Sort more misplaced applets into coreutils or util-linux
[oweals/busybox.git] / debianutils / start_stop_daemon.c
index d1f5e94c0146231562ca815b53f75644e439d3ff..4a9e0653e29a8da9a5a9c519fccab74e654490ae 100644 (file)
  * Written by Marek Michalkiewicz <marekm@i17linuxb.ists.pwr.wroc.pl>,
  * Adapted for busybox David Kimdon <dwhedon@gordian.com>
  *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 
-#include "busybox.h"
-#include <getopt.h>
+/*
+This is how it is supposed to work:
+
+start-stop-daemon [OPTIONS] [--start|--stop] [[--] arguments...]
+
+One (only) of these must be given:
+        -S,--start              Start
+        -K,--stop               Stop
+
+Search for matching processes.
+If --stop is given, stop all matching processes (by sending a signal).
+If --start is given, start a new process unless a matching process was found.
+
+Options controlling process matching
+(if multiple conditions are specified, all must match):
+        -u,--user USERNAME|UID  Only consider this user's processes
+        -n,--name PROCESS_NAME  Look for processes by matching PROCESS_NAME
+                                with comm field in /proc/$PID/stat.
+                                Only basename is compared:
+                                "ntpd" == "./ntpd" == "/path/to/ntpd".
+[TODO: can PROCESS_NAME be a full pathname? Should we require full match then
+with /proc/$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/$PID/exe and /proc/$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
+
+Options which are valid for --start only:
+        -x,--exec EXECUTABLE    Program to run (1st arg of execvp). Mandatory.
+        -a,--startas NAME       argv[0] (defaults to EXECUTABLE)
+        -b,--background         Put process into background
+        -N,--nicelevel N        Add N to process' nice level
+        -c,--chuid USER[:[GRP]] Change to specified user [and group]
+        -m,--make-pidfile       Write PID to the pidfile
+                                (both -m and -p must be given!)
+
+Options which are valid for --stop only:
+        -s,--signal SIG         Signal to send (default:TERM)
+        -t,--test               Exit with status 0 if process is found
+                                (we don't actually start or stop daemons)
+
+Misc options:
+        -o,--oknodo             Exit with status 0 if nothing is done
+        -q,--quiet              Quiet
+        -v,--verbose            Verbose
+*/
+//config:config START_STOP_DAEMON
+//config:      bool "start-stop-daemon"
+//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))
+
+//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/{exe,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:     "\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       All specified conditions must match"
+//usage:     "\n-S only:"
+//usage:     "\n       -x EXECUTABLE   Program to run"
+//usage:     "\n       -a NAME         Zeroth argument"
+//usage:     "\n       -b              Background"
+//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-K only:"
+//usage:     "\n       -s SIG          Signal to send"
+//usage:     "\n       -t              Match only, exit with 0 if a process is 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>
 
-static int signal_nr = 15;
-static int user_id = -1;
-static int quiet;
-static char *userspec;
-static char *chuid;
-static char *cmdname;
-static char *execname;
-static char *pidfile;
+/* Override ENABLE_FEATURE_PIDFILE */
+#define WANT_PIDFILE 1
+#include "libbb.h"
+#include "common_bufsiz.h"
 
 struct pid_list {
        struct pid_list *next;
        pid_t pid;
 };
 
-static struct pid_list *found;
-
-static inline void push(pid_t pid)
+enum {
+       CTX_STOP       = (1 <<  0),
+       CTX_START      = (1 <<  1),
+       OPT_BACKGROUND = (1 <<  2), // -b
+       OPT_QUIET      = (1 <<  3), // -q
+       OPT_TEST       = (1 <<  4), // -t
+       OPT_MAKEPID    = (1 <<  5), // -m
+       OPT_a          = (1 <<  6), // -a
+       OPT_n          = (1 <<  7), // -n
+       OPT_s          = (1 <<  8), // -s
+       OPT_u          = (1 <<  9), // -u
+       OPT_c          = (1 << 10), // -c
+       OPT_x          = (1 << 11), // -x
+       OPT_p          = (1 << 12), // -p
+       OPT_OKNODO     = (1 << 13) * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -o
+       OPT_VERBOSE    = (1 << 14) * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -v
+       OPT_NICELEVEL  = (1 << 15) * ENABLE_FEATURE_START_STOP_DAEMON_FANCY, // -N
+};
+#define QUIET (option_mask32 & OPT_QUIET)
+#define TEST  (option_mask32 & OPT_TEST)
+
+struct globals {
+       struct pid_list *found_procs;
+       char *userspec;
+       char *cmdname;
+       char *execname;
+       char *pidfile;
+       char *execname_cmpbuf;
+       unsigned execname_sizeof;
+       int user_id;
+       smallint signal_nr;
+} FIX_ALIASING;
+#define G (*(struct globals*)bb_common_bufsiz1)
+#define userspec          (G.userspec            )
+#define cmdname           (G.cmdname             )
+#define execname          (G.execname            )
+#define pidfile           (G.pidfile             )
+#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)
+
+#ifdef OLDER_VERSION_OF_X
+/* -x,--exec EXECUTABLE
+ * Look for processes with matching /proc/$PID/exe.
+ * Match is performed using device+inode.
+ */
+static int pid_is_exec(pid_t pid)
 {
-       struct pid_list *p;
+       struct stat st;
+       char buf[sizeof("/proc/%u/exe") + sizeof(int)*3];
 
-       p = xmalloc(sizeof(*p));
-       p->next = found;
-       p->pid = pid;
-       found = p;
+       sprintf(buf, "/proc/%u/exe", (unsigned)pid);
+       if (stat(buf, &st) < 0)
+               return 0;
+       if (st.st_dev == execstat.st_dev
+        && st.st_ino == execstat.st_ino)
+               return 1;
+       return 0;
 }
+#endif
 
-static int pid_is_exec(pid_t pid, const char *name)
+static int pid_is_exec(pid_t pid)
 {
-       char buf[sizeof("/proc//exe") + sizeof(int)*3];
-       char *execbuf;
-       int sz;
-       int equal;
-
-       sprintf(buf, "/proc/%d/exe", pid);
-       sz = strlen(name) + 1;
-       execbuf = xzalloc(sz);
-       readlink(buf, execbuf, sz);
-
-       /* if readlink fails, execbuf still contains "" */
-       equal = !strcmp(execbuf, name);
-       if (ENABLE_FEATURE_CLEAN_UP)
-               free(execbuf);
-       return equal;
+       ssize_t bytes;
+       char buf[sizeof("/proc/%u/cmdline") + sizeof(int)*3];
+       char *procname, *exelink;
+       int match;
+
+       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';
+               return strcmp(execname, G.execname_cmpbuf) == 0;
+       }
+       return 0;
 }
 
-static int pid_is_user(int pid, int uid)
+static int pid_is_name(pid_t pid)
 {
-       struct stat sb;
-       char buf[sizeof("/proc/") + sizeof(int)*3];
+       /* /proc/PID/stat is "PID (comm_15_bytes_max) ..." */
+       char buf[32]; /* should be enough */
+       char *p, *pe;
 
-       sprintf(buf, "/proc/%u", pid);
-       if (stat(buf, &sb) != 0)
+       sprintf(buf, "/proc/%u/stat", (unsigned)pid);
+       if (open_read_close(buf, buf, sizeof(buf) - 1) < 0)
                return 0;
-       return (sb.st_uid == uid);
+       buf[sizeof(buf) - 1] = '\0'; /* paranoia */
+       p = strchr(buf, '(');
+       if (!p)
+               return 0;
+       pe = strrchr(++p, ')');
+       if (!pe)
+               return 0;
+       *pe = '\0';
+       /* we require comm to match and to not be truncated */
+       /* in Linux, if comm is 15 chars, it may be a truncated
+        * name, so we don't allow that to match */
+       if (strlen(p) >= COMM_LEN - 1) /* COMM_LEN is 16 */
+               return 0;
+       return strcmp(p, cmdname) == 0;
 }
 
-static int pid_is_cmd(pid_t pid, const char *name)
+static int pid_is_user(int pid)
 {
-       char fname[sizeof("/proc//stat") + sizeof(int)*3];
-       char *buf;
-       int r = 0;
-
-       sprintf(fname, "/proc/%u/stat", pid);
-       buf = xmalloc_open_read_close(fname, NULL);
-       if (buf) {
-               char *p = strchr(buf, '(');
-               if (p) {
-                       char *pe = strrchr(++p, ')');
-                       if (pe) {
-                               *pe = '\0';
-                               r = !strcmp(p, name);
-                       }
-               }
-               free(buf);
-       }
-       return r;
-}
+       struct stat sb;
+       char buf[sizeof("/proc/") + sizeof(int)*3];
 
+       sprintf(buf, "/proc/%u", (unsigned)pid);
+       if (stat(buf, &sb) != 0)
+               return 0;
+       return (sb.st_uid == (uid_t)user_id);
+}
 
 static void check(int pid)
 {
-       if (execname && !pid_is_exec(pid, execname)) {
+       struct pid_list *p;
+
+       if (execname && !pid_is_exec(pid)) {
                return;
        }
-       if (userspec && !pid_is_user(pid, user_id)) {
+       if (cmdname && !pid_is_name(pid)) {
                return;
        }
-       if (cmdname && !pid_is_cmd(pid, cmdname)) {
+       if (userspec && !pid_is_user(pid)) {
                return;
        }
-       push(pid);
+       p = xmalloc(sizeof(*p));
+       p->next = G.found_procs;
+       p->pid = pid;
+       G.found_procs = p;
 }
 
-
 static void do_pidfile(void)
 {
        FILE *f;
-       pid_t pid;
+       unsigned pid;
 
-       f = fopen(pidfile, "r");
+       f = fopen_for_read(pidfile);
        if (f) {
                if (fscanf(f, "%u", &pid) == 1)
                        check(pid);
@@ -124,7 +319,7 @@ static void do_procinit(void)
 {
        DIR *procdir;
        struct dirent *entry;
-       int foundany, pid;
+       int pid;
 
        if (pidfile) {
                do_pidfile();
@@ -133,180 +328,228 @@ static void do_procinit(void)
 
        procdir = xopendir("/proc");
 
-       foundany = 0;
-       while ((entry = readdir(procdir)) != NULL) {
+       pid = 0;
+       while (1) {
+               errno = 0; /* clear any previous error */
+               entry = readdir(procdir);
+// TODO: this check is too generic, it's better
+// to check for exact errno(s) which mean that we got stale entry
+               if (errno) /* Stale entry, process has died after opendir */
+                       continue;
+               if (!entry) /* EOF, no more entries */
+                       break;
                pid = bb_strtou(entry->d_name, NULL, 10);
-               if (errno)
+               if (errno) /* NaN */
                        continue;
-               foundany++;
                check(pid);
        }
        closedir(procdir);
-       if (!foundany)
-               bb_error_msg_and_die ("nothing in /proc - not mounted?");
+       if (!pid)
+               bb_error_msg_and_die("nothing in /proc - not mounted?");
 }
 
-
 static int do_stop(void)
 {
        char *what;
        struct pid_list *p;
        int killed = 0;
 
-       do_procinit();
-
-       if (cmdname)
-               what = xstrdup(cmdname);
-       else if (execname)
-               what = xstrdup(execname);
-       else if (pidfile)
+       if (cmdname) {
+               if (ENABLE_FEATURE_CLEAN_UP) what = xstrdup(cmdname);
+               if (!ENABLE_FEATURE_CLEAN_UP) what = cmdname;
+       } else if (execname) {
+               if (ENABLE_FEATURE_CLEAN_UP) what = xstrdup(execname);
+               if (!ENABLE_FEATURE_CLEAN_UP) what = execname;
+       } else if (pidfile) {
                what = xasprintf("process in pidfile '%s'", pidfile);
-       else if (userspec)
+       } else if (userspec) {
                what = xasprintf("process(es) owned by '%s'", userspec);
-       else
+       } else {
                bb_error_msg_and_die("internal error, please report");
+       }
 
-       if (!found) {
-               if (!quiet)
+       if (!G.found_procs) {
+               if (!QUIET)
                        printf("no %s found; none killed\n", what);
-               if (ENABLE_FEATURE_CLEAN_UP)
-                       free(what);
-               return -1;
+               killed = -1;
+               goto ret;
        }
-       for (p = found; p; p = p->next) {
-               if (kill(p->pid, signal_nr) == 0) {
-                       p->pid = -p->pid;
+       for (p = G.found_procs; p; p = p->next) {
+               if (kill(p->pid, TEST ? 0 : signal_nr) == 0) {
                        killed++;
                } else {
-                       bb_perror_msg("warning: failed to kill %d", p->pid);
+                       bb_perror_msg("warning: killing process %u", (unsigned)p->pid);
+                       p->pid = 0;
+                       if (TEST) {
+                               /* Example: -K --test --pidfile PIDFILE detected
+                                * that PIDFILE's pid doesn't exist */
+                               killed = -1;
+                               goto ret;
+                       }
                }
        }
-       if (!quiet && killed) {
+       if (!QUIET && killed) {
                printf("stopped %s (pid", what);
-               for (p = found; p; p = p->next)
-                       if(p->pid < 0)
-                               printf(" %d", -p->pid);
+               for (p = G.found_procs; p; p = p->next)
+                       if (p->pid)
+                               printf(" %u", (unsigned)p->pid);
                puts(")");
        }
+ ret:
        if (ENABLE_FEATURE_CLEAN_UP)
                free(what);
        return killed;
 }
 
 #if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS
-static const struct option long_options[] = {
-       { "stop",               0,      NULL,   'K' },
-       { "start",              0,      NULL,   'S' },
-       { "background",         0,      NULL,   'b' },
-       { "quiet",              0,      NULL,   'q' },
-       { "make-pidfile",       0,      NULL,   'm' },
+static const char start_stop_daemon_longopts[] ALIGN1 =
+       "stop\0"         No_argument       "K"
+       "start\0"        No_argument       "S"
+       "background\0"   No_argument       "b"
+       "quiet\0"        No_argument       "q"
+       "test\0"         No_argument       "t"
+       "make-pidfile\0" No_argument       "m"
 #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
-       { "oknodo",             0,      NULL,   'o' },
-       { "verbose",            0,      NULL,   'v' },
-       { "nicelevel",          1,      NULL,   'N' },
+       "oknodo\0"       No_argument       "o"
+       "verbose\0"      No_argument       "v"
+       "nicelevel\0"    Required_argument "N"
 #endif
-       { "startas",            1,      NULL,   'a' },
-       { "name",               1,      NULL,   'n' },
-       { "signal",             1,      NULL,   's' },
-       { "user",               1,      NULL,   'u' },
-       { "chuid",              1,      NULL,   'c' },
-       { "exec",               1,      NULL,   'x' },
-       { "pidfile",            1,      NULL,   'p' },
+       "startas\0"      Required_argument "a"
+       "name\0"         Required_argument "n"
+       "signal\0"       Required_argument "s"
+       "user\0"         Required_argument "u"
+       "chuid\0"        Required_argument "c"
+       "exec\0"         Required_argument "x"
+       "pidfile\0"      Required_argument "p"
 #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
-       { "retry",              1,      NULL,   'R' },
+       "retry\0"        Required_argument "R"
 #endif
-       { 0,                    0,      0,      0 }
-};
+       ;
 #endif
 
-enum {
-       CTX_STOP       = 0x1,
-       CTX_START      = 0x2,
-       OPT_BACKGROUND = 0x4,
-       OPT_QUIET      = 0x8,
-       OPT_MAKEPID    = 0x10,
-       OPT_OKNODO     = 0x20 * ENABLE_FEATURE_START_STOP_DAEMON_FANCY,
-       OPT_VERBOSE    = 0x40 * ENABLE_FEATURE_START_STOP_DAEMON_FANCY,
-       OPT_NICELEVEL  = 0x80 * ENABLE_FEATURE_START_STOP_DAEMON_FANCY,
-};
-
-int start_stop_daemon_main(int argc, char **argv)
+int start_stop_daemon_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int start_stop_daemon_main(int argc UNUSED_PARAM, char **argv)
 {
        unsigned opt;
-       char *signame = NULL;
-       char *startas = NULL;
+       char *signame;
+       char *startas;
+       char *chuid;
+#ifdef OLDER_VERSION_OF_X
+       struct stat execstat;
+#endif
 #if ENABLE_FEATURE_START_STOP_DAEMON_FANCY
 //     char *retry_arg = NULL;
 //     int retries = -1;
        char *opt_N;
 #endif
-#if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS
-       applet_long_options = long_options;
-#endif
 
-       /* Check required one context option was given */
-       opt_complementary = "K:S:?:K--S:S--K:m?p:K?xpun:S?xa";
-       opt = getopt32(argc, argv, "KSbqm"
-//             USE_FEATURE_START_STOP_DAEMON_FANCY("ovN:R:")
-               USE_FEATURE_START_STOP_DAEMON_FANCY("ovN:")
-               "a:n:s:u:c:x:p:"
-               USE_FEATURE_START_STOP_DAEMON_FANCY(,&opt_N)
-//             USE_FEATURE_START_STOP_DAEMON_FANCY(,&retry_arg)
-               ,&startas, &cmdname, &signame, &userspec, &chuid, &execname, &pidfile);
+       INIT_G();
 
-       quiet = (opt & OPT_QUIET) && !(opt & OPT_VERBOSE);
+#if ENABLE_FEATURE_START_STOP_DAEMON_LONG_OPTIONS
+       applet_long_options = start_stop_daemon_longopts;
+#endif
 
-       if (signame) {
+       /* -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:"),
+               &startas, &cmdname, &signame, &userspec, &chuid, &execname, &pidfile
+               IF_FEATURE_START_STOP_DAEMON_FANCY(,&opt_N)
+               /* We accept and ignore -R <param> / --retry <param> */
+               IF_FEATURE_START_STOP_DAEMON_FANCY(,NULL)
+       );
+
+       if (opt & OPT_s) {
                signal_nr = get_signum(signame);
                if (signal_nr < 0) bb_show_usage();
        }
 
-       if (!startas)
+       if (!(opt & OPT_a))
                startas = execname;
+       if (!execname) /* in case -a is given and -x is not */
+               execname = startas;
+       if (execname) {
+               G.execname_sizeof = strlen(execname) + 1;
+               G.execname_cmpbuf = xmalloc(G.execname_sizeof + 1);
+       }
 
-//     USE_FEATURE_START_STOP_DAEMON_FANCY(
+//     IF_FEATURE_START_STOP_DAEMON_FANCY(
 //             if (retry_arg)
-//                     retries = xatoi_u(retry_arg);
+//                     retries = xatoi_positive(retry_arg);
 //     )
-       argc -= optind;
+       //argc -= optind;
        argv += optind;
 
        if (userspec) {
                user_id = bb_strtou(userspec, NULL, 10);
                if (errno)
-                       user_id = bb_xgetpwnam(userspec);
+                       user_id = xuname2uid(userspec);
        }
+       /* Both start and stop need to know current processes */
+       do_procinit();
 
        if (opt & CTX_STOP) {
                int i = do_stop();
-               return (opt & OPT_OKNODO) ? 0 : (i<=0);
+               return (opt & OPT_OKNODO) ? 0 : (i <= 0);
        }
 
-       do_procinit();
-
-       if (found) {
-               if (!quiet)
-                       printf("%s already running\n%d\n", execname, found->pid);
+       if (G.found_procs) {
+               if (!QUIET)
+                       printf("%s is already running\n%u\n", execname, (unsigned)G.found_procs->pid);
                return !(opt & OPT_OKNODO);
        }
+
+#ifdef OLDER_VERSION_OF_X
+       if (execname)
+               xstat(execname, &execstat);
+#endif
+
        *--argv = startas;
        if (opt & OPT_BACKGROUND) {
-               xdaemon(0, 0);
-               setsid();
+#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
+               pid_t pid = xvfork();
+               if (pid != 0) {
+                       /* parent */
+                       /* why _exit? the child may have changed the stack,
+                        * so "return 0" may do bad things */
+                       _exit(EXIT_SUCCESS);
+               }
+               /* 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 */ );
+#endif
        }
        if (opt & OPT_MAKEPID) {
-               /* user wants _us_ to make the pidfile */
-               FILE *pidf = xfopen(pidfile, "w");
-
-               pid_t pidt = getpid();
-               fprintf(pidf, "%d\n", pidt);
-               fclose(pidf);
+               /* User wants _us_ to make the pidfile */
+               write_pidfile(pidfile);
        }
-       if (chuid) {
-               user_id = bb_strtou(chuid, NULL, 10);
-               if (errno)
-                       user_id = bb_xgetpwnam(chuid);
-               xsetuid(user_id);
+       if (opt & OPT_c) {
+               struct bb_uidgid_t ugid;
+               parse_chown_usergroup_or_die(&ugid, chuid);
+               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) {
@@ -317,6 +560,6 @@ int start_stop_daemon_main(int argc, char **argv)
                }
        }
 #endif
-       execv(startas, argv);
-       bb_perror_msg_and_die("cannot start %s", startas);
+       execvp(startas, argv);
+       bb_perror_msg_and_die("can't execute '%s'", startas);
 }