uwb: add the UWB stack (MLME)

Most of the MAC Layer Management Entity (MLME) support: address, beacon, IE
and scan management.
Signed-off-by: NDavid Vrabel <david.vrabel@csr.com>

drivers/uwb/address.c

+/*
+ * Ultra Wide Band
+ * Address 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/errno.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/random.h>
+#include <linux/etherdevice.h>
+#include <linux/uwb/debug.h>
+#include "uwb-internal.h"
+
+
+/** Device Address Management command */
+struct uwb_rc_cmd_dev_addr_mgmt {
+	struct uwb_rccb rccb;
+	u8 bmOperationType;
+	u8 baAddr[6];
+} __attribute__((packed));
+
+
+/**
+ * Low level command for setting/getting UWB radio's addresses
+ *
+ * @hwarc:	HWA Radio Control interface instance
+ * @bmOperationType:
+ * 		Set/get, MAC/DEV (see WUSB1.0[8.6.2.2])
+ * @baAddr:	address buffer--assumed to have enough data to hold
+ *              the address type requested.
+ * @reply:	Pointer to reply buffer (can be stack allocated)
+ * @returns:	0 if ok, < 0 errno code on error.
+ *
+ * @cmd has to be allocated because USB cannot grok USB or vmalloc
+ * buffers depending on your combination of host architecture.
+ */
+static
+int uwb_rc_dev_addr_mgmt(struct uwb_rc *rc,
+			 u8 bmOperationType, const u8 *baAddr,
+			 struct uwb_rc_evt_dev_addr_mgmt *reply)
+{
+	int result;
+	struct uwb_rc_cmd_dev_addr_mgmt *cmd;
+
+	result = -ENOMEM;
+	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
+	if (cmd == NULL)
+		goto error_kzalloc;
+	cmd->rccb.bCommandType = UWB_RC_CET_GENERAL;
+	cmd->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_DEV_ADDR_MGMT);
+	cmd->bmOperationType = bmOperationType;
+	if (baAddr) {
+		size_t size = 0;
+		switch (bmOperationType >> 1) {
+		case 0:	size = 2; break;
+		case 1:	size = 6; break;
+		default: BUG();
+		}
+		memcpy(cmd->baAddr, baAddr, size);
+	}
+	reply->rceb.bEventType = UWB_RC_CET_GENERAL;
+	reply->rceb.wEvent = UWB_RC_CMD_DEV_ADDR_MGMT;
+	result = uwb_rc_cmd(rc, "DEV-ADDR-MGMT",
+			    &cmd->rccb, sizeof(*cmd),
+			    &reply->rceb, sizeof(*reply));
+	if (result < 0)
+		goto error_cmd;
+	if (result < sizeof(*reply)) {
+		dev_err(&rc->uwb_dev.dev,
+			"DEV-ADDR-MGMT: not enough data replied: "
+			"%d vs %zu bytes needed\n", result, sizeof(*reply));
+		result = -ENOMSG;
+	} else if (reply->bResultCode != UWB_RC_RES_SUCCESS) {
+		dev_err(&rc->uwb_dev.dev,
+			"DEV-ADDR-MGMT: command execution failed: %s (%d)\n",
+			uwb_rc_strerror(reply->bResultCode),
+			reply->bResultCode);
+		result = -EIO;
+	} else
+		result = 0;
+error_cmd:
+	kfree(cmd);
+error_kzalloc:
+	return result;
+}
+
+
+/**
+ * Set the UWB RC MAC or device address.
+ *
+ * @rc:      UWB Radio Controller
+ * @_addr:   Pointer to address to write [assumed to be either a
+ *           'struct uwb_mac_addr *' or a 'struct uwb_dev_addr *'].
+ * @type:    Type of address to set (UWB_ADDR_DEV or UWB_ADDR_MAC).
+ * @returns: 0 if ok, < 0 errno code on error.
+ *
+ * Some anal retentivity here: even if both 'struct
+ * uwb_{dev,mac}_addr' have the actual byte array in the same offset
+ * and I could just pass _addr to hwarc_cmd_dev_addr_mgmt(), I prefer
+ * to use some syntatic sugar in case someday we decide to change the
+ * format of the structs. The compiler will optimize it out anyway.
+ */
+static int uwb_rc_addr_set(struct uwb_rc *rc,
+		    const void *_addr, enum uwb_addr_type type)
+{
+	int result;
+	u8 bmOperationType = 0x1; 		/* Set address */
+	const struct uwb_dev_addr *dev_addr = _addr;
+	const struct uwb_mac_addr *mac_addr = _addr;
+	struct uwb_rc_evt_dev_addr_mgmt reply;
+	const u8 *baAddr;
+
+	result = -EINVAL;
+	switch (type) {
+	case UWB_ADDR_DEV:
+		baAddr = dev_addr->data;
+		break;
+	case UWB_ADDR_MAC:
+		baAddr = mac_addr->data;
+		bmOperationType |= 0x2;
+		break;
+	default:
+		return result;
+	}
+	return uwb_rc_dev_addr_mgmt(rc, bmOperationType, baAddr, &reply);
+}
+
+
+/**
+ * Get the UWB radio's MAC or device address.
+ *
+ * @rc:      UWB Radio Controller
+ * @_addr:   Where to write the address data [assumed to be either a
+ *           'struct uwb_mac_addr *' or a 'struct uwb_dev_addr *'].
+ * @type:    Type of address to get (UWB_ADDR_DEV or UWB_ADDR_MAC).
+ * @returns: 0 if ok (and *_addr set), < 0 errno code on error.
+ *
+ * See comment in uwb_rc_addr_set() about anal retentivity in the
+ * type handling of the address variables.
+ */
+static int uwb_rc_addr_get(struct uwb_rc *rc,
+		    void *_addr, enum uwb_addr_type type)
+{
+	int result;
+	u8 bmOperationType = 0x0; 		/* Get address */
+	struct uwb_rc_evt_dev_addr_mgmt evt;
+	struct uwb_dev_addr *dev_addr = _addr;
+	struct uwb_mac_addr *mac_addr = _addr;
+	u8 *baAddr;
+
+	result = -EINVAL;
+	switch (type) {
+	case UWB_ADDR_DEV:
+		baAddr = dev_addr->data;
+		break;
+	case UWB_ADDR_MAC:
+		bmOperationType |= 0x2;
+		baAddr = mac_addr->data;
+		break;
+	default:
+		return result;
+	}
+	result = uwb_rc_dev_addr_mgmt(rc, bmOperationType, baAddr, &evt);
+	if (result == 0)
+		switch (type) {
+		case UWB_ADDR_DEV:
+			memcpy(&dev_addr->data, evt.baAddr,
+			       sizeof(dev_addr->data));
+			break;
+		case UWB_ADDR_MAC:
+			memcpy(&mac_addr->data, evt.baAddr,
+			       sizeof(mac_addr->data));
+			break;
+		default:		/* shut gcc up */
+			BUG();
+		}
+	return result;
+}
+
+
+/** Get @rc's MAC address to @addr */
+int uwb_rc_mac_addr_get(struct uwb_rc *rc,
+			struct uwb_mac_addr *addr) {
+	return uwb_rc_addr_get(rc, addr, UWB_ADDR_MAC);
+}
+EXPORT_SYMBOL_GPL(uwb_rc_mac_addr_get);
+
+
+/** Get @rc's device address to @addr */
+int uwb_rc_dev_addr_get(struct uwb_rc *rc,
+			struct uwb_dev_addr *addr) {
+	return uwb_rc_addr_get(rc, addr, UWB_ADDR_DEV);
+}
+EXPORT_SYMBOL_GPL(uwb_rc_dev_addr_get);
+
+
+/** Set @rc's address to @addr */
+int uwb_rc_mac_addr_set(struct uwb_rc *rc,
+			const struct uwb_mac_addr *addr)
+{
+	int result = -EINVAL;
+	mutex_lock(&rc->uwb_dev.mutex);
+	result = uwb_rc_addr_set(rc, addr, UWB_ADDR_MAC);
+	mutex_unlock(&rc->uwb_dev.mutex);
+	return result;
+}
+
+
+/** Set @rc's address to @addr */
+int uwb_rc_dev_addr_set(struct uwb_rc *rc,
+			const struct uwb_dev_addr *addr)
+{
+	int result = -EINVAL;
+	mutex_lock(&rc->uwb_dev.mutex);
+	result = uwb_rc_addr_set(rc, addr, UWB_ADDR_DEV);
+	rc->uwb_dev.dev_addr = *addr;
+	mutex_unlock(&rc->uwb_dev.mutex);
+	return result;
+}
+
+/* Returns !0 if given address is already assigned to device. */
+int __uwb_mac_addr_assigned_check(struct device *dev, void *_addr)
+{
+	struct uwb_dev *uwb_dev = to_uwb_dev(dev);
+	struct uwb_mac_addr *addr = _addr;
+
+	if (!uwb_mac_addr_cmp(addr, &uwb_dev->mac_addr))
+		return !0;
+	return 0;
+}
+
+/* Returns !0 if given address is already assigned to device. */
+int __uwb_dev_addr_assigned_check(struct device *dev, void *_addr)
+{
+	struct uwb_dev *uwb_dev = to_uwb_dev(dev);
+	struct uwb_dev_addr *addr = _addr;
+	if (!uwb_dev_addr_cmp(addr, &uwb_dev->dev_addr))
+		return !0;
+	return 0;
+}
+
+/**
+ * uwb_dev_addr_assign - assigned a generated DevAddr to a radio controller
+ * @rc:      the (local) radio controller device requiring a new DevAddr
+ *
+ * A new DevAddr is required when:
+ *    - first setting up a radio controller
+ *    - if the hardware reports a DevAddr conflict
+ *
+ * The DevAddr is randomly generated in the generated DevAddr range
+ * [0x100, 0xfeff]. The number of devices in a beacon group is limited
+ * by mMaxBPLength (96) so this address space will never be exhausted.
+ *
+ * [ECMA-368] 17.1.1, 17.16.
+ */
+int uwb_rc_dev_addr_assign(struct uwb_rc *rc)
+{
+	struct uwb_dev_addr new_addr;
+
+	do {
+		get_random_bytes(new_addr.data, sizeof(new_addr.data));
+	} while (new_addr.data[0] == 0x00 || new_addr.data[0] == 0xff
+		 || __uwb_dev_addr_assigned(rc, &new_addr));
+
+	return uwb_rc_dev_addr_set(rc, &new_addr);
+}
+
+/**
+ * uwbd_evt_handle_rc_dev_addr_conflict - handle a DEV_ADDR_CONFLICT event
+ * @evt: the DEV_ADDR_CONFLICT notification from the radio controller
+ *
+ * A new (non-conflicting) DevAddr is assigned to the radio controller.
+ *
+ * [ECMA-368] 17.1.1.1.
+ */
+int uwbd_evt_handle_rc_dev_addr_conflict(struct uwb_event *evt)
+{
+	struct uwb_rc *rc = evt->rc;
+
+	return uwb_rc_dev_addr_assign(rc);
+}
+
+/*
+ * Print the 48-bit EUI MAC address of the radio controller when
+ * reading /sys/class/uwb_rc/XX/mac_address
+ */
+static ssize_t uwb_rc_mac_addr_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;
+	struct uwb_mac_addr addr;
+	ssize_t result;
+
+	mutex_lock(&rc->uwb_dev.mutex);
+	result = uwb_rc_addr_get(rc, &addr, UWB_ADDR_MAC);
+	mutex_unlock(&rc->uwb_dev.mutex);
+	if (result >= 0) {
+		result = uwb_mac_addr_print(buf, UWB_ADDR_STRSIZE, &addr);
+		buf[result++] = '\n';
+	}
+	return result;
+}
+
+/*
+ * Parse a 48 bit address written to /sys/class/uwb_rc/XX/mac_address
+ * and if correct, set it.
+ */
+static ssize_t uwb_rc_mac_addr_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;
+	struct uwb_mac_addr addr;
+	ssize_t result;
+
+	result = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx\n",
+			&addr.data[0], &addr.data[1], &addr.data[2],
+			&addr.data[3], &addr.data[4], &addr.data[5]);
+	if (result != 6) {
+		result = -EINVAL;
+		goto out;
+	}
+	if (is_multicast_ether_addr(addr.data)) {
+		dev_err(&rc->uwb_dev.dev, "refusing to set multicast "
+			"MAC address %s\n", buf);
+		result = -EINVAL;
+		goto out;
+	}
+	result = uwb_rc_mac_addr_set(rc, &addr);
+	if (result == 0)
+		rc->uwb_dev.mac_addr = addr;
+out:
+	return result < 0 ? result : size;
+}
+DEVICE_ATTR(mac_address, S_IRUGO | S_IWUSR, uwb_rc_mac_addr_show, uwb_rc_mac_addr_store);
+
+/** Print @addr to @buf, @return bytes written */
+size_t __uwb_addr_print(char *buf, size_t buf_size, const unsigned char *addr,
+			int type)
+{
+	size_t result;
+	if (type)
+		result = scnprintf(buf, buf_size,
+				  "%02x:%02x:%02x:%02x:%02x:%02x",
+				  addr[0], addr[1], addr[2],
+				  addr[3], addr[4], addr[5]);
+	else
+		result = scnprintf(buf, buf_size, "%02x:%02x",
+				  addr[1], addr[0]);
+	return result;
+}
+EXPORT_SYMBOL_GPL(__uwb_addr_print);

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 "uwb-internal.h"
+
+#define D_LOCAL 0
+#include <linux/uwb/debug.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;
+
+	mutex_lock(&rc->uwb_dev.mutex);
+	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)
+			goto out_up;
+		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;
+			} else
+				result = 0;
+		}
+	}
+
+	if (result < 0)
+		goto out_up;
+	rc->beaconing = channel;
+
+	uwb_notify(rc, NULL, uwb_bg_joined(rc) ? UWB_NOTIF_BG_JOIN : UWB_NOTIF_BG_LEAVE);
+
+out_up:
+	mutex_unlock(&rc->uwb_dev.mutex);
+	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
+ */
+
+struct uwb_beca uwb_beca = {
+	.list = LIST_HEAD_INIT(uwb_beca.list),
+	.mutex = __MUTEX_INITIALIZER(uwb_beca.mutex)
+};
+
+
+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(const struct uwb_dev_addr *dev_addr)
+{
+	struct uwb_beca_e *bce, *next;
+	list_for_each_entry_safe(bce, next, &uwb_beca.list, node) {
+		d_printf(6, NULL, "looking for addr %02x:%02x in %02x:%02x\n",
+			 dev_addr->data[0], dev_addr->data[1],
+			 bce->dev_addr.data[0], bce->dev_addr.data[1]);
+		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(const struct uwb_mac_addr *mac_addr)
+{
+	struct uwb_beca_e *bce, *next;
+	list_for_each_entry_safe(bce, next, &uwb_beca.list, node) {
+		if (!memcmp(bce->mac_addr, mac_addr->data,
+			    sizeof(bce->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(&uwb_beca.mutex);
+	bce = __uwb_beca_find_bydev(devaddr);
+	if (bce)
+		found = uwb_dev_try_get(rc, bce->uwb_dev);
+	mutex_unlock(&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(&uwb_beca.mutex);
+	bce = __uwb_beca_find_bymac(macaddr);
+	if (bce)
+		found = uwb_dev_try_get(rc, bce->uwb_dev);
+	mutex_unlock(&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
+ */
+struct uwb_beca_e *__uwb_beca_add(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, &uwb_beca.list);
+	return bce;
+}
+
+/*
+ * Wipe out beacon entries that became stale
+ *
+ * Remove associated devicest too.
+ */
+void uwb_beca_purge(void)
+{
+	struct uwb_beca_e *bce, *next;
+	unsigned long now = jiffies;
+	mutex_lock(&uwb_beca.mutex);
+	list_for_each_entry_safe(bce, next, &uwb_beca.list, node) {
+		if (now - bce->ts_jiffies
+		    > msecs_to_jiffies(beacon_timeout_ms)) {
+			uwbd_dev_offair(bce);
+			list_del(&bce->node);
+			uwb_bce_put(bce);
+		}
+	}
+	mutex_unlock(&uwb_beca.mutex);
+}
+
+/* Clean up the whole beacon cache. Called on shutdown */
+void uwb_beca_release(void)
+{
+	struct uwb_beca_e *bce, *next;
+	mutex_lock(&uwb_beca.mutex);
+	list_for_each_entry_safe(bce, next, &uwb_beca.list, node) {
+		list_del(&bce->node);
+		uwb_bce_put(bce);
+	}
+	mutex_unlock(&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;
+	struct uwb_buf_ctx ctx = {
+		.buf = buf,
+		.bytes = 0,
+		.size = size
+	};
+
+	mutex_lock(&bce->mutex);
+	be = bce->be;
+	if (be == NULL)
+		goto out;
+	bf = (void *) be->BeaconInfo;
+	uwb_ie_for_each(uwb_dev, uwb_ie_dump_hex, &ctx,
+			bf->IEData, be->wBeaconInfoLength - sizeof(*bf));
+	result = ctx.bytes;
+out:
+	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;
+	struct device *dev = &evt->rc->uwb_dev.dev;
+	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;
+
+	/* Ignore beacon if it is from an alien. */
+	if (be->bBeaconType == UWB_RC_BEACON_TYPE_OL_ALIEN ||
+	    be->bBeaconType == UWB_RC_BEACON_TYPE_NOL_ALIEN) {
+		if (printk_ratelimit())
+			dev_err(dev, "BEACON received from ALIEN. Action? \n");
+		result = -ENOSYS;
+		return 0;
+	}
+	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(&uwb_beca.mutex);
+	bce = __uwb_beca_find_bymac(&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(be, bf, evt->ts_jiffies);
+		if (bce == NULL) {
+			mutex_unlock(&uwb_beca.mutex);
+			return -ENOMEM;
+		}
+	}
+	mutex_unlock(&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;
+}
+
+/**
+ * uwb_bg_joined - is the RC in a beacon group?
+ * @rc: the radio controller
+ *
+ * Returns true if the radio controller is in a beacon group (even if
+ * it's the sole member).
+ */
+int uwb_bg_joined(struct uwb_rc *rc)
+{
+	return rc->beaconing != -1;
+}
+EXPORT_SYMBOL_GPL(uwb_bg_joined);
+
+/*
+ * 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.
+ *
+ * The BPST offset of when to start searching for a beacon group to
+ * join may be specified.
+ */
+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;
+	unsigned bpst_offset = 0;
+	ssize_t result = -EINVAL;
+
+	result = sscanf(buf, "%d %u\n", &channel, &bpst_offset);
+	if (result >= 1)
+		result = uwb_rc_beacon(rc, channel, bpst_offset);
+
+	return result < 0 ? result : size;
+}
+DEVICE_ATTR(beacon, S_IRUGO | S_IWUSR, uwb_rc_beacon_show, uwb_rc_beacon_store);

drivers/uwb/ie.c

+/*
+ * Ultra Wide Band
+ * Information Element Handling
+ *
+ * Copyright (C) 2005-2006 Intel Corporation
+ * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
+ * Reinette Chatre <reinette.chatre@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 "uwb-internal.h"
+#define D_LOCAL 0
+#include <linux/uwb/debug.h>
+
+/**
+ * uwb_ie_next - get the next IE in a buffer
+ * @ptr: start of the buffer containing the IE data
+ * @len: length of the buffer
+ *
+ * Both @ptr and @len are updated so subsequent calls to uwb_ie_next()
+ * will get the next IE.
+ *
+ * NULL is returned (and @ptr and @len will not be updated) if there
+ * are no more IEs in the buffer or the buffer is too short.
+ */
+struct uwb_ie_hdr *uwb_ie_next(void **ptr, size_t *len)
+{
+	struct uwb_ie_hdr *hdr;
+	size_t ie_len;
+
+	if (*len < sizeof(struct uwb_ie_hdr))
+		return NULL;
+
+	hdr = *ptr;
+	ie_len = sizeof(struct uwb_ie_hdr) + hdr->length;
+
+	if (*len < ie_len)
+		return NULL;
+
+	*ptr += ie_len;
+	*len -= ie_len;
+
+	return hdr;
+}
+EXPORT_SYMBOL_GPL(uwb_ie_next);
+
+/**
+ * Get the IEs that a radio controller is sending in its beacon
+ *
+ * @uwb_rc:  UWB Radio Controller
+ * @returns: Size read from the system
+ *
+ * We don't need to lock the uwb_rc's mutex because we don't modify
+ * anything. Once done with the iedata buffer, call
+ * uwb_rc_ie_release(iedata). Don't call kfree on it.
+ */
+ssize_t uwb_rc_get_ie(struct uwb_rc *uwb_rc, struct uwb_rc_evt_get_ie **pget_ie)
+{
+	ssize_t result;
+	struct device *dev = &uwb_rc->uwb_dev.dev;
+	struct uwb_rccb *cmd = NULL;
+	struct uwb_rceb *reply = NULL;
+	struct uwb_rc_evt_get_ie *get_ie;
+
+	d_fnstart(3, dev, "(%p, %p)\n", uwb_rc, pget_ie);
+	result = -ENOMEM;
+	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
+	if (cmd == NULL)
+		goto error_kzalloc;
+	cmd->bCommandType = UWB_RC_CET_GENERAL;
+	cmd->wCommand = cpu_to_le16(UWB_RC_CMD_GET_IE);
+	result = uwb_rc_vcmd(uwb_rc, "GET_IE", cmd, sizeof(*cmd),
+			     UWB_RC_CET_GENERAL, UWB_RC_CMD_GET_IE,
+			     &reply);
+	if (result < 0)
+		goto error_cmd;
+	get_ie = container_of(reply, struct uwb_rc_evt_get_ie, rceb);
+	if (result < sizeof(*get_ie)) {
+		dev_err(dev, "not enough data returned for decoding GET IE "
+			"(%zu bytes received vs %zu needed)\n",
+			result, sizeof(*get_ie));
+		result = -EINVAL;
+	} else if (result < sizeof(*get_ie) + le16_to_cpu(get_ie->wIELength)) {
+		dev_err(dev, "not enough data returned for decoding GET IE "
+			"payload (%zu bytes received vs %zu needed)\n", result,
+			sizeof(*get_ie) + le16_to_cpu(get_ie->wIELength));
+		result = -EINVAL;
+	} else
+		*pget_ie = get_ie;
+error_cmd:
+	kfree(cmd);
+error_kzalloc:
+	d_fnend(3, dev, "(%p, %p) = %d\n", uwb_rc, pget_ie, (int)result);
+	return result;
+}
+EXPORT_SYMBOL_GPL(uwb_rc_get_ie);
+
+
+/*
+ * Given a pointer to an IE, print it in ASCII/hex followed by a new line
+ *
+ * @ie_hdr: pointer to the IE header. Length is in there, and it is
+ *          guaranteed that the ie_hdr->length bytes following it are
+ *          safely accesible.
+ *
+ * @_data: context data passed from uwb_ie_for_each(), an struct output_ctx
+ */
+int uwb_ie_dump_hex(struct uwb_dev *uwb_dev, const struct uwb_ie_hdr *ie_hdr,
+		    size_t offset, void *_ctx)
+{
+	struct uwb_buf_ctx *ctx = _ctx;
+	const u8 *pl = (void *)(ie_hdr + 1);
+	u8 pl_itr;
+
+	ctx->bytes += scnprintf(ctx->buf + ctx->bytes, ctx->size - ctx->bytes,
+				"%02x %02x ", (unsigned) ie_hdr->element_id,
+				(unsigned) ie_hdr->length);
+	pl_itr = 0;
+	while (pl_itr < ie_hdr->length && ctx->bytes < ctx->size)
+		ctx->bytes += scnprintf(ctx->buf + ctx->bytes,
+					ctx->size - ctx->bytes,
+					"%02x ", (unsigned) pl[pl_itr++]);
+	if (ctx->bytes < ctx->size)
+		ctx->buf[ctx->bytes++] = '\n';
+	return 0;
+}
+EXPORT_SYMBOL_GPL(uwb_ie_dump_hex);
+
+
+/**
+ * Verify that a pointer in a buffer points to valid IE
+ *
+ * @start: pointer to start of buffer in which IE appears
+ * @itr:   pointer to IE inside buffer that will be verified
+ * @top:   pointer to end of buffer
+ *
+ * @returns: 0 if IE is valid, <0 otherwise
+ *
+ * Verification involves checking that the buffer can contain a
+ * header and the amount of data reported in the IE header can be found in
+ * the buffer.
+ */
+static
+int uwb_rc_ie_verify(struct uwb_dev *uwb_dev, const void *start,
+		     const void *itr, const void *top)
+{
+	struct device *dev = &uwb_dev->dev;
+	const struct uwb_ie_hdr *ie_hdr;
+
+	if (top - itr < sizeof(*ie_hdr)) {
+		dev_err(dev, "Bad IE: no data to decode header "
+			"(%zu bytes left vs %zu needed) at offset %zu\n",
+			top - itr, sizeof(*ie_hdr), itr - start);
+		return -EINVAL;
+	}
+	ie_hdr = itr;
+	itr += sizeof(*ie_hdr);
+	if (top - itr < ie_hdr->length) {
+		dev_err(dev, "Bad IE: not enough data for payload "
+			"(%zu bytes left vs %zu needed) at offset %zu\n",
+			top - itr, (size_t)ie_hdr->length,
+			(void *)ie_hdr - start);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+
+/**
+ * Walk a buffer filled with consecutive IE's a buffer
+ *
+ * @uwb_dev: UWB device this IEs belong to (for err messages mainly)
+ *
+ * @fn: function to call with each IE; if it returns 0, we keep
+ *      traversing the buffer. If it returns !0, we'll stop and return
+ *      that value.
+ *
+ * @data: pointer passed to @fn
+ *
+ * @buf: buffer where the consecutive IEs are located
+ *
+ * @size: size of @buf
+ *
+ * Each IE is checked for basic correctness (there is space left for
+ * the header and the payload). If that test is failed, we stop
+ * processing. For every good IE, @fn is called.
+ */
+ssize_t uwb_ie_for_each(struct uwb_dev *uwb_dev, uwb_ie_f fn, void *data,
+			const void *buf, size_t size)
+{
+	ssize_t result = 0;
+	const struct uwb_ie_hdr *ie_hdr;
+	const void *itr = buf, *top = itr + size;
+
+	while (itr < top) {
+		if (uwb_rc_ie_verify(uwb_dev, buf, itr, top) != 0)
+			break;
+		ie_hdr = itr;
+		itr += sizeof(*ie_hdr) + ie_hdr->length;
+		result = fn(uwb_dev, ie_hdr, itr - buf, data);
+		if (result != 0)
+			break;
+	}
+	return result;
+}
+EXPORT_SYMBOL_GPL(uwb_ie_for_each);
+
+
+/**
+ * Replace all IEs currently being transmitted by a device
+ *
+ * @cmd:    pointer to the SET-IE command with the IEs to set
+ * @size:   size of @buf
+ */
+int uwb_rc_set_ie(struct uwb_rc *rc, struct uwb_rc_cmd_set_ie *cmd)
+{
+	int result;
+	struct device *dev = &rc->uwb_dev.dev;
+	struct uwb_rc_evt_set_ie reply;
+
+	reply.rceb.bEventType = UWB_RC_CET_GENERAL;
+	reply.rceb.wEvent = UWB_RC_CMD_SET_IE;
+	result = uwb_rc_cmd(rc, "SET-IE", &cmd->rccb,
+			    sizeof(*cmd) + le16_to_cpu(cmd->wIELength),
+			    &reply.rceb, sizeof(reply));
+	if (result < 0)
+		goto error_cmd;
+	else if (result != sizeof(reply)) {
+		dev_err(dev, "SET-IE: not enough data to decode reply "
+			"(%d bytes received vs %zu needed)\n",
+			result, sizeof(reply));
+		result = -EIO;
+	} else if (reply.bResultCode != UWB_RC_RES_SUCCESS) {
+		dev_err(dev, "SET-IE: command execution failed: %s (%d)\n",
+			uwb_rc_strerror(reply.bResultCode), reply.bResultCode);
+		result = -EIO;
+	} else
+		result = 0;
+error_cmd:
+	return result;
+}
+
+/**
+ * Determine by IE id if IE is host settable
+ * WUSB 1.0 [8.6.2.8 Table 8.85]
+ *
+ * EXCEPTION:
+ * All but UWB_IE_WLP appears in Table 8.85 from WUSB 1.0. Setting this IE
+ * is required for the WLP substack to perform association with its WSS so
+ * we hope that the WUSB spec will be changed to reflect this.
+ */
+static
+int uwb_rc_ie_is_host_settable(enum uwb_ie element_id)
+{
+	if (element_id == UWB_PCA_AVAILABILITY ||
+	    element_id == UWB_BP_SWITCH_IE ||
+	    element_id == UWB_MAC_CAPABILITIES_IE ||
+	    element_id == UWB_PHY_CAPABILITIES_IE ||
+	    element_id == UWB_APP_SPEC_PROBE_IE ||
+	    element_id == UWB_IDENTIFICATION_IE ||
+	    element_id == UWB_MASTER_KEY_ID_IE ||
+	    element_id == UWB_IE_WLP ||
+	    element_id == UWB_APP_SPEC_IE)
+		return 1;
+	return 0;
+}
+
+
+/**
+ * Extract Host Settable IEs from IE
+ *
+ * @ie_data: pointer to buffer containing all IEs
+ * @size:    size of buffer
+ *
+ * @returns: length of buffer that only includes host settable IEs
+ *
+ * Given a buffer of IEs we move all Host Settable IEs to front of buffer
+ * by overwriting the IEs that are not Host Settable.
+ * Buffer length is adjusted accordingly.
+ */
+static
+ssize_t uwb_rc_parse_host_settable_ie(struct uwb_dev *uwb_dev,
+				      void *ie_data, size_t size)
+{
+	size_t new_len = size;
+	struct uwb_ie_hdr *ie_hdr;
+	size_t ie_length;
+	void *itr = ie_data, *top = itr + size;
+
+	while (itr < top) {
+		if (uwb_rc_ie_verify(uwb_dev, ie_data, itr, top) != 0)
+			break;
+		ie_hdr = itr;
+		ie_length = sizeof(*ie_hdr) + ie_hdr->length;
+		if (uwb_rc_ie_is_host_settable(ie_hdr->element_id)) {
+			itr += ie_length;
+		} else {
+			memmove(itr, itr + ie_length, top - (itr + ie_length));
+			new_len -= ie_length;
+			top -= ie_length;
+		}
+	}
+	return new_len;
+}
+
+
+/* Cleanup the whole IE management subsystem */
+void uwb_rc_ie_init(struct uwb_rc *uwb_rc)
+{
+	mutex_init(&uwb_rc->ies_mutex);
+}
+
+
+/**
+ * Set up cache for host settable IEs currently being transmitted
+ *
+ * First we just call GET-IE to get the current IEs being transmitted
+ * (or we workaround and pretend we did) and (because the format is
+ * the same) reuse that as the IE cache (with the command prefix, as
+ * explained in 'struct uwb_rc').
+ *
+ * @returns: size of cache created
+ */
+ssize_t uwb_rc_ie_setup(struct uwb_rc *uwb_rc)
+{
+	struct device *dev = &uwb_rc->uwb_dev.dev;
+	ssize_t result;
+	size_t capacity;
+	struct uwb_rc_evt_get_ie *ie_info;
+
+	d_fnstart(3, dev, "(%p)\n", uwb_rc);
+	mutex_lock(&uwb_rc->ies_mutex);
+	result = uwb_rc_get_ie(uwb_rc, &ie_info);
+	if (result < 0)
+		goto error_get_ie;
+	capacity = result;
+	d_printf(5, dev, "Got IEs %zu bytes (%zu long at %p)\n", result,
+		 (size_t)le16_to_cpu(ie_info->wIELength), ie_info);
+
+	/* Remove IEs that host should not set. */
+	result = uwb_rc_parse_host_settable_ie(&uwb_rc->uwb_dev,
+			ie_info->IEData, le16_to_cpu(ie_info->wIELength));
+	if (result < 0)
+		goto error_parse;
+	d_printf(5, dev, "purged non-settable IEs to %zu bytes\n", result);
+	uwb_rc->ies = (void *) ie_info;
+	uwb_rc->ies->rccb.bCommandType = UWB_RC_CET_GENERAL;
+	uwb_rc->ies->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_SET_IE);
+	uwb_rc->ies_capacity = capacity;
+	d_printf(5, dev, "IE cache at %p %zu bytes, %zu capacity\n",
+		 ie_info, result, capacity);
+	result = 0;
+error_parse:
+error_get_ie:
+	mutex_unlock(&uwb_rc->ies_mutex);
+	d_fnend(3, dev, "(%p) = %zu\n", uwb_rc, result);
+	return result;
+}
+
+
+/* Cleanup the whole IE management subsystem */
+void uwb_rc_ie_release(struct uwb_rc *uwb_rc)
+{
+	kfree(uwb_rc->ies);
+	uwb_rc->ies = NULL;
+	uwb_rc->ies_capacity = 0;
+}
+
+
+static
+int __acc_size(struct uwb_dev *uwb_dev, const struct uwb_ie_hdr *ie_hdr,
+	       size_t offset, void *_ctx)
+{
+	size_t *acc_size = _ctx;
+	*acc_size += sizeof(*ie_hdr) + ie_hdr->length;
+	d_printf(6, &uwb_dev->dev, "new acc size %zu\n", *acc_size);
+	return 0;
+}
+
+
+/**
+ * Add a new IE to IEs currently being transmitted by device
+ *
+ * @ies: the buffer containing the new IE or IEs to be added to
+ *       the device's beacon. The buffer will be verified for
+ *       consistence (meaning the headers should be right) and
+ *       consistent with the buffer size.
+ * @size: size of @ies (in bytes, total buffer size)
+ * @returns: 0 if ok, <0 errno code on error
+ *
+ * According to WHCI 0.95 [4.13.6] the driver will only receive the RCEB
+ * after the device sent the first beacon that includes the IEs specified
+ * in the SET IE command. We thus cannot send this command if the device is
+ * not beaconing. Instead, a SET IE command will be sent later right after
+ * we start beaconing.
+ *
+ * Setting an IE on the device will overwrite all current IEs in device. So
+ * we take the current IEs being transmitted by the device, append the
+ * new one, and call SET IE with all the IEs needed.
+ *
+ * The local IE cache will only be updated with the new IE if SET IE
+ * completed successfully.
+ */
+int uwb_rc_ie_add(struct uwb_rc *uwb_rc,
+		  const struct uwb_ie_hdr *ies, size_t size)
+{
+	int result = 0;
+	struct device *dev = &uwb_rc->uwb_dev.dev;
+	struct uwb_rc_cmd_set_ie *new_ies;
+	size_t ies_size, total_size, acc_size = 0;
+
+	if (uwb_rc->ies == NULL)
+		return -ESHUTDOWN;
+	uwb_ie_for_each(&uwb_rc->uwb_dev, __acc_size, &acc_size, ies, size);
+	if (acc_size != size) {
+		dev_err(dev, "BUG: bad IEs, misconstructed headers "
+			"[%zu bytes reported vs %zu calculated]\n",
+			size, acc_size);
+		WARN_ON(1);
+		return -EINVAL;
+	}
+	mutex_lock(&uwb_rc->ies_mutex);
+	ies_size = le16_to_cpu(uwb_rc->ies->wIELength);
+	total_size = sizeof(*uwb_rc->ies) + ies_size;
+	if (total_size + size > uwb_rc->ies_capacity) {
+		d_printf(4, dev, "Reallocating IE cache from %p capacity %zu "
+			 "to capacity %zu\n", uwb_rc->ies, uwb_rc->ies_capacity,
+			 total_size + size);
+		new_ies = kzalloc(total_size + size, GFP_KERNEL);
+		if (new_ies == NULL) {
+			dev_err(dev, "No memory for adding new IE\n");
+			result = -ENOMEM;
+			goto error_alloc;
+		}
+		memcpy(new_ies, uwb_rc->ies, total_size);
+		uwb_rc->ies_capacity = total_size + size;
+		kfree(uwb_rc->ies);
+		uwb_rc->ies = new_ies;
+		d_printf(4, dev, "New IE cache at %p capacity %zu\n",
+			 uwb_rc->ies, uwb_rc->ies_capacity);
+	}
+	memcpy((void *)uwb_rc->ies + total_size, ies, size);
+	uwb_rc->ies->wIELength = cpu_to_le16(ies_size + size);
+	if (uwb_rc->beaconing != -1) {
+		result = uwb_rc_set_ie(uwb_rc, uwb_rc->ies);
+		if (result < 0) {
+			dev_err(dev, "Cannot set new IE on device: %d\n",
+				result);
+			uwb_rc->ies->wIELength = cpu_to_le16(ies_size);
+		} else
+			result = 0;
+	}
+	d_printf(4, dev, "IEs now occupy %hu bytes of %zu capacity at %p\n",
+		 le16_to_cpu(uwb_rc->ies->wIELength), uwb_rc->ies_capacity,
+		 uwb_rc->ies);
+error_alloc:
+	mutex_unlock(&uwb_rc->ies_mutex);
+	return result;
+}
+EXPORT_SYMBOL_GPL(uwb_rc_ie_add);
+
+
+/*
+ * Remove an IE from internal cache
+ *
+ * We are dealing with our internal IE cache so no need to verify that the
+ * IEs are valid (it has been done already).
+ *
+ * Should be called with ies_mutex held
+ *
+ * We do not break out once an IE is found in the cache. It is currently
+ * possible to have more than one IE with the same ID included in the
+ * beacon. We don't reallocate, we just mark the size smaller.
+ */
+static
+int uwb_rc_ie_cache_rm(struct uwb_rc *uwb_rc, enum uwb_ie to_remove)
+{
+	struct uwb_ie_hdr *ie_hdr;
+	size_t new_len = le16_to_cpu(uwb_rc->ies->wIELength);
+	void *itr = uwb_rc->ies->IEData;
+	void *top = itr + new_len;
+
+	while (itr < top) {
+		ie_hdr = itr;
+		if (ie_hdr->element_id != to_remove) {
+			itr += sizeof(*ie_hdr) + ie_hdr->length;
+		} else {
+			int ie_length;
+			ie_length = sizeof(*ie_hdr) + ie_hdr->length;
+			if (top - itr != ie_length)
+				memmove(itr, itr + ie_length, top - itr + ie_length);
+			top -= ie_length;
+			new_len -= ie_length;
+		}
+	}
+	uwb_rc->ies->wIELength = cpu_to_le16(new_len);
+	return 0;
+}
+
+
+/**
+ * Remove an IE currently being transmitted by device
+ *
+ * @element_id: id of IE to be removed from device's beacon
+ */
+int uwb_rc_ie_rm(struct uwb_rc *uwb_rc, enum uwb_ie element_id)
+{
+	struct device *dev = &uwb_rc->uwb_dev.dev;
+	int result;
+
+	if (uwb_rc->ies == NULL)
+		return -ESHUTDOWN;
+	mutex_lock(&uwb_rc->ies_mutex);
+	result = uwb_rc_ie_cache_rm(uwb_rc, element_id);
+	if (result < 0)
+		dev_err(dev, "Cannot remove IE from cache.\n");
+	if (uwb_rc->beaconing != -1) {
+		result = uwb_rc_set_ie(uwb_rc, uwb_rc->ies);
+		if (result < 0)
+			dev_err(dev, "Cannot set new IE on device.\n");
+	}
+	mutex_unlock(&uwb_rc->ies_mutex);
+	return result;
+}
+EXPORT_SYMBOL_GPL(uwb_rc_ie_rm);
+
+
+/**
+ * Create and set new Identification IE
+ *
+ * Currently only sets the Vendor ID. The Vendor ID is set from the OUI,
+ * which is obtained from the first three bytes from the MAC address.
+ */
+int uwb_rc_set_identification_ie(struct uwb_rc *uwb_rc)
+{
+	struct {
+		struct uwb_identification_ie id_ie;
+		struct uwb_dev_info dev_info;
+		struct uwb_vendor_id vendor_id;
+	} ie_data;
+
+	ie_data.id_ie.hdr.element_id = UWB_IDENTIFICATION_IE;
+	ie_data.id_ie.hdr.length = sizeof(struct uwb_dev_info) +
+				   sizeof(struct uwb_vendor_id);
+
+	ie_data.dev_info.type = UWB_DEV_INFO_VENDOR_ID;
+	ie_data.dev_info.length = sizeof(struct uwb_vendor_id);
+
+	ie_data.vendor_id.data[0] = uwb_rc->uwb_dev.mac_addr.data[0];
+	ie_data.vendor_id.data[1] = uwb_rc->uwb_dev.mac_addr.data[1];
+	ie_data.vendor_id.data[2] = uwb_rc->uwb_dev.mac_addr.data[2];
+
+	return uwb_rc_ie_add(uwb_rc, &ie_data.id_ie.hdr, sizeof(ie_data));
+}

drivers/uwb/scan.c

+/*
+ * Ultra Wide Band
+ * Scanning 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
+ * FIXME: there are issues here on how BEACON and SCAN on USB RCI deal
+ *        with each other. Currently seems that START_BEACON while
+ *        SCAN_ONLY will cancel the scan, so we need to update the
+ *        state here. Clarification request sent by email on
+ *        10/05/2005.
+ *        10/28/2005 No clear answer heard--maybe we'll hack the API
+ *                   so that when we start beaconing, if the HC is
+ *                   scanning in a mode not compatible with beaconing
+ *                   we just fail.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include "uwb-internal.h"
+
+
+/**
+ * Start/stop scanning in a radio controller
+ *
+ * @rc:      UWB Radio Controlller
+ * @channel: Channel to scan; encodings in WUSB1.0[Table 5.12]
+ * @type:    Type of scanning to do.
+ * @bpst_offset: value at which to start scanning (if type ==
+ *                UWB_SCAN_ONLY_STARTTIME)
+ * @returns: 0 if ok, < 0 errno code on error
+ *
+ * We put the command on kmalloc'ed memory as some arches cannot do
+ * USB from the stack. The reply event is copied from an stage buffer,
+ * so it can be in the stack. See WUSB1.0[8.6.2.4] for more details.
+ */
+int uwb_rc_scan(struct uwb_rc *rc,
+		unsigned channel, enum uwb_scan_type type,
+		unsigned bpst_offset)
+{
+	int result;
+	struct uwb_rc_cmd_scan *cmd;
+	struct uwb_rc_evt_confirm reply;
+
+	result = -ENOMEM;
+	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
+	if (cmd == NULL)
+		goto error_kzalloc;
+	mutex_lock(&rc->uwb_dev.mutex);
+	cmd->rccb.bCommandType = UWB_RC_CET_GENERAL;
+	cmd->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_SCAN);
+	cmd->bChannelNumber = channel;
+	cmd->bScanState = type;
+	cmd->wStartTime = cpu_to_le16(bpst_offset);
+	reply.rceb.bEventType = UWB_RC_CET_GENERAL;
+	reply.rceb.wEvent = UWB_RC_CMD_SCAN;
+	result = uwb_rc_cmd(rc, "SCAN", &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,
+			"SCAN: command execution failed: %s (%d)\n",
+			uwb_rc_strerror(reply.bResultCode), reply.bResultCode);
+		result = -EIO;
+		goto error_cmd;
+	}
+	rc->scanning = channel;
+	rc->scan_type = type;
+error_cmd:
+	mutex_unlock(&rc->uwb_dev.mutex);
+	kfree(cmd);
+error_kzalloc:
+	return result;
+}
+
+/*
+ * Print scanning state
+ */
+static ssize_t uwb_rc_scan_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 %d\n", rc->scanning, rc->scan_type);
+	mutex_unlock(&rc->uwb_dev.mutex);
+	return result;
+}
+
+/*
+ *
+ */
+static ssize_t uwb_rc_scan_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;
+	unsigned channel;
+	unsigned type;
+	unsigned bpst_offset = 0;
+	ssize_t result = -EINVAL;
+
+	result = sscanf(buf, "%u %u %u\n", &channel, &type, &bpst_offset);
+	if (result >= 2 && type < UWB_SCAN_TOP)
+		result = uwb_rc_scan(rc, channel, type, bpst_offset);
+
+	return result < 0 ? result : size;
+}
+
+/** Radio Control sysfs interface (declaration) */
+DEVICE_ATTR(scan, S_IRUGO | S_IWUSR, uwb_rc_scan_show, uwb_rc_scan_store);