Refactor bind address configuration

src/config.c

@@ -224,6 +224,22 @@ bool fastd_config_crypto(fastd_context *ctx, fastd_config *conf, const char *alg
 	return false;
 }
 
+void fastd_config_bind_address(fastd_context *ctx, fastd_config *conf, const fastd_peer_address *address, const char *bindtodev, bool default_v4, bool default_v6) {
+	fastd_bind_address *addr = malloc(sizeof(fastd_bind_address));
+	addr->next = conf->bind_addrs;
+	conf->bind_addrs = addr;
+	conf->n_bind_addrs++;
+
+	addr->addr = *address;
+	addr->bindtodev = bindtodev ? strdup(bindtodev) : NULL;
+
+	if (address->sa.sa_family != AF_INET6 && (default_v4 || !conf->bind_addr_default_v4))
+		conf->bind_addr_default_v4 = addr;
+
+	if (address->sa.sa_family != AF_INET && (default_v6 || !conf->bind_addr_default_v6))
+		conf->bind_addr_default_v6 = addr;
+}
+
 bool fastd_config_add_log_file(fastd_context *ctx, fastd_config *conf, const char *name, int level) {
 	char *name2 = strdup(name);
 	char *name3 = strdup(name);
@@ -418,6 +434,7 @@ bool fastd_read_config(fastd_context *ctx, fastd_config *conf, const char *filen
 }
 
 static void count_peers(fastd_context *ctx, fastd_config *conf) {
+	conf->n_peers = 0;
 	conf->n_floating = 0;
 	conf->n_v4 = 0;
 	conf->n_v6 = 0;
@@ -427,6 +444,8 @@ static void count_peers(fastd_context *ctx, fastd_config *conf) {
 
 	fastd_peer_config *peer;
 	for (peer = conf->peers; peer; peer = peer->next) {
+		conf->n_peers++;
+
 		switch (peer->address.sa.sa_family) {
 		case AF_UNSPEC:
 			if (peer->hostname)
@@ -629,35 +648,29 @@ static void option_bind(fastd_context *ctx, fastd_config *conf, const char *arg)
 		l = 0;
 	}
 
-	fastd_bind_address *addr = calloc(1, sizeof(fastd_bind_address));
+	fastd_peer_address addr = {};
-	addr->next = conf->bind_addrs;
-	conf->bind_addrs = addr;
 
 	if (strcmp(addrstr, "any") == 0) {
 		/* nothing to do */
 	}
 	else if (arg[0] == '[') {
-		addr->addr.in6.sin6_family = AF_INET6;
+		addr.in6.sin6_family = AF_INET6;
-		addr->addr.in6.sin6_port = htons(l);
+		addr.in6.sin6_port = htons(l);
 
-		if (inet_pton(AF_INET6, addrstr, &addr->addr.in6.sin6_addr) != 1)
+		if (inet_pton(AF_INET6, addrstr, &addr.in6.sin6_addr) != 1)
 			exit_error(ctx, "invalid bind address `%s'", addrstr);
 	}
 	else {
-		addr->addr.in.sin_family = AF_INET;
+		addr.in.sin_family = AF_INET;
-		addr->addr.in.sin_port = htons(l);
+		addr.in.sin_port = htons(l);
 
-		if (inet_pton(AF_INET, addrstr, &addr->addr.in.sin_addr) != 1)
+		if (inet_pton(AF_INET, addrstr, &addr.in.sin_addr) != 1)
 			exit_error(ctx, "invalid bind address `%s'", addrstr);
 	}
 
-	if (!conf->bind_addr_default_v4 && addr->addr.sa.sa_family != AF_INET6)
-		conf->bind_addr_default_v4 = addr;
-
-	if (!conf->bind_addr_default_v6 && addr->addr.sa.sa_family != AF_INET)
-		conf->bind_addr_default_v6 = addr;
-
 	free(addrstr);
+
+	fastd_config_bind_address(ctx, conf, &addr, NULL, false, false);
 }
 
 static void option_protocol(fastd_context *ctx, fastd_config *conf, const char *arg) {

src/config.l

@@ -104,12 +104,12 @@ default		{ TOKEN(TOK_DEFAULT); }
 [0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3} {
 			UPDATE_LOCATION;
 
-			if (!inet_pton(AF_INET, yytext, &yylval->addr)) {
+			if (!inet_pton(AF_INET, yytext, &yylval->addr4)) {
 				yylval->error = "invalid address";
 				return -1;
 			}
 
-			return TOK_ADDR;
+			return TOK_ADDR4;
 		}
 
 [;:\{\}]	{ UPDATE_LOCATION; return yytext[0]; }

src/config.y

@@ -45,8 +45,9 @@
 	fastd_string_stack *str;
 	char *error;
 	bool boolean;
-	struct in_addr addr;
+	struct in_addr addr4;
 	struct in6_addr addr6;
+	fastd_peer_address addr;
 }
 
 %token START_CONFIG
@@ -99,7 +100,7 @@
 %token TOK_USE
 %token TOK_DEFAULT
 
-%token <addr> TOK_ADDR
+%token <addr4> TOK_ADDR4
 %token <addr6> TOK_ADDR6
 
 
@@ -121,6 +122,10 @@
 %type <str> maybe_as
 %type <num> maybe_af
 %type <boolean> maybe_float
+%type <addr> bind_address
+%type <str> maybe_bind_interface
+%type <num> maybe_bind_default
+%type <num> bind_default
 
 %%
 start:		START_CONFIG config
@@ -188,70 +193,50 @@ log_level:	TOK_FATAL	{ $$ = LOG_CRIT; }
 interface:	TOK_STRING	{ free(conf->ifname); conf->ifname = strdup($1->str); }
 	;
 
-bind_new:	{
+bind:		bind_address maybe_bind_interface maybe_bind_default {
-			fastd_bind_address *addr = calloc(1, sizeof(fastd_bind_address));
+			fastd_config_bind_address(ctx, conf, &$1, $2 ? $2->str : NULL, $3 == AF_UNSPEC || $3 == AF_INET, $3 == AF_UNSPEC || $3 == AF_INET6);
-			addr->next = conf->bind_addrs;
-			conf->bind_addrs = addr;
 		}
 	;
 
-bind:		bind_new TOK_ADDR maybe_port maybe_bind_to_device maybe_bind_default {
+bind_address:
-			conf->bind_addrs->addr.in.sin_family = AF_INET;
+		TOK_ADDR4 maybe_port {
-			conf->bind_addrs->addr.in.sin_addr = $2;
+			$$ = (fastd_peer_address){ .in = { .sin_family = AF_INET, .sin_addr = $1, .sin_port = htons($2) } };
-			conf->bind_addrs->addr.in.sin_port = htons($3);
-			if (!conf->bind_addr_default_v4)
-				conf->bind_addr_default_v4 = conf->bind_addrs;
 		}
-	|	bind_new TOK_ADDR6 maybe_port maybe_bind_to_device maybe_bind_default {
+	|	TOK_ADDR6 maybe_port {
-			conf->bind_addrs->addr.in6.sin6_family = AF_INET6;
+			$$ = (fastd_peer_address){ .in6 = { .sin6_family = AF_INET6, .sin6_addr = $1, .sin6_port = htons($2) } };
-			conf->bind_addrs->addr.in6.sin6_addr = $2;
-			conf->bind_addrs->addr.in6.sin6_port = htons($3);
-			if (!conf->bind_addr_default_v6)
-				conf->bind_addr_default_v6 = conf->bind_addrs;
 		}
-	|	bind_new TOK_ANY maybe_port maybe_bind_to_device maybe_bind_default {
+	|	TOK_ANY maybe_port {
-			conf->bind_addrs->addr.in.sin_port = htons($3);
+			$$ = (fastd_peer_address){ .in = { .sin_family = AF_UNSPEC, .sin_port = htons($2) } };
-			if (!conf->bind_addr_default_v4)
-				conf->bind_addr_default_v4 = conf->bind_addrs;
-			if (!conf->bind_addr_default_v6)
-				conf->bind_addr_default_v6 = conf->bind_addrs;
 		}
 	;
 
-maybe_bind_to_device:
+maybe_bind_interface:
 		TOK_INTERFACE TOK_STRING {
-			conf->bind_addrs->bindtodev = strdup($2->str);
+			$$ = $2;
+		}
+	|	{
+			$$ = NULL;
 		}
-	|
 	;
 
 maybe_bind_default:
-		TOK_DEFAULT bind_default
+		TOK_DEFAULT bind_default {
-	|
+			$$ = $2;
+		}
+	|	{
+			$$ = -1;
+		}
 	;
 
 bind_default:
 		TOK_IPV4 {
-			if (conf->bind_addrs->addr.sa.sa_family == AF_INET6) {
+			$$ = AF_INET;
-				fastd_config_error(&@$, ctx, conf, filename, depth, "tried to set IPv6 bind as IPv4 default");
-				YYERROR;
-			}
-
-			conf->bind_addr_default_v4 = conf->bind_addrs;
 		}
 	|	TOK_IPV6 {
-			if (conf->bind_addrs->addr.sa.sa_family == AF_INET) {
+			$$ = AF_INET6;
-				fastd_config_error(&@$, ctx, conf, filename, depth, "tried to set IPv4 bind as IPv6 default");
-				YYERROR;
-			}
-
-			conf->bind_addr_default_v6 = conf->bind_addrs;
 		}
 	|	{
-			if (conf->bind_addrs->addr.sa.sa_family != AF_INET6)
+			$$ = AF_UNSPEC;
-				conf->bind_addr_default_v4 = conf->bind_addrs;
-			if (conf->bind_addrs->addr.sa.sa_family != AF_INET)
-				conf->bind_addr_default_v6 = conf->bind_addrs;
 		}
 	;
 
@@ -340,7 +325,7 @@ peer_statement: TOK_REMOTE peer_remote ';'
 	|	TOK_INCLUDE peer_include  ';'
 	;
 
-peer_remote:	TOK_ADDR port {
+peer_remote:	TOK_ADDR4 port {
 			free(conf->peers->hostname);
 			conf->peers->hostname = NULL;
 

src/fastd.c

@@ -147,48 +147,38 @@ static void crypto_free(fastd_context *ctx) {
 }
 
 
-static unsigned max_sockets(const fastd_config *conf) {
+static void init_sockets(fastd_context *ctx) {
-	unsigned n = 0;
+	ctx->socks = malloc(ctx->conf->n_bind_addrs * sizeof(fastd_socket));
-	fastd_bind_address *addr;
 
-	for (addr = conf->bind_addrs; addr; addr = addr->next)
+	unsigned i;
-		n++;
+	fastd_bind_address *addr = ctx->conf->bind_addrs;
+	for (i = 0; i < ctx->conf->n_bind_addrs; i++) {
+		ctx->socks[i] = (fastd_socket){-2, addr};
 
-	return n;
+		if (addr == ctx->conf->bind_addr_default_v4)
+			ctx->sock_default_v4 = &ctx->socks[i];
+
+		if (addr == ctx->conf->bind_addr_default_v6)
+			ctx->sock_default_v6 = &ctx->socks[i];
+
+		addr = addr->next;
 	}
 
-static void init_sockets(fastd_context *ctx) {
+	ctx->n_socks = ctx->conf->n_bind_addrs;
-	static const fastd_bind_address bind_any = {};
+}
 
-	const fastd_bind_address *addr = ctx->conf->bind_addrs;
+static int bind_socket(fastd_context *ctx, const fastd_bind_address *addr, bool warn) {
-	const fastd_bind_address *default_v4 = ctx->conf->bind_addr_default_v4;
-	const fastd_bind_address *default_v6 = ctx->conf->bind_addr_default_v6;
-
-	if (!addr)
-		addr = default_v4 = default_v6 = &bind_any;
-
-	unsigned n_v4 = 0, n_v6 = 0;
-	bool info_ipv6 = true;
-
-	ctx->socks = calloc(max_sockets(ctx->conf), sizeof(fastd_socket));
-
-	while (addr) {
 	int fd = -1;
 	int af = AF_UNSPEC;
 
 	if (addr->addr.sa.sa_family != AF_INET) {
 		fd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
-			if (fd < 0) {
+		if (fd >= 0) {
-				if (info_ipv6) {
-					pr_warn(ctx, "there seems to be no IPv6 support; explicitely bind to an IPv4 address (or 0.0.0.0) to disable this warning");
-					info_ipv6 = false;
-				}
-			}
-			else {
 			af = AF_INET6;
 
 			int val = (addr->addr.sa.sa_family == AF_INET6);
 			if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val))) {
+				if (warn)
 					pr_warn_errno(ctx, "setsockopt");
 				goto error;
 			}
@@ -207,6 +197,7 @@ static void init_sockets(fastd_context *ctx) {
 
 	if (addr->bindtodev) {
 		if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, addr->bindtodev, strlen(addr->bindtodev))) {
+			if (warn)
 				pr_warn_errno(ctx, "setsockopt: unable to bind to device");
 			goto error;
 		}
@@ -225,36 +216,12 @@ static void init_sockets(fastd_context *ctx) {
 	}
 
 	if (bind(fd, (struct sockaddr*)&bind_address, af == AF_INET6 ? sizeof(struct sockaddr_in6) : sizeof(struct sockaddr_in))) {
+		if (warn)
 			pr_warn(ctx, "bind");
 		goto error;
 	}
 
-		ctx->socks[ctx->n_socks] = (fastd_socket){fd, addr};
+	return fd;
-
-		if (af == AF_INET6) {
-			if (addr == default_v6)
-				ctx->sock_default_v6 = &ctx->socks[ctx->n_socks];
-
-			n_v6++;
-
-			if (addr->addr.sa.sa_family == AF_UNSPEC) {
-				if (addr == default_v4)
-					ctx->sock_default_v4 = &ctx->socks[ctx->n_socks];
-
-				n_v4++;
-			}
-		}
-		else {
-			if (addr == default_v4)
-				ctx->sock_default_v4 = &ctx->socks[ctx->n_socks];
-
-			n_v4++;
-		}
-
-		ctx->n_socks++;
-
-		addr = addr->next;
-		continue;
 
  error:
 	if (fd >= 0) {
@@ -262,25 +229,32 @@ static void init_sockets(fastd_context *ctx) {
 			pr_error_errno(ctx, "close");
 	}
 
+	if (warn) {
 		if (addr->bindtodev)
 			pr_warn(ctx, "unable to bind to %I on `%s'", &addr->addr, addr->bindtodev);
                 else
 			pr_warn(ctx, "unable to bind to %I", &addr->addr);
-
-		if (addr == default_v4 || addr == default_v6)
-			exit_error(ctx, "unable to bind to default address");
-
-		addr = addr->next;
 	}
 
-	if (!ctx->n_socks)
+	return -1;
-		exit_error(ctx, "all bind attempts failed");
+}
 
-	if (!n_v4 && ctx->conf->n_v4)
+static void bind_sockets(fastd_context *ctx) {
-		pr_warn(ctx, "there are IPv4 peers defined, but there was no successful IPv4 bind");
+	unsigned i;
 
-	if (!n_v6 && ctx->conf->n_v6)
+	for (i = 0; i < ctx->n_socks; i++) {
-		pr_warn(ctx, "there are IPv6 peers defined, but there was no successful IPv4 bind");
+		if (ctx->socks[i].fd >= 0)
+			continue;
+
+		ctx->socks[i].fd = bind_socket(ctx, ctx->socks[i].addr, ctx->socks[i].fd < -1);
+
+		if (ctx->socks[i].fd >= 0) {
+			if (ctx->socks[i].addr->bindtodev)
+				pr_info(ctx, "successfully bound to %I on `%s'", &ctx->socks[i].addr->addr, ctx->socks[i].addr->bindtodev);
+			else
+				pr_info(ctx, "successfully bound to %I", &ctx->socks[i].addr->addr);
+		}
+	}
 }
 
 static void init_tuntap(fastd_context *ctx) {
@@ -315,12 +289,17 @@ static void init_tuntap(fastd_context *ctx) {
 
 	ctx->ifname = strndup(ifr.ifr_name, IFNAMSIZ);
 
-	int ctl_sock = ctx->socks[0].fd;
+	int ctl_sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
+	if (ctl_sock < 0)
+		exit_errno(ctx, "socket");
 
 	ifr.ifr_mtu = ctx->conf->mtu;
 	if (ioctl(ctl_sock, SIOCSIFMTU, &ifr) < 0)
 		exit_errno(ctx, "SIOCSIFMTU ioctl failed");
 
+	if (close(ctl_sock))
+		pr_error_errno(ctx, "close");
+
 	pr_debug(ctx, "tun/tap device initialized.");
 }
 
@@ -924,6 +903,8 @@ int main(int argc, char *argv[]) {
 	pr_info(&ctx, "fastd " FASTD_VERSION " starting");
 
 	init_sockets(&ctx);
+	bind_sockets(&ctx);
+
 	init_tuntap(&ctx);
 
 	init_peers(&ctx);
@@ -949,6 +930,8 @@ int main(int argc, char *argv[]) {
 
 	while (!terminate) {
 		handle_tasks(&ctx);
+
+		bind_sockets(&ctx);
 		handle_input(&ctx);
 
 		maintenance(&ctx);

src/fastd.h

@@ -160,6 +160,7 @@ struct _fastd_config {
 
 	char *ifname;
 
+	unsigned n_bind_addrs;
 	fastd_bind_address *bind_addrs;
 
 	fastd_bind_address *bind_addr_default_v4;
@@ -187,6 +188,7 @@ struct _fastd_config {
 	fastd_string_stack *peer_dirs;
 	fastd_peer_config *peers;
 
+	unsigned n_peers;
 	unsigned n_floating;
 	unsigned n_v4;
 	unsigned n_v6;
@@ -277,6 +279,7 @@ bool fastd_config_protocol(fastd_context *ctx, fastd_config *conf, const char *n
 bool fastd_config_method(fastd_context *ctx, fastd_config *conf, const char *name);
 bool fastd_config_crypto(fastd_context *ctx, fastd_config *conf, const char *alg, const char *impl);
 bool fastd_config_add_log_file(fastd_context *ctx, fastd_config *conf, const char *name, int level);
+void fastd_config_bind_address(fastd_context *ctx, fastd_config *conf, const fastd_peer_address *address, const char *bindtodev, bool default_v4, bool default_v6);
 void fastd_configure(fastd_context *ctx, fastd_config *conf, int argc, char *const argv[]);
 void fastd_reconfigure(fastd_context *ctx, fastd_config *conf);
 void fastd_config_release(fastd_context *ctx, fastd_config *conf);