resources/net/icmp.cpp

   1 #include "icmp.h"
   2
   3 #include "ipv4_packet.h"
   4
   5 #include "libs/array.h"
   6
   7 using namespace net;
   8
   9 void icmp::ping(const ipv4_addr &addr) {
  10         p<icmp_packet> pkg = new icmp_packet;
  11         pkg->type = 8;
  12         pkg->code = 0;
  13         pkg->checksum = 0;
  14         pkg->id = to_be16(0xfeed);
  15         pkg->sequence = to_be16(1);
  16
  17         array<u8> data(36 - sizeof(icmp_packet));
  18         for (unsigned int i = 0; i < 36 - sizeof(icmp_packet); i++)
  19                 data[i] = '0' + i;
  20
  21         buffer buf = buffer::to_mem(pkg);
  22         buf += data.to_buffer();
  23
  24         array<u16> words = array<u16>::from_buffer(buf);
  25         u32 sum = 0;
  26         for (int i = 0; i < words.length(); i++)
  27                 sum += words[i];
  28
  29         sum = (sum & 0xffff) + (sum >> 16);
  30         sum += (sum >> 16);
  31
  32         buf.cast<icmp_packet>()->checksum = to_le16(~sum);
  33
  34         down->send_data(addr, ipv4_packet::p_icmp, buf);
  35
  36         pkg.dispose();
  37 }
  38
  39 void icmp::receive(const ipv4_addr &addr, const buffer &data) {
  40         p<icmp_packet> request = data.cast<icmp_packet>();
  41
  42         if (request->type != 8 || request->code != 0)
  43                 return;
  44
  45         p<icmp_packet> pkg = new icmp_packet;
  46         pkg->type = 0;
  47         pkg->code = 0;
  48         pkg->checksum = 0;
  49         pkg->id = request->id;
  50         pkg->sequence = request->sequence;
  51
  52         buffer buf = buffer::to_mem(pkg);
  53         buf += data.cut_first(sizeof(icmp_packet));
  54
  55         array<u16> words = array<u16>::from_buffer(buf);
  56         u32 sum = 0;
  57         for (int i = 0; i < words.length(); i++)
  58                 sum += words[i];
  59
  60         sum = (sum & 0xffff) + (sum >> 16);
  61         sum += (sum >> 16);
  62
  63         buf.cast<icmp_packet>()->checksum = to_le16(~sum);
  64
  65         down->send_data(addr, ipv4_packet::p_icmp, buf);
  66
  67         request.dispose();
  68 }