tools/hexnet: Implement UDP support (and minor refactoring)

src/tools/hexnet.cpp

@@ -25,6 +25,8 @@
 #include <sockpp/tcp_connector.h>
 #include <sockpp/tcp6_acceptor.h>
 #include <sockpp/tcp6_connector.h>
+#include <sockpp/udp_socket.h>
+#include <sockpp/udp6_socket.h>
 #include <thread>
 #include <vector>
 
@@ -47,6 +49,10 @@ sockpp::tcp6_socket tcp6Socket;
 sockpp::tcp6_acceptor tcp6Acceptor;
 // TCP v6 client
 sockpp::tcp6_connector tcp6Connector;
+// UDP v4 server and client
+sockpp::udp_socket udpSocket;
+// UDP v6 server and client
+sockpp::udp6_socket udp6Socket;
 
 bool exitProgram = false;
 
@@ -58,6 +64,12 @@ bool outgoing = false;
 std::string host;
 in_port_t port;
 
+// This is probably bigger than the MTU on any given network.
+// This should allow us to read entire packets at once when they arrive
+// slowly enough to be read individually.
+const uint32_t bufferSize = 2048;
+uint8_t networkBuffer[bufferSize];
+
 void signalHandler(int signal) {
     // shut down gracefully
     exitProgram = true;
@@ -75,10 +87,9 @@ void signalHandler(int signal) {
 
 void readFromTCP() {
     ssize_t byteCount;
-    uint8_t buffer[1536];
+    while (!exitProgram && (outgoing? (byteCount = tcpConnector.read(networkBuffer, bufferSize)) > 0 : (byteCount = tcpSocket.read(networkBuffer, bufferSize)) > 0)) {
-    while (!exitProgram && (outgoing? (byteCount = tcpConnector.read(buffer, sizeof(buffer))) > 0 : (byteCount = tcpSocket.read(buffer, sizeof(buffer))) > 0)) {
         for (ssize_t i=0; i<byteCount; i++) {
-            std::cout << std::hex << std::setfill('0') << std::setw(2) << (short) buffer[i] << " ";
+            std::cout << std::hex << std::setfill('0') << std::setw(2) << (short) networkBuffer[i] << " ";
         }
         std::cout.flush();
     }
@@ -86,15 +97,38 @@ void readFromTCP() {
 
 void readFromTCP6() {
     ssize_t byteCount;
-    uint8_t buffer[1536];
+    while (!exitProgram && (outgoing? (byteCount = tcp6Connector.read(networkBuffer, bufferSize)) > 0 : (byteCount = tcp6Socket.read(networkBuffer, bufferSize)) > 0)) {
-    while (!exitProgram && (outgoing? (byteCount = tcp6Connector.read(buffer, sizeof(buffer))) > 0 : (byteCount = tcp6Socket.read(buffer, sizeof(buffer))) > 0)) {
         for (ssize_t i=0; i<byteCount; i++) {
-            std::cout << std::hex << std::setfill('0') << std::setw(2) << (short) buffer[i] << " ";
+            std::cout << std::hex << std::setfill('0') << std::setw(2) << (short) networkBuffer[i] << " ";
         }
         std::cout.flush();
     }
 }
 
+void readFromUDP() {
+    ssize_t byteCount;
+    sockpp::udp_socket::addr_t peer;
+    while ((byteCount = udpSocket.recv_from(networkBuffer, bufferSize, &peer)) > 0) {
+        std::cout << peer << ": ";
+        for (ssize_t i=0; i<byteCount; i++) {
+            std::cout << std::hex << std::setfill('0') << std::setw(2) << (short) networkBuffer[i] << " ";
+        }
+        std::cout << std::dec << std::endl;
+    }
+}
+
+void readFromUDP6() {
+    ssize_t byteCount;
+    sockpp::udp6_socket::addr_t peer;
+    while ((byteCount = udp6Socket.recv_from(networkBuffer, bufferSize, &peer)) > 0) {
+        std::cout << peer << ": ";
+        for (ssize_t i=0; i<byteCount; i++) {
+            std::cout << std::hex << std::setfill('0') << std::setw(2) << (short) networkBuffer[i] << " ";
+        }
+        std::cout << std::dec << std::endl;
+    }
+}
+
 int main(int argc, char* argv[]) {
     std::signal(SIGINT, signalHandler);
     std::signal(SIGTERM, signalHandler);
@@ -109,6 +143,7 @@ int main(int argc, char* argv[]) {
 
     std::vector<CLI::Option> options;
     options.push_back(CLI::Option('c', "connect", "HOST", "make an outgoing connection to HOST instead of listening for an incoming connection"));
+    options.push_back(CLI::Option('b', "bind", "ADDRESS", "(UDP only) bind to ADDRESS instead of localhost"));
 
     std::vector<CLI::Argument> arguments;
     arguments.push_back(CLI::Argument("PORT", "the port to lsiten on (or connect to)"));
@@ -204,10 +239,42 @@ int main(int argc, char* argv[]) {
             std::cerr << "Talking to " << host << " on port " << (int) port << " (UDP)..." << std::endl;
             if (ipv4) {
                 // UDP v4 out
-                return EXIT_UNIMPLEMENTED;
+                if (!udpSocket) {
+                    std::cerr << "Error creating UDP socket: " << udpSocket.last_error_str() << std::endl;
+                }
+                // Btw: Did you know that UDP has no concept of a connection?
+                if (!udpSocket.connect(sockpp::inet_address(host, port))) {
+                    std::cerr << "Error associating socket with " << host << " port " << port << std::endl;
+                    std::cerr << udpSocket.last_error_str() << std::endl;
+                }
+
+                std::thread threadReadFromUDP = std::thread(readFromUDP);
+                //std::thread threadWriteToUDP = std::thread(writeToUDP);
+
+                threadReadFromUDP.join();
+                //threadWriteToUDP.join();
+
+                std::cout << std::endl;
+                return EXIT_SUCCESS;
             } else {
                 // UDP v6 out
-                return EXIT_UNIMPLEMENTED;
+                if (!udp6Socket) {
+                    std::cerr << "Error creating UDP socket: " << udp6Socket.last_error_str() << std::endl;
+                }
+                // Btw: Did you know that UDP has no concept of a connection?
+                if (!udp6Socket.connect(sockpp::inet6_address(host, port))) {
+                    std::cerr << "Error associating socket with " << host << " port " << port << std::endl;
+                    std::cerr << udp6Socket.last_error_str() << std::endl;
+                }
+
+                std::thread threadReadFromUDP6 = std::thread(readFromUDP6);
+                //std::thread threadWriteToUDP6 = std::thread(writeToUDP6);
+
+                threadReadFromUDP6.join();
+                //threadWriteToUDP6.join();
+
+                std::cout << std::endl;
+                return EXIT_SUCCESS;
             }
         }
     } else {
@@ -263,13 +330,45 @@ int main(int argc, char* argv[]) {
                 return EXIT_SUCCESS;
             }
         } else {
-            std::cerr << "Listening on port " << (int) port << " (UDP)..." << std::endl;
+            std::string address = "localhost";
+            if (cliParser.getOption("bind").errorCode != ErrorCodes::NOT_PRESENT) {
+                address = cliParser.getOption("bind").value;
+            }
+            std::cerr << "Listening on " << address << " port " << (int) port << " (UDP)..." << std::endl;
             if (ipv4) {
                 // UDP v4 in
-                return EXIT_UNIMPLEMENTED;
+                if (!udpSocket) {
+                    std::cerr << "Error creating UDP socket: " << udpSocket.last_error_str() << std::endl;
+                }
+                if (!udpSocket.bind(sockpp::inet_address(address, port))) {
+                    std::cerr << "Error binding UDP socket to " << address << " port " << port << ": " << udpSocket.last_error_str() << std::endl;
+                }
+
+                std::thread threadReadFromUDP = std::thread(readFromUDP);
+                //std::thread threadWriteToUDP = std::thread(writeToUDP);
+
+                threadReadFromUDP.join();
+                //threadWriteToUDP.join();
+
+                std::cout << std::endl;
+                return EXIT_SUCCESS;
             } else {
                 // UDP v6 in
-                return EXIT_UNIMPLEMENTED;
+                if (!udp6Socket) {
+                    std::cerr << "Error creating UDP socket: " << udp6Socket.last_error_str() << std::endl;
+                }
+                if (!udp6Socket.bind(sockpp::inet6_address(address, port))) {
+                    std::cerr << "Error binding UDP socket to " << address << " port " << port << ": " << udp6Socket.last_error_str() << std::endl;
+                }
+
+                std::thread threadReadFromUDP6 = std::thread(readFromUDP6);
+                //std::thread threadWriteToUDP6 = std::thread(writeToUDP6);
+
+                threadReadFromUDP6.join();
+                //threadWriteToUDP6.join();
+
+                std::cout << std::endl;
+                return EXIT_SUCCESS;
             }
         }
     }