/*
 * ng_hci_main.c
 */

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * 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_hci_main.c,v 1.2 2003/03/18 00:09:36 max Exp $
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/endian.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/hci/ng_hci_var.h>
#include <netgraph/bluetooth/hci/ng_hci_prse.h>
#include <netgraph/bluetooth/hci/ng_hci_cmds.h>
#include <netgraph/bluetooth/hci/ng_hci_evnt.h>
#include <netgraph/bluetooth/hci/ng_hci_ulpi.h>
#include <netgraph/bluetooth/hci/ng_hci_misc.h>

/******************************************************************************
 ******************************************************************************
 **     This node implements Bluetooth Host Controller Interface (HCI)
 ******************************************************************************
 ******************************************************************************/

/* MALLOC define */
#ifdef NG_SEPARATE_MALLOC
MALLOC_DEFINE(M_NETGRAPH_HCI, "netgraph_hci", "Netgraph Bluetooth HCI node");
#else
#define M_NETGRAPH_HCI M_NETGRAPH
#endif /* NG_SEPARATE_MALLOC */

/* Netgraph node methods */
static  ng_constructor_t        ng_hci_constructor;
static  ng_shutdown_t           ng_hci_shutdown;
static  ng_newhook_t            ng_hci_newhook;
static  ng_connect_t            ng_hci_connect;
static  ng_disconnect_t         ng_hci_disconnect;
static  ng_rcvmsg_t             ng_hci_default_rcvmsg;
static  ng_rcvmsg_t             ng_hci_upper_rcvmsg;
static  ng_rcvdata_t            ng_hci_drv_rcvdata;
static  ng_rcvdata_t            ng_hci_acl_rcvdata;
static  ng_rcvdata_t            ng_hci_sco_rcvdata;
static  ng_rcvdata_t            ng_hci_raw_rcvdata;

/* Netgraph node type descriptor */
static  struct ng_type          typestruct = {
        .version =      NG_ABI_VERSION,
        .name =         NG_HCI_NODE_TYPE,
        .constructor =  ng_hci_constructor,
        .rcvmsg =       ng_hci_default_rcvmsg,
        .shutdown =     ng_hci_shutdown,
        .newhook =      ng_hci_newhook,
        .connect =      ng_hci_connect,
        .rcvdata =      ng_hci_drv_rcvdata,
        .disconnect =   ng_hci_disconnect,
        .cmdlist =      ng_hci_cmdlist,
};
NETGRAPH_INIT(hci, &typestruct);
MODULE_VERSION(ng_hci, NG_BLUETOOTH_VERSION);
MODULE_DEPEND(ng_hci, ng_bluetooth, NG_BLUETOOTH_VERSION,
        NG_BLUETOOTH_VERSION, NG_BLUETOOTH_VERSION);
static int ng_hci_linktype_to_addrtype(int linktype);

static int ng_hci_linktype_to_addrtype(int linktype)
{
        switch(linktype){
        case NG_HCI_LINK_LE_PUBLIC:
                return BDADDR_LE_PUBLIC;
        case NG_HCI_LINK_LE_RANDOM:
                return BDADDR_LE_RANDOM;
        case NG_HCI_LINK_ACL:
                /*FALLTHROUGH*/
        default:
                return BDADDR_BREDR;
        }
        return BDADDR_BREDR;
}
/*****************************************************************************
 *****************************************************************************
 **                   Netgraph methods implementation
 *****************************************************************************
 *****************************************************************************/

/*
 * Create new instance of HCI node (new unit)
 */

static int
ng_hci_constructor(node_p node)
{
        ng_hci_unit_p   unit = NULL;

        unit = malloc(sizeof(*unit), M_NETGRAPH_HCI, M_WAITOK | M_ZERO);

        unit->node = node;
        unit->debug = NG_HCI_WARN_LEVEL;

        unit->link_policy_mask = 0xffff; /* Enable all supported modes */
        unit->packet_mask = 0xffff; /* Enable all packet types */
        unit->role_switch = 1; /* Enable role switch (if device supports it) */

        /*
         * Set default buffer info
         *
         * One HCI command
         * One ACL packet with max. size of 17 bytes (1 DM1 packet)
         * One SCO packet with max. size of 10 bytes (1 HV1 packet)
         */

        NG_HCI_BUFF_CMD_SET(unit->buffer, 1);
        NG_HCI_BUFF_ACL_SET(unit->buffer, 1, 17, 1);  
        NG_HCI_BUFF_SCO_SET(unit->buffer, 1, 10, 1);

        /* Init command queue & command timeout handler */
        ng_callout_init(&unit->cmd_timo);
        NG_BT_MBUFQ_INIT(&unit->cmdq, NG_HCI_CMD_QUEUE_LEN);

        /* Init lists */
        LIST_INIT(&unit->con_list);
        LIST_INIT(&unit->neighbors);

        /*
         * This node has to be a WRITER because both data and messages
         * can change node state. 
         */

        NG_NODE_FORCE_WRITER(node);
        NG_NODE_SET_PRIVATE(node, unit);

        return (0);
} /* ng_hci_constructor */

/*
 * Destroy the node
 */

static int
ng_hci_shutdown(node_p node)
{
        ng_hci_unit_p   unit = (ng_hci_unit_p) NG_NODE_PRIVATE(node);

        NG_NODE_SET_PRIVATE(node, NULL);
        NG_NODE_UNREF(node);

        unit->node = NULL;
        ng_hci_unit_clean(unit, 0x16 /* Connection terminated by local host */);

        NG_BT_MBUFQ_DESTROY(&unit->cmdq);

        bzero(unit, sizeof(*unit));
        free(unit, M_NETGRAPH_HCI);

        return (0);
} /* ng_hci_shutdown */

/*
 * Give our OK for a hook to be added. Unit driver is connected to the driver 
 * (NG_HCI_HOOK_DRV) hook. Upper layer protocols are connected to appropriate
 * (NG_HCI_HOOK_ACL or NG_HCI_HOOK_SCO) hooks.
 */

static int
ng_hci_newhook(node_p node, hook_p hook, char const *name)
{
        ng_hci_unit_p    unit = (ng_hci_unit_p) NG_NODE_PRIVATE(node);
        hook_p          *h = NULL;

        if (strcmp(name, NG_HCI_HOOK_DRV) == 0)
                h = &unit->drv;
        else if (strcmp(name, NG_HCI_HOOK_ACL) == 0)
                h = &unit->acl;
        else if (strcmp(name, NG_HCI_HOOK_SCO) == 0)
                h = &unit->sco;
        else if (strcmp(name, NG_HCI_HOOK_RAW) == 0)
                h = &unit->raw;
        else
                return (EINVAL);

        if (*h != NULL)
                return (EISCONN);

        *h = hook;

        return (0);
} /* ng_hci_newhook */

/*
 * Give our final OK to connect hook
 */

static int
ng_hci_connect(hook_p hook)
{
        ng_hci_unit_p   unit = (ng_hci_unit_p) NG_NODE_PRIVATE(NG_HOOK_NODE(hook));

        if (hook != unit->drv) {
                if (hook == unit->acl) {
                        NG_HOOK_SET_RCVMSG(hook, ng_hci_upper_rcvmsg);
                        NG_HOOK_SET_RCVDATA(hook, ng_hci_acl_rcvdata);
                } else if (hook == unit->sco) {
                        NG_HOOK_SET_RCVMSG(hook, ng_hci_upper_rcvmsg);
                        NG_HOOK_SET_RCVDATA(hook, ng_hci_sco_rcvdata);
                } else
                        NG_HOOK_SET_RCVDATA(hook, ng_hci_raw_rcvdata);

                /* Send delayed notification to the upper layers */
                if (hook != unit->raw) 
                        ng_send_fn(unit->node, hook, ng_hci_node_is_up, NULL,0);
        } else
                unit->state |= NG_HCI_UNIT_CONNECTED;

        return (0);
} /* ng_hci_connect */

/*
 * Disconnect the hook
 */

static int
ng_hci_disconnect(hook_p hook)
{
        ng_hci_unit_p    unit = (ng_hci_unit_p) NG_NODE_PRIVATE(NG_HOOK_NODE(hook));

        if (hook == unit->acl)
                unit->acl = NULL;
        else if (hook == unit->sco)
                unit->sco = NULL;
        else if (hook == unit->raw)
                unit->raw = NULL;
        else if (hook == unit->drv) {
                unit->drv = NULL;

                /* Connection terminated by local host */
                ng_hci_unit_clean(unit, 0x16);
                unit->state &= ~(NG_HCI_UNIT_CONNECTED|NG_HCI_UNIT_INITED);
        } else
                return (EINVAL);

        /* 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_hci_disconnect */

/*
 * Default control message processing routine. Control message could be:
 *
 * 1) GENERIC Netgraph messages
 *
 * 2) Control message directed to the node itself.
 */

static int
ng_hci_default_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
        ng_hci_unit_p    unit = (ng_hci_unit_p) NG_NODE_PRIVATE(node);
        struct ng_mesg  *msg = NULL, *rsp = NULL;
        int              error = 0;

        NGI_GET_MSG(item, msg); 

        switch (msg->header.typecookie) {
        case NGM_GENERIC_COOKIE:
                switch (msg->header.cmd) {
                case NGM_TEXT_STATUS: {
                        int     cmd_avail,
                                acl_total, acl_avail, acl_size,
                                sco_total, sco_avail, sco_size;

                        NG_MKRESPONSE(rsp, msg, NG_TEXTRESPONSE, M_NOWAIT);
                        if (rsp == NULL) {
                                error = ENOMEM;
                                break;
                        }

                        NG_HCI_BUFF_CMD_GET(unit->buffer, cmd_avail);

                        NG_HCI_BUFF_ACL_AVAIL(unit->buffer, acl_avail);
                        NG_HCI_BUFF_ACL_TOTAL(unit->buffer, acl_total);
                        NG_HCI_BUFF_ACL_SIZE(unit->buffer, acl_size);

                        NG_HCI_BUFF_SCO_AVAIL(unit->buffer, sco_avail);
                        NG_HCI_BUFF_SCO_TOTAL(unit->buffer, sco_total);
                        NG_HCI_BUFF_SCO_SIZE(unit->buffer, sco_size);

                        snprintf(rsp->data, NG_TEXTRESPONSE,
                                "bdaddr %x:%x:%x:%x:%x:%x\n" \
                                "Hooks  %s %s %s %s\n" \
                                "State  %#x\n" \
                                "Queue  cmd:%d\n" \
                                "Buffer cmd:%d,acl:%d,%d,%d,sco:%d,%d,%d",
                                unit->bdaddr.b[5], unit->bdaddr.b[4],
                                unit->bdaddr.b[3], unit->bdaddr.b[2],
                                unit->bdaddr.b[1], unit->bdaddr.b[0],
                                (unit->drv != NULL)? NG_HCI_HOOK_DRV : "",
                                (unit->acl != NULL)? NG_HCI_HOOK_ACL : "",
                                (unit->sco != NULL)? NG_HCI_HOOK_SCO : "",
                                (unit->raw != NULL)? NG_HCI_HOOK_RAW : "",
                                unit->state,
                                NG_BT_MBUFQ_LEN(&unit->cmdq),
                                cmd_avail,
                                acl_avail, acl_total, acl_size, 
                                sco_avail, sco_total, sco_size);
                        } break;

                default:
                        error = EINVAL;
                        break;
                }
                break;

        case NGM_HCI_COOKIE:
                switch (msg->header.cmd) {
                /* Get current node state */
                case NGM_HCI_NODE_GET_STATE:
                        NG_MKRESPONSE(rsp, msg, sizeof(unit->state), M_NOWAIT);
                        if (rsp == NULL) {
                                error = ENOMEM;
                                break;
                        }

                        *((ng_hci_node_state_ep *)(rsp->data)) = unit->state;
                        break;

                /* Turn INITED bit - node initialized */
                case NGM_HCI_NODE_INIT:
                        if (bcmp(&unit->bdaddr, NG_HCI_BDADDR_ANY,
                                        sizeof(bdaddr_t)) == 0) {
                                error = ENXIO;
                                break;
                        }
                                
                        unit->state |= NG_HCI_UNIT_INITED;

                        ng_hci_node_is_up(unit->node, unit->acl, NULL, 0);
                        ng_hci_node_is_up(unit->node, unit->sco, NULL, 0);
                        break;

                /* Get node debug level */
                case NGM_HCI_NODE_GET_DEBUG:
                        NG_MKRESPONSE(rsp, msg, sizeof(unit->debug), M_NOWAIT);
                        if (rsp == NULL) {
                                error = ENOMEM;
                                break;
                        }

                        *((ng_hci_node_debug_ep *)(rsp->data)) = unit->debug;
                        break;

                /* Set node debug level */
                case NGM_HCI_NODE_SET_DEBUG:
                        if (msg->header.arglen != sizeof(ng_hci_node_debug_ep)){
                                error = EMSGSIZE;
                                break;
                        }

                        unit->debug = *((ng_hci_node_debug_ep *)(msg->data));
                        break;

                /* Get buffer info */
                case NGM_HCI_NODE_GET_BUFFER: {
                        ng_hci_node_buffer_ep   *ep = NULL;

                        NG_MKRESPONSE(rsp, msg, sizeof(ng_hci_node_buffer_ep),
                                M_NOWAIT);
                        if (rsp == NULL) {
                                error = ENOMEM;
                                break;
                        }

                        ep = (ng_hci_node_buffer_ep *)(rsp->data);

                        NG_HCI_BUFF_CMD_GET(unit->buffer, ep->cmd_free);
                        NG_HCI_BUFF_ACL_AVAIL(unit->buffer, ep->acl_free);
                        NG_HCI_BUFF_ACL_TOTAL(unit->buffer, ep->acl_pkts);
                        NG_HCI_BUFF_ACL_SIZE(unit->buffer, ep->acl_size);
                        NG_HCI_BUFF_SCO_AVAIL(unit->buffer, ep->sco_free);
                        NG_HCI_BUFF_SCO_TOTAL(unit->buffer, ep->sco_pkts);
                        NG_HCI_BUFF_SCO_SIZE(unit->buffer, ep->sco_size);
                        } break;

                /* Get BDADDR */
                case NGM_HCI_NODE_GET_BDADDR:
                        NG_MKRESPONSE(rsp, msg, sizeof(bdaddr_t), M_NOWAIT);
                        if (rsp == NULL) {
                                error = ENOMEM;
                                break;
                        }

                        bcopy(&unit->bdaddr, rsp->data, sizeof(bdaddr_t));
                        break;

                /* Get features */
                case NGM_HCI_NODE_GET_FEATURES:
                        NG_MKRESPONSE(rsp,msg,sizeof(unit->features),M_NOWAIT);
                        if (rsp == NULL) {
                                error = ENOMEM;
                                break;
                        }

                        bcopy(&unit->features,rsp->data,sizeof(unit->features));
                        break;

                /* Get stat */
                case NGM_HCI_NODE_GET_STAT:
                        NG_MKRESPONSE(rsp, msg, sizeof(unit->stat), M_NOWAIT);
                        if (rsp == NULL) {
                                error = ENOMEM;
                                break;
                        }

                        bcopy(&unit->stat, rsp->data, sizeof(unit->stat));
                        break;

                /* Reset stat */
                case NGM_HCI_NODE_RESET_STAT:
                        NG_HCI_STAT_RESET(unit->stat);
                        break;

                /* Clean up neighbors list */
                case NGM_HCI_NODE_FLUSH_NEIGHBOR_CACHE:
                        ng_hci_flush_neighbor_cache(unit);
                        break;

                /* Get neighbor cache entries */
                case NGM_HCI_NODE_GET_NEIGHBOR_CACHE: {
                        ng_hci_neighbor_p                        n = NULL;
                        ng_hci_node_get_neighbor_cache_ep       *e1 = NULL;
                        ng_hci_node_neighbor_cache_entry_ep     *e2 = NULL;
                        int                                      s = 0;

                        /* Look for the fresh entries in the cache */
                        for (n = LIST_FIRST(&unit->neighbors); n != NULL; ) {
                                ng_hci_neighbor_p       nn = LIST_NEXT(n, next);

                                if (ng_hci_neighbor_stale(n))
                                        ng_hci_free_neighbor(n);
                                else
                                        s ++;

                                n = nn;
                        }
                        if (s > NG_HCI_MAX_NEIGHBOR_NUM)
                                s = NG_HCI_MAX_NEIGHBOR_NUM;

                        /* Prepare response */
                        NG_MKRESPONSE(rsp, msg, sizeof(*e1) + s * sizeof(*e2),
                                M_NOWAIT);
                        if (rsp == NULL) {
                                error = ENOMEM;
                                break;
                        }

                        e1 = (ng_hci_node_get_neighbor_cache_ep *)(rsp->data);
                        e2 = (ng_hci_node_neighbor_cache_entry_ep *)(e1 + 1);

                        e1->num_entries = s;

                        LIST_FOREACH(n, &unit->neighbors, next) {
                                e2->page_scan_rep_mode = n->page_scan_rep_mode;
                                e2->page_scan_mode = n->page_scan_mode;
                                e2->clock_offset = n->clock_offset;
                                e2->addrtype =
                                        ng_hci_linktype_to_addrtype(n->addrtype);
                                e2->extinq_size = n->extinq_size;
                                bcopy(&n->bdaddr, &e2->bdaddr, 
                                        sizeof(e2->bdaddr));
                                bcopy(&n->features, &e2->features,
                                        sizeof(e2->features));
                                bcopy(&n->extinq_data, &e2->extinq_data,
                                      n->extinq_size);
                                e2 ++;
                                if (--s <= 0)
                                        break;
                        }
                        } break;

                /* Get connection list */
                case NGM_HCI_NODE_GET_CON_LIST: {
                        ng_hci_unit_con_p        c = NULL;
                        ng_hci_node_con_list_ep *e1 = NULL;
                        ng_hci_node_con_ep      *e2 = NULL;
                        int                      s = 0;

                        /* Count number of connections in the list */
                        LIST_FOREACH(c, &unit->con_list, next)
                                s ++;
                        if (s > NG_HCI_MAX_CON_NUM)
                                s = NG_HCI_MAX_CON_NUM;

                        /* Prepare response */
                        NG_MKRESPONSE(rsp, msg, sizeof(*e1) + s * sizeof(*e2), 
                                M_NOWAIT);
                        if (rsp == NULL) {
                                error = ENOMEM;
                                break;
                        }

                        e1 = (ng_hci_node_con_list_ep *)(rsp->data);
                        e2 = (ng_hci_node_con_ep *)(e1 + 1);

                        e1->num_connections = s;

                        LIST_FOREACH(c, &unit->con_list, next) {
                                e2->link_type = c->link_type;
                                e2->encryption_mode= c->encryption_mode;
                                e2->mode = c->mode;
                                e2->role = c->role;

                                e2->state = c->state;

                                e2->pending = c->pending;
                                e2->queue_len = NG_BT_ITEMQ_LEN(&c->conq);

                                e2->con_handle = c->con_handle;
                                bcopy(&c->bdaddr, &e2->bdaddr, 
                                        sizeof(e2->bdaddr));

                                e2 ++;
                                if (--s <= 0)
                                        break;
                        }
                        } break;

                /* Get link policy settings mask */
                case NGM_HCI_NODE_GET_LINK_POLICY_SETTINGS_MASK:
                        NG_MKRESPONSE(rsp, msg, sizeof(unit->link_policy_mask),
                                M_NOWAIT);
                        if (rsp == NULL) {
                                error = ENOMEM;
                                break;
                        }

                        *((ng_hci_node_link_policy_mask_ep *)(rsp->data)) = 
                                unit->link_policy_mask;
                        break;

                /* Set link policy settings mask */
                case NGM_HCI_NODE_SET_LINK_POLICY_SETTINGS_MASK:
                        if (msg->header.arglen !=
                                sizeof(ng_hci_node_link_policy_mask_ep)) {
                                error = EMSGSIZE;
                                break;
                        }

                        unit->link_policy_mask = 
                                *((ng_hci_node_link_policy_mask_ep *)
                                        (msg->data));
                        break;

                /* Get packet mask */
                case NGM_HCI_NODE_GET_PACKET_MASK:
                        NG_MKRESPONSE(rsp, msg, sizeof(unit->packet_mask),
                                M_NOWAIT);
                        if (rsp == NULL) {
                                error = ENOMEM;
                                break;
                        }

                        *((ng_hci_node_packet_mask_ep *)(rsp->data)) = 
                                unit->packet_mask;
                        break;

                /* Set packet mask */
                case NGM_HCI_NODE_SET_PACKET_MASK:
                        if (msg->header.arglen !=
                                        sizeof(ng_hci_node_packet_mask_ep)) {
                                error = EMSGSIZE;
                                break;
                        }

                        unit->packet_mask = 
                                *((ng_hci_node_packet_mask_ep *)(msg->data));
                        break;

                /* Get role switch */
                case NGM_HCI_NODE_GET_ROLE_SWITCH:
                        NG_MKRESPONSE(rsp, msg, sizeof(unit->role_switch),
                                M_NOWAIT);
                        if (rsp == NULL) {
                                error = ENOMEM;
                                break;
                        }

                        *((ng_hci_node_role_switch_ep *)(rsp->data)) = 
                                unit->role_switch;
                        break;

                /* Set role switch */
                case NGM_HCI_NODE_SET_ROLE_SWITCH:
                        if (msg->header.arglen !=
                                        sizeof(ng_hci_node_role_switch_ep)) {
                                error = EMSGSIZE;
                                break;
                        }

                        unit->role_switch = 
                                *((ng_hci_node_role_switch_ep *)(msg->data));
                        break;

                default:
                        error = EINVAL;
                        break;
                }
                break;

        default:
                error = EINVAL;
                break;
        }

        /* NG_RESPOND_MSG should take care of "item" and "rsp" */
        NG_RESPOND_MSG(error, node, item, rsp);
        NG_FREE_MSG(msg);

        return (error);
} /* ng_hci_default_rcvmsg */

/*
 * Process control message from upstream hooks (ACL and SCO).
 * Handle LP_xxx messages here, give everything else to default routine.
 */

static int
ng_hci_upper_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
        ng_hci_unit_p   unit = (ng_hci_unit_p) NG_NODE_PRIVATE(node);
        int             error = 0;

        switch (NGI_MSG(item)->header.typecookie) {
        case NGM_HCI_COOKIE:
                switch (NGI_MSG(item)->header.cmd) {
                case NGM_HCI_LP_CON_REQ:
                        error = ng_hci_lp_con_req(unit, item, lasthook);
                        break;

                case NGM_HCI_LP_DISCON_REQ: /* XXX not defined by specs */
                        error = ng_hci_lp_discon_req(unit, item, lasthook);
                        break;

                case NGM_HCI_LP_CON_RSP:
                        error = ng_hci_lp_con_rsp(unit, item, lasthook);
                        break;

                case NGM_HCI_LP_QOS_REQ:
                        error = ng_hci_lp_qos_req(unit, item, lasthook);
                        break;

                default:
                        error = ng_hci_default_rcvmsg(node, item, lasthook);
                        break;
                }
                break;

        default:
                error = ng_hci_default_rcvmsg(node, item, lasthook);
                break;
        }

        return (error);
} /* ng_hci_upper_rcvmsg */

/*
 * Process data packet from the driver hook. 
 * We expect HCI events, ACL or SCO data packets.
 */

static int
ng_hci_drv_rcvdata(hook_p hook, item_p item)
{
        ng_hci_unit_p    unit = (ng_hci_unit_p) NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
        struct mbuf     *m = NULL;
        int              error = 0;

        /* Process packet */
        m = NGI_M(item); /* item still has mbuf, just peeking */
        m->m_flags |= M_PROTO1; /* mark as incoming packet */

        NG_HCI_STAT_BYTES_RECV(unit->stat, m->m_pkthdr.len);

        /* Give copy packet to RAW hook */
        ng_hci_mtap(unit, m);

        /*
         * XXX XXX XXX
         * Lower layer drivers MUST NOT send mbuf chain with empty mbuf at
         * the beginning of the chain. HCI layer WILL NOT call m_pullup() here.
         */

        switch (*mtod(m, u_int8_t *)) {
        case NG_HCI_ACL_DATA_PKT:
                NG_HCI_STAT_ACL_RECV(unit->stat);

                if ((unit->state & NG_HCI_UNIT_READY) != NG_HCI_UNIT_READY ||
                    unit->acl == NULL || NG_HOOK_NOT_VALID(unit->acl)) {
                        NG_HCI_WARN(
"%s: %s - could not forward HCI ACL data packet, state=%#x, hook=%p\n",
                                __func__, NG_NODE_NAME(unit->node), 
                                unit->state, unit->acl);

                        NG_FREE_ITEM(item);
                } else
                        NG_FWD_ITEM_HOOK(error, item, unit->acl);
                break;

        case NG_HCI_SCO_DATA_PKT:
                NG_HCI_STAT_SCO_RECV(unit->stat);

                if ((unit->state & NG_HCI_UNIT_READY) != NG_HCI_UNIT_READY ||
                    unit->sco == NULL || NG_HOOK_NOT_VALID(unit->sco)) {
                        NG_HCI_INFO(
"%s: %s - could not forward HCI SCO data packet, state=%#x, hook=%p\n",
                                __func__, NG_NODE_NAME(unit->node), 
                                unit->state, unit->sco);

                        NG_FREE_ITEM(item);
                } else
                        NG_FWD_ITEM_HOOK(error, item, unit->sco);
                break;

        case NG_HCI_EVENT_PKT:
                NG_HCI_STAT_EVNT_RECV(unit->stat);

                /* Detach mbuf, discard item and process event */
                NGI_GET_M(item, m);
                NG_FREE_ITEM(item);

                error = ng_hci_process_event(unit, m);
                break;
                
        default:
                NG_HCI_ALERT(
"%s: %s - got unknown HCI packet type=%#x\n",
                        __func__, NG_NODE_NAME(unit->node),
                        *mtod(m, u_int8_t *));

                NG_FREE_ITEM(item);

                error = EINVAL;
                break;
        }

        return (error);
} /* ng_hci_drv_rcvdata */

/*
 * Process data packet from ACL upstream hook.
 * We expect valid HCI ACL data packets.
 */

static int
ng_hci_acl_rcvdata(hook_p hook, item_p item)
{
        ng_hci_unit_p            unit = (ng_hci_unit_p) NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
        struct mbuf             *m = NULL;
        ng_hci_unit_con_p        con = NULL;
        u_int16_t                con_handle;
        int                      size, error = 0;

        NG_HCI_BUFF_ACL_SIZE(unit->buffer, size);
        /* Check packet */
        NGI_GET_M(item, m);

        if (*mtod(m, u_int8_t *) != NG_HCI_ACL_DATA_PKT) {
                NG_HCI_ALERT(
"%s: %s - invalid HCI data packet type=%#x\n",
                        __func__, NG_NODE_NAME(unit->node),
                        *mtod(m, u_int8_t *));

                error = EINVAL;
                goto drop;
        }
        if (m->m_pkthdr.len < sizeof(ng_hci_acldata_pkt_t) ||
            m->m_pkthdr.len > sizeof(ng_hci_acldata_pkt_t) + size) {
                NG_HCI_ALERT(
"%s: %s - invalid HCI ACL data packet, len=%d, mtu=%d\n",
                        __func__, NG_NODE_NAME(unit->node), 
                        m->m_pkthdr.len, size);

                error = EMSGSIZE;
                goto drop;
        }

        NG_HCI_M_PULLUP(m, sizeof(ng_hci_acldata_pkt_t));
        if (m == NULL) {
                error = ENOBUFS;
                goto drop;
        }

        con_handle = NG_HCI_CON_HANDLE(le16toh(
                        mtod(m, ng_hci_acldata_pkt_t *)->con_handle));
        size = le16toh(mtod(m, ng_hci_acldata_pkt_t *)->length);

        if (m->m_pkthdr.len != sizeof(ng_hci_acldata_pkt_t) + size) {
                NG_HCI_ALERT(
"%s: %s - invalid HCI ACL data packet size, len=%d, length=%d\n",
                        __func__, NG_NODE_NAME(unit->node), 
                        m->m_pkthdr.len, size);

                error = EMSGSIZE;
                goto drop;
        }

        /* Queue packet */
        con = ng_hci_con_by_handle(unit, con_handle);
        if (con == NULL) {
                NG_HCI_ERR(
"%s: %s - unexpected HCI ACL data packet. Connection does not exists, " \
"con_handle=%d\n",      __func__, NG_NODE_NAME(unit->node), con_handle);

                error = ENOENT;
                goto drop;
        }

        if (con->link_type == NG_HCI_LINK_SCO) {
                NG_HCI_ERR(
"%s: %s - unexpected HCI ACL data packet. Not ACL link, con_handle=%d, " \
"link_type=%d\n",       __func__, NG_NODE_NAME(unit->node), 
                        con_handle, con->link_type);

                error = EINVAL;
                goto drop;
        }

        if (con->state != NG_HCI_CON_OPEN) {
                NG_HCI_ERR(
"%s: %s - unexpected HCI ACL data packet. Invalid connection state=%d, " \
"con_handle=%d\n",       __func__, NG_NODE_NAME(unit->node), 
                        con->state, con_handle);

                error = EHOSTDOWN;
                goto drop;
        }

        if (NG_BT_ITEMQ_FULL(&con->conq)) {
                NG_HCI_ALERT(
"%s: %s - dropping HCI ACL data packet, con_handle=%d, len=%d, queue_len=%d\n",
                         __func__, NG_NODE_NAME(unit->node), con_handle, 
                        m->m_pkthdr.len, NG_BT_ITEMQ_LEN(&con->conq));

                NG_BT_ITEMQ_DROP(&con->conq);

                error = ENOBUFS;
                goto drop;
        }

        /* Queue item and schedule data transfer */
        NGI_M(item) = m;
        NG_BT_ITEMQ_ENQUEUE(&con->conq, item);
        item = NULL;
        m = NULL;

        ng_hci_send_data(unit);
drop:
        if (item != NULL)
                NG_FREE_ITEM(item);

        NG_FREE_M(m); /* NG_FREE_M() checks for m != NULL */

        return (error);
} /* ng_hci_acl_rcvdata */

/*
 * Process data packet from SCO upstream hook.
 * We expect valid HCI SCO data packets
 */

static int
ng_hci_sco_rcvdata(hook_p hook, item_p item)
{
        ng_hci_unit_p            unit = (ng_hci_unit_p) NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
        struct mbuf             *m = NULL;
        ng_hci_unit_con_p        con = NULL;
        u_int16_t                con_handle;
        int                      size, error = 0;

        NG_HCI_BUFF_SCO_SIZE(unit->buffer, size);

        /* Check packet */
        NGI_GET_M(item, m);

        if (*mtod(m, u_int8_t *) != NG_HCI_SCO_DATA_PKT) {
                NG_HCI_ALERT(
"%s: %s - invalid HCI data packet type=%#x\n",
                        __func__, NG_NODE_NAME(unit->node),
                        *mtod(m, u_int8_t *));

                error = EINVAL;
                goto drop;
        }

        if (m->m_pkthdr.len < sizeof(ng_hci_scodata_pkt_t) ||
            m->m_pkthdr.len > sizeof(ng_hci_scodata_pkt_t) + size) {
                NG_HCI_ALERT(
"%s: %s - invalid HCI SCO data packet, len=%d, mtu=%d\n",
                        __func__, NG_NODE_NAME(unit->node), 
                        m->m_pkthdr.len, size);

                error = EMSGSIZE;
                goto drop;
        }

        NG_HCI_M_PULLUP(m, sizeof(ng_hci_scodata_pkt_t));
        if (m == NULL) {
                error = ENOBUFS;
                goto drop;
        }

        con_handle = NG_HCI_CON_HANDLE(le16toh(
                        mtod(m, ng_hci_scodata_pkt_t *)->con_handle));
        size = mtod(m, ng_hci_scodata_pkt_t *)->length;

        if (m->m_pkthdr.len != sizeof(ng_hci_scodata_pkt_t) + size) {
                NG_HCI_ALERT(
"%s: %s - invalid HCI SCO data packet size, len=%d, length=%d\n",
                        __func__, NG_NODE_NAME(unit->node), 
                        m->m_pkthdr.len, size);

                error = EMSGSIZE;
                goto drop;
        }

        /* Queue packet */
        con = ng_hci_con_by_handle(unit, con_handle);
        if (con == NULL) {
                NG_HCI_ERR(
"%s: %s - unexpected HCI SCO data packet. Connection does not exists, " \
"con_handle=%d\n",      __func__, NG_NODE_NAME(unit->node), con_handle);

                error = ENOENT;
                goto drop;
        }

        if (con->link_type != NG_HCI_LINK_SCO) {
                NG_HCI_ERR(
"%s: %s - unexpected HCI SCO data packet. Not SCO link, con_handle=%d, " \
"link_type=%d\n",       __func__, NG_NODE_NAME(unit->node), 
                        con_handle, con->link_type);

                error = EINVAL;
                goto drop;
        }

        if (con->state != NG_HCI_CON_OPEN) {
                NG_HCI_ERR(
"%s: %s - unexpected HCI SCO data packet. Invalid connection state=%d, " \
"con_handle=%d\n",      __func__, NG_NODE_NAME(unit->node), 
                        con->state, con_handle);

                error = EHOSTDOWN;
                goto drop;
        }

        if (NG_BT_ITEMQ_FULL(&con->conq)) {
                NG_HCI_ALERT(
"%s: %s - dropping HCI SCO data packet, con_handle=%d, len=%d, queue_len=%d\n",
                        __func__, NG_NODE_NAME(unit->node), con_handle, 
                        m->m_pkthdr.len, NG_BT_ITEMQ_LEN(&con->conq));

                NG_BT_ITEMQ_DROP(&con->conq);

                error = ENOBUFS;
                goto drop;
        }

        /* Queue item and schedule data transfer */
        NGI_M(item) = m;
        NG_BT_ITEMQ_ENQUEUE(&con->conq, item);
        item = NULL;
        m = NULL;

        ng_hci_send_data(unit);
drop:
        if (item != NULL)
                NG_FREE_ITEM(item);

        NG_FREE_M(m); /* NG_FREE_M() checks for m != NULL */

        return (error);
} /* ng_hci_sco_rcvdata */

/*
 * Process data packet from uptream RAW hook.
 * We expect valid HCI command packets.
 */

static int
ng_hci_raw_rcvdata(hook_p hook, item_p item)
{
        ng_hci_unit_p    unit = (ng_hci_unit_p) NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
        struct mbuf     *m = NULL;
        int              error = 0;

        NGI_GET_M(item, m); 
        NG_FREE_ITEM(item);

        /* Check packet */
        if (*mtod(m, u_int8_t *) != NG_HCI_CMD_PKT) {
                NG_HCI_ALERT(
"%s: %s - invalid HCI command packet type=%#x\n",
                        __func__, NG_NODE_NAME(unit->node),
                        *mtod(m, u_int8_t *));

                error = EINVAL;
                goto drop;
        }

        if (m->m_pkthdr.len < sizeof(ng_hci_cmd_pkt_t)) {
                NG_HCI_ALERT(
"%s: %s - invalid HCI command packet len=%d\n",
                        __func__, NG_NODE_NAME(unit->node), m->m_pkthdr.len);

                error = EMSGSIZE;
                goto drop;
        }

        NG_HCI_M_PULLUP(m, sizeof(ng_hci_cmd_pkt_t));
        if (m == NULL) {
                error = ENOBUFS;
                goto drop;
        }

        if (m->m_pkthdr.len != 
            mtod(m, ng_hci_cmd_pkt_t *)->length + sizeof(ng_hci_cmd_pkt_t)) {
                NG_HCI_ALERT(
"%s: %s - invalid HCI command packet size, len=%d, length=%d\n",
                        __func__, NG_NODE_NAME(unit->node), m->m_pkthdr.len,
                        mtod(m, ng_hci_cmd_pkt_t *)->length);

                error = EMSGSIZE;
                goto drop;
        }

        if (mtod(m, ng_hci_cmd_pkt_t *)->opcode == 0) {
                NG_HCI_ALERT(
"%s: %s - invalid HCI command opcode\n", 
                        __func__, NG_NODE_NAME(unit->node));

                error = EINVAL;
                goto drop;
        }

        if (NG_BT_MBUFQ_FULL(&unit->cmdq)) {
                NG_HCI_ALERT(
"%s: %s - dropping HCI command packet, len=%d, queue_len=%d\n",
                        __func__, NG_NODE_NAME(unit->node), m->m_pkthdr.len, 
                        NG_BT_MBUFQ_LEN(&unit->cmdq));

                NG_BT_MBUFQ_DROP(&unit->cmdq);

                error = ENOBUFS;
                goto drop;
        }

        /* Queue and send command */
        NG_BT_MBUFQ_ENQUEUE(&unit->cmdq, m);
        m = NULL;

        if (!(unit->state & NG_HCI_UNIT_COMMAND_PENDING))
                error = ng_hci_send_command(unit);
drop:
        NG_FREE_M(m); /* NG_FREE_M() checks for m != NULL */

        return (error);
} /* ng_hci_raw_rcvdata */