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/*
* Copyright (c) 1999 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the Kungliga Tekniska
* Högskolan and its contributors.
*
* 4. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <config.h>
#include "netdissect-stdinc.h"
#include "addrtostr.h"
#include <stdio.h>
#include <string.h>
/*
*
*/
#ifndef IN6ADDRSZ
#define IN6ADDRSZ 16 /* IPv6 T_AAAA */
#endif
#ifndef INT16SZ
#define INT16SZ 2 /* word size */
#endif
const char *
addrtostr (const void *src, char *dst, size_t size)
{
const u_char *srcaddr = (const u_char *)src;
const char digits[] = "0123456789";
int i;
const char *orig_dst = dst;
if (size < INET_ADDRSTRLEN) {
errno = ENOSPC;
return NULL;
}
for (i = 0; i < 4; ++i) {
int n = *srcaddr++;
int non_zerop = 0;
if (non_zerop || n / 100 > 0) {
*dst++ = digits[n / 100];
n %= 100;
non_zerop = 1;
}
if (non_zerop || n / 10 > 0) {
*dst++ = digits[n / 10];
n %= 10;
non_zerop = 1;
}
*dst++ = digits[n];
if (i != 3)
*dst++ = '.';
}
*dst++ = '\0';
return orig_dst;
}
/*
* Convert IPv6 binary address into presentation (printable) format.
*/
const char *
addrtostr6 (const void *src, char *dst, size_t size)
{
/*
* Note that int32_t and int16_t need only be "at least" large enough
* to contain a value of the specified size. On some systems, like
* Crays, there is no such thing as an integer variable with 16 bits.
* Keep this in mind if you think this function should have been coded
* to use pointer overlays. All the world's not a VAX.
*/
const u_char *srcaddr = (const u_char *)src;
char *dp;
size_t space_left, added_space;
int snprintfed;
struct {
int base;
int len;
} best, cur;
uint16_t words [IN6ADDRSZ / INT16SZ];
int i;
/* Preprocess:
* Copy the input (bytewise) array into a wordwise array.
* Find the longest run of 0x00's in src[] for :: shorthanding.
*/
for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++)
words[i] = (srcaddr[2*i] << 8) | srcaddr[2*i + 1];
best.len = 0;
best.base = -1;
cur.len = 0;
cur.base = -1;
for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
if (words[i] == 0) {
if (cur.base == -1)
cur.base = i, cur.len = 1;
else cur.len++;
} else if (cur.base != -1) {
if (best.base == -1 || cur.len > best.len)
best = cur;
cur.base = -1;
}
}
if ((cur.base != -1) && (best.base == -1 || cur.len > best.len))
best = cur;
if (best.base != -1 && best.len < 2)
best.base = -1;
/* Format the result.
*/
dp = dst;
space_left = size;
#define APPEND_CHAR(c) \
{ \
if (space_left == 0) { \
errno = ENOSPC; \
return (NULL); \
} \
*dp++ = c; \
space_left--; \
}
for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
/* Are we inside the best run of 0x00's?
*/
if (best.base != -1 && i >= best.base && i < (best.base + best.len)) {
if (i == best.base)
APPEND_CHAR(':');
continue;
}
/* Are we following an initial run of 0x00s or any real hex?
*/
if (i != 0)
APPEND_CHAR(':');
/* Is this address an encapsulated IPv4?
*/
if (i == 6 && best.base == 0 &&
(best.len == 6 || (best.len == 5 && words[5] == 0xffff)))
{
if (!addrtostr(srcaddr+12, dp, space_left)) {
errno = ENOSPC;
return (NULL);
}
added_space = strlen(dp);
dp += added_space;
space_left -= added_space;
break;
}
snprintfed = snprintf (dp, space_left, "%x", words[i]);
if (snprintfed < 0)
return (NULL);
if ((size_t) snprintfed >= space_left) {
errno = ENOSPC;
return (NULL);
}
dp += snprintfed;
space_left -= snprintfed;
}
/* Was it a trailing run of 0x00's?
*/
if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ))
APPEND_CHAR(':');
APPEND_CHAR('\0');
return (dst);
}
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