commands/ping/ping.c

   1 /*
   2 ping.c
   3 */
   4
   5 #define DEBUG   1
   6
   7 #include <sys/types.h>
   8 #include <errno.h>
   9 #include <signal.h>
  10 #include <net/gen/netdb.h>
  11 #include <sys/ioctl.h>
  12 #include <stdlib.h>
  13 #include <stdio.h>
  14 #include <unistd.h>
  15 #include <net/gen/oneCsum.h>
  16 #include <fcntl.h>
  17 #include <net/gen/in.h>
  18 #include <net/gen/inet.h>
  19 #include <net/gen/ip_hdr.h>
  20 #include <net/gen/icmp_hdr.h>
  21 #include <net/gen/ip_io.h>
  22
  23 #define WRITE_SIZE 30
  24 char buffer[16*1024];
  25
  26 int main(int argc, char *argv[]);
  27
  28 #if DEBUG
  29 #define where() fprintf(stderr, "%s %d:", __FILE__, __LINE__);
  30 #endif
  31
  32 #if __STDC__
  33 #define PROTO(x,y) x y
  34 #else
  35 #define PROTO(x,y) X ()
  36 #endif
  37
  38 PROTO (int main, (int argc, char *argv[]) );
  39 static PROTO (void sig_hand, (int signal) );
  40
  41 main(argc, argv)
  42 int argc;
  43 char *argv[];
  44 {
  45         int fd, i;
  46         int result, result1;
  47         nwio_ipopt_t ipopt;
  48         ip_hdr_t *ip_hdr;
  49         int ihl;
  50         icmp_hdr_t *icmp_hdr;
  51         ipaddr_t dst_addr;
  52         struct hostent *hostent;
  53         int length;
  54
  55         if (argc<2 || argc>3)
  56         {
  57                 fprintf(stderr, "Usage: %s hostname [length]\n", argv[0]);
  58                 exit(1);
  59         }
  60         hostent= gethostbyname(argv[1]);
  61         if (!hostent)
  62         {
  63                 dst_addr= inet_addr(argv[1]);
  64                 if (dst_addr == -1)
  65                 {
  66                         fprintf(stderr, "%s: unknown host (%s)\n",
  67                                 argv[0], argv[1]);
  68                         exit(1);
  69                 }
  70         }
  71         else
  72                 dst_addr= *(ipaddr_t *)(hostent->h_addr);
  73         if (argc == 3)
  74         {
  75                 length= strtol (argv[2], (char **)0, 0);
  76                 if (length< sizeof(icmp_hdr_t) + IP_MIN_HDR_SIZE)
  77                 {
  78                         fprintf(stderr, "%s: length too small (%s)\n",
  79                                 argv[0], argv[2]);
  80                         exit(1);
  81                 }
  82         }
  83         else
  84                 length= WRITE_SIZE;
  85
  86         fd= open ("/dev/ip", O_RDWR);
  87         if (fd<0)
  88                 perror("open"), exit(1);
  89
  90         ipopt.nwio_flags= NWIO_COPY | NWIO_PROTOSPEC;
  91         ipopt.nwio_proto= 1;
  92
  93         result= ioctl (fd, NWIOSIPOPT, &ipopt);
  94         if (result<0)
  95                 perror("ioctl (NWIOSIPOPT)"), exit(1);
  96
  97         result= ioctl (fd, NWIOGIPOPT, &ipopt);
  98         if (result<0)
  99                 perror("ioctl (NWIOGIPOPT)"), exit(1);
 100
 101         for (i= 0; i< 20; i++)
 102         {
 103                 ip_hdr= (ip_hdr_t *)buffer;
 104                 ip_hdr->ih_dst= dst_addr;
 105
 106                 icmp_hdr= (icmp_hdr_t *)(buffer+20);
 107                 icmp_hdr->ih_type= 8;
 108                 icmp_hdr->ih_code= 0;
 109                 icmp_hdr->ih_chksum= 0;
 110                 icmp_hdr->ih_chksum= ~oneC_sum(0, (u16_t *)icmp_hdr,
 111                         WRITE_SIZE-20);
 112                 result= write(fd, buffer, length);
 113                 if (result<0)
 114                 {
 115                         perror("write");
 116                         exit(1);
 117                 }
 118                 if (result != length)
 119                 {
 120                         where();
 121                         fprintf(stderr, "result= %d\n", result);
 122                         exit(1);
 123                 }
 124
 125                 alarm(0);
 126                 signal (SIGALRM, sig_hand);
 127                 alarm(1);
 128
 129                 result= read(fd, buffer, sizeof(buffer));
 130                 if (result>= 0 || errno != EINTR)
 131                         break;
 132         }
 133         if (i >= 20)
 134         {
 135                 printf("no answer from %s\n", argv[1]);
 136                 exit(1);
 137         }
 138         if (result<0)
 139         {
 140                 perror ("read");
 141                 exit(1);
 142         }
 143         printf("%s is alive\n", argv[1]);
 144         exit(0);
 145 }
 146
 147 static void sig_hand(signal)
 148 int signal;
 149 {
 150 }