2021-01-19 08:15:06

by Aloka Dixit

Subject: [PATCH V6 1/4] nl80211: add basic multiple bssid support

From: John Crispin <[email protected]>

This patch adds support for passing the multiple bssid config to the
kernel when an AP gets started. If the BSS is non-transmitting we need
to pass

* the ifidx of the transmitting parent
* the BSS index in the set
* the BSS count of the set
* flag indicating if we want to do EMA
* the multiple bssid elements as an array inside the beacon data

This allows use to generate multiple bssid beacons aswell as EMA ones.

Signed-off-by: John Crispin <[email protected]>
Signed-off-by: Aloka Dixit <[email protected]>
---
v6: Addressed V5 review comments such as,
Dynamic memory allocation for netlink structures,
Limits for variable array accepted from driver,
Used _ELEMS instead of _IE in netlink attribute and made it nested,
Used cfg80211_* instead of ieee80211_* for new struct,
Modified descritptions in comments.

include/net/cfg80211.h | 47 +++++++++
include/uapi/linux/nl80211.h | 66 ++++++++++++
net/wireless/nl80211.c | 197 +++++++++++++++++++++++++++++------
3 files changed, 279 insertions(+), 31 deletions(-)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 9a4bbccddc7f..0573626b61d4 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -485,6 +485,21 @@ struct ieee80211_supported_band {
const struct ieee80211_sband_iftype_data *iftype_data;
};

+/**
+ * struct cfg80211_multiple_bssid - AP settings for multi bssid
+ *
+ * @index: the index of this AP in the multi bssid group.
+ * @count: the total number of multi bssid peer APs.
+ * @parent: non-transmitted BSSs transmitted parents index
+ * @ema: Shall the beacons be sent out in EMA mode.
+ */
+struct cfg80211_multiple_bssid {
+ u8 index;
+ u8 count;
+ u32 parent;
+ bool ema;
+};
+
/**
* ieee80211_get_sband_iftype_data - return sband data for a given iftype
* @sband: the sband to search for the STA on
@@ -1032,6 +1047,23 @@ struct cfg80211_crypto_settings {
enum nl80211_sae_pwe_mechanism sae_pwe;
};

+/**
+ * struct cfg80211_multiple_bssid_data - Multiple BSSID elements
+ *
+ * @cnt: Number of elements in array %elems.
+ *
+ * @elems: Array of multiple BSSID element(s) to be added into Beacon frames.
+ * @elems.data: Data for multiple BSSID elements.
+ * @elems.len: Length of data.
+ */
+struct cfg80211_multiple_bssid_data {
+ u8 cnt;
+ struct {
+ u8 *data;
+ size_t len;
+ } elems[];
+};
+
/**
* struct cfg80211_beacon_data - beacon data
* @head: head portion of beacon (before TIM IE)
@@ -1058,6 +1090,7 @@ struct cfg80211_crypto_settings {
* Token (measurement type 11)
* @lci_len: LCI data length
* @civicloc_len: Civic location data length
+ * @multiple_bssid: multiple_bssid elements
*/
struct cfg80211_beacon_data {
const u8 *head, *tail;
@@ -1076,6 +1109,8 @@ struct cfg80211_beacon_data {
size_t probe_resp_len;
size_t lci_len;
size_t civicloc_len;
+
+ struct cfg80211_multiple_bssid_data *multiple_bssid;
};

struct mac_address {
@@ -1181,6 +1216,7 @@ enum cfg80211_ap_settings_flags {
* @he_oper: HE operation IE (or %NULL if HE isn't enabled)
* @fils_discovery: FILS discovery transmission parameters
* @unsol_bcast_probe_resp: Unsolicited broadcast probe response parameters
+ * @multiple_bssid: AP settings for multiple bssid.
*/
struct cfg80211_ap_settings {
struct cfg80211_chan_def chandef;
@@ -1213,6 +1249,7 @@ struct cfg80211_ap_settings {
struct cfg80211_he_bss_color he_bss_color;
struct cfg80211_fils_discovery fils_discovery;
struct cfg80211_unsol_bcast_probe_resp unsol_bcast_probe_resp;
+ struct cfg80211_multiple_bssid multiple_bssid;
};

/**
@@ -4929,6 +4966,11 @@ struct wiphy_iftype_akm_suites {
* @max_data_retry_count: maximum supported per TID retry count for
* configuration through the %NL80211_TID_CONFIG_ATTR_RETRY_SHORT and
* %NL80211_TID_CONFIG_ATTR_RETRY_LONG attributes
+ *
+ * @multiple_bssid: Describes device's multiple BSSID config support
+ * @multiple_bssid.max_num_vaps: Maximum number of VAPS supported by the driver
+ * @multiple_bssid.max_num_elems: Maximum number of multiple BSSID elements
+ * supported by the driver
*/
struct wiphy {
/* assign these fields before you register the wiphy */
@@ -5069,6 +5111,11 @@ struct wiphy {

const struct cfg80211_sar_capa *sar_capa;

+ struct {
+ u8 max_num_vaps;
+ u8 max_profile_periodicity;
+ } multiple_bssid;
+
char priv[] __aligned(NETDEV_ALIGN);
};

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 40832d13c2f1..02e6b4af7786 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -2550,6 +2550,14 @@ enum nl80211_commands {
* disassoc events to indicate that an immediate reconnect to the AP
* is desired.
*
+ * @NL80211_ATTR_MULTIPLE_BSSID_CONFIG: Optional parameter to configure multiple
+ * BSSID and enhanced multi-BSSID advertisements.
+ * It is a nested attribute, see &enum nl80211_multiple_bssid_attributes.
+ *
+ * @NL80211_ATTR_MULTIPLE_BSSID_ELEMS: Optional parameter for multiple BSSID
+ * elements. It is a nested attribute, see
+ * &enum nl80211_multiple_bssid_elems_attributes.
+ *
* @NUM_NL80211_ATTR: total number of nl80211_attrs available
* @NL80211_ATTR_MAX: highest attribute number currently defined
* @__NL80211_ATTR_AFTER_LAST: internal use
@@ -3045,6 +3053,9 @@ enum nl80211_attrs {

NL80211_ATTR_SAR_SPEC,

+ NL80211_ATTR_MULTIPLE_BSSID_CONFIG,
+ NL80211_ATTR_MULTIPLE_BSSID_ELEMS,
+
/* add attributes here, update the policy in nl80211.c */

__NL80211_ATTR_AFTER_LAST,
@@ -7268,4 +7279,59 @@ enum nl80211_sar_specs_attrs {
NL80211_SAR_ATTR_SPECS_MAX = __NL80211_SAR_ATTR_SPECS_LAST - 1,
};

+/**
+ * enum nl80211_multiple_bssid_attributes - Attributes to configure
+ * multiple BSSID and enhanced multi-BSSID advertisements.
+ *
+ * @__NL80211_MULTIPLE_BSSID_ATTR_INVALID: Invalid
+ *
+ * @NL80211_MULTIPLE_BSSID_ATTR_PARENT: For a non-transmitted BSSID, this
+ * attribute provides the interface index (u32) of the transmitted profile
+ * in the multiple BSSID set.
+ *
+ * @NL80211_MULTIPLE_BSSID_ATTR_INDEX: The index of this BSS (u8) inside
+ * multiple BSSID set.
+ *
+ * @NL80211_MULTIPLE_BSSID_ATTR_COUNT: Total number of BSSs (u8) in the
+ * multiple BSSID set.
+ *
+ * @NL80211_MULTIPLE_BSSID_ATTR_EMA: Flag to indicate if enhanced multi-BSSID
+ * advertisements (EMA) feature is enabled.
+ * If set to 1, elements provided through attribute
+ * %NL80211_ATTR_MULTIPLE_BSSID_ELEMS are split into multiple beacons.
+ * Otherwise, all elements will be included in every beacon.
+ */
+enum nl80211_multiple_bssid_attributes {
+ __NL80211_MULTIPLE_BSSID_ATTR_INVALID,
+
+ NL80211_MULTIPLE_BSSID_ATTR_PARENT,
+ NL80211_MULTIPLE_BSSID_ATTR_INDEX,
+ NL80211_MULTIPLE_BSSID_ATTR_COUNT,
+ NL80211_MULTIPLE_BSSID_ATTR_EMA,
+
+ __NL80211_MULTIPLE_BSSID_ATTR_LAST,
+ NL80211_MULTIPLE_BSSID_ATTR_MAX = __NL80211_MULTIPLE_BSSID_ATTR_LAST - 1,
+};
+
+/**
+ * enum nl80211_multiple_bssid_elems_attributes - Attributes used to pass
+ * multiple BSSID elements data.
+ *
+ * @__NL80211_MULTIPLE_BSSID_ELEMS_ATTR_INVALID: Invalid
+ *
+ * @NL80211_MULTIPLE_BSSID_ELEMS_ATTR_COUNT: Number of multiple BSSID
+ * elements (u8).
+ *
+ * @NL80211_MULTIPLE_BSSID_ELEMS_ATTR_DATA: Array of multiple BSSID elements.
+ */
+enum nl80211_multiple_bssid_elems_attributes {
+ __NL80211_MULTIPLE_BSSID_ELEMS_ATTR_INVALID,
+
+ NL80211_MULTIPLE_BSSID_ELEMS_ATTR_COUNT,
+ NL80211_MULTIPLE_BSSID_ELEMS_ATTR_DATA,
+
+ __NL80211_MULTIPLE_BSSID_ELEMS_ATTR_LAST,
+ NL80211_MULTIPLE_BSSID_ELEMS_ATTR_MAX = __NL80211_MULTIPLE_BSSID_ELEMS_ATTR_LAST - 1,
+};
+
#endif /* __LINUX_NL80211_H */
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 775d0c4d86c3..dd2f3370bc24 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -411,6 +411,20 @@ sar_policy[NL80211_SAR_ATTR_MAX + 1] = {
[NL80211_SAR_ATTR_SPECS] = NLA_POLICY_NESTED_ARRAY(sar_specs_policy),
};

+static const struct nla_policy
+nl80211_multiple_bssid_elems_policy[NL80211_MULTIPLE_BSSID_ELEMS_ATTR_MAX + 1] = {
+ [NL80211_MULTIPLE_BSSID_ELEMS_ATTR_COUNT] = { .type = NLA_U8 },
+ [NL80211_MULTIPLE_BSSID_ELEMS_ATTR_DATA] = { .type = NLA_NESTED },
+};
+
+static const struct nla_policy
+nl80211_multiple_bssid_policy[NL80211_MULTIPLE_BSSID_ATTR_MAX + 1] = {
+ [NL80211_MULTIPLE_BSSID_ATTR_PARENT] = { .type = NLA_U32 },
+ [NL80211_MULTIPLE_BSSID_ATTR_INDEX] = { .type = NLA_U8 },
+ [NL80211_MULTIPLE_BSSID_ATTR_COUNT] = { .type = NLA_U8 },
+ [NL80211_MULTIPLE_BSSID_ATTR_EMA] = { .type = NLA_FLAG },
+};
+
static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
[0] = { .strict_start_type = NL80211_ATTR_HE_OBSS_PD },
[NL80211_ATTR_WIPHY] = { .type = NLA_U32 },
@@ -732,6 +746,10 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
NL80211_SAE_PWE_BOTH),
[NL80211_ATTR_RECONNECT_REQUESTED] = { .type = NLA_REJECT },
[NL80211_ATTR_SAR_SPEC] = NLA_POLICY_NESTED(sar_policy),
+ [NL80211_ATTR_MULTIPLE_BSSID_CONFIG] =
+ NLA_POLICY_NESTED(nl80211_multiple_bssid_policy),
+ [NL80211_ATTR_MULTIPLE_BSSID_ELEMS] =
+ NLA_POLICY_NESTED(nl80211_multiple_bssid_elems_policy),
};

/* policy for the key attributes */
@@ -4864,6 +4882,79 @@ static int validate_beacon_tx_rate(struct cfg80211_registered_device *rdev,
return 0;
}

+static int
+nl80211_parse_multiple_bssid_config(struct wiphy *wiphy,
+ struct nlattr *attrs,
+ struct cfg80211_ap_settings *params)
+{
+ struct nlattr *tb[NL80211_MULTIPLE_BSSID_ATTR_MAX + 1];
+ int ret;
+ struct cfg80211_multiple_bssid *config = &params->multiple_bssid;
+
+ ret = nla_parse_nested(tb, NL80211_MULTIPLE_BSSID_ATTR_MAX, attrs, NULL,
+ NULL);
+ if (ret)
+ return ret;
+
+ if (!tb[NL80211_MULTIPLE_BSSID_ATTR_COUNT])
+ return -EINVAL;
+
+ config->count = nla_get_u8(tb[NL80211_MULTIPLE_BSSID_ATTR_COUNT]);
+ if (config->count > wiphy->multiple_bssid.max_num_vaps)
+ return -EINVAL;
+
+ if (tb[NL80211_MULTIPLE_BSSID_ATTR_PARENT])
+ config->parent = nla_get_u32(tb[NL80211_MULTIPLE_BSSID_ATTR_PARENT]);
+
+ if (tb[NL80211_MULTIPLE_BSSID_ATTR_INDEX])
+ config->index = nla_get_u8(tb[NL80211_MULTIPLE_BSSID_ATTR_INDEX]);
+
+ if (tb[NL80211_MULTIPLE_BSSID_ATTR_EMA]) {
+ config->ema = nla_get_flag(tb[NL80211_MULTIPLE_BSSID_ATTR_EMA]);
+ if (config->ema &&
+ params->beacon.multiple_bssid->cnt >
+ wiphy->multiple_bssid.max_profile_periodicity)
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static struct cfg80211_multiple_bssid_data *
+nl80211_parse_multiple_bssid_elems(struct wiphy *wiphy, struct nlattr *attrs)
+{
+ struct cfg80211_multiple_bssid_data *multiple_bssid;
+ struct nlattr *nl_ie;
+ struct nlattr *tb[NL80211_MULTIPLE_BSSID_ELEMS_ATTR_MAX + 1];
+ int rem_ie;
+ u8 i = 0, err, num_elems;
+
+ err = nla_parse_nested(tb, NL80211_MULTIPLE_BSSID_ELEMS_ATTR_MAX,
+ attrs, NULL, NULL);
+ if (err)
+ return NULL;
+
+ if (!tb[NL80211_MULTIPLE_BSSID_ELEMS_ATTR_COUNT] ||
+ !tb[NL80211_MULTIPLE_BSSID_ELEMS_ATTR_DATA])
+ return NULL;
+
+ num_elems = nla_get_u8(tb[NL80211_MULTIPLE_BSSID_ELEMS_ATTR_COUNT]);
+ multiple_bssid = kzalloc(struct_size(multiple_bssid, elems, num_elems),
+ GFP_KERNEL);
+ if (!multiple_bssid)
+ return NULL;
+
+ multiple_bssid->cnt = num_elems;
+ nla_for_each_nested(nl_ie, tb[NL80211_MULTIPLE_BSSID_ELEMS_ATTR_DATA],
+ rem_ie) {
+ multiple_bssid->elems[i].data = nla_data(nl_ie);
+ multiple_bssid->elems[i].len = nla_len(nl_ie);
+ i++;
+ }
+
+ return multiple_bssid;
+}
+
static int nl80211_parse_beacon(struct cfg80211_registered_device *rdev,
struct nlattr *attrs[],
struct cfg80211_beacon_data *bcn)
@@ -4944,6 +5035,14 @@ static int nl80211_parse_beacon(struct cfg80211_registered_device *rdev,
bcn->ftm_responder = -1;
}

+ if (attrs[NL80211_ATTR_MULTIPLE_BSSID_ELEMS]) {
+ bcn->multiple_bssid =
+ nl80211_parse_multiple_bssid_elems(&rdev->wiphy,
+ attrs[NL80211_ATTR_MULTIPLE_BSSID_ELEMS]);
+ if (IS_ERR(bcn->multiple_bssid))
+ return PTR_ERR(bcn->multiple_bssid);
+ }
+
return 0;
}

@@ -5229,7 +5328,7 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)

err = nl80211_parse_beacon(rdev, info->attrs, &params.beacon);
if (err)
- return err;
+ goto out;

params.beacon_interval =
nla_get_u32(info->attrs[NL80211_ATTR_BEACON_INTERVAL]);
@@ -5239,7 +5338,7 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
err = cfg80211_validate_beacon_int(rdev, dev->ieee80211_ptr->iftype,
params.beacon_interval);
if (err)
- return err;
+ goto out;

/*
* In theory, some of these attributes should be required here
@@ -5266,57 +5365,73 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
params.auth_type = nla_get_u32(
info->attrs[NL80211_ATTR_AUTH_TYPE]);
if (!nl80211_valid_auth_type(rdev, params.auth_type,
- NL80211_CMD_START_AP))
- return -EINVAL;
+ NL80211_CMD_START_AP)) {
+ err = -EINVAL;
+ goto out;
+ }
} else
params.auth_type = NL80211_AUTHTYPE_AUTOMATIC;

err = nl80211_crypto_settings(rdev, info, &params.crypto,
NL80211_MAX_NR_CIPHER_SUITES);
if (err)
- return err;
+ goto out;

if (info->attrs[NL80211_ATTR_INACTIVITY_TIMEOUT]) {
- if (!(rdev->wiphy.features & NL80211_FEATURE_INACTIVITY_TIMER))
- return -EOPNOTSUPP;
+ if (!(rdev->wiphy.features & NL80211_FEATURE_INACTIVITY_TIMER)) {
+ err = -EOPNOTSUPP;
+ goto out;
+ }
params.inactivity_timeout = nla_get_u16(
info->attrs[NL80211_ATTR_INACTIVITY_TIMEOUT]);
}

if (info->attrs[NL80211_ATTR_P2P_CTWINDOW]) {
- if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO)
- return -EINVAL;
+ if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO) {
+ err = -EINVAL;
+ goto out;
+ }
params.p2p_ctwindow =
nla_get_u8(info->attrs[NL80211_ATTR_P2P_CTWINDOW]);
if (params.p2p_ctwindow != 0 &&
- !(rdev->wiphy.features & NL80211_FEATURE_P2P_GO_CTWIN))
- return -EINVAL;
+ !(rdev->wiphy.features & NL80211_FEATURE_P2P_GO_CTWIN)) {
+ err = -EINVAL;
+ goto out;
+ }
}

if (info->attrs[NL80211_ATTR_P2P_OPPPS]) {
u8 tmp;

- if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO)
- return -EINVAL;
+ if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO) {
+ err = -EINVAL;
+ goto out;
+ }
tmp = nla_get_u8(info->attrs[NL80211_ATTR_P2P_OPPPS]);
params.p2p_opp_ps = tmp;
if (params.p2p_opp_ps != 0 &&
- !(rdev->wiphy.features & NL80211_FEATURE_P2P_GO_OPPPS))
- return -EINVAL;
+ !(rdev->wiphy.features & NL80211_FEATURE_P2P_GO_OPPPS)) {
+ err = -EINVAL;
+ goto out;
+ }
}

if (info->attrs[NL80211_ATTR_WIPHY_FREQ]) {
err = nl80211_parse_chandef(rdev, info, &params.chandef);
if (err)
- return err;
+ goto out;
} else if (wdev->preset_chandef.chan) {
params.chandef = wdev->preset_chandef;
- } else if (!nl80211_get_ap_channel(rdev, &params))
- return -EINVAL;
+ } else if (!nl80211_get_ap_channel(rdev, &params)) {
+ err = -EINVAL;
+ goto out;
+ }

if (!cfg80211_reg_can_beacon_relax(&rdev->wiphy, &params.chandef,
- wdev->iftype))
- return -EINVAL;
+ wdev->iftype)) {
+ err = -EINVAL;
+ goto out;
+ }

if (info->attrs[NL80211_ATTR_TX_RATES]) {
err = nl80211_parse_tx_bitrate_mask(info, info->attrs,
@@ -5400,6 +5515,14 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
return err;
}

+ if (info->attrs[NL80211_ATTR_MULTIPLE_BSSID_CONFIG]) {
+ err = nl80211_parse_multiple_bssid_config(&rdev->wiphy,
+ info->attrs[NL80211_ATTR_MULTIPLE_BSSID_CONFIG],
+ &params);
+ if (err)
+ goto out;
+ }
+
nl80211_calculate_ap_params(&params);

if (info->attrs[NL80211_ATTR_EXTERNAL_AUTH_SUPPORT])
@@ -5421,7 +5544,7 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)

out:
kfree(params.acl);
-
+ kfree(params.beacon.multiple_bssid);
return err;
}

@@ -5445,12 +5568,14 @@ static int nl80211_set_beacon(struct sk_buff *skb, struct genl_info *info)

err = nl80211_parse_beacon(rdev, info->attrs, &params);
if (err)
- return err;
+ goto out;

wdev_lock(wdev);
err = rdev_change_beacon(rdev, dev, &params);
wdev_unlock(wdev);

+out:
+ kfree(params.multiple_bssid);
return err;
}

@@ -9173,35 +9298,42 @@ static int nl80211_channel_switch(struct sk_buff *skb, struct genl_info *info)
for (i = 0; i < params.n_counter_offsets_presp; i++) {
u16 offset = params.counter_offsets_presp[i];

- if (offset >= params.beacon_csa.probe_resp_len)
- return -EINVAL;
+ if (offset >= params.beacon_csa.probe_resp_len) {
+ err = -EINVAL;
+ goto out;
+ }

if (params.beacon_csa.probe_resp[offset] !=
- params.count)
- return -EINVAL;
+ params.count) {
+ err = -EINVAL;
+ goto out;
+ }
}
}

skip_beacons:
err = nl80211_parse_chandef(rdev, info, &params.chandef);
if (err)
- return err;
+ goto out;

if (!cfg80211_reg_can_beacon_relax(&rdev->wiphy, &params.chandef,
- wdev->iftype))
- return -EINVAL;
+ wdev->iftype)) {
+ err = -EINVAL;
+ goto out;
+ }

err = cfg80211_chandef_dfs_required(wdev->wiphy,
&params.chandef,
wdev->iftype);
if (err < 0)
- return err;
+ goto out;

if (err > 0) {
params.radar_required = true;
if (need_handle_dfs_flag &&
!nla_get_flag(info->attrs[NL80211_ATTR_HANDLE_DFS])) {
- return -EINVAL;
+ err = -EINVAL;
+ goto out;
}
}

@@ -9212,6 +9344,9 @@ static int nl80211_channel_switch(struct sk_buff *skb, struct genl_info *info)
err = rdev_channel_switch(rdev, dev, &params);
wdev_unlock(wdev);

+out:
+ kfree(params.beacon_after.multiple_bssid);
+ kfree(params.beacon_csa.multiple_bssid);
return err;
}

--
2.25.0