/* * Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC") * Copyright (C) 1996-2001 Internet Software Consortium. * * Permission to use, copy, modify, and/or 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. */ /*! \file */ #if defined(LIBC_SCCS) && !defined(lint) static char rcsid[] = "$Id: inet_ntop.c,v 1.19 2007/06/19 23:47:17 tbox Exp $"; #endif /* LIBC_SCCS and not lint */ #include <config.h> #include <errno.h> #include <stdio.h> #include <string.h> #include <isc/net.h> #include <isc/print.h> #include "ntp_sprintf.h" /* NTP local change, helps SunOS 4 */ #define NS_INT16SZ 2 #define NS_IN6ADDRSZ 16 /* * 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 unsigned char *src, char *dst, size_t size); #ifdef AF_INET6 static const char *inet_ntop6(const unsigned char *src, char *dst, size_t size); #endif /*! char * * isc_net_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 * isc_net_ntop(int af, const void *src, char *dst, size_t size) { switch (af) { case AF_INET: return (inet_ntop4(src, dst, size)); #ifdef AF_INET6 case AF_INET6: return (inet_ntop6(src, dst, size)); #endif default: errno = EAFNOSUPPORT; return (NULL); } /* NOTREACHED */ } /*! const char * * inet_ntop4(src, dst, size) * format an IPv4 address * \return * `dst' (as a const) * \note * (1) uses no statics * \note * (2) takes a unsigned char* not an in_addr as input * \author * Paul Vixie, 1996. */ static const char * inet_ntop4(const unsigned char *src, char *dst, size_t size) { static const char *fmt = "%u.%u.%u.%u"; char tmp[sizeof("255.255.255.255")]; /* NTP local change to use SNPRINTF() macro for SunOS4 compat */ if (SNPRINTF((tmp, sizeof(tmp), fmt, src[0], src[1], src[2], src[3])) >= size) { errno = ENOSPC; return (NULL); } strcpy(dst, tmp); return (dst); } /*! const char * * isc_inet_ntop6(src, dst, size) * convert IPv6 binary address into presentation (printable) format * \author * Paul Vixie, 1996. */ #ifdef AF_INET6 static const 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")], *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++) words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3)); 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; } tp += SPRINTF((tp, "%x", words[i])); /* NTP local change */ } /* 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 ((size_t)(tp - tmp) > size) { errno = ENOSPC; return (NULL); } strcpy(dst, tmp); return (dst); } #endif /* AF_INET6 */