First work towards multi-interface support

10 files changed, 121 insertions, 96 deletions

diff --git a/src/fastd.c b/src/fastd.c
index 52bbf9c..228d65e 100644
--- a/src/fastd.c
+++ b/src/fastd.c
@@ -211,13 +211,19 @@ static inline void on_pre_up(void) {
 }
 
 /** Calls the on-up command */
-static inline void on_up(void) {
-	fastd_shell_command_exec(&conf.on_up, NULL);
+static inline void on_up(fastd_iface_t *iface) {
+	fastd_shell_env_t *env = fastd_shell_env_alloc();
+	fastd_shell_env_set_iface(env, iface);
+	fastd_shell_command_exec(&conf.on_up, env);
+	fastd_shell_env_free(env);
 }
 
 /** Calls the on-down command */
-static inline void on_down(void) {
-	fastd_shell_command_exec(&conf.on_down, NULL);
+static inline void on_down(fastd_iface_t *iface) {
+	fastd_shell_env_t *env = fastd_shell_env_alloc();
+	fastd_shell_env_set_iface(env, iface);
+	fastd_shell_command_exec(&conf.on_down, env);
+	fastd_shell_env_free(env);
 }
 
 /** Calls the on-post-down command */
@@ -520,7 +526,7 @@ static inline void init(int argc, char *argv[]) {
 
 	on_pre_up();
 
-	fastd_tuntap_open();
+	ctx.iface = fastd_tuntap_open(NULL);
 
 	/* change groups before trying to write the PID file as they can be relevant for file access */
 	set_groups();
@@ -541,7 +547,7 @@ static inline void init(int argc, char *argv[]) {
 	if (conf.drop_caps == DROP_CAPS_EARLY)
 		drop_caps();
 
-	on_up();
+	on_up(ctx.iface);
 
 	if (conf.drop_caps == DROP_CAPS_ON)
 		drop_caps();
@@ -632,17 +638,17 @@ static void delete_peers(void) {
    Performs cleanup of resources used by fastd
 
    Besides running the on-down scripts and closing the TUN/TAP interface, this
-   also frees all memory allocatedby fastd to make debugging memory leaks with
+   also frees all memory allocated by fastd to make debugging memory leaks with
    valgrind as easy as possible.
 */
 static inline void cleanup(void) {
 	pr_info("terminating fastd");
 
-	on_down();
-
 	delete_peers();
 
-	fastd_tuntap_close();
+	on_down(ctx.iface);
+	fastd_tuntap_close(ctx.iface);
+
 	fastd_status_close();
 	close_sockets();
 	fastd_poll_free();
@@ -658,7 +664,6 @@ static inline void cleanup(void) {
 	VECTOR_FREE(ctx.eth_addrs);
 
 	free(ctx.protocol_state);
-	free(ctx.ifname);
 
 #ifdef ENABLE_OPENSSL
 	CONF_modules_free();
diff --git a/src/fastd.h b/src/fastd.h
index ba6acfb..5e81890 100644
--- a/src/fastd.h
+++ b/src/fastd.h
@@ -154,6 +154,13 @@ struct fastd_socket {
 	fastd_peer_t *peer;			/**< If the socket belongs to a single peer (as it was create dynamically when sending a handshake), contains that peer */
 };
 
+/** A TUN/TAP interface */
+struct fastd_iface {
+	fastd_poll_fd_t fd;			/**< The file descriptor of the tunnel interface */
+	char *name;				/**< The interface name */
+	fastd_peer_t *peer;			/**< The peer associated with the interface (if any) */
+};
+
 
 /** Type of a traffic stat counter */
 typedef enum fastd_stat_type {
@@ -261,16 +268,17 @@ struct fastd_config {
 	bool verify_config;			/**< Does basic verification of the configuration and exits */
 };
 
+
 /** The dynamic state of \em fastd */
 struct fastd_context {
 	bool log_initialized;			/**< true if the logging facilities have been properly initialized */
 
-	char *ifname;				/**< The actual interface name */
-
 	int64_t started;			/**< The timestamp when fastd was started */
 
 	int64_t now;				/**< The current monotonous timestamp in microseconds after an arbitrary point in time */
 
+	fastd_iface_t *iface;			/**< The default tunnel interface */
+
 	uint64_t next_peer_id;			/**< An monotonously increasing ID peers are identified with in some components */
 	VECTOR(fastd_peer_t *) peers;		/**< The currectly active peers */
 
@@ -305,8 +313,6 @@ struct fastd_context {
 
 	pthread_attr_t detached_thread;		/**< pthread_attr_t for creating detached threads */
 
-	fastd_poll_fd_t tunfd;			/**< The file descriptor of the tunnel interface */
-
 #ifdef __ANDROID__
 	int android_ctrl_sock_fd;		/**< The unix domain socket for communicating with Android GUI */
 #endif
@@ -362,10 +368,10 @@ bool fastd_android_protect_socket(int fd);
 
 void fastd_resolve_peer(fastd_peer_t *peer, fastd_remote_t *remote);
 
-void fastd_tuntap_open(void);
-void fastd_tuntap_handle(void);
-void fastd_tuntap_write(fastd_buffer_t buffer);
-void fastd_tuntap_close(void);
+fastd_iface_t * fastd_tuntap_open(fastd_peer_t *peer);
+void fastd_tuntap_handle(fastd_iface_t *iface);
+void fastd_tuntap_write(fastd_iface_t *iface, fastd_buffer_t buffer);
+void fastd_tuntap_close(fastd_iface_t *iface);
 
 void fastd_cap_init(void);
 void fastd_cap_drop(void);
diff --git a/src/peer.c b/src/peer.c
index 5ac517c..417e213 100644
--- a/src/peer.c
+++ b/src/peer.c
@@ -44,6 +44,8 @@ void fastd_peer_set_shell_env(fastd_shell_env_t *env, const fastd_peer_t *peer,
 
 	fastd_shell_env_set(env, "PEER_NAME", peer ? peer->name : NULL);
 
+	fastd_shell_env_set_iface(env, peer->iface ?: ctx.iface);
+
 	switch(local_addr ? local_addr->sa.sa_family : AF_UNSPEC) {
 	case AF_INET:
 		inet_ntop(AF_INET, &local_addr->in.sin_addr, buf, sizeof(buf));
diff --git a/src/peer.h b/src/peer.h
index 348b256..631957e 100644
--- a/src/peer.h
+++ b/src/peer.h
@@ -72,6 +72,8 @@ struct fastd_peer {
 	fastd_protocol_key_t *key;			/**< The peer's public key */
 	fastd_protocol_peer_state_t *protocol_state;	/**< Protocol-specific peer state */
 
+	fastd_iface_t *iface;				/**< The interface this peer is associated with */
+
 	/* Starting here, more dynamic fields follow: */
 
 	/** The socket used by the peer. This can either be a common bound socket or a
diff --git a/src/poll.c b/src/poll.c
index 6c83f97..dbb3c18 100644
--- a/src/poll.c
+++ b/src/poll.c
@@ -82,8 +82,12 @@ static inline void handle_fd(fastd_poll_fd_t *fd, bool input, bool error) {
 #endif
 
 	case POLL_TYPE_IFACE:
+	{
+		fastd_iface_t *iface = container_of(fd, fastd_iface_t, fd);
+
 		if (input)
-			fastd_tuntap_handle();
+			fastd_tuntap_handle(iface);
+	}
 		break;
 
 	case POLL_TYPE_SOCKET:
diff --git a/src/receive.c b/src/receive.c
index 8bb926c..a19039e 100644
--- a/src/receive.c
+++ b/src/receive.c
@@ -306,7 +306,7 @@ void fastd_handle_receive(fastd_peer_t *peer, fastd_buffer_t buffer, bool reorde
 	if (reordered)
 		fastd_stats_add(peer, STAT_RX_REORDERED, buffer.len);
 
-	fastd_tuntap_write(buffer);
+	fastd_tuntap_write(peer->iface ?: ctx.iface, buffer);
 
 	if (conf.mode == MODE_TAP && conf.forward) {
 		fastd_send_data(buffer, peer);
diff --git a/src/shell.c b/src/shell.c
index 90102a2..3a617be 100644
--- a/src/shell.c
+++ b/src/shell.c
@@ -75,6 +75,13 @@ void fastd_shell_env_free(fastd_shell_env_t *env) {
 	free(env);
 }
 
+void fastd_shell_env_set_iface(fastd_shell_env_t *env, const fastd_iface_t *iface) {
+	if (iface)
+		fastd_shell_env_set(env, "INTERFACE", iface->name);
+	else
+		fastd_shell_env_set(env, "INTERFACE", NULL);
+}
+
 /** Applies a shell environment to the current process */
 static void shell_command_setenv(pid_t pid, const fastd_shell_env_t *env) {
 	char buf[20];
@@ -84,21 +91,6 @@ static void shell_command_setenv(pid_t pid, const fastd_shell_env_t *env) {
 	snprintf(buf, sizeof(buf), "%u", (unsigned)pid);
 	setenv("FASTD_PID", buf, 1);
 
-	if (ctx.ifname) {
-		setenv("INTERFACE", ctx.ifname, 1);
-	}
-	else if (conf.ifname) {
-		char ifname[IF_NAMESIZE];
-
-		strncpy(ifname, conf.ifname, sizeof(ifname)-1);
-		ifname[sizeof(ifname)-1] = 0;
-
-		setenv("INTERFACE", ifname, 1);
-	}
-	else {
-		unsetenv("INTERFACE");
-	}
-
 	snprintf(buf, sizeof(buf), "%u", conf.mtu);
 	setenv("INTERFACE_MTU", buf, 1);
 
diff --git a/src/shell.h b/src/shell.h
index d39bcef..57b09e6 100644
--- a/src/shell.h
+++ b/src/shell.h
@@ -71,6 +71,7 @@ static inline bool fastd_shell_command_isset(const fastd_shell_command_t *comman
 
 fastd_shell_env_t * fastd_shell_env_alloc(void);
 void fastd_shell_env_set(fastd_shell_env_t *env, const char *key, const char *value);
+void fastd_shell_env_set_iface(fastd_shell_env_t *env, const fastd_iface_t *iface);
 void fastd_shell_env_free(fastd_shell_env_t *env);
 
 bool fastd_shell_command_exec_sync(const fastd_shell_command_t *command, const fastd_shell_env_t *env, int *ret);
diff --git a/src/tuntap.c b/src/tuntap.c
index 591f8d4..a303d20 100644
--- a/src/tuntap.c
+++ b/src/tuntap.c
@@ -66,13 +66,13 @@ static const bool multiaf_tun = true;
 #ifdef __linux__
 
 /** Opens the TUN/TAP device helper shared by Android and Linux targets */
-static void tuntap_open_linux(const char * dev_name) {
+static void tuntap_open_linux(fastd_iface_t *iface, const char *dev_name) {
 	pr_debug("initializing tun/tap device...");
 
 	struct ifreq ifr = {};
 
-	ctx.tunfd = FASTD_POLL_FD(POLL_TYPE_IFACE, open(dev_name, O_RDWR|O_NONBLOCK));
-	if (ctx.tunfd.fd < 0)
+	iface->fd = FASTD_POLL_FD(POLL_TYPE_IFACE, open(dev_name, O_RDWR|O_NONBLOCK));
+	if (iface->fd.fd < 0)
 		exit_errno("could not open tun/tap device file");
 
 	if (conf.ifname)
@@ -92,10 +92,10 @@ static void tuntap_open_linux(const char * dev_name) {
 	}
 
 	ifr.ifr_flags |= IFF_NO_PI;
-	if (ioctl(ctx.tunfd.fd, TUNSETIFF, &ifr) < 0)
+	if (ioctl(iface->fd.fd, TUNSETIFF, &ifr) < 0)
 		exit_errno("TUNSETIFF ioctl failed");
 
-	ctx.ifname = fastd_strndup(ifr.ifr_name, IFNAMSIZ-1);
+	iface->name = fastd_strndup(ifr.ifr_name, IFNAMSIZ-1);
 
 	int ctl_sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
 	if (ctl_sock < 0)
@@ -113,7 +113,7 @@ static void tuntap_open_linux(const char * dev_name) {
 	if (close(ctl_sock))
 		pr_error_errno("close");
 
-	fastd_poll_fd_register(&ctx.tunfd);
+	fastd_poll_fd_register(&iface->fd);
 
 	pr_debug("tun/tap device initialized.");
 }
@@ -123,7 +123,7 @@ static void tuntap_open_linux(const char * dev_name) {
 #if defined(__ANDROID__)
 
 /** Opens the TUN/TAP device */
-void fastd_tuntap_open(void) {
+static void tuntap_open(fastd_iface_t *iface) {
 	pr_debug("initializing tun device...");
 
 	if (conf.android_integration) {
@@ -132,38 +132,38 @@ void fastd_tuntap_open(void) {
 		}
 
 		pr_debug("using android TUN fd");
-		ctx.tunfd = FASTD_POLL_FD(POLL_TYPE_IFACE, fastd_android_receive_tunfd());
+		iface->fd = FASTD_POLL_FD(POLL_TYPE_IFACE, fastd_android_receive_tunfd());
 
 		fastd_android_send_pid();
 
-		fastd_poll_fd_register(&ctx.tunfd);
+		fastd_poll_fd_register(&iface->fd);
 
 		pr_debug("tun device initialized.");
 	} else {
 		/* this requires root on Android */
-		tuntap_open_linux("/dev/tun");
+		tuntap_open_linux(iface, "/dev/tun");
 	}
 }
 
 #elif defined(__linux__)
 
 /** Opens the TUN/TAP device */
-void fastd_tuntap_open(void) {
-	tuntap_open_linux("/dev/net/tun");
+static void tuntap_open(fastd_iface_t *iface) {
+	tuntap_open_linux(iface, "/dev/net/tun");
 }
 
 #elif defined(__FreeBSD__) || defined(__OpenBSD__)
 
 /** Sets the MTU of the TUN/TAP device */
-static void set_tun_mtu(void) {
+static void set_tun_mtu(fastd_iface_t *iface) {
 	struct tuninfo tuninfo;
 
-	if (ioctl(ctx.tunfd.fd, TUNGIFINFO, &tuninfo) < 0)
+	if (ioctl(iface->fd.fd, TUNGIFINFO, &tuninfo) < 0)
 		exit_errno("TUNGIFINFO ioctl failed");
 
 	tuninfo.mtu = conf.mtu;
 
-	if (ioctl(ctx.tunfd.fd, TUNSIFINFO, &tuninfo) < 0)
+	if (ioctl(iface->fd.fd, TUNSIFINFO, &tuninfo) < 0)
 		exit_errno("TUNSIFINFO ioctl failed");
 }
 
@@ -171,42 +171,42 @@ static void set_tun_mtu(void) {
 #ifdef __FreeBSD__
 
 /** Sets the MTU of the TAP device */
-static void set_tap_mtu(void) {
+static void set_tap_mtu(fastd_iface_t *iface) {
 	struct tapinfo tapinfo;
 
-	if (ioctl(ctx.tunfd.fd, TAPGIFINFO, &tapinfo) < 0)
+	if (ioctl(iface->fd.fd, TAPGIFINFO, &tapinfo) < 0)
 		exit_errno("TAPGIFINFO ioctl failed");
 
 	tapinfo.mtu = conf.mtu;
 
-	if (ioctl(ctx.tunfd.fd, TAPSIFINFO, &tapinfo) < 0)
+	if (ioctl(iface->fd.fd, TAPSIFINFO, &tapinfo) < 0)
 		exit_errno("TAPSIFINFO ioctl failed");
 }
 
 /** Sets up the TUN device */
-static void setup_tun(void) {
+static void setup_tun(fastd_iface_t *iface) {
 	int one = 1;
-	if (ioctl(ctx.tunfd.fd, TUNSIFHEAD, &one) < 0)
+	if (ioctl(iface->fd.fd, TUNSIFHEAD, &one) < 0)
 		exit_errno("TUNSIFHEAD ioctl failed");
 
-	set_tun_mtu();
+	set_tun_mtu(iface);
 }
 
 /** Sets up the TAP device */
-static void setup_tap(void) {
+static void setup_tap(fastd_iface_t *iface) {
 	struct ifreq ifr = {};
 
-	if (ioctl(ctx.tunfd.fd, TAPGIFNAME, &ifr) < 0)
+	if (ioctl(iface->fd.fd, TAPGIFNAME, &ifr) < 0)
 		exit_errno("TAPGIFNAME ioctl failed");
 
-	free(ctx.ifname);
-	ctx.ifname = fastd_strndup(ifr.ifr_name, IFNAMSIZ-1);
+	free(iface->name);
+	iface->name = fastd_strndup(ifr.ifr_name, IFNAMSIZ-1);
 
-	set_tap_mtu();
+	set_tap_mtu(iface);
 }
 
 /** Opens the TUN/TAP device */
-void fastd_tuntap_open(void) {
+static void tuntap_open(fastd_iface_t *iface) {
 	pr_debug("initializing tun/tap device...");
 
 	char ifname[5+IFNAMSIZ] = "/dev/";
@@ -235,41 +235,41 @@ void fastd_tuntap_open(void) {
 		strncat(ifname, type, IFNAMSIZ-1);
 	}
 
-	ctx.tunfd = FASTD_POLL_FD(POLL_TYPE_IFACE, open(ifname, O_RDWR|O_NONBLOCK));
-	if (ctx.tunfd.fd < 0)
+	iface->fd = FASTD_POLL_FD(POLL_TYPE_IFACE, open(ifname, O_RDWR|O_NONBLOCK));
+	if (iface->fd.fd < 0)
 		exit_errno("could not open tun/tap device file");
 
-	if (!(ctx.ifname = fdevname_r(ctx.tunfd.fd, fastd_alloc(IFNAMSIZ), IFNAMSIZ)))
+	if (!(iface->name = fdevname_r(iface->fd.fd, fastd_alloc(IFNAMSIZ), IFNAMSIZ)))
 		exit_errno("could not get tun/tap interface name");
 
 	switch (conf.mode) {
 	case MODE_TAP:
-		setup_tap();
+		setup_tap(iface);
 		break;
 
 	case MODE_TUN:
-		setup_tun();
+		setup_tun(iface);
 		break;
 
 	default:
 		exit_bug("invalid mode");
 	}
 
-	fastd_poll_fd_register(&ctx.tunfd);
+	fastd_poll_fd_register(&iface->fd);
 
 	pr_debug("tun/tap device initialized.");
 }
 
 #else /* __OpenBSD__ */
 
-static void set_link0(bool set) {
+static void set_link0(fastd_iface_t *iface, bool set) {
 	struct ifreq ifr = {};
 
 	int ctl_sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
 	if (ctl_sock < 0)
 		exit_errno("socket");
 
-	strncpy(ifr.ifr_name, ctx.ifname, IFNAMSIZ-1);
+	strncpy(ifr.ifr_name, iface->name, IFNAMSIZ-1);
 	if (ioctl(ctl_sock, SIOCGIFFLAGS, &ifr) < 0)
 		exit_errno("SIOCGIFFLAGS ioctl failed");
 
@@ -286,19 +286,19 @@ static void set_link0(bool set) {
 }
 
 /** Sets up the TUN device */
-static void setup_tun(void) {
-	set_link0(false);
-	set_tun_mtu();
+static void setup_tun(fastd_iface_t *iface) {
+	set_link0(iface, false);
+	set_tun_mtu(iface);
 }
 
 /** Sets up the TAP device */
-static void setup_tap(void) {
-	set_link0(true);
-	set_tun_mtu();
+static void setup_tap(fastd_iface_t *iface) {
+	set_link0(iface, true);
+	set_tun_mtu(iface);
 }
 
 /** Opens the TUN/TAP device */
-void fastd_tuntap_open(void) {
+static void tuntap_open(fastd_iface_t *iface) {
 	char ifname[5+IFNAMSIZ] = "/dev/";
 	if (!conf.ifname)
 		exit_error("config error: no interface name given.");
@@ -309,26 +309,26 @@ void fastd_tuntap_open(void) {
 
 	pr_debug("initializing tun device...");
 
-	ctx.tunfd = FASTD_POLL_FD(POLL_TYPE_IFACE, open(ifname, O_RDWR|O_NONBLOCK));
-	if (ctx.tunfd.fd < 0)
+	iface->fd = FASTD_POLL_FD(POLL_TYPE_IFACE, open(ifname, O_RDWR|O_NONBLOCK));
+	if (iface->fd.fd < 0)
 		exit_errno("could not open tun device file");
 
-	ctx.ifname = fastd_strndup(conf.ifname, IFNAMSIZ-1);
+	iface->name = fastd_strndup(conf.ifname, IFNAMSIZ-1);
 
 	switch (conf.mode) {
 	case MODE_TAP:
-		setup_tap();
+		setup_tap(iface);
 		break;
 
 	case MODE_TUN:
-		setup_tun();
+		setup_tun(iface);
 		break;
 
 	default:
 		exit_bug("invalid mode");
 	}
 
-	fastd_poll_fd_register(&ctx.tunfd);
+	fastd_poll_fd_register(&iface->fd);
 
 	pr_debug("tun device initialized.");
 }
@@ -338,7 +338,7 @@ void fastd_tuntap_open(void) {
 #elif __APPLE__
 
 /** Opens the TUN/TAP device */
-void fastd_tuntap_open(void) {
+static void tuntap_open(fastd_iface_t *iface) {
 	const char *devtype;
 	switch (conf.mode) {
 	case MODE_TAP:
@@ -363,11 +363,11 @@ void fastd_tuntap_open(void) {
 
 	pr_debug("initializing tun device...");
 
-	ctx.tunfd = FASTD_POLL_FD(POLL_TYPE_IFACE, open(ifname, O_RDWR|O_NONBLOCK));
-	if (ctx.tunfd.fd < 0)
+	iface->fd = FASTD_POLL_FD(POLL_TYPE_IFACE, open(ifname, O_RDWR|O_NONBLOCK));
+	if (iface->fd.fd < 0)
 		exit_errno("could not open tun device file");
 
-	ctx.ifname = fastd_strndup(conf.ifname, IFNAMSIZ-1);
+	iface->name = fastd_strndup(conf.ifname, IFNAMSIZ-1);
 
 	int ctl_sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
 	if (ctl_sock < 0)
@@ -382,7 +382,7 @@ void fastd_tuntap_open(void) {
 	if (close(ctl_sock))
 		pr_error_errno("close");
 
-	fastd_poll_fd_register(&ctx.tunfd);
+	fastd_poll_fd_register(&iface->fd);
 
 	pr_debug("tun device initialized.");
 }
@@ -395,7 +395,7 @@ void fastd_tuntap_open(void) {
 
 
 /** Reads a packet from the TUN/TAP device */
-void fastd_tuntap_handle(void) {
+void fastd_tuntap_handle(fastd_iface_t *iface) {
 	size_t max_len = fastd_max_payload();
 
 	fastd_buffer_t buffer;
@@ -404,7 +404,7 @@ void fastd_tuntap_handle(void) {
 	else
 		buffer = fastd_buffer_alloc(max_len, conf.min_encrypt_head_space, conf.min_encrypt_tail_space);
 
-	ssize_t len = read(ctx.tunfd.fd, buffer.data, max_len);
+	ssize_t len = read(iface->fd.fd, buffer.data, max_len);
 	if (len < 0)
 		exit_errno("read");
 
@@ -413,11 +413,11 @@ void fastd_tuntap_handle(void) {
 	if (multiaf_tun && conf.mode == MODE_TUN)
 		fastd_buffer_push_head(&buffer, 4);
 
-	fastd_send_data(buffer, NULL);
+	fastd_send_data(buffer, iface->peer);
 }
 
 /** Writes a packet to the TUN/TAP device */
-void fastd_tuntap_write(fastd_buffer_t buffer) {
+void fastd_tuntap_write(fastd_iface_t *iface, fastd_buffer_t buffer) {
 	if (multiaf_tun && conf.mode == MODE_TUN) {
 		uint8_t version = *((uint8_t *)buffer.data) >> 4;
 		uint32_t af;
@@ -440,12 +440,24 @@ void fastd_tuntap_write(fastd_buffer_t buffer) {
 		memcpy(buffer.data, &af, 4);
 	}
 
-	if (write(ctx.tunfd.fd, buffer.data, buffer.len) < 0)
+	if (write(iface->fd.fd, buffer.data, buffer.len) < 0)
 		pr_debug2_errno("write");
 }
 
+fastd_iface_t * fastd_tuntap_open(fastd_peer_t *peer) {
+	fastd_iface_t *iface = fastd_new(fastd_iface_t);
+	iface->peer = peer;
+
+	tuntap_open(iface);
+
+	return iface;
+}
+
 /** Closes the TUN/TAP device */
-void fastd_tuntap_close(void) {
-	if (!fastd_poll_fd_close(&ctx.tunfd))
+void fastd_tuntap_close(fastd_iface_t *iface) {
+	if (!fastd_poll_fd_close(&iface->fd))
 		pr_warn_errno("closing tun/tap: close");
+
+	free(iface->name);
+	free(iface);
 }
diff --git a/src/types.h b/src/types.h
index 2a854c2..dbb4d3c 100644
--- a/src/types.h
+++ b/src/types.h
@@ -94,6 +94,7 @@ typedef struct fastd_poll_fd fastd_poll_fd_t;
 
 typedef union fastd_peer_address fastd_peer_address_t;
 typedef struct fastd_bind_address fastd_bind_address_t;
+typedef struct fastd_iface fastd_iface_t;
 typedef struct fastd_socket fastd_socket_t;
 typedef struct fastd_peer_group fastd_peer_group_t;
 typedef struct fastd_eth_addr fastd_eth_addr_t;