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Commit d08e1ad9 authored by Thomas Pugliese's avatar Thomas Pugliese Committed by Greg Kroah-Hartman
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uwb: add an ASIE sysfs attribute to uwb_rc devices 



Allow user mode to add and remove application specific information
elements (ASIEs) to the beacon of a uwb_rc device.

Signed-off-by: default avatarThomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 005799d5

drivers/uwb/lc-rc.c

+99 −0
Original line number Diff line number Diff line
@@ -119,10 +119,109 @@ struct uwb_rc *uwb_rc_alloc(void) 
}

EXPORT_SYMBOL_GPL(uwb_rc_alloc);



/*

 * Show the ASIE that is broadcast in the UWB beacon by this uwb_rc device.

 */

static ssize_t ASIE_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_ie_hdr *ie;

	void *ptr;

	size_t len;

	int result = 0;



	/* init empty buffer. */

	result = scnprintf(buf, PAGE_SIZE, "\n");

	mutex_lock(&rc->ies_mutex);

	/* walk IEData looking for an ASIE. */

	ptr = rc->ies->IEData;

	len = le16_to_cpu(rc->ies->wIELength);

	for (;;) {

		ie = uwb_ie_next(&ptr, &len);

		if (!ie)

			break;

		if (ie->element_id == UWB_APP_SPEC_IE) {

			result = uwb_ie_dump_hex(ie,

					ie->length + sizeof(struct uwb_ie_hdr),

					buf, PAGE_SIZE);

			break;

		}

	}

	mutex_unlock(&rc->ies_mutex);



	return result;

}



/*

 * Update the ASIE that is broadcast in the UWB beacon by this uwb_rc device.

 */

static ssize_t ASIE_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;

	char ie_buf[255];

	int result, ie_len = 0;

	const char *cur_ptr = buf;

	struct uwb_ie_hdr *ie;



	/* empty string means clear the ASIE. */

	if (strlen(buf) <= 1) {

		uwb_rc_ie_rm(rc, UWB_APP_SPEC_IE);

		return size;

	}



	/* if non-empty string, convert string of hex chars to binary. */

	while (ie_len < sizeof(ie_buf)) {

		int char_count;



		if (sscanf(cur_ptr, " %02hhX %n",

				&(ie_buf[ie_len]), &char_count) > 0) {

			++ie_len;

			/* skip chars read from cur_ptr. */

			cur_ptr += char_count;

		} else {

			break;

		}

	}



	/* validate IE length and type. */

	if (ie_len < sizeof(struct uwb_ie_hdr)) {

		dev_err(dev, "%s: Invalid ASIE size %d.\n", __func__, ie_len);

		return -EINVAL;

	}



	ie = (struct uwb_ie_hdr *)ie_buf;

	if (ie->element_id != UWB_APP_SPEC_IE) {

		dev_err(dev, "%s: Invalid IE element type size = 0x%02X.\n",

				__func__, ie->element_id);

		return -EINVAL;

	}



	/* bounds check length field from user. */

	if (ie->length > (ie_len - sizeof(struct uwb_ie_hdr)))

		ie->length = ie_len - sizeof(struct uwb_ie_hdr);



	/*

	 * Valid ASIE received. Remove current ASIE then add the new one using

	 * uwb_rc_ie_add.

	 */

	uwb_rc_ie_rm(rc, UWB_APP_SPEC_IE);



	result = uwb_rc_ie_add(rc, ie, ie->length + sizeof(struct uwb_ie_hdr));



	return result >= 0 ? size : result;

}

static DEVICE_ATTR_RW(ASIE);



static struct attribute *rc_attrs[] = {

		&dev_attr_mac_address.attr,

		&dev_attr_scan.attr,

		&dev_attr_beacon.attr,

		&dev_attr_ASIE.attr,

		NULL,

};