144743Smarkm /* 244743Smarkm * Routines for controlled evaluation of host names, user names, and so on. 344743Smarkm * They are, in fact, wrappers around the functions that are specific for 444743Smarkm * the sockets or TLI programming interfaces. The request_info and host_info 544743Smarkm * structures are used for result cacheing. 644743Smarkm * 744743Smarkm * These routines allows us to postpone expensive operations until their 844743Smarkm * results are really needed. Examples are hostname lookups and double 944743Smarkm * checks, or username lookups. Information that cannot be retrieved is 1044743Smarkm * given the value "unknown" ("paranoid" in case of hostname problems). 1144743Smarkm * 1244743Smarkm * When ALWAYS_HOSTNAME is off, hostname lookup is done only when required by 1344743Smarkm * tcpd paranoid mode, by access control patterns, or by %letter expansions. 1444743Smarkm * 1544743Smarkm * When ALWAYS_RFC931 mode is off, user lookup is done only when required by 1644743Smarkm * access control patterns or %letter expansions. 1744743Smarkm * 1844743Smarkm * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands. 1944743Smarkm */ 2044743Smarkm 2144743Smarkm#ifndef lint 2244743Smarkmstatic char sccsid[] = "@(#) eval.c 1.3 95/01/30 19:51:45"; 2344743Smarkm#endif 2444743Smarkm 2544743Smarkm/* System libraries. */ 2644743Smarkm 2744743Smarkm#include <stdio.h> 2844743Smarkm#include <string.h> 2944743Smarkm 3044743Smarkm/* Local stuff. */ 3144743Smarkm 3244743Smarkm#include "tcpd.h" 3344743Smarkm 3444743Smarkm /* 3544743Smarkm * When a string has the value STRING_UNKNOWN, it means: don't bother, I 3644743Smarkm * tried to look up the data but it was unavailable for some reason. When a 3744743Smarkm * host name has the value STRING_PARANOID it means there was a name/address 3844743Smarkm * conflict. 3944743Smarkm */ 4044743Smarkmchar unknown[] = STRING_UNKNOWN; 4144743Smarkmchar paranoid[] = STRING_PARANOID; 4244743Smarkm 4344743Smarkm/* eval_user - look up user name */ 4444743Smarkm 4544743Smarkmchar *eval_user(request) 4644743Smarkmstruct request_info *request; 4744743Smarkm{ 4844743Smarkm if (request->user[0] == 0) { 4944743Smarkm strcpy(request->user, unknown); 5044743Smarkm if (request->sink == 0 && request->client->sin && request->server->sin) 5144743Smarkm rfc931(request->client->sin, request->server->sin, request->user); 5244743Smarkm } 5344743Smarkm return (request->user); 5444743Smarkm} 5544743Smarkm 5644743Smarkm/* eval_hostaddr - look up printable address */ 5744743Smarkm 5844743Smarkmchar *eval_hostaddr(host) 5944743Smarkmstruct host_info *host; 6044743Smarkm{ 6144743Smarkm if (host->addr[0] == 0) { 6244743Smarkm strcpy(host->addr, unknown); 6344743Smarkm if (host->request->hostaddr != 0) 6444743Smarkm host->request->hostaddr(host); 6544743Smarkm } 6644743Smarkm return (host->addr); 6744743Smarkm} 6844743Smarkm 6944743Smarkm/* eval_hostname - look up host name */ 7044743Smarkm 7144743Smarkmchar *eval_hostname(host) 7244743Smarkmstruct host_info *host; 7344743Smarkm{ 7444743Smarkm if (host->name[0] == 0) { 7544743Smarkm strcpy(host->name, unknown); 7644743Smarkm if (host->request->hostname != 0) 7744743Smarkm host->request->hostname(host); 7844743Smarkm } 7944743Smarkm return (host->name); 8044743Smarkm} 8144743Smarkm 8244743Smarkm/* eval_hostinfo - return string with host name (preferred) or address */ 8344743Smarkm 8444743Smarkmchar *eval_hostinfo(host) 8544743Smarkmstruct host_info *host; 8644743Smarkm{ 8744743Smarkm char *hostname; 8844743Smarkm 8944743Smarkm#ifndef ALWAYS_HOSTNAME /* no implicit host lookups */ 9044743Smarkm if (host->name[0] == 0) 9144743Smarkm return (eval_hostaddr(host)); 9244743Smarkm#endif 9344743Smarkm hostname = eval_hostname(host); 9444743Smarkm if (HOSTNAME_KNOWN(hostname)) { 9544743Smarkm return (host->name); 9644743Smarkm } else { 9744743Smarkm return (eval_hostaddr(host)); 9844743Smarkm } 9944743Smarkm} 10044743Smarkm 10144743Smarkm/* eval_client - return string with as much about the client as we know */ 10244743Smarkm 10344743Smarkmchar *eval_client(request) 10444743Smarkmstruct request_info *request; 10544743Smarkm{ 10644743Smarkm static char both[2 * STRING_LENGTH]; 10744743Smarkm char *hostinfo = eval_hostinfo(request->client); 10844743Smarkm 10944743Smarkm#ifndef ALWAYS_RFC931 /* no implicit user lookups */ 11044743Smarkm if (request->user[0] == 0) 11144743Smarkm return (hostinfo); 11244743Smarkm#endif 11344743Smarkm if (STR_NE(eval_user(request), unknown)) { 11444743Smarkm sprintf(both, "%s@%s", request->user, hostinfo); 11544743Smarkm return (both); 11644743Smarkm } else { 11744743Smarkm return (hostinfo); 11844743Smarkm } 11944743Smarkm} 12044743Smarkm 12144743Smarkm/* eval_server - return string with as much about the server as we know */ 12244743Smarkm 12344743Smarkmchar *eval_server(request) 12444743Smarkmstruct request_info *request; 12544743Smarkm{ 12644743Smarkm static char both[2 * STRING_LENGTH]; 12744743Smarkm char *host = eval_hostinfo(request->server); 12844743Smarkm char *daemon = eval_daemon(request); 12944743Smarkm 13044743Smarkm if (STR_NE(host, unknown)) { 13144743Smarkm sprintf(both, "%s@%s", daemon, host); 13244743Smarkm return (both); 13344743Smarkm } else { 13444743Smarkm return (daemon); 13544743Smarkm } 13644743Smarkm} 137