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construct/authd/providers/rdns.c
Elizabeth Myers 2b0cc3d36a Redo of the authd-framework branch.
This is basically most of the code from the authd-framework branch, but
written to the new DNS code in master. Not quite done yet but getting
there.
2016-03-17 16:23:27 -05:00

210 lines
5 KiB
C

/* authd/providers/rdns.c - rDNS lookup provider for authd
* Copyright (c) 2016 Elizabeth Myers <elizabeth@interlinked.me>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice is present in all copies.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "stdinc.h"
#include "rb_commio.h"
#include "authd.h"
#include "provider.h"
#include "res.h"
#include "dns.h"
struct user_query
{
rb_dlink_node node;
struct auth_client *auth; /* Our client */
struct dns_query *query; /* Pending DNS query */
time_t timeout; /* When the request times out */
};
/* Goinked from old s_auth.c --Elizabeth */
static const char *messages[] =
{
"*** Looking up your hostname...",
"*** Found your hostname",
"*** Couldn't look up your hostname",
"*** Your hostname is too long, ignoring hostname",
};
typedef enum
{
REPORT_LOOKUP,
REPORT_FOUND,
REPORT_FAIL,
REPORT_TOOLONG,
} dns_message;
static void client_fail(struct user_query *query, dns_message message);
static void client_success(struct user_query *query);
static void get_dns_answer(const char *res, bool status, query_type type, void *data);
static struct ev_entry *timeout_ev;
static EVH timeout_dns_queries_event;
static int rdns_timeout = 30;
static rb_dlink_list queries; /* Stored here for easy timeout */
bool client_dns_init(void)
{
timeout_ev = rb_event_addish("timeout_dns_queries_event", timeout_dns_queries_event, NULL, 5);
return (timeout_ev != NULL);
}
void client_dns_destroy(void)
{
rb_dlink_node *ptr, *nptr;
struct user_query *query;
RB_DLINK_FOREACH_SAFE(ptr, nptr, queries.head)
{
client_fail(ptr->data, REPORT_FAIL);
rb_dlinkDelete(ptr, &queries);
rb_free(ptr);
}
rb_event_delete(timeout_ev);
}
bool client_dns_start(struct auth_client *auth)
{
struct user_query *query = rb_malloc(sizeof(struct user_query));
query->auth = auth;
query->timeout = rb_current_time() + rdns_timeout;
query->query = lookup_hostname(auth->c_ip, get_dns_answer, query);
notice_client(auth, messages[REPORT_LOOKUP]);
set_provider(auth, PROVIDER_RDNS);
return true;
}
void client_dns_cancel(struct auth_client *auth)
{
rb_dlink_node *ptr, *nptr;
RB_DLINK_FOREACH_SAFE(ptr, nptr, queries.head)
{
struct user_query *query = ptr->data;
if(query->auth == auth)
{
/* Victim found */
client_fail(query, REPORT_FAIL);
rb_dlinkDelete(ptr, &queries);
rb_free(query);
return;
}
}
}
static void
get_dns_answer(const char *res, bool status, query_type type, void *data)
{
struct user_query *query = data;
struct auth_client *auth = query->auth;
bool fail = false;
dns_message response;
rb_dlink_node *ptr, *nptr;
if(res == NULL || status == false)
{
response = REPORT_FAIL;
fail = true;
goto cleanup;
}
else if(strlen(res) > HOSTLEN)
{
/* Ah well. */
response = REPORT_TOOLONG;
fail = true;
goto cleanup;
}
rb_strlcpy(auth->hostname, res, HOSTLEN + 1);
cleanup:
/* Clean us up off the pending queries list */
RB_DLINK_FOREACH_SAFE(ptr, nptr, queries.head)
{
struct user_query *query_l = ptr->data;
if(query == query_l)
{
/* Found */
if(fail)
client_fail(query, response);
else
client_success(query);
rb_dlinkDelete(ptr, &queries);
rb_free(query);
return;
}
}
}
/* Timeout outstanding queries */
static void timeout_dns_queries_event(void *notused)
{
rb_dlink_node *ptr, *nptr;
RB_DLINK_FOREACH_SAFE(ptr, nptr, queries.head)
{
struct user_query *query = ptr->data;
if(query->auth && query->timeout < rb_current_time())
{
client_fail(query, REPORT_FAIL);
rb_dlinkDelete(ptr, &queries);
rb_free(query);
return;
}
}
}
static void client_fail(struct user_query *query, dns_message report)
{
struct auth_client *auth = query->auth;
rb_strlcpy(auth->hostname, "*", sizeof(auth->hostname));
notice_client(auth, messages[report]);
cancel_query(query->query);
provider_done(auth, PROVIDER_RDNS);
}
static void client_success(struct user_query *query)
{
struct auth_client *auth = query->auth;
notice_client(auth, messages[REPORT_FOUND]);
cancel_query(query->query);
provider_done(auth, PROVIDER_RDNS);
}
struct auth_provider rdns_provider =
{
.id = PROVIDER_RDNS,
.init = client_dns_init,
.destroy = client_dns_destroy,
.start = client_dns_start,
.cancel = client_dns_cancel,
.completed = NULL,
};