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// Copyright (c) 2015 Intel Research and Development Ireland Ltd.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <pcap.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netinet/if_ether.h>
static int expected_tos = -1;
static int cmatch = 0;
/* 4 bytes IP address */
typedef struct ip_address
{
u_char byte1;
u_char byte2;
u_char byte3;
u_char byte4;
} ip_address;
/* IPv4 header */
typedef struct ip_header
{
u_char ver_ihl;
u_char tos;
u_short tlen;
u_short identification;
u_short flags_fo;
u_char ttl;
u_char proto;
u_short crc;
ip_address saddr;
ip_address daddr;
u_int op_pad;
} ip_header;
/* UDP header*/
typedef struct udp_header
{
u_short sport; // Source port
u_short dport; // Destination port
u_short len; // Datagram length
u_short crc; // Checksum
} udp_header;
/* Save results on file */
void save_and_exit(int sig)
{
write_file();
exit(0);
}
/*
* This callback function is called for each received packet
*/
void stats_collection(u_char *useless,
const struct pcap_pkthdr* pkthdr,
const u_char* packet)
{
ip_header *ih;
udp_header *uh;
u_int ip_len;
ih = (ip_header *) (packet + 14);
ip_len = (ih->ver_ihl & 0xf) * 4;
u_char tos = ih->tos;
// Counter update
if(tos==expected_tos)
cmatch ++;
}
int main(int argc,char **argv)
{
int i;
char *dev;
char errbuf[PCAP_ERRBUF_SIZE];
pcap_t* descr;
const u_char *packet;
struct pcap_pkthdr hdr;
struct ether_header *eptr;
if(argc != 3)
{
fprintf(stdout,"Usage: %s interface_name expected_tos\n", argv[0]);
exit(1);
}
expected_tos = atoi(argv[2]);
/* Setup signal to stop the sniffer */
signal(SIGTERM, save_and_exit);
/* Take a device to read from */
dev = argv[1];
if(dev == NULL)
{
printf("%s\n",errbuf);
exit(1);
}
/* Open device for reading */
descr = pcap_open_live(dev, BUFSIZ, 0, -1, errbuf);
if(descr == NULL)
{
printf("pcap_open_live(): %s\n", errbuf);
exit(1);
}
/* Start the loop to be run for each packet */
pcap_loop(descr, -1, stats_collection, NULL);
return 0;
}
int write_file()
{
FILE *f = fopen("/tmp/apexlake/results/packet_checker.res", "w");
if (f == NULL)
{
printf("Error opening file!\n");
exit(1);
}
fprintf(f, "%d\n", cmatch);
fclose(f);
}
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