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     return;
  60
  61   if(payload_type == PAYLOAD_TYPE_TUN) {
  62     if(!payload_) {
  63       *payload_type_ = PAYLOAD_TYPE_T_HTON(0);
  64       return;
  65     }
  66
  67     struct ip* hdr = reinterpret_cast<struct ip*>(payload_);
  68     if(hdr->ip_v == 4)
  69       *payload_type_ = PAYLOAD_TYPE_T_HTON(PAYLOAD_TYPE_TUN4);
  70     else if(hdr->ip_v == 6)
  71       *payload_type_ = PAYLOAD_TYPE_T_HTON(PAYLOAD_TYPE_TUN6);
  72   }
  73   else
  74     *payload_type_ = PAYLOAD_TYPE_T_HTON(payload_type);
  75 }
  76
  77 u_int32_t PlainPacket::getPayloadLength() const
  78 {
  79   if(!payload_)
  80     return 0;
  81
  82   return (length_ > sizeof(payload_type_t)) ? (length_ - sizeof(payload_type_t)) : 0;
  83 }
  84
  85 void PlainPacket::setPayloadLength(u_int32_t payload_length)
  86 {
  87   Buffer::setLength(payload_length + sizeof(payload_type_t));
  88       // depending on allow_realloc buf_ may point to another address
  89       // therefore in this case reinit() gets called by Buffer::setLength()
  90 }
  91
  92 void PlainPacket::reinit()
  93 {
  94   payload_type_ = reinterpret_cast<payload_type_t*>(buf_);
  95   payload_ = buf_ + sizeof(payload_type_t);
  96
  97   if(length_ <= (sizeof(payload_type_t)))
  98     payload_ = NULL;
  99
 100   if(length_ < (sizeof(payload_type_t))) {
 101     payload_type_ = NULL;
 102     throw std::runtime_error("packet can't be initialized, buffer is too small");
 103   }
 104
 105 }
 106
 107 u_int8_t* PlainPacket::getPayload()
 108 {
 109   return payload_;
 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)+sizeof(struct ip)))
 156       return NetworkAddress();
 157     struct ip* hdr = reinterpret_cast<struct ip*>(payload_);
 158     return NetworkAddress(hdr->ip_dst);
 159   }
 160   else if(type == PAYLOAD_TYPE_TUN6) // IPv6
 161   {
 162     if(length_ < (sizeof(payload_type_t)+sizeof(struct ip6_hdr)))
 163       return NetworkAddress();
 164     struct ip6_hdr* hdr = reinterpret_cast<struct ip6_hdr*>(payload_);
 165     return NetworkAddress(hdr->ip6_dst);
 166   }
 167   return NetworkAddress();
 168 }