diff options
Diffstat (limited to 'debianutils/start_stop_daemon.c')
| -rw-r--r-- | debianutils/start_stop_daemon.c | 447 |
1 files changed, 447 insertions, 0 deletions
diff --git a/debianutils/start_stop_daemon.c b/debianutils/start_stop_daemon.c new file mode 100644 index 0000000..ab607bd --- /dev/null +++ b/debianutils/start_stop_daemon.c @@ -0,0 +1,447 @@ +/* vi: set sw=4 ts=4: */ +/* + * Mini start-stop-daemon implementation(s) for busybox + * + * 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. + */ + +/* +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/cmdline. + 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 +*/ + +#include <sys/resource.h> + +/* Override ENABLE_FEATURE_PIDFILE */ +#define WANT_PIDFILE 1 +#include "libbb.h" + +struct pid_list { + struct pid_list *next; + 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; + char *userspec; + char *cmdname; + char *execname; + char *pidfile; + int user_id; + smallint signal_nr; +}; +#define G (*(struct globals*)&bb_common_bufsiz1) +#define found (G.found ) +#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 { \ + 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 stat st; + char buf[sizeof("/proc//exe") + sizeof(int)*3]; + + 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) +{ + ssize_t bytes; + char buf[PATH_MAX]; + + sprintf(buf, "/proc/%u/cmdline", (unsigned)pid); + bytes = open_read_close(buf, buf, sizeof(buf) - 1); + if (bytes > 0) { + buf[bytes] = '\0'; + return strcmp(buf, execname) == 0; + } + return 0; +} + +static int pid_is_name(pid_t pid) +{ + /* /proc/PID/stat is "PID (comm_15_bytes_max) ..." */ + char buf[32]; /* should be enough */ + char *p, *pe; + + sprintf(buf, "/proc/%u/stat", (unsigned)pid); + if (open_read_close(buf, buf, sizeof(buf) - 1) < 0) + return 0; + 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_user(int pid) +{ + 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) +{ + struct pid_list *p; + + if (execname && !pid_is_exec(pid)) { + return; + } + if (cmdname && !pid_is_name(pid)) { + return; + } + if (userspec && !pid_is_user(pid)) { + return; + } + p = xmalloc(sizeof(*p)); + p->next = found; + p->pid = pid; + found = p; +} + +static void do_pidfile(void) +{ + FILE *f; + unsigned pid; + + f = fopen_for_read(pidfile); + if (f) { + if (fscanf(f, "%u", &pid) == 1) + check(pid); + fclose(f); + } else if (errno != ENOENT) + bb_perror_msg_and_die("open pidfile %s", pidfile); +} + +static void do_procinit(void) +{ + DIR *procdir; + struct dirent *entry; + int pid; + + if (pidfile) { + do_pidfile(); + return; + } + + procdir = xopendir("/proc"); + + 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) /* NaN */ + continue; + check(pid); + } + closedir(procdir); + 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; + + 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) { + what = xasprintf("process(es) owned by '%s'", userspec); + } else { + bb_error_msg_and_die("internal error, please report"); + } + + if (!found) { + if (!QUIET) + printf("no %s found; none killed\n", what); + killed = -1; + goto ret; + } + for (p = found; p; p = p->next) { + if (TEST || kill(p->pid, signal_nr) == 0) { + killed++; + } else { + p->pid = 0; + bb_perror_msg("warning: killing process %u", (unsigned)p->pid); + } + } + if (!QUIET && killed) { + printf("stopped %s (pid", what); + for (p = found; 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 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" No_argument "o" + "verbose\0" No_argument "v" + "nicelevel\0" Required_argument "N" +#endif + "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\0" Required_argument "R" +#endif + ; +#endif + +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; + 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 + + 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" + USE_FEATURE_START_STOP_DAEMON_FANCY("q-v"); + opt = getopt32(argv, "KSbqtma:n:s:u:c:x:p:" + USE_FEATURE_START_STOP_DAEMON_FANCY("ovN:R:"), + &startas, &cmdname, &signame, &userspec, &chuid, &execname, &pidfile + USE_FEATURE_START_STOP_DAEMON_FANCY(,&opt_N) + /* We accept and ignore -R <param> / --retry <param> */ + USE_FEATURE_START_STOP_DAEMON_FANCY(,NULL) + ); + + if (opt & OPT_s) { + signal_nr = get_signum(signame); + if (signal_nr < 0) bb_show_usage(); + } + + if (!(opt & OPT_a)) + startas = execname; + if (!execname) /* in case -a is given and -x is not */ + execname = startas; + +// USE_FEATURE_START_STOP_DAEMON_FANCY( +// if (retry_arg) +// retries = xatoi_u(retry_arg); +// ) + //argc -= optind; + argv += optind; + + if (userspec) { + user_id = bb_strtou(userspec, NULL, 10); + if (errno) + 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); + } + + if (found) { + if (!QUIET) + printf("%s is already running\n%u\n", execname, (unsigned)found->pid); + return !(opt & OPT_OKNODO); + } + +#ifdef OLDER_VERSION_OF_X + if (execname) + xstat(execname, &execstat); +#endif + + *--argv = startas; + if (opt & OPT_BACKGROUND) { +#if BB_MMU + bb_daemonize(DAEMON_DEVNULL_STDIO + DAEMON_CLOSE_EXTRA_FDS); + /* DAEMON_DEVNULL_STDIO is superfluous - + * it's always done by bb_daemonize() */ +#else + pid_t pid = vfork(); + if (pid < 0) /* error */ + bb_perror_msg_and_die("vfork"); + 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 */ + write_pidfile(pidfile); + } + if (opt & OPT_c) { + struct bb_uidgid_t ugid = { -1, -1 }; + 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 ENABLE_FEATURE_START_STOP_DAEMON_FANCY + if (opt & OPT_NICELEVEL) { + /* Set process priority */ + int prio = getpriority(PRIO_PROCESS, 0) + xatoi_range(opt_N, INT_MIN/2, INT_MAX/2); + if (setpriority(PRIO_PROCESS, 0, prio) < 0) { + bb_perror_msg_and_die("setpriority(%d)", prio); + } + } +#endif + execvp(startas, argv); + bb_perror_msg_and_die("cannot start %s", startas); +} |