/* $OpenBSD: inet_net_ntop.c,v 1.9 2019/07/03 03:24:04 deraadt Exp $ */ /* * Copyright (c) 2012 by Gilles Chehade * Copyright (c) 1996 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 #include #include #include #include #include #include #include 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) { 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 * 0x11110000 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; ep = dst + size; if (ep <= dst) goto emsgsize; if (bits < 0 || bits > 32) { errno = EINVAL; return (NULL); } if (bits == 0) { if (ep - dst < sizeof "0") goto emsgsize; *dst++ = '0'; *dst = '\0'; } /* Format whole octets. */ for (b = bits / 8; b > 0; b--) { if (ep - dst < sizeof "255.") goto emsgsize; advance = snprintf(dst, 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 (ep - dst < sizeof ".255") goto emsgsize; if (dst != odst) *dst++ = '.'; m = ((1 << b) - 1) << (8 - b); advance = snprintf(dst, ep - dst, "%u", *src & m); if (advance <= 0 || advance >= ep - dst) goto emsgsize; dst += advance; } /* Format CIDR /width. */ if (ep - dst < sizeof "/32") goto emsgsize; advance = snprintf(dst, 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(const u_char *src, int bits, char *dst, size_t size) { int ret; char buf[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255:255:255:255/128")]; if (bits < 0 || bits > 128) { errno = EINVAL; return (NULL); } if (inet_ntop(AF_INET6, src, buf, size) == NULL) return (NULL); ret = snprintf(dst, size, "%s/%d", buf, bits); if (ret < 0 || ret >= size) { errno = EMSGSIZE; return (NULL); } return (dst); }