Add support for setting packet marks

cmake/config.cmake

@@ -8,6 +8,7 @@ endif()
 set(USE_BINDTODEVICE ${LINUX})
 set(USE_PMTU ${LINUX})
 set(USE_PKTINFO ${LINUX})
+set(USE_PACKET_MARK ${LINUX})
 
 if(${CMAKE_SYSTEM_NAME} MATCHES "OpenBSD")
   set(USE_MULTIAF_BIND FALSE)

src/config.c

@@ -554,6 +554,11 @@ void fastd_config_check(fastd_context_t *ctx, fastd_config_t *conf) {
 		exit_error(ctx, "config error: setting pmtu is not supported on this system");
 #endif
 
+#ifndef USE_PACKET_MARK
+	if (conf->packet_mark)
+		exit_error(ctx, "config error: setting a packet mark is not supported on this system");
+#endif
+
 	if (!conf->method_list) {
 		pr_warn(ctx, "no encryption method configured, falling back to method `null' (unencrypted)");
 		fastd_config_method(ctx, conf, "null");

src/config.y

@@ -95,11 +95,13 @@
 %token TOK_LIMIT
 %token TOK_LOG
 %token TOK_MAC
+%token TOK_MARK
 %token TOK_METHOD
 %token TOK_MODE
 %token TOK_MTU
 %token TOK_NO
 %token TOK_ON
+%token TOK_PACKET
 %token TOK_PEER
 %token TOK_PEERS
 %token TOK_PMTU
@@ -175,6 +177,7 @@ statement:	peer_group_statement
 	|	TOK_HIDE hide ';'
 	|	TOK_INTERFACE interface ';'
 	|	TOK_BIND bind ';'
+	|	TOK_PACKET TOK_MARK packet_mark ';'
 	|	TOK_MTU mtu ';'
 	|	TOK_PMTU pmtu ';'
 	|	TOK_MODE mode ';'
@@ -328,6 +331,10 @@ bind_default:
 		}
 	;
 
+packet_mark:	TOK_UINT {
+			conf->packet_mark = $1;
+		}
+
 mtu:		TOK_UINT {
 			if ($1 < 576 || $1 > 65535) {
 				fastd_config_error(&@$, ctx, conf, filename, depth, "invalid MTU");

src/fastd.h

@@ -172,6 +172,7 @@ struct fastd_config {
 	uint16_t mtu;
 	fastd_mode_t mode;
 
+	uint32_t packet_mark;
 	bool forward;
 	fastd_tristate_t pmtu;
 	bool secure_handshakes_set;

src/fastd_config.h.in

@@ -35,6 +35,7 @@
 #cmakedefine USE_BINDTODEVICE
 #cmakedefine USE_PMTU
 #cmakedefine USE_PKTINFO
+#cmakedefine USE_PACKET_MARK
 #cmakedefine USE_MULTIAF_BIND
 
 

src/lex.c

@@ -82,11 +82,13 @@ static const keyword_t keywords[] = {
 	{ "limit", TOK_LIMIT },
 	{ "log", TOK_LOG },
 	{ "mac", TOK_MAC },
+	{ "mark", TOK_MARK },
 	{ "method", TOK_METHOD },
 	{ "mode", TOK_MODE },
 	{ "mtu", TOK_MTU },
 	{ "no", TOK_NO },
 	{ "on", TOK_ON },
+	{ "packet", TOK_PACKET },
 	{ "peer", TOK_PEER },
 	{ "peers", TOK_PEERS },
 	{ "pmtu", TOK_PMTU },

src/socket.c

@@ -96,6 +96,15 @@ static int bind_socket(fastd_context_t *ctx, const fastd_bind_address_t *addr, b
 	}
 #endif
 
+#ifdef USE_PACKET_MARK
+	if (ctx->conf->packet_mark) {
+		if (setsockopt(fd, SOL_SOCKET, SO_MARK, &ctx->conf->packet_mark, sizeof(ctx->conf->packet_mark))) {
+			pr_error_errno(ctx, "setsockopt: unable to set packet mark");
+			goto error;
+		}
+	}
+#endif
+
 	fastd_peer_address_t bind_address = addr->addr;
 
 	if (bind_address.sa.sa_family == AF_UNSPEC) {