MODRET wrap_handle_request(cmd_rec *cmd) {
/* these variables are names expected to be set by the TCP wrapper code
*/
struct request_info request;
char *user = NULL;
config_rec *conf = NULL, *access_conf = NULL, *syslog_conf = NULL;
hosts_allow_table = NULL;
hosts_deny_table = NULL;
/* hide passwords */
session.hide_password = TRUE;
/* Sneaky...found in mod_auth.c's cmd_pass() function. Need to find the
* login UID in order to resolve the possibly-login-dependent filename.
*/
user = (char *) get_param_ptr(cmd->server->conf, C_USER, FALSE);
/* It's possible that a PASS command came before USER. This is a PRE_CMD
* handler, so it won't be protected from this case; we'll need to do
* it manually.
*/
if (!user)
return DECLINED(cmd);
/* Use mod_auth's _auth_resolve_user() [imported for use here] to get the
* right configuration set, since the user may be logging in anonymously,
* and the session struct hasn't yet been set for that yet (thus short-
* circuiting the easiest way to get the right context...the macros.
*/
conf = wrap_resolve_user(cmd->pool, &user);
/* Search first for user-specific access files. Multiple TCPUserAccessFiles
* directives are allowed.
*/
if ((access_conf = find_config(conf ? conf->subset : CURRENT_CONF, CONF_PARAM,
"TCPUserAccessFiles", FALSE)) != NULL) {
int matched = FALSE;
array_header *user_array = NULL;
while (access_conf) {
user_array = make_array(cmd->tmp_pool, 0, sizeof(char *));
*((char **) push_array(user_array)) = pstrdup(cmd->tmp_pool, user);
/* Check the user expression -- don't forget the offset, to skip
* the access file name strings in argv
*/
if (wrap_eval_expression(((char **) access_conf->argv) + 2,
user_array)) {
pr_log_debug(DEBUG4, MOD_WRAP_VERSION
": matched TCPUserAccessFiles expression");
matched = TRUE;
break;
}
access_conf = find_config_next(access_conf, access_conf->next,
CONF_PARAM, "TCPUserAccessFiles", FALSE);
}
if (!matched)
access_conf = NULL;
}
/* Next, search for group-specific access files. Multiple
* TCPGroupAccessFiles directives are allowed.
*/
if (!access_conf && (access_conf = find_config(conf ? conf->subset :
CURRENT_CONF, CONF_PARAM, "TCPGroupAccessFiles", FALSE)) != NULL) {
unsigned char matched = FALSE;
/* NOTE: this gid_array is only necessary until Bug#1461 is fixed */
array_header *gid_array = make_array(cmd->pool, 0, sizeof(gid_t));
array_header *group_array = make_array(cmd->pool, 0, sizeof(char *));
while (access_conf) {
if (pr_auth_getgroups(cmd->pool, user, &gid_array, &group_array) < 1) {
pr_log_debug(DEBUG3, MOD_WRAP_VERSION
": no supplemental groups found for user '%s'", user);
} else {
/* Check the group expression -- don't forget the offset, to skip
* the access file names strings in argv
*/
if (wrap_eval_expression(((char **) access_conf->argv) + 2,
group_array)) {
pr_log_debug(DEBUG4, MOD_WRAP_VERSION
": matched TCPGroupAccessFiles expression");
matched = TRUE;
break;
}
}
access_conf = find_config_next(access_conf, access_conf->next,
CONF_PARAM, "TCPGroupAccessFiles", FALSE);
}
if (!matched)
access_conf = NULL;
}
/* Finally for globally-applicable access files. Only one such directive
* is allowed.
*/
if (!access_conf) {
access_conf = find_config(conf ? conf->subset : CURRENT_CONF,
CONF_PARAM, "TCPAccessFiles", FALSE);
}
if (access_conf) {
hosts_allow_table = (char *) access_conf->argv[0];
hosts_deny_table = (char *) access_conf->argv[1];
}
/* Now, check the retrieved filename, and see if it requires a login-time
* file.
*/
if (hosts_allow_table != NULL && hosts_allow_table[0] == '~' &&
hosts_allow_table[1] == '/') {
char *allow_real_table = NULL;
allow_real_table = wrap_get_user_table(cmd, user, hosts_allow_table);
if (!wrap_is_usable_file(allow_real_table)) {
pr_log_pri(PR_LOG_WARNING, MOD_WRAP_VERSION
": configured TCPAllowFile %s is unusable", hosts_allow_table);
hosts_allow_table = NULL;
} else
hosts_allow_table = allow_real_table;
}
if (hosts_deny_table != NULL && hosts_deny_table[0] == '~' &&
hosts_deny_table[1] == '/') {
char *deny_real_table = NULL;
deny_real_table = dir_realpath(cmd->pool, hosts_deny_table);
if (!wrap_is_usable_file(deny_real_table)) {
pr_log_pri(PR_LOG_WARNING, MOD_WRAP_VERSION
": configured TCPDenyFile %s is unusable", hosts_deny_table);
hosts_deny_table = NULL;
} else
hosts_deny_table = deny_real_table;
}
/* Make sure that _both_ allow and deny TCPAccessFiles are present.
* If not, log the missing file, and by default allow request to succeed.
*/
if (hosts_allow_table != NULL && hosts_deny_table != NULL) {
/* Most common case...nothing more necessary */
} else if (hosts_allow_table == NULL && hosts_deny_table != NULL) {
/* Log the missing file */
pr_log_pri(PR_LOG_INFO, MOD_WRAP_VERSION ": no usable allow access file -- "
"allowing connection");
return DECLINED(cmd);
} else if (hosts_allow_table != NULL && hosts_deny_table == NULL) {
/* log the missing file */
pr_log_pri(PR_LOG_INFO, MOD_WRAP_VERSION ": no usable deny access file -- "
"allowing connection");
return DECLINED(cmd);
} else {
/* Neither set -- assume the admin hasn't configured these directives
* at all.
*/
return DECLINED(cmd);
}
/* Log the names of the allow/deny files being used. */
pr_log_pri(PR_LOG_DEBUG, MOD_WRAP_VERSION ": using access files: %s, %s",
hosts_allow_table, hosts_deny_table);
/* retrieve the user-defined syslog priorities, if any. Fall back to the
* defaults as seen in tcpd.h if not defined.
*/
syslog_conf = find_config(main_server->conf, CONF_PARAM,
"TCPAccessSyslogLevels", FALSE);
if (syslog_conf) {
allow_severity = (int) syslog_conf->argv[1];
deny_severity = (int) syslog_conf->argv[2];
} else {
allow_severity = PR_LOG_INFO;
deny_severity = PR_LOG_WARNING;
}
pr_log_debug(DEBUG4, MOD_WRAP_VERSION ": checking under service name '%s'",
wrap_service_name);
request_init(&request, RQ_DAEMON, wrap_service_name, RQ_FILE,
session.c->rfd, 0);
fromhost(&request);
if (STR_EQ(eval_hostname(request.client), paranoid) ||
!hosts_access(&request)) {
char *denymsg = NULL;
/* log the denied connection */
wrap_log_request_denied(deny_severity, &request);
/* check for AccessDenyMsg */
if ((denymsg = (char *) get_param_ptr(TOPLEVEL_CONF, "AccessDenyMsg",
FALSE)) != NULL)
denymsg = sreplace(cmd->tmp_pool, denymsg, "%u", user, NULL);
if (denymsg)
return ERROR_MSG(cmd, R_530, denymsg);
else
return ERROR_MSG(cmd, R_530, "Access denied.");
}
/* If request is allowable, return DECLINED (for engine to act as if this
* handler was never called, else ERROR (for engine to abort processing and
* deny request.
*/
wrap_log_request_allowed(allow_severity, &request);
return DECLINED(cmd);
}
int main(int argc, char *argv[])
{
struct request_info request;
char path[MAXPATHNAMELEN];
/* Attempt to prevent the creation of world-writable files. */
#ifdef DAEMON_UMASK
umask(DAEMON_UMASK);
#endif
/*
* If argv[0] is an absolute path name, ignore REAL_DAEMON_DIR, and strip
* argv[0] to its basename.
*/
if (argv[0][0] == '/') {
strlcpy(path, argv[0], sizeof path);
argv[0] = strrchr(argv[0], '/') + 1;
} else {
snprintf(path, sizeof path, "%s/%s", REAL_DAEMON_DIR, argv[0]);
}
/*
* Open a channel to the syslog daemon. Older versions of openlog()
* require only two arguments.
*/
#ifdef LOG_MAIL
(void) openlog(argv[0], LOG_PID, FACILITY);
#else
(void) openlog(argv[0], LOG_PID);
#endif
/*
* Find out the endpoint addresses of this conversation. Host name
* lookups and double checks will be done on demand.
*/
request_init(&request, RQ_DAEMON, argv[0], RQ_FILE, STDIN_FILENO, 0);
fromhost(&request);
/*
* Optionally look up and double check the remote host name. Sites
* concerned with security may choose to refuse connections from hosts
* that pretend to have someone elses host name.
*/
#ifdef PARANOID
if (STR_EQ(eval_hostname(request.client), paranoid))
refuse(&request);
#endif
/*
* The BSD rlogin and rsh daemons that came out after 4.3 BSD disallow
* socket options at the IP level. They do so for a good reason.
* Unfortunately, we cannot use this with SunOS 4.1.x because the
* getsockopt() system call can panic the system.
*/
#ifdef KILL_IP_OPTIONS
fix_options(&request);
#endif
/*
* Check whether this host can access the service in argv[0]. The
* access-control code invokes optional shell commands as specified in
* the access-control tables.
*/
#ifdef HOSTS_ACCESS
if (!hosts_access(&request))
refuse(&request);
#endif
/* Report request and invoke the real daemon program. */
syslog(allow_severity, "connect from %s", eval_client(&request));
closelog();
(void) execv(path, argv);
syslog(LOG_ERR, "error: cannot execute %s: %m", path);
clean_exit(&request);
/* NOTREACHED */
}
