fix: support tcp binding ip:port or ip of ipv4 or ipv6

Author: oyaya

README.markdown

@@ -7855,13 +7855,14 @@ See also [ngx.socket.udp](#ngxsocketudp).
 
 tcpsock:bind
 ------------
-**syntax:** *ok, err = tcpsock:bind(address)*
+**syntax:** *ok, err = tcpsock:bind(address, port?)*
 
 **context:** *rewrite_by_lua*, access_by_lua*, content_by_lua*, ngx.timer.*, ssl_certificate_by_lua*,ssl_session_fetch_by_lua*,ssl_client_hello_by_lua**
 
 Just like the standard [proxy_bind](http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_bind) directive, this api makes the outgoing connection to a upstream server originate from the specified local IP address.
 
-Only IP addresses can be specified as the `address` argument.
+IP addresses can be specified as the `address` argument.
+The optional `port` argument is usually used in the transparent proxy.
 
 Here is an example for connecting to a TCP server from the specified local IP address:
 

src/ngx_http_lua_socket_tcp.c

@@ -862,8 +862,9 @@ ngx_http_lua_socket_tcp_bind(lua_State *L)
 
     n = lua_gettop(L);
 
-    if (n != 2) {
-        return luaL_error(L, "expecting 2 arguments, but got %d",
+    /* Correct the parameter check and allow 2 or 3 parameters */
+    if (n != 2 && n != 3) {
+        return luaL_error(L, "expecting 2 or 3 arguments, but got %d",
                           lua_gettop(L));
     }
 
@@ -881,6 +882,26 @@ ngx_http_lua_socket_tcp_bind(lua_State *L)
 
     luaL_checktype(L, 1, LUA_TTABLE);
 
+    port = 0;
+    /* handle case: host:port */
+    /* Hit the following parameter combination:
+     * sock:bind("127.0.0.1", port)     */
+    if (n == 3) {
+        if (!lua_isnumber(L, 3)) {
+            lua_pushnil(L);
+            lua_pushfstring(L, "expecting port to be a"
+                            "number but got type: %s", luaL_typename(L, 3));
+            return 2;
+        }
+
+        port = (int) lua_tointeger(L, 3);
+        if (port < 0 || port > 65535) {
+            lua_pushnil(L);
+            lua_pushfstring(L, "bad port number: %d", port);
+            return 2;
+        }
+    }
+
     text = (u_char *) luaL_checklstring(L, 2, &len);
 
     local = ngx_http_lua_parse_addr(L, text, len);
@@ -890,9 +911,11 @@ ngx_http_lua_socket_tcp_bind(lua_State *L)
         return 2;
     }
 
+    if (port > 0) {
+        ngx_inet_set_port(local->sockaddr, (in_port_t) port);
+    }
     /* TODO: we may reuse the userdata here */
     lua_rawseti(L, 1, SOCKET_BIND_INDEX);
-
     ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                    "lua tcp socket bind ip: %V", &local->name);
 
@@ -1145,6 +1168,10 @@ ngx_http_lua_socket_tcp_connect(lua_State *L)
 
     lua_rawgeti(L, 1, SOCKET_BIND_INDEX);
     local = lua_touserdata(L, -1);
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+        "lua tcp socket sock:connect ip: %V", &local->name);
+
     lua_pop(L, 1);
 
     if (local) {
@@ -3435,7 +3462,7 @@ ngx_http_lua_socket_tcp_handler(ngx_event_t *ev)
 static ngx_int_t
 ngx_http_lua_socket_tcp_get_peer(ngx_peer_connection_t *pc, void *data)
 {
-    /* empty */
+    pc->type = SOCK_STREAM;
     return NGX_OK;
 }
 

t/168-tcp-socket-bind.t

@@ -365,3 +365,64 @@ GET /t
 connected: 1
 --- no_error_log
 [error]
+
+
+
+=== TEST 7: upstream sockets bind with ip port
+--- config
+   server_tokens off;
+   location /t {
+        set $port $TEST_NGINX_SERVER_PORT;
+        content_by_lua_block {
+            local ip = "127.0.0.1"
+            local port = ngx.var.port
+
+            local sock = ngx.socket.tcp()
+
+            local ok, err = sock:bind(ip, 12345)
+            if not ok then
+                ngx.say("failed to bind", err)
+                return
+            end
+  
+            local ok, err = sock:connect("127.0.0.1", port)
+            if not ok then
+                ngx.say("failed to connect: ", err)
+                return
+            end
+
+            local ok, err = sock:setoption("reuseaddr", 1)
+            if not ok then
+                ngx.say("setoption reuseaddr failed: ", err)
+            end                  
+
+            ngx.say("connected: ", ok)
+
+            local bytes, err = sock:send("GET /foo HTTP/1.1\r\nHost: localhost\r\nConnection: keepalive\r\n\r\n")
+            if not bytes then
+                ngx.say("failed to send request: ", err)
+                return
+            end
+
+            local reader = sock:receiveuntil("\r\n0\r\n\r\n")
+            local data, err = reader()
+
+            if not data then
+                ngx.say("failed to receive response body: ", err)
+                return
+            end
+            sock:close()
+            ngx.say(data)
+
+        }
+    }
+
+    location /foo {
+        echo bind: $remote_addr:$remote_port;
+    }
+--- request
+GET /t
+--- response_body eval
+qr/bind:\s127\.0\.0\.1:12345|failed\s+to\s+connect:\s+address\s+already\s+in\s+use/
+--- error_log eval
+"lua tcp socket bind ip: 127.0.0.1"