diff options
Diffstat (limited to 'tools/dbus-launch.c')
| -rw-r--r-- | tools/dbus-launch.c | 187 |
1 files changed, 142 insertions, 45 deletions
diff --git a/tools/dbus-launch.c b/tools/dbus-launch.c index bbaac2c3..7ecee63e 100644 --- a/tools/dbus-launch.c +++ b/tools/dbus-launch.c @@ -43,6 +43,47 @@ extern Display *xdisplay; #endif +/* PROCESSES + * + * If you are in a shell and run "dbus-launch myapp", here is what happens: + * + * shell [*] + * \- main() --exec--> myapp[*] + * \- "intermediate parent" + * \- bus-runner --exec--> dbus-daemon --fork + * \- babysitter[*] \- final dbus-daemon[*] + * + * Processes marked [*] survive the initial flurry of activity. + * + * If you run "dbus-launch --sh-syntax" then the diagram is the same, except + * that main() prints variables and exits 0 instead of exec'ing myapp. + * + * PIPES + * + * dbus-daemon --print-pid -> bus_pid_to_launcher_pipe -> main + * dbus-daemon --print-address -> bus_address_to_launcher_pipe -> main + * main -> bus_pid_to_babysitter_pipe -> babysitter + * + * The intermediate parent looks pretty useless at first glance. Its purpose + * is to avoid the bus-runner becoming a zombie: when the intermediate parent + * terminates, the bus-runner and babysitter are reparented to init, which + * reaps them if they have finished. We can't rely on main() to reap arbitrary + * children because it might exec myapp, after which it can't be relied on to + * reap its children. We *can* rely on main() to reap the intermediate parent, + * because that happens before it execs myapp. + * + * It's unclear why dbus-daemon needs to fork, but we explicitly tell it to + * for some reason, then wait for it. If we left it undefined, a forking + * dbus-daemon would get the parent process reparented to init and reaped + * when the intermediate parent terminated, and a non-forking dbus-daemon + * would get reparented to init and carry on there. + * + * myapp is exec'd by the process that initially ran main() so that it's + * the shell's child, so the shell knows how to do job control and stuff. + * This is desirable for the "dbus-launch an application" use-case, less so + * for the "dbus-launch a test suite in an isolated session" use-case. + */ + static char* machine_uuid = NULL; const char* @@ -64,6 +105,7 @@ save_machine_uuid (const char *uuid_arg) machine_uuid = xstrdup (uuid_arg); } +#ifdef DBUS_BUILD_X11 #define UUID_MAXLEN 40 /* Read the machine uuid from file if needed. Returns TRUE if machine_uuid is * set after this function */ @@ -90,7 +132,7 @@ read_machine_uuid_if_needed (void) goto out; /* rstrip the read uuid */ - while (len > 31 && isspace(uuid[len - 1])) + while (len > 31 && isspace((int) uuid[len - 1])) len--; if (len != 32) @@ -105,12 +147,13 @@ out: fclose(f); return ret; } - +#endif /* DBUS_BUILD_X11 */ void verbose (const char *format, ...) { +#ifdef DBUS_ENABLE_VERBOSE_MODE va_list args; static int verbose = TRUE; static int verbose_initted = FALSE; @@ -135,12 +178,16 @@ verbose (const char *format, va_start (args, format); vfprintf (stderr, format, args); va_end (args); +#endif /* DBUS_ENABLE_VERBOSE_MODE */ } static void usage (int ecode) { - fprintf (stderr, "dbus-launch [--version] [--help] [--sh-syntax] [--csh-syntax] [--auto-syntax] [--exit-with-session]\n"); + fprintf (stderr, "dbus-launch [--version] [--help] [--sh-syntax]" + " [--csh-syntax] [--auto-syntax] [--binary-syntax] [--close-stderr]" + " [--exit-with-session] [--autolaunch=MACHINEID]" + " [--config-file=FILENAME] [PROGRAM] [ARGS...]\n"); exit (ecode); } @@ -175,6 +222,26 @@ xstrdup (const char *str) return copy; } +static char * +concat2 (const char *a, + const char *b) +{ + size_t la, lb; + char *ret; + + la = strlen (a); + lb = strlen (b); + + ret = malloc (la + lb + 1); + + if (ret == NULL) + return NULL; + + memcpy (ret, a, la); + memcpy (ret + la, b, lb + 1); + return ret; +} + typedef enum { READ_STATUS_OK, /**< Read succeeded */ @@ -404,9 +471,7 @@ signal_handler (int sig) { switch (sig) { -#ifdef SIGHUP case SIGHUP: -#endif case SIGINT: case SIGTERM: got_sighup = TRUE; @@ -451,11 +516,20 @@ kill_bus_when_session_ends (void) else tty_fd = -1; - if (tty_fd >= 0) - verbose ("stdin isatty(), monitoring it\n"); + if (x_fd >= 0) + { + verbose ("session lifetime is defined by X, not monitoring stdin\n"); + tty_fd = -1; + } + else if (tty_fd >= 0) + { + verbose ("stdin isatty(), monitoring it\n"); + } else - verbose ("stdin was not a TTY, not monitoring it\n"); - + { + verbose ("stdin was not a TTY, not monitoring it\n"); + } + if (tty_fd < 0 && x_fd < 0) { fprintf (stderr, "No terminal on standard input and no X display; cannot attach message bus to session lifetime\n"); @@ -583,6 +657,7 @@ babysit (int exit_with_session, s = getenv ("DBUS_DEBUG_OUTPUT"); if (s == NULL || *s == '\0') dup2 (dev_null_fd, 2); + close (dev_null_fd); } else { @@ -704,31 +779,35 @@ pass_info (const char *runprog, const char *bus_address, pid_t bus_pid, if (envvar == NULL || args == NULL) goto oom; - args[0] = xstrdup (runprog); + args[0] = xstrdup (runprog); if (!args[0]) goto oom; - for (i = 1; i <= (argc-remaining_args); i++) - { - size_t len = strlen (argv[remaining_args+i-1])+1; - args[i] = malloc (len); - if (!args[i]) - goto oom; - strncpy (args[i], argv[remaining_args+i-1], len); - } - args[i] = NULL; + for (i = 1; i <= (argc-remaining_args); i++) + { + size_t len = strlen (argv[remaining_args+i-1])+1; + args[i] = malloc (len); + if (!args[i]) + { + while (i > 1) + free (args[--i]); + goto oom; + } + strncpy (args[i], argv[remaining_args+i-1], len); + } + args[i] = NULL; - strcpy (envvar, "DBUS_SESSION_BUS_ADDRESS="); - strcat (envvar, bus_address); - putenv (envvar); + strcpy (envvar, "DBUS_SESSION_BUS_ADDRESS="); + strcat (envvar, bus_address); + putenv (envvar); - execvp (runprog, args); - fprintf (stderr, "Couldn't exec %s: %s\n", runprog, strerror (errno)); - exit (1); + execvp (runprog, args); + fprintf (stderr, "Couldn't exec %s: %s\n", runprog, strerror (errno)); + exit (1); } else { print_variables (bus_address, bus_pid, bus_wid, c_shell_syntax, - bourne_shell_syntax, binary_syntax); + bourne_shell_syntax, binary_syntax); } verbose ("dbus-launch exiting\n"); @@ -1049,24 +1128,41 @@ main (int argc, char **argv) verbose ("Calling exec()\n"); -#ifdef DBUS_BUILD_TESTS - /* exec from testdir */ - if (getenv("DBUS_USE_TEST_BINARY") != NULL) - { - execl (TEST_BUS_BINARY, - TEST_BUS_BINARY, - "--fork", - "--print-pid", write_pid_fd_as_string, - "--print-address", write_address_fd_as_string, - config_file ? "--config-file" : "--session", - config_file, /* has to be last in this varargs list */ - NULL); - - fprintf (stderr, - "Failed to execute test message bus daemon %s: %s. Will try again with the system path.\n", - TEST_BUS_BINARY, strerror (errno)); - } - #endif /* DBUS_BUILD_TESTS */ +#ifdef DBUS_ENABLE_EMBEDDED_TESTS + { + const char *test_daemon; + /* exec from testdir */ + if (getenv ("DBUS_USE_TEST_BINARY") != NULL && + (test_daemon = getenv ("DBUS_TEST_DAEMON")) != NULL) + { + if (config_file == NULL && getenv ("DBUS_TEST_DATA") != NULL) + { + config_file = concat2 (getenv ("DBUS_TEST_DATA"), + "/valid-config-files/session.conf"); + + if (config_file == NULL) + { + fprintf (stderr, "Out of memory\n"); + exit (1); + } + } + + execl (test_daemon, + test_daemon, + "--fork", + "--print-pid", write_pid_fd_as_string, + "--print-address", write_address_fd_as_string, + config_file ? "--config-file" : "--session", + config_file, /* has to be last in this varargs list */ + NULL); + + fprintf (stderr, + "Failed to execute test message bus daemon %s: %s.\n", + test_daemon, strerror (errno)); + exit (1); + } + } + #endif /* DBUS_ENABLE_EMBEDDED_TESTS */ execl (DBUS_DAEMONDIR"/dbus-daemon", DBUS_DAEMONDIR"/dbus-daemon", @@ -1111,7 +1207,6 @@ main (int argc, char **argv) char *end; long wid = 0; long val; - int ret2; verbose ("=== Parent dbus-launch continues\n"); @@ -1185,6 +1280,8 @@ main (int argc, char **argv) #ifdef DBUS_ENABLE_X11_AUTOLAUNCH if (xdisplay != NULL) { + int ret2; + verbose("Saving x11 address\n"); ret2 = x11_save_address (bus_address, bus_pid, &wid); /* Only get an existing dbus session when autolaunching */ |