Updated to new config system.

lib/config.cpp

@@ -12,6 +12,7 @@
 #endif
 #include <errno.h>
 #include <iostream>
+#include <signal.h>
 #include <sys/types.h>
 #include <unistd.h>
 #include <fcntl.h>
@@ -21,55 +22,278 @@
 #include <stdio.h>
 #include <fstream>
 
+bool Util::Config::is_active = false;
+
 /// Creates a new configuration manager.
-Util::Config::Config(){
+Util::Config::Config(std::string cmd, std::string version){
-  listen_port = 4242;
+  vals.null();
-  daemon_mode = true;
+  long_count = 0;
-  interface = "0.0.0.0";
+  vals["cmd"]["current"] = cmd;
-  username = "root";
+  vals["version"]["long"] = "version";
+  vals["version"]["short"] = "v";
+  vals["version"]["help"] = "Display library and application version, then exit.";
+  vals["help"]["long"] = "help";
+  vals["help"]["short"] = "h";
+  vals["help"]["help"] = "Display usage and version information, then exit.";
+  vals["version"]["current"] = version;
 }
 
+/// Adds an option to the configuration parser.
+/// The option needs an unique name (doubles will overwrite the previous) and can contain the following in the option itself:
+/// {
+///   "short":"o",          //The short option letter
+///   "long":"onName",      //The long option
+///   "short_off":"n",      //The short option-off letter
+///   "long_off":"offName", //The long option-off
+///   "arg":"integer",          //The type of argument, if required.
+///   "default":1234,       //The default value for this option if it is not given on the commandline.
+///   "arg_num":1,          //The count this value has on the commandline, after all the options have been processed.
+///   "help":"Blahblahblah" //The helptext for this option.
+/// }
+void Util::Config::addOption(std::string optname, JSON::Value option){
+  vals[optname] = option;
+  long_count = 0;
+  for (JSON::ObjIter it = vals.ObjBegin(); it != vals.ObjEnd(); it++){
+    if (it->second.isMember("long")){long_count++;}
+    if (it->second.isMember("long_off")){long_count++;}
+  }
+}
+
+/// Prints a usage message to the given output.
+void Util::Config::printHelp(std::ostream & output){
+  int longest = 0;
+  std::map<long long int, std::string> args;
+  for (JSON::ObjIter it = vals.ObjBegin(); it != vals.ObjEnd(); it++){
+    int current = 0;
+    if (it->second.isMember("long")){current += it->second["long"].asString().size() + 4;}
+    if (it->second.isMember("short")){current += it->second["short"].asString().size() + 3;}
+    if (current > longest){longest = current;}
+    current = 0;
+    if (it->second.isMember("long_off")){current += it->second["long_off"].asString().size() + 4;}
+    if (it->second.isMember("short_off")){current += it->second["short_off"].asString().size() + 3;}
+    if (current > longest){longest = current;}
+    if (it->second.isMember("arg_num")){
+      current = it->first.size() + 3;
+      if (current > longest){longest = current;}
+      args[it->second["arg_num"].asInt()] = it->first;
+    }
+  }
+  output << "Usage: " << getString("cmd") << " [options]";
+  for (std::map<long long int, std::string>::iterator i = args.begin(); i != args.end(); i++){
+    if (vals[i->second].isMember("default")){
+      output << " [" << i->second << "]";
+    }else{
+      output << " " << i->second;
+    }
+  }
+  output << std::endl << std::endl;
+  for (JSON::ObjIter it = vals.ObjBegin(); it != vals.ObjEnd(); it++){
+    std::string f;
+    if (it->second.isMember("long") || it->second.isMember("short")){
+      if (it->second.isMember("long") && it->second.isMember("short")){
+        f = "--" + it->second["long"].asString() + ", -" + it->second["short"].asString();
+      }else{
+        if (it->second.isMember("long")){
+          f = "--" + it->second["long"].asString();
+        }
+        if (it->second.isMember("short")){
+          f = "-" + it->second["short"].asString();
+        }
+      }
+      while (f.size() < longest){f.append(" ");}
+      if (it->second.isMember("arg")){
+        output << f << "(" << it->second["arg"].asString() << ") " << it->second["help"].asString() << std::endl;
+      }else{
+        output << f << it->second["help"].asString() << std::endl;
+      }
+    }
+    if (it->second.isMember("long_off") || it->second.isMember("short_off")){
+      if (it->second.isMember("long_off") && it->second.isMember("short_off")){
+        f = "--" + it->second["long_off"].asString() + ", -" + it->second["short_off"].asString();
+      }else{
+        if (it->second.isMember("long_off")){
+          f = "--" + it->second["long_off"].asString();
+        }
+        if (it->second.isMember("short_off")){
+          f = "-" + it->second["short_off"].asString();
+        }
+      }
+      while (f.size() < longest){f.append(" ");}
+      if (it->second.isMember("arg")){
+        output << f << "(" << it->second["arg"].asString() << ") " << it->second["help"].asString() << std::endl;
+      }else{
+        output << f << it->second["help"].asString() << std::endl;
+      }
+    }
+    if (it->second.isMember("arg_num")){
+      f = it->first;
+      while (f.size() < longest){f.append(" ");}
+      output << f << "(" << it->second["arg"].asString() << ") " << it->second["help"].asString() << std::endl;
+    }
+  }
+}
+
+
 /// Parses commandline arguments.
 /// Calls exit if an unknown option is encountered, printing a help message.
-/// confsection must be either already set or never be set at all when this function is called.
-/// In other words: do not change confsection after calling this function.
 void Util::Config::parseArgs(int argc, char ** argv){
   int opt = 0;
-  static const char *optString = "ndvp:i:u:c:h?";
+  std::string shortopts;
-  static const struct option longOpts[] = {
+  struct option * longOpts = (struct option*)calloc(long_count+1, sizeof(struct option));
-    {"help",0,0,'h'},
+  int long_i = 0;
-    {"port",1,0,'p'},
+  int arg_count = 0;
-    {"interface",1,0,'i'},
+  for (JSON::ObjIter it = vals.ObjBegin(); it != vals.ObjEnd(); it++){
-    {"username",1,0,'u'},
+    if (it->second.isMember("short")){
-    {"nodaemon",0,0,'n'},
+      shortopts += it->second["short"].asString();
-    {"daemon",0,0,'d'},
+      if (it->second.isMember("arg")){shortopts += ":";}
-    {"version",0,0,'v'},
+    }
-    0
+    if (it->second.isMember("short_off")){
-  };
+      shortopts += it->second["short_off"].asString();
-  while ((opt = getopt_long(argc, argv, optString, longOpts, 0)) != -1){
+      if (it->second.isMember("arg")){shortopts += ":";}
+    }
+    if (it->second.isMember("long")){
+      longOpts[long_i].name = it->second["long"].asString().c_str();
+      longOpts[long_i].val = it->second["short"].asString()[0];
+      if (it->second.isMember("arg")){longOpts[long_i].has_arg = 1;}
+      long_i++;
+    }
+    if (it->second.isMember("long_off")){
+      longOpts[long_i].name = it->second["long_off"].asString().c_str();
+      longOpts[long_i].val = it->second["short_off"].asString()[0];
+      if (it->second.isMember("arg")){longOpts[long_i].has_arg = 1;}
+      long_i++;
+    }
+    if (it->second.isMember("arg_num") && !it->second.isMember("default")){
+      if (it->second["arg_num"].asInt() > arg_count){
+        arg_count = it->second["arg_num"].asInt();
+      }
+    }
+  }
+  while ((opt = getopt_long(argc, argv, shortopts.c_str(), longOpts, 0)) != -1){
     switch (opt){
-      case 'p': listen_port = atoi(optarg); break;
-      case 'i': interface = optarg; break;
-      case 'n': daemon_mode = false; break;
-      case 'd': daemon_mode = true; break;
-      case 'u': username = optarg; break;
-      case 'v':
-        printf("%s\n", PACKAGE_VERSION);
-        exit(1);
-        break;
       case 'h':
       case '?':
-        std::string doingdaemon = "true";
+        printHelp(std::cout);
-        if (!daemon_mode){doingdaemon = "false";}
+      case 'v':
-        printf("Options: -h[elp], -?, -v[ersion], -n[odaemon], -d[aemon], -p[ort] VAL, -i[nterface] VAL, -u[sername] VAL\n");
+        std::cout << "Library version: " PACKAGE_VERSION << std::endl;
-        printf("Defaults:\n  interface: %s\n  port: %i\n  daemon mode: %s\n  username: %s\n", interface.c_str(), listen_port, doingdaemon.c_str(), username.c_str());
+        std::cout << "Application version: " << getString("version") << std::endl;
-        printf("Username root means no change to UID, no matter what the UID is.\n");
-        printf("This is %s version %s\n", argv[0], PACKAGE_VERSION);
         exit(1);
         break;
+      default:
+        for (JSON::ObjIter it = vals.ObjBegin(); it != vals.ObjEnd(); it++){
+          if (it->second.isMember("short") && it->second["short"].asString()[0] == opt){
+            if (it->second.isMember("arg")){
+              it->second["current"] = (std::string)optarg;
+            }else{
+              it->second["current"] = 1;
+            }
+            break;
+          }
+          if (it->second.isMember("short_off") && it->second["short_off"].asString()[0] == opt){
+            it->second["current"] = 0;
+          }
+        }
+        break;
     }
   }//commandline options parser
+  free(longOpts);//free the long options array
+  long_i = 1;//re-use long_i as an argument counter
+  while (optind < argc){//parse all remaining options, ignoring anything unexpected.
+    for (JSON::ObjIter it = vals.ObjBegin(); it != vals.ObjEnd(); it++){
+      if (it->second.isMember("arg_num") && it->second["arg_num"].asInt() == long_i){
+        it->second["current"] = (std::string)argv[optind];
+        optind++;
+        long_i++;
+        break;
       }
+    }
+  }
+  if (long_i <= arg_count){
+    std::cerr << "Usage error: missing argument(s)." << std::endl;
+    printHelp(std::cout);
+    exit(1);
+  }
+}
+
+/// Returns a reference to the current value of an option or default if none was set.
+/// If the option does not exist, this exits the application with a return code of 37.
+JSON::Value & Util::Config::getOption(std::string optname){
+  if (!vals.isMember(optname)){
+    std::cout << "Fatal error: a non-existent option was accessed." << std::endl;
+    exit(37);
+  }
+  if (vals[optname].isMember("current")){
+    return vals[optname]["current"];
+  }else{
+    return vals[optname]["default"];
+  }
+}
+
+/// Returns the current value of an option or default if none was set as a string.
+/// Calls getOption internally.
+std::string Util::Config::getString(std::string optname){
+  return getOption(optname).asString();
+}
+
+/// Returns the current value of an option or default if none was set as a long long int.
+/// Calls getOption internally.
+long long int Util::Config::getInteger(std::string optname){
+  return getOption(optname).asInt();
+}
+
+/// Returns the current value of an option or default if none was set as a bool.
+/// Calls getOption internally.
+bool Util::Config::getBool(std::string optname){
+  return getOption(optname).asBool();
+}
+
+/// Activated the stored config. This will:
+/// - Drop permissions to the stored "username".
+/// - Daemonize the process if "daemonize" is true.
+/// - Set is_active to true.
+/// - Set up a signal handler to set is_active to false for the SIGINT, SIGHUP and SIGTERM signals.
+void Util::Config::activate(){
+  setUser(getString("username"));
+  if (getBool("daemonize")){Daemonize();}
+  struct sigaction new_action;
+  new_action.sa_handler = signal_handler;
+  sigemptyset (&new_action.sa_mask);
+  new_action.sa_flags = 0;
+  sigaction(SIGINT, &new_action, NULL);
+  sigaction(SIGHUP, &new_action, NULL);
+  sigaction(SIGTERM, &new_action, NULL);
+  sigaction(SIGPIPE, &new_action, NULL);
+  sigaction(SIGCHLD, &new_action, NULL);
+  is_active = true;
+}
+
+/// Basic signal handler. Sets is_active to false if it receives
+/// a SIGINT, SIGHUP or SIGTERM signal, reaps children for the SIGCHLD
+/// signal, and ignores all other signals.
+void Util::Config::signal_handler(int signum){
+  switch (signum){
+    case SIGINT://these three signals will set is_active to false.
+    case SIGHUP:
+    case SIGTERM:
+      is_active = false;
+      break;
+    case SIGCHLD://when a child dies, reap it.
+      wait(0);
+      break;
+    default: //other signals are ignored
+      break;
+  }
+}//signal_handler
+
+/// Adds the default connector options to this Util::Config object.
+void Util::Config::addConnectorOptions(int port){
+  JSON::Value stored_port = JSON::fromString("{\"long\":\"port\", \"short\":\"p\", \"arg\":\"integer\", \"help\":\"TCP port to listen on.\"}");
+  stored_port["default"] = port;
+  addOption("listen_port", stored_port);
+  addOption("listen_interface", JSON::fromString("{\"long\":\"interface\", \"default\":\"0.0.0.0\", \"short\":\"i\", \"arg\":\"string\", \"help\":\"Interface address to listen on, or 0.0.0.0 for all available interfaces.\"}"));
+  addOption("username", JSON::fromString("{\"long\":\"username\", \"default\":\"root\", \"short\":\"u\", \"arg\":\"string\", \"help\":\"Username to drop privileges to, or root to not drop provileges.\"}"));
+  addOption("daemonize", JSON::fromString("{\"long\":\"daemon\", \"short\":\"d\", \"default\":1, \"long_off\":\"nodaemon\", \"short_off\":\"n\", \"help\":\"Whether or not to daemonize the process after starting.\"}"));
+}//addConnectorOptions
 
 /// Sets the current process' running user
 void Util::setUser(std::string username){

lib/config.h

@@ -3,22 +3,31 @@
 
 #pragma once
 #include <string>
-
+#include "json.h"
-#define STRINGIFY(x) #x
-#define TOSTRING(x) STRINGIFY(x)
 
 /// Contains utility code, not directly related to streaming media
 namespace Util{
 
   /// Deals with parsing configuration from commandline options.
   class Config{
+    private:
+      JSON::Value vals; ///< Holds all current config values
+      int long_count;
+      static void signal_handler(int signum);
     public:
-      bool daemon_mode;
+      //variables
-      std::string interface;
+      static bool is_active; ///< Set to true by activate(), set to false by the signal handler.
-      int listen_port;
+      //functions
-      std::string username;
+      Config(std::string cmd, std::string version);
-      Config();
+      void addOption(std::string optname, JSON::Value option);
+      void printHelp(std::ostream & output);
       void parseArgs(int argc, char ** argv);
+      JSON::Value & getOption(std::string optname);
+      std::string getString(std::string optname);
+      long long int getInteger(std::string optname);
+      bool getBool(std::string optname);
+      void activate();
+      void addConnectorOptions(int port);
   };
 
   /// Will set the active user to the named username.