+++ /dev/null
-/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
-/* dbus-spawn.c Wrapper around fork/exec
- *
- * Copyright (C) 2002, 2003, 2004 Red Hat, Inc.
- * Copyright (C) 2003 CodeFactory AB
- *
- * Licensed under the Academic Free License version 2.1
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- */
-#include "dbus-spawn.h"
-#include "dbus-sysdeps-unix.h"
-#include "dbus-internals.h"
-#include "dbus-test.h"
-#include "dbus-protocol.h"
-
-#include <unistd.h>
-#include <fcntl.h>
-#include <signal.h>
-#include <sys/wait.h>
-#include <stdlib.h>
-#ifdef HAVE_ERRNO_H
-#include <errno.h>
-#endif
-
-extern char **environ;
-
-/**
- * @addtogroup DBusInternalsUtils
- * @{
- */
-
-/*
- * I'm pretty sure this whole spawn file could be made simpler,
- * if you thought about it a bit.
- */
-
-/**
- * Enumeration for status of a read()
- */
-typedef enum
-{
- READ_STATUS_OK, /**< Read succeeded */
- READ_STATUS_ERROR, /**< Some kind of error */
- READ_STATUS_EOF /**< EOF returned */
-} ReadStatus;
-
-static ReadStatus
-read_ints (int fd,
- int *buf,
- int n_ints_in_buf,
- int *n_ints_read,
- DBusError *error)
-{
- size_t bytes = 0;
- ReadStatus retval;
-
- _DBUS_ASSERT_ERROR_IS_CLEAR (error);
-
- retval = READ_STATUS_OK;
-
- while (TRUE)
- {
- size_t chunk;
- ssize_t to_read;
-
- to_read = sizeof (int) * n_ints_in_buf - bytes;
-
- if (to_read == 0)
- break;
-
- again:
-
- chunk = read (fd,
- ((char*)buf) + bytes,
- to_read);
-
- if (chunk < 0 && errno == EINTR)
- goto again;
-
- if (chunk < 0)
- {
- dbus_set_error (error,
- DBUS_ERROR_SPAWN_FAILED,
- "Failed to read from child pipe (%s)",
- _dbus_strerror (errno));
-
- retval = READ_STATUS_ERROR;
- break;
- }
- else if (chunk == 0)
- {
- retval = READ_STATUS_EOF;
- break; /* EOF */
- }
- else /* chunk > 0 */
- bytes += chunk;
- }
-
- *n_ints_read = (int)(bytes / sizeof(int));
-
- return retval;
-}
-
-static ReadStatus
-read_pid (int fd,
- pid_t *buf,
- DBusError *error)
-{
- size_t bytes = 0;
- ReadStatus retval;
-
- _DBUS_ASSERT_ERROR_IS_CLEAR (error);
-
- retval = READ_STATUS_OK;
-
- while (TRUE)
- {
- size_t chunk;
- ssize_t to_read;
-
- to_read = sizeof (pid_t) - bytes;
-
- if (to_read == 0)
- break;
-
- again:
-
- chunk = read (fd,
- ((char*)buf) + bytes,
- to_read);
- if (chunk < 0 && errno == EINTR)
- goto again;
-
- if (chunk < 0)
- {
- dbus_set_error (error,
- DBUS_ERROR_SPAWN_FAILED,
- "Failed to read from child pipe (%s)",
- _dbus_strerror (errno));
-
- retval = READ_STATUS_ERROR;
- break;
- }
- else if (chunk == 0)
- {
- retval = READ_STATUS_EOF;
- break; /* EOF */
- }
- else /* chunk > 0 */
- bytes += chunk;
- }
-
- return retval;
-}
-
-/* The implementation uses an intermediate child between the main process
- * and the grandchild. The grandchild is our spawned process. The intermediate
- * child is a babysitter process; it keeps track of when the grandchild
- * exits/crashes, and reaps the grandchild.
- */
-
-/* Messages from children to parents */
-enum
-{
- CHILD_EXITED, /* This message is followed by the exit status int */
- CHILD_FORK_FAILED, /* Followed by errno */
- CHILD_EXEC_FAILED, /* Followed by errno */
- CHILD_PID /* Followed by pid_t */
-};
-
-/**
- * Babysitter implementation details
- */
-struct DBusBabysitter
-{
- int refcount; /**< Reference count */
-
- char *executable; /**< executable name to use in error messages */
-
- int socket_to_babysitter; /**< Connection to the babysitter process */
- int error_pipe_from_child; /**< Connection to the process that does the exec() */
-
- pid_t sitter_pid; /**< PID Of the babysitter */
- pid_t grandchild_pid; /**< PID of the grandchild */
-
- DBusWatchList *watches; /**< Watches */
-
- DBusWatch *error_watch; /**< Error pipe watch */
- DBusWatch *sitter_watch; /**< Sitter pipe watch */
-
- int errnum; /**< Error number */
- int status; /**< Exit status code */
- unsigned int have_child_status : 1; /**< True if child status has been reaped */
- unsigned int have_fork_errnum : 1; /**< True if we have an error code from fork() */
- unsigned int have_exec_errnum : 1; /**< True if we have an error code from exec() */
-};
-
-static DBusBabysitter*
-_dbus_babysitter_new (void)
-{
- DBusBabysitter *sitter;
-
- sitter = dbus_new0 (DBusBabysitter, 1);
- if (sitter == NULL)
- return NULL;
-
- sitter->refcount = 1;
-
- sitter->socket_to_babysitter = -1;
- sitter->error_pipe_from_child = -1;
-
- sitter->sitter_pid = -1;
- sitter->grandchild_pid = -1;
-
- sitter->watches = _dbus_watch_list_new ();
- if (sitter->watches == NULL)
- goto failed;
-
- return sitter;
-
- failed:
- _dbus_babysitter_unref (sitter);
- return NULL;
-}
-
-/**
- * Increment the reference count on the babysitter object.
- *
- * @param sitter the babysitter
- * @returns the babysitter
- */
-DBusBabysitter *
-_dbus_babysitter_ref (DBusBabysitter *sitter)
-{
- _dbus_assert (sitter != NULL);
- _dbus_assert (sitter->refcount > 0);
-
- sitter->refcount += 1;
-
- return sitter;
-}
-
-/**
- * Decrement the reference count on the babysitter object.
- * When the reference count of the babysitter object reaches
- * zero, the babysitter is killed and the child that was being
- * babysat gets emancipated.
- *
- * @param sitter the babysitter
- */
-void
-_dbus_babysitter_unref (DBusBabysitter *sitter)
-{
- _dbus_assert (sitter != NULL);
- _dbus_assert (sitter->refcount > 0);
-
- sitter->refcount -= 1;
- if (sitter->refcount == 0)
- {
- if (sitter->socket_to_babysitter >= 0)
- {
- /* If we haven't forked other babysitters
- * since this babysitter and socket were
- * created then this close will cause the
- * babysitter to wake up from poll with
- * a hangup and then the babysitter will
- * quit itself.
- */
- _dbus_close_socket (sitter->socket_to_babysitter, NULL);
- sitter->socket_to_babysitter = -1;
- }
-
- if (sitter->error_pipe_from_child >= 0)
- {
- _dbus_close_socket (sitter->error_pipe_from_child, NULL);
- sitter->error_pipe_from_child = -1;
- }
-
- if (sitter->sitter_pid > 0)
- {
- int status;
- int ret;
-
- /* It's possible the babysitter died on its own above
- * from the close, or was killed randomly
- * by some other process, so first try to reap it
- */
- ret = waitpid (sitter->sitter_pid, &status, WNOHANG);
-
- /* If we couldn't reap the child then kill it, and
- * try again
- */
- if (ret == 0)
- kill (sitter->sitter_pid, SIGKILL);
-
- again:
- if (ret == 0)
- ret = waitpid (sitter->sitter_pid, &status, 0);
-
- if (ret < 0)
- {
- if (errno == EINTR)
- goto again;
- else if (errno == ECHILD)
- _dbus_warn ("Babysitter process not available to be reaped; should not happen\n");
- else
- _dbus_warn ("Unexpected error %d in waitpid() for babysitter: %s\n",
- errno, _dbus_strerror (errno));
- }
- else
- {
- _dbus_verbose ("Reaped %ld, waiting for babysitter %ld\n",
- (long) ret, (long) sitter->sitter_pid);
-
- if (WIFEXITED (sitter->status))
- _dbus_verbose ("Babysitter exited with status %d\n",
- WEXITSTATUS (sitter->status));
- else if (WIFSIGNALED (sitter->status))
- _dbus_verbose ("Babysitter received signal %d\n",
- WTERMSIG (sitter->status));
- else
- _dbus_verbose ("Babysitter exited abnormally\n");
- }
-
- sitter->sitter_pid = -1;
- }
-
- if (sitter->error_watch)
- {
- _dbus_watch_invalidate (sitter->error_watch);
- _dbus_watch_unref (sitter->error_watch);
- sitter->error_watch = NULL;
- }
-
- if (sitter->sitter_watch)
- {
- _dbus_watch_invalidate (sitter->sitter_watch);
- _dbus_watch_unref (sitter->sitter_watch);
- sitter->sitter_watch = NULL;
- }
-
- if (sitter->watches)
- _dbus_watch_list_free (sitter->watches);
-
- dbus_free (sitter->executable);
-
- dbus_free (sitter);
- }
-}
-
-static ReadStatus
-read_data (DBusBabysitter *sitter,
- int fd)
-{
- int what;
- int got;
- DBusError error = DBUS_ERROR_INIT;
- ReadStatus r;
-
- r = read_ints (fd, &what, 1, &got, &error);
-
- switch (r)
- {
- case READ_STATUS_ERROR:
- _dbus_warn ("Failed to read data from fd %d: %s\n", fd, error.message);
- dbus_error_free (&error);
- return r;
-
- case READ_STATUS_EOF:
- return r;
-
- case READ_STATUS_OK:
- break;
- }
-
- if (got == 1)
- {
- switch (what)
- {
- case CHILD_EXITED:
- case CHILD_FORK_FAILED:
- case CHILD_EXEC_FAILED:
- {
- int arg;
-
- r = read_ints (fd, &arg, 1, &got, &error);
-
- switch (r)
- {
- case READ_STATUS_ERROR:
- _dbus_warn ("Failed to read arg from fd %d: %s\n", fd, error.message);
- dbus_error_free (&error);
- return r;
- case READ_STATUS_EOF:
- return r;
- case READ_STATUS_OK:
- break;
- }
-
- if (got == 1)
- {
- if (what == CHILD_EXITED)
- {
- sitter->have_child_status = TRUE;
- sitter->status = arg;
- sitter->errnum = 0;
- _dbus_verbose ("recorded child status exited = %d signaled = %d exitstatus = %d termsig = %d\n",
- WIFEXITED (sitter->status), WIFSIGNALED (sitter->status),
- WEXITSTATUS (sitter->status), WTERMSIG (sitter->status));
- }
- else if (what == CHILD_FORK_FAILED)
- {
- sitter->have_fork_errnum = TRUE;
- sitter->errnum = arg;
- _dbus_verbose ("recorded fork errnum %d\n", sitter->errnum);
- }
- else if (what == CHILD_EXEC_FAILED)
- {
- sitter->have_exec_errnum = TRUE;
- sitter->errnum = arg;
- _dbus_verbose ("recorded exec errnum %d\n", sitter->errnum);
- }
- }
- }
- break;
- case CHILD_PID:
- {
- pid_t pid = -1;
-
- r = read_pid (fd, &pid, &error);
-
- switch (r)
- {
- case READ_STATUS_ERROR:
- _dbus_warn ("Failed to read PID from fd %d: %s\n", fd, error.message);
- dbus_error_free (&error);
- return r;
- case READ_STATUS_EOF:
- return r;
- case READ_STATUS_OK:
- break;
- }
-
- sitter->grandchild_pid = pid;
-
- _dbus_verbose ("recorded grandchild pid %d\n", sitter->grandchild_pid);
- }
- break;
- default:
- _dbus_warn ("Unknown message received from babysitter process\n");
- break;
- }
- }
-
- return r;
-}
-
-static void
-close_socket_to_babysitter (DBusBabysitter *sitter)
-{
- _dbus_verbose ("Closing babysitter\n");
- _dbus_close_socket (sitter->socket_to_babysitter, NULL);
- sitter->socket_to_babysitter = -1;
-}
-
-static void
-close_error_pipe_from_child (DBusBabysitter *sitter)
-{
- _dbus_verbose ("Closing child error\n");
- _dbus_close_socket (sitter->error_pipe_from_child, NULL);
- sitter->error_pipe_from_child = -1;
-}
-
-static void
-handle_babysitter_socket (DBusBabysitter *sitter,
- int revents)
-{
- /* Even if we have POLLHUP, we want to keep reading
- * data until POLLIN goes away; so this function only
- * looks at HUP/ERR if no IN is set.
- */
- if (revents & _DBUS_POLLIN)
- {
- _dbus_verbose ("Reading data from babysitter\n");
- if (read_data (sitter, sitter->socket_to_babysitter) != READ_STATUS_OK)
- close_socket_to_babysitter (sitter);
- }
- else if (revents & (_DBUS_POLLERR | _DBUS_POLLHUP))
- {
- close_socket_to_babysitter (sitter);
- }
-}
-
-static void
-handle_error_pipe (DBusBabysitter *sitter,
- int revents)
-{
- if (revents & _DBUS_POLLIN)
- {
- _dbus_verbose ("Reading data from child error\n");
- if (read_data (sitter, sitter->error_pipe_from_child) != READ_STATUS_OK)
- close_error_pipe_from_child (sitter);
- }
- else if (revents & (_DBUS_POLLERR | _DBUS_POLLHUP))
- {
- close_error_pipe_from_child (sitter);
- }
-}
-
-/* returns whether there were any poll events handled */
-static dbus_bool_t
-babysitter_iteration (DBusBabysitter *sitter,
- dbus_bool_t block)
-{
- DBusPollFD fds[2];
- int i;
- dbus_bool_t descriptors_ready;
-
- descriptors_ready = FALSE;
-
- i = 0;
-
- if (sitter->error_pipe_from_child >= 0)
- {
- fds[i].fd = sitter->error_pipe_from_child;
- fds[i].events = _DBUS_POLLIN;
- fds[i].revents = 0;
- ++i;
- }
-
- if (sitter->socket_to_babysitter >= 0)
- {
- fds[i].fd = sitter->socket_to_babysitter;
- fds[i].events = _DBUS_POLLIN;
- fds[i].revents = 0;
- ++i;
- }
-
- if (i > 0)
- {
- int ret;
-
- do
- {
- ret = _dbus_poll (fds, i, 0);
- }
- while (ret < 0 && errno == EINTR);
-
- if (ret == 0 && block)
- {
- do
- {
- ret = _dbus_poll (fds, i, -1);
- }
- while (ret < 0 && errno == EINTR);
- }
-
- if (ret > 0)
- {
- descriptors_ready = TRUE;
-
- while (i > 0)
- {
- --i;
- if (fds[i].fd == sitter->error_pipe_from_child)
- handle_error_pipe (sitter, fds[i].revents);
- else if (fds[i].fd == sitter->socket_to_babysitter)
- handle_babysitter_socket (sitter, fds[i].revents);
- }
- }
- }
-
- return descriptors_ready;
-}
-
-/**
- * Macro returns #TRUE if the babysitter still has live sockets open to the
- * babysitter child or the grandchild.
- */
-#define LIVE_CHILDREN(sitter) ((sitter)->socket_to_babysitter >= 0 || (sitter)->error_pipe_from_child >= 0)
-
-/**
- * Blocks until the babysitter process gives us the PID of the spawned grandchild,
- * then kills the spawned grandchild.
- *
- * @param sitter the babysitter object
- */
-void
-_dbus_babysitter_kill_child (DBusBabysitter *sitter)
-{
- /* be sure we have the PID of the child */
- while (LIVE_CHILDREN (sitter) &&
- sitter->grandchild_pid == -1)
- babysitter_iteration (sitter, TRUE);
-
- _dbus_verbose ("Got child PID %ld for killing\n",
- (long) sitter->grandchild_pid);
-
- if (sitter->grandchild_pid == -1)
- return; /* child is already dead, or we're so hosed we'll never recover */
-
- kill (sitter->grandchild_pid, SIGKILL);
-}
-
-/**
- * Checks whether the child has exited, without blocking.
- *
- * @param sitter the babysitter
- */
-dbus_bool_t
-_dbus_babysitter_get_child_exited (DBusBabysitter *sitter)
-{
-
- /* Be sure we're up-to-date */
- while (LIVE_CHILDREN (sitter) &&
- babysitter_iteration (sitter, FALSE))
- ;
-
- /* We will have exited the babysitter when the child has exited */
- return sitter->socket_to_babysitter < 0;
-}
-
-/**
- * Gets the exit status of the child. We do this so implementation specific
- * detail is not cluttering up dbus, for example the system launcher code.
- * This can only be called if the child has exited, i.e. call
- * _dbus_babysitter_get_child_exited(). It returns FALSE if the child
- * did not return a status code, e.g. because the child was signaled
- * or we failed to ever launch the child in the first place.
- *
- * @param sitter the babysitter
- * @param status the returned status code
- * @returns #FALSE on failure
- */
-dbus_bool_t
-_dbus_babysitter_get_child_exit_status (DBusBabysitter *sitter,
- int *status)
-{
- if (!_dbus_babysitter_get_child_exited (sitter))
- _dbus_assert_not_reached ("Child has not exited");
-
- if (!sitter->have_child_status ||
- !(WIFEXITED (sitter->status)))
- return FALSE;
-
- *status = WEXITSTATUS (sitter->status);
- return TRUE;
-}
-
-/**
- * Sets the #DBusError with an explanation of why the spawned
- * child process exited (on a signal, or whatever). If
- * the child process has not exited, does nothing (error
- * will remain unset).
- *
- * @param sitter the babysitter
- * @param error an error to fill in
- */
-void
-_dbus_babysitter_set_child_exit_error (DBusBabysitter *sitter,
- DBusError *error)
-{
- if (!_dbus_babysitter_get_child_exited (sitter))
- return;
-
- /* Note that if exec fails, we will also get a child status
- * from the babysitter saying the child exited,
- * so we need to give priority to the exec error
- */
- if (sitter->have_exec_errnum)
- {
- dbus_set_error (error, DBUS_ERROR_SPAWN_EXEC_FAILED,
- "Failed to execute program %s: %s",
- sitter->executable, _dbus_strerror (sitter->errnum));
- }
- else if (sitter->have_fork_errnum)
- {
- dbus_set_error (error, DBUS_ERROR_NO_MEMORY,
- "Failed to fork a new process %s: %s",
- sitter->executable, _dbus_strerror (sitter->errnum));
- }
- else if (sitter->have_child_status)
- {
- if (WIFEXITED (sitter->status))
- dbus_set_error (error, DBUS_ERROR_SPAWN_CHILD_EXITED,
- "Process %s exited with status %d",
- sitter->executable, WEXITSTATUS (sitter->status));
- else if (WIFSIGNALED (sitter->status))
- dbus_set_error (error, DBUS_ERROR_SPAWN_CHILD_SIGNALED,
- "Process %s received signal %d",
- sitter->executable, WTERMSIG (sitter->status));
- else
- dbus_set_error (error, DBUS_ERROR_FAILED,
- "Process %s exited abnormally",
- sitter->executable);
- }
- else
- {
- dbus_set_error (error, DBUS_ERROR_FAILED,
- "Process %s exited, reason unknown",
- sitter->executable);
- }
-}
-
-/**
- * Sets watch functions to notify us when the
- * babysitter object needs to read/write file descriptors.
- *
- * @param sitter the babysitter
- * @param add_function function to begin monitoring a new descriptor.
- * @param remove_function function to stop monitoring a descriptor.
- * @param toggled_function function to notify when the watch is enabled/disabled
- * @param data data to pass to add_function and remove_function.
- * @param free_data_function function to be called to free the data.
- * @returns #FALSE on failure (no memory)
- */
-dbus_bool_t
-_dbus_babysitter_set_watch_functions (DBusBabysitter *sitter,
- DBusAddWatchFunction add_function,
- DBusRemoveWatchFunction remove_function,
- DBusWatchToggledFunction toggled_function,
- void *data,
- DBusFreeFunction free_data_function)
-{
- return _dbus_watch_list_set_functions (sitter->watches,
- add_function,
- remove_function,
- toggled_function,
- data,
- free_data_function);
-}
-
-static dbus_bool_t
-handle_watch (DBusWatch *watch,
- unsigned int condition,
- void *data)
-{
- DBusBabysitter *sitter = data;
- int revents;
- int fd;
-
- revents = 0;
- if (condition & DBUS_WATCH_READABLE)
- revents |= _DBUS_POLLIN;
- if (condition & DBUS_WATCH_ERROR)
- revents |= _DBUS_POLLERR;
- if (condition & DBUS_WATCH_HANGUP)
- revents |= _DBUS_POLLHUP;
-
- fd = dbus_watch_get_socket (watch);
-
- if (fd == sitter->error_pipe_from_child)
- handle_error_pipe (sitter, revents);
- else if (fd == sitter->socket_to_babysitter)
- handle_babysitter_socket (sitter, revents);
-
- while (LIVE_CHILDREN (sitter) &&
- babysitter_iteration (sitter, FALSE))
- ;
-
- return TRUE;
-}
-
-/** Helps remember which end of the pipe is which */
-#define READ_END 0
-/** Helps remember which end of the pipe is which */
-#define WRITE_END 1
-
-
-/* Avoids a danger in threaded situations (calling close()
- * on a file descriptor twice, and another thread has
- * re-opened it since the first close)
- */
-static int
-close_and_invalidate (int *fd)
-{
- int ret;
-
- if (*fd < 0)
- return -1;
- else
- {
- ret = _dbus_close_socket (*fd, NULL);
- *fd = -1;
- }
-
- return ret;
-}
-
-static dbus_bool_t
-make_pipe (int p[2],
- DBusError *error)
-{
- _DBUS_ASSERT_ERROR_IS_CLEAR (error);
-
- if (pipe (p) < 0)
- {
- dbus_set_error (error,
- DBUS_ERROR_SPAWN_FAILED,
- "Failed to create pipe for communicating with child process (%s)",
- _dbus_strerror (errno));
- return FALSE;
- }
-
- return TRUE;
-}
-
-static void
-do_write (int fd, const void *buf, size_t count)
-{
- size_t bytes_written;
- int ret;
-
- bytes_written = 0;
-
- again:
-
- ret = write (fd, ((const char*)buf) + bytes_written, count - bytes_written);
-
- if (ret < 0)
- {
- if (errno == EINTR)
- goto again;
- else
- {
- _dbus_warn ("Failed to write data to pipe!\n");
- exit (1); /* give up, we suck */
- }
- }
- else
- bytes_written += ret;
-
- if (bytes_written < count)
- goto again;
-}
-
-static void
-write_err_and_exit (int fd, int msg)
-{
- int en = errno;
-
- do_write (fd, &msg, sizeof (msg));
- do_write (fd, &en, sizeof (en));
-
- exit (1);
-}
-
-static void
-write_pid (int fd, pid_t pid)
-{
- int msg = CHILD_PID;
-
- do_write (fd, &msg, sizeof (msg));
- do_write (fd, &pid, sizeof (pid));
-}
-
-static void
-write_status_and_exit (int fd, int status)
-{
- int msg = CHILD_EXITED;
-
- do_write (fd, &msg, sizeof (msg));
- do_write (fd, &status, sizeof (status));
-
- exit (0);
-}
-
-static void
-do_exec (int child_err_report_fd,
- char **argv,
- char **envp,
- DBusSpawnChildSetupFunc child_setup,
- void *user_data)
-{
-#ifdef DBUS_BUILD_TESTS
- int i, max_open;
-#endif
-
- _dbus_verbose_reset ();
- _dbus_verbose ("Child process has PID " DBUS_PID_FORMAT "\n",
- _dbus_getpid ());
-
- if (child_setup)
- (* child_setup) (user_data);
-
-#ifdef DBUS_BUILD_TESTS
- max_open = sysconf (_SC_OPEN_MAX);
-
- for (i = 3; i < max_open; i++)
- {
- int retval;
-
- if (i == child_err_report_fd)
- continue;
-
- retval = fcntl (i, F_GETFD);
-
- if (retval != -1 && !(retval & FD_CLOEXEC))
- _dbus_warn ("Fd %d did not have the close-on-exec flag set!\n", i);
- }
-#endif
-
- if (envp == NULL)
- {
- _dbus_assert (environ != NULL);
-
- envp = environ;
- }
-
- execve (argv[0], argv, envp);
-
- /* Exec failed */
- write_err_and_exit (child_err_report_fd,
- CHILD_EXEC_FAILED);
-}
-
-static void
-check_babysit_events (pid_t grandchild_pid,
- int parent_pipe,
- int revents)
-{
- pid_t ret;
- int status;
-
- do
- {
- ret = waitpid (grandchild_pid, &status, WNOHANG);
- /* The man page says EINTR can't happen with WNOHANG,
- * but there are reports of it (maybe only with valgrind?)
- */
- }
- while (ret < 0 && errno == EINTR);
-
- if (ret == 0)
- {
- _dbus_verbose ("no child exited\n");
-
- ; /* no child exited */
- }
- else if (ret < 0)
- {
- /* This isn't supposed to happen. */
- _dbus_warn ("unexpected waitpid() failure in check_babysit_events(): %s\n",
- _dbus_strerror (errno));
- exit (1);
- }
- else if (ret == grandchild_pid)
- {
- /* Child exited */
- _dbus_verbose ("reaped child pid %ld\n", (long) ret);
-
- write_status_and_exit (parent_pipe, status);
- }
- else
- {
- _dbus_warn ("waitpid() reaped pid %d that we've never heard of\n",
- (int) ret);
- exit (1);
- }
-
- if (revents & _DBUS_POLLIN)
- {
- _dbus_verbose ("babysitter got POLLIN from parent pipe\n");
- }
-
- if (revents & (_DBUS_POLLERR | _DBUS_POLLHUP))
- {
- /* Parent is gone, so we just exit */
- _dbus_verbose ("babysitter got POLLERR or POLLHUP from parent\n");
- exit (0);
- }
-}
-
-static int babysit_sigchld_pipe = -1;
-
-static void
-babysit_signal_handler (int signo)
-{
- char b = '\0';
- again:
- if (write (babysit_sigchld_pipe, &b, 1) <= 0)
- if (errno == EINTR)
- goto again;
-}
-
-static void
-babysit (pid_t grandchild_pid,
- int parent_pipe)
-{
- int sigchld_pipe[2];
-
- /* We don't exec, so we keep parent state, such as the pid that
- * _dbus_verbose() uses. Reset the pid here.
- */
- _dbus_verbose_reset ();
-
- /* I thought SIGCHLD would just wake up the poll, but
- * that didn't seem to work, so added this pipe.
- * Probably the pipe is more likely to work on busted
- * operating systems anyhow.
- */
- if (pipe (sigchld_pipe) < 0)
- {
- _dbus_warn ("Not enough file descriptors to create pipe in babysitter process\n");
- exit (1);
- }
-
- babysit_sigchld_pipe = sigchld_pipe[WRITE_END];
-
- _dbus_set_signal_handler (SIGCHLD, babysit_signal_handler);
-
- write_pid (parent_pipe, grandchild_pid);
-
- check_babysit_events (grandchild_pid, parent_pipe, 0);
-
- while (TRUE)
- {
- DBusPollFD pfds[2];
-
- pfds[0].fd = parent_pipe;
- pfds[0].events = _DBUS_POLLIN;
- pfds[0].revents = 0;
-
- pfds[1].fd = sigchld_pipe[READ_END];
- pfds[1].events = _DBUS_POLLIN;
- pfds[1].revents = 0;
-
- if (_dbus_poll (pfds, _DBUS_N_ELEMENTS (pfds), -1) < 0 && errno != EINTR)
- {
- _dbus_warn ("_dbus_poll() error: %s\n", strerror (errno));
- exit (1);
- }
-
- if (pfds[0].revents != 0)
- {
- check_babysit_events (grandchild_pid, parent_pipe, pfds[0].revents);
- }
- else if (pfds[1].revents & _DBUS_POLLIN)
- {
- char b;
- read (sigchld_pipe[READ_END], &b, 1);
- /* do waitpid check */
- check_babysit_events (grandchild_pid, parent_pipe, 0);
- }
- }
-
- exit (1);
-}
-
-/**
- * Spawns a new process. The executable name and argv[0]
- * are the same, both are provided in argv[0]. The child_setup
- * function is passed the given user_data and is run in the child
- * just before calling exec().
- *
- * Also creates a "babysitter" which tracks the status of the
- * child process, advising the parent if the child exits.
- * If the spawn fails, no babysitter is created.
- * If sitter_p is #NULL, no babysitter is kept.
- *
- * @param sitter_p return location for babysitter or #NULL
- * @param argv the executable and arguments
- * @param env the environment (not used on unix yet)
- * @param child_setup function to call in child pre-exec()
- * @param user_data user data for setup function
- * @param error error object to be filled in if function fails
- * @returns #TRUE on success, #FALSE if error is filled in
- */
-dbus_bool_t
-_dbus_spawn_async_with_babysitter (DBusBabysitter **sitter_p,
- char **argv,
- char **env,
- DBusSpawnChildSetupFunc child_setup,
- void *user_data,
- DBusError *error)
-{
- DBusBabysitter *sitter;
- int child_err_report_pipe[2] = { -1, -1 };
- int babysitter_pipe[2] = { -1, -1 };
- pid_t pid;
-
- _DBUS_ASSERT_ERROR_IS_CLEAR (error);
-
- if (sitter_p != NULL)
- *sitter_p = NULL;
-
- sitter = NULL;
-
- sitter = _dbus_babysitter_new ();
- if (sitter == NULL)
- {
- dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
- return FALSE;
- }
-
- sitter->executable = _dbus_strdup (argv[0]);
- if (sitter->executable == NULL)
- {
- dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
- goto cleanup_and_fail;
- }
-
- if (!make_pipe (child_err_report_pipe, error))
- goto cleanup_and_fail;
-
- _dbus_fd_set_close_on_exec (child_err_report_pipe[READ_END]);
- _dbus_fd_set_close_on_exec (child_err_report_pipe[WRITE_END]);
-
- if (!_dbus_full_duplex_pipe (&babysitter_pipe[0], &babysitter_pipe[1], TRUE, error))
- goto cleanup_and_fail;
-
- _dbus_fd_set_close_on_exec (babysitter_pipe[0]);
- _dbus_fd_set_close_on_exec (babysitter_pipe[1]);
-
- /* Setting up the babysitter is only useful in the parent,
- * but we don't want to run out of memory and fail
- * after we've already forked, since then we'd leak
- * child processes everywhere.
- */
- sitter->error_watch = _dbus_watch_new (child_err_report_pipe[READ_END],
- DBUS_WATCH_READABLE,
- TRUE, handle_watch, sitter, NULL);
- if (sitter->error_watch == NULL)
- {
- dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
- goto cleanup_and_fail;
- }
-
- if (!_dbus_watch_list_add_watch (sitter->watches, sitter->error_watch))
- {
- dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
- goto cleanup_and_fail;
- }
-
- sitter->sitter_watch = _dbus_watch_new (babysitter_pipe[0],
- DBUS_WATCH_READABLE,
- TRUE, handle_watch, sitter, NULL);
- if (sitter->sitter_watch == NULL)
- {
- dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
- goto cleanup_and_fail;
- }
-
- if (!_dbus_watch_list_add_watch (sitter->watches, sitter->sitter_watch))
- {
- dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
- goto cleanup_and_fail;
- }
-
- _DBUS_ASSERT_ERROR_IS_CLEAR (error);
-
- pid = fork ();
-
- if (pid < 0)
- {
- dbus_set_error (error,
- DBUS_ERROR_SPAWN_FORK_FAILED,
- "Failed to fork (%s)",
- _dbus_strerror (errno));
- goto cleanup_and_fail;
- }
- else if (pid == 0)
- {
- /* Immediate child, this is the babysitter process. */
- int grandchild_pid;
-
- /* Be sure we crash if the parent exits
- * and we write to the err_report_pipe
- */
- signal (SIGPIPE, SIG_DFL);
-
- /* Close the parent's end of the pipes. */
- close_and_invalidate (&child_err_report_pipe[READ_END]);
- close_and_invalidate (&babysitter_pipe[0]);
-
- /* Create the child that will exec () */
- grandchild_pid = fork ();
-
- if (grandchild_pid < 0)
- {
- write_err_and_exit (babysitter_pipe[1],
- CHILD_FORK_FAILED);
- _dbus_assert_not_reached ("Got to code after write_err_and_exit()");
- }
- else if (grandchild_pid == 0)
- {
- do_exec (child_err_report_pipe[WRITE_END],
- argv,
- env,
- child_setup, user_data);
- _dbus_assert_not_reached ("Got to code after exec() - should have exited on error");
- }
- else
- {
- babysit (grandchild_pid, babysitter_pipe[1]);
- _dbus_assert_not_reached ("Got to code after babysit()");
- }
- }
- else
- {
- /* Close the uncared-about ends of the pipes */
- close_and_invalidate (&child_err_report_pipe[WRITE_END]);
- close_and_invalidate (&babysitter_pipe[1]);
-
- sitter->socket_to_babysitter = babysitter_pipe[0];
- babysitter_pipe[0] = -1;
-
- sitter->error_pipe_from_child = child_err_report_pipe[READ_END];
- child_err_report_pipe[READ_END] = -1;
-
- sitter->sitter_pid = pid;
-
- if (sitter_p != NULL)
- *sitter_p = sitter;
- else
- _dbus_babysitter_unref (sitter);
-
- dbus_free_string_array (env);
-
- _DBUS_ASSERT_ERROR_IS_CLEAR (error);
-
- return TRUE;
- }
-
- cleanup_and_fail:
-
- _DBUS_ASSERT_ERROR_IS_SET (error);
-
- close_and_invalidate (&child_err_report_pipe[READ_END]);
- close_and_invalidate (&child_err_report_pipe[WRITE_END]);
- close_and_invalidate (&babysitter_pipe[0]);
- close_and_invalidate (&babysitter_pipe[1]);
-
- if (sitter != NULL)
- _dbus_babysitter_unref (sitter);
-
- return FALSE;
-}
-
-/** @} */
-
-#ifdef DBUS_BUILD_TESTS
-
-static void
-_dbus_babysitter_block_for_child_exit (DBusBabysitter *sitter)
-{
- while (LIVE_CHILDREN (sitter))
- babysitter_iteration (sitter, TRUE);
-}
-
-static dbus_bool_t
-check_spawn_nonexistent (void *data)
-{
- char *argv[4] = { NULL, NULL, NULL, NULL };
- DBusBabysitter *sitter = NULL;
- DBusError error = DBUS_ERROR_INIT;
-
- /*** Test launching nonexistent binary */
-
- argv[0] = "/this/does/not/exist/32542sdgafgafdg";
- if (_dbus_spawn_async_with_babysitter (&sitter, argv,
- NULL, NULL, NULL,
- &error))
- {
- _dbus_babysitter_block_for_child_exit (sitter);
- _dbus_babysitter_set_child_exit_error (sitter, &error);
- }
-
- if (sitter)
- _dbus_babysitter_unref (sitter);
-
- if (!dbus_error_is_set (&error))
- {
- _dbus_warn ("Did not get an error launching nonexistent executable\n");
- return FALSE;
- }
-
- if (!(dbus_error_has_name (&error, DBUS_ERROR_NO_MEMORY) ||
- dbus_error_has_name (&error, DBUS_ERROR_SPAWN_EXEC_FAILED)))
- {
- _dbus_warn ("Not expecting error when launching nonexistent executable: %s: %s\n",
- error.name, error.message);
- dbus_error_free (&error);
- return FALSE;
- }
-
- dbus_error_free (&error);
-
- return TRUE;
-}
-
-static dbus_bool_t
-check_spawn_segfault (void *data)
-{
- char *argv[4] = { NULL, NULL, NULL, NULL };
- DBusBabysitter *sitter = NULL;
- DBusError error = DBUS_ERROR_INIT;
-
- /*** Test launching segfault binary */
-
- argv[0] = TEST_SEGFAULT_BINARY;
- if (_dbus_spawn_async_with_babysitter (&sitter, argv,
- NULL, NULL, NULL,
- &error))
- {
- _dbus_babysitter_block_for_child_exit (sitter);
- _dbus_babysitter_set_child_exit_error (sitter, &error);
- }
-
- if (sitter)
- _dbus_babysitter_unref (sitter);
-
- if (!dbus_error_is_set (&error))
- {
- _dbus_warn ("Did not get an error launching segfaulting binary\n");
- return FALSE;
- }
-
- if (!(dbus_error_has_name (&error, DBUS_ERROR_NO_MEMORY) ||
- dbus_error_has_name (&error, DBUS_ERROR_SPAWN_CHILD_SIGNALED)))
- {
- _dbus_warn ("Not expecting error when launching segfaulting executable: %s: %s\n",
- error.name, error.message);
- dbus_error_free (&error);
- return FALSE;
- }
-
- dbus_error_free (&error);
-
- return TRUE;
-}
-
-static dbus_bool_t
-check_spawn_exit (void *data)
-{
- char *argv[4] = { NULL, NULL, NULL, NULL };
- DBusBabysitter *sitter = NULL;
- DBusError error = DBUS_ERROR_INIT;
-
- /*** Test launching exit failure binary */
-
- argv[0] = TEST_EXIT_BINARY;
- if (_dbus_spawn_async_with_babysitter (&sitter, argv,
- NULL, NULL, NULL,
- &error))
- {
- _dbus_babysitter_block_for_child_exit (sitter);
- _dbus_babysitter_set_child_exit_error (sitter, &error);
- }
-
- if (sitter)
- _dbus_babysitter_unref (sitter);
-
- if (!dbus_error_is_set (&error))
- {
- _dbus_warn ("Did not get an error launching binary that exited with failure code\n");
- return FALSE;
- }
-
- if (!(dbus_error_has_name (&error, DBUS_ERROR_NO_MEMORY) ||
- dbus_error_has_name (&error, DBUS_ERROR_SPAWN_CHILD_EXITED)))
- {
- _dbus_warn ("Not expecting error when launching exiting executable: %s: %s\n",
- error.name, error.message);
- dbus_error_free (&error);
- return FALSE;
- }
-
- dbus_error_free (&error);
-
- return TRUE;
-}
-
-static dbus_bool_t
-check_spawn_and_kill (void *data)
-{
- char *argv[4] = { NULL, NULL, NULL, NULL };
- DBusBabysitter *sitter = NULL;
- DBusError error = DBUS_ERROR_INIT;
-
- /*** Test launching sleeping binary then killing it */
-
- argv[0] = TEST_SLEEP_FOREVER_BINARY;
- if (_dbus_spawn_async_with_babysitter (&sitter, argv,
- NULL, NULL, NULL,
- &error))
- {
- _dbus_babysitter_kill_child (sitter);
-
- _dbus_babysitter_block_for_child_exit (sitter);
-
- _dbus_babysitter_set_child_exit_error (sitter, &error);
- }
-
- if (sitter)
- _dbus_babysitter_unref (sitter);
-
- if (!dbus_error_is_set (&error))
- {
- _dbus_warn ("Did not get an error after killing spawned binary\n");
- return FALSE;
- }
-
- if (!(dbus_error_has_name (&error, DBUS_ERROR_NO_MEMORY) ||
- dbus_error_has_name (&error, DBUS_ERROR_SPAWN_CHILD_SIGNALED)))
- {
- _dbus_warn ("Not expecting error when killing executable: %s: %s\n",
- error.name, error.message);
- dbus_error_free (&error);
- return FALSE;
- }
-
- dbus_error_free (&error);
-
- return TRUE;
-}
-
-dbus_bool_t
-_dbus_spawn_test (const char *test_data_dir)
-{
- if (!_dbus_test_oom_handling ("spawn_nonexistent",
- check_spawn_nonexistent,
- NULL))
- return FALSE;
-
- if (!_dbus_test_oom_handling ("spawn_segfault",
- check_spawn_segfault,
- NULL))
- return FALSE;
-
- if (!_dbus_test_oom_handling ("spawn_exit",
- check_spawn_exit,
- NULL))
- return FALSE;
-
- if (!_dbus_test_oom_handling ("spawn_and_kill",
- check_spawn_and_kill,
- NULL))
- return FALSE;
-
- return TRUE;
-}
-#endif
projects / monky / blobdiff