3 files changed, 24 insertions, 0 deletions
diff --git a/sysdep/unix/io.c b/sysdep/unix/io.c
index 4030b86b..ed5b89fa 100644
--- a/sysdep/unix/io.c
+++ b/sysdep/unix/io.c
@@ -1194,3 +1194,23 @@ io_loop(void)
 	}
     }
 }
+
+void
+test_old_bird(char *path)
+{
+  int fd;
+  struct sockaddr_un sa;
+
+  fd = socket(AF_UNIX, SOCK_STREAM, 0);
+
+  if (fd < 0)
+    die("Cannot create socket: %m");
+  bzero(&sa, sizeof(sa));
+  sa.sun_family = AF_UNIX;
+  strcpy(sa.sun_path, path);
+  if (connect(fd, (struct sockaddr *) &sa, SUN_LEN(&sa)) == 0)
+    die("I found another BIRD running.");
+  close(fd);
+}
+
+
diff --git a/sysdep/unix/main.c b/sysdep/unix/main.c
index ec8802bd..335f42a1 100644
--- a/sysdep/unix/main.c
+++ b/sysdep/unix/main.c
@@ -412,6 +412,8 @@ main(int argc, char **argv)
     log_init_debug("");
   log_init(debug_flag, 1);
 
+  test_old_bird(path_control_socket);
+
   DBG("Initializing.\n");
   resource_init();
   olock_init();
diff --git a/sysdep/unix/unix.h b/sysdep/unix/unix.h
index 72b6ef56..997a4088 100644
--- a/sysdep/unix/unix.h
+++ b/sysdep/unix/unix.h
@@ -46,6 +46,8 @@ void fill_in_sockaddr(sockaddr *sa, ip_addr a, unsigned port);
 void get_sockaddr(sockaddr *sa, ip_addr *a, unsigned *port, int check);
 int sk_open_unix(struct birdsock *s, char *name);
 void *tracked_fopen(struct pool *, char *name, char *mode);
+void test_old_bird(char *path);
+
 
 /* krt.c bits */