Library interface to start ss local with a callback

src/local.c

@@ -1722,7 +1722,7 @@ main(int argc, char **argv)
 #else
 
 int
-start_ss_local_server(profile_t profile)
+_start_ss_local_server(profile_t profile, ss_local_callback callback, void *udata)
 {
     srand(time(NULL));
 
@@ -1831,6 +1831,10 @@ start_ss_local_server(profile_t profile)
     // Init connections
     cork_dllist_init(&connections);
 
+    if (callback) {
+        callback(listen_ctx.fd, udp_fd, udata);
+    }
+
     // Enter the loop
     ev_run(loop, 0);
 
@@ -1852,4 +1856,16 @@ start_ss_local_server(profile_t profile)
     return 0;
 }
 
+int
+start_ss_local_server(profile_t profile)
+{
+    return _start_ss_local_server(profile, NULL, NULL);
+}
+
+int
+start_ss_local_server_with_callback(profile_t profile, ss_local_callback callback, void *udata)
+{
+    return _start_ss_local_server(profile, callback, udata);
+}
+
 #endif

src/shadowsocks.h

@@ -64,6 +64,8 @@ typedef struct {
 extern "C" {
 #endif
 
+typedef void (*ss_local_callback) (int socks_fd, int udp_fd, void *data);
+
 /*
  * Create and start a shadowsocks local server.
  *
@@ -77,6 +79,16 @@ extern "C" {
  */
 int start_ss_local_server(profile_t profile);
 
+/*
+ * Create and start a shadowsocks local server, specifying a callback.
+ *
+ * The callback is invoked when the local server has started successfully. It passes the SOCKS
+ * server and UDP relay file descriptors, along with any supplied user data.
+ *
+ * Returns -1 on failure.
+ */
+int start_ss_local_server_with_callback(profile_t profile, ss_local_callback callback, void *udata);
+
 #ifdef __cplusplus
 }
 #endif