path: root/src/mesh/mesh_api_new.c

/*
     This file is part of GNUnet.
     (C) 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 mesh/mesh_api_new.c
 * @brief mesh api: client implementation of mesh service
 * @author Bartlomiej Polot
 * 
 * STRUCTURE:
 * - CONSTANTS
 * - DATA STRUCTURES
 * - SEND CALLBACKS
 * - RECEIVE HANDLERS
 * - API CALL DEFINITIONS
 */

#ifdef __cplusplus

extern "C"
{
#if 0                           /* keep Emacsens' auto-indent happy */
}
#endif
#endif


#include "platform.h"
#include "gnunet_common.h"
#include "gnunet_client_lib.h"
#include "gnunet_util_lib.h"
#include "gnunet_mesh_service_new.h"
#include "mesh.h"

/******************************************************************************/
/**************************       CONSTANTS      ******************************/
/******************************************************************************/

#define GNUNET_MESH_LOCAL_TUNNEL_ID_MARK 0x80000000

/******************************************************************************/
/************************      DATA STRUCTURES     ****************************/
/******************************************************************************/

/**
 * Opaque handle to the service.
 */
struct GNUNET_MESH_Handle {
    /**
     * Handle to the server connection, to send messages later
     */
    struct GNUNET_CLIENT_Connection             *client;

    /**
     * Set of handlers used for processing incoming messages in the tunnels
     */
    const struct GNUNET_MESH_MessageHandler     *message_handlers;
    int                                         n_handlers;

    /**
     * Set of applications that should be claimed to be offered at this node.
     * Note that this is just informative, the appropiate handlers must be
     * registered independently and the mapping is up to the developer of the
     * client application.
     */
    const GNUNET_MESH_ApplicationType           *applications;
    int                                         n_applications;

    /**
     * Double linked list of the tunnels this client is connected to.
     */
    struct GNUNET_MESH_Tunnel                   *tunnels_head;
    struct GNUNET_MESH_Tunnel                   *tunnels_tail;

    /**
     * tid of the next tunnel to create (to avoid reusing IDs often)
     */
    MESH_TunnelID                               next_tid;

    /**
     * Callback for tunnel disconnection
     */
    GNUNET_MESH_TunnelEndHandler                *cleaner;

    /**
     * Handle to cancel pending transmissions in case of disconnection
     */
    struct GNUNET_CLIENT_TransmitHandle         *th;

    /**
     * Closure for all the handlers given by the client
     */
    void                                        *cls;
};

/**
 * Opaque handle to a tunnel.
 */
struct GNUNET_MESH_Tunnel {

    /**
     * DLL
     */
    struct GNUNET_MESH_Tunnel                   *next;
    struct GNUNET_MESH_Tunnel                   *prev;

    /**
     * Owner of the tunnel, either local or remote
     */
    GNUNET_PEER_Id                              owner;

    /**
     * Local ID of the tunnel
     */
    MESH_TunnelID                               tid;

    /**
     * Callback to execute when peers connect to the tunnel
     */
    GNUNET_MESH_TunnelConnectHandler            connect_handler;

    /**
     * Callback to execute when peers disconnect to the tunnel
     */
    GNUNET_MESH_TunnelDisconnectHandler         disconnect_handler;

    /**
     * All peers added to the tunnel
     */
    GNUNET_PEER_Id                              *peers;

    /**
     * Closure for the connect/disconnect handlers
     */
    void                                        *cls;

    /**
     * Handle to the mesh this tunnel belongs to
     */
    struct GNUNET_MESH_Handle                   *mesh;
};

struct GNUNET_MESH_TransmitHandle {
    // TODO
};

/******************************************************************************/
/***********************     AUXILIARY FUNCTIONS      *************************/
/******************************************************************************/

/**
 * Get the tunnel handler for the tunnel specified by id from the given handle
 * @param h Mesh handle
 * @param tid ID of the wanted tunnel
 * @return handle to the required tunnel or NULL if not found
 */
static struct GNUNET_MESH_Tunnel *
retrieve_tunnel (struct GNUNET_MESH_Handle *h, MESH_TunnelID tid) 
{
    struct GNUNET_MESH_Tunnel           *t;

    t = h->tunnels_head;
    while (t != NULL) {
        if (t->tid == tid) return t;
        t = t->next;
    }
    return NULL;
}


/******************************************************************************/
/************************       SEND CALLBACKS     ****************************/
/******************************************************************************/


/**
 * Function called to send a connect message to the service, specifying the
 * types and applications that the client is interested in.
 * "buf" will be NULL and "size" zero if the socket was closed for writing in
 * the meantime.
 *
 * @param cls closure, the mesh handle
 * @param size number of bytes available in buf
 * @param buf where the callee should write the connect message
 * @return number of bytes written to buf
 */
static size_t 
send_connect_packet (void *cls, size_t size, void *buf)
{
    struct GNUNET_MESH_Handle           *h = cls;
    struct GNUNET_MESH_ClientConnect    *msg;
    uint16_t                            *types;
    uint16_t                            ntypes;
    GNUNET_MESH_ApplicationType         *apps;
    uint16_t                            napps;

    h->th = NULL;
    if (0 == size || buf == NULL) {
        GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                    "Send connect packet: buffer size 0 or buffer invalid\n");
	// FIXME: disconnect, reconnect, retry!
        return 0;
    }
    if (sizeof(struct GNUNET_MessageHeader) > size) {
        GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                    "Send connect packet: buffer size too small\n");
	// FIXME: disconnect, reconnect, retry!
        return 0;
    }
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Send connect packet: %lu bytes buffer\n",
                size);
    msg = (struct GNUNET_MESH_ClientConnect *) buf;
    msg->header.type = htons(GNUNET_MESSAGE_TYPE_MESH_LOCAL_CONNECT);

    for (ntypes = 0, types = NULL; h->message_handlers[ntypes].type; ntypes++) {
        types = GNUNET_realloc(types, sizeof(uint16_t) * (ntypes + 1));
        types[ntypes] = h->message_handlers[ntypes].type;
    }

    for(napps = 0, apps = NULL; h->applications[napps]; napps++) {
        apps = GNUNET_realloc(apps,
                              sizeof(GNUNET_MESH_ApplicationType) *
                                (napps + 1));
        apps[napps] = h->applications[napps];
    }

    msg->header.size = htons(sizeof(struct GNUNET_MESH_ClientConnect) +
                             sizeof(uint16_t) * ntypes +
                             sizeof(GNUNET_MESH_ApplicationType) * napps);

    memcpy(&msg[1], types, sizeof(uint16_t) * ntypes);
    memcpy(&msg[1] + sizeof(uint16_t) * ntypes,
           apps,
           sizeof(GNUNET_MESH_ApplicationType) * napps);
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Sent %lu bytes long message %d types and %d apps\n",
                ntohs(msg->header.size),
                ntypes,
                napps
               );
    msg->applications = htons(napps);
    msg->types = htons(ntypes);

    return ntohs(msg->header.size);
}


/**
 * Function called to send a create tunnel message, specifying the tunnel
 * number chosen by the client.
 * "buf" will be NULL and "size" zero if the socket was closed for
 * writing in the meantime.
 *
 * @param cls closure, the tunnel handle
 * @param size number of bytes available in buf
 * @param buf where the callee should write the create tunnel message
 * @return number of bytes written to buf
 */
static size_t 
send_tunnel_create_packet (void *cls, size_t size, void *buf)
{
    struct GNUNET_MESH_Tunnel           *t = cls;
    struct GNUNET_MESH_Handle           *h;
    struct GNUNET_MESH_TunnelMessage    *msg;

    h = t->mesh;
    h->th = NULL;
    if (0 == size || buf == NULL) {
        GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                    "Send connect packet: buffer size 0 or buffer invalid\n");
        // FIXME: disconnect, reconnect, retry!
        return 0;
    }
    if (sizeof(struct GNUNET_MessageHeader) > size) {
        GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                    "Send connect packet: buffer size too small\n");
        // FIXME: disconnect, reconnect, retry!
        return 0;
    }
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Send connect packet: %lu bytes buffer\n",
                size);
    msg = (struct GNUNET_MESH_TunnelMessage *) buf;
    msg->header.type = htons(GNUNET_MESSAGE_TYPE_MESH_LOCAL_CONNECT);

    msg->header.size = htons(sizeof(struct GNUNET_MESH_TunnelMessage));
    msg->tunnel_id = htonl(t->tid);

    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Sent %lu bytes long message\n",
                ntohs(msg->header.size));

    return ntohs(msg->header.size);
}


/******************************************************************************/
/***********************      RECEIVE HANDLERS     ****************************/
/******************************************************************************/

/**
 * Process the new tunnel notification and add it to the tunnels in the handle
 * 
 * @param h     The mesh handle
 * @param msh   A message with the details of the new incoming tunnel
 */
static void
process_tunnel_create(struct GNUNET_MESH_Handle *h, 
                      const struct GNUNET_MESH_TunnelMessage *msg)
{
    struct GNUNET_MESH_Tunnel                   *t;
    MESH_TunnelID                               tid;

    tid = ntohl(msg->tunnel_id);
    if (tid >= GNUNET_MESH_LOCAL_TUNNEL_ID_MARK) {
        GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
            "MESH: received an incoming tunnel with tid in local range (%X)\n",
            tid);
        return; //FIXME abort? reconnect?
    }
    t = GNUNET_malloc(sizeof(struct GNUNET_MESH_Tunnel));
    t->cls = h->cls;
    t->connect_handler = NULL;
    t->disconnect_handler = NULL;
    t->mesh = h;
    t->tid = tid;
    return;
}


/**
 * Process the incoming data packets
 * 
 * @param h     The mesh handle
 * @param msh   A message encapsulating the data
 */
static void
process_incoming_data(struct GNUNET_MESH_Handle *h, 
                      const struct GNUNET_MESH_Data *msg)
{
    const struct GNUNET_MESH_Data               *payload;
    const struct GNUNET_MESH_MessageHandler     *handler;
    struct GNUNET_MESH_Tunnel                   *t;
    uint16_t                                    type;
    int                                         i;

    t = retrieve_tunnel(h, ntohl(msg->tunnel_id));

    payload = (struct GNUNET_MESH_Data *) &msg[1];
    type = ntohs(payload->header.type);
    for (i = 0; i < h->n_handlers; i++) {
        handler = &h->message_handlers[i];
        if (handler->type == type) {
            /* FIXME */
            if (GNUNET_OK == handler->callback (h->cls,
                                                t,
                                                NULL,
                                                NULL,
                                                NULL,
                                                NULL))
            {
                GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
                            "MESH: callback completed successfully\n");
            } else {
                GNUNET_log(GNUNET_ERROR_TYPE_WARNING,
                            "MESH: callback caused disconnection\n");
                GNUNET_MESH_disconnect(h);
            }
        }
    }
    return;
}


/**
 * Function to process all messages received from the service
 *
 * @param cls closure
 * @param msg message received, NULL on timeout or fatal error
 */
static void
msg_received (void *cls, const struct GNUNET_MessageHeader * msg)
{
    struct GNUNET_MESH_Handle                   *h = cls;

    if (msg == NULL) {
        GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
               "received a NULL message from mesh\n");
        return;
    }

    switch (ntohs(msg->type)) {
        /* Notify of a new incoming tunnel */
        case GNUNET_MESSAGE_TYPE_MESH_LOCAL_TUNNEL_CREATE:
            process_tunnel_create(h, (struct GNUNET_MESH_TunnelMessage *)msg);
            break;
        /* Notify of a new peer in the tunnel */
        case GNUNET_MESSAGE_TYPE_MESH_LOCAL_PEER_CONNECTED:
            break;
        /* Notify of a peer leaving the tunnel */
        case GNUNET_MESSAGE_TYPE_MESH_LOCAL_PEER_DISCONNECTED:
            break;
        /* Notify of a new data packet in the tunnel */
        case GNUNET_MESSAGE_TYPE_MESH_LOCAL_DATA:
            process_incoming_data(h, (struct GNUNET_MESH_Data *)msg);
            break;
        /* We shouldn't get any other packages, log and ignore */
        default:
            GNUNET_log(GNUNET_ERROR_TYPE_WARNING,
                        "MESH: unsolicited message form service (type %d)\n",
                        ntohs(msg->type));
    }

    GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
               "received a message from mesh\n");
    GNUNET_CLIENT_receive (h->client,
                        &msg_received,
                        h, 
                        GNUNET_TIME_UNIT_FOREVER_REL);
    return;
}

/******************************************************************************/
/**********************      API CALL DEFINITIONS     *************************/
/******************************************************************************/

/**
 * Connect to the mesh service.
 *
 * @param cfg configuration to use
 * @param cls closure for the various callbacks that follow
 *            (including handlers in the handlers array)
 * @param cleaner function called when an *inbound* tunnel is destroyed
 * @param handlers callbacks for messages we care about, NULL-terminated
 *                 note that the mesh is allowed to drop notifications about
 *                 inbound messages if the client does not process them fast
 *                 enough (for this notification type, a bounded queue is used)
 * @param stypes Application Types the client claims to offer
 * @return handle to the mesh service 
 *         NULL on error (in this case, init is never called)
 */
struct GNUNET_MESH_Handle *
GNUNET_MESH_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
                     void *cls,
                     GNUNET_MESH_TunnelEndHandler cleaner,
                     const struct GNUNET_MESH_MessageHandler *handlers,
                     const GNUNET_MESH_ApplicationType *stypes) 
{
    struct GNUNET_MESH_Handle           *h;
    size_t                              size;

    h = GNUNET_malloc(sizeof(struct GNUNET_MESH_Handle));

    h->cleaner = cleaner;
    h->client = GNUNET_CLIENT_connect("mesh", cfg);
    GNUNET_CLIENT_receive (h->client,
                         &msg_received,
                         h, 
                         GNUNET_TIME_UNIT_FOREVER_REL);
    if(h->client == NULL) {
        GNUNET_free(h);
        return NULL;
    }

    h->cls = cls;
    h->message_handlers = handlers;
    h->applications = stypes;
    h->next_tid = 0x80000000;

    for(h->n_handlers = 0; handlers[h->n_handlers].type; h->n_handlers++);
    for(h->n_applications = 0; stypes[h->n_applications]; h->n_applications++);

    size = sizeof(struct GNUNET_MESH_ClientConnect);
    size += h->n_handlers * sizeof(uint16_t);
    size += h->n_applications * sizeof(GNUNET_MESH_ApplicationType);

    h->th = GNUNET_CLIENT_notify_transmit_ready(h->client,
                                                size,
                                                GNUNET_TIME_UNIT_FOREVER_REL,
                                                GNUNET_YES,
                                                &send_connect_packet,
                                                (void *)h);

    return h;
}


/**
 * Disconnect from the mesh service.
 *
 * @param handle connection to mesh to disconnect
 */
void 
GNUNET_MESH_disconnect (struct GNUNET_MESH_Handle *handle) 
{
    if (NULL != handle->th) {
        GNUNET_CLIENT_notify_transmit_ready_cancel (handle->th);
    }
    if (NULL != handle->client) {
        GNUNET_CLIENT_disconnect (handle->client, GNUNET_NO);
    }
    GNUNET_free(handle);
}


/**
 * Create a new tunnel (we're initiator and will be allowed to add/remove peers
 * and to broadcast).
 *
 * @param h mesh handle
 * @param connect_handler function to call when peers are actually connected
 * @param disconnect_handler function to call when peers are disconnected
 * @param handler_cls closure for connect/disconnect handlers
 */
struct GNUNET_MESH_Tunnel *
GNUNET_MESH_tunnel_create (struct GNUNET_MESH_Handle *h,
                           GNUNET_MESH_TunnelConnectHandler
                           connect_handler,
                           GNUNET_MESH_TunnelDisconnectHandler
                           disconnect_handler,
                           void *handler_cls)
{
    struct GNUNET_MESH_Tunnel           *tunnel;

    GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
               "MESH: Creating new tunnel\n");
    tunnel = GNUNET_malloc(sizeof(struct GNUNET_MESH_Tunnel));

    tunnel->connect_handler = connect_handler;
    tunnel->disconnect_handler = disconnect_handler;
    tunnel->cls = handler_cls;
    tunnel->mesh = h;
    tunnel->tid = h->next_tid++;
    h->next_tid |= GNUNET_MESH_LOCAL_TUNNEL_ID_MARK; // keep in range

    h->th = GNUNET_CLIENT_notify_transmit_ready(h->client,
                                    sizeof(struct GNUNET_MESH_TunnelMessage),
                                    GNUNET_TIME_UNIT_FOREVER_REL,
                                    GNUNET_YES,
                                    &send_tunnel_create_packet,
                                    (void *)tunnel);

    return tunnel;
}


/**
 * Request that a peer should be added to the tunnel.  The existing
 * connect handler will be called ONCE with either success or failure.
 *
 * @param tunnel handle to existing tunnel
 * @param timeout how long to try to establish a connection
 * @param peer peer to add
 */
void
GNUNET_MESH_peer_request_connect_add (struct GNUNET_MESH_Tunnel *tunnel,
                                      struct GNUNET_TIME_Relative timeout,
                                      const struct GNUNET_PeerIdentity *peer)
{
    static GNUNET_PEER_Id       peer_id;

    peer_id = GNUNET_PEER_intern(peer);

    /* FIXME ACTUALLY DO STUFF */
    tunnel->peers = &peer_id;
    tunnel->connect_handler(tunnel->cls, peer, NULL);
    return;
}


/**
 * Request that a peer should be removed from the tunnel.  The existing
 * disconnect handler will be called ONCE if we were connected.
 *
 * @param tunnel handle to existing tunnel
 * @param peer peer to remove
 */
void
GNUNET_MESH_peer_request_connect_del (struct GNUNET_MESH_Tunnel *tunnel,
                                      const struct GNUNET_PeerIdentity *peer)
{
    /* FIXME ACTUALLY DO STUFF */
    tunnel->peers = NULL;
    tunnel->disconnect_handler(tunnel->cls, peer);
    return;
}


/**
 * Request that the mesh should try to connect to a peer supporting the given
 * message type.
 *
 * @param tunnel handle to existing tunnel
 * @param timeout how long to try to establish a connection
 * @param app_type application type that must be supported by the peer (MESH
 *                 should discover peer in proximity handling this type)
 */
void
GNUNET_MESH_peer_request_connect_by_type (struct GNUNET_MESH_Tunnel *tunnel,
                                          struct GNUNET_TIME_Relative timeout,
                                          GNUNET_MESH_ApplicationType
                                          app_type)
{
    return;
}


/**
 * Ask the mesh to call "notify" once it is ready to transmit the
 * given number of bytes to the specified "target".  If we are not yet
 * connected to the specified peer, a call to this function will cause
 * us to try to establish a connection.
 *
 * @param tunnel tunnel to use for transmission
 * @param cork is corking allowed for this transmission?
 * @param priority how important is the message?
 * @param maxdelay how long can the message wait?
 * @param target destination for the message,
 *               NULL for multicast to all tunnel targets 
 * @param notify_size how many bytes of buffer space does notify want?
 * @param notify function to call when buffer space is available;
 *        will be called with NULL on timeout or if the overall queue
 *        for this peer is larger than queue_size and this is currently
 *        the message with the lowest priority
 * @param notify_cls closure for notify
 * @return non-NULL if the notify callback was queued,
 *         NULL if we can not even queue the request (insufficient
 *         memory); if NULL is returned, "notify" will NOT be called.
 */
struct GNUNET_MESH_TransmitHandle *
GNUNET_MESH_notify_transmit_ready (struct GNUNET_MESH_Tunnel *tunnel,
                                   int cork,
                                   uint32_t priority,
                                   struct GNUNET_TIME_Relative maxdelay,
                                   const struct GNUNET_PeerIdentity *target,
                                   size_t notify_size,
                                   GNUNET_CONNECTION_TransmitReadyNotify
                                   notify,
                                   void *notify_cls)
{
    struct GNUNET_MESH_TransmitHandle   *handle;

    handle = GNUNET_malloc(sizeof(struct GNUNET_MESH_TransmitHandle));

    return handle;
}


#if 0                           /* keep Emacsens' auto-indent happy */
{
#endif
#ifdef __cplusplus
}
#endif