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NetBSD/usr.sbin/pppd/main.c

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/*
* main.c - Point-to-Point Protocol main module
*
* 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.
*/
#ifndef lint
static char rcsid[] = "$NetBSD: main.c,v 1.20 1996/11/26 07:53:02 mikel Exp $";
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <errno.h>
#include <fcntl.h>
#include <syslog.h>
#include <netdb.h>
#include <utmp.h>
#include <pwd.h>
#include <sys/param.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <net/if.h>
#include "pppd.h"
#include "magic.h"
#include "fsm.h"
#include "lcp.h"
#include "ipcp.h"
#include "upap.h"
#include "chap.h"
#include "ccp.h"
#include "pathnames.h"
#include "patchlevel.h"
#ifdef IPX_CHANGE
#include "ipxcp.h"
#endif /* IPX_CHANGE */
/*
* If REQ_SYSOPTIONS is defined to 1, pppd will not run unless
* /etc/ppp/options exists.
*/
#ifndef REQ_SYSOPTIONS
#define REQ_SYSOPTIONS 1
#endif
/* interface vars */
char ifname[IFNAMSIZ]; /* Interface name */
int ifunit; /* Interface unit number */
char *progname; /* Name of this program */
char hostname[MAXNAMELEN]; /* Our hostname */
static char pidfilename[MAXPATHLEN]; /* name of pid file */
static char default_devnam[MAXPATHLEN]; /* name of default device */
static pid_t pid; /* Our pid */
static uid_t uid; /* Our real user-id */
int ttyfd = -1; /* Serial port file descriptor */
int phase; /* where the link is at */
int kill_link;
int open_ccp_flag;
u_char outpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for outgoing packet */
u_char inpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for incoming packet */
int hungup; /* terminal has been hung up */
static int n_children; /* # child processes still running */
int baud_rate; /* Actual bits/second for serial device */
static int locked; /* lock() has succeeded */
char *no_ppp_msg = "Sorry - this system lacks PPP kernel support\n";
/* Prototypes for procedures local to this file. */
static void cleanup __P((void));
static void close_tty __P((void));
static void get_input __P((void));
static void connect_time_expired __P((caddr_t));
static void calltimeout __P((void));
static struct timeval *timeleft __P((struct timeval *));
static void hup __P((int));
static void term __P((int));
static void chld __P((int));
static void toggle_debug __P((int));
static void open_ccp __P((int));
static void bad_signal __P((int));
static void holdoff_end __P((void *));
static int device_script __P((char *, int, int));
static void reap_kids __P((void));
static void pr_log __P((void *, char *, ...));
extern char *ttyname __P((int));
extern char *getlogin __P((void));
#ifdef ultrix
#undef O_NONBLOCK
#define O_NONBLOCK O_NDELAY
#endif
/*
* PPP Data Link Layer "protocol" table.
* One entry per supported protocol.
* The last entry must be NULL.
*/
struct protent *protocols[] = {
&lcp_protent,
&pap_protent,
&chap_protent,
&ipcp_protent,
&ccp_protent,
#ifdef IPX_CHANGE
&ipxcp_protent,
#endif
NULL
};
int
main(argc, argv)
int argc;
char *argv[];
{
int i, nonblock, fdflags;
struct sigaction sa;
FILE *pidfile;
char *p;
struct passwd *pw;
struct timeval timo;
sigset_t mask;
struct protent *protp;
p = ttyname(0);
if (p)
strcpy(devnam, p);
strcpy(default_devnam, devnam);
if (gethostname(hostname, MAXNAMELEN) < 0 ) {
perror("couldn't get hostname");
die(1);
}
hostname[MAXNAMELEN-1] = 0;
uid = getuid();
/*
* Initialize to the standard option set, then parse, in order,
* the system options file, the user's options file, and the command
* line arguments.
*/
for (i = 0; (protp = protocols[i]) != NULL; ++i)
(*protp->init)(0);
progname = *argv;
if (!options_from_file(_PATH_SYSOPTIONS, REQ_SYSOPTIONS, 0) ||
!options_from_user() ||
!parse_args(argc-1, argv+1) ||
!options_for_tty())
exit(1);
if (!ppp_available()) {
fprintf(stderr, no_ppp_msg);
exit(1);
}
/*
* Check that the options given are valid and consistent.
*/
sys_check_options();
auth_check_options();
for (i = 0; (protp = protocols[i]) != NULL; ++i)
if (protp->check_options != NULL)
(*protp->check_options)();
if (demand && connector == 0) {
fprintf(stderr, "%s: connect script required for demand-dialling\n",
progname);
exit(1);
}
/*
* If the user has specified the default device name explicitly,
* pretend they hadn't.
*/
if (!default_device && strcmp(devnam, default_devnam) == 0)
default_device = 1;
/*
* Initialize system-dependent stuff and magic number package.
*/
sys_init();
magic_init();
/*
* Detach ourselves from the terminal, if required,
* and identify who is running us.
*/
if (!default_device && !nodetach && daemon(0, 0) < 0) {
perror("Couldn't detach from controlling terminal");
exit(1);
}
pid = getpid();
p = getlogin();
if (p == NULL) {
pw = getpwuid(uid);
if (pw != NULL && pw->pw_name != NULL)
p = pw->pw_name;
else
p = "(unknown)";
}
syslog(LOG_NOTICE, "pppd %s.%d started by %s, uid %d",
VERSION, PATCHLEVEL, p, uid);
/*
* Compute mask of all interesting signals and install signal handlers
* for each. Only one signal handler may be active at a time. Therefore,
* all other signals should be masked when any handler is executing.
*/
sigemptyset(&mask);
sigaddset(&mask, SIGHUP);
sigaddset(&mask, SIGINT);
sigaddset(&mask, SIGTERM);
sigaddset(&mask, SIGCHLD);
#define SIGNAL(s, handler) { \
sa.sa_handler = handler; \
if (sigaction(s, &sa, NULL) < 0) { \
syslog(LOG_ERR, "Couldn't establish signal handler (%d): %m", s); \
die(1); \
} \
}
sa.sa_mask = mask;
sa.sa_flags = 0;
SIGNAL(SIGHUP, hup); /* Hangup */
SIGNAL(SIGINT, term); /* Interrupt */
SIGNAL(SIGTERM, term); /* Terminate */
SIGNAL(SIGCHLD, chld);
SIGNAL(SIGUSR1, toggle_debug); /* Toggle debug flag */
SIGNAL(SIGUSR2, open_ccp); /* Reopen CCP */
/*
* Install a handler for other signals which would otherwise
* cause pppd to exit without cleaning up.
*/
SIGNAL(SIGABRT, bad_signal);
SIGNAL(SIGALRM, bad_signal);
SIGNAL(SIGFPE, bad_signal);
SIGNAL(SIGILL, bad_signal);
SIGNAL(SIGPIPE, bad_signal);
SIGNAL(SIGQUIT, bad_signal);
SIGNAL(SIGSEGV, bad_signal);
#ifdef SIGBUS
SIGNAL(SIGBUS, bad_signal);
#endif
#ifdef SIGEMT
SIGNAL(SIGEMT, bad_signal);
#endif
#ifdef SIGPOLL
SIGNAL(SIGPOLL, bad_signal);
#endif
#ifdef SIGPROF
SIGNAL(SIGPROF, bad_signal);
#endif
#ifdef SIGSYS
SIGNAL(SIGSYS, bad_signal);
#endif
#ifdef SIGTRAP
SIGNAL(SIGTRAP, bad_signal);
#endif
#ifdef SIGVTALRM
SIGNAL(SIGVTALRM, bad_signal);
#endif
#ifdef SIGXCPU
SIGNAL(SIGXCPU, bad_signal);
#endif
#ifdef SIGXFSZ
SIGNAL(SIGXFSZ, bad_signal);
#endif
/*
* If we're doing dial-on-demand, set up the interface now.
*/
if (demand) {
/*
* Open the loopback channel and set it up to be the ppp interface.
*/
open_ppp_loopback();
syslog(LOG_INFO, "Using interface ppp%d", ifunit);
(void) sprintf(ifname, "ppp%d", ifunit);
/* write pid to file */
(void) sprintf(pidfilename, "%s%s.pid", _PATH_VARRUN, ifname);
if ((pidfile = fopen(pidfilename, "w")) != NULL) {
fprintf(pidfile, "%d\n", pid);
(void) fclose(pidfile);
} else {
syslog(LOG_ERR, "Failed to create pid file %s: %m", pidfilename);
pidfilename[0] = 0;
}
/*
* Configure the interface and mark it up, etc.
*/
demand_conf();
}
for (;;) {
if (demand) {
/*
* Don't do anything until we see some activity.
*/
phase = PHASE_DORMANT;
kill_link = 0;
demand_unblock();
for (;;) {
wait_loop_output(timeleft(&timo));
calltimeout();
if (kill_link) {
if (!persist)
die(0);
kill_link = 0;
}
if (get_loop_output())
break;
reap_kids();
}
/*
* Now we want to bring up the link.
*/
demand_block();
syslog(LOG_INFO, "Starting link");
}
/*
* Lock the device if we've been asked to.
*/
if (lockflag && !default_device) {
if (lock(devnam) < 0)
goto fail;
locked = 1;
}
/*
* Open the serial device and set it up to be the ppp interface.
* If we're dialling out, or we don't want to use the modem lines,
* we open it in non-blocking mode, but then we need to clear
* the non-blocking I/O bit.
*/
nonblock = (connector || !modem)? O_NONBLOCK: 0;
if ((ttyfd = open(devnam, nonblock | O_RDWR, 0)) < 0) {
syslog(LOG_ERR, "Failed to open %s: %m", devnam);
goto fail;
}
if (nonblock) {
if ((fdflags = fcntl(ttyfd, F_GETFL)) == -1
|| fcntl(ttyfd, F_SETFL, fdflags & ~O_NONBLOCK) < 0)
syslog(LOG_WARNING,
"Couldn't reset non-blocking mode on device: %m");
}
hungup = 0;
kill_link = 0;
/* run connection script */
if (connector && connector[0]) {
MAINDEBUG((LOG_INFO, "Connecting with <%s>", connector));
/* set line speed, flow control, etc.; set CLOCAL for now */
set_up_tty(ttyfd, 1);
/* drop dtr to hang up in case modem is off hook */
if (!default_device && modem) {
setdtr(ttyfd, FALSE);
sleep(1);
setdtr(ttyfd, TRUE);
}
if (device_script(connector, ttyfd, ttyfd) < 0) {
syslog(LOG_ERR, "Connect script failed");
setdtr(ttyfd, FALSE);
goto fail;
}
syslog(LOG_INFO, "Serial connection established.");
sleep(1); /* give it time to set up its terminal */
}
/* set line speed, flow control, etc.; clear CLOCAL if modem option */
set_up_tty(ttyfd, 0);
/* run welcome script, if any */
if (welcomer && welcomer[0]) {
if (device_script(welcomer, ttyfd, ttyfd) < 0)
syslog(LOG_WARNING, "Welcome script failed");
}
/* set up the serial device as a ppp interface */
establish_ppp(ttyfd);
if (!demand) {
syslog(LOG_INFO, "Using interface ppp%d", ifunit);
(void) sprintf(ifname, "ppp%d", ifunit);
/* write pid to file */
(void) sprintf(pidfilename, "%s%s.pid", _PATH_VARRUN, ifname);
if ((pidfile = fopen(pidfilename, "w")) != NULL) {
fprintf(pidfile, "%d\n", pid);
(void) fclose(pidfile);
} else {
syslog(LOG_ERR, "Failed to create pid file %s: %m",
pidfilename);
pidfilename[0] = 0;
}
}
/*
* Set a timeout to close the connection once the maximum
* connect time has expired.
*/
if (maxconnect > 0)
TIMEOUT(connect_time_expired, 0, maxconnect);
/*
* Start opening the connection and wait for
* incoming events (reply, timeout, etc.).
*/
syslog(LOG_NOTICE, "Connect: %s <--> %s", ifname, devnam);
lcp_lowerup(0);
lcp_open(0); /* Start protocol */
for (phase = PHASE_ESTABLISH; phase != PHASE_DEAD; ) {
wait_input(timeleft(&timo));
calltimeout();
get_input();
if (kill_link) {
lcp_close(0, "User request");
phase = PHASE_TERMINATE;
kill_link = 0;
}
if (open_ccp_flag) {
if (phase == PHASE_NETWORK) {
ccp_fsm[0].flags = OPT_RESTART; /* clears OPT_SILENT */
ccp_open(0);
}
open_ccp_flag = 0;
}
reap_kids(); /* Don't leave dead kids lying around */
}
/*
* If we may want to bring the link up again, transfer
* the ppp unit back to the loopback. Set the
* real serial device back to its normal mode of operation.
*/
clean_check();
if (demand)
restore_loop();
disestablish_ppp(ttyfd);
/*
* Run disconnector script, if requested.
* XXX we may not be able to do this if the line has hung up!
*/
if (disconnector && !hungup) {
set_up_tty(ttyfd, 1);
if (device_script(disconnector, ttyfd, ttyfd) < 0) {
syslog(LOG_WARNING, "disconnect script failed");
} else {
syslog(LOG_INFO, "Serial link disconnected.");
}
}
fail:
close_tty();
if (locked) {
unlock();
locked = 0;
}
if (!demand && pidfilename[0] != 0) {
if (unlink(pidfilename) < 0 && errno != ENOENT)
syslog(LOG_WARNING, "unable to delete pid file: %m");
pidfilename[0] = 0;
}
if (!persist)
break;
if (demand)
demand_discard();
if (holdoff > 0) {
phase = PHASE_HOLDOFF;
TIMEOUT(holdoff_end, NULL, holdoff);
do {
wait_time(timeleft(&timo));
calltimeout();
if (kill_link) {
if (!persist)
die(0);
kill_link = 0;
phase = PHASE_DORMANT; /* allow signal to end holdoff */
}
reap_kids();
} while (phase == PHASE_HOLDOFF);
}
}
die(0);
}
/*
* holdoff_end - called via a timeout when the holdoff period ends.
*/
static void
holdoff_end(arg)
void *arg;
{
phase = PHASE_DORMANT;
}
/*
* get_input - called when incoming data is available.
*/
static void
get_input()
{
int len, i;
u_char *p;
u_short protocol;
struct protent *protp;
p = inpacket_buf; /* point to beginning of packet buffer */
len = read_packet(inpacket_buf);
if (len < 0)
return;
if (len == 0) {
syslog(LOG_NOTICE, "Modem hangup");
hungup = 1;
lcp_lowerdown(0); /* serial link is no longer available */
link_terminated(0);
return;
}
if (debug /*&& (debugflags & DBG_INPACKET)*/)
log_packet(p, len, "rcvd ");
if (len < PPP_HDRLEN) {
MAINDEBUG((LOG_INFO, "io(): Received short packet."));
return;
}
p += 2; /* Skip address and control */
GETSHORT(protocol, p);
len -= PPP_HDRLEN;
/*
* Toss all non-LCP packets unless LCP is OPEN.
*/
if (protocol != PPP_LCP && lcp_fsm[0].state != OPENED) {
MAINDEBUG((LOG_INFO,
"io(): Received non-LCP packet when LCP not open."));
return;
}
/*
* Upcall the proper protocol input routine.
*/
for (i = 0; (protp = protocols[i]) != NULL; ++i) {
if (protp->protocol == protocol && protp->enabled_flag) {
(*protp->input)(0, p, len);
return;
}
if (protocol == (protp->protocol & ~0x8000) && protp->enabled_flag
&& protp->datainput != NULL) {
(*protp->datainput)(0, p, len);
return;
}
}
if (debug)
syslog(LOG_WARNING, "Unsupported protocol (0x%x) received", protocol);
lcp_sprotrej(0, p - PPP_HDRLEN, len + PPP_HDRLEN);
}
/*
* quit - Clean up state and exit (with an error indication).
*/
void
quit()
{
die(1);
}
/*
* die - like quit, except we can specify an exit status.
*/
void
die(status)
int status;
{
cleanup();
syslog(LOG_INFO, "Exit.");
exit(status);
}
/*
* connect_time_expired - log a message and close the connection.
*/
static void
connect_time_expired(arg)
caddr_t arg;
{
syslog(LOG_INFO, "Connect time expired");
phase = PHASE_TERMINATE;
lcp_close(0, "Connect time expired"); /* Close connection */
}
/*
* cleanup - restore anything which needs to be restored before we exit
*/
/* ARGSUSED */
static void
cleanup()
{
sys_cleanup();
if (ttyfd >= 0)
close_tty();
if (pidfilename[0] != 0 && unlink(pidfilename) < 0 && errno != ENOENT)
syslog(LOG_WARNING, "unable to delete pid file: %m");
pidfilename[0] = 0;
if (locked)
unlock();
}
/*
* close_tty - restore the terminal device and close it.
*/
static void
close_tty()
{
disestablish_ppp(ttyfd);
/* drop dtr to hang up */
if (modem) {
setdtr(ttyfd, FALSE);
/*
* This sleep is in case the serial port has CLOCAL set by default,
* and consequently will reassert DTR when we close the device.
*/
sleep(1);
}
restore_tty(ttyfd);
close(ttyfd);
ttyfd = -1;
}
struct callout {
struct timeval c_time; /* time at which to call routine */
caddr_t c_arg; /* argument to routine */
void (*c_func)(); /* routine */
struct callout *c_next;
};
static struct callout *callout = NULL; /* Callout list */
static struct timeval timenow; /* Current time */
/*
* timeout - Schedule a timeout.
*
* Note that this timeout takes the number of seconds, NOT hz (as in
* the kernel).
*/
void
timeout(func, arg, time)
void (*func)();
caddr_t arg;
int time;
{
struct callout *newp, *p, **pp;
MAINDEBUG((LOG_DEBUG, "Timeout %lx:%lx in %d seconds.",
(long) func, (long) arg, time));
/*
* Allocate timeout.
*/
if ((newp = (struct callout *) malloc(sizeof(struct callout))) == NULL) {
syslog(LOG_ERR, "Out of memory in timeout()!");
die(1);
}
newp->c_arg = arg;
newp->c_func = func;
gettimeofday(&timenow, NULL);
newp->c_time.tv_sec = timenow.tv_sec + time;
newp->c_time.tv_usec = timenow.tv_usec;
/*
* Find correct place and link it in.
*/
for (pp = &callout; (p = *pp); pp = &p->c_next)
if (newp->c_time.tv_sec < p->c_time.tv_sec
|| (newp->c_time.tv_sec == p->c_time.tv_sec
&& newp->c_time.tv_usec < p->c_time.tv_sec))
break;
newp->c_next = p;
*pp = newp;
}
/*
* untimeout - Unschedule a timeout.
*/
void
untimeout(func, arg)
void (*func)();
caddr_t arg;
{
struct callout **copp, *freep;
MAINDEBUG((LOG_DEBUG, "Untimeout %lx:%lx.", (long) func, (long) arg));
/*
* Find first matching timeout and remove it from the list.
*/
for (copp = &callout; (freep = *copp); copp = &freep->c_next)
if (freep->c_func == func && freep->c_arg == arg) {
*copp = freep->c_next;
(void) free((char *) freep);
break;
}
}
/*
* calltimeout - Call any timeout routines which are now due.
*/
static void
calltimeout()
{
struct callout *p;
while (callout != NULL) {
p = callout;
if (gettimeofday(&timenow, NULL) < 0) {
syslog(LOG_ERR, "Failed to get time of day: %m");
die(1);
}
if (!(p->c_time.tv_sec < timenow.tv_sec
|| (p->c_time.tv_sec == timenow.tv_sec
&& p->c_time.tv_usec <= timenow.tv_usec)))
break; /* no, it's not time yet */
callout = p->c_next;
(*p->c_func)(p->c_arg);
free((char *) p);
}
}
/*
* timeleft - return the length of time until the next timeout is due.
*/
static struct timeval *
timeleft(tvp)
struct timeval *tvp;
{
if (callout == NULL)
return NULL;
gettimeofday(&timenow, NULL);
tvp->tv_sec = callout->c_time.tv_sec - timenow.tv_sec;
tvp->tv_usec = callout->c_time.tv_usec - timenow.tv_usec;
if (tvp->tv_usec < 0) {
tvp->tv_usec += 1000000;
tvp->tv_sec -= 1;
}
if (tvp->tv_sec < 0)
tvp->tv_sec = tvp->tv_usec = 0;
return tvp;
}
/*
* hup - Catch SIGHUP signal.
*
* Indicates that the physical layer has been disconnected.
* We don't rely on this indication; if the user has sent this
* signal, we just take the link down.
*/
static void
hup(sig)
int sig;
{
syslog(LOG_INFO, "Hangup (SIGHUP)");
kill_link = 1;
}
/*
* term - Catch SIGTERM signal and SIGINT signal (^C/del).
*
* Indicates that we should initiate a graceful disconnect and exit.
*/
/*ARGSUSED*/
static void
term(sig)
int sig;
{
syslog(LOG_INFO, "Terminating on signal %d.", sig);
persist = 0; /* don't try to restart */
kill_link = 1;
}
/*
* chld - Catch SIGCHLD signal.
* Calls reap_kids to get status for any dead kids.
*/
static void
chld(sig)
int sig;
{
reap_kids();
}
/*
* toggle_debug - Catch SIGUSR1 signal.
*
* Toggle debug flag.
*/
/*ARGSUSED*/
static void
toggle_debug(sig)
int sig;
{
debug = !debug;
note_debug_level();
}
/*
* open_ccp - Catch SIGUSR2 signal.
*
* Try to (re)negotiate compression.
*/
/*ARGSUSED*/
static void
open_ccp(sig)
int sig;
{
open_ccp_flag = 1;
}
/*
* bad_signal - We've caught a fatal signal. Clean up state and exit.
*/
static void
bad_signal(sig)
int sig;
{
syslog(LOG_ERR, "Fatal signal %d", sig);
die(1);
}
/*
* device_script - run a program to connect or disconnect the
* serial device.
*/
static int
device_script(program, in, out)
char *program;
int in, out;
{
int pid;
int status;
int errfd;
pid = fork();
if (pid < 0) {
syslog(LOG_ERR, "Failed to create child process: %m");
die(1);
}
if (pid == 0) {
sys_close();
dup2(in, 0);
dup2(out, 1);
errfd = open(_PATH_CONNERRS, O_WRONLY | O_APPEND | O_CREAT, 0644);
if (errfd >= 0)
dup2(errfd, 2);
setuid(getuid());
setgid(getgid());
execl("/bin/sh", "sh", "-c", program, (char *)0);
syslog(LOG_ERR, "could not exec /bin/sh: %m");
_exit(99);
/* NOTREACHED */
}
while (waitpid(pid, &status, 0) < 0) {
if (errno == EINTR)
continue;
syslog(LOG_ERR, "error waiting for (dis)connection process: %m");
die(1);
}
return (status == 0 ? 0 : -1);
}
/*
* run-program - execute a program with given arguments,
* but don't wait for it.
* If the program can't be executed, logs an error unless
* must_exist is 0 and the program file doesn't exist.
*/
int
run_program(prog, args, must_exist)
char *prog;
char **args;
int must_exist;
{
int pid;
char *nullenv[1];
pid = fork();
if (pid == -1) {
syslog(LOG_ERR, "Failed to create child process for %s: %m", prog);
return -1;
}
if (pid == 0) {
int new_fd;
/* Leave the current location */
(void) setsid(); /* No controlling tty. */
(void) umask (S_IRWXG|S_IRWXO);
(void) chdir ("/"); /* no current directory. */
setuid(geteuid());
setgid(getegid());
/* Ensure that nothing of our device environment is inherited. */
sys_close();
close (0);
close (1);
close (2);
close (ttyfd); /* tty interface to the ppp device */
/* Don't pass handles to the PPP device, even by accident. */
new_fd = open (_PATH_DEVNULL, O_RDWR);
if (new_fd >= 0) {
if (new_fd != 0) {
dup2 (new_fd, 0); /* stdin <- /dev/null */
close (new_fd);
}
dup2 (0, 1); /* stdout -> /dev/null */
dup2 (0, 2); /* stderr -> /dev/null */
}
#ifdef BSD
/* Force the priority back to zero if pppd is running higher. */
if (setpriority (PRIO_PROCESS, 0, 0) < 0)
syslog (LOG_WARNING, "can't reset priority to 0: %m");
#endif
/* SysV recommends a second fork at this point. */
/* run the program; give it a null environment */
nullenv[0] = NULL;
execve(prog, args, nullenv);
if (must_exist || errno != ENOENT)
syslog(LOG_WARNING, "Can't execute %s: %m", prog);
_exit(-1);
}
MAINDEBUG((LOG_DEBUG, "Script %s started; pid = %d", prog, pid));
++n_children;
return 0;
}
/*
* reap_kids - get status from any dead child processes,
* and log a message for abnormal terminations.
*/
static void
reap_kids()
{
int pid, status;
if (n_children == 0)
return;
if ((pid = waitpid(-1, &status, WNOHANG)) == -1) {
if (errno != ECHILD)
syslog(LOG_ERR, "Error waiting for child process: %m");
return;
}
if (pid > 0) {
--n_children;
if (WIFSIGNALED(status)) {
syslog(LOG_WARNING, "Child process %d terminated with signal %d",
pid, WTERMSIG(status));
}
}
}
/*
* log_packet - format a packet and log it.
*/
char line[256]; /* line to be logged accumulated here */
char *linep;
void
log_packet(p, len, prefix)
u_char *p;
int len;
char *prefix;
{
strcpy(line, prefix);
linep = line + strlen(line);
format_packet(p, len, pr_log, NULL);
if (linep != line)
syslog(LOG_DEBUG, "%s", line);
}
/*
* format_packet - make a readable representation of a packet,
* calling `printer(arg, format, ...)' to output it.
*/
void
format_packet(p, len, printer, arg)
u_char *p;
int len;
void (*printer) __P((void *, char *, ...));
void *arg;
{
int i, n;
u_short proto;
u_char x;
struct protent *protp;
if (len >= PPP_HDRLEN && p[0] == PPP_ALLSTATIONS && p[1] == PPP_UI) {
p += 2;
GETSHORT(proto, p);
len -= PPP_HDRLEN;
for (i = 0; (protp = protocols[i]) != NULL; ++i)
if (proto == protp->protocol)
break;
if (protp != NULL) {
printer(arg, "[%s", protp->name);
n = (*protp->printpkt)(p, len, printer, arg);
printer(arg, "]");
p += n;
len -= n;
} else {
printer(arg, "[proto=0x%x]", proto);
}
}
for (; len > 0; --len) {
GETCHAR(x, p);
printer(arg, " %.2x", x);
}
}
#ifdef __STDC__
#include <stdarg.h>
static void
pr_log(void *arg, char *fmt, ...)
{
int n;
va_list pvar;
char buf[256];
va_start(pvar, fmt);
vsprintf(buf, fmt, pvar);
va_end(pvar);
n = strlen(buf);
if (linep + n + 1 > line + sizeof(line)) {
syslog(LOG_DEBUG, "%s", line);
linep = line;
}
strcpy(linep, buf);
linep += n;
}
#else /* __STDC__ */
#include <varargs.h>
static void
pr_log(arg, fmt, va_alist)
void *arg;
char *fmt;
va_dcl
{
int n;
va_list pvar;
char buf[256];
va_start(pvar);
vsprintf(buf, fmt, pvar);
va_end(pvar);
n = strlen(buf);
if (linep + n + 1 > line + sizeof(line)) {
syslog(LOG_DEBUG, "%s", line);
linep = line;
}
strcpy(linep, buf);
linep += n;
}
#endif
/*
* print_string - print a readable representation of a string using
* printer.
*/
void
print_string(p, len, printer, arg)
char *p;
int len;
void (*printer) __P((void *, char *, ...));
void *arg;
{
int c;
printer(arg, "\"");
for (; len > 0; --len) {
c = *p++;
if (' ' <= c && c <= '~')
printer(arg, "%c", c);
else
printer(arg, "\\%.3o", c);
}
printer(arg, "\"");
}
/*
* novm - log an error message saying we ran out of memory, and die.
*/
void
novm(msg)
char *msg;
{
syslog(LOG_ERR, "Virtual memory exhausted allocating %s\n", msg);
die(1);
}
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