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freebsd-dev/sys/net/ppp_tty.c
Olivier Houchard 7358f4bb52 Don't abuse tp->t_sc, as it is now used by tty drivers. 
This fixes the panic that occurs when using ppp(4)

Reported and tested by:	Yann Berthier (yb at sainte-barbe dot org)
2004-11-07 14:35:53 +00:00

1089 lines
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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/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(struct cdev *dev, struct tty *tp);
static int pppclose(struct tty *tp, int flag);
static int pppread(struct tty *tp, struct uio *uio, int flag);
static int pppwrite(struct tty *tp, struct uio *uio, int flag);
static int ppptioctl(struct tty *tp, u_long cmd, caddr_t data,
int flag, struct thread *td);
static int pppinput(int c, struct tty *tp);
static int pppstart(struct tty *tp);
static u_short pppfcs(u_short fcs, u_char *cp, int len);
static void pppasyncstart(struct ppp_softc *);
static void pppasyncctlp(struct ppp_softc *);
static void pppasyncrelinq(struct ppp_softc *);
static void pppasyncsetmtu(struct ppp_softc *);
static void ppp_timeout(void *);
static void pppgetm(struct ppp_softc *sc);
static void ppplogchar(struct ppp_softc *, int);
/* XXX called from if_ppp.c - layering violation */
void pppasyncattach(void *);
void pppasyncdetach(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
};
void
pppasyncattach(dummy)
void *dummy;
{
ldisc_register(PPPDISC, &pppdisc);
}
void
pppasyncdetach()
{
ldisc_deregister(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)
struct cdev *dev;
register struct tty *tp;
{
struct thread *td = curthread; /* XXX */
register struct ppp_softc *sc;
int error, s;
if ((error = suser(td)) != 0)
return (error);
s = spltty();
tp->t_hotchar = PPP_FLAG;
if ((sc = pppalloc(td->td_proc->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_hotchar = PPP_FLAG;
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 tty_close().
*/
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);
sc = ppp_for_tty(tp);
if (sc != NULL) {
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 = ppp_for_tty(tp);
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 = ppp_for_tty(tp);
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)
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, td)
struct tty *tp;
u_long cmd;
caddr_t data;
int flag;
struct thread *td;
{
struct ppp_softc *sc = ppp_for_tty(tp);
int error, s;
if (sc == NULL || tp != (struct tty *) sc->sc_devp)
return (ENOIOCTL);
error = 0;
switch (cmd) {
case PPPIOCSASYNCMAP:
if ((error = suser(td)) != 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(td)) != 0)
break;
sc->sc_rasyncmap = *(u_int *)data;
break;
case PPPIOCGRASYNCMAP:
*(u_int *)data = sc->sc_rasyncmap;
break;
case PPPIOCSXASYNCMAP:
if ((error = suser(td)) != 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, td);
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;
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. */
m = m_free(m);
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.
*/
static int
pppstart(tp)
register struct tty *tp;
{
register struct ppp_softc *sc = ppp_for_tty(tp);
/*
* 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) {
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 = ppp_for_tty(tp);
if (sc == NULL)
return 0;
++tk_nin;
++sc->sc_stats.ppp_ibytes;
if ((tp->t_state & TS_CONNECTED) == 0) {
if (sc->sc_flags & SC_DEBUG)
if_printf(&sc->sc_if, "no carrier\n");
goto flush;
}
if (c & TTY_ERRORMASK) {
/* framing error or overrun on this char - abort packet */
if (sc->sc_flags & SC_DEBUG)
if_printf(&sc->sc_if, "line error %x\n", 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)
if_printf(&sc->sc_if, "bad fcs %x, pkt len %d\n",
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)
if_printf(&sc->sc_if, "too short (%d)\n", 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)
if_printf(&sc->sc_if, "no input mbufs!\n");
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)
if_printf(&sc->sc_if,
"garbage received: 0x%x (need 0xFF)\n", 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)
if_printf(&sc->sc_if, "missing UI (0x3), got 0x%x\n", 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)
if_printf(&sc->sc_if, "bad protocol %x\n",
(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)
if_printf(&sc->sc_if, "packet too big\n");
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)
if_printf(&sc->sc_if, "too few input mbufs!\n");
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("%s input: %*D", sc->sc_if.if_xname,
sc->sc_rawin_count, sc->sc_rawin, " ");
sc->sc_rawin_count = 0;
}
}
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