1 /* 2 * Copyright 2001 Sun Microsystems, Inc. All rights reserved. 3 * Use is subject to license terms. 4 */ 5 #pragma ident "%Z%%M% %I% %E% SMI" 6 7 /* 8 * Routines for controlled evaluation of host names, user names, and so on. 9 * They are, in fact, wrappers around the functions that are specific for 10 * the sockets or TLI programming interfaces. The request_info and host_info 11 * structures are used for result cacheing. 12 * 13 * These routines allows us to postpone expensive operations until their 14 * results are really needed. Examples are hostname lookups and double 15 * checks, or username lookups. Information that cannot be retrieved is 16 * given the value "unknown" ("paranoid" in case of hostname problems). 17 * 18 * When ALWAYS_HOSTNAME is off, hostname lookup is done only when required by 19 * tcpd paranoid mode, by access control patterns, or by %letter expansions. 20 * 21 * When ALWAYS_RFC931 mode is off, user lookup is done only when required by 22 * access control patterns or %letter expansions. 23 * 24 * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands. 25 */ 26 27 #ifndef lint 28 static char sccsid[] = "@(#) eval.c 1.3 95/01/30 19:51:45"; 29 #endif 30 31 /* System libraries. */ 32 33 #include <stdio.h> 34 #include <string.h> 35 36 /* Local stuff. */ 37 38 #include "tcpd.h" 39 40 /* 41 * When a string has the value STRING_UNKNOWN, it means: don't bother, I 42 * tried to look up the data but it was unavailable for some reason. When a 43 * host name has the value STRING_PARANOID it means there was a name/address 44 * conflict. 45 */ 46 char unknown[] = STRING_UNKNOWN; 47 char paranoid[] = STRING_PARANOID; 48 49 /* eval_user - look up user name */ 50 51 char *eval_user(request) 52 struct request_info *request; 53 { 54 if (request->user[0] == 0) { 55 strcpy(request->user, unknown); 56 if (request->sink == 0 && request->client->sin && request->server->sin) 57 rfc931(request->client->sin, request->server->sin, request->user); 58 } 59 return (request->user); 60 } 61 62 /* eval_hostaddr - look up printable address */ 63 64 char *eval_hostaddr(host) 65 struct host_info *host; 66 { 67 if (host->addr[0] == 0) { 68 strcpy(host->addr, unknown); 69 if (host->request->hostaddr != 0) 70 host->request->hostaddr(host); 71 } 72 return (host->addr); 73 } 74 75 /* eval_hostname - look up host name */ 76 77 char *eval_hostname(host) 78 struct host_info *host; 79 { 80 if (host->name[0] == 0) { 81 strcpy(host->name, unknown); 82 if (host->request->hostname != 0) 83 host->request->hostname(host); 84 } 85 return (host->name); 86 } 87 88 /* eval_hostinfo - return string with host name (preferred) or address */ 89 90 char *eval_hostinfo(host) 91 struct host_info *host; 92 { 93 char *hostname; 94 95 #ifndef ALWAYS_HOSTNAME /* no implicit host lookups */ 96 if (host->name[0] == 0) 97 return (eval_hostaddr(host)); 98 #endif 99 hostname = eval_hostname(host); 100 if (HOSTNAME_KNOWN(hostname)) { 101 return (host->name); 102 } else { 103 return (eval_hostaddr(host)); 104 } 105 } 106 107 /* eval_client - return string with as much about the client as we know */ 108 109 char *eval_client(request) 110 struct request_info *request; 111 { 112 static char both[2 * STRING_LENGTH]; 113 char *hostinfo = eval_hostinfo(request->client); 114 115 #ifndef ALWAYS_RFC931 /* no implicit user lookups */ 116 if (request->user[0] == 0) 117 return (hostinfo); 118 #endif 119 if (STR_NE(eval_user(request), unknown)) { 120 sprintf(both, "%s@%s", request->user, hostinfo); 121 return (both); 122 } else { 123 return (hostinfo); 124 } 125 } 126 127 /* eval_server - return string with as much about the server as we know */ 128 129 char *eval_server(request) 130 struct request_info *request; 131 { 132 static char both[2 * STRING_LENGTH]; 133 char *host = eval_hostinfo(request->server); 134 char *daemon = eval_daemon(request); 135 136 if (STR_NE(host, unknown)) { 137 sprintf(both, "%s@%s", daemon, host); 138 return (both); 139 } else { 140 return (daemon); 141 } 142 } 143