mirror of
https://github.com/mfontanini/libtins
synced 2026-01-24 11:11:35 +01:00
101 lines
3.2 KiB
C++
101 lines
3.2 KiB
C++
/*
|
|
* libtins is a net packet wrapper library for crafting and
|
|
* interpreting sniffed packets.
|
|
*
|
|
* Copyright (C) 2011 Nasel
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* This library is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with this library; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
#include <stdexcept>
|
|
#include <cassert>
|
|
#include <cstring>
|
|
#include "udp.h"
|
|
#include "constants.h"
|
|
#include "ip.h"
|
|
#include "rawpdu.h"
|
|
|
|
Tins::UDP::UDP(uint16_t dport, uint16_t sport, PDU *child) : PDU(Constants::IP::PROTO_TCP, child) {
|
|
this->dport(dport);
|
|
this->sport(sport);
|
|
_udp.check = 0;
|
|
_udp.len = 0;
|
|
}
|
|
|
|
Tins::UDP::UDP(const uint8_t *buffer, uint32_t total_sz) : PDU(Constants::IP::PROTO_TCP) {
|
|
if(total_sz < sizeof(udphdr))
|
|
throw std::runtime_error("Not enough size for an UDP header in the buffer.");
|
|
std::memcpy(&_udp, buffer, sizeof(udphdr));
|
|
total_sz -= sizeof(udphdr);
|
|
if(total_sz)
|
|
inner_pdu(new RawPDU(buffer + sizeof(udphdr), total_sz));
|
|
}
|
|
|
|
Tins::UDP::UDP(const UDP &other) : PDU(other) {
|
|
copy_fields(&other);
|
|
}
|
|
|
|
Tins::UDP &Tins::UDP::operator= (const UDP& other) {
|
|
copy_fields(&other);
|
|
copy_inner_pdu(other);
|
|
return *this;
|
|
}
|
|
|
|
void Tins::UDP::payload(uint8_t *new_payload, uint32_t new_payload_size) {
|
|
inner_pdu(new RawPDU(new_payload, new_payload_size));
|
|
}
|
|
|
|
void Tins::UDP::dport(uint16_t new_dport) {
|
|
_udp.dport = Utils::net_to_host_s(new_dport);
|
|
}
|
|
|
|
void Tins::UDP::sport(uint16_t new_sport) {
|
|
_udp.sport = Utils::net_to_host_s(new_sport);
|
|
}
|
|
|
|
void Tins::UDP::length(uint16_t new_len) {
|
|
_udp.len = Utils::net_to_host_s(new_len);
|
|
}
|
|
|
|
uint32_t Tins::UDP::header_size() const {
|
|
return sizeof(udphdr);
|
|
}
|
|
|
|
void Tins::UDP::write_serialization(uint8_t *buffer, uint32_t total_sz, const PDU *parent) {
|
|
assert(total_sz >= sizeof(udphdr));
|
|
const Tins::IP *ip_packet = dynamic_cast<const Tins::IP*>(parent);
|
|
if(inner_pdu())
|
|
length(sizeof(udphdr) + inner_pdu()->size());
|
|
std::memcpy(buffer, &_udp, sizeof(udphdr));
|
|
if(!_udp.check && ip_packet) {
|
|
uint32_t checksum = Utils::pseudoheader_checksum(ip_packet->src_addr(), ip_packet->dst_addr(), size(), Constants::IP::PROTO_TCP) +
|
|
Utils::do_checksum(buffer, buffer + total_sz);
|
|
while (checksum >> 16)
|
|
checksum = (checksum & 0xffff)+(checksum >> 16);
|
|
((udphdr*)buffer)->check = Utils::net_to_host_s(~checksum);
|
|
}
|
|
_udp.check = 0;
|
|
}
|
|
|
|
void Tins::UDP::copy_fields(const UDP *other) {
|
|
std::memcpy(&_udp, &other->_udp, sizeof(_udp));
|
|
}
|
|
|
|
Tins::PDU *Tins::UDP::clone_pdu() const {
|
|
UDP *new_pdu = new UDP();
|
|
new_pdu->copy_fields(this);
|
|
return new_pdu;
|
|
}
|