gnunet-service-core_sessions.c File Reference

code for managing of 'encrypted' sessions (key exchange done) More...

#include "platform.h"
#include "gnunet-service-core.h"
#include "gnunet-service-core_kx.h"
#include "gnunet-service-core_typemap.h"
#include "gnunet-service-core_sessions.h"
#include "gnunet_constants.h"
#include "core.h"

Include dependency graph for gnunet-service-core_sessions.c:

Go to the source code of this file.

Data Structures
struct	SessionMessageEntry
	Message ready for encryption. More...
struct	Session
	Data kept per session. More...
struct	TypeMapConfirmationMessage
	Message sent to confirm that a typemap was received. More...

Macros
#define	MAX_ENCRYPTED_MESSAGE_QUEUE_SIZE   4
	How many encrypted messages do we queue at most? Needed to bound memory consumption. More...

Functions
static struct Session *	find_session (const struct GNUNET_PeerIdentity *peer)
	Find the session for the given peer. More...
void	GSC_SESSIONS_end (const struct GNUNET_PeerIdentity *pid)
	End the session with the given peer (we are no longer connected). More...
static void	transmit_typemap_task (void *cls)
	Transmit our current typemap message to the other peer. More...
static void	start_typemap_task (struct Session *session)
	Restart the typemap task for the given session. More...
void	GSC_SESSIONS_create (const struct GNUNET_PeerIdentity *peer, struct GSC_KeyExchangeInfo *kx)
	Create a session, a key exchange was just completed. More...
void	GSC_SESSIONS_reinit (const struct GNUNET_PeerIdentity *peer)
	The other peer has indicated that it 'lost' the session (KX down), reinitialize the session on our end, in particular this means to restart the typemap transmission. More...
void	GSC_SESSIONS_confirm_typemap (const struct GNUNET_PeerIdentity *peer, const struct GNUNET_MessageHeader *msg)
	The other peer has confirmed receiving our type map, check if it is current and if so, stop retransmitting it. More...
static int	notify_client_about_session (void *cls, const struct GNUNET_PeerIdentity *key, void *value)
	Notify the given client about the session (client is new). More...
void	GSC_SESSIONS_notify_client_about_sessions (struct GSC_Client *client)
	We have a new client, notify it about all current sessions. More...
static void	try_transmission (struct Session *session)
	Try to perform a transmission on the given session. More...
void	GSC_SESSIONS_queue_request (struct GSC_ClientActiveRequest *car)
	Queue a request from a client for transmission to a particular peer. More...
void	GSC_SESSIONS_dequeue_request (struct GSC_ClientActiveRequest *car)
	Dequeue a request from a client from transmission to a particular peer. More...
static void	solicit_messages (struct Session *session, size_t msize)
	Solicit messages for transmission, starting with those of the highest priority. More...
static void	pop_cork_task (void *cls)
	Some messages were delayed (corked), but the timeout has now expired. More...
static int	do_restart_typemap_message (void *cls, const struct GNUNET_PeerIdentity *key, void *value)
	Send an updated typemap message to the neighbour now, and restart typemap transmissions. More...
void	GSC_SESSIONS_broadcast_typemap (const struct GNUNET_MessageHeader *msg)
	Broadcast an updated typemap message to all neighbours. More...
void	GSC_SESSIONS_solicit (const struct GNUNET_PeerIdentity *pid)
	Traffic is being solicited for the given peer. More...
void	GSC_SESSIONS_transmit (struct GSC_ClientActiveRequest *car, const struct GNUNET_MessageHeader *msg, enum GNUNET_MQ_PriorityPreferences priority)
	Transmit a message to a particular peer. More...
void	GSC_SESSIONS_set_typemap (const struct GNUNET_PeerIdentity *peer, const struct GNUNET_MessageHeader *msg)
	We've received a typemap message from a peer, update ours. More...
void	GSC_SESSIONS_add_to_typemap (const struct GNUNET_PeerIdentity *peer, uint16_t type)
	The given peer send a message of the specified type. More...
void	GSC_SESSIONS_init ()
	Initialize sessions subsystem. More...
static int	free_session_helper (void *cls, const struct GNUNET_PeerIdentity *key, void *value)
	Helper function for GSC_SESSIONS_done() to free all active sessions. More...
void	GSC_SESSIONS_done ()
	Shutdown sessions subsystem. More...

Variables
static GNUNET_NETWORK_STRUCT_END struct GNUNET_CONTAINER_MultiPeerMap *	sessions
	Map of peer identities to struct Session. More...

Detailed Description

code for managing of 'encrypted' sessions (key exchange done)

Author

Christian Grothoff

Definition in file gnunet-service-core_sessions.c.

Macro Definition Documentation

MAX_ENCRYPTED_MESSAGE_QUEUE_SIZE

#define MAX_ENCRYPTED_MESSAGE_QUEUE_SIZE   4

How many encrypted messages do we queue at most? Needed to bound memory consumption.

Definition at line 39 of file gnunet-service-core_sessions.c.

Function Documentation

find_session()

static struct Session* find_session ( const struct GNUNET_PeerIdentity *  peer )

static

Find the session for the given peer.

Parameters

peer	identity of the peer

Returns

NULL if we are not connected, otherwise the session handle

Definition at line 196 of file gnunet-service-core_sessions.c.

{
  if (NULL == sessions)
    return NULL;
  return GNUNET_CONTAINER_multipeermap_get (sessions, peer);
}

References GNUNET_CONTAINER_multipeermap_get(), peer, and sessions.

Referenced by GSC_SESSIONS_add_to_typemap(), GSC_SESSIONS_confirm_typemap(), GSC_SESSIONS_dequeue_request(), GSC_SESSIONS_end(), GSC_SESSIONS_queue_request(), GSC_SESSIONS_reinit(), GSC_SESSIONS_set_typemap(), GSC_SESSIONS_solicit(), and GSC_SESSIONS_transmit().

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GSC_SESSIONS_end()

void GSC_SESSIONS_end

(

const struct GNUNET_PeerIdentity *

pid

)

End the session with the given peer (we are no longer connected).

Parameters

pid	identity of peer to kill session with

Definition at line 211 of file gnunet-service-core_sessions.c.

{
  struct Session *session;
  struct GSC_ClientActiveRequest *car;
  struct SessionMessageEntry *sme;
 
  session = find_session (pid);
  if (NULL == session)
    return;
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Destroying session for peer `%s'\n",
              GNUNET_i2s (session->peer));
  if (NULL != session->cork_task)
  {
    GNUNET_SCHEDULER_cancel (session->cork_task);
    session->cork_task = NULL;
  }
  while (NULL != (car = session->active_client_request_head))
  {
    GNUNET_CONTAINER_DLL_remove (session->active_client_request_head,
                                 session->active_client_request_tail,
                                 car);
    GSC_CLIENTS_reject_request (car, GNUNET_NO);
  }
  while (NULL != (sme = session->sme_head))
  {
    GNUNET_CONTAINER_DLL_remove (session->sme_head, session->sme_tail, sme);
    GNUNET_free (sme);
  }
  if (NULL != session->typemap_task)
  {
    GNUNET_SCHEDULER_cancel (session->typemap_task);
    session->typemap_task = NULL;
  }
  GSC_CLIENTS_notify_clients_about_neighbour (session->peer,
                                              session->tmap,
                                              NULL);
  GNUNET_assert (
    GNUNET_YES ==
    GNUNET_CONTAINER_multipeermap_remove (sessions, session->peer, session));
  GNUNET_STATISTICS_set (GSC_stats,
                         gettext_noop ("# peers connected"),
                         GNUNET_CONTAINER_multipeermap_size (sessions),
                         GNUNET_NO);
  GSC_TYPEMAP_destroy (session->tmap);
  session->tmap = NULL;
  GNUNET_free (session);
}

References Session::active_client_request_head, Session::active_client_request_tail, Session::cork_task, find_session(), gettext_noop, GNUNET_assert, GNUNET_CONTAINER_DLL_remove, GNUNET_CONTAINER_multipeermap_remove(), GNUNET_CONTAINER_multipeermap_size(), GNUNET_ERROR_TYPE_DEBUG, GNUNET_free, GNUNET_i2s(), GNUNET_log, GNUNET_NO, GNUNET_SCHEDULER_cancel(), GNUNET_STATISTICS_set(), GNUNET_YES, GSC_CLIENTS_notify_clients_about_neighbour(), GSC_CLIENTS_reject_request(), GSC_stats, GSC_TYPEMAP_destroy(), Session::peer, pid, sessions, Session::sme_head, Session::sme_tail, Session::tmap, and Session::typemap_task.

Referenced by free_session_helper(), handle_encrypted(), handle_transport_notify_disconnect(), and send_keep_alive().

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transmit_typemap_task()

static void transmit_typemap_task ( void *  cls )

static

Transmit our current typemap message to the other peer.

(Done periodically until the typemap is confirmed).

Parameters

cls	the struct Session *

Definition at line 268 of file gnunet-service-core_sessions.c.

{
  struct Session *session = cls;
  struct GNUNET_MessageHeader *hdr;
  struct GNUNET_TIME_Relative delay;
 
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Sending TYPEMAP to %s\n",
              GNUNET_i2s (session->peer));
  session->typemap_delay = GNUNET_TIME_STD_BACKOFF (session->typemap_delay);
  delay = session->typemap_delay;
  /* randomize a bit to avoid spont. sync */
  delay.rel_value_us +=
    GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, 1000 * 1000);
  session->typemap_task =
    GNUNET_SCHEDULER_add_delayed (delay, &transmit_typemap_task, session);
  GNUNET_STATISTICS_update (GSC_stats,
                            gettext_noop ("# type map refreshes sent"),
                            1,
                            GNUNET_NO);
  hdr = GSC_TYPEMAP_compute_type_map_message ();
  GSC_KX_encrypt_and_transmit (session->kx, hdr, ntohs (hdr->size));
  GNUNET_free (hdr);
}

References delay, gettext_noop, GNUNET_CRYPTO_QUALITY_WEAK, GNUNET_CRYPTO_random_u32(), GNUNET_ERROR_TYPE_DEBUG, GNUNET_free, GNUNET_i2s(), GNUNET_log, GNUNET_NO, GNUNET_SCHEDULER_add_delayed(), GNUNET_STATISTICS_update(), GNUNET_TIME_STD_BACKOFF, GSC_KX_encrypt_and_transmit(), GSC_stats, GSC_TYPEMAP_compute_type_map_message(), Session::kx, Session::peer, GNUNET_TIME_Relative::rel_value_us, GNUNET_MessageHeader::size, Session::typemap_delay, and Session::typemap_task.

Referenced by start_typemap_task().

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start_typemap_task()

static void start_typemap_task ( struct Session *  session )

static

Restart the typemap task for the given session.

Parameters

session

session to restart typemap transmission for

Definition at line 300 of file gnunet-service-core_sessions.c.

{
  if (NULL != session->typemap_task)
    GNUNET_SCHEDULER_cancel (session->typemap_task);
  session->typemap_delay = GNUNET_TIME_UNIT_SECONDS;
  session->typemap_task = GNUNET_SCHEDULER_add_delayed (session->typemap_delay,
                                                        &transmit_typemap_task,
                                                        session);
}

References GNUNET_SCHEDULER_add_delayed(), GNUNET_SCHEDULER_cancel(), GNUNET_TIME_UNIT_SECONDS, transmit_typemap_task(), Session::typemap_delay, and Session::typemap_task.

Referenced by do_restart_typemap_message(), GSC_SESSIONS_create(), and GSC_SESSIONS_reinit().

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GSC_SESSIONS_create()

void GSC_SESSIONS_create	(	const struct GNUNET_PeerIdentity *	peer,
		struct GSC_KeyExchangeInfo *	kx
	)

Create a session, a key exchange was just completed.

Parameters

peer	peer that is now connected
kx	key exchange that completed

Definition at line 318 of file gnunet-service-core_sessions.c.

{
  struct Session *session;
 
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Creating session for peer `%s'\n",
              GNUNET_i2s (peer));
  session = GNUNET_new (struct Session);
  session->tmap = GSC_TYPEMAP_create ();
  session->peer = peer;
  session->kx = kx;
  GNUNET_assert (GNUNET_OK ==
                 GNUNET_CONTAINER_multipeermap_put (
                   sessions,
                   session->peer,
                   session,
                   GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
  GNUNET_STATISTICS_set (GSC_stats,
                         gettext_noop ("# peers connected"),
                         GNUNET_CONTAINER_multipeermap_size (sessions),
                         GNUNET_NO);
  GSC_CLIENTS_notify_clients_about_neighbour (peer, NULL, session->tmap);
  start_typemap_task (session);
}

References gettext_noop, GNUNET_assert, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY, GNUNET_CONTAINER_multipeermap_put(), GNUNET_CONTAINER_multipeermap_size(), GNUNET_ERROR_TYPE_DEBUG, GNUNET_i2s(), GNUNET_log, GNUNET_new, GNUNET_NO, GNUNET_OK, GNUNET_STATISTICS_set(), GSC_CLIENTS_notify_clients_about_neighbour(), GSC_stats, GSC_TYPEMAP_create(), Session::kx, Session::peer, peer, sessions, start_typemap_task(), and Session::tmap.

Referenced by handle_pong().

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GSC_SESSIONS_reinit()

void GSC_SESSIONS_reinit

(

const struct GNUNET_PeerIdentity *

peer

)

The other peer has indicated that it 'lost' the session (KX down), reinitialize the session on our end, in particular this means to restart the typemap transmission.

Parameters

peer	peer that is now connected

Definition at line 353 of file gnunet-service-core_sessions.c.

{
  struct Session *session;
 
  session = find_session (peer);
  if (NULL == session)
  {
    /* KX/session is new for both sides; thus no need to restart what
       has not yet begun */
    return;
  }
  start_typemap_task (session);
}

References find_session(), peer, and start_typemap_task().

Referenced by handle_ephemeral_key().

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GSC_SESSIONS_confirm_typemap()

void GSC_SESSIONS_confirm_typemap	(	const struct GNUNET_PeerIdentity *	peer,
		const struct GNUNET_MessageHeader *	msg
	)

The other peer has confirmed receiving our type map, check if it is current and if so, stop retransmitting it.

Parameters

peer	peer that confirmed the type map
msg	confirmation message we received

Definition at line 376 of file gnunet-service-core_sessions.c.

{
  const struct TypeMapConfirmationMessage *cmsg;
  struct Session *session;
 
  session = find_session (peer);
  if (NULL == session)
  {
    GNUNET_break (0);
    return;
  }
  if (ntohs (msg->size) != sizeof(struct TypeMapConfirmationMessage))
  {
    GNUNET_break_op (0);
    return;
  }
  cmsg = (const struct TypeMapConfirmationMessage *) msg;
  if (GNUNET_YES != GSC_TYPEMAP_check_hash (&cmsg->tm_hash))
  {
    /* our typemap has changed in the meantime, do not
       accept confirmation */
    GNUNET_STATISTICS_update (GSC_stats,
                              gettext_noop (
                                "# outdated typemap confirmations received"),
                              1,
                              GNUNET_NO);
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Got outdated typemap confirmated from peer `%s'\n",
                GNUNET_i2s (session->peer));
    return;
  }
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Got typemap confirmation from peer `%s'\n",
              GNUNET_i2s (session->peer));
  if (NULL != session->typemap_task)
  {
    GNUNET_SCHEDULER_cancel (session->typemap_task);
    session->typemap_task = NULL;
  }
  GNUNET_STATISTICS_update (GSC_stats,
                            gettext_noop (
                              "# valid typemap confirmations received"),
                            1,
                            GNUNET_NO);
}

References find_session(), gettext_noop, GNUNET_break, GNUNET_break_op, GNUNET_ERROR_TYPE_DEBUG, GNUNET_i2s(), GNUNET_log, GNUNET_NO, GNUNET_SCHEDULER_cancel(), GNUNET_STATISTICS_update(), GNUNET_YES, GSC_stats, GSC_TYPEMAP_check_hash(), msg, Session::peer, peer, GNUNET_MessageHeader::size, TypeMapConfirmationMessage::tm_hash, and Session::typemap_task.

Referenced by deliver_message().

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notify_client_about_session()

static int notify_client_about_session ( void *  cls, const struct GNUNET_PeerIdentity *  key, void *  value  )

static

Notify the given client about the session (client is new).

Parameters

cls	the struct GSC_Client
key	peer identity
value	the struct Session

Returns

GNUNET_OK (continue to iterate)

Definition at line 433 of file gnunet-service-core_sessions.c.

{
  struct GSC_Client *client = cls;
  struct Session *session = value;
 
  GSC_CLIENTS_notify_client_about_neighbour (client,
                                             session->peer,
                                             NULL, /* old TMAP: none */
                                             session->tmap);
  return GNUNET_OK;
}

References GSC_Client::client, GNUNET_OK, GSC_CLIENTS_notify_client_about_neighbour(), Session::peer, Session::tmap, and value.

Referenced by GSC_SESSIONS_notify_client_about_sessions().

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GSC_SESSIONS_notify_client_about_sessions()

void GSC_SESSIONS_notify_client_about_sessions

(

struct GSC_Client *

client

)

We have a new client, notify it about all current sessions.

Parameters

client

the new client

Definition at line 454 of file gnunet-service-core_sessions.c.

{
  /* notify new client about existing sessions */
  GNUNET_CONTAINER_multipeermap_iterate (sessions,
                                         &notify_client_about_session,
                                         client);
}

References GNUNET_CONTAINER_multipeermap_iterate(), notify_client_about_session(), and sessions.

Referenced by handle_client_init().

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try_transmission()

static void try_transmission ( struct Session *  session )

static

Try to perform a transmission on the given session.

Will solicit additional messages if the 'sme' queue is not full enough.

Parameters

session

session to transmit messages from

Will solicit additional messages if the 'sme' queue is not full enough or has only low-priority messages.

Parameters

session

session to transmit messages from

Definition at line 610 of file gnunet-service-core_sessions.c.

{
  struct SessionMessageEntry *pos;
  size_t msize;
  struct GNUNET_TIME_Absolute now;
  struct GNUNET_TIME_Absolute min_deadline;
  enum GNUNET_MQ_PriorityPreferences maxp;
  enum GNUNET_MQ_PriorityPreferences maxpc;
  struct GSC_ClientActiveRequest *car;
  int excess;
 
  msize = 0;
  min_deadline = GNUNET_TIME_UNIT_FOREVER_ABS;
  /* if the peer has excess bandwidth, background traffic is allowed,
     otherwise not */
  if (MAX_ENCRYPTED_MESSAGE_QUEUE_SIZE <=
      GSC_NEIGHBOURS_get_queue_length (session->kx))
  {
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Transmission queue already very long, waiting...\n");
    return;   /* queue already too long */
  }
  excess = GSC_NEIGHBOURS_check_excess_bandwidth (session->kx);
  if (GNUNET_YES == excess)
    maxp = GNUNET_MQ_PRIO_BACKGROUND;
  else
    maxp = GNUNET_MQ_PRIO_BEST_EFFORT;
  /* determine highest priority of 'ready' messages we already solicited from clients */
  pos = session->sme_head;
  while ((NULL != pos) &&
         (msize + pos->size <= GNUNET_CONSTANTS_MAX_ENCRYPTED_MESSAGE_SIZE))
  {
    GNUNET_assert (pos->size < GNUNET_CONSTANTS_MAX_ENCRYPTED_MESSAGE_SIZE);
    msize += pos->size;
    maxp = GNUNET_MAX (maxp, pos->priority & GNUNET_MQ_PRIORITY_MASK);
    min_deadline = GNUNET_TIME_absolute_min (min_deadline, pos->deadline);
    pos = pos->next;
  }
  GNUNET_log (
    GNUNET_ERROR_TYPE_DEBUG,
    "Calculating transmission set with %u priority (%s) and %s earliest deadline\n",
    maxp,
    (GNUNET_YES == excess) ? "excess bandwidth" : "limited bandwidth",
    GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_remaining (
                                              min_deadline),
                                            GNUNET_YES));
 
  if (maxp < GNUNET_MQ_PRIO_CRITICAL_CONTROL)
  {
    /* if highest already solicited priority from clients is not critical,
       check if there are higher-priority messages to be solicited from clients */
    if (GNUNET_YES == excess)
      maxpc = GNUNET_MQ_PRIO_BACKGROUND;
    else
      maxpc = GNUNET_MQ_PRIO_BEST_EFFORT;
    for (car = session->active_client_request_head; NULL != car;
         car = car->next)
    {
      if (GNUNET_YES == car->was_solicited)
        continue;
      maxpc = GNUNET_MAX (maxpc, car->priority & GNUNET_MQ_PRIORITY_MASK);
    }
    if (maxpc > maxp)
    {
      /* we have messages waiting for solicitation that have a higher
         priority than those that we already accepted; solicit the
         high-priority messages first */
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "Soliciting messages based on priority (%u > %u)\n",
                  maxpc,
                  maxp);
      solicit_messages (session, 0);
      return;
    }
  }
  else
  {
    /* never solicit more, we have critical messages to process */
    excess = GNUNET_NO;
    maxpc = GNUNET_MQ_PRIO_BACKGROUND;
  }
  now = GNUNET_TIME_absolute_get ();
  if (((GNUNET_YES == excess) || (maxpc >= GNUNET_MQ_PRIO_BEST_EFFORT)) &&
      ((0 == msize) ||
       ((msize < GNUNET_CONSTANTS_MAX_ENCRYPTED_MESSAGE_SIZE / 2) &&
        (min_deadline.abs_value_us > now.abs_value_us))))
  {
    /* not enough ready yet (tiny message & cork possible), or no messages at all,
       and either excess bandwidth or best-effort or higher message waiting at
       client; in this case, we try to solicit more */
    GNUNET_log (
      GNUNET_ERROR_TYPE_DEBUG,
      "Soliciting messages (excess %d, maxpc %d, message size %u, deadline %s)\n",
      excess,
      maxpc,
      (unsigned int) msize,
      GNUNET_STRINGS_relative_time_to_string (
        GNUNET_TIME_absolute_get_remaining (
          min_deadline),
        GNUNET_YES));
    solicit_messages (session, msize);
    if (msize > 0)
    {
      /* if there is data to send, just not yet, make sure we do transmit
       * it once the deadline is reached */
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "Corking until %s\n",
                  GNUNET_STRINGS_relative_time_to_string (
                    GNUNET_TIME_absolute_get_remaining (min_deadline),
                    GNUNET_YES));
      if (NULL != session->cork_task)
        GNUNET_SCHEDULER_cancel (session->cork_task);
      session->cork_task =
        GNUNET_SCHEDULER_add_at (min_deadline, &pop_cork_task, session);
    }
    else
    {
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "Queue empty, waiting for solicitations\n");
    }
    return;
  }
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Building combined plaintext buffer to transmit message!\n");
  /* create plaintext buffer of all messages (that fit), encrypt and
     transmit */
  {
    static unsigned long long total_bytes;
    static unsigned int total_msgs;
    char pbuf[msize]; /* plaintext */
    size_t used;
 
    used = 0;
    while ((NULL != (pos = session->sme_head)) && (used + pos->size <= msize))
    {
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "Adding message of type %d (%d/%d) to payload for %s\n",
                  ntohs (((const struct GNUNET_MessageHeader *) &pos[1])->type),
                  pos->is_typemap,
                  pos->is_typemap_confirm,
                  GNUNET_i2s (session->peer));
      GNUNET_memcpy (&pbuf[used], &pos[1], pos->size);
      used += pos->size;
      GNUNET_CONTAINER_DLL_remove (session->sme_head, session->sme_tail, pos);
      GNUNET_free (pos);
    }
    /* compute average payload size */
    total_bytes += used;
    total_msgs++;
    if (0 == total_msgs)
    {
      /* 2^32 messages, wrap around... */
      total_msgs = 1;
      total_bytes = used;
    }
    GNUNET_STATISTICS_set (GSC_stats,
                           "# avg payload per encrypted message",
                           total_bytes / total_msgs,
                           GNUNET_NO);
    /* now actually transmit... */
    GSC_KX_encrypt_and_transmit (session->kx, pbuf, used);
  }
}

References GNUNET_TIME_Absolute::abs_value_us, Session::active_client_request_head, Session::cork_task, SessionMessageEntry::deadline, GNUNET_assert, GNUNET_CONSTANTS_MAX_ENCRYPTED_MESSAGE_SIZE, GNUNET_CONTAINER_DLL_remove, GNUNET_ERROR_TYPE_DEBUG, GNUNET_free, GNUNET_i2s(), GNUNET_log, GNUNET_MAX, GNUNET_memcpy, GNUNET_MQ_PRIO_BACKGROUND, GNUNET_MQ_PRIO_BEST_EFFORT, GNUNET_MQ_PRIO_CRITICAL_CONTROL, GNUNET_MQ_PRIORITY_MASK, GNUNET_NO, GNUNET_SCHEDULER_add_at(), GNUNET_SCHEDULER_cancel(), GNUNET_STATISTICS_set(), GNUNET_STRINGS_relative_time_to_string(), GNUNET_TIME_absolute_get(), GNUNET_TIME_absolute_get_remaining(), GNUNET_TIME_absolute_min(), GNUNET_TIME_UNIT_FOREVER_ABS, GNUNET_YES, GSC_KX_encrypt_and_transmit(), GSC_NEIGHBOURS_check_excess_bandwidth(), GSC_NEIGHBOURS_get_queue_length(), GSC_stats, Session::kx, MAX_ENCRYPTED_MESSAGE_QUEUE_SIZE, GSC_ClientActiveRequest::msize, GSC_ClientActiveRequest::next, SessionMessageEntry::next, Session::peer, pop_cork_task(), GSC_ClientActiveRequest::priority, SessionMessageEntry::priority, SessionMessageEntry::size, GNUNET_MessageHeader::size, Session::sme_head, Session::sme_tail, solicit_messages(), type, and GSC_ClientActiveRequest::was_solicited.

Referenced by do_restart_typemap_message(), GSC_SESSIONS_dequeue_request(), GSC_SESSIONS_queue_request(), GSC_SESSIONS_set_typemap(), GSC_SESSIONS_solicit(), GSC_SESSIONS_transmit(), and pop_cork_task().

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GSC_SESSIONS_queue_request()

void GSC_SESSIONS_queue_request

(

struct GSC_ClientActiveRequest *

car

)

Queue a request from a client for transmission to a particular peer.

Parameters

car	request to queue; this handle is then shared between the caller (CLIENTS subsystem) and SESSIONS and must not be released by either until either #GSC_SESSIONS_dequeue(), GSC_SESSIONS_transmit() or #GSC_CLIENTS_failed() have been invoked on it

Definition at line 483 of file gnunet-service-core_sessions.c.

{
  struct Session *session;
 
  session = find_session (&car->target);
  if (NULL == session)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Dropped client request for transmission (am disconnected)\n");
    GNUNET_break (0);  /* should have been rejected earlier */
    GSC_CLIENTS_reject_request (car, GNUNET_NO);
    return;
  }
  if (car->msize > GNUNET_CONSTANTS_MAX_ENCRYPTED_MESSAGE_SIZE)
  {
    GNUNET_break (0);
    GSC_CLIENTS_reject_request (car, GNUNET_YES);
    return;
  }
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Received client transmission request. queueing\n");
  GNUNET_CONTAINER_DLL_insert_tail (session->active_client_request_head,
                                    session->active_client_request_tail,
                                    car);
  try_transmission (session);
}

References Session::active_client_request_head, Session::active_client_request_tail, find_session(), GNUNET_break, GNUNET_CONSTANTS_MAX_ENCRYPTED_MESSAGE_SIZE, GNUNET_CONTAINER_DLL_insert_tail, GNUNET_ERROR_TYPE_DEBUG, GNUNET_log, GNUNET_NO, GNUNET_YES, GSC_CLIENTS_reject_request(), GSC_ClientActiveRequest::msize, GSC_ClientActiveRequest::target, and try_transmission().

Referenced by handle_client_send_request().

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GSC_SESSIONS_dequeue_request()

void GSC_SESSIONS_dequeue_request

(

struct GSC_ClientActiveRequest *

car

)

Dequeue a request from a client from transmission to a particular peer.

Parameters

car	request to dequeue; this handle will then be 'owned' by the caller (CLIENTS sysbsystem)

Definition at line 518 of file gnunet-service-core_sessions.c.

{
  struct Session *session;
 
  if (0 == memcmp (&car->target,
                   &GSC_my_identity,
                   sizeof(struct GNUNET_PeerIdentity)))
    return;
  session = find_session (&car->target);
  GNUNET_assert (NULL != session);
  GNUNET_CONTAINER_DLL_remove (session->active_client_request_head,
                               session->active_client_request_tail,
                               car);
  /* dequeueing of 'high' priority messages may unblock
     transmission for lower-priority messages, so we also
     need to try in this case. */
  try_transmission (session);
}

References Session::active_client_request_head, Session::active_client_request_tail, find_session(), GNUNET_assert, GNUNET_CONTAINER_DLL_remove, GSC_my_identity, GSC_ClientActiveRequest::target, and try_transmission().

Referenced by destroy_active_client_request(), GSC_CLIENTS_solicit_request(), handle_client_send(), and handle_client_send_request().

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solicit_messages()

static void solicit_messages ( struct Session *  session, size_t  msize  )

static

Solicit messages for transmission, starting with those of the highest priority.

Parameters

session	session to solict messages for
msize	how many bytes do we have already

Definition at line 546 of file gnunet-service-core_sessions.c.

{
  struct GSC_ClientActiveRequest *car;
  struct GSC_ClientActiveRequest *nxt;
  size_t so_size;
  enum GNUNET_MQ_PriorityPreferences pmax;
 
  so_size = msize;
  pmax = GNUNET_MQ_PRIO_BACKGROUND;
  for (car = session->active_client_request_head; NULL != car; car = car->next)
  {
    if (GNUNET_YES == car->was_solicited)
      continue;
    pmax = GNUNET_MAX (pmax, car->priority & GNUNET_MQ_PRIORITY_MASK);
  }
  nxt = session->active_client_request_head;
  while (NULL != (car = nxt))
  {
    nxt = car->next;
    if (car->priority < pmax)
      continue;
    if (so_size + car->msize > GNUNET_CONSTANTS_MAX_ENCRYPTED_MESSAGE_SIZE)
      break;
    so_size += car->msize;
    if (GNUNET_YES == car->was_solicited)
      continue;
    car->was_solicited = GNUNET_YES;
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Soliciting message with priority %u\n",
                car->priority);
    GSC_CLIENTS_solicit_request (car);
    /* The above call may *dequeue* requests and thereby
       clobber 'nxt'. Hence we need to restart from the
       head of the list. */
    nxt = session->active_client_request_head;
    so_size = msize;
  }
}

References Session::active_client_request_head, GNUNET_CONSTANTS_MAX_ENCRYPTED_MESSAGE_SIZE, GNUNET_ERROR_TYPE_DEBUG, GNUNET_log, GNUNET_MAX, GNUNET_MQ_PRIO_BACKGROUND, GNUNET_MQ_PRIORITY_MASK, GNUNET_YES, GSC_CLIENTS_solicit_request(), GSC_ClientActiveRequest::msize, GSC_ClientActiveRequest::next, GSC_ClientActiveRequest::priority, and GSC_ClientActiveRequest::was_solicited.

Referenced by try_transmission().

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pop_cork_task()

static void pop_cork_task ( void *  cls )

static

Some messages were delayed (corked), but the timeout has now expired.

Send them now.

Parameters

cls	struct Session with the messages to transmit now

Definition at line 593 of file gnunet-service-core_sessions.c.

{
  struct Session *session = cls;
 
  session->cork_task = NULL;
  try_transmission (session);
}

References Session::cork_task, and try_transmission().

Referenced by try_transmission().

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do_restart_typemap_message()

static int do_restart_typemap_message ( void *  cls, const struct GNUNET_PeerIdentity *  key, void *  value  )

static

Send an updated typemap message to the neighbour now, and restart typemap transmissions.

Parameters

cls	the message
key	neighbour's identity
value	struct Neighbour of the target

Returns

always GNUNET_OK

Definition at line 785 of file gnunet-service-core_sessions.c.

{
  const struct GNUNET_MessageHeader *hdr = cls;
  struct Session *session = value;
  struct SessionMessageEntry *sme;
  uint16_t size;
 
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Restarting sending TYPEMAP to %s\n",
              GNUNET_i2s (session->peer));
  size = ntohs (hdr->size);
  for (sme = session->sme_head; NULL != sme; sme = sme->next)
  {
    if (GNUNET_YES == sme->is_typemap)
    {
      GNUNET_CONTAINER_DLL_remove (session->sme_head, session->sme_tail, sme);
      GNUNET_free (sme);
      break;
    }
  }
  sme = GNUNET_malloc (sizeof(struct SessionMessageEntry) + size);
  sme->is_typemap = GNUNET_YES;
  GNUNET_memcpy (&sme[1], hdr, size);
  sme->size = size;
  sme->priority = GNUNET_MQ_PRIO_CRITICAL_CONTROL;
  GNUNET_CONTAINER_DLL_insert (session->sme_head, session->sme_tail, sme);
  try_transmission (session);
  start_typemap_task (session);
  return GNUNET_OK;
}

References GNUNET_CONTAINER_DLL_insert, GNUNET_CONTAINER_DLL_remove, GNUNET_ERROR_TYPE_DEBUG, GNUNET_free, GNUNET_i2s(), GNUNET_log, GNUNET_malloc, GNUNET_memcpy, GNUNET_MQ_PRIO_CRITICAL_CONTROL, GNUNET_OK, GNUNET_YES, SessionMessageEntry::is_typemap, SessionMessageEntry::next, Session::peer, SessionMessageEntry::priority, SessionMessageEntry::size, GNUNET_MessageHeader::size, size, Session::sme_head, Session::sme_tail, start_typemap_task(), try_transmission(), and value.

Referenced by GSC_SESSIONS_broadcast_typemap().

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GSC_SESSIONS_broadcast_typemap()

void GSC_SESSIONS_broadcast_typemap

(

const struct GNUNET_MessageHeader *

msg

)

Broadcast an updated typemap message to all neighbours.

Restarts the retransmissions until the typemaps are confirmed.

Parameters

msg	message to transmit

Definition at line 826 of file gnunet-service-core_sessions.c.

{
  if (NULL == sessions)
    return;
  GNUNET_CONTAINER_multipeermap_iterate (sessions,
                                         &do_restart_typemap_message,
                                         (void *) msg);
}

References do_restart_typemap_message(), GNUNET_CONTAINER_multipeermap_iterate(), msg, and sessions.

Referenced by broadcast_my_type_map().

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GSC_SESSIONS_solicit()

void GSC_SESSIONS_solicit

(

const struct GNUNET_PeerIdentity *

pid

)

Traffic is being solicited for the given peer.

This means that the message queue on the transport-level (NEIGHBOURS subsystem) is now empty and it is now OK to transmit another (non-control) message.

Parameters

pid	identity of peer ready to receive data

Definition at line 844 of file gnunet-service-core_sessions.c.

{
  struct Session *session;
 
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Transport solicits for %s\n",
              GNUNET_i2s (pid));
  session = find_session (pid);
  if (NULL == session)
    return;
  try_transmission (session);
}

References find_session(), GNUNET_ERROR_TYPE_DEBUG, GNUNET_i2s(), GNUNET_log, pid, and try_transmission().

Referenced by handle_transport_notify_excess_bw().

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GSC_SESSIONS_transmit()

void GSC_SESSIONS_transmit	(	struct GSC_ClientActiveRequest *	car,
		const struct GNUNET_MessageHeader *	msg,
		enum GNUNET_MQ_PriorityPreferences	priority
	)

Transmit a message to a particular peer.

Parameters

car	original request that was queued and then solicited, ownership does not change (dequeue will be called soon).
msg	message to transmit
priority	how important is this message

Definition at line 859 of file gnunet-service-core_sessions.c.

{
  struct Session *session;
  struct SessionMessageEntry *sme;
  struct SessionMessageEntry *pos;
  size_t msize;
 
  session = find_session (&car->target);
  if (NULL == session)
    return;
  msize = ntohs (msg->size);
  sme = GNUNET_malloc (sizeof(struct SessionMessageEntry) + msize);
  GNUNET_memcpy (&sme[1], msg, msize);
  sme->size = msize;
  sme->priority = priority;
  if (0 != (GNUNET_MQ_PREF_CORK_ALLOWED & priority))
  {
    sme->deadline =
      GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_MAX_CORK_DELAY);
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Message corked, delaying transmission\n");
  }
  pos = session->sme_head;
  while ((NULL != pos) && (pos->priority >= sme->priority))
    pos = pos->next;
  if (NULL == pos)
    GNUNET_CONTAINER_DLL_insert_tail (session->sme_head,
                                      session->sme_tail,
                                      sme);
  else
    GNUNET_CONTAINER_DLL_insert_after (session->sme_head,
                                       session->sme_tail,
                                       pos->prev,
                                       sme);
  try_transmission (session);
}

References SessionMessageEntry::deadline, find_session(), GNUNET_CONSTANTS_MAX_CORK_DELAY, GNUNET_CONTAINER_DLL_insert_after, GNUNET_CONTAINER_DLL_insert_tail, GNUNET_ERROR_TYPE_DEBUG, GNUNET_log, GNUNET_malloc, GNUNET_memcpy, GNUNET_MQ_PREF_CORK_ALLOWED, GNUNET_TIME_relative_to_absolute(), msg, SessionMessageEntry::next, SessionMessageEntry::prev, SessionMessageEntry::priority, SessionMessageEntry::size, GNUNET_MessageHeader::size, Session::sme_head, Session::sme_tail, GSC_ClientActiveRequest::target, and try_transmission().

Referenced by tokenized_cb().

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GSC_SESSIONS_set_typemap()

void GSC_SESSIONS_set_typemap	(	const struct GNUNET_PeerIdentity *	peer,
		const struct GNUNET_MessageHeader *	msg
	)

We've received a typemap message from a peer, update ours.

Notifies clients about the session.

Parameters

peer	peer this is about
msg	typemap update message

Definition at line 900 of file gnunet-service-core_sessions.c.

{
  struct Session *session;
  struct GSC_TypeMap *nmap;
  struct SessionMessageEntry *sme;
  struct TypeMapConfirmationMessage *tmc;
 
  nmap = GSC_TYPEMAP_get_from_message (msg);
  if (NULL == nmap)
  {
    GNUNET_break_op (0);
    return;   /* malformed */
  }
  session = find_session (peer);
  if (NULL == session)
  {
    GSC_TYPEMAP_destroy (nmap);
    GNUNET_break (0);
    return;
  }
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Received TYPEMAP from %s\n",
              GNUNET_i2s (session->peer));
  for (sme = session->sme_head; NULL != sme; sme = sme->next)
  {
    if (GNUNET_YES == sme->is_typemap_confirm)
    {
      GNUNET_CONTAINER_DLL_remove (session->sme_head, session->sme_tail, sme);
      GNUNET_free (sme);
      break;
    }
  }
  sme = GNUNET_malloc (sizeof(struct SessionMessageEntry)
                       + sizeof(struct TypeMapConfirmationMessage));
  sme->deadline = GNUNET_TIME_absolute_get ();
  sme->size = sizeof(struct TypeMapConfirmationMessage);
  sme->priority = GNUNET_MQ_PRIO_CRITICAL_CONTROL;
  sme->is_typemap_confirm = GNUNET_YES;
  tmc = (struct TypeMapConfirmationMessage *) &sme[1];
  tmc->header.size = htons (sizeof(struct TypeMapConfirmationMessage));
  tmc->header.type = htons (GNUNET_MESSAGE_TYPE_CORE_CONFIRM_TYPE_MAP);
  tmc->reserved = htonl (0);
  GSC_TYPEMAP_hash (nmap, &tmc->tm_hash);
  GNUNET_CONTAINER_DLL_insert (session->sme_head, session->sme_tail, sme);
  try_transmission (session);
  GSC_CLIENTS_notify_clients_about_neighbour (peer, session->tmap, nmap);
  GSC_TYPEMAP_destroy (session->tmap);
  session->tmap = nmap;
}

References SessionMessageEntry::deadline, find_session(), GNUNET_break, GNUNET_break_op, GNUNET_CONTAINER_DLL_insert, GNUNET_CONTAINER_DLL_remove, GNUNET_ERROR_TYPE_DEBUG, GNUNET_free, GNUNET_i2s(), GNUNET_log, GNUNET_malloc, GNUNET_MESSAGE_TYPE_CORE_CONFIRM_TYPE_MAP, GNUNET_MQ_PRIO_CRITICAL_CONTROL, GNUNET_TIME_absolute_get(), GNUNET_YES, GSC_CLIENTS_notify_clients_about_neighbour(), GSC_TYPEMAP_destroy(), GSC_TYPEMAP_get_from_message(), GSC_TYPEMAP_hash(), TypeMapConfirmationMessage::header, SessionMessageEntry::is_typemap_confirm, msg, SessionMessageEntry::next, Session::peer, peer, SessionMessageEntry::priority, TypeMapConfirmationMessage::reserved, SessionMessageEntry::size, GNUNET_MessageHeader::size, Session::sme_head, Session::sme_tail, TypeMapConfirmationMessage::tm_hash, Session::tmap, try_transmission(), and GNUNET_MessageHeader::type.

Referenced by deliver_message().

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GSC_SESSIONS_add_to_typemap()

void GSC_SESSIONS_add_to_typemap	(	const struct GNUNET_PeerIdentity *	peer,
		uint16_t	type
	)

The given peer send a message of the specified type.

Make sure the respective bit is set in its type-map and that clients are notified about the session.

Parameters

peer	peer this is about
type	type of the message

Definition at line 961 of file gnunet-service-core_sessions.c.

{
  struct Session *session;
  struct GSC_TypeMap *nmap;
 
  if (0 == memcmp (peer, &GSC_my_identity, sizeof(struct GNUNET_PeerIdentity)))
    return;
  session = find_session (peer);
  GNUNET_assert (NULL != session);
  if (GNUNET_YES == GSC_TYPEMAP_test_match (session->tmap, &type, 1))
    return; /* already in it */
  nmap = GSC_TYPEMAP_extend (session->tmap, &type, 1);
  GSC_CLIENTS_notify_clients_about_neighbour (peer, session->tmap, nmap);
  GSC_TYPEMAP_destroy (session->tmap);
  session->tmap = nmap;
}

References find_session(), GNUNET_assert, GNUNET_YES, GSC_CLIENTS_notify_clients_about_neighbour(), GSC_my_identity, GSC_TYPEMAP_destroy(), GSC_TYPEMAP_extend(), GSC_TYPEMAP_test_match(), peer, Session::tmap, and type.

Referenced by GSC_CLIENTS_deliver_message().

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GSC_SESSIONS_init()

void GSC_SESSIONS_init

(

void

)

Initialize sessions subsystem.

Definition at line 984 of file gnunet-service-core_sessions.c.

{
  sessions = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_YES);
}

References GNUNET_CONTAINER_multipeermap_create(), GNUNET_YES, and sessions.

Referenced by run().

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free_session_helper()

static int free_session_helper ( void *  cls, const struct GNUNET_PeerIdentity *  key, void *  value  )

static

Helper function for GSC_SESSIONS_done() to free all active sessions.

Parameters

cls	NULL
key	identity of the connected peer
value	the struct Session for the peer

Returns

GNUNET_OK (continue to iterate)

Definition at line 1000 of file gnunet-service-core_sessions.c.

{
  /* struct Session *session = value; */
 
  GSC_SESSIONS_end (key);
  return GNUNET_OK;
}

References GNUNET_OK, GSC_SESSIONS_end(), and key.

Referenced by GSC_SESSIONS_done().

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GSC_SESSIONS_done()

void GSC_SESSIONS_done

(

void

)

Shutdown sessions subsystem.

Definition at line 1015 of file gnunet-service-core_sessions.c.

{
  if (NULL != sessions)
  {
    GNUNET_CONTAINER_multipeermap_iterate (sessions,
                                           &free_session_helper,
                                           NULL);
    GNUNET_CONTAINER_multipeermap_destroy (sessions);
    sessions = NULL;
  }
}

References free_session_helper(), GNUNET_CONTAINER_multipeermap_destroy(), GNUNET_CONTAINER_multipeermap_iterate(), and sessions.

Referenced by shutdown_task().

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Variable Documentation

sessions

GNUNET_NETWORK_STRUCT_END struct GNUNET_CONTAINER_MultiPeerMap* sessions

static

Map of peer identities to struct Session.

Definition at line 185 of file gnunet-service-core_sessions.c.

Referenced by find_session(), GSC_SESSIONS_broadcast_typemap(), GSC_SESSIONS_create(), GSC_SESSIONS_done(), GSC_SESSIONS_end(), GSC_SESSIONS_init(), and GSC_SESSIONS_notify_client_about_sessions().