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       1                 :            : /*
       2                 :            : ** Copyright (C) 2023 Sylvain Fargier
       3                 :            : **
       4                 :            : ** This software is provided 'as-is', without any express or implied
       5                 :            : ** warranty.  In no event will the authors be held liable for any damages
       6                 :            : ** arising from the use of this software.
       7                 :            : **
       8                 :            : ** Permission is granted to anyone to use this software for any purpose,
       9                 :            : ** including commercial applications, and to alter it and redistribute it
      10                 :            : ** freely, subject to the following restrictions:
      11                 :            : **
      12                 :            : ** 1. The origin of this software must not be misrepresented; you must not
      13                 :            : **    claim that you wrote the original software. If you use this software
      14                 :            : **    in a product, an acknowledgment in the product documentation would be
      15                 :            : **    appreciated but is not required.
      16                 :            : ** 2. Altered source versions must be plainly marked as such, and must not be
      17                 :            : **    misrepresented as being the original software.
      18                 :            : ** 3. This notice may not be removed or altered from any source distribution.
      19                 :            : **
      20                 :            : ** Created on: 2023-12-21T22:20:54
      21                 :            : ** Author: Sylvain Fargier <fargier.sylvain@gmail.com>
      22                 :            : */
      23                 :            : 
      24                 :            : #include "RawIPSocket.hpp"
      25                 :            : 
      26                 :            : #include <netinet/in.h>
      27                 :            : #include <sys/socket.h>
      28                 :            : 
      29                 :            : #include "../../Exception.hpp"
      30                 :            : #include "RawIPMessage.hpp"
      31                 :            : 
      32                 :            : namespace ccut {
      33                 :            : namespace net {
      34                 :            : 
      35                 :            : static const std::string s_logCat{"ccut:net:raw"};
      36                 :            : 
      37                 :          1 : RawIPv4Socket::RawIPv4Socket(Protocol proto, const std::string &name) :
      38                 :            :     Socket(name),
      39                 :          1 :     m_proto(proto)
      40                 :          1 : {}
      41                 :            : 
      42                 :          1 : int RawIPv4Socket::makeSocket(bool ipv6)
      43                 :            : {
      44                 :          1 :     if (ipv6)
      45                 :          0 :         throw Exception(ErrorCode::Runtime,
      46                 :          0 :                         "can't bind a v4 socket using bind6");
      47                 :            : 
      48                 :          1 :     int ret = socket(AF_INET, SOCK_RAW, enum_cast(m_proto));
      49                 :          1 :     if (ret >= 0)
      50                 :            :     {
      51                 :          0 :         int value = 1;
      52                 :          0 :         setsockopt(ret, IPPROTO_IP, IP_HDRINCL, &value, sizeof(value));
      53                 :            :     }
      54                 :          1 :     else if (errno == EPERM)
      55                 :            :     {
      56                 :          1 :         logger::error(s_logCat) << "failed to open RAW socket";
      57                 :          2 :         logger::info(s_logCat) << "try `setcap cap_net_raw=ep <exe>` on "
      58                 :          1 :                                   "run this process as root";
      59                 :            :     }
      60                 :            : 
      61                 :          1 :     return ret;
      62                 :            : }
      63                 :            : 
      64                 :          0 : RawIPv4Socket::Message RawIPv4Socket::processMessage(
      65                 :            :     const address_t &from,
      66                 :            :     const address_t &to,
      67                 :            :     const cow_ptr<buffer_t> &buffer)
      68                 :            : {
      69                 :          0 :     logger::debug(s_logCat) << "(raw) message received " << from << " -> " << to
      70                 :          0 :                             << " size:" << (buffer ? buffer->size() : -1);
      71                 :          0 :     return Message(from, to, buffer);
      72                 :            : }
      73                 :            : 
      74                 :          1 : RawIPv6Socket::RawIPv6Socket(Protocol proto, const std::string &name) :
      75                 :            :     Socket(name),
      76                 :          1 :     m_proto(proto)
      77                 :          1 : {}
      78                 :            : 
      79                 :          1 : int RawIPv6Socket::makeSocket(bool ipv6)
      80                 :            : {
      81                 :          1 :     if (!ipv6)
      82                 :          0 :         throw Exception(ErrorCode::Runtime,
      83                 :          0 :                         "can't bind a v6 socket using bind4");
      84                 :            : 
      85                 :            : #ifndef IPV6_HDRINCL
      86                 :            :         /* see
      87                 :            :          * https://github.com/torvalds/linux/commit/715f504b118998c41a2079a17e16bf5a8a114885
      88                 :            :          * for details
      89                 :            :          */
      90                 :            : #ifndef STATIC_ANALYSIS
      91                 :            : #warning RawIPv6Socket not supported, kernel too old
      92                 :            : #endif
      93                 :            : 
      94                 :            :     throw Exception(ErrorCode::NotSupported,
      95                 :            :                     "Raw IPv6 not supported, kernel headers must be >=4.5");
      96                 :            : 
      97                 :            : #else
      98                 :          1 :     int ret = socket(AF_INET6, SOCK_RAW, enum_cast(m_proto));
      99                 :          1 :     if (ret >= 0)
     100                 :            :     {
     101                 :          0 :         int value = 1;
     102                 :          0 :         setsockopt(ret, IPPROTO_IPV6, IPV6_HDRINCL, &value, sizeof(value));
     103                 :            :     }
     104                 :          1 :     else if (errno == EPERM)
     105                 :            :     {
     106                 :          1 :         logger::error(s_logCat) << "failed to open RAW socket";
     107                 :          2 :         logger::info(s_logCat) << "try `setcap cap_net_raw=ep <exe>` on "
     108                 :          1 :                                   "run this process as root";
     109                 :            :     }
     110                 :            : 
     111                 :          1 :     return ret;
     112                 :            : #endif
     113                 :            : }
     114                 :            : 
     115                 :          0 : RawIPv6Socket::Message RawIPv6Socket::processMessage(
     116                 :            :     const address_t &from,
     117                 :            :     const address_t &to,
     118                 :            :     const cow_ptr<buffer_t> &buffer)
     119                 :            : {
     120                 :          0 :     logger::debug(s_logCat) << "(raw) message received " << from << " -> " << to
     121                 :          0 :                             << " size:" << (buffer ? buffer->size() : -1);
     122                 :            :     /* even with IPV6_HDRINCL it seems that header is not present when receiving
     123                 :            :      * packets, let's reconstruct (until a better solution is found)
     124                 :            :      * FIXME: one should use recvmsg to better reconstruct this (adding hoplimit
     125                 :            :      * and other fields) */
     126                 :          0 :     Message ret(from, to);
     127                 :          0 :     ret.data = make_cow<buffer_t>(RawIPv6Message::MinDataSize + buffer->size());
     128                 :          0 :     ret.setNextHeader(m_proto);
     129                 :          0 :     std::copy(buffer->cbegin(), buffer->cend(),
     130                 :          0 :               ret.data.data() + RawIPv6Message::MinDataSize);
     131                 :          0 :     ret.prepare();
     132                 :          0 :     return ret;
     133                 :          0 : }
     134                 :            : 
     135                 :            : } // namespace net
     136                 :            : } // namespace ccut