[wpan-next,v2,6/6] mac802154: Handle passive scanning

Message ID	20221217000226.646767-7-miquel.raynal@bootlin.com (mailing list archive)
State	Superseded
Headers	show Return-Path: <linux-wpan-owner@kernel.org> sender: miquel.raynal@bootlin.com) by mail.gandi.net (Postfix) with ESMTPSA id 7356260004; Sat, 17 Dec 2022 00:02:39 +0000 (UTC) From: Miquel Raynal <miquel.raynal@bootlin.com> To: Alexander Aring <alex.aring@gmail.com>, Stefan Schmidt <stefan@datenfreihafen.org>, linux-wpan@vger.kernel.org Cc: David Girault <david.girault@qorvo.com>, Romuald Despres <romuald.despres@qorvo.com>, Frederic Blain <frederic.blain@qorvo.com>, Nicolas Schodet <nico@ni.fr.eu.org>, Guilhem Imberton <guilhem.imberton@qorvo.com>, Thomas Petazzoni <thomas.petazzoni@bootlin.com>, "David S. Miller" <davem@davemloft.net>, Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>, Eric Dumazet <edumazet@google.com>, netdev@vger.kernel.org, Miquel Raynal <miquel.raynal@bootlin.com> Subject: [PATCH wpan-next v2 6/6] mac802154: Handle passive scanning Date: Sat, 17 Dec 2022 01:02:26 +0100 Message-Id: <20221217000226.646767-7-miquel.raynal@bootlin.com> In-Reply-To: <20221217000226.646767-1-miquel.raynal@bootlin.com> References: <20221217000226.646767-1-miquel.raynal@bootlin.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	IEEE 802.15.4 passive scan support \| expand [wpan-next,v2,0/6] IEEE 802.15.4 passive scan support [wpan-next,v2,1/6] ieee802154: Add support for user scanning requests [wpan-next,v2,2/6] ieee802154: Define a beacon frame header [wpan-next,v2,3/6] ieee802154: Introduce a helper to validate a channel [wpan-next,v2,4/6] mac802154: Prepare forcing specific symbol duration [wpan-next,v2,5/6] mac802154: Add MLME Tx locked helpers [wpan-next,v2,6/6] mac802154: Handle passive scanning

diff --git a/include/linux/ieee802154.h b/include/linux/ieee802154.h index b22e4147d334..140f61ec0f5f 100644 --- a/include/linux/ieee802154.h +++ b/include/linux/ieee802154.h @@ -47,6 +47,10 @@ /* Duration in superframe order */ #define IEEE802154_MAX_SCAN_DURATION 14 #define IEEE802154_ACTIVE_SCAN_DURATION 15 +/* Superframe duration in slots */ +#define IEEE802154_SUPERFRAME_PERIOD 16 +/* Various periods expressed in symbols */ +#define IEEE802154_SLOT_PERIOD 60 #define IEEE802154_LIFS_PERIOD 40 #define IEEE802154_SIFS_PERIOD 12 #define IEEE802154_MAX_SIFS_FRAME_SIZE 18 diff --git a/include/net/cfg802154.h b/include/net/cfg802154.h index 5d4750d24f13..090e1ad64a55 100644 --- a/include/net/cfg802154.h +++ b/include/net/cfg802154.h @@ -314,6 +314,22 @@ struct cfg802154_scan_request { struct wpan_phy *wpan_phy; }; +/** + * struct cfg802154_mac_pkt - MAC packet descriptor (beacon/command) + * @node: MAC packets to process list member + * @skb: the received sk_buff + * @sdata: the interface on which @skb was received + * @page: page configuration when @skb was received + * @channel: channel configuration when @skb was received + */ +struct cfg802154_mac_pkt { + struct list_head node; + struct sk_buff *skb; + struct ieee802154_sub_if_data *sdata; + u8 page; + u8 channel; +}; + struct ieee802154_llsec_key_id { u8 mode; u8 id; diff --git a/net/mac802154/Makefile b/net/mac802154/Makefile index 4059295fdbf8..43d1347b37ee 100644 --- a/net/mac802154/Makefile +++ b/net/mac802154/Makefile @@ -1,6 +1,6 @@ # SPDX-License-Identifier: GPL-2.0-only obj-$(CONFIG_MAC802154) += mac802154.o mac802154-objs := main.o rx.o tx.o mac_cmd.o mib.o \ - iface.o llsec.o util.o cfg.o trace.o + iface.o llsec.o util.o cfg.o scan.o trace.o CFLAGS_trace.o := -I$(src) diff --git a/net/mac802154/cfg.c b/net/mac802154/cfg.c index 469d6e8dd2dd..187cebcaf233 100644 --- a/net/mac802154/cfg.c +++ b/net/mac802154/cfg.c @@ -114,6 +114,10 @@ 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)) + return -EBUSY; + ret = drv_set_channel(local, page, channel); if (!ret) { wpan_phy->current_page = page; @@ -261,6 +265,31 @@ ieee802154_set_ackreq_default(struct wpan_phy *wpan_phy, return 0; } +static int mac802154_trigger_scan(struct wpan_phy *wpan_phy, + struct cfg802154_scan_request *request) +{ + struct ieee802154_sub_if_data *sdata; + + sdata = IEEE802154_WPAN_DEV_TO_SUB_IF(request->wpan_dev); + + ASSERT_RTNL(); + + return mac802154_trigger_scan_locked(sdata, request); +} + +static int mac802154_abort_scan(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_abort_scan_locked(local, sdata); +} + #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL static void ieee802154_get_llsec_table(struct wpan_phy *wpan_phy, @@ -468,6 +497,8 @@ const struct cfg802154_ops mac802154_config_ops = { .set_max_frame_retries = ieee802154_set_max_frame_retries, .set_lbt_mode = ieee802154_set_lbt_mode, .set_ackreq_default = ieee802154_set_ackreq_default, + .trigger_scan = mac802154_trigger_scan, + .abort_scan = mac802154_abort_scan, #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 aeadee543a9c..0e4db967bd1d 100644 --- a/net/mac802154/ieee802154_i.h +++ b/net/mac802154/ieee802154_i.h @@ -21,6 +21,10 @@ #include "llsec.h" +enum ieee802154_ongoing { + IEEE802154_IS_SCANNING = BIT(0), +}; + /* mac802154 device private data */ struct ieee802154_local { struct ieee802154_hw hw; @@ -43,15 +47,26 @@ struct ieee802154_local { struct list_head interfaces; struct mutex iflist_mtx; - /* This one is used for scanning and other jobs not to be interfered - * with serial driver. - */ + /* Data related workqueue */ struct workqueue_struct *workqueue; + /* MAC commands related workqueue */ + struct workqueue_struct *mac_wq; struct hrtimer ifs_timer; + /* Scanning */ + u8 scan_page; + u8 scan_channel; + struct cfg802154_scan_request __rcu *scan_req; + struct delayed_work scan_work; + + /* Asynchronous tasks */ + struct list_head rx_beacon_list; + struct work_struct rx_beacon_work; + bool started; bool suspended; + unsigned long ongoing; struct tasklet_struct tasklet; struct sk_buff_head skb_queue; @@ -226,6 +241,22 @@ void mac802154_unlock_table(struct net_device *dev); int mac802154_wpan_update_llsec(struct net_device *dev); +/* PAN management handling */ +void mac802154_scan_worker(struct work_struct *work); +int mac802154_trigger_scan_locked(struct ieee802154_sub_if_data *sdata, + struct cfg802154_scan_request *request); +int mac802154_abort_scan_locked(struct ieee802154_local *local, + struct ieee802154_sub_if_data *sdata); +int mac802154_process_beacon(struct ieee802154_local *local, + struct sk_buff *skb, + u8 page, u8 channel); +void mac802154_rx_beacon_worker(struct work_struct *work); + +static inline bool mac802154_is_scanning(struct ieee802154_local *local) +{ + return test_bit(IEEE802154_IS_SCANNING, &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 7de2f843379c..a5958d323ea3 100644 --- a/net/mac802154/iface.c +++ b/net/mac802154/iface.c @@ -302,6 +302,9 @@ static int mac802154_slave_close(struct net_device *dev) ASSERT_RTNL(); + if (mac802154_is_scanning(local)) + mac802154_abort_scan_locked(local, sdata); + netif_stop_queue(dev); local->open_count--; diff --git a/net/mac802154/main.c b/net/mac802154/main.c index 12a13a850fdf..b1111279e06d 100644 --- a/net/mac802154/main.c +++ b/net/mac802154/main.c @@ -89,6 +89,7 @@ ieee802154_alloc_hw(size_t priv_data_len, const struct ieee802154_ops *ops) local->ops = ops; INIT_LIST_HEAD(&local->interfaces); + INIT_LIST_HEAD(&local->rx_beacon_list); mutex_init(&local->iflist_mtx); tasklet_setup(&local->tasklet, ieee802154_tasklet_handler); @@ -96,6 +97,8 @@ ieee802154_alloc_hw(size_t priv_data_len, const struct ieee802154_ops *ops) skb_queue_head_init(&local->skb_queue); 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 supported flags with 802.15.4 default ranges */ phy->supported.max_minbe = 8; @@ -185,6 +188,7 @@ static void ieee802154_setup_wpan_phy_pib(struct wpan_phy *wpan_phy) int ieee802154_register_hw(struct ieee802154_hw *hw) { struct ieee802154_local *local = hw_to_local(hw); + char mac_wq_name[IFNAMSIZ + 10] = {}; struct net_device *dev; int rc = -ENOSYS; @@ -195,6 +199,13 @@ int ieee802154_register_hw(struct ieee802154_hw *hw) goto out; } + snprintf(mac_wq_name, IFNAMSIZ + 10, "%s-mac-cmds", wpan_phy_name(local->phy)); + local->mac_wq = create_singlethread_workqueue(mac_wq_name); + if (!local->mac_wq) { + rc = -ENOMEM; + goto out_wq; + } + hrtimer_init(&local->ifs_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); local->ifs_timer.function = ieee802154_xmit_ifs_timer; @@ -224,7 +235,7 @@ int ieee802154_register_hw(struct ieee802154_hw *hw) rc = wpan_phy_register(local->phy); if (rc < 0) - goto out_wq; + goto out_mac_wq; rtnl_lock(); @@ -243,6 +254,8 @@ int ieee802154_register_hw(struct ieee802154_hw *hw) out_phy: wpan_phy_unregister(local->phy); +out_mac_wq: + destroy_workqueue(local->mac_wq); out_wq: destroy_workqueue(local->workqueue); out: @@ -263,6 +276,7 @@ void ieee802154_unregister_hw(struct ieee802154_hw *hw) rtnl_unlock(); + destroy_workqueue(local->mac_wq); destroy_workqueue(local->workqueue); wpan_phy_unregister(local->phy); } diff --git a/net/mac802154/rx.c b/net/mac802154/rx.c index 97bb4401dd3e..da0628ee3c89 100644 --- a/net/mac802154/rx.c +++ b/net/mac802154/rx.c @@ -29,12 +29,31 @@ static int ieee802154_deliver_skb(struct sk_buff *skb) return netif_receive_skb(skb); } +void mac802154_rx_beacon_worker(struct work_struct *work) +{ + struct ieee802154_local *local = + container_of(work, struct ieee802154_local, rx_beacon_work); + struct cfg802154_mac_pkt *mac_pkt; + + mac_pkt = list_first_entry_or_null(&local->rx_beacon_list, + struct cfg802154_mac_pkt, node); + if (!mac_pkt) + return; + + mac802154_process_beacon(local, mac_pkt->skb, mac_pkt->page, mac_pkt->channel); + + 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) { - struct wpan_dev *wpan_dev = &sdata->wpan_dev; struct wpan_phy *wpan_phy = sdata->local->hw.phy; + struct wpan_dev *wpan_dev = &sdata->wpan_dev; + struct cfg802154_mac_pkt *mac_pkt; __le16 span, sshort; int rc; @@ -106,6 +125,21 @@ ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata, switch (mac_cb(skb)->type) { case IEEE802154_FC_TYPE_BEACON: + dev_dbg(&sdata->dev->dev, "BEACON received\n"); + if (!mac802154_is_scanning(sdata->local)) + goto fail; + + mac_pkt = kzalloc(sizeof(*mac_pkt), GFP_ATOMIC); + if (!mac_pkt) + goto fail; + + mac_pkt->skb = skb_get(skb); + mac_pkt->sdata = sdata; + mac_pkt->page = sdata->local->scan_page; + mac_pkt->channel = sdata->local->scan_channel; + 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: goto fail; diff --git a/net/mac802154/scan.c b/net/mac802154/scan.c new file mode 100644 index 000000000000..2d3d2d5a4e34 --- /dev/null +++ b/net/mac802154/scan.c @@ -0,0 +1,289 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * IEEE 802.15.4 scanning management + * + * Copyright (C) 2021 Qorvo US, Inc + * Authors: + * - David Girault <david.girault@qorvo.com> + * - Miquel Raynal <miquel.raynal@bootlin.com> + */ + +#include <linux/module.h> +#include <linux/rtnetlink.h> +#include <net/mac802154.h> + +#include "ieee802154_i.h" +#include "driver-ops.h" +#include "../ieee802154/nl802154.h" + +/* + * 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. + * - Aborts are decided by userspace, and locked by the rtnl. + * + * Concurrent modifications to the PHY, the interfaces or the hardware is in + * general prevented by the rtnl. So in most cases we don't need additional + * protection. + * + * However, the scan worker get's triggered without anybody noticing and thus we + * must ensure the presence of the devices as well as data consistency: + * - The sub-interface and device driver module get both their reference + * counters incremented whenever we start a scan, so they cannot disappear + * during operation. + * - Data consistency is achieved by the use of rcu protected pointers. + */ +static int mac802154_scan_cleanup_locked(struct ieee802154_local *local, + struct ieee802154_sub_if_data *sdata, + bool aborted) +{ + struct wpan_dev *wpan_dev = &sdata->wpan_dev; + struct wpan_phy *wpan_phy = local->phy; + struct cfg802154_scan_request *request; + u8 arg; + + /* Prevent any further use of the scan request */ + clear_bit(IEEE802154_IS_SCANNING, &local->ongoing); + cancel_delayed_work(&local->scan_work); + request = rcu_replace_pointer(local->scan_req, NULL, 1); + if (!request) + return 0; + kfree_rcu(request); + + /* Advertize first, while we know the devices cannot be removed */ + if (aborted) + arg = NL802154_SCAN_DONE_REASON_ABORTED; + else + arg = NL802154_SCAN_DONE_REASON_FINISHED; + nl802154_scan_done(wpan_phy, wpan_dev, arg); + + /* Cleanup software stack */ + ieee802154_mlme_op_post(local); + + /* Set the hardware back in its original state */ + drv_set_channel(local, wpan_phy->current_page, + wpan_phy->current_channel); + ieee802154_configure_durations(wpan_phy, wpan_phy->current_page, + wpan_phy->current_channel); + drv_stop(local); + synchronize_net(); + sdata->required_filtering = sdata->iface_default_filtering; + drv_start(local, sdata->required_filtering, &local->addr_filt); + + return 0; +} + +int mac802154_abort_scan_locked(struct ieee802154_local *local, + struct ieee802154_sub_if_data *sdata) +{ + ASSERT_RTNL(); + + if (!mac802154_is_scanning(local)) + return -ESRCH; + + return mac802154_scan_cleanup_locked(local, sdata, true); +} + +static unsigned int mac802154_scan_get_channel_time(u8 duration_order, + u8 symbol_duration) +{ + u64 base_super_frame_duration = (u64)symbol_duration * + IEEE802154_SUPERFRAME_PERIOD * IEEE802154_SLOT_PERIOD; + + return usecs_to_jiffies(base_super_frame_duration * + (BIT(duration_order) + 1)); +} + +static void mac802154_flush_queued_beacons(struct ieee802154_local *local) +{ + struct cfg802154_mac_pkt *mac_pkt, *tmp; + + list_for_each_entry_safe(mac_pkt, tmp, &local->rx_beacon_list, node) { + list_del(&mac_pkt->node); + kfree_skb(mac_pkt->skb); + kfree(mac_pkt); + } +} + +static void +mac802154_scan_get_next_channel(struct ieee802154_local *local, + struct cfg802154_scan_request *scan_req, + u8 *channel) +{ + (*channel)++; + *channel = find_next_bit((const unsigned long *)&scan_req->channels, + IEEE802154_MAX_CHANNEL + 1, + *channel); +} + +static int mac802154_scan_find_next_chan(struct ieee802154_local *local, + struct cfg802154_scan_request *scan_req, + u8 page, u8 *channel) +{ + mac802154_scan_get_next_channel(local, scan_req, channel); + if (*channel > IEEE802154_MAX_CHANNEL) + return -EINVAL; + + return 0; +} + +void mac802154_scan_worker(struct work_struct *work) +{ + struct ieee802154_local *local = + container_of(work, struct ieee802154_local, scan_work.work); + struct cfg802154_scan_request *scan_req; + struct ieee802154_sub_if_data *sdata; + unsigned int scan_duration = 0; + struct wpan_phy* wpan_phy; + u8 scan_req_duration; + u8 page, channel; + int ret; + + /* Ensure the device receiver is turned off when changing channels + * because there is no atomic way to change the channel and know on + * which one a beacon might have been received. + */ + drv_stop(local); + synchronize_net(); + mac802154_flush_queued_beacons(local); + + rcu_read_lock(); + scan_req = rcu_dereference(local->scan_req); + if (unlikely(!scan_req)) { + rcu_read_unlock(); + return; + } + + sdata = IEEE802154_WPAN_DEV_TO_SUB_IF(scan_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->scan_work, + msecs_to_jiffies(1000)); + return; + } + + wpan_phy = scan_req->wpan_phy; + scan_req_duration = scan_req->duration; + + /* Look for the next valid chan */ + page = local->scan_page; + channel = local->scan_channel; + do { + ret = mac802154_scan_find_next_chan(local, scan_req, page, &channel); + if (ret) { + rcu_read_unlock(); + goto end_scan; + } + } while (!ieee802154_chan_is_valid(scan_req->wpan_phy, page, channel)); + + rcu_read_unlock(); + + /* Bypass the stack on purpose when changing the channel */ + rtnl_lock(); + ret = drv_set_channel(local, page, channel); + rtnl_unlock(); + if (ret) { + dev_err(&sdata->dev->dev, + "Channel change failure during scan, aborting (%d)\n", ret); + goto end_scan; + } + + local->scan_page = page; + local->scan_channel = channel; + + rtnl_lock(); + ret = drv_start(local, IEEE802154_FILTERING_3_SCAN, &local->addr_filt); + rtnl_unlock(); + if (ret) { + dev_err(&sdata->dev->dev, + "Restarting failure after channel change, aborting (%d)\n", ret); + goto end_scan; + } + + ieee802154_configure_durations(wpan_phy, page, channel); + scan_duration = mac802154_scan_get_channel_time(scan_req_duration, + wpan_phy->symbol_duration); + dev_dbg(&sdata->dev->dev, + "Scan page %u channel %u for %ums\n", + page, channel, jiffies_to_msecs(scan_duration)); + queue_delayed_work(local->mac_wq, &local->scan_work, scan_duration); + return; + +end_scan: + rtnl_lock(); + mac802154_scan_cleanup_locked(local, sdata, false); + rtnl_unlock(); +} + +int mac802154_trigger_scan_locked(struct ieee802154_sub_if_data *sdata, + struct cfg802154_scan_request *request) +{ + struct ieee802154_local *local = sdata->local; + + ASSERT_RTNL(); + + if (mac802154_is_scanning(local)) + return -EBUSY; + + /* TODO: support other scanning type */ + if (request->type != NL802154_SCAN_PASSIVE) + return -EOPNOTSUPP; + + /* Store scanning parameters */ + rcu_assign_pointer(local->scan_req, request); + + /* Software scanning requires to set promiscuous mode, so we need to + * pause the Tx queue during the entire operation. + */ + ieee802154_mlme_op_pre(local); + + sdata->required_filtering = IEEE802154_FILTERING_3_SCAN; + local->scan_page = request->page; + local->scan_channel = -1; + set_bit(IEEE802154_IS_SCANNING, &local->ongoing); + + nl802154_scan_started(request->wpan_phy, request->wpan_dev); + + queue_delayed_work(local->mac_wq, &local->scan_work, 0); + + return 0; +} + +int mac802154_process_beacon(struct ieee802154_local *local, + struct sk_buff *skb, + u8 page, u8 channel) +{ + struct ieee802154_beacon_hdr *bh = (void *)skb->data; + struct ieee802154_addr *src = &mac_cb(skb)->source; + struct cfg802154_scan_request *scan_req; + struct ieee802154_coord_desc desc; + + if (skb->len != sizeof(*bh)) + return -EINVAL; + + if (unlikely(src->mode == IEEE802154_ADDR_NONE)) + return -EINVAL; + + dev_dbg(&skb->dev->dev, + "BEACON received on page %u channel %u\n", + page, channel); + + memcpy(&desc.addr, src, sizeof(desc.addr)); + desc.page = page; + desc.channel = channel; + desc.link_quality = mac_cb(skb)->lqi; + desc.superframe_spec = get_unaligned_le16(skb->data); + desc.gts_permit = bh->gts_permit; + + trace_802154_scan_event(&desc); + + rcu_read_lock(); + scan_req = rcu_dereference(local->scan_req); + if (likely(scan_req)) + nl802154_scan_event(scan_req->wpan_phy, scan_req->wpan_dev, &desc); + rcu_read_unlock(); + + return 0; +}

[wpan-next,v2,6/6] mac802154: Handle passive scanning

Commit Message

Comments

Patch