-/*
- This file is part of GNUnet.
- (C) 2010,2011 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 ats/ats_api_scheduling.c
- * @brief automatic transport selection and outbound bandwidth determination
- * @author Christian Grothoff
- * @author Matthias Wachs
- */
-#include "platform.h"
-#include "gnunet_ats_service.h"
-#include "ats.h"
-
-
-/**
- * Message in linked list we should send to the ATS service. The
- * actual binary message follows this struct.
- */
-struct PendingMessage
-{
-
- /**
- * Kept in a DLL.
- */
- struct PendingMessage *next;
-
- /**
- * Kept in a DLL.
- */
- struct PendingMessage *prev;
-
- /**
- * Size of the message.
- */
- size_t size;
-
- /**
- * Is this the 'ATS_START' message?
- */
- int is_init;
-};
-
-
-/**
- * Handle to the ATS subsystem for bandwidth/transport scheduling information.
- */
-struct GNUNET_ATS_SchedulingHandle
-{
-
- /**
- * Our configuration.
- */
- const struct GNUNET_CONFIGURATION_Handle *cfg;
-
- /**
- * Callback to invoke on suggestions.
- */
- GNUNET_ATS_AddressSuggestionCallback suggest_cb;
-
- /**
- * Closure for 'suggest_cb'.
- */
- void *suggest_cb_cls;
-
- /**
- * Connection to ATS service.
- */
- struct GNUNET_CLIENT_Connection *client;
-
- /**
- * Head of list of messages for the ATS service.
- */
- struct PendingMessage *pending_head;
-
- /**
- * Tail of list of messages for the ATS service
- */
- struct PendingMessage *pending_tail;
-
- /**
- * Current request for transmission to ATS.
- */
- struct GNUNET_CLIENT_TransmitHandle *th;
-
- /**
- * Array of session objects (we need to translate them to numbers and back
- * for the protocol; the offset in the array is the session number on the
- * network). Index 0 is always NULL and reserved to represent the NULL pointer.
- * Unused entries are also NULL.
- */
- struct Session **session_array;
-
- /**
- * Size of the session array.
- */
- unsigned int session_array_size;
-
-};
-
-
-/**
- * Re-establish the connection to the ATS service.
- *
- * @param sh handle to use to re-connect.
- */
-static void
-reconnect (struct GNUNET_ATS_SchedulingHandle *sh);
-
-
-/**
- * Transmit messages from the message queue to the service
- * (if there are any, and if we are not already trying).
- *
- * @param sh handle to use
- */
-static void
-do_transmit (struct GNUNET_ATS_SchedulingHandle *sh);
-
-
-/**
- * We can now transmit a message to ATS. Do it.
- *
- * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
- * @param size number of bytes we can transmit to ATS
- * @param buf where to copy the messages
- * @return number of bytes copied into buf
- */
-static size_t
-transmit_message_to_ats (void *cls,
- size_t size,
- void *buf)
-{
- struct GNUNET_ATS_SchedulingHandle *sh = cls;
- struct PendingMessage *p;
- size_t ret;
- char *cbuf;
-
- sh->th = NULL;
- ret = 0;
- cbuf = buf;
- while ( (NULL != (p = sh->pending_head)) &&
- (p->size <= size) )
- {
- memcpy (&cbuf[ret], &p[1], p->size);
- ret += p->size;
- GNUNET_CONTAINER_DLL_remove (sh->pending_head,
- sh->pending_tail,
- p);
- GNUNET_free (p);
- }
- do_transmit (sh);
- return ret;
-}
-
-
-/**
- * Transmit messages from the message queue to the service
- * (if there are any, and if we are not already trying).
- *
- * @param sh handle to use
- */
-static void
-do_transmit (struct GNUNET_ATS_SchedulingHandle *sh)
-{
- struct PendingMessage *p;
-
- if (NULL != sh->th)
- return;
- if (NULL == (p = sh->pending_head))
- return;
- sh->th = GNUNET_CLIENT_notify_transmit_ready (sh->client,
- p->size,
- GNUNET_TIME_UNIT_FOREVER_REL,
- GNUNET_YES,
- &transmit_message_to_ats, sh);
-}
-
-
-/**
- * Find the session object corresponding to the given session ID.
- *
- * @param sh our handle
- * @param session_id current session ID
- * @return the session object (or NULL)
- */
-static struct Session*
-find_session (struct GNUNET_ATS_SchedulingHandle *sh,
- uint32_t session_id)
-{
- if (session_id >= sh->session_array_size)
- {
- GNUNET_break (0);
- return NULL;
- }
- return sh->session_array[session_id];
-}
-
-
-/**
- * Get the ID for the given session object. If we do not have an ID for
- * the given session object, allocate one.
- *
- * @param sh our handle
- * @param session session object
- * @return the session id
- */
-static uint32_t
-get_session_id (struct GNUNET_ATS_SchedulingHandle *sh,
- struct Session *session)
-{
- unsigned int i;
- unsigned int f;
-
- f = 0;
- for (i=1;i<sh->session_array_size;i++)
- {
- if (session == sh->session_array[i])
- return i;
- if ( (f == 0) &&
- (sh->session_array[i] == NULL) )
- f = i;
- }
- if (f == 0)
- {
- f = sh->session_array_size;
- GNUNET_array_grow (sh->session_array,
- sh->session_array_size,
- sh->session_array_size * 2);
- }
- sh->session_array[f] = session;
- return f;
-}
-
-
-/**
- * Remove the session of the given session ID from the session
- * table (it is no longer valid).
- *
- * @param sh our handle
- * @param session_id identifies session that is no longer valid
- */
-static void
-remove_session (struct GNUNET_ATS_SchedulingHandle *sh,
- uint32_t session_id)
-{
- GNUNET_assert (session_id < sh->session_array_size);
- sh->session_array[session_id] = NULL;
-}
-
-
-/**
- * Type of a function to call when we receive a message
- * from the service.
- *
- * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
- * @param msg message received, NULL on timeout or fatal error
- */
-static void
-process_ats_message (void *cls,
- const struct GNUNET_MessageHeader *msg)
-{
- struct GNUNET_ATS_SchedulingHandle *sh = cls;
- const struct AddressSuggestionMessage *m;
- const char *address;
- const char *plugin_name;
- uint16_t address_length;
-
- if (NULL == msg)
- {
- GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
- sh->client = NULL;
- reconnect (sh);
- return;
- }
- if ( (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_ATS_ADDRESS_SUGGESTION) ||
- (ntohs (msg->size) <= sizeof (struct AddressSuggestionMessage)) )
- {
- GNUNET_break (0);
- GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
- sh->client = NULL;
- reconnect (sh);
- return;
- }
- m = (const struct AddressSuggestionMessage*) msg;
- address = (const char*) &m[1];
- address_length = ntohs (m->address_length);
- plugin_name = &address[address_length];
- GNUNET_break (0 == ntohl (m->reserved));
- if ( (ntohs (m->address_length) +
- ntohs (m->plugin_name_length) +
- sizeof (struct AddressSuggestionMessage) != ntohs (msg->size)) ||
- (plugin_name[ntohs (m->plugin_name_length) - 1] != '\0') )
- {
- GNUNET_break (0);
- GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
- sh->client = NULL;
- reconnect (sh);
- return;
- }
- sh->suggest_cb (sh->suggest_cb_cls,
- &m->peer,
- plugin_name,
- address, address_length,
- find_session (sh, ntohl (m->session_id)),
- m->bandwidth_out,
- m->bandwidth_in);
- GNUNET_CLIENT_receive (sh->client,
- &process_ats_message, sh,
- GNUNET_TIME_UNIT_FOREVER_REL);
-}
-
-
-/**
- * Re-establish the connection to the ATS service.
- *
- * @param sh handle to use to re-connect.
- */
-static void
-reconnect (struct GNUNET_ATS_SchedulingHandle *sh)
-{
- struct PendingMessage *p;
- struct ClientStartMessage *init;
-
- GNUNET_assert (NULL == sh->client);
- sh->client = GNUNET_CLIENT_connect ("ats", sh->cfg);
- GNUNET_assert (NULL != sh->client);
- GNUNET_CLIENT_receive (sh->client,
- &process_ats_message, sh,
- GNUNET_TIME_UNIT_FOREVER_REL);
- if ( (NULL == (p = sh->pending_head)) ||
- (GNUNET_YES != p->is_init) )
- {
- p = GNUNET_malloc (sizeof (struct PendingMessage) +
- sizeof (struct ClientStartMessage));
- p->size = sizeof (struct ClientStartMessage);
- p->is_init = GNUNET_YES;
- init = (struct ClientStartMessage *) &p[1];
- init->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_START);
- init->header.size = htons (sizeof (struct ClientStartMessage));
- init->start_flag = htonl (START_FLAG_SCHEDULING);
- GNUNET_CONTAINER_DLL_insert (sh->pending_head,
- sh->pending_tail,
- p);
- }
- do_transmit (sh);
-}
-
-
-/**
- * Initialize the ATS subsystem.
- *
- * @param cfg configuration to use
- * @param suggest_cb notification to call whenever the suggestation changed
- * @param suggest_cb_cls closure for 'suggest_cb'
- * @return ats context
- */
-struct GNUNET_ATS_SchedulingHandle *
-GNUNET_ATS_scheduling_init (const struct GNUNET_CONFIGURATION_Handle *cfg,
- GNUNET_ATS_AddressSuggestionCallback suggest_cb,
- void *suggest_cb_cls)
-{
- struct GNUNET_ATS_SchedulingHandle *sh;
-
- sh = GNUNET_malloc (sizeof (struct GNUNET_ATS_SchedulingHandle));
- sh->cfg = cfg;
- sh->suggest_cb = suggest_cb;
- sh->suggest_cb_cls = suggest_cb_cls;
- GNUNET_array_grow (sh->session_array,
- sh->session_array_size,
- 4);
- reconnect (sh);
- return sh;
-}
-
-
-/**
- * Client is done with ATS scheduling, release resources.
- *
- * @param sh handle to release
- */
-void
-GNUNET_ATS_scheduling_done (struct GNUNET_ATS_SchedulingHandle *sh)
-{
- struct PendingMessage *p;
-
- while (NULL != (p = sh->pending_head))
- {
- GNUNET_CONTAINER_DLL_remove (sh->pending_head,
- sh->pending_tail,
- p);
- GNUNET_free (p);
- }
- GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
- GNUNET_array_grow (sh->session_array,
- sh->session_array_size,
- 0);
- GNUNET_free (sh);
-}
-
-
-/**
- * We would like to establish a new connection with a peer. ATS
- * should suggest a good address to begin with.
- *
- * @param sh handle
- * @param peer identity of the peer we need an address for
- */
-void
-GNUNET_ATS_suggest_address (struct GNUNET_ATS_SchedulingHandle *sh,
- const struct GNUNET_PeerIdentity *peer)
-{
- struct PendingMessage *p;
- struct RequestAddressMessage *m;
-
- p = GNUNET_malloc (sizeof (struct PendingMessage) +
- sizeof (struct RequestAddressMessage));
- p->size = sizeof (struct RequestAddressMessage);
- p->is_init = GNUNET_NO;
- m = (struct RequestAddressMessage*) &p[1];
- m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_REQUEST_ADDRESS);
- m->header.size = htons (sizeof (struct RequestAddressMessage));
- m->reserved = htonl (0);
- m->peer = *peer;
- GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head,
- sh->pending_tail,
- p);
- do_transmit (sh);
-}
-
-
-/**
- * We have updated performance statistics for a given address. Note
- * that this function can be called for addresses that are currently
- * in use as well as addresses that are valid but not actively in use.
- * Furthermore, the peer may not even be connected to us right now (in
- * which case the call may be ignored or the information may be stored
- * for later use). Update bandwidth assignments.
- *
- * @param sh handle
- * @param peer identity of the new peer
- * @param plugin_name name of the transport plugin
- * @param plugin_addr address (if available)
- * @param plugin_addr_len number of bytes in plugin_addr
- * @param session session handle (if available)
- * @param ats performance data for the address
- * @param ats_count number of performance records in 'ats'
- */
-void
-GNUNET_ATS_address_update (struct GNUNET_ATS_SchedulingHandle *sh,
- const struct GNUNET_PeerIdentity *peer,
- const char *plugin_name,
- const void *plugin_addr, size_t plugin_addr_len,
- struct Session *session,
- const struct GNUNET_TRANSPORT_ATS_Information *ats,
- uint32_t ats_count)
-{
- struct PendingMessage *p;
- struct AddressUpdateMessage *m;
- struct GNUNET_TRANSPORT_ATS_Information *am;
- char *pm;
- size_t namelen;
- size_t msize;
-
- namelen = (plugin_name == NULL) ? 0 : strlen (plugin_name) + 1;
- msize = sizeof (struct AddressUpdateMessage) + plugin_addr_len +
- ats_count * sizeof (struct GNUNET_TRANSPORT_ATS_Information) + namelen;
- if ( (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
- (plugin_addr_len >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
- (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
- (ats_count >= GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_TRANSPORT_ATS_Information)) )
- {
- GNUNET_break (0);
- return;
- }
- p = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
- p->size = msize;
- p->is_init = GNUNET_NO;
- m = (struct AddressUpdateMessage*) &p[1];
- m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_ADDRESS_UPDATE);
- m->header.size = htons (msize);
- m->ats_count = htonl (ats_count);
- m->peer = *peer;
- m->address_length = htons (plugin_addr_len);
- m->plugin_name_length = htons (namelen);
- m->session_id = htonl (get_session_id (sh, session));
- am = (struct GNUNET_TRANSPORT_ATS_Information*) &m[1];
- memcpy (am, ats, ats_count * sizeof (struct GNUNET_TRANSPORT_ATS_Information));
- pm = (char *) &am[ats_count];
- memcpy (pm, plugin_addr, plugin_addr_len);
- memcpy (&pm[plugin_addr_len], plugin_name, namelen);
- GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head,
- sh->pending_tail,
- p);
- do_transmit (sh);
-}
-
-
-/**
- * A session got destroyed, stop including it as a valid address.
- *
- * @param sh handle
- * @param peer identity of the peer
- * @param plugin_name name of the transport plugin
- * @param plugin_addr address (if available)
- * @param plugin_addr_len number of bytes in plugin_addr
- * @param session session handle that is no longer valid
- */
-void
-GNUNET_ATS_address_destroyed (struct GNUNET_ATS_SchedulingHandle *sh,
- const struct GNUNET_PeerIdentity *peer,
- const char *plugin_name,
- const void *plugin_addr,
- size_t plugin_addr_len,
- struct Session *session)
-{
- struct PendingMessage *p;
- struct AddressDestroyedMessage *m;
- char *pm;
- size_t namelen;
- size_t msize;
- uint32_t session_id;
-
- namelen = (plugin_name == NULL) ? 0 : strlen (plugin_name) + 1;
- msize = sizeof (struct AddressUpdateMessage) + plugin_addr_len +
- namelen;
- if ( (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
- (plugin_addr_len >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
- (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE) )
- {
- GNUNET_break (0);
- return;
- }
- p = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
- p->size = msize;
- p->is_init = GNUNET_NO;
- m = (struct AddressDestroyedMessage*) &p[1];
- m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_ADDRESS_DESTROYED);
- m->header.size = htons (msize);
- m->reserved = htonl (0);
- m->peer = *peer;
- m->address_length = htons (plugin_addr_len);
- m->plugin_name_length = htons (namelen);
- m->session_id = htonl (session_id = get_session_id (sh, session));
- pm = (char *) &m[1];
- memcpy (pm, plugin_addr, plugin_addr_len);
- memcpy (&pm[plugin_addr_len], plugin_name, namelen);
- GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head,
- sh->pending_tail,
- p);
- do_transmit (sh);
- remove_session (sh, session_id);
-}
-
-/* end of ats_api_scheduling.c */