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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
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+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,
};