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Diffstat (limited to 'src/hostlist/hostlist-server.c')
| -rw-r--r-- | src/hostlist/hostlist-server.c | 700 |
1 files changed, 700 insertions, 0 deletions
diff --git a/src/hostlist/hostlist-server.c b/src/hostlist/hostlist-server.c new file mode 100644 index 0000000..8e79ace --- /dev/null +++ b/src/hostlist/hostlist-server.c @@ -0,0 +1,700 @@ +/* + 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 <microhttpd.h> +#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 */ |