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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 address the address (ignored)
145 * @param expiration expiration time (call is ignored if this is in the past)
146 * @return GNUNET_SYSERR to stop iterating (unless expiration has occured)
149 check_has_addr (void *cls, const struct GNUNET_HELLO_Address *address,
150 struct GNUNET_TIME_Absolute expiration)
154 if (GNUNET_TIME_absolute_get_remaining (expiration).rel_value == 0)
156 GNUNET_STATISTICS_update (stats,
157 gettext_noop ("expired addresses encountered"), 1,
159 return GNUNET_YES; /* ignore this address */
162 return GNUNET_SYSERR;
167 * Callback that processes each of the known HELLOs for the
168 * hostlist response construction.
171 host_processor (void *cls, const struct GNUNET_PeerIdentity *peer,
172 const struct GNUNET_HELLO_Message *hello, const char *err_msg)
174 struct HostSet *results = cls;
181 GNUNET_assert (NULL == peer);
183 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
184 _("Error in communication with PEERINFO service: %s\n"),
191 finish_response (results);
196 has_addr = GNUNET_NO;
197 GNUNET_HELLO_iterate_addresses (hello, GNUNET_NO, &check_has_addr, &has_addr);
198 if (GNUNET_NO == has_addr)
200 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
201 "HELLO for peer `%4s' has no address, not suitable for hostlist!\n",
203 GNUNET_STATISTICS_update (stats,
205 ("HELLOs without addresses encountered (ignored)"),
210 s = GNUNET_HELLO_size (hello);
211 #if DEBUG_HOSTLIST_SERVER
212 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
213 "Received %u bytes of `%s' from peer `%s' for hostlist.\n",
214 (unsigned int) s, "HELLO", GNUNET_i2s (peer));
216 if ((old + s >= GNUNET_MAX_MALLOC_CHECKED) ||
217 (old + s >= MAX_BYTES_PER_HOSTLISTS))
219 GNUNET_STATISTICS_update (stats,
221 ("bytes not included in hostlist (size limit)"),
223 return; /* too large, skip! */
225 #if DEBUG_HOSTLIST_SERVER
226 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
227 "Adding peer `%s' to hostlist (%u bytes)\n", GNUNET_i2s (peer),
230 GNUNET_array_grow (results->data, results->size, old + s);
231 memcpy (&results->data[old], hello, s);
237 * Hostlist access policy (very permissive, allows everything).
240 accept_policy_callback (void *cls, const struct sockaddr *addr,
243 if (NULL == response)
245 #if DEBUG_HOSTLIST_SERVER
246 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
247 "Received request for hostlist, but I am not yet ready; rejecting!\n");
251 return MHD_YES; /* accept all */
256 * Main request handler.
259 access_handler_callback (void *cls, struct MHD_Connection *connection,
260 const char *url, const char *method,
261 const char *version, const char *upload_data,
262 size_t * upload_data_size, void **con_cls)
266 if (0 != strcmp (method, MHD_HTTP_METHOD_GET))
268 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
269 _("Refusing `%s' request to hostlist server\n"), method);
270 GNUNET_STATISTICS_update (stats,
272 ("hostlist requests refused (not HTTP GET)"), 1,
276 if (NULL == *con_cls)
279 #if DEBUG_HOSTLIST_SERVER
280 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _("Sending 100 CONTINUE reply\n"));
282 return MHD_YES; /* send 100 continue */
284 if (*upload_data_size != 0)
286 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
287 _("Refusing `%s' request with %llu bytes of upload data\n"),
288 method, (unsigned long long) *upload_data_size);
289 GNUNET_STATISTICS_update (stats,
291 ("hostlist requests refused (upload data)"), 1,
293 return MHD_NO; /* do not support upload data */
295 if (response == NULL)
297 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
299 ("Could not handle hostlist request since I do not have a response yet\n"));
300 GNUNET_STATISTICS_update (stats,
302 ("hostlist requests refused (not ready)"), 1,
304 return MHD_NO; /* internal error, no response yet */
306 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Received request for our hostlist\n"));
307 GNUNET_STATISTICS_update (stats, gettext_noop ("hostlist requests processed"),
309 return MHD_queue_response (connection, MHD_HTTP_OK, response);
314 * Handler called by core when core is ready to transmit message
316 * @param size size of buffer to copy message to
317 * @param buf buffer to copy message to
320 adv_transmit_ready (void *cls, size_t size, void *buf)
322 static uint64_t hostlist_adv_count;
324 size_t transmission_size;
325 size_t uri_size; /* Including \0 termination! */
326 struct GNUNET_MessageHeader header;
331 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
332 "Transmission failed, buffer invalid!\n");
335 uri_size = strlen (hostlist_uri) + 1;
336 transmission_size = sizeof (struct GNUNET_MessageHeader) + uri_size;
337 header.type = htons (GNUNET_MESSAGE_TYPE_HOSTLIST_ADVERTISEMENT);
338 header.size = htons (transmission_size);
339 GNUNET_assert (size >= transmission_size);
340 memcpy (buf, &header, sizeof (struct GNUNET_MessageHeader));
342 memcpy (&cbuf[sizeof (struct GNUNET_MessageHeader)], hostlist_uri, uri_size);
343 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
344 "Sent advertisement message: Copied %u bytes into buffer!\n",
345 (unsigned int) transmission_size);
346 hostlist_adv_count++;
347 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, " # Sent advertisement message: %u\n",
349 GNUNET_STATISTICS_update (stats,
350 gettext_noop ("# hostlist advertisements send"), 1,
352 return transmission_size;
357 * Method called whenever a given peer connects.
360 * @param peer peer identity this notification is about
361 * @param atsi performance data
362 * @param atsi_count number of records in 'atsi'
365 connect_handler (void *cls, const struct GNUNET_PeerIdentity *peer,
366 const struct GNUNET_ATS_Information *atsi,
367 unsigned int atsi_count)
373 if (hostlist_uri == NULL)
375 size = strlen (hostlist_uri) + 1;
376 if (size + sizeof (struct GNUNET_MessageHeader) >=
377 GNUNET_SERVER_MAX_MESSAGE_SIZE)
382 size += sizeof (struct GNUNET_MessageHeader);
388 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
389 "Asked core to transmit advertisement message with a size of %u bytes to peer `%s'\n",
390 size, GNUNET_i2s (peer));
392 GNUNET_CORE_notify_transmit_ready (core, GNUNET_YES, 0,
393 GNUNET_ADV_TIMEOUT, peer, size,
394 &adv_transmit_ready, NULL))
396 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
397 _("Advertisement message could not be queued by core\n"));
403 * Method called whenever a given peer disconnects.
406 * @param peer peer identity this notification is about
409 disconnect_handler (void *cls, const struct GNUNET_PeerIdentity *peer)
415 * PEERINFO calls this function to let us know about a possible peer
416 * that we might want to connect to.
418 * @param cls closure (not used)
419 * @param peer potential peer to connect to
420 * @param hello HELLO for this peer (or NULL)
421 * @param err_msg NULL if successful, otherwise contains error message
424 process_notify (void *cls, const struct GNUNET_PeerIdentity *peer,
425 const struct GNUNET_HELLO_Message *hello, const char *err_msg)
427 struct HostSet *results;
429 #if DEBUG_HOSTLIST_SERVER
430 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
431 "Peerinfo is notifying us to rebuild our hostlist\n");
435 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
436 _("Error in communication with PEERINFO service\n"));
439 results = GNUNET_malloc (sizeof (struct HostSet));
440 GNUNET_assert (peerinfo != NULL);
442 GNUNET_PEERINFO_iterate (peerinfo, NULL, GNUNET_TIME_UNIT_MINUTES,
443 &host_processor, results);
447 * Function that queries MHD's select sets and
448 * starts the task waiting for them.
450 static GNUNET_SCHEDULER_TaskIdentifier
451 prepare_daemon (struct MHD_Daemon *daemon_handle);
455 * Call MHD to process pending requests and then go back
456 * and schedule the next run.
459 run_daemon (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
461 struct MHD_Daemon *daemon_handle = cls;
463 if (daemon_handle == daemon_handle_v4)
464 hostlist_task_v4 = GNUNET_SCHEDULER_NO_TASK;
466 hostlist_task_v6 = GNUNET_SCHEDULER_NO_TASK;
468 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
470 GNUNET_assert (MHD_YES == MHD_run (daemon_handle));
471 if (daemon_handle == daemon_handle_v4)
472 hostlist_task_v4 = prepare_daemon (daemon_handle);
474 hostlist_task_v6 = prepare_daemon (daemon_handle);
479 * Function that queries MHD's select sets and
480 * starts the task waiting for them.
482 static GNUNET_SCHEDULER_TaskIdentifier
483 prepare_daemon (struct MHD_Daemon *daemon_handle)
485 GNUNET_SCHEDULER_TaskIdentifier ret;
489 struct GNUNET_NETWORK_FDSet *wrs;
490 struct GNUNET_NETWORK_FDSet *wws;
491 struct GNUNET_NETWORK_FDSet *wes;
493 unsigned long long timeout;
495 struct GNUNET_TIME_Relative tv;
500 wrs = GNUNET_NETWORK_fdset_create ();
501 wes = GNUNET_NETWORK_fdset_create ();
502 wws = GNUNET_NETWORK_fdset_create ();
504 GNUNET_assert (MHD_YES == MHD_get_fdset (daemon_handle, &rs, &ws, &es, &max));
505 haveto = MHD_get_timeout (daemon_handle, &timeout);
506 if (haveto == MHD_YES)
507 tv.rel_value = (uint64_t) timeout;
509 tv = GNUNET_TIME_UNIT_FOREVER_REL;
510 GNUNET_NETWORK_fdset_copy_native (wrs, &rs, max + 1);
511 GNUNET_NETWORK_fdset_copy_native (wws, &ws, max + 1);
512 GNUNET_NETWORK_fdset_copy_native (wes, &es, max + 1);
514 GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_HIGH,
515 GNUNET_SCHEDULER_NO_TASK, tv, wrs, wws,
516 &run_daemon, daemon_handle);
517 GNUNET_NETWORK_fdset_destroy (wrs);
518 GNUNET_NETWORK_fdset_destroy (wws);
519 GNUNET_NETWORK_fdset_destroy (wes);
526 * Start server offering our hostlist.
528 * @return GNUNET_OK on success
531 GNUNET_HOSTLIST_server_start (const struct GNUNET_CONFIGURATION_Handle *c,
532 struct GNUNET_STATISTICS_Handle *st,
533 struct GNUNET_CORE_Handle *co,
534 GNUNET_CORE_ConnectEventHandler *server_ch,
535 GNUNET_CORE_DisconnectEventHandler *server_dh,
538 unsigned long long port;
542 advertising = advertise;
544 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
545 "Advertising not enabled on this hostlist server\n");
547 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
548 "Advertising enabled on this hostlist server\n");
551 peerinfo = GNUNET_PEERINFO_connect (cfg);
552 if (peerinfo == NULL)
554 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
555 _("Could not access PEERINFO service. Exiting.\n"));
556 return GNUNET_SYSERR;
559 GNUNET_CONFIGURATION_get_value_number (cfg, "HOSTLIST", "HTTPPORT",
561 return GNUNET_SYSERR;
562 if ((port == 0) || (port > UINT16_MAX))
564 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
565 _("Invalid port number %llu. Exiting.\n"), port);
566 return GNUNET_SYSERR;
570 GNUNET_CONFIGURATION_get_value_string (cfg, "HOSTLIST",
571 "EXTERNAL_DNS_NAME", &hostname))
572 hostname = GNUNET_RESOLVER_local_fqdn_get ();
574 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Hostlist service starts on %s:%llu\n"),
576 if (NULL != hostname)
578 size = strlen (hostname);
579 if (size + 15 > MAX_URL_LEN)
585 GNUNET_asprintf (&hostlist_uri, "http://%s:%u/", hostname,
586 (unsigned int) port);
587 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
588 _("Address to obtain hostlist: `%s'\n"), hostlist_uri);
590 GNUNET_free (hostname);
592 daemon_handle_v6 = MHD_start_daemon (MHD_USE_IPv6
593 #if DEBUG_HOSTLIST_SERVER
596 , (unsigned short) port,
597 &accept_policy_callback, NULL,
598 &access_handler_callback, NULL,
599 MHD_OPTION_CONNECTION_LIMIT,
601 MHD_OPTION_PER_IP_CONNECTION_LIMIT,
603 MHD_OPTION_CONNECTION_TIMEOUT,
605 MHD_OPTION_CONNECTION_MEMORY_LIMIT,
606 (size_t) (16 * 1024), MHD_OPTION_END);
607 daemon_handle_v4 = MHD_start_daemon (MHD_NO_FLAG
608 #if DEBUG_HOSTLIST_SERVER
611 , (unsigned short) port,
612 &accept_policy_callback, NULL,
613 &access_handler_callback, NULL,
614 MHD_OPTION_CONNECTION_LIMIT,
616 MHD_OPTION_PER_IP_CONNECTION_LIMIT,
618 MHD_OPTION_CONNECTION_TIMEOUT,
620 MHD_OPTION_CONNECTION_MEMORY_LIMIT,
621 (size_t) (16 * 1024), MHD_OPTION_END);
623 if ((daemon_handle_v6 == NULL) && (daemon_handle_v4 == NULL))
625 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
626 _("Could not start hostlist HTTP server on port %u\n"),
627 (unsigned short) port);
628 return GNUNET_SYSERR;
633 *server_ch = &connect_handler;
634 *server_dh = &disconnect_handler;
636 if (daemon_handle_v4 != NULL)
637 hostlist_task_v4 = prepare_daemon (daemon_handle_v4);
638 if (daemon_handle_v6 != NULL)
639 hostlist_task_v6 = prepare_daemon (daemon_handle_v6);
641 notify = GNUNET_PEERINFO_notify (cfg, process_notify, NULL);
647 * Stop server offering our hostlist.
650 GNUNET_HOSTLIST_server_stop ()
652 #if DEBUG_HOSTLIST_SERVER
653 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Hostlist server shutdown\n");
657 GNUNET_PEERINFO_notify_cancel (notify);
660 if (GNUNET_SCHEDULER_NO_TASK != hostlist_task_v6)
662 GNUNET_SCHEDULER_cancel (hostlist_task_v6);
663 hostlist_task_v6 = GNUNET_SCHEDULER_NO_TASK;
665 if (GNUNET_SCHEDULER_NO_TASK != hostlist_task_v4)
667 GNUNET_SCHEDULER_cancel (hostlist_task_v4);
668 hostlist_task_v4 = GNUNET_SCHEDULER_NO_TASK;
672 GNUNET_PEERINFO_iterate_cancel (pitr);
675 if (NULL != daemon_handle_v4)
677 MHD_stop_daemon (daemon_handle_v4);
678 daemon_handle_v4 = NULL;
680 if (NULL != daemon_handle_v6)
682 MHD_stop_daemon (daemon_handle_v6);
683 daemon_handle_v6 = NULL;
685 if (response != NULL)
687 MHD_destroy_response (response);
690 if (peerinfo != NULL)
692 GNUNET_PEERINFO_disconnect (peerinfo);
700 /* end of hostlist-server.c */