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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_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;
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);
126 response = MHD_create_response_from_data (results->size,
127 results->data, MHD_YES, MHD_NO);
128 if ((daemon_handle_v4 == NULL) && (daemon_handle_v6 == NULL))
130 MHD_destroy_response (response);
133 GNUNET_STATISTICS_set (stats,
134 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,
153 struct GNUNET_TIME_Absolute expiration,
154 const void *addr, uint16_t addrlen)
158 if (GNUNET_TIME_absolute_get_remaining (expiration).rel_value == 0)
160 GNUNET_STATISTICS_update (stats,
161 gettext_noop ("expired addresses encountered"),
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,
176 const struct GNUNET_PeerIdentity *peer,
177 const struct GNUNET_HELLO_Message *hello, const char *err_msg)
179 struct HostSet *results = cls;
186 GNUNET_assert (NULL == peer);
188 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
189 _("Error in communication with PEERINFO service: %s\n"),
196 finish_response (results);
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 #if DEBUG_HOSTLIST_SERVER
217 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
218 "Received %u bytes of `%s' from peer `%s' for hostlist.\n",
219 (unsigned int) s, "HELLO", GNUNET_i2s (peer));
221 if ((old + s >= GNUNET_MAX_MALLOC_CHECKED) ||
222 (old + s >= MAX_BYTES_PER_HOSTLISTS))
224 GNUNET_STATISTICS_update (stats,
226 ("bytes not included in hostlist (size limit)"),
228 return; /* too large, skip! */
230 #if DEBUG_HOSTLIST_SERVER
231 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
232 "Adding peer `%s' to hostlist (%u bytes)\n",
233 GNUNET_i2s (peer), (unsigned int) s);
235 GNUNET_array_grow (results->data, results->size, old + s);
236 memcpy (&results->data[old], hello, s);
242 * Hostlist access policy (very permissive, allows everything).
245 accept_policy_callback (void *cls,
246 const struct sockaddr *addr, socklen_t addrlen)
248 if (NULL == response)
250 #if DEBUG_HOSTLIST_SERVER
251 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
252 "Received request for hostlist, but I am not yet ready; rejecting!\n");
256 return MHD_YES; /* accept all */
261 * Main request handler.
264 access_handler_callback (void *cls,
265 struct MHD_Connection *connection,
269 const char *upload_data,
270 size_t * upload_data_size, void **con_cls)
274 if (0 != strcmp (method, MHD_HTTP_METHOD_GET))
276 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
277 _("Refusing `%s' request to hostlist server\n"), method);
278 GNUNET_STATISTICS_update (stats,
280 ("hostlist requests refused (not HTTP GET)"), 1,
284 if (NULL == *con_cls)
287 #if DEBUG_HOSTLIST_SERVER
288 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _("Sending 100 CONTINUE reply\n"));
290 return MHD_YES; /* send 100 continue */
292 if (*upload_data_size != 0)
294 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
295 _("Refusing `%s' request with %llu bytes of upload data\n"),
296 method, (unsigned long long) *upload_data_size);
297 GNUNET_STATISTICS_update (stats,
299 ("hostlist requests refused (upload data)"), 1,
301 return MHD_NO; /* do not support upload data */
303 if (response == NULL)
305 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
307 ("Could not handle hostlist request since I do not have a response yet\n"));
308 GNUNET_STATISTICS_update (stats,
310 ("hostlist requests refused (not ready)"), 1,
312 return MHD_NO; /* internal error, no response yet */
314 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Received request for our hostlist\n"));
315 GNUNET_STATISTICS_update (stats,
316 gettext_noop ("hostlist requests processed"),
318 return MHD_queue_response (connection, MHD_HTTP_OK, response);
323 * Handler called by core when core is ready to transmit message
325 * @param size size of buffer to copy message to
326 * @param buf buffer to copy message to
329 adv_transmit_ready (void *cls, size_t size, void *buf)
331 static uint64_t hostlist_adv_count;
333 size_t transmission_size;
334 size_t uri_size; /* Including \0 termination! */
335 struct GNUNET_MessageHeader header;
340 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
341 "Transmission failed, buffer invalid!\n");
344 uri_size = strlen (hostlist_uri) + 1;
345 transmission_size = sizeof (struct GNUNET_MessageHeader) + uri_size;
346 header.type = htons (GNUNET_MESSAGE_TYPE_HOSTLIST_ADVERTISEMENT);
347 header.size = htons (transmission_size);
348 GNUNET_assert (size >= transmission_size);
349 memcpy (buf, &header, sizeof (struct GNUNET_MessageHeader));
351 memcpy (&cbuf[sizeof (struct GNUNET_MessageHeader)], hostlist_uri, uri_size);
352 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
353 "Sent advertisement message: Copied %u bytes into buffer!\n",
354 (unsigned int) transmission_size);
355 hostlist_adv_count++;
356 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
357 " # Sent advertisement message: %u\n", hostlist_adv_count);
358 GNUNET_STATISTICS_update (stats,
359 gettext_noop ("# hostlist advertisements send"),
361 return transmission_size;
366 * Method called whenever a given peer connects.
369 * @param peer peer identity this notification is about
370 * @param atsi performance data
373 connect_handler (void *cls,
375 GNUNET_PeerIdentity *peer,
376 const struct GNUNET_TRANSPORT_ATS_Information *atsi)
382 if (hostlist_uri == NULL)
384 size = strlen (hostlist_uri) + 1;
385 if (size + sizeof (struct GNUNET_MessageHeader) >=
386 GNUNET_SERVER_MAX_MESSAGE_SIZE)
391 size += sizeof (struct GNUNET_MessageHeader);
397 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
398 "Asked core to transmit advertisement message with a size of %u bytes to peer `%s'\n",
399 size, GNUNET_i2s (peer));
400 if (NULL == GNUNET_CORE_notify_transmit_ready (core,
406 &adv_transmit_ready, NULL))
408 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
409 _("Advertisement message could not be queued by core\n"));
415 * Method called whenever a given peer disconnects.
418 * @param peer peer identity this notification is about
421 disconnect_handler (void *cls, const struct GNUNET_PeerIdentity *peer)
427 * PEERINFO calls this function to let us know about a possible peer
428 * that we might want to connect to.
430 * @param cls closure (not used)
431 * @param peer potential peer to connect to
432 * @param hello HELLO for this peer (or NULL)
433 * @param err_msg NULL if successful, otherwise contains error message
436 process_notify (void *cls,
437 const struct GNUNET_PeerIdentity *peer,
438 const struct GNUNET_HELLO_Message *hello, const char *err_msg)
440 struct HostSet *results;
442 #if DEBUG_HOSTLIST_SERVER
443 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
444 "Peerinfo is notifying us to rebuild our hostlist\n");
448 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
449 _("Error in communication with PEERINFO service\n"));
452 results = GNUNET_malloc (sizeof (struct HostSet));
453 GNUNET_assert (peerinfo != NULL);
454 pitr = GNUNET_PEERINFO_iterate (peerinfo,
456 GNUNET_TIME_UNIT_MINUTES,
457 &host_processor, results);
461 * Function that queries MHD's select sets and
462 * starts the task waiting for them.
464 static GNUNET_SCHEDULER_TaskIdentifier
465 prepare_daemon (struct MHD_Daemon *daemon_handle);
469 * Call MHD to process pending requests and then go back
470 * and schedule the next run.
473 run_daemon (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
475 struct MHD_Daemon *daemon_handle = cls;
477 if (daemon_handle == daemon_handle_v4)
478 hostlist_task_v4 = GNUNET_SCHEDULER_NO_TASK;
480 hostlist_task_v6 = GNUNET_SCHEDULER_NO_TASK;
482 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
484 GNUNET_assert (MHD_YES == MHD_run (daemon_handle));
485 if (daemon_handle == daemon_handle_v4)
486 hostlist_task_v4 = prepare_daemon (daemon_handle);
488 hostlist_task_v6 = prepare_daemon (daemon_handle);
493 * Function that queries MHD's select sets and
494 * starts the task waiting for them.
496 static GNUNET_SCHEDULER_TaskIdentifier
497 prepare_daemon (struct MHD_Daemon *daemon_handle)
499 GNUNET_SCHEDULER_TaskIdentifier ret;
503 struct GNUNET_NETWORK_FDSet *wrs;
504 struct GNUNET_NETWORK_FDSet *wws;
505 struct GNUNET_NETWORK_FDSet *wes;
507 unsigned long long timeout;
509 struct GNUNET_TIME_Relative tv;
514 wrs = GNUNET_NETWORK_fdset_create ();
515 wes = GNUNET_NETWORK_fdset_create ();
516 wws = GNUNET_NETWORK_fdset_create ();
518 GNUNET_assert (MHD_YES == MHD_get_fdset (daemon_handle, &rs, &ws, &es, &max));
519 haveto = MHD_get_timeout (daemon_handle, &timeout);
520 if (haveto == MHD_YES)
521 tv.rel_value = (uint64_t) timeout;
523 tv = GNUNET_TIME_UNIT_FOREVER_REL;
524 GNUNET_NETWORK_fdset_copy_native (wrs, &rs, max + 1);
525 GNUNET_NETWORK_fdset_copy_native (wws, &ws, max + 1);
526 GNUNET_NETWORK_fdset_copy_native (wes, &es, max + 1);
527 ret = GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_HIGH,
528 GNUNET_SCHEDULER_NO_TASK,
529 tv, wrs, wws, &run_daemon, daemon_handle);
530 GNUNET_NETWORK_fdset_destroy (wrs);
531 GNUNET_NETWORK_fdset_destroy (wws);
532 GNUNET_NETWORK_fdset_destroy (wes);
539 * Start server offering our hostlist.
541 * @return GNUNET_OK on success
544 GNUNET_HOSTLIST_server_start (const struct GNUNET_CONFIGURATION_Handle *c,
545 struct GNUNET_STATISTICS_Handle *st,
546 struct GNUNET_CORE_Handle *co,
547 GNUNET_CORE_ConnectEventHandler *server_ch,
548 GNUNET_CORE_DisconnectEventHandler *server_dh,
551 unsigned long long port;
555 advertising = advertise;
557 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
558 "Advertising not enabled on this hostlist server\n");
560 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
561 "Advertising enabled on this hostlist server\n");
564 peerinfo = GNUNET_PEERINFO_connect (cfg);
565 if (peerinfo == NULL)
567 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
568 _("Could not access PEERINFO service. Exiting.\n"));
569 return GNUNET_SYSERR;
571 if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_number (cfg,
574 return GNUNET_SYSERR;
575 if ((port == 0) || (port > UINT16_MAX))
577 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
578 _("Invalid port number %llu. Exiting.\n"), port);
579 return GNUNET_SYSERR;
582 if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string (cfg,
586 hostname = GNUNET_RESOLVER_local_fqdn_get ();
588 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
589 _("Hostlist service starts on %s:%llu\n"), hostname, port);
590 if (NULL != hostname)
592 size = strlen (hostname);
593 if (size + 15 > MAX_URL_LEN)
599 GNUNET_asprintf (&hostlist_uri,
600 "http://%s:%u/", hostname, (unsigned int) port);
601 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
602 _("Address to obtain hostlist: `%s'\n"), hostlist_uri);
604 GNUNET_free (hostname);
606 daemon_handle_v6 = MHD_start_daemon (MHD_USE_IPv6
607 #if DEBUG_HOSTLIST_SERVER
611 (unsigned short) port,
612 &accept_policy_callback,
614 &access_handler_callback,
616 MHD_OPTION_CONNECTION_LIMIT,
618 MHD_OPTION_PER_IP_CONNECTION_LIMIT,
620 MHD_OPTION_CONNECTION_TIMEOUT,
622 MHD_OPTION_CONNECTION_MEMORY_LIMIT,
623 (size_t) (16 * 1024), MHD_OPTION_END);
624 daemon_handle_v4 = MHD_start_daemon (MHD_NO_FLAG
625 #if DEBUG_HOSTLIST_SERVER
629 (unsigned short) port,
630 &accept_policy_callback,
632 &access_handler_callback,
634 MHD_OPTION_CONNECTION_LIMIT,
636 MHD_OPTION_PER_IP_CONNECTION_LIMIT,
638 MHD_OPTION_CONNECTION_TIMEOUT,
640 MHD_OPTION_CONNECTION_MEMORY_LIMIT,
641 (size_t) (16 * 1024), MHD_OPTION_END);
643 if ((daemon_handle_v6 == NULL) && (daemon_handle_v4 == NULL))
645 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
646 _("Could not start hostlist HTTP server on port %u\n"),
647 (unsigned short) port);
648 return GNUNET_SYSERR;
653 *server_ch = &connect_handler;
654 *server_dh = &disconnect_handler;
656 if (daemon_handle_v4 != NULL)
657 hostlist_task_v4 = prepare_daemon (daemon_handle_v4);
658 if (daemon_handle_v6 != NULL)
659 hostlist_task_v6 = prepare_daemon (daemon_handle_v6);
661 notify = GNUNET_PEERINFO_notify (cfg, process_notify, NULL);
667 * Stop server offering our hostlist.
670 GNUNET_HOSTLIST_server_stop ()
672 #if DEBUG_HOSTLIST_SERVER
673 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Hostlist server shutdown\n");
677 GNUNET_PEERINFO_notify_cancel (notify);
680 if (GNUNET_SCHEDULER_NO_TASK != hostlist_task_v6)
682 GNUNET_SCHEDULER_cancel (hostlist_task_v6);
683 hostlist_task_v6 = GNUNET_SCHEDULER_NO_TASK;
685 if (GNUNET_SCHEDULER_NO_TASK != hostlist_task_v4)
687 GNUNET_SCHEDULER_cancel (hostlist_task_v4);
688 hostlist_task_v4 = GNUNET_SCHEDULER_NO_TASK;
692 GNUNET_PEERINFO_iterate_cancel (pitr);
695 if (NULL != daemon_handle_v4)
697 MHD_stop_daemon (daemon_handle_v4);
698 daemon_handle_v4 = NULL;
700 if (NULL != daemon_handle_v6)
702 MHD_stop_daemon (daemon_handle_v6);
703 daemon_handle_v6 = NULL;
705 if (response != NULL)
707 MHD_destroy_response (response);
710 if (peerinfo != NULL)
712 GNUNET_PEERINFO_disconnect (peerinfo);
720 /* end of hostlist-server.c */