/*
* main.c - Point-to-Point Protocol main module
*
* Copyright (c) 1984-2000 Carnegie Mellon University. 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.
*
* 3. The name "Carnegie Mellon University" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For permission or any legal
* details, please contact
* Office of Technology Transfer
* Carnegie Mellon University
* 5000 Forbes Avenue
* Pittsburgh, PA 15213-3890
* (412) 268-4387, fax: (412) 268-7395
* tech-transfer@andrew.cmu.edu
*
* 4. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by Computing Services
* at Carnegie Mellon University (http://www.cmu.edu/computing/)."
*
* CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
* FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Copyright (c) 1999-2004 Paul Mackerras. 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. The name(s) of the authors of this software must not be used to
* endorse or promote products derived from this software without
* prior written permission.
*
* 3. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by Paul Mackerras
* <paulus@samba.org>".
*
* THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
* SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#define RCSID "$Id: main.c,v 1.156 2008/06/23 11:47:18 paulus Exp $"
#include <stdio.h>
#include <ctype.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 <setjmp.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 <netinet/in.h>
#include <arpa/inet.h>
#include "pppd.h"
#include "magic.h"
#include "fsm.h"
#include "lcp.h"
#include "ipcp.h"
#ifdef INET6
#include "ipv6cp.h"
#endif
#include "upap.h"
#include "chap-new.h"
#include "eap.h"
#include "ccp.h"
#include "ecp.h"
#include "pathnames.h"
#ifdef USE_TDB
#include "tdb.h"
#endif
#ifdef CBCP_SUPPORT
#include "cbcp.h"
#endif
#ifdef IPX_CHANGE
#include "ipxcp.h"
#endif /* IPX_CHANGE */
#ifdef AT_CHANGE
#include "atcp.h"
#endif
static const char rcsid[] = RCSID;
/* interface vars */
char ifname[32]; /* Interface name */
int ifunit; /* Interface unit number */
struct channel *the_channel;
char *progname; /* Name of this program */
char hostname[MAXNAMELEN]; /* Our hostname */
static char pidfilename[MAXPATHLEN]; /* name of pid file */
static char linkpidfile[MAXPATHLEN]; /* name of linkname pid file */
char ppp_devnam[MAXPATHLEN]; /* name of PPP tty (maybe ttypx) */
uid_t uid; /* Our real user-id */
struct notifier *pidchange = NULL;
struct notifier *phasechange = NULL;
struct notifier *exitnotify = NULL;
struct notifier *sigreceived = NULL;
struct notifier *fork_notifier = NULL;
int hungup; /* terminal has been hung up */
int privileged; /* we're running as real uid root */
int need_holdoff; /* need holdoff period before restarting */
int detached; /* have detached from terminal */
volatile int status; /* exit status for pppd */
int unsuccess; /* # unsuccessful connection attempts */
int do_callback; /* != 0 if we should do callback next */
int doing_callback; /* != 0 if we are doing callback */
int ppp_session_number; /* Session number, for channels with such a
concept (eg PPPoE) */
int childwait_done; /* have timed out waiting for children */
#ifdef USE_TDB
TDB_CONTEXT *pppdb; /* database for storing status etc. */
#endif
char db_key[32];
int (*holdoff_hook) __P((void)) = NULL;
int (*new_phase_hook) __P((int)) = NULL;
void (*snoop_recv_hook) __P((unsigned char *p, int len)) = NULL;
void (*snoop_send_hook) __P((unsigned char *p, int len)) = NULL;
static int conn_running; /* we have a [dis]connector running */
static int fd_loop; /* fd for getting demand-dial packets */
int fd_devnull; /* fd for /dev/null */
int devfd = -1; /* fd of underlying device */
int fd_ppp = -1; /* fd for talking PPP */
int phase; /* where the link is at */
int kill_link;
int asked_to_quit;
int open_ccp_flag;
int listen_time;
int got_sigusr2;
int got_sigterm;
int got_sighup;
static sigset_t signals_handled;
static int waiting;
static sigjmp_buf sigjmp;
char **script_env; /* Env. variable values for scripts */
int s_env_nalloc; /* # words avail at script_env */
u_char outpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for outgoing packet */
u_char inpacket_buf[PPP_MRU+PPP_HDRLEN]; /* buffer for incoming packet */
static int n_children; /* # child processes still running */
static int got_sigchld; /* set if we have received a SIGCHLD */
int privopen; /* don't lock, open device as root */
char *no_ppp_msg = "Sorry - this system lacks PPP kernel support\n";
GIDSET_TYPE groups[NGROUPS_MAX];/* groups the user is in */
int ngroups; /* How many groups valid in groups */
static struct timeval start_time; /* Time when link was started. */
static struct pppd_stats old_link_stats;
struct pppd_stats link_stats;
unsigned link_connect_time;
int link_stats_valid;
int error_count;
bool bundle_eof;
bool bundle_terminating;
/*
* We maintain a list of child process pids and
* functions to call when they exit.
*/
struct subprocess {
pid_t pid;
char *prog;
void (*done) __P((void *));
void *arg;
int killable;
struct subprocess *next;
};
static struct subprocess *children;
/* Prototypes for procedures local to this file. */
static void setup_signals __P((void));
static void create_pidfile __P((int pid));
static void create_linkpidfile __P((int pid));
static void cleanup __P((void));
static void get_input __P((void));
static void calltimeout __P((void));
static struct timeval *timeleft __P((struct timeval *));
static void kill_my_pg __P((int));
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 void forget_child __P((int pid, int status));
static int reap_kids __P((void));
static void childwait_end __P((void *));
#ifdef USE_TDB
static void update_db_entry __P((void));
static void add_db_key __P((const char *));
static void delete_db_key __P((const char *));
static void cleanup_db __P((void));
#endif
static void handle_events __P((void));
void print_link_stats __P((void));
extern char *ttyname __P((int));
extern char *getlogin __P((void));
int main __P((int, char *[]));
#ifdef ultrix
#undef O_NONBLOCK
#define O_NONBLOCK O_NDELAY
#endif
#ifdef ULTRIX
#define setlogmask(x)
#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,
#ifdef CBCP_SUPPORT
&cbcp_protent,
#endif
&ipcp_protent,
#ifdef INET6
&ipv6cp_protent,
#endif
&ccp_protent,
&ecp_protent,
#ifdef IPX_CHANGE
&ipxcp_protent,
#endif
#ifdef AT_CHANGE
&atcp_protent,
#endif
&eap_protent,
NULL
};
/*
* If PPP_DRV_NAME is not defined, use the default "ppp" as the device name.
*/
#if !defined(PPP_DRV_NAME)
#define PPP_DRV_NAME "ppp"
#endif /* !defined(PPP_DRV_NAME) */
int
main(argc, argv)
int argc;
char *argv[];
{
int i, t;
char *p;
struct passwd *pw;
struct protent *protp;
char numbuf[16];
link_stats_valid = 0;
new_phase(PHASE_INITIALIZE);
script_env = NULL;
/* Initialize syslog facilities */
reopen_log();
if (gethostname(hostname, MAXNAMELEN) < 0 ) {
option_error("Couldn't get hostname: %m");
exit(1);
}
hostname[MAXNAMELEN-1] = 0;
/* make sure we don't create world or group writable files. */
umask(umask(0777) | 022);
uid = getuid();
privileged = uid == 0;
slprintf(numbuf, sizeof(numbuf), "%d", uid);
script_setenv("ORIG_UID", numbuf, 0);
ngroups = getgroups(NGROUPS_MAX, groups);
/*
* Initialize magic number generator now so that protocols may
* use magic numbers in initialization.
*/
magic_init();
/*
* Initialize each protocol.
*/
for (i = 0; (protp = protocols[i]) != NULL; ++i)
(*protp->init)(0);
/*
* Initialize the default channel.
*/
tty_init();
progname = *argv;
#if defined(__ANDROID__)
{
extern void pppox_init();
pppox_init();
privileged = 1;
}
{
char *envargs = getenv("envargs");
if (envargs) {
int i;
/* Decode the arguments in-place and count the number of them.
* They were hex encoded using [A-P] instead of [0-9A-F]. */
for (argc = 0, i = 0; envargs[i] && envargs[i + 1]; i += 2) {
char c = ((envargs[i] - 'A') << 4) + (envargs[i + 1] - 'A');
if (c == 0) {
++argc;
}
envargs[i / 2 + 1] = c;
}
if (argc == 0 || (argv = malloc(sizeof(char *) * argc)) == NULL) {
fatal("Failed to parse envargs!");
}
for (envargs[0] = 0, i = 0; i < argc; ++envargs) {
if (envargs[0] == 0) {
argv[i++] = &envargs[1];
}
}
}
}
#endif
/*
* Parse, in order, the system options file, the user's options file,
* and the command line arguments.
*/
#if defined(__ANDROID__)
/* Android: only take options from commandline */
if (!parse_args(argc-1, argv+1))
exit(EXIT_OPTION_ERROR);
#else
if (!options_from_file(_PATH_SYSOPTIONS, !privileged, 0, 1)
|| !options_from_user()
|| !parse_args(argc-1, argv+1))
exit(EXIT_OPTION_ERROR);
#endif
devnam_fixed = 1; /* can no longer change device name */
/*
* Work out the device name, if it hasn't already been specified,
* and parse the tty's options file.
*/
if (the_channel->process_extra_options)
(*the_channel->process_extra_options)();
if (debug)
setlogmask(LOG_UPTO(LOG_DEBUG));
#if !defined(__ANDROID__)
/*
* Check that we are running as root.
*/
if (geteuid() != 0) {
option_error("must be root to run %s, since it is not setuid-root",
argv[0]);
exit(EXIT_NOT_ROOT);
}
#endif
if (!ppp_available()) {
option_error("%s", no_ppp_msg);
exit(EXIT_NO_KERNEL_SUPPORT);
}
/*
* Check that the options given are valid and consistent.
*/
check_options();
if (!sys_check_options())
exit(EXIT_OPTION_ERROR);
auth_check_options();
#ifdef HAVE_MULTILINK
mp_check_options();
#endif
for (i = 0; (protp = protocols[i]) != NULL; ++i)
if (protp->check_options != NULL)
(*protp->check_options)();
if (the_channel->check_options)
(*the_channel->check_options)();
if (dump_options || dryrun) {
init_pr_log(NULL, LOG_INFO);
print_options(pr_log, NULL);
end_pr_log();
}
if (dryrun)
die(0);
/* Make sure fds 0, 1, 2 are open to somewhere. */
fd_devnull = open(_PATH_DEVNULL, O_RDWR);
if (fd_devnull < 0)
fatal("Couldn't open %s: %m", _PATH_DEVNULL);
while (fd_devnull <= 2) {
i = dup(fd_devnull);
if (i < 0)
fatal("Critical shortage of file descriptors: dup failed: %m");
fd_devnull = i;
}
/*
* Initialize system-dependent stuff.
*/
sys_init();
#ifdef USE_TDB
pppdb = tdb_open(_PATH_PPPDB, 0, 0, O_RDWR|O_CREAT, 0644);
if (pppdb != NULL) {
slprintf(db_key, sizeof(db_key), "pppd%d", getpid());
update_db_entry();
} else {
warn("Warning: couldn't open ppp database %s", _PATH_PPPDB);
if (multilink) {
warn("Warning: disabling multilink");
multilink = 0;
}
}
#endif
/*
* Detach ourselves from the terminal, if required,
* and identify who is running us.
*/
if (!nodetach && !updetach)
detach();
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 started by %s, uid %d", VERSION, p, uid);
script_setenv("PPPLOGNAME", p, 0);
if (devnam[0])
script_setenv("DEVICE", devnam, 1);
slprintf(numbuf, sizeof(numbuf), "%d", getpid());
script_setenv("PPPD_PID", numbuf, 1);
setup_signals();
create_linkpidfile(getpid());
waiting = 0;
/*
* 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.
*/
fd_loop = open_ppp_loopback();
set_ifunit(1);
/*
* Configure the interface and mark it up, etc.
*/
demand_conf();
}
do_callback = 0;
for (;;) {
bundle_eof = 0;
bundle_terminating = 0;
listen_time = 0;
need_holdoff = 1;
devfd = -1;
status = EXIT_OK;
++unsuccess;
doing_callback = do_callback;
do_callback = 0;
if (demand && !doing_callback) {
/*
* Don't do anything until we see some activity.
*/
new_phase(PHASE_DORMANT);
demand_unblock();
add_fd(fd_loop);
for (;;) {
handle_events();
if (asked_to_quit)
break;
if (get_loop_output())
break;
}
remove_fd(fd_loop);
if (asked_to_quit)
break;
/*
* Now we want to bring up the link.
*/
demand_block();
info("Starting link");
}
gettimeofday(&start_time, NULL);
script_unsetenv("CONNECT_TIME");
script_unsetenv("BYTES_SENT");
script_unsetenv("BYTES_RCVD");
lcp_open(0); /* Start protocol */
start_link(0);
while (phase != PHASE_DEAD) {
handle_events();
get_input();
if (kill_link)
lcp_close(0, "User request");
if (asked_to_quit) {
bundle_terminating = 1;
if (phase == PHASE_MASTER)
mp_bundle_terminated();
}
if (open_ccp_flag) {
if (phase == PHASE_NETWORK || phase == PHASE_RUNNING) {
ccp_fsm[0].flags = OPT_RESTART; /* clears OPT_SILENT */
(*ccp_protent.open)(0);
}
}
}
/* restore FSMs to original state */
lcp_close(0, "");
if (!persist || asked_to_quit || (maxfail > 0 && unsuccess >= maxfail))
break;
if (demand)
demand_discard();
t = need_holdoff? holdoff: 0;
if (holdoff_hook)
t = (*holdoff_hook)();
if (t > 0) {
new_phase(PHASE_HOLDOFF);
TIMEOUT(holdoff_end, NULL, t);
do {
handle_events();
if (kill_link)
new_phase(PHASE_DORMANT); /* allow signal to end holdoff */
} while (phase == PHASE_HOLDOFF);
if (!persist)
break;
}
}
/* Wait for scripts to finish */
reap_kids();
if (n_children > 0) {
if (child_wait > 0)
TIMEOUT(childwait_end, NULL, child_wait);
if (debug) {
struct subprocess *chp;
dbglog("Waiting for %d child processes...", n_children);
for (chp = children; chp != NULL; chp = chp->next)
dbglog(" script %s, pid %d", chp->prog, chp->pid);
}
while (n_children > 0 && !childwait_done) {
handle_events();
if (kill_link && !childwait_done)
childwait_end(NULL);
}
}
die(status);
return 0;
}
/*
* handle_events - wait for something to happen and respond to it.
*/
static void
handle_events()
{
struct timeval timo;
kill_link = open_ccp_flag = 0;
if (sigsetjmp(sigjmp, 1) == 0) {
sigprocmask(SIG_BLOCK, &signals_handled, NULL);
if (got_sighup || got_sigterm || got_sigusr2 || got_sigchld) {
sigprocmask(SIG_UNBLOCK, &signals_handled, NULL);
} else {
waiting = 1;
sigprocmask(SIG_UNBLOCK, &signals_handled, NULL);
wait_input(timeleft(&timo));
}
}
waiting = 0;
calltimeout();
if (got_sighup) {
info("Hangup (SIGHUP)");
kill_link = 1;
got_sighup = 0;
if (status != EXIT_HANGUP)
status = EXIT_USER_REQUEST;
}
if (got_sigterm) {
info("Terminating on signal %d", got_sigterm);
kill_link = 1;
asked_to_quit = 1;
persist = 0;
status = EXIT_USER_REQUEST;
got_sigterm = 0;
}
if (got_sigchld) {
got_sigchld = 0;
reap_kids(); /* Don't leave dead kids lying around */
}
if (got_sigusr2) {
open_ccp_flag = 1;
got_sigusr2 = 0;
}
}
/*
* setup_signals - initialize signal handling.
*/
static void
setup_signals()
{
struct sigaction sa;
/*
* 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(&signals_handled);
sigaddset(&signals_handled, SIGHUP);
sigaddset(&signals_handled, SIGINT);
sigaddset(&signals_handled, SIGTERM);
sigaddset(&signals_handled, SIGCHLD);
sigaddset(&signals_handled, SIGUSR2);
#define SIGNAL(s, handler) do { \
sa.sa_handler = handler; \
if (sigaction(s, &sa, NULL) < 0) \
fatal("Couldn't establish signal handler (%d): %m", s); \
} while (0)
sa.sa_mask = signals_handled;
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
/*
* Apparently we can get a SIGPIPE when we call syslog, if
* syslogd has died and been restarted. Ignoring it seems
* be sufficient.
*/
signal(SIGPIPE, SIG_IGN);
}
/*
* set_ifunit - do things we need to do once we know which ppp
* unit we are using.
*/
void
set_ifunit(iskey)
int iskey;
{
info("Using interface %s%d", PPP_DRV_NAME, ifunit);
slprintf(ifname, sizeof(ifname), "%s%d", PPP_DRV_NAME, ifunit);
script_setenv("IFNAME", ifname, iskey);
if (iskey) {
create_pidfile(getpid()); /* write pid to file */
create_linkpidfile(getpid());
}
}
/*
* detach - detach us from the controlling terminal.
*/
void
detach()
{
int pid;
char numbuf[16];
int pipefd[2];
if (detached)
return;
if (pipe(pipefd) == -1)
pipefd[0] = pipefd[1] = -1;
if ((pid = fork()) < 0) {
error("Couldn't detach (fork failed: %m)");
die(1); /* or just return? */
}
if (pid != 0) {
/* parent */
notify(pidchange, pid);
/* update pid files if they have been written already */
if (pidfilename[0])
create_pidfile(pid);
if (linkpidfile[0])
create_linkpidfile(pid);
exit(0); /* parent dies */
}
setsid();
chdir("/");
dup2(fd_devnull, 0);
dup2(fd_devnull, 1);
dup2(fd_devnull, 2);
detached = 1;
if (log_default)
log_to_fd = -1;
slprintf(numbuf, sizeof(numbuf), "%d", getpid());
script_setenv("PPPD_PID", numbuf, 1);
/* wait for parent to finish updating pid & lock files and die */
close(pipefd[1]);
complete_read(pipefd[0], numbuf, 1);
close(pipefd[0]);
}
/*
* reopen_log - (re)open our connection to syslog.
*/
void
reopen_log()
{
openlog("pppd", LOG_PID | LOG_NDELAY, LOG_PPP);
setlogmask(LOG_UPTO(LOG_INFO));
}
/*
* Create a file containing our process ID.
*/
static void
create_pidfile(pid)
int pid;
{
#if !defined(__ANDROID__)
FILE *pidfile;
slprintf(pidfilename, sizeof(pidfilename), "%s%s.pid",
_PATH_VARRUN, ifname);
if ((pidfile = fopen(pidfilename, "w")) != NULL) {
fprintf(pidfile, "%d\n", pid);
(void) fclose(pidfile);
} else {
error("Failed to create pid file %s: %m", pidfilename);
pidfilename[0] = 0;
}
#endif
}
void
create_linkpidfile(pid)
int pid;
{
#if !defined(__ANDROID__)
FILE *pidfile;
if (linkname[0] == 0)
return;
script_setenv("LINKNAME", linkname, 1);
slprintf(linkpidfile, sizeof(linkpidfile), "%sppp-%s.pid",
_PATH_VARRUN, linkname);
if ((pidfile = fopen(linkpidfile, "w")) != NULL) {
fprintf(pidfile, "%d\n", pid);
if (ifname[0])
fprintf(pidfile, "%s\n", ifname);
(void) fclose(pidfile);
} else {
error("Failed to create pid file %s: %m", linkpidfile);
linkpidfile[0] = 0;
}
#endif
}
/*
* remove_pidfile - remove our pid files
*/
void remove_pidfiles()
{
#if !defined(__ANDROID__)
if (pidfilename[0] != 0 && unlink(pidfilename) < 0 && errno != ENOENT)
warn("unable to delete pid file %s: %m", pidfilename);
pidfilename[0] = 0;
if (linkpidfile[0] != 0 && unlink(linkpidfile) < 0 && errno != ENOENT)
warn("unable to delete pid file %s: %m", linkpidfile);
linkpidfile[0] = 0;
#endif
}
/*
* holdoff_end - called via a timeout when the holdoff period ends.
*/
static void
holdoff_end(arg)
void *arg;
{
new_phase(PHASE_DORMANT);
}
/* List of protocol names, to make our messages a little more informative. */
struct protocol_list {
u_short proto;
const char *name;
} protocol_list[] = {
{ 0x21, "IP" },
{ 0x23, "OSI Network Layer" },
{ 0x25, "Xerox NS IDP" },
{ 0x27, "DECnet Phase IV" },
{ 0x29, "Appletalk" },
{ 0x2b, "Novell IPX" },
{ 0x2d, "VJ compressed TCP/IP" },
{ 0x2f, "VJ uncompressed TCP/IP" },
{ 0x31, "Bridging PDU" },
{ 0x33, "Stream Protocol ST-II" },
{ 0x35, "Banyan Vines" },
{ 0x39, "AppleTalk EDDP" },
{ 0x3b, "AppleTalk SmartBuffered" },
{ 0x3d, "Multi-Link" },
{ 0x3f, "NETBIOS Framing" },
{ 0x41, "Cisco Systems" },
{ 0x43, "Ascom Timeplex" },
{ 0x45, "Fujitsu Link Backup and Load Balancing (LBLB)" },
{ 0x47, "DCA Remote Lan" },
{ 0x49, "Serial Data Transport Protocol (PPP-SDTP)" },
{ 0x4b, "SNA over 802.2" },
{ 0x4d, "SNA" },
{ 0x4f, "IP6 Header Compression" },
{ 0x51, "KNX Bridging Data" },
{ 0x53, "Encryption" },
{ 0x55, "Individual Link Encryption" },
{ 0x57, "IPv6" },
{ 0x59, "PPP Muxing" },
{ 0x5b, "Vendor-Specific Network Protocol" },
{ 0x61, "RTP IPHC Full Header" },
{ 0x63, "RTP IPHC Compressed TCP" },
{ 0x65, "RTP IPHC Compressed non-TCP" },
{ 0x67, "RTP IPHC Compressed UDP 8" },
{ 0x69, "RTP IPHC Compressed RTP 8" },
{ 0x6f, "Stampede Bridging" },
{ 0x73, "MP+" },
{ 0xc1, "NTCITS IPI" },
{ 0xfb, "single-link compression" },
{ 0xfd, "Compressed Datagram" },
{ 0x0201, "802.1d Hello Packets" },
{ 0x0203, "IBM Source Routing BPDU" },
{ 0x0205, "DEC LANBridge100 Spanning Tree" },
{ 0x0207, "Cisco Discovery Protocol" },
{ 0x0209, "Netcs Twin Routing" },
{ 0x020b, "STP - Scheduled Transfer Protocol" },
{ 0x020d, "EDP - Extreme Discovery Protocol" },
{ 0x0211, "Optical Supervisory Channel Protocol" },
{ 0x0213, "Optical Supervisory Channel Protocol" },
{ 0x0231, "Luxcom" },
{ 0x0233, "Sigma Network Systems" },
{ 0x0235, "Apple Client Server Protocol" },
{ 0x0281, "MPLS Unicast" },
{ 0x0283, "MPLS Multicast" },
{ 0x0285, "IEEE p1284.4 standard - data packets" },
{ 0x0287, "ETSI TETRA Network Protocol Type 1" },
{ 0x0289, "Multichannel Flow Treatment Protocol" },
{ 0x2063, "RTP IPHC Compressed TCP No Delta" },
{ 0x2065, "RTP IPHC Context State" },
{ 0x2067, "RTP IPHC Compressed UDP 16" },
{ 0x2069, "RTP IPHC Compressed RTP 16" },
{ 0x4001, "Cray Communications Control Protocol" },
{ 0x4003, "CDPD Mobile Network Registration Protocol" },
{ 0x4005, "Expand accelerator protocol" },
{ 0x4007, "ODSICP NCP" },
{ 0x4009, "DOCSIS DLL" },
{ 0x400B, "Cetacean Network Detection Protocol" },
{ 0x4021, "Stacker LZS" },
{ 0x4023, "RefTek Protocol" },
{ 0x4025, "Fibre Channel" },
{ 0x4027, "EMIT Protocols" },
{ 0x405b, "Vendor-Specific Protocol (VSP)" },
{ 0x8021, "Internet Protocol Control Protocol" },
{ 0x8023, "OSI Network Layer Control Protocol" },
{ 0x8025, "Xerox NS IDP Control Protocol" },
{ 0x8027, "DECnet Phase IV Control Protocol" },
{ 0x8029, "Appletalk Control Protocol" },
{ 0x802b, "Novell IPX Control Protocol" },
{ 0x8031, "Bridging NCP" },
{ 0x8033, "Stream Protocol Control Protocol" },
{ 0x8035, "Banyan Vines Control Protocol" },
{ 0x803d, "Multi-Link Control Protocol" },
{ 0x803f, "NETBIOS Framing Control Protocol" },
{ 0x8041, "Cisco Systems Control Protocol" },
{ 0x8043, "Ascom Timeplex" },
{ 0x8045, "Fujitsu LBLB Control Protocol" },
{ 0x8047, "DCA Remote Lan Network Control Protocol (RLNCP)" },
{ 0x8049, "Serial Data Control Protocol (PPP-SDCP)" },
{ 0x804b, "SNA over 802.2 Control Protocol" },
{ 0x804d, "SNA Control Protocol" },
{ 0x804f, "IP6 Header Compression Control Protocol" },
{ 0x8051, "KNX Bridging Control Protocol" },
{ 0x8053, "Encryption Control Protocol" },
{ 0x8055, "Individual Link Encryption Control Protocol" },
{ 0x8057, "IPv6 Control Protocol" },
{ 0x8059, "PPP Muxing Control Protocol" },
{ 0x805b, "Vendor-Specific Network Control Protocol (VSNCP)" },
{ 0x806f, "Stampede Bridging Control Protocol" },
{ 0x8073, "MP+ Control Protocol" },
{ 0x80c1, "NTCITS IPI Control Protocol" },
{ 0x80fb, "Single Link Compression Control Protocol" },
{ 0x80fd, "Compression Control Protocol" },
{ 0x8207, "Cisco Discovery Protocol Control" },
{ 0x8209, "Netcs Twin Routing" },
{ 0x820b, "STP - Control Protocol" },
{ 0x820d, "EDPCP - Extreme Discovery Protocol Ctrl Prtcl" },
{ 0x8235, "Apple Client Server Protocol Control" },
{ 0x8281, "MPLSCP" },
{ 0x8285, "IEEE p1284.4 standard - Protocol Control" },
{ 0x8287, "ETSI TETRA TNP1 Control Protocol" },
{ 0x8289, "Multichannel Flow Treatment Protocol" },
{ 0xc021, "Link Control Protocol" },
{ 0xc023, "Password Authentication Protocol" },
{ 0xc025, "Link Quality Report" },
{ 0xc027, "Shiva Password Authentication Protocol" },
{ 0xc029, "CallBack Control Protocol (CBCP)" },
{ 0xc02b, "BACP Bandwidth Allocation Control Protocol" },
{ 0xc02d, "BAP" },
{ 0xc05b, "Vendor-Specific Authentication Protocol (VSAP)" },
{ 0xc081, "Container Control Protocol" },
{ 0xc223, "Challenge Handshake Authentication Protocol" },
{ 0xc225, "RSA Authentication Protocol" },
{ 0xc227, "Extensible Authentication Protocol" },
{ 0xc229, "Mitsubishi Security Info Exch Ptcl (SIEP)" },
{ 0xc26f, "Stampede Bridging Authorization Protocol" },
{ 0xc281, "Proprietary Authentication Protocol" },
{ 0xc283, "Proprietary Authentication Protocol" },
{ 0xc481, "Proprietary Node ID Authentication Protocol" },
{ 0, NULL },
};
/*
* protocol_name - find a name for a PPP protocol.
*/
const char *
protocol_name(proto)
int proto;
{
struct protocol_list *lp;
for (lp = protocol_list; lp->proto != 0; ++lp)
if (proto == lp->proto)
return lp->name;
return NULL;
}
/*
* 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) {
if (bundle_eof && multilink_master) {
notice("Last channel has disconnected");
mp_bundle_terminated();
return;
}
notice("Modem hangup");
hungup = 1;
status = EXIT_HANGUP;
lcp_lowerdown(0); /* serial link is no longer available */
link_terminated(0);
return;
}
if (len < PPP_HDRLEN) {
dbglog("received short packet:%.*B", len, p);
return;
}
dump_packet("rcvd", p, len);
if (snoop_recv_hook) snoop_recv_hook(p, len);
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) {
dbglog("Discarded non-LCP packet when LCP not open");
return;
}
/*
* Until we get past the authentication phase, toss all packets
* except LCP, LQR and authentication packets.
*/
if (phase <= PHASE_AUTHENTICATE
&& !(protocol == PPP_LCP || protocol == PPP_LQR
|| protocol == PPP_PAP || protocol == PPP_CHAP ||
protocol == PPP_EAP)) {
dbglog("discarding proto 0x%x in phase %d",
protocol, phase);
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) {
const char *pname = protocol_name(protocol);
if (pname != NULL)
warn("Unsupported protocol '%s' (0x%x) received", pname, protocol);
else
warn("Unsupported protocol 0x%x received", protocol);
}
lcp_sprotrej(0, p - PPP_HDRLEN, len + PPP_HDRLEN);
}
/*
* ppp_send_config - configure the transmit-side characteristics of
* the ppp interface. Returns -1, indicating an error, if the channel
* send_config procedure called error() (or incremented error_count
* itself), otherwise 0.
*/
int
ppp_send_config(unit, mtu, accm, pcomp, accomp)
int unit, mtu;
u_int32_t accm;
int pcomp, accomp;
{
int errs;
if (the_channel->send_config == NULL)
return 0;
errs = error_count;
(*the_channel->send_config)(mtu, accm, pcomp, accomp);
return (error_count != errs)? -1: 0;
}
/*
* ppp_recv_config - configure the receive-side characteristics of
* the ppp interface. Returns -1, indicating an error, if the channel
* recv_config procedure called error() (or incremented error_count
* itself), otherwise 0.
*/
int
ppp_recv_config(unit, mru, accm, pcomp, accomp)
int unit, mru;
u_int32_t accm;
int pcomp, accomp;
{
int errs;
if (the_channel->recv_config == NULL)
return 0;
errs = error_count;
(*the_channel->recv_config)(mru, accm, pcomp, accomp);
return (error_count != errs)? -1: 0;
}
/*
* new_phase - signal the start of a new phase of pppd's operation.
*/
void
new_phase(p)
int p;
{
phase = p;
if (new_phase_hook)
(*new_phase_hook)(p);
notify(phasechange, p);
}
/*
* die - clean up state and exit with the specified status.
*/
void
die(status)
int status;
{
if (!doing_multilink || multilink_master)
print_link_stats();
cleanup();
notify(exitnotify, status);
syslog(LOG_INFO, "Exit.");
exit(status);
}
/*
* cleanup - restore anything which needs to be restored before we exit
*/
/* ARGSUSED */
static void
cleanup()
{
sys_cleanup();
if (fd_ppp >= 0)
the_channel->disestablish_ppp(devfd);
if (the_channel->cleanup)
(*the_channel->cleanup)();
remove_pidfiles();
#ifdef USE_TDB
if (pppdb != NULL)
cleanup_db();
#endif
}
void
print_link_stats()
{
/*
* Print connect time and statistics.
*/
if (link_stats_valid) {
int t = (link_connect_time + 5) / 6; /* 1/10ths of minutes */
info("Connect time %d.%d minutes.", t/10, t%10);
info("Sent %u bytes, received %u bytes.",
link_stats.bytes_out, link_stats.bytes_in);
link_stats_valid = 0;
}
}
/*
* reset_link_stats - "reset" stats when link goes up.
*/
void
reset_link_stats(u)
int u;
{
if (!get_ppp_stats(u, &old_link_stats))
return;
gettimeofday(&start_time, NULL);
}
/*
* update_link_stats - get stats at link termination.
*/
void
update_link_stats(u)
int u;
{
struct timeval now;
char numbuf[32];
if (!get_ppp_stats(u, &link_stats)
|| gettimeofday(&now, NULL) < 0)
return;
link_connect_time = now.tv_sec - start_time.tv_sec;
link_stats_valid = 1;
link_stats.bytes_in -= old_link_stats.bytes_in;
link_stats.bytes_out -= old_link_stats.bytes_out;
link_stats.pkts_in -= old_link_stats.pkts_in;
link_stats.pkts_out -= old_link_stats.pkts_out;
slprintf(numbuf, sizeof(numbuf), "%u", link_connect_time);
script_setenv("CONNECT_TIME", numbuf, 0);
slprintf(numbuf, sizeof(numbuf), "%u", link_stats.bytes_out);
script_setenv("BYTES_SENT", numbuf, 0);
slprintf(numbuf, sizeof(numbuf), "%u", link_stats.bytes_in);
script_setenv("BYTES_RCVD", numbuf, 0);
}
struct callout {
struct timeval c_time; /* time at which to call routine */
void *c_arg; /* argument to routine */
void (*c_func) __P((void *)); /* routine */
struct callout *c_next;
};
static struct callout *callout = NULL; /* Callout list */
static struct timeval timenow; /* Current time */
/*
* timeout - Schedule a timeout.
*/
void
timeout(func, arg, secs, usecs)
void (*func) __P((void *));
void *arg;
int secs, usecs;
{
struct callout *newp, *p, **pp;
/*
* Allocate timeout.
*/
if ((newp = (struct callout *) malloc(sizeof(struct callout))) == NULL)
fatal("Out of memory in timeout()!");
newp->c_arg = arg;
newp->c_func = func;
gettimeofday(&timenow, NULL);
newp->c_time.tv_sec = timenow.tv_sec + secs;
newp->c_time.tv_usec = timenow.tv_usec + usecs;
if (newp->c_time.tv_usec >= 1000000) {
newp->c_time.tv_sec += newp->c_time.tv_usec / 1000000;
newp->c_time.tv_usec %= 1000000;
}
/*
* 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_usec))
break;
newp->c_next = p;
*pp = newp;
}
/*
* untimeout - Unschedule a timeout.
*/
void
untimeout(func, arg)
void (*func) __P((void *));
void *arg;
{
struct callout **copp, *freep;
/*
* 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;
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)
fatal("Failed to get time of day: %m");
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;
}
/*
* kill_my_pg - send a signal to our process group, and ignore it ourselves.
* We assume that sig is currently blocked.
*/
static void
kill_my_pg(sig)
int sig;
{
struct sigaction act, oldact;
struct subprocess *chp;
if (!detached) {
/*
* There might be other things in our process group that we
* didn't start that would get hit if we did a kill(0), so
* just send the signal individually to our children.
*/
for (chp = children; chp != NULL; chp = chp->next)
if (chp->killable)
kill(chp->pid, sig);
return;
}
/* We've done a setsid(), so we can just use a kill(0) */
sigemptyset(&act.sa_mask); /* unnecessary in fact */
act.sa_handler = SIG_IGN;
act.sa_flags = 0;
kill(0, sig);
/*
* The kill() above made the signal pending for us, as well as
* the rest of our process group, but we don't want it delivered
* to us. It is blocked at the moment. Setting it to be ignored
* will cause the pending signal to be discarded. If we did the
* kill() after setting the signal to be ignored, it is unspecified
* (by POSIX) whether the signal is immediately discarded or left
* pending, and in fact Linux would leave it pending, and so it
* would be delivered after the current signal handler exits,
* leading to an infinite loop.
*/
sigaction(sig, &act, &oldact);
sigaction(sig, &oldact, NULL);
}
/*
* 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;
{
/* can't log a message here, it can deadlock */
got_sighup = 1;
if (conn_running)
/* Send the signal to the [dis]connector process(es) also */
kill_my_pg(sig);
notify(sigreceived, sig);
if (waiting)
siglongjmp(sigjmp, 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;
{
/* can't log a message here, it can deadlock */
got_sigterm = sig;
if (conn_running)
/* Send the signal to the [dis]connector process(es) also */
kill_my_pg(sig);
notify(sigreceived, sig);
if (waiting)
siglongjmp(sigjmp, 1);
}
/*
* chld - Catch SIGCHLD signal.
* Sets a flag so we will call reap_kids in the mainline.
*/
static void
chld(sig)
int sig;
{
got_sigchld = 1;
if (waiting)
siglongjmp(sigjmp, 1);
}
/*
* toggle_debug - Catch SIGUSR1 signal.
*
* Toggle debug flag.
*/
/*ARGSUSED*/
static void
toggle_debug(sig)
int sig;
{
debug = !debug;
if (debug) {
setlogmask(LOG_UPTO(LOG_DEBUG));
} else {
setlogmask(LOG_UPTO(LOG_WARNING));
}
}
/*
* open_ccp - Catch SIGUSR2 signal.
*
* Try to (re)negotiate compression.
*/
/*ARGSUSED*/
static void
open_ccp(sig)
int sig;
{
got_sigusr2 = 1;
if (waiting)
siglongjmp(sigjmp, 1);
}
/*
* bad_signal - We've caught a fatal signal. Clean up state and exit.
*/
static void
bad_signal(sig)
int sig;
{
static int crashed = 0;
if (crashed)
_exit(127);
crashed = 1;
error("Fatal signal %d", sig);
if (conn_running)
kill_my_pg(SIGTERM);
notify(sigreceived, sig);
die(127);
}
/*
* safe_fork - Create a child process. The child closes all the
* file descriptors that we don't want to leak to a script.
* The parent waits for the child to do this before returning.
* This also arranges for the specified fds to be dup'd to
* fds 0, 1, 2 in the child.
*/
pid_t
safe_fork(int infd, int outfd, int errfd)
{
pid_t pid;
int fd, pipefd[2];
char buf[1];
/* make sure fds 0, 1, 2 are occupied (probably not necessary) */
while ((fd = dup(fd_devnull)) >= 0) {
if (fd > 2) {
close(fd);
break;
}
}
if (pipe(pipefd) == -1)
pipefd[0] = pipefd[1] = -1;
pid = fork();
if (pid < 0) {
error("fork failed: %m");
return -1;
}
if (pid > 0) {
/* parent */
close(pipefd[1]);
/* this read() blocks until the close(pipefd[1]) below */
complete_read(pipefd[0], buf, 1);
close(pipefd[0]);
return pid;
}
/* Executing in the child */
sys_close();
#ifdef USE_TDB
tdb_close(pppdb);
#endif
/* make sure infd, outfd and errfd won't get tromped on below */
if (infd == 1 || infd == 2)
infd = dup(infd);
if (outfd == 0 || outfd == 2)
outfd = dup(outfd);
if (errfd == 0 || errfd == 1)
errfd = dup(errfd);
closelog();
/* dup the in, out, err fds to 0, 1, 2 */
if (infd != 0)
dup2(infd, 0);
if (outfd != 1)
dup2(outfd, 1);
if (errfd != 2)
dup2(errfd, 2);
if (log_to_fd > 2)
close(log_to_fd);
if (the_channel->close)
(*the_channel->close)();
else
close(devfd); /* some plugins don't have a close function */
close(fd_ppp);
close(fd_devnull);
if (infd != 0)
close(infd);
if (outfd != 1)
close(outfd);
if (errfd != 2)
close(errfd);
notify(fork_notifier, 0);
close(pipefd[0]);
/* this close unblocks the read() call above in the parent */
close(pipefd[1]);
return 0;
}
static bool
add_script_env(pos, newstring)
int pos;
char *newstring;
{
if (pos + 1 >= s_env_nalloc) {
int new_n = pos + 17;
char **newenv = realloc(script_env, new_n * sizeof(char *));
if (newenv == NULL) {
free(newstring - 1);
return 0;
}
script_env = newenv;
s_env_nalloc = new_n;
}
script_env[pos] = newstring;
script_env[pos + 1] = NULL;
return 1;
}
static void
remove_script_env(pos)
int pos;
{
free(script_env[pos] - 1);
while ((script_env[pos] = script_env[pos + 1]) != NULL)
pos++;
}
/*
* update_system_environment - process the list of set/unset options
* and update the system environment.
*/
static void
update_system_environment()
{
struct userenv *uep;
for (uep = userenv_list; uep != NULL; uep = uep->ue_next) {
if (uep->ue_isset)
setenv(uep->ue_name, uep->ue_value, 1);
else
unsetenv(uep->ue_name);
}
}
/*
* device_script - run a program to talk to the specified fds
* (e.g. to run the connector or disconnector script).
* stderr gets connected to the log fd or to the _PATH_CONNERRS file.
*/
int
device_script(program, in, out, dont_wait)
char *program;
int in, out;
int dont_wait;
{
int pid;
int status = -1;
int errfd;
if (log_to_fd >= 0)
errfd = log_to_fd;
else
errfd = open(_PATH_CONNERRS, O_WRONLY | O_APPEND | O_CREAT, 0600);
++conn_running;
pid = safe_fork(in, out, errfd);
if (pid != 0 && log_to_fd < 0)
close(errfd);
if (pid < 0) {
--conn_running;
error("Failed to create child process: %m");
return -1;
}
if (pid != 0) {
record_child(pid, program, NULL, NULL, 1);
status = 0;
if (!dont_wait) {
while (waitpid(pid, &status, 0) < 0) {
if (errno == EINTR)
continue;
fatal("error waiting for (dis)connection process: %m");
}
forget_child(pid, status);
--conn_running;
}
return (status == 0 ? 0 : -1);
}
/* here we are executing in the child */
setgid(getgid());
setuid(uid);
if (getuid() != uid) {
fprintf(stderr, "pppd: setuid failed\n");
exit(1);
}
update_system_environment();
#if defined(__ANDROID__)
execl("/system/bin/sh", "sh", "-c", program, NULL);
#else
execl("/bin/sh", "sh", "-c", program, (char *)0);
#endif
perror("pppd: could not exec /bin/sh");
_exit(99);
/* NOTREACHED */
}
/*
* update_script_environment - process the list of set/unset options
* and update the script environment. Note that we intentionally do
* not update the TDB. These changes are layered on top right before
* exec. It is not possible to use script_setenv() or
* script_unsetenv() safely after this routine is run.
*/
static void
update_script_environment()
{
struct userenv *uep;
for (uep = userenv_list; uep != NULL; uep = uep->ue_next) {
int i;
char *p, *newstring;
int nlen = strlen(uep->ue_name);
for (i = 0; (p = script_env[i]) != NULL; i++) {
if (strncmp(p, uep->ue_name, nlen) == 0 && p[nlen] == '=')
break;
}
if (uep->ue_isset) {
nlen += strlen(uep->ue_value) + 2;
newstring = malloc(nlen + 1);
if (newstring == NULL)
continue;
*newstring++ = 0;
slprintf(newstring, nlen, "%s=%s", uep->ue_name, uep->ue_value);
if (p != NULL)
script_env[i] = newstring;
else
add_script_env(i, newstring);
} else {
remove_script_env(i);
}
}
}
/*
* run_program - execute a program with given arguments,
* but don't wait for it unless wait is non-zero.
* If the program can't be executed, logs an error unless
* must_exist is 0 and the program file doesn't exist.
* Returns -1 if it couldn't fork, 0 if the file doesn't exist
* or isn't an executable plain file, or the process ID of the child.
* If done != NULL, (*done)(arg) will be called later (within
* reap_kids) iff the return value is > 0.
*/
pid_t
run_program(prog, args, must_exist, done, arg, wait)
char *prog;
char **args;
int must_exist;
void (*done) __P((void *));
void *arg;
int wait;
{
int pid, status;
struct stat sbuf;
#if defined(__ANDROID__)
/* Originally linkname is used to create named pid files, which is
* meaningless to android. Here we use it as a suffix of program names,
* so different users can run their own program by specifying it. For
* example, "/etc/ppp/ip-up-vpn" will be executed when IPCP is up and
* linkname is "vpn". Note that "/" is not allowed for security reasons. */
char file[MAXPATHLEN];
if (linkname[0] && !strchr(linkname, '/')) {
snprintf(file, MAXPATHLEN, "%s-%s", prog, linkname);
file[MAXPATHLEN - 1] = '\0';
prog = file;
}
#endif
/*
* First check if the file exists and is executable.
* We don't use access() because that would use the
* real user-id, which might not be root, and the script
* might be accessible only to root.
*/
errno = EINVAL;
if (stat(prog, &sbuf) < 0 || !S_ISREG(sbuf.st_mode)
|| (sbuf.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0) {
if (must_exist || errno != ENOENT)
warn("Can't execute %s: %m", prog);
return 0;
}
pid = safe_fork(fd_devnull, fd_devnull, fd_devnull);
if (pid == -1) {
error("Failed to create child process for %s: %m", prog);
return -1;
}
if (pid != 0) {
if (debug)
dbglog("Script %s started (pid %d)", prog, pid);
record_child(pid, prog, done, arg, 0);
if (wait) {
while (waitpid(pid, &status, 0) < 0) {
if (errno == EINTR)
continue;
fatal("error waiting for script %s: %m", prog);
}
forget_child(pid, status);
}
return pid;
}
/* Leave the current location */
(void) setsid(); /* No controlling tty. */
(void) umask (S_IRWXG|S_IRWXO);
(void) chdir ("/"); /* no current directory. */
setuid(0); /* set real UID = root */
setgid(getegid());
#ifdef BSD
/* Force the priority back to zero if pppd is running higher. */
if (setpriority (PRIO_PROCESS, 0, 0) < 0)
warn("can't reset priority to 0: %m");
#endif
/* run the program */
update_script_environment();
execve(prog, args, script_env);
if (must_exist || errno != ENOENT) {
/* have to reopen the log, there's nowhere else
for the message to go. */
reopen_log();
syslog(LOG_ERR, "Can't execute %s: %m", prog);
closelog();
}
_exit(99);
}
/*
* record_child - add a child process to the list for reap_kids
* to use.
*/
void
record_child(pid, prog, done, arg, killable)
int pid;
char *prog;
void (*done) __P((void *));
void *arg;
int killable;
{
struct subprocess *chp;
++n_children;
chp = (struct subprocess *) malloc(sizeof(struct subprocess));
if (chp == NULL) {
warn("losing track of %s process", prog);
} else {
chp->pid = pid;
chp->prog = prog;
chp->done = done;
chp->arg = arg;
chp->next = children;
chp->killable = killable;
children = chp;
}
}
/*
* childwait_end - we got fed up waiting for the child processes to
* exit, send them all a SIGTERM.
*/
static void
childwait_end(arg)
void *arg;
{
struct subprocess *chp;
for (chp = children; chp != NULL; chp = chp->next) {
if (debug)
dbglog("sending SIGTERM to process %d", chp->pid);
kill(chp->pid, SIGTERM);
}
childwait_done = 1;
}
/*
* forget_child - clean up after a dead child
*/
static void
forget_child(pid, status)
int pid, status;
{
struct subprocess *chp, **prevp;
for (prevp = &children; (chp = *prevp) != NULL; prevp = &chp->next) {
if (chp->pid == pid) {
--n_children;
*prevp = chp->next;
break;
}
}
if (WIFSIGNALED(status)) {
warn("Child process %s (pid %d) terminated with signal %d",
(chp? chp->prog: "??"), pid, WTERMSIG(status));
} else if (debug)
dbglog("Script %s finished (pid %d), status = 0x%x",
(chp? chp->prog: "??"), pid,
WIFEXITED(status) ? WEXITSTATUS(status) : status);
if (chp && chp->done)
(*chp->done)(chp->arg);
if (chp)
free(chp);
}
/*
* reap_kids - get status from any dead child processes,
* and log a message for abnormal terminations.
*/
static int
reap_kids()
{
int pid, status;
if (n_children == 0)
return 0;
while ((pid = waitpid(-1, &status, WNOHANG)) != -1 && pid != 0) {
forget_child(pid, status);
}
if (pid == -1) {
if (errno == ECHILD)
return -1;
if (errno != EINTR)
error("Error waiting for child process: %m");
}
return 0;
}
/*
* add_notifier - add a new function to be called when something happens.
*/
void
add_notifier(notif, func, arg)
struct notifier **notif;
notify_func func;
void *arg;
{
struct notifier *np;
np = malloc(sizeof(struct notifier));
if (np == 0)
novm("notifier struct");
np->next = *notif;
np->func = func;
np->arg = arg;
*notif = np;
}
/*
* remove_notifier - remove a function from the list of things to
* be called when something happens.
*/
void
remove_notifier(notif, func, arg)
struct notifier **notif;
notify_func func;
void *arg;
{
struct notifier *np;
for (; (np = *notif) != 0; notif = &np->next) {
if (np->func == func && np->arg == arg) {
*notif = np->next;
free(np);
break;
}
}
}
/*
* notify - call a set of functions registered with add_notifier.
*/
void
notify(notif, val)
struct notifier *notif;
int val;
{
struct notifier *np;
while ((np = notif) != 0) {
notif = np->next;
(*np->func)(np->arg, val);
}
}
/*
* novm - log an error message saying we ran out of memory, and die.
*/
void
novm(msg)
char *msg;
{
fatal("Virtual memory exhausted allocating %s\n", msg);
}
/*
* script_setenv - set an environment variable value to be used
* for scripts that we run (e.g. ip-up, auth-up, etc.)
*/
void
script_setenv(var, value, iskey)
char *var, *value;
int iskey;
{
size_t varl = strlen(var);
size_t vl = varl + strlen(value) + 2;
int i;
char *p, *newstring;
newstring = (char *) malloc(vl+1);
if (newstring == 0)
return;
*newstring++ = iskey;
slprintf(newstring, vl, "%s=%s", var, value);
/* check if this variable is already set */
if (script_env != 0) {
for (i = 0; (p = script_env[i]) != 0; ++i) {
if (strncmp(p, var, varl) == 0 && p[varl] == '=') {
#ifdef USE_TDB
if (p[-1] && pppdb != NULL)
delete_db_key(p);
#endif
free(p-1);
script_env[i] = newstring;
#ifdef USE_TDB
if (pppdb != NULL) {
if (iskey)
add_db_key(newstring);
update_db_entry();
}
#endif
return;
}
}
} else {
/* no space allocated for script env. ptrs. yet */
i = 0;
script_env = malloc(16 * sizeof(char *));
if (script_env == 0) {
free(newstring - 1);
return;
}
s_env_nalloc = 16;
}
if (!add_script_env(i, newstring))
return;
#ifdef USE_TDB
if (pppdb != NULL) {
if (iskey)
add_db_key(newstring);
update_db_entry();
}
#endif
}
/*
* script_unsetenv - remove a variable from the environment
* for scripts.
*/
void
script_unsetenv(var)
char *var;
{
int vl = strlen(var);
int i;
char *p;
if (script_env == 0)
return;
for (i = 0; (p = script_env[i]) != 0; ++i) {
if (strncmp(p, var, vl) == 0 && p[vl] == '=') {
#ifdef USE_TDB
if (p[-1] && pppdb != NULL)
delete_db_key(p);
#endif
remove_script_env(i);
break;
}
}
#ifdef USE_TDB
if (pppdb != NULL)
update_db_entry();
#endif
}
/*
* Any arbitrary string used as a key for locking the database.
* It doesn't matter what it is as long as all pppds use the same string.
*/
#define PPPD_LOCK_KEY "pppd lock"
/*
* lock_db - get an exclusive lock on the TDB database.
* Used to ensure atomicity of various lookup/modify operations.
*/
void lock_db()
{
#ifdef USE_TDB
TDB_DATA key;
key.dptr = PPPD_LOCK_KEY;
key.dsize = strlen(key.dptr);
tdb_chainlock(pppdb, key);
#endif
}
/*
* unlock_db - remove the exclusive lock obtained by lock_db.
*/
void unlock_db()
{
#ifdef USE_TDB
TDB_DATA key;
key.dptr = PPPD_LOCK_KEY;
key.dsize = strlen(key.dptr);
tdb_chainunlock(pppdb, key);
#endif
}
#ifdef USE_TDB
/*
* update_db_entry - update our entry in the database.
*/
static void
update_db_entry()
{
TDB_DATA key, dbuf;
int vlen, i;
char *p, *q, *vbuf;
if (script_env == NULL)
return;
vlen = 0;
for (i = 0; (p = script_env[i]) != 0; ++i)
vlen += strlen(p) + 1;
vbuf = malloc(vlen + 1);
if (vbuf == 0)
novm("database entry");
q = vbuf;
for (i = 0; (p = script_env[i]) != 0; ++i)
q += slprintf(q, vbuf + vlen - q, "%s;", p);
key.dptr = db_key;
key.dsize = strlen(db_key);
dbuf.dptr = vbuf;
dbuf.dsize = vlen;
if (tdb_store(pppdb, key, dbuf, TDB_REPLACE))
error("tdb_store failed: %s", tdb_errorstr(pppdb));
if (vbuf)
free(vbuf);
}
/*
* add_db_key - add a key that we can use to look up our database entry.
*/
static void
add_db_key(str)
const char *str;
{
TDB_DATA key, dbuf;
key.dptr = (char *) str;
key.dsize = strlen(str);
dbuf.dptr = db_key;
dbuf.dsize = strlen(db_key);
if (tdb_store(pppdb, key, dbuf, TDB_REPLACE))
error("tdb_store key failed: %s", tdb_errorstr(pppdb));
}
/*
* delete_db_key - delete a key for looking up our database entry.
*/
static void
delete_db_key(str)
const char *str;
{
TDB_DATA key;
key.dptr = (char *) str;
key.dsize = strlen(str);
tdb_delete(pppdb, key);
}
/*
* cleanup_db - delete all the entries we put in the database.
*/
static void
cleanup_db()
{
TDB_DATA key;
int i;
char *p;
key.dptr = db_key;
key.dsize = strlen(db_key);
tdb_delete(pppdb, key);
for (i = 0; (p = script_env[i]) != 0; ++i)
if (p[-1])
delete_db_key(p);
}
#endif /* USE_TDB */