/*
This file is part of GNUnet.
Copyright (C) 2009-2013 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 util/server.c
* @brief library for building GNUnet network servers
* @author Christian Grothoff
*/
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_protocols.h"
#define LOG_STRERROR_FILE(kind,syscall,filename) GNUNET_log_from_strerror_file (kind, "util-server", syscall, filename)
/**
* List of arrays of message handlers.
*/
struct HandlerList
{
/**
* This is a linked list.
*/
struct HandlerList *next;
/**
* NULL-terminated array of handlers.
*/
const struct GNUNET_SERVER_MessageHandler *handlers;
};
/**
* List of arrays of message handlers.
*/
struct NotifyList
{
/**
* This is a doubly linked list.
*/
struct NotifyList *next;
/**
* This is a doubly linked list.
*/
struct NotifyList *prev;
/**
* Function to call.
*/
GNUNET_SERVER_DisconnectCallback callback;
/**
* Closure for callback.
*/
void *callback_cls;
};
/**
* @brief handle for a server
*/
struct GNUNET_SERVER_Handle
{
/**
* List of handlers for incoming messages.
*/
struct HandlerList *handlers;
/**
* Head of list of our current clients.
*/
struct GNUNET_SERVER_Client *clients_head;
/**
* Head of list of our current clients.
*/
struct GNUNET_SERVER_Client *clients_tail;
/**
* Head of linked list of functions to call on disconnects by clients.
*/
struct NotifyList *disconnect_notify_list_head;
/**
* Tail of linked list of functions to call on disconnects by clients.
*/
struct NotifyList *disconnect_notify_list_tail;
/**
* Head of linked list of functions to call on connects by clients.
*/
struct NotifyList *connect_notify_list_head;
/**
* Tail of linked list of functions to call on connects by clients.
*/
struct NotifyList *connect_notify_list_tail;
/**
* Function to call for access control.
*/
GNUNET_CONNECTION_AccessCheck access_cb;
/**
* Closure for @e access_cb.
*/
void *access_cb_cls;
/**
* NULL-terminated array of sockets used to listen for new
* connections.
*/
struct GNUNET_NETWORK_Handle **listen_sockets;
/**
* After how long should an idle connection time
* out (on write).
*/
struct GNUNET_TIME_Relative idle_timeout;
/**
* Task scheduled to do the listening.
*/
struct GNUNET_SCHEDULER_Task * listen_task;
/**
* Alternative function to create a MST instance.
*/
GNUNET_SERVER_MstCreateCallback mst_create;
/**
* Alternative function to destroy a MST instance.
*/
GNUNET_SERVER_MstDestroyCallback mst_destroy;
/**
* Alternative function to give data to a MST instance.
*/
GNUNET_SERVER_MstReceiveCallback mst_receive;
/**
* Closure for 'mst_'-callbacks.
*/
void *mst_cls;
/**
* Do we ignore messages of types that we do not understand or do we
* require that a handler is found (and if not kill the connection)?
*/
int require_found;
/**
* Set to #GNUNET_YES once we are in 'soft' shutdown where we wait for
* all non-monitor clients to disconnect before we call
* #GNUNET_SERVER_destroy. See test_monitor_clients(). Set to
* #GNUNET_SYSERR once the final destroy task has been scheduled
* (we cannot run it in the same task).
*/
int in_soft_shutdown;
};
/**
* Handle server returns for aborting transmission to a client.
*/
struct GNUNET_SERVER_TransmitHandle
{
/**
* Function to call to get the message.
*/
GNUNET_CONNECTION_TransmitReadyNotify callback;
/**
* Closure for @e callback
*/
void *callback_cls;
/**
* Active connection transmission handle.
*/
struct GNUNET_CONNECTION_TransmitHandle *cth;
};
/**
* @brief handle for a client of the server
*/
struct GNUNET_SERVER_Client
{
/**
* This is a doubly linked list.
*/
struct GNUNET_SERVER_Client *next;
/**
* This is a doubly linked list.
*/
struct GNUNET_SERVER_Client *prev;
/**
* Processing of incoming data.
*/
void *mst;
/**
* Server that this client belongs to.
*/
struct GNUNET_SERVER_Handle *server;
/**
* Client closure for callbacks.
*/
struct GNUNET_CONNECTION_Handle *connection;
/**
* User context value, manipulated using
* 'GNUNET_SERVER_client_{get/set}_user_context' functions.
*/
void *user_context;
/**
* ID of task used to restart processing.
*/
struct GNUNET_SCHEDULER_Task * restart_task;
/**
* Task that warns about missing calls to #GNUNET_SERVER_receive_done.
*/
struct GNUNET_SCHEDULER_Task * warn_task;
/**
* Time when the warn task was started.
*/
struct GNUNET_TIME_Absolute warn_start;
/**
* Last activity on this socket (used to time it out
* if reference_count == 0).
*/
struct GNUNET_TIME_Absolute last_activity;
/**
* Transmission handle we return for this client from
* #GNUNET_SERVER_notify_transmit_ready.
*/
struct GNUNET_SERVER_TransmitHandle th;
/**
* After how long should an idle connection time
* out (on write).
*/
struct GNUNET_TIME_Relative idle_timeout;
/**
* Number of external entities with a reference to
* this client object.
*/
unsigned int reference_count;
/**
* Was processing if incoming messages suspended while
* we were still processing data already received?
* This is a counter saying how often processing was
* suspended (once per handler invoked).
*/
unsigned int suspended;
/**
* Last size given when user context was initialized; used for
* sanity check.
*/
size_t user_context_size;
/**
* Are we currently in the "process_client_buffer" function (and
* will hence restart the receive job on exit if suspended == 0 once
* we are done?). If this is set, then "receive_done" will
* essentially only decrement suspended; if this is not set, then
* "receive_done" may need to restart the receive process (either
* from the side-buffer or via select/recv).
*/
int in_process_client_buffer;
/**
* We're about to close down this client.
*/
int shutdown_now;
/**
* Are we currently trying to receive? (#GNUNET_YES if we are,
* #GNUNET_NO if we are not, #GNUNET_SYSERR if data is already
* available in MST).
*/
int receive_pending;
/**
* Persist the file handle for this client no matter what happens,
* force the OS to close once the process actually dies. Should only
* be used in special cases!
*/
int persist;
/**
* Is this client a 'monitor' client that should not be counted
* when deciding on destroying the server during soft shutdown?
* (see also #GNUNET_SERVICE_start)
*/
int is_monitor;
/**
* Type of last message processed (for warn_no_receive_done).
*/
uint16_t warn_type;
};
/**
* Return user context associated with the given client.
* Note: you should probably use the macro (call without the underscore).
*
* @param client client to query
* @param size number of bytes in user context struct (for verification only)
* @return pointer to user context
*/
void *
GNUNET_SERVER_client_get_user_context_ (struct GNUNET_SERVER_Client *client,
size_t size)
{
if ((0 == client->user_context_size) &&
(NULL == client->user_context))
return NULL; /* never set */
GNUNET_assert (size == client->user_context_size);
return client->user_context;
}
/**
* Set user context to be associated with the given client.
* Note: you should probably use the macro (call without the underscore).
*
* @param client client to query
* @param ptr pointer to user context
* @param size number of bytes in user context struct (for verification only)
*/
void
GNUNET_SERVER_client_set_user_context_ (struct GNUNET_SERVER_Client *client,
void *ptr,
size_t size)
{
if (NULL == ptr)
{
client->user_context_size = 0;
client->user_context = ptr;
return;
}
client->user_context_size = size;
client->user_context = ptr;
}
/**
* Scheduler says our listen socket is ready. Process it!
*
* @param cls handle to our server for which we are processing the listen
* socket
*/
static void
process_listen_socket (void *cls)
{
struct GNUNET_SERVER_Handle *server = cls;
const struct GNUNET_SCHEDULER_TaskContext *tc;
struct GNUNET_CONNECTION_Handle *sock;
unsigned int i;
server->listen_task = NULL;
tc = GNUNET_SCHEDULER_get_task_context ();
for (i = 0; NULL != server->listen_sockets[i]; i++)
{
if (GNUNET_NETWORK_fdset_isset (tc->read_ready,
server->listen_sockets[i]))
{
sock =
GNUNET_CONNECTION_create_from_accept (server->access_cb,
server->access_cb_cls,
server->listen_sockets[i]);
if (NULL != sock)
{
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Server accepted incoming connection.\n");
(void) GNUNET_SERVER_connect_socket (server,
sock);
}
}
}
/* listen for more! */
GNUNET_SERVER_resume (server);
}
/**
* Create and initialize a listen socket for the server.
*
* @param server_addr address to listen on
* @param socklen length of @a server_addr
* @return NULL on error, otherwise the listen socket
*/
static struct GNUNET_NETWORK_Handle *
open_listen_socket (const struct sockaddr *server_addr,
socklen_t socklen)
{
struct GNUNET_NETWORK_Handle *sock;
uint16_t port;
int eno;
switch (server_addr->sa_family)
{
case AF_INET:
port = ntohs (((const struct sockaddr_in *) server_addr)->sin_port);
break;
case AF_INET6:
port = ntohs (((const struct sockaddr_in6 *) server_addr)->sin6_port);
break;
case AF_UNIX:
port = 0;
break;
default:
GNUNET_break (0);
port = 0;
break;
}
sock = GNUNET_NETWORK_socket_create (server_addr->sa_family, SOCK_STREAM, 0);
if (NULL == sock)
{
LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR, "socket");
errno = 0;
return NULL;
}
/* bind the socket */
if (GNUNET_OK != GNUNET_NETWORK_socket_bind (sock, server_addr, socklen))
{
eno = errno;
if (EADDRINUSE != errno)
{
/* we don't log 'EADDRINUSE' here since an IPv4 bind may
* fail if we already took the port on IPv6; if both IPv4 and
* IPv6 binds fail, then our caller will log using the
* errno preserved in 'eno' */
LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR,
"bind");
if (0 != port)
LOG (GNUNET_ERROR_TYPE_ERROR,
_("`%s' failed for port %d (%s).\n"),
"bind",
port,
(AF_INET == server_addr->sa_family) ? "IPv4" : "IPv6");
eno = 0;
}
else
{
if (0 != port)
LOG (GNUNET_ERROR_TYPE_WARNING,
_("`%s' failed for port %d (%s): address already in use\n"),
"bind", port,
(AF_INET == server_addr->sa_family) ? "IPv4" : "IPv6");
else if (AF_UNIX == server_addr->sa_family)
{
LOG (GNUNET_ERROR_TYPE_WARNING,
_("`%s' failed for `%s': address already in use\n"),
"bind",
GNUNET_a2s (server_addr, socklen));
}
}
GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (sock));
errno = eno;
return NULL;
}
if (GNUNET_OK != GNUNET_NETWORK_socket_listen (sock, 5))
{
LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR,
"listen");
GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (sock));
errno = 0;
return NULL;
}
if (0 != port)
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Server starts to listen on port %u.\n",
port);
return sock;
}
/**
* Create a new server.
*
* @param access_cb function for access control
* @param access_cb_cls closure for @a access_cb
* @param lsocks NULL-terminated array of listen sockets
* @param idle_timeout after how long should we timeout idle connections?
* @param require_found if #GNUNET_YES, connections sending messages of unknown type
* will be closed
* @return handle for the new server, NULL on error
* (typically, "port" already in use)
*/
struct GNUNET_SERVER_Handle *
GNUNET_SERVER_create_with_sockets (GNUNET_CONNECTION_AccessCheck access_cb,
void *access_cb_cls,
struct GNUNET_NETWORK_Handle **lsocks,
struct GNUNET_TIME_Relative idle_timeout,
int require_found)
{
struct GNUNET_SERVER_Handle *server;
server = GNUNET_new (struct GNUNET_SERVER_Handle);
server->idle_timeout = idle_timeout;
server->listen_sockets = lsocks;
server->access_cb = access_cb;
server->access_cb_cls = access_cb_cls;
server->require_found = require_found;
if (NULL != lsocks)
GNUNET_SERVER_resume (server);
return server;
}
/**
* Create a new server.
*
* @param access_cb function for access control
* @param access_cb_cls closure for @a access_cb
* @param server_addr address to listen on (including port), NULL terminated array
* @param socklen length of server_addr
* @param idle_timeout after how long should we timeout idle connections?
* @param require_found if YES, connections sending messages of unknown type
* will be closed
* @return handle for the new server, NULL on error
* (typically, "port" already in use)
*/
struct GNUNET_SERVER_Handle *
GNUNET_SERVER_create (GNUNET_CONNECTION_AccessCheck access_cb,
void *access_cb_cls,
struct sockaddr *const *server_addr,
const socklen_t * socklen,
struct GNUNET_TIME_Relative idle_timeout,
int require_found)
{
struct GNUNET_NETWORK_Handle **lsocks;
unsigned int i;
unsigned int j;
unsigned int k;
int seen;
i = 0;
while (NULL != server_addr[i])
i++;
if (i > 0)
{
lsocks = GNUNET_malloc (sizeof (struct GNUNET_NETWORK_Handle *) * (i + 1));
i = 0;
j = 0;
while (NULL != server_addr[i])
{
seen = 0;
for (k=0;kis_monitor = GNUNET_YES;
}
/**
* Helper function for #test_monitor_clients() to trigger
* #GNUNET_SERVER_destroy() after the stack has unwound.
*
* @param cls the `struct GNUNET_SERVER_Handle *` to destroy
*/
static void
do_destroy (void *cls)
{
struct GNUNET_SERVER_Handle *server = cls;
GNUNET_SERVER_destroy (server);
}
/**
* Check if only 'monitor' clients are left. If so, destroy the
* server completely.
*
* @param server server to test for full shutdown
*/
static void
test_monitor_clients (struct GNUNET_SERVER_Handle *server)
{
struct GNUNET_SERVER_Client *client;
if (GNUNET_YES != server->in_soft_shutdown)
return;
for (client = server->clients_head; NULL != client; client = client->next)
if (GNUNET_NO == client->is_monitor)
return; /* not done yet */
server->in_soft_shutdown = GNUNET_SYSERR;
(void) GNUNET_SCHEDULER_add_now (&do_destroy, server);
}
/**
* Suspend accepting connections from the listen socket temporarily.
*
* @param server server to stop accepting connections.
*/
void
GNUNET_SERVER_suspend (struct GNUNET_SERVER_Handle *server)
{
if (NULL != server->listen_task)
{
GNUNET_SCHEDULER_cancel (server->listen_task);
server->listen_task = NULL;
}
}
/**
* Resume accepting connections from the listen socket.
*
* @param server server to stop accepting connections.
*/
void
GNUNET_SERVER_resume (struct GNUNET_SERVER_Handle *server)
{
struct GNUNET_NETWORK_FDSet *r;
unsigned int i;
if (NULL == server->listen_sockets)
return;
if (NULL == server->listen_sockets[0])
return; /* nothing to do, no listen sockets! */
if (NULL == server->listen_sockets[1])
{
/* simplified method: no fd set needed; this is then much simpler
and much more efficient */
server->listen_task =
GNUNET_SCHEDULER_add_read_net_with_priority (GNUNET_TIME_UNIT_FOREVER_REL,
GNUNET_SCHEDULER_PRIORITY_HIGH,
server->listen_sockets[0],
&process_listen_socket, server);
return;
}
r = GNUNET_NETWORK_fdset_create ();
i = 0;
while (NULL != server->listen_sockets[i])
GNUNET_NETWORK_fdset_set (r, server->listen_sockets[i++]);
server->listen_task =
GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_HIGH,
GNUNET_TIME_UNIT_FOREVER_REL, r, NULL,
&process_listen_socket, server);
GNUNET_NETWORK_fdset_destroy (r);
}
/**
* Stop the listen socket and get ready to shutdown the server
* once only 'monitor' clients are left.
*
* @param server server to stop listening on
*/
void
GNUNET_SERVER_stop_listening (struct GNUNET_SERVER_Handle *server)
{
unsigned int i;
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Server in soft shutdown\n");
if (NULL != server->listen_task)
{
GNUNET_SCHEDULER_cancel (server->listen_task);
server->listen_task = NULL;
}
if (NULL != server->listen_sockets)
{
i = 0;
while (NULL != server->listen_sockets[i])
GNUNET_break (GNUNET_OK ==
GNUNET_NETWORK_socket_close (server->listen_sockets[i++]));
GNUNET_free (server->listen_sockets);
server->listen_sockets = NULL;
}
if (GNUNET_NO == server->in_soft_shutdown)
server->in_soft_shutdown = GNUNET_YES;
test_monitor_clients (server);
}
/**
* Free resources held by this server.
*
* @param server server to destroy
*/
void
GNUNET_SERVER_destroy (struct GNUNET_SERVER_Handle *server)
{
struct HandlerList *hpos;
struct NotifyList *npos;
unsigned int i;
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Server shutting down.\n");
if (NULL != server->listen_task)
{
GNUNET_SCHEDULER_cancel (server->listen_task);
server->listen_task = NULL;
}
if (NULL != server->listen_sockets)
{
i = 0;
while (NULL != server->listen_sockets[i])
GNUNET_break (GNUNET_OK ==
GNUNET_NETWORK_socket_close (server->listen_sockets[i++]));
GNUNET_free (server->listen_sockets);
server->listen_sockets = NULL;
}
while (NULL != server->clients_head)
GNUNET_SERVER_client_disconnect (server->clients_head);
while (NULL != (hpos = server->handlers))
{
server->handlers = hpos->next;
GNUNET_free (hpos);
}
while (NULL != (npos = server->disconnect_notify_list_head))
{
npos->callback (npos->callback_cls,
NULL);
GNUNET_CONTAINER_DLL_remove (server->disconnect_notify_list_head,
server->disconnect_notify_list_tail,
npos);
GNUNET_free (npos);
}
while (NULL != (npos = server->connect_notify_list_head))
{
npos->callback (npos->callback_cls,
NULL);
GNUNET_CONTAINER_DLL_remove (server->connect_notify_list_head,
server->connect_notify_list_tail,
npos);
GNUNET_free (npos);
}
GNUNET_free (server);
}
/**
* Add additional handlers to an existing server.
*
* @param server the server to add handlers to
* @param handlers array of message handlers for
* incoming messages; the last entry must
* have "NULL" for the "callback"; multiple
* entries for the same type are allowed,
* they will be called in order of occurence.
* These handlers can be removed later;
* the handlers array must exist until removed
* (or server is destroyed).
*/
void
GNUNET_SERVER_add_handlers (struct GNUNET_SERVER_Handle *server,
const struct GNUNET_SERVER_MessageHandler *handlers)
{
struct HandlerList *p;
p = GNUNET_new (struct HandlerList);
p->handlers = handlers;
p->next = server->handlers;
server->handlers = p;
}
/**
* Change functions used by the server to tokenize the message stream.
* (very rarely used).
*
* @param server server to modify
* @param create new tokenizer initialization function
* @param destroy new tokenizer destruction function
* @param receive new tokenizer receive function
* @param cls closure for @a create, @a receive, @a destroy
*/
void
GNUNET_SERVER_set_callbacks (struct GNUNET_SERVER_Handle *server,
GNUNET_SERVER_MstCreateCallback create,
GNUNET_SERVER_MstDestroyCallback destroy,
GNUNET_SERVER_MstReceiveCallback receive,
void *cls)
{
server->mst_create = create;
server->mst_destroy = destroy;
server->mst_receive = receive;
server->mst_cls = cls;
}
/**
* Task run to warn about missing calls to #GNUNET_SERVER_receive_done.
*
* @param cls our `struct GNUNET_SERVER_Client *` to process more requests from
*/
static void
warn_no_receive_done (void *cls)
{
struct GNUNET_SERVER_Client *client = cls;
GNUNET_break (0 != client->warn_type); /* type should never be 0 here, as we don't use 0 */
client->warn_task =
GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
&warn_no_receive_done, client);
LOG (GNUNET_ERROR_TYPE_WARNING,
_("Processing code for message of type %u did not call `GNUNET_SERVER_receive_done' after %s\n"),
(unsigned int) client->warn_type,
GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_duration (client->warn_start),
GNUNET_YES));
}
/**
* Disable the warning the server issues if a message is not acknowledged
* in a timely fashion. Use this call if a client is intentionally delayed
* for a while. Only applies to the current message.
*
* @param client client for which to disable the warning
*/
void
GNUNET_SERVER_disable_receive_done_warning (struct GNUNET_SERVER_Client *client)
{
if (NULL != client->warn_task)
{
GNUNET_SCHEDULER_cancel (client->warn_task);
client->warn_task = NULL;
}
}
/**
* Inject a message into the server, pretend it came
* from the specified client. Delivery of the message
* will happen instantly (if a handler is installed;
* otherwise the call does nothing).
*
* @param server the server receiving the message
* @param sender the "pretended" sender of the message
* can be NULL!
* @param message message to transmit
* @return #GNUNET_OK if the message was OK and the
* connection can stay open
* #GNUNET_SYSERR if the connection to the
* client should be shut down
*/
int
GNUNET_SERVER_inject (struct GNUNET_SERVER_Handle *server,
struct GNUNET_SERVER_Client *sender,
const struct GNUNET_MessageHeader *message)
{
struct HandlerList *pos;
const struct GNUNET_SERVER_MessageHandler *mh;
unsigned int i;
uint16_t type;
uint16_t size;
int found;
type = ntohs (message->type);
size = ntohs (message->size);
LOG (GNUNET_ERROR_TYPE_INFO,
"Received message of type %u and size %u from client\n",
type, size);
found = GNUNET_NO;
for (pos = server->handlers; NULL != pos; pos = pos->next)
{
i = 0;
while (pos->handlers[i].callback != NULL)
{
mh = &pos->handlers[i];
if ((mh->type == type) || (mh->type == GNUNET_MESSAGE_TYPE_ALL))
{
if ((0 != mh->expected_size) && (mh->expected_size != size))
{
#if GNUNET8_NETWORK_IS_DEAD
LOG (GNUNET_ERROR_TYPE_WARNING,
"Expected %u bytes for message of type %u, got %u\n",
mh->expected_size, mh->type, size);
GNUNET_break_op (0);
#else
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Expected %u bytes for message of type %u, got %u\n",
mh->expected_size, mh->type, size);
#endif
return GNUNET_SYSERR;
}
if (NULL != sender)
{
if ( (0 == sender->suspended) &&
(NULL == sender->warn_task) )
{
GNUNET_break (0 != type); /* type should never be 0 here, as we don't use 0 */
sender->warn_start = GNUNET_TIME_absolute_get ();
sender->warn_task =
GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
&warn_no_receive_done,
sender);
sender->warn_type = type;
}
sender->suspended++;
}
mh->callback (mh->callback_cls, sender, message);
found = GNUNET_YES;
}
i++;
}
}
if (GNUNET_NO == found)
{
LOG (GNUNET_ERROR_TYPE_DEBUG | GNUNET_ERROR_TYPE_BULK,
"Received message of unknown type %d\n", type);
if (GNUNET_YES == server->require_found)
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
/**
* We are receiving an incoming message. Process it.
*
* @param cls our closure (handle for the client)
* @param buf buffer with data received from network
* @param available number of bytes available in buf
* @param addr address of the sender
* @param addrlen length of @a addr
* @param errCode code indicating errors receiving, 0 for success
*/
static void
process_incoming (void *cls,
const void *buf,
size_t available,
const struct sockaddr *addr,
socklen_t addrlen,
int errCode);
/**
* Process messages from the client's message tokenizer until either
* the tokenizer is empty (and then schedule receiving more), or
* until some handler is not immediately done (then wait for restart_processing)
* or shutdown.
*
* @param client the client to process, RC must have already been increased
* using #GNUNET_SERVER_client_keep and will be decreased by one in this
* function
* @param ret #GNUNET_NO to start processing from the buffer,
* #GNUNET_OK if the mst buffer is drained and we should instantly go back to receiving
* #GNUNET_SYSERR if we should instantly abort due to error in a previous step
*/
static void
process_mst (struct GNUNET_SERVER_Client *client,
int ret)
{
while ((GNUNET_SYSERR != ret) && (NULL != client->server) &&
(GNUNET_YES != client->shutdown_now) && (0 == client->suspended))
{
if (GNUNET_OK == ret)
{
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Server re-enters receive loop, timeout: %s.\n",
GNUNET_STRINGS_relative_time_to_string (client->idle_timeout, GNUNET_YES));
client->receive_pending = GNUNET_YES;
if (GNUNET_OK !=
GNUNET_CONNECTION_receive (client->connection,
GNUNET_MAX_MESSAGE_SIZE - 1,
client->idle_timeout,
&process_incoming,
client))
return;
break;
}
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Server processes additional messages instantly.\n");
if (NULL != client->server->mst_receive)
ret =
client->server->mst_receive (client->server->mst_cls, client->mst,
client, NULL, 0, GNUNET_NO, GNUNET_YES);
else
ret =
GNUNET_SERVER_mst_receive (client->mst, client, NULL, 0, GNUNET_NO,
GNUNET_YES);
}
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Server leaves instant processing loop: ret = %d, server = %p, shutdown = %d, suspended = %u\n",
ret, client->server,
client->shutdown_now,
client->suspended);
if (GNUNET_NO == ret)
{
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Server has more data pending but is suspended.\n");
client->receive_pending = GNUNET_SYSERR; /* data pending */
}
if ( (GNUNET_SYSERR == ret) ||
(GNUNET_YES == client->shutdown_now) )
GNUNET_SERVER_client_disconnect (client);
}
/**
* We are receiving an incoming message. Process it.
*
* @param cls our closure (handle for the client)
* @param buf buffer with data received from network
* @param available number of bytes available in buf
* @param addr address of the sender
* @param addrlen length of @a addr
* @param errCode code indicating errors receiving, 0 for success
*/
static void
process_incoming (void *cls,
const void *buf,
size_t available,
const struct sockaddr *addr,
socklen_t addrlen,
int errCode)
{
struct GNUNET_SERVER_Client *client = cls;
struct GNUNET_SERVER_Handle *server = client->server;
struct GNUNET_TIME_Absolute end;
struct GNUNET_TIME_Absolute now;
int ret;
GNUNET_assert (GNUNET_YES == client->receive_pending);
client->receive_pending = GNUNET_NO;
now = GNUNET_TIME_absolute_get ();
end = GNUNET_TIME_absolute_add (client->last_activity,
client->idle_timeout);
if ( (NULL == buf) &&
(0 == available) &&
(NULL == addr) &&
(0 == errCode) &&
(GNUNET_YES != client->shutdown_now) &&
(NULL != server) &&
(GNUNET_YES == GNUNET_CONNECTION_check (client->connection)) &&
(end.abs_value_us > now.abs_value_us) )
{
/* wait longer, timeout changed (i.e. due to us sending) */
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Receive time out, but no disconnect due to sending (%p)\n",
client);
client->receive_pending = GNUNET_YES;
GNUNET_CONNECTION_receive (client->connection,
GNUNET_MAX_MESSAGE_SIZE - 1,
GNUNET_TIME_absolute_get_remaining (end),
&process_incoming,
client);
return;
}
if ( (NULL == buf) ||
(0 == available) ||
(0 != errCode) ||
(NULL == server) ||
(GNUNET_YES == client->shutdown_now) ||
(GNUNET_YES != GNUNET_CONNECTION_check (client->connection)) )
{
/* other side closed connection, error connecting, etc. */
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Failed to connect or other side closed connection (%p)\n",
client);
GNUNET_SERVER_client_disconnect (client);
return;
}
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Server receives %u bytes from `%s'.\n",
(unsigned int) available,
GNUNET_a2s (addr, addrlen));
GNUNET_SERVER_client_keep (client);
client->last_activity = now;
if (NULL != server->mst_receive)
{
ret = client->server->mst_receive (client->server->mst_cls,
client->mst,
client,
buf,
available,
GNUNET_NO,
GNUNET_YES);
}
else if (NULL != client->mst)
{
ret =
GNUNET_SERVER_mst_receive (client->mst,
client,
buf,
available,
GNUNET_NO,
GNUNET_YES);
}
else
{
GNUNET_break (0);
return;
}
process_mst (client,
ret);
GNUNET_SERVER_client_drop (client);
}
/**
* Task run to start again receiving from the network
* and process requests.
*
* @param cls our `struct GNUNET_SERVER_Client *` to process more requests from
*/
static void
restart_processing (void *cls)
{
struct GNUNET_SERVER_Client *client = cls;
GNUNET_assert (GNUNET_YES != client->shutdown_now);
client->restart_task = NULL;
if (GNUNET_NO == client->receive_pending)
{
LOG (GNUNET_ERROR_TYPE_DEBUG, "Server begins to read again from client.\n");
client->receive_pending = GNUNET_YES;
GNUNET_CONNECTION_receive (client->connection,
GNUNET_MAX_MESSAGE_SIZE - 1,
client->idle_timeout,
&process_incoming,
client);
return;
}
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Server continues processing messages still in the buffer.\n");
GNUNET_SERVER_client_keep (client);
client->receive_pending = GNUNET_NO;
process_mst (client,
GNUNET_NO);
GNUNET_SERVER_client_drop (client);
}
/**
* This function is called whenever our inbound message tokenizer has
* received a complete message.
*
* @param cls closure (struct GNUNET_SERVER_Handle)
* @param client identification of the client (`struct GNUNET_SERVER_Client *`)
* @param message the actual message
*
* @return #GNUNET_OK on success, #GNUNET_SYSERR to stop further processing
*/
static int
client_message_tokenizer_callback (void *cls,
void *client,
const struct GNUNET_MessageHeader *message)
{
struct GNUNET_SERVER_Handle *server = cls;
struct GNUNET_SERVER_Client *sender = client;
int ret;
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Tokenizer gives server message of type %u and size %u from client\n",
ntohs (message->type), ntohs (message->size));
sender->in_process_client_buffer = GNUNET_YES;
ret = GNUNET_SERVER_inject (server, sender, message);
sender->in_process_client_buffer = GNUNET_NO;
if ( (GNUNET_OK != ret) || (GNUNET_YES == sender->shutdown_now) )
{
GNUNET_SERVER_client_disconnect (sender);
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
/**
* Add a TCP socket-based connection to the set of handles managed by
* this server. Use this function for outgoing (P2P) connections that
* we initiated (and where this server should process incoming
* messages).
*
* @param server the server to use
* @param connection the connection to manage (client must
* stop using this connection from now on)
* @return the client handle
*/
struct GNUNET_SERVER_Client *
GNUNET_SERVER_connect_socket (struct GNUNET_SERVER_Handle *server,
struct GNUNET_CONNECTION_Handle *connection)
{
struct GNUNET_SERVER_Client *client;
struct NotifyList *n;
client = GNUNET_new (struct GNUNET_SERVER_Client);
client->connection = connection;
client->server = server;
client->last_activity = GNUNET_TIME_absolute_get ();
client->idle_timeout = server->idle_timeout;
GNUNET_CONTAINER_DLL_insert (server->clients_head,
server->clients_tail,
client);
if (NULL != server->mst_create)
client->mst =
server->mst_create (server->mst_cls, client);
else
client->mst =
GNUNET_SERVER_mst_create (&client_message_tokenizer_callback,
server);
GNUNET_assert (NULL != client->mst);
for (n = server->connect_notify_list_head; NULL != n; n = n->next)
n->callback (n->callback_cls, client);
client->receive_pending = GNUNET_YES;
if (GNUNET_SYSERR ==
GNUNET_CONNECTION_receive (client->connection,
GNUNET_MAX_MESSAGE_SIZE - 1,
client->idle_timeout,
&process_incoming,
client))
return NULL;
return client;
}
/**
* Change the timeout for a particular client. Decreasing the timeout
* may not go into effect immediately (only after the previous timeout
* times out or activity happens on the socket).
*
* @param client the client to update
* @param timeout new timeout for activities on the socket
*/
void
GNUNET_SERVER_client_set_timeout (struct GNUNET_SERVER_Client *client,
struct GNUNET_TIME_Relative timeout)
{
client->idle_timeout = timeout;
}
/**
* Notify the server that the given client handle should
* be kept (keeps the connection up if possible, increments
* the internal reference counter).
*
* @param client the client to keep
*/
void
GNUNET_SERVER_client_keep (struct GNUNET_SERVER_Client *client)
{
client->reference_count++;
}
/**
* Notify the server that the given client handle is no
* longer required. Decrements the reference counter. If
* that counter reaches zero an inactive connection maybe
* closed.
*
* @param client the client to drop
*/
void
GNUNET_SERVER_client_drop (struct GNUNET_SERVER_Client *client)
{
GNUNET_assert (client->reference_count > 0);
client->reference_count--;
if ((GNUNET_YES == client->shutdown_now) && (0 == client->reference_count))
GNUNET_SERVER_client_disconnect (client);
}
/**
* Obtain the network address of the other party.
*
* @param client the client to get the address for
* @param addr where to store the address
* @param addrlen where to store the length of the @a addr
* @return #GNUNET_OK on success
*/
int
GNUNET_SERVER_client_get_address (struct GNUNET_SERVER_Client *client,
void **addr, size_t * addrlen)
{
return GNUNET_CONNECTION_get_address (client->connection, addr, addrlen);
}
/**
* Ask the server to notify us whenever a client disconnects.
* This function is called whenever the actual network connection
* is closed; the reference count may be zero or larger than zero
* at this point.
*
* @param server the server manageing the clients
* @param callback function to call on disconnect
* @param callback_cls closure for @a callback
*/
void
GNUNET_SERVER_disconnect_notify (struct GNUNET_SERVER_Handle *server,
GNUNET_SERVER_DisconnectCallback callback,
void *callback_cls)
{
struct NotifyList *n;
n = GNUNET_new (struct NotifyList);
n->callback = callback;
n->callback_cls = callback_cls;
GNUNET_CONTAINER_DLL_insert (server->disconnect_notify_list_head,
server->disconnect_notify_list_tail,
n);
}
/**
* Ask the server to notify us whenever a client connects.
* This function is called whenever the actual network connection
* is opened. If the server is destroyed before this
* notification is explicitly cancelled, the 'callback' will
* once be called with a 'client' argument of NULL to indicate
* that the server itself is now gone (and that the callback
* won't be called anymore and also can no longer be cancelled).
*
* @param server the server manageing the clients
* @param callback function to call on sconnect
* @param callback_cls closure for @a callback
*/
void
GNUNET_SERVER_connect_notify (struct GNUNET_SERVER_Handle *server,
GNUNET_SERVER_ConnectCallback callback,
void *callback_cls)
{
struct NotifyList *n;
struct GNUNET_SERVER_Client *client;
n = GNUNET_new (struct NotifyList);
n->callback = callback;
n->callback_cls = callback_cls;
GNUNET_CONTAINER_DLL_insert (server->connect_notify_list_head,
server->connect_notify_list_tail,
n);
for (client = server->clients_head; NULL != client; client = client->next)
callback (callback_cls, client);
}
/**
* Ask the server to stop notifying us whenever a client connects.
*
* @param server the server manageing the clients
* @param callback function to call on connect
* @param callback_cls closure for @a callback
*/
void
GNUNET_SERVER_disconnect_notify_cancel (struct GNUNET_SERVER_Handle *server,
GNUNET_SERVER_DisconnectCallback callback,
void *callback_cls)
{
struct NotifyList *pos;
for (pos = server->disconnect_notify_list_head; NULL != pos; pos = pos->next)
if ((pos->callback == callback) && (pos->callback_cls == callback_cls))
break;
if (NULL == pos)
{
GNUNET_break (0);
return;
}
GNUNET_CONTAINER_DLL_remove (server->disconnect_notify_list_head,
server->disconnect_notify_list_tail,
pos);
GNUNET_free (pos);
}
/**
* Ask the server to stop notifying us whenever a client disconnects.
*
* @param server the server manageing the clients
* @param callback function to call on disconnect
* @param callback_cls closure for @a callback
*/
void
GNUNET_SERVER_connect_notify_cancel (struct GNUNET_SERVER_Handle *server,
GNUNET_SERVER_ConnectCallback callback,
void *callback_cls)
{
struct NotifyList *pos;
for (pos = server->connect_notify_list_head; NULL != pos; pos = pos->next)
if ((pos->callback == callback) && (pos->callback_cls == callback_cls))
break;
if (NULL == pos)
{
GNUNET_break (0);
return;
}
GNUNET_CONTAINER_DLL_remove (server->connect_notify_list_head,
server->connect_notify_list_tail,
pos);
GNUNET_free (pos);
}
/**
* Ask the server to disconnect from the given client.
* This is the same as returning #GNUNET_SYSERR from a message
* handler, except that it allows dropping of a client even
* when not handling a message from that client.
*
* @param client the client to disconnect from
*/
void
GNUNET_SERVER_client_disconnect (struct GNUNET_SERVER_Client *client)
{
struct GNUNET_SERVER_Handle *server = client->server;
struct NotifyList *n;
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Client is being disconnected from the server.\n");
if (NULL != client->restart_task)
{
GNUNET_SCHEDULER_cancel (client->restart_task);
client->restart_task = NULL;
}
if (NULL != client->warn_task)
{
GNUNET_SCHEDULER_cancel (client->warn_task);
client->warn_task = NULL;
}
if (GNUNET_YES == client->receive_pending)
{
GNUNET_CONNECTION_receive_cancel (client->connection);
client->receive_pending = GNUNET_NO;
}
client->shutdown_now = GNUNET_YES;
client->reference_count++; /* make sure nobody else clean up client... */
if ( (NULL != client->mst) &&
(NULL != server) )
{
GNUNET_CONTAINER_DLL_remove (server->clients_head,
server->clients_tail,
client);
if (NULL != server->mst_destroy)
server->mst_destroy (server->mst_cls,
client->mst);
else
GNUNET_SERVER_mst_destroy (client->mst);
client->mst = NULL;
for (n = server->disconnect_notify_list_head; NULL != n; n = n->next)
n->callback (n->callback_cls,
client);
}
client->reference_count--;
if (client->reference_count > 0)
{
LOG (GNUNET_ERROR_TYPE_DEBUG,
"RC of %p still positive, not destroying everything.\n",
client);
client->server = NULL;
return;
}
if (GNUNET_YES == client->in_process_client_buffer)
{
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Still processing inputs of %p, not destroying everything.\n",
client);
return;
}
LOG (GNUNET_ERROR_TYPE_DEBUG,
"RC of %p now zero, destroying everything.\n",
client);
if (GNUNET_YES == client->persist)
GNUNET_CONNECTION_persist_ (client->connection);
if (NULL != client->th.cth)
GNUNET_SERVER_notify_transmit_ready_cancel (&client->th);
GNUNET_CONNECTION_destroy (client->connection);
/* need to cancel again, as it might have been re-added
in the meantime (i.e. during callbacks) */
if (NULL != client->warn_task)
{
GNUNET_SCHEDULER_cancel (client->warn_task);
client->warn_task = NULL;
}
if (GNUNET_YES == client->receive_pending)
{
GNUNET_CONNECTION_receive_cancel (client->connection);
client->receive_pending = GNUNET_NO;
}
GNUNET_free (client);
/* we might be in soft-shutdown, test if we're done */
if (NULL != server)
test_monitor_clients (server);
}
/**
* Disable the "CORK" feature for communication with the given client,
* forcing the OS to immediately flush the buffer on transmission
* instead of potentially buffering multiple messages.
*
* @param client handle to the client
* @return #GNUNET_OK on success
*/
int
GNUNET_SERVER_client_disable_corking (struct GNUNET_SERVER_Client *client)
{
return GNUNET_CONNECTION_disable_corking (client->connection);
}
/**
* Wrapper for transmission notification that calls the original
* callback and update the last activity time for our connection.
*
* @param cls the `struct GNUNET_SERVER_Client *`
* @param size number of bytes we can transmit
* @param buf where to copy the message
* @return number of bytes actually transmitted
*/
static size_t
transmit_ready_callback_wrapper (void *cls, size_t size, void *buf)
{
struct GNUNET_SERVER_Client *client = cls;
GNUNET_CONNECTION_TransmitReadyNotify callback;
client->th.cth = NULL;
callback = client->th.callback;
client->th.callback = NULL;
client->last_activity = GNUNET_TIME_absolute_get ();
return callback (client->th.callback_cls, size, buf);
}
/**
* Notify us when the server has enough space to transmit
* a message of the given size to the given client.
*
* @param client client to transmit message to
* @param size requested amount of buffer space
* @param timeout after how long should we give up (and call
* notify with buf NULL and size 0)?
* @param callback function to call when space is available
* @param callback_cls closure for @a callback
* @return non-NULL if the notify callback was queued; can be used
* to cancel the request using
* #GNUNET_SERVER_notify_transmit_ready_cancel().
* NULL if we are already going to notify someone else (busy)
*/
struct GNUNET_SERVER_TransmitHandle *
GNUNET_SERVER_notify_transmit_ready (struct GNUNET_SERVER_Client *client,
size_t size,
struct GNUNET_TIME_Relative timeout,
GNUNET_CONNECTION_TransmitReadyNotify callback,
void *callback_cls)
{
if (NULL != client->th.callback)
return NULL;
client->th.callback_cls = callback_cls;
client->th.callback = callback;
client->th.cth = GNUNET_CONNECTION_notify_transmit_ready (client->connection, size,
timeout,
&transmit_ready_callback_wrapper,
client);
return &client->th;
}
/**
* Abort transmission request.
*
* @param th request to abort
*/
void
GNUNET_SERVER_notify_transmit_ready_cancel (struct GNUNET_SERVER_TransmitHandle *th)
{
GNUNET_CONNECTION_notify_transmit_ready_cancel (th->cth);
th->cth = NULL;
th->callback = NULL;
}
/**
* Set the persistent flag on this client, used to setup client connection
* to only be killed when the service it's connected to is actually dead.
*
* @param client the client to set the persistent flag on
*/
void
GNUNET_SERVER_client_persist_ (struct GNUNET_SERVER_Client *client)
{
client->persist = GNUNET_YES;
}
/**
* Resume receiving from this client, we are done processing the
* current request. This function must be called from within each
* GNUNET_SERVER_MessageCallback (or its respective continuations).
*
* @param client client we were processing a message of
* @param success #GNUNET_OK to keep the connection open and
* continue to receive
* #GNUNET_NO to close the connection (normal behavior)
* #GNUNET_SYSERR to close the connection (signal
* serious error)
*/
void
GNUNET_SERVER_receive_done (struct GNUNET_SERVER_Client *client,
int success)
{
if (NULL == client)
return;
GNUNET_assert (client->suspended > 0);
client->suspended--;
if (GNUNET_OK != success)
{
LOG (GNUNET_ERROR_TYPE_DEBUG,
"GNUNET_SERVER_receive_done called with failure indication\n");
if ( (client->reference_count > 0) || (client->suspended > 0) )
client->shutdown_now = GNUNET_YES;
else
GNUNET_SERVER_client_disconnect (client);
return;
}
if (client->suspended > 0)
{
LOG (GNUNET_ERROR_TYPE_DEBUG,
"GNUNET_SERVER_receive_done called, but more clients pending\n");
return;
}
if (NULL != client->warn_task)
{
GNUNET_SCHEDULER_cancel (client->warn_task);
client->warn_task = NULL;
}
if (GNUNET_YES == client->in_process_client_buffer)
{
LOG (GNUNET_ERROR_TYPE_DEBUG,
"GNUNET_SERVER_receive_done called while still in processing loop\n");
return;
}
if ((NULL == client->server) || (GNUNET_YES == client->shutdown_now))
{
GNUNET_SERVER_client_disconnect (client);
return;
}
LOG (GNUNET_ERROR_TYPE_DEBUG,
"GNUNET_SERVER_receive_done causes restart in reading from the socket\n");
GNUNET_assert (NULL == client->restart_task);
client->restart_task = GNUNET_SCHEDULER_add_now (&restart_processing,
client);
}
/* end of server.c */