Merge branch 'pick-local-port'

Author: daurnimator

doc/modules/http.client.md

@@ -37,6 +37,7 @@ This function returns a new connection to an HTTP server. Once a connection has
 		e.g. `"80"` or `80`
 	  - `path` (string): path to connect to (UNIX sockets)
 	  - `v6only` (boolean, optional): if the `IPV6_V6ONLY` flag should be set on the underlying socket.
+	  - `bind` (string, optional): the local outgoing address and optionally port to bind in the form of `"address[:port]"`, IPv6 addresses may be specified via square bracket notation. e.g. `"127.0.0.1"`, `"127.0.0.1:50000"`, `"[::1]:30000"`.
   - `timeout` (optional) is the maximum amount of time (in seconds) to allow for connection to be established.  
 	This includes time for DNS lookup, connection, TLS negotiation (if TLS enabled) and in the case of HTTP 2: settings exchange.
 

doc/modules/http.request.md

@@ -22,6 +22,15 @@ The host this request should be sent to.
 The port this request should be sent to.
 
 
+### `request.bind` <!-- --> {#http.request.bind}
+
+The local outgoing address and optionally port to bind in the form of `"address[:port]"`. Default is to allow the kernel to choose an address+port.
+
+IPv6 addresses may be specified via square bracket notation. e.g. `"127.0.0.1"`, `"127.0.0.1:50000"`, `"[::1]:30000"`.
+
+This option is rarely needed. Supplying an address can be used to manually select the network interface to make the request from, while supplying a port is only really used to interoperate with firewalls or devices that demand use of a certain port.
+
+
 ### `request.tls` <!-- --> {#http.request.tls}
 
 A boolean indicating if TLS should be used.

http/client.lua

@@ -84,11 +84,30 @@ local function negotiate(s, options, timeout)
 end
 
 local function connect(options, timeout)
+	local bind = options.bind
+	if bind ~= nil then
+		assert(type(bind) == "string")
+		local bind_address, bind_port = bind:match("^(.-):(%d+)$")
+		if bind_address then
+			bind_port = tonumber(bind_port, 10)
+		else
+			bind_address = bind
+		end
+		local ipv6 = bind_address:match("^%[([:%x]+)%]$")
+		if ipv6 then
+			bind_address = ipv6
+		end
+		bind = {
+			address = bind_address;
+			port = bind_port;
+		}
+	end
 	local s, err, errno = ca.fileresult(cs.connect {
 		family = options.family;
 		host = options.host;
 		port = options.port;
 		path = options.path;
+		bind = bind;
 		sendname = false;
 		v6only = options.v6only;
 		nodelay = true;

http/request.lua

@@ -107,6 +107,7 @@ function request_methods:clone()
 	return setmetatable({
 		host = self.host;
 		port = self.port;
+		bind = self.bind;
 		tls = self.tls;
 		ctx = self.ctx;
 		sendname = self.sendname;
@@ -467,6 +468,7 @@ function request_methods:go(timeout)
 		connection, err, errno = client.connect({
 			host = host;
 			port = port;
+			bind = self.bind;
 			tls = tls;
 			ctx = self.ctx;
 			sendname = self.sendname;