}
}
-#if 0
-/*
- * This is a little bit tricky due to how POSIX job control works and
- * we fact that we have two different controlling terminals to deal with.
- * There are three processes:
- * 1) parent, which forks a child and does all the I/O passing.
- * Handles job control signals send by its child to bridge the
- * two sessions (and ttys).
- * 2) child, creates a new session so it can receive notification of
- * tty stop signals (SIGTSTP, SIGTTIN, SIGTTOU). Waits for the
- * command to stop or die and passes back tty stop signals to parent
- * so job control works in the user's shell.
- * 3) grandchild, executes the actual command with the pty slave as its
- * controlling tty, belongs to child's session but has its own pgrp.
- */
-int
-sudo_execve(struct command_details *details, char *argv[], char *envp[],
- struct command_status *cstat)
-{
- sigaction_t sa;
- struct io_buffer *iob, *iobufs = NULL;
- int n, nready;
- int io_pipe[3][2], sv[2];
- fd_set *fdsr, *fdsw;
- int rbac_enabled = 0;
- int log_io, maxfd, status;
-
- cstat->type = CMD_INVALID;
-
- log_io = !tq_empty(&io_plugins);
- if (log_io) {
- sudo_debug(8, "allocate pty for I/O logging");
- pty_setup(details->euid);
- }
-
-#ifdef HAVE_SELINUX
- rbac_enabled = is_selinux_enabled() > 0 && details->selinux_role != NULL;
-#endif
-
- ppgrp = getpgrp(); /* parent's pgrp, so child can signal us */
-
- /*
- * We communicate with the child over a bi-directional pipe.
- * Parent sends signal info to child and child sends back wait status.
- */
- if (socketpair(PF_UNIX, SOCK_DGRAM, 0, sv) != 0)
- error(1, "cannot create sockets");
-
- zero_bytes(&sa, sizeof(sa));
- sigemptyset(&sa.sa_mask);
-
- /* Note: HP-UX select() will not be interrupted if SA_RESTART set */
- sa.sa_flags = 0; /* do not restart syscalls */
- sa.sa_handler = handler;
- sigaction(SIGALRM, &sa, NULL);
- sigaction(SIGCHLD, &sa, NULL);
- sigaction(SIGHUP, &sa, NULL);
- sigaction(SIGINT, &sa, NULL);
- sigaction(SIGPIPE, &sa, NULL);
- sigaction(SIGQUIT, &sa, NULL);
- sigaction(SIGTERM, &sa, NULL);
-
- if (log_io) {
- if (io_fds[SFD_USERTTY] != -1) {
- sa.sa_flags = SA_RESTART;
- sa.sa_handler = sigwinch;
- sigaction(SIGWINCH, &sa, NULL);
- }
-
- /* So we can block tty-generated signals */
- sigemptyset(&ttyblock);
- sigaddset(&ttyblock, SIGINT);
- sigaddset(&ttyblock, SIGQUIT);
- sigaddset(&ttyblock, SIGTSTP);
- sigaddset(&ttyblock, SIGTTIN);
- sigaddset(&ttyblock, SIGTTOU);
-
- /*
- * Setup stdin/stdout/stderr for child, to be duped after forking.
- */
- io_fds[SFD_STDIN] = io_fds[SFD_SLAVE];
- io_fds[SFD_STDOUT] = io_fds[SFD_SLAVE];
- io_fds[SFD_STDERR] = io_fds[SFD_SLAVE];
-
- /* Copy /dev/tty -> pty master */
- if (io_fds[SFD_USERTTY] != -1) {
- iobufs = io_buf_new(io_fds[SFD_USERTTY], io_fds[SFD_MASTER],
- log_ttyin, iobufs);
-
- /* Copy pty master -> /dev/tty */
- iobufs = io_buf_new(io_fds[SFD_MASTER], io_fds[SFD_USERTTY],
- log_ttyout, iobufs);
-
- /* Are we the foreground process? */
- foreground = tcgetpgrp(io_fds[SFD_USERTTY]) == ppgrp;
- }
-
- /*
- * If either stdin, stdout or stderr is not a tty we use a pipe
- * to interpose ourselves instead of duping the pty fd.
- */
- memset(io_pipe, 0, sizeof(io_pipe));
- if (!isatty(STDIN_FILENO)) {
- pipeline = TRUE;
- if (pipe(io_pipe[STDIN_FILENO]) != 0)
- error(1, "unable to create pipe");
- iobufs = io_buf_new(STDIN_FILENO, io_pipe[STDIN_FILENO][1],
- log_stdin, iobufs);
- io_fds[SFD_STDIN] = io_pipe[STDIN_FILENO][0];
- }
- if (!isatty(STDOUT_FILENO)) {
- pipeline = TRUE;
- if (pipe(io_pipe[STDOUT_FILENO]) != 0)
- error(1, "unable to create pipe");
- iobufs = io_buf_new(io_pipe[STDOUT_FILENO][0], STDOUT_FILENO,
- log_stdout, iobufs);
- io_fds[SFD_STDOUT] = io_pipe[STDOUT_FILENO][1];
- }
- if (!isatty(STDERR_FILENO)) {
- if (pipe(io_pipe[STDERR_FILENO]) != 0)
- error(1, "unable to create pipe");
- iobufs = io_buf_new(io_pipe[STDERR_FILENO][0], STDERR_FILENO,
- log_stderr, iobufs);
- io_fds[SFD_STDERR] = io_pipe[STDERR_FILENO][1];
- }
-
- /* Job control signals to relay from parent to child. */
- sa.sa_flags = 0; /* do not restart syscalls */
- sa.sa_handler = handler;
- sigaction(SIGTSTP, &sa, NULL);
-#if 0 /* XXX - add these? */
- sigaction(SIGTTIN, &sa, NULL);
- sigaction(SIGTTOU, &sa, NULL);
-#endif
-
- if (foreground) {
- /* Copy terminal attrs from user tty -> pty slave. */
- if (term_copy(io_fds[SFD_USERTTY], io_fds[SFD_SLAVE])) {
- tty_initialized = 1;
- sync_ttysize(io_fds[SFD_USERTTY], io_fds[SFD_SLAVE]);
- }
-
- /* Start out in raw mode if we are not part of a pipeline. */
- if (!pipeline) {
- ttymode = TERM_RAW;
- do {
- n = term_raw(io_fds[SFD_USERTTY], 0);
- } while (!n && errno == EINTR);
- if (!n)
- error(1, "Can't set terminal to raw mode");
- }
- }
- }
-
- /*
- * Child will run the command in the pty, parent will pass data
- * to and from pty.
- */
- child = fork();
- switch (child) {
- case -1:
- error(1, "fork");
- break;
- case 0:
- /* child */
- close(sv[0]);
- fcntl(sv[1], F_SETFD, FD_CLOEXEC);
- if (exec_setup(details) == TRUE) {
- /* headed for execve() */
- if (log_io) {
- /* Close the other end of the stdin/stdout/stderr pipes. */
- if (io_pipe[STDIN_FILENO][1])
- close(io_pipe[STDIN_FILENO][1]);
- if (io_pipe[STDOUT_FILENO][0])
- close(io_pipe[STDOUT_FILENO][0]);
- if (io_pipe[STDERR_FILENO][0])
- close(io_pipe[STDERR_FILENO][0]);
- exec_monitor(details, argv, envp, sv[1], rbac_enabled);
- } else {
- if (details->closefrom >= 0)
- closefrom(details->closefrom);
-#ifdef HAVE_SELINUX
- if (rbac_enabled)
- selinux_execve(details->command, argv, envp);
- else
-#endif
- my_execve(details->command, argv, envp);
- }
- }
- cstat->type = CMD_ERRNO;
- cstat->val = errno;
- send(sv[1], cstat, sizeof(*cstat), 0);
- _exit(1);
- }
- close(sv[1]);
-
- /* Set command timeout if specified. */
- if (ISSET(details->flags, CD_SET_TIMEOUT))
- alarm(details->timeout);
-
- /* Max fd we will be selecting on. */
- maxfd = sv[0];
-
- if (log_io) {
- /* Close the other end of the stdin/stdout/stderr pipes. */
- if (io_pipe[STDIN_FILENO][0])
- close(io_pipe[STDIN_FILENO][0]);
- if (io_pipe[STDOUT_FILENO][1])
- close(io_pipe[STDOUT_FILENO][1]);
- if (io_pipe[STDERR_FILENO][1])
- close(io_pipe[STDERR_FILENO][1]);
-
- for (iob = iobufs; iob; iob = iob->next) {
- /* Determine maxfd */
- if (iob->rfd > maxfd)
- maxfd = iob->rfd;
- if (iob->wfd > maxfd)
- maxfd = iob->wfd;
-
- /* Set non-blocking mode. */
- n = fcntl(iob->rfd, F_GETFL, 0);
- if (n != -1 && !ISSET(n, O_NONBLOCK))
- (void) fcntl(iob->rfd, F_SETFL, n | O_NONBLOCK);
- n = fcntl(iob->wfd, F_GETFL, 0);
- if (n != -1 && !ISSET(n, O_NONBLOCK))
- (void) fcntl(iob->wfd, F_SETFL, n | O_NONBLOCK);
- }
- }
-
- /*
- * In the event loop we pass input from user tty to master
- * and pass output from master to stdout and IO plugin.
- */
- fdsr = (fd_set *)emalloc2(howmany(maxfd + 1, NFDBITS), sizeof(fd_mask));
- fdsw = (fd_set *)emalloc2(howmany(maxfd + 1, NFDBITS), sizeof(fd_mask));
- for (;;) {
- if (recvsig[SIGCHLD]) {
- pid_t pid;
-
- /*
- * If logging I/O, child is the intermediate process,
- * otherwise it is the command itself.
- */
- recvsig[SIGCHLD] = FALSE;
- do {
- pid = waitpid(child, &status, WNOHANG);
- } while (pid == -1 && errno == EINTR);
- if (pid == child) {
- /* If not logging I/O and child has exited we are done. */
- if (!log_io) {
- cstat->type = CMD_WSTATUS;
- cstat->val = status;
- return 0;
- }
- }
- }
-
- zero_bytes(fdsw, howmany(maxfd + 1, NFDBITS) * sizeof(fd_mask));
- zero_bytes(fdsr, howmany(maxfd + 1, NFDBITS) * sizeof(fd_mask));
-
- FD_SET(sv[0], fdsr);
- for (iob = iobufs; iob; iob = iob->next) {
- if (iob->rfd == -1 && iob->wfd == -1)
- continue;
- if (iob->off == iob->len) {
- iob->off = iob->len = 0;
- /* Forward the EOF from reader to writer. */
- if (iob->rfd == -1) {
- safe_close(iob->wfd);
- iob->wfd = -1;
- }
- }
- /* Don't read/write /dev/tty if we are not in the foreground. */
- if (iob->rfd != -1 &&
- (ttymode == TERM_RAW || iob->rfd != io_fds[SFD_USERTTY])) {
- if (iob->len != sizeof(iob->buf))
- FD_SET(iob->rfd, fdsr);
- }
- if (iob->wfd != -1 &&
- (foreground || iob->wfd != io_fds[SFD_USERTTY])) {
- if (iob->len > iob->off)
- FD_SET(iob->wfd, fdsw);
- }
- }
- for (n = 0; n < NSIG; n++) {
- if (recvsig[n] && n != SIGCHLD) {
- if (log_io) {
- FD_SET(sv[0], fdsw);
- break;
- } else {
- /* nothing listening on sv[0], send directly */
- if (n == SIGALRM) {
- terminate_child(child, FALSE);
- } else {
- kill(child, n);
- }
- }
- }
- }
-
- if (recvsig[SIGCHLD])
- continue;
- nready = select(maxfd + 1, fdsr, fdsw, NULL, NULL);
- if (nready == -1) {
- if (errno == EINTR)
- continue;
- error(1, "select failed");
- }
- if (FD_ISSET(sv[0], fdsr)) {
- /* read child status */
- n = recv(sv[0], cstat, sizeof(*cstat), 0);
- if (n == -1) {
- if (errno == EINTR)
- continue;
- /*
- * If not logging I/O we will receive ECONNRESET when
- * the command is executed. It is safe to ignore this.
- */
- if (log_io && errno != EAGAIN) {
- cstat->type = CMD_ERRNO;
- cstat->val = errno;
- break;
- }
- }
- if (cstat->type == CMD_WSTATUS) {
- if (WIFSTOPPED(cstat->val)) {
- /* Suspend parent and tell child how to resume on return. */
- sudo_debug(8, "child stopped, suspending parent");
- n = suspend_parent(WSTOPSIG(cstat->val));
- recvsig[n] = TRUE;
- continue;
- } else {
- /* Child exited or was killed, either way we are done. */
- break;
- }
- } else if (cstat->type == CMD_ERRNO) {
- /* Child was unable to execute command or broken pipe. */
- break;
- }
- }
-
- if (FD_ISSET(sv[0], fdsw)) {
- for (n = 0; n < NSIG; n++) {
- if (!recvsig[n])
- continue;
- recvsig[n] = FALSE;
- sudo_debug(9, "sending signal %d to child over backchannel", n);
- cstat->type = CMD_SIGNO;
- cstat->val = n;
- do {
- n = send(sv[0], cstat, sizeof(*cstat), 0);
- } while (n == -1 && errno == EINTR);
- if (n != sizeof(*cstat)) {
- recvsig[n] = TRUE;
- break;
- }
- }
- }
- if (perform_io(fdsr, fdsw, cstat) != 0)
- break;
- }
-
- if (log_io) {
- /* Flush any remaining output (the plugin already got it) */
- if (io_fds[SFD_USERTTY] != -1) {
- n = fcntl(io_fds[SFD_USERTTY], F_GETFL, 0);
- if (n != -1 && ISSET(n, O_NONBLOCK)) {
- CLR(n, O_NONBLOCK);
- (void) fcntl(io_fds[SFD_USERTTY], F_SETFL, n);
- }
- }
- flush_output();
-
- if (io_fds[SFD_USERTTY] != -1) {
- do {
- n = term_restore(io_fds[SFD_USERTTY], 0);
- } while (!n && errno == EINTR);
- }
-
- if (cstat->type == CMD_WSTATUS && WIFSIGNALED(cstat->val)) {
- int signo = WTERMSIG(cstat->val);
- if (signo && signo != SIGINT && signo != SIGPIPE) {
- char *reason = strsignal(signo);
- n = io_fds[SFD_USERTTY] != -1 ?
- io_fds[SFD_USERTTY] : STDOUT_FILENO;
- write(n, reason, strlen(reason));
- if (WCOREDUMP(cstat->val))
- write(n, " (core dumped)", 14);
- write(n, "\n", 1);
- }
- }
- }
-
-#ifdef HAVE_SELINUX
- if (rbac_enabled) {
- /* This is probably not needed in log_io mode. */
- if (selinux_restore_tty() != 0)
- warningx("unable to restore tty label");
- }
-#endif
-
- efree(fdsr);
- efree(fdsw);
- while ((iob = iobufs) != NULL) {
- iobufs = iobufs->next;
- efree(iob);
- }
-
- return cstat->type == CMD_ERRNO ? -1 : 0;
-}
-#endif
-
static void
deliver_signal(pid_t pid, int signo)
{
projects / sudo / commitdiff