2 This file is part of GNUnet.
3 (C) 2008, 2009, 2010 Christian Grothoff (and other contributing authors)
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22 * @file hostlist/hostlist-server.c
23 * @author Christian Grothoff
24 * @brief application to provide an integrated hostlist HTTP server
28 #include <microhttpd.h>
29 #include "hostlist-server.h"
30 #include "gnunet_hello_lib.h"
31 #include "gnunet_peerinfo_service.h"
32 #include "gnunet-daemon-hostlist.h"
33 #include "gnunet_resolver_service.h"
35 #define DEBUG_HOSTLIST_SERVER GNUNET_NO
38 * How often should we recalculate our response to hostlist requests?
40 #define RESPONSE_UPDATE_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 5)
43 * Handle to the HTTP server as provided by libmicrohttpd for IPv6.
45 static struct MHD_Daemon *daemon_handle_v6;
48 * Handle to the HTTP server as provided by libmicrohttpd for IPv4.
50 static struct MHD_Daemon *daemon_handle_v4;
55 static const struct GNUNET_CONFIGURATION_Handle *cfg;
60 static struct GNUNET_SCHEDULER_Handle *sched;
63 * For keeping statistics.
65 static struct GNUNET_STATISTICS_Handle *stats;
68 * Handle to the core service (NULL until we've connected to it).
70 struct GNUNET_CORE_Handle *core;
73 * Our primary task for IPv4.
75 static GNUNET_SCHEDULER_TaskIdentifier hostlist_task_v4;
78 * Our primary task for IPv6.
80 static GNUNET_SCHEDULER_TaskIdentifier hostlist_task_v6;
83 * Task that updates our HTTP response.
85 static GNUNET_SCHEDULER_TaskIdentifier response_task;
88 * Our canonical response.
90 static struct MHD_Response *response;
93 * NULL if we are not currenlty iterating over peer information.
95 static struct GNUNET_PEERINFO_IteratorContext *pitr;
98 * Context for host processor.
108 * Task that will produce a new response object.
111 update_response (void *cls,
112 const struct GNUNET_SCHEDULER_TaskContext *tc);
115 * Function that assembles our response.
118 finish_response (struct HostSet *results)
120 struct GNUNET_TIME_Relative freq;
122 if (response != NULL)
123 MHD_destroy_response (response);
124 #if DEBUG_HOSTLIST_SERVER
125 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
126 "Creating hostlist response with %u bytes\n",
127 (unsigned int) results->size);
129 response = MHD_create_response_from_data (results->size,
130 results->data, MHD_YES, MHD_NO);
131 if ( (daemon_handle_v4 != NULL) ||
132 (daemon_handle_v6 != NULL) )
134 freq = RESPONSE_UPDATE_FREQUENCY;
135 if (results->size == 0)
136 freq = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 250);
137 /* schedule next update of the response */
138 response_task = GNUNET_SCHEDULER_add_delayed (sched,
145 /* already past shutdown */
146 MHD_destroy_response (response);
149 GNUNET_STATISTICS_set (stats,
150 gettext_noop("bytes in hostlist"),
153 GNUNET_free (results);
158 * Set 'cls' to GNUNET_YES (we have an address!).
160 * @param cls closure, an 'int*'
161 * @param tname name of the transport (ignored)
162 * @param expiration expiration time (call is ignored if this is in the past)
163 * @param addr the address (ignored)
164 * @param addrlen length of the address (ignored)
165 * @return GNUNET_SYSERR to stop iterating (unless expiration has occured)
168 check_has_addr (void *cls,
170 struct GNUNET_TIME_Absolute expiration,
171 const void *addr, size_t addrlen)
175 if (GNUNET_TIME_absolute_get_remaining (expiration).value == 0)
177 GNUNET_STATISTICS_update (stats,
178 gettext_noop("expired addresses encountered"),
181 return GNUNET_YES; /* ignore this address */
184 return GNUNET_SYSERR;
189 * Callback that processes each of the known HELLOs for the
190 * hostlist response construction.
193 host_processor (void *cls,
194 const struct GNUNET_PeerIdentity * peer,
195 const struct GNUNET_HELLO_Message *hello,
198 struct HostSet *results = cls;
206 finish_response (results);
209 has_addr = GNUNET_NO;
210 GNUNET_HELLO_iterate_addresses (hello,
214 if (GNUNET_NO == has_addr)
216 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
217 "HELLO for peer `%4s' has no address, not suitable for hostlist!\n",
219 GNUNET_STATISTICS_update (stats,
220 gettext_noop("HELLOs without addresses encountered (ignored)"),
226 s = GNUNET_HELLO_size(hello);
227 #if DEBUG_HOSTLIST_SERVER
228 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
229 "Received %u bytes of `%s' from peer `%s' for hostlist.\n",
234 if (old + s >= GNUNET_MAX_MALLOC_CHECKED)
236 GNUNET_STATISTICS_update (stats,
237 gettext_noop("bytes not included in hostlist (size limit)"),
240 return; /* too large, skip! */
242 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
243 "Adding peer `%s' to hostlist (%u bytes)\n",
246 GNUNET_array_grow (results->data,
249 memcpy (&results->data[old], hello, s);
254 * Task that will produce a new response object.
257 update_response (void *cls,
258 const struct GNUNET_SCHEDULER_TaskContext *tc)
260 struct HostSet *results;
262 response_task = GNUNET_SCHEDULER_NO_TASK;
263 results = GNUNET_malloc(sizeof(struct HostSet));
264 pitr = GNUNET_PEERINFO_iterate (cfg, sched,
267 GNUNET_TIME_UNIT_MINUTES,
274 * Hostlist access policy (very permissive, allows everything).
277 accept_policy_callback (void *cls,
278 const struct sockaddr *addr, socklen_t addrlen)
280 if (NULL == response)
282 #if DEBUG_HOSTLIST_SERVER
283 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
284 "Received request for hostlist, but I am not yet ready; rejecting!\n");
288 return MHD_YES; /* accept all */
293 * Main request handler.
296 access_handler_callback (void *cls,
297 struct MHD_Connection *connection,
301 const char *upload_data,
302 size_t*upload_data_size, void **con_cls)
306 if (0 != strcmp (method, MHD_HTTP_METHOD_GET))
308 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
309 _("Refusing `%s' request to hostlist server\n"),
311 GNUNET_STATISTICS_update (stats,
312 gettext_noop("hostlist requests refused (not HTTP GET)"),
317 if (NULL == *con_cls)
320 #if DEBUG_HOSTLIST_SERVER
321 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
322 _("Sending 100 CONTINUE reply\n"));
324 return MHD_YES; /* send 100 continue */
326 if (*upload_data_size != 0)
328 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
329 _("Refusing `%s' request with %llu bytes of upload data\n"),
331 (unsigned long long) *upload_data_size);
332 GNUNET_STATISTICS_update (stats,
333 gettext_noop("hostlist requests refused (upload data)"),
336 return MHD_NO; /* do not support upload data */
338 if (response == NULL)
340 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
341 _("Could not handle hostlist request since I do not have a response yet\n"));
342 GNUNET_STATISTICS_update (stats,
343 gettext_noop("hostlist requests refused (not ready)"),
346 return MHD_NO; /* internal error, no response yet */
348 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
349 _("Received request for our hostlist\n"));
350 GNUNET_STATISTICS_update (stats,
351 gettext_noop("hostlist requests processed"),
354 return MHD_queue_response (connection, MHD_HTTP_OK, response);
359 adv_transmit_ready ( void *cls, size_t size, void *buf)
361 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
362 _("Ready to transmit %u bytes of adv\n"), size);
367 adv_transmit_message ( const struct GNUNET_PeerIdentity * peer, int size )
369 /* transmit message to peer */
372 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
373 _("Not connected to core, unable to send advertisement message\n"));
377 struct GNUNET_TIME_Relative timeout = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, GNUNET_ADV_TIMEOUT);
378 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
379 _("Asked to transmit %u bytes of adv\n"), size);
380 GNUNET_CORE_notify_transmit_ready (core,
385 &adv_transmit_ready, NULL);
391 * Function that assembles our hostlist adv message.
394 adv_create_message ( const struct GNUNET_PeerIdentity * peer,
395 struct GNUNET_HOSTLIST_ADV_Message * adv_msg )
400 unsigned long long port;
403 char hostname[GNUNET_OS_get_hostname_max_length() + 1];
404 char *protocol = "http://";
405 char *port_s = GNUNET_malloc(6 * sizeof(char));
407 if (0 != gethostname (hostname, sizeof (hostname) - 1))
409 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR,
410 "Could not get system's hostname, unable to create advertisement message");
413 if (-1 == GNUNET_CONFIGURATION_get_value_number (cfg,
417 return GNUNET_SYSERR;
419 sprintf(port_s, "%llu", port);
420 length = strlen(hostname)+strlen(protocol)+strlen(port_s)+2;
421 size = (length+1) * sizeof (char);
422 uri = GNUNET_malloc(size);
423 uri = strcpy(uri, protocol);
424 uri = strcat(uri, hostname);
425 uri = strcat(uri, ":");
426 uri = strcat(uri, port_s);
427 uri = strcat(uri, "/");
428 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,"Address to obtain hostlist: %s\n", uri);
431 adv_msg = GNUNET_malloc ( sizeof(struct GNUNET_HOSTLIST_ADV_Message) + size);
433 GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
434 "Creating message:address null\n",sizeof(struct GNUNET_HOSTLIST_ADV_Message));
436 if ( NULL == adv_msg)
438 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR,
439 "Could not allocate memory for the message");
442 GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
443 "size ADV_Message: %u\n",sizeof(struct GNUNET_HOSTLIST_ADV_Message));
444 GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
445 "size uri: %u\n", (length + 1) * sizeof (char));
448 if ( ( size + sizeof( struct GNUNET_HOSTLIST_ADV_Message )) > GNUNET_SERVER_MAX_MESSAGE_SIZE)
450 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR,
451 "Advertisement message is bigger than GNUNET allows");
455 adv_msg->header.type = htons (GNUNET_MESSAGE_TYPE_HOSTLIST_ADVERTISEMENT);
456 adv_msg->header.size = htons (sizeof (struct GNUNET_HOSTLIST_ADV_Message) + size);
457 memcpy(&adv_msg[1],uri,size);
459 /* Request core to transmit message to peer
460 adv_transmit_message(peer, size); */
462 GNUNET_free ( port_s );
464 GNUNET_free ( adv_msg );
470 * Method called whenever a given peer connects.
473 * @param peer peer identity this notification is about
474 * @param latency reported latency of the connection with 'other'
475 * @param distance reported distance (DV) to 'other'
478 connect_handler (void *cls,
480 GNUNET_PeerIdentity * peer,
481 struct GNUNET_TIME_Relative latency,
485 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
486 "A new peer connected to the server, preparing to send hostlist advertisement\n");
487 /* create a new advertisement message */
488 struct GNUNET_HOSTLIST_ADV_Message *adv_msg = NULL;
489 if ( (GNUNET_OK != adv_create_message(peer, adv_msg)))
491 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
492 _(" GNUNET_OK Could not create a hostlist advertisement message, impossible to advertise hostlist\n"));
499 * Method called whenever a given peer disconnects.
502 * @param peer peer identity this notification is about
505 disconnect_handler (void *cls,
507 GNUNET_PeerIdentity * peer)
514 * Function that queries MHD's select sets and
515 * starts the task waiting for them.
517 static GNUNET_SCHEDULER_TaskIdentifier
518 prepare_daemon (struct MHD_Daemon *daemon_handle);
521 * Call MHD to process pending requests and then go back
522 * and schedule the next run.
525 run_daemon (void *cls,
526 const struct GNUNET_SCHEDULER_TaskContext *tc)
528 struct MHD_Daemon *daemon_handle = cls;
530 if (daemon_handle == daemon_handle_v4)
531 hostlist_task_v4 = GNUNET_SCHEDULER_NO_TASK;
533 hostlist_task_v6 = GNUNET_SCHEDULER_NO_TASK;
535 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
537 GNUNET_assert (MHD_YES == MHD_run (daemon_handle));
538 if (daemon_handle == daemon_handle_v4)
539 hostlist_task_v4 = prepare_daemon (daemon_handle);
541 hostlist_task_v6 = prepare_daemon (daemon_handle);
546 * Function that queries MHD's select sets and
547 * starts the task waiting for them.
549 static GNUNET_SCHEDULER_TaskIdentifier
550 prepare_daemon (struct MHD_Daemon *daemon_handle)
552 GNUNET_SCHEDULER_TaskIdentifier ret;
556 struct GNUNET_NETWORK_FDSet *wrs;
557 struct GNUNET_NETWORK_FDSet *wws;
558 struct GNUNET_NETWORK_FDSet *wes;
560 unsigned long long timeout;
562 struct GNUNET_TIME_Relative tv;
567 wrs = GNUNET_NETWORK_fdset_create ();
568 wes = GNUNET_NETWORK_fdset_create ();
569 wws = GNUNET_NETWORK_fdset_create ();
571 GNUNET_assert (MHD_YES ==
572 MHD_get_fdset (daemon_handle,
577 haveto = MHD_get_timeout (daemon_handle, &timeout);
578 if (haveto == MHD_YES)
579 tv.value = (uint64_t) timeout;
581 tv = GNUNET_TIME_UNIT_FOREVER_REL;
582 GNUNET_NETWORK_fdset_copy_native (wrs, &rs, max);
583 GNUNET_NETWORK_fdset_copy_native (wws, &ws, max);
584 GNUNET_NETWORK_fdset_copy_native (wes, &es, max);
585 ret = GNUNET_SCHEDULER_add_select (sched,
586 GNUNET_SCHEDULER_PRIORITY_HIGH,
587 GNUNET_SCHEDULER_NO_TASK,
593 GNUNET_NETWORK_fdset_destroy (wrs);
594 GNUNET_NETWORK_fdset_destroy (wws);
595 GNUNET_NETWORK_fdset_destroy (wes);
602 * Start server offering our hostlist.
604 * @return GNUNET_OK on success
607 GNUNET_HOSTLIST_server_start (const struct GNUNET_CONFIGURATION_Handle *c,
608 struct GNUNET_SCHEDULER_Handle *s,
609 struct GNUNET_STATISTICS_Handle *st,
610 struct GNUNET_CORE_Handle *co,
611 GNUNET_CORE_ConnectEventHandler *server_ch,
612 GNUNET_CORE_DisconnectEventHandler *server_dh)
614 unsigned long long port;
619 if (-1 == GNUNET_CONFIGURATION_get_value_number (cfg,
623 return GNUNET_SYSERR;
624 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
625 _("Hostlist service starts on port %llu\n"),
627 daemon_handle_v6 = MHD_start_daemon (MHD_USE_IPv6
628 #if DEBUG_HOSTLIST_SERVER
632 (unsigned short) port,
633 &accept_policy_callback,
635 &access_handler_callback,
637 MHD_OPTION_CONNECTION_LIMIT, (unsigned int) 16,
638 MHD_OPTION_PER_IP_CONNECTION_LIMIT, (unsigned int) 1,
639 MHD_OPTION_CONNECTION_TIMEOUT, (unsigned int) 16,
640 MHD_OPTION_CONNECTION_MEMORY_LIMIT, (size_t) (16 * 1024),
642 daemon_handle_v4 = MHD_start_daemon (MHD_NO_FLAG
643 #if DEBUG_HOSTLIST_SERVER
647 (unsigned short) port,
648 &accept_policy_callback,
650 &access_handler_callback,
652 MHD_OPTION_CONNECTION_LIMIT, (unsigned int) 16,
653 MHD_OPTION_PER_IP_CONNECTION_LIMIT, (unsigned int) 1,
654 MHD_OPTION_CONNECTION_TIMEOUT, (unsigned int) 16,
655 MHD_OPTION_CONNECTION_MEMORY_LIMIT, (size_t) (16 * 1024),
658 if ( (daemon_handle_v6 == NULL) &&
659 (daemon_handle_v4 == NULL) )
661 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
662 _("Could not start hostlist HTTP server on port %u\n"),
663 (unsigned short) port);
664 return GNUNET_SYSERR;
667 *server_ch = &connect_handler;
668 *server_dh = &disconnect_handler;
670 if (daemon_handle_v4 != NULL)
671 hostlist_task_v4 = prepare_daemon (daemon_handle_v4);
672 if (daemon_handle_v6 != NULL)
673 hostlist_task_v6 = prepare_daemon (daemon_handle_v6);
674 response_task = GNUNET_SCHEDULER_add_now (sched,
681 * Stop server offering our hostlist.
684 GNUNET_HOSTLIST_server_stop ()
686 #if DEBUG_HOSTLIST_SERVER
687 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
688 "Hostlist server shutdown\n");
690 if (GNUNET_SCHEDULER_NO_TASK != hostlist_task_v6)
692 GNUNET_SCHEDULER_cancel (sched, hostlist_task_v6);
693 hostlist_task_v6 = GNUNET_SCHEDULER_NO_TASK;
695 if (GNUNET_SCHEDULER_NO_TASK != hostlist_task_v4)
697 GNUNET_SCHEDULER_cancel (sched, hostlist_task_v4);
698 hostlist_task_v4 = GNUNET_SCHEDULER_NO_TASK;
702 GNUNET_PEERINFO_iterate_cancel (pitr);
705 if (GNUNET_SCHEDULER_NO_TASK != response_task)
707 GNUNET_SCHEDULER_cancel (sched, response_task);
708 response_task = GNUNET_SCHEDULER_NO_TASK;
710 if (NULL != daemon_handle_v4)
712 MHD_stop_daemon (daemon_handle_v4);
713 daemon_handle_v4 = NULL;
715 if (NULL != daemon_handle_v6)
717 MHD_stop_daemon (daemon_handle_v6);
718 daemon_handle_v6 = NULL;
720 if (response != NULL)
722 MHD_destroy_response (response);
727 /* end of hostlist-server.c */