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Added RawPDU class. Removed payload member from TCP and UDP. They're not represented by RawPDUs.

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This commit is contained in:
Matias
2011-08-13 17:22:01 -03:00
parent 398ba31111
commit 759139da3f
6 changed files with 161 additions and 36 deletions
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39
src/udp.cpp
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@@ -1,3 +1,24 @@
/*
* 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
*/
#ifndef WIN32
#include <netinet/in.h>
#endif
@@ -6,8 +27,9 @@
#include "utils.h"
#include "udp.h"
#include "ip.h"
#include "rawpdu.h"
Tins::UDP::UDP(uint16_t sport, uint16_t dport) : PDU(IPPROTO_UDP), _payload(0), _payload_size(0) {
Tins::UDP::UDP(uint16_t sport, uint16_t dport) : PDU(IPPROTO_UDP) {
_udp.sport = sport;
_udp.dport = dport;
_udp.check = 0;
@@ -15,9 +37,8 @@ Tins::UDP::UDP(uint16_t sport, uint16_t dport) : PDU(IPPROTO_UDP), _payload(0),
}
void Tins::UDP::payload(uint8_t *new_payload, uint32_t new_payload_size) {
_payload = new_payload;
_payload_size = new_payload_size;
_udp.len = Utils::net_to_host_s(sizeof(udphdr) + _payload_size);
inner_pdu(new RawPDU(new_payload, new_payload_size));
_udp.len = Utils::net_to_host_s(sizeof(udphdr) + new_payload_size);
}
void Tins::UDP::dport(uint16_t new_dport) {
@@ -29,21 +50,19 @@ void Tins::UDP::sport(uint16_t new_sport) {
}
uint32_t Tins::UDP::header_size() const {
/* Round? */
return sizeof(udphdr) + _payload_size;
return sizeof(udphdr);
}
void Tins::UDP::write_serialization(uint8_t *buffer, uint32_t total_sz, const PDU *parent) {
assert(total_sz >= sizeof(udphdr) + _payload_size);
assert(total_sz >= sizeof(udphdr));
const IP *ip_packet = dynamic_cast<const IP*>(parent);
if(!_udp.check && ip_packet) {
uint32_t checksum = PDU::pseudoheader_checksum(ip_packet->source_address(), ip_packet->dest_address(), header_size(), IPPROTO_UDP) +
PDU::do_checksum(_payload, _payload + _payload_size) + PDU::do_checksum((uint8_t*)&_udp, ((uint8_t*)&_udp) + sizeof(udphdr));
uint32_t checksum = PDU::pseudoheader_checksum(ip_packet->source_address(), ip_packet->dest_address(), size(), IPPROTO_UDP) +
PDU::do_checksum(buffer + sizeof(udphdr), buffer + total_sz) + PDU::do_checksum((uint8_t*)&_udp, ((uint8_t*)&_udp) + sizeof(udphdr));
while (checksum >> 16)
checksum = (checksum & 0xffff)+(checksum >> 16);
_udp.check = Utils::net_to_host_s(~checksum);
}
std::memcpy(buffer, &_udp, sizeof(udphdr));
std::memcpy(buffer + sizeof(udphdr), _payload, _payload_size);
}