Fix dnn encoding

src/common/utils/string.cpp

@@ -144,3 +144,9 @@ void util::string_to_bstring(const std::string& str, bstring bstr) {
   bstr->slen = str.length();
   memcpy((void*) bstr->data, (void*) str.c_str(), str.length());
 }
+
+void util::string_to_dnn(const std::string& str, bstring bstr) {
+  std::string tmp = std::to_string(str.length()) + str;
+  bstr->slen      = tmp.length();
+  memcpy((void*) bstr->data, (void*) tmp.c_str(), tmp.length());
+}

src/common/utils/string.hpp

@@ -61,5 +61,6 @@ void ipv4v6_to_pdu_address_information(
     struct in_addr ipv4_address, struct in6_addr ipv6_address, bstring str);
 
 void string_to_bstring(const std::string& str, bstring bstr);
+void string_to_dnn(const std::string& str, bstring bstr);
 }  // namespace util
 #endif

src/smf_app/smf_n1.cpp

@@ -250,8 +250,8 @@ bool smf_n1::create_n1_pdu_session_establishment_accept(
 
   // DNN
   sm_msg->pdu_session_establishment_accept.dnn =
-      bfromcstralloc(sm_context_res.get_dnn().length(), "\0");
-  util::string_to_bstring(
+      bfromcstralloc(sm_context_res.get_dnn().length() + 1, "\0");
+  util::string_to_dnn(
       sm_context_res.get_dnn(), sm_msg->pdu_session_establishment_accept.dnn);
   Logger::smf_n1().debug("DNN %s", sm_context_res.get_dnn().c_str());