Wiesner András
8676a392e5
- TCPWindow added - Checksum bug fixed (again) - CBD introduced - ConnBlock modified - PackSieve report funtionality modified to decrease memory consumption
55 lines
2.0 KiB
C
55 lines
2.0 KiB
C
#include <stdbool.h>
|
|
#include "udp_packet.h"
|
|
#include "../../utils.h"
|
|
#include "ipv4_packet.h"
|
|
#include "ethernet_frame.h"
|
|
|
|
#include "tcp_udp_common.h"
|
|
|
|
#define ETH_UDP_HEADER_SIZE (8)
|
|
|
|
static bool check_udp_validity(const uint8_t * hdr, const PcktHeaderElement *pcktHdrLe) {
|
|
const UdpProps *udpProps = HEADER_FETCH_PROPS(UdpProps, pcktHdrLe);
|
|
const IPv4Props *ipProps = (IPv4Props *) &pcktHdrLe->prev->props;
|
|
IPv4PseudoHeader ph = {ipProps->SourceIPAddr, ipProps->DestIPAddr, 0, ETH_UDP_PACKET_CLASS, htons(udpProps->Length)};
|
|
uint16_t chkSum = ~tcp_udp_checksum(&ph, hdr, udpProps->Length);
|
|
bool valid = chkSum == 0;
|
|
return valid;
|
|
}
|
|
|
|
int parse_udp(const uint8_t *hdr, uint32_t size, PcktHeaderElement *pcktHdrLe, struct EthInterface_ *intf) {
|
|
const uint8_t * hdrBegin = hdr;
|
|
UdpProps *udpProps = HEADER_FETCH_PROPS(UdpProps, pcktHdrLe);
|
|
FETCH_WORD_H2N_ADVANCE(&udpProps->SourcePort, hdr);
|
|
FETCH_WORD_H2N_ADVANCE(&udpProps->DestinationPort, hdr);
|
|
FETCH_WORD_H2N_ADVANCE(&udpProps->Length, hdr);
|
|
FETCH_WORD_H2N_ADVANCE(&udpProps->Checksum, hdr);
|
|
|
|
// common fields...
|
|
udpProps->headerSize = ETH_UDP_HEADER_SIZE;
|
|
udpProps->validityOK = check_udp_validity(hdrBegin, pcktHdrLe);
|
|
udpProps->containedPacketClass = 0;
|
|
|
|
return udpProps->validityOK ? 0 : -1;
|
|
}
|
|
|
|
void insert_udp_header(uint8_t *hdr, const PcktHeaderElement *headers) {
|
|
uint8_t *hdrBegin = hdr;
|
|
UdpProps *udpProps = (UdpProps *) &headers->props;
|
|
FILL_WORD_H2N_ADVANCE(hdr, udpProps->SourcePort);
|
|
FILL_WORD_H2N_ADVANCE(hdr, udpProps->DestinationPort);
|
|
FILL_WORD_H2N_ADVANCE(hdr, udpProps->Length);
|
|
uint8_t *ChkSumPtr = hdr;
|
|
udpProps->Checksum = 0;
|
|
FILL_WORD_H2N_ADVANCE(hdr, udpProps->Checksum);
|
|
|
|
// calculate checksum
|
|
const IPv4Props *ipProps = (IPv4Props *) &headers->prev->props;
|
|
IPv4PseudoHeader ph = {ipProps->SourceIPAddr, ipProps->DestIPAddr, 0, ETH_UDP_PACKET_CLASS, htons(udpProps->Length)};
|
|
udpProps->Checksum = tcp_udp_checksum(&ph, hdrBegin, udpProps->Length);
|
|
memcpy(ChkSumPtr, &udpProps->Checksum, 2);
|
|
}
|
|
|
|
|
|
|