On 23-11-2016 23:07, Jouni Malinen wrote: > From: vamsi krishna <vamsin@xxxxxxxxxxxxxxxx> > > Enhance sched scan to support option of finding a better BSS while in > connected state. Firmware scans the medium and reports when it finds a > known BSS which has a significantly better RSSI than the current > connected BSS. I suppose the intent here is to be notified about roaming candidates and hence the "connected state" prerequisite. It seems there has already been taken a shot at this which may be used/extended [1]. Regards, Arend [1] http://lxr.free-electrons.com/source/include/uapi/linux/nl80211.h#L2945 [2] http://lxr.free-electrons.com/source/include/uapi/linux/nl80211.h#L4826 > Signed-off-by: vamsi krishna <vamsin@xxxxxxxxxxxxxxxx> > Signed-off-by: Jouni Malinen <jouni@xxxxxxxxxxxxxxxx> > --- > include/net/cfg80211.h | 17 +++++++++++++++++ > include/uapi/linux/nl80211.h | 17 +++++++++++++++++ > net/wireless/nl80211.c | 32 ++++++++++++++++++++++++++++++-- > 3 files changed, 64 insertions(+), 2 deletions(-) > > diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h > index ef42749..c62c42a 100644 > --- a/include/net/cfg80211.h > +++ b/include/net/cfg80211.h > @@ -1626,6 +1626,20 @@ struct cfg80211_sched_scan_plan { > * cycle. The driver may ignore this parameter and start > * immediately (or at any other time), if this feature is not > * supported. > + * @relative_rssi: Relative RSSI threshold to restrict scan result reporting in > + * connected state to cases where a matching BSS is determined to have a > + * significantly better RSSI than the current connected BSS. > + * @relative_rssi_5g_pref: The amount of RSSI preference that is given to a > + * 5 GHz BSS over 2.4 GHz BSS while looking for better BSSs in connected > + * state. > + * If the current connected BSS is in the 2.4 GHz band, other BSSs in the > + * 2.4 GHz band to be reported should have better RSSI by @relative_rssi > + * and other BSSs in the 5 GHz band to be reported should have better RSSI > + * by (@relative_rssi - @relative_rssi_5g_pref). > + * If the current connected BSS is in the 5 GHz band, other BSSs in the > + * 2.4 GHz band to be reported should have better RSSI by > + * (@relative_rssi + @relative_rssi_5g_pref) and other BSSs in the 5 GHz > + * band to be reported should have better RSSI by by @relative_rssi. > */ > struct cfg80211_sched_scan_request { > struct cfg80211_ssid *ssids; > @@ -1645,6 +1659,9 @@ struct cfg80211_sched_scan_request { > u8 mac_addr[ETH_ALEN] __aligned(2); > u8 mac_addr_mask[ETH_ALEN] __aligned(2); > > + int relative_rssi; > + int relative_rssi_5g_pref; I suppose s8 would be sufficient here, right? > /* internal */ > struct wiphy *wiphy; > struct net_device *dev; > diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h > index 984a35ac..34b16a4 100644 > --- a/include/uapi/linux/nl80211.h > +++ b/include/uapi/linux/nl80211.h > @@ -1981,6 +1981,16 @@ enum nl80211_commands { > * %NL80211_ATTR_MAC has also been used in various commands/events for > * specifying the BSSID. > * > + * @NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI: Relative RSSI threshold by which > + * other BSSs has to be better than the current connected BSS so that they > + * get reported to user space. This will give an opportunity to userspace > + * to consider connecting to other matching BSSs which have better RSSI > + * than the current connected BSS. > + * > + * @NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI_5G_PREF: The amount of RSSI preference > + * to be given to 5 GHz APs over 2.4 GHz APs while searching for better > + * BSSs than the current connected BSS. > + * > * @NUM_NL80211_ATTR: total number of nl80211_attrs available > * @NL80211_ATTR_MAX: highest attribute number currently defined > * @__NL80211_ATTR_AFTER_LAST: internal use > @@ -2387,6 +2397,9 @@ enum nl80211_attrs { > > NL80211_ATTR_BSSID, > > + NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI, > + NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI_5G_PREF, > + > /* add attributes here, update the policy in nl80211.c */ > > __NL80211_ATTR_AFTER_LAST, > @@ -4698,6 +4711,9 @@ enum nl80211_feature_flags { > * configuration (AP/mesh) with VHT rates. > * @NL80211_EXT_FEATURE_FILS_STA: This driver supports Fast Initial Link Setup > * with user space SME (NL80211_CMD_AUTHENTICATE) in station mode. > + * @NL80211_EXT_FEATURE_SCHED_SCAN_BETTER_BSS: The driver supports sched_scan > + * for reporting BSSs with better RSSI than the current connected BSS > + * (%NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI). > * > * @NUM_NL80211_EXT_FEATURES: number of extended features. > * @MAX_NL80211_EXT_FEATURES: highest extended feature index. > @@ -4713,6 +4729,7 @@ enum nl80211_ext_feature_index { > NL80211_EXT_FEATURE_BEACON_RATE_HT, > NL80211_EXT_FEATURE_BEACON_RATE_VHT, > NL80211_EXT_FEATURE_FILS_STA, > + NL80211_EXT_FEATURE_SCHED_SCAN_BETTER_BSS, > > /* add new features before the definition below */ > NUM_NL80211_EXT_FEATURES, > diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c > index 8db5cb1..af018a5 100644 > --- a/net/wireless/nl80211.c > +++ b/net/wireless/nl80211.c > @@ -405,6 +405,8 @@ enum nl80211_multicast_groups { > [NL80211_ATTR_FILS_NONCES] = { .len = 2 * FILS_NONCE_LEN }, > [NL80211_ATTR_MULTICAST_TO_UNICAST_ENABLED] = { .type = NLA_FLAG, }, > [NL80211_ATTR_BSSID] = { .len = ETH_ALEN }, > + [NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI] = { .type = NLA_U32 }, > + [NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI_5G_PREF] = { .type = NLA_U32 }, Related to earlier comment this could be NLA_U8. > }; > > /* policy for the key attributes */ > @@ -6856,6 +6858,7 @@ static int nl80211_abort_scan(struct sk_buff *skb, struct genl_info *info) > size_t ie_len; > struct nlattr *tb[NL80211_SCHED_SCAN_MATCH_ATTR_MAX + 1]; > s32 default_match_rssi = NL80211_SCAN_RSSI_THOLD_OFF; > + int bbr; > > if (!is_valid_ie_attr(attrs[NL80211_ATTR_IE])) > return ERR_PTR(-EINVAL); > @@ -6950,6 +6953,13 @@ static int nl80211_abort_scan(struct sk_buff *skb, struct genl_info *info) > if (!n_plans || n_plans > wiphy->max_sched_scan_plans) > return ERR_PTR(-EINVAL); > > + bbr = wiphy_ext_feature_isset( > + wiphy, NL80211_EXT_FEATURE_SCHED_SCAN_BETTER_BSS); > + if (!bbr && > + (attrs[NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI] || > + attrs[NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI_5G_PREF])) > + return ERR_PTR(-EINVAL); > + > request = kzalloc(sizeof(*request) > + sizeof(*request->ssids) * n_ssids > + sizeof(*request->match_sets) * n_match_sets > @@ -7156,6 +7166,14 @@ static int nl80211_abort_scan(struct sk_buff *skb, struct genl_info *info) > request->delay = > nla_get_u32(attrs[NL80211_ATTR_SCHED_SCAN_DELAY]); > > + if (attrs[NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI]) > + request->relative_rssi = nla_get_s32( > + attrs[NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI]); > + > + if (attrs[NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI_5G_PREF]) > + request->relative_rssi_5g_pref = nla_get_s32( > + attrs[NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI_5G_PREF]); > + > err = nl80211_parse_sched_scan_plans(wiphy, n_plans, request, attrs); > if (err) > goto out_free; > @@ -9649,7 +9667,8 @@ static int nl80211_send_wowlan_tcp(struct sk_buff *msg, > return 0; > } > > -static int nl80211_send_wowlan_nd(struct sk_buff *msg, > +static int nl80211_send_wowlan_nd(struct wiphy *wiphy, > + struct sk_buff *msg, > struct cfg80211_sched_scan_request *req) > { > struct nlattr *nd, *freqs, *matches, *match, *scan_plans, *scan_plan; > @@ -9670,6 +9689,15 @@ static int nl80211_send_wowlan_nd(struct sk_buff *msg, > if (nla_put_u32(msg, NL80211_ATTR_SCHED_SCAN_DELAY, req->delay)) > return -ENOBUFS; > > + if (wiphy_ext_feature_isset( > + wiphy, NL80211_EXT_FEATURE_SCHED_SCAN_BETTER_BSS) && > + (nla_put_u32(msg, NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI, > + req->relative_rssi) || > + nla_put_u32(msg, > + NL80211_ATTR_SCHED_SCAN_RELATIVE_RSSI_5G_PREF, > + req->relative_rssi_5g_pref))) > + return -ENOBUFS; > + > freqs = nla_nest_start(msg, NL80211_ATTR_SCAN_FREQUENCIES); > if (!freqs) > return -ENOBUFS; > @@ -9783,7 +9811,7 @@ static int nl80211_get_wowlan(struct sk_buff *skb, struct genl_info *info) > goto nla_put_failure; > > if (nl80211_send_wowlan_nd( > - msg, > + &rdev->wiphy, msg, > rdev->wiphy.wowlan_config->nd_config)) > goto nla_put_failure; > >
