| /* $NetBSD: inet_ntop.c,v 1.9 2012/03/20 17:08:13 matt Exp $ */ |
| |
| /* |
| * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") |
| * Copyright (c) 1996-1999 by 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 ISC DISCLAIMS ALL WARRANTIES |
| * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC 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. |
| */ |
| |
| #include <sys/cdefs.h> |
| #if defined(LIBC_SCCS) && !defined(lint) |
| #if 0 |
| static const char rcsid[] = "Id: inet_ntop.c,v 1.5 2005/11/03 22:59:52 marka Exp"; |
| #else |
| __RCSID("$NetBSD: inet_ntop.c,v 1.9 2012/03/20 17:08:13 matt Exp $"); |
| #endif |
| #endif /* LIBC_SCCS and not lint */ |
| |
| #include "port_before.h" |
| |
| #include "namespace.h" |
| #include <sys/param.h> |
| #include <sys/types.h> |
| #include <sys/socket.h> |
| |
| #include <netinet/in.h> |
| #include <arpa/inet.h> |
| #include <arpa/nameser.h> |
| |
| #include <assert.h> |
| #include <errno.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "port_after.h" |
| |
| #ifdef __weak_alias |
| __weak_alias(inet_ntop,_inet_ntop) |
| #endif |
| |
| /*% |
| * WARNING: Don't even consider trying to compile this on a system where |
| * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX. |
| */ |
| |
| static const char *inet_ntop4(const u_char *src, char *dst, socklen_t size); |
| static const char *inet_ntop6(const u_char *src, char *dst, socklen_t size); |
| |
| /* char * |
| * inet_ntop(af, src, dst, size) |
| * convert a network format address to presentation format. |
| * return: |
| * pointer to presentation format address (`dst'), or NULL (see errno). |
| * author: |
| * Paul Vixie, 1996. |
| */ |
| const char * |
| inet_ntop(int af, const void *src, char *dst, socklen_t size) |
| { |
| |
| _DIAGASSERT(src != NULL); |
| _DIAGASSERT(dst != NULL); |
| |
| switch (af) { |
| case AF_INET: |
| return (inet_ntop4(src, dst, size)); |
| case AF_INET6: |
| return (inet_ntop6(src, dst, size)); |
| default: |
| errno = EAFNOSUPPORT; |
| return (NULL); |
| } |
| /* NOTREACHED */ |
| } |
| |
| /* const char * |
| * inet_ntop4(src, dst, size) |
| * format an IPv4 address, more or less like inet_ntoa() |
| * return: |
| * `dst' (as a const) |
| * notes: |
| * (1) uses no statics |
| * (2) takes a u_char* not an in_addr as input |
| * author: |
| * Paul Vixie, 1996. |
| */ |
| static const char * |
| inet_ntop4(const u_char *src, char *dst, socklen_t size) |
| { |
| char tmp[sizeof "255.255.255.255"]; |
| int l; |
| |
| _DIAGASSERT(src != NULL); |
| _DIAGASSERT(dst != NULL); |
| |
| l = snprintf(tmp, sizeof(tmp), "%u.%u.%u.%u", |
| src[0], src[1], src[2], src[3]); |
| if (l <= 0 || (socklen_t) l >= size) { |
| errno = ENOSPC; |
| return (NULL); |
| } |
| strlcpy(dst, tmp, size); |
| return (dst); |
| } |
| |
| /* const char * |
| * inet_ntop6(src, dst, size) |
| * convert IPv6 binary address into presentation (printable) format |
| * author: |
| * Paul Vixie, 1996. |
| */ |
| static const char * |
| inet_ntop6(const u_char *src, char *dst, socklen_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, *ep; |
| struct { int base, len; } best, cur; |
| u_int words[NS_IN6ADDRSZ / NS_INT16SZ]; |
| int i; |
| int advance; |
| |
| _DIAGASSERT(src != NULL); |
| _DIAGASSERT(dst != NULL); |
| |
| /* |
| * 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 < NS_IN6ADDRSZ; i++) |
| words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3)); |
| best.base = -1; |
| best.len = 0; |
| cur.base = -1; |
| cur.len = 0; |
| for (i = 0; i < (NS_IN6ADDRSZ / NS_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) { |
| if (best.base == -1 || cur.len > best.len) |
| best = cur; |
| } |
| if (best.base != -1 && best.len < 2) |
| best.base = -1; |
| |
| /* |
| * Format the result. |
| */ |
| tp = tmp; |
| ep = tmp + sizeof(tmp); |
| for (i = 0; i < (NS_IN6ADDRSZ / NS_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 != 0) { |
| if (tp + 1 >= ep) |
| return (NULL); |
| *tp++ = ':'; |
| } |
| /* Is this address an encapsulated IPv4? */ |
| if (i == 6 && best.base == 0 && |
| (best.len == 6 || |
| (best.len == 7 && words[7] != 0x0001) || |
| (best.len == 5 && words[5] == 0xffff))) { |
| if (!inet_ntop4(src+12, tp, (socklen_t)(ep - tp))) |
| return (NULL); |
| tp += strlen(tp); |
| break; |
| } |
| advance = snprintf(tp, (size_t)(ep - tp), "%x", words[i]); |
| if (advance <= 0 || advance >= ep - tp) |
| return (NULL); |
| tp += advance; |
| } |
| /* Was it a trailing run of 0x00's? */ |
| if (best.base != -1 && (best.base + best.len) == |
| (NS_IN6ADDRSZ / NS_INT16SZ)) { |
| if (tp + 1 >= ep) |
| return (NULL); |
| *tp++ = ':'; |
| } |
| if (tp + 1 >= ep) |
| return (NULL); |
| *tp++ = '\0'; |
| |
| /* |
| * Check for overflow, copy, and we're done. |
| */ |
| if ((size_t)(tp - tmp) > size) { |
| errno = ENOSPC; |
| return (NULL); |
| } |
| strlcpy(dst, tmp, size); |
| return (dst); |
| } |
| |
| /*! \file */ |