ng_l2cap_main.c

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/*
 * ng_l2cap_main.c
 */
 
/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) Maksim Yevmenkin <m_evmenkin@yahoo.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $Id: ng_l2cap_main.c,v 1.2 2003/04/28 21:44:59 max Exp $
 * $FreeBSD$
 */
 
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/queue.h>
#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_parse.h>
#include <netgraph/bluetooth/include/ng_bluetooth.h>
#include <netgraph/bluetooth/include/ng_hci.h>
#include <netgraph/bluetooth/include/ng_l2cap.h>
#include <netgraph/bluetooth/l2cap/ng_l2cap_var.h>
#include <netgraph/bluetooth/l2cap/ng_l2cap_cmds.h>
#include <netgraph/bluetooth/l2cap/ng_l2cap_evnt.h>
#include <netgraph/bluetooth/l2cap/ng_l2cap_llpi.h>
#include <netgraph/bluetooth/l2cap/ng_l2cap_ulpi.h>
#include <netgraph/bluetooth/l2cap/ng_l2cap_misc.h>
#include <netgraph/bluetooth/l2cap/ng_l2cap_prse.h>
 
/******************************************************************************
 ******************************************************************************
 **  This node implements Link Layer Control and Adaptation Protocol (L2CAP)
 ******************************************************************************
 ******************************************************************************/
 
/* MALLOC define */
#ifdef NG_SEPARATE_MALLOC
MALLOC_DEFINE(M_NETGRAPH_L2CAP, "netgraph_l2cap", 
        "Netgraph Bluetooth L2CAP node");
#else
#define M_NETGRAPH_L2CAP M_NETGRAPH
#endif /* NG_SEPARATE_MALLOC */
 
/* Netgraph node methods */
static  ng_constructor_t        ng_l2cap_constructor;
static  ng_shutdown_t           ng_l2cap_shutdown;
static  ng_newhook_t            ng_l2cap_newhook;
static  ng_connect_t            ng_l2cap_connect;
static  ng_disconnect_t         ng_l2cap_disconnect;
static  ng_rcvmsg_t             ng_l2cap_lower_rcvmsg;
static  ng_rcvmsg_t             ng_l2cap_upper_rcvmsg;
static  ng_rcvmsg_t             ng_l2cap_default_rcvmsg;
static  ng_rcvdata_t            ng_l2cap_rcvdata;
 
/* Netgraph node type descriptor */
static  struct ng_type typestruct = {
        .version =      NG_ABI_VERSION,
        .name =         NG_L2CAP_NODE_TYPE,
        .constructor =  ng_l2cap_constructor,
        .rcvmsg =       ng_l2cap_default_rcvmsg,
        .shutdown =     ng_l2cap_shutdown,
        .newhook =      ng_l2cap_newhook,
        .connect =      ng_l2cap_connect,
        .rcvdata =      ng_l2cap_rcvdata,
        .disconnect =   ng_l2cap_disconnect,
        .cmdlist =      ng_l2cap_cmdlist,
};
NETGRAPH_INIT(l2cap, &typestruct);
MODULE_VERSION(ng_l2cap, NG_BLUETOOTH_VERSION);
MODULE_DEPEND(ng_l2cap, ng_bluetooth, NG_BLUETOOTH_VERSION,
        NG_BLUETOOTH_VERSION, NG_BLUETOOTH_VERSION);
 
/*****************************************************************************
 *****************************************************************************
 **                   Netgraph methods implementation
 *****************************************************************************
 *****************************************************************************/
 
static void ng_l2cap_cleanup          (ng_l2cap_p);
static void ng_l2cap_destroy_channels (ng_l2cap_p);
 
/*
 * Create new instance of L2CAP node
 */
 
static int
ng_l2cap_constructor(node_p node)
{
        ng_l2cap_p      l2cap = NULL;
 
        /* Create new L2CAP node */
        l2cap = malloc(sizeof(*l2cap), M_NETGRAPH_L2CAP, M_WAITOK | M_ZERO);
 
        l2cap->node = node;
        l2cap->debug = NG_L2CAP_WARN_LEVEL;
        l2cap->discon_timo = 5; /* sec */
 
        LIST_INIT(&l2cap->con_list);
        LIST_INIT(&l2cap->chan_list);
 
        NG_NODE_SET_PRIVATE(node, l2cap);
        NG_NODE_FORCE_WRITER(node);
 
        return (0);
} /* ng_l2cap_constructor */
 
/*
 * Shutdown L2CAP node
 */
 
static int
ng_l2cap_shutdown(node_p node)
{
        ng_l2cap_p      l2cap = (ng_l2cap_p) NG_NODE_PRIVATE(node);
 
        NG_NODE_SET_PRIVATE(node, NULL);
        NG_NODE_UNREF(node);
 
        /* Clean up L2CAP node. Delete all connection, channels and commands */
        l2cap->node = NULL;
        ng_l2cap_cleanup(l2cap);
 
        bzero(l2cap, sizeof(*l2cap));
        free(l2cap, M_NETGRAPH_L2CAP);
 
        return (0);
} /* ng_l2cap_shutdown */
 
/*
 * Give our OK for a hook to be added. HCI layer is connected to the HCI 
 * (NG_L2CAP_HOOK_HCI) hook. As per specification L2CAP layer MUST provide
 * Procol/Service Multiplexing, so the L2CAP node provides separate hooks 
 * for SDP (NG_L2CAP_HOOK_SDP), RFCOMM (NG_L2CAP_HOOK_RFCOMM) and TCP 
 * (NG_L2CAP_HOOK_TCP) protcols. Unknown PSM will be forwarded to 
 * NG_L2CAP_HOOK_ORPHAN hook. Control node/application is connected to 
 * control (NG_L2CAP_HOOK_CTL) hook. 
 */
 
static int
ng_l2cap_newhook(node_p node, hook_p hook, char const *name)
{
        ng_l2cap_p       l2cap = (ng_l2cap_p) NG_NODE_PRIVATE(node);
        hook_p          *h = NULL;
 
        if (strcmp(name, NG_L2CAP_HOOK_HCI) == 0)
                h = &l2cap->hci;
        else if (strcmp(name, NG_L2CAP_HOOK_L2C) == 0)
                h = &l2cap->l2c;
        else if (strcmp(name, NG_L2CAP_HOOK_CTL) == 0)
                h = &l2cap->ctl;
        else
                return (EINVAL);
 
        if (*h != NULL)
                return (EISCONN);
 
        *h = hook;
 
        return (0);
} /* ng_l2cap_newhook */
 
/*
 * Give our final OK to connect hook. Nothing to do here.
 */
 
static int
ng_l2cap_connect(hook_p hook)
{
        ng_l2cap_p      l2cap = (ng_l2cap_p) NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
        int             error = 0;
 
        if (hook == l2cap->hci)
                NG_HOOK_SET_RCVMSG(hook, ng_l2cap_lower_rcvmsg);
        else
        if (hook == l2cap->l2c || hook == l2cap->ctl) {
                NG_HOOK_SET_RCVMSG(hook, ng_l2cap_upper_rcvmsg);
 
                /* Send delayed notification to the upper layer */
                error = ng_send_fn(l2cap->node, hook, ng_l2cap_send_hook_info,
                                NULL, 0);
        } else
                error = EINVAL;
 
        return (error);
} /* ng_l2cap_connect */
 
/*
 * Disconnect the hook. For downstream hook we must notify upper layers.
 * 
 * XXX For upstream hooks this is really ugly :( Hook was disconnected and it 
 * XXX is now too late to do anything. For now we just clean up our own mess
 * XXX and remove all channels that use disconnected upstream hook. If we don't 
 * XXX do that then L2CAP node can get out of sync with upper layers.
 * XXX No notification will be sent to remote peer. 
 */
 
static int
ng_l2cap_disconnect(hook_p hook)
{
        ng_l2cap_p       l2cap = (ng_l2cap_p) NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
        hook_p          *h = NULL;
 
        if (hook == l2cap->hci) {
                ng_l2cap_cleanup(l2cap);
                h = &l2cap->hci;
        } else
        if (hook == l2cap->l2c) {
                ng_l2cap_destroy_channels(l2cap);
                h = &l2cap->l2c;
        } else
        if (hook == l2cap->ctl)
                h = &l2cap->ctl;
        else
                return (EINVAL);
 
        *h = NULL;
 
        /* Shutdown when all hooks are disconnected */
        if (NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0 &&
            NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
                ng_rmnode_self(NG_HOOK_NODE(hook));
 
        return (0);
} /* ng_l2cap_disconnect */
 
/*
 * Process control message from lower layer
 */
 
static int
ng_l2cap_lower_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
        ng_l2cap_p       l2cap = (ng_l2cap_p) NG_NODE_PRIVATE(node);
        struct ng_mesg  *msg = NGI_MSG(item); /* item still has message */
        int              error = 0;
 
        switch (msg->header.typecookie) {
        case NGM_HCI_COOKIE:
                switch (msg->header.cmd) {
                /* HCI node is ready */
                case NGM_HCI_NODE_UP: {
                        ng_hci_node_up_ep       *ep = NULL;
 
                        if (msg->header.arglen != sizeof(*ep))
                                error = EMSGSIZE;
                        else {
                                ep = (ng_hci_node_up_ep *)(msg->data);
 
                                NG_L2CAP_INFO(
"%s: %s - HCI node is up, bdaddr: %x:%x:%x:%x:%x:%x, " \
"pkt_size=%d bytes, num_pkts=%d\n",     __func__, NG_NODE_NAME(l2cap->node),
                                        ep->bdaddr.b[5], ep->bdaddr.b[4],
                                        ep->bdaddr.b[3], ep->bdaddr.b[2],
                                        ep->bdaddr.b[1], ep->bdaddr.b[0],
                                        ep->pkt_size, ep->num_pkts);
 
                                bcopy(&ep->bdaddr, &l2cap->bdaddr,
                                        sizeof(l2cap->bdaddr));
                                l2cap->pkt_size = ep->pkt_size;
                                l2cap->num_pkts = ep->num_pkts;
 
                                /* Notify upper layers */
                                ng_l2cap_send_hook_info(l2cap->node,
                                        l2cap->l2c, NULL, 0);
                                ng_l2cap_send_hook_info(l2cap->node,
                                        l2cap->ctl, NULL, 0);
                        }
                        } break;
 
                case NGM_HCI_SYNC_CON_QUEUE: {
                        ng_hci_sync_con_queue_ep        *ep = NULL;
                        ng_l2cap_con_p                   con = NULL;
 
                        if (msg->header.arglen != sizeof(*ep))
                                error = EMSGSIZE;
                        else {
                                ep = (ng_hci_sync_con_queue_ep *)(msg->data);
                                con = ng_l2cap_con_by_handle(l2cap,
                                                        ep->con_handle);
                                if (con == NULL)
                                        break;
 
                                NG_L2CAP_INFO(
"%s: %s - sync HCI connection queue, con_handle=%d, pending=%d, completed=%d\n",
                                         __func__, NG_NODE_NAME(l2cap->node),
                                        ep->con_handle, con->pending,
                                        ep->completed);
 
                                con->pending -= ep->completed;
                                if (con->pending < 0) {
                                        NG_L2CAP_WARN(
"%s: %s - pending packet counter is out of sync! " \
"con_handle=%d, pending=%d, completed=%d\n",    __func__, 
                                                NG_NODE_NAME(l2cap->node),
                                                con->con_handle, con->pending, 
                                                ep->completed);
 
                                        con->pending = 0;
                                }
 
                                ng_l2cap_lp_deliver(con);
                        }
                        } break;
 
                /* LP_ConnectCfm[Neg] */
                case NGM_HCI_LP_CON_CFM:
                        error = ng_l2cap_lp_con_cfm(l2cap, msg);
                        break;
 
                /* LP_ConnectInd */
                case NGM_HCI_LP_CON_IND:
                        error = ng_l2cap_lp_con_ind(l2cap, msg);
                        break;
 
                /* LP_DisconnectInd */
                case NGM_HCI_LP_DISCON_IND:
                        error = ng_l2cap_lp_discon_ind(l2cap, msg);
                        break;
 
                /* LP_QoSSetupCfm[Neg] */
                case NGM_HCI_LP_QOS_CFM:
                        error = ng_l2cap_lp_qos_cfm(l2cap, msg);
                        break;
 
                /* LP_OoSViolationInd */
                case NGM_HCI_LP_QOS_IND:
                        error = ng_l2cap_lp_qos_ind(l2cap, msg);
                        break;
                case NGM_HCI_LP_ENC_CHG:
                        error = ng_l2cap_lp_enc_change(l2cap, msg);
                        break;
                default:
                        error = EINVAL;
                        break;
                }
                break;
 
        default:
                return (ng_l2cap_default_rcvmsg(node, item, lasthook));
                /* NOT REACHED */
        }
 
        NG_FREE_ITEM(item);
 
        return (error);
} /* ng_l2cap_lower_rcvmsg */
 
/*
 * Process control message from upper layer
 */
 
static int
ng_l2cap_upper_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
        ng_l2cap_p       l2cap = (ng_l2cap_p) NG_NODE_PRIVATE(node);
        struct ng_mesg  *msg = NGI_MSG(item); /* item still has message */
        int              error = 0;
 
        switch (msg->header.typecookie) {
        case NGM_L2CAP_COOKIE:
                switch (msg->header.cmd) {
                /* L2CA_Connect */
                case NGM_L2CAP_L2CA_CON:
                        error = ng_l2cap_l2ca_con_req(l2cap, msg);
                        break;
 
                /* L2CA_ConnectRsp */
                case NGM_L2CAP_L2CA_CON_RSP:
                        error = ng_l2cap_l2ca_con_rsp_req(l2cap, msg);
                        break;
 
                /* L2CA_Config */
                case NGM_L2CAP_L2CA_CFG:
                        error = ng_l2cap_l2ca_cfg_req(l2cap, msg);
                        break;
 
                /* L2CA_ConfigRsp */
                case NGM_L2CAP_L2CA_CFG_RSP:
                        error = ng_l2cap_l2ca_cfg_rsp_req(l2cap, msg);
                        break;
 
                /* L2CA_Disconnect */
                case NGM_L2CAP_L2CA_DISCON:
                        error = ng_l2cap_l2ca_discon_req(l2cap, msg);
                        break;
 
                /* L2CA_GroupCreate */
                case NGM_L2CAP_L2CA_GRP_CREATE:
                        error = ng_l2cap_l2ca_grp_create(l2cap, msg);
                        break;
 
                /* L2CA_GroupClose */
                case NGM_L2CAP_L2CA_GRP_CLOSE:
                        error = ng_l2cap_l2ca_grp_close(l2cap, msg);
                        break;
 
                /* L2CA_GroupAddMember */
                case NGM_L2CAP_L2CA_GRP_ADD_MEMBER:
                        error = ng_l2cap_l2ca_grp_add_member_req(l2cap, msg);
                        break;
 
                /* L2CA_GroupDeleteMember */
                case NGM_L2CAP_L2CA_GRP_REM_MEMBER:
                        error = ng_l2cap_l2ca_grp_rem_member(l2cap, msg);
                        break;
 
                /* L2CA_GroupMembership */
                case NGM_L2CAP_L2CA_GRP_MEMBERSHIP:
                        error = ng_l2cap_l2ca_grp_get_members(l2cap, msg);
                        break;
 
                /* L2CA_Ping */
                case NGM_L2CAP_L2CA_PING:
                        error = ng_l2cap_l2ca_ping_req(l2cap, msg);
                        break;
 
                /* L2CA_GetInfo */
                case NGM_L2CAP_L2CA_GET_INFO:
                        error = ng_l2cap_l2ca_get_info_req(l2cap, msg);
                        break;
 
                /* L2CA_EnableCLT */
                case NGM_L2CAP_L2CA_ENABLE_CLT:
                        error = ng_l2cap_l2ca_enable_clt(l2cap, msg);
                        break;
 
                default:
                        return (ng_l2cap_default_rcvmsg(node, item, lasthook));
                        /* NOT REACHED */
                }
                break;
 
        default:
                return (ng_l2cap_default_rcvmsg(node, item, lasthook));
                /* NOT REACHED */
        }
 
        NG_FREE_ITEM(item);
 
        return (error);
} /* ng_l2cap_upper_rcvmsg */
 
/*
 * Default control message processing routine
 */
 
static int
ng_l2cap_default_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
        ng_l2cap_p       l2cap = (ng_l2cap_p) NG_NODE_PRIVATE(node);
        struct ng_mesg  *msg = NULL, *rsp = NULL;
        int              error = 0;
 
        /* Detach and process message */
        NGI_GET_MSG(item, msg);
 
        switch (msg->header.typecookie) {
        case NGM_GENERIC_COOKIE:
                switch (msg->header.cmd) {
                case NGM_TEXT_STATUS:
                        NG_MKRESPONSE(rsp, msg, NG_TEXTRESPONSE, M_NOWAIT);
                        if (rsp == NULL)
                                error = ENOMEM;
                        else
                                snprintf(rsp->data, NG_TEXTRESPONSE,
                                        "bdaddr %x:%x:%x:%x:%x:%x, " \
                                        "pkt_size %d\n" \
                                        "Hooks %s %s %s\n" \
                                        "Flags %#x\n",
                                        l2cap->bdaddr.b[5], l2cap->bdaddr.b[4],
                                        l2cap->bdaddr.b[3], l2cap->bdaddr.b[2],
                                        l2cap->bdaddr.b[1], l2cap->bdaddr.b[0],
                                        l2cap->pkt_size,
                                        (l2cap->hci != NULL)?
                                                NG_L2CAP_HOOK_HCI : "",
                                        (l2cap->l2c != NULL)?
                                                NG_L2CAP_HOOK_L2C : "", 
                                        (l2cap->ctl != NULL)?
                                                NG_L2CAP_HOOK_CTL : "", 
                                        l2cap->flags);
                        break;
 
                default:
                        error = EINVAL;
                        break;
                }
                break;
 
        /* Messages from the upper layer or directed to the local node */
        case NGM_L2CAP_COOKIE:
                switch (msg->header.cmd) {
                /* Get node flags */
                case NGM_L2CAP_NODE_GET_FLAGS:
                        NG_MKRESPONSE(rsp, msg, sizeof(ng_l2cap_node_flags_ep),
                                M_NOWAIT);
                        if (rsp == NULL)
                                error = ENOMEM;
                        else
                                *((ng_l2cap_node_flags_ep *)(rsp->data)) =
                                        l2cap->flags;
                        break;
 
                /* Get node debug */
                case NGM_L2CAP_NODE_GET_DEBUG:
                        NG_MKRESPONSE(rsp, msg, sizeof(ng_l2cap_node_debug_ep),
                                M_NOWAIT);
                        if (rsp == NULL)
                                error = ENOMEM;
                        else
                                *((ng_l2cap_node_debug_ep *)(rsp->data)) =
                                        l2cap->debug;
                        break;
 
                /* Set node debug */
                case NGM_L2CAP_NODE_SET_DEBUG:
                        if (msg->header.arglen !=
                                        sizeof(ng_l2cap_node_debug_ep))
                                error = EMSGSIZE;
                        else
                                l2cap->debug =
                                        *((ng_l2cap_node_debug_ep *)(msg->data));
                        break;
 
                /* Get connection list */
                case NGM_L2CAP_NODE_GET_CON_LIST: {
                        ng_l2cap_con_p                   con = NULL;
                        ng_l2cap_node_con_list_ep       *e1 = NULL;
                        ng_l2cap_node_con_ep            *e2 = NULL;
                        int                              n = 0;
 
                        /* Count number of connections */
                        LIST_FOREACH(con, &l2cap->con_list, next)
                                n++;
                        if (n > NG_L2CAP_MAX_CON_NUM)
                                n = NG_L2CAP_MAX_CON_NUM;
 
                        /* Prepare response */
                        NG_MKRESPONSE(rsp, msg,
                                sizeof(*e1) + n * sizeof(*e2), M_NOWAIT);
                        if (rsp == NULL) {
                                error = ENOMEM;
                                break;
                        }
 
                        e1 = (ng_l2cap_node_con_list_ep *)(rsp->data);
                        e2 = (ng_l2cap_node_con_ep *)(e1 + 1);
 
                        e1->num_connections = n;
 
                        LIST_FOREACH(con, &l2cap->con_list, next) {
                                e2->state = con->state;
 
                                e2->flags = con->flags;
                                if (con->tx_pkt != NULL)
                                        e2->flags |= NG_L2CAP_CON_TX;
                                if (con->rx_pkt != NULL)
                                        e2->flags |= NG_L2CAP_CON_RX;
 
                                e2->pending = con->pending;
 
                                e2->con_handle = con->con_handle;
                                bcopy(&con->remote, &e2->remote,
                                        sizeof(e2->remote));
 
                                e2 ++;
                                if (--n <= 0)
                                        break;
                        }
                        } break;
 
                /* Get channel list */
                case NGM_L2CAP_NODE_GET_CHAN_LIST: {
                        ng_l2cap_chan_p                  ch = NULL;
                        ng_l2cap_node_chan_list_ep      *e1 = NULL;
                        ng_l2cap_node_chan_ep           *e2 = NULL;
                        int                              n = 0;
 
                        /* Count number of channels */
                        LIST_FOREACH(ch, &l2cap->chan_list, next)
                                n ++;
                        if (n > NG_L2CAP_MAX_CHAN_NUM)
                                n = NG_L2CAP_MAX_CHAN_NUM;
 
                        /* Prepare response */
                        NG_MKRESPONSE(rsp, msg,
                                sizeof(ng_l2cap_node_chan_list_ep) +
                                n * sizeof(ng_l2cap_node_chan_ep), M_NOWAIT);
                        if (rsp == NULL) {
                                error = ENOMEM;
                                break;
                        }
 
                        e1 = (ng_l2cap_node_chan_list_ep *)(rsp->data);
                        e2 = (ng_l2cap_node_chan_ep *)(e1 + 1);
 
                        e1->num_channels = n;
 
                        LIST_FOREACH(ch, &l2cap->chan_list, next) {
                                e2->state = ch->state;
 
                                e2->scid = ch->scid;
                                e2->dcid = ch->dcid;
 
                                e2->imtu = ch->imtu;
                                e2->omtu = ch->omtu;
 
                                e2->psm = ch->psm;
                                bcopy(&ch->con->remote, &e2->remote,
                                        sizeof(e2->remote));
 
                                e2 ++;
                                if (--n <= 0)
                                        break;
                        }
                        } break;
 
                case NGM_L2CAP_NODE_GET_AUTO_DISCON_TIMO:
                        NG_MKRESPONSE(rsp, msg,
                                sizeof(ng_l2cap_node_auto_discon_ep), M_NOWAIT);
                        if (rsp == NULL)
                                error = ENOMEM;
                        else
                                *((ng_l2cap_node_auto_discon_ep *)(rsp->data)) =
                                        l2cap->discon_timo;
                        break;
 
                case NGM_L2CAP_NODE_SET_AUTO_DISCON_TIMO:
                        if (msg->header.arglen !=
                                        sizeof(ng_l2cap_node_auto_discon_ep))
                                error = EMSGSIZE;
                        else
                                l2cap->discon_timo =
                                        *((ng_l2cap_node_auto_discon_ep *)
                                                        (msg->data));
                        break;
 
                default:
                        error = EINVAL;
                        break;
                }
                break;
 
        default:
                error = EINVAL;
                break;
        }
 
        NG_RESPOND_MSG(error, node, item, rsp);
        NG_FREE_MSG(msg);
 
        return (error);
} /* ng_l2cap_rcvmsg */
 
/*
 * Process data packet from one of our hooks.
 *
 * From the HCI hook we expect to receive ACL data packets. ACL data packets 
 * gets re-assembled into one L2CAP packet (according to length) and then gets 
 * processed.
 *
 * NOTE: We expect to receive L2CAP packet header in the first fragment. 
 *       Otherwise we WILL NOT be able to get length of the L2CAP packet.
 * 
 * Signaling L2CAP packets (destination channel ID == 0x1) are processed within
 * the node. Connectionless data packets (destination channel ID == 0x2) will 
 * be forwarded to appropriate upstream hook unless it is not connected or 
 * connectionless traffic for the specified PSM was disabled.
 *
 * From the upstream hooks we expect to receive data packets. These data 
 * packets will be converted into L2CAP data packets. The length of each
 * L2CAP packet must not exceed channel's omtu (our peer's imtu). Then
 * these L2CAP packets will be converted to ACL data packets (according to 
 * HCI layer MTU) and sent to lower layer.
 *
 * No data is expected from the control hook.
 */
 
static int
ng_l2cap_rcvdata(hook_p hook, item_p item)
{
        ng_l2cap_p       l2cap = (ng_l2cap_p) NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
        struct mbuf     *m = NULL;
        int              error = 0;
 
        /* Detach mbuf, discard item and process data */
        NGI_GET_M(item, m);
        NG_FREE_ITEM(item);
 
        if (hook == l2cap->hci)
                error = ng_l2cap_lp_receive(l2cap, m);
        else if (hook == l2cap->l2c)
                error = ng_l2cap_l2ca_write_req(l2cap, m);
        else {
                NG_FREE_M(m);
                error = EINVAL;
        }
 
        return (error);
} /* ng_l2cap_rcvdata */
 
/*
 * Clean all connections, channels and commands for the L2CAP node
 */
 
static void
ng_l2cap_cleanup(ng_l2cap_p l2cap)
{
        ng_l2cap_con_p  con = NULL;
 
        /* Clean up connection and channels */
        while (!LIST_EMPTY(&l2cap->con_list)) {
                con = LIST_FIRST(&l2cap->con_list);
 
                if (con->flags & NG_L2CAP_CON_LP_TIMO)
                        ng_l2cap_lp_untimeout(con);
                else if (con->flags & NG_L2CAP_CON_AUTO_DISCON_TIMO)
                        ng_l2cap_discon_untimeout(con);
 
                /* Connection terminated by local host */
                ng_l2cap_con_fail(con, 0x16);
        }
} /* ng_l2cap_cleanup */
 
/*
 * Destroy all channels that use specified upstream hook
 */
 
static void
ng_l2cap_destroy_channels(ng_l2cap_p l2cap)
{
        while (!LIST_EMPTY(&l2cap->chan_list))
                ng_l2cap_free_chan(LIST_FIRST(&l2cap->chan_list));
} /* ng_l2cap_destroy_channels_by_hook */