t7x/deps/curl/lib/inet_ntop.c

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2023-12-06 17:43:39 -05:00
/*
* Copyright (C) 1996-2022 Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
* DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
* INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* SPDX-License-Identifier: ISC
*/
/*
* Original code by Paul Vixie. "curlified" by Gisle Vanem.
*/
#include "curl_setup.h"
#ifndef HAVE_INET_NTOP
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#include "inet_ntop.h"
#include "curl_printf.h"
#define IN6ADDRSZ 16
#define INADDRSZ 4
#define INT16SZ 2
/*
* If ENABLE_IPV6 is disabled, we still want to parse IPv6 addresses, so make
* sure we have _some_ value for AF_INET6 without polluting our fake value
* everywhere.
*/
#if !defined(ENABLE_IPV6) && !defined(AF_INET6)
#define AF_INET6 (AF_INET + 1)
#endif
/*
* Format an IPv4 address, more or less like inet_ntop().
*
* Returns `dst' (as a const)
* Note:
* - uses no statics
* - takes a unsigned char* not an in_addr as input
*/
static char *inet_ntop4 (const unsigned char *src, char *dst, size_t size)
{
char tmp[sizeof("255.255.255.255")];
size_t len;
DEBUGASSERT(size >= 16);
tmp[0] = '\0';
(void)msnprintf(tmp, sizeof(tmp), "%d.%d.%d.%d",
((int)((unsigned char)src[0])) & 0xff,
((int)((unsigned char)src[1])) & 0xff,
((int)((unsigned char)src[2])) & 0xff,
((int)((unsigned char)src[3])) & 0xff);
len = strlen(tmp);
if(len == 0 || len >= size) {
errno = ENOSPC;
return (NULL);
}
strcpy(dst, tmp);
return dst;
}
/*
* Convert IPv6 binary address into presentation (printable) format.
*/
static char *inet_ntop6 (const unsigned char *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.
*/
char tmp[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")];
char *tp;
struct {
int base;
int len;
} best, cur;
unsigned int 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.
*/
memset(words, '\0', sizeof(words));
for(i = 0; i < IN6ADDRSZ; i++)
words[i/2] |= ((unsigned int)src[i] << ((1 - (i % 2)) << 3));
best.base = -1;
cur.base = -1;
best.len = 0;
cur.len = 0;
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. */
tp = tmp;
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)
*tp++ = ':';
continue;
}
/* Are we following an initial run of 0x00s or any real hex?
*/
if(i)
*tp++ = ':';
/* Is this address an encapsulated IPv4?
*/
if(i == 6 && best.base == 0 &&
(best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
if(!inet_ntop4(src + 12, tp, sizeof(tmp) - (tp - tmp))) {
errno = ENOSPC;
return (NULL);
}
tp += strlen(tp);
break;
}
tp += msnprintf(tp, 5, "%x", words[i]);
}
/* Was it a trailing run of 0x00's?
*/
if(best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ))
*tp++ = ':';
*tp++ = '\0';
/* Check for overflow, copy, and we're done.
*/
if((size_t)(tp - tmp) > size) {
errno = ENOSPC;
return (NULL);
}
strcpy(dst, tmp);
return dst;
}
/*
* Convert a network format address to presentation format.
*
* Returns pointer to presentation format address (`buf').
* Returns NULL on error and errno set with the specific
* error, EAFNOSUPPORT or ENOSPC.
*
* On Windows we store the error in the thread errno, not
* in the winsock error code. This is to avoid losing the
* actual last winsock error. So when this function returns
* NULL, check errno not SOCKERRNO.
*/
char *Curl_inet_ntop(int af, const void *src, char *buf, size_t size)
{
switch(af) {
case AF_INET:
return inet_ntop4((const unsigned char *)src, buf, size);
case AF_INET6:
return inet_ntop6((const unsigned char *)src, buf, size);
default:
errno = EAFNOSUPPORT;
return NULL;
}
}
#endif /* HAVE_INET_NTOP */