Merge slepp's REGISTER RFC compliance fixes (bug #1538)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@2866 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index a75f2f8..e288bdc 100755 (executable)
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -69,7 +69,17 @@
 #define SIPDUMPER
 #define DEFAULT_DEFAULT_EXPIRY  120
 #define DEFAULT_MAX_EXPIRY      3600
-#define EXPIRY_GUARD_SECS      15
+
+/* guard limit must be larger than guard secs */
+/* guard min must be > 1 */
+#define EXPIRY_GUARD_SECS      15      /* How long before expiry do we reregister */
+#define EXPIRY_GUARD_LIMIT      30     /* Below here, we use EXPIRY_GUARD_PCT instead of EXPIRY_GUARD_SECS */
+#define EXPIRY_GUARD_MIN        3      /* Below here, we use expires=1 instead of EXPIRY_GUARD_PCT * expires */
+#define EXPIRY_GUARD_PCT        0.20   /* Percentage of expires timeout to use when below EXPIRY_GUARD_LIMIT */
+
+#ifndef MAX
+#define MAX(a,b) ((a) > (b) ? (a) : (b))
+#endif
 
 #define CALLERID_UNKNOWN       "Unknown"
 
@@ -5341,10 +5351,37 @@ static void handle_response(struct sip_pvt *p, int resp, char *rest, struct sip_
                                        /* figure out how long we got registered for */
                                        if (r->expire > -1)
                                                ast_sched_del(sched, r->expire);
-                                       expires=atoi(get_header(req, "expires"));
+                                       /* according to section 6.13 of RFC, contact headers override
+                                          expires headers, so check those first */
+                                       expires = 0;
+                                       if (strlen(get_header(req, "Contact")) != 0) {
+                                               char *contact = NULL;
+                                               char *tmptmp = NULL;
+                                               int start = 0;
+                                               for(;;) {
+                                                       contact = __get_header(req, "Contact", &start);
+                                                       /* this loop ensures we get a contact header about our register request */
+                                                       if(strlen(contact)) {
+                                                               if(strstr(contact, p->our_contact))
+                                                                       break;
+                                                       } else
+                                                               break;
+                                               }
+                                               tmptmp = strstr(contact, "expires=");
+                                               if (tmptmp) {
+                                                       if (sscanf(tmptmp + 8, "%d;", &expires) != 1)
+                                                               expires = 0;
+                                               }
+                                       }
+                                       if (!expires) expires=atoi(get_header(req, "expires"));
                                        if (!expires) expires=default_expiry;
-                                       if (expires > EXPIRY_GUARD_SECS)
-                                               expires -= EXPIRY_GUARD_SECS;
+                                       if (expires <= EXPIRY_GUARD_MIN)
+                                               expires = 1;
+                                       else
+                                               if (expires <= EXPIRY_GUARD_LIMIT)
+                                                       expires -= MAX((expires * EXPIRY_GUARD_PCT),(EXPIRY_GUARD_MIN - 1));
+                                               else
+                                                       expires -= EXPIRY_GUARD_SECS;
                                        r->expire=ast_sched_add(sched, expires*1000, sip_reregister, r); 
                                } else
                                        ast_log(LOG_WARNING, "Got 200 OK on REGISTER that isn't a register\n");