sip: add RFC 331 support

README.md

@@ -167,6 +167,7 @@ legend:
 * [RFC 2915](https://tools.ietf.org/html/rfc2915) - The Naming Authority Pointer (NAPTR) DNS Resource Record
 * [RFC 3261](https://tools.ietf.org/html/rfc3261) - SIP: Session Initiation Protocol
 * [RFC 3262](https://tools.ietf.org/html/rfc3262) - SIP Reliability of Provisional Responses
+* [RFC 3311](https://tools.ietf.org/html/rfc3311) - The SIP UPDATE Method
 * [RFC 3263](https://tools.ietf.org/html/rfc3263) - Locating SIP Servers
 * [RFC 3264](https://tools.ietf.org/html/rfc3264) - An Offer/Answer Model with SDP
 * [RFC 3265](https://tools.ietf.org/html/rfc3265) - SIP-Specific Event Notification

src/sipsess/listen.c

@@ -273,6 +273,54 @@ static void reinvite_handler(struct sipsess_sock *sock,
 }
 
 
+static void update_handler(struct sipsess_sock *sock, const struct sip_msg *msg)
+{
+	struct sip *sip = sock->sip;
+	struct sipsess *sess;
+	struct mbuf *desc;
+	char m[256];
+	int err;
+
+	sess = sipsess_find(sock, msg);
+	if (!sess || sess->terminated) {
+		(void)sip_treply(NULL, sip, msg, 481, "Call Does Not Exist");
+		return;
+	}
+
+	if (!sip_dialog_rseq_valid(sess->dlg, msg)) {
+		(void)sip_treply(NULL, sip, msg, 500, "Server Internal Error");
+		return;
+	}
+
+	if (sess->st || sess->awaiting_answer) {
+		(void)sip_treplyf(NULL, NULL, sip, msg, false,
+				  500, "Server Internal Error",
+				  "Retry-After: 5\r\n"
+				  "Content-Length: 0\r\n"
+				  "\r\n");
+		return;
+	}
+
+	err = sess->offerh(&desc, msg, sess->arg);
+	if (err) {
+		(void)sip_reply(sip, msg, 488, str_error(err, m, sizeof(m)));
+		return;
+	}
+
+	sess->received_update = true;
+
+	(void)sip_dialog_update(sess->dlg, msg);
+	(void)sipsess_reply_2xx(sess, msg, 200, "OK", desc, NULL, NULL);
+
+	/* pending modifications considered outdated;
+	 * sdp may have changed in above exchange */
+	sess->desc = mem_deref(sess->desc);
+	sess->modify_pending = false;
+	tmr_cancel(&sess->tmr);
+	mem_deref(desc);
+}
+
+
 static void invite_handler(struct sipsess_sock *sock,
 			   const struct sip_msg *msg)
 {
@@ -293,6 +341,10 @@ static bool request_handler(const struct sip_msg *msg, void *arg)
 
 		return true;
 	}
+	else if (!pl_strcmp(&msg->met, "UPDATE")) {
+		update_handler(sock, msg);
+		return true;
+	}
 	else if (!pl_strcmp(&msg->met, "ACK")) {
 		ack_handler(sock, msg);
 		return true;

src/sipsess/modify.c

@@ -106,6 +106,82 @@ static void reinvite_resp_handler(int err, const struct sip_msg *msg,
 }
 
 
+static void update_resp_handler(int err, const struct sip_msg *msg, void *arg)
+{
+	struct sipsess *sess = arg;
+	const struct sip_hdr *hdr;
+	struct mbuf *desc = NULL;
+
+	if (err || sip_request_loops(&sess->ls, msg->scode))
+		goto out;
+
+	if (msg->scode < 200) {
+		return;
+	}
+	else if (msg->scode < 300) {
+		(void)sip_dialog_update(sess->dlg, msg);
+
+		if (sess->sent_offer)
+			(void)sess->answerh(msg, sess->arg);
+		else {
+			sess->modify_pending = false;
+			(void)sess->offerh(&desc, msg, sess->arg);
+		}
+
+		mem_deref(desc);
+	}
+	else {
+		if (sess->terminated)
+			goto out;
+
+		switch (msg->scode) {
+
+		case 401:
+		case 407:
+			err = sip_auth_authenticate(sess->auth, msg);
+			if (err) {
+				err = (err == EAUTH) ? 0 : err;
+				break;
+			}
+
+			err = sipsess_update(sess, false);
+			if (err)
+				break;
+
+			return;
+
+		case 408:
+		case 481:
+			sipsess_terminate(sess, 0, msg);
+			return;
+
+		case 491:
+			tmr_start(&sess->tmr, sess->owner ? 3000 : 1000,
+				  tmr_handler, sess);
+			return;
+
+		case 500:
+			hdr = sip_msg_hdr(msg, SIP_HDR_RETRY_AFTER);
+			if (!hdr)
+				break;
+
+			tmr_start(&sess->tmr, pl_u32(&hdr->val) * 1000,
+				  tmr_handler, sess);
+			return;
+		}
+	}
+ out:
+	if (sess->terminated)
+		mem_deref(sess);
+	else if (err == ETIMEDOUT)
+		sipsess_terminate(sess, err, NULL);
+	else if (sess->modify_pending)
+		(void)sipsess_update(sess, true);
+	else
+		sess->desc = mem_deref(sess->desc);
+}
+
+
 static int send_handler(enum sip_transp tp, struct sa *src,
 			const struct sa *dst, struct mbuf *mb,
 			struct mbuf **contp, void *arg)
@@ -148,6 +224,30 @@ int sipsess_reinvite(struct sipsess *sess, bool reset_ls)
 }
 
 
+int sipsess_update(struct sipsess *sess, bool reset_ls)
+{
+	sess->sent_offer = sess->desc ? true : false;
+	sess->modify_pending = false;
+
+	if (reset_ls)
+		sip_loopstate_reset(&sess->ls);
+
+	return sip_drequestf(&sess->req, sess->sip, true, "UPDATE",
+			     sess->dlg, 0, sess->auth,
+			     send_handler, update_resp_handler, sess,
+			     "%s%s%s"
+			     "Content-Length: %zu\r\n"
+			     "\r\n"
+			     "%b",
+			     sess->desc ? "Content-Type: " : "",
+			     sess->desc ? sess->ctype : "",
+			     sess->desc ? "\r\n" : "",
+			     sess->desc ? mbuf_get_left(sess->desc) :(size_t)0,
+			     sess->desc ? mbuf_buf(sess->desc) : NULL,
+			     sess->desc ? mbuf_get_left(sess->desc):(size_t)0);
+}
+
+
 /**
  * Modify an established SIP Session sending Re-INVITE or UPDATE
  *
@@ -158,16 +258,20 @@ int sipsess_reinvite(struct sipsess *sess, bool reset_ls)
  */
 int sipsess_modify(struct sipsess *sess, struct mbuf *desc)
 {
-	if (!sess || sess->st || sess->terminated)
+	if (!sess || (sess->st && sess->established) || sess->terminated)
 		return EINVAL;
 
 	mem_deref(sess->desc);
 	sess->desc = mem_ref(desc);
 
-	if (sess->req || sess->tmr.th || sess->replyl.head) {
+	if (sess->tmr.th || sess->replyl.head ||
+	    (sess->req && sess->established)) {
 		sess->modify_pending = true;
 		return 0;
 	}
 
-	return sipsess_reinvite(sess, true);
+	if (sess->established)
+		return sipsess_reinvite(sess, true);
+	else
+		return sipsess_update(sess, true);
 }

src/sipsess/reply.c

@@ -103,8 +103,8 @@ int sipsess_reply_2xx(struct sipsess *sess, const struct sip_msg *msg,
 
 	sip_contact_set(&contact, sess->cuser, &msg->dst, msg->tp);
 
-	err = sip_treplyf(&sess->st, &reply->mb, sess->sip,
-			  msg, true, scode, reason,
+	err = sip_treplyf(sess->received_update ? NULL : &sess->st, &reply->mb,
+			  sess->sip, msg, true, scode, reason,
 			  "%H"
 			  "%v"
 			  "%s%s%s"
@@ -123,7 +123,7 @@ int sipsess_reply_2xx(struct sipsess *sess, const struct sip_msg *msg,
 	if (err)
 		goto out;
 
-	if (pl_strcmp(&msg->met, "PRACK")) {
+	if (pl_strcmp(&msg->met, "PRACK") && pl_strcmp(&msg->met, "UPDATE")) {
 		tmr_start(&reply->tmr, 64 * SIP_T1, tmr_handler, reply);
 		tmr_start(&reply->tmrg, SIP_T1, retransmit_handler, reply);
 	}

src/sipsess/sipsess.h

@@ -40,6 +40,7 @@ struct sipsess {
 	bool established;
 	bool peerterm;
 	bool rel100_supported;
+	bool received_update;
 	int terminated;
 };
 
@@ -97,6 +98,7 @@ int  sipsess_reply_ack(struct sipsess *sess, const struct sip_msg *msg,
 int  sipsess_reply_prack(struct sipsess *sess, const struct sip_msg *msg,
 			 bool *awaiting_answer);
 int  sipsess_reinvite(struct sipsess *sess, bool reset_ls);
+int  sipsess_update(struct sipsess *sess, bool reset_ls);
 int  sipsess_bye(struct sipsess *sess, bool reset_ls);
 int  sipsess_request_alloc(struct sipsess_request **reqp, struct sipsess *sess,
 			   const char *ctype, struct mbuf *body,