hexedit: position in correct column on "goto" command
[oweals/busybox.git] / debianutils / start_stop_daemon.c
index bc61959d28c736de8737647c006826360c662886..c8b7fa8f21d912b3cfdb0ef735b350cdcb2359da 100644 (file)
@@ -31,7 +31,8 @@ Options controlling process matching
 [TODO: can PROCESS_NAME be a full pathname? Should we require full match then
 with /proc/$PID/exe or argv[0] (comm can't be matched, it never contains path)]
         -x,--exec EXECUTABLE    Look for processes that were started with this
-                                command in /proc/$PID/cmdline.
+                                command in /proc/$PID/exe and /proc/$PID/cmdline
+                                (/proc/$PID/cmdline is a bbox extension)
                                 Unlike -n, we match against the full path:
                                 "ntpd" != "./ntpd" != "/path/to/ntpd"
         -p,--pidfile PID_FILE   Look for processes with PID from this file
@@ -55,49 +56,46 @@ Misc options:
         -q,--quiet              Quiet
         -v,--verbose            Verbose
 */
+//config:config START_STOP_DAEMON
+//config:      bool "start-stop-daemon (12 kb)"
+//config:      default y
+//config:      help
+//config:      start-stop-daemon is used to control the creation and
+//config:      termination of system-level processes, usually the ones
+//config:      started during the startup of the system.
+//config:
+//config:config FEATURE_START_STOP_DAEMON_LONG_OPTIONS
+//config:      bool "Enable long options"
+//config:      default y
+//config:      depends on START_STOP_DAEMON && LONG_OPTS
+//config:
+//config:config FEATURE_START_STOP_DAEMON_FANCY
+//config:      bool "Support additional arguments"
+//config:      default y
+//config:      depends on START_STOP_DAEMON
+//config:      help
+//config:      -o|--oknodo ignored since we exit with 0 anyway
+//config:      -v|--verbose
+//config:      -N|--nicelevel N
+
+//applet:IF_START_STOP_DAEMON(APPLET_ODDNAME(start-stop-daemon, start_stop_daemon, BB_DIR_SBIN, BB_SUID_DROP, start_stop_daemon))
+/* not NOEXEC: uses bb_common_bufsiz1 */
+
+//kbuild:lib-$(CONFIG_START_STOP_DAEMON) += start_stop_daemon.o
 
 //usage:#define start_stop_daemon_trivial_usage
 //usage:       "[OPTIONS] [-S|-K] ... [-- ARGS...]"
 //usage:#define start_stop_daemon_full_usage "\n\n"
 //usage:       "Search for matching processes, and then\n"
-//usage:       "-K: stop all matching processes.\n"
-//usage:       "-S: start a process unless a matching process is found.\n"
-//usage:       IF_FEATURE_START_STOP_DAEMON_LONG_OPTIONS(
-//usage:     "\nProcess matching:"
-//usage:     "\n       -u,--user USERNAME|UID  Match only this user's processes"
-//usage:     "\n       -n,--name NAME          Match processes with NAME"
-//usage:     "\n                               in comm field in /proc/PID/stat"
-//usage:     "\n       -x,--exec EXECUTABLE    Match processes with this command"
-//usage:     "\n                               in /proc/PID/cmdline"
-//usage:     "\n       -p,--pidfile FILE       Match a process with PID from the file"
-//usage:     "\n       All specified conditions must match"
-//usage:     "\n-S only:"
-//usage:     "\n       -x,--exec EXECUTABLE    Program to run"
-//usage:     "\n       -a,--startas NAME       Zeroth argument"
-//usage:     "\n       -b,--background         Background"
-//usage:       IF_FEATURE_START_STOP_DAEMON_FANCY(
-//usage:     "\n       -N,--nicelevel N        Change nice level"
-//usage:       )
-//usage:     "\n       -c,--chuid USER[:[GRP]] Change to user/group"
-//usage:     "\n       -m,--make-pidfile       Write PID to the pidfile specified by -p"
-//usage:     "\n-K only:"
-//usage:     "\n       -s,--signal SIG         Signal to send"
-//usage:     "\n       -t,--test               Match only, exit with 0 if a process is found"
-//usage:     "\nOther:"
-//usage:       IF_FEATURE_START_STOP_DAEMON_FANCY(
-//usage:     "\n       -o,--oknodo             Exit with status 0 if nothing is done"
-//usage:     "\n       -v,--verbose            Verbose"
-//usage:       )
-//usage:     "\n       -q,--quiet              Quiet"
-//usage:       )
-//usage:       IF_NOT_FEATURE_START_STOP_DAEMON_LONG_OPTIONS(
+//usage:       "-K: stop all matching processes\n"
+//usage:       "-S: start a process unless a matching process is found\n"
 //usage:     "\nProcess matching:"
 //usage:     "\n       -u USERNAME|UID Match only this user's processes"
 //usage:     "\n       -n NAME         Match processes with NAME"
 //usage:     "\n                       in comm field in /proc/PID/stat"
 //usage:     "\n       -x EXECUTABLE   Match processes with this command"
 //usage:     "\n                       command in /proc/PID/cmdline"
-//usage:     "\n       -p FILE         Match a process with PID from the file"
+//usage:     "\n       -p FILE         Match a process with PID from FILE"
 //usage:     "\n       All specified conditions must match"
 //usage:     "\n-S only:"
 //usage:     "\n       -x EXECUTABLE   Program to run"
@@ -106,24 +104,24 @@ Misc options:
 //usage:       IF_FEATURE_START_STOP_DAEMON_FANCY(
 //usage:     "\n       -N N            Change nice level"
 //usage:       )
-//usage:     "\n       -c USER[:[GRP]] Change to user/group"
-//usage:     "\n       -m              Write PID to the pidfile specified by -p"
+//usage:     "\n       -c USER[:[GRP]] Change user/group"
+//usage:     "\n       -m              Write PID to pidfile specified by -p"
 //usage:     "\n-K only:"
 //usage:     "\n       -s SIG          Signal to send"
-//usage:     "\n       -t              Match only, exit with 0 if a process is found"
+//usage:     "\n       -t              Match only, exit with 0 if found"
 //usage:     "\nOther:"
 //usage:       IF_FEATURE_START_STOP_DAEMON_FANCY(
 //usage:     "\n       -o              Exit with status 0 if nothing is done"
 //usage:     "\n       -v              Verbose"
 //usage:       )
 //usage:     "\n       -q              Quiet"
-//usage:       )
 
 #include <sys/resource.h>
 
 /* Override ENABLE_FEATURE_PIDFILE */
 #define WANT_PIDFILE 1
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 struct pid_list {
        struct pid_list *next;
@@ -162,7 +160,7 @@ struct globals {
        int user_id;
        smallint signal_nr;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define userspec          (G.userspec            )
 #define cmdname           (G.cmdname             )
 #define execname          (G.execname            )
@@ -170,6 +168,7 @@ struct globals {
 #define user_id           (G.user_id             )
 #define signal_nr         (G.signal_nr           )
 #define INIT_G() do { \
+       setup_common_bufsiz(); \
        user_id = -1; \
        signal_nr = 15; \
 } while (0)
@@ -198,8 +197,18 @@ static int pid_is_exec(pid_t pid)
 {
        ssize_t bytes;
        char buf[sizeof("/proc/%u/cmdline") + sizeof(int)*3];
+       char *procname, *exelink;
+       int match;
 
-       sprintf(buf, "/proc/%u/cmdline", (unsigned)pid);
+       procname = buf + sprintf(buf, "/proc/%u/exe", (unsigned)pid) - 3;
+
+       exelink = xmalloc_readlink(buf);
+       match = (exelink && strcmp(execname, exelink) == 0);
+       free(exelink);
+       if (match)
+               return match;
+
+       strcpy(procname, "cmdline");
        bytes = open_read_close(buf, G.execname_cmpbuf, G.execname_sizeof);
        if (bytes > 0) {
                G.execname_cmpbuf[bytes] = '\0';
@@ -371,11 +380,11 @@ static const char start_stop_daemon_longopts[] ALIGN1 =
        "quiet\0"        No_argument       "q"
        "test\0"         No_argument       "t"
        "make-pidfile\0" No_argument       "m"
-#if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
+# if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
        "oknodo\0"       No_argument       "o"
        "verbose\0"      No_argument       "v"
        "nicelevel\0"    Required_argument "N"
-#endif
+# endif
        "startas\0"      Required_argument "a"
        "name\0"         Required_argument "n"
        "signal\0"       Required_argument "s"
@@ -383,10 +392,15 @@ static const char start_stop_daemon_longopts[] ALIGN1 =
        "chuid\0"        Required_argument "c"
        "exec\0"         Required_argument "x"
        "pidfile\0"      Required_argument "p"
-#if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
+# if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
        "retry\0"        Required_argument "R"
-#endif
+# endif
        ;
+# define GETOPT32 getopt32long
+# define LONGOPTS start_stop_daemon_longopts,
+#else
+# define GETOPT32 getopt32
+# define LONGOPTS
 #endif
 
 int start_stop_daemon_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
@@ -407,19 +421,18 @@ int start_stop_daemon_main(int argc UNUSED_PARAM, char **argv)
 
        INIT_G();
 
-#if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS
-       applet_long_options = start_stop_daemon_longopts;
-#endif
-
-       /* -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 */
-       /* -q turns off -v */
-       opt_complementary = "K:S:K--S:S--K:m?p:K?xpun:S?xa"
-               IF_FEATURE_START_STOP_DAEMON_FANCY("q-v");
-       opt = getopt32(argv, "KSbqtma:n:s:u:c:x:p:"
-               IF_FEATURE_START_STOP_DAEMON_FANCY("ovN:R:"),
+       opt = GETOPT32(argv, "^"
+               "KSbqtma:n:s:u:c:x:p:"
+               IF_FEATURE_START_STOP_DAEMON_FANCY("ovN:R:")
+                       /* -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 */
+                       /* -q turns off -v */
+                       "\0"
+                       "K:S:K--S:S--K:m?p:K?xpun:S?xa"
+                       IF_FEATURE_START_STOP_DAEMON_FANCY("q-v"),
+               LONGOPTS
                &startas, &cmdname, &signame, &userspec, &chuid, &execname, &pidfile
                IF_FEATURE_START_STOP_DAEMON_FANCY(,&opt_N)
                /* We accept and ignore -R <param> / --retry <param> */
@@ -474,10 +487,15 @@ int start_stop_daemon_main(int argc UNUSED_PARAM, char **argv)
        *--argv = startas;
        if (opt & OPT_BACKGROUND) {
 #if BB_MMU
-               bb_daemonize(DAEMON_DEVNULL_STDIO + DAEMON_CLOSE_EXTRA_FDS);
+               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.
+                */
                pid_t pid = xvfork();
                if (pid != 0) {
                        /* parent */
@@ -487,12 +505,8 @@ int start_stop_daemon_main(int argc UNUSED_PARAM, char **argv)
                }
                /* Child */
                setsid(); /* detach from controlling tty */
-               /* Redirect stdio to /dev/null, close extra FDs.
-                * We do not actually daemonize because of DAEMON_ONLY_SANITIZE */
-               bb_daemonize_or_rexec(DAEMON_DEVNULL_STDIO
-                       + DAEMON_CLOSE_EXTRA_FDS
-                       + DAEMON_ONLY_SANITIZE,
-                       NULL /* argv, unused */ );
+               /* Redirect stdio to /dev/null, close extra FDs */
+               bb_daemon_helper(DAEMON_DEVNULL_STDIO + DAEMON_CLOSE_EXTRA_FDS);
 #endif
        }
        if (opt & OPT_MAKEPID) {
@@ -500,10 +514,18 @@ int start_stop_daemon_main(int argc UNUSED_PARAM, char **argv)
                write_pidfile(pidfile);
        }
        if (opt & OPT_c) {
-               struct bb_uidgid_t ugid = { -1, -1 };
+               struct bb_uidgid_t ugid;
                parse_chown_usergroup_or_die(&ugid, chuid);
-               if (ugid.gid != (gid_t) -1) xsetgid(ugid.gid);
-               if (ugid.uid != (uid_t) -1) xsetuid(ugid.uid);
+               if (ugid.uid != (uid_t) -1L) {
+                       struct passwd *pw = xgetpwuid(ugid.uid);
+                       if (ugid.gid != (gid_t) -1L)
+                               pw->pw_gid = ugid.gid;
+                       /* initgroups, setgid, setuid: */
+                       change_identity(pw);
+               } else if (ugid.gid != (gid_t) -1L) {
+                       xsetgid(ugid.gid);
+                       setgroups(1, &ugid.gid);
+               }
        }
 #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
        if (opt & OPT_NICELEVEL) {