Merged revisions 215682 via svnmerge from
authorTerry Wilson <twilson@digium.com>
Wed, 2 Sep 2009 23:31:04 +0000 (23:31 +0000)
committerTerry Wilson <twilson@digium.com>
Wed, 2 Sep 2009 23:31:04 +0000 (23:31 +0000)
https://origsvn.digium.com/svn/asterisk/branches/1.4

........
  r215682 | twilson | 2009-09-02 16:41:22 -0500 (Wed, 02 Sep 2009) | 18 lines

  Re-send non-100 provisional responses to prevent cancellation

  From section 13.3.1.1 of RFC 3261:

     If the UAS desires an extended period of time to answer the INVITE,
     it will need to ask for an "extension" in order to prevent proxies
     from canceling the transaction. A proxy has the option of canceling
     a transaction when there is a gap of 3 minutes between responses in a
     transaction. To prevent cancellation, the UAS MUST send a non-100
     provisional response at every minute, to handle the possibility of
     lost provisional responses.

  (closes issue #11157)
  Reported by: rjain
  Tested by: twilson

  Review: https://reviewboard.asterisk.org/r/315/
........

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@215758 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

index a80a2af..df69d3c 100644 (file)
@@ -38,8 +38,6 @@
  * \todo Better support of forking
  * \todo VIA branch tag transaction checking
  * \todo Transaction support
- * \todo Asterisk should send a non-100 provisional response every minute to keep proxies
- *  from cancelling the transaction (RFC 3261 13.3.1.1). See bug #11157.
  *
  * ******** Wishlist: Improvements
  * - Support of SIP domains for devices, so that we match on username@domain in the From: header
@@ -614,6 +612,7 @@ static int mwi_expiry = DEFAULT_MWI_EXPIRY;
                                                       \todo Use known T1 for timeout (peerpoke)
                                                       */
 #define DEFAULT_TRANS_TIMEOUT        -1               /*!< Use default SIP transaction timeout */
+#define PROVIS_KEEPALIVE_TIMEOUT     60000            /*!< How long to wait before retransmitting a provisional response (rfc 3261 13.3.1.1) */
 #define MAX_AUTHTRIES                3                /*!< Try authentication three times, then fail */
 
 #define SIP_MAX_HEADERS              64               /*!< Max amount of SIP headers to read */
@@ -1753,6 +1752,8 @@ struct sip_pvt {
        int redircodecs;                        /*!< Redirect codecs */
        int maxcallbitrate;                     /*!< Maximum Call Bitrate for Video Calls */    
        int request_queue_sched_id;             /*!< Scheduler ID of any scheduled action to process queued requests */
+       int provisional_keepalive_sched_id; /*!< Scheduler ID for provisional responses that need to be sent out to avoid cancellation */
+       const char *last_provisional;   /*!< The last successfully transmitted provisonal response message */
        int authtries;                          /*!< Times we've tried to authenticate */
        struct sip_proxy *outboundproxy;        /*!< Outbound proxy for this dialog. Use ref_proxy to set this instead of setting it directly*/
        struct t38properties t38;               /*!< T38 settings */
@@ -2365,6 +2366,7 @@ static int transmit_response_with_date(struct sip_pvt *p, const char *msg, const
 static int transmit_response_with_sdp(struct sip_pvt *p, const char *msg, const struct sip_request *req, enum xmittype reliable, int oldsdp, int rpid);
 static int transmit_response_with_unsupported(struct sip_pvt *p, const char *msg, const struct sip_request *req, const char *unsupported);
 static int transmit_response_with_auth(struct sip_pvt *p, const char *msg, const struct sip_request *req, const char *rand, enum xmittype reliable, const char *header, int stale);
+static int transmit_provisional_response(struct sip_pvt *p, const char *msg, const struct sip_request *req, int with_sdp);
 static int transmit_response_with_allow(struct sip_pvt *p, const char *msg, const struct sip_request *req, enum xmittype reliable);
 static void transmit_fake_auth_response(struct sip_pvt *p, int sipmethod, struct sip_request *req, enum xmittype reliable);
 static int transmit_request(struct sip_pvt *p, int sipmethod, int inc, enum xmittype reliable, int newbranch);
@@ -3085,6 +3087,8 @@ static void *dialog_unlink_all(struct sip_pvt *dialog, int lockowner, int lockdi
                AST_SCHED_DEL_UNREF(sched, dialog->request_queue_sched_id, dialog_unref(dialog, "when you delete the request_queue_sched_id sched, you should dec the refcount for the stored dialog ptr"));
        }
 
+       AST_SCHED_DEL_UNREF(sched, dialog->provisional_keepalive_sched_id, dialog_unref(dialog, "when you delete the provisional_keepalive_sched_id, you should dec the refcount for the stored dialog ptr"));
+
        if (dialog->t38id > -1) {
                AST_SCHED_DEL_UNREF(sched, dialog->t38id, dialog_unref(dialog, "when you delete the t38id sched, you should dec the refcount for the stored dialog ptr"));
        }
@@ -4033,6 +4037,46 @@ static void add_blank(struct sip_request *req)
        }
 }
 
+static int send_provisional_keepalive_full(struct sip_pvt *pvt, int with_sdp)
+{
+       const char *msg = NULL;
+
+       if (!pvt->last_provisional || !strncasecmp(pvt->last_provisional, "100", 3)) {
+               msg = "183 Session Progress";
+       }
+
+       if (pvt->invitestate < INV_COMPLETED) {
+               if (with_sdp) {
+                       transmit_response_with_sdp(pvt, S_OR(msg, pvt->last_provisional), &pvt->initreq, XMIT_UNRELIABLE, FALSE, FALSE);
+               } else {
+                       transmit_response(pvt, S_OR(msg, pvt->last_provisional), &pvt->initreq);
+               }
+               return PROVIS_KEEPALIVE_TIMEOUT;
+       }
+
+       return 0;
+}
+
+static int send_provisional_keepalive(const void *data) {
+       struct sip_pvt *pvt = (struct sip_pvt *) data;
+
+       return send_provisional_keepalive_full(pvt, 0);
+}
+
+static int send_provisional_keepalive_with_sdp(const void *data) {
+       struct sip_pvt *pvt = (void *)data;
+
+       return send_provisional_keepalive_full(pvt, 1);
+}
+
+static void update_provisional_keepalive(struct sip_pvt *pvt, int with_sdp)
+{
+       AST_SCHED_DEL_UNREF(sched, pvt->provisional_keepalive_sched_id, dialog_unref(pvt, "when you delete the provisional_keepalive_sched_id, you should dec the refcount for the stored dialog ptr"));
+
+       pvt->provisional_keepalive_sched_id = ast_sched_add(sched, PROVIS_KEEPALIVE_TIMEOUT,
+               with_sdp ? send_provisional_keepalive_with_sdp : send_provisional_keepalive, dialog_ref(pvt, "Increment refcount to pass dialog pointer to sched callback"));
+}
+
 /*! \brief Transmit response on SIP request*/
 static int send_response(struct sip_pvt *p, struct sip_request *req, enum xmittype reliable, int seqno)
 {
@@ -4054,6 +4098,12 @@ static int send_response(struct sip_pvt *p, struct sip_request *req, enum xmitty
                        (tmp.method == SIP_RESPONSE || tmp.method == SIP_UNKNOWN) ? REQ_OFFSET_TO_STR(&tmp, rlPart2) : sip_methods[tmp.method].text);
                ast_free(tmp.data);
        }
+
+       /* If we are sending a final response to an INVITE, stop retransmitting provisional responses */
+       if (p->initreq.method == SIP_INVITE && reliable == XMIT_CRITICAL) {
+               AST_SCHED_DEL_UNREF(sched, p->provisional_keepalive_sched_id, dialog_unref(p, "when you delete the provisional_keepalive_sched_id, you should dec the refcount for the stored dialog ptr"));
+       }
+
        res = (reliable) ?
                 __sip_reliable_xmit(p, seqno, 1, req->data, req->len, (reliable == XMIT_CRITICAL), req->method) :
                __sip_xmit(p, req->data, req->len);
@@ -6200,7 +6250,7 @@ static int sip_write(struct ast_channel *ast, struct ast_frame *frame)
                                    !ast_test_flag(&p->flags[0], SIP_OUTGOING)) {
                                        ast_rtp_instance_new_source(p->rtp);
                                        p->invitestate = INV_EARLY_MEDIA;
-                                       transmit_response_with_sdp(p, "183 Session Progress", &p->initreq, XMIT_UNRELIABLE, FALSE, FALSE);
+                                       transmit_provisional_response(p, "183 Session Progress", &p->initreq, TRUE);
                                        ast_set_flag(&p->flags[0], SIP_PROGRESS_SENT);
                                } else if (p->t38.state == T38_ENABLED) {
                                        change_t38_state(p, T38_DISABLED);
@@ -6222,7 +6272,7 @@ static int sip_write(struct ast_channel *ast, struct ast_frame *frame)
                                    !ast_test_flag(&p->flags[0], SIP_PROGRESS_SENT) &&
                                    !ast_test_flag(&p->flags[0], SIP_OUTGOING)) {
                                        p->invitestate = INV_EARLY_MEDIA;
-                                       transmit_response_with_sdp(p, "183 Session Progress", &p->initreq, XMIT_UNRELIABLE, FALSE, FALSE);
+                                       transmit_provisional_response(p, "183 Session Progress", &p->initreq, TRUE);
                                        ast_set_flag(&p->flags[0], SIP_PROGRESS_SENT);
                                }
                                p->lastrtptx = time(NULL);
@@ -6243,7 +6293,7 @@ static int sip_write(struct ast_channel *ast, struct ast_frame *frame)
                                            !ast_test_flag(&p->flags[0], SIP_PROGRESS_SENT) &&
                                            !ast_test_flag(&p->flags[0], SIP_OUTGOING)) {
                                                p->invitestate = INV_EARLY_MEDIA;
-                                               transmit_response_with_sdp(p, "183 Session Progress", &p->initreq, XMIT_UNRELIABLE, FALSE, FALSE);
+                                               transmit_provisional_response(p, "183 Session Progress", &p->initreq, TRUE);
                                                ast_set_flag(&p->flags[0], SIP_PROGRESS_SENT);
                                        }
                                        p->lastrtptx = time(NULL);
@@ -6465,7 +6515,7 @@ static int sip_indicate(struct ast_channel *ast, int condition, const void *data
                        if (!ast_test_flag(&p->flags[0], SIP_PROGRESS_SENT) ||
                            (ast_test_flag(&p->flags[0], SIP_PROG_INBAND) == SIP_PROG_INBAND_NEVER)) {                          
                                /* Send 180 ringing if out-of-band seems reasonable */
-                               transmit_response(p, "180 Ringing", &p->initreq);
+                               transmit_provisional_response(p, "180 Ringing", &p->initreq, 0);
                                ast_set_flag(&p->flags[0], SIP_RINGING);
                                if (ast_test_flag(&p->flags[0], SIP_PROG_INBAND) != SIP_PROG_INBAND_YES)
                                        break;
@@ -6510,7 +6560,7 @@ static int sip_indicate(struct ast_channel *ast, int condition, const void *data
                    !ast_test_flag(&p->flags[0], SIP_PROGRESS_SENT) &&
                    !ast_test_flag(&p->flags[0], SIP_OUTGOING)) {
                        p->invitestate = INV_EARLY_MEDIA;
-                       transmit_response_with_sdp(p, "183 Session Progress", &p->initreq, XMIT_UNRELIABLE, FALSE, FALSE);
+                       transmit_provisional_response(p, "183 Session Progress", &p->initreq, TRUE);
                        ast_set_flag(&p->flags[0], SIP_PROGRESS_SENT);
                        break;
                }
@@ -7100,6 +7150,7 @@ static struct sip_pvt *sip_alloc(ast_string_field callid, struct sockaddr_in *si
        p->waitid = -1;
        p->autokillid = -1;
        p->request_queue_sched_id = -1;
+       p->provisional_keepalive_sched_id = -1;
        p->t38id = -1;
        p->subscribed = NONE;
        p->stateid = -1;
@@ -9687,6 +9738,19 @@ static void get_realm(struct sip_pvt *p, const struct sip_request *req)
        ast_string_field_set(p, realm, sip_cfg.realm);
 }
 
+/* Only use a static string for the msg, here! */
+static int transmit_provisional_response(struct sip_pvt *p, const char *msg, const struct sip_request *req, int with_sdp)
+{
+       int res;
+
+       if (!(res = with_sdp ? transmit_response_with_sdp(p, msg, req, XMIT_UNRELIABLE, FALSE, FALSE) : transmit_response(p, msg, req))) {
+               p->last_provisional = msg;
+               update_provisional_keepalive(p, with_sdp);
+       }
+
+       return res;
+}
+
 /*! \brief Add text body to SIP message */
 static int add_text(struct sip_request *req, const char *text)
 {
@@ -20672,7 +20736,7 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int
                switch(c_state) {
                case AST_STATE_DOWN:
                        ast_debug(2, "%s: New call is still down.... Trying... \n", c->name);
-                       transmit_response(p, "100 Trying", req);
+                       transmit_provisional_response(p, "100 Trying", req, 0);
                        p->invitestate = INV_PROCEEDING;
                        ast_setstate(c, AST_STATE_RING);
                        if (strcmp(p->exten, ast_pickup_ext())) {       /* Call to extension -start pbx on this call */
@@ -20726,11 +20790,11 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int
                        }
                        break;
                case AST_STATE_RING:
-                       transmit_response(p, "100 Trying", req);
+                       transmit_provisional_response(p, "100 Trying", req, 0);
                        p->invitestate = INV_PROCEEDING;
                        break;
                case AST_STATE_RINGING:
-                       transmit_response(p, "180 Ringing", req);
+                       transmit_provisional_response(p, "180 Ringing", req, 0);
                        p->invitestate = INV_PROCEEDING;
                        break;
                case AST_STATE_UP: