mtu+2) {
splx(s);
break;
}
splx(s);
/*
* Get a packet and send it to the interface.
*/
s = splnet();
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)
break;
/*
* 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 make a deep copy of the
* entire packet (since this is a serial
* line, packets should be short and/or the
* copy should be negligible cost compared
* to the packet transmission time).
*/
bpf_m = m_dup(m, 0, M_COPYALL, M_DONTWAIT);
} else
bpf_m = NULL;
#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_if.if_bpf && bpf_m != NULL) {
/*
* Put the SLIP pseudo-"link header" in
* place. The compressed header is now
* at the beginning of the mbuf.
*/
struct mbuf n;
u_char *hp;
n.m_next = bpf_m;
n.m_data = n.m_dat;
n.m_len = SLIP_HDRLEN;
hp = mtod(&n, u_char *);
hp[SLX_DIR] = SLIPDIR_OUT;
memcpy(&hp[SLX_CHDR], mtod(m, caddr_t),
CHDR_LEN);
s = splnet();
bpf_mtap(sc->sc_if.if_bpf, &n);
splx(s);
m_freem(bpf_m);
}
#endif
sc->sc_if.if_lastchange = time;
s = spltty();
/*
* 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) {
u_char *bp, *cp, *ep;
bp = 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.
*/
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(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++;
}
/*
* We now have characters in the output queue,
* kick the serial port.
*/
(*tp->t_oproc)(tp);
splx(s);
}
/*
* Input processing loop.
*/
for (;;) {
s = spltty();
IF_DEQUEUE(&sc->sc_inq, m);
splx(s);
if (m == NULL)
break;
pktstart = mtod(m, u_char *);
len = m->m_pkthdr.len;
#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.
*/
memcpy(chdr, pktstart, CHDR_LEN);
}
#endif /* NBPFILTER > 0 */
if ((c = (*pktstart & 0xf0)) != (IPVERSION << 4)) {
if (c & 0x80)
c = TYPE_COMPRESSED_TCP;
else if (c == TYPE_UNCOMPRESSED_TCP)
*pktstart &= 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(&pktstart, len,
(u_int)c, &sc->sc_comp);
if (len <= 0) {
m_freem(m);
continue;
}
} else if ((sc->sc_if.if_flags & SC_AUTOCOMP) &&
c == TYPE_UNCOMPRESSED_TCP && len >= 40) {
len = sl_uncompress_tcp(&pktstart, len,
(u_int)c, &sc->sc_comp);
if (len <= 0) {
m_freem(m);
continue;
}
sc->sc_if.if_flags |= SC_COMPRESS;
} else {
m_freem(m);
continue;
}
}
m->m_data = (caddr_t) pktstart;
m->m_pkthdr.len = m->m_len = len;
#if NBPFILTER > 0
if (sc->sc_if.if_bpf) {
/*
* Put the SLIP pseudo-"link header" in place.
* Note this M_PREPEND() should bever fail,
* since we know we always have enough space
* in the input buffer.
*/
u_char *hp;
M_PREPEND(m, SLIP_HDRLEN, M_DONTWAIT);
if (m == NULL)
continue;
hp = mtod(m, u_char *);
hp[SLX_DIR] = SLIPDIR_IN;
memcpy(&hp[SLX_CHDR], chdr, CHDR_LEN);
s = splnet();
bpf_mtap(sc->sc_if.if_bpf, m);
splx(s);
m_adj(m, SLIP_HDRLEN);
}
#endif /* NBPFILTER > 0 */
/*
* If the packet will fit into a single
* header mbuf, copy it into one, to save
* memory.
*/
if (m->m_pkthdr.len < MHLEN) {
struct mbuf *n;
MGETHDR(n, M_DONTWAIT, MT_DATA);
M_COPY_PKTHDR(n, m);
memcpy(mtod(n, caddr_t), mtod(m, caddr_t),
m->m_pkthdr.len);
n->m_len = m->m_len;
m_freem(m);
m = n;
}
sc->sc_if.if_ipackets++;
sc->sc_if.if_lastchange = time;
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);
}
}
/*
* Process an ioctl request.
*/
int
slioctl(ifp, cmd, data)
struct ifnet *ifp;
u_long cmd;
caddr_t data;
{
struct ifaddr *ifa = (struct ifaddr *)data;
struct ifreq *ifr = (struct ifreq *)data;
int s = splnet(), error = 0;
struct sl_softc *sc = ifp->if_softc;
switch (cmd) {
case SIOCSIFADDR:
if (ifa->ifa_addr->sa_family == AF_INET)
ifp->if_flags |= IFF_UP;
else
error = EAFNOSUPPORT;
break;
case SIOCSIFDSTADDR:
if (ifa->ifa_addr->sa_family != AF_INET)
error = EAFNOSUPPORT;
break;
case SIOCSIFMTU:
if ((ifr->ifr_mtu < 3) || (ifr->ifr_mtu > SLMAX)) {
error = EINVAL;
break;
}
sc->sc_if.if_mtu = ifr->ifr_mtu;
break;
case SIOCGIFMTU:
ifr->ifr_mtu = sc->sc_if.if_mtu;
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;
default:
error = EINVAL;
}
splx(s);
return (error);
}
#endif