Truncate the PID file so that even if we fail to unlink it, the daemon can be restart...

diff --git a/src/charon/charon.c b/src/charon/charon.c
index 33866881f5e08e900ce69b9e14567518eed97143..826fab8661832d3b5ade86b36f57973338c2ed35 100644 (file)
--- a/src/charon/charon.c
+++ b/src/charon/charon.c
@@ -43,6 +43,11 @@
  */
 #define PID_FILE IPSEC_PIDDIR "/charon.pid"
 
+/**
+ * Global reference to PID file (required to truncate, if undeletable)
+ */
+static FILE *pidfile = NULL;
+
 /**
  * hook in library for debugging messages
  */
@@ -203,22 +208,21 @@ static void segv_handler(int signal)
 static bool check_pidfile()
 {
        struct stat stb;
-       FILE *file;
 
        if (stat(PID_FILE, &stb) == 0)
        {
-               file = fopen(PID_FILE, "r");
-               if (file)
+               pidfile = fopen(PID_FILE, "r");
+               if (pidfile)
                {
                        char buf[64];
                        pid_t pid = 0;
 
                        memset(buf, 0, sizeof(buf));
-                       if (fread(buf, 1, sizeof(buf), file))
+                       if (fread(buf, 1, sizeof(buf), pidfile))
                        {
                                pid = atoi(buf);
                        }
-                       fclose(file);
+                       fclose(pidfile);
                        if (pid && kill(pid, 0) == 0)
                        {       /* such a process is running */
                                return TRUE;
@@ -229,16 +233,34 @@ static bool check_pidfile()
        }
 
        /* create new pidfile */
-       file = fopen(PID_FILE, "w");
-       if (file)
+       pidfile = fopen(PID_FILE, "w");
+       if (pidfile)
        {
-               fprintf(file, "%d\n", getpid());
-               ignore_result(fchown(fileno(file), charon->uid, charon->gid));
-               fclose(file);
+               ignore_result(fchown(fileno(pidfile), charon->uid, charon->gid));
+               fprintf(pidfile, "%d\n", getpid());
+               fflush(pidfile);
        }
        return FALSE;
 }
 
+/**
+ * Delete/truncate the PID file
+ */
+static void unlink_pidfile()
+{
+       /* because unlinking the PID file may fail, we truncate it to ensure the
+        * daemon can be properly restarted.  one probable cause for this is the
+        * combination of not running as root and the effective user lacking
+        * permissions on the parent dir(s) of the PID file */
+       if (pidfile)
+       {
+               ftruncate(fileno(pidfile), 0);
+               fclose(pidfile);
+       }
+       unlink(PID_FILE);
+}
+
+
 /**
  * print command line usage and exit
  */
@@ -406,7 +428,7 @@ int main(int argc, char *argv[])
        run();
 
        /* normal termination, cleanup and exit */
-       unlink(PID_FILE);
+       unlink_pidfile();
        status = 0;
 
 deinit: