/* $NetBSD: inet_net_ntop.c,v 1.19 2002/11/17 20:49:33 itojun Exp $ */ /* * 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. */ #include #if defined(LIBC_SCCS) && !defined(lint) #if 0 static const char rcsid[] = "Id: inet_net_ntop.c,v 1.8 2001/09/27 15:08:36 marka Exp "; #else __RCSID("$NetBSD: inet_net_ntop.c,v 1.19 2002/11/17 20:49:33 itojun Exp $"); #endif #endif #include "namespace.h" #include #include #include #include #include #include #include #include #include #ifdef __weak_alias __weak_alias(inet_net_ntop,_inet_net_ntop) #endif static char * inet_net_ntop_ipv4(const u_char *, int, char *, size_t); static char * inet_net_ntop_ipv6(const u_char *, int, char *, size_t); /* * char * * inet_net_ntop(af, src, bits, dst, size) * convert network number from network to presentation format. * generates CIDR style result always. * return: * pointer to dst, or NULL if an error occurred (check errno). * author: * Paul Vixie (ISC), July 1996 */ char * inet_net_ntop(int af, const void *src, int bits, char *dst, size_t size) { _DIAGASSERT(src != NULL); _DIAGASSERT(dst != NULL); switch (af) { case AF_INET: return (inet_net_ntop_ipv4(src, bits, dst, size)); case AF_INET6: return (inet_net_ntop_ipv6(src, bits, dst, size)); default: errno = EAFNOSUPPORT; return (NULL); } } /* * static char * * inet_net_ntop_ipv4(src, bits, dst, size) * convert IPv4 network number from network to presentation format. * generates CIDR style result always. * return: * pointer to dst, or NULL if an error occurred (check errno). * note: * network byte order assumed. this means 192.5.5.240/28 has * 0b11110000 in its fourth octet. * author: * Paul Vixie (ISC), July 1996 */ static char * inet_net_ntop_ipv4(const u_char *src, int bits, char *dst, size_t size) { char *odst = dst; u_int m; int b; char *ep; int advance; _DIAGASSERT(src != NULL); _DIAGASSERT(dst != NULL); ep = dst + size; if (ep <= dst) goto emsgsize; if (bits < 0 || bits > 32) { errno = EINVAL; return (NULL); } if (bits == 0) { if ((size_t) (ep - dst) < sizeof "0") goto emsgsize; *dst++ = '0'; *dst = '\0'; } /* Format whole octets. */ for (b = bits / 8; b > 0; b--) { if ((size_t) (ep - dst) <= sizeof "255.") goto emsgsize; advance = snprintf(dst, (size_t)(ep - dst), "%u", *src++); if (advance <= 0 || advance >= ep - dst) goto emsgsize; dst += advance; if (b > 1) { if (dst + 1 >= ep) goto emsgsize; *dst++ = '.'; *dst = '\0'; } } /* Format partial octet. */ b = bits % 8; if (b > 0) { if ((size_t) (ep - dst) <= sizeof ".255") goto emsgsize; if (dst != odst) { if (dst + 1 >= ep) goto emsgsize; *dst++ = '.'; } m = ((1 << b) - 1) << (8 - b); advance = snprintf(dst, (size_t)(ep - dst), "%u", *src & m); if (advance <= 0 || advance >= ep - dst) goto emsgsize; dst += advance; } /* Format CIDR /width. */ if ((size_t) (ep - dst) <= sizeof "/32") goto emsgsize; advance = snprintf(dst, (size_t)(ep - dst), "/%u", bits); if (advance <= 0 || advance >= ep - dst) goto emsgsize; dst += advance; return (odst); emsgsize: errno = EMSGSIZE; return (NULL); } /* * static char * * inet_net_ntop_ipv6(src, bits, fakebits, dst, size) * convert IPv6 network number from network to presentation format. * generates CIDR style result always. Picks the shortest representation * unless the IP is really IPv4. * always prints specified number of bits (bits). * return: * pointer to dst, or NULL if an error occurred (check errno). * note: * network byte order assumed. this means 192.5.5.240/28 has * 0x11110000 in its fourth octet. * author: * Vadim Kogan (UCB), June 2001 * Original version (IPv4) by Paul Vixie (ISC), July 1996 */ static char * inet_net_ntop_ipv6(const u_char *src, int bits, char *dst, size_t size) { size_t bytes; u_int m; int b; int p; int zero_s, zero_l, tmp_zero_s, tmp_zero_l; int i; int is_ipv4 = 0; u_char inbuf[16]; char outbuf[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255/128")]; char *cp; int words; u_char *s; char *ep; int advance; _DIAGASSERT(src != NULL); _DIAGASSERT(dst != NULL); if (bits < 0 || bits > 128) { errno = EINVAL; return (NULL); } cp = outbuf; ep = outbuf + sizeof(outbuf); if (bits == 0) { *cp++ = ':'; *cp++ = ':'; *cp = '\0'; } else { /* Copy src to private buffer. Zero host part. */ bytes = (bits + 7) / 8; memcpy(inbuf, src, bytes); memset(inbuf + bytes, 0, 16 - bytes); b = bits % 8; if (b != 0) { m = ~0 << (8 - b); inbuf[bytes-1] &= m; } s = inbuf; /* how many words need to be displayed in output */ words = (bits + 15) / 16; if (words == 1) words = 2; /* Find the longest substring of zero's */ zero_s = zero_l = tmp_zero_s = tmp_zero_l = 0; for (i = 0; i < (words * 2); i += 2) { if ((s[i] | s[i+1]) == 0) { if (tmp_zero_l == 0) tmp_zero_s = i / 2; tmp_zero_l++; } else { if (tmp_zero_l && zero_l < tmp_zero_l) { zero_s = tmp_zero_s; zero_l = tmp_zero_l; tmp_zero_l = 0; } } } if (tmp_zero_l && zero_l < tmp_zero_l) { zero_s = tmp_zero_s; zero_l = tmp_zero_l; } if (zero_l != words && zero_s == 0 && ((zero_l == 6) || ((zero_l == 5 && s[10] == 0xff && s[11] == 0xff) || ((zero_l == 7 && s[14] != 0 && s[15] != 1))))) is_ipv4 = 1; /* Format whole words. */ for (p = 0; p < words; p++) { if (zero_l != 0 && p >= zero_s && p < zero_s + zero_l) { /* Time to skip some zeros */ if (p == zero_s) *cp++ = ':'; if (p == words - 1) *cp++ = ':'; s++; s++; continue; } if (is_ipv4 && p > 5) { *cp++ = (p == 6) ? ':' : '.'; advance = snprintf(cp, (size_t)(ep - cp), "%u", *s++); if (advance <= 0 || advance >= ep - cp) goto emsgsize; cp += advance; /* we can potentially drop the last octet */ if (p != 7 || bits > 120) { *cp++ = '.'; advance = snprintf(cp, (size_t)(ep - cp), "%u", *s++); if (advance <= 0 || advance >= ep - cp) goto emsgsize; cp += advance; } } else { if (cp != outbuf) *cp++ = ':'; advance = snprintf(cp, (size_t)(ep - cp), "%x", *s * 256 + s[1]); if (advance <= 0 || advance >= ep - cp) goto emsgsize; cp += advance; s += 2; } } } /* Format CIDR /width. */ /* LINTED */ snprintf(cp, ep - cp, "/%u", bits); if (strlen(outbuf) + 1 > size) goto emsgsize; strlcpy(dst, outbuf, size); return (dst); emsgsize: errno = EMSGSIZE; return (NULL); }