chan_sip: Add precautionary p->owner checks.

* Add precautionary p->owner checks in sip_hangup(), get_refer_info(),
get_also_info(), and interpret_t38_parameters().

* Simplify some tangled logic in get_refer_info(), get_also_info(), and
add_rpid().

* Removed some dead code in handle_request_invite().

(closes issue ASTERISK-23323)
Reported by: Walter Doekes
Patches:
      issueA23323-more_p_owner_checks-1.8.x.patch (license #5674) uploaded by wdoekes (modified)
      issueA23323-more_p_owner_checks-11.x.patch (license #5674) uploaded by wdoekes (modified)
      issueA23323-more_p_owner_checks-12.x.patch (license #5674) uploaded by wdoekes (modified)
      issueA23323-more_p_owner_checks-trunk.patch (license #5674) uploaded by wdoekes (modified)

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@409207 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 02c670628c3c54a47db39fda32125352f1224ac3..4b293e0eee48cd2c71c633d2290e0768d2a0d137 100644 (file)
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -6674,10 +6674,12 @@ static int sip_hangup(struct ast_channel *ast)
                sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
                ast_clear_flag(&p->flags[0], SIP_DEFER_BYE_ON_TRANSFER);        /* Really hang up next time */
                p->needdestroy = 0;
-               p->owner->tech_pvt = dialog_unref(p->owner->tech_pvt, "unref p->owner->tech_pvt");
-               sip_pvt_lock(p);
-               p->owner = NULL;  /* Owner will be gone after we return, so take it away */
-               sip_pvt_unlock(p);
+               if (p->owner) {
+                       p->owner->tech_pvt = dialog_unref(p->owner->tech_pvt, "unref p->owner->tech_pvt");
+                       sip_pvt_lock(p);
+                       p->owner = NULL;  /* Owner will be gone after we return, so take it away */
+                       sip_pvt_unlock(p);
+               }
                ast_module_unref(ast_module_info->self);
                return 0;
        }
@@ -6706,7 +6708,7 @@ static int sip_hangup(struct ast_channel *ast)
 
        stop_media_flows(p); /* Immediately stop RTP, VRTP and UDPTL as applicable */
 
-       append_history(p, needcancel ? "Cancel" : "Hangup", "Cause %s", p->owner ? ast_cause2str(p->hangupcause) : "Unknown");
+       append_history(p, needcancel ? "Cancel" : "Hangup", "Cause %s", ast_cause2str(p->hangupcause));
 
        /* Disconnect */
        disable_dsp_detect(p);
@@ -7206,7 +7208,9 @@ static int interpret_t38_parameters(struct sip_pvt *p, const struct ast_control_
                        AST_SCHED_DEL_UNREF(sched, p->t38id, dialog_unref(p, "when you delete the t38id sched, you should dec the refcount for the stored dialog ptr"));
                        parameters.max_ifp = ast_udptl_get_far_max_ifp(p->udptl);
                        parameters.request_response = AST_T38_REQUEST_NEGOTIATE;
-                       ast_queue_control_data(p->owner, AST_CONTROL_T38_PARAMETERS, &parameters, sizeof(parameters));
+                       if (p->owner) {
+                               ast_queue_control_data(p->owner, AST_CONTROL_T38_PARAMETERS, &parameters, sizeof(parameters));
+                       }
                        /* we need to return a positive value here, so that applications that
                         * send this request can determine conclusively whether it was accepted or not...
                         * older versions of chan_sip would just silently accept it and return zero.
@@ -11395,8 +11399,8 @@ static int add_rpid(struct sip_request *req, struct sip_pvt *p)
 {
        struct ast_str *tmp = ast_str_alloca(256);
        char tmp2[256];
-       char *lid_num = NULL;
-       char *lid_name = NULL;
+       char *lid_num;
+       char *lid_name;
        int lid_pres;
        const char *fromdomain;
        const char *privacy = NULL;
@@ -11407,20 +11411,23 @@ static int add_rpid(struct sip_request *req, struct sip_pvt *p)
                return 0;
        }
 
-       if (p->owner && p->owner->connected.id.number.valid
-               && p->owner->connected.id.number.str) {
-               lid_num = p->owner->connected.id.number.str;
-       }
-       if (p->owner && p->owner->connected.id.name.valid
-               && p->owner->connected.id.name.str) {
-               lid_name = p->owner->connected.id.name.str;
+       if (!p->owner) {
+               return 0;
        }
-       lid_pres = (p->owner) ? ast_party_id_presentation(&p->owner->connected.id) : AST_PRES_NUMBER_NOT_AVAILABLE;
-
-       if (ast_strlen_zero(lid_num))
+       lid_num = S_COR(p->owner->connected.id.number.valid,
+               p->owner->connected.id.number.str,
+               NULL);
+       if (!lid_num) {
                return 0;
-       if (ast_strlen_zero(lid_name))
+       }
+       lid_name = S_COR(p->owner->connected.id.name.valid,
+               p->owner->connected.id.name.str,
+               NULL);
+       if (!lid_name) {
                lid_name = lid_num;
+       }
+       lid_pres = ast_party_id_presentation(&p->owner->connected.id);
+
        fromdomain = S_OR(p->fromdomain, ast_sockaddr_stringify_host_remote(&p->ourip));
 
        lid_num = ast_uri_encode(lid_num, tmp2, sizeof(tmp2), 0);
@@ -16414,13 +16421,15 @@ static int get_refer_info(struct sip_pvt *transferer, struct sip_request *outgoi
        }
 
        /* Determine transfer context */
-       if (transferer->owner)  /* Mimic behaviour in res_features.c */
+       if (transferer->owner) {
+               /* By default, use the context in the channel sending the REFER */
                transfer_context = pbx_builtin_getvar_helper(transferer->owner, "TRANSFER_CONTEXT");
-
-       /* By default, use the context in the channel sending the REFER */
+               if (ast_strlen_zero(transfer_context)) {
+                       transfer_context = transferer->owner->macrocontext;
+               }
+       }
        if (ast_strlen_zero(transfer_context)) {
-               transfer_context = S_OR(transferer->owner->macrocontext,
-                                       S_OR(transferer->context, sip_cfg.default_context));
+               transfer_context = S_OR(transferer->context, sip_cfg.default_context);
        }
 
        ast_copy_string(referdata->refer_to_context, transfer_context, sizeof(referdata->refer_to_context));
@@ -16474,14 +16483,18 @@ static int get_also_info(struct sip_pvt *p, struct sip_request *oreq)
        if (sip_debug_test_pvt(p))
                ast_verbose("Looking for %s in %s\n", c, p->context);
 
-       if (p->owner)   /* Mimic behaviour in res_features.c */
+       /* Determine transfer context */
+       if (p->owner) {
+               /* By default, use the context in the channel sending the REFER */
                transfer_context = pbx_builtin_getvar_helper(p->owner, "TRANSFER_CONTEXT");
-
-       /* By default, use the context in the channel sending the REFER */
+               if (ast_strlen_zero(transfer_context)) {
+                       transfer_context = p->owner->macrocontext;
+               }
+       }
        if (ast_strlen_zero(transfer_context)) {
-               transfer_context = S_OR(p->owner->macrocontext,
-                                       S_OR(p->context, sip_cfg.default_context));
+               transfer_context = S_OR(p->context, sip_cfg.default_context);
        }
+
        if (ast_exists_extension(NULL, transfer_context, c, 1, NULL)) {
                /* This is a blind transfer */
                ast_debug(1, "SIP Bye-also transfer to Extension %s@%s \n", c, transfer_context);
@@ -23455,12 +23468,6 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int
                        ast_debug(2, "No SDP in Invite, third party call control\n");
                }
 
-               /* Queue NULL frame to prod ast_rtp_bridge if appropriate */
-               /* This seems redundant ... see !p-owner above */
-               if (p->owner)
-                       ast_queue_frame(p->owner, &ast_null_frame);
-
-
                /* Initialize the context if it hasn't been already */
                if (ast_strlen_zero(p->context))
                        ast_string_field_set(p, context, sip_cfg.default_context);
@@ -27515,7 +27522,7 @@ static struct ast_channel *sip_request_call(const char *type, format_t format, c
        if (sip_cfg.callevents)
                manager_event(EVENT_FLAG_SYSTEM, "ChannelUpdate",
                        "Channel: %s\r\nChanneltype: %s\r\nSIPcallid: %s\r\nSIPfullcontact: %s\r\nPeername: %s\r\n",
-                       p->owner? p->owner->name : "", "SIP", p->callid, p->fullcontact, p->peername);
+                       p->owner ? p->owner->name : "", "SIP", p->callid, p->fullcontact, p->peername);
        sip_pvt_unlock(p);
        if (!tmpc) {
                dialog_unlink_all(p);