release/src/router/iproute2/lib/dnet_ntop.c

   1 #include <errno.h>
   2 #include <sys/types.h>
   3 #include <netinet/in.h>
   4
   5 #include "utils.h"
   6
   7 static __inline__ u_int16_t dn_ntohs(u_int16_t addr)
   8 {
   9         union {
  10                 u_int8_t byte[2];
  11                 u_int16_t word;
  12         } u;
  13
  14         u.word = addr;
  15         return ((u_int16_t)u.byte[0]) | (((u_int16_t)u.byte[1]) << 8);
  16 }
  17
  18 static __inline__ int do_digit(char *str, u_int16_t *addr, u_int16_t scale, size_t *pos, size_t len, int *started)
  19 {
  20         u_int16_t tmp = *addr / scale;
  21
  22         if (*pos == len)
  23                 return 1;
  24
  25         if (((tmp) > 0) || *started || (scale == 1)) {
  26                 *str = tmp + '0';
  27                 *started = 1;
  28                 (*pos)++;
  29                 *addr -= (tmp * scale);
  30         }
  31
  32         return 0;
  33 }
  34
  35
  36 static const char *dnet_ntop1(const struct dn_naddr *dna, char *str, size_t len)
  37 {
  38         u_int16_t addr = dn_ntohs(*(u_int16_t *)dna->a_addr);
  39         u_int16_t area = addr >> 10;
  40         size_t pos = 0;
  41         int started = 0;
  42
  43         if (dna->a_len != 2)
  44                 return NULL;
  45
  46         addr &= 0x03ff;
  47
  48         if (len == 0)
  49                 return str;
  50
  51         if (do_digit(str + pos, &area, 10, &pos, len, &started))
  52                 return str;
  53
  54         if (do_digit(str + pos, &area, 1, &pos, len, &started))
  55                 return str;
  56
  57         if (pos == len)
  58                 return str;
  59
  60         *(str + pos) = '.';
  61         pos++;
  62         started = 0;
  63
  64         if (do_digit(str + pos, &addr, 1000, &pos, len, &started))
  65                 return str;
  66
  67         if (do_digit(str + pos, &addr, 100, &pos, len, &started))
  68                 return str;
  69
  70         if (do_digit(str + pos, &addr, 10, &pos, len, &started))
  71                 return str;
  72
  73         if (do_digit(str + pos, &addr, 1, &pos, len, &started))
  74                 return str;
  75
  76         if (pos == len)
  77                 return str;
  78
  79         *(str + pos) = 0;
  80
  81         return str;
  82 }
  83
  84
  85 const char *dnet_ntop(int af, const void *addr, char *str, size_t len)
  86 {
  87         switch(af) {
  88                 case AF_DECnet:
  89                         errno = 0;
  90                         return dnet_ntop1((struct dn_naddr *)addr, str, len);
  91                 default:
  92                         errno = EAFNOSUPPORT;
  93         }
  94
  95         return NULL;
  96 }
  97
  98