mac802154: Handle received BEACON_REQ

When performing an active scan, devices emit BEACON_REQ which
must be answered by other PANs receiving the request, unless they are
already passively sending beacons.

Answering a beacon request becomes a duty when the user tells us to send
beacons and the request provides an interval of 15.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20230310145346.1397068-5-miquel.raynal@bootlin.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>

diff --git a/include/net/ieee802154_netdev.h b/include/net/ieee802154_netdev.h
index 257c9b2e9c9add1ef6a2a35335e7a1eefc931566..063313df447da0716d9c001ad0046304ccf22a3d 100644 (file)
--- a/include/net/ieee802154_netdev.h
+++ b/include/net/ieee802154_netdev.h
@@ -193,6 +193,8 @@ int ieee802154_beacon_push(struct sk_buff *skb,
                           struct ieee802154_beacon_frame *beacon);
 int ieee802154_mac_cmd_push(struct sk_buff *skb, void *frame,
                            const void *pl, unsigned int pl_len);
+int ieee802154_mac_cmd_pl_pull(struct sk_buff *skb,
+                              struct ieee802154_mac_cmd_pl *mac_pl);
 
 int ieee802154_max_payload(const struct ieee802154_hdr *hdr);
 

diff --git a/net/ieee802154/header_ops.c b/net/ieee802154/header_ops.c
index a5ff1017a4b2303f20cc9107d16082a821d7d7ab..41a556be101790b305a13c34b46fbd8f4f321a92 100644 (file)
--- a/net/ieee802154/header_ops.c
+++ b/net/ieee802154/header_ops.c
@@ -307,6 +307,19 @@ ieee802154_hdr_pull(struct sk_buff *skb, struct ieee802154_hdr *hdr)
 }
 EXPORT_SYMBOL_GPL(ieee802154_hdr_pull);
 
+int ieee802154_mac_cmd_pl_pull(struct sk_buff *skb,
+                              struct ieee802154_mac_cmd_pl *mac_pl)
+{
+       if (!pskb_may_pull(skb, sizeof(*mac_pl)))
+               return -EINVAL;
+
+       memcpy(mac_pl, skb->data, sizeof(*mac_pl));
+       skb_pull(skb, sizeof(*mac_pl));
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(ieee802154_mac_cmd_pl_pull);
+
 int
 ieee802154_hdr_peek_addrs(const struct sk_buff *skb, struct ieee802154_hdr *hdr)
 {

diff --git a/net/mac802154/ieee802154_i.h b/net/mac802154/ieee802154_i.h
index 7bfd5411a1641c88e4ac518b4c45698419d63e35..c347ec9ff8c942cd38e7d75c83b79bcc832dccd9 100644 (file)
--- a/net/mac802154/ieee802154_i.h
+++ b/net/mac802154/ieee802154_i.h
@@ -71,6 +71,8 @@ struct ieee802154_local {
        /* Asynchronous tasks */
        struct list_head rx_beacon_list;
        struct work_struct rx_beacon_work;
+       struct list_head rx_mac_cmd_list;
+       struct work_struct rx_mac_cmd_work;
 
        bool started;
        bool suspended;
@@ -155,6 +157,22 @@ ieee802154_sdata_running(struct ieee802154_sub_if_data *sdata)
        return test_bit(SDATA_STATE_RUNNING, &sdata->state);
 }
 
+static inline int ieee802154_get_mac_cmd(struct sk_buff *skb, u8 *mac_cmd)
+{
+       struct ieee802154_mac_cmd_pl mac_pl;
+       int ret;
+
+       if (mac_cb(skb)->type != IEEE802154_FC_TYPE_MAC_CMD)
+               return -EINVAL;
+
+       ret = ieee802154_mac_cmd_pl_pull(skb, &mac_pl);
+       if (ret)
+               return ret;
+
+       *mac_cmd = mac_pl.cmd_id;
+       return 0;
+}
+
 extern struct ieee802154_mlme_ops mac802154_mlme_wpan;
 
 void ieee802154_rx(struct ieee802154_local *local, struct sk_buff *skb);
@@ -276,6 +294,8 @@ static inline bool mac802154_is_beaconing(struct ieee802154_local *local)
        return test_bit(IEEE802154_IS_BEACONING, &local->ongoing);
 }
 
+void mac802154_rx_mac_cmd_worker(struct work_struct *work);
+
 /* interface handling */
 int ieee802154_iface_init(void);
 void ieee802154_iface_exit(void);

diff --git a/net/mac802154/main.c b/net/mac802154/main.c
index ee23e234b998b3e7fff3c1d34f06461511e4cb61..357ece67432b1a6ea9288244123137e835fe1ab7 100644 (file)
--- a/net/mac802154/main.c
+++ b/net/mac802154/main.c
@@ -90,6 +90,7 @@ ieee802154_alloc_hw(size_t priv_data_len, const struct ieee802154_ops *ops)
 
        INIT_LIST_HEAD(&local->interfaces);
        INIT_LIST_HEAD(&local->rx_beacon_list);
+       INIT_LIST_HEAD(&local->rx_mac_cmd_list);
        mutex_init(&local->iflist_mtx);
 
        tasklet_setup(&local->tasklet, ieee802154_tasklet_handler);
@@ -100,6 +101,7 @@ ieee802154_alloc_hw(size_t priv_data_len, const struct ieee802154_ops *ops)
        INIT_DELAYED_WORK(&local->scan_work, mac802154_scan_worker);
        INIT_WORK(&local->rx_beacon_work, mac802154_rx_beacon_worker);
        INIT_DELAYED_WORK(&local->beacon_work, mac802154_beacon_worker);
+       INIT_WORK(&local->rx_mac_cmd_work, mac802154_rx_mac_cmd_worker);
 
        /* init supported flags with 802.15.4 default ranges */
        phy->supported.max_minbe = 8;

diff --git a/net/mac802154/rx.c b/net/mac802154/rx.c
index da0628ee3c890b5ca60375cfa0c671dcbd3318f7..e2434b4fe51497e0c7941a5369c5974f1cee2c5f 100644 (file)
--- a/net/mac802154/rx.c
+++ b/net/mac802154/rx.c
@@ -47,6 +47,62 @@ void mac802154_rx_beacon_worker(struct work_struct *work)
        kfree(mac_pkt);
 }
 
+static bool mac802154_should_answer_beacon_req(struct ieee802154_local *local)
+{
+       struct cfg802154_beacon_request *beacon_req;
+       unsigned int interval;
+
+       rcu_read_lock();
+       beacon_req = rcu_dereference(local->beacon_req);
+       if (!beacon_req) {
+               rcu_read_unlock();
+               return false;
+       }
+
+       interval = beacon_req->interval;
+       rcu_read_unlock();
+
+       if (!mac802154_is_beaconing(local))
+               return false;
+
+       return interval == IEEE802154_ACTIVE_SCAN_DURATION;
+}
+
+void mac802154_rx_mac_cmd_worker(struct work_struct *work)
+{
+       struct ieee802154_local *local =
+               container_of(work, struct ieee802154_local, rx_mac_cmd_work);
+       struct cfg802154_mac_pkt *mac_pkt;
+       u8 mac_cmd;
+       int rc;
+
+       mac_pkt = list_first_entry_or_null(&local->rx_mac_cmd_list,
+                                          struct cfg802154_mac_pkt, node);
+       if (!mac_pkt)
+               return;
+
+       rc = ieee802154_get_mac_cmd(mac_pkt->skb, &mac_cmd);
+       if (rc)
+               goto out;
+
+       switch (mac_cmd) {
+       case IEEE802154_CMD_BEACON_REQ:
+               dev_dbg(&mac_pkt->sdata->dev->dev, "processing BEACON REQ\n");
+               if (!mac802154_should_answer_beacon_req(local))
+                       break;
+
+               queue_delayed_work(local->mac_wq, &local->beacon_work, 0);
+               break;
+       default:
+               break;
+       }
+
+out:
+       list_del(&mac_pkt->node);
+       kfree_skb(mac_pkt->skb);
+       kfree(mac_pkt);
+}
+
 static int
 ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata,
                       struct sk_buff *skb, const struct ieee802154_hdr *hdr)
@@ -140,8 +196,20 @@ ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata,
                list_add_tail(&mac_pkt->node, &sdata->local->rx_beacon_list);
                queue_work(sdata->local->mac_wq, &sdata->local->rx_beacon_work);
                return NET_RX_SUCCESS;
-       case IEEE802154_FC_TYPE_ACK:
+
        case IEEE802154_FC_TYPE_MAC_CMD:
+               dev_dbg(&sdata->dev->dev, "MAC COMMAND received\n");
+               mac_pkt = kzalloc(sizeof(*mac_pkt), GFP_ATOMIC);
+               if (!mac_pkt)
+                       goto fail;
+
+               mac_pkt->skb = skb_get(skb);
+               mac_pkt->sdata = sdata;
+               list_add_tail(&mac_pkt->node, &sdata->local->rx_mac_cmd_list);
+               queue_work(sdata->local->mac_wq, &sdata->local->rx_mac_cmd_work);
+               return NET_RX_SUCCESS;
+
+       case IEEE802154_FC_TYPE_ACK:
                goto fail;
 
        case IEEE802154_FC_TYPE_DATA:

diff --git a/net/mac802154/scan.c b/net/mac802154/scan.c
index 201bfc567a439814f3b78d4f06e8ac977e90bc57..618553a2e02682a73aeda3bd44382d26156d2e26 100644 (file)
--- a/net/mac802154/scan.c
+++ b/net/mac802154/scan.c
@@ -403,6 +403,7 @@ void mac802154_beacon_worker(struct work_struct *work)
        struct cfg802154_beacon_request *beacon_req;
        struct ieee802154_sub_if_data *sdata;
        struct wpan_dev *wpan_dev;
+       u8 interval;
        int ret;
 
        rcu_read_lock();
@@ -423,6 +424,7 @@ void mac802154_beacon_worker(struct work_struct *work)
        }
 
        wpan_dev = beacon_req->wpan_dev;
+       interval = beacon_req->interval;
 
        rcu_read_unlock();
 
@@ -432,8 +434,9 @@ void mac802154_beacon_worker(struct work_struct *work)
                dev_err(&sdata->dev->dev,
                        "Beacon could not be transmitted (%d)\n", ret);
 
-       queue_delayed_work(local->mac_wq, &local->beacon_work,
-                          local->beacon_interval);
+       if (interval < IEEE802154_ACTIVE_SCAN_DURATION)
+               queue_delayed_work(local->mac_wq, &local->beacon_work,
+                                  local->beacon_interval);
 }
 
 int mac802154_stop_beacons_locked(struct ieee802154_local *local,
@@ -488,13 +491,17 @@ int mac802154_send_beacons_locked(struct ieee802154_sub_if_data *sdata,
        local->beacon.mhr.source.pan_id = request->wpan_dev->pan_id;
        local->beacon.mhr.source.extended_addr = request->wpan_dev->extended_addr;
        local->beacon.mac_pl.beacon_order = request->interval;
-       local->beacon.mac_pl.superframe_order = request->interval;
+       if (request->interval <= IEEE802154_MAX_SCAN_DURATION)
+               local->beacon.mac_pl.superframe_order = request->interval;
        local->beacon.mac_pl.final_cap_slot = 0xf;
        local->beacon.mac_pl.battery_life_ext = 0;
-       /* TODO: Fill this field depending on the coordinator capacity */
+       /* TODO: Fill this field with the coordinator situation in the network */
        local->beacon.mac_pl.pan_coordinator = 1;
        local->beacon.mac_pl.assoc_permit = 1;
 
+       if (request->interval == IEEE802154_ACTIVE_SCAN_DURATION)
+               return 0;
+
        /* Start the beacon work */
        local->beacon_interval =
                mac802154_scan_get_channel_time(request->interval,