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 anytun.org <satp@wirdorange.org>
  15  *
  16  *  This program is free software; you can redistribute it and/or modify
  17  *  it under the terms of the GNU General Public License version 2
  18  *  as published by the Free Software Foundation.
  19  *
  20  *  This program is distributed in the hope that it will be useful,
  21  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  *  GNU General Public License for more details.
  24  *
  25  *  You should have received a copy of the GNU General Public License
  26  *  along with this program (see the file COPYING included with this
  27  *  distribution); if not, write to the Free Software Foundation, Inc.,
  28  *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  29  */
  30
  31 #include <stdexcept>
  32 #include <iostream>
  33 #include <arpa/inet.h>
  34 #include <net/ethernet.h>
  35 #include <netinet/ip.h>
  36 #include <netinet/ip6.h>
  37
  38 #include "datatypes.h"
  39 #include "plainPacket.h"
  40
  41 PlainPacket::PlainPacket(u_int32_t payload_length, bool allow_realloc) : Buffer(payload_length + sizeof(payload_type_t), allow_realloc)
  42 {
  43   payload_type_ = reinterpret_cast<payload_type_t*>(buf_);
  44   payload_ = buf_ + sizeof(payload_type_t);
  45   *payload_type_ = 0;
  46 }
  47
  48 payload_type_t PlainPacket::getPayloadType() const
  49 {
  50   if(payload_type_)
  51     return PAYLOAD_TYPE_T_NTOH(*payload_type_);
  52
  53   return 0;
  54 }
  55
  56 void PlainPacket::setPayloadType(payload_type_t payload_type)
  57 {
  58   if(payload_type_)
  59     *payload_type_ = PAYLOAD_TYPE_T_HTON(payload_type);
  60 }
  61
  62 u_int32_t PlainPacket::getPayloadLength() const
  63 {
  64   if(!payload_)
  65     return 0;
  66
  67   return (length_ > sizeof(payload_type_t)) ? (length_ - sizeof(payload_type_t)) : 0;
  68 }
  69
  70 void PlainPacket::setPayloadLength(u_int32_t payload_length)
  71 {
  72   Buffer::setLength(payload_length + sizeof(payload_type_t));
  73       // depending on allow_realloc buf_ may point to another address
  74       // therefore in this case reinit() gets called by Buffer::setLength()
  75 }
  76
  77 void PlainPacket::reinit()
  78 {
  79   payload_type_ = reinterpret_cast<payload_type_t*>(buf_);
  80   payload_ = buf_ + sizeof(payload_type_t);
  81
  82   if(length_ <= (sizeof(payload_type_t)))
  83     payload_ = NULL;
  84
  85   if(length_ < (sizeof(payload_type_t))) {
  86     payload_type_ = NULL;
  87     throw std::runtime_error("packet can't be initialized, buffer is too small");
  88   }
  89
  90 }
  91
  92 u_int8_t* PlainPacket::getPayload()
  93 {
  94   return payload_;
  95 }
  96
  97 NetworkAddress PlainPacket::getSrcAddr() const
  98 {
  99   if(!payload_type_ || !payload_)
 100     return NetworkAddress();
 101
 102   payload_type_t type = PAYLOAD_TYPE_T_NTOH(*payload_type_);
 103
 104   if(type == PAYLOAD_TYPE_TAP) // Ehternet
 105   {
 106         // TODO
 107     return NetworkAddress();
 108   }
 109   else if(type == PAYLOAD_TYPE_TUN) // IPv4
 110   {
 111     if(length_ < (sizeof(payload_type_t)+sizeof(struct ip)))
 112       return NetworkAddress();
 113     struct ip* hdr = reinterpret_cast<struct ip*>(payload_);
 114     return NetworkAddress(hdr->ip_src);
 115   }
 116   else if(type == PAYLOAD_TYPE_TUN6) // IPv6
 117   {
 118     if(length_ < (sizeof(payload_type_t)+sizeof(struct ip6_hdr)))
 119       return NetworkAddress();
 120     struct ip6_hdr* hdr = reinterpret_cast<struct ip6_hdr*>(payload_);
 121     return NetworkAddress(hdr->ip6_src);
 122   }
 123   return NetworkAddress();
 124 }
 125
 126 NetworkAddress PlainPacket::getDstAddr() const
 127 {
 128   if(!payload_type_ || !payload_)
 129     return NetworkAddress();
 130
 131   payload_type_t type = PAYLOAD_TYPE_T_NTOH(*payload_type_);
 132
 133   if(type == PAYLOAD_TYPE_TAP) // Ehternet
 134   {
 135         // TODO
 136     return NetworkAddress();
 137   }
 138   else if(type == PAYLOAD_TYPE_TUN) // IPv4
 139   {
 140     if(length_ < (sizeof(payload_type_t)+sizeof(struct ip)))
 141       return NetworkAddress();
 142     struct ip* hdr = reinterpret_cast<struct ip*>(payload_);
 143     return NetworkAddress(hdr->ip_dst);
 144   }
 145   else if(type == PAYLOAD_TYPE_TUN6) // IPv6
 146   {
 147     if(length_ < (sizeof(payload_type_t)+sizeof(struct ip6_hdr)))
 148       return NetworkAddress();
 149     struct ip6_hdr* hdr = reinterpret_cast<struct ip6_hdr*>(payload_);
 150     return NetworkAddress(hdr->ip6_dst);
 151   }
 152   return NetworkAddress();
 153 }