statd cleanup

[nfs-utils.git] / utils / statd / statd.c

diff --git a/utils/statd/statd.c b/utils/statd/statd.c
index 127e2580516d461d3a6fe0eeeed5ab4b1e227561..dbd73b313e074600f3428419d52a1632613c6878 100644 (file)
--- a/utils/statd/statd.c
+++ b/utils/statd/statd.c
@@ -12,11 +12,13 @@
 #include <signal.h>
 #include <unistd.h>
 #include <fcntl.h>
+#include <errno.h>
 #include <string.h>
 #include <getopt.h>
 #include <rpc/rpc.h>
 #include <rpc/pmap_clnt.h>
 #include <rpcmisc.h>
+#include <grp.h>
 #include "statd.h"
 #include "version.h"
 
@@ -147,6 +149,57 @@ usage()
        fprintf(stderr,"      -N                   Run in notify only mode.\n");
 }
 
+static const char *pidfile = "/var/run/rpc.statd.pid";
+
+int pidfd = -1;
+static void create_pidfile(void)
+{
+       FILE *fp;
+
+       unlink(pidfile);
+       fp = fopen(pidfile, "w");
+       if (!fp)
+               die("Opening %s failed: %s\n",
+                   pidfile, strerror(errno));
+       fprintf(fp, "%d\n", getpid());
+       pidfd = dup(fileno(fp));
+       if (fclose(fp) < 0)
+               log(L_WARNING, "Flushing pid file failed.\n");
+}
+
+static void truncate_pidfile(void)
+{
+       if (pidfd >= 0)
+               ftruncate(pidfd, 0);
+}
+
+static void drop_privs(void)
+{
+       struct stat st;
+
+       if (stat(SM_DIR, &st) == -1 &&
+           stat(DIR_BASE, &st) == -1)
+               st.st_uid = 0;
+
+       if (st.st_uid == 0) {
+               log(L_WARNING, "statd running as root. chown %s to choose different user\n",
+                   SM_DIR);
+               return;
+       }
+       /* better chown the pid file before dropping, as if it
+        * if over nfs we might loose access
+        */
+       if (pidfd >= 0)
+               fchown(pidfd, st.st_uid, st.st_gid);
+
+       setgroups(0, NULL);
+       if (setgid(st.st_gid) == -1
+           || setuid(st.st_uid) == -1) {
+               log(L_ERROR, "Fail to drop privileges");
+               exit(1);
+       }
+}
+
 /* 
  * Entry routine/main loop.
  */
@@ -157,6 +210,9 @@ int main (int argc, char **argv)
        int arg;
        int port = 0, out_port = 0;
 
+       int pipefds[2] = { -1, -1};
+       char status;
+
        /* Default: daemon mode, no other options */
        run_mode = 0;
 
@@ -264,10 +320,6 @@ int main (int argc, char **argv)
                                                   daemon mode. */
        }
 
-       log_init (name_p,version_p);
-
-       log_modes();
-
 #ifdef SIMULATIONS
        if (argc > 1)
                /* LH - I _really_ need to update simulator... */
@@ -277,28 +329,54 @@ int main (int argc, char **argv)
        if (!(run_mode & MODE_NODAEMON)) {
                int filedes, fdmax, tempfd;
 
+               if (pipe(pipefds)<0) {
+                       perror("statd: unable to create pipe");
+                       exit(1);
+               }
                if ((pid = fork ()) < 0) {
-                       perror ("Could not fork");
+                       perror ("statd: Could not fork");
                        exit (1);
                } else if (pid != 0) {
-                       /* Parent. */
+                       /* Parent.
+                        * Wait for status from child.
+                        */
+                       close(pipefds[1]);
+                       if (read(pipefds[0], &status, 1) != 1)
+                               exit(1);
                        exit (0);
                }
                /* Child.       */
+               close(pipefds[0]);
                setsid ();
-               chdir (DIR_BASE);
+               if (chdir (DIR_BASE) == -1) {
+                       perror("statd: Could not chdir");
+                       exit(1);
+               }
 
+               while (pipefds[1] <= 2) {
+                       pipefds[1] = dup(pipefds[1]);
+                       if (pipefds[1]<0) {
+                               perror("statd: dup");
+                               exit(1);
+                       }
+               }
                tempfd = open("/dev/null", O_RDWR);
                close(0); dup2(tempfd, 0);
                close(1); dup2(tempfd, 1);
                close(2); dup2(tempfd, 2);
                fdmax = sysconf (_SC_OPEN_MAX);
-               for (filedes = 3; filedes < fdmax; filedes++) {
-                       close (filedes);
-               }
+               for (filedes = 3; filedes < fdmax; filedes++) 
+                       if (filedes != pipefds[1])
+                               close (filedes);
+
        }
 
        /* Child. */
+
+       log_init (name_p,version_p);
+
+       log_modes();
+
        signal (SIGHUP, killer);
        signal (SIGINT, killer);
        signal (SIGTERM, killer);
@@ -308,6 +386,10 @@ int main (int argc, char **argv)
        /* initialize out_port */
        statd_get_socket(out_port);
 
+       create_pidfile();
+       atexit(truncate_pidfile);
+       drop_privs();
+
        for (;;) {
                if (!(run_mode & MODE_NOTIFY_ONLY)) {
                        /* Do not do pmap_unset() when running in notify mode.
@@ -319,6 +401,15 @@ int main (int argc, char **argv)
                }
                change_state ();
                shuffle_dirs ();        /* Move directory names around */
+
+               /* If we got this far, we have successfully started, so notify parent */
+               if (pipefds[1] > 0) {
+                       status = 0;
+                       write(pipefds[1], &status, 1);
+                       close(pipefds[1]);
+                       pipefds[1] = -1;
+               }
+
                notify_hosts ();        /* Send out notify requests */
                ++restart;