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