From 45d1479fad0fb55f1775c394e696643dad3e8e4d Mon Sep 17 00:00:00 2001 From: Havoc Pennington Date: Fri, 4 Apr 2003 01:55:28 +0000 Subject: 2003-04-03 Havoc Pennington * dbus/dbus-spawn.c: Move dbus-spawn into a separate file in preparation for modifying it, dbus-sysdeps is getting a bit unmanageable. --- dbus/dbus-sysdeps.c | 301 +--------------------------------------------------- 1 file changed, 1 insertion(+), 300 deletions(-) (limited to 'dbus/dbus-sysdeps.c') diff --git a/dbus/dbus-sysdeps.c b/dbus/dbus-sysdeps.c index 17da1fbe..7e635d9d 100644 --- a/dbus/dbus-sysdeps.c +++ b/dbus/dbus-sysdeps.c @@ -2,6 +2,7 @@ /* dbus-sysdeps.c Wrappers around system/libc features (internal to D-BUS implementation) * * Copyright (C) 2002, 2003 Red Hat, Inc. + * Copyright (C) 2003 CodeFactory AB * * Licensed under the Academic Free License version 1.2 * @@ -32,7 +33,6 @@ #include #include #include -#include #include #include #include @@ -2596,305 +2596,6 @@ _dbus_strerror (int error_number) return msg; } -/* 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 = close (*fd); - *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_errno_to_string (errno)); - return FALSE; - } - else - { - _dbus_fd_set_close_on_exec (p[0]); - _dbus_fd_set_close_on_exec (p[1]); - return TRUE; - } -} - -enum -{ - CHILD_CHDIR_FAILED, - CHILD_EXEC_FAILED, - CHILD_DUP2_FAILED, - CHILD_FORK_FAILED -}; - -static void -write_err_and_exit (int fd, int msg) -{ - int en = errno; - - write (fd, &msg, sizeof(msg)); - write (fd, &en, sizeof(en)); - - _exit (1); -} - -static dbus_bool_t -read_ints (int fd, - int *buf, - int n_ints_in_buf, - int *n_ints_read, - DBusError *error) -{ - size_t bytes = 0; - - _DBUS_ASSERT_ERROR_IS_CLEAR (error); - - while (TRUE) - { - size_t chunk; - - if (bytes >= sizeof(int)*2) - break; /* give up, who knows what happened, should not be - * possible. - */ - - again: - chunk = read (fd, - ((char*)buf) + bytes, - sizeof(int) * n_ints_in_buf - bytes); - if (chunk < 0 && errno == EINTR) - goto again; - - if (chunk < 0) - { - /* Some weird shit happened, bail out */ - - dbus_set_error (error, - DBUS_ERROR_SPAWN_FAILED, - "Failed to read from child pipe (%s)", - _dbus_errno_to_string (errno)); - - return FALSE; - } - else if (chunk == 0) - break; /* EOF */ - else /* chunk > 0 */ - bytes += chunk; - } - - *n_ints_read = (int)(bytes / sizeof(int)); - - return TRUE; -} - -static void -do_exec (int child_err_report_fd, - char **argv, - DBusSpawnChildSetupFunc child_setup, - void *user_data) -{ -#ifdef DBUS_BUILD_TESTS - int i, max_open; -#endif - - 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; - - 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 - - execv (argv[0], argv); - - /* Exec failed */ - write_err_and_exit (child_err_report_fd, - CHILD_EXEC_FAILED); - -} - -/** - * 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(). - * - * @todo this code should be reviewed/double-checked as it's fairly - * complex and no one has reviewed it yet. - * - * @param argv the executable and arguments - * @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 (char **argv, - DBusSpawnChildSetupFunc child_setup, - void *user_data, - DBusError *error) -{ - int pid = -1, grandchild_pid; - int child_err_report_pipe[2] = { -1, -1 }; - int status; - - _DBUS_ASSERT_ERROR_IS_CLEAR (error); - - if (!make_pipe (child_err_report_pipe, error)) - return FALSE; - - pid = fork (); - - if (pid < 0) - { - dbus_set_error (error, - DBUS_ERROR_SPAWN_FORK_FAILED, - "Failed to fork (%s)", - _dbus_errno_to_string (errno)); - return FALSE; - } - else if (pid == 0) - { - /* Immediate child. */ - - /* 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; - * not needed in the close_descriptors case, - * though - */ - close_and_invalidate (&child_err_report_pipe[0]); - - /* We need to fork an intermediate child that launches the - * final child. The purpose of the intermediate child - * is to exit, so we can waitpid() it immediately. - * Then the grandchild will not become a zombie. - */ - grandchild_pid = fork (); - - if (grandchild_pid < 0) - { - write_err_and_exit (child_err_report_pipe[1], - CHILD_FORK_FAILED); - } - else if (grandchild_pid == 0) - { - do_exec (child_err_report_pipe[1], - argv, - child_setup, user_data); - } - else - { - _exit (0); - } - } - else - { - /* Parent */ - - int buf[2]; - int n_ints = 0; - - /* Close the uncared-about ends of the pipes */ - close_and_invalidate (&child_err_report_pipe[1]); - - wait_again: - if (waitpid (pid, &status, 0) < 0) - { - if (errno == EINTR) - goto wait_again; - else if (errno == ECHILD) - ; /* do nothing, child already reaped */ - else - _dbus_warn ("waitpid() should not fail in " - "'_dbus_spawn_async'"); - } - - if (!read_ints (child_err_report_pipe[0], - buf, 2, &n_ints, - error)) - goto cleanup_and_fail; - - if (n_ints >= 2) - { - /* Error from the child. */ - switch (buf[0]) - { - default: - dbus_set_error (error, - DBUS_ERROR_SPAWN_FAILED, - "Unknown error executing child process \"%s\"", - argv[0]); - break; - } - - goto cleanup_and_fail; - } - - - /* Success against all odds! return the information */ - close_and_invalidate (&child_err_report_pipe[0]); - - return TRUE; - } - - cleanup_and_fail: - - /* There was an error from the Child, reap the child to avoid it being - a zombie. - */ - if (pid > 0) - { - wait_failed: - if (waitpid (pid, NULL, 0) < 0) - { - if (errno == EINTR) - goto wait_failed; - else if (errno == ECHILD) - ; /* do nothing, child already reaped */ - else - _dbus_warn ("waitpid() should not fail in " - "'_dbus_spawn_async'"); - } - } - - close_and_invalidate (&child_err_report_pipe[0]); - close_and_invalidate (&child_err_report_pipe[1]); - - return FALSE; -} - /** * signal (SIGPIPE, SIG_IGN); */ -- cgit