freebsd-dev/sys/net/if_ppp.c
1994-11-01 22:18:34 +00:00

1593 lines
38 KiB
C

/*
* if_ppp.c - Point-to-Point Protocol (PPP) Asynchronous driver.
*
* 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).
*/
/* $Id: if_ppp.c,v 1.5 1994/11/01 09:03:16 pst Exp $ */
/* from if_sl.c,v 1.11 84/10/04 12:54:47 rick Exp */
#include "ppp.h"
#if NPPP > 0
#define VJC
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/mbuf.h>
#include <sys/buf.h>
#include <sys/dkstat.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/file.h>
#include <sys/tty.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/vnode.h>
#include <sys/kernel.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/route.h>
#if INET
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#endif
#include "bpfilter.h"
#if NBPFILTER > 0
#include <sys/time.h>
#include <net/bpf.h>
#endif
#ifdef VJC
#include <net/pppcompress.h>
#define HDROFF MAX_HDR
/* HDROFF should really be 128, but other parts of the system will
panic on TCP+IP headers bigger than MAX_HDR = MHLEN (100). */
#else
#define HDROFF (0)
#endif
#include <net/if_ppp.h>
#include <machine/cpu.h>
/* This is a FreeBSD-2.x kernel. */
#define CCOUNT(q) ((q)->c_cc)
#define PPP_HIWAT 400 /* Don't start a new packet if HIWAT on que */
struct ppp_softc ppp_softc[NPPP];
void pppattach __P((void));
int pppopen __P((dev_t dev, struct tty *tp));
int pppclose __P((struct tty *tp, int flag));
int pppread __P((struct tty *tp, struct uio *uio, int flag));
int pppwrite __P((struct tty *tp, struct uio *uio, int flag));
int ppptioctl __P((struct tty *tp, int cmd, caddr_t data, int flag,
struct proc *));
int pppoutput __P((struct ifnet *, struct mbuf *,
struct sockaddr *, struct rtentry *));
int pppinput __P((int c, struct tty *tp));
int pppioctl __P((struct ifnet *ifp, int cmd, caddr_t data));
int pppstart __P((struct tty *tp));
static struct linesw pppdisc = {
pppopen, pppclose, pppread, pppwrite, ppptioctl,
pppinput, pppstart, nullmodem
};
static int pppasyncstart __P((struct ppp_softc *));
static u_short pppfcs __P((u_short fcs, u_char *cp, int len));
static int pppgetm __P((struct ppp_softc *sc));
static struct mbuf *ppp_btom __P((struct ppp_softc *sc));
static void pppdumpm __P((struct mbuf *m0, int pktlen));
static void pppdumpb __P((u_char *b, int l));
static void ppplogchar __P((struct ppp_softc *, int));
/*
* Some useful mbuf macros not in mbuf.h.
*/
#define M_DATASTART(m) \
((m)->m_flags & M_EXT ? (m)->m_ext.ext_buf : \
(m)->m_flags & M_PKTHDR ? (m)->m_pktdat : (m)->m_dat)
#define M_DATASIZE(m) \
((m)->m_flags & M_EXT ? (m)->m_ext.ext_size : \
(m)->m_flags & M_PKTHDR ? MHLEN: MLEN)
/*
* The following disgusting hack gets around the problem that IP TOS
* can't be set yet. We want to put "interactive" traffic on a high
* priority queue. To decide if traffic is interactive, we check that
* a) it is TCP and b) one of its ports is telnet, rlogin or ftp control.
*/
static u_short interactive_ports[8] = {
0, 513, 0, 0,
0, 21, 0, 23,
};
#define INTERACTIVE(p) (interactive_ports[(p) & 7] == (p))
/*
* Does c need to be escaped?
*/
#define ESCAPE_P(c) (sc->sc_asyncmap[(c) >> 5] & (1 << ((c) & 0x1F)))
/*
* Called from boot code to establish ppp interfaces.
*/
void
pppattach()
{
register struct ppp_softc *sc;
register int i = 0;
linesw[PPPDISC] = pppdisc;
for (sc = ppp_softc; i < NPPP; sc++) {
sc->sc_if.if_name = "ppp";
sc->sc_if.if_unit = i++;
sc->sc_if.if_mtu = PPP_MTU;
sc->sc_if.if_flags = IFF_POINTOPOINT;
sc->sc_if.if_type = IFT_PPP;
sc->sc_if.if_hdrlen = PPP_HDRLEN;
sc->sc_if.if_ioctl = pppioctl;
sc->sc_if.if_output = pppoutput;
sc->sc_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
sc->sc_inq.ifq_maxlen = IFQ_MAXLEN;
sc->sc_fastq.ifq_maxlen = IFQ_MAXLEN;
if_attach(&sc->sc_if);
#if NBPFILTER > 0
bpfattach(&sc->sc_bpf, &sc->sc_if, DLT_PPP, PPP_HDRLEN);
#endif
}
}
/*
* Allocate a ppp interface unit and initialize it.
*/
struct ppp_softc *
pppalloc(pid)
pid_t pid;
{
int nppp;
struct ppp_softc *sc;
for (nppp = 0, sc = ppp_softc; nppp < NPPP; nppp++, sc++)
if (sc->sc_xfer == pid) {
sc->sc_xfer = 0;
break;
}
if (nppp >= NPPP)
for (nppp = 0, sc = ppp_softc; nppp < NPPP; nppp++, sc++)
if (sc->sc_devp == NULL)
break;
if (nppp >= NPPP)
return NULL;
sc->sc_flags = 0;
sc->sc_mru = PPP_MRU;
#ifdef VJC
sl_compress_init(&sc->sc_comp);
#endif
sc->sc_if.if_flags |= IFF_RUNNING;
return sc;
}
/*
* Deallocate a ppp unit.
*/
void
pppdealloc(sc)
struct ppp_softc *sc;
{
struct mbuf *m;
if_down(&sc->sc_if);
sc->sc_devp = NULL;
sc->sc_xfer = 0;
for (;;) {
IF_DEQUEUE(&sc->sc_inq, m);
if (m == NULL)
break;
m_freem(m);
}
for (;;) {
IF_DEQUEUE(&sc->sc_fastq, m);
if (m == NULL)
break;
m_freem(m);
}
sc->sc_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
}
/*
* Line specific open routine for async tty devices.
* Attach the given tty to the first available ppp unit.
*/
/* ARGSUSED */
int
pppopen(dev, tp)
dev_t dev;
register struct tty *tp;
{
struct proc *p = curproc; /* XXX */
register struct ppp_softc *sc;
int error, s, i;
if (error = suser(p->p_ucred, &p->p_acflag))
return (error);
if (tp->t_line == PPPDISC) {
sc = (struct ppp_softc *) tp->t_sc;
if (sc != NULL && sc->sc_devp == (void *) tp)
return (0);
}
if ((sc = pppalloc(p->p_pid)) == NULL)
return ENXIO;
if (sc->sc_outm != NULL) {
m_freem(sc->sc_outm);
sc->sc_outm = NULL;
}
if (pppgetm(sc) == 0) {
sc->sc_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
return (ENOBUFS);
}
sc->sc_ilen = 0;
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;
tp->t_sc = (caddr_t) sc;
ttyflush(tp, FREAD | FWRITE);
return (0);
}
/*
* Line specific close routine.
* Detach the tty from the ppp unit.
* Mimics part of ttyclose().
*/
int
pppclose(tp, flag)
struct tty *tp;
int flag;
{
register struct ppp_softc *sc;
struct mbuf *m;
int s;
ttywflush(tp);
s = splimp(); /* paranoid; splnet probably ok */
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) {
m_freem(sc->sc_outm);
sc->sc_outm = NULL;
m_freem(sc->sc_m);
sc->sc_m = NULL;
pppdealloc(sc);
}
}
splx(s);
return (0); /* success */
}
/*
* Line specific (tty) read routine.
*/
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 ((tp->t_state & TS_CARR_ON) == 0 && (tp->t_cflag & CLOCAL) == 0)
return 0; /* end of file */
if (sc == NULL || tp != (struct tty *) sc->sc_devp)
return 0;
s = splimp();
while (sc->sc_inq.ifq_head == NULL && tp->t_line == PPPDISC) {
if (tp->t_state & TS_ASYNC || flag & IO_NDELAY) {
splx(s);
return (EWOULDBLOCK);
}
error = ttysleep(tp, (caddr_t)&tp->t_rawq, TTIPRI|PCATCH, ttyin, 0);
if (error)
return error;
}
if (tp->t_line != PPPDISC) {
splx(s);
return (-1);
}
/* 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))
break;
m_freem(m0);
return (error);
}
/*
* Line specific (tty) write routine.
*/
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;
struct ppp_header *ph1, *ph2;
int len, error;
if ((tp->t_state & TS_CARR_ON) == 0 && (tp->t_cflag & CLOCAL) == 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);
for (mp = &m0; uio->uio_resid; mp = &m->m_next) {
MGET(m, M_WAIT, MT_DATA);
if ((*mp = m) == NULL) {
m_freem(m0);
return (ENOBUFS);
}
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)) {
m_freem(m0);
return (error);
}
m->m_len = len;
}
dst.sa_family = AF_UNSPEC;
ph1 = (struct ppp_header *) &dst.sa_data;
ph2 = mtod(m0, struct ppp_header *);
*ph1 = *ph2;
m0->m_data += PPP_HDRLEN;
m0->m_len -= PPP_HDRLEN;
return (pppoutput(&sc->sc_if, m0, &dst, (struct rtentry *)0));
}
/*
* Line specific (tty) ioctl routine.
* Provide a way to get the ppp unit number.
* This discipline requires that tty device drivers call
* the line specific l_ioctl routine from their ioctl routines.
*/
/* ARGSUSED */
int
ppptioctl(tp, cmd, data, flag, p)
struct tty *tp;
caddr_t data;
int cmd, flag;
struct proc *p;
{
register struct ppp_softc *sc = (struct ppp_softc *) tp->t_sc;
int s, error, flags, mru;
if (sc == NULL || tp != (struct tty *) sc->sc_devp)
return -1;
switch (cmd) {
case FIONREAD:
*(int *)data = sc->sc_inq.ifq_len;
break;
case PPPIOCGUNIT:
*(int *)data = sc->sc_if.if_unit;
break;
case PPPIOCGFLAGS:
*(u_int *)data = sc->sc_flags;
break;
case PPPIOCSFLAGS:
if (error = suser(p->p_ucred, &p->p_acflag))
return (error);
flags = *(int *)data & SC_MASK;
s = splimp();
sc->sc_flags = (sc->sc_flags & ~SC_MASK) | flags;
splx(s);
break;
case PPPIOCSASYNCMAP:
if (error = suser(p->p_ucred, &p->p_acflag))
return (error);
sc->sc_asyncmap[0] = *(u_int *)data;
break;
case PPPIOCGASYNCMAP:
*(u_int *)data = sc->sc_asyncmap[0];
break;
case PPPIOCSRASYNCMAP:
if (error = suser(p->p_ucred, &p->p_acflag))
return (error);
sc->sc_rasyncmap = *(u_int *)data;
break;
case PPPIOCGRASYNCMAP:
*(u_int *)data = sc->sc_rasyncmap;
break;
case PPPIOCSXASYNCMAP:
if (error = suser(p->p_ucred, &p->p_acflag))
return (error);
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 */
break;
case PPPIOCGXASYNCMAP:
bcopy(sc->sc_asyncmap, data, sizeof(sc->sc_asyncmap));
break;
case PPPIOCSMRU:
if (error = suser(p->p_ucred, &p->p_acflag))
return (error);
mru = *(int *)data;
if (mru >= PPP_MRU && mru <= PPP_MAXMRU) {
sc->sc_mru = mru;
if (pppgetm(sc) == 0) {
error = ENOBUFS;
sc->sc_mru = PPP_MRU;
if (pppgetm(sc) == 0)
sc->sc_if.if_flags &= ~IFF_UP;
}
}
break;
case PPPIOCGMRU:
*(int *)data = sc->sc_mru;
break;
#ifdef VJC
case PPPIOCSMAXCID:
if (error = suser(p->p_ucred, &p->p_acflag))
return (error);
sl_compress_setup(&sc->sc_comp, *(int *)data);
break;
#endif
case PPPIOCXFERUNIT:
if (error = suser(p->p_ucred, &p->p_acflag))
return (error);
sc->sc_xfer = p->p_pid;
break;
default:
return (-1);
}
return (0);
}
/*
* 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(fcs, cp, len)
register u_short fcs;
register u_char *cp;
register int len;
{
while (len--)
fcs = PPP_FCS(fcs, *cp++);
return (fcs);
}
/*
* Queue a packet. Start transmission if not active.
* Packet is placed in Information field of PPP frame.
*/
int
pppoutput(ifp, m0, dst, rt)
struct ifnet *ifp;
struct mbuf *m0;
struct sockaddr *dst;
struct rtentry *rt;
{
register struct ppp_softc *sc = &ppp_softc[ifp->if_unit];
struct ppp_header *ph;
int protocol, address, control;
u_char *cp;
int s, error;
struct ip *ip;
struct ifqueue *ifq;
if (sc->sc_devp == NULL || (ifp->if_flags & IFF_RUNNING) == 0
|| (ifp->if_flags & IFF_UP) == 0 && dst->sa_family != AF_UNSPEC) {
error = ENETDOWN; /* sort of */
goto bad;
}
/*
* Compute PPP header.
*/
address = PPP_ALLSTATIONS;
control = PPP_UI;
ifq = &ifp->if_snd;
switch (dst->sa_family) {
#ifdef INET
case AF_INET:
protocol = PPP_IP;
if ((sc->sc_flags & SC_ENABLE_IP) == 0) {
error = ENETDOWN;
goto bad;
}
/*
* If this is a TCP packet to or from an "interactive" port,
* put the packet on the fastq instead.
*/
if ((ip = mtod(m0, struct ip *))->ip_p == IPPROTO_TCP) {
register int p = ntohl(((int *)ip)[ip->ip_hl]);
if (INTERACTIVE(p & 0xffff) || INTERACTIVE(p >> 16))
ifq = &sc->sc_fastq;
}
break;
#endif
#ifdef NS
case AF_NS:
protocol = PPP_XNS;
break;
#endif
case AF_UNSPEC:
ph = (struct ppp_header *) dst->sa_data;
address = ph->ph_address;
control = ph->ph_control;
protocol = ntohs(ph->ph_protocol);
break;
default:
printf("ppp%d: af%d not supported\n", ifp->if_unit, dst->sa_family);
error = EAFNOSUPPORT;
goto bad;
}
/*
* Add PPP header. If no space in first mbuf, allocate another.
* (This assumes M_LEADINGSPACE is always 0 for a cluster mbuf.)
*/
if (M_LEADINGSPACE(m0) < PPP_HDRLEN) {
m0 = m_prepend(m0, PPP_HDRLEN, M_DONTWAIT);
if (m0 == 0) {
error = ENOBUFS;
goto bad;
}
m0->m_len = 0;
} else
m0->m_data -= PPP_HDRLEN;
cp = mtod(m0, u_char *);
*cp++ = address;
*cp++ = control;
*cp++ = protocol >> 8;
*cp++ = protocol & 0xff;
m0->m_len += PPP_HDRLEN;
if (sc->sc_flags & SC_LOG_OUTPKT) {
printf("ppp%d output: ", ifp->if_unit);
pppdumpm(m0, -1);
}
#if NBPFILTER > 0
/* See if bpf wants to look at the packet. */
if (sc->sc_bpf)
bpf_mtap(sc->sc_bpf, m0);
#endif
/*
* Put the packet on the appropriate queue.
*/
s = splimp();
if (IF_QFULL(ifq)) {
IF_DROP(ifq);
splx(s);
sc->sc_if.if_oerrors++;
error = ENOBUFS;
goto bad;
}
IF_ENQUEUE(ifq, m0);
/*
* Tell the device to send it out.
*/
(*sc->sc_start)(sc);
splx(s);
return (0);
bad:
m_freem(m0);
return (error);
}
/*
* Grab another packet off a queue and apply VJ compression,
* address/control and/or protocol compression if appropriate.
*/
struct mbuf *
ppp_dequeue(sc)
struct ppp_softc *sc;
{
int s;
struct mbuf *m;
u_char *cp;
int address, control, protocol;
s = splimp();
IF_DEQUEUE(&sc->sc_fastq, m);
if (m == NULL)
IF_DEQUEUE(&sc->sc_if.if_snd, m);
splx(s);
if (m == NULL)
return NULL;
/*
* Extract the ppp header of the new packet.
* The ppp header will be in one mbuf.
*/
cp = mtod(m, u_char *);
address = cp[0];
control = cp[1];
protocol = (cp[2] << 8) + cp[3];
#ifdef VJC
/*
* If the packet is a TCP/IP packet, see if we can compress it.
*/
if (protocol == PPP_IP && sc->sc_flags & SC_COMP_TCP) {
struct ip *ip;
int type;
struct mbuf *mp;
mp = m;
ip = (struct ip *) (cp + PPP_HDRLEN);
if (mp->m_len <= PPP_HDRLEN) {
mp = mp->m_next;
ip = mtod(mp, struct ip *);
}
/* this code assumes the IP/TCP header is in one non-shared mbuf */
if (ip->ip_p == IPPROTO_TCP) {
type = sl_compress_tcp(mp, ip, &sc->sc_comp,
!(sc->sc_flags & SC_NO_TCP_CCID));
switch (type) {
case TYPE_UNCOMPRESSED_TCP:
protocol = PPP_VJC_UNCOMP;
break;
case TYPE_COMPRESSED_TCP:
protocol = PPP_VJC_COMP;
cp = mtod(m, u_char *);
cp[0] = address; /* header has moved */
cp[1] = control;
cp[2] = 0;
break;
}
cp[3] = protocol; /* update protocol in PPP header */
}
}
#endif /* VJC */
#ifdef BSD_COMP
if (protocol < PPP_COMP && (sc->sc_flags & SC_BSD_COMP)) {
slen = m_totallen(m0);
clen = pf_bsd_comp(sc->sc_bsd_db, cbuf, proto, m0, slen);
}
#endif /* BSD_COMP */
/*
* Compress the address/control and protocol, if possible.
*/
if (sc->sc_flags & SC_COMP_AC && address == PPP_ALLSTATIONS &&
control == PPP_UI && protocol != PPP_ALLSTATIONS &&
protocol != PPP_LCP) {
/* can compress address/control */
m->m_data += 2;
m->m_len -= 2;
}
if (sc->sc_flags & SC_COMP_PROT && protocol < 0xFF) {
/* can compress protocol */
if (mtod(m, u_char *) == cp) {
cp[2] = cp[1]; /* move address/control up */
cp[1] = cp[0];
}
++m->m_data;
--m->m_len;
}
return m;
}
/*
* This gets called from pppoutput when a new packet is
* put on a queue.
*/
static int
pppasyncstart(sc)
register struct ppp_softc *sc;
{
register struct tty *tp = (struct tty *) sc->sc_devp;
pppstart(tp);
return 0;
}
/*
* Start output on async tty interface. Get another datagram
* to send from the interface queue and start sending it.
*/
int
pppstart(tp)
register struct tty *tp;
{
register struct ppp_softc *sc = (struct ppp_softc *) tp->t_sc;
register struct mbuf *m;
register int len;
register u_char *start, *stop, *cp;
int n, s, ndone, done;
struct mbuf *m2;
if ((tp->t_state & TS_CARR_ON) == 0 && (tp->t_cflag & CLOCAL) == 0) {
/* sorry, I can't talk now */
return 0;
}
if (sc == NULL || tp != (struct tty *) sc->sc_devp) {
(*tp->t_oproc)(tp);
return 0;
}
for (;;) {
/*
* If there is more in the output queue, just send it now.
* We are being called in lieu of ttstart and must do what
* it would.
*/
if (CCOUNT(&tp->t_outq) != 0 && tp->t_oproc != NULL) {
(*tp->t_oproc)(tp);
if (CCOUNT(&tp->t_outq) > PPP_HIWAT)
return 0;
}
/*
* See if we have an existing packet partly sent.
* If not, get a new packet and start sending it.
* We take packets on the priority queue ahead of those
* on the normal queue.
*/
m = sc->sc_outm;
if (m == NULL) {
/*
* Get another packet to be sent
*/
m = ppp_dequeue(sc);
if (m == NULL)
return 0;
/*
* 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.
*/
if (CCOUNT(&tp->t_outq) == 0) {
++sc->sc_bytessent;
(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);
}
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_bytessent += 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) {
if (putc(PPP_ESCAPE, &tp->t_outq))
break;
if (putc(*start ^ PPP_TRANS, &tp->t_outq)) {
(void) unputc(&tp->t_outq);
break;
}
sc->sc_bytessent += 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.
*/
for (q = endseq; q < p; ++q)
if (putc(*q, &tp->t_outq)) {
done = 0;
for (; q > endseq; --q)
unputc(&tp->t_outq);
break;
}
}
if (!done) {
m->m_data = start;
m->m_len = len;
sc->sc_outm = m;
if (tp->t_oproc != NULL)
(*tp->t_oproc)(tp);
return 0; /* can't do any more at the moment */
}
/* Finished with this mbuf; free it and move on. */
MFREE(m, m2);
if (m2 == NULL)
break;
m = m2;
sc->sc_outfcs = pppfcs(sc->sc_outfcs, mtod(m, u_char *), m->m_len);
}
/* Finished a packet */
sc->sc_outm = NULL;
sc->sc_bytessent++; /* account for closing flag */
sc->sc_if.if_opackets++;
sc->sc_if.if_obytes = sc->sc_bytessent;
}
return 0;
}
/*
* Allocate enough mbuf to handle current MRU.
*/
static int
pppgetm(sc)
register struct ppp_softc *sc;
{
struct mbuf *m, **mp;
int len = HDROFF + sc->sc_mru + PPP_HDRLEN + PPP_FCSLEN;
int s;
s = splimp();
for (mp = &sc->sc_m; (m = *mp) != NULL; mp = &m->m_next)
if ((len -= M_DATASIZE(m)) <= 0) {
splx(s);
return (1);
}
for (;; mp = &m->m_next) {
MGETHDR(m, M_DONTWAIT, MT_DATA);
if (m == 0) {
m_freem(sc->sc_m);
sc->sc_m = NULL;
splx(s);
printf("ppp%d: can't allocate mbuf\n", sc->sc_if.if_unit);
return (0);
}
*mp = m;
MCLGET(m, M_DONTWAIT);
if ((len -= M_DATASIZE(m)) <= 0) {
splx(s);
return (1);
}
}
}
/*
* Copy mbuf chain. Would like to use m_copy(), but we need a real copy
* of the data, not just copies of pointers to the data.
*/
static struct mbuf *
ppp_btom(sc)
struct ppp_softc *sc;
{
register struct mbuf *m, **mp;
struct mbuf *top = sc->sc_m;
/*
* First check current mbuf. If we have more than a small mbuf,
* return the whole cluster and set beginning of buffer to the
* next mbuf.
* Else, copy the current bytes into a small mbuf, attach the new
* mbuf to the end of the chain and set beginning of buffer to the
* current mbuf.
*/
if (sc->sc_mc->m_len > MHLEN) {
sc->sc_m = sc->sc_mc->m_next;
sc->sc_mc->m_next = NULL;
}
else {
/* rather than waste a whole cluster on <= MHLEN bytes,
alloc a small mbuf and copy to it */
MGETHDR(m, M_DONTWAIT, MT_DATA);
if (m == NULL)
return (NULL);
bcopy(mtod(sc->sc_mc, caddr_t), mtod(m, caddr_t), sc->sc_mc->m_len);
m->m_len = sc->sc_mc->m_len;
for (mp = &top; *mp != sc->sc_mc; mp = &(*mp)->m_next)
;
*mp = m;
sc->sc_m = sc->sc_mc;
}
/*
* Try to allocate enough extra mbufs to handle the next packet.
*/
if (pppgetm(sc) == 0) {
m_freem(top);
if (pppgetm(sc) == 0)
sc->sc_if.if_flags &= ~IFF_UP;
return (NULL);
}
return (top);
}
/*
* PPP packet input routine.
* The caller has checked and removed the FCS.
* The return value is 1 if the packet was put on sc->sc_inq,
* 0 otherwise.
*/
#define COMPTYPE(proto) ((proto) == PPP_VJC_COMP? TYPE_COMPRESSED_TCP: \
TYPE_UNCOMPRESSED_TCP)
int
ppppktin(sc, m, ilen)
struct ppp_softc *sc;
struct mbuf *m;
int ilen;
{
struct ifqueue *inq;
int s, xlen, proto, rv;
struct ppp_header hdr;
sc->sc_if.if_ipackets++;
rv = 0;
hdr = *mtod(m, struct ppp_header *);
proto = ntohs(hdr.ph_protocol);
#ifdef VJC
/*
* See if we have a VJ-compressed packet to uncompress.
*/
if (proto == PPP_VJC_COMP || proto == PPP_VJC_UNCOMP) {
char *pkttype = proto == PPP_VJC_COMP? "": "un";
if (sc->sc_flags & SC_REJ_COMP_TCP) {
if (sc->sc_flags & SC_DEBUG)
printf("ppp%d: %scomp pkt w/o compression; flags 0x%x\n",
sc->sc_if.if_unit, pkttype, sc->sc_flags);
sc->sc_if.if_ierrors++;
return 0;
}
m->m_data += PPP_HDRLEN;
m->m_len -= PPP_HDRLEN;
ilen -= PPP_HDRLEN;
xlen = sl_uncompress_tcp_part((u_char **)(&m->m_data),
m->m_len, ilen,
COMPTYPE(proto), &sc->sc_comp);
if (xlen == 0) {
if (sc->sc_flags & SC_DEBUG)
printf("ppp%d: sl_uncompress failed on type %scomp\n",
sc->sc_if.if_unit, pkttype);
sc->sc_if.if_ierrors++;
return 0;
}
/* adjust the first mbuf by the decompressed amt */
xlen += PPP_HDRLEN;
m->m_len += xlen - ilen;
ilen = xlen;
m->m_data -= PPP_HDRLEN;
proto = PPP_IP;
/* put the ppp header back in place */
hdr.ph_protocol = htons(PPP_IP);
*mtod(m, struct ppp_header *) = hdr;
}
#endif /* VJC */
/* get this packet as an mbuf chain */
if ((m = ppp_btom(sc)) == NULL) {
sc->sc_if.if_ierrors++;
return 0;
}
m->m_pkthdr.len = ilen;
m->m_pkthdr.rcvif = &sc->sc_if;
#if NBPFILTER > 0
/* See if bpf wants to look at the packet. */
if (sc->sc_bpf)
bpf_mtap(sc->sc_bpf, m);
#endif
switch (proto) {
#ifdef INET
case PPP_IP:
/*
* IP packet - take off the ppp header and pass it up to IP.
*/
if ((sc->sc_if.if_flags & IFF_UP) == 0
|| (sc->sc_flags & SC_ENABLE_IP) == 0) {
/* interface is down - drop the packet. */
m_freem(m);
return 0;
}
m->m_pkthdr.len -= PPP_HDRLEN;
m->m_data += PPP_HDRLEN;
m->m_len -= PPP_HDRLEN;
schednetisr(NETISR_IP);
inq = &ipintrq;
break;
#endif
default:
/*
* Some other protocol - place on input queue for read().
*/
inq = &sc->sc_inq;
rv = 1;
break;
}
/*
* Put the packet on the appropriate input queue.
*/
s = splimp();
if (IF_QFULL(inq)) {
IF_DROP(inq);
if (sc->sc_flags & SC_DEBUG)
printf("ppp%d: queue full\n", sc->sc_if.if_unit);
sc->sc_if.if_ierrors++;
sc->sc_if.if_iqdrops++;
m_freem(m);
rv = 0;
} else
IF_ENQUEUE(inq, m);
splx(s);
return rv;
}
/*
* tty interface receiver interrupt.
*/
static unsigned paritytab[8] = {
0x96696996, 0x69969669, 0x69969669, 0x96696996,
0x69969669, 0x96696996, 0x96696996, 0x69969669
};
int
pppinput(c, tp)
int c;
register struct tty *tp;
{
register struct ppp_softc *sc;
struct mbuf *m;
int ilen;
tk_nin++;
sc = (struct ppp_softc *) tp->t_sc;
if (sc == NULL || tp != (struct tty *) sc->sc_devp)
return 0;
++sc->sc_bytesrcvd;
if (c & TTY_FE) {
/* framing error or overrun on this char - abort packet */
if (sc->sc_flags & SC_DEBUG)
printf("ppp%d: bad char %x\n", sc->sc_if.if_unit, c);
goto flush;
}
c &= 0xff;
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;
if (sc->sc_flags & SC_LOG_RAWIN)
ppplogchar(sc, c);
if (c == PPP_FLAG) {
ilen = sc->sc_ilen;
sc->sc_ilen = 0;
sc->sc_if.if_ibytes = sc->sc_bytesrcvd;
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) {
#ifdef VJC
/*
* If we've missed a packet, we must toss subsequent compressed
* packets which don't have an explicit connection ID.
*/
sl_uncompress_tcp(NULL, 0, TYPE_ERROR, &sc->sc_comp);
#endif
if ((sc->sc_flags & (SC_FLUSH | SC_ESCAPED)) == 0){
if (sc->sc_flags & SC_DEBUG)
printf("ppp%d: bad fcs\n", sc->sc_if.if_unit);
sc->sc_if.if_ierrors++;
} else
sc->sc_flags &= ~(SC_FLUSH | SC_ESCAPED);
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);
sc->sc_if.if_ierrors++;
}
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--;
m = sc->sc_m;
if (sc->sc_flags & SC_LOG_INPKT) {
printf("ppp%d: got %d bytes\n", sc->sc_if.if_unit, ilen);
pppdumpm(m, ilen);
}
if (ppppktin(sc, m, ilen)) {
/* Put a placeholder byte in canq for ttselect()/ttnread(). */
putc(0, &tp->t_canq);
ttwakeup(tp);
}
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;
if (sc->sc_flags & SC_ESCAPED) {
sc->sc_flags &= ~SC_ESCAPED;
c ^= PPP_TRANS;
} else if (c == PPP_ESCAPE) {
sc->sc_flags |= SC_ESCAPED;
return 0;
}
/*
* 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 */
m = sc->sc_m;
m->m_len = 0;
m->m_data = M_DATASTART(sc->sc_m) + HDROFF;
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) {
sc->sc_mc = m = m->m_next;
if (m == NULL) {
printf("ppp%d: too few input mbufs!\n", sc->sc_if.if_unit);
goto flush;
}
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)) {
sc->sc_if.if_ierrors++;
sc->sc_flags |= SC_FLUSH;
if (sc->sc_flags & SC_LOG_FLUSH)
ppplogchar(sc, c);
}
return 0;
}
/*
* Process an ioctl request to interface.
*/
int
pppioctl(ifp, cmd, data)
register struct ifnet *ifp;
int cmd;
caddr_t data;
{
struct proc *p = curproc; /* XXX */
register struct ppp_softc *sc = &ppp_softc[ifp->if_unit];
register struct ifaddr *ifa = (struct ifaddr *)data;
register struct ifreq *ifr = (struct ifreq *)data;
int s = splimp(), error = 0;
switch (cmd) {
case SIOCSIFFLAGS:
if ((ifp->if_flags & IFF_RUNNING) == 0)
ifp->if_flags &= ~IFF_UP;
break;
case SIOCSIFADDR:
if (ifa->ifa_addr->sa_family != AF_INET)
error = EAFNOSUPPORT;
break;
case SIOCSIFDSTADDR:
if (ifa->ifa_addr->sa_family != AF_INET)
error = EAFNOSUPPORT;
break;
case SIOCSIFMTU:
if (error = suser(p->p_ucred, &p->p_acflag))
return (error);
sc->sc_if.if_mtu = ifr->ifr_mtu;
break;
case SIOCGIFMTU:
ifr->ifr_mtu = sc->sc_if.if_mtu;
break;
default:
error = EINVAL;
}
splx(s);
return (error);
}
#define MAX_DUMP_BYTES 128
static void
pppdumpm(m0, pktlen)
struct mbuf *m0;
int pktlen;
{
char buf[3*MAX_DUMP_BYTES+4];
char *bp = buf;
struct mbuf *m;
static char digits[] = "0123456789abcdef";
for (m = m0; m && pktlen; m = m->m_next) {
int l = m->m_len;
u_char *rptr = (u_char *)m->m_data;
if (pktlen > 0) {
if (l > pktlen)
l = pktlen;
pktlen -= l;
}
while (l--) {
if (bp > buf + sizeof(buf) - 4)
goto done;
*bp++ = digits[*rptr >> 4]; /* convert byte to ascii hex */
*bp++ = digits[*rptr++ & 0xf];
}
if (m->m_next) {
if (bp > buf + sizeof(buf) - 3)
goto done;
*bp++ = '|';
} else
*bp++ = ' ';
}
done:
if (m && pktlen)
*bp++ = '>';
*bp = 0;
printf("%s\n", buf);
}
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: ", sc->sc_if.if_unit);
pppdumpb(sc->sc_rawin, sc->sc_rawin_count);
sc->sc_rawin_count = 0;
}
}
static void
pppdumpb(b, l)
u_char *b;
int l;
{
char buf[3*MAX_DUMP_BYTES+4];
char *bp = buf;
static char digits[] = "0123456789abcdef";
while (l--) {
if (bp >= buf + sizeof(buf) - 3) {
*bp++ = '>';
break;
}
*bp++ = digits[*b >> 4]; /* convert byte to ascii hex */
*bp++ = digits[*b++ & 0xf];
*bp++ = ' ';
}
*bp = 0;
printf("%s\n", buf);
}
TEXT_SET(pseudo_set, pppattach);
#endif /* NPPP > 0 */