/*
- * Copyright (c) 2009-2011 Todd C. Miller <Todd.Miller@courtesan.com>
+ * Copyright (c) 2009-2013 Todd C. Miller <Todd.Miller@courtesan.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
#include <config.h>
#include <sys/types.h>
-#include <sys/param.h>
#ifdef HAVE_SYS_SYSMACROS_H
# include <sys/sysmacros.h>
#endif
int off; /* write position (how much already consumed) */
int rfd; /* reader (producer) */
int wfd; /* writer (consumer) */
- int (*action)(const char *buf, unsigned int len);
- char buf[16 * 1024];
+ bool (*action)(const char *buf, unsigned int len);
+ char buf[32 * 1024];
};
static char slavename[PATH_MAX];
-static int foreground;
+static bool foreground, pipeline, tty_initialized;
static int io_fds[6] = { -1, -1, -1, -1, -1, -1};
-static int pipeline = FALSE;
-static int tty_initialized;
static int ttymode = TERM_COOKED;
-static pid_t ppgrp, child, child_pgrp;
+static pid_t ppgrp, cmnd_pgrp, mon_pgrp;
static sigset_t ttyblock;
static struct io_buffer *iobufs;
static void flush_output(void);
static int exec_monitor(struct command_details *details, int backchannel);
-static void exec_pty(struct command_details *detail);
+static void exec_pty(struct command_details *details,
+ struct command_status *cstat, int *errfd);
static void sigwinch(int s);
static void sync_ttysize(int src, int dst);
-static void deliver_signal(pid_t pid, int signo);
+static void deliver_signal(pid_t pid, int signo, bool from_parent);
static int safe_close(int fd);
+static void check_foreground(void);
/*
- * Cleanup hook for error()/errorx()
+ * Cleanup hook for fatal()/fatalx()
*/
-void
-cleanup(int gotsignal)
+static void
+pty_cleanup(void)
{
- if (!tq_empty(&io_plugins))
- term_restore(io_fds[SFD_USERTTY], 0);
+ debug_decl(cleanup, SUDO_DEBUG_EXEC);
+
+ if (!tq_empty(&io_plugins) && io_fds[SFD_USERTTY] != -1) {
+ check_foreground();
+ if (foreground)
+ term_restore(io_fds[SFD_USERTTY], 0);
+ }
#ifdef HAVE_SELINUX
selinux_restore_tty();
#endif
utmp_logout(slavename, 0); /* XXX - only if CD_SET_UTMP */
+
+ debug_return;
+}
+
+/*
+ * Generic handler for signals recieved by the monitor process.
+ * The other end of signal_pipe is checked in the monitor event loop.
+ */
+#ifdef SA_SIGINFO
+void
+mon_handler(int s, siginfo_t *info, void *context)
+{
+ unsigned char signo = (unsigned char)s;
+
+ /*
+ * If the signal came from the command we ran, just ignore
+ * it since we don't want the command to indirectly kill itself.
+ * This can happen with, e.g. BSD-derived versions of reboot
+ * that call kill(-1, SIGTERM) to kill all other processes.
+ */
+ if (info != NULL && info->si_code == SI_USER && info->si_pid == cmnd_pid)
+ return;
+
+ /*
+ * The pipe is non-blocking, if we overflow the kernel's pipe
+ * buffer we drop the signal. This is not a problem in practice.
+ */
+ ignore_result(write(signal_pipe[1], &signo, sizeof(signo)));
+}
+#else
+void
+mon_handler(int s)
+{
+ unsigned char signo = (unsigned char)s;
+
+ /*
+ * The pipe is non-blocking, if we overflow the kernel's pipe
+ * buffer we drop the signal. This is not a problem in practice.
+ */
+ ignore_result(write(signal_pipe[1], &signo, sizeof(signo)));
}
+#endif
/*
* Allocate a pty if /dev/tty is a tty.
void
pty_setup(uid_t uid, const char *tty, const char *utmp_user)
{
+ debug_decl(pty_setup, SUDO_DEBUG_EXEC);
+
io_fds[SFD_USERTTY] = open(_PATH_TTY, O_RDWR|O_NOCTTY, 0);
if (io_fds[SFD_USERTTY] != -1) {
if (!get_pty(&io_fds[SFD_MASTER], &io_fds[SFD_SLAVE],
slavename, sizeof(slavename), uid))
- error(1, _("unable to allocate pty"));
+ fatal(_("unable to allocate pty"));
/* Add entry to utmp/utmpx? */
if (utmp_user != NULL)
utmp_login(tty, slavename, io_fds[SFD_SLAVE], utmp_user);
}
+
+ debug_return;
}
/* Call I/O plugin tty input log method. */
-static int
+static bool
log_ttyin(const char *buf, unsigned int n)
{
struct plugin_container *plugin;
sigset_t omask;
- int rval = TRUE;
+ bool rval = true;
+ debug_decl(log_ttyin, SUDO_DEBUG_EXEC);
sigprocmask(SIG_BLOCK, &ttyblock, &omask);
-
tq_foreach_fwd(&io_plugins, plugin) {
if (plugin->u.io->log_ttyin) {
if (!plugin->u.io->log_ttyin(buf, n)) {
- rval = FALSE;
+ rval = false;
break;
}
}
}
-
sigprocmask(SIG_SETMASK, &omask, NULL);
- return rval;
+
+ debug_return_bool(rval);
}
/* Call I/O plugin stdin log method. */
-static int
+static bool
log_stdin(const char *buf, unsigned int n)
{
struct plugin_container *plugin;
sigset_t omask;
- int rval = TRUE;
+ bool rval = true;
+ debug_decl(log_stdin, SUDO_DEBUG_EXEC);
sigprocmask(SIG_BLOCK, &ttyblock, &omask);
-
tq_foreach_fwd(&io_plugins, plugin) {
if (plugin->u.io->log_stdin) {
if (!plugin->u.io->log_stdin(buf, n)) {
- rval = FALSE;
+ rval = false;
break;
}
}
}
-
sigprocmask(SIG_SETMASK, &omask, NULL);
- return rval;
+
+ debug_return_bool(rval);
}
/* Call I/O plugin tty output log method. */
-static int
+static bool
log_ttyout(const char *buf, unsigned int n)
{
struct plugin_container *plugin;
sigset_t omask;
- int rval = TRUE;
+ bool rval = true;
+ debug_decl(log_ttyout, SUDO_DEBUG_EXEC);
sigprocmask(SIG_BLOCK, &ttyblock, &omask);
-
tq_foreach_fwd(&io_plugins, plugin) {
if (plugin->u.io->log_ttyout) {
if (!plugin->u.io->log_ttyout(buf, n)) {
- rval = FALSE;
+ rval = false;
break;
}
}
}
-
sigprocmask(SIG_SETMASK, &omask, NULL);
- return rval;
+
+ debug_return_bool(rval);
}
/* Call I/O plugin stdout log method. */
-static int
+static bool
log_stdout(const char *buf, unsigned int n)
{
struct plugin_container *plugin;
sigset_t omask;
- int rval = TRUE;
+ bool rval = true;
+ debug_decl(log_stdout, SUDO_DEBUG_EXEC);
sigprocmask(SIG_BLOCK, &ttyblock, &omask);
-
tq_foreach_fwd(&io_plugins, plugin) {
if (plugin->u.io->log_stdout) {
if (!plugin->u.io->log_stdout(buf, n)) {
- rval = FALSE;
+ rval = false;
break;
}
}
}
-
sigprocmask(SIG_SETMASK, &omask, NULL);
- return rval;
+
+ debug_return_bool(rval);
}
/* Call I/O plugin stderr log method. */
-static int
+static bool
log_stderr(const char *buf, unsigned int n)
{
struct plugin_container *plugin;
sigset_t omask;
- int rval = TRUE;
+ bool rval = true;
+ debug_decl(log_stderr, SUDO_DEBUG_EXEC);
sigprocmask(SIG_BLOCK, &ttyblock, &omask);
-
tq_foreach_fwd(&io_plugins, plugin) {
if (plugin->u.io->log_stderr) {
if (!plugin->u.io->log_stderr(buf, n)) {
- rval = FALSE;
+ rval = false;
break;
}
}
}
-
sigprocmask(SIG_SETMASK, &omask, NULL);
- return rval;
+
+ debug_return_bool(rval);
}
/*
static void
check_foreground(void)
{
+ debug_decl(check_foreground, SUDO_DEBUG_EXEC);
+
if (io_fds[SFD_USERTTY] != -1) {
foreground = tcgetpgrp(io_fds[SFD_USERTTY]) == ppgrp;
if (foreground && !tty_initialized) {
if (term_copy(io_fds[SFD_USERTTY], io_fds[SFD_SLAVE])) {
- tty_initialized = 1;
+ tty_initialized = true;
sync_ttysize(io_fds[SFD_USERTTY], io_fds[SFD_SLAVE]);
}
}
}
+
+ debug_return;
}
/*
* Suspend sudo if the underlying command is suspended.
- * Returns SIGCONT_FG if the child should be resume in the
+ * Returns SIGCONT_FG if the command should be resumed in the
* foreground or SIGCONT_BG if it is a background process.
*/
int
suspend_parent(int signo)
{
+ char signame[SIG2STR_MAX];
sigaction_t sa, osa;
- int n, oldmode = ttymode, rval = 0;
+ int n, rval = 0;
+ debug_decl(suspend_parent, SUDO_DEBUG_EXEC);
switch (signo) {
case SIGTTOU:
case SIGTTIN:
/*
- * If we are the foreground process, just resume the child.
- * Otherwise, re-send the signal with the handler disabled.
+ * If sudo is already the foreground process, just resume the command
+ * in the foreground. If not, we'll suspend sudo and resume later.
*/
if (!foreground)
check_foreground();
} while (!n && errno == EINTR);
ttymode = TERM_RAW;
}
- rval = SIGCONT_FG; /* resume child in foreground */
+ rval = SIGCONT_FG; /* resume command in foreground */
break;
}
- ttymode = TERM_RAW;
/* FALLTHROUGH */
case SIGSTOP:
case SIGTSTP:
flush_output();
/* Restore original tty mode before suspending. */
- if (oldmode != TERM_COOKED) {
+ if (ttymode != TERM_COOKED) {
do {
n = term_restore(io_fds[SFD_USERTTY], 0);
} while (!n && errno == EINTR);
}
- /* Suspend self and continue child when we resume. */
- sa.sa_handler = SIG_DFL;
- sigaction(signo, &sa, &osa);
- sudo_debug(8, "kill parent %d", signo);
+ if (sig2str(signo, signame) == -1)
+ snprintf(signame, sizeof(signame), "%d", signo);
+
+ /* Suspend self and continue command when we resume. */
+ if (signo != SIGSTOP) {
+ memset(&sa, 0, sizeof(sa));
+ sigemptyset(&sa.sa_mask);
+ sa.sa_flags = SA_RESTART;
+ sa.sa_handler = SIG_DFL;
+ sudo_sigaction(signo, &sa, &osa);
+ }
+ sudo_debug_printf(SUDO_DEBUG_INFO, "kill parent SIG%s", signame);
if (killpg(ppgrp, signo) != 0)
- warning("killpg(%d, %d)", ppgrp, signo);
+ warning("killpg(%d, SIG%s)", (int)ppgrp, signame);
/* Check foreground/background status on resume. */
check_foreground();
/*
- * Only modify term if we are foreground process and either
- * the old tty mode was not cooked or child got SIGTT{IN,OU}
+ * We always resume the command in the foreground if sudo itself
+ * is the foreground process. This helps work around poorly behaved
+ * programs that catch SIGTTOU/SIGTTIN but suspend themselves with
+ * SIGSTOP. At worst, sudo will go into the background but upon
+ * resume the command will be runnable. Otherwise, we can get into
+ * a situation where the command will immediately suspend itself.
*/
- sudo_debug(8, "parent is in %s, ttymode %d -> %d",
- foreground ? "foreground" : "background", oldmode, ttymode);
+ sudo_debug_printf(SUDO_DEBUG_INFO, "parent is in %s, ttymode %d -> %d",
+ foreground ? "foreground" : "background", ttymode,
+ foreground ? TERM_RAW : TERM_COOKED);
- if (ttymode != TERM_COOKED) {
- if (foreground) {
- /* Set raw mode. */
- do {
- n = term_raw(io_fds[SFD_USERTTY], 0);
- } while (!n && errno == EINTR);
- } else {
- /* Background process, no access to tty. */
- ttymode = TERM_COOKED;
- }
+ if (foreground) {
+ /* Foreground process, set tty to raw mode. */
+ do {
+ n = term_raw(io_fds[SFD_USERTTY], 0);
+ } while (!n && errno == EINTR);
+ ttymode = TERM_RAW;
+ } else {
+ /* Background process, no access to tty. */
+ ttymode = TERM_COOKED;
}
- sigaction(signo, &osa, NULL);
+ if (signo != SIGSTOP)
+ sudo_sigaction(signo, &osa, NULL);
rval = ttymode == TERM_RAW ? SIGCONT_FG : SIGCONT_BG;
break;
}
- return rval;
+ debug_return_int(rval);
}
/*
- * Kill child with increasing urgency.
+ * Kill command with increasing urgency.
*/
void
-terminate_child(pid_t pid, int use_pgrp)
+terminate_command(pid_t pid, bool use_pgrp)
{
+ debug_decl(terminate_command, SUDO_DEBUG_EXEC);
+
/*
* Note that SIGCHLD will interrupt the sleep()
*/
if (use_pgrp) {
+ sudo_debug_printf(SUDO_DEBUG_INFO, "killpg %d SIGHUP", (int)pid);
killpg(pid, SIGHUP);
+ sudo_debug_printf(SUDO_DEBUG_INFO, "killpg %d SIGTERM", (int)pid);
killpg(pid, SIGTERM);
sleep(2);
+ sudo_debug_printf(SUDO_DEBUG_INFO, "killpg %d SIGKILL", (int)pid);
killpg(pid, SIGKILL);
} else {
+ sudo_debug_printf(SUDO_DEBUG_INFO, "kill %d SIGHUP", (int)pid);
kill(pid, SIGHUP);
+ sudo_debug_printf(SUDO_DEBUG_INFO, "kill %d SIGTERM", (int)pid);
kill(pid, SIGTERM);
sleep(2);
+ sudo_debug_printf(SUDO_DEBUG_INFO, "kill %d SIGKILL", (int)pid);
kill(pid, SIGKILL);
}
+
+ debug_return;
}
static struct io_buffer *
-io_buf_new(int rfd, int wfd, int (*action)(const char *, unsigned int),
+io_buf_new(int rfd, int wfd, bool (*action)(const char *, unsigned int),
struct io_buffer *head)
{
struct io_buffer *iob;
+ debug_decl(io_buf_new, SUDO_DEBUG_EXEC);
- iob = emalloc(sizeof(*iob));
- zero_bytes(iob, sizeof(*iob));
+ iob = ecalloc(1, sizeof(*iob));
iob->rfd = rfd;
iob->wfd = wfd;
iob->action = action;
iob->next = head;
- return iob;
+
+ debug_return_ptr(iob);
}
/*
{
struct io_buffer *iob;
int n, errors = 0;
+ debug_decl(perform_io, SUDO_DEBUG_EXEC);
for (iob = iobufs; iob; iob = iob->next) {
if (iob->rfd != -1 && FD_ISSET(iob->rfd, fdsr)) {
} while (n == -1 && errno == EINTR);
switch (n) {
case -1:
- if (errno == EAGAIN)
- break;
- if (errno != ENXIO && errno != EBADF) {
- errors++;
- break;
+ if (errno != EAGAIN) {
+ /* treat read error as fatal and close the fd */
+ sudo_debug_printf(SUDO_DEBUG_ERROR,
+ "error reading fd %d: %s", iob->rfd,
+ strerror(errno));
+ safe_close(iob->rfd);
+ iob->rfd = -1;
}
- /* FALLTHROUGH */
+ break;
case 0:
/* got EOF or pty has gone away */
+ sudo_debug_printf(SUDO_DEBUG_INFO,
+ "read EOF from fd %d", iob->rfd);
safe_close(iob->rfd);
iob->rfd = -1;
break;
default:
+ sudo_debug_printf(SUDO_DEBUG_INFO,
+ "read %d bytes from fd %d", n, iob->rfd);
if (!iob->action(iob->buf + iob->len, n))
- terminate_child(child, TRUE);
+ terminate_command(cmnd_pid, true);
iob->len += n;
break;
}
iob->len - iob->off);
} while (n == -1 && errno == EINTR);
if (n == -1) {
- if (errno == EPIPE || errno == ENXIO || errno == EBADF) {
+ if (errno == EPIPE || errno == ENXIO || errno == EIO || errno == EBADF) {
+ sudo_debug_printf(SUDO_DEBUG_INFO,
+ "unable to write %d bytes to fd %d",
+ iob->len - iob->off, iob->wfd);
/* other end of pipe closed or pty revoked */
if (iob->rfd != -1) {
safe_close(iob->rfd);
iob->wfd = -1;
continue;
}
- if (errno != EAGAIN)
+ if (errno != EAGAIN) {
errors++;
+ sudo_debug_printf(SUDO_DEBUG_ERROR,
+ "error writing fd %d: %s", iob->wfd, strerror(errno));
+ }
} else {
+ sudo_debug_printf(SUDO_DEBUG_INFO,
+ "wrote %d bytes to fd %d", n, iob->wfd);
iob->off += n;
}
}
cstat->type = CMD_ERRNO;
cstat->val = errno;
}
- return errors;
+ debug_return_int(errors);
}
/*
* Returns the child pid.
*/
int
-fork_pty(struct command_details *details, int sv[], int *maxfd)
+fork_pty(struct command_details *details, int sv[], int *maxfd, sigset_t *omask)
{
struct command_status cstat;
struct io_buffer *iob;
int io_pipe[3][2], n;
sigaction_t sa;
-
+ sigset_t mask;
+ pid_t child;
+ debug_decl(fork_pty, SUDO_DEBUG_EXEC);
+
ppgrp = getpgrp(); /* parent's pgrp, so child can signal us */
-
- zero_bytes(&sa, sizeof(sa));
+
+ memset(&sa, 0, sizeof(sa));
sigemptyset(&sa.sa_mask);
-
+
if (io_fds[SFD_USERTTY] != -1) {
sa.sa_flags = SA_RESTART;
sa.sa_handler = sigwinch;
- sigaction(SIGWINCH, &sa, NULL);
+ sudo_sigaction(SIGWINCH, &sa, NULL);
}
/* So we can block tty-generated signals */
*/
memset(io_pipe, 0, sizeof(io_pipe));
if (io_fds[SFD_STDIN] == -1 || !isatty(STDIN_FILENO)) {
- pipeline = TRUE;
+ sudo_debug_printf(SUDO_DEBUG_INFO, "stdin not a tty, creating a pipe");
+ pipeline = true;
if (pipe(io_pipe[STDIN_FILENO]) != 0)
- error(1, _("unable to create pipe"));
+ fatal(_("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 (io_fds[SFD_STDOUT] == -1 || !isatty(STDOUT_FILENO)) {
- pipeline = TRUE;
+ sudo_debug_printf(SUDO_DEBUG_INFO, "stdout not a tty, creating a pipe");
+ pipeline = true;
if (pipe(io_pipe[STDOUT_FILENO]) != 0)
- error(1, _("unable to create pipe"));
+ fatal(_("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 (io_fds[SFD_STDERR] == -1 || !isatty(STDERR_FILENO)) {
+ sudo_debug_printf(SUDO_DEBUG_INFO, "stderr not a tty, creating a pipe");
if (pipe(io_pipe[STDERR_FILENO]) != 0)
- error(1, _("unable to create pipe"));
+ fatal(_("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];
}
+ /* We don't want to receive SIGTTIN/SIGTTOU, getting EIO is preferable. */
+ sa.sa_handler = SIG_IGN;
+ sudo_sigaction(SIGTTIN, &sa, NULL);
+ sudo_sigaction(SIGTTOU, &sa, NULL);
+
/* Job control signals to relay from parent to child. */
+ sigfillset(&sa.sa_mask);
sa.sa_flags = SA_INTERRUPT; /* do not restart syscalls */
+#ifdef SA_SIGINFO
+ sa.sa_flags |= SA_SIGINFO;
+ sa.sa_sigaction = handler;
+#else
sa.sa_handler = handler;
- sigaction(SIGTSTP, &sa, NULL);
+#endif
+ sudo_sigaction(SIGTSTP, &sa, NULL);
if (foreground) {
/* Copy terminal attrs from user tty -> pty slave. */
if (term_copy(io_fds[SFD_USERTTY], io_fds[SFD_SLAVE])) {
- tty_initialized = 1;
+ tty_initialized = true;
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) {
+ /* Start out in raw mode unless part of a pipeline or backgrounded. */
+ if (!pipeline && !ISSET(details->flags, CD_EXEC_BG)) {
ttymode = TERM_RAW;
do {
n = term_raw(io_fds[SFD_USERTTY], 0);
} while (!n && errno == EINTR);
if (!n)
- error(1, _("unable to set terminal to raw mode"));
+ fatal(_("unable to set terminal to raw mode"));
}
}
- child = fork();
+ /*
+ * The policy plugin's session init must be run before we fork
+ * or certain pam modules won't be able to track their state.
+ */
+ if (policy_init_session(details) != true)
+ fatalx(_("policy plugin failed session initialization"));
+
+ /*
+ * Block some signals until cmnd_pid is set in the parent to avoid a
+ * race between exec of the command and receipt of a fatal signal from it.
+ */
+ sigemptyset(&mask);
+ sigaddset(&mask, SIGTERM);
+ sigaddset(&mask, SIGHUP);
+ sigaddset(&mask, SIGINT);
+ sigaddset(&mask, SIGQUIT);
+ sigprocmask(SIG_BLOCK, &mask, omask);
+
+ child = sudo_debug_fork();
switch (child) {
case -1:
- error(1, _("unable to fork"));
+ fatal(_("unable to fork"));
break;
case 0:
/* child */
close(signal_pipe[0]);
close(signal_pipe[1]);
fcntl(sv[1], F_SETFD, FD_CLOEXEC);
- if (exec_setup(details, slavename, io_fds[SFD_SLAVE]) == TRUE) {
- /* Close the other end of the stdin/stdout/stderr pipes and exec. */
- 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, sv[1]);
- }
+ sigprocmask(SIG_SETMASK, omask, NULL);
+ /* Close the other end of the stdin/stdout/stderr pipes and exec. */
+ 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, sv[1]);
cstat.type = CMD_ERRNO;
cstat.val = errno;
- send(sv[1], &cstat, sizeof(cstat), 0);
+ ignore_result(send(sv[1], &cstat, sizeof(cstat), 0));
_exit(1);
}
close(io_pipe[STDIN_FILENO][0]);
if (io_pipe[STDOUT_FILENO][1])
close(io_pipe[STDOUT_FILENO][1]);
- if (io_pipe[STDERR_FILENO][1])
+ if (io_pipe[STDERR_FILENO][1])
close(io_pipe[STDERR_FILENO][1]);
for (iob = iobufs; iob; iob = iob->next) {
(void) fcntl(iob->wfd, F_SETFL, n | O_NONBLOCK);
}
- return child;
+ debug_return_int(child);
}
void
pty_close(struct command_status *cstat)
{
int n;
+ debug_decl(pty_close, SUDO_DEBUG_EXEC);
/* Flush any remaining output (the plugin already got it) */
if (io_fds[SFD_USERTTY] != -1) {
flush_output();
if (io_fds[SFD_USERTTY] != -1) {
- do {
- n = term_restore(io_fds[SFD_USERTTY], 0);
- } while (!n && errno == EINTR);
+ check_foreground();
+ if (foreground) {
+ do {
+ n = term_restore(io_fds[SFD_USERTTY], 0);
+ } while (!n && errno == EINTR);
+ }
}
/* If child was signalled, write the reason to stdout like the shell. */
io_fds[SFD_USERTTY] : STDOUT_FILENO;
if (write(n, reason, strlen(reason)) != -1) {
if (WCOREDUMP(cstat->val)) {
- if (write(n, " (core dumped)", 14) == -1)
- /* shut up glibc */;
+ ignore_result(write(n, " (core dumped)", 14));
}
- if (write(n, "\n", 1) == -1)
- /* shut up glibc */;
+ ignore_result(write(n, "\n", 1));
}
}
}
utmp_logout(slavename, cstat->type == CMD_WSTATUS ? cstat->val : 0); /* XXX - only if CD_SET_UTMP */
+ debug_return;
}
/*
fd_set_iobs(fd_set *fdsr, fd_set *fdsw)
{
struct io_buffer *iob;
+ debug_decl(fd_set_iobs, SUDO_DEBUG_EXEC);
for (iob = iobufs; iob; iob = iob->next) {
if (iob->rfd == -1 && iob->wfd == -1)
FD_SET(iob->wfd, fdsw);
}
}
+ debug_return;
}
static void
-deliver_signal(pid_t pid, int signo)
+deliver_signal(pid_t pid, int signo, bool from_parent)
{
+ char signame[SIG2STR_MAX];
int status;
+ debug_decl(deliver_signal, SUDO_DEBUG_EXEC);
+
+ if (signo == SIGCONT_FG)
+ strlcpy(signame, "CONT_FG", sizeof(signame));
+ else if (signo == SIGCONT_BG)
+ strlcpy(signame, "CONT_BG", sizeof(signame));
+ else if (sig2str(signo, signame) == -1)
+ snprintf(signame, sizeof(signame), "%d", signo);
/* Handle signal from parent. */
- sudo_debug(8, "signal %d from parent", signo);
+ sudo_debug_printf(SUDO_DEBUG_INFO, "received SIG%s%s",
+ signame, from_parent ? " from parent" : "");
switch (signo) {
case SIGALRM:
- terminate_child(pid, TRUE);
+ terminate_command(pid, true);
break;
case SIGCONT_FG:
/* Continue in foreground, grant it controlling tty. */
do {
- status = tcsetpgrp(io_fds[SFD_SLAVE], child_pgrp);
+ status = tcsetpgrp(io_fds[SFD_SLAVE], cmnd_pgrp);
} while (status == -1 && errno == EINTR);
killpg(pid, SIGCONT);
break;
case SIGCONT_BG:
/* Continue in background, I take controlling tty. */
do {
- status = tcsetpgrp(io_fds[SFD_SLAVE], getpid());
+ status = tcsetpgrp(io_fds[SFD_SLAVE], mon_pgrp);
} while (status == -1 && errno == EINTR);
killpg(pid, SIGCONT);
break;
_exit(1); /* XXX */
/* NOTREACHED */
default:
- /* Relay signal to child. */
+ /* Relay signal to command. */
killpg(pid, signo);
break;
}
+ debug_return;
}
/*
send_status(int fd, struct command_status *cstat)
{
int n = -1;
+ debug_decl(send_status, SUDO_DEBUG_EXEC);
if (cstat->type != CMD_INVALID) {
+ sudo_debug_printf(SUDO_DEBUG_INFO,
+ "sending status message to parent: [%d, %d]",
+ cstat->type, cstat->val);
do {
n = send(fd, cstat, sizeof(*cstat), 0);
} while (n == -1 && errno == EINTR);
if (n != sizeof(*cstat)) {
- sudo_debug(8, "unable to send status to parent: %s",
- strerror(errno));
- } else {
- sudo_debug(8, "sent status to parent");
+ sudo_debug_printf(SUDO_DEBUG_ERROR,
+ "unable to send status to parent: %s", strerror(errno));
}
cstat->type = CMD_INVALID; /* prevent re-sending */
}
- return n;
+ debug_return_int(n);
}
/*
- * Wait for child status after receiving SIGCHLD.
- * If the child was stopped, the status is send back to the parent.
+ * Wait for command status after receiving SIGCHLD.
+ * If the command was stopped, the status is send back to the parent.
* Otherwise, cstat is filled in but not sent.
- * Returns TRUE if child is still alive, else FALSE.
+ * Returns true if command is still alive, else false.
*/
-static int
+static bool
handle_sigchld(int backchannel, struct command_status *cstat)
{
- int status, alive = TRUE;
+ bool alive = true;
+ int status;
pid_t pid;
+ debug_decl(handle_sigchld, SUDO_DEBUG_EXEC);
- /* read child status */
+ /* read command status */
do {
- pid = waitpid(child, &status, WUNTRACED|WNOHANG);
+ pid = waitpid(cmnd_pid, &status, WUNTRACED|WNOHANG);
} while (pid == -1 && errno == EINTR);
- if (pid == child) {
+ if (pid == cmnd_pid) {
if (cstat->type != CMD_ERRNO) {
+ char signame[SIG2STR_MAX];
+
cstat->type = CMD_WSTATUS;
cstat->val = status;
if (WIFSTOPPED(status)) {
- sudo_debug(8, "command stopped, signal %d", WSTOPSIG(status));
+ if (sig2str(WSTOPSIG(status), signame) == -1)
+ snprintf(signame, sizeof(signame), "%d", WSTOPSIG(status));
+ sudo_debug_printf(SUDO_DEBUG_INFO,
+ "command stopped, SIG%s", signame);
+ /* Saved the foreground pgid so we can restore it later. */
do {
- child_pgrp = tcgetpgrp(io_fds[SFD_SLAVE]);
- } while (child_pgrp == -1 && errno == EINTR);
+ pid = tcgetpgrp(io_fds[SFD_SLAVE]);
+ } while (pid == -1 && errno == EINTR);
+ if (pid != mon_pgrp)
+ cmnd_pgrp = pid;
if (send_status(backchannel, cstat) == -1)
return alive; /* XXX */
} else if (WIFSIGNALED(status)) {
- sudo_debug(8, "command killed, signal %d", WTERMSIG(status));
+ if (sig2str(WTERMSIG(status), signame) == -1)
+ snprintf(signame, sizeof(signame), "%d", WTERMSIG(status));
+ sudo_debug_printf(SUDO_DEBUG_INFO,
+ "command killed, SIG%s", signame);
} else {
- sudo_debug(8, "command exited: %d", WEXITSTATUS(status));
+ sudo_debug_printf(SUDO_DEBUG_INFO, "command exited: %d",
+ WEXITSTATUS(status));
}
}
if (!WIFSTOPPED(status))
- alive = FALSE;
+ alive = false;
}
- return alive;
+ debug_return_bool(alive);
}
/*
struct timeval tv;
fd_set *fdsr;
sigaction_t sa;
- int errpipe[2], maxfd, n, status;
- int alive = TRUE;
+ int errpipe[2], maxfd, n;
+ bool alive = true;
unsigned char signo;
+ debug_decl(exec_monitor, SUDO_DEBUG_EXEC);
/* Close unused fds. */
if (io_fds[SFD_MASTER] != -1)
* the select() loop.
*/
if (pipe_nonblock(signal_pipe) != 0)
- error(1, _("unable to create pipe"));
+ fatal(_("unable to create pipe"));
/* Reset SIGWINCH and SIGALRM. */
- zero_bytes(&sa, sizeof(sa));
+ memset(&sa, 0, sizeof(sa));
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_RESTART;
sa.sa_handler = SIG_DFL;
- sigaction(SIGWINCH, &sa, NULL);
- sigaction(SIGALRM, &sa, NULL);
+ sudo_sigaction(SIGWINCH, &sa, NULL);
+ sudo_sigaction(SIGALRM, &sa, NULL);
/* Ignore any SIGTTIN or SIGTTOU we get. */
sa.sa_handler = SIG_IGN;
- sigaction(SIGTTIN, &sa, NULL);
- sigaction(SIGTTOU, &sa, NULL);
+ sudo_sigaction(SIGTTIN, &sa, NULL);
+ sudo_sigaction(SIGTTOU, &sa, NULL);
+
+ /* Block all signals in mon_handler(). */
+ sigfillset(&sa.sa_mask);
/* Note: HP-UX select() will not be interrupted if SA_RESTART set */
sa.sa_flags = SA_INTERRUPT;
- sa.sa_handler = handler;
- sigaction(SIGCHLD, &sa, NULL);
+#ifdef SA_SIGINFO
+ sa.sa_flags |= SA_SIGINFO;
+ sa.sa_sigaction = mon_handler;
+#else
+ sa.sa_handler = mon_handler;
+#endif
+ sudo_sigaction(SIGCHLD, &sa, NULL);
+
+ /* Catch common signals so we can cleanup properly. */
+ sa.sa_flags = SA_RESTART;
+#ifdef SA_SIGINFO
+ sa.sa_flags |= SA_SIGINFO;
+ sa.sa_sigaction = mon_handler;
+#else
+ sa.sa_handler = mon_handler;
+#endif
+ sudo_sigaction(SIGHUP, &sa, NULL);
+ sudo_sigaction(SIGINT, &sa, NULL);
+ sudo_sigaction(SIGQUIT, &sa, NULL);
+ sudo_sigaction(SIGTERM, &sa, NULL);
+ sudo_sigaction(SIGTSTP, &sa, NULL);
+ sudo_sigaction(SIGUSR1, &sa, NULL);
+ sudo_sigaction(SIGUSR2, &sa, NULL);
/*
* Start a new session with the parent as the session leader
* and the slave pty as the controlling terminal.
- * This allows us to be notified when the child has been suspended.
+ * This allows us to be notified when the command has been suspended.
*/
if (setsid() == -1) {
warning("setsid");
if (io_fds[SFD_SLAVE] != -1) {
#ifdef TIOCSCTTY
if (ioctl(io_fds[SFD_SLAVE], TIOCSCTTY, NULL) != 0)
- error(1, _("unable to set controlling tty"));
+ fatal(_("unable to set controlling tty"));
#else
/* Set controlling tty by reopening slave. */
if ((n = open(slavename, O_RDWR)) >= 0)
#endif
}
+ mon_pgrp = getpgrp(); /* save a copy of our process group */
+
/*
* If stdin/stdout is not a tty, start command in the background
* since it might be part of a pipeline that reads from /dev/tty.
* when it needs access to the controlling tty.
*/
if (pipeline)
- foreground = 0;
+ foreground = false;
/* Start command and wait for it to stop or exit */
if (pipe(errpipe) == -1)
- error(1, _("unable to create pipe"));
- child = fork();
- if (child == -1) {
+ fatal(_("unable to create pipe"));
+ cmnd_pid = sudo_debug_fork();
+ if (cmnd_pid == -1) {
warning(_("unable to fork"));
goto bad;
}
- if (child == 0) {
+ if (cmnd_pid == 0) {
/* We pass errno back to our parent via pipe on exec failure. */
close(backchannel);
close(signal_pipe[0]);
restore_signals();
/* setup tty and exec command */
- exec_pty(details);
- cstat.type = CMD_ERRNO;
- cstat.val = errno;
- if (write(errpipe[1], &cstat, sizeof(cstat)) == -1)
- /* shut up glibc */;
+ exec_pty(details, &cstat, &errpipe[1]);
+ ignore_result(write(errpipe[1], &cstat, sizeof(cstat)));
_exit(1);
}
close(errpipe[1]);
+ /* Send the command's pid to main sudo process. */
+ cstat.type = CMD_PID;
+ cstat.val = cmnd_pid;
+ ignore_result(send(backchannel, &cstat, sizeof(cstat), 0));
+
/* If any of stdin/stdout/stderr are pipes, close them in parent. */
if (io_fds[SFD_STDIN] != io_fds[SFD_SLAVE])
close(io_fds[SFD_STDIN]);
if (io_fds[SFD_STDERR] != io_fds[SFD_SLAVE])
close(io_fds[SFD_STDERR]);
- /*
- * Put child in its own process group. If we are starting the command
- * in the foreground, assign its pgrp to the tty.
- */
- child_pgrp = child;
- setpgid(child, child_pgrp);
- if (foreground) {
+ /* Put command in its own process group. */
+ cmnd_pgrp = cmnd_pid;
+ setpgid(cmnd_pid, cmnd_pgrp);
+
+ /* Make the command the foreground process for the pty slave. */
+ if (foreground && !ISSET(details->flags, CD_EXEC_BG)) {
do {
- status = tcsetpgrp(io_fds[SFD_SLAVE], child_pgrp);
- } while (status == -1 && errno == EINTR);
+ n = tcsetpgrp(io_fds[SFD_SLAVE], cmnd_pgrp);
+ } while (n == -1 && errno == EINTR);
}
/* Wait for errno on pipe, signal on backchannel or for SIGCHLD */
maxfd = MAX(MAX(errpipe[0], signal_pipe[0]), backchannel);
- fdsr = (fd_set *)emalloc2(howmany(maxfd + 1, NFDBITS), sizeof(fd_mask));
- zero_bytes(fdsr, howmany(maxfd + 1, NFDBITS) * sizeof(fd_mask));
- zero_bytes(&cstat, sizeof(cstat));
+ fdsr = ecalloc(howmany(maxfd + 1, NFDBITS), sizeof(fd_mask));
+ memset(&cstat, 0, sizeof(cstat));
tv.tv_sec = 0;
tv.tv_usec = 0;
for (;;) {
if (n <= 0) {
if (n == 0)
goto done;
- if (errno == EINTR)
+ if (errno == EINTR || errno == ENOMEM)
continue;
- error(1, _("select failed"));
+ warning("monitor: %s", _("select failed"));
+ break;
}
if (FD_ISSET(signal_pipe[0], fdsr)) {
}
/*
* Handle SIGCHLD specially and deliver other signals
- * directly to the child.
+ * directly to the command.
*/
- if (signo == SIGCHLD)
- alive = handle_sigchld(backchannel, &cstat);
- else
- deliver_signal(child, signo);
+ if (signo == SIGCHLD) {
+ if (!handle_sigchld(backchannel, &cstat))
+ alive = false;
+ } else {
+ deliver_signal(cmnd_pid, signo, false);
+ }
continue;
}
if (errpipe[0] != -1 && FD_ISSET(errpipe[0], fdsr)) {
cstmp.type);
continue;
}
- deliver_signal(child, cstmp.val);
+ deliver_signal(cmnd_pid, cstmp.val, true);
}
}
done:
if (alive) {
/* XXX An error occurred, should send an error back. */
- kill(child, SIGKILL);
+ kill(cmnd_pid, SIGKILL);
} else {
/* Send parent status. */
send_status(backchannel, &cstat);
}
+ sudo_debug_exit_int(__func__, __FILE__, __LINE__, sudo_debug_subsys, 1);
_exit(1);
bad:
- return errno;
+ debug_return_int(errno);
}
/*
struct timeval tv;
fd_set *fdsr, *fdsw;
int nready, nwriters, maxfd = -1;
+ debug_decl(flush_output, SUDO_DEBUG_EXEC);
/* Determine maxfd */
for (iob = iobufs; iob; iob = iob->next) {
maxfd = iob->wfd;
}
if (maxfd == -1)
- return;
+ debug_return;
- fdsr = (fd_set *)emalloc2(howmany(maxfd + 1, NFDBITS), sizeof(fd_mask));
- fdsw = (fd_set *)emalloc2(howmany(maxfd + 1, NFDBITS), sizeof(fd_mask));
+ fdsr = emalloc2(howmany(maxfd + 1, NFDBITS), sizeof(fd_mask));
+ fdsw = emalloc2(howmany(maxfd + 1, NFDBITS), sizeof(fd_mask));
for (;;) {
- zero_bytes(fdsw, howmany(maxfd + 1, NFDBITS) * sizeof(fd_mask));
- zero_bytes(fdsr, howmany(maxfd + 1, NFDBITS) * sizeof(fd_mask));
+ memset(fdsw, 0, howmany(maxfd + 1, NFDBITS) * sizeof(fd_mask));
+ memset(fdsr, 0, howmany(maxfd + 1, NFDBITS) * sizeof(fd_mask));
nwriters = 0;
for (iob = iobufs; iob; iob = iob->next) {
if (nready <= 0) {
if (nready == 0)
break; /* all I/O flushed */
- if (errno == EINTR)
+ if (errno == EINTR || errno == ENOMEM)
continue;
- error(1, _("select failed"));
+ warning(_("select failed"));
}
- if (perform_io(fdsr, fdsw, NULL) != 0)
+ if (perform_io(fdsr, fdsw, NULL) != 0 || nready == -1)
break;
}
efree(fdsr);
efree(fdsw);
+ debug_return;
}
/*
* Returns only if execve() fails.
*/
static void
-exec_pty(struct command_details *details)
+exec_pty(struct command_details *details,
+ struct command_status *cstat, int *errfd)
{
pid_t self = getpid();
+ debug_decl(exec_pty, SUDO_DEBUG_EXEC);
- /* Set child process group here too to avoid a race. */
+ /* Register cleanup function */
+ fatal_callback_register(pty_cleanup);
+
+ /* Set command process group here too to avoid a race. */
setpgid(0, self);
/* Wire up standard fds, note that stdout/stderr may be pipes. */
if (dup2(io_fds[SFD_STDIN], STDIN_FILENO) == -1 ||
dup2(io_fds[SFD_STDOUT], STDOUT_FILENO) == -1 ||
dup2(io_fds[SFD_STDERR], STDERR_FILENO) == -1)
- error(1, "dup2");
+ fatal("dup2");
/* Wait for parent to grant us the tty if we are foreground. */
- if (foreground) {
+ if (foreground && !ISSET(details->flags, CD_EXEC_BG)) {
while (tcgetpgrp(io_fds[SFD_SLAVE]) != self)
; /* spin */
}
if (io_fds[SFD_STDERR] != io_fds[SFD_SLAVE])
close(io_fds[SFD_STDERR]);
- if (details->closefrom >= 0)
- closefrom(details->closefrom);
-#ifdef HAVE_SELINUX
- if (ISSET(details->flags, CD_RBAC_ENABLED))
- selinux_execve(details->command, details->argv, details->envp);
- else
-#endif
- my_execve(details->command, details->argv, details->envp);
+ /* Execute command; only returns on error. */
+ exec_cmnd(details, cstat, errfd);
+
+ debug_return;
}
/*
#ifdef TIOCGWINSZ
struct winsize wsize;
pid_t pgrp;
+ debug_decl(sync_ttysize, SUDO_DEBUG_EXEC);
if (ioctl(src, TIOCGWINSZ, &wsize) == 0) {
ioctl(dst, TIOCSWINSZ, &wsize);
if ((pgrp = tcgetpgrp(dst)) != -1)
killpg(pgrp, SIGWINCH);
}
+
+ debug_return;
#endif
}
static int
safe_close(int fd)
{
+ debug_decl(safe_close, SUDO_DEBUG_EXEC);
+
/* Avoid closing /dev/tty or std{in,out,err}. */
if (fd < 3 || fd == io_fds[SFD_USERTTY]) {
errno = EINVAL;
- return -1;
+ debug_return_int(-1);
}
- return close(fd);
+ debug_return_int(close(fd));
}
projects / debian / sudo / blobdiff