Simplify network.cpp to transmit only strings.

crypto.cpp

@@ -5,9 +5,25 @@
 #include "base64.h"
 
 using namespace std;
+using namespace Crypto;
 
 const char rdev[] = "/dev/urandom";
 
+long int myatoi( char *str )
+{
+  char *end;
+
+  errno = 0;
+  long int ret = strtol( str, &end, 10 );
+
+  if ( ( errno != 0 )
+       || ( end != str + strlen( str ) ) ) {
+    throw CryptoException( "Bad integer." );
+  }
+
+  return ret;
+}
+
 static void * sse_alloc( int len )
 {
   void *ptr = NULL;
@@ -178,7 +194,7 @@ Message Session::decrypt( string ciphertext )
   int body_len = ciphertext.size() - 8;
   int pt_len = body_len - 16;
 
-  if ( pt_len <= 0 ) { /* super-assertion that does not equal AE_INVALID */
+  if ( pt_len < 0 ) { /* super-assertion that pt_len does not equal AE_INVALID */
     fprintf( stderr, "BUG.\n" );
     exit( 1 );
   }
@@ -200,7 +216,7 @@ Message Session::decrypt( string ciphertext )
 			     AE_FINALIZE ) ) {  /* final */
     free( plaintext );
     free( body );
-    throw CryptoException( "ae_decrypt() returned error." );
+    throw CryptoException( "Packet failed integrity check." );
   }
 
   Message ret( nonce, string( plaintext, pt_len ) );

crypto.hpp

@@ -3,63 +3,68 @@
 
 #include "ae.hpp"
 #include <string>
+#include <string.h>
 
 using namespace std;
 
-class CryptoException {
-public:
-  string text;
-  CryptoException( string s_text ) : text( s_text ) {};
-};
+long int myatoi( char *str );
 
-class Base64Key {
-private:
-  unsigned char key[ 16 ];
+namespace Crypto {
+  class CryptoException {
+  public:
+    string text;
+    CryptoException( string s_text ) : text( s_text ) {};
+  };
 
-public:
-  Base64Key(); /* random key */
-  Base64Key( string printable_key );
-  string printable_key( void );
-  unsigned char *data( void ) { return key; }
-};
+  class Base64Key {
+  private:
+    unsigned char key[ 16 ];
 
-class Nonce {
-private:
-  char bytes[ 12 ];
+  public:
+    Base64Key(); /* random key */
+    Base64Key( string printable_key );
+    string printable_key( void );
+    unsigned char *data( void ) { return key; }
+  };
 
-public:
-  Nonce( uint64_t val );
-  Nonce( char *s_bytes, size_t len );
+  class Nonce {
+  private:
+    char bytes[ 12 ];
 
-  string cpp_str( void ) { return string( (char *)( bytes + 4 ), 8 ); }
-  char *data( void ) { return bytes; }
-  uint64_t val( void );
-};
+  public:
+    Nonce( uint64_t val );
+    Nonce( char *s_bytes, size_t len );
     
-class Message {
-public:
-  Nonce nonce;
-  string text;
+    string cpp_str( void ) { return string( (char *)( bytes + 4 ), 8 ); }
+    char *data( void ) { return bytes; }
+    uint64_t val( void );
+  };
   
-  Message( char *nonce_bytes, size_t nonce_len,
-	   char *text_bytes, size_t text_len );
-  Message( Nonce s_nonce, string s_text );
-};
+  class Message {
+  public:
+    Nonce nonce;
+    string text;
     
-class Session {
-private:
-  Base64Key key;
-  ae_ctx *ctx;
+    Message( char *nonce_bytes, size_t nonce_len,
+	     char *text_bytes, size_t text_len );
+    Message( Nonce s_nonce, string s_text );
+  };
   
-public:
-  Session( Base64Key s_key );
-  ~Session();
+  class Session {
+  private:
+    Base64Key key;
+    ae_ctx *ctx;
     
-  string encrypt( Message plaintext );
-  Message decrypt( string ciphertext );
+  public:
+    Session( Base64Key s_key );
+    ~Session();
     
-  Session( const Session & );
-  Session & operator=( const Session & );
-};
+    string encrypt( Message plaintext );
+    Message decrypt( string ciphertext );
+    
+    Session( const Session & );
+    Session & operator=( const Session & );
+  };
+}
 
 #endif

decrypt.cpp

@@ -8,6 +8,8 @@
 
 #include "crypto.hpp"
 
+using namespace Crypto;
+
 int main( int argc, char *argv[] )
 {
   if ( argc != 2 ) {

dos_assert.hpp

@@ -11,7 +11,7 @@ static void dos_detected( const char *expression, const char *file, int line, co
   char buffer[ 2048 ];
   snprintf( buffer, 2048, "Illegal counterparty input (possible denial of service) in function %s at %s:%d, failed test: %s\n",
 	    function, file, line, expression );
-  throw CryptoException( buffer );
+  throw Crypto::CryptoException( buffer );
 }
 
 #define dos_assert(expr)						\

encrypt.cpp

@@ -8,20 +8,7 @@
 
 #include "crypto.hpp"
 
-long int myatoi( char *str )
-{
-  char *end;
-
-  errno = 0;
-  long int ret = strtol( str, &end, 10 );
-
-  if ( ( errno != 0 )
-       || ( end != str + strlen( str ) ) ) {
-    throw CryptoException( "Bad integer." );
-  }
-
-  return ret;
-}
+using namespace Crypto;
 
 int main( int argc, char *argv[] )
 {

network.cpp

@@ -10,50 +10,40 @@
 
 using namespace std;
 using namespace Network;
+using namespace Crypto;
 
-template <class Payload>
-Flow<Payload>::Packet::DecodingCache::DecodingCache( string coded_packet, Session *session )
-  : direction( TO_CLIENT ), seq( -1 ), payload_string()
+/* Read in packet from coded string */
+Packet::Packet( string coded_packet, Session *session )
+  : seq( -1 ),
+    direction( TO_SERVER ),
+    payload()
 {
   Message message = session->decrypt( coded_packet );
 
   direction = (message.nonce.val() & 8000000000000000) ? TO_CLIENT : TO_SERVER;
   seq = message.nonce.val() & 0x7FFFFFFFFFFFFFFF;
-  payload_string = message.text;
+  payload = message.text;
 }
 
-template <class Payload>
-Flow<Payload>::Packet::Packet( string coded_packet, Session *session )
-  : decoding_cache( coded_packet, session ),
-    seq( decoding_cache.seq ),
-    direction( decoding_cache.direction ),
-    payload( decoding_cache.payload_string )
-{
-  decoding_cache = DecodingCache();
-}
-
-template <class Payload>
-string Flow<Payload>::Packet::tostring( Session *session )
+/* Output coded string from packet */
+string Packet::tostring( Session *session )
 {
   uint64_t direction_seq = (uint64_t( direction == TO_CLIENT ) << 63) | (seq & 0x7FFFFFFFFFFFFFFF);
 
-  return session->encrypt( Message( direction_seq, payload.tostring() ) );
+  return session->encrypt( Message( direction_seq, payload ) );
 }
 
-template <class Payload>
-typename Flow<Payload>::Packet Flow<Payload>::new_packet( Payload &s_payload )
+Packet Connection::new_packet( string &s_payload )
 {
   return Packet( next_seq++, direction, s_payload );
 }
 
-template <class Outgoing, class Incoming>
-void Connection<Outgoing, Incoming>::setup( void )
+void Connection::setup( void )
 {
   /* create socket */
   sock = socket( AF_INET, SOCK_DGRAM, 0 );
   if ( sock < 0 ) {
-    perror( "socket" );
-    exit( 1 );
+    throw NetworkException( "socket", errno );
   }
 
   /* Bind to free local port.
@@ -63,21 +53,18 @@ void Connection<Outgoing, Incoming>::setup( void )
   local_addr.sin_port = htons( 0 );
   local_addr.sin_addr.s_addr = INADDR_ANY;
   if ( bind( sock, (sockaddr *)&local_addr, sizeof( local_addr ) ) < 0 ) {
-    perror( "bind" );
-    exit( 1 );
+    throw NetworkException( "bind", errno );
   }
 
   /* Enable path MTU discovery */
   char flag = IP_PMTUDISC_DO;
   socklen_t optlen = sizeof( flag );
   if ( setsockopt( sock, IPPROTO_IP, IP_MTU_DISCOVER, &flag, optlen ) < 0 ) {
-    perror( "setsockopt" );
-    exit( 1 );
+    throw NetworkException( "setsockopt", errno );
   }  
 }
 
-template <class Outgoing, class Incoming>
-Connection<Outgoing, Incoming>::Connection() /* server */
+Connection::Connection() /* server */
   : sock( -1 ),
     remote_addr(),
     server( true ),
@@ -85,13 +72,13 @@ Connection<Outgoing, Incoming>::Connection() /* server */
     MTU( RECEIVE_MTU ),
     key(),
     session( key ),
-    flow( TO_CLIENT, &session )
+    direction( TO_CLIENT ),
+    next_seq( 0 )
 {
   setup();
 }
 
-template <class Outgoing, class Incoming>
-Connection<Outgoing, Incoming>::Connection( const char *key_str, const char *ip, int port ) /* client */
+Connection::Connection( const char *key_str, const char *ip, int port ) /* client */
   : sock( -1 ),
     remote_addr(),
     server( false ),
@@ -99,7 +86,8 @@ Connection<Outgoing, Incoming>::Connection( const char *key_str, const char *ip,
     MTU( RECEIVE_MTU ),
     key( key_str ),
     session( key ),
-    flow( TO_SERVER, &session )
+    direction( TO_SERVER ),
+    next_seq( 0 )
 {
   setup();
 
@@ -107,59 +95,53 @@ Connection<Outgoing, Incoming>::Connection( const char *key_str, const char *ip,
   remote_addr.sin_family = AF_INET;
   remote_addr.sin_port = htons( port );
   if ( !inet_aton( ip, &remote_addr.sin_addr ) ) {
-    fprintf( stderr, "Bad IP address %s\n", ip );
-    exit( 1 );
+    int saved_errno = errno;
+    char buffer[ 2048 ];
+    snprintf( buffer, 2048, "Bad IP address (%s)", ip );
+    throw NetworkException( buffer, saved_errno );
   }
 
   if ( connect( sock, (sockaddr *)&remote_addr, sizeof( remote_addr ) ) < 0 ) {
-    perror( "connect" );
-    exit( 1 );
+    throw NetworkException( "connect", errno );
   }
 
   attached = true;
 }
 
-template <class Outgoing, class Incoming>
-void Connection<Outgoing, Incoming>::update_MTU( void )
+void Connection::update_MTU( void )
 {
   socklen_t optlen = sizeof( MTU );
   if ( getsockopt( sock, IPPROTO_IP, IP_MTU, &MTU, &optlen ) < 0 ) {
-    perror( "getsockopt" );
-    exit( 1 );
+    throw NetworkException( "getsockopt", errno );
   }
 
   if ( optlen != sizeof( MTU ) ) {
-    fprintf( stderr, "Error getting path MTU.\n" );
-    exit( 1 );
+    throw NetworkException( "Error getting path MTU", errno );
   }
 
   fprintf( stderr, "Path MTU: %d\n", MTU );  
 }
 
-template <class Outgoing, class Incoming>
-bool Connection<Outgoing, Incoming>::send( Outgoing &s )
+void Connection::send( string &s )
 {
   assert( attached );
 
-  string p = flow.new_packet( s ).tostring( &session );
+  string p = new_packet( s ).tostring( &session );
 
   ssize_t bytes_sent = sendto( sock, p.data(), p.size(), 0,
 			       (sockaddr *)&remote_addr, sizeof( remote_addr ) );
 
   if ( (bytes_sent < 0) && (errno == EMSGSIZE) ) {
     update_MTU();
-    return false;
+    throw MTUException( MTU );
   } else if ( bytes_sent == static_cast<int>( p.size() ) ) {
-    return true;
+    return;
   } else {
-    perror( "sendto" );
-    exit( 1 );
-    return false;
+    throw NetworkException( "sendto", errno );
   }
 }
 
-template <class Outgoing, class Incoming>
-Incoming Connection<Outgoing, Incoming>::recv( void )
+string Connection::recv( void )
 {
   struct sockaddr_in packet_remote_addr;
 
@@ -170,17 +152,17 @@ Incoming Connection<Outgoing, Incoming>::recv( void )
   ssize_t received_len = recvfrom( sock, buf, RECEIVE_MTU, 0, (sockaddr *)&packet_remote_addr, &addrlen );
 
   if ( received_len < 0 ) {
-    perror( "recvfrom" );
-    exit( 1 );
+    throw NetworkException( "recvfrom", errno );
   }
 
   if ( received_len > RECEIVE_MTU ) {
-    fprintf( stderr, "Received oversize datagram (size %d) and limit is %d.\n",
-	     static_cast<int>( received_len ), RECEIVE_MTU );
-    exit( 1 );
+    char buffer[ 2048 ];
+    snprintf( buffer, 2048, "Received oversize datagram (size %d) and limit is %d\n",
+	      static_cast<int>( received_len ), RECEIVE_MTU );
+    throw NetworkException( buffer, errno );
   }
 
-  typename Flow<Incoming>::Packet p( string( buf, received_len ), &session );
+  Packet p( string( buf, received_len ), &session );
   dos_assert( p.direction == (server ? TO_SERVER : TO_CLIENT) ); /* prevent malicious playback to sender */
 
   /* server auto-adjusts to client */
@@ -199,15 +181,13 @@ Incoming Connection<Outgoing, Incoming>::recv( void )
   return p.payload;
 }
 
-template <class Outgoing, class Incoming>
-int Connection<Outgoing, Incoming>::port( void )
+int Connection::port( void )
 {
   struct sockaddr_in local_addr;
   socklen_t addrlen = sizeof( local_addr );
 
   if ( getsockname( sock, (sockaddr *)&local_addr, &addrlen ) < 0 ) {
-    perror( "getsockname" );
-    exit( 1 );
+    throw NetworkException( "getsockname", errno );
   }
 
   return ntohs( local_addr.sin_port );

network.hpp

@@ -10,57 +10,42 @@
 #include "crypto.hpp"
 
 using namespace std;
+using namespace Crypto;
 
 namespace Network {
+  class MTUException {
+  public:
+    int MTU;
+    MTUException( int s_MTU ) : MTU( s_MTU ) {};
+  };
+
+  class NetworkException {
+  public:
+    string function;
+    int the_errno;
+    NetworkException( string s_function, int s_errno ) : function( s_function ), the_errno( s_errno ) {}
+  };
+
   enum Direction {
     TO_SERVER = 0,
     TO_CLIENT = 1
   };
 
-  template <class Payload>
-  class Flow {
+  class Packet {
   public:
-    class Packet {
-    private:
-      class DecodingCache
-      {
-      public:
-	Direction direction;
-	uint64_t seq;
-	string payload_string;
-
-	DecodingCache( string coded_packet, Session *session );
-	DecodingCache() : direction( TO_CLIENT ), seq( -1 ), payload_string() {}
-      };
-
-      DecodingCache decoding_cache;
-
-    public:
-      uint64_t seq;
-      Direction direction;
-      Payload payload;
-      
-      Packet( uint64_t s_seq, Direction s_direction, Payload s_payload )
-	: decoding_cache(), seq( s_seq ), direction( s_direction ), payload( s_payload )
-      {}
-      
-      Packet( string coded_packet, Session *session );
-      
-      string tostring( Session *session );
-    };
-
-    uint64_t next_seq;
+    uint64_t seq;
     Direction direction;
-    Session *session;
+    string payload;
     
-    Flow( Direction s_direction, Session *s_session )
-      : next_seq( 0 ), direction( s_direction ), session( s_session )
+    Packet( uint64_t s_seq, Direction s_direction, string s_payload )
+      : seq( s_seq ), direction( s_direction ), payload( s_payload )
     {}
     
-    Packet new_packet( Payload &s_payload );
+    Packet( string coded_packet, Session *session );
+    
+    string tostring( Session *session );
   };
 
-  template <class Outgoing, class Incoming>
   class Connection {
   private:
     static const int RECEIVE_MTU = 2048;
@@ -76,18 +61,20 @@ namespace Network {
     Base64Key key;
     Session session;
 
-    Flow<Outgoing> flow;
-
     void update_MTU( void );
 
     void setup( void );
 
+    Direction direction;
+    uint64_t next_seq;
+    Packet new_packet( string &s_payload );
+
   public:
     Connection();
     Connection( const char *key_str, const char *ip, int port );
     
-    bool send( Outgoing &s );
-    Incoming recv( void );
+    void send( string &s );
+    string recv( void );
     int fd( void ) { return sock; }
     int port( void );
     int get_MTU( void ) { return MTU; }

networktransport.hpp

@@ -0,0 +1,27 @@
+#ifndef NETWORK_TRANSPORT_HPP
+#define NETWORK_TRANSPORT_HPP
+
+#include <google/dense_hash_map>
+
+using google::dense_hash_map;
+
+namespace Network {
+  template <class MyState, class RemoteState>
+  class Transport
+  {
+  private:
+    Connection<typename MyState::Conveyance, typename RemoteState::Conveyance> connection;
+
+    uint64_t last_acknowledged_state;
+    uint64_t assumed_receiver_state;
+    uint64_t last_sent_state;
+
+  public:
+    Transport();
+    Transport( const char *key_str, const char *ip, int port );
+
+    
+  };
+};
+
+#endif

ntester.cpp

@@ -11,7 +11,7 @@ int main( int argc, char *argv[] )
   char *ip;
   int port;
 
-  Network::Connection<KeyStroke, KeyStroke> *n;
+  Network::Connection *n;
 
   try {
     if ( argc > 1 ) {
@@ -22,9 +22,9 @@ int main( int argc, char *argv[] )
       ip = argv[ 2 ];
       port = atoi( argv[ 3 ] );
       
-      n = new Network::Connection<KeyStroke, KeyStroke>( key, ip, port );
+      n = new Network::Connection( key, ip, port );
     } else {
-      n = new Network::Connection<KeyStroke, KeyStroke>();
+      n = new Network::Connection();
     }
   } catch ( CryptoException e ) {
     fprintf( stderr, "Fatal error: %s\n", e.text.c_str() );
@@ -36,34 +36,47 @@ int main( int argc, char *argv[] )
   if ( server ) {
     while ( true ) {
       try {
-	KeyStroke s = n->recv();
-	printf( "%c", s.letter );
+	string s = n->recv();
+	printf( "%s", s.c_str() );
 	fflush( NULL );
       } catch ( CryptoException e ) {
-	fprintf( stderr, "Error: %s\n", e.text.c_str() );
+	fprintf( stderr, "Cryptographic error: %s\n", e.text.c_str() );
       }
     }
   } else {
-      struct termios the_termios;
+    struct termios saved_termios;
+    struct termios the_termios;
 
-      if ( tcgetattr( STDIN_FILENO, &the_termios ) < 0 ) {
-	perror( "tcgetattr" );
-	exit( 1 );
-      }
+    if ( tcgetattr( STDIN_FILENO, &the_termios ) < 0 ) {
+      perror( "tcgetattr" );
+      exit( 1 );
+    }
 
-      cfmakeraw( &the_termios );
+    saved_termios = the_termios;
 
-      if ( tcsetattr( STDIN_FILENO, TCSANOW, &the_termios ) < 0 ) {
-	perror( "tcsetattr" );
-	exit( 1 );
-      }
+    cfmakeraw( &the_termios );
+
+    if ( tcsetattr( STDIN_FILENO, TCSANOW, &the_termios ) < 0 ) {
+      perror( "tcsetattr" );
+      exit( 1 );
+    }
 
     while( true ) {
       char x = getchar();
       
-      KeyStroke t( string( &x, 1 ) );
+      string prefix = "Key(" + string( &x, 1 ) + ")";
       
-      n->send( t );
+      try {
+	n->send( prefix );
+      } catch ( Network::NetworkException e ) {
+	fprintf( stderr, "%s: %s\r\n", e.function.c_str(), strerror( e.the_errno ) );
+	break;
+      }
+    }
+
+    if ( tcsetattr( STDIN_FILENO, TCSANOW, &saved_termios ) < 0 ) {
+      perror( "tcsetattr" );
+      exit( 1 );
     }    
   }
 }

templates.cpp

@@ -6,9 +6,6 @@
 
 #include "terminal.hpp"
 
-#include "network.cpp"
-#include "keystroke.hpp"
-
 namespace Parser {
   class Action;
 }
@@ -24,4 +21,4 @@ template class vector<wchar_t>;
 template class vector<int>;
 template class map<string, Function>;
 template class vector<bool>;
-template class Network::Connection<KeyStroke, KeyStroke>;
+