From 3accf4762734a69ebd03cba989249c78ac7dfc7e Mon Sep 17 00:00:00 2001 From: Miquel Raynal Date: Wed, 25 Jan 2023 11:29:23 +0100 Subject: [PATCH] mac802154: Handle basic beaconing Implement the core hooks in order to provide the softMAC layer support for sending beacons. Coordinators may be requested to send beacons in a beacon enabled PAN in order for the other devices around to self discover the available PANs automatically. Changing the channels is prohibited while a beacon operation is ongoing. The implementation uses a workqueue triggered at a certain interval depending on the symbol duration for the current channel and the interval order provided. Sending beacons in response to a BEACON_REQ frame (ie. answering active scans) is not yet supported. This initial patchset has no security support (llsec). Co-developed-by: David Girault Signed-off-by: David Girault Signed-off-by: Miquel Raynal Acked-by: Alexander Aring Link: https://lore.kernel.org/r/20230125102923.135465-3-miquel.raynal@bootlin.com Signed-off-by: Stefan Schmidt --- include/net/ieee802154_netdev.h | 16 +++++ net/ieee802154/header_ops.c | 24 +++++++ net/mac802154/cfg.c | 31 ++++++++- net/mac802154/ieee802154_i.h | 18 +++++ net/mac802154/iface.c | 3 + net/mac802154/llsec.c | 5 +- net/mac802154/main.c | 1 + net/mac802154/scan.c | 151 ++++++++++++++++++++++++++++++++++++++++ 8 files changed, 246 insertions(+), 3 deletions(-) diff --git a/include/net/ieee802154_netdev.h b/include/net/ieee802154_netdev.h index 2f21960..da8a3e6 100644 --- a/include/net/ieee802154_netdev.h +++ b/include/net/ieee802154_netdev.h @@ -129,6 +129,13 @@ enum ieee802154_frame_version { IEEE802154_MULTIPURPOSE_STD = IEEE802154_2003_STD, }; +enum ieee802154_addressing_mode { + IEEE802154_NO_ADDRESSING, + IEEE802154_RESERVED, + IEEE802154_SHORT_ADDRESSING, + IEEE802154_EXTENDED_ADDRESSING, +}; + struct ieee802154_hdr { struct ieee802154_hdr_fc fc; u8 seq; @@ -137,6 +144,11 @@ struct ieee802154_hdr { struct ieee802154_sechdr sec; }; +struct ieee802154_beacon_frame { + struct ieee802154_hdr mhr; + struct ieee802154_beacon_hdr mac_pl; +}; + /* pushes hdr onto the skb. fields of hdr->fc that can be calculated from * the contents of hdr will be, and the actual value of those bits in * hdr->fc will be ignored. this includes the INTRA_PAN bit and the frame @@ -162,6 +174,10 @@ int ieee802154_hdr_peek_addrs(const struct sk_buff *skb, */ int ieee802154_hdr_peek(const struct sk_buff *skb, struct ieee802154_hdr *hdr); +/* pushes a beacon frame into an skb */ +int ieee802154_beacon_push(struct sk_buff *skb, + struct ieee802154_beacon_frame *beacon); + int ieee802154_max_payload(const struct ieee802154_hdr *hdr); static inline int diff --git a/net/ieee802154/header_ops.c b/net/ieee802154/header_ops.c index af337cf..35d384d 100644 --- a/net/ieee802154/header_ops.c +++ b/net/ieee802154/header_ops.c @@ -120,6 +120,30 @@ ieee802154_hdr_push(struct sk_buff *skb, struct ieee802154_hdr *hdr) } EXPORT_SYMBOL_GPL(ieee802154_hdr_push); +int ieee802154_beacon_push(struct sk_buff *skb, + struct ieee802154_beacon_frame *beacon) +{ + struct ieee802154_beacon_hdr *mac_pl = &beacon->mac_pl; + struct ieee802154_hdr *mhr = &beacon->mhr; + int ret; + + skb_reserve(skb, sizeof(*mhr)); + ret = ieee802154_hdr_push(skb, mhr); + if (ret < 0) + return ret; + + skb_reset_mac_header(skb); + skb->mac_len = ret; + + skb_put_data(skb, mac_pl, sizeof(*mac_pl)); + + if (mac_pl->pend_short_addr_count || mac_pl->pend_ext_addr_count) + return -EOPNOTSUPP; + + return 0; +} +EXPORT_SYMBOL_GPL(ieee802154_beacon_push); + static int ieee802154_hdr_get_addr(const u8 *buf, int mode, bool omit_pan, struct ieee802154_addr *addr) diff --git a/net/mac802154/cfg.c b/net/mac802154/cfg.c index 187cebc..5c3cb01 100644 --- a/net/mac802154/cfg.c +++ b/net/mac802154/cfg.c @@ -114,8 +114,8 @@ ieee802154_set_channel(struct wpan_phy *wpan_phy, u8 page, u8 channel) wpan_phy->current_channel == channel) return 0; - /* Refuse to change channels during a scanning operation */ - if (mac802154_is_scanning(local)) + /* Refuse to change channels during scanning or beaconing */ + if (mac802154_is_scanning(local) || mac802154_is_beaconing(local)) return -EBUSY; ret = drv_set_channel(local, page, channel); @@ -290,6 +290,31 @@ static int mac802154_abort_scan(struct wpan_phy *wpan_phy, return mac802154_abort_scan_locked(local, sdata); } +static int mac802154_send_beacons(struct wpan_phy *wpan_phy, + struct cfg802154_beacon_request *request) +{ + struct ieee802154_sub_if_data *sdata; + + sdata = IEEE802154_WPAN_DEV_TO_SUB_IF(request->wpan_dev); + + ASSERT_RTNL(); + + return mac802154_send_beacons_locked(sdata, request); +} + +static int mac802154_stop_beacons(struct wpan_phy *wpan_phy, + struct wpan_dev *wpan_dev) +{ + struct ieee802154_local *local = wpan_phy_priv(wpan_phy); + struct ieee802154_sub_if_data *sdata; + + sdata = IEEE802154_WPAN_DEV_TO_SUB_IF(wpan_dev); + + ASSERT_RTNL(); + + return mac802154_stop_beacons_locked(local, sdata); +} + #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL static void ieee802154_get_llsec_table(struct wpan_phy *wpan_phy, @@ -499,6 +524,8 @@ const struct cfg802154_ops mac802154_config_ops = { .set_ackreq_default = ieee802154_set_ackreq_default, .trigger_scan = mac802154_trigger_scan, .abort_scan = mac802154_abort_scan, + .send_beacons = mac802154_send_beacons, + .stop_beacons = mac802154_stop_beacons, #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL .get_llsec_table = ieee802154_get_llsec_table, .lock_llsec_table = ieee802154_lock_llsec_table, diff --git a/net/mac802154/ieee802154_i.h b/net/mac802154/ieee802154_i.h index 0e4db96..63bab99 100644 --- a/net/mac802154/ieee802154_i.h +++ b/net/mac802154/ieee802154_i.h @@ -23,6 +23,7 @@ enum ieee802154_ongoing { IEEE802154_IS_SCANNING = BIT(0), + IEEE802154_IS_BEACONING = BIT(1), }; /* mac802154 device private data */ @@ -60,6 +61,12 @@ struct ieee802154_local { struct cfg802154_scan_request __rcu *scan_req; struct delayed_work scan_work; + /* Beaconing */ + unsigned int beacon_interval; + struct ieee802154_beacon_frame beacon; + struct cfg802154_beacon_request __rcu *beacon_req; + struct delayed_work beacon_work; + /* Asynchronous tasks */ struct list_head rx_beacon_list; struct work_struct rx_beacon_work; @@ -257,6 +264,17 @@ static inline bool mac802154_is_scanning(struct ieee802154_local *local) return test_bit(IEEE802154_IS_SCANNING, &local->ongoing); } +void mac802154_beacon_worker(struct work_struct *work); +int mac802154_send_beacons_locked(struct ieee802154_sub_if_data *sdata, + struct cfg802154_beacon_request *request); +int mac802154_stop_beacons_locked(struct ieee802154_local *local, + struct ieee802154_sub_if_data *sdata); + +static inline bool mac802154_is_beaconing(struct ieee802154_local *local) +{ + return test_bit(IEEE802154_IS_BEACONING, &local->ongoing); +} + /* interface handling */ int ieee802154_iface_init(void); void ieee802154_iface_exit(void); diff --git a/net/mac802154/iface.c b/net/mac802154/iface.c index a5958d3..9d59cae 100644 --- a/net/mac802154/iface.c +++ b/net/mac802154/iface.c @@ -305,6 +305,9 @@ static int mac802154_slave_close(struct net_device *dev) if (mac802154_is_scanning(local)) mac802154_abort_scan_locked(local, sdata); + if (mac802154_is_beaconing(local)) + mac802154_stop_beacons_locked(local, sdata); + netif_stop_queue(dev); local->open_count--; diff --git a/net/mac802154/llsec.c b/net/mac802154/llsec.c index 55550ea..8d2eabc 100644 --- a/net/mac802154/llsec.c +++ b/net/mac802154/llsec.c @@ -707,7 +707,10 @@ int mac802154_llsec_encrypt(struct mac802154_llsec *sec, struct sk_buff *skb) hlen = ieee802154_hdr_pull(skb, &hdr); - if (hlen < 0 || hdr.fc.type != IEEE802154_FC_TYPE_DATA) + /* TODO: control frames security support */ + if (hlen < 0 || + (hdr.fc.type != IEEE802154_FC_TYPE_DATA && + hdr.fc.type != IEEE802154_FC_TYPE_BEACON)) return -EINVAL; if (!hdr.fc.security_enabled || diff --git a/net/mac802154/main.c b/net/mac802154/main.c index b111127..ee23e234 100644 --- a/net/mac802154/main.c +++ b/net/mac802154/main.c @@ -99,6 +99,7 @@ ieee802154_alloc_hw(size_t priv_data_len, const struct ieee802154_ops *ops) INIT_WORK(&local->sync_tx_work, ieee802154_xmit_sync_worker); 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 supported flags with 802.15.4 default ranges */ phy->supported.max_minbe = 8; diff --git a/net/mac802154/scan.c b/net/mac802154/scan.c index 56056b9..cfbe20b 100644 --- a/net/mac802154/scan.c +++ b/net/mac802154/scan.c @@ -16,6 +16,11 @@ #include "driver-ops.h" #include "../ieee802154/nl802154.h" +#define IEEE802154_BEACON_MHR_SZ 13 +#define IEEE802154_BEACON_PL_SZ 4 +#define IEEE802154_BEACON_SKB_SZ (IEEE802154_BEACON_MHR_SZ + \ + IEEE802154_BEACON_PL_SZ) + /* mac802154_scan_cleanup_locked() must be called upon scan completion or abort. * - Completions are asynchronous, not locked by the rtnl and decided by the * scan worker. @@ -286,3 +291,149 @@ int mac802154_process_beacon(struct ieee802154_local *local, return 0; } + +static int mac802154_transmit_beacon(struct ieee802154_local *local, + struct wpan_dev *wpan_dev) +{ + struct cfg802154_beacon_request *beacon_req; + struct ieee802154_sub_if_data *sdata; + struct sk_buff *skb; + int ret; + + /* Update the sequence number */ + local->beacon.mhr.seq = atomic_inc_return(&wpan_dev->bsn) & 0xFF; + + skb = alloc_skb(IEEE802154_BEACON_SKB_SZ, GFP_KERNEL); + if (!skb) + return -ENOBUFS; + + rcu_read_lock(); + beacon_req = rcu_dereference(local->beacon_req); + if (unlikely(!beacon_req)) { + rcu_read_unlock(); + kfree_skb(skb); + return -EINVAL; + } + + sdata = IEEE802154_WPAN_DEV_TO_SUB_IF(beacon_req->wpan_dev); + skb->dev = sdata->dev; + + rcu_read_unlock(); + + ret = ieee802154_beacon_push(skb, &local->beacon); + if (ret) { + kfree_skb(skb); + return ret; + } + + return ieee802154_subif_start_xmit(skb, sdata->dev); +} + +void mac802154_beacon_worker(struct work_struct *work) +{ + struct ieee802154_local *local = + container_of(work, struct ieee802154_local, beacon_work.work); + struct cfg802154_beacon_request *beacon_req; + struct ieee802154_sub_if_data *sdata; + struct wpan_dev *wpan_dev; + int ret; + + rcu_read_lock(); + beacon_req = rcu_dereference(local->beacon_req); + if (unlikely(!beacon_req)) { + rcu_read_unlock(); + return; + } + + sdata = IEEE802154_WPAN_DEV_TO_SUB_IF(beacon_req->wpan_dev); + + /* Wait an arbitrary amount of time in case we cannot use the device */ + if (local->suspended || !ieee802154_sdata_running(sdata)) { + rcu_read_unlock(); + queue_delayed_work(local->mac_wq, &local->beacon_work, + msecs_to_jiffies(1000)); + return; + } + + wpan_dev = beacon_req->wpan_dev; + + rcu_read_unlock(); + + dev_dbg(&sdata->dev->dev, "Sending beacon\n"); + ret = mac802154_transmit_beacon(local, wpan_dev); + if (ret) + dev_err(&sdata->dev->dev, + "Beacon could not be transmitted (%d)\n", ret); + + if (local->beacon_interval >= 0) + queue_delayed_work(local->mac_wq, &local->beacon_work, + local->beacon_interval); +} + +int mac802154_stop_beacons_locked(struct ieee802154_local *local, + struct ieee802154_sub_if_data *sdata) +{ + struct wpan_dev *wpan_dev = &sdata->wpan_dev; + struct cfg802154_beacon_request *request; + + ASSERT_RTNL(); + + if (!mac802154_is_beaconing(local)) + return -ESRCH; + + clear_bit(IEEE802154_IS_BEACONING, &local->ongoing); + cancel_delayed_work(&local->beacon_work); + request = rcu_replace_pointer(local->beacon_req, NULL, 1); + if (!request) + return 0; + kfree_rcu(request); + + nl802154_beaconing_done(wpan_dev); + + return 0; +} + +int mac802154_send_beacons_locked(struct ieee802154_sub_if_data *sdata, + struct cfg802154_beacon_request *request) +{ + struct ieee802154_local *local = sdata->local; + + ASSERT_RTNL(); + + if (mac802154_is_beaconing(local)) + mac802154_stop_beacons_locked(local, sdata); + + /* Store beaconing parameters */ + rcu_assign_pointer(local->beacon_req, request); + + set_bit(IEEE802154_IS_BEACONING, &local->ongoing); + + memset(&local->beacon, 0, sizeof(local->beacon)); + local->beacon.mhr.fc.type = IEEE802154_FC_TYPE_BEACON; + local->beacon.mhr.fc.security_enabled = 0; + local->beacon.mhr.fc.frame_pending = 0; + local->beacon.mhr.fc.ack_request = 0; + local->beacon.mhr.fc.intra_pan = 0; + local->beacon.mhr.fc.dest_addr_mode = IEEE802154_NO_ADDRESSING; + local->beacon.mhr.fc.version = IEEE802154_2003_STD; + local->beacon.mhr.fc.source_addr_mode = IEEE802154_EXTENDED_ADDRESSING; + atomic_set(&request->wpan_dev->bsn, -1); + local->beacon.mhr.source.mode = IEEE802154_ADDR_LONG; + local->beacon.mhr.source.pan_id = cpu_to_le16(request->wpan_dev->pan_id); + local->beacon.mhr.source.extended_addr = cpu_to_le64(request->wpan_dev->extended_addr); + local->beacon.mac_pl.beacon_order = request->interval; + 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 */ + local->beacon.mac_pl.pan_coordinator = 1; + local->beacon.mac_pl.assoc_permit = 1; + + /* Start the beacon work */ + local->beacon_interval = + mac802154_scan_get_channel_time(request->interval, + request->wpan_phy->symbol_duration); + queue_delayed_work(local->mac_wq, &local->beacon_work, 0); + + return 0; +} -- 2.7.4