1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 #include <sys/types.h> 30 #include <sys/socket.h> 31 #include <netdb.h> 32 #include <netinet/in.h> 33 #include <string.h> 34 #include <syslog.h> 35 #include <addr_match.h> 36 37 /* 38 * Function to compare IP addresses. It walks the list provided in 39 * the res parameter, comparing to the original address in sin or sin6, 40 * with some addition guidance provided by fromp. It returns B_TRUE 41 * if a match is found, otherwise B_FALSE. 42 */ 43 44 static boolean_t 45 find_match(const struct addrinfo *res, 46 const struct sockaddr_storage *fromp, 47 const struct sockaddr_in *sin, 48 const struct sockaddr_in6 *sin6) 49 { 50 const struct addrinfo *ai; 51 52 /* This is the moral equivalent of an assert. */ 53 if ((fromp->ss_family == AF_INET && sin == NULL) || 54 (fromp->ss_family == AF_INET6 && sin6 == NULL)) 55 return (B_FALSE); 56 57 for (ai = res; ai != NULL; ai = ai->ai_next) { 58 struct sockaddr_in *s4; 59 struct sockaddr_in6 *s6; 60 void *addr1, *addr2; 61 size_t size; 62 63 if (ai->ai_family != fromp->ss_family) 64 continue; 65 if (ai->ai_family == AF_INET) { 66 /* LINTED E_BAD_PTR_CAST_ALIGN */ 67 s4 = (struct sockaddr_in *)ai->ai_addr; 68 addr1 = &s4->sin_addr; 69 addr2 = &((struct sockaddr_in *)sin)->sin_addr; 70 size = sizeof (struct in_addr); 71 } else if (ai->ai_family == AF_INET6) { 72 /* LINTED E_BAD_PTR_CAST_ALIGN */ 73 s6 = (struct sockaddr_in6 *)ai->ai_addr; 74 addr1 = &s6->sin6_addr; 75 addr2 = &((struct sockaddr_in6 *)sin6)->sin6_addr; 76 size = sizeof (struct in6_addr); 77 } else { 78 continue; 79 } 80 if (memcmp(addr1, addr2, size) == 0) 81 return (B_TRUE); 82 } 83 return (B_FALSE); 84 } 85 86 void 87 check_address(const char *prog, 88 const struct sockaddr_storage *fromp, 89 const struct sockaddr_in *sin, 90 const struct sockaddr_in6 *sin6, 91 const char *printable_addr, 92 char *hostname, 93 size_t hostsize) 94 { 95 /* 96 * We have to check for spoofing. So take hostname, look up its 97 * address(es), and walk the list until we have a match with the 98 * original IP address. If no match is found, log a warning and 99 * use the original IP address for authentication purposes. 100 */ 101 struct addrinfo *res, hints; 102 boolean_t match_found = B_FALSE; 103 104 (void) memset(&hints, 0, sizeof (hints)); 105 hints.ai_flags = AI_CANONNAME|AI_V4MAPPED|AI_ADDRCONFIG; 106 hints.ai_family = fromp->ss_family; 107 if (getaddrinfo(hostname, NULL, &hints, &res) == 0) 108 match_found = find_match(res, fromp, sin, sin6); 109 if (!match_found) { 110 syslog(LOG_WARNING, "%s: IP address '%s' maps to host " 111 "name '%s',\r\n but that host name does not map to " 112 "the same IP address.", prog, printable_addr, hostname); 113 (void) strlcpy(hostname, printable_addr, hostsize); 114 } 115 freeaddrinfo(res); 116 } 117