# HG changeset patch
# User jbe
# Date 1428664114 -7200
# Node ID 118e320a7812cb2fe99b189b0c74f51527cbfd4f
# Parent  d8469c1039e64ed0fabc68b43182eec9e6d08cf9
Delete local socket in filesystem before and after listening

diff -r d8469c1039e6 -r 118e320a7812 moonbridge_io.c
--- a/moonbridge_io.c	Fri Apr 10 02:40:43 2015 +0200
+++ b/moonbridge_io.c	Fri Apr 10 13:08:34 2015 +0200
@@ -12,6 +12,7 @@
 #include <netinet/tcp.h>
 #include <arpa/inet.h>
 #include <sys/types.h>
+#include <sys/stat.h>
 #include <netdb.h>
 #include <signal.h>
 #include <time.h>
@@ -63,6 +64,7 @@
 
 typedef struct {
   int fd;
+  sa_family_t addrfam;
   int nonblocking;
 } moonbr_io_listener_t;
 
@@ -760,6 +762,7 @@
 static int moonbr_io_locallisten(lua_State *L) {
   moonbr_io_listener_t *listener;
   const char *path;
+  struct stat sb;
   struct sockaddr_un sockaddr = { .sun_family = AF_LOCAL };
   const int path_maxlen = sizeof(struct sockaddr_un) - (
     (void *)sockaddr.sun_path - (void *)&sockaddr
@@ -768,6 +771,9 @@
   path = luaL_checkstring(L, 1);
   if (strlen(path) > path_maxlen) luaL_error(L, "Path too long; only %i characters allowed", path_maxlen);
   strcpy(sockaddr.sun_path, path);
+  if (stat(path, &sb) == 0) {
+    if (S_ISSOCK(sb.st_mode)) unlink(path);
+  }
   listener = lua_newuserdata(L, sizeof(moonbr_io_listener_t));
   listener->fd = -1;
   luaL_setmetatable(L, MOONBR_IO_LISTENER_MT_REGKEY);
@@ -797,6 +803,7 @@
     return 2;
   }
   listener->fd = sock;
+  listener->addrfam = AF_LOCAL;
   listener->nonblocking = -1;
   return 1;
 }
@@ -838,6 +845,7 @@
   }
   addrinfo = res;
   moonbr_io_tcpconnect_found:
+  listener->addrfam = addrinfo->ai_family;
   sock = socket(
     addrinfo->ai_family,
     addrinfo->ai_socktype | SOCK_CLOEXEC,
@@ -925,16 +933,31 @@
 
 static int moonbr_io_unlisten(lua_State *L) {
   moonbr_io_listener_t *listener;
+  struct sockaddr_un addr;
+  socklen_t addrlen;
+  struct stat sb;
   listener = luaL_checkudata(L, 1, MOONBR_IO_LISTENER_MT_REGKEY);
   if (listener->fd < 0) luaL_error(L, "Attempt to close a closed listener");
+  addrlen = sizeof(addr);
+  if (getsockname(listener->fd, (struct sockaddr *)&addr, &addrlen)) addrlen = 0;
   if (close(listener->fd)) {
     moonbr_io_errmsg();
     listener->fd = -1;
+    if (addrlen && addrlen <= sizeof(addr)) {
+      if (stat(addr.sun_path, &sb) == 0) {
+        if (S_ISSOCK(sb.st_mode)) unlink(addr.sun_path);
+      }
+    }
     lua_pushnil(L);
     lua_pushstring(L, errmsg);
     return 2;
   }
   listener->fd = -1;
+  if (addrlen && addrlen <= sizeof(addr)) {
+    if (stat(addr.sun_path, &sb) == 0) {
+      if (S_ISSOCK(sb.st_mode)) unlink(addr.sun_path);
+    }
+  }
   lua_pushboolean(L, 1);
   return 1;
 }
diff -r d8469c1039e6 -r 118e320a7812 reference.txt
--- a/reference.txt	Fri Apr 10 02:40:43 2015 +0200
+++ b/reference.txt	Fri Apr 10 13:08:34 2015 +0200
@@ -264,11 +264,8 @@
 ### moonbridge_io.locallisten(path)
 
 Attempts to create a local socket (also known as Unix Domain Socket) to accept
-incoming connections.
-
-Note: The caller is responsible for unlinking the socket in the filesystem
-before opening or after closing the listening socket. If a file (or socket)
-already exists at the given path, this function returns with an I/O error.
+incoming connections. If the file does already exist and is a socket, then it
+is deleted automatically before being re-created.
 
 In case of an I/O error, nil (as first return value) plus an error message (as
 second return value) may be returned.On success, a listener object is returned