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Diffstat (limited to 'lib/inet_ntop.c')
| -rw-r--r-- | lib/inet_ntop.c | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/lib/inet_ntop.c b/lib/inet_ntop.c new file mode 100644 index 000000000..8329c827d --- /dev/null +++ b/lib/inet_ntop.c @@ -0,0 +1,239 @@ +/* inet_ntop.c -- convert IPv4 and IPv6 addresses from binary to text form + Copyright (c) 2005, 2006 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + +/* + * 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 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. + */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +/* Specification. */ +#include "inet_ntop.h" + +#include <stdio.h> +#include <string.h> +#include <errno.h> + +#ifndef EAFNOSUPPORT +# define EAFNOSUPPORT EINVAL +#endif + +#define NS_IN6ADDRSZ 16 +#define NS_INT16SZ 2 + +/* + * 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. + */ +typedef int verify_int_size[2 * sizeof (int) - 7]; + +static const char *inet_ntop4 (const unsigned char *src, char *dst, socklen_t size); +#if HAVE_IPV6 +static const char *inet_ntop6 (const unsigned char *src, char *dst, socklen_t size); +#endif + + +/* 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 *restrict src, + char *restrict dst, socklen_t cnt) +{ + switch (af) + { +#if HAVE_IPV4 + case AF_INET: + return (inet_ntop4 (src, dst, cnt)); +#endif + +#if HAVE_IPV6 + case AF_INET6: + return (inet_ntop6 (src, dst, cnt)); +#endif + + default: + errno = EAFNOSUPPORT; + return (NULL); + } + /* NOTREACHED */ +} + +/* const char * + * inet_ntop4(src, dst, size) + * format an IPv4 address + * 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 unsigned char *src, char *dst, socklen_t size) +{ + char tmp[sizeof "255.255.255.255"]; + int len; + + len = sprintf (tmp, "%u.%u.%u.%u", src[0], src[1], src[2], src[3]); + if (len < 0) + return NULL; + + if (len > size) + { + errno = ENOSPC; + return NULL; + } + + return strcpy (dst, tmp); +} + +#if HAVE_IPV6 + +/* 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 unsigned 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"], *tp; + struct + { + int base, len; + } best, cur; + unsigned int words[NS_IN6ADDRSZ / NS_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 < NS_IN6ADDRSZ; i += 2) + words[i / 2] = (src[i] << 8) | src[i + 1]; + best.base = -1; + cur.base = -1; + 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; + 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) + *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))) + return (NULL); + tp += strlen (tp); + break; + } + { + int len = sprintf (tp, "%x", words[i]); + if (len < 0) + return NULL; + tp += len; + } + } + /* Was it a trailing run of 0x00's? */ + if (best.base != -1 && (best.base + best.len) == + (NS_IN6ADDRSZ / NS_INT16SZ)) + *tp++ = ':'; + *tp++ = '\0'; + + /* + * Check for overflow, copy, and we're done. + */ + if ((socklen_t) (tp - tmp) > size) + { + errno = ENOSPC; + return NULL; + } + + return strcpy (dst, tmp); +} + +#endif |