From 38de03d2a28925b489c11546804e2f5418cc17a4 Mon Sep 17 00:00:00 2001 From: Arend van Spriel Date: Wed, 2 Mar 2016 20:37:18 +0100 Subject: nl80211: add feature for BSS selection support 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 Reviewed-by: Franky (Zhenhui) Lin Reviewed-by: Pieter-Paul Giesberts Reviewed-by: Lei Zhang Signed-off-by: Arend van Spriel [move wiphy support check into parse_bss_select()] Signed-off-by: Johannes Berg --- net/wireless/core.c | 7 ++++ net/wireless/nl80211.c | 111 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 118 insertions(+) (limited to 'net/wireless') diff --git a/net/wireless/core.c b/net/wireless/core.c index 9f1c4aa851ef..5327e4b974fa 100644 --- a/net/wireless/core.c +++ b/net/wireless/core.c @@ -626,6 +626,13 @@ int wiphy_register(struct wiphy *wiphy) !rdev->ops->set_mac_acl))) return -EINVAL; + /* assure only valid behaviours are flagged by driver + * hence subtract 2 as bit 0 is invalid. + */ + if (WARN_ON(wiphy->bss_select_support && + (wiphy->bss_select_support & ~(BIT(__NL80211_BSS_SELECT_ATTR_AFTER_LAST) - 2)))) + 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 1b43f7839eeb..d6c6449c0389 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -402,6 +402,7 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = { [NL80211_ATTR_SCHED_SCAN_DELAY] = { .type = NLA_U32 }, [NL80211_ATTR_REG_INDOOR] = { .type = NLA_FLAG }, [NL80211_ATTR_PBSS] = { .type = NLA_FLAG }, + [NL80211_ATTR_BSS_SELECT] = { .type = NLA_NESTED }, }; /* policy for the key attributes */ @@ -486,6 +487,15 @@ 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] = { + .len = sizeof(struct nl80211_bss_select_rssi_adjust) + }, +}; + static int nl80211_prepare_wdev_dump(struct sk_buff *skb, struct netlink_callback *cb, struct cfg80211_registered_device **rdev, @@ -1731,6 +1741,25 @@ 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; @@ -5758,6 +5787,73 @@ static int validate_scan_freqs(struct nlattr *freqs) return n_channels; } +static bool is_band_valid(struct wiphy *wiphy, enum ieee80211_band b) +{ + return b < IEEE80211_NUM_BANDS && wiphy->bands[b]; +} + +static int parse_bss_select(struct nlattr *nla, struct wiphy *wiphy, + struct cfg80211_bss_selection *bss_select) +{ + struct nlattr *attr[NL80211_BSS_SELECT_ATTR_MAX + 1]; + struct nlattr *nest; + int err; + bool found = false; + int i; + + /* only process one nested attribute */ + nest = nla_data(nla); + if (!nla_ok(nest, nla_len(nest))) + return -EINVAL; + + err = nla_parse(attr, NL80211_BSS_SELECT_ATTR_MAX, nla_data(nest), + nla_len(nest), nl80211_bss_select_policy); + if (err) + return err; + + /* only one attribute may be given */ + for (i = 0; i <= NL80211_BSS_SELECT_ATTR_MAX; i++) { + if (attr[i]) { + if (found) + return -EINVAL; + found = true; + } + } + + 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 (!is_band_valid(wiphy, bss_select->param.band_pref)) + return -EINVAL; + } + + if (attr[NL80211_BSS_SELECT_ATTR_RSSI_ADJUST]) { + struct nl80211_bss_select_rssi_adjust *adj_param; + + adj_param = nla_data(attr[NL80211_BSS_SELECT_ATTR_RSSI_ADJUST]); + bss_select->behaviour = NL80211_BSS_SELECT_ATTR_RSSI_ADJUST; + bss_select->param.adjust.band = adj_param->band; + bss_select->param.adjust.delta = adj_param->delta; + if (!is_band_valid(wiphy, bss_select->param.adjust.band)) + return -EINVAL; + } + + /* user-space did not provide behaviour attribute */ + if (bss_select->behaviour == __NL80211_BSS_SELECT_ATTR_INVALID) + return -EINVAL; + + if (!(wiphy->bss_select_support & BIT(bss_select->behaviour))) + return -EINVAL; + + return 0; +} + static int nl80211_parse_random_mac(struct nlattr **attrs, u8 *mac_addr, u8 *mac_addr_mask) { @@ -8001,6 +8097,21 @@ static int nl80211_connect(struct sk_buff *skb, struct genl_info *info) return -EOPNOTSUPP; } + if (info->attrs[NL80211_ATTR_BSS_SELECT]) { + /* bss selection makes no sense if bssid is set */ + if (connect.bssid) { + kzfree(connkeys); + return -EINVAL; + } + + err = parse_bss_select(info->attrs[NL80211_ATTR_BSS_SELECT], + wiphy, &connect.bss_select); + if (err) { + kzfree(connkeys); + return err; + } + } + wdev_lock(dev->ieee80211_ptr); err = cfg80211_connect(rdev, dev, &connect, connkeys, NULL); wdev_unlock(dev->ieee80211_ptr); -- cgit v1.2.3