No subject
Sun Jul 19 19:54:31 CDT 2009
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/
Modified:
branches/1.4/channels/chan_sip.c
Modified: branches/1.4/channels/chan_sip.c
URL: http://svn.asterisk.org/svn-view/asterisk/branches/1.4/channels/chan_sip.c?view=diff&rev=215682&r1=215681&r2=215682
==============================================================================
--- branches/1.4/channels/chan_sip.c (original)
+++ branches/1.4/channels/chan_sip.c Wed Sep 2 16:41:22 2009
@@ -211,6 +211,7 @@
\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 */
@@ -1034,6 +1035,8 @@
struct ast_variable *chanvars; /*!< Channel variables to set for inbound call */
AST_LIST_HEAD_NOLOCK(request_queue, sip_request) request_queue; /*!< Requests that arrived but could not be processed immediately */
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 */
struct sip_pvt *next; /*!< Next dialog in chain */
struct sip_invite_param *options; /*!< Options for INVITE */
int autoframing;
@@ -1290,6 +1293,7 @@
static int transmit_response_with_sdp(struct sip_pvt *p, const char *msg, const struct sip_request *req, enum xmittype reliable);
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);
@@ -2321,6 +2325,46 @@
}
}
+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);
+ } 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(sched, pvt->provisional_keepalive_sched_id);
+
+ pvt->provisional_keepalive_sched_id = ast_sched_add(sched, PROVIS_KEEPALIVE_TIMEOUT,
+ with_sdp ? send_provisional_keepalive_with_sdp : send_provisional_keepalive, pvt);
+}
+
/*! \brief Transmit response on SIP request*/
static int send_response(struct sip_pvt *p, struct sip_request *req, enum xmittype reliable, int seqno)
{
@@ -2341,6 +2385,12 @@
append_history(p, reliable ? "TxRespRel" : "TxResp", "%s / %s - %s", tmp.data, get_header(&tmp, "CSeq"),
(tmp.method == SIP_RESPONSE || tmp.method == SIP_UNKNOWN) ? tmp.rlPart2 : sip_methods[tmp.method].text);
}
+
+ /* 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(sched, p->provisional_keepalive_sched_id);
+ }
+
res = (reliable) ?
__sip_reliable_xmit(p, seqno, 1, req->data, req->len, (reliable == XMIT_CRITICAL), req->method) :
__sip_xmit(p, req->data, req->len);
@@ -3228,6 +3278,7 @@
AST_SCHED_DEL(sched, p->waitid);
AST_SCHED_DEL(sched, p->autokillid);
AST_SCHED_DEL(sched, p->request_queue_sched_id);
+ AST_SCHED_DEL(sched, p->provisional_keepalive_sched_id);
if (p->rtp) {
ast_rtp_destroy(p->rtp);
@@ -3844,7 +3895,7 @@
!ast_test_flag(&p->flags[0], SIP_OUTGOING)) {
ast_rtp_new_source(p->rtp);
p->invitestate = INV_EARLY_MEDIA;
- transmit_response_with_sdp(p, "183 Session Progress", &p->initreq, XMIT_UNRELIABLE);
+ transmit_provisional_response(p, "183 Session Progress", &p->initreq, 1);
ast_set_flag(&p->flags[0], SIP_PROGRESS_SENT);
} else if (p->t38.state == T38_ENABLED && !p->t38.direct) {
p->t38.state = T38_DISABLED;
@@ -3866,7 +3917,7 @@
!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);
+ transmit_provisional_response(p, "183 Session Progress", &p->initreq, 1);
ast_set_flag(&p->flags[0], SIP_PROGRESS_SENT);
}
p->lastrtptx = time(NULL);
@@ -4037,7 +4088,7 @@
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;
@@ -4082,7 +4133,7 @@
!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);
+ transmit_provisional_response(p, "183 Session Progress", &p->initreq, 1);
ast_set_flag(&p->flags[0], SIP_PROGRESS_SENT);
break;
}
@@ -4594,6 +4645,7 @@
p->waitid = -1;
p->autokillid = -1;
p->request_queue_sched_id = -1;
+ p->provisional_keepalive_sched_id = -1;
p->subscribed = NONE;
p->stateid = -1;
p->prefs = default_prefs; /* Set default codecs for this call */
@@ -6517,6 +6569,19 @@
add_header_contentLength(&resp, 0);
append_history(p, "AuthChal", "Auth challenge sent for %s - nc %d", p->username, p->noncecount);
return send_response(p, &resp, reliable, seqno);
+}
+
+/* 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) : transmit_response(p, msg, req))) {
+ p->last_provisional = msg;
+ update_provisional_keepalive(p, with_sdp);
+ }
+
+ return res;
}
/*! \brief Add text body to SIP message */
@@ -14975,7 +15040,7 @@
case AST_STATE_DOWN:
if (option_debug > 1)
ast_log(LOG_DEBUG, "%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 */
@@ -15039,11 +15104,11 @@
}
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:
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