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3 (C) 2008, 2009, 2010 Christian Grothoff (and other contributing authors)
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13 General Public License for more details.
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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_EXTRA_LOGGING
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;
53 * For keeping statistics.
55 static struct GNUNET_STATISTICS_Handle *stats;
58 * Handle to the core service (NULL until we've connected to it).
60 static struct GNUNET_CORE_Handle *core;
63 * Handle to the peerinfo notify service (NULL until we've connected to it).
65 static struct GNUNET_PEERINFO_NotifyContext *notify;
68 * Our primary task for IPv4.
70 static GNUNET_SCHEDULER_TaskIdentifier hostlist_task_v4;
73 * Our primary task for IPv6.
75 static GNUNET_SCHEDULER_TaskIdentifier hostlist_task_v6;
78 * Our canonical response.
80 static struct MHD_Response *response;
83 * NULL if we are not currenlty iterating over peer information.
85 static struct GNUNET_PEERINFO_IteratorContext *pitr;
88 * Handle for accessing peerinfo service.
90 static struct GNUNET_PEERINFO_Handle *peerinfo;
93 * Context for host processor.
103 * Set if we are allowed to advertise our hostlist to others.
105 static int advertising;
108 * Buffer for the hostlist address
110 static char *hostlist_uri;
114 * Function that assembles our response.
117 finish_response (struct HostSet *results)
119 if (response != NULL)
120 MHD_destroy_response (response);
121 #if DEBUG_HOSTLIST_SERVER
122 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
123 "Creating hostlist response with %u bytes\n",
124 (unsigned int) results->size);
127 MHD_create_response_from_data (results->size, results->data, MHD_YES,
129 if ((daemon_handle_v4 == NULL) && (daemon_handle_v6 == NULL))
131 MHD_destroy_response (response);
134 GNUNET_STATISTICS_set (stats, gettext_noop ("bytes in hostlist"),
135 results->size, GNUNET_YES);
136 GNUNET_free (results);
141 * Set 'cls' to GNUNET_YES (we have an address!).
143 * @param cls closure, an 'int*'
144 * @param tname name of the transport (ignored)
145 * @param expiration expiration time (call is ignored if this is in the past)
146 * @param addr the address (ignored)
147 * @param addrlen length of the address (ignored)
148 * @return GNUNET_SYSERR to stop iterating (unless expiration has occured)
151 check_has_addr (void *cls, const char *tname,
152 struct GNUNET_TIME_Absolute expiration, const void *addr,
157 if (GNUNET_TIME_absolute_get_remaining (expiration).rel_value == 0)
159 GNUNET_STATISTICS_update (stats,
160 gettext_noop ("expired addresses encountered"), 1,
162 return GNUNET_YES; /* ignore this address */
165 return GNUNET_SYSERR;
170 * Callback that processes each of the known HELLOs for the
171 * hostlist response construction.
174 host_processor (void *cls, const struct GNUNET_PeerIdentity *peer,
175 const struct GNUNET_HELLO_Message *hello, const char *err_msg)
177 struct HostSet *results = cls;
184 GNUNET_assert (NULL == peer);
186 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
187 _("Error in communication with PEERINFO service: %s\n"),
194 finish_response (results);
199 has_addr = GNUNET_NO;
200 GNUNET_HELLO_iterate_addresses (hello, GNUNET_NO, &check_has_addr, &has_addr);
201 if (GNUNET_NO == has_addr)
203 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
204 "HELLO for peer `%4s' has no address, not suitable for hostlist!\n",
206 GNUNET_STATISTICS_update (stats,
208 ("HELLOs without addresses encountered (ignored)"),
213 s = GNUNET_HELLO_size (hello);
214 #if DEBUG_HOSTLIST_SERVER
215 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
216 "Received %u bytes of `%s' from peer `%s' for hostlist.\n",
217 (unsigned int) s, "HELLO", GNUNET_i2s (peer));
219 if ((old + s >= GNUNET_MAX_MALLOC_CHECKED) ||
220 (old + s >= MAX_BYTES_PER_HOSTLISTS))
222 GNUNET_STATISTICS_update (stats,
224 ("bytes not included in hostlist (size limit)"),
226 return; /* too large, skip! */
228 #if DEBUG_HOSTLIST_SERVER
229 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
230 "Adding peer `%s' to hostlist (%u bytes)\n", GNUNET_i2s (peer),
233 GNUNET_array_grow (results->data, results->size, old + s);
234 memcpy (&results->data[old], hello, s);
240 * Hostlist access policy (very permissive, allows everything).
243 accept_policy_callback (void *cls, const struct sockaddr *addr,
246 if (NULL == response)
248 #if DEBUG_HOSTLIST_SERVER
249 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
250 "Received request for hostlist, but I am not yet ready; rejecting!\n");
254 return MHD_YES; /* accept all */
259 * Main request handler.
262 access_handler_callback (void *cls, struct MHD_Connection *connection,
263 const char *url, const char *method,
264 const char *version, const char *upload_data,
265 size_t * upload_data_size, void **con_cls)
269 if (0 != strcmp (method, MHD_HTTP_METHOD_GET))
271 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
272 _("Refusing `%s' request to hostlist server\n"), method);
273 GNUNET_STATISTICS_update (stats,
275 ("hostlist requests refused (not HTTP GET)"), 1,
279 if (NULL == *con_cls)
282 #if DEBUG_HOSTLIST_SERVER
283 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _("Sending 100 CONTINUE reply\n"));
285 return MHD_YES; /* send 100 continue */
287 if (*upload_data_size != 0)
289 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
290 _("Refusing `%s' request with %llu bytes of upload data\n"),
291 method, (unsigned long long) *upload_data_size);
292 GNUNET_STATISTICS_update (stats,
294 ("hostlist requests refused (upload data)"), 1,
296 return MHD_NO; /* do not support upload data */
298 if (response == NULL)
300 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
302 ("Could not handle hostlist request since I do not have a response yet\n"));
303 GNUNET_STATISTICS_update (stats,
305 ("hostlist requests refused (not ready)"), 1,
307 return MHD_NO; /* internal error, no response yet */
309 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Received request for our hostlist\n"));
310 GNUNET_STATISTICS_update (stats, gettext_noop ("hostlist requests processed"),
312 return MHD_queue_response (connection, MHD_HTTP_OK, response);
317 * Handler called by core when core is ready to transmit message
319 * @param size size of buffer to copy message to
320 * @param buf buffer to copy message to
323 adv_transmit_ready (void *cls, size_t size, void *buf)
325 static uint64_t hostlist_adv_count;
327 size_t transmission_size;
328 size_t uri_size; /* Including \0 termination! */
329 struct GNUNET_MessageHeader header;
334 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
335 "Transmission failed, buffer invalid!\n");
338 uri_size = strlen (hostlist_uri) + 1;
339 transmission_size = sizeof (struct GNUNET_MessageHeader) + uri_size;
340 header.type = htons (GNUNET_MESSAGE_TYPE_HOSTLIST_ADVERTISEMENT);
341 header.size = htons (transmission_size);
342 GNUNET_assert (size >= transmission_size);
343 memcpy (buf, &header, sizeof (struct GNUNET_MessageHeader));
345 memcpy (&cbuf[sizeof (struct GNUNET_MessageHeader)], hostlist_uri, uri_size);
346 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
347 "Sent advertisement message: Copied %u bytes into buffer!\n",
348 (unsigned int) transmission_size);
349 hostlist_adv_count++;
350 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, " # Sent advertisement message: %u\n",
352 GNUNET_STATISTICS_update (stats,
353 gettext_noop ("# hostlist advertisements send"), 1,
355 return transmission_size;
360 * Method called whenever a given peer connects.
363 * @param peer peer identity this notification is about
364 * @param atsi performance data
365 * @param atsi_count number of records in 'atsi'
368 connect_handler (void *cls, const struct GNUNET_PeerIdentity *peer,
369 const struct GNUNET_ATS_Information *atsi,
370 unsigned int atsi_count)
376 if (hostlist_uri == NULL)
378 size = strlen (hostlist_uri) + 1;
379 if (size + sizeof (struct GNUNET_MessageHeader) >=
380 GNUNET_SERVER_MAX_MESSAGE_SIZE)
385 size += sizeof (struct GNUNET_MessageHeader);
391 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
392 "Asked core to transmit advertisement message with a size of %u bytes to peer `%s'\n",
393 size, GNUNET_i2s (peer));
395 GNUNET_CORE_notify_transmit_ready (core, GNUNET_YES, 0,
396 GNUNET_ADV_TIMEOUT, peer, size,
397 &adv_transmit_ready, NULL))
399 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
400 _("Advertisement message could not be queued by core\n"));
406 * Method called whenever a given peer disconnects.
409 * @param peer peer identity this notification is about
412 disconnect_handler (void *cls, const struct GNUNET_PeerIdentity *peer)
418 * PEERINFO calls this function to let us know about a possible peer
419 * that we might want to connect to.
421 * @param cls closure (not used)
422 * @param peer potential peer to connect to
423 * @param hello HELLO for this peer (or NULL)
424 * @param err_msg NULL if successful, otherwise contains error message
427 process_notify (void *cls, const struct GNUNET_PeerIdentity *peer,
428 const struct GNUNET_HELLO_Message *hello, const char *err_msg)
430 struct HostSet *results;
432 #if DEBUG_HOSTLIST_SERVER
433 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
434 "Peerinfo is notifying us to rebuild our hostlist\n");
438 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
439 _("Error in communication with PEERINFO service\n"));
442 results = GNUNET_malloc (sizeof (struct HostSet));
443 GNUNET_assert (peerinfo != NULL);
445 GNUNET_PEERINFO_iterate (peerinfo, NULL, GNUNET_TIME_UNIT_MINUTES,
446 &host_processor, results);
450 * Function that queries MHD's select sets and
451 * starts the task waiting for them.
453 static GNUNET_SCHEDULER_TaskIdentifier
454 prepare_daemon (struct MHD_Daemon *daemon_handle);
458 * Call MHD to process pending requests and then go back
459 * and schedule the next run.
462 run_daemon (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
464 struct MHD_Daemon *daemon_handle = cls;
466 if (daemon_handle == daemon_handle_v4)
467 hostlist_task_v4 = GNUNET_SCHEDULER_NO_TASK;
469 hostlist_task_v6 = GNUNET_SCHEDULER_NO_TASK;
471 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
473 GNUNET_assert (MHD_YES == MHD_run (daemon_handle));
474 if (daemon_handle == daemon_handle_v4)
475 hostlist_task_v4 = prepare_daemon (daemon_handle);
477 hostlist_task_v6 = prepare_daemon (daemon_handle);
482 * Function that queries MHD's select sets and
483 * starts the task waiting for them.
485 static GNUNET_SCHEDULER_TaskIdentifier
486 prepare_daemon (struct MHD_Daemon *daemon_handle)
488 GNUNET_SCHEDULER_TaskIdentifier ret;
492 struct GNUNET_NETWORK_FDSet *wrs;
493 struct GNUNET_NETWORK_FDSet *wws;
494 struct GNUNET_NETWORK_FDSet *wes;
496 unsigned long long timeout;
498 struct GNUNET_TIME_Relative tv;
503 wrs = GNUNET_NETWORK_fdset_create ();
504 wes = GNUNET_NETWORK_fdset_create ();
505 wws = GNUNET_NETWORK_fdset_create ();
507 GNUNET_assert (MHD_YES == MHD_get_fdset (daemon_handle, &rs, &ws, &es, &max));
508 haveto = MHD_get_timeout (daemon_handle, &timeout);
509 if (haveto == MHD_YES)
510 tv.rel_value = (uint64_t) timeout;
512 tv = GNUNET_TIME_UNIT_FOREVER_REL;
513 GNUNET_NETWORK_fdset_copy_native (wrs, &rs, max + 1);
514 GNUNET_NETWORK_fdset_copy_native (wws, &ws, max + 1);
515 GNUNET_NETWORK_fdset_copy_native (wes, &es, max + 1);
517 GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_HIGH,
518 GNUNET_SCHEDULER_NO_TASK, tv, wrs, wws,
519 &run_daemon, daemon_handle);
520 GNUNET_NETWORK_fdset_destroy (wrs);
521 GNUNET_NETWORK_fdset_destroy (wws);
522 GNUNET_NETWORK_fdset_destroy (wes);
529 * Start server offering our hostlist.
531 * @return GNUNET_OK on success
534 GNUNET_HOSTLIST_server_start (const struct GNUNET_CONFIGURATION_Handle *c,
535 struct GNUNET_STATISTICS_Handle *st,
536 struct GNUNET_CORE_Handle *co,
537 GNUNET_CORE_ConnectEventHandler *server_ch,
538 GNUNET_CORE_DisconnectEventHandler *server_dh,
541 unsigned long long port;
545 advertising = advertise;
547 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
548 "Advertising not enabled on this hostlist server\n");
550 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
551 "Advertising enabled on this hostlist server\n");
554 peerinfo = GNUNET_PEERINFO_connect (cfg);
555 if (peerinfo == NULL)
557 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
558 _("Could not access PEERINFO service. Exiting.\n"));
559 return GNUNET_SYSERR;
562 GNUNET_CONFIGURATION_get_value_number (cfg, "HOSTLIST", "HTTPPORT",
564 return GNUNET_SYSERR;
565 if ((port == 0) || (port > UINT16_MAX))
567 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
568 _("Invalid port number %llu. Exiting.\n"), port);
569 return GNUNET_SYSERR;
573 GNUNET_CONFIGURATION_get_value_string (cfg, "HOSTLIST",
574 "EXTERNAL_DNS_NAME", &hostname))
575 hostname = GNUNET_RESOLVER_local_fqdn_get ();
577 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Hostlist service starts on %s:%llu\n"),
579 if (NULL != hostname)
581 size = strlen (hostname);
582 if (size + 15 > MAX_URL_LEN)
588 GNUNET_asprintf (&hostlist_uri, "http://%s:%u/", hostname,
589 (unsigned int) port);
590 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
591 _("Address to obtain hostlist: `%s'\n"), hostlist_uri);
593 GNUNET_free (hostname);
595 daemon_handle_v6 = MHD_start_daemon (MHD_USE_IPv6
596 #if DEBUG_HOSTLIST_SERVER
599 , (unsigned short) port,
600 &accept_policy_callback, NULL,
601 &access_handler_callback, NULL,
602 MHD_OPTION_CONNECTION_LIMIT,
604 MHD_OPTION_PER_IP_CONNECTION_LIMIT,
606 MHD_OPTION_CONNECTION_TIMEOUT,
608 MHD_OPTION_CONNECTION_MEMORY_LIMIT,
609 (size_t) (16 * 1024), MHD_OPTION_END);
610 daemon_handle_v4 = MHD_start_daemon (MHD_NO_FLAG
611 #if DEBUG_HOSTLIST_SERVER
614 , (unsigned short) port,
615 &accept_policy_callback, NULL,
616 &access_handler_callback, NULL,
617 MHD_OPTION_CONNECTION_LIMIT,
619 MHD_OPTION_PER_IP_CONNECTION_LIMIT,
621 MHD_OPTION_CONNECTION_TIMEOUT,
623 MHD_OPTION_CONNECTION_MEMORY_LIMIT,
624 (size_t) (16 * 1024), MHD_OPTION_END);
626 if ((daemon_handle_v6 == NULL) && (daemon_handle_v4 == NULL))
628 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
629 _("Could not start hostlist HTTP server on port %u\n"),
630 (unsigned short) port);
631 return GNUNET_SYSERR;
636 *server_ch = &connect_handler;
637 *server_dh = &disconnect_handler;
639 if (daemon_handle_v4 != NULL)
640 hostlist_task_v4 = prepare_daemon (daemon_handle_v4);
641 if (daemon_handle_v6 != NULL)
642 hostlist_task_v6 = prepare_daemon (daemon_handle_v6);
644 notify = GNUNET_PEERINFO_notify (cfg, process_notify, NULL);
650 * Stop server offering our hostlist.
653 GNUNET_HOSTLIST_server_stop ()
655 #if DEBUG_HOSTLIST_SERVER
656 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Hostlist server shutdown\n");
660 GNUNET_PEERINFO_notify_cancel (notify);
663 if (GNUNET_SCHEDULER_NO_TASK != hostlist_task_v6)
665 GNUNET_SCHEDULER_cancel (hostlist_task_v6);
666 hostlist_task_v6 = GNUNET_SCHEDULER_NO_TASK;
668 if (GNUNET_SCHEDULER_NO_TASK != hostlist_task_v4)
670 GNUNET_SCHEDULER_cancel (hostlist_task_v4);
671 hostlist_task_v4 = GNUNET_SCHEDULER_NO_TASK;
675 GNUNET_PEERINFO_iterate_cancel (pitr);
678 if (NULL != daemon_handle_v4)
680 MHD_stop_daemon (daemon_handle_v4);
681 daemon_handle_v4 = NULL;
683 if (NULL != daemon_handle_v6)
685 MHD_stop_daemon (daemon_handle_v6);
686 daemon_handle_v6 = NULL;
688 if (response != NULL)
690 MHD_destroy_response (response);
693 if (peerinfo != NULL)
695 GNUNET_PEERINFO_disconnect (peerinfo);
703 /* end of hostlist-server.c */