diff options
Diffstat (limited to 'eval.c')
| -rw-r--r-- | eval.c | 136 |
1 files changed, 136 insertions, 0 deletions
@@ -0,0 +1,136 @@ + /* + * Routines for controlled evaluation of host names, user names, and so on. + * They are, in fact, wrappers around the functions that are specific for + * the sockets or TLI programming interfaces. The request_info and host_info + * structures are used for result cacheing. + * + * These routines allows us to postpone expensive operations until their + * results are really needed. Examples are hostname lookups and double + * checks, or username lookups. Information that cannot be retrieved is + * given the value "unknown" ("paranoid" in case of hostname problems). + * + * When ALWAYS_HOSTNAME is off, hostname lookup is done only when required by + * tcpd paranoid mode, by access control patterns, or by %letter expansions. + * + * When ALWAYS_RFC931 mode is off, user lookup is done only when required by + * access control patterns or %letter expansions. + * + * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands. + */ + +#ifndef lint +static char sccsid[] = "@(#) eval.c 1.3 95/01/30 19:51:45"; +#endif + +/* System libraries. */ + +#include <stdio.h> +#include <string.h> + +/* Local stuff. */ + +#include "tcpd.h" + + /* + * When a string has the value STRING_UNKNOWN, it means: don't bother, I + * tried to look up the data but it was unavailable for some reason. When a + * host name has the value STRING_PARANOID it means there was a name/address + * conflict. + */ +char unknown[] = STRING_UNKNOWN; +char paranoid[] = STRING_PARANOID; + +/* eval_user - look up user name */ + +char *eval_user(request) +struct request_info *request; +{ + if (request->user[0] == 0) { + strcpy(request->user, unknown); + if (request->sink == 0 && request->client->sin && request->server->sin) + rfc931(request->client->sin, request->server->sin, request->user); + } + return (request->user); +} + +/* eval_hostaddr - look up printable address */ + +char *eval_hostaddr(host) +struct host_info *host; +{ + if (host->addr[0] == 0) { + strcpy(host->addr, unknown); + if (host->request->hostaddr != 0) + host->request->hostaddr(host); + } + return (host->addr); +} + +/* eval_hostname - look up host name */ + +char *eval_hostname(host) +struct host_info *host; +{ + if (host->name[0] == 0) { + strcpy(host->name, unknown); + if (host->request->hostname != 0) + host->request->hostname(host); + } + return (host->name); +} + +/* eval_hostinfo - return string with host name (preferred) or address */ + +char *eval_hostinfo(host) +struct host_info *host; +{ + char *hostname; + +#ifndef ALWAYS_HOSTNAME /* no implicit host lookups */ + if (host->name[0] == 0) + return (eval_hostaddr(host)); +#endif + hostname = eval_hostname(host); + if (HOSTNAME_KNOWN(hostname)) { + return (host->name); + } else { + return (eval_hostaddr(host)); + } +} + +/* eval_client - return string with as much about the client as we know */ + +char *eval_client(request) +struct request_info *request; +{ + static char both[2 * STRING_LENGTH]; + char *hostinfo = eval_hostinfo(request->client); + +#ifndef ALWAYS_RFC931 /* no implicit user lookups */ + if (request->user[0] == 0) + return (hostinfo); +#endif + if (STR_NE(eval_user(request), unknown)) { + sprintf(both, "%s@%s", request->user, hostinfo); + return (both); + } else { + return (hostinfo); + } +} + +/* eval_server - return string with as much about the server as we know */ + +char *eval_server(request) +struct request_info *request; +{ + static char both[2 * STRING_LENGTH]; + char *host = eval_hostinfo(request->server); + char *daemon = eval_daemon(request); + + if (STR_NE(host, unknown)) { + sprintf(both, "%s@%s", daemon, host); + return (both); + } else { + return (daemon); + } +} |