dialog: add dlg_inc_cseq function

modules/dialog/dialog.c

@@ -159,6 +159,7 @@ static int dlg_on_answer(struct sip_msg* msg, void *route_id);
 static int dlg_on_hangup(struct sip_msg* msg, void *route_id);
 static int dlg_send_sequential(struct sip_msg* msg, str *method, int leg,
 		str *body, str *ct, str *headers);
+static int dlg_inc_cseq(struct sip_msg *msg, str *tag, int *_count);
 
 
 /* item/pseudo-variables functions */
@@ -282,6 +283,10 @@ static const cmd_export_t cmds[]={
 		{CMD_PARAM_STR|CMD_PARAM_OPT, 0, 0},
 		{CMD_PARAM_STR|CMD_PARAM_OPT, 0, 0}, {0,0,0}},
 		ALL_ROUTES},
+	{"dlg_inc_cseq", (cmd_function)dlg_inc_cseq, {
+		{CMD_PARAM_STR|CMD_PARAM_OPT, 0, 0},
+		{CMD_PARAM_INT|CMD_PARAM_OPT, 0, 0}, {0,0,0}},
+		REQUEST_ROUTE|FAILURE_ROUTE|ONREPLY_ROUTE|BRANCH_ROUTE|LOCAL_ROUTE},
 	{"load_dlg", (cmd_function)load_dlg, {{0,0,0}}, 0},
 	{0,0,{{0,0,0}},0}
 };
@@ -2566,3 +2571,55 @@ static int dlg_send_sequential(struct sip_msg* msg, str *method, int leg,
 			body, ct, headers, NULL, NULL) == 0?1:-1;
 
 }
+
+static int dlg_inc_cseq(struct sip_msg *msg, str *tag, int *_count)
+{
+	struct dlg_cell *dlg;
+	int count = (_count?*_count:1);
+	int leg, ret = -1;
+	str cseq;
+	unsigned int loc_seq;
+
+	if ( (dlg=get_current_dialog())==NULL ) {
+		LM_DBG("no current dialog found\n");
+		return -2;
+	}
+
+	if (!tag) {
+		if ((!msg->to && parse_headers(msg, HDR_TO_F, 0) < 0) || !msg->to) {
+			LM_ERR("inexisting or invalid to header!\n");
+			return -1;
+		}
+		tag = &get_to(msg)->tag_value;
+	}
+	dlg_lock_dlg(dlg);
+	for (leg = DLG_FIRST_CALLEE_LEG ; leg < dlg->legs_no[DLG_LEGS_USED]; leg++) {
+		if (str_match(tag, &dlg->legs[leg].tag))
+			break;
+	}
+	if (leg == dlg->legs_no[DLG_LEGS_USED]) {
+		LM_ERR("leg with tag <%.*s> not found\n", tag->len, tag->s);
+		goto end;
+	}
+	if (dlg->legs[leg].last_gen_cseq == 0) {
+		/*local sequence number*/
+		cseq = dlg->legs[leg].r_cseq;
+		if (!cseq.s || !cseq.len || str2int(&cseq, &loc_seq) != 0){
+			LM_ERR("invalid cseq\n");
+			goto end;
+		}
+
+		dlg->legs[leg].last_gen_cseq = loc_seq + count;
+	} else {
+		dlg->legs[leg].last_gen_cseq += count;
+		loc_seq = -1;
+	}
+	LM_DBG("increasing leg=%d cseq=%u count=%d gen=%d\n",
+		leg, loc_seq, count, dlg->legs[leg].last_gen_cseq);
+	ret = 1;
+
+	dlg->flags |= DLG_FLAG_CSEQ_ENFORCE;
+end:
+	dlg_unlock_dlg(dlg);
+	return ret;
+}

modules/dialog/doc/dialog_admin.xml

@@ -2602,6 +2602,45 @@ event_route[E_RTPPROXY_DTMF] {
     }
 }
 ...
+</programlisting>
+		</example>
+	</section>
+	<section id="func_dlg_inc_cseq" xreflabel="dlg_inc_cseq()">
+		<title>
+			<function moreinfo="none">dlg_inc_cseq([tag, ][inc])</function>
+		</title>
+		<para>Increments the dialog's generated CSeq associated to the leg
+		identified by the dialog's tag.
+		</para>
+		<para>Parameters:</para>
+		<itemizedlist>
+			<listitem><para><emphasis>tag (string, optional)</emphasis> -
+			the tag to increment the CSeq value for. If missing, the
+			message's <emphasis>To</emphasis> tag is used to identify
+			the leg to increment the CSeq for.
+			</para></listitem>
+			<listitem><para><emphasis>inc (integer, optional)</emphasis> - the
+			value used to increment/decrement (if negative) the CSeq of
+			the identified leg. If not used, the value is incremented with
+			<emphasis>1</emphasis>.
+			</para></listitem>
+		</itemizedlist>
+		<para>
+			This function can be used from REQUEST_ROUTE, FAILURE_ROUTE,
+			ONREPLY_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE routes.
+		</para>
+		<example>
+		<title><function>dlg_inc_cseq</function> usage</title>
+		<programlisting format="linespecific">
+...
+route {
+	...
+	if (has_totag()) {
+		if (loose_route())
+			dlg_inc_cseq(); # increment upstream CSeq after each in-dialog request
+	}
+}
+...
 </programlisting>
 		</example>
 	</section>