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   return (length_ > sizeof(payload_type_t)) ? (length_ - sizeof(payload_type_t)) : 0;
  65 }
  66
  67 void PlainPacket::setPayloadLength(u_int32_t payload_length)
  68 {
  69   Buffer::setLength(payload_length + sizeof(payload_type_t));
  70       // depending on allow_realloc buf_ may point to another address
  71       // therefore in this case reinit() gets called by Buffer::setLength()
  72 }
  73
  74 void PlainPacket::reinit()
  75 {
  76   Buffer::reinit();
  77   payload_type_ = reinterpret_cast<payload_type_t*>(buf_);
  78   payload_ = buf_ + sizeof(payload_type_t);
  79 }
  80
  81 u_int8_t* PlainPacket::getPayload()
  82 {
  83   return payload_;
  84 }
  85
  86
  87 NetworkAddress PlainPacket::getSrcAddr() const
  88 {
  89   if(!payload_type_ || !payload_)
  90     return NetworkAddress();
  91
  92   payload_type_t type = PAYLOAD_TYPE_T_NTOH(*payload_type_);
  93
  94   if(type == PAYLOAD_TYPE_TAP) // Ehternet
  95   {
  96         // TODO
  97     return NetworkAddress();
  98   }
  99   else if(type == PAYLOAD_TYPE_TUN) // IPv4
 100   {
 101     if(length_ < (sizeof(payload_type_t)+sizeof(struct ip)))
 102       return NetworkAddress();
 103     struct ip* hdr = reinterpret_cast<struct ip*>(payload_);
 104     return NetworkAddress(hdr->ip_src);
 105   }
 106   else if(type == PAYLOAD_TYPE_TUN6) // IPv6
 107   {
 108     if(length_ < (sizeof(payload_type_t)+sizeof(struct ip6_hdr)))
 109       return NetworkAddress();
 110     struct ip6_hdr* hdr = reinterpret_cast<struct ip6_hdr*>(payload_);
 111     return NetworkAddress(hdr->ip6_dst);
 112   }
 113   return NetworkAddress();
 114 }
 115
 116
 117 NetworkAddress PlainPacket::getDstAddr() const
 118 {
 119   if(!payload_type_ || !payload_)
 120     return NetworkAddress();
 121
 122   payload_type_t type = PAYLOAD_TYPE_T_NTOH(*payload_type_);
 123
 124   if(type == PAYLOAD_TYPE_TAP) // Ehternet
 125   {
 126         // TODO
 127     return NetworkAddress();
 128   }
 129   else if(type == PAYLOAD_TYPE_TUN) // IPv4
 130   {
 131     if(length_ < (sizeof(payload_type_t)+sizeof(struct ip)))
 132       return NetworkAddress();
 133     struct ip* hdr = reinterpret_cast<struct ip*>(payload_);
 134     return NetworkAddress(hdr->ip_dst);
 135   }
 136   else if(type == PAYLOAD_TYPE_TUN6) // IPv6
 137   {
 138     if(length_ < (sizeof(payload_type_t)+sizeof(struct ip6_hdr)))
 139       return NetworkAddress();
 140     struct ip6_hdr* hdr = reinterpret_cast<struct ip6_hdr*>(payload_);
 141     return NetworkAddress(hdr->ip6_dst);
 142   }
 143   return NetworkAddress();
 144 }