* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
-#define RCSID "$Id: main.c,v 1.142 2004/11/04 10:05:23 paulus Exp $"
+#define RCSID "$Id: main.c,v 1.143 2004/11/06 05:42:29 paulus Exp $"
#include <stdio.h>
#include <ctype.h>
void
reopen_log()
{
-#ifdef ULTRIX
- openlog("pppd", LOG_PID);
-#else
openlog("pppd", LOG_PID | LOG_NDELAY, LOG_PPP);
setlogmask(LOG_UPTO(LOG_INFO));
-#endif
}
/*
* 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()
+safe_fork(int infd, int outfd, int errfd)
{
pid_t pid;
- int pipefd[2];
+ 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)
+ 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);
+
+ /* 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);
+
+ closelog();
+ 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;
}
int pid;
int status = -1;
int errfd;
- int fd;
+
+ 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();
+ pid = safe_fork(in, out, errfd);
+
+ if (pid != 0 && log_to_fd < 0)
+ close(errfd);
if (pid < 0) {
--conn_running;
/* here we are executing in the child */
- /* make sure fds 0, 1, 2 are occupied */
- while ((fd = dup(in)) >= 0) {
- if (fd > 2) {
- close(fd);
- break;
- }
- }
-
- /* dup in and out to fds > 2 */
- {
- int fd1 = in, fd2 = out, fd3 = log_to_fd;
-
- in = dup(in);
- out = dup(out);
- if (log_to_fd >= 0) {
- errfd = dup(log_to_fd);
- } else {
- errfd = open(_PATH_CONNERRS, O_WRONLY | O_APPEND | O_CREAT, 0600);
- }
- close(fd1);
- close(fd2);
- close(fd3);
- }
-
- /* close fds 0 - 2 and any others we can think of */
- close(0);
- close(1);
- close(2);
- if (the_channel->close)
- (*the_channel->close)();
- else
- close(devfd); /* some plugins don't have a close function */
- closelog();
- close(fd_devnull);
-
- /* dup the in, out, err fds to 0, 1, 2 */
- dup2(in, 0);
- close(in);
- dup2(out, 1);
- close(out);
- if (errfd >= 0) {
- dup2(errfd, 2);
- close(errfd);
- }
-
+ setgid(getgid());
setuid(uid);
if (getuid() != uid) {
- error("setuid failed");
+ fprintf(stderr, "pppd: setuid failed\n");
exit(1);
}
- setgid(getgid());
execl("/bin/sh", "sh", "-c", program, (char *)0);
- error("could not exec /bin/sh: %m");
+ perror("pppd: could not exec /bin/sh");
exit(99);
/* NOTREACHED */
}
return 0;
}
- pid = safe_fork();
+ pid = safe_fork(fd_devnull, fd_devnull, fd_devnull);
if (pid == -1) {
error("Failed to create child process for %s: %m", prog);
return -1;
setuid(0); /* set real UID = root */
setgid(getegid());
- /* Ensure that nothing of our device environment is inherited. */
- closelog();
- if (the_channel->close)
- (*the_channel->close)();
-
- /* Don't pass handles to the PPP device, even by accident. */
- dup2(fd_devnull, 0);
- dup2(fd_devnull, 1);
- dup2(fd_devnull, 2);
- close(fd_devnull);
-
#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
- /* SysV recommends a second fork at this point. */
-
/* run the program */
execve(prog, args, script_env);
if (must_exist || errno != ENOENT) {
projects / ppp.git / blobdiff