From dde8157bf1a5b1e86a4b57a7dc9464c775ac3d93 Mon Sep 17 00:00:00 2001
From: Pedro Alvarez <pedro.alvarez@softwareradiosystems.com>
Date: Thu, 18 Mar 2021 15:25:06 +0000
Subject: [PATCH] Make sure that S1 Setup request is restarted regardless of
 which error made the procedure fail.

---
 lib/src/common/network_utils.cc |  9 +--------
 srsenb/src/stack/upper/s1ap.cc  | 17 +++++++++++------
 2 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/lib/src/common/network_utils.cc b/lib/src/common/network_utils.cc
index e3f903de5..3356af1f9 100644
--- a/lib/src/common/network_utils.cc
+++ b/lib/src/common/network_utils.cc
@@ -474,14 +474,7 @@ public:
 
     bool ret     = true;
     pdu->N_bytes = static_cast<uint32_t>(n_recv);
-    if (flags & MSG_NOTIFICATION) {
-      // Received notification
-      union sctp_notification* notification = (union sctp_notification*)pdu->msg;
-      if (notification->sn_header.sn_type == SCTP_SHUTDOWN_EVENT) {
-        // Socket Shutdown
-        ret = false;
-      }
-    }
+    // SCTP notifications handled in callback.
     func(std::move(pdu), from, sri, flags);
     return ret;
   }
diff --git a/srsenb/src/stack/upper/s1ap.cc b/srsenb/src/stack/upper/s1ap.cc
index 695e565c0..9b5f296af 100644
--- a/srsenb/src/stack/upper/s1ap.cc
+++ b/srsenb/src/stack/upper/s1ap.cc
@@ -174,11 +174,7 @@ srslte::proc_outcome_t s1ap::s1_setup_proc_t::start_mme_connection()
   }
 
   if (not s1ap_ptr->connect_mme()) {
-    procInfo("Failed to initiate SCTP socket. Attempting reconnection in %d seconds",
-             s1ap_ptr->mme_connect_timer.duration() / 1000);
-    srslte::console("Failed to initiate SCTP socket. Attempting reconnection in %d seconds\n",
-                    s1ap_ptr->mme_connect_timer.duration() / 1000);
-    s1ap_ptr->mme_connect_timer.run();
+    procInfo("Could not connect to MME");
     return srslte::proc_outcome_t::error;
   }
 
@@ -203,7 +199,7 @@ srslte::proc_outcome_t s1ap::s1_setup_proc_t::react(const srsenb::s1ap::s1_setup
     procInfo("S1Setup procedure completed successfully");
     return srslte::proc_outcome_t::success;
   }
-  procError("S1Setup failed. Exiting...");
+  procError("S1Setup failed.");
   srslte::console("S1setup failed\n");
   return srslte::proc_outcome_t::error;
 }
@@ -211,8 +207,15 @@ srslte::proc_outcome_t s1ap::s1_setup_proc_t::react(const srsenb::s1ap::s1_setup
 void s1ap::s1_setup_proc_t::then(const srslte::proc_state_t& result) const
 {
   if (result.is_error()) {
+    procInfo("Failed to initiate S1 connection. Attempting reconnection in %d seconds",
+             s1ap_ptr->mme_connect_timer.duration() / 1000);
+    srslte::console("Failed to initiate S1 connection. Attempting reconnection in %d seconds\n",
+                    s1ap_ptr->mme_connect_timer.duration() / 1000);
+    s1ap_ptr->mme_connect_timer.run();
+    s1ap_ptr->stack->remove_mme_socket(s1ap_ptr->s1ap_socket.get_socket());
     s1ap_ptr->s1ap_socket.reset();
     procInfo("S1AP socket closed.");
+    // Try again with in 10 seconds
   }
 }
 
@@ -429,11 +432,13 @@ bool s1ap::connect_mme()
           &s1ap_socket, srslte::net_utils::socket_type::seqpacket, args.s1c_bind_addr.c_str())) {
     return false;
   }
+  logger.info("SCTP socket opened. fd=%d", s1ap_socket.fd());
 
   // Connect to the MME address
   if (not s1ap_socket.connect_to(args.mme_addr.c_str(), MME_PORT, &mme_addr)) {
     return false;
   }
+  logger.info("SCTP socket connected with MME. fd=%d", s1ap_socket.fd());
 
   // Assign a handler to rx MME packets (going to run in a different thread)
   stack->add_mme_socket(s1ap_socket.fd());