- 根目录:
- drivers
- uwb
- beacon.c
/*
* Ultra Wide Band
* Beacon management
*
* Copyright (C) 2005-2006 Intel Corporation
* Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
*
* FIXME: docs
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/kdev_t.h>
#include <linux/slab.h>
#include "uwb-internal.h"
/* Start Beaconing command structure */
struct uwb_rc_cmd_start_beacon {
struct uwb_rccb rccb;
__le16 wBPSTOffset;
u8 bChannelNumber;
} __attribute__((packed));
static int uwb_rc_start_beacon(struct uwb_rc *rc, u16 bpst_offset, u8 channel)
{
int result;
struct uwb_rc_cmd_start_beacon *cmd;
struct uwb_rc_evt_confirm reply;
cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
if (cmd == NULL)
return -ENOMEM;
cmd->rccb.bCommandType = UWB_RC_CET_GENERAL;
cmd->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_START_BEACON);
cmd->wBPSTOffset = cpu_to_le16(bpst_offset);
cmd->bChannelNumber = channel;
reply.rceb.bEventType = UWB_RC_CET_GENERAL;
reply.rceb.wEvent = UWB_RC_CMD_START_BEACON;
result = uwb_rc_cmd(rc, "START-BEACON", &cmd->rccb, sizeof(*cmd),
&reply.rceb, sizeof(reply));
if (result < 0)
goto error_cmd;
if (reply.bResultCode != UWB_RC_RES_SUCCESS) {
dev_err(&rc->uwb_dev.dev,
"START-BEACON: command execution failed: %s (%d)\n",
uwb_rc_strerror(reply.bResultCode), reply.bResultCode);
result = -EIO;
}
error_cmd:
kfree(cmd);
return result;
}
static int uwb_rc_stop_beacon(struct uwb_rc *rc)
{
int result;
struct uwb_rccb *cmd;
struct uwb_rc_evt_confirm reply;
cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
if (cmd == NULL)
return -ENOMEM;
cmd->bCommandType = UWB_RC_CET_GENERAL;
cmd->wCommand = cpu_to_le16(UWB_RC_CMD_STOP_BEACON);
reply.rceb.bEventType = UWB_RC_CET_GENERAL;
reply.rceb.wEvent = UWB_RC_CMD_STOP_BEACON;
result = uwb_rc_cmd(rc, "STOP-BEACON", cmd, sizeof(*cmd),
&reply.rceb, sizeof(reply));
if (result < 0)
goto error_cmd;
if (reply.bResultCode != UWB_RC_RES_SUCCESS) {
dev_err(&rc->uwb_dev.dev,
"STOP-BEACON: command execution failed: %s (%d)\n",
uwb_rc_strerror(reply.bResultCode), reply.bResultCode);
result = -EIO;
}
error_cmd:
kfree(cmd);
return result;
}
/*
* Start/stop beacons
*
* @rc: UWB Radio Controller to operate on
* @channel: UWB channel on which to beacon (WUSB[table
* 5-12]). If -1, stop beaconing.
* @bpst_offset: Beacon Period Start Time offset; FIXME-do zero
*
* According to WHCI 0.95 [4.13.6] the driver will only receive the RCEB
* of a SET IE command after the device sent the first beacon that includes
* the IEs specified in the SET IE command. So, after we start beaconing we
* check if there is anything in the IE cache and call the SET IE command
* if needed.
*/
int uwb_rc_beacon(struct uwb_rc *rc, int channel, unsigned bpst_offset)
{
int result;
struct device *dev = &rc->uwb_dev.dev;
if (channel < 0)
channel = -1;
if (channel == -1)
result = uwb_rc_stop_beacon(rc);
else {
/* channel >= 0...dah */
result = uwb_rc_start_beacon(rc, bpst_offset, channel);
if (result < 0)
return result;
if (le16_to_cpu(rc->ies->wIELength) > 0) {
result = uwb_rc_set_ie(rc, rc->ies);
if (result < 0) {
dev_err(dev, "Cannot set new IE on device: "
"%d\n", result);
result = uwb_rc_stop_beacon(rc);
channel = -1;
bpst_offset = 0;
}
}
}
if (result >= 0)
rc->beaconing = channel;
return result;
}
/*
* Beacon cache
*
* The purpose of this is to speed up the lookup of becon information
* when a new beacon arrives. The UWB Daemon uses it also to keep a
* tab of which devices are in radio distance and which not. When a
* device's beacon stays present for more than a certain amount of
* time, it is considered a new, usable device. When a beacon ceases
* to be received for a certain amount of time, it is considered that
* the device is gone.
*
* FIXME: use an allocator for the entries
* FIXME: use something faster for search than a list
*/
void uwb_bce_kfree(struct kref *_bce)
{
struct uwb_beca_e *bce = container_of(_bce, struct uwb_beca_e, refcnt);
kfree(bce->be);
kfree(bce);
}
/* Find a beacon by dev addr in the cache */
static
struct uwb_beca_e *__uwb_beca_find_bydev(struct uwb_rc *rc,
const struct uwb_dev_addr *dev_addr)
{
struct uwb_beca_e *bce, *next;
list_for_each_entry_safe(bce, next, &rc->uwb_beca.list, node) {
if (!memcmp(&bce->dev_addr, dev_addr, sizeof(bce->dev_addr)))
goto out;
}
bce = NULL;
out:
return bce;
}
/* Find a beacon by dev addr in the cache */
static
struct uwb_beca_e *__uwb_beca_find_bymac(struct uwb_rc *rc,
const struct uwb_mac_addr *mac_addr)
{
struct uwb_beca_e *bce, *next;
list_for_each_entry_safe(bce, next, &rc->uwb_beca.list, node) {
if (!memcmp(bce->mac_addr, mac_addr->data,
sizeof(struct uwb_mac_addr)))
goto out;
}
bce = NULL;
out:
return bce;
}
/**
* uwb_dev_get_by_devaddr - get a UWB device with a specific DevAddr
* @rc: the radio controller that saw the device
* @devaddr: DevAddr of the UWB device to find
*
* There may be more than one matching device (in the case of a
* DevAddr conflict), but only the first one is returned.
*/
struct uwb_dev *uwb_dev_get_by_devaddr(struct uwb_rc *rc,
const struct uwb_dev_addr *devaddr)
{
struct uwb_dev *found = NULL;
struct uwb_beca_e *bce;
mutex_lock(&rc->uwb_beca.mutex);
bce = __uwb_beca_find_bydev(rc, devaddr);
if (bce)
found = uwb_dev_try_get(rc, bce->uwb_dev);
mutex_unlock(&rc->uwb_beca.mutex);
return found;
}
/**
* uwb_dev_get_by_macaddr - get a UWB device with a specific EUI-48
* @rc: the radio controller that saw the device
* @devaddr: EUI-48 of the UWB device to find
*/
struct uwb_dev *uwb_dev_get_by_macaddr(struct uwb_rc *rc,
const struct uwb_mac_addr *macaddr)
{
struct uwb_dev *found = NULL;
struct uwb_beca_e *bce;
mutex_lock(&rc->uwb_beca.mutex);
bce = __uwb_beca_find_bymac(rc, macaddr);
if (bce)
found = uwb_dev_try_get(rc, bce->uwb_dev);
mutex_unlock(&rc->uwb_beca.mutex);
return found;
}
/* Initialize a beacon cache entry */
static void uwb_beca_e_init(struct uwb_beca_e *bce)
{
mutex_init(&bce->mutex);
kref_init(&bce->refcnt);
stats_init(&bce->lqe_stats);
stats_init(&bce->rssi_stats);
}
/*
* Add a beacon to the cache
*
* @be: Beacon event information
* @bf: Beacon frame (part of b, really)
* @ts_jiffies: Timestamp (in jiffies) when the beacon was received
*/
static
struct uwb_beca_e *__uwb_beca_add(struct uwb_rc *rc,
struct uwb_rc_evt_beacon *be,
struct uwb_beacon_frame *bf,
unsigned long ts_jiffies)
{
struct uwb_beca_e *bce;
bce = kzalloc(sizeof(*bce), GFP_KERNEL);
if (bce == NULL)
return NULL;
uwb_beca_e_init(bce);
bce->ts_jiffies = ts_jiffies;
bce->uwb_dev = NULL;
list_add(&bce->node, &rc->uwb_beca.list);
return bce;
}
/*
* Wipe out beacon entries that became stale
*
* Remove associated devicest too.
*/
void uwb_beca_purge(struct uwb_rc *rc)
{
struct uwb_beca_e *bce, *next;
unsigned long expires;
mutex_lock(&rc->uwb_beca.mutex);
list_for_each_entry_safe(bce, next, &rc->uwb_beca.list, node) {
expires = bce->ts_jiffies + msecs_to_jiffies(beacon_timeout_ms);
if (time_after(jiffies, expires)) {
uwbd_dev_offair(bce);
}
}
mutex_unlock(&rc->uwb_beca.mutex);
}
/* Clean up the whole beacon cache. Called on shutdown */
void uwb_beca_release(struct uwb_rc *rc)
{
struct uwb_beca_e *bce, *next;
mutex_lock(&rc->uwb_beca.mutex);
list_for_each_entry_safe(bce, next, &rc->uwb_beca.list, node) {
list_del(&bce->node);
uwb_bce_put(bce);
}
mutex_unlock(&rc->uwb_beca.mutex);
}
static void uwb_beacon_print(struct uwb_rc *rc, struct uwb_rc_evt_beacon *be,
struct uwb_beacon_frame *bf)
{
char macbuf[UWB_ADDR_STRSIZE];
char devbuf[UWB_ADDR_STRSIZE];
char dstbuf[UWB_ADDR_STRSIZE];
uwb_mac_addr_print(macbuf, sizeof(macbuf), &bf->Device_Identifier);
uwb_dev_addr_print(devbuf, sizeof(devbuf), &bf->hdr.SrcAddr);
uwb_dev_addr_print(dstbuf, sizeof(dstbuf), &bf->hdr.DestAddr);
dev_info(&rc->uwb_dev.dev,
"BEACON from %s to %s (ch%u offset %u slot %u MAC %s)\n",
devbuf, dstbuf, be->bChannelNumber, be->wBPSTOffset,
bf->Beacon_Slot_Number, macbuf);
}
/*
* @bce: beacon cache entry, referenced
*/
ssize_t uwb_bce_print_IEs(struct uwb_dev *uwb_dev, struct uwb_beca_e *bce,
char *buf, size_t size)
{
ssize_t result = 0;
struct uwb_rc_evt_beacon *be;
struct uwb_beacon_frame *bf;
int ies_len;
struct uwb_ie_hdr *ies;
mutex_lock(&bce->mutex);
be = bce->be;
if (be) {
bf = (struct uwb_beacon_frame *)bce->be->BeaconInfo;
ies_len = be->wBeaconInfoLength - sizeof(struct uwb_beacon_frame);
ies = (struct uwb_ie_hdr *)bf->IEData;
result = uwb_ie_dump_hex(ies, ies_len, buf, size);
}
mutex_unlock(&bce->mutex);
return result;
}
/*
* Verify that the beacon event, frame and IEs are ok
*/
static int uwb_verify_beacon(struct uwb_rc *rc, struct uwb_event *evt,
struct uwb_rc_evt_beacon *be)
{
int result = -EINVAL;
struct uwb_beacon_frame *bf;
struct device *dev = &rc->uwb_dev.dev;
/* Is there enough data to decode a beacon frame? */
if (evt->notif.size < sizeof(*be) + sizeof(*bf)) {
dev_err(dev, "BEACON event: Not enough data to decode "
"(%zu vs %zu bytes needed)\n", evt->notif.size,
sizeof(*be) + sizeof(*bf));
goto error;
}
/* FIXME: make sure beacon frame IEs are fine and that the whole thing
* is consistent */
result = 0;
error:
return result;
}
/*
* Handle UWB_RC_EVT_BEACON events
*
* We check the beacon cache to see how the received beacon fares. If
* is there already we refresh the timestamp. If not we create a new
* entry.
*
* According to the WHCI and WUSB specs, only one beacon frame is
* allowed per notification block, so we don't bother about scanning
* for more.
*/
int uwbd_evt_handle_rc_beacon(struct uwb_event *evt)
{
int result = -EINVAL;
struct uwb_rc *rc;
struct uwb_rc_evt_beacon *be;
struct uwb_beacon_frame *bf;
struct uwb_beca_e *bce;
unsigned long last_ts;
rc = evt->rc;
be = container_of(evt->notif.rceb, struct uwb_rc_evt_beacon, rceb);
result = uwb_verify_beacon(rc, evt, be);
if (result < 0)
return result;
/* FIXME: handle alien beacons. */
if (be->bBeaconType == UWB_RC_BEACON_TYPE_OL_ALIEN ||
be->bBeaconType == UWB_RC_BEACON_TYPE_NOL_ALIEN) {
return -ENOSYS;
}
bf = (struct uwb_beacon_frame *) be->BeaconInfo;
/*
* Drop beacons from devices with a NULL EUI-48 -- they cannot
* be uniquely identified.
*
* It's expected that these will all be WUSB devices and they
* have a WUSB specific connection method so ignoring them
* here shouldn't be a problem.
*/
if (uwb_mac_addr_bcast(&bf->Device_Identifier))
return 0;
mutex_lock(&rc->uwb_beca.mutex);
bce = __uwb_beca_find_bymac(rc, &bf->Device_Identifier);
if (bce == NULL) {
/* Not in there, a new device is pinging */
uwb_beacon_print(evt->rc, be, bf);
bce = __uwb_beca_add(rc, be, bf, evt->ts_jiffies);
if (bce == NULL) {
mutex_unlock(&rc->uwb_beca.mutex);
return -ENOMEM;
}
}
mutex_unlock(&rc->uwb_beca.mutex);
mutex_lock(&bce->mutex);
/* purge old beacon data */
kfree(bce->be);
last_ts = bce->ts_jiffies;
/* Update commonly used fields */
bce->ts_jiffies = evt->ts_jiffies;
bce->be = be;
bce->dev_addr = bf->hdr.SrcAddr;
bce->mac_addr = &bf->Device_Identifier;
be->wBPSTOffset = le16_to_cpu(be->wBPSTOffset);
be->wBeaconInfoLength = le16_to_cpu(be->wBeaconInfoLength);
stats_add_sample(&bce->lqe_stats, be->bLQI - 7);
stats_add_sample(&bce->rssi_stats, be->bRSSI + 18);
/*
* This might be a beacon from a new device.
*/
if (bce->uwb_dev == NULL)
uwbd_dev_onair(evt->rc, bce);
mutex_unlock(&bce->mutex);
return 1; /* we keep the event data */
}
/*
* Handle UWB_RC_EVT_BEACON_SIZE events
*
* XXXXX
*/
int uwbd_evt_handle_rc_beacon_size(struct uwb_event *evt)
{
int result = -EINVAL;
struct device *dev = &evt->rc->uwb_dev.dev;
struct uwb_rc_evt_beacon_size *bs;
/* Is there enough data to decode the event? */
if (evt->notif.size < sizeof(*bs)) {
dev_err(dev, "BEACON SIZE notification: Not enough data to "
"decode (%zu vs %zu bytes needed)\n",
evt->notif.size, sizeof(*bs));
goto error;
}
bs = container_of(evt->notif.rceb, struct uwb_rc_evt_beacon_size, rceb);
if (0)
dev_info(dev, "Beacon size changed to %u bytes "
"(FIXME: action?)\n", le16_to_cpu(bs->wNewBeaconSize));
else {
/* temporary hack until we do something with this message... */
static unsigned count;
if (++count % 1000 == 0)
dev_info(dev, "Beacon size changed %u times "
"(FIXME: action?)\n", count);
}
result = 0;
error:
return result;
}
/**
* uwbd_evt_handle_rc_bp_slot_change - handle a BP_SLOT_CHANGE event
* @evt: the BP_SLOT_CHANGE notification from the radio controller
*
* If the event indicates that no beacon period slots were available
* then radio controller has transitioned to a non-beaconing state.
* Otherwise, simply save the current beacon slot.
*/
int uwbd_evt_handle_rc_bp_slot_change(struct uwb_event *evt)
{
struct uwb_rc *rc = evt->rc;
struct device *dev = &rc->uwb_dev.dev;
struct uwb_rc_evt_bp_slot_change *bpsc;
if (evt->notif.size < sizeof(*bpsc)) {
dev_err(dev, "BP SLOT CHANGE event: Not enough data\n");
return -EINVAL;
}
bpsc = container_of(evt->notif.rceb, struct uwb_rc_evt_bp_slot_change, rceb);
mutex_lock(&rc->uwb_dev.mutex);
if (uwb_rc_evt_bp_slot_change_no_slot(bpsc)) {
dev_info(dev, "stopped beaconing: No free slots in BP\n");
rc->beaconing = -1;
} else
rc->uwb_dev.beacon_slot = uwb_rc_evt_bp_slot_change_slot_num(bpsc);
mutex_unlock(&rc->uwb_dev.mutex);
return 0;
}
/**
* Handle UWB_RC_EVT_BPOIE_CHANGE events
*
* XXXXX
*/
struct uwb_ie_bpo {
struct uwb_ie_hdr hdr;
u8 bp_length;
u8 data[];
} __attribute__((packed));
int uwbd_evt_handle_rc_bpoie_change(struct uwb_event *evt)
{
int result = -EINVAL;
struct device *dev = &evt->rc->uwb_dev.dev;
struct uwb_rc_evt_bpoie_change *bpoiec;
struct uwb_ie_bpo *bpoie;
static unsigned count; /* FIXME: this is a temp hack */
size_t iesize;
/* Is there enough data to decode it? */
if (evt->notif.size < sizeof(*bpoiec)) {
dev_err(dev, "BPOIEC notification: Not enough data to "
"decode (%zu vs %zu bytes needed)\n",
evt->notif.size, sizeof(*bpoiec));
goto error;
}
bpoiec = container_of(evt->notif.rceb, struct uwb_rc_evt_bpoie_change, rceb);
iesize = le16_to_cpu(bpoiec->wBPOIELength);
if (iesize < sizeof(*bpoie)) {
dev_err(dev, "BPOIEC notification: Not enough IE data to "
"decode (%zu vs %zu bytes needed)\n",
iesize, sizeof(*bpoie));
goto error;
}
if (++count % 1000 == 0) /* Lame placeholder */
dev_info(dev, "BPOIE: %u changes received\n", count);
/*
* FIXME: At this point we should go over all the IEs in the
* bpoiec->BPOIE array and act on each.
*/
result = 0;
error:
return result;
}
/*
* Print beaconing state.
*/
static ssize_t uwb_rc_beacon_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct uwb_dev *uwb_dev = to_uwb_dev(dev);
struct uwb_rc *rc = uwb_dev->rc;
ssize_t result;
mutex_lock(&rc->uwb_dev.mutex);
result = sprintf(buf, "%d\n", rc->beaconing);
mutex_unlock(&rc->uwb_dev.mutex);
return result;
}
/*
* Start beaconing on the specified channel, or stop beaconing.
*/
static ssize_t uwb_rc_beacon_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t size)
{
struct uwb_dev *uwb_dev = to_uwb_dev(dev);
struct uwb_rc *rc = uwb_dev->rc;
int channel;
ssize_t result = -EINVAL;
result = sscanf(buf, "%d", &channel);
if (result >= 1)
result = uwb_radio_force_channel(rc, channel);
return result < 0 ? result : size;
}
DEVICE_ATTR(beacon, S_IRUGO | S_IWUSR, uwb_rc_beacon_show, uwb_rc_beacon_store);