cfg80211: support multicast RX registration

For DPP, there's a need to receive multicast action frames,
but many drivers need a special filter configuration for this.

Support announcing from userspace in the management registration
that multicast RX is required, with an extended feature flag if
the driver handles this.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Sergey Matyukevich <sergey.matyukevich.os@quantenna.com>
Link: https://lore.kernel.org/r/20200417124013.c46238801048.Ib041d437ce0bff28a0c6d5dc915f68f1d8591002@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index bc273f6d60f2e224fd964eed7cef93ac1b782f25..dbb9675fe38f55f0c5f2a937a1e99ca710c52e8f 100644 (file)
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -3390,9 +3390,13 @@ struct cfg80211_update_owe_info {
  *     for the entire device
  * @interface_stypes: bitmap of management frame subtypes registered
  *     for the given interface
+ * @global_mcast_rx: mcast RX is needed globally for these subtypes
+ * @interface_mcast_stypes: mcast RX is needed on this interface
+ *     for these subtypes
  */
 struct mgmt_frame_regs {
        u32 global_stypes, interface_stypes;
+       u32 global_mcast_stypes, interface_mcast_stypes;
 };
 
 /**

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index afdd9802ccb831531556d23e07c807e5662251ff..e0dc89eceab863de62b0c064ddbb49385dee3c25 100644 (file)
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -687,6 +687,10 @@
  *     four bytes for vendor frames including the OUI. The registration
  *     cannot be dropped, but is removed automatically when the netlink
  *     socket is closed. Multiple registrations can be made.
+ *     The %NL80211_ATTR_RECEIVE_MULTICAST flag attribute can be given if
+ *     %NL80211_EXT_FEATURE_MULTICAST_REGISTRATIONS is available, in which
+ *     case the registration can also be modified to include/exclude the
+ *     flag, rather than requiring unregistration to change it.
  * @NL80211_CMD_REGISTER_ACTION: Alias for @NL80211_CMD_REGISTER_FRAME for
  *     backward compatibility
  * @NL80211_CMD_FRAME: Management frame TX request and RX notification. This
@@ -2477,6 +2481,9 @@ enum nl80211_commands {
  *     no roaming occurs between the reauth threshold and PMK expiration,
  *     disassociation is still forced.
  *
+ * @NL80211_ATTR_RECEIVE_MULTICAST: multicast flag for the
+ *     %NL80211_CMD_REGISTER_FRAME command, see the description there.
+ *
  * @NUM_NL80211_ATTR: total number of nl80211_attrs available
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
@@ -2952,6 +2959,8 @@ enum nl80211_attrs {
        NL80211_ATTR_PMK_LIFETIME,
        NL80211_ATTR_PMK_REAUTH_THRESHOLD,
 
+       NL80211_ATTR_RECEIVE_MULTICAST,
+
        /* add attributes here, update the policy in nl80211.c */
 
        __NL80211_ATTR_AFTER_LAST,
@@ -5691,6 +5700,9 @@ enum nl80211_feature_flags {
  * @NL80211_EXT_FEATURE_DEL_IBSS_STA: The driver supports removing stations
  *      in IBSS mode, essentially by dropping their state.
  *
+ * @NL80211_EXT_FEATURE_MULTICAST_REGISTRATIONS: management frame registrations
+ *     are possible for multicast frames and those will be reported properly.
+ *
  * @NUM_NL80211_EXT_FEATURES: number of extended features.
  * @MAX_NL80211_EXT_FEATURES: highest extended feature index.
  */
@@ -5742,6 +5754,7 @@ enum nl80211_ext_feature_index {
        NL80211_EXT_FEATURE_CONTROL_PORT_NO_PREAUTH,
        NL80211_EXT_FEATURE_PROTECTED_TWT,
        NL80211_EXT_FEATURE_DEL_IBSS_STA,
+       NL80211_EXT_FEATURE_MULTICAST_REGISTRATIONS,
 
        /* add new features before the definition below */
        NUM_NL80211_EXT_FEATURES,

diff --git a/net/wireless/core.h b/net/wireless/core.h
index 30fb2c35ae43b10473226de0cbe95cf795c6f22e..639d418965734a9f2a235d55314256768a5262a7 100644 (file)
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -381,7 +381,8 @@ void cfg80211_mlme_down(struct cfg80211_registered_device *rdev,
                        struct net_device *dev);
 int cfg80211_mlme_register_mgmt(struct wireless_dev *wdev, u32 snd_pid,
                                u16 frame_type, const u8 *match_data,
-                               int match_len, struct netlink_ext_ack *extack);
+                               int match_len, bool multicast_rx,
+                               struct netlink_ext_ack *extack);
 void cfg80211_mgmt_registrations_update_wk(struct work_struct *wk);
 void cfg80211_mlme_unregister_socket(struct wireless_dev *wdev, u32 nlpid);
 void cfg80211_mlme_purge_registrations(struct wireless_dev *wdev);

diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
index 2e1a21e90b83a597f5a18ed95e3c4a8e68819d17..409497a3527db517997c55bf849e92c4f93132fe 100644 (file)
--- a/net/wireless/mlme.c
+++ b/net/wireless/mlme.c
@@ -426,6 +426,8 @@ struct cfg80211_mgmt_registration {
 
        __le16 frame_type;
 
+       bool multicast_rx;
+
        u8 match[];
 };
 
@@ -442,10 +444,18 @@ static void cfg80211_mgmt_registrations_update(struct wireless_dev *wdev)
        list_for_each_entry_rcu(tmp, &rdev->wiphy.wdev_list, list) {
                list_for_each_entry_rcu(reg, &tmp->mgmt_registrations, list) {
                        u32 mask = BIT(le16_to_cpu(reg->frame_type) >> 4);
+                       u32 mcast_mask = 0;
+
+                       if (reg->multicast_rx)
+                               mcast_mask = mask;
 
                        upd.global_stypes |= mask;
-                       if (tmp == wdev)
+                       upd.global_mcast_stypes |= mcast_mask;
+
+                       if (tmp == wdev) {
                                upd.interface_stypes |= mask;
+                               upd.interface_mcast_stypes |= mcast_mask;
+                       }
                }
        }
        rcu_read_unlock();
@@ -465,11 +475,13 @@ void cfg80211_mgmt_registrations_update_wk(struct work_struct *wk)
 
 int cfg80211_mlme_register_mgmt(struct wireless_dev *wdev, u32 snd_portid,
                                u16 frame_type, const u8 *match_data,
-                               int match_len, struct netlink_ext_ack *extack)
+                               int match_len, bool multicast_rx,
+                               struct netlink_ext_ack *extack)
 {
        struct cfg80211_mgmt_registration *reg, *nreg;
        int err = 0;
        u16 mgmt_type;
+       bool update_multicast = false;
 
        if (!wdev->wiphy->mgmt_stypes)
                return -EOPNOTSUPP;
@@ -520,6 +532,11 @@ int cfg80211_mlme_register_mgmt(struct wireless_dev *wdev, u32 snd_portid,
                        continue;
 
                if (memcmp(reg->match, match_data, mlen) == 0) {
+                       if (reg->multicast_rx != multicast_rx) {
+                               update_multicast = true;
+                               reg->multicast_rx = multicast_rx;
+                               break;
+                       }
                        NL_SET_ERR_MSG(extack, "Match already configured");
                        err = -EALREADY;
                        break;
@@ -529,12 +546,17 @@ int cfg80211_mlme_register_mgmt(struct wireless_dev *wdev, u32 snd_portid,
        if (err)
                goto out;
 
-       memcpy(nreg->match, match_data, match_len);
-       nreg->match_len = match_len;
-       nreg->nlportid = snd_portid;
-       nreg->frame_type = cpu_to_le16(frame_type);
-       nreg->wdev = wdev;
-       list_add(&nreg->list, &wdev->mgmt_registrations);
+       if (update_multicast) {
+               kfree(nreg);
+       } else {
+               memcpy(nreg->match, match_data, match_len);
+               nreg->match_len = match_len;
+               nreg->nlportid = snd_portid;
+               nreg->frame_type = cpu_to_le16(frame_type);
+               nreg->wdev = wdev;
+               nreg->multicast_rx = multicast_rx;
+               list_add(&nreg->list, &wdev->mgmt_registrations);
+       }
        spin_unlock_bh(&wdev->mgmt_registrations_lock);
 
        cfg80211_mgmt_registrations_update(wdev);

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 2127e5344b1a55addb9e242240ca4edd202cd190..73a3e885d4dd14beaf7a637cc10860139d418184 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -661,6 +661,7 @@ const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
        [NL80211_ATTR_CONTROL_PORT_NO_PREAUTH] = { .type = NLA_FLAG },
        [NL80211_ATTR_PMK_LIFETIME] = NLA_POLICY_MIN(NLA_U32, 1),
        [NL80211_ATTR_PMK_REAUTH_THRESHOLD] = NLA_POLICY_RANGE(NLA_U8, 1, 100),
+       [NL80211_ATTR_RECEIVE_MULTICAST] = { .type = NLA_FLAG },
 };
 
 /* policy for the key attributes */
@@ -10773,9 +10774,18 @@ static int nl80211_register_mgmt(struct sk_buff *skb, struct genl_info *info)
        if (!rdev->ops->mgmt_tx)
                return -EOPNOTSUPP;
 
+       if (info->attrs[NL80211_ATTR_RECEIVE_MULTICAST] &&
+           !wiphy_ext_feature_isset(&rdev->wiphy,
+                                    NL80211_EXT_FEATURE_MULTICAST_REGISTRATIONS)) {
+               GENL_SET_ERR_MSG(info,
+                                "multicast RX registrations are not supported");
+               return -EOPNOTSUPP;
+       }
+
        return cfg80211_mlme_register_mgmt(wdev, info->snd_portid, frame_type,
                                           nla_data(info->attrs[NL80211_ATTR_FRAME_MATCH]),
                                           nla_len(info->attrs[NL80211_ATTR_FRAME_MATCH]),
+                                          info->attrs[NL80211_ATTR_RECEIVE_MULTICAST],
                                           info->extack);
 }