NetBSD/sys/netbt/hci_link.c

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/* $NetBSD: hci_link.c,v 1.7 2006/10/12 01:32:37 christos Exp $ */
/*-
* Copyright (c) 2005 Iain Hibbert.
* Copyright (c) 2006 Itronix Inc.
* 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.
* 3. The name of Itronix Inc. may not be used to endorse
* or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY ITRONIX INC. ``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 ITRONIX INC. 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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: hci_link.c,v 1.7 2006/10/12 01:32:37 christos Exp $");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/systm.h>
#include <netbt/bluetooth.h>
#include <netbt/hci.h>
#include <netbt/l2cap.h>
#include <netbt/sco.h>
/*******************************************************************************
*
* HCI ACL Connections
*/
/*
* Automatically expire unused ACL connections after this number of
* seconds (if zero, do not expire unused connections) [sysctl]
*/
int hci_acl_expiry = 10; /* seconds */
/*
* hci_acl_open(unit, bdaddr)
*
* open ACL connection to remote bdaddr. Only one ACL connection is permitted
* between any two Bluetooth devices, so we look for an existing one before
* trying to start a new one.
*/
struct hci_link *
hci_acl_open(struct hci_unit *unit, bdaddr_t *bdaddr)
{
struct hci_link *link;
struct hci_memo *memo;
hci_create_con_cp cp;
int err;
KASSERT(unit);
KASSERT(bdaddr);
link = hci_link_lookup_bdaddr(unit, bdaddr, HCI_LINK_ACL);
if (link == NULL) {
link = hci_link_alloc(unit);
if (link == NULL)
return NULL;
link->hl_type = HCI_LINK_ACL;
bdaddr_copy(&link->hl_bdaddr, bdaddr);
}
switch(link->hl_state) {
case HCI_LINK_CLOSED:
/*
* open connection to remote device
*/
memset(&cp, 0, sizeof(cp));
bdaddr_copy(&cp.bdaddr, bdaddr);
cp.pkt_type = htole16(unit->hci_packet_type);
memo = hci_memo_find(unit, bdaddr);
if (memo != NULL) {
cp.page_scan_rep_mode = memo->response.page_scan_rep_mode;
cp.page_scan_mode = memo->response.page_scan_mode;
cp.clock_offset = htole16(memo->response.clock_offset);
}
if (unit->hci_link_policy & HCI_LINK_POLICY_ENABLE_ROLE_SWITCH)
cp.accept_role_switch = 1;
err = hci_send_cmd(unit, HCI_CMD_CREATE_CON, &cp, sizeof(cp));
if (err) {
hci_link_free(link, err);
return NULL;
}
link->hl_state = HCI_LINK_WAIT_CONNECT;
break;
case HCI_LINK_WAIT_CONNECT:
/*
* somebody else already trying to connect, we just
* sit on the bench with them..
*/
break;
case HCI_LINK_OPEN:
/*
* If already open, halt any expiry timeouts. We dont need
* to care about already invoking timeouts since refcnt >0
* will keep the link alive.
*/
callout_stop(&link->hl_expire);
break;
default:
UNKNOWN(link->hl_state);
return NULL;
}
/* open */
link->hl_refcnt++;
return link;
}
/*
* Close ACL connection. When there are no more references to this link,
* we can either close it down or schedule a delayed closedown.
*/
void
hci_acl_close(struct hci_link *link, int err)
{
KASSERT(link);
if (--link->hl_refcnt == 0) {
if (link->hl_state == HCI_LINK_CLOSED)
hci_link_free(link, err);
else if (hci_acl_expiry > 0)
callout_schedule(&link->hl_expire, hci_acl_expiry * hz);
}
}
/*
* Incoming ACL connection.
*
* For now, we accept all connections but it would be better to check
* the L2CAP listen list and only accept when there is a listener
* available.
*
* There should not be a link to the same bdaddr already, we check
* anyway though its left unhandled for now.
*/
struct hci_link *
hci_acl_newconn(struct hci_unit *unit, bdaddr_t *bdaddr)
{
struct hci_link *link;
link = hci_link_lookup_bdaddr(unit, bdaddr, HCI_LINK_ACL);
if (link != NULL)
return NULL;
link = hci_link_alloc(unit);
if (link != NULL) {
link->hl_state = HCI_LINK_WAIT_CONNECT;
link->hl_type = HCI_LINK_ACL;
bdaddr_copy(&link->hl_bdaddr, bdaddr);
if (hci_acl_expiry > 0)
callout_schedule(&link->hl_expire, hci_acl_expiry * hz);
}
return link;
}
void
hci_acl_timeout(void *arg)
{
struct hci_link *link = arg;
hci_discon_cp cp;
int s, err;
s = splsoftnet();
callout_ack(&link->hl_expire);
if (link->hl_refcnt > 0)
goto out;
DPRINTF("link #%d expired\n", link->hl_handle);
switch (link->hl_state) {
case HCI_LINK_CLOSED:
case HCI_LINK_WAIT_CONNECT:
hci_link_free(link, ECONNRESET);
break;
case HCI_LINK_OPEN:
cp.con_handle = htole16(link->hl_handle);
cp.reason = 0x13; /* "Remote User Terminated Connection" */
err = hci_send_cmd(link->hl_unit, HCI_CMD_DISCONNECT,
&cp, sizeof(cp));
2006-10-04 19:49:59 +04:00
if (err) {
DPRINTF("error %d sending HCI_CMD_DISCONNECT\n",
2006-10-04 19:49:59 +04:00
err);
}
break;
default:
UNKNOWN(link->hl_state);
break;
}
out:
splx(s);
}
/*
* Receive ACL Data
*
* we accumulate packet fragments on the hci_link structure
* until a full L2CAP frame is ready, then send it on.
*/
void
hci_acl_recv(struct mbuf *m, struct hci_unit *unit)
{
struct hci_link *link;
hci_acldata_hdr_t hdr;
uint16_t handle, want;
int pb, got;
KASSERT(m);
KASSERT(unit);
KASSERT(m->m_pkthdr.len >= sizeof(hdr));
m_copydata(m, 0, sizeof(hdr), &hdr);
m_adj(m, sizeof(hdr));
#ifdef DIAGNOSTIC
if (hdr.type != HCI_ACL_DATA_PKT) {
printf("%s: bad ACL packet type\n", unit->hci_devname);
goto bad;
}
if (m->m_pkthdr.len != le16toh(hdr.length)) {
printf("%s: bad ACL packet length (%d != %d)\n",
unit->hci_devname, m->m_pkthdr.len, le16toh(hdr.length));
goto bad;
}
#endif
hdr.length = le16toh(hdr.length);
hdr.con_handle = le16toh(hdr.con_handle);
handle = HCI_CON_HANDLE(hdr.con_handle);
pb = HCI_PB_FLAG(hdr.con_handle);
link = hci_link_lookup_handle(unit, handle);
if (link == NULL) {
hci_discon_cp cp;
DPRINTF("%s: dumping packet for unknown handle #%d\n",
unit->hci_devname, handle);
/*
* There is no way to find out what this connection handle is
* for, just get rid of it. This may happen, if a USB dongle
* is plugged into a self powered hub and does not reset when
* the system is shut down.
*/
cp.con_handle = htole16(handle);
cp.reason = 0x13; /* "Remote User Terminated Connection" */
hci_send_cmd(unit, HCI_CMD_DISCONNECT, &cp, sizeof(cp));
goto bad;
}
switch (pb) {
case HCI_PACKET_START:
if (link->hl_rxp != NULL)
printf("%s: dropped incomplete ACL packet\n",
unit->hci_devname);
if (m->m_pkthdr.len < sizeof(l2cap_hdr_t)) {
printf("%s: short ACL packet\n",
unit->hci_devname);
goto bad;
}
link->hl_rxp = m;
got = m->m_pkthdr.len;
break;
case HCI_PACKET_FRAGMENT:
if (link->hl_rxp == NULL) {
printf("%s: unexpected packet fragment\n",
unit->hci_devname);
goto bad;
}
got = m->m_pkthdr.len + link->hl_rxp->m_pkthdr.len;
m_cat(link->hl_rxp, m);
m = link->hl_rxp;
m->m_pkthdr.len = got;
break;
default:
printf("%s: unknown packet type\n",
unit->hci_devname);
goto bad;
}
m_copydata(m, 0, sizeof(want), &want);
want = le16toh(want) + sizeof(l2cap_hdr_t) - got;
if (want > 0)
return;
link->hl_rxp = NULL;
if (want == 0) {
l2cap_recv_frame(m, link);
return;
}
bad:
m_freem(m);
}
/*
* Send ACL data on link
*
* We must fragment packets into chunks of less than unit->hci_max_acl_size and
* prepend a relevant ACL header to each fragment. We keep a PDU structure
* attached to the link, so that completed fragments can be marked off and
* more data requested from above once the PDU is sent.
*/
int
hci_acl_send(struct mbuf *m, struct hci_link *link,
struct l2cap_channel *chan)
{
struct l2cap_pdu *pdu;
struct mbuf *n = NULL;
int plen, mlen, num = 0;
KASSERT(link);
KASSERT(m);
KASSERT(m->m_flags & M_PKTHDR);
KASSERT(m->m_pkthdr.len > 0);
if (link->hl_state == HCI_LINK_CLOSED) {
m_freem(m);
return ENETDOWN;
}
pdu = pool_get(&l2cap_pdu_pool, PR_NOWAIT);
if (pdu == NULL)
goto nomem;
pdu->lp_chan = chan;
pdu->lp_pending = 0;
MBUFQ_INIT(&pdu->lp_data);
plen = m->m_pkthdr.len;
mlen = link->hl_unit->hci_max_acl_size;
DPRINTFN(5, "%s: handle #%d, plen = %d, max = %d\n",
link->hl_unit->hci_devname, link->hl_handle, plen, mlen);
while (plen > 0) {
if (plen > mlen) {
n = m_split(m, mlen, M_DONTWAIT);
if (n == NULL)
goto nomem;
} else {
mlen = plen;
}
if (num++ == 0)
m->m_flags |= M_PROTO1; /* tag first fragment */
DPRINTFN(10, "chunk of %d (plen = %d) bytes\n", mlen, plen);
MBUFQ_ENQUEUE(&pdu->lp_data, m);
m = n;
plen -= mlen;
}
TAILQ_INSERT_TAIL(&link->hl_txq, pdu, lp_next);
link->hl_txqlen += num;
hci_acl_start(link);
return 0;
nomem:
if (m) m_freem(m);
if (n) m_freem(n);
if (pdu) {
MBUFQ_DRAIN(&pdu->lp_data);
pool_put(&l2cap_pdu_pool, pdu);
}
return ENOMEM;
}
/*
* Start sending ACL data on link.
*
* We may use all the available packet slots. The reason that we add
* the ACL encapsulation here rather than in hci_acl_send() is that L2CAP
* signal packets may be queued before the handle is given to us..
*
* this is called from hci_acl_send() above, and the event processing
* code (for CON_COMPL and NUM_COMPL_PKTS)
*/
void
hci_acl_start(struct hci_link *link)
{
struct hci_unit *unit;
hci_acldata_hdr_t *hdr;
struct l2cap_pdu *pdu;
struct mbuf *m;
uint16_t handle;
KASSERT(link);
unit = link->hl_unit;
KASSERT(unit);
/* this is mainly to block ourselves (below) */
if (link->hl_state != HCI_LINK_OPEN)
return;
if (link->hl_txqlen == 0 || unit->hci_num_acl_pkts == 0)
return;
/* find first PDU with data to send */
pdu = TAILQ_FIRST(&link->hl_txq);
for (;;) {
if (pdu == NULL)
return;
if (MBUFQ_FIRST(&pdu->lp_data) != NULL)
break;
pdu = TAILQ_NEXT(pdu, lp_next);
}
while (unit->hci_num_acl_pkts > 0) {
MBUFQ_DEQUEUE(&pdu->lp_data, m);
KASSERT(m != NULL);
if (m->m_flags & M_PROTO1)
handle = HCI_MK_CON_HANDLE(link->hl_handle,
HCI_PACKET_START, 0);
else
handle = HCI_MK_CON_HANDLE(link->hl_handle,
HCI_PACKET_FRAGMENT, 0);
M_PREPEND(m, sizeof(*hdr), M_DONTWAIT);
if (m == NULL)
break;
hdr = mtod(m, hci_acldata_hdr_t *);
hdr->type = HCI_ACL_DATA_PKT;
hdr->con_handle = htole16(handle);
hdr->length = htole16(m->m_pkthdr.len - sizeof(*hdr));
link->hl_txqlen--;
pdu->lp_pending++;
hci_output_acl(unit, m);
if (MBUFQ_FIRST(&pdu->lp_data) == NULL) {
if (pdu->lp_chan) {
/*
* This should enable streaming of PDUs - when
* we have placed all the fragments on the acl
* output queue, we trigger the L2CAP layer to
* send us down one more. Use a false state so
* we dont run into ourselves coming back from
* the future..
*/
link->hl_state = HCI_LINK_BLOCK;
l2cap_start(pdu->lp_chan);
link->hl_state = HCI_LINK_OPEN;
}
pdu = TAILQ_NEXT(pdu, lp_next);
if (pdu == NULL)
break;
}
}
/*
* We had our turn now, move to the back of the queue to let
* other links have a go at the output buffers..
*/
if (TAILQ_NEXT(link, hl_next)) {
TAILQ_REMOVE(&unit->hci_links, link, hl_next);
TAILQ_INSERT_TAIL(&unit->hci_links, link, hl_next);
}
}
/*
* Confirm ACL packets cleared from Controller buffers. We scan our PDU
* list to clear pending fragments and signal upstream for more data
* when a PDU is complete.
*/
void
hci_acl_complete(struct hci_link *link, int num)
{
struct l2cap_pdu *pdu;
struct l2cap_channel *chan;
DPRINTFN(5, "handle #%d (%d)\n", link->hl_handle, num);
while (num > 0) {
pdu = TAILQ_FIRST(&link->hl_txq);
if (pdu == NULL) {
printf("%s: %d packets completed on handle #%x "
"but none pending!\n",
link->hl_unit->hci_devname, num,
link->hl_handle);
return;
}
if (num >= pdu->lp_pending) {
num -= pdu->lp_pending;
pdu->lp_pending = 0;
if (MBUFQ_FIRST(&pdu->lp_data) == NULL) {
TAILQ_REMOVE(&link->hl_txq, pdu, lp_next);
chan = pdu->lp_chan;
if (chan != NULL) {
chan->lc_pending--;
(*chan->lc_proto->complete)
(chan->lc_upper, 1);
if (chan->lc_pending == 0)
l2cap_start(chan);
}
pool_put(&l2cap_pdu_pool, pdu);
}
} else {
pdu->lp_pending -= num;
num = 0;
}
}
}
/*******************************************************************************
*
* HCI SCO Connections
*/
/*
* Incoming SCO Connection. We check the list for anybody willing
* to take it.
*/
struct hci_link *
hci_sco_newconn(struct hci_unit *unit, bdaddr_t *bdaddr)
{
struct sockaddr_bt laddr, raddr;
struct sco_pcb *pcb, *new;
struct hci_link *sco, *acl;
memset(&laddr, 0, sizeof(laddr));
laddr.bt_len = sizeof(laddr);
laddr.bt_family = AF_BLUETOOTH;
bdaddr_copy(&laddr.bt_bdaddr, &unit->hci_bdaddr);
memset(&raddr, 0, sizeof(raddr));
raddr.bt_len = sizeof(raddr);
raddr.bt_family = AF_BLUETOOTH;
bdaddr_copy(&raddr.bt_bdaddr, bdaddr);
/*
* There should already be an ACL link up and running before
* the controller sends us SCO connection requests, but you
* never know..
*/
acl = hci_link_lookup_bdaddr(unit, bdaddr, HCI_LINK_ACL);
if (acl == NULL || acl->hl_state != HCI_LINK_OPEN)
return NULL;
LIST_FOREACH(pcb, &sco_pcb, sp_next) {
if ((pcb->sp_flags & SP_LISTENING) == 0)
continue;
new = (*pcb->sp_proto->newconn)(pcb->sp_upper, &laddr, &raddr);
if (new == NULL)
continue;
/*
* Ok, got new pcb so we can start a new link and fill
* in all the details.
*/
bdaddr_copy(&new->sp_laddr, &unit->hci_bdaddr);
bdaddr_copy(&new->sp_raddr, bdaddr);
sco = hci_link_alloc(unit);
if (sco == NULL) {
sco_detach(&new);
return NULL;
}
sco->hl_type = HCI_LINK_SCO;
bdaddr_copy(&sco->hl_bdaddr, bdaddr);
sco->hl_link = hci_acl_open(unit, bdaddr);
KASSERT(sco->hl_link == acl);
sco->hl_sco = new;
new->sp_link = sco;
new->sp_mtu = unit->hci_max_sco_size;
return sco;
}
return NULL;
}
/*
* receive SCO packet, we only need to strip the header and send
* it to the right handler
*/
void
hci_sco_recv(struct mbuf *m, struct hci_unit *unit)
{
struct hci_link *link;
hci_scodata_hdr_t hdr;
uint16_t handle;
KASSERT(m);
KASSERT(unit);
KASSERT(m->m_pkthdr.len >= sizeof(hdr));
m_copydata(m, 0, sizeof(hdr), &hdr);
m_adj(m, sizeof(hdr));
#ifdef DIAGNOSTIC
if (hdr.type != HCI_SCO_DATA_PKT) {
printf("%s: bad SCO packet type\n", unit->hci_devname);
goto bad;
}
if (m->m_pkthdr.len != hdr.length) {
printf("%s: bad SCO packet length (%d != %d)\n", unit->hci_devname, m->m_pkthdr.len, hdr.length);
goto bad;
}
#endif
hdr.con_handle = le16toh(hdr.con_handle);
handle = HCI_CON_HANDLE(hdr.con_handle);
link = hci_link_lookup_handle(unit, handle);
if (link == NULL || link->hl_type == HCI_LINK_ACL) {
DPRINTF("%s: dumping packet for unknown handle #%d\n",
unit->hci_devname, handle);
goto bad;
}
(*link->hl_sco->sp_proto->input)(link->hl_sco->sp_upper, m);
return;
bad:
m_freem(m);
}
void
hci_sco_start(struct hci_link *link __unused)
{
}
/*
* SCO packets have completed at the controller, so we can
* signal up to free the buffer space.
*/
void
hci_sco_complete(struct hci_link *link, int num)
{
DPRINTFN(5, "handle #%d (num=%d)\n", link->hl_handle, num);
link->hl_sco->sp_pending--;
(*link->hl_sco->sp_proto->complete)(link->hl_sco->sp_upper, num);
}
/*******************************************************************************
*
* Generic HCI Connection alloc/free/lookup etc
*/
struct hci_link *
hci_link_alloc(struct hci_unit *unit)
{
struct hci_link *link;
KASSERT(unit);
link = malloc(sizeof(struct hci_link), M_BLUETOOTH, M_NOWAIT | M_ZERO);
if (link == NULL)
return NULL;
link->hl_unit = unit;
link->hl_state = HCI_LINK_CLOSED;
/* init ACL portion */
callout_init(&link->hl_expire);
callout_setfunc(&link->hl_expire, hci_acl_timeout, link);
TAILQ_INIT(&link->hl_txq); /* outgoing packets */
TAILQ_INIT(&link->hl_reqs); /* request queue */
link->hl_mtu = L2CAP_MTU_DEFAULT; /* L2CAP signal mtu */
link->hl_flush = L2CAP_FLUSH_TIMO_DEFAULT; /* flush timeout */
/* init SCO portion */
MBUFQ_INIT(&link->hl_data);
/* attach to unit */
TAILQ_INSERT_HEAD(&unit->hci_links, link, hl_next);
return link;
}
void
hci_link_free(struct hci_link *link, int err)
{
struct l2cap_req *req;
struct l2cap_pdu *pdu;
struct l2cap_channel *chan, *next;
KASSERT(link);
DPRINTF("#%d, type = %d, state = %d, refcnt = %d\n",
link->hl_handle, link->hl_type,
link->hl_state, link->hl_refcnt);
/* ACL reference count */
if (link->hl_refcnt > 0) {
next = LIST_FIRST(&l2cap_active_list);
while ((chan = next) != NULL) {
next = LIST_NEXT(chan, lc_ncid);
if (chan->lc_link == link)
l2cap_close(chan, err);
}
}
KASSERT(link->hl_refcnt == 0);
/* ACL L2CAP requests.. */
while ((req = TAILQ_FIRST(&link->hl_reqs)) != NULL)
l2cap_request_free(req);
KASSERT(TAILQ_EMPTY(&link->hl_reqs));
/* ACL outgoing data queue */
while ((pdu = TAILQ_FIRST(&link->hl_txq)) != NULL) {
TAILQ_REMOVE(&link->hl_txq, pdu, lp_next);
MBUFQ_DRAIN(&pdu->lp_data);
if (pdu->lp_pending)
link->hl_unit->hci_num_acl_pkts += pdu->lp_pending;
pool_put(&l2cap_pdu_pool, pdu);
}
KASSERT(TAILQ_EMPTY(&link->hl_txq));
/* ACL incoming data packet */
if (link->hl_rxp != NULL) {
m_freem(link->hl_rxp);
link->hl_rxp = NULL;
}
/* SCO master ACL link */
if (link->hl_link != NULL) {
hci_acl_close(link->hl_link, err);
link->hl_link = NULL;
}
/* SCO pcb */
if (link->hl_sco != NULL) {
struct sco_pcb *pcb;
pcb = link->hl_sco;
pcb->sp_link = NULL;
link->hl_sco = NULL;
(*pcb->sp_proto->disconnected)(pcb->sp_upper, err);
}
/* flush any SCO data */
MBUFQ_DRAIN(&link->hl_data);
/*
* Halt the callout - if its already running we cannot free the
* link structure but the timeout function will call us back in
* any case.
*/
link->hl_state = HCI_LINK_CLOSED;
callout_stop(&link->hl_expire);
if (callout_invoking(&link->hl_expire))
return;
TAILQ_REMOVE(&link->hl_unit->hci_links, link, hl_next);
free(link, M_BLUETOOTH);
}
/*
* Lookup HCI link by address and type. Note that for SCO links there may
* be more than one link per address, so we only return links with no
* handle (ie new links)
*/
struct hci_link *
hci_link_lookup_bdaddr(struct hci_unit *unit, bdaddr_t *bdaddr, uint16_t type)
{
struct hci_link *link;
KASSERT(unit);
KASSERT(bdaddr);
TAILQ_FOREACH(link, &unit->hci_links, hl_next) {
if (link->hl_type != type)
continue;
if (type == HCI_LINK_SCO && link->hl_handle != 0)
continue;
if (bdaddr_same(&link->hl_bdaddr, bdaddr))
break;
}
return link;
}
struct hci_link *
hci_link_lookup_handle(struct hci_unit *unit, uint16_t handle)
{
struct hci_link *link;
KASSERT(unit);
TAILQ_FOREACH(link, &unit->hci_links, hl_next) {
if (handle == link->hl_handle)
break;
}
return link;
}