enb,s1ap: adding SCTP configuration to enb.conf

lib/include/srsran/common/network_utils.h

@@ -80,8 +80,8 @@ public:
   bool start_listen();
   bool reuse_addr();
   bool sctp_subscribe_to_events();
-  bool sctp_set_rto_opts();
-  bool sctp_set_init_msg_opts();
+  bool sctp_set_rto_opts(int rto_max);
+  bool sctp_set_init_msg_opts(int max_init_attempts, int max_init_timeo);
   int  get_socket() const { return sockfd; };
 
 protected:

lib/include/srsran/interfaces/enb_s1ap_interfaces.h

@@ -29,11 +29,14 @@ struct s1ap_args_t {
   std::string gtp_advertise_addr;
   std::string s1c_bind_addr;
   uint16_t    s1c_bind_port;
-  bool        s1c_reuse_addr;
   std::string enb_name;
   uint32_t    ts1_reloc_prep_timeout;
   uint32_t    ts1_reloc_overall_timeout;
   int32_t     max_s1_setup_retries;
+  bool        sctp_reuse_addr;
+  int32_t     sctp_rto_max;
+  int32_t     sctp_init_max_attempts;
+  int32_t     sctp_max_init_timeo;
 };
 
 // S1AP interface for RRC

lib/src/common/network_utils.cc

@@ -111,9 +111,6 @@ int open_socket(net_utils::addr_family ip_type, net_utils::socket_type socket_ty
   }
   srslog::fetch_basic_logger(LOGSERVICE).debug("Opened %s socket=%d", net_utils::protocol_to_string(protocol), fd);
 
-  if (protocol == protocol_type::SCTP) {
-  }
-
   return fd;
 }
 
@@ -237,13 +234,12 @@ bool sctp_subscribe_to_events(int fd)
   return true;
 }
 
-bool sctp_set_rto_opts(int fd)
+/*
+ * Modify SCTP default parameters for quicker detection of broken links.
+ * Changes to the maximum re-transmission timeout (rto_max).
+ */
+bool sctp_set_rto_opts(int fd, int rto_max)
 {
-  /*
-   * Modify SCTP default parameters for quicker detection of broken links.
-   * This includes changes to the SCTP_INITMSG parameters (to control the timeout of the connect() syscall)
-   * And changes to the maximum re-transmission timeout (rto_max), for quicker detection of broken links.
-   */
   // Set RTO_MAX to quickly detect broken links.
   sctp_rtoinfo rto_opts;
   socklen_t    rto_sz    = sizeof(sctp_rtoinfo);
@@ -254,7 +250,7 @@ bool sctp_set_rto_opts(int fd)
     return false;
   }
 
-  rto_opts.srto_max = 6000; // 6 seconds
+  rto_opts.srto_max = rto_max;
 
   srslog::fetch_basic_logger(LOGSERVICE)
       .debug("Setting RTO_INFO options on SCTP socket. Association %d, Initial RTO %d, Minimum RTO %d, Maximum RTO %d",
@@ -271,7 +267,11 @@ bool sctp_set_rto_opts(int fd)
   return true;
 }
 
-bool sctp_set_init_msg_opts(int fd)
+/*
+ * Modify SCTP default parameters for quicker detection of broken links.
+ * Changes to the SCTP_INITMSG parameters (to control the timeout of the connect() syscall)
+ */
+bool sctp_set_init_msg_opts(int fd, int init_max_attempts, int max_init_timeo)
 {
   // Set SCTP INITMSG options to reduce blocking timeout of connect()
   sctp_initmsg init_opts;
@@ -282,8 +282,8 @@ bool sctp_set_init_msg_opts(int fd)
     return false;
   }
 
-  init_opts.sinit_max_attempts   = 3;
-  init_opts.sinit_max_init_timeo = 5000; // 5 seconds
+  init_opts.sinit_max_attempts   = init_max_attempts;
+  init_opts.sinit_max_init_timeo = max_init_timeo;
 
   srslog::fetch_basic_logger(LOGSERVICE)
       .debug("Setting SCTP_INITMSG options on SCTP socket. Max attempts %d, Max init attempts timeout %d",
@@ -372,14 +372,14 @@ bool unique_socket::sctp_subscribe_to_events()
   return net_utils::sctp_subscribe_to_events(sockfd);
 }
 
-bool unique_socket::sctp_set_rto_opts()
+bool unique_socket::sctp_set_rto_opts(int rto_max)
 {
-  return net_utils::sctp_set_rto_opts(sockfd);
+  return net_utils::sctp_set_rto_opts(sockfd, rto_max);
 }
 
-bool unique_socket::sctp_set_init_msg_opts()
+bool unique_socket::sctp_set_init_msg_opts(int max_init_attempts, int max_init_timeo)
 {
-  return net_utils::sctp_set_init_msg_opts(sockfd);
+  return net_utils::sctp_set_init_msg_opts(sockfd, max_init_attempts, max_init_timeo);
 }
 
 /***************************************************************

lib/test/common/network_utils_test.cc

@@ -127,8 +127,8 @@ int test_sctp_bind_error()
   TESTASSERT(sock.open_socket(srsran::net_utils::addr_family::ipv4,
                               srsran::net_utils::socket_type::seqpacket,
                               srsran::net_utils::protocol_type::SCTP));
-  TESTASSERT(sock.bind_addr("1.1.1.1", 8000)); // Bogus IP address
-                                               // should not be able to bind
+  TESTASSERT(not sock.bind_addr("1.1.1.1", 8000)); // Bogus IP address
+                                                   // should not be able to bind
 
   srsran::unique_socket sock2;
   TESTASSERT(sock2.open_socket(srsran::net_utils::addr_family::ipv4,

srsenb/src/main.cc

@@ -79,7 +79,6 @@ void parse_args(all_args_t* args, int argc, char* argv[])
     ("enb.gtp_advertise_addr", bpo::value<string>(&args->stack.s1ap.gtp_advertise_addr)->default_value(""), "IP address of eNB to advertise for DL GTP-U Traffic")
     ("enb.s1c_bind_addr",      bpo::value<string>(&args->stack.s1ap.s1c_bind_addr)->default_value("192.168.3.1"), "Local IP address to bind for S1AP connection")
     ("enb.s1c_bind_port",      bpo::value<uint16_t>(&args->stack.s1ap.s1c_bind_port)->default_value(0), "Source port for S1AP connection (0 means any)")
-    ("enb.s1c_reuse_addr",     bpo::value<bool>(&args->stack.s1ap.s1c_reuse_addr)->default_value(false), "Use SO_REUSE_ADDR on S1-C interface.")
     ("enb.n_prb",              bpo::value<uint32_t>(&args->enb.n_prb)->default_value(25),               "Number of PRB")
     ("enb.nof_ports",          bpo::value<uint32_t>(&args->enb.nof_ports)->default_value(1),            "Number of ports")
     ("enb.tm",                 bpo::value<uint32_t>(&args->enb.transmission_mode)->default_value(1),    "Transmission mode (1-8)")
@@ -259,7 +258,12 @@ void parse_args(all_args_t* args, int argc, char* argv[])
     ("expert.ts1_reloc_prep_timeout", bpo::value<uint32_t>(&args->stack.s1ap.ts1_reloc_prep_timeout)->default_value(10000), "S1AP TS 36.413 TS1RelocPrep Expiry Timeout value in milliseconds.")
     ("expert.ts1_reloc_overall_timeout", bpo::value<uint32_t>(&args->stack.s1ap.ts1_reloc_overall_timeout)->default_value(10000), "S1AP TS 36.413 TS1RelocOverall Expiry Timeout value in milliseconds.")
     ("expert.rlf_min_ul_snr_estim", bpo::value<int>(&args->stack.mac.rlf_min_ul_snr_estim)->default_value(-2), "SNR threshold in dB below which the eNB is notified with rlf ko.")
+
+    ("expert.sctp_reuse_addr",     bpo::value<bool>(&args->stack.s1ap.sctp_reuse_addr)->default_value(false), "Use SO_REUSE_ADDR on S1-C interface.")
     ("expert.max_s1_setup_retries", bpo::value<int32_t>(&args->stack.s1ap.max_s1_setup_retries)->default_value(-1), "Max S1 setup retries")
+    ("expert.sctp_rto_max", bpo::value<int32_t>(&args->stack.s1ap.sctp_rto_max)->default_value(6000), "SCTP maximum RTO.")
+    ("expert.sctp_init_max_attempts", bpo::value<int32_t>(&args->stack.s1ap.sctp_init_max_attempts)->default_value(3), "Maximum SCTP init attempts.")
+    ("expert.sctp_max_init_timeo)", bpo::value<int32_t>(&args->stack.s1ap.sctp_max_init_timeo)->default_value(5000),     "Maximum SCTP init timeout.")
     ("expert.rx_gain_offset", bpo::value<float>(&args->phy.rx_gain_offset)->default_value(62), "RX Gain offset to add to rx_gain to calibrate RSRP readings")
     ("expert.mac_prach_bi", bpo::value<uint32_t>(&args->stack.mac.prach_bi)->default_value(0), "Backoff Indicator to reduce contention in the PRACH channel")
 

srsenb/src/stack/s1ap/s1ap.cc

@@ -498,16 +498,28 @@ bool s1ap::connect_mme()
   }
 
   // Set SO_REUSE_ADDR if necessary
-  if (args.s1c_reuse_addr) {
+  if (args.sctp_reuse_addr) {
     if (not mme_socket.reuse_addr()) {
       mme_socket.close();
       return false;
     }
   }
 
-  mme_socket.sctp_subscribe_to_events();
-  mme_socket.sctp_set_rto_opts();
-  mme_socket.sctp_set_init_msg_opts();
+  // Subscribe to shutdown events
+  if (not mme_socket.sctp_subscribe_to_events()) {
+    mme_socket.close();
+    return false;
+  }
+
+  // Set SRTO_MAX
+  if (not mme_socket.sctp_set_rto_opts(args.sctp_rto_max)) {
+    return false;
+  }
+
+  // Set SCTP init options
+  if (not mme_socket.sctp_set_init_msg_opts(args.sctp_init_max_attempts, args.sctp_max_init_timeo)) {
+    return false;
+  }
 
   // Bind socket
   if (not mme_socket.bind_addr(args.s1c_bind_addr.c_str(), args.s1c_bind_port)) {

srsgnb/src/stack/ngap/ngap.cc

@@ -640,9 +640,20 @@ bool ngap::connect_amf()
   }
   logger.info("SCTP socket opened. fd=%d", amf_socket.fd());
 
-  amf_socket.sctp_subscribe_to_events();
-  amf_socket.sctp_set_rto_opts();
-  amf_socket.sctp_set_init_msg_opts();
+  if (not amf_socket.sctp_subscribe_to_events()) {
+    amf_socket.close();
+    return false;
+  }
+
+  if (not amf_socket.sctp_set_rto_opts(5000)) {
+    amf_socket.close();
+    return false;
+  }
+
+  if (not amf_socket.sctp_set_init_msg_opts(3, 6000)) {
+    amf_socket.close();
+    return false;
+  }
 
   // Bind socket
   if (not amf_socket.bind_addr(args.ngc_bind_addr.c_str(), 0)) {