nl80211_trigger_scan() processes scan request netlink attributes,
defined in enum nl80211_attrs, and fills struct
cfg80211_scan_request *request.
Currently there is no logic to fill this member:
enum nl80211_bss_scan_width scan_width;
We have a requirement to fill this member for drone use cases, in
which drone controller needs to scan and connect to drone in 5 MHz
or 10 MHz channel width (may support other channel widths lower
than 20 MHz later).
Unfortunately there is not an existing attribute in enum
nl80211_attrs that has enum nl80211_bss_scan_width semantics. The
only attribute which has those semantics is NL80211_BSS_CHAN_WIDTH
in enum nl80211_bss, and of course we can't mix attributes from
different enums in a netlink command, at least not at the same
nesting level.
enum nl80211_attrs does define another attribute,
NL80211_ATTR_CHANNEL_WIDTH, but it has enum nl80211_chan_width
semantics.
In order to support the requirement to fill the scan_width with
an enum nl80211_bss_scan_width value we seem to have two options:
1) Use NL80211_ATTR_CHANNEL_WIDTH and convert from enum
nl80211_chan_width semantics to enum nl80211_bss_scan_width semantics
when filling struct cfg80211_scan_request *request.
2) Introduce a new NL80211_ATTR_SCAN_CHANNEL_WIDTH attribute to
enum nl80211_attrs that has enum nl80211_bss_scan_width semantics.
The following series of patches is the implementations of above two
options. In order to make them a series, a revert patch is included,
which can be ignored. Please review and decide which option is more
reasonable and acceptable.
Xinyue Ling (4):
nl80211: Add 4/8/16 MHz BSS control channel width definitions
wifi: nl80211: Add support to specify channel width for scan (option
1)
Revert "wifi: nl80211: Add support to specify channel width for scan
(option 1)"
wifi: nl80211: Add support to specify channel width for scan (option
2)
include/net/cfg80211.h | 6 ++++++
include/uapi/linux/nl80211.h | 34 ++++++++++++++++++++++++++++++++--
net/wireless/nl80211.c | 14 ++++++++++++++
3 files changed, 52 insertions(+), 2 deletions(-)
--
2.25.1
