* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
-#include <paths.h>
-#include "busybox.h" /* for struct bb_applet */
+#include "busybox.h" /* uses applet tables */
/* 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 spawn(char **argv)
+pid_t FAST_FUNC spawn(char **argv)
{
/* Compiler should not optimize stores here */
volatile int failed;
pid_t pid;
-// Ain't it a good place to fflush(NULL)?
+ fflush_all();
/* Be nice to nommu machines. */
failed = 0;
* (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 */
}
/* Die with an error message if we can't spawn a child process. */
-pid_t xspawn(char **argv)
+pid_t FAST_FUNC xspawn(char **argv)
{
pid_t pid = spawn(argv);
if (pid < 0)
- bb_perror_msg_and_die("%s", *argv);
+ bb_simple_perror_msg_and_die(*argv);
return pid;
}
+pid_t FAST_FUNC safe_waitpid(pid_t pid, int *wstat, int options)
+{
+ pid_t r;
+
+ do
+ r = waitpid(pid, wstat, options);
+ while ((r == -1) && (errno == EINTR));
+ return r;
+}
+
+pid_t FAST_FUNC wait_any_nohang(int *wstat)
+{
+ return safe_waitpid(-1, wstat, WNOHANG);
+}
+
// Wait for the specified child PID to exit, returning child's error return.
-int wait4pid(int pid)
+int FAST_FUNC wait4pid(pid_t pid)
{
int status;
/* we expect errno to be already set from failed [v]fork/exec */
return -1;
}
- if (waitpid(pid, &status, 0) == -1)
+ if (safe_waitpid(pid, &status, 0) == -1)
return -1;
if (WIFEXITED(status))
return WEXITSTATUS(status);
return 0;
}
-int wait_nohang(int *wstat)
+#if ENABLE_FEATURE_PREFER_APPLETS
+void FAST_FUNC save_nofork_data(struct nofork_save_area *save)
{
- return waitpid(-1, wstat, WNOHANG);
+ memcpy(&save->die_jmp, &die_jmp, sizeof(die_jmp));
+ save->applet_name = applet_name;
+ save->xfunc_error_retval = xfunc_error_retval;
+ save->option_mask32 = option_mask32;
+ save->die_sleep = die_sleep;
+ save->saved = 1;
}
-int wait_pid(int *wstat, int pid)
+void FAST_FUNC restore_nofork_data(struct nofork_save_area *save)
{
- int r;
-
- do
- r = waitpid(pid, wstat, 0);
- while ((r == -1) && (errno == EINTR));
- return r;
+ memcpy(&die_jmp, &save->die_jmp, sizeof(die_jmp));
+ applet_name = save->applet_name;
+ xfunc_error_retval = save->xfunc_error_retval;
+ option_mask32 = save->option_mask32;
+ die_sleep = save->die_sleep;
}
-int spawn_and_wait(char **argv)
+int FAST_FUNC run_nofork_applet_prime(struct nofork_save_area *old, int applet_no, char **argv)
{
- int rc;
-
-#if ENABLE_FEATURE_EXEC_PREFER_APPLETS
- {
- const struct bb_applet *a = find_applet_by_name(argv[0]);
- if (a && (a->nofork
-#ifndef BB_NOMMU
- || a->noexec /* NOEXEC cannot be used on NOMMU */
-#endif
- )) {
- int argc = 1;
- char **pp = argv;
- while (*++pp)
- argc++;
-#ifndef BB_NOMMU
- if (a->nofork)
+ int rc, argc;
+
+ applet_name = APPLET_NAME(applet_no);
+
+ xfunc_error_retval = EXIT_FAILURE;
+
+ /* Special flag for xfunc_die(). If xfunc will "die"
+ * in NOFORK applet, xfunc_die() sees negative
+ * die_sleep and longjmp here instead. */
+ die_sleep = -1;
+
+ /* In case getopt() or getopt32() was already called:
+ * reset the libc getopt() function, which keeps internal state.
+ *
+ * BSD-derived getopt() functions require that optind be set to 1 in
+ * order to reset getopt() state. This used to be generally accepted
+ * way of resetting getopt(). However, glibc's getopt()
+ * has additional getopt() state beyond optind, and requires that
+ * optind be set to zero to reset its state. So the unfortunate state of
+ * affairs is that BSD-derived versions of getopt() misbehave if
+ * optind is set to 0 in order to reset getopt(), and glibc's getopt()
+ * will core dump if optind is set 1 in order to reset getopt().
+ *
+ * More modern versions of BSD require that optreset be set to 1 in
+ * order to reset getopt(). Sigh. Standards, anyone?
+ */
+#ifdef __GLIBC__
+ optind = 0;
+#else /* BSD style */
+ optind = 1;
+ /* optreset = 1; */
#endif
- {
- int old_sleep = die_sleep;
- int old_x = xfunc_error_retval;
- die_sleep = -1; /* special flag */
- /* xfunc_die() checks for it */
-
- rc = setjmp(die_jmp);
- if (!rc) {
- const struct bb_applet *old_a = current_applet;
- current_applet = a;
- applet_name = a->name;
-// what else should we save/restore?
- rc = a->main(argc, argv);
- current_applet = old_a;
- applet_name = old_a->name;
- } else {
- /* xfunc died in NOFORK applet */
- if (rc == -111)
- rc = 0;
- }
-
- die_sleep = old_sleep;
- xfunc_error_retval = old_x;
- return rc;
- }
-#ifndef BB_NOMMU /* MMU only */
- /* a->noexec is true */
- rc = fork();
- if (rc)
- goto w;
- /* child */
- current_applet = a;
- run_current_applet_and_exit(argc, argv);
-#endif
- }
-
+ /* optarg = NULL; opterr = 1; optopt = 63; - do we need this too? */
+ /* (values above are what they initialized to in glibc and uclibc) */
+ /* option_mask32 = 0; - not needed, no applet depends on it being 0 */
+
+ argc = 1;
+ while (argv[argc])
+ argc++;
+
+ rc = setjmp(die_jmp);
+ if (!rc) {
+ /* Some callers (xargs)
+ * need argv untouched because they free argv[i]! */
+ char *tmp_argv[argc+1];
+ memcpy(tmp_argv, argv, (argc+1) * sizeof(tmp_argv[0]));
+ /* Finally we can call NOFORK applet's main() */
+ rc = applet_main[applet_no](argc, tmp_argv);
+
+ /* The whole reason behind nofork_save_area is that <applet>_main
+ * may exit non-locally! For example, in hush Ctrl-Z tries
+ * (modulo bugs) to dynamically create a child (backgrounded task)
+ * if it detects that Ctrl-Z was pressed when a NOFORK was running.
+ * Testcase: interactive "rm -i".
+ * Don't fool yourself into thinking "and <applet>_main() returns
+ * quickly here" and removing "useless" nofork_save_area code. */
+
+ } else { /* xfunc died in NOFORK applet */
+ /* in case they meant to return 0... */
+ if (rc == -2222)
+ rc = 0;
}
- rc = spawn(argv);
- w:
-#else /* !FEATURE_EXEC_PREFER_APPLETS */
- rc = spawn(argv);
-#endif /* FEATURE_EXEC_PREFER_APPLETS */
- return wait4pid(rc);
-}
+ /* Restoring some globals */
+ restore_nofork_data(old);
-#if 0 //ndef BB_NOMMU
-// Die with an error message if we can't daemonize.
-void xdaemon(int nochdir, int noclose)
-{
- if (daemon(nochdir, noclose))
- bb_perror_msg_and_die("daemon");
-}
+ /* Other globals can be simply reset to defaults */
+#ifdef __GLIBC__
+ optind = 0;
+#else /* BSD style */
+ optind = 1;
#endif
-#if 0 // def BB_NOMMU
-void vfork_daemon_rexec(int nochdir, int noclose, char **argv)
-{
- int fd;
+ return rc & 0xff; /* don't confuse people with "exitcodes" >255 */
+}
- /* Maybe we are already re-execed and come here again? */
- if (re_execed)
- return;
+int FAST_FUNC run_nofork_applet(int applet_no, char **argv)
+{
+ struct nofork_save_area old;
- setsid();
+ /* Saving globals */
+ save_nofork_data(&old);
+ return run_nofork_applet_prime(&old, applet_no, argv);
+}
+#endif /* FEATURE_PREFER_APPLETS */
- if (!nochdir)
- xchdir("/");
+int FAST_FUNC spawn_and_wait(char **argv)
+{
+ int rc;
+#if ENABLE_FEATURE_PREFER_APPLETS
+ int a = find_applet_by_name(argv[0]);
- if (!noclose) {
- /* if "/dev/null" doesn't exist, bail out! */
- fd = xopen(bb_dev_null, O_RDWR);
- dup2(fd, STDIN_FILENO);
- dup2(fd, STDOUT_FILENO);
- dup2(fd, STDERR_FILENO);
- while (fd > 2)
- close(fd--);
+ if (a >= 0 && (APPLET_IS_NOFORK(a)
+#if BB_MMU
+ || APPLET_IS_NOEXEC(a) /* NOEXEC trick needs fork() */
+#endif
+ )) {
+#if BB_MMU
+ if (APPLET_IS_NOFORK(a))
+#endif
+ {
+ return run_nofork_applet(a, argv);
+ }
+#if BB_MMU
+ /* MMU only */
+ /* a->noexec is true */
+ rc = fork();
+ if (rc) /* parent or error */
+ return wait4pid(rc);
+ /* child */
+ xfunc_error_retval = EXIT_FAILURE;
+ run_applet_no_and_exit(a, argv);
+#endif
}
+#endif /* FEATURE_PREFER_APPLETS */
+ rc = spawn(argv);
+ return wait4pid(rc);
+}
- switch (vfork()) {
- case 0: /* child */
- /* Make certain we are not a session leader, or else we
- * might reacquire a controlling terminal */
- if (vfork())
- _exit(0);
- /* High-order bit of first char in argv[0] is a hidden
- * "we have (alrealy) re-execed, don't do it again" flag */
- argv[0][0] |= 0x80;
- execv(CONFIG_BUSYBOX_EXEC_PATH, argv);
- bb_perror_msg_and_die("exec %s", CONFIG_BUSYBOX_EXEC_PATH);
- case -1: /* error */
- bb_perror_msg_and_die("vfork");
- default: /* parent */
- exit(0);
- }
+#if !BB_MMU
+void FAST_FUNC re_exec(char **argv)
+{
+ /* high-order bit of first char in argv[0] is a hidden
+ * "we have (already) re-execed, don't do it again" flag */
+ argv[0][0] |= 0x80;
+ execv(bb_busybox_exec_path, argv);
+ bb_perror_msg_and_die("exec %s", bb_busybox_exec_path);
}
-#endif /* BB_NOMMU */
-#ifdef BB_NOMMU
-void forkexit_or_rexec(char **argv)
+pid_t FAST_FUNC fork_or_rexec(char **argv)
{
pid_t pid;
/* Maybe we are already re-execed and come here again? */
if (re_execed)
- return;
-
+ return 0;
pid = vfork();
if (pid < 0) /* wtf? */
bb_perror_msg_and_die("vfork");
if (pid) /* parent */
- exit(0);
+ return pid;
/* child - re-exec ourself */
- /* high-order bit of first char in argv[0] is a hidden
- * "we have (alrealy) re-execed, don't do it again" flag */
- argv[0][0] |= 0x80;
- execv(CONFIG_BUSYBOX_EXEC_PATH, argv);
- bb_perror_msg_and_die("exec %s", CONFIG_BUSYBOX_EXEC_PATH);
+ re_exec(argv);
}
#else
/* Dance around (void)...*/
-#undef forkexit_or_rexec
-void forkexit_or_rexec(void)
+#undef fork_or_rexec
+pid_t FAST_FUNC fork_or_rexec(void)
{
pid_t pid;
pid = fork();
if (pid < 0) /* wtf? */
bb_perror_msg_and_die("fork");
- if (pid) /* parent */
- exit(0);
- /* child */
+ return pid;
}
-#define forkexit_or_rexec(argv) forkexit_or_rexec()
+#define fork_or_rexec(argv) fork_or_rexec()
#endif
-
/* Due to a #define in libbb.h on MMU systems we actually have 1 argument -
* char **argv "vanishes" */
-void bb_daemonize_or_rexec(int flags, char **argv)
+void FAST_FUNC bb_daemonize_or_rexec(int flags, char **argv)
{
int fd;
- fd = xopen(bb_dev_null, O_RDWR);
-
if (flags & DAEMON_CHDIR_ROOT)
xchdir("/");
close(2);
}
+ fd = open(bb_dev_null, O_RDWR);
+ if (fd < 0) {
+ /* NB: we can be called as bb_sanitize_stdio() from init
+ * or mdev, and there /dev/null may legitimately not (yet) exist!
+ * Do not use xopen above, but obtain _ANY_ open descriptor,
+ * even bogus one as below. */
+ fd = xopen("/", O_RDONLY); /* don't believe this can fail */
+ }
+
while ((unsigned)fd < 2)
fd = dup(fd); /* have 0,1,2 open at least to /dev/null */
if (!(flags & DAEMON_ONLY_SANITIZE)) {
- forkexit_or_rexec(argv);
- /* if daemonizing, make sure we detach from stdio */
+ if (fork_or_rexec(argv))
+ exit(EXIT_SUCCESS); /* parent */
+ /* if daemonizing, make sure we detach from stdio & ctty */
setsid();
dup2(fd, 0);
dup2(fd, 1);
dup2(fd, 2);
}
- if (fd > 2)
+ while (fd > 2) {
close(fd--);
- if (flags & DAEMON_CLOSE_EXTRA_FDS)
- while (fd > 2)
- close(fd--); /* close everything after fd#2 */
+ if (!(flags & DAEMON_CLOSE_EXTRA_FDS))
+ return;
+ /* else close everything after fd#2 */
+ }
}
-void bb_sanitize_stdio(void)
+void FAST_FUNC bb_sanitize_stdio(void)
{
bb_daemonize_or_rexec(DAEMON_ONLY_SANITIZE, NULL);
}
projects / oweals / busybox.git / blobdiff