sys/src/ape/lib/bsd/inet_aton.c

   1 /* posix */
   2 #include <sys/types.h>
   3 #include <unistd.h>
   4 #include <stdlib.h>
   5 #include <string.h>
   6
   7 /* bsd extensions */
   8 #include <sys/uio.h>
   9 #include <sys/socket.h>
  10 #include <netinet/in.h>
  11
  12 #define CLASS(x)        (x[0]>>6)
  13
  14 int
  15 inet_aton(char *from, struct in_addr *in)
  16 {
  17         unsigned char *to;
  18         unsigned long x;
  19         char *p;
  20         int i;
  21
  22         in->s_addr = 0;
  23         to = (unsigned char*)&in->s_addr;
  24         if(*from == 0)
  25                 return 0;
  26         for(i = 0; i < 4 && *from; i++, from = p){
  27                 x = strtoul(from, &p, 0);
  28                 if(x != (unsigned char)x || p == from)
  29                         return 0;       /* parse error */
  30                 to[i] = x;
  31                 if(*p == '.')
  32                         p++;
  33                 else if(*p != 0)
  34                         return 0;       /* parse error */
  35         }
  36
  37         switch(CLASS(to)){
  38         case 0: /* class A - 1 byte net */
  39         case 1:
  40                 if(i == 3){
  41                         to[3] = to[2];
  42                         to[2] = to[1];
  43                         to[1] = 0;
  44                 } else if (i == 2){
  45                         to[3] = to[1];
  46                         to[1] = 0;
  47                 }
  48                 break;
  49         case 2: /* class B - 2 byte net */
  50                 if(i == 3){
  51                         to[3] = to[2];
  52                         to[2] = 0;
  53                 }
  54                 break;
  55         }
  56         return 1;
  57 }