minix/commands/simple/ping.c

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2005-04-21 16:53:53 +02:00
/*
ping.c
*/
#define DEBUG 1
#include <sys/types.h>
#include <errno.h>
#include <signal.h>
#include <net/gen/netdb.h>
#include <sys/ioctl.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <net/gen/oneCsum.h>
#include <fcntl.h>
#include <net/gen/in.h>
#include <net/gen/inet.h>
#include <net/gen/ip_hdr.h>
#include <net/gen/icmp_hdr.h>
#include <net/gen/ip_io.h>
#define WRITE_SIZE 30
char buffer[16*1024];
int main(int argc, char *argv[]);
#if DEBUG
#define where() fprintf(stderr, "%s %d:", __FILE__, __LINE__);
#endif
#if __STDC__
#define PROTO(x,y) x y
#else
#define PROTO(x,y) X ()
#endif
PROTO (int main, (int argc, char *argv[]) );
static PROTO (void sig_hand, (int signal) );
main(argc, argv)
int argc;
char *argv[];
{
int fd, i;
int result, result1;
nwio_ipopt_t ipopt;
ip_hdr_t *ip_hdr;
int ihl;
icmp_hdr_t *icmp_hdr;
ipaddr_t dst_addr;
struct hostent *hostent;
int length;
if (argc<2 || argc>3)
{
fprintf(stderr, "Usage: %s hostname [length]\n", argv[0]);
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exit(1);
}
hostent= gethostbyname(argv[1]);
if (!hostent)
{
dst_addr= inet_addr(argv[1]);
if (dst_addr == -1)
{
fprintf(stderr, "%s: unknown host (%s)\n",
argv[0], argv[1]);
exit(1);
}
}
else
dst_addr= *(ipaddr_t *)(hostent->h_addr);
if (argc == 3)
{
length= strtol (argv[2], (char **)0, 0);
if (length< sizeof(icmp_hdr_t) + IP_MIN_HDR_SIZE)
{
fprintf(stderr, "%s: length too small (%s)\n",
argv[0], argv[2]);
exit(1);
}
}
else
length= WRITE_SIZE;
fd= open ("/dev/ip", O_RDWR);
if (fd<0)
perror("open"), exit(1);
ipopt.nwio_flags= NWIO_COPY | NWIO_PROTOSPEC;
ipopt.nwio_proto= 1;
result= ioctl (fd, NWIOSIPOPT, &ipopt);
if (result<0)
perror("ioctl (NWIOSIPOPT)"), exit(1);
result= ioctl (fd, NWIOGIPOPT, &ipopt);
if (result<0)
perror("ioctl (NWIOGIPOPT)"), exit(1);
for (i= 0; i< 20; i++)
{
ip_hdr= (ip_hdr_t *)buffer;
ip_hdr->ih_dst= dst_addr;
icmp_hdr= (icmp_hdr_t *)(buffer+20);
icmp_hdr->ih_type= 8;
icmp_hdr->ih_code= 0;
icmp_hdr->ih_chksum= 0;
icmp_hdr->ih_chksum= ~oneC_sum(0, (u16_t *)icmp_hdr,
WRITE_SIZE-20);
result= write(fd, buffer, length);
if (result<0)
{
perror("write");
exit(1);
}
if (result != length)
{
where();
fprintf(stderr, "result= %d\n", result);
exit(1);
}
alarm(0);
signal (SIGALRM, sig_hand);
alarm(1);
result= read(fd, buffer, sizeof(buffer));
if (result>= 0 || errno != EINTR)
break;
}
if (i >= 20)
{
printf("no answer from %s\n", argv[1]);
exit(1);
}
if (result<0)
{
perror ("read");
exit(1);
}
printf("%s is alive\n", argv[1]);
exit(0);
}
static void sig_hand(signal)
int signal;
{
}