On 10/12/2018 12:08 PM, Johannes Berg wrote:
From: Johannes Berg <johannes.berg@xxxxxxxxx>
Add a new "peer measurement" API, that can be used to measure
certain things related to a peer. Right now, only implement
FTM (flight time measurement) over it, but the idea is that
it'll be extensible to also support measuring the necessary
things to calculate e.g. angle-of-arrival for WiGig.
The API is structured to have a generic list of peers and
channels to measure with/on, and then for each of those a
set of measurements (again, only FTM right now) to perform.
Results are sent to the requesting socket, including a final
complete message.
Closing the controlling netlink socket will abort a running
measurement.
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
---
You have no recollection what happened in the earlier versions, right? :-p
v3:
- add a bit to report "final" for partial results
- remove list keeping etc. and just unicast out the results
to the requester (big code reduction ...)
- also send complete message unicast, and as a result
remove the multicast group
- separate out struct cfg80211_pmsr_ftm_request_peer
from struct cfg80211_pmsr_request_peer
- document timeout == 0 if no timeout
- disallow setting timeout nl80211 attribute to 0,
must not include attribute for no timeout
All these negations make my head spin (a little). Let's look at the
actual documentation further down...
- make MAC address randomization optional
- change num bursts exponent default to 0 (1 burst, rather
rather than the old default of 15==don't care)
---
include/net/cfg80211.h | 255 +++++++++++++++++++
include/uapi/linux/nl80211.h | 410 ++++++++++++++++++++++++++++++
net/wireless/Makefile | 1 +
net/wireless/core.c | 33 +++
net/wireless/core.h | 4 +
net/wireless/nl80211.c | 200 ++++++++++++---
net/wireless/nl80211.h | 41 +++
net/wireless/pmsr.c | 576 +++++++++++++++++++++++++++++++++++++++++++
net/wireless/rdev-ops.h | 25 ++
net/wireless/trace.h | 68 +++++
10 files changed, 1579 insertions(+), 34 deletions(-)
create mode 100644 net/wireless/pmsr.c
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 0e16e723dcef..2837ea5f37e1 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -2841,6 +2841,191 @@ struct cfg80211_ftm_responder_stats {
u32 out_of_window_triggers_num;
};
+/**
+ * struct cfg80211_pmsr_ftm_result - FTM result
+ * @failure_reason: if this measurement failed (PMSR status is
+ * %NL80211_PMSR_STATUS_FAILURE), this gives a more precise
+ * reason than just "failure"
+ * @burst_index: if reporting partial results, this is the index
+ * in [0 .. num_bursts-1] of the burst that's being reported
+ * @num_ftmr_attempts: number of FTM request frames transmitted
+ * @num_ftmr_successes: number of FTM request frames acked
+ * @busy_retry_time: if failure_reason is %NL80211_PMSR_FTM_FAILURE_PEER_BUSY,
+ * fill this to indicate in how many seconds a retry is deemed possible
+ * by the responder
+ * @num_bursts_exp: actual number of bursts exponent negotiated
+ * @burst_duration: actual burst duration negotiated
+ * @frames_per_burst: actual frames per burst negotiated
+ * @lci_len: length of LCI information (if present)
+ * @civicloc_len: length of civic location information (if present)
+ * @lci: LCI data (may be %NULL)
+ * @civicloc: civic location data (may be %NULL)
+ * @rssi_avg: average RSSI over FTM action frames reported
+ * @rssi_spread: spread of the RSSI over FTM action frames reported
+ * @tx_rate: bitrate for transmitted FTM action frame response
+ * @rx_rate: bitrate of received FTM action frame
+ * @rtt_avg: average of RTTs measured (must have either this or @dist_avg)
+ * @rtt_variance: variance of RTTs measured (note that standard deviation is
+ * the square root of the variance)
+ * @rtt_spread: spread of the RTTs measured
+ * @dist_avg: average of distances (mm) measured
+ * (must have either this or @rtt_avg)
+ * @dist_variance: variance of distances measured (see also @rtt_variance)
+ * @dist_spread: spread of distances measured (see also @rtt_spread)
+ * @num_ftmr_attempts_valid: @num_ftmr_attempts is valid
+ * @num_ftmr_successes_valid: @num_ftmr_successes is valid
+ * @rssi_avg_valid: @rssi_avg is valid
+ * @rssi_spread_valid: @rssi_spread is valid
+ * @tx_rate_valid: @tx_rate is valid
+ * @rx_rate_valid: @rx_rate is valid
+ * @rtt_avg_valid: @rtt_avg is valid
+ * @rtt_variance_valid: @rtt_variance is valid
+ * @rtt_spread_valid: @rtt_spread is valid
+ * @dist_avg_valid: @dist_avg is valid
+ * @dist_variance_valid: @dist_variance is valid
+ * @dist_spread_valid: @dist_spread is valid
+ */
+struct cfg80211_pmsr_ftm_result {
+ const u8 *lci;
+ const u8 *civicloc;
+ unsigned int lci_len;
+ unsigned int civicloc_len;
+ enum nl80211_peer_measurement_ftm_failure_reasons failure_reason;
+ u32 num_ftmr_attempts, num_ftmr_successes;
Maybe there is a good reason, but can we move the above line a bit down...
+ s16 burst_index;
+ u8 busy_retry_time;
+ u8 num_bursts_exp;
+ u8 burst_duration;
+ u8 frames_per_burst;
ie. here so they match with valid bitfields below.
+ s32 rssi_avg;
+ s32 rssi_spread;
+ struct rate_info tx_rate, rx_rate;
+ s64 rtt_avg;
+ s64 rtt_variance;
+ s64 rtt_spread;
+ s64 dist_avg;
+ s64 dist_variance;
+ s64 dist_spread;
+
+ u16 num_ftmr_attempts_valid:1,
+ num_ftmr_successes_valid:1,
+ rssi_avg_valid:1,
+ rssi_spread_valid:1,
+ tx_rate_valid:1,
+ rx_rate_valid:1,
+ rtt_avg_valid:1,
+ rtt_variance_valid:1,
+ rtt_spread_valid:1,
+ dist_avg_valid:1,
+ dist_variance_valid:1,
+ dist_spread_valid:1;
Did not expect to learn something new about C standard ;-) At least I
never seen comma separated bitfield definition in a struct. Nice.
+};
+
[...]
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index dc6d5a1ef470..40be8968f60b 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -2254,6 +2282,14 @@ enum nl80211_commands {
* @NL80211_ATTR_FTM_RESPONDER_STATS: Nested attribute with FTM responder
* statistics, see &enum nl80211_ftm_responder_stats.
*
+ * @NL80211_ATTR_TIMEOUT: Timeout for the given operation, in milliseconds (u32)
+ *
+ * @NL80211_ATTR_PEER_MEASUREMENTS: peer measurements request (and result)
+ * data, uses nested attributes specified in
+ * &enum nl80211_peer_measurement_attrs.
+ * This is also used for capability advertisement in the wiphy information,
+ * with the appropriate sub-attributes.
+ *
* @NUM_NL80211_ATTR: total number of nl80211_attrs available
* @NL80211_ATTR_MAX: highest attribute number currently defined
* @__NL80211_ATTR_AFTER_LAST: internal use
@@ -2699,6 +2735,10 @@ enum nl80211_attrs {
NL80211_ATTR_FTM_RESPONDER_STATS,
+ NL80211_ATTR_TIMEOUT,
+
Guess you consider reuse of the TIMEOUT attribute? I checked the policy
definition in nl80211_policy so it disallows 0 value as mentioned in the
changelog. How about adding that to the documentation here, ie. "when
timeout attribute is not provided the timeout is disabled for the given
operation" or something like that.
Regards,
Arend
