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freebsd-dev/sys/net/ppp_tty.c
bmilekic 4c48d530e1 * Rename M_WAIT mbuf subsystem flag to M_TRYWAIT. 
This is because calls with M_WAIT (now M_TRYWAIT) may not wait
  forever when nothing is available for allocation, and may end up
  returning NULL. Hopefully we now communicate more of the right thing
  to developers and make it very clear that it's necessary to check whether
  calls with M_(TRY)WAIT also resulted in a failed allocation.
  M_TRYWAIT basically means "try harder, block if necessary, but don't
  necessarily wait forever." The time spent blocking is tunable with
  the kern.ipc.mbuf_wait sysctl.
  M_WAIT is now deprecated but still defined for the next little while.

* Fix a typo in a comment in mbuf.h

* Fix some code that was actually passing the mbuf subsystem's M_WAIT to
  malloc(). Made it pass M_WAITOK instead. If we were ever to redefine the
  value of the M_WAIT flag, this could have became a big problem.
2000-12-21 21:44:31 +00:00

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/*
* ppp_tty.c - Point-to-Point Protocol (PPP) driver for asynchronous
* tty devices.
*
* Copyright (c) 1989 Carnegie Mellon University.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by Carnegie Mellon University. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* Drew D. Perkins
* Carnegie Mellon University
* 4910 Forbes Ave.
* Pittsburgh, PA 15213
* (412) 268-8576
* ddp@andrew.cmu.edu
*
* Based on:
* @(#)if_sl.c 7.6.1.2 (Berkeley) 2/15/89
*
* Copyright (c) 1987 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* 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).
* Converted to 4.3BSD Beta by Chris Torek.
* Other changes made at Berkeley, based in part on code by Kirk Smith.
*
* Converted to 4.3BSD+ 386BSD by Brad Parker (brad@cayman.com)
* Added VJ tcp header compression; more unified ioctls
*
* Extensively modified by Paul Mackerras (paulus@cs.anu.edu.au).
* Cleaned up a lot of the mbuf-related code to fix bugs that
* caused system crashes and packet corruption. Changed pppstart
* so that it doesn't just give up with a "collision" if the whole
* packet doesn't fit in the output ring buffer.
*
* Added priority queueing for interactive IP packets, following
* the model of if_sl.c, plus hooks for bpf.
* Paul Mackerras (paulus@cs.anu.edu.au).
*/
/* $FreeBSD$ */
#include "opt_ppp.h" /* XXX for ppp_defs.h */
#define VJC /* XXX for ppp_defs.h */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/mbuf.h>
#include <sys/dkstat.h>
#include <sys/socket.h>
#include <sys/fcntl.h>
#include <sys/tty.h>
#include <sys/conf.h>
#include <sys/uio.h>
#include <sys/vnode.h>
#ifdef PPP_FILTER
#include <net/bpf.h>
#endif
#include <net/if_ppp.h>
#include <net/if_pppvar.h>
static int pppopen __P((dev_t dev, struct tty *tp));
static int pppclose __P((struct tty *tp, int flag));
static int pppread __P((struct tty *tp, struct uio *uio, int flag));
static int pppwrite __P((struct tty *tp, struct uio *uio, int flag));
static int ppptioctl __P((struct tty *tp, u_long cmd, caddr_t data, int flag,
struct proc *));
static int pppinput __P((int c, struct tty *tp));
static int pppstart __P((struct tty *tp));
static u_short pppfcs __P((u_short fcs, u_char *cp, int len));
static void pppasyncstart __P((struct ppp_softc *));
static void pppasyncctlp __P((struct ppp_softc *));
static void pppasyncrelinq __P((struct ppp_softc *));
static void pppasyncsetmtu __P((struct ppp_softc *));
static void ppp_timeout __P((void *));
static void pppgetm __P((struct ppp_softc *sc));
static void ppplogchar __P((struct ppp_softc *, int));
/* XXX called from if_ppp.c - layering violation */
void pppasyncattach __P((void *));
/*
* Some useful mbuf macros not in mbuf.h.
*/
#define M_IS_CLUSTER(m) ((m)->m_flags & M_EXT)
#define M_DATASTART(m) \
(M_IS_CLUSTER(m) ? (m)->m_ext.ext_buf : \
(m)->m_flags & M_PKTHDR ? (m)->m_pktdat : (m)->m_dat)
#define M_DATASIZE(m) \
(M_IS_CLUSTER(m) ? (m)->m_ext.ext_size : \
(m)->m_flags & M_PKTHDR ? MHLEN: MLEN)
/*
* Does c need to be escaped?
*/
#define ESCAPE_P(c) (sc->sc_asyncmap[(c) >> 5] & (1 << ((c) & 0x1F)))
/*
* Procedures for using an async tty interface for PPP.
*/
/* This is a FreeBSD-2.X kernel. */
#define CCOUNT(q) ((q)->c_cc)
#define PPP_LOWAT 100 /* Process more output when < LOWAT on queue */
#define PPP_HIWAT 400 /* Don't start a new packet if HIWAT on que */
/*
* Define the PPP line discipline.
*/
static struct linesw pppdisc = {
pppopen, pppclose, pppread, pppwrite,
ppptioctl, pppinput, pppstart, ttymodem,
PPP_FLAG
};
void
pppasyncattach(dummy)
void *dummy;
{
/* register line discipline */
linesw[PPPDISC] = pppdisc;
}
/*
* Line specific open routine for async tty devices.
* Attach the given tty to the first available ppp unit.
* Called from device open routine or ttioctl() at >= splsofttty()
*/
/* ARGSUSED */
static int
pppopen(dev, tp)
dev_t dev;
register struct tty *tp;
{
struct proc *p = curproc; /* XXX */
register struct ppp_softc *sc;
int error, s;
if ((error = suser(p)) != 0)
return (error);
s = spltty();
if (tp->t_line == PPPDISC) {
sc = (struct ppp_softc *) tp->t_sc;
if (sc != NULL && sc->sc_devp == (void *) tp) {
splx(s);
return (0);
}
}
if ((sc = pppalloc(p->p_pid)) == NULL) {
splx(s);
return ENXIO;
}
if (sc->sc_relinq)
(*sc->sc_relinq)(sc); /* get previous owner to relinquish the unit */
sc->sc_ilen = 0;
sc->sc_m = NULL;
bzero(sc->sc_asyncmap, sizeof(sc->sc_asyncmap));
sc->sc_asyncmap[0] = 0xffffffff;
sc->sc_asyncmap[3] = 0x60000000;
sc->sc_rasyncmap = 0;
sc->sc_devp = (void *) tp;
sc->sc_start = pppasyncstart;
sc->sc_ctlp = pppasyncctlp;
sc->sc_relinq = pppasyncrelinq;
sc->sc_setmtu = pppasyncsetmtu;
sc->sc_outm = NULL;
pppgetm(sc);
sc->sc_if.if_flags |= IFF_RUNNING;
getmicrotime(&sc->sc_if.if_lastchange);
sc->sc_if.if_baudrate = tp->t_ospeed;
tp->t_sc = (caddr_t) sc;
ttyflush(tp, FREAD | FWRITE);
/*
* Pre-allocate cblocks to the "just right" amount. The 1 byte t_canq
* allocation helps avoid the need for select and/or FIONREAD.
* We also pass 1 byte tokens through t_canq...
*/
clist_alloc_cblocks(&tp->t_canq, 1, 1);
clist_alloc_cblocks(&tp->t_outq, sc->sc_if.if_mtu + PPP_HIWAT,
sc->sc_if.if_mtu + PPP_HIWAT);
clist_alloc_cblocks(&tp->t_rawq, 0, 0);
splx(s);
return (0);
}
/*
* Line specific close routine, called from device close routine
* and from ttioctl at >= splsofttty().
* Detach the tty from the ppp unit.
* Mimics part of ttyclose().
*/
static int
pppclose(tp, flag)
struct tty *tp;
int flag;
{
register struct ppp_softc *sc;
int s;
s = spltty();
ttyflush(tp, FREAD | FWRITE);
clist_free_cblocks(&tp->t_canq);
clist_free_cblocks(&tp->t_outq);
tp->t_line = 0;
sc = (struct ppp_softc *) tp->t_sc;
if (sc != NULL) {
tp->t_sc = NULL;
if (tp == (struct tty *) sc->sc_devp) {
pppasyncrelinq(sc);
pppdealloc(sc);
}
}
splx(s);
return 0;
}
/*
* Relinquish the interface unit to another device.
*/
static void
pppasyncrelinq(sc)
struct ppp_softc *sc;
{
int s;
s = spltty();
if (sc->sc_outm) {
m_freem(sc->sc_outm);
sc->sc_outm = NULL;
}
if (sc->sc_m) {
m_freem(sc->sc_m);
sc->sc_m = NULL;
}
if (sc->sc_flags & SC_TIMEOUT) {
untimeout(ppp_timeout, (void *) sc, sc->sc_ch);
sc->sc_flags &= ~SC_TIMEOUT;
}
splx(s);
}
/*
* This gets called from the upper layer to notify a mtu change
*/
static void
pppasyncsetmtu(sc)
register struct ppp_softc *sc;
{
register struct tty *tp = (struct tty *) sc->sc_devp;
int s;
s = spltty();
if (tp != NULL)
clist_alloc_cblocks(&tp->t_outq, sc->sc_if.if_mtu + PPP_HIWAT,
sc->sc_if.if_mtu + PPP_HIWAT);
splx(s);
}
/*
* Line specific (tty) read routine.
* called at zero spl from the device driver in the response to user-level
* reads on the tty file descriptor (ie: pppd).
*/
static int
pppread(tp, uio, flag)
register struct tty *tp;
struct uio *uio;
int flag;
{
register struct ppp_softc *sc = (struct ppp_softc *)tp->t_sc;
struct mbuf *m, *m0;
register int s;
int error = 0;
if (sc == NULL)
return 0;
/*
* Loop waiting for input, checking that nothing disasterous
* happens in the meantime.
*/
s = spltty();
for (;;) {
if (tp != (struct tty *) sc->sc_devp || tp->t_line != PPPDISC) {
splx(s);
return 0;
}
if (sc->sc_inq.ifq_head != NULL)
break;
if ((tp->t_state & TS_CONNECTED) == 0) {
splx(s);
return 0; /* end of file */
}
if (tp->t_state & TS_ASYNC || flag & IO_NDELAY) {
splx(s);
return (EWOULDBLOCK);
}
error = ttysleep(tp, TSA_HUP_OR_INPUT(tp), TTIPRI | PCATCH, "pppin", 0);
if (error) {
splx(s);
return error;
}
}
/* Pull place-holder byte out of canonical queue */
getc(&tp->t_canq);
/* Get the packet from the input queue */
IF_DEQUEUE(&sc->sc_inq, m0);
splx(s);
for (m = m0; m && uio->uio_resid; m = m->m_next)
if ((error = uiomove(mtod(m, u_char *), m->m_len, uio)) != 0)
break;
m_freem(m0);
return (error);
}
/*
* Line specific (tty) write routine.
* called at zero spl from the device driver in the response to user-level
* writes on the tty file descriptor (ie: pppd).
*/
static int
pppwrite(tp, uio, flag)
register struct tty *tp;
struct uio *uio;
int flag;
{
register struct ppp_softc *sc = (struct ppp_softc *)tp->t_sc;
struct mbuf *m, *m0, **mp;
struct sockaddr dst;
int len, error, s;
if ((tp->t_state & TS_CONNECTED) == 0)
return 0; /* wrote 0 bytes */
if (tp->t_line != PPPDISC)
return (EINVAL);
if (sc == NULL || tp != (struct tty *) sc->sc_devp)
return EIO;
if (uio->uio_resid > sc->sc_if.if_mtu + PPP_HDRLEN ||
uio->uio_resid < PPP_HDRLEN)
return (EMSGSIZE);
s = spltty();
for (mp = &m0; uio->uio_resid; mp = &m->m_next) {
MGET(m, M_TRYWAIT, MT_DATA);
if ((*mp = m) == NULL) {
m_freem(m0);
splx(s);
return (ENOBUFS);
}
m->m_len = 0;
if (uio->uio_resid >= MCLBYTES / 2)
MCLGET(m, M_DONTWAIT);
len = M_TRAILINGSPACE(m);
if (len > uio->uio_resid)
len = uio->uio_resid;
if ((error = uiomove(mtod(m, u_char *), len, uio)) != 0) {
m_freem(m0);
splx(s);
return (error);
}
m->m_len = len;
}
dst.sa_family = AF_UNSPEC;
bcopy(mtod(m0, u_char *), dst.sa_data, PPP_HDRLEN);
m0->m_data += PPP_HDRLEN;
m0->m_len -= PPP_HDRLEN;
/* call the upper layer to "transmit" it... */
error = pppoutput(&sc->sc_if, m0, &dst, (struct rtentry *)0);
splx(s);
return (error);
}
/*
* Line specific (tty) ioctl routine.
* This discipline requires that tty device drivers call
* the line specific l_ioctl routine from their ioctl routines.
*/
/* ARGSUSED */
static int
ppptioctl(tp, cmd, data, flag, p)
struct tty *tp;
u_long cmd;
caddr_t data;
int flag;
struct proc *p;
{
struct ppp_softc *sc = (struct ppp_softc *) tp->t_sc;
int error, s;
if (sc == NULL || tp != (struct tty *) sc->sc_devp)
return (ENOIOCTL);
error = 0;
switch (cmd) {
case PPPIOCSASYNCMAP:
if ((error = suser(p)) != 0)
break;
sc->sc_asyncmap[0] = *(u_int *)data;
break;
case PPPIOCGASYNCMAP:
*(u_int *)data = sc->sc_asyncmap[0];
break;
case PPPIOCSRASYNCMAP:
if ((error = suser(p)) != 0)
break;
sc->sc_rasyncmap = *(u_int *)data;
break;
case PPPIOCGRASYNCMAP:
*(u_int *)data = sc->sc_rasyncmap;
break;
case PPPIOCSXASYNCMAP:
if ((error = suser(p)) != 0)
break;
s = spltty();
bcopy(data, sc->sc_asyncmap, sizeof(sc->sc_asyncmap));
sc->sc_asyncmap[1] = 0; /* mustn't escape 0x20 - 0x3f */
sc->sc_asyncmap[2] &= ~0x40000000; /* mustn't escape 0x5e */
sc->sc_asyncmap[3] |= 0x60000000; /* must escape 0x7d, 0x7e */
splx(s);
break;
case PPPIOCGXASYNCMAP:
bcopy(sc->sc_asyncmap, data, sizeof(sc->sc_asyncmap));
break;
default:
error = pppioctl(sc, cmd, data, flag, p);
if (error == 0 && cmd == PPPIOCSMRU)
pppgetm(sc);
}
return error;
}
/*
* FCS lookup table as calculated by genfcstab.
*/
static u_short fcstab[256] = {
0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
};
/*
* Calculate a new FCS given the current FCS and the new data.
*/
static u_short
pppfcs(u_short fcs, u_char *cp, int len)
{
while (len--)
fcs = PPP_FCS(fcs, *cp++);
return (fcs);
}
/*
* This gets called at splsoftnet from if_ppp.c at various times
* when there is data ready to be sent.
*/
static void
pppasyncstart(sc)
register struct ppp_softc *sc;
{
register struct tty *tp = (struct tty *) sc->sc_devp;
register struct mbuf *m;
register int len;
register u_char *start, *stop, *cp;
int n, ndone, done, idle;
struct mbuf *m2;
int s;
idle = 0;
/* XXX assumes atomic access to *tp although we're not at spltty(). */
while (CCOUNT(&tp->t_outq) < PPP_HIWAT) {
/*
* See if we have an existing packet partly sent.
* If not, get a new packet and start sending it.
*/
m = sc->sc_outm;
if (m == NULL) {
/*
* Get another packet to be sent.
*/
m = ppp_dequeue(sc);
if (m == NULL) {
idle = 1;
break;
}
/*
* The extra PPP_FLAG 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.
*/
/* XXX as above. */
if (CCOUNT(&tp->t_outq) == 0) {
++sc->sc_stats.ppp_obytes;
(void) putc(PPP_FLAG, &tp->t_outq);
}
/* Calculate the FCS for the first mbuf's worth. */
sc->sc_outfcs = pppfcs(PPP_INITFCS, mtod(m, u_char *), m->m_len);
getmicrotime(&sc->sc_if.if_lastchange);
}
for (;;) {
start = mtod(m, u_char *);
len = m->m_len;
stop = start + len;
while (len > 0) {
/*
* Find out how many bytes in the string we can
* handle without doing something special.
*/
for (cp = start; cp < stop; cp++)
if (ESCAPE_P(*cp))
break;
n = cp - start;
if (n) {
/* NetBSD (0.9 or later), 4.3-Reno or similar. */
ndone = n - b_to_q(start, n, &tp->t_outq);
len -= ndone;
start += ndone;
sc->sc_stats.ppp_obytes += ndone;
if (ndone < n)
break; /* packet doesn't fit */
}
/*
* If there are characters left in the mbuf,
* the first one must be special.
* Put it out in a different form.
*/
if (len) {
s = spltty();
if (putc(PPP_ESCAPE, &tp->t_outq)) {
splx(s);
break;
}
if (putc(*start ^ PPP_TRANS, &tp->t_outq)) {
(void) unputc(&tp->t_outq);
splx(s);
break;
}
splx(s);
sc->sc_stats.ppp_obytes += 2;
start++;
len--;
}
}
/*
* If we didn't empty this mbuf, remember where we're up to.
* If we emptied the last mbuf, try to add the FCS and closing
* flag, and if we can't, leave sc_outm pointing to m, but with
* m->m_len == 0, to remind us to output the FCS and flag later.
*/
done = len == 0;
if (done && m->m_next == NULL) {
u_char *p, *q;
int c;
u_char endseq[8];
/*
* We may have to escape the bytes in the FCS.
*/
p = endseq;
c = ~sc->sc_outfcs & 0xFF;
if (ESCAPE_P(c)) {
*p++ = PPP_ESCAPE;
*p++ = c ^ PPP_TRANS;
} else
*p++ = c;
c = (~sc->sc_outfcs >> 8) & 0xFF;
if (ESCAPE_P(c)) {
*p++ = PPP_ESCAPE;
*p++ = c ^ PPP_TRANS;
} else
*p++ = c;
*p++ = PPP_FLAG;
/*
* Try to output the FCS and flag. If the bytes
* don't all fit, back out.
*/
s = spltty();
for (q = endseq; q < p; ++q)
if (putc(*q, &tp->t_outq)) {
done = 0;
for (; q > endseq; --q)
unputc(&tp->t_outq);
break;
}
splx(s);
if (done)
sc->sc_stats.ppp_obytes += q - endseq;
}
if (!done) {
/* remember where we got to */
m->m_data = start;
m->m_len = len;
break;
}
/* Finished with this mbuf; free it and move on. */
MFREE(m, m2);
m = m2;
if (m == NULL) {
/* Finished a packet */
break;
}
sc->sc_outfcs = pppfcs(sc->sc_outfcs, mtod(m, u_char *), m->m_len);
}
/*
* If m == NULL, we have finished a packet.
* If m != NULL, we've either done as much work this time
* as we need to, or else we've filled up the output queue.
*/
sc->sc_outm = m;
if (m)
break;
}
/* Call pppstart to start output again if necessary. */
s = spltty();
pppstart(tp);
/*
* This timeout is needed for operation on a pseudo-tty,
* because the pty code doesn't call pppstart after it has
* drained the t_outq.
*/
if (!idle && (sc->sc_flags & SC_TIMEOUT) == 0) {
sc->sc_ch = timeout(ppp_timeout, (void *) sc, 1);
sc->sc_flags |= SC_TIMEOUT;
}
splx(s);
}
/*
* This gets called when a received packet is placed on
* the inq, at splsoftnet. The pppd daemon is to be woken up to do a read().
*/
static void
pppasyncctlp(sc)
struct ppp_softc *sc;
{
struct tty *tp;
int s;
/* Put a placeholder byte in canq for ttselect()/ttnread(). */
s = spltty();
tp = (struct tty *) sc->sc_devp;
putc(0, &tp->t_canq);
ttwakeup(tp);
splx(s);
}
/*
* Start output on async tty interface. If the transmit queue
* has drained sufficiently, arrange for pppasyncstart to be
* called later at splsoftnet.
* Called at spltty or higher.
*/
int
pppstart(tp)
register struct tty *tp;
{
register struct ppp_softc *sc = (struct ppp_softc *) tp->t_sc;
/*
* Call output process whether or not there is any output.
* We are being called in lieu of ttstart and must do what it would.
*/
if (tp->t_oproc != NULL)
(*tp->t_oproc)(tp);
/*
* If the transmit queue has drained and the tty has not hung up
* or been disconnected from the ppp unit, then tell if_ppp.c that
* we need more output.
*/
if (CCOUNT(&tp->t_outq) < PPP_LOWAT
&& !((tp->t_state & TS_CONNECTED) == 0)
&& sc != NULL && tp == (struct tty *) sc->sc_devp) {
ppp_restart(sc);
}
return 0;
}
/*
* Timeout routine - try to start some more output.
*/
static void
ppp_timeout(x)
void *x;
{
struct ppp_softc *sc = (struct ppp_softc *) x;
struct tty *tp = (struct tty *) sc->sc_devp;
int s;
s = spltty();
sc->sc_flags &= ~SC_TIMEOUT;
pppstart(tp);
splx(s);
}
/*
* Allocate enough mbuf to handle current MRU.
*/
static void
pppgetm(sc)
register struct ppp_softc *sc;
{
struct mbuf *m, **mp;
int len;
mp = &sc->sc_m;
for (len = sc->sc_mru + PPP_HDRLEN + PPP_FCSLEN; len > 0; ){
if ((m = *mp) == NULL) {
MGETHDR(m, M_DONTWAIT, MT_DATA);
if (m == NULL)
break;
*mp = m;
MCLGET(m, M_DONTWAIT);
}
len -= M_DATASIZE(m);
mp = &m->m_next;
}
}
/*
* tty interface receiver interrupt.
*/
static unsigned paritytab[8] = {
0x96696996, 0x69969669, 0x69969669, 0x96696996,
0x69969669, 0x96696996, 0x96696996, 0x69969669
};
/*
* Called when character is available from device driver.
* Only guaranteed to be at splsofttty() or spltty()
* This is safe to be called while the upper half's netisr is preempted.
*/
static int
pppinput(c, tp)
int c;
register struct tty *tp;
{
register struct ppp_softc *sc;
struct mbuf *m;
int ilen, s;
sc = (struct ppp_softc *) tp->t_sc;
if (sc == NULL || tp != (struct tty *) sc->sc_devp)
return 0;
++tk_nin;
++sc->sc_stats.ppp_ibytes;
if ((tp->t_state & TS_CONNECTED) == 0) {
if (sc->sc_flags & SC_DEBUG)
printf("ppp%d: no carrier\n", sc->sc_if.if_unit);
goto flush;
}
if (c & TTY_ERRORMASK) {
/* framing error or overrun on this char - abort packet */
if (sc->sc_flags & SC_DEBUG)
printf("ppp%d: line error %x\n", sc->sc_if.if_unit,
c & TTY_ERRORMASK);
goto flush;
}
c &= TTY_CHARMASK;
/*
* Handle software flow control of output.
*/
if (tp->t_iflag & IXON) {
if (c == tp->t_cc[VSTOP] && tp->t_cc[VSTOP] != _POSIX_VDISABLE) {
if ((tp->t_state & TS_TTSTOP) == 0) {
tp->t_state |= TS_TTSTOP;
tp->t_stop(tp, 0);
}
return 0;
}
if (c == tp->t_cc[VSTART] && tp->t_cc[VSTART] != _POSIX_VDISABLE) {
tp->t_state &= ~TS_TTSTOP;
if (tp->t_oproc != NULL)
(*tp->t_oproc)(tp);
return 0;
}
}
s = spltty();
if (c & 0x80)
sc->sc_flags |= SC_RCV_B7_1;
else
sc->sc_flags |= SC_RCV_B7_0;
if (paritytab[c >> 5] & (1 << (c & 0x1F)))
sc->sc_flags |= SC_RCV_ODDP;
else
sc->sc_flags |= SC_RCV_EVNP;
splx(s);
if (sc->sc_flags & SC_LOG_RAWIN)
ppplogchar(sc, c);
if (c == PPP_FLAG) {
ilen = sc->sc_ilen;
sc->sc_ilen = 0;
if (sc->sc_rawin_count > 0)
ppplogchar(sc, -1);
/*
* If SC_ESCAPED is set, then we've seen the packet
* abort sequence "}~".
*/
if (sc->sc_flags & (SC_FLUSH | SC_ESCAPED)
|| (ilen > 0 && sc->sc_fcs != PPP_GOODFCS)) {
s = spltty();
sc->sc_flags |= SC_PKTLOST; /* note the dropped packet */
if ((sc->sc_flags & (SC_FLUSH | SC_ESCAPED)) == 0){
if (sc->sc_flags & SC_DEBUG)
printf("ppp%d: bad fcs %x, pkt len %d\n",
sc->sc_if.if_unit, sc->sc_fcs, ilen);
sc->sc_if.if_ierrors++;
sc->sc_stats.ppp_ierrors++;
} else
sc->sc_flags &= ~(SC_FLUSH | SC_ESCAPED);
splx(s);
return 0;
}
if (ilen < PPP_HDRLEN + PPP_FCSLEN) {
if (ilen) {
if (sc->sc_flags & SC_DEBUG)
printf("ppp%d: too short (%d)\n", sc->sc_if.if_unit, ilen);
s = spltty();
sc->sc_if.if_ierrors++;
sc->sc_stats.ppp_ierrors++;
sc->sc_flags |= SC_PKTLOST;
splx(s);
}
return 0;
}
/*
* Remove FCS trailer. Somewhat painful...
*/
ilen -= 2;
if (--sc->sc_mc->m_len == 0) {
for (m = sc->sc_m; m->m_next != sc->sc_mc; m = m->m_next)
;
sc->sc_mc = m;
}
sc->sc_mc->m_len--;
/* excise this mbuf chain */
m = sc->sc_m;
sc->sc_m = sc->sc_mc->m_next;
sc->sc_mc->m_next = NULL;
ppppktin(sc, m, sc->sc_flags & SC_PKTLOST);
if (sc->sc_flags & SC_PKTLOST) {
s = spltty();
sc->sc_flags &= ~SC_PKTLOST;
splx(s);
}
pppgetm(sc);
return 0;
}
if (sc->sc_flags & SC_FLUSH) {
if (sc->sc_flags & SC_LOG_FLUSH)
ppplogchar(sc, c);
return 0;
}
if (c < 0x20 && (sc->sc_rasyncmap & (1 << c)))
return 0;
s = spltty();
if (sc->sc_flags & SC_ESCAPED) {
sc->sc_flags &= ~SC_ESCAPED;
c ^= PPP_TRANS;
} else if (c == PPP_ESCAPE) {
sc->sc_flags |= SC_ESCAPED;
splx(s);
return 0;
}
splx(s);
/*
* Initialize buffer on first octet received.
* First octet could be address or protocol (when compressing
* address/control).
* Second octet is control.
* Third octet is first or second (when compressing protocol)
* octet of protocol.
* Fourth octet is second octet of protocol.
*/
if (sc->sc_ilen == 0) {
/* reset the first input mbuf */
if (sc->sc_m == NULL) {
pppgetm(sc);
if (sc->sc_m == NULL) {
if (sc->sc_flags & SC_DEBUG)
printf("ppp%d: no input mbufs!\n", sc->sc_if.if_unit);
goto flush;
}
}
m = sc->sc_m;
m->m_len = 0;
m->m_data = M_DATASTART(sc->sc_m);
sc->sc_mc = m;
sc->sc_mp = mtod(m, char *);
sc->sc_fcs = PPP_INITFCS;
if (c != PPP_ALLSTATIONS) {
if (sc->sc_flags & SC_REJ_COMP_AC) {
if (sc->sc_flags & SC_DEBUG)
printf("ppp%d: garbage received: 0x%x (need 0xFF)\n",
sc->sc_if.if_unit, c);
goto flush;
}
*sc->sc_mp++ = PPP_ALLSTATIONS;
*sc->sc_mp++ = PPP_UI;
sc->sc_ilen += 2;
m->m_len += 2;
}
}
if (sc->sc_ilen == 1 && c != PPP_UI) {
if (sc->sc_flags & SC_DEBUG)
printf("ppp%d: missing UI (0x3), got 0x%x\n",
sc->sc_if.if_unit, c);
goto flush;
}
if (sc->sc_ilen == 2 && (c & 1) == 1) {
/* a compressed protocol */
*sc->sc_mp++ = 0;
sc->sc_ilen++;
sc->sc_mc->m_len++;
}
if (sc->sc_ilen == 3 && (c & 1) == 0) {
if (sc->sc_flags & SC_DEBUG)
printf("ppp%d: bad protocol %x\n", sc->sc_if.if_unit,
(sc->sc_mp[-1] << 8) + c);
goto flush;
}
/* packet beyond configured mru? */
if (++sc->sc_ilen > sc->sc_mru + PPP_HDRLEN + PPP_FCSLEN) {
if (sc->sc_flags & SC_DEBUG)
printf("ppp%d: packet too big\n", sc->sc_if.if_unit);
goto flush;
}
/* is this mbuf full? */
m = sc->sc_mc;
if (M_TRAILINGSPACE(m) <= 0) {
if (m->m_next == NULL) {
pppgetm(sc);
if (m->m_next == NULL) {
if (sc->sc_flags & SC_DEBUG)
printf("ppp%d: too few input mbufs!\n", sc->sc_if.if_unit);
goto flush;
}
}
sc->sc_mc = m = m->m_next;
m->m_len = 0;
m->m_data = M_DATASTART(m);
sc->sc_mp = mtod(m, char *);
}
++m->m_len;
*sc->sc_mp++ = c;
sc->sc_fcs = PPP_FCS(sc->sc_fcs, c);
return 0;
flush:
if (!(sc->sc_flags & SC_FLUSH)) {
s = spltty();
sc->sc_if.if_ierrors++;
sc->sc_stats.ppp_ierrors++;
sc->sc_flags |= SC_FLUSH;
splx(s);
if (sc->sc_flags & SC_LOG_FLUSH)
ppplogchar(sc, c);
}
return 0;
}
#define MAX_DUMP_BYTES 128
static void
ppplogchar(sc, c)
struct ppp_softc *sc;
int c;
{
if (c >= 0)
sc->sc_rawin[sc->sc_rawin_count++] = c;
if (sc->sc_rawin_count >= sizeof(sc->sc_rawin)
|| (c < 0 && sc->sc_rawin_count > 0)) {
printf("ppp%d input: %*D", sc->sc_if.if_unit,
sc->sc_rawin_count, sc->sc_rawin, " ");
sc->sc_rawin_count = 0;
}
}
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