contrib/ntp/libntp/decodenetnum.c

   1 /*
   2  * decodenetnum - return a net number (this is crude, but careful)
   3  */
   4 #include <sys/types.h>
   5 #include <ctype.h>
   6 #include <sys/socket.h>
   7 #include <netinet/in.h>
   8
   9 #include "ntp_stdlib.h"
  10
  11 int
  12 decodenetnum(
  13         const char *num,
  14         u_int32 *netnum
  15         )
  16 {
  17         register const char *cp;
  18         register char *bp;
  19         register int i;
  20         register int temp;
  21         register int eos;
  22         char buf[80];           /* will core dump on really stupid stuff */
  23
  24         cp = num;
  25         *netnum = 0;
  26
  27         if (*cp == '[') {
  28                 eos = ']';
  29                 cp++;
  30         } else {
  31                 eos = '\0';
  32         }
  33
  34         for (i = 0; i < 4; i++) {
  35                 bp = buf;
  36                 while (isdigit((int)*cp))
  37                     *bp++ = *cp++;
  38                 if (bp == buf)
  39                     break;
  40
  41                 if (i < 3) {
  42                         if (*cp++ != '.')
  43                             break;
  44                 } else if (*cp != eos)
  45                     break;
  46
  47                 *bp = '\0';
  48                 temp = atoi(buf);
  49                 if (temp > 255)
  50                     break;
  51                 *netnum <<= 8;
  52                 *netnum += temp;
  53         }
  54
  55         if (i < 4)
  56             return 0;
  57         *netnum = htonl(*netnum);
  58         return 1;
  59 }