September 15 18:23 hours

client.cpp

@@ -53,15 +53,17 @@ void Client::bind_client() {
 
 	client_socket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 	report_error(client_socket, "Error in creating sockets ");	
-	setsockopt(client_socket, SOL_SOCKET, SO_REUSEADDR, &g_reuse, sizeof(int));	
+	status = setsockopt(client_socket, SOL_SOCKET, SO_REUSEADDR, &g_reuse, sizeof(int));	
+	report_error(status, "At Client side - Error in setting socket options");
 	socklen_t len = sizeof(sockaddr_in);
 	bzero((char *) &client_sock_addr, sizeof(client_sock_addr));
 	client_sock_addr.sin_family = AF_INET;  
 	client_sock_addr.sin_addr.s_addr = INADDR_ANY;	
 	client_sock_addr.sin_port = 0;
 	status = bind(client_socket, (struct sockaddr*)&client_sock_addr, sizeof(client_sock_addr));
 	report_error(status, "Error in binding");	
-	getsockname(client_socket, (struct sockaddr*)&client_sock_addr, &len);
+	status = getsockname(client_socket, (struct sockaddr*)&client_sock_addr, &len);
+	report_error(status, "At Client side - Error in getting socket name");
 	client_port = ntohs(client_sock_addr.sin_port);	
 	strcpy(client_addr, inet_ntoa(client_sock_addr.sin_addr));
 	//cout << "client binded with port " << client_port << endl;

enodeb.cpp

@@ -152,6 +152,7 @@ void EnodeB::set_tun_data(bool &data_invalid) {
 		data_invalid = false;
 	}
 	else {
+		cout << "Invalid data received!" << endl;
 		data_invalid = true;
 	}
 	// cout << "Details fetched are: " << "UE IP - " << ue_ip_str << " SGW - port " << tun_data.sgw_port << " SGW addr " << tun_data.sgw_addr << endl;
@@ -162,7 +163,7 @@ void EnodeB::set_sgw_num() {
 	if (socket_table.find(tun_data.sgw_addr) != socket_table.end())
 		num = socket_table[tun_data.sgw_addr];
 	else {
-		cout << "At Enodeb: 	Trying to connect with a new SGW" << endl;
+		cout << "At Enodeb: Trying to connect with a new SGW" << endl;
 		connect_with_sgw();
 		socket_table[tun_data.sgw_addr] = pos;
 		pos++;

mme.cpp

@@ -193,8 +193,12 @@ void MME::authenticate_ue() {
 		cout << "Authentication is successful for UE - " << ue_num << endl;
 	}	
 	else {
-		cout << "Authentication failed: Please disconnect and connect again with proper authentication" << endl;
-		handle_exceptions();
+		strcpy(reply, "FAILED");
+		mme_server.pkt.clear_data();
+		mme_server.pkt.fill_data(0, strlen(reply), reply);
+		mme_server.pkt.make_data_packet();
+		mme_server.write_data();
+		cout << "Authentication is not successful for UE - " << ue_num << endl;
 	}
 }
 

notes.txt

@@ -24,14 +24,16 @@ In the future, I might have to add the following in addition to the "constructor
 - PGW disconnected for no known reason without printing any error message for Threads = 2 and Time = 3s
 - SGW disconnected for no known reason without printing any error message for Threads = 2, 20 and Time = 3s
 - PGW is eratic in responding to SGW's Create Session request and Modify session request. In some cases, SGW is not even able to connect with the PGW for 'Create session request'.
+- "ERROR: Invalid argument" at PGW while writing data into the rawsocket
+- *** Error in `./pgw': corrupted double-linked list: 0x00007fc7d4080d00 ***
 
 Findings/Bugs Solved:
 
 - Number of sockets that can be opened simultaneously is 1021. Important thing is that this number(1021) might be fixed for a particular time, because other processes might increase the number of file descriptors at a later time, but I am not sure about this and I think this number should pretty much work fine. 
 - Changing "ulimit -n 4096" will reduce this problem. I can now create upto 1021 + (4096 - 1024) = 4093 connections!
 
 - Finding the CPU utilization for a particular process using "top" command:
-top -p $(pgrep process_name | tr \\n , | sed 's/,//')
+top -p $(pgrep pgw | tr \\n , | sed 's/,//')
 
 
 Things to do:

sgw_server.cpp

@@ -98,5 +98,6 @@ int main(int argc, char *argv[]) {
 	sgw_server.fill_server_details(g_sgw1_port, g_sgw1_addr);
 	sgw_server.bind_server();
 	sgw_server.listen_accept();
+	cout << "Oops! Comes here" << endl;
 	return 0;
 }

sgwc.cpp

@@ -96,6 +96,7 @@ void SGWc::create_session_req_from_mme(Server &sgw_server) {
 	set_ue_num();
 	set_bearer_id();
 	set_cteid();
+	cout << "Create session request has been received at SGW for UE - " << ue_num << endl;
 }
 
 void SGWc::copy_data(Packet &arg) {
@@ -162,7 +163,7 @@ void SGWc::handshake_with_pgw() {
 
 void SGWc::create_session_res_from_pgw(uint16_t &pgw_uteid) {
 
-	cout << "Waiting to read Create session response from PGW" << endl;
+	cout << "Waiting to read Create session response from PGW for UE - " << ue_num << endl;
 	to_pgw.read_data();
 	to_pgw.pkt.rem_gtpc_hdr();
 	set_tun_cdata();
@@ -193,6 +194,7 @@ void SGWc::create_session_res_to_mme(Server &sgw_server) {
 	sgw_server.pkt.add_gtpc_hdr();
 	sgw_server.pkt.make_data_packet();
 	sgw_server.write_data();
+	cout << "Create session response has been sent to MME for UE - " << ue_num << endl;
 }
 
 void SGWc::modify_session_req_from_mme(Server &sgw_server, uint16_t &enodeb_uteid) {
@@ -201,6 +203,7 @@ void SGWc::modify_session_req_from_mme(Server &sgw_server, uint16_t &enodeb_utei
 	sgw_server.pkt.rem_gtpc_hdr();
 	copy_data(sgw_server.pkt);
 	memcpy(&enodeb_uteid, pkt.data, sizeof(uint16_t));
+	cout << "Modify session request has been received at SGW for UE - " << ue_num << endl;
 }
 
 void SGWc::modify_session_res_to_mme(Server &sgw_server, uint16_t &sgw_uteid) {
@@ -214,6 +217,7 @@ void SGWc::modify_session_res_to_mme(Server &sgw_server, uint16_t &sgw_uteid) {
 	sgw_server.pkt.add_gtpc_hdr();
 	sgw_server.pkt.make_data_packet();
 	sgw_server.write_data();
+	cout << "Modify session response has been sent to MME for UE - " << ue_num << endl;
 }
 
 void SGWc::fill_pgw_addr(int &pgw_port, string &pgw_addr) {
@@ -262,7 +266,7 @@ void SGWc::erase_bearer_table() {
 void SGWc::delete_session_res_from_pgw() {
 	string res;
 
-	cout << "Waiting to read Delete session response from PGW" << endl;
+	cout << "Waiting to read Delete session response from PGW for UE - " << ue_num << endl;
 	to_pgw.read_data();
 	to_pgw.pkt.rem_gtpc_hdr();
 	memcpy(reply, to_pgw.pkt.data, to_pgw.pkt.data_len);
@@ -283,6 +287,7 @@ void SGWc::delete_session_res_to_mme(Server &sgw_server) {
 	sgw_server.pkt.make_data_packet();
 	sgw_server.write_data();
 	erase_tun_ctable();
+	cout << "Delete session response has been sent to MME for UE - " << ue_num << endl;
 }
 
 void SGWc::erase_tun_ctable() {

sgwu.cpp

@@ -168,7 +168,7 @@ void SGWu::send_enodeb(Server &sgw_server) {
 	sgw_server.pkt.fill_data(0, pkt.data_len, pkt.data);
 	sgw_server.pkt.make_data_packet();
 	sgw_server.write_data();
-	// cout << "Sent data to the Enodeb successfully" << endl << endl;
+	cout << "Sent data to Enodeb" << endl << endl;
 }
 
 void SGWu::recv_pgw(int &pgw_num) {
@@ -179,6 +179,7 @@ void SGWu::recv_pgw(int &pgw_num) {
 
 
 	to_pgw[pgw_num].read_data();
+	cout << "Received data from PGW" << endl;
 	copy_data(to_pgw[pgw_num].pkt);
 	pkt.rem_gtpu_hdr();
 

ue.cpp

@@ -82,8 +82,7 @@ void UE::authenticate(Client &to_mme) {
 	else {
 		cout << "Authentication is not successful for UE - " << num << endl;
 		handle_exceptions();
-	}
-
+	}		
 }
 
 unsigned long long UE::get_autn_res(unsigned long long autn, unsigned long long rand) {
@@ -126,7 +125,7 @@ void UE::send_traffic() {
 	command = "iperf3 -B " + ip_addr_str + " -c " + sink_addr + " -p " + to_string(sink_port) + rate + mtu + time_limit; 
 	cout << command << endl;
 	system(command.c_str());
-	cout << "IPERF Traffic successfully sent" << endl;
+	cout << "IPERF Traffic successfully sent for UE - " << num << endl;
 	// generate_data();
 	// to_sink.fill_client_details(ip_addr);
 	// to_sink.bind_client();