freebsd-nq/sys/net/if_ppp.c
2002-09-24 17:37:32 +00:00

1635 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).
*/
/* $FreeBSD$ */
/* from if_sl.c,v 1.11 84/10/04 12:54:47 rick Exp */
/* from NetBSD: if_ppp.c,v 1.15.2.2 1994/07/28 05:17:58 cgd Exp */
#include "opt_inet.h"
#include "opt_ipx.h"
#include "opt_mac.h"
#include "opt_ppp.h"
#ifdef INET
#define VJC
#endif
#define PPP_COMPRESS
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/mac.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/filio.h>
#include <sys/sockio.h>
#include <sys/kernel.h>
#include <sys/time.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/bpf.h>
#if INET
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#endif
#if IPX
#include <netipx/ipx.h>
#include <netipx/ipx_if.h>
#endif
#ifdef VJC
#include <net/slcompress.h>
#endif
#include <net/if_ppp.h>
#include <net/if_pppvar.h>
/* minimise diffs */
#ifndef splsoftnet
#define splsoftnet splnet
#endif
#ifdef PPP_COMPRESS
#define PACKETPTR struct mbuf *
#include <net/ppp_comp.h>
#endif
#define PPPNAME "ppp"
static MALLOC_DEFINE(M_PPP, PPPNAME, "PPP interface");
static LIST_HEAD(, ppp_softc) ppp_softc_list;
/* XXX layering violation */
extern void pppasyncattach(void *);
extern void pppasyncdetach(void);
static int pppsioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
static void pppintr(void);
static void ppp_requeue(struct ppp_softc *);
static void ppp_ccp(struct ppp_softc *, struct mbuf *m, int rcvd);
static void ppp_ccp_closed(struct ppp_softc *);
static void ppp_inproc(struct ppp_softc *, struct mbuf *);
static void pppdumpm(struct mbuf *m0);
static int ppp_clone_create(struct if_clone *, int);
static void ppp_clone_destroy(struct ifnet *);
static struct if_clone ppp_cloner = IF_CLONE_INITIALIZER(PPPNAME,
ppp_clone_create, ppp_clone_destroy, 0, IF_MAXUNIT);
/*
* 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)
/*
* We steal two bits in the mbuf m_flags, to mark high-priority packets
* for output, and received packets following lost/corrupted packets.
*/
#define M_HIGHPRI 0x2000 /* output packet for sc_fastq */
#define M_ERRMARK 0x4000 /* steal a bit in mbuf m_flags */
#ifdef PPP_COMPRESS
/*
* List of compressors we know about.
* We leave some space so maybe we can modload compressors.
*/
extern struct compressor ppp_bsd_compress;
extern struct compressor ppp_deflate, ppp_deflate_draft;
static struct compressor *ppp_compressors[8] = {
#if DO_BSD_COMPRESS && defined(PPP_BSDCOMP)
&ppp_bsd_compress,
#endif
#if DO_DEFLATE && defined(PPP_DEFLATE)
&ppp_deflate,
&ppp_deflate_draft,
#endif
NULL
};
#endif /* PPP_COMPRESS */
static int
ppp_clone_create(struct if_clone *ifc, int unit)
{
struct ppp_softc *sc;
sc = malloc(sizeof(struct ppp_softc), M_PPP, M_WAITOK | M_ZERO);
sc->sc_if.if_softc = sc;
sc->sc_if.if_name = PPPNAME;
sc->sc_if.if_unit = unit;
sc->sc_if.if_mtu = PPP_MTU;
sc->sc_if.if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
sc->sc_if.if_type = IFT_PPP;
sc->sc_if.if_hdrlen = PPP_HDRLEN;
sc->sc_if.if_ioctl = pppsioctl;
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;
sc->sc_rawq.ifq_maxlen = IFQ_MAXLEN;
mtx_init(&sc->sc_inq.ifq_mtx, "ppp_inq", NULL, MTX_DEF);
mtx_init(&sc->sc_fastq.ifq_mtx, "ppp_fastq", NULL, MTX_DEF);
mtx_init(&sc->sc_rawq.ifq_mtx, "ppp_rawq", NULL, MTX_DEF);
if_attach(&sc->sc_if);
bpfattach(&sc->sc_if, DLT_PPP, PPP_HDRLEN);
LIST_INSERT_HEAD(&ppp_softc_list, sc, sc_list);
return (0);
}
static void
ppp_clone_destroy(struct ifnet *ifp)
{
struct ppp_softc *sc;
sc = ifp->if_softc;
LIST_REMOVE(sc, sc_list);
bpfdetach(ifp);
if_detach(ifp);
mtx_destroy(&sc->sc_rawq.ifq_mtx);
mtx_destroy(&sc->sc_fastq.ifq_mtx);
mtx_destroy(&sc->sc_inq.ifq_mtx);
}
static int
ppp_modevent(module_t mod, int type, void *data)
{
switch (type) {
case MOD_LOAD:
if_clone_attach(&ppp_cloner);
register_netisr(NETISR_PPP, pppintr);
/*
* XXX layering violation - if_ppp can work over any lower
* level transport that cares to attach to it.
*/
pppasyncattach(NULL);
break;
case MOD_UNLOAD:
/* XXX: layering violation */
pppasyncdetach();
unregister_netisr(NETISR_PPP);
if_clone_detach(&ppp_cloner);
while (!LIST_EMPTY(&ppp_softc_list))
ppp_clone_destroy(
&LIST_FIRST(&ppp_softc_list)->sc_if);
break;
}
return 0;
}
static moduledata_t ppp_mod = {
"if_ppp",
ppp_modevent,
0
};
DECLARE_MODULE(if_ppp, ppp_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
/*
* Allocate a ppp interface unit and initialize it.
*/
struct ppp_softc *
pppalloc(pid)
pid_t pid;
{
int i;
char tmpname[IFNAMSIZ];
struct ifnet *ifp;
struct ppp_softc *sc;
LIST_FOREACH(sc, &ppp_softc_list, sc_list) {
if (sc->sc_xfer == pid) {
sc->sc_xfer = 0;
return sc;
}
}
LIST_FOREACH(sc, &ppp_softc_list, sc_list) {
if (sc->sc_devp == NULL)
break;
}
/* Try to clone an interface if we don't have a free one */
if (sc == NULL) {
strcpy(tmpname, PPPNAME);
if (if_clone_create(tmpname, sizeof(tmpname)) != 0)
return NULL;
ifp = ifunit(tmpname);
if (ifp == NULL)
return NULL;
sc = ifp->if_softc;
}
if (sc == NULL || sc->sc_devp != NULL)
return NULL;
sc->sc_flags = 0;
sc->sc_mru = PPP_MRU;
sc->sc_relinq = NULL;
bzero((char *)&sc->sc_stats, sizeof(sc->sc_stats));
#ifdef VJC
MALLOC(sc->sc_comp, struct slcompress *, sizeof(struct slcompress),
M_DEVBUF, M_NOWAIT);
if (sc->sc_comp)
sl_compress_init(sc->sc_comp, -1);
#endif
#ifdef PPP_COMPRESS
sc->sc_xc_state = NULL;
sc->sc_rc_state = NULL;
#endif /* PPP_COMPRESS */
for (i = 0; i < NUM_NP; ++i)
sc->sc_npmode[i] = NPMODE_ERROR;
sc->sc_npqueue = NULL;
sc->sc_npqtail = &sc->sc_npqueue;
sc->sc_last_sent = sc->sc_last_recv = time_second;
return sc;
}
/*
* Deallocate a ppp unit. Must be called at splsoftnet or higher.
*/
void
pppdealloc(sc)
struct ppp_softc *sc;
{
struct mbuf *m;
if_down(&sc->sc_if);
sc->sc_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
getmicrotime(&sc->sc_if.if_lastchange);
sc->sc_devp = NULL;
sc->sc_xfer = 0;
IF_DRAIN(&sc->sc_rawq);
IF_DRAIN(&sc->sc_inq);
IF_DRAIN(&sc->sc_fastq);
while ((m = sc->sc_npqueue) != NULL) {
sc->sc_npqueue = m->m_nextpkt;
m_freem(m);
}
#ifdef PPP_COMPRESS
ppp_ccp_closed(sc);
sc->sc_xc_state = NULL;
sc->sc_rc_state = NULL;
#endif /* PPP_COMPRESS */
#ifdef PPP_FILTER
if (sc->sc_pass_filt.bf_insns != 0) {
free(sc->sc_pass_filt.bf_insns, M_DEVBUF);
sc->sc_pass_filt.bf_insns = 0;
sc->sc_pass_filt.bf_len = 0;
}
if (sc->sc_active_filt.bf_insns != 0) {
free(sc->sc_active_filt.bf_insns, M_DEVBUF);
sc->sc_active_filt.bf_insns = 0;
sc->sc_active_filt.bf_len = 0;
}
#endif /* PPP_FILTER */
#ifdef VJC
if (sc->sc_comp != 0) {
free(sc->sc_comp, M_DEVBUF);
sc->sc_comp = 0;
}
#endif
}
/*
* Ioctl routine for generic ppp devices.
*/
int
pppioctl(sc, cmd, data, flag, td)
struct ppp_softc *sc;
u_long cmd;
caddr_t data;
int flag;
struct thread *td;
{
struct proc *p = td->td_proc;
int s, flags, mru, npx;
u_int nb;
int error = 0;
struct ppp_option_data *odp;
struct compressor **cp;
struct npioctl *npi;
time_t t;
#ifdef PPP_FILTER
struct bpf_program *bp, *nbp;
struct bpf_insn *newcode, *oldcode;
int newcodelen;
#endif /* PPP_FILTER */
#ifdef PPP_COMPRESS
u_char ccp_option[CCP_MAX_OPTION_LENGTH];
#endif
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(td)) != 0)
break;
flags = *(int *)data & SC_MASK;
s = splsoftnet();
#ifdef PPP_COMPRESS
if (sc->sc_flags & SC_CCP_OPEN && !(flags & SC_CCP_OPEN))
ppp_ccp_closed(sc);
#endif
splimp();
sc->sc_flags = (sc->sc_flags & ~SC_MASK) | flags;
splx(s);
break;
case PPPIOCSMRU:
if ((error = suser(td)) != 0)
return (error);
mru = *(int *)data;
if (mru >= PPP_MRU && mru <= PPP_MAXMRU)
sc->sc_mru = mru;
break;
case PPPIOCGMRU:
*(int *)data = sc->sc_mru;
break;
#ifdef VJC
case PPPIOCSMAXCID:
if ((error = suser(td)) != 0)
break;
if (sc->sc_comp) {
s = splsoftnet();
sl_compress_init(sc->sc_comp, *(int *)data);
splx(s);
}
break;
#endif
case PPPIOCXFERUNIT:
if ((error = suser(td)) != 0)
break;
sc->sc_xfer = p->p_pid;
break;
#ifdef PPP_COMPRESS
case PPPIOCSCOMPRESS:
if ((error = suser(td)) != 0)
break;
odp = (struct ppp_option_data *) data;
nb = odp->length;
if (nb > sizeof(ccp_option))
nb = sizeof(ccp_option);
if ((error = copyin(odp->ptr, ccp_option, nb)) != 0)
break;
if (ccp_option[1] < 2) { /* preliminary check on the length byte */
error = EINVAL;
break;
}
for (cp = ppp_compressors; *cp != NULL; ++cp)
if ((*cp)->compress_proto == ccp_option[0]) {
/*
* Found a handler for the protocol - try to allocate
* a compressor or decompressor.
*/
error = 0;
if (odp->transmit) {
s = splsoftnet();
if (sc->sc_xc_state != NULL)
(*sc->sc_xcomp->comp_free)(sc->sc_xc_state);
sc->sc_xcomp = *cp;
sc->sc_xc_state = (*cp)->comp_alloc(ccp_option, nb);
if (sc->sc_xc_state == NULL) {
if (sc->sc_flags & SC_DEBUG)
if_printf(&sc->sc_if, "comp_alloc failed\n");
error = ENOBUFS;
}
splimp();
sc->sc_flags &= ~SC_COMP_RUN;
splx(s);
} else {
s = splsoftnet();
if (sc->sc_rc_state != NULL)
(*sc->sc_rcomp->decomp_free)(sc->sc_rc_state);
sc->sc_rcomp = *cp;
sc->sc_rc_state = (*cp)->decomp_alloc(ccp_option, nb);
if (sc->sc_rc_state == NULL) {
if (sc->sc_flags & SC_DEBUG)
if_printf(&sc->sc_if, "decomp_alloc failed\n");
error = ENOBUFS;
}
splimp();
sc->sc_flags &= ~SC_DECOMP_RUN;
splx(s);
}
break;
}
if (sc->sc_flags & SC_DEBUG)
if_printf(&sc->sc_if, "no compressor for [%x %x %x], %x\n",
ccp_option[0], ccp_option[1], ccp_option[2], nb);
error = EINVAL; /* no handler found */
break;
#endif /* PPP_COMPRESS */
case PPPIOCGNPMODE:
case PPPIOCSNPMODE:
npi = (struct npioctl *) data;
npx = 0; /* XXX: quiet gcc */
switch (npi->protocol) {
case PPP_IP:
npx = NP_IP;
break;
default:
error = EINVAL;
}
if (error)
break;
if (cmd == PPPIOCGNPMODE) {
npi->mode = sc->sc_npmode[npx];
} else {
if ((error = suser(td)) != 0)
break;
if (npi->mode != sc->sc_npmode[npx]) {
s = splsoftnet();
sc->sc_npmode[npx] = npi->mode;
if (npi->mode != NPMODE_QUEUE) {
ppp_requeue(sc);
(*sc->sc_start)(sc);
}
splx(s);
}
}
break;
case PPPIOCGIDLE:
s = splsoftnet();
t = time_second;
((struct ppp_idle *)data)->xmit_idle = t - sc->sc_last_sent;
((struct ppp_idle *)data)->recv_idle = t - sc->sc_last_recv;
splx(s);
break;
#ifdef PPP_FILTER
case PPPIOCSPASS:
case PPPIOCSACTIVE:
nbp = (struct bpf_program *) data;
if ((unsigned) nbp->bf_len > BPF_MAXINSNS) {
error = EINVAL;
break;
}
newcodelen = nbp->bf_len * sizeof(struct bpf_insn);
if (newcodelen != 0) {
MALLOC(newcode, struct bpf_insn *, newcodelen, M_DEVBUF, M_WAITOK);
if (newcode == 0) {
error = EINVAL; /* or sumpin */
break;
}
if ((error = copyin((caddr_t)nbp->bf_insns, (caddr_t)newcode,
newcodelen)) != 0) {
free(newcode, M_DEVBUF);
break;
}
if (!bpf_validate(newcode, nbp->bf_len)) {
free(newcode, M_DEVBUF);
error = EINVAL;
break;
}
} else
newcode = 0;
bp = (cmd == PPPIOCSPASS)? &sc->sc_pass_filt: &sc->sc_active_filt;
oldcode = bp->bf_insns;
s = splimp();
bp->bf_len = nbp->bf_len;
bp->bf_insns = newcode;
splx(s);
if (oldcode != 0)
free(oldcode, M_DEVBUF);
break;
#endif
default:
error = ENOIOCTL;
break;
}
return (error);
}
/*
* Process an ioctl request to the ppp network interface.
*/
static int
pppsioctl(ifp, cmd, data)
register struct ifnet *ifp;
u_long cmd;
caddr_t data;
{
struct thread *td = curthread; /* XXX */
register struct ppp_softc *sc = ifp->if_softc;
register struct ifaddr *ifa = (struct ifaddr *)data;
register struct ifreq *ifr = (struct ifreq *)data;
struct ppp_stats *psp;
#ifdef PPP_COMPRESS
struct ppp_comp_stats *pcp;
#endif
int s = splimp(), error = 0;
switch (cmd) {
case SIOCSIFFLAGS:
if ((ifp->if_flags & IFF_RUNNING) == 0)
ifp->if_flags &= ~IFF_UP;
break;
case SIOCSIFADDR:
case SIOCAIFADDR:
switch(ifa->ifa_addr->sa_family) {
#ifdef INET
case AF_INET:
break;
#endif
#ifdef IPX
case AF_IPX:
break;
#endif
default:
error = EAFNOSUPPORT;
break;
}
break;
case SIOCSIFDSTADDR:
switch(ifa->ifa_addr->sa_family) {
#ifdef INET
case AF_INET:
break;
#endif
#ifdef IPX
case AF_IPX:
break;
#endif
default:
error = EAFNOSUPPORT;
break;
}
break;
case SIOCSIFMTU:
if ((error = suser(td)) != 0)
break;
if (ifr->ifr_mtu > PPP_MAXMTU)
error = EINVAL;
else {
sc->sc_if.if_mtu = ifr->ifr_mtu;
if (sc->sc_setmtu)
(*sc->sc_setmtu)(sc);
}
break;
case SIOCGIFMTU:
ifr->ifr_mtu = sc->sc_if.if_mtu;
break;
case SIOCADDMULTI:
case SIOCDELMULTI:
if (ifr == 0) {
error = EAFNOSUPPORT;
break;
}
switch(ifr->ifr_addr.sa_family) {
#ifdef INET
case AF_INET:
break;
#endif
default:
error = EAFNOSUPPORT;
break;
}
break;
case SIOCGPPPSTATS:
psp = &((struct ifpppstatsreq *) data)->stats;
bzero(psp, sizeof(*psp));
psp->p = sc->sc_stats;
#if defined(VJC) && !defined(SL_NO_STATS)
if (sc->sc_comp) {
psp->vj.vjs_packets = sc->sc_comp->sls_packets;
psp->vj.vjs_compressed = sc->sc_comp->sls_compressed;
psp->vj.vjs_searches = sc->sc_comp->sls_searches;
psp->vj.vjs_misses = sc->sc_comp->sls_misses;
psp->vj.vjs_uncompressedin = sc->sc_comp->sls_uncompressedin;
psp->vj.vjs_compressedin = sc->sc_comp->sls_compressedin;
psp->vj.vjs_errorin = sc->sc_comp->sls_errorin;
psp->vj.vjs_tossed = sc->sc_comp->sls_tossed;
}
#endif /* VJC */
break;
#ifdef PPP_COMPRESS
case SIOCGPPPCSTATS:
pcp = &((struct ifpppcstatsreq *) data)->stats;
bzero(pcp, sizeof(*pcp));
if (sc->sc_xc_state != NULL)
(*sc->sc_xcomp->comp_stat)(sc->sc_xc_state, &pcp->c);
if (sc->sc_rc_state != NULL)
(*sc->sc_rcomp->decomp_stat)(sc->sc_rc_state, &pcp->d);
break;
#endif /* PPP_COMPRESS */
default:
error = ENOTTY;
}
splx(s);
return (error);
}
/*
* Queue a packet. Start transmission if not active.
* Packet is placed in Information field of PPP frame.
* Called at splnet as the if->if_output handler.
* Called at splnet from pppwrite().
*/
int
pppoutput(ifp, m0, dst, rtp)
struct ifnet *ifp;
struct mbuf *m0;
struct sockaddr *dst;
struct rtentry *rtp;
{
register struct ppp_softc *sc = ifp->if_softc;
int protocol, address, control;
u_char *cp;
int s, error;
struct ip *ip;
struct ifqueue *ifq;
enum NPmode mode;
int len;
#ifdef MAC
error = mac_check_ifnet_transmit(ifp, m0);
if (error)
goto bad;
#endif
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.
*/
m0->m_flags &= ~M_HIGHPRI;
switch (dst->sa_family) {
#ifdef INET
case AF_INET:
address = PPP_ALLSTATIONS;
control = PPP_UI;
protocol = PPP_IP;
mode = sc->sc_npmode[NP_IP];
/*
* If this packet has the "low delay" bit set in the IP header,
* put it on the fastq instead.
*/
ip = mtod(m0, struct ip *);
if (ip->ip_tos & IPTOS_LOWDELAY)
m0->m_flags |= M_HIGHPRI;
break;
#endif
#ifdef IPX
case AF_IPX:
/*
* This is pretty bogus.. We dont have an ipxcp module in pppd
* yet to configure the link parameters. Sigh. I guess a
* manual ifconfig would do.... -Peter
*/
address = PPP_ALLSTATIONS;
control = PPP_UI;
protocol = PPP_IPX;
mode = NPMODE_PASS;
break;
#endif
case AF_UNSPEC:
address = PPP_ADDRESS(dst->sa_data);
control = PPP_CONTROL(dst->sa_data);
protocol = PPP_PROTOCOL(dst->sa_data);
mode = NPMODE_PASS;
break;
default:
if_printf(ifp, "af%d not supported\n", dst->sa_family);
error = EAFNOSUPPORT;
goto bad;
}
/*
* Drop this packet, or return an error, if necessary.
*/
if (mode == NPMODE_ERROR) {
error = ENETDOWN;
goto bad;
}
if (mode == NPMODE_DROP) {
error = 0;
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;
len = m_length(m0, NULL);
if (sc->sc_flags & SC_LOG_OUTPKT) {
printf("ppp%d output: ", ifp->if_unit);
pppdumpm(m0);
}
if ((protocol & 0x8000) == 0) {
#ifdef PPP_FILTER
/*
* Apply the pass and active filters to the packet,
* but only if it is a data packet.
*/
*mtod(m0, u_char *) = 1; /* indicates outbound */
if (sc->sc_pass_filt.bf_insns != 0
&& bpf_filter(sc->sc_pass_filt.bf_insns, (u_char *) m0,
len, 0) == 0) {
error = 0; /* drop this packet */
goto bad;
}
/*
* Update the time we sent the most recent packet.
*/
if (sc->sc_active_filt.bf_insns == 0
|| bpf_filter(sc->sc_active_filt.bf_insns, (u_char *) m0, len, 0))
sc->sc_last_sent = time_second;
*mtod(m0, u_char *) = address;
#else
/*
* Update the time we sent the most recent data packet.
*/
sc->sc_last_sent = time_second;
#endif /* PPP_FILTER */
}
/*
* See if bpf wants to look at the packet.
*/
if (ifp->if_bpf)
bpf_mtap(ifp, m0);
/*
* Put the packet on the appropriate queue.
*/
s = splsoftnet(); /* redundant */
if (mode == NPMODE_QUEUE) {
/* XXX we should limit the number of packets on this queue */
*sc->sc_npqtail = m0;
m0->m_nextpkt = NULL;
sc->sc_npqtail = &m0->m_nextpkt;
} else {
/* fastq and if_snd are emptied at spl[soft]net now */
ifq = (m0->m_flags & M_HIGHPRI)? &sc->sc_fastq: &ifp->if_snd;
IF_LOCK(ifq);
if (_IF_QFULL(ifq) && dst->sa_family != AF_UNSPEC) {
_IF_DROP(ifq);
IF_UNLOCK(ifq);
sc->sc_if.if_oerrors++;
sc->sc_stats.ppp_oerrors++;
error = ENOBUFS;
goto bad;
}
_IF_ENQUEUE(ifq, m0);
IF_UNLOCK(ifq);
(*sc->sc_start)(sc);
}
getmicrotime(&ifp->if_lastchange);
ifp->if_opackets++;
ifp->if_obytes += len;
splx(s);
return (0);
bad:
m_freem(m0);
return (error);
}
/*
* After a change in the NPmode for some NP, move packets from the
* npqueue to the send queue or the fast queue as appropriate.
* Should be called at spl[soft]net.
*/
static void
ppp_requeue(sc)
struct ppp_softc *sc;
{
struct mbuf *m, **mpp;
struct ifqueue *ifq;
enum NPmode mode;
for (mpp = &sc->sc_npqueue; (m = *mpp) != NULL; ) {
switch (PPP_PROTOCOL(mtod(m, u_char *))) {
case PPP_IP:
mode = sc->sc_npmode[NP_IP];
break;
default:
mode = NPMODE_PASS;
}
switch (mode) {
case NPMODE_PASS:
/*
* This packet can now go on one of the queues to be sent.
*/
*mpp = m->m_nextpkt;
m->m_nextpkt = NULL;
ifq = (m->m_flags & M_HIGHPRI)? &sc->sc_fastq: &sc->sc_if.if_snd;
if (! IF_HANDOFF(ifq, m, NULL)) {
sc->sc_if.if_oerrors++;
sc->sc_stats.ppp_oerrors++;
}
break;
case NPMODE_DROP:
case NPMODE_ERROR:
*mpp = m->m_nextpkt;
m_freem(m);
break;
case NPMODE_QUEUE:
mpp = &m->m_nextpkt;
break;
}
}
sc->sc_npqtail = mpp;
}
/*
* Transmitter has finished outputting some stuff;
* remember to call sc->sc_start later at splsoftnet.
*/
void
ppp_restart(sc)
struct ppp_softc *sc;
{
int s = splimp();
sc->sc_flags &= ~SC_TBUSY;
schednetisr(NETISR_PPP);
splx(s);
}
/*
* Get a packet to send. This procedure is intended to be called at
* splsoftnet, since it may involve time-consuming operations such as
* applying VJ compression, packet compression, address/control and/or
* protocol field compression to the packet.
*/
struct mbuf *
ppp_dequeue(sc)
struct ppp_softc *sc;
{
struct mbuf *m, *mp;
u_char *cp;
int address, control, protocol;
/*
* Grab a packet to send: first try the fast queue, then the
* normal queue.
*/
IF_DEQUEUE(&sc->sc_fastq, m);
if (m == NULL)
IF_DEQUEUE(&sc->sc_if.if_snd, m);
if (m == NULL)
return NULL;
++sc->sc_stats.ppp_opackets;
/*
* Extract the ppp header of the new packet.
* The ppp header will be in one mbuf.
*/
cp = mtod(m, u_char *);
address = PPP_ADDRESS(cp);
control = PPP_CONTROL(cp);
protocol = PPP_PROTOCOL(cp);
switch (protocol) {
case PPP_IP:
#ifdef VJC
/*
* If the packet is a TCP/IP packet, see if we can compress it.
*/
if ((sc->sc_flags & SC_COMP_TCP) && sc->sc_comp != NULL) {
struct ip *ip;
int type;
mp = m;
ip = (struct ip *) (cp + PPP_HDRLEN);
if (mp->m_len <= PPP_HDRLEN) {
mp = mp->m_next;
if (mp == NULL)
break;
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 */
break;
#ifdef PPP_COMPRESS
case PPP_CCP:
ppp_ccp(sc, m, 0);
break;
#endif /* PPP_COMPRESS */
}
#ifdef PPP_COMPRESS
if (protocol != PPP_LCP && protocol != PPP_CCP
&& sc->sc_xc_state && (sc->sc_flags & SC_COMP_RUN)) {
struct mbuf *mcomp = NULL;
int slen, clen;
slen = m_length(m, NULL);
clen = (*sc->sc_xcomp->compress)
(sc->sc_xc_state, &mcomp, m, slen, sc->sc_if.if_mtu + PPP_HDRLEN);
if (mcomp != NULL) {
if (sc->sc_flags & SC_CCP_UP) {
/* Send the compressed packet instead of the original. */
m_freem(m);
m = mcomp;
cp = mtod(m, u_char *);
protocol = cp[3];
} else {
/* Can't transmit compressed packets until CCP is up. */
m_freem(mcomp);
}
}
}
#endif /* PPP_COMPRESS */
/*
* 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;
}
/*
* Software interrupt routine, called at spl[soft]net.
*/
static void
pppintr()
{
struct ppp_softc *sc;
int s;
struct mbuf *m;
LIST_FOREACH(sc, &ppp_softc_list, sc_list) {
s = splimp();
if (!(sc->sc_flags & SC_TBUSY)
&& (sc->sc_if.if_snd.ifq_head || sc->sc_fastq.ifq_head)) {
sc->sc_flags |= SC_TBUSY;
splx(s);
(*sc->sc_start)(sc);
} else
splx(s);
for (;;) {
s = splimp();
IF_DEQUEUE(&sc->sc_rawq, m);
splx(s);
if (m == NULL)
break;
#ifdef MAC
mac_create_mbuf_from_ifnet(&sc->sc_if, m);
#endif
ppp_inproc(sc, m);
}
}
}
#ifdef PPP_COMPRESS
/*
* Handle a CCP packet. `rcvd' is 1 if the packet was received,
* 0 if it is about to be transmitted.
*/
static void
ppp_ccp(sc, m, rcvd)
struct ppp_softc *sc;
struct mbuf *m;
int rcvd;
{
u_char *dp, *ep;
struct mbuf *mp;
int slen, s;
/*
* Get a pointer to the data after the PPP header.
*/
if (m->m_len <= PPP_HDRLEN) {
mp = m->m_next;
if (mp == NULL)
return;
dp = (mp != NULL)? mtod(mp, u_char *): NULL;
} else {
mp = m;
dp = mtod(mp, u_char *) + PPP_HDRLEN;
}
ep = mtod(mp, u_char *) + mp->m_len;
if (dp + CCP_HDRLEN > ep)
return;
slen = CCP_LENGTH(dp);
if (dp + slen > ep) {
if (sc->sc_flags & SC_DEBUG)
printf("if_ppp/ccp: not enough data in mbuf (%p+%x > %p+%x)\n",
dp, slen, mtod(mp, u_char *), mp->m_len);
return;
}
switch (CCP_CODE(dp)) {
case CCP_CONFREQ:
case CCP_TERMREQ:
case CCP_TERMACK:
/* CCP must be going down - disable compression */
if (sc->sc_flags & SC_CCP_UP) {
s = splimp();
sc->sc_flags &= ~(SC_CCP_UP | SC_COMP_RUN | SC_DECOMP_RUN);
splx(s);
}
break;
case CCP_CONFACK:
if (sc->sc_flags & SC_CCP_OPEN && !(sc->sc_flags & SC_CCP_UP)
&& slen >= CCP_HDRLEN + CCP_OPT_MINLEN
&& slen >= CCP_OPT_LENGTH(dp + CCP_HDRLEN) + CCP_HDRLEN) {
if (!rcvd) {
/* we're agreeing to send compressed packets. */
if (sc->sc_xc_state != NULL
&& (*sc->sc_xcomp->comp_init)
(sc->sc_xc_state, dp + CCP_HDRLEN, slen - CCP_HDRLEN,
sc->sc_if.if_unit, 0, sc->sc_flags & SC_DEBUG)) {
s = splimp();
sc->sc_flags |= SC_COMP_RUN;
splx(s);
}
} else {
/* peer is agreeing to send compressed packets. */
if (sc->sc_rc_state != NULL
&& (*sc->sc_rcomp->decomp_init)
(sc->sc_rc_state, dp + CCP_HDRLEN, slen - CCP_HDRLEN,
sc->sc_if.if_unit, 0, sc->sc_mru,
sc->sc_flags & SC_DEBUG)) {
s = splimp();
sc->sc_flags |= SC_DECOMP_RUN;
sc->sc_flags &= ~(SC_DC_ERROR | SC_DC_FERROR);
splx(s);
}
}
}
break;
case CCP_RESETACK:
if (sc->sc_flags & SC_CCP_UP) {
if (!rcvd) {
if (sc->sc_xc_state && (sc->sc_flags & SC_COMP_RUN))
(*sc->sc_xcomp->comp_reset)(sc->sc_xc_state);
} else {
if (sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN)) {
(*sc->sc_rcomp->decomp_reset)(sc->sc_rc_state);
s = splimp();
sc->sc_flags &= ~SC_DC_ERROR;
splx(s);
}
}
}
break;
}
}
/*
* CCP is down; free (de)compressor state if necessary.
*/
static void
ppp_ccp_closed(sc)
struct ppp_softc *sc;
{
if (sc->sc_xc_state) {
(*sc->sc_xcomp->comp_free)(sc->sc_xc_state);
sc->sc_xc_state = NULL;
}
if (sc->sc_rc_state) {
(*sc->sc_rcomp->decomp_free)(sc->sc_rc_state);
sc->sc_rc_state = NULL;
}
}
#endif /* PPP_COMPRESS */
/*
* PPP packet input routine.
* The caller has checked and removed the FCS and has inserted
* the address/control bytes and the protocol high byte if they
* were omitted.
*/
void
ppppktin(sc, m, lost)
struct ppp_softc *sc;
struct mbuf *m;
int lost;
{
int s = splimp();
if (lost)
m->m_flags |= M_ERRMARK;
IF_ENQUEUE(&sc->sc_rawq, m);
schednetisr(NETISR_PPP);
splx(s);
}
/*
* Process a received PPP packet, doing decompression as necessary.
* Should be called at splsoftnet.
*/
#define COMPTYPE(proto) ((proto) == PPP_VJC_COMP? TYPE_COMPRESSED_TCP: \
TYPE_UNCOMPRESSED_TCP)
static void
ppp_inproc(sc, m)
struct ppp_softc *sc;
struct mbuf *m;
{
struct ifnet *ifp = &sc->sc_if;
struct ifqueue *inq;
int s, ilen = 0, xlen, proto, rv;
u_char *cp, adrs, ctrl;
struct mbuf *mp, *dmp = NULL;
u_char *iphdr;
u_int hlen;
sc->sc_stats.ppp_ipackets++;
if (sc->sc_flags & SC_LOG_INPKT) {
ilen = m_length(m, NULL);
if_printf(ifp, "got %d bytes\n", ilen);
pppdumpm(m);
}
cp = mtod(m, u_char *);
adrs = PPP_ADDRESS(cp);
ctrl = PPP_CONTROL(cp);
proto = PPP_PROTOCOL(cp);
if (m->m_flags & M_ERRMARK) {
m->m_flags &= ~M_ERRMARK;
s = splimp();
sc->sc_flags |= SC_VJ_RESET;
splx(s);
}
#ifdef PPP_COMPRESS
/*
* Decompress this packet if necessary, update the receiver's
* dictionary, or take appropriate action on a CCP packet.
*/
if (proto == PPP_COMP && sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN)
&& !(sc->sc_flags & SC_DC_ERROR) && !(sc->sc_flags & SC_DC_FERROR)) {
/* decompress this packet */
rv = (*sc->sc_rcomp->decompress)(sc->sc_rc_state, m, &dmp);
if (rv == DECOMP_OK) {
m_freem(m);
if (dmp == NULL) {
/* no error, but no decompressed packet produced */
return;
}
m = dmp;
cp = mtod(m, u_char *);
proto = PPP_PROTOCOL(cp);
} else {
/*
* An error has occurred in decompression.
* Pass the compressed packet up to pppd, which may take
* CCP down or issue a Reset-Req.
*/
if (sc->sc_flags & SC_DEBUG)
if_printf(ifp, "decompress failed %d\n", rv);
s = splimp();
sc->sc_flags |= SC_VJ_RESET;
if (rv == DECOMP_ERROR)
sc->sc_flags |= SC_DC_ERROR;
else
sc->sc_flags |= SC_DC_FERROR;
splx(s);
}
} else {
if (sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN)) {
(*sc->sc_rcomp->incomp)(sc->sc_rc_state, m);
}
if (proto == PPP_CCP) {
ppp_ccp(sc, m, 1);
}
}
#endif
ilen = m_length(m, NULL);
#ifdef VJC
if (sc->sc_flags & SC_VJ_RESET) {
/*
* If we've missed a packet, we must toss subsequent compressed
* packets which don't have an explicit connection ID.
*/
if (sc->sc_comp)
sl_uncompress_tcp(NULL, 0, TYPE_ERROR, sc->sc_comp);
s = splimp();
sc->sc_flags &= ~SC_VJ_RESET;
splx(s);
}
/*
* See if we have a VJ-compressed packet to uncompress.
*/
if (proto == PPP_VJC_COMP) {
if ((sc->sc_flags & SC_REJ_COMP_TCP) || sc->sc_comp == 0)
goto bad;
xlen = sl_uncompress_tcp_core(cp + PPP_HDRLEN, m->m_len - PPP_HDRLEN,
ilen - PPP_HDRLEN, TYPE_COMPRESSED_TCP,
sc->sc_comp, &iphdr, &hlen);
if (xlen <= 0) {
if (sc->sc_flags & SC_DEBUG)
if_printf(ifp, "VJ uncompress failed on type comp\n");
goto bad;
}
/* Copy the PPP and IP headers into a new mbuf. */
MGETHDR(mp, M_DONTWAIT, MT_DATA);
if (mp == NULL)
goto bad;
mp->m_len = 0;
mp->m_next = NULL;
if (hlen + PPP_HDRLEN > MHLEN) {
MCLGET(mp, M_DONTWAIT);
if (M_TRAILINGSPACE(mp) < hlen + PPP_HDRLEN) {
m_freem(mp);
goto bad; /* lose if big headers and no clusters */
}
}
#ifdef MAC
mac_create_mbuf_from_mbuf(m, mp);
#endif
cp = mtod(mp, u_char *);
cp[0] = adrs;
cp[1] = ctrl;
cp[2] = 0;
cp[3] = PPP_IP;
proto = PPP_IP;
bcopy(iphdr, cp + PPP_HDRLEN, hlen);
mp->m_len = hlen + PPP_HDRLEN;
/*
* Trim the PPP and VJ headers off the old mbuf
* and stick the new and old mbufs together.
*/
m->m_data += PPP_HDRLEN + xlen;
m->m_len -= PPP_HDRLEN + xlen;
if (m->m_len <= M_TRAILINGSPACE(mp)) {
bcopy(mtod(m, u_char *), mtod(mp, u_char *) + mp->m_len, m->m_len);
mp->m_len += m->m_len;
mp->m_next = m_free(m);
} else {
mp->m_next = m;
}
m = mp;
ilen += hlen - xlen;
} else if (proto == PPP_VJC_UNCOMP) {
if ((sc->sc_flags & SC_REJ_COMP_TCP) || sc->sc_comp == 0)
goto bad;
xlen = sl_uncompress_tcp_core(cp + PPP_HDRLEN, m->m_len - PPP_HDRLEN,
ilen - PPP_HDRLEN, TYPE_UNCOMPRESSED_TCP,
sc->sc_comp, &iphdr, &hlen);
if (xlen < 0) {
if (sc->sc_flags & SC_DEBUG)
if_printf(ifp, "VJ uncompress failed on type uncomp\n");
goto bad;
}
proto = PPP_IP;
cp[3] = PPP_IP;
}
#endif /* VJC */
/*
* If the packet will fit in a header mbuf, don't waste a
* whole cluster on it.
*/
if (ilen <= MHLEN && M_IS_CLUSTER(m)) {
MGETHDR(mp, M_DONTWAIT, MT_DATA);
if (mp != NULL) {
#ifdef MAC
mac_create_mbuf_from_mbuf(m, mp);
#endif
m_copydata(m, 0, ilen, mtod(mp, caddr_t));
m_freem(m);
m = mp;
m->m_len = ilen;
}
}
m->m_pkthdr.len = ilen;
m->m_pkthdr.rcvif = ifp;
if ((proto & 0x8000) == 0) {
#ifdef PPP_FILTER
/*
* See whether we want to pass this packet, and
* if it counts as link activity.
*/
adrs = *mtod(m, u_char *); /* save address field */
*mtod(m, u_char *) = 0; /* indicate inbound */
if (sc->sc_pass_filt.bf_insns != 0
&& bpf_filter(sc->sc_pass_filt.bf_insns, (u_char *) m,
ilen, 0) == 0) {
/* drop this packet */
m_freem(m);
return;
}
if (sc->sc_active_filt.bf_insns == 0
|| bpf_filter(sc->sc_active_filt.bf_insns, (u_char *) m, ilen, 0))
sc->sc_last_recv = time_second;
*mtod(m, u_char *) = adrs;
#else
/*
* Record the time that we received this packet.
*/
sc->sc_last_recv = time_second;
#endif /* PPP_FILTER */
}
/* See if bpf wants to look at the packet. */
if (sc->sc_if.if_bpf)
bpf_mtap(&sc->sc_if, m);
rv = 0;
switch (proto) {
#ifdef INET
case PPP_IP:
/*
* IP packet - take off the ppp header and pass it up to IP.
*/
if ((ifp->if_flags & IFF_UP) == 0
|| sc->sc_npmode[NP_IP] != NPMODE_PASS) {
/* interface is down - drop the packet. */
m_freem(m);
return;
}
m->m_pkthdr.len -= PPP_HDRLEN;
m->m_data += PPP_HDRLEN;
m->m_len -= PPP_HDRLEN;
if (ipflow_fastforward(m))
return;
schednetisr(NETISR_IP);
inq = &ipintrq;
break;
#endif
#ifdef IPX
case PPP_IPX:
/*
* IPX packet - take off the ppp header and pass it up to IPX.
*/
if ((sc->sc_if.if_flags & IFF_UP) == 0
/* XXX: || sc->sc_npmode[NP_IPX] != NPMODE_PASS*/) {
/* interface is down - drop the packet. */
m_freem(m);
return;
}
m->m_pkthdr.len -= PPP_HDRLEN;
m->m_data += PPP_HDRLEN;
m->m_len -= PPP_HDRLEN;
schednetisr(NETISR_IPX);
inq = &ipxintrq;
sc->sc_last_recv = time_second; /* update time of last pkt rcvd */
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.
*/
if (! IF_HANDOFF(inq, m, NULL)) {
if (sc->sc_flags & SC_DEBUG)
if_printf(ifp, "input queue full\n");
ifp->if_iqdrops++;
goto bad;
}
ifp->if_ipackets++;
ifp->if_ibytes += ilen;
getmicrotime(&ifp->if_lastchange);
if (rv)
(*sc->sc_ctlp)(sc);
return;
bad:
if (m)
m_freem(m);
sc->sc_if.if_ierrors++;
sc->sc_stats.ppp_ierrors++;
}
#define MAX_DUMP_BYTES 128
static void
pppdumpm(m0)
struct mbuf *m0;
{
char buf[3*MAX_DUMP_BYTES+4];
char *bp = buf;
struct mbuf *m;
for (m = m0; m; m = m->m_next) {
int l = m->m_len;
u_char *rptr = (u_char *)m->m_data;
while (l--) {
if (bp > buf + sizeof(buf) - 4)
goto done;
*bp++ = hex2ascii(*rptr >> 4);
*bp++ = hex2ascii(*rptr++ & 0xf);
}
if (m->m_next) {
if (bp > buf + sizeof(buf) - 3)
goto done;
*bp++ = '|';
} else
*bp++ = ' ';
}
done:
if (m)
*bp++ = '>';
*bp = 0;
printf("%s\n", buf);
}