/* * Copyright (C) 1996-2022 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. * * SPDX-License-Identifier: ISC */ /* * Original code by Paul Vixie. "curlified" by Gisle Vanem. */ #include "curl_setup.h" #ifndef HAVE_INET_NTOP #ifdef HAVE_SYS_PARAM_H #include #endif #ifdef HAVE_NETINET_IN_H #include #endif #ifdef HAVE_ARPA_INET_H #include #endif #include "inet_ntop.h" #include "curl_printf.h" #define IN6ADDRSZ 16 #define INADDRSZ 4 #define INT16SZ 2 /* * If ENABLE_IPV6 is disabled, we still want to parse IPv6 addresses, so make * sure we have _some_ value for AF_INET6 without polluting our fake value * everywhere. */ #if !defined(ENABLE_IPV6) && !defined(AF_INET6) #define AF_INET6 (AF_INET + 1) #endif /* * Format an IPv4 address, more or less like inet_ntop(). * * Returns `dst' (as a const) * Note: * - uses no statics * - takes a unsigned char* not an in_addr as input */ static char *inet_ntop4 (const unsigned char *src, char *dst, size_t size) { char tmp[sizeof("255.255.255.255")]; size_t len; DEBUGASSERT(size >= 16); tmp[0] = '\0'; (void)msnprintf(tmp, sizeof(tmp), "%d.%d.%d.%d", ((int)((unsigned char)src[0])) & 0xff, ((int)((unsigned char)src[1])) & 0xff, ((int)((unsigned char)src[2])) & 0xff, ((int)((unsigned char)src[3])) & 0xff); len = strlen(tmp); if(len == 0 || len >= size) { errno = ENOSPC; return (NULL); } strcpy(dst, tmp); return dst; } /* * Convert IPv6 binary address into presentation (printable) format. */ static 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")]; char *tp; struct { long base; long len; } best, cur; unsigned long words[IN6ADDRSZ / 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 < IN6ADDRSZ; i++) words[i/2] |= (src[i] << ((1 - (i % 2)) << 3)); best.base = -1; cur.base = -1; best.len = 0; cur.len = 0; for(i = 0; i < (IN6ADDRSZ / 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) && (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 < (IN6ADDRSZ / 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) *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))) { errno = ENOSPC; return (NULL); } tp += strlen(tp); break; } tp += msnprintf(tp, 5, "%lx", words[i]); } /* Was it a trailing run of 0x00's? */ if(best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / 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; } /* * Convert a network format address to presentation format. * * Returns pointer to presentation format address (`buf'). * Returns NULL on error and errno set with the specific * error, EAFNOSUPPORT or ENOSPC. * * On Windows we store the error in the thread errno, not * in the winsock error code. This is to avoid losing the * actual last winsock error. So when this function returns * NULL, check errno not SOCKERRNO. */ char *Curl_inet_ntop(int af, const void *src, char *buf, size_t size) { switch(af) { case AF_INET: return inet_ntop4((const unsigned char *)src, buf, size); case AF_INET6: return inet_ntop6((const unsigned char *)src, buf, size); default: errno = EAFNOSUPPORT; return NULL; } } #endif /* HAVE_INET_NTOP */