OSX/libsecurity_utilities/lib/socks++4.cpp

   1 /*
   2  * Copyright (c) 2000-2004,2011,2014 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24
  25 //
  26 // socks++int - internal Socks implementation
  27 //
  28 #include "socks++4.h"
  29 #include "hosts.h"
  30 #include <set>
  31
  32
  33 namespace Security {
  34 namespace IPPlusPlus {
  35 namespace Socks4 {
  36
  37
  38
  39 //
  40 // Socks4 Protocol implementation
  41 //
  42 void Server::connect(SocksClientSocket &me, const IPSockAddress &peer)
  43 {
  44     me.Socket::open(SOCK_STREAM);
  45     me.Socket::connect(mServerAddress);
  46     Message request(socksConnect, peer);
  47     request.send(me, "nobody");
  48     (Message(me));                              // read and check reply message
  49     me.mPeerAddress = peer;             // best guess, Mr. Sulu
  50     secdebug("socks", "%d socks4 connected to %s", me.fd(), string(peer).c_str());
  51 }
  52
  53 void Server::connect(SocksClientSocket &me, const Host &host, IPPort port)
  54 {
  55     // Socks4 has no name resolution support. Do it here
  56     //@@@ error reporting sucks here
  57     set<IPAddress> addrs = host.addresses();
  58     for (set<IPAddress>::const_iterator it = addrs.begin(); it != addrs.end(); it++) {
  59         try {
  60             IPSockAddress addr(*it, port);
  61             connect(me, addr);
  62             return;
  63         } catch (const UnixError &err) {
  64             errno = err.error;
  65         }
  66     }
  67     // exhausted
  68     UnixError::throwMe();
  69 }
  70
  71
  72 void Server::bind(SocksServerSocket &me, const IPAddress &peer, IPPort port)
  73 {
  74     me.Socket::open(SOCK_STREAM);
  75     me.Socket::connect(mServerAddress);
  76     Message request(socksBind, IPSockAddress(peer, port));
  77     request.send(me, "nobody");
  78     Message reply(me);
  79     me.mLocalAddress = reply.address().defaults(mServerAddress.address());
  80     secdebug("socks", "%d socks4 bound to %s", me.fd(), string(me.mLocalAddress).c_str());
  81 }
  82
  83 void Server::receive(SocksServerSocket &me, SocksClientSocket &receiver)
  84 {
  85     Message reply(me);
  86     receiver.setFd(me.fd(), me.mLocalAddress, reply.address());
  87     me.clear();                                 // clear our own (don't close on destruction)
  88     secdebug("socks", "%d socks4 inbound connect", receiver.fd());
  89 }
  90
  91
  92 //
  93 // Message properties
  94 //
  95 Message::Message(Command cmd, const IPSockAddress &address)
  96     : version(4), message(cmd), port(htons(address.port())), addr(address.address())
  97 {
  98 }
  99
 100
 101 void Message::send(Socket &s, const char *userid)
 102 {
 103     if (s.write(this, sizeof(*this)) != sizeof(*this))
 104         UnixError::throwMe();
 105     // now append zero-terminated userid (what a crock)
 106     size_t length = strlen(userid) + 1;
 107     if (s.write(userid, length) != length) {
 108         s.close();
 109         UnixError::throwMe();
 110     }
 111 }
 112
 113 Message::Message(Socket &s)
 114 {
 115     if (s.read(this, sizeof(*this)) != sizeof(*this)) {
 116         s.close();
 117         UnixError::throwMe();
 118     }
 119     if (version != 0) {
 120         s.close();
 121         UnixError::throwMe(EPROTONOSUPPORT);
 122     }
 123     switch (message) {
 124     case requestAccepted:
 125         return;
 126     default:
 127         UnixError::throwMe(ECONNREFUSED);       //@@@ hardly any diagnostics here
 128     }
 129 }
 130
 131
 132 }       // end namespace Socks
 133 }       // end namespace IPPlusPlus
 134 }       // end namespace Security