resources/arp.cpp

   1 #include "arp.h"
   2 #include "mac_addr.h"
   3
   4 using namespace resources;
   5
   6 mac_addr arp::get_haddr(ipv4_addr ipaddr) {
   7         p<arp_table::arp_record> rec = table.get(ipaddr);
   8         if (rec.valid())
   9                 return rec->haddr;
  10
  11         p<arp_packet> pkg = new arp_packet;
  12
  13         pkg->htype = to_be16(ethernet);
  14         pkg->ptype = to_be16(ipv4);
  15
  16         pkg->hlen = sizeof(mac_addr);
  17         pkg->plen = sizeof(ipv4_addr);
  18
  19         pkg->oper = to_be16(request);
  20
  21         pkg->sha0 = my_haddr.first_be32();
  22         pkg->sha1 = my_haddr.last_be16();
  23         pkg->spa = to_be32(my_paddr);
  24
  25         pkg->tha0 = 0;
  26         pkg->tha1 = 0;
  27         pkg->tpa = to_be32(ipaddr);
  28
  29         mac_addr broadcast = mac_addr::from_be(0xffffffff, 0xffff);
  30         network->send_data(broadcast, et_arp, buffer::to_mem(pkg));
  31
  32         rec = 0;//p<arp_table::arp_record>::invalid;
  33         do {
  34                 while (!received) __asm__("hlt");
  35                 received = false;
  36
  37                 rec = table.get(ipaddr);
  38         } while (!rec.valid());
  39
  40         return rec->haddr;
  41 }
  42
  43
  44 void arp::receive_packet(p<arp_packet> pkg) {
  45         if (from_be16(pkg->oper) == request) {
  46                 if (from_be32(pkg->tpa) != my_paddr)
  47                         return;
  48
  49                 mac_addr mac = mac_addr::from_be(pkg->sha0, pkg->sha1);
  50
  51                 p<arp_packet> rpl = new arp_packet;
  52
  53                 rpl->htype = pkg->htype;
  54                 rpl->ptype = pkg->ptype;
  55
  56                 rpl->hlen = pkg->hlen;
  57                 rpl->plen = pkg->plen;
  58
  59                 rpl->oper = to_be16(reply);
  60
  61                 rpl->sha0 = my_haddr.first_be32();
  62                 rpl->sha1 = my_haddr.last_be16();
  63                 rpl->spa = to_be32(my_paddr);
  64
  65                 rpl->tha0 = mac.first_be16();
  66                 rpl->tha1 = mac.last_be32();
  67                 rpl->tpa = pkg->spa;
  68
  69                 network->send_data(mac, et_arp, buffer::to_mem(rpl));
  70
  71         } else if (from_be16(pkg->oper) == reply) {
  72                 p<arp_table::arp_record> rec = new arp_table::arp_record;
  73                 rec->prot = from_be16(pkg->ptype);
  74                 rec->paddr = from_be32(pkg->spa);
  75                 rec->haddr = mac_addr::from_be(pkg->sha0, pkg->sha1);
  76
  77                 table.add(rec);
  78                 received = true;
  79         }
  80 }
  81
  82
  83 void arp::receive_data(const buffer &x) {
  84         if ((unsigned int)x.get_size() >= sizeof(arp_packet))
  85                 receive_packet(x.cast<arp_packet>());
  86 }