X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Futil%2Fclient.c;h=7e688059044211cebf40dcea045f51534252b4a0;hb=bb83cd2d04ff5a3f7a8d05fc9a724b0246e958b6;hp=4e6e09066fe2ae5072ec0c0de14c152a021df94d;hpb=b309c5f5ae339faf3632f7ee3a86520981f6523a;p=oweals%2Fgnunet.git diff --git a/src/util/client.c b/src/util/client.c index 4e6e09066..7e6880590 100644 --- a/src/util/client.c +++ b/src/util/client.c @@ -36,6 +36,105 @@ #define DEBUG_CLIENT GNUNET_NO +/** + * How often do we re-try tranmsitting requests before giving up? + * Note that if we succeeded transmitting a request but failed to read + * a response, we do NOT re-try. + */ +#define MAX_ATTEMPTS 50 + +/** + * Handle for a transmission request. + */ +struct GNUNET_CLIENT_TransmitHandle +{ + /** + * Connection state. + */ + struct GNUNET_CLIENT_Connection *sock; + + /** + * Function to call to get the data for transmission. + */ + GNUNET_CONNECTION_TransmitReadyNotify notify; + + /** + * Closure for notify. + */ + void *notify_cls; + + /** + * Handle to the transmission with the underlying + * connection. + */ + struct GNUNET_CONNECTION_TransmitHandle *th; + + /** + * If we are re-trying and are delaying to do so, + * handle to the scheduled task managing the delay. + */ + GNUNET_SCHEDULER_TaskIdentifier reconnect_task; + + /** + * Timeout for the operation overall. + */ + struct GNUNET_TIME_Absolute timeout; + + /** + * Number of bytes requested. + */ + size_t size; + + /** + * Are we allowed to re-try to connect without telling + * the user (of this API) about the connection troubles? + */ + int auto_retry; + + /** + * Number of attempts left for transmitting the request. We may + * fail the first time (say because the service is not yet up), in + * which case (if auto_retry is set) we wait a bit and re-try + * (timeout permitting). + */ + unsigned int attempts_left; + +}; + + +/** + * Context for processing + * "GNUNET_CLIENT_transmit_and_get_response" requests. + */ +struct TransmitGetResponseContext +{ + /** + * Client handle. + */ + struct GNUNET_CLIENT_Connection *sock; + + /** + * Message to transmit; do not free, allocated + * right after this struct. + */ + const struct GNUNET_MessageHeader *hdr; + + /** + * Timeout to use. + */ + struct GNUNET_TIME_Absolute timeout; + + /** + * Function to call when done. + */ + GNUNET_CLIENT_MessageHandler rn; + + /** + * Closure for "rn". + */ + void *rn_cls; +}; + /** * Struct to refer to a GNUnet TCP connection. * This is more than just a socket because if the server @@ -48,12 +147,13 @@ struct GNUNET_CLIENT_Connection /** * the socket handle, NULL if not live */ - struct GNUNET_NETWORK_ConnectionHandle *sock; + struct GNUNET_CONNECTION_Handle *sock; /** - * Our scheduler. + * Our configuration. + * FIXME: why do we DUP the configuration? Avoid this! */ - struct GNUNET_SCHEDULER_Handle *sched; + struct GNUNET_CONFIGURATION_Handle *cfg; /** * Name of the service we interact with. @@ -61,9 +161,10 @@ struct GNUNET_CLIENT_Connection char *service_name; /** - * ID of task used for receiving. + * Context of a transmit_and_get_response operation, NULL + * if no such operation is pending. */ - GNUNET_SCHEDULER_TaskIdentifier receiver_task; + struct TransmitGetResponseContext *tag; /** * Handler for current receiver task. @@ -75,11 +176,28 @@ struct GNUNET_CLIENT_Connection */ void *receiver_handler_cls; + /** + * Handle for a pending transmission request, NULL if there is + * none pending. + */ + struct GNUNET_CLIENT_TransmitHandle *th; + /** * Handler for service test completion (NULL unless in service_test) */ GNUNET_SCHEDULER_Task test_cb; + /** + * Deadline for calling 'test_cb'. + */ + struct GNUNET_TIME_Absolute test_deadline; + + /** + * If we are re-trying and are delaying to do so, + * handle to the scheduled task managing the delay. + */ + GNUNET_SCHEDULER_TaskIdentifier receive_task; + /** * Closure for test_cb (NULL unless in service_test) */ @@ -95,6 +213,12 @@ struct GNUNET_CLIENT_Connection */ struct GNUNET_TIME_Absolute receive_timeout; + /** + * Current value for our incremental back-off (for + * connect re-tries). + */ + struct GNUNET_TIME_Relative back_off; + /** * Number of bytes in received_buf that are valid. */ @@ -110,27 +234,68 @@ struct GNUNET_CLIENT_Connection */ int msg_complete; + /** + * Are we currently busy doing receive-processing? + * GNUNET_YES if so, GNUNET_NO if not. + */ + int in_receive; + + /** + * Are we ignoring shutdown signals? + */ + int ignore_shutdown; + + /** + * How often have we tried to connect? + */ + unsigned int attempts; + }; /** - * Get a connection with a service. + * Try to connect to the service. * - * @param sched scheduler to use - * @param service_name name of the service + * @param service_name name of service to connect to * @param cfg configuration to use - * @return NULL on error (service unknown to configuration) + * @param attempt counter used to alternate between IP and UNIX domain sockets + * @return NULL on error */ -struct GNUNET_CLIENT_Connection * -GNUNET_CLIENT_connect (struct GNUNET_SCHEDULER_Handle *sched, - const char *service_name, - const struct GNUNET_CONFIGURATION_Handle *cfg) +static struct GNUNET_CONNECTION_Handle * +do_connect (const char *service_name, + const struct GNUNET_CONFIGURATION_Handle *cfg, + unsigned int attempt) { - struct GNUNET_CLIENT_Connection *ret; - struct GNUNET_NETWORK_ConnectionHandle *sock; + struct GNUNET_CONNECTION_Handle *sock; char *hostname; + char *unixpath; unsigned long long port; + sock = NULL; +#if AF_UNIX + if (0 == (attempt % 2)) + { + /* on even rounds, try UNIX */ + if ((GNUNET_OK == + GNUNET_CONFIGURATION_get_value_string (cfg, + service_name, + "UNIXPATH", &unixpath)) && + (0 < strlen (unixpath))) /* We have a non-NULL unixpath, does that mean it's valid? */ + { + sock = GNUNET_CONNECTION_create_from_connect_to_unixpath (cfg, unixpath); + if (sock != NULL) + { +#if DEBUG_CLIENT + GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Connected to unixpath `%s'!\n", unixpath); +#endif + GNUNET_free(unixpath); + return sock; + } + } + GNUNET_free_non_null (unixpath); + } +#endif + if ((GNUNET_OK != GNUNET_CONFIGURATION_get_value_number (cfg, service_name, @@ -143,67 +308,157 @@ GNUNET_CLIENT_connect (struct GNUNET_SCHEDULER_Handle *sched, "HOSTNAME", &hostname))) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, - "Could not determine valid hostname and port for service `%s' from configuration.\n", + _("Could not determine valid hostname and port for service `%s' from configuration.\n"), + service_name); + return NULL; + } + if (0 == strlen (hostname)) + { + GNUNET_free (hostname); + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, + _("Need a non-empty hostname for service `%s'.\n"), service_name); return NULL; } - sock = GNUNET_NETWORK_connection_create_from_connect (sched, - hostname, - port, - GNUNET_SERVER_MAX_MESSAGE_SIZE); + if (port == 0) + { +#if AF_UNIX + if (0 != (attempt % 2)) + { + /* try UNIX */ + if ((GNUNET_OK == + GNUNET_CONFIGURATION_get_value_string (cfg, + service_name, + "UNIXPATH", &unixpath)) && + (0 < strlen (unixpath))) + { + sock = GNUNET_CONNECTION_create_from_connect_to_unixpath (cfg, + unixpath); + GNUNET_free (unixpath); + if (sock != NULL) + return sock; + } + } +#endif +#if DEBUG_CLIENT + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Port is 0 for service `%s', UNIXPATH did not work, returning NULL!\n", + service_name); +#endif + GNUNET_free (hostname); + return NULL; + } + + sock = GNUNET_CONNECTION_create_from_connect (cfg, + hostname, + port); GNUNET_free (hostname); + return sock; +} + + +/** + * Get a connection with a service. + * + * @param service_name name of the service + * @param cfg configuration to use + * @return NULL on error (service unknown to configuration) + */ +struct GNUNET_CLIENT_Connection * +GNUNET_CLIENT_connect (const char *service_name, + const struct GNUNET_CONFIGURATION_Handle *cfg) +{ + struct GNUNET_CLIENT_Connection *ret; + struct GNUNET_CONNECTION_Handle *sock; + + sock = do_connect (service_name, + cfg, 0); if (sock == NULL) return NULL; ret = GNUNET_malloc (sizeof (struct GNUNET_CLIENT_Connection)); + ret->attempts = 1; ret->sock = sock; - ret->sched = sched; ret->service_name = GNUNET_strdup (service_name); + ret->cfg = GNUNET_CONFIGURATION_dup (cfg); + ret->back_off = GNUNET_TIME_UNIT_MILLISECONDS; return ret; } /** - * Receiver task has completed, free rest of client - * data structures. + * Configure this connection to ignore shutdown signals. + * + * @param h client handle + * @param do_ignore GNUNET_YES to ignore, GNUNET_NO to restore default */ -static void -finish_cleanup (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) +void +GNUNET_CLIENT_ignore_shutdown (struct GNUNET_CLIENT_Connection *h, + int do_ignore) { - struct GNUNET_CLIENT_Connection *sock = cls; - - GNUNET_array_grow (sock->received_buf, sock->received_size, 0); - GNUNET_free (sock->service_name); - GNUNET_free (sock); + h->ignore_shutdown = do_ignore; + if (h->sock != NULL) + GNUNET_CONNECTION_ignore_shutdown (h->sock, + do_ignore); } /** - * Destroy connection with the service. + * Destroy connection with the service. This will automatically + * cancel any pending "receive" request (however, the handler will + * *NOT* be called, not even with a NULL message). Any pending + * transmission request will also be cancelled UNLESS the callback for + * the transmission request has already been called, in which case the + * transmission 'finish_pending_write' argument determines whether or + * not the write is guaranteed to complete before the socket is fully + * destroyed (unless, of course, there is an error with the server in + * which case the message may still be lost). + * + * @param finish_pending_write should a transmission already passed to the + * handle be completed? + * @param sock handle to the service connection */ void -GNUNET_CLIENT_disconnect (struct GNUNET_CLIENT_Connection *sock) +GNUNET_CLIENT_disconnect (struct GNUNET_CLIENT_Connection *sock, + int finish_pending_write) { GNUNET_assert (sock->sock != NULL); - GNUNET_NETWORK_connection_destroy (sock->sock); + if (sock->in_receive == GNUNET_YES) + { + GNUNET_CONNECTION_receive_cancel (sock->sock); + sock->in_receive = GNUNET_NO; + } + GNUNET_CONNECTION_destroy (sock->sock, finish_pending_write); sock->sock = NULL; + if (sock->tag != NULL) + { + GNUNET_free (sock->tag); + sock->tag = NULL; + } sock->receiver_handler = NULL; - GNUNET_SCHEDULER_add_after (sock->sched, - GNUNET_YES, - GNUNET_SCHEDULER_PRIORITY_KEEP, - sock->receiver_task, &finish_cleanup, sock); + if (sock->th != NULL) + GNUNET_CLIENT_notify_transmit_ready_cancel (sock->th); + if (sock->receive_task != GNUNET_SCHEDULER_NO_TASK) + { + GNUNET_SCHEDULER_cancel (sock->receive_task); + sock->receive_task = GNUNET_SCHEDULER_NO_TASK; + } + GNUNET_array_grow (sock->received_buf, sock->received_size, 0); + GNUNET_free (sock->service_name); + GNUNET_CONFIGURATION_destroy (sock->cfg); + GNUNET_free (sock); } /** - * check if message is complete + * Check if message is complete */ static void check_complete (struct GNUNET_CLIENT_Connection *conn) { if ((conn->received_pos >= sizeof (struct GNUNET_MessageHeader)) && (conn->received_pos >= - ntohs (((const struct GNUNET_MessageHeader *) conn-> - received_buf)->size))) + ntohs (((const struct GNUNET_MessageHeader *) conn->received_buf)-> + size))) conn->msg_complete = GNUNET_YES; } @@ -228,17 +483,22 @@ receive_helper (void *cls, { struct GNUNET_CLIENT_Connection *conn = cls; struct GNUNET_TIME_Relative remaining; + GNUNET_CLIENT_MessageHandler receive_handler; + void *receive_handler_cls; GNUNET_assert (conn->msg_complete == GNUNET_NO); - conn->receiver_task = GNUNET_SCHEDULER_NO_TASK; - + conn->in_receive = GNUNET_NO; if ((available == 0) || (conn->sock == NULL) || (errCode != 0)) { /* signal timeout! */ - if (conn->receiver_handler != NULL) +#if DEBUG_CLIENT + GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "timeout in receive_helper, available %d, conn->sock %s, errCode %d\n", available, conn->sock == NULL ? "NULL" : "non-NULL", errCode); +#endif + if (NULL != (receive_handler = conn->receiver_handler)) { - conn->receiver_handler (conn->receiver_handler_cls, NULL); + receive_handler_cls = conn->receiver_handler_cls; conn->receiver_handler = NULL; + receive_handler (receive_handler_cls, NULL); } return; } @@ -256,7 +516,7 @@ receive_helper (void *cls, check_complete (conn); /* check for timeout */ remaining = GNUNET_TIME_absolute_get_remaining (conn->receive_timeout); - if (remaining.value == 0) + if (remaining.rel_value == 0) { /* signal timeout! */ conn->receiver_handler (conn->receiver_handler_cls, NULL); @@ -271,101 +531,82 @@ receive_helper (void *cls, /** * Continuation to call the receive callback. + * + * @param cls our handle to the client connection + * @param tc scheduler context */ static void -receive_task (void *scls, const struct GNUNET_SCHEDULER_TaskContext *tc) +receive_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { - struct GNUNET_CLIENT_Connection *sock = scls; + struct GNUNET_CLIENT_Connection *sock = cls; GNUNET_CLIENT_MessageHandler handler = sock->receiver_handler; - const struct GNUNET_MessageHeader *cmsg = (const struct GNUNET_MessageHeader *) sock->received_buf; - void *cls = sock->receiver_handler_cls; + const struct GNUNET_MessageHeader *cmsg = + (const struct GNUNET_MessageHeader *) sock->received_buf; + void *handler_cls = sock->receiver_handler_cls; uint16_t msize = ntohs (cmsg->size); char mbuf[msize]; - struct GNUNET_MessageHeader *msg = (struct GNUNET_MessageHeader*) mbuf; + struct GNUNET_MessageHeader *msg = (struct GNUNET_MessageHeader *) mbuf; +#if DEBUG_CLIENT + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Received message of type %u and size %u\n", + ntohs (cmsg->type), + msize); +#endif + sock->receive_task = GNUNET_SCHEDULER_NO_TASK; GNUNET_assert (GNUNET_YES == sock->msg_complete); - sock->receiver_task = GNUNET_SCHEDULER_NO_TASK; GNUNET_assert (sock->received_pos >= msize); memcpy (msg, cmsg, msize); memmove (sock->received_buf, - &sock->received_buf[msize], sock->received_pos - msize); + &sock->received_buf[msize], sock->received_pos - msize); sock->received_pos -= msize; sock->msg_complete = GNUNET_NO; - sock->receiver_handler = NULL; + sock->receiver_handler = NULL; check_complete (sock); if (handler != NULL) - handler (cls, msg); + handler (handler_cls, msg); } /** * Read from the service. * - * @param sched scheduler to use * @param sock the service * @param handler function to call with the message - * @param cls closure for handler + * @param handler_cls closure for handler * @param timeout how long to wait until timing out */ void GNUNET_CLIENT_receive (struct GNUNET_CLIENT_Connection *sock, GNUNET_CLIENT_MessageHandler handler, - void *cls, struct GNUNET_TIME_Relative timeout) + void *handler_cls, struct GNUNET_TIME_Relative timeout) { if (sock->sock == NULL) { /* already disconnected, fail instantly! */ GNUNET_break (0); /* this should not happen in well-written code! */ - handler (cls, NULL); + handler (handler_cls, NULL); return; } - GNUNET_assert (sock->receiver_task == - GNUNET_SCHEDULER_NO_TASK); sock->receiver_handler = handler; - sock->receiver_handler_cls = cls; + sock->receiver_handler_cls = handler_cls; sock->receive_timeout = GNUNET_TIME_relative_to_absolute (timeout); if (GNUNET_YES == sock->msg_complete) - sock->receiver_task = GNUNET_SCHEDULER_add_after (sock->sched, - GNUNET_YES, - GNUNET_SCHEDULER_PRIORITY_KEEP, - GNUNET_SCHEDULER_NO_TASK, - &receive_task, sock); + { + sock->receive_task = GNUNET_SCHEDULER_add_after (GNUNET_SCHEDULER_NO_TASK, + &receive_task, sock); + } else - sock->receiver_task = GNUNET_NETWORK_connection_receive (sock->sock, - GNUNET_SERVER_MAX_MESSAGE_SIZE, - timeout, - &receive_helper, sock); -} - - -static size_t -write_shutdown (void *cls, size_t size, void *buf) -{ - struct GNUNET_MessageHeader *msg; - - if (size < sizeof (struct GNUNET_MessageHeader)) - return 0; /* client disconnected */ - msg = (struct GNUNET_MessageHeader *) buf; - msg->type = htons (GNUNET_MESSAGE_TYPE_SHUTDOWN); - msg->size = htons (sizeof (struct GNUNET_MessageHeader)); - return sizeof (struct GNUNET_MessageHeader); -} - - -/** - * Request that the service should shutdown. - * Afterwards, the connection should be disconnected. - * - * @param sched scheduler to use - * @param sock the socket connected to the service - */ -void -GNUNET_CLIENT_service_shutdown (struct GNUNET_CLIENT_Connection *sock) -{ - GNUNET_NETWORK_connection_notify_transmit_ready (sock->sock, - sizeof (struct GNUNET_MessageHeader), - GNUNET_TIME_UNIT_FOREVER_REL, - &write_shutdown, NULL); + { + GNUNET_assert (sock->in_receive == GNUNET_NO); + sock->in_receive = GNUNET_YES; +#if DEBUG_CLIENT + GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "calling GNUNET_CONNECTION_receive\n"); +#endif + GNUNET_CONNECTION_receive (sock->sock, + GNUNET_SERVER_MAX_MESSAGE_SIZE - 1, + timeout, &receive_helper, sock); + } } @@ -373,12 +614,9 @@ GNUNET_CLIENT_service_shutdown (struct GNUNET_CLIENT_Connection *sock) * Report service unavailable. */ static void -service_test_error (struct GNUNET_SCHEDULER_Handle *s, - GNUNET_SCHEDULER_Task task, void *task_cls) +service_test_error (GNUNET_SCHEDULER_Task task, void *task_cls) { - GNUNET_SCHEDULER_add_continuation (s, - GNUNET_YES, - task, + GNUNET_SCHEDULER_add_continuation (task, task_cls, GNUNET_SCHEDULER_REASON_TIMEOUT); } @@ -403,23 +641,22 @@ confirm_handler (void *cls, const struct GNUNET_MessageHeader *msg) GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received confirmation that service is running.\n"); #endif - GNUNET_SCHEDULER_add_continuation (conn->sched, - GNUNET_YES, - conn->test_cb, + GNUNET_SCHEDULER_add_continuation (conn->test_cb, conn->test_cb_cls, GNUNET_SCHEDULER_REASON_PREREQ_DONE); } else { - service_test_error (conn->sched, conn->test_cb, conn->test_cb_cls); + service_test_error (conn->test_cb, conn->test_cb_cls); } - GNUNET_CLIENT_disconnect (conn); + GNUNET_CLIENT_disconnect (conn, GNUNET_NO); } static size_t write_test (void *cls, size_t size, void *buf) { + struct GNUNET_CLIENT_Connection *conn = cls; struct GNUNET_MessageHeader *msg; if (size < sizeof (struct GNUNET_MessageHeader)) @@ -428,14 +665,21 @@ write_test (void *cls, size_t size, void *buf) GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _("Failure to transmit TEST request.\n")); #endif + service_test_error (conn->test_cb, conn->test_cb_cls); + GNUNET_CLIENT_disconnect (conn, GNUNET_NO); return 0; /* client disconnected */ } #if DEBUG_CLIENT - GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _("Transmitting TEST request.\n")); + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Transmitting `%s' request.\n", "TEST"); #endif msg = (struct GNUNET_MessageHeader *) buf; msg->type = htons (GNUNET_MESSAGE_TYPE_TEST); msg->size = htons (sizeof (struct GNUNET_MessageHeader)); + GNUNET_CLIENT_receive (conn, + &confirm_handler, + conn, + GNUNET_TIME_absolute_get_remaining (conn->test_deadline)); return sizeof (struct GNUNET_MessageHeader); } @@ -443,7 +687,6 @@ write_test (void *cls, size_t size, void *buf) /** * Wait until the service is running. * - * @param sched scheduler to use * @param service name of the service to wait for * @param cfg configuration to use * @param timeout how long to wait at most in ms @@ -453,8 +696,7 @@ write_test (void *cls, size_t size, void *buf) * @param task_cls closure for task */ void -GNUNET_CLIENT_service_test (struct GNUNET_SCHEDULER_Handle *sched, - const char *service, +GNUNET_CLIENT_service_test (const char *service, const struct GNUNET_CONFIGURATION_Handle *cfg, struct GNUNET_TIME_Relative timeout, GNUNET_SCHEDULER_Task task, void *task_cls) @@ -465,32 +707,153 @@ GNUNET_CLIENT_service_test (struct GNUNET_SCHEDULER_Handle *sched, GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Testing if service `%s' is running.\n", service); #endif - conn = GNUNET_CLIENT_connect (sched, service, cfg); + conn = GNUNET_CLIENT_connect (service, cfg); if (conn == NULL) { GNUNET_log (GNUNET_ERROR_TYPE_INFO, _ ("Could not connect to service `%s', must not be running.\n"), service); - service_test_error (sched, task, task_cls); + service_test_error (task, task_cls); return; } conn->test_cb = task; conn->test_cb_cls = task_cls; - if (NULL == - GNUNET_NETWORK_connection_notify_transmit_ready (conn->sock, - sizeof (struct - GNUNET_MessageHeader), - timeout, &write_test, NULL)) + conn->test_deadline = GNUNET_TIME_relative_to_absolute (timeout); + + if (NULL == GNUNET_CLIENT_notify_transmit_ready (conn, + sizeof (struct GNUNET_MessageHeader), + timeout, + GNUNET_YES, + &write_test, conn)) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _("Failure to transmit request to service `%s'\n"), service); - service_test_error (sched, task, task_cls); - GNUNET_CLIENT_disconnect (conn); + service_test_error (task, task_cls); + GNUNET_CLIENT_disconnect (conn, GNUNET_NO); + return; + } +} + + +/** + * Connection notifies us about failure or success of + * a transmission request. Either pass it on to our + * user or, if possible, retry. + * + * @param cls our "struct GNUNET_CLIENT_TransmissionHandle" + * @param size number of bytes available for transmission + * @param buf where to write them + * @return number of bytes written to buf + */ +static size_t client_notify (void *cls, size_t size, void *buf); + + +/** + * This task is run if we should re-try connection to the + * service after a while. + * + * @param cls our "struct GNUNET_CLIENT_TransmitHandle" of the request + * @param tc unused + */ +static void +client_delayed_retry (void *cls, + const struct GNUNET_SCHEDULER_TaskContext *tc) +{ + struct GNUNET_CLIENT_TransmitHandle *th = cls; + + th->reconnect_task = GNUNET_SCHEDULER_NO_TASK; + if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) + { +#if DEBUG_CLIENT + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Transmission failed due to shutdown.\n"); +#endif + th->sock->th = NULL; + th->notify (th->notify_cls, 0, NULL); + GNUNET_free (th); + return; + } + th->th = GNUNET_CONNECTION_notify_transmit_ready (th->sock->sock, + th->size, + GNUNET_TIME_absolute_get_remaining + (th->timeout), + &client_notify, th); + if (th->th == NULL) + { + GNUNET_break (0); + th->notify (th->notify_cls, 0, NULL); + GNUNET_free (th); return; } - GNUNET_CLIENT_receive (conn, &confirm_handler, conn, timeout); +} + + +/** + * Connection notifies us about failure or success of a transmission + * request. Either pass it on to our user or, if possible, retry. + * + * @param cls our "struct GNUNET_CLIENT_TransmissionHandle" + * @param size number of bytes available for transmission + * @param buf where to write them + * @return number of bytes written to buf + */ +static size_t +client_notify (void *cls, size_t size, void *buf) +{ + struct GNUNET_CLIENT_TransmitHandle *th = cls; + size_t ret; + struct GNUNET_TIME_Relative delay; + + th->th = NULL; + th->sock->th = NULL; + if (buf == NULL) + { + delay = GNUNET_TIME_absolute_get_remaining (th->timeout); + delay.rel_value /= 2; + if ( (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & GNUNET_SCHEDULER_get_reason ())) || + (GNUNET_YES != th->auto_retry) || + (0 == --th->attempts_left) || + (delay.rel_value < 1) ) + { +#if DEBUG_CLIENT + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Transmission failed %u times, giving up.\n", + MAX_ATTEMPTS - th->attempts_left); +#endif + GNUNET_break (0 == th->notify (th->notify_cls, 0, NULL)); + GNUNET_free (th); + return 0; + } + /* auto-retry */ + GNUNET_CONNECTION_destroy (th->sock->sock, GNUNET_NO); + th->sock->sock = do_connect (th->sock->service_name, + th->sock->cfg, + th->sock->attempts++); + GNUNET_assert (NULL != th->sock->sock); + GNUNET_CONNECTION_ignore_shutdown (th->sock->sock, + th->sock->ignore_shutdown); + delay = GNUNET_TIME_relative_min (delay, th->sock->back_off); + th->sock->back_off + = GNUNET_TIME_relative_min (GNUNET_TIME_relative_multiply (th->sock->back_off, 2), + GNUNET_TIME_UNIT_SECONDS); +#if DEBUG_CLIENT + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Transmission failed %u times, trying again in %llums.\n", + MAX_ATTEMPTS - th->attempts_left, + (unsigned long long) delay.rel_value); +#endif + th->reconnect_task = GNUNET_SCHEDULER_add_delayed (delay, + &client_delayed_retry, + th); + th->sock->th = th; + return 0; + } + GNUNET_assert (size >= th->size); + ret = th->notify (th->notify_cls, size, buf); + GNUNET_free (th); + return ret; } @@ -499,26 +862,180 @@ GNUNET_CLIENT_service_test (struct GNUNET_SCHEDULER_Handle *sched, * are free in the transmission buffer. May call the notify * method immediately if enough space is available. * - * @param client connection to the service + * @param sock connection to the service * @param size number of bytes to send * @param timeout after how long should we give up (and call * notify with buf NULL and size 0)? + * @param auto_retry if the connection to the service dies, should we + * automatically re-connect and retry (within the timeout period) + * or should we immediately fail in this case? Pass GNUNET_YES + * if the caller does not care about temporary connection errors, + * for example because the protocol is stateless * @param notify function to call * @param notify_cls closure for notify * @return NULL if our buffer will never hold size bytes, * a handle if the notify callback was queued (can be used to cancel) */ -struct GNUNET_NETWORK_TransmitHandle * +struct GNUNET_CLIENT_TransmitHandle * GNUNET_CLIENT_notify_transmit_ready (struct GNUNET_CLIENT_Connection *sock, size_t size, struct GNUNET_TIME_Relative timeout, - GNUNET_NETWORK_TransmitReadyNotify + int auto_retry, + GNUNET_CONNECTION_TransmitReadyNotify notify, void *notify_cls) { - return GNUNET_NETWORK_connection_notify_transmit_ready (sock->sock, - size, - timeout, notify, notify_cls); + struct GNUNET_CLIENT_TransmitHandle *th; + + if (NULL != sock->th) + return NULL; + th = GNUNET_malloc (sizeof (struct GNUNET_CLIENT_TransmitHandle)); + th->sock = sock; + th->size = size; + th->timeout = GNUNET_TIME_relative_to_absolute (timeout); + th->auto_retry = auto_retry; + th->notify = notify; + th->notify_cls = notify_cls; + th->attempts_left = MAX_ATTEMPTS; + th->th = GNUNET_CONNECTION_notify_transmit_ready (sock->sock, + size, + timeout, + &client_notify, th); + if (NULL == th->th) + { + GNUNET_break (0); + GNUNET_free (th); + return NULL; + } + sock->th = th; + return th; } +/** + * Cancel a request for notification. + * + * @param th handle from the original request. + */ +void +GNUNET_CLIENT_notify_transmit_ready_cancel (struct + GNUNET_CLIENT_TransmitHandle *th) +{ + if (th->reconnect_task != GNUNET_SCHEDULER_NO_TASK) + { + GNUNET_break (NULL == th->th); + GNUNET_SCHEDULER_cancel (th->reconnect_task); + th->reconnect_task = GNUNET_SCHEDULER_NO_TASK; + } + else + { + GNUNET_assert (NULL != th->th); + GNUNET_CONNECTION_notify_transmit_ready_cancel (th->th); + } + th->sock->th = NULL; + GNUNET_free (th); +} + + +/** + * Function called to notify a client about the socket + * begin ready to queue the message. "buf" will be + * NULL and "size" zero if the socket was closed for + * writing in the meantime. + * + * @param cls closure of type "struct TransmitGetResponseContext*" + * @param size number of bytes available in buf + * @param buf where the callee should write the message + * @return number of bytes written to buf + */ +static size_t +transmit_for_response (void *cls, size_t size, void *buf) +{ + struct TransmitGetResponseContext *tc = cls; + uint16_t msize; + + tc->sock->tag = NULL; + msize = ntohs (tc->hdr->size); + if (NULL == buf) + { +#if DEBUG_CLIENT + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + _("Could not submit request, not expecting to receive a response.\n")); +#endif + tc->rn (tc->rn_cls, NULL); + GNUNET_free (tc); + return 0; + } + GNUNET_assert (size >= msize); + memcpy (buf, tc->hdr, msize); + GNUNET_CLIENT_receive (tc->sock, + tc->rn, + tc->rn_cls, + GNUNET_TIME_absolute_get_remaining (tc->timeout)); + GNUNET_free (tc); + return msize; +} + + +/** + * Convenience API that combines sending a request + * to the service and waiting for a response. + * If either operation times out, the callback + * will be called with a "NULL" response (in which + * case the connection should probably be destroyed). + * + * @param sock connection to use + * @param hdr message to transmit + * @param timeout when to give up (for both transmission + * and for waiting for a response) + * @param auto_retry if the connection to the service dies, should we + * automatically re-connect and retry (within the timeout period) + * or should we immediately fail in this case? Pass GNUNET_YES + * if the caller does not care about temporary connection errors, + * for example because the protocol is stateless + * @param rn function to call with the response + * @param rn_cls closure for rn + * @return GNUNET_OK on success, GNUNET_SYSERR if a request + * is already pending + */ +int +GNUNET_CLIENT_transmit_and_get_response (struct GNUNET_CLIENT_Connection + *sock, + const struct GNUNET_MessageHeader + *hdr, + struct GNUNET_TIME_Relative timeout, + int auto_retry, + GNUNET_CLIENT_MessageHandler rn, + void *rn_cls) +{ + struct TransmitGetResponseContext *tc; + uint16_t msize; + + if (NULL != sock->th) + return GNUNET_SYSERR; + GNUNET_assert (sock->tag == NULL); + msize = ntohs (hdr->size); + tc = GNUNET_malloc (sizeof (struct TransmitGetResponseContext) + msize); + tc->sock = sock; + tc->hdr = (const struct GNUNET_MessageHeader *) &tc[1]; + memcpy (&tc[1], hdr, msize); + tc->timeout = GNUNET_TIME_relative_to_absolute (timeout); + tc->rn = rn; + tc->rn_cls = rn_cls; + if (NULL == GNUNET_CLIENT_notify_transmit_ready (sock, + msize, + timeout, + auto_retry, + &transmit_for_response, + tc)) + { + GNUNET_break (0); + GNUNET_free (tc); + return GNUNET_SYSERR; + } + sock->tag = tc; + return GNUNET_OK; +} + + + /* end of client.c */