nsz Git - musl/blob - src/network/inet_ntop.c

   1 #include <sys/socket.h>
   2 #include <netinet/in.h>
   3 #include <arpa/inet.h>
   4 #include <netdb.h>
   5 #include <errno.h>
   6 #include <stdio.h>
   7 #include <string.h>
   8
   9 const char *inet_ntop(int af, const void *a0, char *s, socklen_t l)
  10 {
  11         const unsigned char *a = a0;
  12         int i, j, max, best;
  13         char buf[100];
  14
  15         switch (af) {
  16         case AF_INET:
  17                 if (snprintf(s, l, "%d.%d.%d.%d", a[0],a[1],a[2],a[3]) < l)
  18                         return s;
  19                 break;
  20         case AF_INET6:
  21                 memset(buf, 'x', sizeof buf);
  22                 buf[sizeof buf-1]=0;
  23                 snprintf(buf, sizeof buf,
  24                         "%.0x%x:%.0x%x:%.0x%x:%.0x%x:%.0x%x:%.0x%x:%.0x%x:%.0x%x",
  25                         a[0],a[1],a[2],a[3],a[4],a[5],a[6],a[7],
  26                         a[8],a[9],a[10],a[11],a[12],a[13],a[14],a[15]);
  27                 /* Replace longest /(^0|:)[:0]{2,}/ with "::" */
  28                 for (i=best=0, max=2; buf[i]; i++) {
  29                         if (i && buf[i] != ':') continue;
  30                         j = strspn(buf+i, ":0");
  31                         if (j>max) best=i, max=j;
  32                 }
  33                 if (max>2) {
  34                         buf[best] = buf[best+1] = ':';
  35                         strcpy(buf+best+2, buf+best+max);
  36                 }
  37                 if (strlen(buf) < l) {
  38                         strcpy(s, buf);
  39                         return s;
  40                 }
  41                 break;
  42         default:
  43                 errno = EAFNOSUPPORT;
  44                 return 0;
  45         }
  46         errno = ENOSPC;
  47         return 0;
  48 }