unixsock plugin: Implement the "DeleteSocket" option.

diff --git a/src/collectd.conf.in b/src/collectd.conf.in
index 42addd2..e194d14 100644 (file)
--- a/src/collectd.conf.in
+++ b/src/collectd.conf.in
@@ -913,6 +913,7 @@
 #      SocketFile "@prefix@/var/run/@PACKAGE_NAME@-unixsock"
 #      SocketGroup "collectd"
 #      SocketPerms "0660"
+#      DeleteSocket false
 #</Plugin>
 
 #<Plugin uuid>

diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod
index 1da3598..1c31d97 100644 (file)
--- a/src/collectd.conf.pod
+++ b/src/collectd.conf.pod
@@ -4558,6 +4558,13 @@ Change the file permissions of the UNIX-socket after it has been created. The
 permissions must be given as a numeric, octal value as you would pass to
 L<chmod(1)>. Defaults to B<0770>.
 
+=item B<DeleteSocket> B<false>|B<true>
+
+If set to B<true>, delete the socket file before calling L<bind(2)>, if a file
+with the given name already exists. If I<collectd> crashes a socket file may be
+left over, preventing the daemon from opening a new socket when restarted.
+Since this is potentially dangerous, this defaults to B<false>.
+
 =back
 
 =head2 Plugin C<uuid>

diff --git a/src/unixsock.c b/src/unixsock.c
index 0b89748..6de1395 100644 (file)
--- a/src/unixsock.c
+++ b/src/unixsock.c
@@ -54,7 +54,8 @@ static const char *config_keys[] =
 {
        "SocketFile",
        "SocketGroup",
-       "SocketPerms"
+       "SocketPerms",
+       "DeleteSocket"
 };
 static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
 
@@ -65,6 +66,7 @@ static int   sock_fd    = -1;
 static char *sock_file  = NULL;
 static char *sock_group = NULL;
 static int   sock_perms = S_IRWXU | S_IRWXG;
+static _Bool delete_socket = 0;
 
 static pthread_t listen_thread = (pthread_t) 0;
 
@@ -89,10 +91,27 @@ static int us_open_socket (void)
        sa.sun_family = AF_UNIX;
        sstrncpy (sa.sun_path, (sock_file != NULL) ? sock_file : US_DEFAULT_PATH,
                        sizeof (sa.sun_path));
-       /* unlink (sa.sun_path); */
 
        DEBUG ("unixsock plugin: socket path = %s", sa.sun_path);
 
+       if (delete_socket)
+       {
+               errno = 0;
+               status = unlink (sa.sun_path);
+               if ((status != 0) && (errno != ENOENT))
+               {
+                       char errbuf[1024];
+                       WARNING ("unixsock plugin: Deleting socket file \"%s\" failed: %s",
+                                       sa.sun_path,
+                                       sstrerror (errno, errbuf, sizeof (errbuf)));
+               }
+               else if (status == 0)
+               {
+                       INFO ("unixsock plugin: Successfully deleted socket file \"%s\".",
+                                       sa.sun_path);
+               }
+       }
+
        status = bind (sock_fd, (struct sockaddr *) &sa, sizeof (sa));
        if (status != 0)
        {
@@ -392,6 +411,13 @@ static int us_config (const char *key, const char *val)
        {
                sock_perms = (int) strtol (val, NULL, 8);
        }
+       else if (strcasecmp (key, "DeleteSocket") == 0)
+       {
+               if (IS_TRUE (val))
+                       delete_socket = 1;
+               else
+                       delete_socket = 0;
+       }
        else
        {
                return (-1);