1 /* 2 * Copyright (c) 1999 - 2002 Kungliga Tekniska Högskolan 3 * (Royal Institute of Technology, Stockholm, Sweden). 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * 3. Neither the name of the Institute nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include <config.h> 35 36 #include "roken.h" 37 38 /* 39 * Try to obtain a verified name for the address in `sa, salen' (much 40 * similar to getnameinfo). 41 * Verified in this context means that forwards and backwards lookups 42 * in DNS are consistent. If that fails, return an error if the 43 * NI_NAMEREQD flag is set or return the numeric address as a string. 44 */ 45 46 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL 47 getnameinfo_verified(const struct sockaddr *sa, socklen_t salen, 48 char *host, size_t hostlen, 49 char *serv, size_t servlen, 50 int flags) 51 { 52 int ret; 53 struct addrinfo *ai, *a; 54 char servbuf[NI_MAXSERV]; 55 struct addrinfo hints; 56 void *saaddr; 57 size_t sasize; 58 59 if (host == NULL) 60 return EAI_NONAME; 61 62 if (serv == NULL) { 63 serv = servbuf; 64 servlen = sizeof(servbuf); 65 } 66 67 ret = getnameinfo (sa, salen, host, hostlen, serv, servlen, 68 flags | NI_NUMERICSERV); 69 if (ret) 70 goto fail; 71 72 memset (&hints, 0, sizeof(hints)); 73 hints.ai_socktype = SOCK_STREAM; 74 ret = getaddrinfo (host, serv, &hints, &ai); 75 if (ret) 76 goto fail; 77 78 saaddr = socket_get_address(sa); 79 sasize = socket_addr_size(sa); 80 for (a = ai; a != NULL; a = a->ai_next) { 81 if (sasize == socket_addr_size(a->ai_addr) && 82 memcmp(saaddr, socket_get_address(a->ai_addr), sasize) == 0) { 83 freeaddrinfo (ai); 84 return 0; 85 } 86 } 87 freeaddrinfo (ai); 88 fail: 89 if (flags & NI_NAMEREQD) 90 return EAI_NONAME; 91 ret = getnameinfo (sa, salen, host, hostlen, serv, servlen, 92 flags | NI_NUMERICSERV | NI_NUMERICHOST); 93 return ret; 94 } 95