diff options
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | dbus/Makefile.am | 2 | ||||
| -rw-r--r-- | dbus/dbus-spawn.c | 339 | ||||
| -rw-r--r-- | dbus/dbus-spawn.h | 35 | ||||
| -rw-r--r-- | dbus/dbus-sysdeps.c | 301 | ||||
| -rw-r--r-- | dbus/dbus-sysdeps.h | 3 |
6 files changed, 385 insertions, 301 deletions
@@ -1,3 +1,9 @@ +2003-04-03 Havoc Pennington <hp@pobox.com> + + * dbus/dbus-spawn.c: Move dbus-spawn into a separate file + in preparation for modifying it, dbus-sysdeps is getting + a bit unmanageable. + 2003-04-03 Havoc Pennington <hp@redhat.com> * bus/loop.h, bus/loop.c: make the mainloop an object so we can diff --git a/dbus/Makefile.am b/dbus/Makefile.am index 27293807..2065e75e 100644 --- a/dbus/Makefile.am +++ b/dbus/Makefile.am @@ -84,6 +84,8 @@ UTIL_SOURCES= \ dbus-mempool.h \ dbus-message-builder.c \ dbus-message-builder.h \ + dbus-spawn.c \ + dbus-spawn.h \ dbus-string.c \ dbus-string.h \ dbus-string-private.h \ diff --git a/dbus/dbus-spawn.c b/dbus/dbus-spawn.c new file mode 100644 index 00000000..27fb6e6c --- /dev/null +++ b/dbus/dbus-spawn.c @@ -0,0 +1,339 @@ +/* -*- mode: C; c-file-style: "gnu" -*- */ +/* dbus-spawn.c Wrapper around fork/exec + * + * Copyright (C) 2002, 2003 Red Hat, Inc. + * Copyright (C) 2003 CodeFactory AB + * + * Licensed under the Academic Free License version 1.2 + * + * 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.h" +#include "dbus-internals.h" + +#include <unistd.h> +#include <fcntl.h> +#include <signal.h> +#include <sys/wait.h> +#include <errno.h> + +/** + * @addtogroup DBusInternalsUtils + * @{ + */ + +/* 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; +} + + +/** @} */ diff --git a/dbus/dbus-spawn.h b/dbus/dbus-spawn.h new file mode 100644 index 00000000..04348d75 --- /dev/null +++ b/dbus/dbus-spawn.h @@ -0,0 +1,35 @@ +/* -*- mode: C; c-file-style: "gnu" -*- */ +/* dbus-spawn.h Wrapper around fork/exec + * + * Copyright (C) 2002, 2003 Red Hat, Inc. + * Copyright (C) 2003 CodeFactory AB + * + * Licensed under the Academic Free License version 1.2 + * + * 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 + * + */ + +#ifndef DBUS_SPAWN_H +#define DBUS_SPAWN_H + +#include <dbus/dbus-string.h> +#include <dbus/dbus-errors.h> + +DBUS_BEGIN_DECLS; + +DBUS_END_DECLS; + +#endif /* DBUS_SPAWN_H */ 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 <unistd.h> #include <stdio.h> #include <errno.h> -#include <unistd.h> #include <fcntl.h> #include <sys/socket.h> #include <dirent.h> @@ -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); */ diff --git a/dbus/dbus-sysdeps.h b/dbus/dbus-sysdeps.h index 113db5eb..5057f521 100644 --- a/dbus/dbus-sysdeps.h +++ b/dbus/dbus-sysdeps.h @@ -1,7 +1,8 @@ /* -*- mode: C; c-file-style: "gnu" -*- */ /* dbus-sysdeps.h Wrappers around system/libc features (internal to D-BUS implementation) * - * Copyright (C) 2002 Red Hat, Inc. + * Copyright (C) 2002, 2003 Red Hat, Inc. + * Copyright (C) 2003 CodeFactory AB * * Licensed under the Academic Free License version 1.2 * |