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3 (C) 2008, 2009, 2010, 2014 Christian Grothoff (and other contributing authors)
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22 * @file hostlist/hostlist-server.c
23 * @author Christian Grothoff, Matthias Wachs, David Barksdale
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"
37 * Handle to the HTTP server as provided by libmicrohttpd for IPv6.
39 static struct MHD_Daemon *daemon_handle_v6;
42 * Handle to the HTTP server as provided by libmicrohttpd for IPv4.
44 static struct MHD_Daemon *daemon_handle_v4;
49 static const struct GNUNET_CONFIGURATION_Handle *cfg;
52 * For keeping statistics.
54 static struct GNUNET_STATISTICS_Handle *stats;
57 * Handle to the core service (NULL until we've connected to it).
59 static struct GNUNET_CORE_Handle *core;
62 * Handle to the peerinfo notify service (NULL until we've connected to it).
64 static struct GNUNET_PEERINFO_NotifyContext *notify;
67 * Our primary task for IPv4.
69 static GNUNET_SCHEDULER_TaskIdentifier hostlist_task_v4;
72 * Our primary task for IPv6.
74 static GNUNET_SCHEDULER_TaskIdentifier hostlist_task_v6;
77 * Our canonical response.
79 static struct MHD_Response *response;
82 * Handle for accessing peerinfo service.
84 static struct GNUNET_PEERINFO_Handle *peerinfo;
87 * Set if we are allowed to advertise our hostlist to others.
89 static int advertising;
92 * Buffer for the hostlist address
94 static char *hostlist_uri;
98 * Context for host processor.
106 struct GNUNET_PEERINFO_IteratorContext *pitr;
111 * NULL if we are not currenlty iterating over peer information.
113 static struct HostSet *builder;
119 * Function that assembles our response.
124 if (NULL != response)
125 MHD_destroy_response (response);
126 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
127 "Creating hostlist response with %u bytes\n",
128 (unsigned int) builder->size);
130 MHD_create_response_from_data (builder->size, builder->data, MHD_YES,
132 if ((NULL == daemon_handle_v4) && (NULL == daemon_handle_v6))
134 MHD_destroy_response (response);
137 GNUNET_STATISTICS_set (stats, gettext_noop ("bytes in hostlist"),
138 builder->size, GNUNET_YES);
139 GNUNET_free (builder);
145 * Set 'cls' to GNUNET_YES (we have an address!).
147 * @param cls closure, an 'int*'
148 * @param address the address (ignored)
149 * @param expiration expiration time (call is ignored if this is in the past)
150 * @return GNUNET_SYSERR to stop iterating (unless expiration has occured)
153 check_has_addr (void *cls, const struct GNUNET_HELLO_Address *address,
154 struct GNUNET_TIME_Absolute expiration)
158 if (0 == GNUNET_TIME_absolute_get_remaining (expiration).rel_value_us)
160 GNUNET_STATISTICS_update (stats,
161 gettext_noop ("expired addresses encountered"), 1,
163 return GNUNET_YES; /* ignore this address */
166 return GNUNET_SYSERR;
171 * Callback that processes each of the known HELLOs for the
172 * hostlist response construction.
175 host_processor (void *cls, const struct GNUNET_PeerIdentity *peer,
176 const struct GNUNET_HELLO_Message *hello, const char *err_msg)
184 GNUNET_assert (NULL == peer);
185 builder->pitr = NULL;
186 GNUNET_free_non_null (builder->data);
187 GNUNET_free (builder);
188 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
189 _("Error in communication with PEERINFO service: %s\n"),
195 builder->pitr = NULL;
201 has_addr = GNUNET_NO;
202 GNUNET_HELLO_iterate_addresses (hello, GNUNET_NO, &check_has_addr, &has_addr);
203 if (GNUNET_NO == has_addr)
205 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
206 "HELLO for peer `%4s' has no address, not suitable for hostlist!\n",
208 GNUNET_STATISTICS_update (stats,
210 ("HELLOs without addresses encountered (ignored)"),
215 s = GNUNET_HELLO_size (hello);
216 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
217 "Received %u bytes of `%s' from peer `%s' for hostlist.\n",
218 (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 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
229 "Adding peer `%s' to hostlist (%u bytes)\n", GNUNET_i2s (peer),
231 GNUNET_array_grow (builder->data, builder->size, old + s);
232 memcpy (&builder->data[old], hello, s);
238 * Hostlist access policy (very permissive, allows everything).
241 accept_policy_callback (void *cls, const struct sockaddr *addr,
244 if (NULL == response)
246 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
247 "Received request for hostlist, but I am not yet ready; rejecting!\n");
250 return MHD_YES; /* accept all */
254 * Add headers to a request indicating that we allow Cross-Origin Resource
258 add_cors_headers(struct MHD_Response *response)
260 MHD_add_response_header (response,
261 "Access-Control-Allow-Origin",
263 MHD_add_response_header (response,
264 "Access-Control-Allow-Methods",
266 MHD_add_response_header (response,
267 "Access-Control-Max-Age",
272 * Main request handler.
275 access_handler_callback (void *cls, struct MHD_Connection *connection,
276 const char *url, const char *method,
277 const char *version, const char *upload_data,
278 size_t * upload_data_size, void **con_cls)
282 /* CORS pre-flight request */
283 if (0 == strcmp (MHD_HTTP_METHOD_OPTIONS, method))
285 struct MHD_Response *options_response;
288 options_response = MHD_create_response_from_buffer (0, NULL,
289 MHD_RESPMEM_PERSISTENT);
290 add_cors_headers(options_response);
291 rc = MHD_queue_response (connection, MHD_HTTP_OK, options_response);
292 MHD_destroy_response (options_response);
295 if (0 != strcmp (method, MHD_HTTP_METHOD_GET))
297 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
298 _("Refusing `%s' request to hostlist server\n"), method);
299 GNUNET_STATISTICS_update (stats,
301 ("hostlist requests refused (not HTTP GET)"), 1,
305 if (NULL == *con_cls)
308 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sending 100 CONTINUE reply\n");
309 return MHD_YES; /* send 100 continue */
311 if (0 != *upload_data_size)
313 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
314 _("Refusing `%s' request with %llu bytes of upload data\n"),
315 method, (unsigned long long) *upload_data_size);
316 GNUNET_STATISTICS_update (stats,
318 ("hostlist requests refused (upload data)"), 1,
320 return MHD_NO; /* do not support upload data */
322 if (NULL == response)
324 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
326 ("Could not handle hostlist request since I do not have a response yet\n"));
327 GNUNET_STATISTICS_update (stats,
329 ("hostlist requests refused (not ready)"), 1,
331 return MHD_NO; /* internal error, no response yet */
333 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Received request for our hostlist\n"));
334 GNUNET_STATISTICS_update (stats, gettext_noop ("hostlist requests processed"),
336 add_cors_headers(response);
337 return MHD_queue_response (connection, MHD_HTTP_OK, response);
342 * Handler called by core when core is ready to transmit message
344 * @param size size of buffer to copy message to
345 * @param buf buffer to copy message to
348 adv_transmit_ready (void *cls, size_t size, void *buf)
350 static uint64_t hostlist_adv_count;
351 size_t transmission_size;
352 size_t uri_size; /* Including \0 termination! */
353 struct GNUNET_MessageHeader header;
358 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
359 "Transmission failed, buffer invalid!\n");
362 uri_size = strlen (hostlist_uri) + 1;
363 transmission_size = sizeof (struct GNUNET_MessageHeader) + uri_size;
364 header.type = htons (GNUNET_MESSAGE_TYPE_HOSTLIST_ADVERTISEMENT);
365 header.size = htons (transmission_size);
366 GNUNET_assert (size >= transmission_size);
367 memcpy (buf, &header, sizeof (struct GNUNET_MessageHeader));
369 memcpy (&cbuf[sizeof (struct GNUNET_MessageHeader)], hostlist_uri, uri_size);
370 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
371 "Sent advertisement message: Copied %u bytes into buffer!\n",
372 (unsigned int) transmission_size);
373 hostlist_adv_count++;
374 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, " # Sent advertisement message: %u\n",
376 GNUNET_STATISTICS_update (stats,
377 gettext_noop ("# hostlist advertisements send"), 1,
379 return transmission_size;
384 * Method called whenever a given peer connects.
387 * @param peer peer identity this notification is about
390 connect_handler (void *cls, const struct GNUNET_PeerIdentity *peer)
396 if (NULL == hostlist_uri)
398 size = strlen (hostlist_uri) + 1;
399 if (size + sizeof (struct GNUNET_MessageHeader) >=
400 GNUNET_SERVER_MAX_MESSAGE_SIZE)
405 size += sizeof (struct GNUNET_MessageHeader);
411 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
412 "Asked core to transmit advertisement message with a size of %u bytes to peer `%s'\n",
413 size, GNUNET_i2s (peer));
415 GNUNET_CORE_notify_transmit_ready (core, GNUNET_YES,
416 GNUNET_CORE_PRIO_BEST_EFFORT,
417 GNUNET_ADV_TIMEOUT, peer, size,
418 &adv_transmit_ready, NULL))
420 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
421 _("Advertisement message could not be queued by core\n"));
427 * Method called whenever a given peer disconnects.
430 * @param peer peer identity this notification is about
433 disconnect_handler (void *cls, const struct GNUNET_PeerIdentity *peer)
440 * PEERINFO calls this function to let us know about a possible peer
441 * that we might want to connect to.
443 * @param cls closure (not used)
444 * @param peer potential peer to connect to
445 * @param hello HELLO for this peer (or NULL)
446 * @param err_msg NULL if successful, otherwise contains error message
449 process_notify (void *cls, const struct GNUNET_PeerIdentity *peer,
450 const struct GNUNET_HELLO_Message *hello, const char *err_msg)
452 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
453 "Peerinfo is notifying us to rebuild our hostlist\n");
455 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
456 _("Error in communication with PEERINFO service: %s\n"),
460 /* restart re-build already in progress ... */
461 GNUNET_PEERINFO_iterate_cancel (builder->pitr);
462 GNUNET_free_non_null (builder->data);
464 builder->data = NULL;
468 builder = GNUNET_new (struct HostSet);
470 GNUNET_assert (NULL != peerinfo);
472 GNUNET_PEERINFO_iterate (peerinfo, GNUNET_NO, NULL, GNUNET_TIME_UNIT_MINUTES,
473 &host_processor, NULL);
478 * Function that queries MHD's select sets and
479 * starts the task waiting for them.
481 static GNUNET_SCHEDULER_TaskIdentifier
482 prepare_daemon (struct MHD_Daemon *daemon_handle);
486 * Call MHD to process pending requests and then go back
487 * and schedule the next run.
490 run_daemon (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
492 struct MHD_Daemon *daemon_handle = cls;
494 if (daemon_handle == daemon_handle_v4)
495 hostlist_task_v4 = GNUNET_SCHEDULER_NO_TASK;
497 hostlist_task_v6 = GNUNET_SCHEDULER_NO_TASK;
499 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
501 GNUNET_assert (MHD_YES == MHD_run (daemon_handle));
502 if (daemon_handle == daemon_handle_v4)
503 hostlist_task_v4 = prepare_daemon (daemon_handle);
505 hostlist_task_v6 = prepare_daemon (daemon_handle);
508 #define UNSIGNED_MHD_LONG_LONG unsigned MHD_LONG_LONG
511 * Function that queries MHD's select sets and
512 * starts the task waiting for them.
514 static GNUNET_SCHEDULER_TaskIdentifier
515 prepare_daemon (struct MHD_Daemon *daemon_handle)
517 GNUNET_SCHEDULER_TaskIdentifier ret;
521 struct GNUNET_NETWORK_FDSet *wrs;
522 struct GNUNET_NETWORK_FDSet *wws;
524 UNSIGNED_MHD_LONG_LONG timeout;
526 struct GNUNET_TIME_Relative tv;
531 wrs = GNUNET_NETWORK_fdset_create ();
532 wws = GNUNET_NETWORK_fdset_create ();
534 GNUNET_assert (MHD_YES == MHD_get_fdset (daemon_handle, &rs, &ws, &es, &max));
535 haveto = MHD_get_timeout (daemon_handle, &timeout);
536 if (haveto == MHD_YES)
537 tv.rel_value_us = (uint64_t) timeout * 1000LL;
539 tv = GNUNET_TIME_UNIT_FOREVER_REL;
540 GNUNET_NETWORK_fdset_copy_native (wrs, &rs, max + 1);
541 GNUNET_NETWORK_fdset_copy_native (wws, &ws, max + 1);
543 GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_HIGH,
545 &run_daemon, daemon_handle);
546 GNUNET_NETWORK_fdset_destroy (wrs);
547 GNUNET_NETWORK_fdset_destroy (wws);
553 * Start server offering our hostlist.
555 * @return GNUNET_OK on success
558 GNUNET_HOSTLIST_server_start (const struct GNUNET_CONFIGURATION_Handle *c,
559 struct GNUNET_STATISTICS_Handle *st,
560 struct GNUNET_CORE_Handle *co,
561 GNUNET_CORE_ConnectEventHandler *server_ch,
562 GNUNET_CORE_DisconnectEventHandler *server_dh,
565 unsigned long long port;
571 struct sockaddr_in v4;
572 struct sockaddr_in6 v6;
573 const struct sockaddr *sa;
575 advertising = advertise;
577 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
578 "Advertising not enabled on this hostlist server\n");
580 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
581 "Advertising enabled on this hostlist server\n");
584 peerinfo = GNUNET_PEERINFO_connect (cfg);
585 if (NULL == peerinfo)
587 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
588 _("Could not access PEERINFO service. Exiting.\n"));
589 return GNUNET_SYSERR;
592 GNUNET_CONFIGURATION_get_value_number (cfg, "HOSTLIST", "HTTPPORT",
594 return GNUNET_SYSERR;
595 if ((0 == port) || (port > UINT16_MAX))
597 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
598 _("Invalid port number %llu. Exiting.\n"), port);
599 return GNUNET_SYSERR;
603 GNUNET_CONFIGURATION_get_value_string (cfg, "HOSTLIST",
604 "EXTERNAL_DNS_NAME", &hostname))
605 hostname = GNUNET_RESOLVER_local_fqdn_get ();
607 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Hostlist service starts on %s:%llu\n"),
609 if (NULL != hostname)
611 size = strlen (hostname);
612 if (size + 15 > MAX_URL_LEN)
618 GNUNET_asprintf (&hostlist_uri, "http://%s:%u/", hostname,
619 (unsigned int) port);
620 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
621 _("Address to obtain hostlist: `%s'\n"), hostlist_uri);
623 GNUNET_free (hostname);
626 if (GNUNET_CONFIGURATION_have_value (cfg, "HOSTLIST", "BINDTOIP"))
628 GNUNET_break (GNUNET_OK ==
629 GNUNET_CONFIGURATION_get_value_string (cfg, "HOSTLIST",
636 if (1 == inet_pton (AF_INET, ip, &i4))
638 memset (&v4, 0, sizeof (v4));
639 v4.sin_family = AF_INET;
641 v4.sin_port = htons (port);
642 #if HAVE_SOCKADDR_IN_SIN_LEN
643 v4.sin_len = sizeof (v4);
645 sa = (const struct sockaddr *) &v4;
647 else if (1 == inet_pton (AF_INET6, ip, &i6))
649 memset (&v6, 0, sizeof (v6));
650 v6.sin6_family = AF_INET6;
652 v6.sin6_port = htons (port);
653 #if HAVE_SOCKADDR_IN_SIN_LEN
654 v6.sin6_len = sizeof (v6);
656 sa = (const struct sockaddr *) &v6;
660 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
661 _("`%s' is not a valid IP address! Ignoring BINDTOIP.\n"),
670 daemon_handle_v6 = MHD_start_daemon (MHD_USE_IPv6 | MHD_USE_DEBUG,
672 &accept_policy_callback, NULL,
673 &access_handler_callback, NULL,
674 MHD_OPTION_CONNECTION_LIMIT,
676 MHD_OPTION_PER_IP_CONNECTION_LIMIT,
678 MHD_OPTION_CONNECTION_TIMEOUT,
680 MHD_OPTION_CONNECTION_MEMORY_LIMIT,
681 (size_t) (16 * 1024),
682 MHD_OPTION_SOCK_ADDR,
685 daemon_handle_v4 = MHD_start_daemon (MHD_NO_FLAG | MHD_USE_DEBUG,
687 &accept_policy_callback, NULL,
688 &access_handler_callback, NULL,
689 MHD_OPTION_CONNECTION_LIMIT,
691 MHD_OPTION_PER_IP_CONNECTION_LIMIT,
693 MHD_OPTION_CONNECTION_TIMEOUT,
695 MHD_OPTION_CONNECTION_MEMORY_LIMIT,
696 (size_t) (16 * 1024),
697 MHD_OPTION_SOCK_ADDR,
701 if ((NULL == daemon_handle_v6) && (NULL == daemon_handle_v4))
703 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
704 _("Could not start hostlist HTTP server on port %u\n"),
705 (unsigned short) port);
706 return GNUNET_SYSERR;
710 *server_ch = &connect_handler;
711 *server_dh = &disconnect_handler;
712 if (daemon_handle_v4 != NULL)
713 hostlist_task_v4 = prepare_daemon (daemon_handle_v4);
714 if (daemon_handle_v6 != NULL)
715 hostlist_task_v6 = prepare_daemon (daemon_handle_v6);
717 notify = GNUNET_PEERINFO_notify (cfg, GNUNET_NO, &process_notify, NULL);
724 * Stop server offering our hostlist.
727 GNUNET_HOSTLIST_server_stop ()
729 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Hostlist server shutdown\n");
730 if (GNUNET_SCHEDULER_NO_TASK != hostlist_task_v6)
732 GNUNET_SCHEDULER_cancel (hostlist_task_v6);
733 hostlist_task_v6 = GNUNET_SCHEDULER_NO_TASK;
735 if (GNUNET_SCHEDULER_NO_TASK != hostlist_task_v4)
737 GNUNET_SCHEDULER_cancel (hostlist_task_v4);
738 hostlist_task_v4 = GNUNET_SCHEDULER_NO_TASK;
740 if (NULL != daemon_handle_v4)
742 MHD_stop_daemon (daemon_handle_v4);
743 daemon_handle_v4 = NULL;
745 if (NULL != daemon_handle_v6)
747 MHD_stop_daemon (daemon_handle_v6);
748 daemon_handle_v6 = NULL;
750 if (NULL != response)
752 MHD_destroy_response (response);
757 GNUNET_PEERINFO_notify_cancel (notify);
762 GNUNET_PEERINFO_iterate_cancel (builder->pitr);
763 builder->pitr = NULL;
764 GNUNET_free_non_null (builder->data);
765 GNUNET_free (builder);
767 if (NULL != peerinfo)
769 GNUNET_PEERINFO_disconnect (peerinfo);
777 /* end of hostlist-server.c */