From 9f3d14cfabad06bfb0caa730980418f7e1d8f475 Mon Sep 17 00:00:00 2001
From: David Rupprecht <david.rupprecht@rub.de>
Date: Sun, 28 Jan 2018 14:49:53 +0100
Subject: [PATCH] Increment sqn

---
 srsepc/hdr/hss/hss.h  |  2 ++
 srsepc/src/hss/hss.cc | 30 +++++++++++++++++++++++++++++-
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/srsepc/hdr/hss/hss.h b/srsepc/hdr/hss/hss.h
index d80f0441f..0f05a02bb 100644
--- a/srsepc/hdr/hss/hss.h
+++ b/srsepc/hdr/hss/hss.h
@@ -91,6 +91,8 @@ private:
 
   std::map<uint64_t,hss_ue_ctx_t*> m_imsi_to_ue_ctx;
 
+  void increment_sqn(uint64_t imsi);
+
   bool set_auth_algo(std::string auth_algo);
   bool read_db_file(std::string db_file);
   bool write_db_file(std::string db_file);
diff --git a/srsepc/src/hss/hss.cc b/srsepc/src/hss/hss.cc
index 948c6752a..0dd5bec9b 100644
--- a/srsepc/src/hss/hss.cc
+++ b/srsepc/src/hss/hss.cc
@@ -95,7 +95,7 @@ hss::init(hss_args_t *hss_args, srslte::log_filter *hss_log)
   db_file = hss_args->db_file;
 
   m_hss_log->info("HSS Initialized. DB file %s, authentication algorithm %s, MCC: %d, MNC: %d\n", hss_args->db_file.c_str(),hss_args->auth_algo.c_str(), mcc, mnc);
-  m_hss_log->console("HSS Initialized\n");
+  m_hss_log->console("HSS Initialized.\n");
   return 0;
 }
 
@@ -238,6 +238,7 @@ hss::gen_auth_info_answer(uint64_t imsi, uint8_t *k_asme, uint8_t *autn, uint8_t
     ret = gen_auth_info_answer_milenage(imsi, k_asme, autn, rand, xres);
     break;
   }
+  increment_sqn(imsi);
   return ret;
 
 }
@@ -448,6 +449,33 @@ hss::get_k_amf_op_sqn(uint64_t imsi, uint8_t *k, uint8_t *amf, uint8_t *op, uint
   return true;
 }
 
+void 
+hss::increment_sqn(uint64_t imsi)
+{
+  std::map<uint64_t,hss_ue_ctx_t*>::iterator ue_ctx_it = m_imsi_to_ue_ctx.find(imsi);
+  if(ue_ctx_it == m_imsi_to_ue_ctx.end())
+  {
+    m_hss_log->info("User not found. IMSI: %015lu\n",imsi);
+  }
+  
+  hss_ue_ctx_t *ue_ctx = ue_ctx_it->second;
+
+  // Awkward 48 bit sqn and doing arithmetic 
+  uint64_t sqn = 0;
+  uint8_t *p = (uint8_t *)&sqn;
+  
+  for(int i = 0; i < 6; i++) {
+    p[5-i] = (uint8_t) ((ue_ctx_it->second->sqn[i]));
+  }
+
+  sqn++;
+  
+  m_hss_log->debug("Incremented IMSI: %015lu SQN: %d", imsi, sqn);
+
+  for(int i = 0; i < 6; i++){
+    ue_ctx_it->second->sqn[i] = p[5-i];
+  }
+}
 
 void
 hss::gen_rand(uint8_t rand_[16])