lokinet/llarp/ip.cpp
2018-08-23 13:48:41 -05:00

57 lines
1.0 KiB
C++

#include <llarp/endian.h>
#include <algorithm>
#include <llarp/ip.hpp>
#include "llarp/buffer.hpp"
#include "mem.hpp"
namespace llarp
{
namespace net
{
bool
IPv4Packet::Load(llarp_buffer_t pkt)
{
#ifndef MIN
#define MIN(a, b) (a < b ? a : b)
sz = MIN(pkt.sz, sizeof(buf));
#undef MIN
#endif
memcpy(buf, pkt.base, sz);
llarp::DumpBufferHex(pkt);
return true;
}
llarp_buffer_t
IPv4Packet::Buffer()
{
return llarp::InitBuffer(buf, sz);
}
void
IPv4Packet::UpdateChecksum()
{
auto hdr = Header();
hdr->check = 0;
size_t count = hdr->ihl;
uint32_t sum = 0;
byte_t *addr = buf;
while(count > 1)
{
sum += ntohs(*(uint16_t *)addr);
count -= sizeof(uint16_t);
addr += sizeof(uint16_t);
}
if(count > 0)
sum += *(byte_t *)addr;
while(sum >> 16)
sum = (sum & 0xffff) + (sum >> 16);
hdr->check = htons(~sum);
}
} // namespace net
} // namespace llarp