New option listen::spoof-ip, only valid when using UNIX domain sockets

(so listen::file). This way you can override the IP address that users come
online with when they use the socket (default was and still is `127.0.0.1`).

Add a new guide https://www.unrealircd.org/docs/Running_Tor_hidden_service_with_UnrealIRCd
which uses the new listen::spoof-ip and optionally requires a services account.

doc/RELEASE-NOTES.md

@@ -81,6 +81,12 @@ You can help us by testing this release and reporting any issues at https://bugs
 * New module `whowasdb` (persistent `WHOWAS` history): this saves the WHOWAS
   history on disk periodically and when we terminate, so next server boot
   still has the WHOWAS history. This module is currently not loaded by default.
+* New option [listen::spoof-ip](https://www.unrealircd.org/docs/Listen_block#spoof-ip),
+  only valid when using UNIX domain sockets (so listen::file).
+  This way you can override the IP address that users come online with when
+  they use the socket (default was and still is `127.0.0.1`).
+* Add a new guide [Running Tor hidden service with UnrealIRCd](https://www.unrealircd.org/docs/Running_Tor_hidden_service_with_UnrealIRCd)
+  which uses the new listen::spoof-ip and optionally requires a services account.
 
 ### Changes:
 * The RPC modules are enabled by default now. This so remote RPC works

include/struct.h

@@ -1850,6 +1850,7 @@ struct ConfigItem_listen {
 	int options;			/**< e.g. LISTENER_BOUND if active */
 	int clients;			/**< Clients connected to this socket / listener */
 	int fd;				/**< File descriptor (if open), or -1 (if not open yet) */
+	char *spoof_ip;			/**< listen::spoof-ip (only for listen::file, if you want to override 127.0.0.1) */
 	SSL_CTX *ssl_ctx;		/**< SSL/TLS context */
 	TLSOptions *tls_options;	/**< SSL/TLS options */
 	WebServer *webserver;		/**< For the webserver module */

src/conf.c

@@ -4969,7 +4969,10 @@ void conf_listen_configure(const char *ip, int port, SocketType socket_type, int
 			/* Yeah, we actually do something with this one.. */
 			if (cep->value)
 				listen->mode = strtol(cep->value, NULL, 8); /* octal */
-		} else if (!strcmp(cep->name, "ip"))
+		}
+		else if (!strcmp(cep->name, "spoof-ip"))
+			safe_strdup(listen->spoof_ip, cep->value);
+		else if (!strcmp(cep->name, "ip"))
 			;
 		else if (!strcmp(cep->name, "port"))
 			;
@@ -5009,6 +5012,7 @@ int	_conf_listen(ConfigFile *conf, ConfigEntry *ce)
 	ConfigEntry *tlsconfig = NULL;
 	char *file = NULL;
 	char *ip = NULL;
+	char *spoof_ip = NULL;
 	int start=0, end=0, port;
 	int listener_flags =0;
 	Hook *h;
@@ -5028,6 +5032,10 @@ int	_conf_listen(ConfigFile *conf, ConfigEntry *ce)
 		{
 			ip = cep->value;
 		} else
+		if (!strcmp(cep->name, "spoof-ip"))
+		{
+			spoof_ip = cep->value;
+		} else
 		if (!strcmp(cep->name, "port"))
 		{
 			port_range(cep->value, &start, &end);
@@ -5092,7 +5100,7 @@ int	_test_listen(ConfigFile *conf, ConfigEntry *ce)
 	ConfigEntry *cep;
 	ConfigEntry *cepp;
 	int errors = 0;
-	char has_file = 0, has_ip = 0, has_port = 0, has_options = 0, port_6667 = 0;
+	char has_file = 0, has_ip = 0, has_port = 0, has_options = 0, port_6667 = 0, has_spoof_ip = 0;
 	char *file = NULL;
 	char *ip = NULL;
 	Hook *h;
@@ -5213,6 +5221,16 @@ int	_test_listen(ConfigFile *conf, ConfigEntry *ce)
 			has_file = 1;
 			file = cep->value;
 		} else
+		if (!strcmp(cep->name, "spoof-ip"))
+		{
+			has_spoof_ip = 1;
+			if (!is_valid_ip(cep->value))
+			{
+				config_error("%s:%i: listen::spoof-ip is not a valid IP address (%s)",
+				             cep->file->filename, cep->line_number, cep->value);
+				errors++;
+			}
+		} else
 		if (!strcmp(cep->name, "mode"))
 		{
 			int mode = strtol(cep->value, NULL, 8);
@@ -5325,6 +5343,13 @@ int	_test_listen(ConfigFile *conf, ConfigEntry *ce)
 		}
 	}
 
+	if (has_spoof_ip && !has_file)
+	{
+		config_error("%s:%d: listen::spoof-ip is only valid when listen::file is used (UNIX domain sockets)",
+		             ce->file->filename, ce->line_number);
+		errors++;
+	}
+
 	if (port_6667)
 		safe_strdup(port_6667_ip, ip);
 

src/socket.c

@@ -831,7 +831,7 @@ Client *add_connection(ConfigItem_listen *listener, int fd)
 	client->local->listener->clients++;
 
 	if (listener->socket_type == SOCKET_TYPE_UNIX)
-		ip = "127.0.0.1";
+		ip = listener->spoof_ip ? listener->spoof_ip : "127.0.0.1";
 	else
 		ip = getpeerip(client, fd, &port);