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/* See LICENSE file for copyright and license details. */
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/ip_icmp.h>
#include <netdb.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <signal.h>
#include <time.h>
#include "util.h"
static volatile int terminate = 0;
static void
usage(void)
{
eprintf("usage: %s <destination>\n", argv0);
}
static void
terminateHandler(int sig)
{
terminate = 1;
}
/* as per RFC 1035 section 2.3.4 it is reasonable to assume host names
* are not longer than 255 characters */
#define FQDN_LEN 255
#define PING_PACKET_SIZE 64
struct ping_packet {
struct icmphdr header;
char msg[PING_PACKET_SIZE-sizeof(struct icmphdr)];
};
/* see Stevens Unix Networking Programming Vol. 1, p. 672 */
static
unsigned short checksum(void *b, int buflen)
{
unsigned short *buf = b;
unsigned int sum = 0;
unsigned short result = 0;
for (sum = 0; buflen > 1; buflen -= 2) {
sum += *buf++;
}
if (buflen == 1) {
sum += *(unsigned char*)buf;
}
sum = (sum >> 16) + (sum & 0xFFFF);
sum += (sum >>16);
result = ~sum;
return result;
}
int
main(int argc, char *argv[])
{
struct addrinfo hints;
char *host;
struct addrinfo *addresses, *address;
struct sockaddr *ping_address;
struct sockaddr_in sending_address;
int res, fd;
struct timespec time_start, time_end;
ARGBEGIN {
default:
usage();
} ARGEND
if (argc != 1) {
weprintf("Expecting exactly one 'destination' to ping\n");
usage();
}
host = argv[0];
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_INET; /* IPv4 for now only */
hints.ai_socktype = SOCK_RAW;
hints.ai_flags = AI_CANONNAME;
hints.ai_protocol = IPPROTO_ICMP;
hints.ai_canonname = NULL;
hints.ai_addr = NULL;
hints.ai_next = NULL;
if ((res=getaddrinfo(host, NULL, &hints, &addresses)) != 0) {
weprintf("error calling getaddrinfo for '%s': %s\n", host, gai_strerror(res));
return 1;
}
char ip_addr[INET_ADDRSTRLEN];
char canon_host[FQDN_LEN];
ping_address = NULL;
for (address = addresses; address != NULL; address = address->ai_next) {
struct sockaddr_in* addr = (struct sockaddr_in*)address->ai_addr;
inet_ntop(AF_INET, &addr->sin_addr, ip_addr, INET_ADDRSTRLEN);
strncpy(canon_host, address->ai_canonname, sizeof(canon_host));
fd = socket(address->ai_family, address->ai_socktype, address->ai_protocol);
if (fd == -1) {
if (errno == EPERM) {
weprintf("Permission denied, are you root?\n");
continue;
}
weprintf("socket failed: %s\n", strerror(errno));
continue;
} else {
ping_address = address->ai_addr;
}
break;
}
if (ping_address == NULL) {
return 1;
}
signal(SIGINT, terminateHandler);
printf("PING %s (%s)\n", canon_host, ip_addr);
int ttl_val = 255;
if (setsockopt(fd, SOL_IP, IP_TTL, &ttl_val, sizeof(ttl_val)) < 0) {
freeaddrinfo(addresses);
close(fd);
eprintf("Unable to set TTL on socket: %s\n", host, strerror(errno));
}
struct timeval tv_out;
tv_out.tv_sec = 1;
tv_out.tv_usec = 0;
if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, (const char*)&tv_out, sizeof(tv_out)) < 0) {
freeaddrinfo(addresses);
close(fd);
eprintf("Unable to set receive time on socket: %s\n", host, strerror(errno));
}
int counter = 0;
int sent = 0;
int received = 0;
while (!terminate) {
struct ping_packet packet;
memset(&packet, 0, sizeof(packet));
packet.header.type = ICMP_ECHO;
packet.header.code = 0; /* ECHO */
packet.header.un.echo.id = getpid();
packet.header.un.echo.sequence = counter;
for (int i = 0; i < sizeof(packet.msg)-1; i++) {
packet.msg[i] = counter+i;
}
packet.header.checksum = 0; /* set to 0 for checksum computation */
packet.header.checksum = checksum(&packet, sizeof(packet));
counter++;
sleep(1);
if (terminate) {
continue;
}
clock_gettime(CLOCK_MONOTONIC, &time_start);
if (sendto(fd, &packet, sizeof(packet), 0, ping_address, sizeof(*ping_address)) < 0) {
weprintf("Unable to send packet to '%s': %s\n", host, strerror(errno));
sent = 0;
} else {
sent = 1;
}
unsigned int address_len = sizeof(sending_address);
if (recvfrom(fd, &packet, sizeof(packet), 0, (struct sockaddr *)&sending_address, &address_len) <= 0) {
if (errno == EAGAIN || errno == EINTR) {
// ok, not reachable or interrupted by Ctrl-C
} else {
freeaddrinfo(addresses);
close(fd);
eprintf("Unable to receive packet from '%s': %s\n", host, strerror(errno));
}
} else {
if (sent) {
if (packet.header.type != 69 || packet.header.code != 0) {
freeaddrinfo(addresses);
close(fd);
eprintf("Received unknown ICMP package with code=%d and type=%d from '%s'",
packet.header.code, packet.header.type, host);
} else {
inet_ntop(AF_INET, &sending_address.sin_addr, ip_addr, INET_ADDRSTRLEN);
clock_gettime(CLOCK_MONOTONIC, &time_end);
double timeElapsed = ((double)(time_end.tv_nsec - time_start.tv_nsec)) / 1000000.0;
long double rtt_msec = (time_end.tv_sec - time_start.tv_sec) * 1000.0 + timeElapsed;
printf("%ld bytes from %s (%s): icmp_seq=%d ttl=%d time=%0.3Lf ms\n",
sizeof(packet), host, ip_addr, counter, ttl_val, rtt_msec);
received++;
}
}
}
}
printf("--- %s ping statistics ---\n"
"%d packets transmitted, %d received , %0.0f%% packet loss\n",
canon_host, counter, received,
((counter - received)/counter) * 100.0);
freeaddrinfo(addresses);
close(fd);
return 0;
}
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