From c97532fdbb5562369b3af79606f34c8599b959d3 Mon Sep 17 00:00:00 2001
From: Thomas Ries <tries@gmx.net>
Date: Thu, 24 May 2007 18:38:59 +0000
Subject: [PATCH] - new feature: can masquerade User-agent header

---
 ChangeLog                |  1 +
 doc/siproxd.conf.example | 11 +++++++++++
 src/proxy.c              | 39 +++++++++++++++++++++++++++++++++++----
 src/readconf.c           |  1 +
 src/siproxd.h            |  2 ++
 5 files changed, 50 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 0511f89..8ad7cb5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,6 @@
 0.6.0
 =====
+  24-May-2007:  - new feature: can masquerade User-agent header
   13-May-2007:  - deal with locally running UAs on same host (inboud IF side)
   07-May-2007:  - Client-ID in RTP proxy is derived from Client IP address.
                   This should fix an issue with unexpectedly timing-out RTP
diff --git a/doc/siproxd.conf.example b/doc/siproxd.conf.example
index b9193f4..777af75 100644
--- a/doc/siproxd.conf.example
+++ b/doc/siproxd.conf.example
@@ -232,6 +232,17 @@ debug_port = 0
 # mask_host=10.0.1.1			-- inbound IP address of proxy
 # masked_host=my.public.host		-- outbound hostname proxy
 
+######################################################################
+# User Agent Masquerading
+#
+# Siproxd can masquerade the User Agent string of your local UAs.
+# Useful for Providers that do not work with some specific UAs
+# (e.g. sipcall.ch - it does not work if your outgoing SIP
+# traffic contains an Asterisk UA string...)
+# Default is to do no replacement.
+#
+#ua_string = Siproxd-UA
+
 ######################################################################
 # Outbound proxy
 #
diff --git a/src/proxy.c b/src/proxy.c
index 964a6a8..93a3d10 100644
--- a/src/proxy.c
+++ b/src/proxy.c
@@ -189,7 +189,6 @@ int proxy_request (sip_ticket_t *ticket) {
       /* 'i' still holds the valid index into the URLMAP table */
       proxy_rewrite_request_uri(request, i);
 
-
       /* if this is CANCEL/BYE request, stop RTP proxying */
       if (MSG_IS_BYE(request) || MSG_IS_CANCEL(request)) {
          /* stop the RTP proxying stream(s) */
@@ -243,9 +242,12 @@ int proxy_request (sip_ticket_t *ticket) {
       }
 #endif
 
-      /* rewrite Contact header to represent the masqued address */
+      /* Rewrite Contact header to represent the masqued address */
       sip_rewrite_contact(ticket, DIR_OUTGOING);
 
+      /* Masquerade the User-Agent if configured to do so */
+      proxy_rewrite_useragent(ticket);
+
       /* if an INVITE, rewrite body */
       if (MSG_IS_INVITE(request)) {
          sts = proxy_rewrite_invitation_body(ticket, DIR_OUTGOING);
@@ -605,7 +607,7 @@ int proxy_response (sip_ticket_t *ticket) {
        *   response merely indicates that the subscription has been
        *   understood, and that authorization may or may not have been
        *   granted), which then of course is forwarded back to the phone.
-       *   Ans it seems that the Grandstream can *not* *handle* this
+       *   And it seems that the Grandstream can *not* *handle* this
        *   response, as it immediately sends another SUBSCRIBE request.
        *   And this games goes on and on and on...
        *
@@ -636,9 +638,12 @@ int proxy_response (sip_ticket_t *ticket) {
 	     response->from->url->host ? 
                 response->from->url->host : "*NULL*");
 
-      /* rewrite Contact header to represent the masqued address */
+      /* Rewrite Contact header to represent the masqued address */
       sip_rewrite_contact(ticket, DIR_OUTGOING);
 
+      /* Masquerade the User-Agent if configured to do so */
+      proxy_rewrite_useragent(ticket);
+
       /*
        * If an 2xx OK or 1xx response, answer to an INVITE request,
        * rewrite body
@@ -1204,3 +1209,29 @@ int proxy_rewrite_request_uri(osip_message_t *mymsg, int idx){
    }
    return STS_SUCCESS;
 }
+
+
+/*
+ * PROXY_REWRITE_USERAGENT
+ *
+ * rewrites the User Agent String
+ * 
+ * RETURNS
+ *	STS_SUCCESS on success
+ */
+int proxy_rewrite_useragent(sip_ticket_t *ticket){
+   osip_header_t *ua_hdr=NULL;
+   char *useragent;
+
+   osip_message_get_user_agent(ticket->sipmsg, 0, &ua_hdr);
+
+   /* Configured? & Does User-Agent header exist? */
+   if ((configuration.ua_string) && (ua_hdr && ua_hdr->hvalue)) {
+      DEBUGC(DBCLASS_PROXY,"proxy_rewrite_useragent: [%s] -> [%s]",
+             ua_hdr->hvalue, configuration.ua_string);
+      osip_free(ua_hdr->hvalue);
+      ua_hdr->hvalue=osip_malloc(strlen(configuration.ua_string)+1);
+      strcpy(ua_hdr->hvalue, configuration.ua_string);
+   }
+   return STS_SUCCESS;
+}
diff --git a/src/readconf.c b/src/readconf.c
index 3de1960..a7b26f5 100644
--- a/src/readconf.c
+++ b/src/readconf.c
@@ -183,6 +183,7 @@ static int parse_config (FILE *configfile) {
       { "pi_shortdial_enable", TYP_INT4,   &configuration.pi_shortdial },
       { "pi_shortdial_akey",   TYP_STRING, &configuration.pi_shortdial_akey },
       { "pi_shortdial_entry",  TYP_STRINGA,&configuration.pi_shortdial_entry },
+      { "ua_string",           TYP_STRING, &configuration.ua_string },
       {0, 0, 0}
    };
 
diff --git a/src/siproxd.h b/src/siproxd.h
index 84e6576..9f6917f 100644
--- a/src/siproxd.h
+++ b/src/siproxd.h
@@ -94,6 +94,7 @@ struct siproxd_config {
    int  pi_shortdial;
    char *pi_shortdial_akey;
    stringa_t pi_shortdial_entry;
+   char *ua_string;
 };
 
 /*
@@ -143,6 +144,7 @@ int proxy_request (sip_ticket_t *ticket);				/*X*/
 int proxy_response (sip_ticket_t *ticket);				/*X*/
 int proxy_rewrite_invitation_body(sip_ticket_t *ticket, int direction); /*X*/
 int proxy_rewrite_request_uri(osip_message_t *mymsg, int idx);		/*X*/
+int proxy_rewrite_useragent(sip_ticket_t *ticket);			/*X*/
 
 /* route_preprocessing.c */
 int route_preprocess(sip_ticket_t *ticket);				/*X*/