Commit the start-stop-daemon applet. This was contributed by David

Kimdon <dwhedon@gordian.com> on october 7th -- the day I was fired from
Lineo.  So it seems I totally forgot about this patch until now.
Sorry about that David!

1 files changed, 271 insertions, 0 deletions

diff --git a/debianutils/start_stop_daemon.c b/debianutils/start_stop_daemon.c
new file mode 100644
index 000000000..0152283ad
--- /dev/null
+++ b/debianutils/start_stop_daemon.c
@@ -0,0 +1,271 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Mini start-stop-daemon implementation(s) for busybox
+ *
+ * Written by Marek Michalkiewicz <marekm@i17linuxb.ists.pwr.wroc.pl>,
+ * public domain.
+ * Adapted for busybox David Kimdon <dwhedon@gordian.com>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <signal.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <pwd.h>
+
+#include "busybox.h"
+
+static int start = 0;
+static int stop = 0;
+static int signal_nr = 15;
+static int user_id = -1;
+static const char *userspec = NULL;
+static const char *cmdname = NULL;
+static char *execname = NULL;
+static char *startas = NULL;
+static const char *progname = "";
+
+struct pid_list {
+        struct pid_list *next;
+        int pid;
+};
+
+static struct pid_list *found = NULL;
+static struct pid_list *killed = NULL;
+
+static void
+push(struct pid_list **list, int pid)
+{
+        struct pid_list *p;
+
+        p = xmalloc(sizeof(*p));
+        p->next = *list;
+        p->pid = pid;
+        *list = p;
+}
+
+
+static void
+parse_options(int argc, char * const *argv)
+{
+        
+        int c;
+
+        for (;;) {
+            c = getopt (argc, argv, "a:n:s:u:x:KS");
+                if (c == EOF)
+                        break;
+                switch (c) {
+                case 'K':
+                        stop = 1;
+                        break;
+                case 'S':
+                        start = 1;
+                        break;
+                case 'a':
+                        startas = optarg;
+                        break;
+                case 'n':
+                        cmdname = optarg;
+                        break;
+                case 's':
+                        if (sscanf(optarg, "%d", &signal_nr) != 1)
+                                error_msg_and_die ("-s takes a numeric argument");
+                        break;
+                case 'u':
+                        userspec = optarg;
+                        break;
+                case 'x':
+                        execname = optarg;
+                        break;
+                default:
+                        show_usage();
+                        exit(1);
+                }
+        }
+
+        if (start == stop)
+                error_msg_and_die ("need one of -S or -K");
+
+        if (!execname && !userspec)
+                error_msg_and_die ("need at least one of -x or -u");
+
+        if (!startas)
+                startas = execname;
+
+        if (start && !startas)
+                error_msg_and_die ("-S needs -x or -a");
+}
+
+
+static int
+pid_is_exec(int pid, const char *exec)
+{
+        char buf[PATH_MAX];
+        FILE *fp;
+
+        sprintf(buf, "/proc/%d/cmdline", pid);
+        fp = fopen(buf, "r");
+        if (fp && fgets (buf, sizeof (buf), fp) ) {
+            if (strncmp (buf, exec, strlen(exec)) == 0)
+                return 1;
+        }
+        return 0;
+}
+
+
+static int
+pid_is_user(int pid, int uid)
+{
+        struct stat sb;
+        char buf[32];
+
+        sprintf(buf, "/proc/%d", pid);
+        if (stat(buf, &sb) != 0)
+                return 0;
+        return (sb.st_uid == uid);
+}
+
+
+static int
+pid_is_cmd(int pid, const char *name)
+{
+        char buf[32];
+        FILE *f;
+        int c;
+
+        sprintf(buf, "/proc/%d/stat", pid);
+        f = fopen(buf, "r");
+        if (!f)
+                return 0;
+        while ((c = getc(f)) != EOF && c != '(')
+                ;
+        if (c != '(') {
+                fclose(f);
+                return 0;
+        }
+        /* this hopefully handles command names containing ')' */
+        while ((c = getc(f)) != EOF && c == *name)
+                name++;
+        fclose(f);
+        return (c == ')' && *name == '\0');
+}
+
+
+static void
+check(int pid)
+{
+        if (execname && !pid_is_exec(pid, execname)) {
+                return;
+        }
+        if (userspec && !pid_is_user(pid, user_id)) {
+                return;
+        }
+        if (cmdname && !pid_is_cmd(pid, cmdname)) {
+                return;
+        }
+        push(&found, pid);
+}
+
+
+
+static void
+do_procfs(void)
+{
+        DIR *procdir;
+        struct dirent *entry;
+        int foundany, pid;
+
+        procdir = opendir("/proc");
+        if (!procdir)
+                perror_msg_and_die ("opendir /proc");
+
+        foundany = 0;
+        while ((entry = readdir(procdir)) != NULL) {
+                if (sscanf(entry->d_name, "%d", &pid) != 1)
+                        continue;
+                foundany++;
+                check(pid);
+        }
+        closedir(procdir);
+        if (!foundany)
+                error_msg_and_die ("nothing in /proc - not mounted?");
+}
+
+
+static void
+do_stop(void)
+{
+        char what[1024];
+        struct pid_list *p;
+
+        if (cmdname)
+                strcpy(what, cmdname);
+        else if (execname)
+                strcpy(what, execname);
+        else if (userspec)
+                sprintf(what, "process(es) owned by `%s'", userspec);
+        else
+                error_msg_and_die ("internal error, please report");
+
+        if (!found) {
+                printf("no %s found; none killed.\n", what);
+                exit(0);
+        }
+        for (p = found; p; p = p->next) {
+                if (kill(p->pid, signal_nr) == 0)
+                        push(&killed, p->pid);
+                else
+                        printf("%s: warning: failed to kill %d: %s\n",
+                               progname, p->pid, strerror(errno));
+        }
+        if (killed) {
+                printf("stopped %s (pid", what);
+                for (p = killed; p; p = p->next)
+                        printf(" %d", p->pid);
+                printf(").\n");
+        }
+}
+
+
+int
+start_stop_daemon_main(int argc, char **argv)
+{
+        progname = argv[0];
+
+        parse_options(argc, argv);
+        argc -= optind;
+        argv += optind;
+
+        if (userspec && sscanf(userspec, "%d", &user_id) != 1) {
+                struct passwd *pw;
+
+                pw = getpwnam(userspec);
+                if (!pw)
+                        error_msg_and_die ("user `%s' not found\n", userspec);
+
+                user_id = pw->pw_uid;
+        }
+
+        do_procfs();
+
+        if (stop) {
+                do_stop();
+                exit(0);
+        }
+
+        if (found) {
+                printf("%s already running.\n", execname);
+                printf("%d\n",found->pid);
+                exit(0);
+        }
+        *--argv = startas;
+        execv(startas, argv);
+        perror_msg_and_die ("unable to start %s", startas);
+}
+