start work on stun support

daemon/Makefile

@@ -28,7 +28,7 @@ LDFLAGS+=       `dpkg-buildflags --get LDFLAGS`
 endif
 
 SRCS=		main.c kernel.c poller.c aux.c control_tcp.c streambuf.c call.c control_udp.c redis.c \
-		bencode.c cookie_cache.c udp_listener.c control_ng.c sdp.c str.c
+		bencode.c cookie_cache.c udp_listener.c control_ng.c sdp.c str.c stun.c
 OBJS=		$(SRCS:.c=.o)
 
 

daemon/call.c

@@ -25,6 +25,7 @@
 #include "bencode.h"
 #include "sdp.h"
 #include "str.h"
+#include "stun.h"
 
 
 
@@ -233,6 +234,11 @@ static int stream_packet(struct streamrelay *r, char *b, int l, struct sockaddr_
 	m = c->callmaster;
 	smart_ntop_port(addr, fsin, sizeof(addr));
 
+	if (r->stun && is_stun(b, l)) {
+		if (!stun(b, l))
+			return 0;
+	}
+
 	if (p->fd.fd == -1) {
 		mylog(LOG_WARNING, LOG_PREFIX_C "RTP packet to port %u discarded from %s", 
 			LOG_PARAMS_C(c), r->fd.localport, addr);

daemon/call.h

@@ -78,6 +78,7 @@ struct streamrelay {
 	struct stats		stats;
 	struct stats		kstats;
 	time_t			last;
+	int			stun:1;
 };
 struct relays_cache {
 	struct udp_fd		relays_A[16];

daemon/sdp.c

@@ -866,6 +866,9 @@ int sdp_replace(struct sdp_chopper *chop, GQueue *sessions, struct call *call,
 			chopper_append_c(chop, "\r\na=ice-pwd:");
 			chopper_append_str(chop, &call->ice_pwd);
 			chopper_append_c(chop, "\r\n");
+
+			rtp->stun = 1;
+			rtcp->stun = 1;
 		}
 
 		for (k = session->media_streams.head; k; k = k->next) {

daemon/stun.c

@@ -0,0 +1,24 @@
+#include "stun.h"
+#include <sys/types.h>
+
+struct stun {
+	u_int16_t msg_type;
+	u_int16_t msg_len;
+	u_int32_t cookie;
+	unsigned char transaction[12];
+} __attribute__ ((packed));
+
+
+int stun(const char *buf, int len) {
+	const struct stun *s = (const void *) buf;
+	int msglen, method, class;
+
+	msglen = ntohs(s->msg_len);
+	class = method = ntohl(s->msg_type);
+	class = ((class & 0x10) >> 4) | ((class & 0x100) >> 7);
+	method = (method & 0xf) | ((method & 0xe0) >> 1) | ((method & 0x3e00) >> 2);
+	if (method != 0x1) /* binding */
+		return -1;
+
+	return 0;
+}

daemon/stun.h

@@ -0,0 +1,30 @@
+#ifndef _STUN_H_
+#define _STUN_H_
+
+
+#include <string.h>
+#include <arpa/inet.h>
+
+
+static inline int is_stun(const char *bx, int len) {
+	const unsigned char *b = (const void *) bx;
+	const u_int32_t *u;
+
+	if (len < 20)
+		return 0;
+	if ((b[0] & 0xb0) != 0x00)
+		return 0;
+	if ((b[3] & 0x3) != 0x0)
+		return 0;
+	u = (const void *) &b[4];
+	if (*u != htonl(0x2112A442))
+		return 0;
+
+	return 1;
+}
+
+
+int stun(const char *buf, int len);
+
+
+#endif