File:  [ELWIX - Embedded LightWeight unIX -] / embedaddon / curl / lib / inet_ntop.c
Revision 1.1.1.1 (vendor branch): download - view: text, annotated - select for diffs - revision graph
Wed Jun 3 10:01:15 2020 UTC (5 years ago) by misho
Branches: curl, MAIN
CVS tags: v7_70_0p4, HEAD
curl

    1: /*
    2:  * Copyright (C) 1996-2019  Internet Software Consortium.
    3:  *
    4:  * Permission to use, copy, modify, and distribute this software for any
    5:  * purpose with or without fee is hereby granted, provided that the above
    6:  * copyright notice and this permission notice appear in all copies.
    7:  *
    8:  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
    9:  * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
   10:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
   11:  * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
   12:  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
   13:  * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
   14:  * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
   15:  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
   16:  */
   17: /*
   18:  * Original code by Paul Vixie. "curlified" by Gisle Vanem.
   19:  */
   20: 
   21: #include "curl_setup.h"
   22: 
   23: #ifndef HAVE_INET_NTOP
   24: 
   25: #ifdef HAVE_SYS_PARAM_H
   26: #include <sys/param.h>
   27: #endif
   28: #ifdef HAVE_NETINET_IN_H
   29: #include <netinet/in.h>
   30: #endif
   31: #ifdef HAVE_ARPA_INET_H
   32: #include <arpa/inet.h>
   33: #endif
   34: 
   35: #include "inet_ntop.h"
   36: #include "curl_printf.h"
   37: 
   38: #define IN6ADDRSZ       16
   39: #define INADDRSZ         4
   40: #define INT16SZ          2
   41: 
   42: /*
   43:  * Format an IPv4 address, more or less like inet_ntoa().
   44:  *
   45:  * Returns `dst' (as a const)
   46:  * Note:
   47:  *  - uses no statics
   48:  *  - takes a unsigned char* not an in_addr as input
   49:  */
   50: static char *inet_ntop4 (const unsigned char *src, char *dst, size_t size)
   51: {
   52:   char tmp[sizeof("255.255.255.255")];
   53:   size_t len;
   54: 
   55:   DEBUGASSERT(size >= 16);
   56: 
   57:   tmp[0] = '\0';
   58:   (void)msnprintf(tmp, sizeof(tmp), "%d.%d.%d.%d",
   59:                   ((int)((unsigned char)src[0])) & 0xff,
   60:                   ((int)((unsigned char)src[1])) & 0xff,
   61:                   ((int)((unsigned char)src[2])) & 0xff,
   62:                   ((int)((unsigned char)src[3])) & 0xff);
   63: 
   64:   len = strlen(tmp);
   65:   if(len == 0 || len >= size) {
   66:     errno = ENOSPC;
   67:     return (NULL);
   68:   }
   69:   strcpy(dst, tmp);
   70:   return dst;
   71: }
   72: 
   73: #ifdef ENABLE_IPV6
   74: /*
   75:  * Convert IPv6 binary address into presentation (printable) format.
   76:  */
   77: static char *inet_ntop6 (const unsigned char *src, char *dst, size_t size)
   78: {
   79:   /*
   80:    * Note that int32_t and int16_t need only be "at least" large enough
   81:    * to contain a value of the specified size.  On some systems, like
   82:    * Crays, there is no such thing as an integer variable with 16 bits.
   83:    * Keep this in mind if you think this function should have been coded
   84:    * to use pointer overlays.  All the world's not a VAX.
   85:    */
   86:   char tmp[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")];
   87:   char *tp;
   88:   struct {
   89:     long base;
   90:     long len;
   91:   } best, cur;
   92:   unsigned long words[IN6ADDRSZ / INT16SZ];
   93:   int i;
   94: 
   95:   /* Preprocess:
   96:    *  Copy the input (bytewise) array into a wordwise array.
   97:    *  Find the longest run of 0x00's in src[] for :: shorthanding.
   98:    */
   99:   memset(words, '\0', sizeof(words));
  100:   for(i = 0; i < IN6ADDRSZ; i++)
  101:     words[i/2] |= (src[i] << ((1 - (i % 2)) << 3));
  102: 
  103:   best.base = -1;
  104:   cur.base  = -1;
  105:   best.len = 0;
  106:   cur.len = 0;
  107: 
  108:   for(i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
  109:     if(words[i] == 0) {
  110:       if(cur.base == -1)
  111:         cur.base = i, cur.len = 1;
  112:       else
  113:         cur.len++;
  114:     }
  115:     else if(cur.base != -1) {
  116:       if(best.base == -1 || cur.len > best.len)
  117:         best = cur;
  118:       cur.base = -1;
  119:     }
  120:   }
  121:   if((cur.base != -1) && (best.base == -1 || cur.len > best.len))
  122:     best = cur;
  123:   if(best.base != -1 && best.len < 2)
  124:     best.base = -1;
  125:   /* Format the result. */
  126:   tp = tmp;
  127:   for(i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
  128:     /* Are we inside the best run of 0x00's? */
  129:     if(best.base != -1 && i >= best.base && i < (best.base + best.len)) {
  130:       if(i == best.base)
  131:         *tp++ = ':';
  132:       continue;
  133:     }
  134: 
  135:     /* Are we following an initial run of 0x00s or any real hex?
  136:      */
  137:     if(i != 0)
  138:       *tp++ = ':';
  139: 
  140:     /* Is this address an encapsulated IPv4?
  141:      */
  142:     if(i == 6 && best.base == 0 &&
  143:         (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
  144:       if(!inet_ntop4(src + 12, tp, sizeof(tmp) - (tp - tmp))) {
  145:         errno = ENOSPC;
  146:         return (NULL);
  147:       }
  148:       tp += strlen(tp);
  149:       break;
  150:     }
  151:     tp += msnprintf(tp, 5, "%lx", words[i]);
  152:   }
  153: 
  154:   /* Was it a trailing run of 0x00's?
  155:    */
  156:   if(best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ))
  157:      *tp++ = ':';
  158:   *tp++ = '\0';
  159: 
  160:   /* Check for overflow, copy, and we're done.
  161:    */
  162:   if((size_t)(tp - tmp) > size) {
  163:     errno = ENOSPC;
  164:     return (NULL);
  165:   }
  166:   strcpy(dst, tmp);
  167:   return dst;
  168: }
  169: #endif  /* ENABLE_IPV6 */
  170: 
  171: /*
  172:  * Convert a network format address to presentation format.
  173:  *
  174:  * Returns pointer to presentation format address (`buf').
  175:  * Returns NULL on error and errno set with the specific
  176:  * error, EAFNOSUPPORT or ENOSPC.
  177:  *
  178:  * On Windows we store the error in the thread errno, not
  179:  * in the winsock error code. This is to avoid losing the
  180:  * actual last winsock error. So when this function returns
  181:  * NULL, check errno not SOCKERRNO.
  182:  */
  183: char *Curl_inet_ntop(int af, const void *src, char *buf, size_t size)
  184: {
  185:   switch(af) {
  186:   case AF_INET:
  187:     return inet_ntop4((const unsigned char *)src, buf, size);
  188: #ifdef ENABLE_IPV6
  189:   case AF_INET6:
  190:     return inet_ntop6((const unsigned char *)src, buf, size);
  191: #endif
  192:   default:
  193:     errno = EAFNOSUPPORT;
  194:     return NULL;
  195:   }
  196: }
  197: #endif  /* HAVE_INET_NTOP */

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