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author | Thomas Pugliese <thomas.pugliese@gmail.com> | 2014-09-16 16:10:50 -0500 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-09-23 22:05:26 -0700 |
commit | d08e1ad994afb70daf4ebf340f50425c1c5a2b75 (patch) | |
tree | 9dfc564046e2101ce868c3a5b62bf7740a349d1a | |
parent | 005799d560769bca8d87b08502c34317ab5e3bcd (diff) | |
download | linux-d08e1ad994afb70daf4ebf340f50425c1c5a2b75.tar.bz2 |
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: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | drivers/uwb/lc-rc.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/drivers/uwb/lc-rc.c b/drivers/uwb/lc-rc.c index 3eca6ceb9844..d059ad4d0dbd 100644 --- a/drivers/uwb/lc-rc.c +++ b/drivers/uwb/lc-rc.c @@ -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, }; |