27 #include "dbus-spawn.h"    28 #include "dbus-sysdeps-unix.h"    29 #include "dbus-internals.h"    30 #include "dbus-test.h"    31 #include "dbus-protocol.h"    45 #include <systemd/sd-journal.h>    48 extern char **environ;
    80   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
    89       to_read = 
sizeof (int) * n_ints_in_buf - bytes;
   100       if (chunk < 0 && errno == EINTR)
   107                           "Failed to read from child pipe (%s)",
   108                           _dbus_strerror (errno));
   122   *n_ints_read = (int)(bytes / 
sizeof(
int));
   135   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
   144       to_read = 
sizeof (pid_t) - bytes;
   152                     ((
char*)buf) + bytes,
   154       if (chunk < 0 && errno == EINTR)
   161                           "Failed to read from child pipe (%s)",
   162                           _dbus_strerror (errno));
   257   DBusBabysitterFinishedFunc finished_cb;
   268 _dbus_babysitter_new (
void)
   276   sitter->refcount = 1;
   307   sitter->refcount += 1;
   329   sitter->refcount -= 1;
   330   if (sitter->refcount == 0)
   339       close_socket_to_babysitter (sitter);
   341       close_error_pipe_from_child (sitter);
   352           ret = waitpid (sitter->
sitter_pid, &status, WNOHANG);
   364                   ret = waitpid (sitter->
sitter_pid, &status, 0);
   366               while (_DBUS_UNLIKELY (ret < 0 && errno == EINTR));
   372                 _dbus_warn (
"Babysitter process not available to be reaped; should not happen\n");
   374                 _dbus_warn (
"Unexpected error %d in waitpid() for babysitter: %s\n",
   375                             errno, _dbus_strerror (errno));
   379               _dbus_verbose (
"Reaped %ld, waiting for babysitter %ld\n",
   382               if (WIFEXITED (sitter->
status))
   383                 _dbus_verbose (
"Babysitter exited with status %d\n",
   384                                WEXITSTATUS (sitter->
status));
   385               else if (WIFSIGNALED (sitter->
status))
   386                 _dbus_verbose (
"Babysitter received signal %d\n",
   387                                WTERMSIG (sitter->
status));
   389                 _dbus_verbose (
"Babysitter exited abnormally\n");
   413   r = read_ints (fd, &what, 1, &got, &error);
   434         case CHILD_FORK_FAILED:
   435         case CHILD_EXEC_FAILED:
   439             r = read_ints (fd, &arg, 1, &got, &error);
   455                 if (what == CHILD_EXITED)
   474                     sitter->have_child_status = 
TRUE;
   476                     _dbus_verbose (
"recorded child status exited = %d signaled = %d exitstatus = %d termsig = %d\n",
   477                                    WIFEXITED (sitter->
status), WIFSIGNALED (sitter->
status),
   478                                    WEXITSTATUS (sitter->
status), WTERMSIG (sitter->
status));
   480                 else if (what == CHILD_FORK_FAILED)
   484                     _dbus_verbose (
"recorded fork errnum %d\n", sitter->
errnum);
   486                 else if (what == CHILD_EXEC_FAILED)
   490                     _dbus_verbose (
"recorded exec errnum %d\n", sitter->
errnum);
   499             r = read_pid (fd, &pid, &error);
   515             _dbus_verbose (
"recorded grandchild pid %d\n", sitter->
grandchild_pid);
   519           _dbus_warn (
"Unknown message received from babysitter process\n");
   530   _dbus_verbose (
"Closing babysitter\n");
   551   _dbus_verbose (
"Closing child error\n");
   579       _dbus_verbose (
"Reading data from babysitter\n");
   581         close_socket_to_babysitter (sitter);
   585       close_socket_to_babysitter (sitter);
   595       _dbus_verbose (
"Reading data from child error\n");
   597         close_error_pipe_from_child (sitter);
   601       close_error_pipe_from_child (sitter);
   614   descriptors_ready = 
FALSE;
   642       while (ret < 0 && errno == EINTR);
   644       if (ret == 0 && block)
   650           while (ret < 0 && errno == EINTR);
   655           descriptors_ready = 
TRUE;
   661                 handle_error_pipe (sitter, fds[i].revents);
   663                 handle_babysitter_socket (sitter, fds[i].revents);
   668   return descriptors_ready;
   675 #define LIVE_CHILDREN(sitter) ((sitter)->socket_to_babysitter.fd >= 0 || (sitter)->error_pipe_from_child >= 0)   689     babysitter_iteration (sitter, 
TRUE);
   691   _dbus_verbose (
"Got child PID %ld for killing\n",
   711          babysitter_iteration (sitter, 
FALSE))
   737   if (!sitter->have_child_status ||
   738       !(WIFEXITED (sitter->
status)))
   741   *status = WEXITSTATUS (sitter->
status);
   768                       "Failed to execute program %s: %s",
   774                       "Failed to fork a new process %s: %s",
   777   else if (sitter->have_child_status)
   779       if (WIFEXITED (sitter->
status))
   781                         "Process %s exited with status %d",
   783       else if (WIFSIGNALED (sitter->
status))
   785                         "Process %s received signal %d",
   789                         "Process %s exited abnormally",
   795                       "Process %s exited, reason unknown",
   830               unsigned int     condition,
   848     handle_error_pipe (sitter, revents);
   850     handle_babysitter_socket (sitter, revents);
   853          babysitter_iteration (sitter, 
FALSE))
   862       sitter->finished_cb != 
NULL)
   864       sitter->finished_cb (sitter, sitter->finished_data);
   865       sitter->finished_cb = 
NULL;
   888 close_and_invalidate (
int *fd)
   912   retval = pipe2 (p, O_CLOEXEC);
   913   cloexec_done = retval >= 0;
   917   if (retval < 0 && errno == ENOSYS)
   923   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
   929                       "Failed to create pipe for communicating with child process (%s)",
   930                       _dbus_strerror (errno));
   946 do_write (
int fd, 
const void *buf, 
size_t count)
   948   size_t bytes_written;
   955   ret = write (fd, ((
const char*)buf) + bytes_written, count - bytes_written);
   963           _dbus_warn (
"Failed to write data to pipe!\n");
   968     bytes_written += ret;
   970   if (bytes_written < count)
   975 write_err_and_exit (
int fd, 
int msg)
   979   do_write (fd, &msg, 
sizeof (msg));
   980   do_write (fd, &en, 
sizeof (en));
   986 write_pid (
int fd, pid_t pid)
   990   do_write (fd, &msg, 
sizeof (msg));
   991   do_write (fd, &pid, 
sizeof (pid));
   995 write_status_and_exit (
int fd, 
int status)
   997   int msg = CHILD_EXITED;
   999   do_write (fd, &msg, 
sizeof (msg));
  1000   do_write (fd, &status, 
sizeof (status));
  1006 do_exec (
int                       child_err_report_fd,
  1009          DBusSpawnChildSetupFunc   child_setup,
  1012 #ifdef DBUS_ENABLE_EMBEDDED_TESTS  1016   _dbus_verbose_reset ();
  1021     (* child_setup) (user_data);
  1023 #ifdef DBUS_ENABLE_EMBEDDED_TESTS  1024   max_open = sysconf (_SC_OPEN_MAX);
  1026   for (i = 3; i < max_open; i++)
  1030       if (i == child_err_report_fd)
  1033       retval = fcntl (i, F_GETFD);
  1035       if (retval != -1 && !(retval & FD_CLOEXEC))
  1036         _dbus_warn (
"Fd %d did not have the close-on-exec flag set!\n", i);
  1047   execve (argv[0], argv, envp);
  1050   write_err_and_exit (child_err_report_fd,
  1069   while (ret < 0 && errno == EINTR);
  1073       _dbus_verbose (
"no child exited\n");
  1080       _dbus_warn (
"unexpected waitpid() failure in check_babysit_events(): %s\n",
  1081                   _dbus_strerror (errno));
  1087       _dbus_verbose (
"reaped child pid %ld\n", (
long) ret);
  1089       write_status_and_exit (parent_pipe, status);
  1093       _dbus_warn (
"waitpid() reaped pid %d that we've never heard of\n",
  1100       _dbus_verbose (
"babysitter got POLLIN from parent pipe\n");
  1106       _dbus_verbose (
"babysitter got POLLERR or POLLHUP from parent\n");
  1111 static int babysit_sigchld_pipe = -1;
  1114 babysit_signal_handler (
int signo)
  1118   if (write (babysit_sigchld_pipe, &b, 1) <= 0) 
  1127   int sigchld_pipe[2];
  1132   _dbus_verbose_reset ();
  1139   if (pipe (sigchld_pipe) < 0)
  1141       _dbus_warn (
"Not enough file descriptors to create pipe in babysitter process\n");
  1145   babysit_sigchld_pipe = sigchld_pipe[
WRITE_END];
  1157       pfds[0].
fd = parent_pipe;
  1167           _dbus_warn (
"_dbus_poll() error: %s\n", strerror (errno));
  1171       if (pfds[0].revents != 0)
  1173           check_babysit_events (
grandchild_pid, parent_pipe, pfds[0].revents);
  1178           if (read (sigchld_pipe[
READ_END], &b, 1) == -1)
  1214                                    DBusSpawnChildSetupFunc   child_setup,
  1219   int child_err_report_pipe[2] = { -1, -1 };
  1220   DBusSocket babysitter_pipe[2] = { DBUS_SOCKET_INIT, DBUS_SOCKET_INIT };
  1227   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  1230   if (sitter_p != 
NULL)
  1235   sitter = _dbus_babysitter_new ();
  1246       goto cleanup_and_fail;
  1255       goto cleanup_and_fail;
  1258   if (!make_pipe (child_err_report_pipe, error))
  1259     goto cleanup_and_fail;
  1262     goto cleanup_and_fail;
  1275       goto cleanup_and_fail;
  1287       goto cleanup_and_fail;
  1296       goto cleanup_and_fail;
  1308       goto cleanup_and_fail;
  1311   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  1318   fd_out = sd_journal_stream_fd (sitter->
log_name, LOG_INFO, 
FALSE);
  1319   fd_err = sd_journal_stream_fd (sitter->
log_name, LOG_WARNING, 
FALSE);
  1328                       "Failed to fork (%s)",
  1329                       _dbus_strerror (errno));
  1330       goto cleanup_and_fail;
  1340       signal (SIGPIPE, SIG_DFL);
  1343       close_and_invalidate (&child_err_report_pipe[READ_END]);
  1344       close_and_invalidate (&babysitter_pipe[0].fd);
  1347       grandchild_pid = fork ();
  1349       if (grandchild_pid < 0)
  1351           write_err_and_exit (babysitter_pipe[1].fd,
  1355       else if (grandchild_pid == 0)
  1361           fd = open (
"/proc/self/oom_score_adj", O_WRONLY | O_CLOEXEC);
  1366               fd = open (
"/proc/self/oom_score_adj", O_WRONLY);
  1372               if (write (fd, 
"0", 
sizeof (
char)) < 0)
  1373                 _dbus_warn (
"writing oom_score_adj error: %s\n", strerror (errno));
  1379           signal (SIGPIPE, SIG_IGN);
  1381           close_and_invalidate (&babysitter_pipe[1].fd);
  1385             dup2 (fd_out, STDOUT_FILENO);
  1387             dup2 (fd_err, STDERR_FILENO);
  1388           close_and_invalidate (&fd_out);
  1389           close_and_invalidate (&fd_err);
  1391           do_exec (child_err_report_pipe[
WRITE_END],
  1394                    child_setup, user_data);
  1399           close_and_invalidate (&child_err_report_pipe[
WRITE_END]);
  1401           close_and_invalidate (&fd_out);
  1402           close_and_invalidate (&fd_err);
  1404           babysit (grandchild_pid, babysitter_pipe[1].fd);
  1411       close_and_invalidate (&child_err_report_pipe[
WRITE_END]);
  1412       close_and_invalidate (&babysitter_pipe[1].fd);
  1414       close_and_invalidate (&fd_out);
  1415       close_and_invalidate (&fd_err);
  1419       babysitter_pipe[0].fd = -1;
  1422       child_err_report_pipe[
READ_END] = -1;
  1426       if (sitter_p != 
NULL)
  1433       _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  1440   _DBUS_ASSERT_ERROR_IS_SET (error);
  1442   close_and_invalidate (&child_err_report_pipe[READ_END]);
  1443   close_and_invalidate (&child_err_report_pipe[
WRITE_END]);
  1444   close_and_invalidate (&babysitter_pipe[0].fd);
  1445   close_and_invalidate (&babysitter_pipe[1].fd);
  1447   close_and_invalidate (&fd_out);
  1448   close_and_invalidate (&fd_err);
  1459                                        DBusBabysitterFinishedFunc  finished,
  1462   sitter->finished_cb = finished;
  1463   sitter->finished_data = user_data;
  1468 #ifdef DBUS_ENABLE_EMBEDDED_TESTS  1471 get_test_exec (
const char *exe,
  1474   const char *dbus_test_exec;
  1478   if (dbus_test_exec == 
NULL)
  1479     dbus_test_exec = DBUS_TEST_EXEC;
  1485                                    dbus_test_exec, exe, DBUS_EXEEXT))
  1491   return _dbus_string_get_data (scratch_space);
  1498     babysitter_iteration (sitter, 
TRUE);
  1502 check_spawn_nonexistent (
void *data)
  1510   argv[0] = 
"/this/does/not/exist/32542sdgafgafdg";
  1515       _dbus_babysitter_block_for_child_exit (sitter);
  1524       _dbus_warn (
"Did not get an error launching nonexistent executable\n");
  1531       _dbus_warn (
"Not expecting error when launching nonexistent executable: %s: %s\n",
  1543 check_spawn_segfault (
void *data)
  1552   argv[0] = get_test_exec (
"test-segfault", &argv0);
  1554   if (argv[0] == NULL)
  1564       _dbus_babysitter_block_for_child_exit (sitter);
  1575       _dbus_warn (
"Did not get an error launching segfaulting binary\n");
  1582       _dbus_warn (
"Not expecting error when launching segfaulting executable: %s: %s\n",
  1594 check_spawn_exit (
void *data)
  1603   argv[0] = get_test_exec (
"test-exit", &argv0);
  1605   if (argv[0] == NULL)
  1615       _dbus_babysitter_block_for_child_exit (sitter);
  1626       _dbus_warn (
"Did not get an error launching binary that exited with failure code\n");
  1633       _dbus_warn (
"Not expecting error when launching exiting executable: %s: %s\n",
  1645 check_spawn_and_kill (
void *data)
  1654   argv[0] = get_test_exec (
"test-sleep-forever", &argv0);
  1656   if (argv[0] == NULL)
  1668       _dbus_babysitter_block_for_child_exit (sitter);
  1680       _dbus_warn (
"Did not get an error after killing spawned binary\n");
  1687       _dbus_warn (
"Not expecting error when killing executable: %s: %s\n",
  1699 _dbus_spawn_test (
const char *test_data_dir)
  1701   if (!_dbus_test_oom_handling (
"spawn_nonexistent",
  1702                                 check_spawn_nonexistent,
  1706   if (!_dbus_test_oom_handling (
"spawn_segfault",
  1707                                 check_spawn_segfault,
  1711   if (!_dbus_test_oom_handling (
"spawn_exit",
  1716   if (!_dbus_test_oom_handling (
"spawn_and_kill",
  1717                                 check_spawn_and_kill,
 dbus_bool_t dbus_error_has_name(const DBusError *error, const char *name)
Checks whether the error is set and has the given name. 
const char * message
public error message field 
#define DBUS_ERROR_SPAWN_FAILED
While starting a new process, something went wrong. 
DBusWatch * _dbus_watch_new(DBusPollable fd, unsigned int flags, dbus_bool_t enabled, DBusWatchHandler handler, void *data, DBusFreeFunction free_data_function)
Creates a new DBusWatch. 
Implementation of DBusWatch. 
#define NULL
A null pointer, defined appropriately for C or C++. 
#define DBUS_ERROR_SPAWN_EXEC_FAILED
While starting a new process, the exec() call failed. 
void(* DBusFreeFunction)(void *memory)
The type of a function which frees a block of memory. 
#define LIVE_CHILDREN(sitter)
Macro returns TRUE if the babysitter still has live sockets open to the babysitter child or the grand...
#define _DBUS_POLLHUP
Hung up. 
unsigned int have_exec_errnum
True if we have an error code from exec() 
void dbus_free(void *memory)
Frees a block of memory previously allocated by dbus_malloc() or dbus_malloc0(). 
DBusWatch * error_watch
Error pipe watch. 
dbus_bool_t _dbus_socketpair(DBusSocket *fd1, DBusSocket *fd2, dbus_bool_t blocking, DBusError *error)
Creates pair of connect sockets (as in socketpair()). 
#define DBUS_PID_FORMAT
an appropriate printf format for dbus_pid_t 
void(* DBusWatchToggledFunction)(DBusWatch *watch, void *data)
Called when dbus_watch_get_enabled() may return a different value than it did before. 
#define DBUS_ERROR_SPAWN_CHILD_EXITED
While starting a new process, the child exited with a status code. 
int status
Exit status code. 
#define _dbus_assert(condition)
Aborts with an error message if the condition is false. 
#define DBUS_ERROR_INIT
Expands to a suitable initializer for a DBusError on the stack. 
void dbus_error_free(DBusError *error)
Frees an error that's been set (or just initialized), then reinitializes the error as in dbus_error_i...
void _dbus_watch_list_free(DBusWatchList *watch_list)
Frees a DBusWatchList. 
dbus_pid_t _dbus_getpid(void)
Gets our process ID. 
#define _DBUS_POLLIN
There is data to read. 
DBusWatchList * _dbus_watch_list_new(void)
Creates a new watch list. 
dbus_bool_t _dbus_string_init(DBusString *str)
Initializes a string. 
short events
Events to poll for. 
dbus_bool_t _dbus_close_socket(DBusSocket fd, DBusError *error)
Closes a socket. 
dbus_bool_t _dbus_babysitter_get_child_exited(DBusBabysitter *sitter)
Checks whether the child has exited, without blocking. 
dbus_bool_t _dbus_watch_list_set_functions(DBusWatchList *watch_list, DBusAddWatchFunction add_function, DBusRemoveWatchFunction remove_function, DBusWatchToggledFunction toggled_function, void *data, DBusFreeFunction free_data_function)
Sets the watch functions. 
DBusWatchList * watches
Watches. 
#define DBUS_ERROR_SPAWN_CHILD_SIGNALED
While starting a new process, the child exited on a signal. 
#define dbus_new0(type, count)
Safe macro for using dbus_malloc0(). 
dbus_uint32_t dbus_bool_t
A boolean, valid values are TRUE and FALSE. 
DBusWatch * sitter_watch
Sitter pipe watch. 
DBUS_EXPORT int dbus_watch_get_socket(DBusWatch *watch)
Returns a socket to be watched, on UNIX this will return -1 if our transport is not socket-based so d...
dbus_bool_t _dbus_babysitter_get_child_exit_status(DBusBabysitter *sitter, int *status)
Gets the exit status of the child. 
void _dbus_babysitter_kill_child(DBusBabysitter *sitter)
Blocks until the babysitter process gives us the PID of the spawned grandchild, then kills the spawne...
Babysitter implementation details. 
ReadStatus
Enumeration for status of a read() 
dbus_bool_t _dbus_spawn_async_with_babysitter(DBusBabysitter **sitter_p, const char *log_name, char **argv, char **env, DBusSpawnChildSetupFunc child_setup, void *user_data, DBusError *error)
Spawns a new process. 
void _dbus_warn(const char *format,...)
Prints a warning message to stderr. 
pid_t sitter_pid
PID Of the babysitter. 
dbus_bool_t _dbus_string_append_printf(DBusString *str, const char *format,...)
Appends a printf-style formatted string to the DBusString. 
void _dbus_watch_invalidate(DBusWatch *watch)
Clears the file descriptor from a now-invalid watch object so that no one tries to use it...
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)
Sets watch functions to notify us when the babysitter object needs to read/write file descriptors...
Object representing an exception. 
void dbus_set_error(DBusError *error, const char *name, const char *format,...)
Assigns an error name and message to a DBusError. 
pid_t grandchild_pid
PID of the grandchild. 
#define _DBUS_N_ELEMENTS(array)
Computes the number of elements in a fixed-size array using sizeof(). 
int refcount
Reference count. 
unsigned int have_child_status
True if child status has been reaped. 
As in POLLERR (can't watch for this, but can be present in current state passed to dbus_watch_handle(...
void _dbus_string_free(DBusString *str)
Frees a string created by _dbus_string_init(). 
#define TRUE
Expands to "1". 
DBusPollable fd
File descriptor. 
#define _dbus_assert_not_reached(explanation)
Aborts with an error message if called. 
As in POLLHUP (can't watch for it, but can be present in current state passed to dbus_watch_handle())...
#define DBUS_ERROR_FAILED
A generic error; "something went wrong" - see the error message for more. 
dbus_bool_t _dbus_watch_list_add_watch(DBusWatchList *watch_list, DBusWatch *watch)
Adds a new watch to the watch list, invoking the application DBusAddWatchFunction if appropriate...
const char * name
public error name field 
dbus_bool_t(* DBusAddWatchFunction)(DBusWatch *watch, void *data)
Called when libdbus needs a new watch to be monitored by the main loop. 
#define READ_END
Helps remember which end of the pipe is which. 
void(* DBusRemoveWatchFunction)(DBusWatch *watch, void *data)
Called when libdbus no longer needs a watch to be monitored by the main loop. 
DBusWatchList implementation details. 
void _dbus_fd_set_close_on_exec(int fd)
Sets the file descriptor to be close on exec. 
void _dbus_watch_list_remove_watch(DBusWatchList *watch_list, DBusWatch *watch)
Removes a watch from the watch list, invoking the application's DBusRemoveWatchFunction if appropriat...
void _dbus_babysitter_unref(DBusBabysitter *sitter)
Decrement the reference count on the babysitter object. 
#define DBUS_ERROR_SPAWN_FORK_FAILED
While starting a new process, the fork() call failed. 
void _dbus_set_signal_handler(int sig, DBusSignalHandler handler)
Installs a UNIX signal handler. 
void dbus_free_string_array(char **str_array)
Frees a NULL-terminated array of strings. 
char * log_name
the name under which to log messages about this process being spawned 
void _dbus_watch_unref(DBusWatch *watch)
Decrements the reference count of a DBusWatch object and finalizes the object if the count reaches ze...
#define DBUS_ERROR_NO_MEMORY
There was not enough memory to complete an operation. 
dbus_bool_t _dbus_close(int fd, DBusError *error)
Closes a file descriptor. 
unsigned int have_fork_errnum
True if we have an error code from fork() 
#define FALSE
Expands to "0". 
int error_pipe_from_child
Connection to the process that does the exec() 
DBusSocket socket_to_babysitter
Connection to the babysitter process. 
#define WRITE_END
Helps remember which end of the pipe is which. 
char * _dbus_strdup(const char *str)
Duplicates a string. 
void _dbus_babysitter_set_child_exit_error(DBusBabysitter *sitter, DBusError *error)
Sets the DBusError with an explanation of why the spawned child process exited (on a signal...
const char * _dbus_getenv(const char *varname)
Wrapper for getenv(). 
int _dbus_poll(DBusPollFD *fds, int n_fds, int timeout_milliseconds)
Wrapper for poll(). 
short revents
Events that occurred. 
dbus_bool_t dbus_error_is_set(const DBusError *error)
Checks whether an error occurred (the error is set). 
#define _DBUS_POLLERR
Error condition. 
DBusBabysitter * _dbus_babysitter_ref(DBusBabysitter *sitter)
Increment the reference count on the babysitter object.