/*
This file is part of GNUnet.
Copyright (C) 2016, 2017 GNUnet e.V.
GNUnet is free software: you can redistribute it and/or modify it
under the terms of the GNU Affero General Public License as published
by the Free Software Foundation, either version 3 of the License,
or (at your option) any later version.
GNUnet is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see .
SPDX-License-Identifier: AGPL3.0-or-later
*/
/**
* @file nat-auto/gnunet-service-nat-auto.c
* @brief NAT autoconfiguration service
* @author Christian Grothoff
*
* TODO:
* - merge client handle and autoconfig context
* - implement "more" autoconfig:
* + re-work gnunet-nat-server & integrate!
* + integrate "legacy" code
* + test manually punched NAT (how?)
*/
#include "platform.h"
#include
#include "gnunet_util_lib.h"
#include "gnunet_protocols.h"
#include "gnunet_signatures.h"
#include "gnunet_nat_service.h"
#include "gnunet_statistics_service.h"
#include "gnunet_resolver_service.h"
#include "nat-auto.h"
#include
/**
* How long do we wait until we forcefully terminate autoconfiguration?
*/
#define AUTOCONFIG_TIMEOUT GNUNET_TIME_relative_multiply ( \
GNUNET_TIME_UNIT_SECONDS, 5)
/**
* Internal data structure we track for each of our clients.
*/
struct ClientHandle
{
/**
* Kept in a DLL.
*/
struct ClientHandle *next;
/**
* Kept in a DLL.
*/
struct ClientHandle *prev;
/**
* Underlying handle for this client with the service.
*/
struct GNUNET_SERVICE_Client *client;
/**
* Message queue for communicating with the client.
*/
struct GNUNET_MQ_Handle *mq;
};
/**
* Context for autoconfiguration operations.
*/
struct AutoconfigContext
{
/**
* Kept in a DLL.
*/
struct AutoconfigContext *prev;
/**
* Kept in a DLL.
*/
struct AutoconfigContext *next;
/**
* Which client asked the question.
*/
struct ClientHandle *ch;
/**
* Configuration we are creating.
*/
struct GNUNET_CONFIGURATION_Handle *c;
/**
* Original configuration (for diffing).
*/
struct GNUNET_CONFIGURATION_Handle *orig;
/**
* Timeout task to force termination.
*/
struct GNUNET_SCHEDULER_Task *timeout_task;
/**
* #GNUNET_YES if upnpc should be used,
* #GNUNET_NO if upnpc should not be used,
* #GNUNET_SYSERR if we should simply not change the option.
*/
int enable_upnpc;
/**
* Status code to return to the client.
*/
enum GNUNET_NAT_StatusCode status_code;
/**
* NAT type to return to the client.
*/
enum GNUNET_NAT_Type type;
};
/**
* Head of client DLL.
*/
static struct ClientHandle *ch_head;
/**
* Tail of client DLL.
*/
static struct ClientHandle *ch_tail;
/**
* DLL of our autoconfiguration operations.
*/
static struct AutoconfigContext *ac_head;
/**
* DLL of our autoconfiguration operations.
*/
static struct AutoconfigContext *ac_tail;
/**
* Handle to our current configuration.
*/
static const struct GNUNET_CONFIGURATION_Handle *cfg;
/**
* Handle to the statistics service.
*/
static struct GNUNET_STATISTICS_Handle *stats;
/**
* Check validity of #GNUNET_MESSAGE_TYPE_NAT_REQUEST_AUTO_CFG message
* from client.
*
* @param cls client who sent the message
* @param message the message received
* @return #GNUNET_OK if message is well-formed
*/
static int
check_autoconfig_request (void *cls,
const struct
GNUNET_NAT_AUTO_AutoconfigRequestMessage *message)
{
return GNUNET_OK; /* checked later */
}
/**
* Stop all pending activities with respect to the @a ac
*
* @param ac autoconfiguration to terminate activities for
*/
static void
terminate_ac_activities (struct AutoconfigContext *ac)
{
if (NULL != ac->timeout_task)
{
GNUNET_SCHEDULER_cancel (ac->timeout_task);
ac->timeout_task = NULL;
}
}
/**
* Finish handling the autoconfiguration request and send
* the response to the client.
*
* @param cls the `struct AutoconfigContext` to conclude
*/
static void
conclude_autoconfig_request (void *cls)
{
struct AutoconfigContext *ac = cls;
struct ClientHandle *ch = ac->ch;
struct GNUNET_NAT_AUTO_AutoconfigResultMessage *arm;
struct GNUNET_MQ_Envelope *env;
size_t c_size;
char *buf;
struct GNUNET_CONFIGURATION_Handle *diff;
ac->timeout_task = NULL;
terminate_ac_activities (ac);
/* Send back response */
diff = GNUNET_CONFIGURATION_get_diff (ac->orig,
ac->c);
buf = GNUNET_CONFIGURATION_serialize (diff,
&c_size);
GNUNET_CONFIGURATION_destroy (diff);
env = GNUNET_MQ_msg_extra (arm,
c_size,
GNUNET_MESSAGE_TYPE_NAT_AUTO_CFG_RESULT);
arm->status_code = htonl ((uint32_t) ac->status_code);
arm->type = htonl ((uint32_t) ac->type);
GNUNET_memcpy (&arm[1],
buf,
c_size);
GNUNET_free (buf);
GNUNET_MQ_send (ch->mq,
env);
/* clean up */
GNUNET_CONFIGURATION_destroy (ac->orig);
GNUNET_CONFIGURATION_destroy (ac->c);
GNUNET_CONTAINER_DLL_remove (ac_head,
ac_tail,
ac);
GNUNET_free (ac);
GNUNET_SERVICE_client_continue (ch->client);
}
/**
* Check if all autoconfiguration operations have concluded,
* and if they have, send the result back to the client.
*
* @param ac autoconfiguation context to check
*/
static void
check_autoconfig_finished (struct AutoconfigContext *ac)
{
GNUNET_SCHEDULER_cancel (ac->timeout_task);
ac->timeout_task
= GNUNET_SCHEDULER_add_now (&conclude_autoconfig_request,
ac);
}
/**
* Update ENABLE_UPNPC configuration option.
*
* @param ac autoconfiguration to update
*/
static void
update_enable_upnpc_option (struct AutoconfigContext *ac)
{
switch (ac->enable_upnpc)
{
case GNUNET_YES:
GNUNET_CONFIGURATION_set_value_string (ac->c,
"NAT",
"ENABLE_UPNP",
"YES");
break;
case GNUNET_NO:
GNUNET_CONFIGURATION_set_value_string (ac->c,
"NAT",
"ENABLE_UPNP",
"NO");
break;
case GNUNET_SYSERR:
/* We are unsure, do not change option */
break;
}
}
/**
* Handler for #GNUNET_MESSAGE_TYPE_NAT_REQUEST_AUTO_CFG message from
* client.
*
* @param cls client who sent the message
* @param message the message received
*/
static void
handle_autoconfig_request (void *cls,
const struct
GNUNET_NAT_AUTO_AutoconfigRequestMessage *message)
{
struct ClientHandle *ch = cls;
size_t left = ntohs (message->header.size) - sizeof(*message);
struct AutoconfigContext *ac;
ac = GNUNET_new (struct AutoconfigContext);
ac->status_code = GNUNET_NAT_ERROR_SUCCESS;
ac->ch = ch;
ac->c = GNUNET_CONFIGURATION_create ();
if (GNUNET_OK !=
GNUNET_CONFIGURATION_deserialize (ac->c,
(const char *) &message[1],
left,
NULL))
{
GNUNET_break (0);
GNUNET_SERVICE_client_drop (ch->client);
GNUNET_CONFIGURATION_destroy (ac->c);
GNUNET_free (ac);
return;
}
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Received REQUEST_AUTO_CONFIG message from client\n");
GNUNET_CONTAINER_DLL_insert (ac_head,
ac_tail,
ac);
ac->orig
= GNUNET_CONFIGURATION_dup (ac->c);
ac->timeout_task
= GNUNET_SCHEDULER_add_delayed (AUTOCONFIG_TIMEOUT,
&conclude_autoconfig_request,
ac);
ac->enable_upnpc = GNUNET_SYSERR; /* undecided */
/* Probe for upnpc */
if (GNUNET_SYSERR ==
GNUNET_OS_check_helper_binary ("upnpc",
GNUNET_NO,
NULL))
{
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
_ ("UPnP client `upnpc` command not found, disabling UPnP\n"));
ac->enable_upnpc = GNUNET_NO;
}
else
{
/* We might at some point be behind NAT, try upnpc */
ac->enable_upnpc = GNUNET_YES;
}
update_enable_upnpc_option (ac);
/* Finally, check if we are already done */
check_autoconfig_finished (ac);
}
/**
* Task run during shutdown.
*
* @param cls unused
*/
static void
shutdown_task (void *cls)
{
struct AutoconfigContext *ac;
while (NULL != (ac = ac_head))
{
GNUNET_CONTAINER_DLL_remove (ac_head,
ac_tail,
ac);
terminate_ac_activities (ac);
GNUNET_free (ac);
}
if (NULL != stats)
{
GNUNET_STATISTICS_destroy (stats,
GNUNET_NO);
stats = NULL;
}
}
/**
* Setup NAT service.
*
* @param cls closure
* @param c configuration to use
* @param service the initialized service
*/
static void
run (void *cls,
const struct GNUNET_CONFIGURATION_Handle *c,
struct GNUNET_SERVICE_Handle *service)
{
cfg = c;
GNUNET_SCHEDULER_add_shutdown (&shutdown_task,
NULL);
stats = GNUNET_STATISTICS_create ("nat-auto",
cfg);
}
/**
* Callback called when a client connects to the service.
*
* @param cls closure for the service
* @param c the new client that connected to the service
* @param mq the message queue used to send messages to the client
* @return a `struct ClientHandle`
*/
static void *
client_connect_cb (void *cls,
struct GNUNET_SERVICE_Client *c,
struct GNUNET_MQ_Handle *mq)
{
struct ClientHandle *ch;
ch = GNUNET_new (struct ClientHandle);
ch->mq = mq;
ch->client = c;
GNUNET_CONTAINER_DLL_insert (ch_head,
ch_tail,
ch);
return ch;
}
/**
* Callback called when a client disconnected from the service
*
* @param cls closure for the service
* @param c the client that disconnected
* @param internal_cls a `struct ClientHandle *`
*/
static void
client_disconnect_cb (void *cls,
struct GNUNET_SERVICE_Client *c,
void *internal_cls)
{
struct ClientHandle *ch = internal_cls;
GNUNET_CONTAINER_DLL_remove (ch_head,
ch_tail,
ch);
GNUNET_free (ch);
}
/**
* Define "main" method using service macro.
*/
GNUNET_SERVICE_MAIN
("nat-auto",
GNUNET_SERVICE_OPTION_NONE,
&run,
&client_connect_cb,
&client_disconnect_cb,
NULL,
GNUNET_MQ_hd_var_size (autoconfig_request,
GNUNET_MESSAGE_TYPE_NAT_AUTO_REQUEST_CFG,
struct GNUNET_NAT_AUTO_AutoconfigRequestMessage,
NULL),
GNUNET_MQ_handler_end ());
#if defined(__linux__) && defined(__GLIBC__)
#include
/**
* MINIMIZE heap size (way below 128k) since this process doesn't need much.
*/
void __attribute__ ((constructor))
GNUNET_ARM_memory_init ()
{
mallopt (M_TRIM_THRESHOLD, 4 * 1024);
mallopt (M_TOP_PAD, 1 * 1024);
malloc_trim (0);
}
#endif
/* end of gnunet-service-nat.c */