From afed750ea14890966f9c06955cc8b985844769ba Mon Sep 17 00:00:00 2001
From: Aleksandar Yosifov <alexyosifov@gmail.com>
Date: Wed, 15 Jun 2022 10:14:24 +0300
Subject: [PATCH] ims_registrar_scscf: 200OK changes according to RFC3261

Added corrections for 200OK reply on Re-Registration
according to RFC3261 - registrar respond with multiple bindings in case
of multiple bindings.
Added a new parameter skip_multiple_bindings_on_reg_resp
for 200OK reply used for Re-Registration. Default value is 0.
If set to 1 - registrar replies only with current contact, not with
multiple bindings.
---
 .../doc/ims_registrar_scscf_admin.xml         | 20 +++++++++++++++++++
 .../ims_registrar_scscf_mod.c                 |  2 ++
 src/modules/ims_registrar_scscf/save.c        |  5 +++--
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/src/modules/ims_registrar_scscf/doc/ims_registrar_scscf_admin.xml b/src/modules/ims_registrar_scscf/doc/ims_registrar_scscf_admin.xml
index 124c5a14ded..979ccfbd0f7 100644
--- a/src/modules/ims_registrar_scscf/doc/ims_registrar_scscf_admin.xml
+++ b/src/modules/ims_registrar_scscf/doc/ims_registrar_scscf_admin.xml
@@ -431,6 +431,26 @@
       </example>
     </section>
 
+    <section>
+      <title>skip_multiple_bindings_on_reg_resp (int)</title>
+
+      <para>If set to 1 - on Re-Registration registrar sends in 200OK reply only
+      current contact in case of multiple bindings.
+      If set to 0 - on Re-Registration registrar sends in 200OK reply all
+      contacts in case of multiple bindings according to RFC3261.
+      </para>
+
+      <para><emphasis> Default value is 0. </emphasis></para>
+
+      <example>
+        <title>Set <varname>skip_multiple_bindings_on_reg_resp</varname> parameter</title>
+
+        <programlisting format="linespecific">...
+        modparam("ims_registrar_scscf", "skip_multiple_bindings_on_reg_resp", 1)
+...</programlisting>
+      </example>
+    </section>
+
   </section>
 
   <section>
diff --git a/src/modules/ims_registrar_scscf/ims_registrar_scscf_mod.c b/src/modules/ims_registrar_scscf/ims_registrar_scscf_mod.c
index 8022011e592..b2d7a38d455 100644
--- a/src/modules/ims_registrar_scscf/ims_registrar_scscf_mod.c
+++ b/src/modules/ims_registrar_scscf/ims_registrar_scscf_mod.c
@@ -98,6 +98,7 @@ char *scscf_user_data_xsd = 0; /* Path to "CxDataType_Rel6.xsd" or "CxDataType_R
 int scscf_support_wildcardPSI = 0;
 int store_data_on_dereg = 0; /**< should we store SAR data on de-registration  */
 unsigned int send_vs_callid_avp = 1;	/* flag to enable/disable proprietary use of a callid AVP. TODO: add call-id as per TS129.229 */
+int skip_multiple_bindings_on_reg_resp = 0; /* For RE-REGISTRATION in 200OK add only the current contact and skip all other bindings */
 
 int ue_unsubscribe_on_dereg = 0;  /*many UEs do not unsubscribe on de reg - therefore we should remove their subscription and not send a notify
 				   Some UEs do unsubscribe then everything is fine*/
@@ -287,6 +288,7 @@ static param_export_t params[] = {
 	{"max_notification_list_size", INT_PARAM, &max_notification_list_size},
 	{"notification_processes", INT_PARAM, &notification_processes},
 	{"send_vs_callid_avp", INT_PARAM, &send_vs_callid_avp},
+	{"skip_multiple_bindings_on_reg_resp", INT_PARAM, &skip_multiple_bindings_on_reg_resp},
     {0, 0, 0}
 };
 
diff --git a/src/modules/ims_registrar_scscf/save.c b/src/modules/ims_registrar_scscf/save.c
index 6c8127d289c..c89f71de30d 100644
--- a/src/modules/ims_registrar_scscf/save.c
+++ b/src/modules/ims_registrar_scscf/save.c
@@ -83,6 +83,7 @@ extern int store_data_on_dereg; /**< should we store SAR user data on de-registr
 
 extern int ue_unsubscribe_on_dereg;
 extern int user_data_always;
+extern int skip_multiple_bindings_on_reg_resp;
 
 #define DO_NOT_USE_REALM_FOR_PRIVATE_IDENTITY         0x01
 
@@ -872,7 +873,7 @@ int update_contacts(struct sip_msg* msg, udomain_t* _d,
                 goto error;
             }
             //build the contact buffer for the exact registered contact for reply on explicit IMPU
-            build_contact(impu_rec, contact_header, msg);
+            build_contact(impu_rec, contact_header, skip_multiple_bindings_on_reg_resp == 1 ? msg : 0);
             build_p_associated_uri(impu_rec->s);
 
             subscription = impu_rec->s;
@@ -883,7 +884,7 @@ int update_contacts(struct sip_msg* msg, udomain_t* _d,
                         ecf1, ecf2, &impu_rec) != 0) {
                     LM_ERR("Unable to update explicit impurecord for <%.*s>\n", public_identity->len, public_identity->s);
                 }
-                build_contact(impu_rec, contact_header, msg);
+                build_contact(impu_rec, contact_header, skip_multiple_bindings_on_reg_resp == 1 ? msg : 0);
                 ul.unlock_udomain(_d, public_identity);
                 break;
             }