Bump to version 1.22.1
[platform/upstream/busybox.git] / runit / runsv.c
index 7cf142d..d941e89 100644 (file)
@@ -25,10 +25,14 @@ OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
-/* Busyboxed by Denis Vlasenko <vda.linux@googlemail.com> */
+/* Busyboxed by Denys Vlasenko <vda.linux@googlemail.com> */
 /* TODO: depends on runit_lib.c - review and reduce/eliminate */
 
-#include <sys/poll.h>
+//usage:#define runsv_trivial_usage
+//usage:       "DIR"
+//usage:#define runsv_full_usage "\n\n"
+//usage:       "Start and monitor a service and optionally an appendant log service"
+
 #include <sys/file.h>
 #include "libbb.h"
 #include "runit_lib.h"
@@ -78,23 +82,24 @@ struct svdir {
        int pid;
        smallint state;
        smallint ctrl;
-       smallint want;
+       smallint sd_want;
        smallint islog;
        struct timespec start;
        int fdlock;
        int fdcontrol;
        int fdcontrolwrite;
+       int wstat;
 };
 
 struct globals {
        smallint haslog;
        smallint sigterm;
        smallint pidchanged;
-       int selfpipe[2];
-       int logpipe[2];
+       struct fd_pair selfpipe;
+       struct fd_pair logpipe;
        char *dir;
        struct svdir svd[2];
-};
+} FIX_ALIASING;
 #define G (*(struct globals*)&bb_common_bufsiz1)
 #define haslog       (G.haslog      )
 #define sigterm      (G.sigterm     )
@@ -103,10 +108,9 @@ struct globals {
 #define logpipe      (G.logpipe     )
 #define dir          (G.dir         )
 #define svd          (G.svd         )
-#define INIT_G() \
-       do { \
-               pidchanged = 1; \
-       } while (0)
+#define INIT_G() do { \
+       pidchanged = 1; \
+} while (0)
 
 static void fatal2_cannot(const char *m1, const char *m2)
 {
@@ -128,45 +132,27 @@ static void warn_cannot(const char *m)
        bb_perror_msg("%s: warning: cannot %s", dir, m);
 }
 
-static void s_child(int sig_no)
+static void s_child(int sig_no UNUSED_PARAM)
 {
-       write(selfpipe[1], "", 1);
+       write(selfpipe.wr, "", 1);
 }
 
-static void s_term(int sig_no)
+static void s_term(int sig_no UNUSED_PARAM)
 {
        sigterm = 1;
-       write(selfpipe[1], "", 1); /* XXX */
-}
-
-static char *add_str(char *p, const char *to_add)
-{
-       while ((*p = *to_add) != '\0') {
-               p++;
-               to_add++;
-       }
-       return p;
+       write(selfpipe.wr, "", 1); /* XXX */
 }
 
 static int open_trunc_or_warn(const char *name)
 {
-       int fd = open_trunc(name);
+       /* Why O_NDELAY? */
+       int fd = open(name, O_WRONLY | O_NDELAY | O_TRUNC | O_CREAT, 0644);
        if (fd < 0)
                bb_perror_msg("%s: warning: cannot open %s",
                                dir, name);
        return fd;
 }
 
-static int rename_or_warn(const char *old, const char *new)
-{
-       if (rename(old, new) == -1) {
-               bb_perror_msg("%s: warning: cannot rename %s to %s",
-                               dir, old, new);
-               return -1;
-       }
-       return 0;
-}
-
 static void update_status(struct svdir *s)
 {
        ssize_t sz;
@@ -185,7 +171,7 @@ static void update_status(struct svdir *s)
                }
                close(fd);
                if (rename_or_warn("supervise/pid.new",
-                   s->islog ? "log/supervise/pid" : "log/supervise/pid"+4))
+                               s->islog ? "log/supervise/pid" : "log/supervise/pid"+4))
                        return;
                pidchanged = 0;
        }
@@ -200,24 +186,26 @@ static void update_status(struct svdir *s)
                char *p = stat_buf;
                switch (s->state) {
                case S_DOWN:
-                       p = add_str(p, "down");
+                       p = stpcpy(p, "down");
                        break;
                case S_RUN:
-                       p = add_str(p, "run");
+                       p = stpcpy(p, "run");
                        break;
                case S_FINISH:
-                       p = add_str(p, "finish");
+                       p = stpcpy(p, "finish");
                        break;
                }
-               if (s->ctrl & C_PAUSE) p = add_str(p, ", paused");
-               if (s->ctrl & C_TERM) p = add_str(p, ", got TERM");
+               if (s->ctrl & C_PAUSE)
+                       p = stpcpy(p, ", paused");
+               if (s->ctrl & C_TERM)
+                       p = stpcpy(p, ", got TERM");
                if (s->state != S_DOWN)
-                       switch (s->want) {
+                       switch (s->sd_want) {
                        case W_DOWN:
-                               p = add_str(p, ", want down");
+                               p = stpcpy(p, ", want down");
                                break;
                        case W_EXIT:
-                               p = add_str(p, ", want exit");
+                               p = stpcpy(p, ", want exit");
                                break;
                        }
                *p++ = '\n';
@@ -235,7 +223,7 @@ static void update_status(struct svdir *s)
        status.pid_le32 = SWAP_LE32(s->pid);
        if (s->ctrl & C_PAUSE)
                status.paused = 1;
-       if (s->want == W_UP)
+       if (s->sd_want == W_UP)
                status.want = 'u';
        else
                status.want = 'd';
@@ -258,36 +246,35 @@ static void update_status(struct svdir *s)
 
 static unsigned custom(struct svdir *s, char c)
 {
-       int pid;
+       pid_t pid;
        int w;
        char a[10];
        struct stat st;
-       char *prog[2];
 
-       if (s->islog) return 0;
+       if (s->islog)
+               return 0;
        strcpy(a, "control/?");
-       a[8] = c;
+       a[8] = c; /* replace '?' */
        if (stat(a, &st) == 0) {
                if (st.st_mode & S_IXUSR) {
-                       pid = fork();
+                       pid = vfork();
                        if (pid == -1) {
-                               warn_cannot("fork for control/?");
+                               warn_cannot("vfork for control/?");
                                return 0;
                        }
-                       if (!pid) {
-                               if (haslog && dup2(logpipe[1], 1) == -1)
+                       if (pid == 0) {
+                               /* child */
+                               if (haslog && dup2(logpipe.wr, 1) == -1)
                                        warn_cannot("setup stdout for control/?");
-                               prog[0] = a;
-                               prog[1] = NULL;
-                               execve(a, prog, environ);
+                               execl(a, a, (char *) NULL);
                                fatal_cannot("run control/?");
                        }
-                       while (wait_pid(&w, pid) == -1) {
-                               if (errno == EINTR) continue;
+                       /* parent */
+                       if (safe_waitpid(pid, &w, 0) == -1) {
                                warn_cannot("wait for child control/?");
                                return 0;
                        }
-                       return !wait_exitcode(w);
+                       return WEXITSTATUS(w) == 0;
                }
        } else {
                if (errno != ENOENT)
@@ -303,12 +290,12 @@ static void stopservice(struct svdir *s)
                s->ctrl |= C_TERM;
                update_status(s);
        }
-       if (s->want == W_DOWN) {
+       if (s->sd_want == W_DOWN) {
                kill(s->pid, SIGCONT);
                custom(s, 'd');
                return;
        }
-       if (s->want == W_EXIT) {
+       if (s->sd_want == W_EXIT) {
                kill(s->pid, SIGCONT);
                custom(s, 'x');
        }
@@ -317,41 +304,64 @@ static void stopservice(struct svdir *s)
 static void startservice(struct svdir *s)
 {
        int p;
-       char *run[2];
-
-       if (s->state == S_FINISH)
-               run[0] = (char*)"./finish";
-       else {
-               run[0] = (char*)"./run";
+       const char *arg[4];
+       char exitcode[sizeof(int)*3 + 2];
+
+       if (s->state == S_FINISH) {
+/* Two arguments are given to ./finish. The first one is ./run exit code,
+ * or -1 if ./run didnt exit normally. The second one is
+ * the least significant byte of the exit status as determined by waitpid;
+ * for instance it is 0 if ./run exited normally, and the signal number
+ * if ./run was terminated by a signal. If runsv cannot start ./run
+ * for some reason, the exit code is 111 and the status is 0.
+ */
+               arg[0] = "./finish";
+               arg[1] = "-1";
+               if (WIFEXITED(s->wstat)) {
+                       *utoa_to_buf(WEXITSTATUS(s->wstat), exitcode, sizeof(exitcode)) = '\0';
+                       arg[1] = exitcode;
+               }
+               //arg[2] = "0";
+               //if (WIFSIGNALED(s->wstat)) {
+                       arg[2] = utoa(WTERMSIG(s->wstat));
+               //}
+               arg[3] = NULL;
+       } else {
+               arg[0] = "./run";
+               arg[1] = NULL;
                custom(s, 'u');
        }
-       run[1] = NULL;
 
        if (s->pid != 0)
                stopservice(s); /* should never happen */
-       while ((p = fork()) == -1) {
-               warn_cannot("fork, sleeping");
+       while ((p = vfork()) == -1) {
+               warn_cannot("vfork, sleeping");
                sleep(5);
        }
        if (p == 0) {
                /* child */
                if (haslog) {
+                       /* NB: bug alert! right order is close, then dup2 */
                        if (s->islog) {
-                               xdup2(logpipe[0], 0);
-                               close(logpipe[1]);
                                xchdir("./log");
+                               close(logpipe.wr);
+                               xdup2(logpipe.rd, 0);
                        } else {
-                               xdup2(logpipe[1], 1);
-                               close(logpipe[0]);
+                               close(logpipe.rd);
+                               xdup2(logpipe.wr, 1);
                        }
                }
-               signal(SIGCHLD, SIG_DFL);
-               signal(SIGTERM, SIG_DFL);
+               /* Non-ignored signals revert to SIG_DFL on exec anyway */
+               /*bb_signals(0
+                       + (1 << SIGCHLD)
+                       + (1 << SIGTERM)
+                       , SIG_DFL);*/
                sig_unblock(SIGCHLD);
                sig_unblock(SIGTERM);
-               execvp(*run, run);
-               fatal2_cannot(s->islog ? "start log/" : "start ", *run);
+               execv(arg[0], (char**) arg);
+               fatal2_cannot(s->islog ? "start log/" : "start ", arg[0]);
        }
+       /* parent */
        if (s->state != S_FINISH) {
                gettimeofday_ns(&s->start);
                s->state = S_RUN;
@@ -368,13 +378,13 @@ static int ctrl(struct svdir *s, char c)
 
        switch (c) {
        case 'd': /* down */
-               s->want = W_DOWN;
+               s->sd_want = W_DOWN;
                update_status(s);
                if (s->pid && s->state != S_FINISH)
                        stopservice(s);
                break;
        case 'u': /* up */
-               s->want = W_UP;
+               s->sd_want = W_UP;
                update_status(s);
                if (s->pid == 0)
                        startservice(s);
@@ -382,7 +392,7 @@ static int ctrl(struct svdir *s, char c)
        case 'x': /* exit */
                if (s->islog)
                        break;
-               s->want = W_EXIT;
+               s->sd_want = W_EXIT;
                update_status(s);
                /* FALLTHROUGH */
        case 't': /* sig term */
@@ -403,12 +413,11 @@ static int ctrl(struct svdir *s, char c)
        case 'c': /* sig cont */
                if (s->pid && !custom(s, c))
                        kill(s->pid, SIGCONT);
-               if (s->ctrl & C_PAUSE)
-                       s->ctrl &= ~C_PAUSE;
+               s->ctrl &= ~C_PAUSE;
                update_status(s);
                break;
        case 'o': /* once */
-               s->want = W_DOWN;
+               s->sd_want = W_DOWN;
                update_status(s);
                if (!s->pid)
                        startservice(s);
@@ -439,8 +448,8 @@ static int ctrl(struct svdir *s, char c)
        return 1;
 }
 
-int runsv_main(int argc, char **argv);
-int runsv_main(int argc, char **argv)
+int runsv_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int runsv_main(int argc UNUSED_PARAM, char **argv)
 {
        struct stat s;
        int fd;
@@ -449,30 +458,29 @@ int runsv_main(int argc, char **argv)
 
        INIT_G();
 
-       if (!argv[1] || argv[2])
-               bb_show_usage();
-       dir = argv[1];
+       dir = single_argv(argv);
 
-       xpipe(selfpipe);
-       close_on_exec_on(selfpipe[0]);
-       close_on_exec_on(selfpipe[1]);
-       ndelay_on(selfpipe[0]);
-       ndelay_on(selfpipe[1]);
+       xpiped_pair(selfpipe);
+       close_on_exec_on(selfpipe.rd);
+       close_on_exec_on(selfpipe.wr);
+       ndelay_on(selfpipe.rd);
+       ndelay_on(selfpipe.wr);
 
        sig_block(SIGCHLD);
-       sig_catch(SIGCHLD, s_child);
+       bb_signals_recursive_norestart(1 << SIGCHLD, s_child);
        sig_block(SIGTERM);
-       sig_catch(SIGTERM, s_term);
+       bb_signals_recursive_norestart(1 << SIGTERM, s_term);
 
        xchdir(dir);
        /* bss: svd[0].pid = 0; */
        if (S_DOWN) svd[0].state = S_DOWN; /* otherwise already 0 (bss) */
        if (C_NOOP) svd[0].ctrl = C_NOOP;
-       if (W_UP) svd[0].want = W_UP;
+       if (W_UP) svd[0].sd_want = W_UP;
        /* bss: svd[0].islog = 0; */
        /* bss: svd[1].pid = 0; */
        gettimeofday_ns(&svd[0].start);
-       if (stat("down", &s) != -1) svd[0].want = W_DOWN;
+       if (stat("down", &s) != -1)
+               svd[0].sd_want = W_DOWN;
 
        if (stat("log", &s) == -1) {
                if (errno != ENOENT)
@@ -485,14 +493,14 @@ int runsv_main(int argc, char **argv)
                        haslog = 1;
                        svd[1].state = S_DOWN;
                        svd[1].ctrl = C_NOOP;
-                       svd[1].want = W_UP;
+                       svd[1].sd_want = W_UP;
                        svd[1].islog = 1;
                        gettimeofday_ns(&svd[1].start);
                        if (stat("log/down", &s) != -1)
-                               svd[1].want = W_DOWN;
-                       xpipe(logpipe);
-                       close_on_exec_on(logpipe[0]);
-                       close_on_exec_on(logpipe[1]);
+                               svd[1].sd_want = W_DOWN;
+                       xpiped_pair(logpipe);
+                       close_on_exec_on(logpipe.rd);
+                       close_on_exec_on(logpipe.wr);
                }
        }
 
@@ -510,7 +518,7 @@ int runsv_main(int argc, char **argv)
        }
        svd[0].fdlock = xopen3("log/supervise/lock"+4,
                        O_WRONLY|O_NDELAY|O_APPEND|O_CREAT, 0600);
-       if (lock_exnb(svd[0].fdlock) == -1)
+       if (flock(svd[0].fdlock, LOCK_EX | LOCK_NB) == -1)
                fatal_cannot("lock supervise/lock");
        close_on_exec_on(svd[0].fdlock);
        if (haslog) {
@@ -534,7 +542,7 @@ int runsv_main(int argc, char **argv)
                }
                svd[1].fdlock = xopen3("log/supervise/lock",
                                O_WRONLY|O_NDELAY|O_APPEND|O_CREAT, 0600);
-               if (lock_ex(svd[1].fdlock) == -1)
+               if (flock(svd[1].fdlock, LOCK_EX) == -1)
                        fatal_cannot("lock log/supervise/lock");
                close_on_exec_on(svd[1].fdlock);
        }
@@ -567,13 +575,13 @@ int runsv_main(int argc, char **argv)
                char ch;
 
                if (haslog)
-                       if (!svd[1].pid && svd[1].want == W_UP)
+                       if (!svd[1].pid && svd[1].sd_want == W_UP)
                                startservice(&svd[1]);
                if (!svd[0].pid)
-                       if (svd[0].want == W_UP || svd[0].state == S_FINISH)
+                       if (svd[0].sd_want == W_UP || svd[0].state == S_FINISH)
                                startservice(&svd[0]);
 
-               x[0].fd = selfpipe[0];
+               x[0].fd = selfpipe.rd;
                x[0].events = POLLIN;
                x[1].fd = svd[0].fdcontrol;
                x[1].events = POLLIN;
@@ -586,24 +594,25 @@ int runsv_main(int argc, char **argv)
                sig_block(SIGTERM);
                sig_block(SIGCHLD);
 
-               while (read(selfpipe[0], &ch, 1) == 1)
+               while (read(selfpipe.rd, &ch, 1) == 1)
                        continue;
 
                for (;;) {
-                       int child;
+                       pid_t child;
                        int wstat;
 
-                       child = wait_nohang(&wstat);
+                       child = wait_any_nohang(&wstat);
                        if (!child)
                                break;
                        if ((child == -1) && (errno != EINTR))
                                break;
                        if (child == svd[0].pid) {
+                               svd[0].wstat = wstat;
                                svd[0].pid = 0;
                                pidchanged = 1;
-                               svd[0].ctrl &=C_TERM;
+                               svd[0].ctrl &= ~C_TERM;
                                if (svd[0].state != S_FINISH) {
-                                       fd = open_read("finish");
+                                       fd = open("finish", O_RDONLY|O_NDELAY);
                                        if (fd != -1) {
                                                close(fd);
                                                svd[0].state = S_FINISH;
@@ -620,6 +629,7 @@ int runsv_main(int argc, char **argv)
                        }
                        if (haslog) {
                                if (child == svd[1].pid) {
+                                       svd[0].wstat = wstat;
                                        svd[1].pid = 0;
                                        pidchanged = 1;
                                        svd[1].state = S_DOWN;
@@ -631,7 +641,7 @@ int runsv_main(int argc, char **argv)
                                                sleep(1);
                                }
                        }
-               }
+               } /* for (;;) */
                if (read(svd[0].fdcontrol, &ch, 1) == 1)
                        ctrl(&svd[0], ch);
                if (haslog)
@@ -643,18 +653,18 @@ int runsv_main(int argc, char **argv)
                        sigterm = 0;
                }
 
-               if (svd[0].want == W_EXIT && svd[0].state == S_DOWN) {
+               if (svd[0].sd_want == W_EXIT && svd[0].state == S_DOWN) {
                        if (svd[1].pid == 0)
-                               _exit(0);
-                       if (svd[1].want != W_EXIT) {
-                               svd[1].want = W_EXIT;
+                               _exit(EXIT_SUCCESS);
+                       if (svd[1].sd_want != W_EXIT) {
+                               svd[1].sd_want = W_EXIT;
                                /* stopservice(&svd[1]); */
                                update_status(&svd[1]);
-                               close(logpipe[1]);
-                               close(logpipe[0]);
+                               close(logpipe.wr);
+                               close(logpipe.rd);
                        }
                }
-       }
+       } /* for (;;) */
        /* not reached */
        return 0;
 }