Added tcp host candidate

4 files changed, 215 insertions, 15 deletions

diff --git a/example/index.js b/example/index.js
index a161a10..6eae9b3 100644
--- a/example/index.js
+++ b/example/index.js
@@ -1,4 +1,5 @@
 window.onload = function demo() {
+
   // create peer connection
   let pc = new RTCPeerConnection({
     iceCandidatePoolSize: 4
@@ -27,10 +28,13 @@ window.onload = function demo() {
       if ('candidate' in d) {
         if (d.candidate) {
           console.log("remote candidate:\n%c%s", "color: blue;", d.candidate);
+					pc.addIceCandidate(d).catch((e) => {
+						console.log("addIceCandidate:\n%c%s", "color: red;", e);
+					});
         }
       } else if ('sdp' in d) {
 				pc.setRemoteDescription(d).catch((e) => {
-					console.log("local error:\n%c%s", "color: red;", e);
+					console.log("setRemoteDescription:\n%c%s", "color: red;", e);
 				});
         console.log("remote answer:\n%c%s", "color: blue;", d.sdp);
       }
diff --git a/example/main.c b/example/main.c
index 33ef4bb..e850a40 100644
--- a/example/main.c
+++ b/example/main.c
@@ -4,6 +4,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <syslog.h>
 #include <unistd.h>
 
 #include "jsmn.h"
@@ -60,7 +61,7 @@ struct trtc_ice_candidate_t parse_ice_candidate(const char *s)
 }
 
 // (callback) Called for each discovered local ICE candidate
-int on_ice_candidate(const struct trtc_ice_candidate_t c, void *arg) {
+void on_ice_candidate(const struct trtc_ice_candidate_t c, void *arg) {
 	// send ice candidate over signaling channel
 	printf("{"
 		"\"candidate\":\"%s\","
@@ -68,15 +69,18 @@ int on_ice_candidate(const struct trtc_ice_candidate_t c, void *arg) {
 		"\"sdpMid\":\"%s\","
 		"\"usernameFragment\":null"
 	"}\n", c.candidate, c.sdp_mline_index, c.sdp_mid);
-
-	return 0;
 }
 
 int main(int argc, char **argv)
 {
+	openlog(NULL, LOG_PERROR, LOG_USER);
+
 	// disable stdout buffering to ensure signaling messages send immediately
 	setvbuf(stdout, NULL, _IONBF, 0);
 
+	// initialize tinyrtc library
+	trtc_init();
+
 	// create peer connection
 	struct trtc_config_t cfg = {
 		.ice_servers = {
@@ -88,6 +92,12 @@ int main(int argc, char **argv)
 		}
 	};
 	struct trtc_peerconn_t* pc = trtc_peer_connection(cfg);
+	if (!pc) {
+		syslog(LOG_ERR, "trtc_peer_connection() failed");
+		return -1;
+	}
+
+	trtc_set_on_ice_candidate(pc, on_ice_candidate, NULL);
 
 	while (true) {
 		int n;
@@ -96,21 +106,32 @@ int main(int argc, char **argv)
 
 
 		if (n = getline(&msg, &msglen, stdin), -1 == n) {
+			syslog(LOG_ERR, "%m");
 			return -1;
 		}
 
+		// case: sdp offer
 		if (strstr(msg, "\"sdp\"")) {
-			// got offer. send answer.
-			printf("{\"sdp\":\"%s\",\"type\":\"answer\"}\n", trtc_create_answer(pc));
+			// XXX trtc_set_remote_description(pc, offer);
+			const char *answer = trtc_create_answer(pc);
+
+			/* send SDP answer via stdout signaling channel */
+			printf("{\"sdp\":\"%s\",\"type\":\"answer\"}\n", answer);
+
+			trtc_set_local_description(pc, answer);
+
+		// case: ice candidate
 		} else if (strstr(msg, "\"candidate\"")) {
 			struct trtc_ice_candidate_t c = parse_ice_candidate(msg);
-			on_ice_candidate(c, NULL);
 			trtc_add_ice_candidate(pc, c);
+
+		// case: error
 		} else {
 			printf("unrecognized signaling message\n");
 		}
-
 	}
+	
+	syslog(LOG_ERR, "terminating");
 
 	return 0;
 }
diff --git a/tinyrtc.c b/tinyrtc.c
index 2092224..2b74890 100644
--- a/tinyrtc.c
+++ b/tinyrtc.c
@@ -26,9 +26,16 @@
  * OF SUCH DAMAGE.
  */
 
+#include <ifaddrs.h>					// freeifaddrs, getifaddrs
 #include <stdbool.h>
 #include <stdio.h>						// snprintf
 #include <string.h>						// memset
+#include <unistd.h>						// close
+
+#include <arpa/inet.h>
+#include <net/if.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
 
 #include "tinyrtc.h"
 
@@ -41,8 +48,21 @@ struct trtc_peerconn_t {
 	char offer[TRTC_MAX_SDP_SIZE];
 	char answer[TRTC_MAX_SDP_SIZE];
 
+	/* local description */
+	const char* ldesc;
+
+	/* remote description */
+	const char* rdesc;
+
 	char l_ice_pwd[TRTC_MAX_ICE_PWD_SIZE];
 	char l_ice_ufrag[TRTC_MAX_ICE_UFRAG_SIZE];
+
+	/* onIceCandidate callback */
+	trtc_on_ice_candidate_t* on_ice_candidate;
+	void* on_ice_candidate_arg;
+
+	/* tcp host candidate socket */
+	int host_tcp_fd;
 };
 
 
@@ -53,20 +73,131 @@ static struct trtc_peerconn_t peer_connection_pool[TRTC_MAX_PEER_CONNECTIONS];
 
 ///  RTC PEER CONNECTION API  ////////////////////////////////////////////////
 
-void rtc_init() {
+void trtc_init() {
 	memset(peer_connection_pool, 0, sizeof(peer_connection_pool));
 }
 
+/**
+ * Get host candidates
+ *
+ * \return 0 on success, -1 on error.
+ */
+static int get_host_candidates(struct trtc_peerconn_t* pc) {
+	struct ifaddrs *ifaddr, *ifa;
+	socklen_t laddrlen;
+
+	/* sanity check */
+	if (!pc) return -1;
+
+	/* create tcp socket */
+	pc->host_tcp_fd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
+	if (-1 == pc->host_tcp_fd) {
+		return -1;
+	}
+
+	/* bind to arbitrary port */
+	struct sockaddr_in laddr = {
+		.sin_family = AF_INET,
+		.sin_addr.s_addr = INADDR_ANY,
+		.sin_port = 0,
+	};
+	if (-1 == bind(pc->host_tcp_fd, (struct sockaddr*)&laddr, sizeof(laddr))) {
+		return -1;
+	}
+	laddrlen = sizeof(struct sockaddr_in);
+	if (-1 == getsockname(pc->host_tcp_fd, (struct sockaddr *)&laddr, &laddrlen)) {
+		return -1;
+	}
+
+	/* listen on socket */
+	if (-1 == listen(pc->host_tcp_fd, 0)) {
+		return -1;
+	}
+
+	/* get network interface addresses */
+	if (-1 == getifaddrs(&ifaddr)) {
+		return -1;
+	}
+
+	/* iterate over addresses */
+	for (ifa = ifaddr; ifa; ifa = ifa->ifa_next) {
+		if (!ifa->ifa_addr) continue;
+
+		/* skip loopback interface addresses */
+		if (IFF_LOOPBACK & ifa->ifa_flags) continue;
+
+		if (AF_INET == ifa->ifa_addr->sa_family) {
+			struct sockaddr_in *sa = (struct sockaddr_in*)ifa->ifa_addr;
+
+			/* host tcp candidate */
+			struct trtc_ice_candidate_t c = {
+				.sdp_mid = "0",
+				.sdp_mline_index = 0
+			};
+			snprintf(c.candidate, TRTC_MAX_ICE_CANDIDATE_SIZE,
+				"candidate:2894319779 1 tcp 212260223 %s %d typ host tcptype passive",
+				inet_ntoa(sa->sin_addr),
+				laddr.sin_port); // XXXX
+
+			/* callback */
+			if (pc->on_ice_candidate) {
+				pc->on_ice_candidate(c, pc->on_ice_candidate_arg);
+			}
+		}
+	}
+
+	freeifaddrs(ifaddr);
+
+	return 0;
+}
+
+/**
+ * Peer connection thread
+ *
+ * Each peer connection uses one background thread for stepping the ICE agent,
+ * handling timeouts, and sending/receiving packets.
+ *
+ * \param arg[in] User-specified argument.
+ *
+ * \return NULL.
+ */
+static void* peer_connection_thread(void *arg) {
+	return NULL;
+}
+
 struct trtc_peerconn_t* trtc_peer_connection(struct trtc_config_t cfg) {
+	struct trtc_peerconn_t* pc = NULL;
+
 	for (int i = 0; i < TRTC_MAX_PEER_CONNECTIONS; i++) {
 		if (!peer_connection_pool[i].active) {
 			memset(&peer_connection_pool[i], 0, sizeof(struct trtc_peerconn_t));
-			peer_connection_pool[i].active = true;
-			return &peer_connection_pool[i];
+			pc = &peer_connection_pool[i];
+			break;
 		}
 	}
 
-	return NULL;
+	return pc;
+}
+
+void trtc_peer_connection_destroy(struct trtc_peerconn_t* pc) {
+	if (!pc) return;
+
+	close(pc->host_tcp_fd);
+
+	// XXX mark as available
+}
+
+int trtc_set_on_ice_candidate(
+	struct trtc_peerconn_t* pc,
+	trtc_on_ice_candidate_t* cb,
+	void* arg
+) {
+	if (!pc || !cb) return -1;
+
+	pc->on_ice_candidate = cb;
+	pc->on_ice_candidate_arg = arg;
+
+	return 0;
 }
 
 int trtc_add_ice_candidate(struct trtc_peerconn_t *pc, const struct trtc_ice_candidate_t c) {
@@ -83,6 +214,7 @@ const char * trtc_create_answer(struct trtc_peerconn_t *pc) {
 		"v=0\\r\\n"
 		"o=- 2210401696197537454 2 IN IP4 127.0.0.1\\r\\n" // XXX
 		"s=-\\r\\n"
+		"u=https://tinyrtc.org/\\r\\n"
 		"t=0 0\\r\\n"
 		"a=group:BUNDLE 0\\r\\n"
 		"a=msid-semantic: WMS\\r\\n"
@@ -118,9 +250,12 @@ const char * trtc_create_answer(struct trtc_peerconn_t *pc) {
 };
 
 int trtc_set_local_description(struct trtc_peerconn_t *pc, const char *sdp) {
+	pc->ldesc = sdp;
+	get_host_candidates(pc);
 	return -1;
 };
 
 int trtc_set_remote_description(struct trtc_peerconn_t *pc, const char *sdp) {
+	pc->rdesc = sdp;
 	return -1;
 };
diff --git a/tinyrtc.h b/tinyrtc.h
index 205ae1b..ff29e15 100644
--- a/tinyrtc.h
+++ b/tinyrtc.h
@@ -70,21 +70,61 @@ struct trtc_ice_candidate_t {
 
 ///  CALLBACKS  //////////////////////////////////////////////////////////////
 
-typedef int (trtc_on_ice_candidate_t)(const struct trtc_ice_candidate_t c, void *arg);
+typedef void (trtc_on_ice_candidate_t)(const struct trtc_ice_candidate_t c, void *arg);
 
 
 ///  RTC PEER CONNECTION API  ////////////////////////////////////////////////
 
+/**
+ * Initialize library. Must call once before calling other functions.
+ */
+void trtc_init();
+
+/**
+ * Create new peer connection
+ *
+ * \param cfg[in] Configuration.
+ *
+ * \return Peer connection. NULL if all peer connections are already in use.
+ */
 struct trtc_peerconn_t* trtc_peer_connection(struct trtc_config_t cfg);
+void trtc_peer_connection_destroy(struct trtc_peerconn_t* pc);
 
-int trtc_add_ice_candidate(struct trtc_peerconn_t *pc, const struct trtc_ice_candidate_t c);
+/**
+ * Adds remote ICE candidate to local ICE agent
+ *
+ * \param pc[in] Peer connection.
+ * \param c[in] ICE candidate from remote peer.
+ *
+ * \return 0 on success. -1 on error.
+ */
+int trtc_add_ice_candidate(
+	struct trtc_peerconn_t *pc, const struct trtc_ice_candidate_t c);
 
 int trtc_add_track(struct trtc_peerconn_t *pc);
 
+/**
+ * Create SDP answer in response to a received SDP offer.
+ *
+ * \param pc[in] Peer connection.
+ *
+ * \return SDP answer. NULL on error.
+ */
 const char * trtc_create_answer(struct trtc_peerconn_t *pc);
 
-int trtc_set_local_description(struct trtc_peerconn_t *pc, const char *sdp);
+/**
+ * Sets callback to call for each discovered local ICE candidate
+ *
+ * \param pc[in] Peer connection.
+ * \param cb[in] Callback function.
+ * \param arg[in] User-specified argument to pass to callback function.
+ *
+ * \return 0 on success. -1 on error.
+ */
+int trtc_set_on_ice_candidate(
+	struct trtc_peerconn_t* pc, trtc_on_ice_candidate_t* cb, void* arg);
 
+int trtc_set_local_description(struct trtc_peerconn_t *pc, const char *sdp);
 int trtc_set_remote_description(struct trtc_peerconn_t *pc, const char *sdp);
 
 #endif