resources/net/udp.cpp

   1 /* Based on RFC768 */
   2
   3 #include "udp.h"
   4 #include "ipv4.h"
   5 #include "arch/low/general.h"
   6
   7 #include "libs/array.h"
   8
   9 using namespace net;
  10
  11 void udp::send(ipv4_addr addr, u16 dst_port, u16 src_port, const buffer &data) {
  12         p<udp_packet> pkg = new udp_packet;
  13         pkg->sender_port = to_be16(src_port);
  14         pkg->receiver_port = to_be16(dst_port);
  15         pkg->length = to_be16(data.get_size() + sizeof(udp_packet));
  16         pkg->checksum = 0;
  17
  18         p<pseudo_header> ph = new pseudo_header;
  19         ph->source = down.cast<ipv4>()->get_my_ip().to_be();
  20         ph->destination = addr.to_be();
  21         ph->zero = 0;
  22         ph->protocol = 17;
  23         ph->length = to_be16(sizeof(udp_packet) + data.get_size());
  24         array<u16> ph_words = array<u16>::from_buffer(buffer::to_mem(ph));
  25
  26         buffer buf = buffer::to_mem(pkg);
  27         buf += data;
  28
  29         array<u16> words = array<u16>::from_buffer(buf);
  30         u32 sum = 0;
  31
  32         for (unsigned int i = 0; i < (sizeof(udp_packet) + data.get_size()) / 2; i++)
  33                 sum += words[i];
  34
  35         if (data.get_size() % 2)
  36                 sum += (u16)data[data.get_size() - 1];
  37
  38         for (unsigned int i = 0; i < sizeof(pseudo_header) / 2; i++)
  39                 sum += ph_words[i];
  40
  41 //      ph.dispose();
  42
  43         sum = (sum & 0xffff) + (sum >> 16);
  44         sum += (sum >> 16);
  45
  46         buf.cast<udp_packet>()->checksum = to_le16(~sum);
  47
  48         down->send_data(addr, 17, buf);
  49
  50 //      pkg.dispose();
  51 }
  52
  53 void udp::receive(const ipv4_addr &sender, const buffer &data) {
  54         p<udp_packet> pkg = data.cast<udp_packet>();
  55
  56         for (int i = 0; i < ports.get_count(); i++)
  57                 if (ports[i] == from_be16(pkg->receiver_port))
  58                         listeners[i](sender, from_be16(pkg->sender_port), data.cut_first(sizeof(udp_packet)));
  59 }
  60
  61 void udp::listen(u16 port, delegate<void, const ipv4_addr &, u16, const buffer &> listener) {
  62 asm("cli\nhlt"::"a"(0xb0000f));
  63         for (int i = 0; i < ports.get_count();) {
  64                 if (ports[i] == port) {
  65                         ports.remove(i);
  66                         listeners.remove(i);
  67                 } else
  68                         i++;
  69         }
  70
  71         ports.add(port);
  72         listeners.add(listener);
  73 }