tools/hexnet: Put the new usage generator to use and remove prefixes for IPv4 and IPv6

The prefixes were part of a planned feature but since a connection is
either IPv4 or IPv6 but never both, it would have been completely useless
to specify which to use. Instead, only TCP and UDP will need to be specified.

src/tools/hexnet.cpp

@@ -57,7 +57,7 @@ void signalHandler(int signal) {
     tcp6Acceptor.shutdown();
     // tell sockpp to close TCP socket if open because it blocks when trying
     // to read and there is no data
-    
+
     if (tcpSocket != nullptr && *tcpSocket) {
         // Intentionally not using the mutex here
         std::cout << "test\n";
@@ -149,17 +149,19 @@ int main(int argc, char* argv[]){
     flags.push_back(CLI::Flag('u', "udp", "use UDP, defaults to both when -t and -u are omitted, otherwise uses what is specified"));
     flags.push_back(CLI::Flag('n', "no-color", "disable coloring the output (intended for terminals that don't work well with color escape sequences)"));
     flags.push_back(CLI::Flag('e', "echo-back", "echo input back to stdout"));
+    flags.push_back(CLI::Flag('h', "help", "print this information and exit"));
+    flags.push_back(CLI::Flag('l', "license", "print license information and exit"));
 
     std::vector<CLI::Option> options;
     options.push_back(CLI::Option('c', "connect", "HOST", "connect to HOST, listen for incoming connections if omitted"));
     options.push_back(CLI::Option('m', "mtu-optimize", "MTU", "Optimize for a specific maximum transfer unit by reading MTU bytes at a time."));
     options.push_back(CLI::Option(
-        'p', "print-prefixes", "TCPv4i:UDPv4i:TCPv6i:UDPv6i:TCPv4o:UDPv4o:TCPv6o:UDPv6o",
+        'p', "print-prefixes", "TCPin:UDPin:TCPout:UDPout",
-        "override default prefixes for output (defaults to spaces + coloring the output or \"t4:u4:t6:u6:T4:U4:T6:U6\" in no-color mode)"
+        "override default prefixes for output (defaults to spaces + coloring the output or \"t:u:T:U\" in no-color mode)"
     ));
     options.push_back(CLI::Option(
-        'i', "input-prefixes", "TCP:UDP:IPv4:IPv6",
+        'i', "input-prefixes", "TCP:UDP",
-        "override default prefixes for input (defaults to \"t:u:4:6\")"
+        "override default prefixes for input (defaults to \"t:u\")"
     ));
 
     std::vector<CLI::Argument> arguments;
@@ -167,25 +169,51 @@ int main(int argc, char* argv[]){
 
     CLI::ArgumentsParser cliParser = CLI::ArgumentsParser(argc, argv, flags, options, arguments, "Arbitrary tcp/udp connections in hex format.");
 
+    if (cliParser.getFlag("help").value){
+        std::cout << cliParser.getUsage() << std::endl;
+        return EXIT_SUCCESS;
+    }
+    if (cliParser.getFlag("license").value){
+        std::cout
+            << "Copyright 2022, FOSS-VG Developers and Contributers\n"
+            << "\n"
+            << "Hexnet is part of the FOSS-VG development tool suite.\n"
+            << "\n"
+            << "This program is free software: you can redistribute it and/or modify it\n"
+            << "under the terms of the GNU Affero General Public License as published\n"
+            << "by the Free Software Foundation, version 3.\n"
+            << "\n"
+            << "This program is distributed in the hope that it will be useful,\n"
+            << "but WITHOUT ANY WARRANTY; without even the implied\n"
+            << "warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
+            << "See the GNU Affero General Public License for more details.\n"
+            << "\n"
+            << "You should have received a copy of the GNU Affero General Public License\n"
+            << "version 3 along with this program.\n"
+            << "If not, see https://www.gnu.org/licenses/agpl-3.0.en.html"
+            << std::endl;
+        return EXIT_SUCCESS;
+    }
+
     if (cliParser.wrongUsage) {
-        //TODO: spit out usage information generated by the parser
+        std::cout << cliParser.getUsage() << std::endl;
         return EXIT_USAGE;
     }
-    if (cliParser.getFlag('4').value || cliParser.getFlag('6').value) {
+    if (cliParser.getFlag("ipv4").value || cliParser.getFlag("ipv6").value) {
-        ipv4 = cliParser.getFlag('4').value;
+        ipv4 = cliParser.getFlag("ipv4").value;
-        ipv6 = cliParser.getFlag('6').value;
+        ipv6 = cliParser.getFlag("ipv4").value;
     }
-    if (cliParser.getFlag('t').value || cliParser.getFlag('u').value) {
+    if (cliParser.getFlag("tcp").value || cliParser.getFlag("udp").value) {
-        tcp = cliParser.getFlag('t').value;
+        tcp = cliParser.getFlag("tcp").value;
-        udp = cliParser.getFlag('u').value;
+        udp = cliParser.getFlag("udp").value;
     }
     if (cliParser.getOption('c').errorCode == ErrorCodes::NOT_PRESENT) {
         listenMode = true;
     }
-    if (cliParser.getOption('m').errorCode == ErrorCodes::SUCCESS) {
+    if (cliParser.getOption("mtu-optimize").errorCode == ErrorCodes::SUCCESS) {
-        mtu = std::stol(cliParser.getOption('m').value);
+        mtu = std::stol(cliParser.getOption("mtu-optimize").value);
     }
-    host = cliParser.getOption('c').value;
+    host = cliParser.getOption("connect").value;
     //FIXME: use a function that returns a fixed-width data type instead,
     //       ensure that the given value is a valid port
     port = (in_port_t) std::stoi(cliParser.getArgument(0).value);
@@ -256,7 +284,7 @@ int main(int argc, char* argv[]){
             delete tcpSocket;
             return EXIT_SUCCESS;
         }
-        
+
     } else {
         std::cerr << "Client mode is not implemented yet." << std::endl;
         return EXIT_UNIMPLEMENTED;