lib/libwrap/eval.c

	eval.c revision 2
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo/*
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * Copyright 2001 Sun Microsystems, Inc.  All rights reserved.
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo * Use is subject to license terms.
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo */
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo#pragma ident   "%Z%%M% %I% %E% SMI"
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo /*
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  * Routines for controlled evaluation of host names, user names, and so on.
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  * They are, in fact, wrappers around the functions that are specific for
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  * the sockets or TLI programming interfaces. The request_info and host_info
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  * structures are used for result cacheing.
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  *
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  * These routines allows us to postpone expensive operations until their
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  * results are really needed. Examples are hostname lookups and double
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  * checks, or username lookups. Information that cannot be retrieved is
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  * given the value "unknown" ("paranoid" in case of hostname problems).
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  *
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  * When ALWAYS_HOSTNAME is off, hostname lookup is done only when required by
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  * tcpd paranoid mode, by access control patterns, or by %letter expansions.
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  *
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  * When ALWAYS_RFC931 mode is off, user lookup is done only when required by
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  * access control patterns or %letter expansions.
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  *
8100efacfab0b6f34c0700fc9bf20aba0cc6ff93dtse  * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  */
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo#ifndef lint
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppostatic char sccsid[] = "@(#) eval.c 1.3 95/01/30 19:51:45";
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo#endif
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo/* System libraries. */
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo#include <stdio.h>
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo#include <string.h>
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo/* Local stuff. */
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo#include "tcpd.h"
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo /*
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  * When a string has the value STRING_UNKNOWN, it means: don't bother, I
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  * tried to look up the data but it was unavailable for some reason. When a
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  * host name has the value STRING_PARANOID it means there was a name/address
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  * conflict.
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo  */
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppochar    unknown[] = STRING_UNKNOWN;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppochar    paranoid[] = STRING_PARANOID;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo/* eval_user - look up user name */
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppochar   *eval_user(request)
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppostruct request_info *request;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo{
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    if (request->user[0] == 0) {
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    strcpy(request->user, unknown);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    if (request->sink == 0 && request->client->sin && request->server->sin)
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo        rfc931(request->client->sin, request->server->sin, request->user);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    }
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    return (request->user);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo}
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo/* eval_hostaddr - look up printable address */
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppochar   *eval_hostaddr(host)
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppostruct host_info *host;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo{
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    if (host->addr[0] == 0) {
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    strcpy(host->addr, unknown);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    if (host->request->hostaddr != 0)
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo        host->request->hostaddr(host);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    }
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    return (host->addr);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo}
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo/* eval_hostname - look up host name */
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppochar   *eval_hostname(host)
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppostruct host_info *host;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo{
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    if (host->name[0] == 0) {
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    strcpy(host->name, unknown);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    if (host->request->hostname != 0)
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo        host->request->hostname(host);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    }
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    return (host->name);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo}
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo/* eval_hostinfo - return string with host name (preferred) or address */
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppochar   *eval_hostinfo(host)
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppostruct host_info *host;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo{
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    char   *hostname;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo#ifndef ALWAYS_HOSTNAME             /* no implicit host lookups */
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    if (host->name[0] == 0)
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    return (eval_hostaddr(host));
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo#endif
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    hostname = eval_hostname(host);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    if (HOSTNAME_KNOWN(hostname)) {
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    return (host->name);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    } else {
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    return (eval_hostaddr(host));
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    }
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo}
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo/* eval_client - return string with as much about the client as we know */
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppochar   *eval_client(request)
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppostruct request_info *request;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo{
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    static char both[2 * STRING_LENGTH];
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    char   *hostinfo = eval_hostinfo(request->client);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo#ifndef ALWAYS_RFC931               /* no implicit user lookups */
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    if (request->user[0] == 0)
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    return (hostinfo);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo#endif
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    if (STR_NE(eval_user(request), unknown)) {
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    sprintf(both, "%s@%s", request->user, hostinfo);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    return (both);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    } else {
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    return (hostinfo);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    }
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo}
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo/* eval_server - return string with as much about the server as we know */
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppochar   *eval_server(request)
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppostruct request_info *request;
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo{
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    static char both[2 * STRING_LENGTH];
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    char   *host = eval_hostinfo(request->server);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    char   *daemon = eval_daemon(request);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    if (STR_NE(host, unknown)) {
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    sprintf(both, "%s@%s", daemon, host);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    return (both);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    } else {
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    return (daemon);
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo    }
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo}
1ae0874509b6811fdde1dfd46f0d93fd09867a3fheppo