sipsess: add a function pointer for the content description

This allows the application to postpone the encoding of the content description
(e.g. the SDP) until the source address of the SIP transport is known.

sipsess_connect() uses this for the INVITE. Other SIP session types do not set
the new function pointer.

include/re_sipsess.h

@@ -9,6 +9,8 @@ struct sipsess;
 
 
 typedef void (sipsess_conn_h)(const struct sip_msg *msg, void *arg);
+typedef int  (sipsess_desc_h)(struct mbuf **descp, const struct sa *src,
+			      const struct sa *dst, void *arg);
 typedef int  (sipsess_offer_h)(struct mbuf **descp, const struct sip_msg *msg,
 			       void *arg);
 typedef int  (sipsess_answer_h)(const struct sip_msg *msg, void *arg);
@@ -30,9 +32,10 @@ int  sipsess_connect(struct sipsess **sessp, struct sipsess_sock *sock,
 		     const char *to_uri, const char *from_name,
 		     const char *from_uri, const char *cuser,
 		     const char *routev[], uint32_t routec,
-		     const char *ctype, struct mbuf *desc,
+		     const char *ctype,
 		     sip_auth_h *authh, void *aarg, bool aref,
 		     const char *callid,
+		     sipsess_desc_h *desch,
 		     sipsess_offer_h *offerh, sipsess_answer_h *answerh,
 		     sipsess_progr_h *progrh, sipsess_estab_h *estabh,
 		     sipsess_info_h *infoh, sipsess_refer_h *referh,

src/sipevent/notify.c

@@ -175,11 +175,13 @@ static void response_handler(int err, const struct sip_msg *msg, void *arg)
 
 
 static int send_handler(enum sip_transp tp, const struct sa *src,
-			const struct sa *dst, struct mbuf *mb, void *arg)
+			const struct sa *dst, struct mbuf *mb,
+			struct mbuf **contp, void *arg)
 {
 	struct sip_contact contact;
 	struct sipnot *not = arg;
 	(void)dst;
+	(void)contp;
 
 	sip_contact_set(&contact, not->cuser, src, tp);
 

src/sipevent/subscribe.c

@@ -296,11 +296,13 @@ static void response_handler(int err, const struct sip_msg *msg, void *arg)
 
 
 static int send_handler(enum sip_transp tp, const struct sa *src,
-			const struct sa *dst, struct mbuf *mb, void *arg)
+			const struct sa *dst, struct mbuf *mb,
+			struct mbuf **contp, void *arg)
 {
 	struct sip_contact contact;
 	struct sipsub *sub = arg;
 	(void)dst;
+	(void)contp;
 
 	sip_contact_set(&contact, sub->cuser, src, tp);
 

src/sipreg/reg.c

@@ -265,12 +265,14 @@ static void response_handler(int err, const struct sip_msg *msg, void *arg)
 
 
 static int send_handler(enum sip_transp tp, const struct sa *src,
-			const struct sa *dst, struct mbuf *mb, void *arg)
+			const struct sa *dst, struct mbuf *mb,
+			struct mbuf **contp, void *arg)
 {
 	struct sipreg *reg = arg;
 	int err;
 
 	(void)dst;
+	(void)contp;
 
 	reg->laddr = *src;
 	reg->tp = tp;

src/sipsess/accept.c

@@ -78,7 +78,7 @@ int sipsess_accept(struct sipsess **sessp, struct sipsess_sock *sock,
 		return EINVAL;
 
 	err = sipsess_alloc(&sess, sock, cuser, ctype, NULL, authh, aarg, aref,
-			    offerh, answerh, NULL, estabh, infoh, referh,
+			    NULL, offerh, answerh, NULL, estabh, infoh, referh,
 			    closeh, arg);
 	if (err)
 		return err;

src/sipsess/ack.c

@@ -51,10 +51,12 @@ static void tmr_handler(void *arg)
 
 
 static int send_handler(enum sip_transp tp, const struct sa *src,
-			const struct sa *dst, struct mbuf *mb, void *arg)
+			const struct sa *dst, struct mbuf *mb,
+			struct mbuf **contp, void *arg)
 {
 	struct sipsess_ack *ack = arg;
 	(void)src;
+	(void)contp;
 
 	mem_deref(ack->mb);
 	ack->mb = mem_ref(mb);

src/sipsess/connect.c

@@ -23,15 +23,53 @@ static int invite(struct sipsess *sess);
 
 
 static int send_handler(enum sip_transp tp, const struct sa *src,
-			const struct sa *dst, struct mbuf *mb, void *arg)
+			const struct sa *dst, struct mbuf *mb,
+			struct mbuf **contp, void *arg)
 {
 	struct sip_contact contact;
 	struct sipsess *sess = arg;
-	(void)dst;
+	struct mbuf *desc = NULL;
+	struct mbuf *cont = NULL;
+	int err;
+
+	if (sess->desch) {
+		err = sess->desch(&desc, src, dst, sess->arg);
+		if (err)
+			return err;
+	}
 
 	sip_contact_set(&contact, sess->cuser, src, tp);
+	err = mbuf_printf(mb, "%H", sip_contact_print, &contact);
+	if (err)
+		goto out;
 
-	return mbuf_printf(mb, "%H", sip_contact_print, &contact);
+	cont = mbuf_alloc(1024);
+	if (!cont) {
+		err = ENOMEM;
+		goto out;
+	}
+
+	err |= mbuf_printf(cont,
+			"%s%s%s"
+			"Content-Length: %zu\r\n"
+			"\r\n"
+			"%b",
+			desc ? "Content-Type: " : "",
+			desc ? sess->ctype : "",
+			desc ? "\r\n" : "",
+			mbuf_get_left(desc),
+			mbuf_buf(desc),
+			mbuf_get_left(desc));
+	cont->pos = 0;
+
+	if (err)
+		mem_deref(cont);
+	else
+		*contp = cont;
+
+out:
+	mem_deref(desc);
+	return err;
 }
 
 
@@ -138,19 +176,10 @@ static int invite(struct sipsess *sess)
 	return sip_drequestf(&sess->req, sess->sip, true, "INVITE",
 			     sess->dlg, 0, sess->auth,
 			     send_handler, invite_resp_handler, sess,
-			     "%b"
-			     "%s%s%s"
-			     "Content-Length: %zu\r\n"
-			     "\r\n"
 			     "%b",
 			     sess->hdrs ? mbuf_buf(sess->hdrs) : NULL,
-			     sess->hdrs ? mbuf_get_left(sess->hdrs) :(size_t)0,
-			     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);
+			     sess->hdrs ? mbuf_get_left(sess->hdrs) :(size_t)0
+			     );
 }
 
 
@@ -186,9 +215,10 @@ int sipsess_connect(struct sipsess **sessp, struct sipsess_sock *sock,
 		    const char *to_uri, const char *from_name,
 		    const char *from_uri, const char *cuser,
 		    const char *routev[], uint32_t routec,
-		    const char *ctype, struct mbuf *desc,
+		    const char *ctype,
 		    sip_auth_h *authh, void *aarg, bool aref,
 		    const char *callid,
+		    sipsess_desc_h *desch,
 		    sipsess_offer_h *offerh, sipsess_answer_h *answerh,
 		    sipsess_progr_h *progrh, sipsess_estab_h *estabh,
 		    sipsess_info_h *infoh, sipsess_refer_h *referh,
@@ -200,7 +230,8 @@ int sipsess_connect(struct sipsess **sessp, struct sipsess_sock *sock,
 	if (!sessp || !sock || !to_uri || !from_uri || !cuser || !ctype)
 		return EINVAL;
 
-	err = sipsess_alloc(&sess, sock, cuser, ctype, desc, authh, aarg, aref,
+	err = sipsess_alloc(&sess, sock, cuser, ctype, NULL, authh, aarg, aref,
+			    desch,
 			    offerh, answerh, progrh, estabh, infoh, referh,
 			    closeh, arg);
 	if (err)

src/sipsess/modify.c

@@ -107,11 +107,13 @@ static void reinvite_resp_handler(int err, const struct sip_msg *msg,
 
 
 static int send_handler(enum sip_transp tp, const struct sa *src,
-			const struct sa *dst, struct mbuf *mb, void *arg)
+			const struct sa *dst, struct mbuf *mb,
+			struct mbuf **contp, void *arg)
 {
 	struct sip_contact contact;
 	struct sipsess *sess = arg;
 	(void)dst;
+	(void)contp;
 
 	sip_contact_set(&contact, sess->cuser, src, tp);
 

src/sipsess/sess.c

@@ -157,6 +157,7 @@ static void destructor(void *arg)
 int sipsess_alloc(struct sipsess **sessp, struct sipsess_sock *sock,
 		  const char *cuser, const char *ctype, struct mbuf *desc,
 		  sip_auth_h *authh, void *aarg, bool aref,
+		  sipsess_desc_h *desch,
 		  sipsess_offer_h *offerh, sipsess_answer_h *answerh,
 		  sipsess_progr_h *progrh, sipsess_estab_h *estabh,
 		  sipsess_info_h *infoh, sipsess_refer_h *referh,
@@ -184,6 +185,7 @@ int sipsess_alloc(struct sipsess **sessp, struct sipsess_sock *sock,
 	sess->sock    = mem_ref(sock);
 	sess->desc    = mem_ref(desc);
 	sess->sip     = mem_ref(sock->sip);
+	sess->desch   = desch;
 	sess->offerh  = offerh  ? offerh  : internal_offer_handler;
 	sess->answerh = answerh ? answerh : internal_answer_handler;
 	sess->progrh  = progrh  ? progrh  : internal_progress_handler;

src/sipsess/sipsess.h

@@ -23,6 +23,7 @@ struct sipsess {
 	char *close_hdrs;
 	struct mbuf *hdrs;
 	struct mbuf *desc;
+	sipsess_desc_h *desch;
 	sipsess_offer_h *offerh;
 	sipsess_answer_h *answerh;
 	sipsess_progr_h *progrh;
@@ -68,6 +69,7 @@ struct sipsess_request {
 int  sipsess_alloc(struct sipsess **sessp, struct sipsess_sock *sock,
 		   const char *cuser, const char *ctype, struct mbuf *desc,
 		   sip_auth_h *authh, void *aarg, bool aref,
+		   sipsess_desc_h *desch,
 		   sipsess_offer_h *offerh, sipsess_answer_h *answerh,
 		   sipsess_progr_h *progrh, sipsess_estab_h *estabh,
 		   sipsess_info_h *infoh, sipsess_refer_h *referh,