From 52909f3faa9628b098913ac6a09de11d18d0313f Mon Sep 17 00:00:00 2001
From: Thomas Ries <tries@gmx.net>
Date: Sat, 21 Apr 2007 18:56:49 +0000
Subject: [PATCH] - Hack to deal with Asterisks broken Alert-Info headers  
 (Asterisk does include Alert-Info header without '<>')

---
 ChangeLog       |  2 ++
 src/sip_utils.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++-
 src/siproxd.c   |  5 +++++
 src/siproxd.h   |  1 +
 4 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 961160d..cddda7f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,7 @@
 0.6.0
 =====
+  21-Apr-2007:  - Hack to deal with Asterisks broken Alert-Info headers
+                  (Asterisk does include Alert-Info header without '<>')
   19-Feb-2007:  - Increased RTP buffer size
   13-Oct-2006:  - Various fixes due to a code review by Andrew Jones
   05-Oct-2006:  - route_determine_nexthop(): don't remove header
diff --git a/src/sip_utils.c b/src/sip_utils.c
index 8627780..43b3887 100644
--- a/src/sip_utils.c
+++ b/src/sip_utils.c
@@ -1097,6 +1097,51 @@ int  sip_find_direction(sip_ticket_t *ticket, int *urlidx) {
 }
 
 
-
+/*
+ * SIP_FIXUP_ALERT_INFO
+ *
+ * Asterisk Hack.
+ * Asterisk seems to include broken Alert-Info headers (without <>)
+ * that cause parsing to fail (libosip2).
+ * This function does try to guess if we have such a broken SIP
+ * message and does simply remove the offending Alert-Info header.
+ *
+ * RETURNS
+ *	STS_SUCCESS on success
+ */
+int  sip_fixup_asterisk(char *buff, int *buflen) {
+   char *alert_info_ptr=NULL;
+   /*
+    * Check for Asterisk UA string
+    * User-Agent: Asterisk PBX
+    */
+   if (strstr(buff, "\r\nUser-Agent: Asterisk PBX\r\n")==NULL)
+      return STS_SUCCESS;
+
+   DEBUGC(DBCLASS_SIP, "sip_fixup_alert_info: SIP message is from Asterisk");
+   /*
+    * Look form Alert-Info: header
+    */
+   alert_info_ptr=strstr(buff, "\r\nAlert-Info: ");
+   if (alert_info_ptr) {
+      char *eol_ptr=NULL;
+      DEBUGC(DBCLASS_SIP, "sip_fixup_alert_info: Asterisk message "
+             "with Alert-Info found");
+      eol_ptr=strstr((alert_info_ptr+2), "\r\n");
+      if (eol_ptr) {
+         int i;
+         // cut the Alert-Info header from the message
+         // (actually move the rest of the message up)
+         DEBUGC(DBCLASS_SIP, "sip_fixup_alert_info: removed malformed "
+                "Alert-Info header");
+         for (i=0; i<(*buflen - (eol_ptr - buff)); i++) {
+            alert_info_ptr[i]=eol_ptr[i];
+         } /* for */
+
+         *buflen=strlen(buff);
+      } /* if */
+   }
+   return STS_SUCCESS;
+}
 
 
diff --git a/src/siproxd.c b/src/siproxd.c
index 3b1cd06..0efb122 100644
--- a/src/siproxd.c
+++ b/src/siproxd.c
@@ -318,6 +318,11 @@ int main (int argc, char *argv[])
          continue; /* there are no resources to free */
       }
 
+      /*
+       * Hacks to fix-up some broken headers
+       */
+      sts=sip_fixup_asterisk(buff, &buflen);
+
       /*
        * init sip_msg
        */
diff --git a/src/siproxd.h b/src/siproxd.h
index 26552d0..84e6576 100644
--- a/src/siproxd.h
+++ b/src/siproxd.h
@@ -175,6 +175,7 @@ int  sip_calculate_branch_id (sip_ticket_t *ticket, char *id);		/*X*/
 int  sip_find_outbound_proxy(sip_ticket_t *ticket, struct in_addr *addr,
                              int *port);				/*X*/
 int  sip_find_direction(sip_ticket_t *ticket, int *urlidx);		/*X*/
+int  sip_fixup_asterisk(char *buff, int *buflen);			/*X*/
 
 /* readconf.c */
 int read_config(char *name, int search);				/*X*/