resources/net/ipv4.cpp

   1 #include "ipv4.h"
   2
   3 #include "manes/error.h"
   4 #include "libs/array.h"
   5
   6 using namespace net;
   7
   8 void ipv4::set_link_layer(p<link_layer> x) {
   9         arp_prot.set_link_layer(x);
  10
  11         down = x;
  12         x->add_handler(0x800, delegate<void, const buffer&>::method(this, &ipv4::receive_data));
  13 }
  14
  15 void ipv4::send_data(const ipv4_addr &addr, int prot, const buffer &x) {
  16         assert("ipv4: packet cannot be smaller than 20 bytes", x.get_size() < 20);
  17
  18         p<ipv4_packet> pkg = new ipv4_packet;
  19         pkg->version_size = 0x45;
  20         pkg->service = 0;
  21         pkg->length = to_be16(x.get_size() + 28);
  22         pkg->id = 0;
  23         pkg->flags_offset = to_le16(0x40);
  24         pkg->ttl = 64;
  25         pkg->prot = prot;
  26         pkg->checksum = 0;
  27         pkg->src = my_ip.to_be();
  28         pkg->dst = addr.to_be();
  29
  30         array<u16> words = array<u16>::from_buffer(buffer::to_mem(pkg));
  31         u32 sum = 0;
  32
  33         for (unsigned int i = 0; i < sizeof(ipv4_packet)/2; i++)
  34                 sum += words[i];
  35
  36         sum = (sum & 0xffff) + (sum >> 16);
  37         sum += (sum >> 16);
  38
  39         pkg->checksum = to_le16(~sum);
  40
  41         buffer buf = buffer::to_mem(pkg);
  42
  43         buf += x;
  44
  45         mac_addr haddr;
  46         if (addr.network(mask) == my_ip.network(mask))
  47                 haddr = arp_prot.get_haddr(addr);
  48         else
  49                 haddr = arp_prot.get_haddr(gateway);
  50
  51         down->send_data(haddr, 0x800, buf);
  52
  53         pkg.dispose();
  54 }
  55
  56 void ipv4::receive_data(const buffer &data) {
  57         p<ipv4_packet> pkg = data.cast<ipv4_packet>();
  58
  59         for (int i = 0; i < protocols.get_count(); i++)
  60                 if (protocols[i] == pkg->prot)
  61                         listeners[i](ipv4_addr::from_be(pkg->src), data.cut_first(sizeof(ipv4_packet)));
  62
  63 }