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uwb: add an ASIE sysfs attribute to uwb_rc devices

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

Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Thomas Pugliese 2014-09-16 16:10:50 -05:00 committed by Greg Kroah-Hartman
parent 005799d560
commit d08e1ad994
1 changed files with 99 additions and 0 deletions
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99
drivers/uwb/lc-rc.c
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@ -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,
};