/* This file is part of GNUnet. (C) 2008, 2009, 2010 Christian Grothoff (and other contributing authors) GNUnet is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GNUnet is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNUnet; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /** * @file hostlist/hostlist-server.c * @author Christian Grothoff, Matthias Wachs * @brief application to provide an integrated hostlist HTTP server */ #include "platform.h" #include #include "hostlist-server.h" #include "gnunet_hello_lib.h" #include "gnunet_peerinfo_service.h" #include "gnunet-daemon-hostlist.h" #include "gnunet_resolver_service.h" #define DEBUG_HOSTLIST_SERVER GNUNET_EXTRA_LOGGING /** * Handle to the HTTP server as provided by libmicrohttpd for IPv6. */ static struct MHD_Daemon *daemon_handle_v6; /** * Handle to the HTTP server as provided by libmicrohttpd for IPv4. */ static struct MHD_Daemon *daemon_handle_v4; /** * Our configuration. */ static const struct GNUNET_CONFIGURATION_Handle *cfg; /** * For keeping statistics. */ static struct GNUNET_STATISTICS_Handle *stats; /** * Handle to the core service (NULL until we've connected to it). */ static struct GNUNET_CORE_Handle *core; /** * Handle to the peerinfo notify service (NULL until we've connected to it). */ static struct GNUNET_PEERINFO_NotifyContext *notify; /** * Our primary task for IPv4. */ static GNUNET_SCHEDULER_TaskIdentifier hostlist_task_v4; /** * Our primary task for IPv6. */ static GNUNET_SCHEDULER_TaskIdentifier hostlist_task_v6; /** * Our canonical response. */ static struct MHD_Response *response; /** * NULL if we are not currenlty iterating over peer information. */ static struct GNUNET_PEERINFO_IteratorContext *pitr; /** * Handle for accessing peerinfo service. */ static struct GNUNET_PEERINFO_Handle *peerinfo; /** * Context for host processor. */ struct HostSet { unsigned int size; char *data; }; /** * Set if we are allowed to advertise our hostlist to others. */ static int advertising; /** * Buffer for the hostlist address */ static char *hostlist_uri; /** * Function that assembles our response. */ static void finish_response (struct HostSet *results) { if (response != NULL) MHD_destroy_response (response); #if DEBUG_HOSTLIST_SERVER GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Creating hostlist response with %u bytes\n", (unsigned int) results->size); #endif response = MHD_create_response_from_data (results->size, results->data, MHD_YES, MHD_NO); if ((daemon_handle_v4 == NULL) && (daemon_handle_v6 == NULL)) { MHD_destroy_response (response); response = NULL; } GNUNET_STATISTICS_set (stats, gettext_noop ("bytes in hostlist"), results->size, GNUNET_YES); GNUNET_free (results); } /** * Set 'cls' to GNUNET_YES (we have an address!). * * @param cls closure, an 'int*' * @param address the address (ignored) * @param expiration expiration time (call is ignored if this is in the past) * @return GNUNET_SYSERR to stop iterating (unless expiration has occured) */ static int check_has_addr (void *cls, const struct GNUNET_HELLO_Address *address, struct GNUNET_TIME_Absolute expiration) { int *arg = cls; if (GNUNET_TIME_absolute_get_remaining (expiration).rel_value == 0) { GNUNET_STATISTICS_update (stats, gettext_noop ("expired addresses encountered"), 1, GNUNET_YES); return GNUNET_YES; /* ignore this address */ } *arg = GNUNET_YES; return GNUNET_SYSERR; } /** * Callback that processes each of the known HELLOs for the * hostlist response construction. */ static void host_processor (void *cls, const struct GNUNET_PeerIdentity *peer, const struct GNUNET_HELLO_Message *hello, const char *err_msg) { struct HostSet *results = cls; size_t old; size_t s; int has_addr; if (err_msg != NULL) { GNUNET_assert (NULL == peer); pitr = NULL; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _("Error in communication with PEERINFO service: %s\n"), err_msg); return; } if (peer == NULL) { pitr = NULL; finish_response (results); return; } if (hello == NULL) return; has_addr = GNUNET_NO; GNUNET_HELLO_iterate_addresses (hello, GNUNET_NO, &check_has_addr, &has_addr); if (GNUNET_NO == has_addr) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "HELLO for peer `%4s' has no address, not suitable for hostlist!\n", GNUNET_i2s (peer)); GNUNET_STATISTICS_update (stats, gettext_noop ("HELLOs without addresses encountered (ignored)"), 1, GNUNET_NO); return; } old = results->size; s = GNUNET_HELLO_size (hello); #if DEBUG_HOSTLIST_SERVER GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received %u bytes of `%s' from peer `%s' for hostlist.\n", (unsigned int) s, "HELLO", GNUNET_i2s (peer)); #endif if ((old + s >= GNUNET_MAX_MALLOC_CHECKED) || (old + s >= MAX_BYTES_PER_HOSTLISTS)) { GNUNET_STATISTICS_update (stats, gettext_noop ("bytes not included in hostlist (size limit)"), s, GNUNET_NO); return; /* too large, skip! */ } #if DEBUG_HOSTLIST_SERVER GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Adding peer `%s' to hostlist (%u bytes)\n", GNUNET_i2s (peer), (unsigned int) s); #endif GNUNET_array_grow (results->data, results->size, old + s); memcpy (&results->data[old], hello, s); } /** * Hostlist access policy (very permissive, allows everything). */ static int accept_policy_callback (void *cls, const struct sockaddr *addr, socklen_t addrlen) { if (NULL == response) { #if DEBUG_HOSTLIST_SERVER GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received request for hostlist, but I am not yet ready; rejecting!\n"); #endif return MHD_NO; } return MHD_YES; /* accept all */ } /** * Main request handler. */ static int access_handler_callback (void *cls, struct MHD_Connection *connection, const char *url, const char *method, const char *version, const char *upload_data, size_t * upload_data_size, void **con_cls) { static int dummy; if (0 != strcmp (method, MHD_HTTP_METHOD_GET)) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _("Refusing `%s' request to hostlist server\n"), method); GNUNET_STATISTICS_update (stats, gettext_noop ("hostlist requests refused (not HTTP GET)"), 1, GNUNET_YES); return MHD_NO; } if (NULL == *con_cls) { (*con_cls) = &dummy; #if DEBUG_HOSTLIST_SERVER GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _("Sending 100 CONTINUE reply\n")); #endif return MHD_YES; /* send 100 continue */ } if (*upload_data_size != 0) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _("Refusing `%s' request with %llu bytes of upload data\n"), method, (unsigned long long) *upload_data_size); GNUNET_STATISTICS_update (stats, gettext_noop ("hostlist requests refused (upload data)"), 1, GNUNET_YES); return MHD_NO; /* do not support upload data */ } if (response == NULL) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _ ("Could not handle hostlist request since I do not have a response yet\n")); GNUNET_STATISTICS_update (stats, gettext_noop ("hostlist requests refused (not ready)"), 1, GNUNET_YES); return MHD_NO; /* internal error, no response yet */ } GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Received request for our hostlist\n")); GNUNET_STATISTICS_update (stats, gettext_noop ("hostlist requests processed"), 1, GNUNET_YES); return MHD_queue_response (connection, MHD_HTTP_OK, response); } /** * Handler called by core when core is ready to transmit message * @param cls closure * @param size size of buffer to copy message to * @param buf buffer to copy message to */ static size_t adv_transmit_ready (void *cls, size_t size, void *buf) { static uint64_t hostlist_adv_count; size_t transmission_size; size_t uri_size; /* Including \0 termination! */ struct GNUNET_MessageHeader header; char *cbuf; if (buf == NULL) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transmission failed, buffer invalid!\n"); return 0; } uri_size = strlen (hostlist_uri) + 1; transmission_size = sizeof (struct GNUNET_MessageHeader) + uri_size; header.type = htons (GNUNET_MESSAGE_TYPE_HOSTLIST_ADVERTISEMENT); header.size = htons (transmission_size); GNUNET_assert (size >= transmission_size); memcpy (buf, &header, sizeof (struct GNUNET_MessageHeader)); cbuf = buf; memcpy (&cbuf[sizeof (struct GNUNET_MessageHeader)], hostlist_uri, uri_size); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sent advertisement message: Copied %u bytes into buffer!\n", (unsigned int) transmission_size); hostlist_adv_count++; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, " # Sent advertisement message: %u\n", hostlist_adv_count); GNUNET_STATISTICS_update (stats, gettext_noop ("# hostlist advertisements send"), 1, GNUNET_NO); return transmission_size; } /** * Method called whenever a given peer connects. * * @param cls closure * @param peer peer identity this notification is about * @param atsi performance data * @param atsi_count number of records in 'atsi' */ static void connect_handler (void *cls, const struct GNUNET_PeerIdentity *peer, const struct GNUNET_ATS_Information *atsi, unsigned int atsi_count) { size_t size; if (!advertising) return; if (hostlist_uri == NULL) return; size = strlen (hostlist_uri) + 1; if (size + sizeof (struct GNUNET_MessageHeader) >= GNUNET_SERVER_MAX_MESSAGE_SIZE) { GNUNET_break (0); return; } size += sizeof (struct GNUNET_MessageHeader); if (NULL == core) { GNUNET_break (0); return; } GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Asked core to transmit advertisement message with a size of %u bytes to peer `%s'\n", size, GNUNET_i2s (peer)); if (NULL == GNUNET_CORE_notify_transmit_ready (core, GNUNET_YES, 0, GNUNET_ADV_TIMEOUT, peer, size, &adv_transmit_ready, NULL)) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _("Advertisement message could not be queued by core\n")); } } /** * Method called whenever a given peer disconnects. * * @param cls closure * @param peer peer identity this notification is about */ static void disconnect_handler (void *cls, const struct GNUNET_PeerIdentity *peer) { /* nothing to do */ } /** * PEERINFO calls this function to let us know about a possible peer * that we might want to connect to. * * @param cls closure (not used) * @param peer potential peer to connect to * @param hello HELLO for this peer (or NULL) * @param err_msg NULL if successful, otherwise contains error message */ static void process_notify (void *cls, const struct GNUNET_PeerIdentity *peer, const struct GNUNET_HELLO_Message *hello, const char *err_msg) { struct HostSet *results; #if DEBUG_HOSTLIST_SERVER GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Peerinfo is notifying us to rebuild our hostlist\n"); #endif if (err_msg != NULL) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _("Error in communication with PEERINFO service\n")); /* return; */ } results = GNUNET_malloc (sizeof (struct HostSet)); GNUNET_assert (peerinfo != NULL); pitr = GNUNET_PEERINFO_iterate (peerinfo, NULL, GNUNET_TIME_UNIT_MINUTES, &host_processor, results); } /** * Function that queries MHD's select sets and * starts the task waiting for them. */ static GNUNET_SCHEDULER_TaskIdentifier prepare_daemon (struct MHD_Daemon *daemon_handle); /** * Call MHD to process pending requests and then go back * and schedule the next run. */ static void run_daemon (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct MHD_Daemon *daemon_handle = cls; if (daemon_handle == daemon_handle_v4) hostlist_task_v4 = GNUNET_SCHEDULER_NO_TASK; else hostlist_task_v6 = GNUNET_SCHEDULER_NO_TASK; if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) return; GNUNET_assert (MHD_YES == MHD_run (daemon_handle)); if (daemon_handle == daemon_handle_v4) hostlist_task_v4 = prepare_daemon (daemon_handle); else hostlist_task_v6 = prepare_daemon (daemon_handle); } /** * Function that queries MHD's select sets and * starts the task waiting for them. */ static GNUNET_SCHEDULER_TaskIdentifier prepare_daemon (struct MHD_Daemon *daemon_handle) { GNUNET_SCHEDULER_TaskIdentifier ret; fd_set rs; fd_set ws; fd_set es; struct GNUNET_NETWORK_FDSet *wrs; struct GNUNET_NETWORK_FDSet *wws; struct GNUNET_NETWORK_FDSet *wes; int max; unsigned long long timeout; int haveto; struct GNUNET_TIME_Relative tv; FD_ZERO (&rs); FD_ZERO (&ws); FD_ZERO (&es); wrs = GNUNET_NETWORK_fdset_create (); wes = GNUNET_NETWORK_fdset_create (); wws = GNUNET_NETWORK_fdset_create (); max = -1; GNUNET_assert (MHD_YES == MHD_get_fdset (daemon_handle, &rs, &ws, &es, &max)); haveto = MHD_get_timeout (daemon_handle, &timeout); if (haveto == MHD_YES) tv.rel_value = (uint64_t) timeout; else tv = GNUNET_TIME_UNIT_FOREVER_REL; GNUNET_NETWORK_fdset_copy_native (wrs, &rs, max + 1); GNUNET_NETWORK_fdset_copy_native (wws, &ws, max + 1); GNUNET_NETWORK_fdset_copy_native (wes, &es, max + 1); ret = GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_HIGH, GNUNET_SCHEDULER_NO_TASK, tv, wrs, wws, &run_daemon, daemon_handle); GNUNET_NETWORK_fdset_destroy (wrs); GNUNET_NETWORK_fdset_destroy (wws); GNUNET_NETWORK_fdset_destroy (wes); return ret; } /** * Start server offering our hostlist. * * @return GNUNET_OK on success */ int GNUNET_HOSTLIST_server_start (const struct GNUNET_CONFIGURATION_Handle *c, struct GNUNET_STATISTICS_Handle *st, struct GNUNET_CORE_Handle *co, GNUNET_CORE_ConnectEventHandler *server_ch, GNUNET_CORE_DisconnectEventHandler *server_dh, int advertise) { unsigned long long port; char *hostname; size_t size; advertising = advertise; if (!advertising) GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Advertising not enabled on this hostlist server\n"); else GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Advertising enabled on this hostlist server\n"); cfg = c; stats = st; peerinfo = GNUNET_PEERINFO_connect (cfg); if (peerinfo == NULL) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("Could not access PEERINFO service. Exiting.\n")); return GNUNET_SYSERR; } if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_number (cfg, "HOSTLIST", "HTTPPORT", &port)) return GNUNET_SYSERR; if ((port == 0) || (port > UINT16_MAX)) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("Invalid port number %llu. Exiting.\n"), port); return GNUNET_SYSERR; } if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string (cfg, "HOSTLIST", "EXTERNAL_DNS_NAME", &hostname)) hostname = GNUNET_RESOLVER_local_fqdn_get (); GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Hostlist service starts on %s:%llu\n"), hostname, port); if (NULL != hostname) { size = strlen (hostname); if (size + 15 > MAX_URL_LEN) { GNUNET_break (0); } else { GNUNET_asprintf (&hostlist_uri, "http://%s:%u/", hostname, (unsigned int) port); GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Address to obtain hostlist: `%s'\n"), hostlist_uri); } GNUNET_free (hostname); } daemon_handle_v6 = MHD_start_daemon (MHD_USE_IPv6 #if DEBUG_HOSTLIST_SERVER | MHD_USE_DEBUG #endif , (unsigned short) port, &accept_policy_callback, NULL, &access_handler_callback, NULL, MHD_OPTION_CONNECTION_LIMIT, (unsigned int) 16, MHD_OPTION_PER_IP_CONNECTION_LIMIT, (unsigned int) 1, MHD_OPTION_CONNECTION_TIMEOUT, (unsigned int) 16, MHD_OPTION_CONNECTION_MEMORY_LIMIT, (size_t) (16 * 1024), MHD_OPTION_END); daemon_handle_v4 = MHD_start_daemon (MHD_NO_FLAG #if DEBUG_HOSTLIST_SERVER | MHD_USE_DEBUG #endif , (unsigned short) port, &accept_policy_callback, NULL, &access_handler_callback, NULL, MHD_OPTION_CONNECTION_LIMIT, (unsigned int) 16, MHD_OPTION_PER_IP_CONNECTION_LIMIT, (unsigned int) 1, MHD_OPTION_CONNECTION_TIMEOUT, (unsigned int) 16, MHD_OPTION_CONNECTION_MEMORY_LIMIT, (size_t) (16 * 1024), MHD_OPTION_END); if ((daemon_handle_v6 == NULL) && (daemon_handle_v4 == NULL)) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("Could not start hostlist HTTP server on port %u\n"), (unsigned short) port); return GNUNET_SYSERR; } core = co; *server_ch = &connect_handler; *server_dh = &disconnect_handler; if (daemon_handle_v4 != NULL) hostlist_task_v4 = prepare_daemon (daemon_handle_v4); if (daemon_handle_v6 != NULL) hostlist_task_v6 = prepare_daemon (daemon_handle_v6); notify = GNUNET_PEERINFO_notify (cfg, process_notify, NULL); return GNUNET_OK; } /** * Stop server offering our hostlist. */ void GNUNET_HOSTLIST_server_stop () { #if DEBUG_HOSTLIST_SERVER GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Hostlist server shutdown\n"); #endif if (NULL != notify) { GNUNET_PEERINFO_notify_cancel (notify); notify = NULL; } if (GNUNET_SCHEDULER_NO_TASK != hostlist_task_v6) { GNUNET_SCHEDULER_cancel (hostlist_task_v6); hostlist_task_v6 = GNUNET_SCHEDULER_NO_TASK; } if (GNUNET_SCHEDULER_NO_TASK != hostlist_task_v4) { GNUNET_SCHEDULER_cancel (hostlist_task_v4); hostlist_task_v4 = GNUNET_SCHEDULER_NO_TASK; } if (pitr != NULL) { GNUNET_PEERINFO_iterate_cancel (pitr); pitr = NULL; } if (NULL != daemon_handle_v4) { MHD_stop_daemon (daemon_handle_v4); daemon_handle_v4 = NULL; } if (NULL != daemon_handle_v6) { MHD_stop_daemon (daemon_handle_v6); daemon_handle_v6 = NULL; } if (response != NULL) { MHD_destroy_response (response); response = NULL; } if (peerinfo != NULL) { GNUNET_PEERINFO_disconnect (peerinfo); peerinfo = NULL; } cfg = NULL; stats = NULL; core = NULL; } /* end of hostlist-server.c */