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/* |
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* inet_ntop.c -- provides inet_ntop() if necessary |
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* |
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* $Id: inet_ntop.c,v 1.3 2010/10/06 19:07:47 pseudo Exp $ |
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*/ |
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/* |
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* Portions Copyright (C) 2010 Eggheads Development Team |
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* |
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* This program is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU General Public License |
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* as published by the Free Software Foundation; either version 2 |
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* of the License, or (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
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*/ |
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|
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#include "inet_ntop.h" |
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|
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#ifndef HAVE_INET_NTOP |
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/* |
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* Copyright (c) 1996-1999 by Internet Software Consortium. |
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* |
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* Permission to use, copy, modify, and distribute this software for any |
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* purpose with or without fee is hereby granted, provided that the above |
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* copyright notice and this permission notice appear in all copies. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS |
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* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES |
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* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE |
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* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL |
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* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR |
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* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS |
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* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS |
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* SOFTWARE. |
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*/ |
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|
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#include <sys/param.h> |
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#include <sys/types.h> |
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#include <arpa/inet.h> |
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|
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#include <stdio.h> |
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#include <string.h> |
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|
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#ifdef SPRINTF_CHAR |
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# define SPRINTF(x) strlen(sprintf/**/x) |
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#else |
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# define SPRINTF(x) ((size_t)sprintf x) |
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#endif |
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|
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#define NS_INADDRSZ 4 /* IPv4 T_A */ |
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#define NS_IN6ADDRSZ 16 /* IPv6 T_AAAA */ |
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#define NS_INT16SZ 2 /* #/bytes of data in a u_int16_t */ |
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|
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/* |
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* WARNING: Don't even consider trying to compile this on a system where |
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* sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX. |
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*/ |
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|
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static const char *inet_ntop4 (const u_char *src, char *dst, socklen_t size); |
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#ifdef IPV6 |
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static const char *inet_ntop6 (const u_char *src, char *dst, socklen_t size); |
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#endif |
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|
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/* char * |
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* inet_ntop(af, src, dst, size) |
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* convert a network format address to presentation format. |
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* return: |
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* pointer to presentation format address (`dst'), or NULL (see errno). |
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* author: |
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* Paul Vixie, 1996. |
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*/ |
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const char * |
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inet_ntop(af, src, dst, size) |
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int af; |
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const void *src; |
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char *dst; |
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socklen_t size; |
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{ |
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switch (af) { |
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case AF_INET: |
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return (inet_ntop4(src, dst, size)); |
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#ifdef IPV6 |
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case AF_INET6: |
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return (inet_ntop6(src, dst, size)); |
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#endif |
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default: |
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return NULL; |
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} |
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/* NOTREACHED */ |
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} |
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|
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/* const char * |
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* inet_ntop4(src, dst, size) |
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* format an IPv4 address |
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* return: |
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* `dst' (as a const) |
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* notes: |
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* (1) uses no statics |
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* (2) takes a u_char* not an in_addr as input |
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* author: |
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* Paul Vixie, 1996. |
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*/ |
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static const char *inet_ntop4(src, dst, size) |
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const u_char *src; |
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char *dst; |
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socklen_t size; |
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{ |
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static const char fmt[] = "%u.%u.%u.%u"; |
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char tmp[sizeof "255.255.255.255"]; |
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|
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if (SPRINTF((tmp, fmt, src[0], src[1], src[2], src[3])) > size) { |
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/* __set_errno (ENOSPC); */ |
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return (NULL); |
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} |
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return strcpy(dst, tmp); |
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} |
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|
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/* const char * |
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* inet_ntop6(src, dst, size) |
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* convert IPv6 binary address into presentation (printable) format |
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* author: |
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* Paul Vixie, 1996. |
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*/ |
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#ifdef IPV6 |
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static const char * |
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inet_ntop6(src, dst, size) |
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const u_char *src; |
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char *dst; |
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socklen_t size; |
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{ |
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/* |
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* Note that int32_t and int16_t need only be "at least" large enough |
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* to contain a value of the specified size. On some systems, like |
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* Crays, there is no such thing as an integer variable with 16 bits. |
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* Keep this in mind if you think this function should have been coded |
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* to use pointer overlays. All the world's not a VAX. |
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*/ |
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char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp; |
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struct { int base, len; } best, cur; |
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u_int words[NS_IN6ADDRSZ / NS_INT16SZ]; |
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int i; |
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|
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/* |
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* Preprocess: |
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* Copy the input (bytewise) array into a wordwise array. |
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* Find the longest run of 0x00's in src[] for :: shorthanding. |
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*/ |
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memset(words, '\0', sizeof words); |
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best.len = cur.len = 0; |
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for (i = 0; i < NS_IN6ADDRSZ; i += 2) |
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words[i / 2] = (src[i] << 8) | src[i + 1]; |
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best.base = -1; |
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cur.base = -1; |
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for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) { |
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if (words[i] == 0) { |
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if (cur.base == -1) |
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cur.base = i, cur.len = 1; |
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else |
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cur.len++; |
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} else { |
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if (cur.base != -1) { |
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if (best.base == -1 || cur.len > best.len) |
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best = cur; |
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cur.base = -1; |
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} |
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} |
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} |
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if (cur.base != -1) { |
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if (best.base == -1 || cur.len > best.len) |
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best = cur; |
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} |
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if (best.base != -1 && best.len < 2) |
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best.base = -1; |
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|
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/* |
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* Format the result. |
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*/ |
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tp = tmp; |
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for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) { |
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/* Are we inside the best run of 0x00's? */ |
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if (best.base != -1 && i >= best.base && |
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i < (best.base + best.len)) { |
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if (i == best.base) |
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*tp++ = ':'; |
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continue; |
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} |
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/* Are we following an initial run of 0x00s or any real hex? */ |
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if (i != 0) |
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*tp++ = ':'; |
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/* Is this address an encapsulated IPv4? */ |
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if (i == 6 && best.base == 0 && |
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(best.len == 6 || (best.len == 5 && words[5] == 0xffff))) { |
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if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp))) |
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return (NULL); |
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tp += strlen(tp); |
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break; |
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} |
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tp += SPRINTF((tp, "%x", words[i])); |
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} |
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/* Was it a trailing run of 0x00's? */ |
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if (best.base != -1 && (best.base + best.len) == |
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(NS_IN6ADDRSZ / NS_INT16SZ)) |
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*tp++ = ':'; |
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*tp++ = '\0'; |
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|
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/* |
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* Check for overflow, copy, and we're done. |
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*/ |
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if ((socklen_t)(tp - tmp) > size) { |
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/* __set_errno (ENOSPC); */ |
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return (NULL); |
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} |
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return strcpy(dst, tmp); |
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} |
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#endif /* IPV6 */ |
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|
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#endif /* HAVE_INET_NTOP */ |
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