Let's understand SIP:

- REFER can create dialog, Asterisk does not support it yet
- NOTIFY can create dialog in Asterisk's implementation (voicemail) even though
  we don't support the server side of it. In this case, the standard is a side issue ;-)
- Added extened functionality for unsupported methods (PING, PUBLISH) so we don't
  create PVT's for those either.

Russellb needs to judge what to do with this in 1.2, but I think the current implementation
n 1.2 is a bug since we're sending bad replies to NOTIFY and REFER outside of dialogs

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@45741 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 599c4fc5f04fb495488338b1900f687d3fb3da02..a67395b142e8828e798f036813b84dc42bc4489c 100644 (file)
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -307,6 +307,7 @@ enum sipmethod {
        SIP_INFO,
        SIP_CANCEL,
        SIP_PUBLISH,            /* Not supported at all */
+       SIP_PING,               /* Not supported at all, no standard but still implemented out there */
 };
 
 /*! \brief Authentication types - proxy or www authentication 
@@ -342,6 +343,9 @@ enum sipregistrystate {
        REG_STATE_FAILED,       /*!< Registration failed after several tries */
 };
 
+#define CAN_NOT_CREATE_DIALOG  0
+#define CAN_CREATE_DIALOG      1
+#define CAN_CREATE_DIALOG_UNSUPPORTED_METHOD   2
 
 /*! XXX Note that sip_methods[i].id == i must hold or the code breaks */
 static const struct  cfsip_methods { 
@@ -350,22 +354,23 @@ static const struct  cfsip_methods {
        char * const text;
        int can_create;
 } sip_methods[] = {
-       { SIP_UNKNOWN,   RTP,    "-UNKNOWN-", 0 },
-       { SIP_RESPONSE,  NO_RTP, "SIP/2.0", 0 },
-       { SIP_REGISTER,  NO_RTP, "REGISTER", 1 },
-       { SIP_OPTIONS,   NO_RTP, "OPTIONS", 1 },
-       { SIP_NOTIFY,    NO_RTP, "NOTIFY", 0 },
-       { SIP_INVITE,    RTP,    "INVITE", 1 },
-       { SIP_ACK,       NO_RTP, "ACK", 0 },
-       { SIP_PRACK,     NO_RTP, "PRACK", 0 },
-       { SIP_BYE,       NO_RTP, "BYE", 0 },
-       { SIP_REFER,     NO_RTP, "REFER", 0 },
-       { SIP_SUBSCRIBE, NO_RTP, "SUBSCRIBE", 1 },
-       { SIP_MESSAGE,   NO_RTP, "MESSAGE", 1 },
-       { SIP_UPDATE,    NO_RTP, "UPDATE", 0 },
-       { SIP_INFO,      NO_RTP, "INFO", 0 },
-       { SIP_CANCEL,    NO_RTP, "CANCEL", 0 },
-       { SIP_PUBLISH,   NO_RTP, "PUBLISH", 1 }
+       { SIP_UNKNOWN,   RTP,    "-UNKNOWN-",   CAN_CREATE_DIALOG },
+       { SIP_RESPONSE,  NO_RTP, "SIP/2.0",     CAN_NOT_CREATE_DIALOG },
+       { SIP_REGISTER,  NO_RTP, "REGISTER",    CAN_CREATE_DIALOG },
+       { SIP_OPTIONS,   NO_RTP, "OPTIONS",     CAN_CREATE_DIALOG },
+       { SIP_NOTIFY,    NO_RTP, "NOTIFY",      CAN_CREATE_DIALOG },
+       { SIP_INVITE,    RTP,    "INVITE",      CAN_CREATE_DIALOG },
+       { SIP_ACK,       NO_RTP, "ACK",         CAN_NOT_CREATE_DIALOG },
+       { SIP_PRACK,     NO_RTP, "PRACK",       CAN_NOT_CREATE_DIALOG },
+       { SIP_BYE,       NO_RTP, "BYE",         CAN_NOT_CREATE_DIALOG },
+       { SIP_REFER,     NO_RTP, "REFER",       CAN_CREATE_DIALOG },
+       { SIP_SUBSCRIBE, NO_RTP, "SUBSCRIBE",   CAN_CREATE_DIALOG },
+       { SIP_MESSAGE,   NO_RTP, "MESSAGE",     CAN_CREATE_DIALOG },
+       { SIP_UPDATE,    NO_RTP, "UPDATE",      CAN_NOT_CREATE_DIALOG },
+       { SIP_INFO,      NO_RTP, "INFO",        CAN_NOT_CREATE_DIALOG },
+       { SIP_CANCEL,    NO_RTP, "CANCEL",      CAN_NOT_CREATE_DIALOG },
+       { SIP_PUBLISH,   NO_RTP, "PUBLISH",     CAN_CREATE_DIALOG_UNSUPPORTED_METHOD },
+       { SIP_PING,      NO_RTP, "PING",        CAN_CREATE_DIALOG_UNSUPPORTED_METHOD }
 };
 
 /*!  Define SIP option tags, used in Require: and Supported: headers 
@@ -4272,12 +4277,30 @@ static struct sip_pvt *find_call(struct sip_request *req, struct sockaddr_in *si
        ast_mutex_unlock(&iflock);
 
        /* See if the method is capable of creating a dialog */
-       if (!sip_methods[intended_method].can_create) {
-               if (intended_method != SIP_RESPONSE)
-                       transmit_response_using_temp(callid, sin, 1, intended_method, req, "481 Call leg/transaction does not exist");
-       } else if ((p = sip_alloc(callid, sin, 1, intended_method))) {
-               ast_mutex_lock(&p->lock);
-       }
+       if (sip_methods[intended_method].can_create == CAN_CREATE_DIALOG) {
+               if (intended_method == SIP_REFER) {
+                       /* We do support REFER, but not outside of a dialog yet */
+                       transmit_response_using_temp(callid, sin, 1, intended_method, req, "603 Declined (no dialog)");
+               } else if (intended_method == SIP_NOTIFY) {
+                       /* We do not support out-of-dialog NOTIFY either,
+                       like voicemail notification, so cancel that early */
+                       transmit_response_using_temp(callid, sin, 1, intended_method, req, "489 Bad event");
+               } else {
+                       /* Ok, time to create a new SIP dialog object, a pvt */
+                       if ((p = sip_alloc(callid, sin, 1, intended_method))) 
+                               /* Ok, we've created a dialog, let's go and process it */
+                               ast_mutex_lock(&p->lock);
+               }
+               return p;
+       } else if( sip_methods[intended_method].can_create == CAN_CREATE_DIALOG_UNSUPPORTED_METHOD) {
+               /* A method we do not support, let's take it on the volley */
+               transmit_response_using_temp(callid, sin, 1, intended_method, req, "501 Method Not Implemented");
+       } else if (intended_method != SIP_RESPONSE) {
+               /* This is a request outside of a dialog that we don't know about */
+               transmit_response_using_temp(callid, sin, 1, intended_method, req, "481 Call leg/transaction does not exist");
+       }
+       /* We do not respond to responses for dialogs that we don't know about, we just drop
+          the session quickly */
 
        return p;
 }