Issue #8575 - Buggy cisco MWI support.

Normally we try not to change our software for bugs in other devices. But in
this case, the Cisco phones are so widespread so we try to implement a fix while
waiting for a bugfix from Cisco.



git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@48982 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -781,10 +781,12 @@ struct sip_auth {
 #define SIP_PAGE2_CALL_ONHOLD		(3 << 23)	/*!< Call states */
 #define SIP_PAGE2_CALL_ONHOLD_ONEDIR	(1 << 23)	/*!< 23: One directional hold */
 #define SIP_PAGE2_CALL_ONHOLD_INACTIVE	(1 << 24)	/*!< 24: Inactive  */
-#define SIP_PAGE2_RFC2833_COMPENSATE    (1 << 25)
+#define SIP_PAGE2_RFC2833_COMPENSATE    (1 << 25)	/*!< 25: ???? */
+#define SIP_PAGE2_BUGGY_CISCO_MWI	(1 << 26)	/*!< 26: Buggy CISCO MWI fix */
 
 #define SIP_PAGE2_FLAGS_TO_COPY \
-	(SIP_PAGE2_ALLOWSUBSCRIBE | SIP_PAGE2_ALLOWOVERLAP | SIP_PAGE2_VIDEOSUPPORT | SIP_PAGE2_T38SUPPORT | SIP_PAGE2_RFC2833_COMPENSATE)
+	(SIP_PAGE2_ALLOWSUBSCRIBE | SIP_PAGE2_ALLOWOVERLAP | SIP_PAGE2_VIDEOSUPPORT | \
+	SIP_PAGE2_T38SUPPORT | SIP_PAGE2_RFC2833_COMPENSATE | SIP_PAGE2_BUGGY_CISCO_MWI)
 
 /* SIP packet flags */
 #define SIP_PKT_DEBUG		(1 << 0)	/*!< Debug this packet */
@@ -6964,7 +6966,11 @@ static int transmit_notify_with_mwi(struct sip_pvt *p, int newmsgs, int oldmsgs,
 	ast_build_string(&t, &maxbytes, "Messages-Waiting: %s\r\n", newmsgs ? "yes" : "no");
 	ast_build_string(&t, &maxbytes, "Message-Account: sip:%s@%s\r\n",
 		S_OR(vmexten, default_vmexten), S_OR(p->fromdomain, ast_inet_ntoa(p->ourip)));
-	ast_build_string(&t, &maxbytes, "Voice-Message: %d/%d (0/0)\r\n", newmsgs, oldmsgs);
+	/* Cisco has a bug in the SIP stack where it can't accept the
+		(0/0) notification. This can temporarily be disabled in
+		sip.conf with the "buggyciscomwi" option */
+	ast_build_string(&t, &maxbytes, "Voice-Message: %d/%d%s\r\n", newmsgs, oldmsgs, (ast_test_flag(&p->flags[1], SIP_PAGE2_BUGGY_CISCO_MWI) ? "" : " (0/0)"));
+
 	if (p->subscribed) {
 		if (p->expiry)
 			add_header(&req, "Subscription-State", "active");
@@ -15326,6 +15332,10 @@ static int handle_common_options(struct ast_flags *flags, struct ast_flags *mask
 		ast_set_flag(&mask[1], SIP_PAGE2_RFC2833_COMPENSATE);
 		ast_set2_flag(&flags[1], ast_true(v->value), SIP_PAGE2_RFC2833_COMPENSATE);
 		res = 1;
+	} else if (!strcasecmp(v->name, "buggyciscomwi")) {
+		ast_set_flag(&mask[1], SIP_PAGE2_BUGGY_CISCO_MWI);
+		ast_set2_flag(&flags[1], ast_true(v->value), SIP_PAGE2_BUGGY_CISCO_MWI);
+		res = 1;
 	} 
 
 	return res;

configs/sip.conf.sample

@@ -66,6 +66,9 @@ srvlookup=yes			; Enable DNS SRV lookups on outbound calls
 				; Defaults to 100 ms
 ;notifymimetype=text/plain	; Allow overriding of mime type in MWI NOTIFY
 ;checkmwi=10			; Default time between mailbox checks for peers
+;buggyciscomwi=no		; Cisco SIP firmware doesn't support the MWI RFC
+				; fully. Enable this option to not get error messages
+				; when sending MWI to phones with this bug.
 ;vmexten=voicemail		; dialplan extension to reach mailbox sets the 
 				; Message-Account in the MWI notify message 
 				; defaults to "asterisk"