src/plainPacket.cpp

   1 /*
   2  *  anytun
   3  *
   4  *  The secure anycast tunneling protocol (satp) defines a protocol used
   5  *  for communication between any combination of unicast and anycast
   6  *  tunnel endpoints.  It has less protocol overhead than IPSec in Tunnel
   7  *  mode and allows tunneling of every ETHER TYPE protocol (e.g.
   8  *  ethernet, ip, arp ...). satp directly includes cryptography and
   9  *  message authentication based on the methodes used by SRTP.  It is
  10  *  intended to deliver a generic, scaleable and secure solution for
  11  *  tunneling and relaying of packets of any protocol.
  12  *
  13  *
  14  *  Copyright (C) 2007-2008 Othmar Gsenger, Erwin Nindl,
  15  *                          Christian Pointner <satp@wirdorange.org>
  16  *
  17  *  This file is part of Anytun.
  18  *
  19  *  Anytun is free software: you can redistribute it and/or modify
  20  *  it under the terms of the GNU General Public License version 3 as
  21  *  published by the Free Software Foundation.
  22  *
  23  *  Anytun is distributed in the hope that it will be useful,
  24  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  25  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  26  *  GNU General Public License for more details.
  27  *
  28  *  You should have received a copy of the GNU General Public License
  29  *  along with anytun.  If not, see <http://www.gnu.org/licenses/>.
  30  */
  31
  32 #include <stdexcept>
  33 #include <iostream>
  34 #include "datatypes.h"
  35 #include "endian.h"
  36 #include "plainPacket.h"
  37
  38 PlainPacket::PlainPacket(u_int32_t payload_length, bool allow_realloc) : Buffer(payload_length + sizeof(payload_type_t), allow_realloc)
  39 {
  40   payload_type_ = reinterpret_cast<payload_type_t*>(buf_);
  41   payload_ = buf_ + sizeof(payload_type_t);
  42   *payload_type_ = 0;
  43 }
  44
  45 payload_type_t PlainPacket::getPayloadType() const
  46 {
  47   if(payload_type_)
  48     return PAYLOAD_TYPE_T_NTOH(*payload_type_);
  49
  50   return 0;
  51 }
  52
  53 void PlainPacket::setPayloadType(payload_type_t payload_type)
  54 {
  55   if(!payload_type_)
  56     return;
  57
  58   if(payload_type == PAYLOAD_TYPE_TUN) {
  59     if(!payload_) {
  60       *payload_type_ = PAYLOAD_TYPE_T_HTON(PAYLOAD_TYPE_TUN);
  61       return;
  62     }
  63
  64     char * ip_version_ptr = reinterpret_cast<char *>(payload_);
  65                 char ip_version = ip_version_ptr[0];
  66                 ip_version >>=4;
  67     if(ip_version == 4)
  68       *payload_type_ = PAYLOAD_TYPE_T_HTON(PAYLOAD_TYPE_TUN4);
  69     else if(ip_version == 6)
  70       *payload_type_ = PAYLOAD_TYPE_T_HTON(PAYLOAD_TYPE_TUN6);
  71   }
  72   else
  73     *payload_type_ = PAYLOAD_TYPE_T_HTON(payload_type);
  74 }
  75
  76 u_int32_t PlainPacket::getPayloadLength() const
  77 {
  78   if(!payload_)
  79     return 0;
  80
  81   return (length_ > sizeof(payload_type_t)) ? (length_ - sizeof(payload_type_t)) : 0;
  82 }
  83
  84 void PlainPacket::setPayloadLength(u_int32_t payload_length)
  85 {
  86   Buffer::setLength(payload_length + sizeof(payload_type_t));
  87       // depending on allow_realloc buf_ may point to another address
  88       // therefore in this case reinit() gets called by Buffer::setLength()
  89 }
  90
  91 void PlainPacket::reinit()
  92 {
  93   payload_type_ = reinterpret_cast<payload_type_t*>(buf_);
  94   payload_ = buf_ + sizeof(payload_type_t);
  95
  96   if(length_ <= (sizeof(payload_type_t)))
  97     payload_ = NULL;
  98
  99   if(length_ < (sizeof(payload_type_t))) {
 100     payload_type_ = NULL;
 101     throw std::runtime_error("packet can't be initialized, buffer is too small");
 102   }
 103
 104 }
 105
 106 u_int8_t* PlainPacket::getPayload()
 107 {
 108   return payload_;
 109 }
 110
 111 /*
 112 NetworkAddress PlainPacket::getSrcAddr() const
 113 {
 114   if(!payload_type_ || !payload_)
 115     return NetworkAddress();
 116
 117   payload_type_t type = PAYLOAD_TYPE_T_NTOH(*payload_type_);
 118
 119   if(type == PAYLOAD_TYPE_TAP) // Ehternet
 120   {
 121         // TODO
 122     return NetworkAddress();
 123   }
 124   else if(type == PAYLOAD_TYPE_TUN4) // IPv4
 125   {
 126     if(length_ < (sizeof(payload_type_t)+sizeof(struct ip)))
 127       return NetworkAddress();
 128     struct ip* hdr = reinterpret_cast<struct ip*>(payload_);
 129     return NetworkAddress(hdr->ip_src);
 130   }
 131   else if(type == PAYLOAD_TYPE_TUN6) // IPv6
 132   {
 133     if(length_ < (sizeof(payload_type_t)+sizeof(struct ip6_hdr)))
 134       return NetworkAddress();
 135     struct ip6_hdr* hdr = reinterpret_cast<struct ip6_hdr*>(payload_);
 136     return NetworkAddress(hdr->ip6_src);
 137   }
 138   return NetworkAddress();
 139 }*/
 140
 141 NetworkAddress PlainPacket::getDstAddr() const
 142 {
 143         if(!payload_type_ || !payload_)
 144                 return NetworkAddress();
 145
 146         payload_type_t type = PAYLOAD_TYPE_T_NTOH(*payload_type_);
 147
 148         if(type == PAYLOAD_TYPE_TAP) // Ehternet
 149         {
 150                 // TODO
 151                 return NetworkAddress();
 152         }
 153         else if(type == PAYLOAD_TYPE_TUN4) // IPv4
 154         {
 155                 if(length_ < (sizeof(payload_type_t)+5*4))
 156                         return NetworkAddress();
 157                 char * hdr = reinterpret_cast<char *>(payload_);
 158                 boost::asio::ip::address_v4::bytes_type ip_octets;
 159                 for (int i=0; i<4;i++)
 160                         ip_octets[i]=hdr[4*4+i];
 161                 return NetworkAddress(boost::asio::ip::address_v4(ip_octets));
 162         }
 163         else if(type == PAYLOAD_TYPE_TUN6) // IPv6
 164         {
 165                 if(length_ < (sizeof(payload_type_t)+2*16+2*4))
 166                         return NetworkAddress();
 167                 char * hdr = reinterpret_cast<char *>(payload_);
 168                 boost::asio::ip::address_v6::bytes_type ip_octets;
 169                 for (int i=0; i<16;i++)
 170                         ip_octets[i]=hdr[2*4+16+i];
 171                 return NetworkAddress(boost::asio::ip::address_v6(ip_octets));
 172         }
 173         return NetworkAddress();
 174 }