ats_api_scheduling.c File Reference

automatic transport selection and outbound bandwidth determination More...

#include "platform.h"
#include "gnunet_ats_service.h"
#include "ats.h"

Include dependency graph for ats_api_scheduling.c:

Go to the source code of this file.

Data Structures
struct	GNUNET_ATS_AddressRecord
	Information we track per address, incoming or outgoing. More...
struct	GNUNET_ATS_SchedulingHandle
	Handle to the ATS subsystem for bandwidth/transport scheduling information. More...

Macros
#define	INTERFACE_PROCESSING_INTERVAL
	How frequently do we scan the interfaces for changes to the addresses? More...
#define	LOG(kind, ...)   GNUNET_log_from (kind, "ats-scheduling-api", __VA_ARGS__)
#define	NOT_FOUND   0
	Session ID we use if there is no session / slot. More...

Functions
static void	reconnect (struct GNUNET_ATS_SchedulingHandle *sh)
	Re-establish the connection to the ATS service. More...
static void	reconnect_task (void *cls)
	Re-establish the connection to the ATS service. More...
static void	force_reconnect (struct GNUNET_ATS_SchedulingHandle *sh)
	Disconnect from ATS and then reconnect. More...
static struct GNUNET_ATS_AddressRecord *	find_session (struct GNUNET_ATS_SchedulingHandle *sh, uint32_t session_id, const struct GNUNET_PeerIdentity *peer)
	Find the session object corresponding to the given session ID. More...
static uint32_t	find_empty_session_slot (struct GNUNET_ATS_SchedulingHandle *sh)
	Get an available session ID. More...
static uint32_t	find_session_id (struct GNUNET_ATS_SchedulingHandle *sh, struct GNUNET_ATS_Session *session, const struct GNUNET_HELLO_Address *address)
	Get the ID for the given session object. More...
static void	release_session (struct GNUNET_ATS_SchedulingHandle *sh, uint32_t session_id)
	Release the session slot from the session table (ATS service is also done using it). More...
static void	handle_ats_session_release (void *cls, const struct GNUNET_ATS_SessionReleaseMessage *srm)
	Type of a function to call when we receive a session release message from the service. More...
static void	handle_ats_address_suggestion (void *cls, const struct AddressSuggestionMessage *m)
	Type of a function to call when we receive a address suggestion message from the service. More...
static void	error_handler (void *cls, enum GNUNET_MQ_Error error)
	We encountered an error handling the MQ to the ATS service. More...
static void	send_add_address_message (struct GNUNET_ATS_SchedulingHandle *sh, const struct GNUNET_ATS_AddressRecord *ar)
	Generate and transmit the struct AddressAddMessage for the given address record. More...
struct GNUNET_ATS_SchedulingHandle *	GNUNET_ATS_scheduling_init (const struct GNUNET_CONFIGURATION_Handle *cfg, GNUNET_ATS_AddressSuggestionCallback suggest_cb, void *suggest_cb_cls)
	Initialize the ATS scheduling subsystem. More...
void	GNUNET_ATS_scheduling_done (struct GNUNET_ATS_SchedulingHandle *sh)
	Client is done with ATS scheduling, release resources. More...
struct GNUNET_ATS_AddressRecord *	GNUNET_ATS_address_add (struct GNUNET_ATS_SchedulingHandle *sh, const struct GNUNET_HELLO_Address *address, struct GNUNET_ATS_Session *session, const struct GNUNET_ATS_Properties *prop)
	We have a new address ATS should know. More...
void	GNUNET_ATS_address_add_session (struct GNUNET_ATS_AddressRecord *ar, struct GNUNET_ATS_Session *session)
	An address was used to initiate a session. More...
int	GNUNET_ATS_address_del_session (struct GNUNET_ATS_AddressRecord *ar, struct GNUNET_ATS_Session *session)
	A session was destroyed, disassociate it from the given address record. More...
void	GNUNET_ATS_address_update (struct GNUNET_ATS_AddressRecord *ar, const struct GNUNET_ATS_Properties *prop)
	We have updated performance statistics for a given address. More...
void	GNUNET_ATS_address_destroy (struct GNUNET_ATS_AddressRecord *ar)
	An address got destroyed, stop using it as a valid address. More...

Detailed Description

automatic transport selection and outbound bandwidth determination

Author

Christian Grothoff

Matthias Wachs

TODO:

• we could avoid a linear scan over the active addresses in some cases, so if there is need, we can still optimize here
• we might want to split off the logic to determine LAN vs. WAN, as it has nothing to do with accessing the ATS service.

Definition in file ats_api_scheduling.c.

Macro Definition Documentation

INTERFACE_PROCESSING_INTERVAL

#define INTERFACE_PROCESSING_INTERVAL

Value:

    GNUNET_TIME_relative_multiply ( \
    GNUNET_TIME_UNIT_MINUTES, 2)

How frequently do we scan the interfaces for changes to the addresses?

Definition at line 41 of file ats_api_scheduling.c.

LOG

#define LOG	(		kind,
			...
	)		GNUNET_log_from (kind, "ats-scheduling-api", __VA_ARGS__)

Definition at line 44 of file ats_api_scheduling.c.

NOT_FOUND

#define NOT_FOUND   0

Session ID we use if there is no session / slot.

Definition at line 49 of file ats_api_scheduling.c.

Function Documentation

reconnect()

static void reconnect ( struct GNUNET_ATS_SchedulingHandle *  sh )

static

Re-establish the connection to the ATS service.

Parameters

sh	handle to use to re-connect.

Definition at line 512 of file ats_api_scheduling.c.

{
  struct GNUNET_MQ_MessageHandler handlers[] = {
    GNUNET_MQ_hd_fixed_size (ats_session_release,
                             GNUNET_MESSAGE_TYPE_ATS_SESSION_RELEASE,
                             struct GNUNET_ATS_SessionReleaseMessage,
                             sh),
    GNUNET_MQ_hd_fixed_size (ats_address_suggestion,
                             GNUNET_MESSAGE_TYPE_ATS_ADDRESS_SUGGESTION,
                             struct AddressSuggestionMessage,
                             sh),
    GNUNET_MQ_handler_end ()
  };
  struct GNUNET_MQ_Envelope *ev;
  struct ClientStartMessage *init;
  unsigned int i;
  struct GNUNET_ATS_AddressRecord *ar;
 
  GNUNET_assert (NULL == sh->mq);
  sh->mq = GNUNET_CLIENT_connect (sh->cfg,
                                  "ats",
                                  handlers,
                                  &error_handler,
                                  sh);
  if (NULL == sh->mq)
  {
    GNUNET_break (0);
    force_reconnect (sh);
    return;
  }
  ev = GNUNET_MQ_msg (init,
                      GNUNET_MESSAGE_TYPE_ATS_START);
  init->start_flag = htonl (START_FLAG_SCHEDULING);
  GNUNET_MQ_send (sh->mq, ev);
  if (NULL == sh->mq)
    return;
  for (i = 0; i < sh->session_array_size; i++)
  {
    ar = sh->session_array[i];
    if (NULL == ar)
      continue;
    send_add_address_message (sh, ar);
    if (NULL == sh->mq)
      return;
  }
}

References error_handler(), force_reconnect(), GNUNET_assert, GNUNET_break, GNUNET_CLIENT_connect(), GNUNET_MESSAGE_TYPE_ATS_ADDRESS_SUGGESTION, GNUNET_MESSAGE_TYPE_ATS_SESSION_RELEASE, GNUNET_MESSAGE_TYPE_ATS_START, GNUNET_MQ_handler_end, GNUNET_MQ_hd_fixed_size, GNUNET_MQ_msg, GNUNET_MQ_send(), handlers, init, send_add_address_message(), sh, and START_FLAG_SCHEDULING.

Referenced by GNUNET_ATS_scheduling_init(), and reconnect_task().

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reconnect_task()

static void reconnect_task ( void *  cls )

static

Re-establish the connection to the ATS service.

Parameters

cls	handle to use to re-connect.

Definition at line 164 of file ats_api_scheduling.c.

{
  struct GNUNET_ATS_SchedulingHandle *sh = cls;
 
  sh->task = NULL;
  reconnect (sh);
}

References reconnect(), and sh.

Referenced by force_reconnect().

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force_reconnect()

static void force_reconnect ( struct GNUNET_ATS_SchedulingHandle *  sh )

static

Disconnect from ATS and then reconnect.

Parameters

sh	our handle

Definition at line 179 of file ats_api_scheduling.c.

{
  if (NULL != sh->mq)
  {
    GNUNET_MQ_destroy (sh->mq);
    sh->mq = NULL;
  }
  sh->suggest_cb (sh->suggest_cb_cls,
                  NULL, NULL, NULL,
                  GNUNET_BANDWIDTH_ZERO,
                  GNUNET_BANDWIDTH_ZERO);
  sh->backoff = GNUNET_TIME_STD_BACKOFF (sh->backoff);
  sh->task = GNUNET_SCHEDULER_add_delayed (sh->backoff,
                                           &reconnect_task,
                                           sh);
}

References GNUNET_BANDWIDTH_ZERO, GNUNET_MQ_destroy(), GNUNET_SCHEDULER_add_delayed(), GNUNET_TIME_STD_BACKOFF, reconnect_task(), and sh.

Referenced by error_handler(), handle_ats_address_suggestion(), reconnect(), and release_session().

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find_session()

static struct GNUNET_ATS_AddressRecord* find_session ( struct GNUNET_ATS_SchedulingHandle *  sh, uint32_t  session_id, const struct GNUNET_PeerIdentity *  peer  )

static

Find the session object corresponding to the given session ID.

Parameters

sh	our handle
session_id	current session ID
peer	peer the session belongs to

Returns

the session object (or NULL)

Definition at line 206 of file ats_api_scheduling.c.

{
  struct GNUNET_ATS_AddressRecord *ar;
 
  if (session_id >= sh->session_array_size)
  {
    GNUNET_break (0);
    return NULL;
  }
  if (0 == session_id)
    return NULL;
  ar = sh->session_array[session_id];
  if (NULL == ar)
  {
    GNUNET_break (0);
    return NULL;
  }
  if (NULL == ar->address)
  {
    /* address was destroyed in the meantime, this can happen
       as we communicate asynchronously with the ATS service. */
    return NULL;
  }
  if (0 != GNUNET_memcmp (peer,
                          &ar->address->peer))
  {
    GNUNET_break (0);
    return NULL;
  }
  return ar;
}

References GNUNET_ATS_AddressRecord::address, GNUNET_break, GNUNET_memcmp, GNUNET_HELLO_Address::peer, peer, session_id, and sh.

Referenced by handle_ats_address_suggestion().

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find_empty_session_slot()

static uint32_t find_empty_session_slot ( struct GNUNET_ATS_SchedulingHandle *  sh )

static

Get an available session ID.

Parameters

sh	our handle

Returns

an unused slot, but never NOT_FOUND (0)

Definition at line 248 of file ats_api_scheduling.c.

{
  static uint32_t off;
  uint32_t i;
 
  GNUNET_assert (0 != sh->session_array_size);
  i = 0;
  while (((NOT_FOUND == off) ||
          (NULL != sh->session_array[off % sh->session_array_size])) &&
         (i < sh->session_array_size))
  {
    off++;
    i++;
  }
  if ((NOT_FOUND != off % sh->session_array_size) &&
      (NULL == sh->session_array[off % sh->session_array_size]))
    return off;
  i = sh->session_array_size;
  GNUNET_array_grow (sh->session_array,
                     sh->session_array_size,
                     sh->session_array_size * 2);
  return i;
}

References GNUNET_array_grow, GNUNET_assert, NOT_FOUND, and sh.

Referenced by GNUNET_ATS_address_add().

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find_session_id()

static uint32_t find_session_id ( struct GNUNET_ATS_SchedulingHandle *  sh, struct GNUNET_ATS_Session *  session, const struct GNUNET_HELLO_Address *  address  )

static

Get the ID for the given session object.

Parameters

sh	our handle
session	session object
address	the address we are looking for

Returns

the session id or NOT_FOUND for error

Definition at line 282 of file ats_api_scheduling.c.

{
  uint32_t i;
 
  if (NULL == address)
  {
    GNUNET_break (0);
    return NOT_FOUND;
  }
  for (i = 1; i < sh->session_array_size; i++)
    if ((NULL != sh->session_array[i]) &&
        (GNUNET_NO == sh->session_array[i]->in_destroy) &&
        ((session == sh->session_array[i]->session) ||
         (NULL == sh->session_array[i]->session)) &&
        (0 == GNUNET_memcmp (&address->peer,
                             &sh->session_array[i]->address->peer)) &&
        (0 == GNUNET_HELLO_address_cmp (address,
                                        sh->session_array[i]->address)))
      return i;
  return NOT_FOUND;
}

References address, GNUNET_break, GNUNET_HELLO_address_cmp(), GNUNET_memcmp, GNUNET_NO, NOT_FOUND, GNUNET_ATS_AddressRecord::session, and sh.

Referenced by GNUNET_ATS_address_add().

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release_session()

static void release_session ( struct GNUNET_ATS_SchedulingHandle *  sh, uint32_t  session_id  )

static

Release the session slot from the session table (ATS service is also done using it).

Parameters

sh	our handle
session_id	identifies session that is no longer valid

Definition at line 315 of file ats_api_scheduling.c.

{
  struct GNUNET_ATS_AddressRecord *ar;
 
  if (NOT_FOUND == session_id)
    return;
  if (session_id >= sh->session_array_size)
  {
    GNUNET_break (0);
    force_reconnect (sh);
    return;
  }
  /* this slot should have been removed from remove_session before */
  ar = sh->session_array[session_id];
  if (NULL != ar->session)
  {
    GNUNET_break (0);
    force_reconnect (sh);
    return;
  }
  GNUNET_HELLO_address_free (ar->address);
  GNUNET_free (ar);
  sh->session_array[session_id] = NULL;
}

References GNUNET_ATS_AddressRecord::address, force_reconnect(), GNUNET_break, GNUNET_free, GNUNET_HELLO_address_free, NOT_FOUND, GNUNET_ATS_AddressRecord::session, session_id, and sh.

Referenced by handle_ats_session_release().

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handle_ats_session_release()

static void handle_ats_session_release ( void *  cls, const struct GNUNET_ATS_SessionReleaseMessage *  srm  )

static

Type of a function to call when we receive a session release message from the service.

Parameters

cls	the struct GNUNET_ATS_SchedulingHandle
srm	message received

Definition at line 350 of file ats_api_scheduling.c.

{
  struct GNUNET_ATS_SchedulingHandle *sh = cls;
 
  /* Note: peer field in srm not necessary right now,
     but might be good to have in the future */
  release_session (sh,
                   ntohl (srm->session_id));
}

References release_session(), GNUNET_ATS_SessionReleaseMessage::session_id, and sh.

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handle_ats_address_suggestion()

static void handle_ats_address_suggestion ( void *  cls, const struct AddressSuggestionMessage *  m  )

static

Type of a function to call when we receive a address suggestion message from the service.

Parameters

cls	the struct GNUNET_ATS_SchedulingHandle
m	message received

Definition at line 370 of file ats_api_scheduling.c.

{
  struct GNUNET_ATS_SchedulingHandle *sh = cls;
  struct GNUNET_ATS_AddressRecord *ar;
  uint32_t session_id;
 
  session_id = ntohl (m->session_id);
  if (0 == session_id)
  {
    GNUNET_break (0);
    force_reconnect (sh);
    return;
  }
  ar = find_session (sh,
                     session_id,
                     &m->peer);
  if (NULL == ar)
  {
    GNUNET_break (0);
    force_reconnect (sh);
    return;
  }
  if (NULL == sh->suggest_cb)
    return;
  if (GNUNET_YES == ar->in_destroy)
  {
    /* ignore suggestion, as this address is dying, unless BW is 0,
       in that case signal 'disconnect' via BW 0 */
    if ((0 == ntohl (m->bandwidth_out.value__)) &&
        (0 == ntohl (m->bandwidth_in.value__)))
    {
      LOG (GNUNET_ERROR_TYPE_DEBUG,
           "ATS suggests disconnect from peer `%s' with BW %u/%u\n",
           GNUNET_i2s (&ar->address->peer),
           (unsigned int) ntohl (m->bandwidth_out.value__),
           (unsigned int) ntohl (m->bandwidth_in.value__));
      sh->suggest_cb (sh->suggest_cb_cls,
                      &m->peer,
                      NULL,
                      NULL,
                      m->bandwidth_out,
                      m->bandwidth_in);
    }
    return;
  }
  if ((NULL == ar->session) &&
      (GNUNET_HELLO_address_check_option (ar->address,
                                          GNUNET_HELLO_ADDRESS_INFO_INBOUND)))
  {
    GNUNET_break (0);
    return;
  }
  sh->backoff = GNUNET_TIME_UNIT_ZERO;
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "ATS suggests address slot %u for peer `%s' using plugin %s\n",
       ar->slot,
       GNUNET_i2s (&ar->address->peer),
       ar->address->transport_name);
  sh->suggest_cb (sh->suggest_cb_cls,
                  &m->peer,
                  ar->address,
                  ar->session,
                  m->bandwidth_out,
                  m->bandwidth_in);
}

References GNUNET_ATS_AddressRecord::address, find_session(), force_reconnect(), GNUNET_break, GNUNET_ERROR_TYPE_DEBUG, GNUNET_HELLO_address_check_option(), GNUNET_HELLO_ADDRESS_INFO_INBOUND, GNUNET_i2s(), GNUNET_TIME_UNIT_ZERO, GNUNET_YES, GNUNET_ATS_AddressRecord::in_destroy, LOG, m, GNUNET_HELLO_Address::peer, GNUNET_ATS_AddressRecord::session, session_id, sh, GNUNET_ATS_AddressRecord::slot, and GNUNET_HELLO_Address::transport_name.

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error_handler()

static void error_handler ( void *  cls, enum GNUNET_MQ_Error  error  )

static

We encountered an error handling the MQ to the ATS service.

Reconnect.

Parameters

cls	the struct GNUNET_ATS_SchedulingHandle
error	details about the error

Definition at line 446 of file ats_api_scheduling.c.

{
  struct GNUNET_ATS_SchedulingHandle *sh = cls;
 
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "ATS connection died (code %d), reconnecting\n",
       (int) error);
  force_reconnect (sh);
}

References force_reconnect(), GNUNET_ERROR_TYPE_DEBUG, LOG, and sh.

Referenced by reconnect().

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send_add_address_message()

static void send_add_address_message ( struct GNUNET_ATS_SchedulingHandle *  sh, const struct GNUNET_ATS_AddressRecord *  ar  )

static

Generate and transmit the struct AddressAddMessage for the given address record.

Parameters

sh	the scheduling handle to use for transmission
ar	the address to inform the ATS service about

Definition at line 466 of file ats_api_scheduling.c.

{
  struct GNUNET_MQ_Envelope *ev;
  struct AddressAddMessage *m;
  char *pm;
  size_t namelen;
  size_t msize;
 
  if (NULL == sh->mq)
    return; /* disconnected, skip for now */
  GNUNET_break (GNUNET_NT_UNSPECIFIED != ar->properties.scope);
  namelen = strlen (ar->address->transport_name) + 1;
  msize = ar->address->address_length + namelen;
  ev = GNUNET_MQ_msg_extra (m, msize, GNUNET_MESSAGE_TYPE_ATS_ADDRESS_ADD);
  m->peer = ar->address->peer;
  m->address_length = htons (ar->address->address_length);
  m->address_local_info = htonl ((uint32_t) ar->address->local_info);
  m->plugin_name_length = htons (namelen);
  m->session_id = htonl (ar->slot);
  m->properties = ar->properties;
 
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Adding address for peer `%s', plugin `%s', session %p slot %u\n",
       GNUNET_i2s (&ar->address->peer),
       ar->address->transport_name,
       ar->session,
       ar->slot);
  pm = (char *) &m[1];
  GNUNET_memcpy (pm,
                 ar->address->address,
                 ar->address->address_length);
  if (NULL != ar->address->transport_name)
    GNUNET_memcpy (&pm[ar->address->address_length],
                   ar->address->transport_name,
                   namelen);
  GNUNET_MQ_send (sh->mq, ev);
}

References GNUNET_ATS_AddressRecord::address, GNUNET_HELLO_Address::address, GNUNET_HELLO_Address::address_length, GNUNET_break, GNUNET_ERROR_TYPE_DEBUG, GNUNET_i2s(), GNUNET_memcpy, GNUNET_MESSAGE_TYPE_ATS_ADDRESS_ADD, GNUNET_MQ_msg_extra, GNUNET_MQ_send(), GNUNET_NT_UNSPECIFIED, GNUNET_HELLO_Address::local_info, LOG, m, GNUNET_HELLO_Address::peer, pm, GNUNET_ATS_AddressRecord::properties, GNUNET_ATS_PropertiesNBO::scope, GNUNET_ATS_AddressRecord::session, sh, GNUNET_ATS_AddressRecord::slot, and GNUNET_HELLO_Address::transport_name.

Referenced by GNUNET_ATS_address_add(), and reconnect().

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