Avoid overflow on M-TMSI allocation.

7 years ago · 308efd4fdc
parent 5f9e0adbb6
commit 308efd4fdc
1 changed files with 3 additions and 2 deletions
--- a/srsepc/src/mme/s1ap.cc
+++ b/srsepc/src/mme/s1ap.cc
@ -542,8 +542,9 @@ s1ap::activate_eps_bearer(uint64_t imsi, uint8_t ebi)
 uint32_t
 s1ap::allocate_m_tmsi(uint64_t imsi)
 {
-  uint32_t m_tmsi = m_next_m_tmsi++;
-  //uint32_t m_tmsi = m_next_m_tmsi;
+  uint32_t m_tmsi = m_next_m_tmsi;
+  m_next_m_tmsi = (m_next_m_tmsi + 1) % UINT32_MAX;
+
  m_tmsi_to_imsi.insert(std::pair<uint32_t,uint64_t>(m_tmsi,imsi));
  m_s1ap_log->debug("Allocated M-TMSI 0x%x to IMSI %015lu,\n",m_tmsi,imsi);
  return m_tmsi;