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Code Issues Releases Wiki Activity

Fix overall checksum calculation

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This commit is contained in:
Matias Fontanini
2015-12-29 09:57:42 -03:00
parent afe778d03c
commit 67d31fd62c
7 changed files with 148 additions and 72 deletions
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45
src/utils.cpp
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@@ -56,9 +56,11 @@
#include "network_interface.h"
#include "packet_sender.h"
#include "cxxstd.h"
#include "memory_helpers.h"
using namespace std;
using Tins::Memory::OutputMemoryStream;
/** \cond */
struct InterfaceCollector {
@@ -248,33 +250,34 @@ uint16_t sum_range(const uint8_t *start, const uint8_t *end) {
return checksum;
}
uint32_t pseudoheader_checksum(IPv4Address source_ip, IPv4Address dest_ip, uint32_t len, uint32_t flag) {
template <size_t buffer_size, typename AddressType>
uint32_t generic_pseudoheader_checksum(const AddressType& source_ip, const AddressType& dest_ip,
uint16_t len, uint16_t flag) {
uint32_t checksum(0);
uint32_t source_ip_int = Endian::host_to_be<uint32_t>(source_ip),
dest_ip_int = Endian::host_to_be<uint32_t>(dest_ip);
char buffer[sizeof(uint32_t) * 2];
uint8_t buffer[buffer_size];
OutputMemoryStream stream(buffer, sizeof(buffer));
stream.write(source_ip);
stream.write(dest_ip);
stream.write(Endian::host_to_be(flag));
stream.write(Endian::host_to_be(len));
uint16_t *ptr = (uint16_t*)buffer, *end = (uint16_t*)(buffer + sizeof(buffer));
std::memcpy(buffer, &source_ip_int, sizeof(source_ip_int));
std::memcpy(buffer + sizeof(uint32_t), &dest_ip_int, sizeof(dest_ip_int));
while(ptr < end)
checksum += (uint32_t)*ptr++;
checksum += flag + len;
while (ptr < end) {
checksum += *ptr++;
}
return checksum;
}
uint32_t pseudoheader_checksum(IPv6Address source_ip, IPv6Address dest_ip, uint32_t len, uint32_t flag) {
uint32_t checksum(0);
uint16_t *ptr = (uint16_t*) source_ip.begin();
uint16_t *end = (uint16_t*) source_ip.end();
while(ptr < end)
checksum += (uint32_t) Endian::be_to_host(*ptr++);
uint32_t pseudoheader_checksum(IPv4Address source_ip, IPv4Address dest_ip, uint16_t len, uint16_t flag) {
return generic_pseudoheader_checksum<sizeof(uint32_t) * 3>(
source_ip, dest_ip, len, flag
);
}
ptr = (uint16_t*) dest_ip.begin();
end = (uint16_t*) dest_ip.end();
while(ptr < end)
checksum += (uint32_t) Endian::be_to_host(*ptr++);
checksum += flag + len;
return checksum;
uint32_t pseudoheader_checksum(IPv6Address source_ip, IPv6Address dest_ip, uint16_t len, uint16_t flag) {
return generic_pseudoheader_checksum<IPv6Address::address_size * 2 + sizeof(uint16_t) * 2>(
source_ip, dest_ip, len, flag
);
}
uint32_t crc32(const uint8_t* data, uint32_t data_size) {