diff options
Diffstat (limited to 'libbb')
| -rw-r--r-- | libbb/vfork_daemon_rexec.c | 125 |
1 files changed, 69 insertions, 56 deletions
diff --git a/libbb/vfork_daemon_rexec.c b/libbb/vfork_daemon_rexec.c index a349459f0..c96cd61a5 100644 --- a/libbb/vfork_daemon_rexec.c +++ b/libbb/vfork_daemon_rexec.c @@ -14,61 +14,12 @@ * * Licensed under GPLv2 or later, see file LICENSE in this source tree. */ - #include "busybox.h" /* uses applet tables */ #include "NUM_APPLETS.h" -/* This does a fork/exec in one call, using vfork(). Returns PID of new child, - * -1 for failure. Runs argv[0], searching path if that has no / in it. */ -pid_t FAST_FUNC spawn(char **argv) -{ - /* Compiler should not optimize stores here */ - volatile int failed; - pid_t pid; - - fflush_all(); - - /* Be nice to nommu machines. */ - failed = 0; - pid = vfork(); - if (pid < 0) /* error */ - return pid; - if (!pid) { /* child */ - /* This macro is ok - it doesn't do NOEXEC/NOFORK tricks */ - BB_EXECVP(argv[0], argv); - - /* We are (maybe) sharing a stack with blocked parent, - * let parent know we failed and then exit to unblock parent - * (but don't run atexit() stuff, which would screw up parent.) - */ - failed = errno; - /* mount, for example, does not want the message */ - /*bb_perror_msg("can't execute '%s'", argv[0]);*/ - _exit(111); - } - /* parent */ - /* Unfortunately, this is not reliable: according to standards - * vfork() can be equivalent to fork() and we won't see value - * of 'failed'. - * Interested party can wait on pid and learn exit code. - * If 111 - then it (most probably) failed to exec */ - if (failed) { - safe_waitpid(pid, NULL, 0); /* prevent zombie */ - errno = failed; - return -1; - } - return pid; -} - -/* Die with an error message if we can't spawn a child process. */ -pid_t FAST_FUNC xspawn(char **argv) -{ - pid_t pid = spawn(argv); - if (pid < 0) - bb_simple_perror_msg_and_die(*argv); - return pid; -} - +/* + * NOFORK support + */ #if ENABLE_FEATURE_PREFER_APPLETS \ || ENABLE_FEATURE_SH_NOFORK static jmp_buf die_jmp; @@ -127,10 +78,10 @@ int FAST_FUNC run_nofork_applet(int applet_no, char **argv) * reset the libc getopt() function, which keeps internal state. */ GETOPT_RESET(); +//? applet_long_options = NULL; +//? opt_complementary = NULL; - argc = 1; - while (argv[argc]) - argc++; + argc = string_array_len(argv); /* If xfunc "dies" in NOFORK applet, die_func longjmp's here instead */ die_func = jump; @@ -153,11 +104,16 @@ int FAST_FUNC run_nofork_applet(int applet_no, char **argv) restore_nofork_data(&old); /* Other globals can be simply reset to defaults */ GETOPT_RESET(); +//? applet_long_options = NULL; +//? opt_complementary = NULL; return rc & 0xff; /* don't confuse people with "exitcodes" >255 */ } #endif /* FEATURE_PREFER_APPLETS || FEATURE_SH_NOFORK */ +/* + * NOEXEC support + */ #if (NUM_APPLETS > 1) && (ENABLE_FEATURE_PREFER_APPLETS || ENABLE_FEATURE_SH_STANDALONE) void FAST_FUNC run_noexec_applet_and_exit(int a, const char *name, char **argv) { @@ -167,17 +123,74 @@ void FAST_FUNC run_noexec_applet_and_exit(int a, const char *name, char **argv) xfunc_error_retval = EXIT_FAILURE; die_func = NULL; GETOPT_RESET(); +//? applet_long_options = NULL; +//? opt_complementary = NULL; //TODO: think pidof, pgrep, pkill! //set_task_comm() makes our pidof find NOEXECs (e.g. "yes >/dev/null"), //but one from procps-ng-3.3.10 needs more! //Rewrite /proc/PID/cmdline? (need to save argv0 and length at init for this to work!) set_task_comm(name); - /* xfunc_error_retval and applet_name are init by: */ + /* applet_name is set by this function: */ run_applet_no_and_exit(a, name, argv); } #endif +/* + * Higher-level code, hiding optional NOFORK/NOEXEC trickery. + */ + +/* This does a fork/exec in one call, using vfork(). Returns PID of new child, + * -1 for failure. Runs argv[0], searching path if that has no / in it. */ +pid_t FAST_FUNC spawn(char **argv) +{ + /* Compiler should not optimize stores here */ + volatile int failed; + pid_t pid; + + fflush_all(); + + /* Be nice to nommu machines. */ + failed = 0; + pid = vfork(); + if (pid < 0) /* error */ + return pid; + if (!pid) { /* child */ + /* This macro is ok - it doesn't do NOEXEC/NOFORK tricks */ + BB_EXECVP(argv[0], argv); + + /* We are (maybe) sharing a stack with blocked parent, + * let parent know we failed and then exit to unblock parent + * (but don't run atexit() stuff, which would screw up parent.) + */ + failed = errno; + /* mount, for example, does not want the message */ + /*bb_perror_msg("can't execute '%s'", argv[0]);*/ + _exit(111); + } + /* parent */ + /* Unfortunately, this is not reliable: according to standards + * vfork() can be equivalent to fork() and we won't see value + * of 'failed'. + * Interested party can wait on pid and learn exit code. + * If 111 - then it (most probably) failed to exec */ + if (failed) { + safe_waitpid(pid, NULL, 0); /* prevent zombie */ + errno = failed; + return -1; + } + return pid; +} + +/* Die with an error message if we can't spawn a child process. */ +pid_t FAST_FUNC xspawn(char **argv) +{ + pid_t pid = spawn(argv); + if (pid < 0) + bb_simple_perror_msg_and_die(*argv); + return pid; +} + int FAST_FUNC spawn_and_wait(char **argv) { int rc; |