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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, Matthias Wachs
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 * Handle to the HTTP server as provided by libmicrohttpd for IPv6.
40 static struct MHD_Daemon *daemon_handle_v6;
43 * Handle to the HTTP server as provided by libmicrohttpd for IPv4.
45 static struct MHD_Daemon *daemon_handle_v4;
50 static const struct GNUNET_CONFIGURATION_Handle *cfg;
55 static struct GNUNET_SCHEDULER_Handle *sched;
58 * For keeping statistics.
60 static struct GNUNET_STATISTICS_Handle *stats;
63 * Handle to the core service (NULL until we've connected to it).
65 struct GNUNET_CORE_Handle *core;
68 * Handle to the peerinfo notify service (NULL until we've connected to it).
70 struct GNUNET_PEERINFO_NotifyContext *notify;
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 * Our canonical response.
85 static struct MHD_Response *response;
88 * NULL if we are not currenlty iterating over peer information.
90 static struct GNUNET_PEERINFO_IteratorContext *pitr;
93 * Handle for accessing peerinfo service.
95 static struct GNUNET_PEERINFO_Handle *peerinfo;
98 * Context for host processor.
108 * Set if we are allowed to advertise our hostlist to others.
110 static int advertising;
113 * How many times was the hostlist advertised?
115 static uint64_t hostlist_adv_count;
118 * Buffer for the hostlist address
120 static char * hostlist_uri;
124 * Function that assembles our response.
127 finish_response (struct HostSet *results)
129 if (response != NULL)
130 MHD_destroy_response (response);
131 #if DEBUG_HOSTLIST_SERVER
132 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
133 "Creating hostlist response with %u bytes\n",
134 (unsigned int) results->size);
136 response = MHD_create_response_from_data (results->size,
137 results->data, MHD_YES, MHD_NO);
138 if ( (daemon_handle_v4 == NULL) &&
139 (daemon_handle_v6 == NULL) )
141 MHD_destroy_response (response);
144 GNUNET_STATISTICS_set (stats,
145 gettext_noop("bytes in hostlist"),
148 GNUNET_free (results);
153 * Set 'cls' to GNUNET_YES (we have an address!).
155 * @param cls closure, an 'int*'
156 * @param tname name of the transport (ignored)
157 * @param expiration expiration time (call is ignored if this is in the past)
158 * @param addr the address (ignored)
159 * @param addrlen length of the address (ignored)
160 * @return GNUNET_SYSERR to stop iterating (unless expiration has occured)
163 check_has_addr (void *cls,
165 struct GNUNET_TIME_Absolute expiration,
166 const void *addr, size_t addrlen)
170 if (GNUNET_TIME_absolute_get_remaining (expiration).value == 0)
172 GNUNET_STATISTICS_update (stats,
173 gettext_noop("expired addresses encountered"),
176 return GNUNET_YES; /* ignore this address */
179 return GNUNET_SYSERR;
184 * Callback that processes each of the known HELLOs for the
185 * hostlist response construction.
188 host_processor (void *cls,
189 const struct GNUNET_PeerIdentity * peer,
190 const struct GNUNET_HELLO_Message *hello,
193 struct HostSet *results = cls;
201 finish_response (results);
206 has_addr = GNUNET_NO;
207 GNUNET_HELLO_iterate_addresses (hello,
211 if (GNUNET_NO == has_addr)
213 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
214 "HELLO for peer `%4s' has no address, not suitable for hostlist!\n",
216 GNUNET_STATISTICS_update (stats,
217 gettext_noop("HELLOs without addresses encountered (ignored)"),
223 s = GNUNET_HELLO_size(hello);
224 #if DEBUG_HOSTLIST_SERVER
225 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
226 "Received %u bytes of `%s' from peer `%s' for hostlist.\n",
231 if (old + s >= GNUNET_MAX_MALLOC_CHECKED)
233 GNUNET_STATISTICS_update (stats,
234 gettext_noop("bytes not included in hostlist (size limit)"),
237 return; /* too large, skip! */
239 #if DEBUG_HOSTLIST_SERVER
240 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
241 "Adding peer `%s' to hostlist (%u bytes)\n",
245 GNUNET_array_grow (results->data,
248 memcpy (&results->data[old], hello, s);
254 * Hostlist access policy (very permissive, allows everything).
257 accept_policy_callback (void *cls,
258 const struct sockaddr *addr, socklen_t addrlen)
260 if (NULL == response)
262 #if DEBUG_HOSTLIST_SERVER
263 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
264 "Received request for hostlist, but I am not yet ready; rejecting!\n");
268 return MHD_YES; /* accept all */
273 * Main request handler.
276 access_handler_callback (void *cls,
277 struct MHD_Connection *connection,
281 const char *upload_data,
282 size_t*upload_data_size, void **con_cls)
286 if (0 != strcmp (method, MHD_HTTP_METHOD_GET))
288 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
289 _("Refusing `%s' request to hostlist server\n"),
291 GNUNET_STATISTICS_update (stats,
292 gettext_noop("hostlist requests refused (not HTTP GET)"),
297 if (NULL == *con_cls)
300 #if DEBUG_HOSTLIST_SERVER
301 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
302 _("Sending 100 CONTINUE reply\n"));
304 return MHD_YES; /* send 100 continue */
306 if (*upload_data_size != 0)
308 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
309 _("Refusing `%s' request with %llu bytes of upload data\n"),
311 (unsigned long long) *upload_data_size);
312 GNUNET_STATISTICS_update (stats,
313 gettext_noop("hostlist requests refused (upload data)"),
316 return MHD_NO; /* do not support upload data */
318 if (response == NULL)
320 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
321 _("Could not handle hostlist request since I do not have a response yet\n"));
322 GNUNET_STATISTICS_update (stats,
323 gettext_noop("hostlist requests refused (not ready)"),
326 return MHD_NO; /* internal error, no response yet */
328 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
329 _("Received request for our hostlist\n"));
330 GNUNET_STATISTICS_update (stats,
331 gettext_noop("hostlist requests processed"),
334 return MHD_queue_response (connection, MHD_HTTP_OK, response);
339 * Handler called by core when core is ready to transmit message
341 * @param size size of buffer to copy message to
342 * @param buf buffer to copy message to
345 adv_transmit_ready ( void *cls, size_t size, void *buf)
347 size_t transmission_size;
348 size_t uri_size; /* Including \0 termination! */
349 struct GNUNET_MessageHeader header;
354 GNUNET_log ( GNUNET_ERROR_TYPE_DEBUG,
355 "Transmission failed, buffer invalid!\n" );
358 uri_size = strlen ( hostlist_uri ) + 1;
359 transmission_size = sizeof (struct GNUNET_MessageHeader) + uri_size;
360 header.type = htons (GNUNET_MESSAGE_TYPE_HOSTLIST_ADVERTISEMENT);
361 header.size = htons (transmission_size);
362 GNUNET_assert (size >= transmission_size);
363 memcpy (buf, &header, sizeof (struct GNUNET_MessageHeader));
365 memcpy (&cbuf[sizeof (struct GNUNET_MessageHeader)],
366 hostlist_uri, uri_size);
367 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
368 "Sent advertisement message: Copied %u bytes into buffer!\n",
369 (unsigned int) transmission_size);
370 hostlist_adv_count++;
371 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
372 " # Sent advertisement message: %u\n",
374 GNUNET_STATISTICS_set (stats,
375 gettext_noop("# hostlist advertisements send"),
378 return transmission_size;
383 * Method called whenever a given peer connects.
386 * @param peer peer identity this notification is about
387 * @param latency reported latency of the connection with 'other'
388 * @param distance reported distance (DV) to 'other'
391 connect_handler (void *cls,
393 GNUNET_PeerIdentity * peer,
394 struct GNUNET_TIME_Relative latency,
401 if (hostlist_uri == NULL)
403 size = strlen (hostlist_uri) + 1;
404 if (size + sizeof (struct GNUNET_MessageHeader) > GNUNET_SERVER_MAX_MESSAGE_SIZE)
409 size += sizeof (struct GNUNET_MessageHeader);
415 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
416 "Asked core to transmit advertisement message with a size of %u bytes to peer `%s'\n",
417 size,GNUNET_i2s(peer));
418 if (NULL == GNUNET_CORE_notify_transmit_ready (core,
423 &adv_transmit_ready, NULL))
425 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
426 _("Advertisement message could not be queued by core\n"));
432 * Method called whenever a given peer disconnects.
435 * @param peer peer identity this notification is about
438 disconnect_handler (void *cls,
440 GNUNET_PeerIdentity * peer)
446 * PEERINFO calls this function to let us know about a possible peer
447 * that we might want to connect to.
449 * @param cls closure (not used)
450 * @param peer potential peer to connect to
451 * @param hello HELLO for this peer (or NULL)
452 * @param trust how much we trust the peer (not used)
455 process_notify (void *cls,
456 const struct GNUNET_PeerIdentity *peer,
457 const struct GNUNET_HELLO_Message *hello,
460 struct HostSet *results;
461 #if DEBUG_HOSTLIST_SERVER
462 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
463 "Peerinfo is notifying us to rebuild our hostlist\n");
465 results = GNUNET_malloc(sizeof(struct HostSet));
466 GNUNET_assert (peerinfo != NULL);
467 pitr = GNUNET_PEERINFO_iterate (peerinfo,
470 GNUNET_TIME_UNIT_MINUTES,
476 * Function that queries MHD's select sets and
477 * starts the task waiting for them.
479 static GNUNET_SCHEDULER_TaskIdentifier
480 prepare_daemon (struct MHD_Daemon *daemon_handle);
484 * Call MHD to process pending requests and then go back
485 * and schedule the next run.
488 run_daemon (void *cls,
489 const struct GNUNET_SCHEDULER_TaskContext *tc)
491 struct MHD_Daemon *daemon_handle = cls;
493 if (daemon_handle == daemon_handle_v4)
494 hostlist_task_v4 = GNUNET_SCHEDULER_NO_TASK;
496 hostlist_task_v6 = GNUNET_SCHEDULER_NO_TASK;
498 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
500 GNUNET_assert (MHD_YES == MHD_run (daemon_handle));
501 if (daemon_handle == daemon_handle_v4)
502 hostlist_task_v4 = prepare_daemon (daemon_handle);
504 hostlist_task_v6 = prepare_daemon (daemon_handle);
509 * Function that queries MHD's select sets and
510 * starts the task waiting for them.
512 static GNUNET_SCHEDULER_TaskIdentifier
513 prepare_daemon (struct MHD_Daemon *daemon_handle)
515 GNUNET_SCHEDULER_TaskIdentifier ret;
519 struct GNUNET_NETWORK_FDSet *wrs;
520 struct GNUNET_NETWORK_FDSet *wws;
521 struct GNUNET_NETWORK_FDSet *wes;
523 unsigned long long timeout;
525 struct GNUNET_TIME_Relative tv;
530 wrs = GNUNET_NETWORK_fdset_create ();
531 wes = GNUNET_NETWORK_fdset_create ();
532 wws = GNUNET_NETWORK_fdset_create ();
534 GNUNET_assert (MHD_YES ==
535 MHD_get_fdset (daemon_handle,
540 haveto = MHD_get_timeout (daemon_handle, &timeout);
541 if (haveto == MHD_YES)
542 tv.value = (uint64_t) timeout;
544 tv = GNUNET_TIME_UNIT_FOREVER_REL;
545 GNUNET_NETWORK_fdset_copy_native (wrs, &rs, max);
546 GNUNET_NETWORK_fdset_copy_native (wws, &ws, max);
547 GNUNET_NETWORK_fdset_copy_native (wes, &es, max);
548 ret = GNUNET_SCHEDULER_add_select (sched,
549 GNUNET_SCHEDULER_PRIORITY_HIGH,
550 GNUNET_SCHEDULER_NO_TASK,
556 GNUNET_NETWORK_fdset_destroy (wrs);
557 GNUNET_NETWORK_fdset_destroy (wws);
558 GNUNET_NETWORK_fdset_destroy (wes);
565 * Start server offering our hostlist.
567 * @return GNUNET_OK on success
570 GNUNET_HOSTLIST_server_start (const struct GNUNET_CONFIGURATION_Handle *c,
571 struct GNUNET_SCHEDULER_Handle *s,
572 struct GNUNET_STATISTICS_Handle *st,
573 struct GNUNET_CORE_Handle *co,
574 GNUNET_CORE_ConnectEventHandler *server_ch,
575 GNUNET_CORE_DisconnectEventHandler *server_dh,
578 unsigned long long port;
582 advertising = advertise;
584 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
585 "Advertising not enabled on this hostlist server\n");
587 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
588 "Advertising enabled on this hostlist server\n");
592 peerinfo = GNUNET_PEERINFO_connect (sched, cfg);
593 if (peerinfo == NULL)
595 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
596 _("Could not access PEERINFO service. Exiting.\n"));
597 return GNUNET_SYSERR;
599 if (-1 == GNUNET_CONFIGURATION_get_value_number (cfg,
603 return GNUNET_SYSERR;
604 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
605 _("Hostlist service starts on port %llu\n"),
607 hostname = GNUNET_RESOLVER_local_fqdn_get ();
608 if (NULL != hostname)
610 size = strlen (hostname);
611 if (size + 15 > MAX_URL_LEN)
617 GNUNET_asprintf (&hostlist_uri,
620 (unsigned int) port);
621 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
622 _("Address to obtain hostlist: `%s'\n"),
625 GNUNET_free ( hostname );
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;
669 *server_ch = &connect_handler;
670 *server_dh = &disconnect_handler;
672 if (daemon_handle_v4 != NULL)
673 hostlist_task_v4 = prepare_daemon (daemon_handle_v4);
674 if (daemon_handle_v6 != NULL)
675 hostlist_task_v6 = prepare_daemon (daemon_handle_v6);
677 notify = GNUNET_PEERINFO_notify ( cfg, sched, process_notify, NULL);
683 * Stop server offering our hostlist.
686 GNUNET_HOSTLIST_server_stop ()
688 #if DEBUG_HOSTLIST_SERVER
689 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
690 "Hostlist server shutdown\n");
694 GNUNET_PEERINFO_notify_cancel (notify);
697 if (GNUNET_SCHEDULER_NO_TASK != hostlist_task_v6)
699 GNUNET_SCHEDULER_cancel (sched, hostlist_task_v6);
700 hostlist_task_v6 = GNUNET_SCHEDULER_NO_TASK;
702 if (GNUNET_SCHEDULER_NO_TASK != hostlist_task_v4)
704 GNUNET_SCHEDULER_cancel (sched, hostlist_task_v4);
705 hostlist_task_v4 = GNUNET_SCHEDULER_NO_TASK;
709 GNUNET_PEERINFO_iterate_cancel (pitr);
712 if (NULL != daemon_handle_v4)
714 MHD_stop_daemon (daemon_handle_v4);
715 daemon_handle_v4 = NULL;
717 if (NULL != daemon_handle_v6)
719 MHD_stop_daemon (daemon_handle_v6);
720 daemon_handle_v6 = NULL;
722 if (response != NULL)
724 MHD_destroy_response (response);
727 if (peerinfo != NULL)
729 GNUNET_PEERINFO_disconnect (peerinfo);
734 /* end of hostlist-server.c */