diff options
Diffstat (limited to 'debianutils/start_stop_daemon.c')
| -rw-r--r-- | debianutils/start_stop_daemon.c | 66 |
1 files changed, 44 insertions, 22 deletions
diff --git a/debianutils/start_stop_daemon.c b/debianutils/start_stop_daemon.c index 43b6fca..fa08f48 100644 --- a/debianutils/start_stop_daemon.c +++ b/debianutils/start_stop_daemon.c @@ -409,7 +409,7 @@ int start_stop_daemon_main(int argc UNUSED_PARAM, char **argv) { unsigned opt; char *signame; - char *startas; + char *startas = NULL; char *chuid; #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY // char *retry_arg = NULL; @@ -425,10 +425,11 @@ int start_stop_daemon_main(int argc UNUSED_PARAM, char **argv) /* -K or -S is required; they are mutually exclusive */ /* -p is required if -m is given */ /* -xpun (at least one) is required if -K is given */ - /* -xa (at least one) is required if -S is given */ +// /* -xa (at least one) is required if -S is given */ +//WRONG: "start-stop-daemon -S -- sleep 5" is a valid invocation /* -q turns off -v */ "\0" - "K:S:K--S:S--K:m?p:K?xpun:S?xa" + "K:S:K--S:S--K:m?p:K?xpun" IF_FEATURE_START_STOP_DAEMON_FANCY("q-v"), LONGOPTS &startas, &cmdname, &signame, &userspec, &chuid, &execname, &pidfile @@ -442,21 +443,34 @@ int start_stop_daemon_main(int argc UNUSED_PARAM, char **argv) if (signal_nr < 0) bb_show_usage(); } - if (!(opt & OPT_a)) - startas = execname; - if (!execname) /* in case -a is given and -x is not */ + //argc -= optind; + argv += optind; +// ARGS contains zeroth arg if -x/-a is not given, else it starts with 1st arg. +// These will try to execute "[/bin/]sleep 5": +// "start-stop-daemon -S -- sleep 5" +// "start-stop-daemon -S -x /bin/sleep -- 5" +// "start-stop-daemon -S -a sleep -- 5" +// NB: -n option does _not_ behave in this way: this will try to execute "5": +// "start-stop-daemon -S -n sleep -- 5" + if (!execname) { /* -x is not given */ execname = startas; - if (execname) { - G.execname_sizeof = strlen(execname) + 1; - G.execname_cmpbuf = xmalloc(G.execname_sizeof + 1); + if (!execname) { /* neither -x nor -a is given */ + execname = argv[0]; + if (!execname) + bb_show_usage(); + argv++; + } } + if (!startas) /* -a is not given: use -x EXECUTABLE or argv[0] */ + startas = execname; + *--argv = startas; + G.execname_sizeof = strlen(execname) + 1; + G.execname_cmpbuf = xmalloc(G.execname_sizeof + 1); // IF_FEATURE_START_STOP_DAEMON_FANCY( // if (retry_arg) // retries = xatoi_positive(retry_arg); // ) - //argc -= optind; - argv += optind; if (userspec) { user_id = bb_strtou(userspec, NULL, 10); @@ -473,7 +487,7 @@ int start_stop_daemon_main(int argc UNUSED_PARAM, char **argv) if (G.found_procs) { if (!QUIET) - printf("%s is already running\n%u\n", execname, (unsigned)G.found_procs->pid); + printf("%s is already running\n", execname); return !(opt & OPT_OKNODO); } @@ -482,30 +496,37 @@ int start_stop_daemon_main(int argc UNUSED_PARAM, char **argv) xstat(execname, &G.execstat); #endif - *--argv = startas; if (opt & OPT_BACKGROUND) { -#if BB_MMU - bb_daemonize(DAEMON_DEVNULL_STDIO + DAEMON_CLOSE_EXTRA_FDS + DAEMON_DOUBLE_FORK); - /* DAEMON_DEVNULL_STDIO is superfluous - - * it's always done by bb_daemonize() */ -#else /* Daemons usually call bb_daemonize_or_rexec(), but SSD can do * without: SSD is not itself a daemon, it _execs_ a daemon. * The usual NOMMU problem of "child can't run indefinitely, * it must exec" does not bite us: we exec anyway. + * + * bb_daemonize(DAEMON_DEVNULL_STDIO | DAEMON_CLOSE_EXTRA_FDS | DAEMON_DOUBLE_FORK) + * can be used on MMU systems, but use of vfork() + * is preferable since we want to create pidfile + * _before_ parent returns, and vfork() on Linux + * ensures that (by blocking parent until exec in the child). */ pid_t pid = xvfork(); if (pid != 0) { - /* parent */ + /* Parent */ /* why _exit? the child may have changed the stack, - * so "return 0" may do bad things */ + * so "return 0" may do bad things + */ _exit(EXIT_SUCCESS); } /* Child */ setsid(); /* detach from controlling tty */ /* Redirect stdio to /dev/null, close extra FDs */ bb_daemon_helper(DAEMON_DEVNULL_STDIO + DAEMON_CLOSE_EXTRA_FDS); -#endif + /* On Linux, session leader can acquire ctty + * unknowingly, by opening a tty. + * Prevent this: stop being a session leader. + */ + pid = xvfork(); + if (pid != 0) + _exit(EXIT_SUCCESS); /* Parent */ } if (opt & OPT_MAKEPID) { /* User wants _us_ to make the pidfile */ @@ -534,6 +555,7 @@ int start_stop_daemon_main(int argc UNUSED_PARAM, char **argv) } } #endif - execvp(startas, argv); +//bb_error_msg("HERE %d '%s'%s'", __LINE__, argv[0], argv[1]); + execvp(argv[0], argv); bb_perror_msg_and_die("can't execute '%s'", startas); } |