mirror of
https://github.com/mfontanini/libtins
synced 2026-01-23 02:35:57 +01:00
96 lines
2.8 KiB
C++
96 lines
2.8 KiB
C++
/*
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* libtins is a net packet wrapper library for crafting and
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* interpreting sniffed packets.
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*
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* Copyright (C) 2011 Nasel
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <cassert>
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#include "utils.h"
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#include "pdu.h"
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Tins::PDU::PDU(uint32_t flag, PDU *next_pdu) : _flag(flag), _inner_pdu(next_pdu) {
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}
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Tins::PDU::~PDU() {
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delete _inner_pdu;
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}
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uint32_t Tins::PDU::size() const {
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uint32_t sz = header_size() + trailer_size();
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const PDU *ptr(_inner_pdu);
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while(ptr) {
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sz += ptr->header_size() + trailer_size();
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ptr = ptr->inner_pdu();
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}
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return sz;
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}
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void Tins::PDU::flag(uint32_t new_flag) {
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_flag = new_flag;
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}
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void Tins::PDU::inner_pdu(PDU *next_pdu) {
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delete _inner_pdu;
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_inner_pdu = next_pdu;
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}
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uint8_t *Tins::PDU::serialize(uint32_t &sz) {
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sz = size();
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uint8_t *buffer = new uint8_t[sz];
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serialize(buffer, sz, 0);
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return buffer;
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}
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void Tins::PDU::serialize(uint8_t *buffer, uint32_t total_sz, const PDU *parent) {
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uint32_t sz = header_size() + trailer_size();
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/* Must not happen... */
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assert(total_sz >= sz);
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if(_inner_pdu)
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_inner_pdu->serialize(buffer + header_size(), total_sz - sz, this);
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write_serialization(buffer, total_sz, parent);
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}
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/* Static methods */
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uint32_t Tins::PDU::do_checksum(uint8_t *start, uint8_t *end) {
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uint32_t checksum(0);
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uint16_t *ptr = (uint16_t*)start, *last = (uint16_t*)end, padding(0);
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if(((end - start) & 1) == 1) {
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last = (uint16_t*)end - 1;
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padding = *(end - 1) << 8;
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}
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while(ptr < last)
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checksum += Utils::net_to_host_s(*(ptr++));
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return checksum + padding;
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}
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uint32_t Tins::PDU::pseudoheader_checksum(uint32_t source_ip, uint32_t dest_ip, uint32_t len, uint32_t flag) {
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uint32_t checksum(0);
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source_ip = Utils::net_to_host_l(source_ip);
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dest_ip = Utils::net_to_host_l(dest_ip);
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uint16_t *ptr = (uint16_t*)&source_ip;
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checksum += (uint32_t)(*ptr) + (uint32_t)(*(ptr+1));
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ptr = (uint16_t*)&dest_ip;
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checksum += (uint32_t)(*ptr) + (uint32_t)(*(ptr+1));
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checksum += flag + len;
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return checksum;
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}
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