Introducing a new feature that the driver can use to indicate the driver/firmware supports configuration of BSS selection criteria upon CONNECT command. This can be useful when multiple BSS-es are found belonging to the same ESS, ie. Infra-BSS with same SSID. The criteria can then be used to offload selection of a preferred BSS.
Reviewed-by: Hante Meuleman <[email protected]> Reviewed-by: Franky (Zhenhui) Lin <[email protected]> Reviewed-by: Pieter-Paul Giesberts <[email protected]> Reviewed-by: Lei Zhang <[email protected]> Signed-off-by: Arend van Spriel <[email protected]> --- include/net/cfg80211.h | 34 ++++++++++++++++++++ include/uapi/linux/nl80211.h | 42 ++++++++++++++++++++++++ net/wireless/core.c | 4 +++ net/wireless/nl80211.c | 76 ++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 156 insertions(+) diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index 9bcaaf7..f571f4a 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -1854,6 +1854,33 @@ struct cfg80211_ibss_params { }; /** + * struct cfg80211_bss_select_adjust - BSS selection with RSSI adjustment. + * + * @band: band of BSS which should match for RSSI level adjustment. + * @delta: value of RSSI level adjustment. + */ +struct cfg80211_bss_select_adjust { + enum nl80211_band band; + s8 delta; +}; + +/** + * struct cfg80211_bss_selection - connection parameters for BSS selection. + * + * @behaviour: requested BSS selection behaviour. + * @param: parameters for requestion behaviour. + * @band_pref: preferred band for %NL80211_BSS_SELECT_ATTR_BAND_PREF. + * @adjust: parameters for %NL80211_BSS_SELECT_ATTR_RSSI_ADJUST. + */ +struct cfg80211_bss_selection { + enum nl80211_bss_select_attr behaviour; + union { + enum nl80211_band band_pref; + struct cfg80211_bss_select_adjust adjust; + } param; +}; + +/** * struct cfg80211_connect_params - Connection parameters * * This structure provides information needed to complete IEEE 802.11 @@ -1888,6 +1915,7 @@ struct cfg80211_ibss_params { * @ht_capa_mask: The bits of ht_capa which are to be used. * @vht_capa: VHT Capability overrides * @vht_capa_mask: The bits of vht_capa which are to be used. + * @bss_select: criteria to be used for BSS selection. */ struct cfg80211_connect_params { struct ieee80211_channel *channel; @@ -1910,6 +1938,7 @@ struct cfg80211_connect_params { struct ieee80211_ht_cap ht_capa_mask; struct ieee80211_vht_cap vht_capa; struct ieee80211_vht_cap vht_capa_mask; + struct cfg80211_bss_selection bss_select; }; /** @@ -3178,6 +3207,9 @@ struct wiphy_vendor_command { * low rssi when a frame is heard on different channel, then it should set * this variable to the maximal offset for which it can compensate. * This value should be set in MHz. + * @bss_select_support: bitmask indicating the BSS selection criteria supported + * by the driver in the .connect() callback. The bit position maps to the + * attribute indices defined in &enum nl80211_bss_select_attr. */ struct wiphy { /* assign these fields before you register the wiphy */ @@ -3300,6 +3332,8 @@ struct wiphy { u8 max_num_csa_counters; u8 max_adj_channel_rssi_comp; + u32 bss_select_support; + char priv[0] __aligned(NETDEV_ALIGN); }; diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h index 5b7b5eb..f3ece95 100644 --- a/include/uapi/linux/nl80211.h +++ b/include/uapi/linux/nl80211.h @@ -1789,6 +1789,12 @@ enum nl80211_commands { * thus it must not specify the number of iterations, only the interval * between scans. The scan plans are executed sequentially. * Each scan plan is a nested attribute of &enum nl80211_sched_scan_plan. + * @NL80211_ATTR_BSS_SELECT: nested attribute for driver supporting the + * BSS selection feature. When used with %NL80211_CMD_GET_WIPHY it contains + * NLA_FLAG type according &enum nl80211_bss_select_attr to indicate what + * BSS selection behaviours are supported. When used with %NL80211_CMD_CONNECT + * it contains the behaviour and parameters for BSS selection to be done by + * driver and/or firmware. * * @NUM_NL80211_ATTR: total number of nl80211_attrs available * @NL80211_ATTR_MAX: highest attribute number currently defined @@ -2164,6 +2170,8 @@ enum nl80211_attrs { NL80211_ATTR_MAX_SCAN_PLAN_ITERATIONS, NL80211_ATTR_SCHED_SCAN_PLANS, + NL80211_ATTR_BSS_SELECT, + /* add attributes here, update the policy in nl80211.c */ __NL80211_ATTR_AFTER_LAST, @@ -4651,4 +4659,38 @@ enum nl80211_sched_scan_plan { __NL80211_SCHED_SCAN_PLAN_AFTER_LAST - 1 }; +/** + * enum nl80211_bss_select_attr - attributes for bss selection. + * + * @__NL80211_BSS_SELECT_ATTR_INVALID: reserved. + * @NL80211_BSS_SELECT_ATTR_RSSI: Flag indicating only RSSI-based BSS selection + * is requested. + * @NL80211_BSS_SELECT_ATTR_BAND_PREF: attribute indicating BSS + * selection should be done such that the specified band is preferred. + * When there are multiple BSS-es in the preferred band, the driver + * shall use RSSI-based BSS selection as a second step. The value of + * this attribute is according to &enum nl80211_band (u32). + * @NL80211_BSS_SELECT_ATTR_RSSI_ADJUST: When present the RSSI level for + * BSS-es in the specified band is to be adjusted before doing + * RSSI-based BSS selection. The attribute value is a packed two-byte + * value. The lower byte contains the adjustment value (s8) and the + * high byte contains the band according &enum nl80211_band. + * @NL80211_BSS_SELECT_ATTR_MAX: highest bss select attribute number. + *@__NL80211_BSS_SELECT_ATTR_AFTER_LAST: internal use. + * + * These attributes are found within %NL80211_ATTR_BSS_SELECT and + * indicate the required BSS selection behaviour which the driver + * should use. + */ +enum nl80211_bss_select_attr { + __NL80211_BSS_SELECT_ATTR_INVALID, + NL80211_BSS_SELECT_ATTR_RSSI, + NL80211_BSS_SELECT_ATTR_BAND_PREF, + NL80211_BSS_SELECT_ATTR_RSSI_ADJUST, + + /* keep last */ + __NL80211_BSS_SELECT_ATTR_AFTER_LAST, + NL80211_BSS_SELECT_ATTR_MAX = __NL80211_BSS_SELECT_ATTR_AFTER_LAST - 1 +}; + #endif /* __LINUX_NL80211_H */ diff --git a/net/wireless/core.c b/net/wireless/core.c index 3a9c41b..f6b2976 100644 --- a/net/wireless/core.c +++ b/net/wireless/core.c @@ -626,6 +626,10 @@ int wiphy_register(struct wiphy *wiphy) !rdev->ops->set_mac_acl))) return -EINVAL; + if (WARN_ON(wiphy->bss_select_support && + (wiphy->bss_select_support & ~(BIT(NL80211_BSS_SELECT_ATTR_MAX) - 1)))) + return -EINVAL; + if (wiphy->addresses) memcpy(wiphy->perm_addr, wiphy->addresses[0].addr, ETH_ALEN); diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index d4786f2..e17044d 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -485,6 +485,13 @@ nl80211_plan_policy[NL80211_SCHED_SCAN_PLAN_MAX + 1] = { [NL80211_SCHED_SCAN_PLAN_ITERATIONS] = { .type = NLA_U32 }, }; +static const struct nla_policy +nl80211_bss_select_policy[NL80211_BSS_SELECT_ATTR_MAX + 1] = { + [NL80211_BSS_SELECT_ATTR_RSSI] = { .type = NLA_FLAG }, + [NL80211_BSS_SELECT_ATTR_BAND_PREF] = { .type = NLA_U32 }, + [NL80211_BSS_SELECT_ATTR_RSSI_ADJUST] = { .type = NLA_U8 }, +}; + static int nl80211_prepare_wdev_dump(struct sk_buff *skb, struct netlink_callback *cb, struct cfg80211_registered_device **rdev, @@ -1730,6 +1737,24 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *rdev, rdev->wiphy.ext_features)) goto nla_put_failure; + if (rdev->wiphy.bss_select_support) { + struct nlattr *nested; + u32 bss_select_support = rdev->wiphy.bss_select_support; + + nested = nla_nest_start(msg, NL80211_ATTR_BSS_SELECT); + if (!nested) + goto nla_put_failure; + + i = 0; + while (bss_select_support) { + if ((bss_select_support & 1) && + nla_put_flag(msg, i)) + goto nla_put_failure; + i++; + bss_select_support >>= 1; + } + nla_nest_end(msg, nested); + } /* done */ state->split_start = 0; break; @@ -5753,6 +5778,42 @@ static int validate_scan_freqs(struct nlattr *freqs) return n_channels; } +static int parse_bss_select(struct nlattr *nla, + struct cfg80211_bss_selection *bss_select) +{ + struct nlattr *attr[NL80211_BSS_SELECT_ATTR_MAX + 1]; + u16 band_delta; + int err; + + err = nla_parse(attr, NL80211_BSS_SELECT_ATTR_MAX, + nla_data(nla), nla_len(nla), nl80211_bss_select_policy); + if (err) + return err; + + bss_select->behaviour = __NL80211_BSS_SELECT_ATTR_INVALID; + + if (attr[NL80211_BSS_SELECT_ATTR_RSSI]) + bss_select->behaviour = NL80211_BSS_SELECT_ATTR_RSSI; + + if (attr[NL80211_BSS_SELECT_ATTR_BAND_PREF]) { + bss_select->behaviour = NL80211_BSS_SELECT_ATTR_BAND_PREF; + bss_select->param.band_pref = + nla_get_u32(attr[NL80211_BSS_SELECT_ATTR_BAND_PREF]); + } + if (attr[NL80211_BSS_SELECT_ATTR_RSSI_ADJUST]) { + bss_select->behaviour = NL80211_BSS_SELECT_ATTR_RSSI_ADJUST; + band_delta = + nla_get_u16(attr[NL80211_BSS_SELECT_ATTR_RSSI_ADJUST]); + bss_select->param.adjust.delta = (s8)(band_delta & 0xFF); + bss_select->param.adjust.band = band_delta >> 8; + } + + if (bss_select->behaviour == __NL80211_BSS_SELECT_ATTR_INVALID) + return -EINVAL; + + return 0; +} + static int nl80211_parse_random_mac(struct nlattr **attrs, u8 *mac_addr, u8 *mac_addr_mask) { @@ -7980,6 +8041,21 @@ static int nl80211_connect(struct sk_buff *skb, struct genl_info *info) connect.flags |= ASSOC_REQ_USE_RRM; } + /* only do bss selection when no BSSID is specified. */ + if (!connect.bssid && rdev->wiphy.bss_select_support && + info->attrs[NL80211_ATTR_BSS_SELECT]) { + err = parse_bss_select(info->attrs[NL80211_ATTR_BSS_SELECT], + &connect.bss_select); + if (err) { + kzfree(connkeys); + return err; + } + if (!(rdev->wiphy.bss_select_support & BIT(connect.bss_select.behaviour))) { + kzfree(connkeys); + return -EINVAL; + } + } + wdev_lock(dev->ieee80211_ptr); err = cfg80211_connect(rdev, dev, &connect, connkeys, NULL); wdev_unlock(dev->ieee80211_ptr); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
