Resolve SMF IP addr when sending PDU session request

src/amf-app/amf_config.cpp

@@ -342,6 +342,8 @@ int amf_config::load(const std::string& config_file) {
       } else {
         std::string smf_fqdn = {};
         smf_addr_item.lookupValue(AMF_CONFIG_STRING_FQDN_DNS, smf_fqdn);
+        smf_inst.fqdn = smf_fqdn;
+        /*
         uint8_t addr_type = 0;
         fqdn::resolve(smf_fqdn, smf_inst.ipv4, smf_port, addr_type);
         if (addr_type != 0) {  // IPv6: TODO
@@ -353,6 +355,7 @@ int amf_config::load(const std::string& config_file) {
           smf_inst.port    = std::to_string(smf_port);
           smf_inst.version = "v1";  // TODO: get API version
         }
+        */
       }
 
       smf_addr_item.lookupValue(
@@ -595,14 +598,12 @@ void amf_config::display() {
   if (!enable_smf_selection) {
     Logger::config().info("- SMF Pool.........: ");
     for (int i = 0; i < smf_pool.size(); i++) {
-      std::string selected;
-      if (smf_pool[i].selected)
-        selected = "true";
-      else
-        selected = "false";
+      std::string selected = smf_pool[i].selected ? "true" : "false";
+      std::string smf_info =
+          use_fqdn_dns ? smf_pool[i].fqdn : smf_pool[i].ipv4.c_str();
       Logger::config().info(
           "    SMF_INSTANCE_ID %d (%s:%s, version %s) is selected: %s",
-          smf_pool[i].id, smf_pool[i].ipv4.c_str(), smf_pool[i].port.c_str(),
+          smf_pool[i].id, smf_info.c_str(), smf_pool[i].port.c_str(),
           smf_pool[i].version.c_str(), selected.c_str());
     }
   }

src/amf-app/amf_config.hpp

@@ -168,6 +168,7 @@ typedef struct {
   std::string port;
   std::string version;
   bool selected;
+  std::string fqdn;
 } smf_inst_t;
 
 class amf_config {

src/amf-app/amf_n11.cpp

@@ -47,6 +47,7 @@
 #include "SmContextCreateData.h"
 #include "mime_parser.hpp"
 #include "ue_context.hpp"
+#include "fqdn.hpp"
 
 extern "C" {
 #include "dynamic_memory_check.h"
@@ -472,8 +473,26 @@ bool amf_n11::smf_selection_from_configuration(
     std::string& smf_addr, std::string& smf_api_version) {
   for (int i = 0; i < amf_cfg.smf_pool.size(); i++) {
     if (amf_cfg.smf_pool[i].selected) {
-      smf_addr = amf_cfg.smf_pool[i].ipv4 + ":" + amf_cfg.smf_pool[i].port;
-      smf_api_version = amf_cfg.smf_pool[i].version;
+      if (!amf_cfg.use_fqdn_dns) {
+        smf_addr = amf_cfg.smf_pool[i].ipv4 + ":" + amf_cfg.smf_pool[i].port;
+        smf_api_version = amf_cfg.smf_pool[i].version;
+        return true;
+      } else {
+        // resolve IP addr from a FQDN/DNS name
+        uint8_t addr_type = 0;
+        uint32_t smf_port = 0;
+        fqdn::resolve(
+            amf_cfg.smf_pool[i].fqdn, amf_cfg.smf_pool[i].ipv4, smf_port,
+            addr_type);
+        if (addr_type != 0) {  // IPv6: TODO
+          Logger::amf_n11().warn("Do not support IPv6 Addr for SMF");
+          return false;
+        } else {  // IPv4
+          smf_addr = amf_cfg.smf_pool[i].ipv4 + ":" + std::to_string(smf_port);
+          smf_api_version = "v1";  // TODO: get API version
+          return true;
+        }
+      }
       return true;
     }
   }