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Diffstat (limited to 'src/util/server.c')
| -rw-r--r-- | src/util/server.c | 1415 |
1 files changed, 1415 insertions, 0 deletions
diff --git a/src/util/server.c b/src/util/server.c new file mode 100644 index 0000000..24804d2 --- /dev/null +++ b/src/util/server.c @@ -0,0 +1,1415 @@ +/* + This file is part of GNUnet. + (C) 2009 Christian Grothoff (and other contributing authors) + + GNUnet is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published + by the Free Software Foundation; either version 2, 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 + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with GNUnet; see the file COPYING. If not, write to the + Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. +*/ + +/** + * @file util/server.c + * @brief library for building GNUnet network servers + * @author Christian Grothoff + */ + +#include "platform.h" +#include "gnunet_common.h" +#include "gnunet_connection_lib.h" +#include "gnunet_scheduler_lib.h" +#include "gnunet_server_lib.h" +#include "gnunet_time_lib.h" +#include "gnunet_disk_lib.h" +#include "gnunet_protocols.h" + +#define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__) + +#define LOG_STRERROR(kind,syscall) GNUNET_log_from_strerror (kind, "util", syscall) + +#define LOG_STRERROR_FILE(kind,syscall,filename) GNUNET_log_from_strerror_file (kind, "util", syscall, filename) + +#define DEBUG_SERVER GNUNET_EXTRA_LOGGING + +/** + * 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 linked list. + */ + struct NotifyList *next; + + /** + * 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; + + /** + * List of our current clients. + */ + struct GNUNET_SERVER_Client *clients; + + /** + * Linked list of functions to call on disconnects by clients. + */ + struct NotifyList *disconnect_notify_list; + + /** + * Function to call for access control. + */ + GNUNET_CONNECTION_AccessCheck access; + + /** + * Closure for access. + */ + void *access_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. + */ + GNUNET_SCHEDULER_TaskIdentifier listen_task; + + /** + * 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; + + /** + * Should all of the clients of this server continue to process + * connections as usual even if we get a shutdown request? (the + * listen socket always ignores shutdown). + */ + int clients_ignore_shutdown; + + GNUNET_SERVER_MstCreateCallback mst_create; + GNUNET_SERVER_MstDestroyCallback mst_destroy; + GNUNET_SERVER_MstReceiveCallback mst_receive; + void *mst_cls; +}; + + +/** + * @brief handle for a client of the server + */ +struct GNUNET_SERVER_Client +{ + + /** + * This is a linked list. + */ + struct GNUNET_SERVER_Client *next; + + /** + * 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; + + /** + * ID of task used to restart processing. + */ + GNUNET_SCHEDULER_TaskIdentifier restart_task; + + /** + * Task that warns about missing calls to 'GNUNET_SERVER_receive_done'. + */ + GNUNET_SCHEDULER_TaskIdentifier 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; + + /** + * + */ + GNUNET_CONNECTION_TransmitReadyNotify callback; + + /** + * callback + */ + void *callback_cls; + + /** + * 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; + + /** + * 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 due to some serious + * error. + */ + int shutdown_now; + + /** + * Are we currently trying to receive? (YES if we are, NO if we are not, + * SYSERR if data is already available in MST). + */ + int receive_pending; + + /** + * Finish pending write when disconnecting? + */ + int finish_pending_write; + + /** + * 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; + + /** + * Type of last message processed (for warn_no_receive_done). + */ + uint16_t warn_type; +}; + + +/** + * Scheduler says our listen socket is ready. Process it! + * + * @param cls handle to our server for which we are processing the listen + * socket + * @param tc reason why we are running right now + */ +static void +process_listen_socket (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) +{ + struct GNUNET_SERVER_Handle *server = cls; + struct GNUNET_CONNECTION_Handle *sock; + struct GNUNET_SERVER_Client *client; + struct GNUNET_NETWORK_FDSet *r; + unsigned int i; + + server->listen_task = GNUNET_SCHEDULER_NO_TASK; + r = GNUNET_NETWORK_fdset_create (); + i = 0; + while (NULL != server->listen_sockets[i]) + GNUNET_NETWORK_fdset_set (r, server->listen_sockets[i++]); + if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) + { + /* ignore shutdown, someone else will take care of it! */ + server->listen_task = + GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_HIGH, + GNUNET_SCHEDULER_NO_TASK, + GNUNET_TIME_UNIT_FOREVER_REL, r, NULL, + &process_listen_socket, server); + GNUNET_NETWORK_fdset_destroy (r); + return; + } + i = 0; + while (NULL != server->listen_sockets[i]) + { + if (GNUNET_NETWORK_fdset_isset (tc->read_ready, server->listen_sockets[i])) + { + sock = + GNUNET_CONNECTION_create_from_accept (server->access, + server->access_cls, + server->listen_sockets[i]); + if (sock != NULL) + { +#if DEBUG_SERVER + LOG (GNUNET_ERROR_TYPE_DEBUG, "Server accepted incoming connection.\n"); +#endif + client = GNUNET_SERVER_connect_socket (server, sock); + GNUNET_CONNECTION_ignore_shutdown (sock, + server->clients_ignore_shutdown); + /* decrement reference count, we don't keep "client" alive */ + GNUNET_SERVER_client_drop (client); + } + } + i++; + } + /* listen for more! */ + server->listen_task = + GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_HIGH, + GNUNET_SCHEDULER_NO_TASK, + GNUNET_TIME_UNIT_FOREVER_REL, r, NULL, + &process_listen_socket, server); + GNUNET_NETWORK_fdset_destroy (r); +} + + +/** + * Create and initialize a listen socket for the server. + * + * @param serverAddr address to listen on + * @param socklen length of address + * @return NULL on error, otherwise the listen socket + */ +static struct GNUNET_NETWORK_Handle * +open_listen_socket (const struct sockaddr *serverAddr, socklen_t socklen) +{ + const static int on = 1; + struct GNUNET_NETWORK_Handle *sock; + uint16_t port; + int eno; + + switch (serverAddr->sa_family) + { + case AF_INET: + port = ntohs (((const struct sockaddr_in *) serverAddr)->sin_port); + break; + case AF_INET6: + port = ntohs (((const struct sockaddr_in6 *) serverAddr)->sin6_port); + break; + case AF_UNIX: + port = 0; + break; + default: + GNUNET_break (0); + port = 0; + break; + } + sock = GNUNET_NETWORK_socket_create (serverAddr->sa_family, SOCK_STREAM, 0); + if (NULL == sock) + { + LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR, "socket"); + errno = 0; + return NULL; + } + if (port != 0) + { + if (GNUNET_NETWORK_socket_setsockopt + (sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof (on)) != GNUNET_OK) + LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK, + "setsockopt"); +#ifdef IPV6_V6ONLY + if ((serverAddr->sa_family == AF_INET6) && + (GNUNET_NETWORK_socket_setsockopt + (sock, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof (on)) != GNUNET_OK)) + LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK, + "setsockopt"); +#endif + } + /* bind the socket */ + if (GNUNET_NETWORK_socket_bind (sock, serverAddr, socklen) != GNUNET_OK) + { + eno = errno; + if (errno != EADDRINUSE) + { + /* 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 (port != 0) + LOG (GNUNET_ERROR_TYPE_ERROR, _("`%s' failed for port %d (%s).\n"), + "bind", port, + (serverAddr->sa_family == AF_INET) ? "IPv4" : "IPv6"); + eno = 0; + } + else + { + if (port != 0) + LOG (GNUNET_ERROR_TYPE_WARNING, + _("`%s' failed for port %d (%s): address already in use\n"), + "bind", port, + (serverAddr->sa_family == AF_INET) ? "IPv4" : "IPv6"); + else if (serverAddr->sa_family == AF_UNIX) + LOG (GNUNET_ERROR_TYPE_WARNING, + _("`%s' failed for `%s': address already in use\n"), "bind", + ((const struct sockaddr_un *) serverAddr)->sun_path); + + } + 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 DEBUG_SERVER + if (port != 0) + LOG (GNUNET_ERROR_TYPE_DEBUG, "Server starts to listen on port %u.\n", + port); +#endif + return sock; +} + + +/** + * Create a new server. + * + * @param access function for access control + * @param access_cls closure for access + * @param lsocks NULL-terminated array of listen sockets + * @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_with_sockets (GNUNET_CONNECTION_AccessCheck access, + void *access_cls, + struct GNUNET_NETWORK_Handle **lsocks, + struct GNUNET_TIME_Relative idle_timeout, + int require_found) +{ + struct GNUNET_SERVER_Handle *ret; + struct GNUNET_NETWORK_FDSet *r; + int i; + + ret = GNUNET_malloc (sizeof (struct GNUNET_SERVER_Handle)); + ret->idle_timeout = idle_timeout; + ret->listen_sockets = lsocks; + ret->access = access; + ret->access_cls = access_cls; + ret->require_found = require_found; + if (lsocks != NULL) + { + r = GNUNET_NETWORK_fdset_create (); + i = 0; + while (NULL != ret->listen_sockets[i]) + GNUNET_NETWORK_fdset_set (r, ret->listen_sockets[i++]); + ret->listen_task = + GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_HIGH, + GNUNET_SCHEDULER_NO_TASK, + GNUNET_TIME_UNIT_FOREVER_REL, r, NULL, + &process_listen_socket, ret); + GNUNET_NETWORK_fdset_destroy (r); + } + return ret; +} + + +/** + * Create a new server. + * + * @param access function for access control + * @param access_cls closure for access + * @param serverAddr address to listen on (including port), NULL terminated array + * @param socklen length of serverAddr + * @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, void *access_cls, + struct sockaddr *const *serverAddr, + const socklen_t * socklen, + struct GNUNET_TIME_Relative idle_timeout, + int require_found) +{ + struct GNUNET_NETWORK_Handle **lsocks; + unsigned int i; + unsigned int j; + + i = 0; + while (serverAddr[i] != NULL) + i++; + if (i > 0) + { + lsocks = GNUNET_malloc (sizeof (struct GNUNET_NETWORK_Handle *) * (i + 1)); + i = 0; + j = 0; + while (serverAddr[i] != NULL) + { + lsocks[j] = open_listen_socket (serverAddr[i], socklen[i]); + if (lsocks[j] != NULL) + j++; + i++; + } + if (j == 0) + { + if (errno != 0) + LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR, "bind"); + GNUNET_free (lsocks); + lsocks = NULL; + } + } + else + { + lsocks = NULL; + } + return GNUNET_SERVER_create_with_sockets (access, access_cls, lsocks, + idle_timeout, require_found); +} + + +/** + * Free resources held by this server. + * + * @param s server to destroy + */ +void +GNUNET_SERVER_destroy (struct GNUNET_SERVER_Handle *s) +{ + struct HandlerList *hpos; + struct NotifyList *npos; + unsigned int i; + +#if DEBUG_SERVER + LOG (GNUNET_ERROR_TYPE_DEBUG, "Server shutting down.\n"); +#endif + if (GNUNET_SCHEDULER_NO_TASK != s->listen_task) + { + GNUNET_SCHEDULER_cancel (s->listen_task); + s->listen_task = GNUNET_SCHEDULER_NO_TASK; + } + if (s->listen_sockets != NULL) + { + i = 0; + while (s->listen_sockets[i] != NULL) + GNUNET_break (GNUNET_OK == + GNUNET_NETWORK_socket_close (s->listen_sockets[i++])); + GNUNET_free (s->listen_sockets); + s->listen_sockets = NULL; + } + while (s->clients != NULL) + GNUNET_SERVER_client_disconnect (s->clients); + while (NULL != (hpos = s->handlers)) + { + s->handlers = hpos->next; + GNUNET_free (hpos); + } + while (NULL != (npos = s->disconnect_notify_list)) + { + npos->callback (npos->callback_cls, NULL); + s->disconnect_notify_list = npos->next; + GNUNET_free (npos); + } + GNUNET_free (s); +} + + +/** + * 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_malloc (sizeof (struct HandlerList)); + p->handlers = handlers; + p->next = server->handlers; + server->handlers = p; +} + + +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 + * @param tc scheduler context (unused) + */ +static void +warn_no_receive_done (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) +{ + struct GNUNET_SERVER_Client *client = cls; + + client->warn_task = + GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES, + &warn_no_receive_done, client); + if (0 == (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason)) + LOG (GNUNET_ERROR_TYPE_WARNING, + _ + ("Processing code for message of type %u did not call GNUNET_SERVER_receive_done after %llums\n"), + (unsigned int) client->warn_type, + (unsigned long long) + GNUNET_TIME_absolute_get_duration (client->warn_start).rel_value); +} + + +/** + * 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 (GNUNET_SCHEDULER_NO_TASK != client->warn_task) + { + GNUNET_SCHEDULER_cancel (client->warn_task); + client->warn_task = GNUNET_SCHEDULER_NO_TASK; + } +} + + +/** + * 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); +#if DEBUG_SERVER + + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Server schedules transmission of %u-byte message of type %u to client.\n", + size, type); +#endif + pos = server->handlers; + found = GNUNET_NO; + while (pos != NULL) + { + i = 0; + while (pos->handlers[i].callback != NULL) + { + mh = &pos->handlers[i]; + if ((mh->type == type) || (mh->type == GNUNET_MESSAGE_TYPE_ALL)) + { + if ((mh->expected_size != 0) && (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); +#endif + return GNUNET_SYSERR; + } + if (sender != NULL) + { + if (0 == sender->suspended) + { + 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++; + } + pos = pos->next; + } + if (found == GNUNET_NO) + { + LOG (GNUNET_ERROR_TYPE_DEBUG | GNUNET_ERROR_TYPE_BULK, + "Received message of unknown type %d\n", type); + if (server->require_found == GNUNET_YES) + 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 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 ((ret != GNUNET_SYSERR) && (client->server != NULL) && + (GNUNET_YES != client->shutdown_now) && (0 == client->suspended)) + { + if (ret == GNUNET_OK) + { + client->receive_pending = GNUNET_YES; +#if DEBUG_SERVER + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Server re-enters receive loop, timeout: %llu.\n", + client->idle_timeout.rel_value); +#endif + GNUNET_CONNECTION_receive (client->connection, + GNUNET_SERVER_MAX_MESSAGE_SIZE - 1, + client->idle_timeout, &process_incoming, + client); + break; + } +#if DEBUG_SERVER + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Server processes additional messages instantly.\n"); +#endif + if (client->server->mst_receive != NULL) + 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); + } +#if DEBUG_SERVER + 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); +#endif + + if (ret == GNUNET_NO) + { +#if DEBUG_SERVER + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Server has more data pending but is suspended.\n"); +#endif + client->receive_pending = GNUNET_SYSERR; /* data pending */ + } + if ((ret == GNUNET_SYSERR) || (GNUNET_YES == client->shutdown_now)) + GNUNET_SERVER_client_disconnect (client); + GNUNET_SERVER_client_drop (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 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 (client->receive_pending == GNUNET_YES); + client->receive_pending = GNUNET_NO; + now = GNUNET_TIME_absolute_get (); + end = GNUNET_TIME_absolute_add (client->last_activity, client->idle_timeout); + + if ((buf == NULL) && (available == 0) && (addr == NULL) && (errCode == 0) && + (client->shutdown_now != GNUNET_YES) && (server != NULL) && + (GNUNET_YES == GNUNET_CONNECTION_check (client->connection)) && + (end.abs_value > now.abs_value)) + { + /* wait longer, timeout changed (i.e. due to us sending) */ +#if DEBUG_SERVER + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Receive time out, but no disconnect due to sending (%p)\n", + GNUNET_a2s (addr, addrlen)); +#endif + client->receive_pending = GNUNET_YES; + GNUNET_CONNECTION_receive (client->connection, + GNUNET_SERVER_MAX_MESSAGE_SIZE - 1, + GNUNET_TIME_absolute_get_remaining (end), + &process_incoming, client); + return; + } + if ((buf == NULL) || (available == 0) || (errCode != 0) || (server == NULL) || + (client->shutdown_now == GNUNET_YES) || + (GNUNET_YES != GNUNET_CONNECTION_check (client->connection))) + { + /* other side closed connection, error connecting, etc. */ + GNUNET_SERVER_client_disconnect (client); + return; + } +#if DEBUG_SERVER + LOG (GNUNET_ERROR_TYPE_DEBUG, "Server receives %u bytes from `%s'.\n", + (unsigned int) available, GNUNET_a2s (addr, addrlen)); +#endif + GNUNET_SERVER_client_keep (client); + client->last_activity = now; + + if (server->mst_receive != NULL) + ret = + client->server->mst_receive (client->server->mst_cls, client->mst, + client, buf, available, GNUNET_NO, GNUNET_YES); + else + ret = + GNUNET_SERVER_mst_receive (client->mst, client, buf, available, GNUNET_NO, + GNUNET_YES); + + process_mst (client, ret); +} + + +/** + * Task run to start again receiving from the network + * and process requests. + * + * @param cls our 'struct GNUNET_SERVER_Client*' to process more requests from + * @param tc scheduler context (unused) + */ +static void +restart_processing (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) +{ + struct GNUNET_SERVER_Client *client = cls; + struct GNUNET_SERVER_Handle *server = client->server; + + client->restart_task = GNUNET_SCHEDULER_NO_TASK; + if ((0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) && + (GNUNET_NO == server->clients_ignore_shutdown)) + { + GNUNET_SERVER_client_disconnect (client); + return; + } + if (client->receive_pending == GNUNET_NO) + { +#if DEBUG_SERVER + LOG (GNUNET_ERROR_TYPE_DEBUG, "Server begins to read again from client.\n"); +#endif + client->receive_pending = GNUNET_YES; + GNUNET_CONNECTION_receive (client->connection, + GNUNET_SERVER_MAX_MESSAGE_SIZE - 1, + client->idle_timeout, &process_incoming, client); + return; + } +#if DEBUG_SERVER + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Server continues processing messages still in the buffer.\n"); +#endif + GNUNET_SERVER_client_keep (client); + client->receive_pending = GNUNET_NO; + process_mst (client, GNUNET_NO); +} + + +/** + * 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 + */ +static void +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; + +#if DEBUG_SERVER + + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Tokenizer gives server message of type %u from client\n", + ntohs (message->type)); +#endif + 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_SERVER_client_disconnect (sender); +} + + +/** + * 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 (client should call + * "client_drop" on the return value eventually) + */ +struct GNUNET_SERVER_Client * +GNUNET_SERVER_connect_socket (struct GNUNET_SERVER_Handle *server, + struct GNUNET_CONNECTION_Handle *connection) +{ + struct GNUNET_SERVER_Client *client; + + client = GNUNET_malloc (sizeof (struct GNUNET_SERVER_Client)); + client->connection = connection; + client->mst = + GNUNET_SERVER_mst_create (&client_message_tokenizer_callback, server); + client->reference_count = 1; + client->server = server; + client->last_activity = GNUNET_TIME_absolute_get (); + client->next = server->clients; + client->idle_timeout = server->idle_timeout; + server->clients = client; + client->receive_pending = GNUNET_YES; + client->callback = NULL; + client->callback_cls = NULL; + + if (server->mst_create != NULL) + client->mst = + server->mst_create (server->mst_cls, client); + else + client->mst = + GNUNET_SERVER_mst_create (&client_message_tokenizer_callback, server); + + GNUNET_CONNECTION_receive (client->connection, + GNUNET_SERVER_MAX_MESSAGE_SIZE - 1, + client->idle_timeout, &process_incoming, client); + 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; +} + + +void +GNUNET_SERVER_client_set_finish_pending_write (struct GNUNET_SERVER_Client *client, + int finish) +{ + client->finish_pending_write = finish; +} + + +/** + * 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 ((client->shutdown_now == GNUNET_YES) && (client->reference_count == 0)) + 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 address + * @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 callback + */ +void +GNUNET_SERVER_disconnect_notify (struct GNUNET_SERVER_Handle *server, + GNUNET_SERVER_DisconnectCallback callback, + void *callback_cls) +{ + struct NotifyList *n; + + n = GNUNET_malloc (sizeof (struct NotifyList)); + n->callback = callback; + n->callback_cls = callback_cls; + n->next = server->disconnect_notify_list; + server->disconnect_notify_list = n; +} + + +/** + * 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 callback + */ +void +GNUNET_SERVER_disconnect_notify_cancel (struct GNUNET_SERVER_Handle *server, + GNUNET_SERVER_DisconnectCallback + callback, void *callback_cls) +{ + struct NotifyList *pos; + struct NotifyList *prev; + + prev = NULL; + pos = server->disconnect_notify_list; + while (pos != NULL) + { + if ((pos->callback == callback) && (pos->callback_cls == callback_cls)) + break; + prev = pos; + pos = pos->next; + } + if (pos == NULL) + { + GNUNET_break (0); + return; + } + if (prev == NULL) + server->disconnect_notify_list = pos->next; + else + prev->next = pos->next; + 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_Client *prev; + struct GNUNET_SERVER_Client *pos; + struct GNUNET_SERVER_Handle *server; + struct NotifyList *n; + unsigned int rc; + +#if DEBUG_SERVER + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Client is being disconnected from the server.\n"); +#endif + if (client->restart_task != GNUNET_SCHEDULER_NO_TASK) + { + GNUNET_SCHEDULER_cancel (client->restart_task); + client->restart_task = GNUNET_SCHEDULER_NO_TASK; + } + if (client->warn_task != GNUNET_SCHEDULER_NO_TASK) + { + GNUNET_SCHEDULER_cancel (client->warn_task); + client->warn_task = GNUNET_SCHEDULER_NO_TASK; + } + if (GNUNET_YES == client->receive_pending) + { + GNUNET_CONNECTION_receive_cancel (client->connection); + client->receive_pending = GNUNET_NO; + } + + rc = client->reference_count; + if (client->shutdown_now != GNUNET_YES) + { + server = client->server; + client->shutdown_now = GNUNET_YES; + prev = NULL; + pos = server->clients; + while ((pos != NULL) && (pos != client)) + { + prev = pos; + pos = pos->next; + } + GNUNET_assert (pos != NULL); + if (prev == NULL) + server->clients = pos->next; + else + prev->next = pos->next; + if (client->restart_task != GNUNET_SCHEDULER_NO_TASK) + { + GNUNET_SCHEDULER_cancel (client->restart_task); + client->restart_task = GNUNET_SCHEDULER_NO_TASK; + } + if (client->warn_task != GNUNET_SCHEDULER_NO_TASK) + { + GNUNET_SCHEDULER_cancel (client->warn_task); + client->warn_task = GNUNET_SCHEDULER_NO_TASK; + } + n = server->disconnect_notify_list; + while (n != NULL) + { + n->callback (n->callback_cls, client); + n = n->next; + } + } + if (rc > 0) + { +#if DEBUG_SERVER + LOG (GNUNET_ERROR_TYPE_DEBUG, + "RC still positive, not destroying everything.\n"); +#endif + return; + } + if (client->in_process_client_buffer == GNUNET_YES) + { +#if DEBUG_SERVER + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Still processing inputs, not destroying everything.\n"); +#endif + return; + } + + if (client->persist == GNUNET_YES) + GNUNET_CONNECTION_persist_ (client->connection); + GNUNET_CONNECTION_destroy (client->connection, client->finish_pending_write); + + if (client->server->mst_destroy != NULL) + client->server->mst_destroy (client->server->mst_cls, client->mst); + else + GNUNET_SERVER_mst_destroy (client->mst); + + GNUNET_free (client); +} + + +/** + * 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; + size_t ret; + + ret = client->callback (client->callback_cls, size, buf); + if (ret > 0) + client->last_activity = GNUNET_TIME_absolute_get (); + return ret; +} + + +/** + * 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 callback + * @return non-NULL if the notify callback was queued; can be used + * to cancel the request using + * GNUNET_CONNECTION_notify_transmit_ready_cancel. + * NULL if we are already going to notify someone else (busy) + */ +struct GNUNET_CONNECTION_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) +{ + client->callback_cls = callback_cls; + client->callback = callback; + return GNUNET_CONNECTION_notify_transmit_ready (client->connection, size, + timeout, + &transmit_ready_callback_wrapper, + client); +} + + +/** + * 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 (client == NULL) + return; + GNUNET_assert (client->suspended > 0); + client->suspended--; + if (success != GNUNET_OK) + { +#if DEBUG_SERVER + LOG (GNUNET_ERROR_TYPE_DEBUG, + "GNUNET_SERVER_receive_done called with failure indication\n"); +#endif + GNUNET_SERVER_client_disconnect (client); + return; + } + if (client->suspended > 0) + { +#if DEBUG_SERVER + LOG (GNUNET_ERROR_TYPE_DEBUG, + "GNUNET_SERVER_receive_done called, but more clients pending\n"); +#endif + return; + } + if (GNUNET_SCHEDULER_NO_TASK != client->warn_task) + { + GNUNET_SCHEDULER_cancel (client->warn_task); + client->warn_task = GNUNET_SCHEDULER_NO_TASK; + } + if (client->in_process_client_buffer == GNUNET_YES) + { +#if DEBUG_SERVER + LOG (GNUNET_ERROR_TYPE_DEBUG, + "GNUNET_SERVER_receive_done called while still in processing loop\n"); +#endif + return; + } + if ((client->server == NULL) || (GNUNET_YES == client->shutdown_now)) + { + GNUNET_SERVER_client_disconnect (client); + return; + } +#if DEBUG_SERVER + LOG (GNUNET_ERROR_TYPE_DEBUG, + "GNUNET_SERVER_receive_done causes restart in reading from the socket\n"); +#endif + GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == client->restart_task); + client->restart_task = GNUNET_SCHEDULER_add_now (&restart_processing, client); +} + + +/** + * Configure this server's connections to continue handling client + * requests as usual even after we get a shutdown signal. The change + * only applies to clients that connect to the server from the outside + * using TCP after this call. Clients managed previously or those + * added using GNUNET_SERVER_connect_socket and + * GNUNET_SERVER_connect_callback are not affected by this option. + * + * @param h server handle + * @param do_ignore GNUNET_YES to ignore, GNUNET_NO to restore default + */ +void +GNUNET_SERVER_ignore_shutdown (struct GNUNET_SERVER_Handle *h, int do_ignore) +{ + h->clients_ignore_shutdown = do_ignore; +} + +/* end of server.c */ |