freebsd-skq/usr.sbin/ppp/main.c
pfg 7551d83c35 various: general adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

No functional change intended.
2017-11-27 15:37:16 +00:00

683 lines
18 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org>
* based on work by Toshiharu OHNO <tony-o@iij.ad.jp>
* Internet Initiative Japan, Inc (IIJ)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <sys/un.h>
#include <sys/socket.h>
#include <net/route.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <termios.h>
#include <unistd.h>
#include <sys/stat.h>
#ifndef NONAT
#ifdef LOCALNAT
#include "alias.h"
#else
#include <alias.h>
#endif
#endif
#include "layer.h"
#include "probe.h"
#include "mbuf.h"
#include "log.h"
#include "defs.h"
#include "id.h"
#include "timer.h"
#include "fsm.h"
#include "lqr.h"
#include "hdlc.h"
#include "lcp.h"
#include "ccp.h"
#include "iplist.h"
#include "throughput.h"
#include "slcompress.h"
#include "ncpaddr.h"
#include "ipcp.h"
#include "filter.h"
#include "descriptor.h"
#include "link.h"
#include "mp.h"
#ifndef NORADIUS
#include "radius.h"
#endif
#include "ipv6cp.h"
#include "ncp.h"
#include "bundle.h"
#include "auth.h"
#include "systems.h"
#include "sig.h"
#include "main.h"
#include "server.h"
#include "prompt.h"
#include "chat.h"
#include "chap.h"
#include "cbcp.h"
#include "datalink.h"
#include "iface.h"
#ifndef O_NONBLOCK
#ifdef O_NDELAY
#define O_NONBLOCK O_NDELAY
#endif
#endif
static void DoLoop(struct bundle *);
static void TerminalStop(int);
static struct bundle *SignalBundle;
static struct prompt *SignalPrompt;
struct libalias *la;
void
Cleanup()
{
SignalBundle->CleaningUp = 1;
bundle_Close(SignalBundle, NULL, CLOSE_STAYDOWN);
}
void
AbortProgram(int excode)
{
if (SignalBundle)
server_Close(SignalBundle);
log_Printf(LogPHASE, "PPP Terminated (%s).\n", ex_desc(excode));
if (SignalBundle) {
bundle_Close(SignalBundle, NULL, CLOSE_STAYDOWN);
bundle_Destroy(SignalBundle);
}
log_Close();
exit(excode);
}
static void
CloseConnection(int signo)
{
/* NOTE, these are manual, we've done a setsid() */
sig_signal(SIGINT, SIG_IGN);
log_Printf(LogPHASE, "Caught signal %d, abort connection(s)\n", signo);
bundle_Down(SignalBundle, CLOSE_STAYDOWN);
sig_signal(SIGINT, CloseConnection);
}
static void
CloseSession(int signo)
{
log_Printf(LogPHASE, "Signal %d, terminate.\n", signo);
Cleanup();
}
static pid_t BGPid = 0;
static void
KillChild(int signo)
{
signal(signo, SIG_IGN);
log_Printf(LogPHASE, "Parent: Signal %d\n", signo);
kill(BGPid, SIGINT);
}
static void
TerminalCont(int signo __unused)
{
signal(SIGCONT, SIG_DFL);
prompt_Continue(SignalPrompt);
}
static void
TerminalStop(int signo __unused)
{
prompt_Suspend(SignalPrompt);
signal(SIGCONT, TerminalCont);
raise(SIGSTOP);
}
static void
BringDownServer(int signo __unused)
{
/* Drops all child prompts too ! */
if (server_Close(SignalBundle))
log_Printf(LogPHASE, "Closed server socket\n");
}
static void
RestartServer(int signo __unused)
{
/* Drops all child prompts and re-opens the socket */
server_Reopen(SignalBundle);
}
static void
Usage(void)
{
fprintf(stderr, "usage: ppp [-auto | -foreground | -background | -direct |"
" -dedicated | -ddial | -interactive]"
#ifndef NONAT
" [-nat]"
#endif
" [-quiet] [-unit N] [system ...]\n");
exit(EX_START);
}
struct switches {
unsigned nat : 1;
unsigned fg : 1;
unsigned quiet : 1;
int mode;
int unit;
};
static int
ProcessArgs(int argc, char **argv, struct switches *sw)
{
int optc, newmode, arg;
char *cp;
optc = 0;
memset(sw, '\0', sizeof *sw);
sw->mode = PHYS_INTERACTIVE;
sw->unit = -1;
for (arg = 1; arg < argc && *argv[arg] == '-'; arg++, optc++) {
cp = argv[arg] + 1;
newmode = Nam2mode(cp);
switch (newmode) {
case PHYS_NONE:
if (strcmp(cp, "nat") == 0) {
#ifdef NONAT
log_Printf(LogWARN, "%s ignored: NAT is compiled out\n", argv[arg]);
#else
sw->nat = 1;
#endif
optc--; /* this option isn't exclusive */
} else if (strcmp(cp, "alias") == 0) {
#ifdef NONAT
log_Printf(LogWARN, "%s ignored: NAT is compiled out\n", argv[arg]);
fprintf(stderr, "%s ignored: NAT is compiled out\n", argv[arg]);
#else
log_Printf(LogWARN, "%s is deprecated\n", argv[arg]);
fprintf(stderr, "%s is deprecated\n", argv[arg]);
sw->nat = 1;
#endif
optc--; /* this option isn't exclusive */
} else if (strncmp(cp, "unit", 4) == 0) {
optc--; /* this option isn't exclusive */
if (cp[4] == '\0') {
optc--; /* nor is the argument */
if (++arg == argc) {
fprintf(stderr, "-unit: Expected unit number\n");
Usage();
} else
sw->unit = atoi(argv[arg]);
} else
sw->unit = atoi(cp + 4);
} else if (strcmp(cp, "quiet") == 0) {
sw->quiet = 1;
optc--; /* this option isn't exclusive */
} else
Usage();
break;
case PHYS_ALL:
Usage();
break;
default:
sw->mode = newmode;
if (newmode == PHYS_FOREGROUND)
sw->fg = 1;
}
}
if (optc > 1) {
fprintf(stderr, "You may specify only one mode.\n");
exit(EX_START);
}
if (sw->mode == PHYS_AUTO && arg == argc) {
fprintf(stderr, "A system must be specified in auto mode.\n");
exit(EX_START);
}
return arg; /* Don't SetLabel yet ! */
}
static void
CheckLabel(const char *label, struct prompt *prompt, int mode)
{
const char *err;
if ((err = system_IsValid(label, prompt, mode)) != NULL) {
fprintf(stderr, "%s: %s\n", label, err);
if (mode == PHYS_DIRECT)
log_Printf(LogWARN, "Label %s rejected -direct connection: %s\n",
label, err);
log_Close();
exit(1);
}
}
int
main(int argc, char **argv)
{
char *name;
const char *lastlabel;
int arg, holdfd[3], label;
unsigned f;
struct bundle *bundle;
struct prompt *prompt;
struct switches sw;
probe_Init();
/*
* We open 3 descriptors to ensure that STDIN_FILENO, STDOUT_FILENO and
* STDERR_FILENO are always open. These are closed before DoLoop(),
* but *after* we've avoided the possibility of erroneously closing
* an important descriptor with close(STD{IN,OUT,ERR}_FILENO).
*/
if ((holdfd[0] = open(_PATH_DEVNULL, O_RDWR)) == -1) {
fprintf(stderr, "Cannot open %s !\n", _PATH_DEVNULL);
return 2;
}
for (f = 1; f < sizeof holdfd / sizeof *holdfd; f++)
holdfd[f] = dup(holdfd[0]);
name = strrchr(argv[0], '/');
log_Open(name ? name + 1 : argv[0]);
#ifndef NONAT
la = LibAliasInit(NULL);
#endif
label = ProcessArgs(argc, argv, &sw);
/*
* A FreeBSD & OpenBSD hack to dodge a bug in the tty driver that drops
* output occasionally.... I must find the real reason some time. To
* display the dodgy behaviour, comment out this bit, make yourself a large
* routing table and then run ppp in interactive mode. The `show route'
* command will drop chunks of data !!!
*/
if (sw.mode == PHYS_INTERACTIVE) {
close(STDIN_FILENO);
if (open(_PATH_TTY, O_RDONLY) != STDIN_FILENO) {
fprintf(stderr, "Cannot open %s for input !\n", _PATH_TTY);
return 2;
}
}
/* Allow output for the moment (except in direct mode) */
if (sw.mode == PHYS_DIRECT)
prompt = NULL;
else
SignalPrompt = prompt = prompt_Create(NULL, NULL, PROMPT_STD);
ID0init();
if (ID0realuid() != 0) {
char conf[200], *ptr;
snprintf(conf, sizeof conf, "%s/%s", PPP_CONFDIR, CONFFILE);
do {
struct stat sb;
if (stat(conf, &sb) == 0 && sb.st_mode & S_IWOTH) {
log_Printf(LogALERT, "ppp: Access violation: Please protect %s\n",
conf);
return -1;
}
ptr = conf + strlen(conf)-2;
while (ptr > conf && *ptr != '/')
*ptr-- = '\0';
} while (ptr >= conf);
}
if (label < argc)
for (arg = label; arg < argc; arg++)
CheckLabel(argv[arg], prompt, sw.mode);
else
CheckLabel("default", prompt, sw.mode);
if (!sw.quiet)
prompt_Printf(prompt, "Working in %s mode\n", mode2Nam(sw.mode));
if ((bundle = bundle_Create(TUN_PREFIX, sw.mode, sw.unit)) == NULL)
return EX_START;
/* NOTE: We may now have changed argv[1] via a ``set proctitle'' */
SignalBundle = bundle;
bundle->NatEnabled = sw.nat;
if (sw.nat)
opt_enable(bundle, OPT_IFACEALIAS);
if (system_Select(bundle, "default", CONFFILE, prompt, NULL) < 0)
prompt_Printf(prompt, "Warning: No default entry found in config file.\n");
sig_signal(SIGHUP, CloseSession);
sig_signal(SIGTERM, CloseSession);
sig_signal(SIGINT, CloseConnection);
sig_signal(SIGQUIT, CloseSession);
sig_signal(SIGALRM, SIG_IGN);
signal(SIGPIPE, SIG_IGN);
if (sw.mode == PHYS_INTERACTIVE)
sig_signal(SIGTSTP, TerminalStop);
sig_signal(SIGUSR1, RestartServer);
sig_signal(SIGUSR2, BringDownServer);
lastlabel = argv[argc - 1];
for (arg = label; arg < argc; arg++) {
/* In case we use LABEL or ``set enddisc label'' */
bundle_SetLabel(bundle, lastlabel);
system_Select(bundle, argv[arg], CONFFILE, prompt, NULL);
}
if (label < argc)
/* In case the last label did a ``load'' */
bundle_SetLabel(bundle, lastlabel);
if (sw.mode == PHYS_AUTO &&
ncprange_family(&bundle->ncp.ipcp.cfg.peer_range) == AF_UNSPEC) {
prompt_Printf(prompt, "You must ``set ifaddr'' with a peer address "
"in auto mode.\n");
AbortProgram(EX_START);
}
if (prompt) {
prompt->bundle = bundle; /* couldn't do it earlier */
if (!sw.quiet)
prompt_Printf(prompt, "Using interface: %s\n", bundle->iface->name);
}
if (sw.mode != PHYS_INTERACTIVE) {
if (sw.mode != PHYS_DIRECT) {
if (!sw.fg) {
int bgpipe[2];
pid_t bgpid;
if (sw.mode == PHYS_BACKGROUND && pipe(bgpipe)) {
log_Printf(LogERROR, "pipe: %s\n", strerror(errno));
AbortProgram(EX_SOCK);
}
bgpid = fork();
if (bgpid == -1) {
log_Printf(LogERROR, "fork: %s\n", strerror(errno));
AbortProgram(EX_SOCK);
}
if (bgpid) {
char c = EX_NORMAL;
int ret;
if (sw.mode == PHYS_BACKGROUND) {
close(bgpipe[1]);
BGPid = bgpid;
/* If we get a signal, kill the child */
signal(SIGHUP, KillChild);
signal(SIGTERM, KillChild);
signal(SIGINT, KillChild);
signal(SIGQUIT, KillChild);
/* Wait for our child to close its pipe before we exit */
while ((ret = read(bgpipe[0], &c, 1)) == 1) {
switch (c) {
case EX_NORMAL:
if (!sw.quiet) {
prompt_Printf(prompt, "PPP enabled\n");
log_Printf(LogPHASE, "Parent: PPP enabled\n");
}
break;
case EX_REDIAL:
if (!sw.quiet)
prompt_Printf(prompt, "Attempting redial\n");
continue;
case EX_RECONNECT:
if (!sw.quiet)
prompt_Printf(prompt, "Attempting reconnect\n");
continue;
default:
prompt_Printf(prompt, "Child failed (%s)\n",
ex_desc((int)c));
log_Printf(LogPHASE, "Parent: Child failed (%s)\n",
ex_desc((int) c));
}
break;
}
if (ret != 1) {
prompt_Printf(prompt, "Child exit, no status.\n");
log_Printf(LogPHASE, "Parent: Child exit, no status.\n");
}
close(bgpipe[0]);
}
return c;
} else if (sw.mode == PHYS_BACKGROUND) {
close(bgpipe[0]);
bundle->notify.fd = bgpipe[1];
}
bundle_ChangedPID(bundle);
bundle_LockTun(bundle); /* we have a new pid */
}
/* -auto, -dedicated, -ddial, -foreground & -background */
prompt_Destroy(prompt, 0);
close(STDOUT_FILENO);
close(STDERR_FILENO);
close(STDIN_FILENO);
if (!sw.fg)
setsid();
} else {
/*
* -direct - STDIN_FILENO gets used by physical_Open. STDOUT_FILENO
* *may* get used in exec/pipe mode.
*/
prompt_TtyInit(NULL);
close(STDERR_FILENO);
}
} else {
/* -interactive */
close(STDERR_FILENO);
prompt_TtyInit(prompt);
prompt_TtyCommandMode(prompt);
prompt_Required(prompt);
}
/* We can get rid of these now */
for (f = 0; f < sizeof holdfd / sizeof *holdfd; f++)
close(holdfd[f]);
log_Printf(LogPHASE, "PPP Started (%s mode).\n", mode2Nam(sw.mode));
DoLoop(bundle);
AbortProgram(EX_NORMAL);
return EX_NORMAL;
}
static void
DoLoop(struct bundle *bundle)
{
fd_set *rfds, *wfds, *efds;
int i, nfds, nothing_done;
if ((rfds = mkfdset()) == NULL) {
log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n");
return;
}
if ((wfds = mkfdset()) == NULL) {
log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n");
free(rfds);
return;
}
if ((efds = mkfdset()) == NULL) {
log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n");
free(rfds);
free(wfds);
return;
}
for (; !bundle_IsDead(bundle); bundle_CleanDatalinks(bundle)) {
nfds = 0;
zerofdset(rfds);
zerofdset(wfds);
zerofdset(efds);
/* All our datalinks, the tun device and the MP socket */
descriptor_UpdateSet(&bundle->desc, rfds, wfds, efds, &nfds);
/* All our prompts and the diagnostic socket */
descriptor_UpdateSet(&server.desc, rfds, NULL, NULL, &nfds);
bundle_CleanDatalinks(bundle);
if (bundle_IsDead(bundle))
/* Don't select - we'll be here forever */
break;
/*
* It's possible that we've had a signal since we last checked. If
* we don't check again before calling select(), we may end up stuck
* after having missed the event.... sig_Handle() tries to be as
* quick as possible if nothing is likely to have happened.
* This is only really likely if we block in open(... O_NONBLOCK)
* which will happen with a misconfigured device.
*/
if (sig_Handle())
continue;
i = select(nfds, rfds, wfds, efds, NULL);
if (i < 0 && errno != EINTR) {
log_Printf(LogERROR, "DoLoop: select(): %s\n", strerror(errno));
if (log_IsKept(LogTIMER)) {
struct timeval t;
for (i = 0; i <= nfds; i++) {
if (FD_ISSET(i, rfds)) {
log_Printf(LogTIMER, "Read set contains %d\n", i);
FD_CLR(i, rfds);
t.tv_sec = t.tv_usec = 0;
if (select(nfds, rfds, wfds, efds, &t) != -1) {
log_Printf(LogTIMER, "The culprit !\n");
break;
}
}
if (FD_ISSET(i, wfds)) {
log_Printf(LogTIMER, "Write set contains %d\n", i);
FD_CLR(i, wfds);
t.tv_sec = t.tv_usec = 0;
if (select(nfds, rfds, wfds, efds, &t) != -1) {
log_Printf(LogTIMER, "The culprit !\n");
break;
}
}
if (FD_ISSET(i, efds)) {
log_Printf(LogTIMER, "Error set contains %d\n", i);
FD_CLR(i, efds);
t.tv_sec = t.tv_usec = 0;
if (select(nfds, rfds, wfds, efds, &t) != -1) {
log_Printf(LogTIMER, "The culprit !\n");
break;
}
}
}
}
break;
}
log_Printf(LogTIMER, "Select returns %d\n", i);
sig_Handle();
if (i <= 0)
continue;
for (i = 0; i <= nfds; i++)
if (FD_ISSET(i, efds)) {
log_Printf(LogPHASE, "Exception detected on descriptor %d\n", i);
/* We deal gracefully with link descriptor exceptions */
if (!bundle_Exception(bundle, i)) {
log_Printf(LogERROR, "Exception cannot be handled !\n");
break;
}
}
if (i <= nfds)
break;
nothing_done = 1;
if (descriptor_IsSet(&server.desc, rfds)) {
descriptor_Read(&server.desc, bundle, rfds);
nothing_done = 0;
}
if (descriptor_IsSet(&bundle->desc, rfds)) {
descriptor_Read(&bundle->desc, bundle, rfds);
nothing_done = 0;
}
if (descriptor_IsSet(&bundle->desc, wfds))
if (descriptor_Write(&bundle->desc, bundle, wfds) <= 0 && nothing_done) {
/*
* This is disastrous. The OS has told us that something is
* writable, and all our write()s have failed. Rather than
* going back immediately to do our UpdateSet()s and select(),
* we sleep for a bit to avoid gobbling up all cpu time.
*/
struct timeval t;
t.tv_sec = 0;
t.tv_usec = 100000;
select(0, NULL, NULL, NULL, &t);
}
}
log_Printf(LogDEBUG, "DoLoop done.\n");
}