/*- * SPDX-License-Identifier: ISC * * 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. */ #if defined(LIBC_SCCS) && !defined(lint) static const char rcsid[] = "$Id: inet_net_ntop.c,v 1.5 2006/06/20 02:50:14 marka Exp $"; #endif #include #include "port_before.h" #include #include #include #include #include #include #include #include #include "port_after.h" #ifdef SPRINTF_CHAR # define SPRINTF(x) strlen(sprintf/**/x) #else # define SPRINTF(x) ((size_t)sprintf x) #endif static char * inet_net_ntop_ipv4(const u_char *src, int bits, char *dst, size_t size); static char * inet_net_ntop_ipv6(const u_char *src, int bits, char *dst, size_t size); /*% * 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) { 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; char *t; u_int m; int b; if (bits < 0 || bits > 32) { errno = EINVAL; return (NULL); } if (bits == 0) { if (size < sizeof "0") goto emsgsize; *dst++ = '0'; size--; *dst = '\0'; } /* Format whole octets. */ for (b = bits / 8; b > 0; b--) { if (size <= sizeof "255.") goto emsgsize; t = dst; dst += SPRINTF((dst, "%u", *src++)); if (b > 1) { *dst++ = '.'; *dst = '\0'; } size -= (size_t)(dst - t); } /* Format partial octet. */ b = bits % 8; if (b > 0) { if (size <= sizeof ".255") goto emsgsize; t = dst; if (dst != odst) *dst++ = '.'; m = ((1 << b) - 1) << (8 - b); dst += SPRINTF((dst, "%u", *src & m)); size -= (size_t)(dst - t); } /* Format CIDR /width. */ if (size <= sizeof "/32") goto emsgsize; dst += SPRINTF((dst, "/%u", bits)); 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 * 0b11110000 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) { u_int m; int b; int p; int zero_s, zero_l, tmp_zero_s, tmp_zero_l; int i; int is_ipv4 = 0; unsigned char inbuf[16]; char outbuf[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255/128")]; char *cp; int words; u_char *s; if (bits < 0 || bits > 128) { errno = EINVAL; return (NULL); } cp = outbuf; if (bits == 0) { *cp++ = ':'; *cp++ = ':'; *cp = '\0'; } else { /* Copy src to private buffer. Zero host part. */ p = (bits + 7) / 8; memcpy(inbuf, src, p); memset(inbuf + p, 0, 16 - p); b = bits % 8; if (b != 0) { m = ~0 << (8 - b); inbuf[p-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) ? ':' : '.'; cp += SPRINTF((cp, "%u", *s++)); /* we can potentially drop the last octet */ if (p != 7 || bits > 120) { *cp++ = '.'; cp += SPRINTF((cp, "%u", *s++)); } } else { if (cp != outbuf) *cp++ = ':'; cp += SPRINTF((cp, "%x", *s * 256 + s[1])); s += 2; } } } /* Format CIDR /width. */ sprintf(cp, "/%u", bits); if (strlen(outbuf) + 1 > size) goto emsgsize; strcpy(dst, outbuf); return (dst); emsgsize: errno = EMSGSIZE; return (NULL); } /* * Weak aliases for applications that use certain private entry points, * and fail to include . */ #undef inet_net_ntop __weak_reference(__inet_net_ntop, inet_net_ntop); /*! \file */