From patchwork Wed Jan 12 17:33:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miquel Raynal X-Patchwork-Id: 12711738 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 17D79C433F5 for ; Wed, 12 Jan 2022 17:36:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355726AbiALRgc (ORCPT ); Wed, 12 Jan 2022 12:36:32 -0500 Received: from relay7-d.mail.gandi.net ([217.70.183.200]:53147 "EHLO relay7-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355708AbiALRdy (ORCPT ); Wed, 12 Jan 2022 12:33:54 -0500 Received: (Authenticated sender: miquel.raynal@bootlin.com) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id 6244F2001E; Wed, 12 Jan 2022 17:33:51 +0000 (UTC) From: Miquel Raynal To: Alexander Aring , Stefan Schmidt , linux-wpan@vger.kernel.org, "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org Cc: Michael Hennerich , Harry Morris , Varka Bhadram , Xue Liu , Alan Ott , David Girault , Romuald Despres , Frederic Blain , Nicolas Schodet , Thomas Petazzoni , linux-wireless@vger.kernel.org, Miquel Raynal Subject: [wpan-next v2 18/27] net: mac802154: Handle scan requests Date: Wed, 12 Jan 2022 18:33:03 +0100 Message-Id: <20220112173312.764660-19-miquel.raynal@bootlin.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220112173312.764660-1-miquel.raynal@bootlin.com> References: <20220112173312.764660-1-miquel.raynal@bootlin.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wpan@vger.kernel.org Implement the core hooks in order to provide the softMAC layer support for scan requests and aborts. Changing the channels is prohibited during the scan. As transceiver enter in a promiscuous mode during scans, they might stop checking frame validity so we ensure this gets done at mac level. The implementation uses a workqueue triggered at a certain interval depending on the symbol duration for the current channel and the duration order provided. Received beacons during a passive scanning procedure are processed and either registered in the list of known PANs or the existing entry gets updated accordingly. Active scanning is not supported yet. Co-developed-by: David Girault Signed-off-by: David Girault Signed-off-by: Miquel Raynal --- include/linux/ieee802154.h | 4 + include/net/mac802154.h | 14 ++ net/mac802154/Makefile | 2 +- net/mac802154/cfg.c | 39 ++++++ net/mac802154/ieee802154_i.h | 22 +++ net/mac802154/main.c | 2 + net/mac802154/rx.c | 21 ++- net/mac802154/scan.c | 255 +++++++++++++++++++++++++++++++++++ net/mac802154/tx.c | 3 + net/mac802154/util.c | 26 ++++ 10 files changed, 382 insertions(+), 6 deletions(-) create mode 100644 net/mac802154/scan.c diff --git a/include/linux/ieee802154.h b/include/linux/ieee802154.h index 41178c87c43c..57bf5317338e 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/mac802154.h b/include/net/mac802154.h index d524ffb9eb25..19bfbf591ea1 100644 --- a/include/net/mac802154.h +++ b/include/net/mac802154.h @@ -486,4 +486,18 @@ void ieee802154_stop_queue(struct ieee802154_hw *hw); void ieee802154_xmit_complete(struct ieee802154_hw *hw, struct sk_buff *skb, bool ifs_handling); +/** + * ieee802154_queue_delayed_work - add work onto the mac802154 workqueue + * + * Drivers and mac802154 use this to queue delayed work onto the mac802154 + * workqueue. + * + * @hw: the hardware struct for the interface we are adding work for + * @dwork: delayable work to queue onto the mac802154 workqueue + * @delay: number of jiffies to wait before queueing + */ +void ieee802154_queue_delayed_work(struct ieee802154_hw *hw, + struct delayed_work *dwork, + unsigned long delay); + #endif /* NET_MAC802154_H */ 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 ba57da07c08e..c1e7bbea3058 100644 --- a/net/mac802154/cfg.c +++ b/net/mac802154/cfg.c @@ -109,6 +109,10 @@ int ieee802154_change_channel(struct wpan_phy *wpan_phy, u8 page, u8 channel) ASSERT_RTNL(); + /* Refuse to change channels during a scanning operation */ + if (mac802154_scan_is_ongoing(local)) + return -EBUSY; + ret = drv_set_channel(local, page, channel); if (!ret) { wpan_phy->current_page = page; @@ -268,6 +272,39 @@ 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 *req) +{ + struct ieee802154_local *local = wpan_phy_priv(wpan_phy); + struct ieee802154_sub_if_data *sdata; + int ret; + + sdata = IEEE802154_WPAN_DEV_TO_SUB_IF(req->wpan_dev); + + ASSERT_RTNL(); + + mutex_lock(&local->scan_lock); + ret = mac802154_trigger_scan_locked(sdata, req); + mutex_unlock(&local->scan_lock); + + return ret; +} + +static int mac802154_abort_scan(struct wpan_phy *wpan_phy, + struct wpan_dev *wpan_dev) +{ + struct ieee802154_local *local = wpan_phy_priv(wpan_phy); + int ret; + + ASSERT_RTNL(); + + mutex_lock(&local->scan_lock); + ret = mac802154_abort_scan_locked(local); + mutex_unlock(&local->scan_lock); + + return ret; +} + #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL static void ieee802154_get_llsec_table(struct wpan_phy *wpan_phy, @@ -475,6 +512,8 @@ 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 8a7f4c83c5b6..5cc3ac8fd4a1 100644 --- a/net/mac802154/ieee802154_i.h +++ b/net/mac802154/ieee802154_i.h @@ -48,6 +48,15 @@ struct ieee802154_local { struct hrtimer ifs_timer; + /* Scanning */ + struct mutex scan_lock; + atomic_t scanning; + __le64 scan_addr; + int scan_channel_idx; + struct cfg802154_scan_request __rcu *scan_req; + struct ieee802154_sub_if_data __rcu *scan_sdata; + struct delayed_work scan_work; + bool started; bool suspended; @@ -167,6 +176,19 @@ void mac802154_unlock_table(struct net_device *dev); int mac802154_wpan_update_llsec(struct net_device *dev); +/* scanning handling */ +void mac802154_scan_work(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); +int mac802154_scan_process_beacon(struct ieee802154_local *local, + struct sk_buff *skb); + +static inline bool mac802154_scan_is_ongoing(struct ieee802154_local *local) +{ + return atomic_read(&local->scanning); +} + /* 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 88826c5aa4ba..09e2fc6848cb 100644 --- a/net/mac802154/main.c +++ b/net/mac802154/main.c @@ -90,12 +90,14 @@ ieee802154_alloc_hw(size_t priv_data_len, const struct ieee802154_ops *ops) INIT_LIST_HEAD(&local->interfaces); mutex_init(&local->iflist_mtx); + mutex_init(&local->scan_lock); tasklet_setup(&local->tasklet, ieee802154_tasklet_handler); skb_queue_head_init(&local->skb_queue); INIT_WORK(&local->tx_work, ieee802154_xmit_worker); + INIT_DELAYED_WORK(&local->scan_work, mac802154_scan_work); /* 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 b8ce84618a55..f2f3eca9bc20 100644 --- a/net/mac802154/rx.c +++ b/net/mac802154/rx.c @@ -94,10 +94,15 @@ ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata, switch (mac_cb(skb)->type) { case IEEE802154_FC_TYPE_BEACON: - case IEEE802154_FC_TYPE_ACK: + if (mac802154_scan_is_ongoing(sdata->local)) { + rc = mac802154_scan_process_beacon(sdata->local, skb); + if (!rc) + goto success; + } + goto fail; case IEEE802154_FC_TYPE_MAC_CMD: + case IEEE802154_FC_TYPE_ACK: goto fail; - case IEEE802154_FC_TYPE_DATA: return ieee802154_deliver_skb(skb); default: @@ -109,6 +114,10 @@ ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata, fail: kfree_skb(skb); return NET_RX_DROP; + +success: + kfree_skb(skb); + return NET_RX_SUCCESS; } static void @@ -268,10 +277,12 @@ void ieee802154_rx(struct ieee802154_local *local, struct sk_buff *skb) ieee802154_monitors_rx(local, skb); - /* Check if transceiver doesn't validate the checksum. - * If not we validate the checksum here. + /* Check if the transceiver doesn't validate the checksum, or if the + * check might have been disabled like during a scan. In these cases, + * we validate the checksum here. */ - if (local->hw.flags & IEEE802154_HW_RX_DROP_BAD_CKSUM) { + if (local->hw.flags & IEEE802154_HW_RX_DROP_BAD_CKSUM || + mac802154_scan_is_ongoing(local)) { crc = crc_ccitt(0, skb->data, skb->len); if (crc) { rcu_read_unlock(); diff --git a/net/mac802154/scan.c b/net/mac802154/scan.c new file mode 100644 index 000000000000..7be63d73caa9 --- /dev/null +++ b/net/mac802154/scan.c @@ -0,0 +1,255 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * IEEE 802.15.4 scanning management + * + * Copyright (C) Qorvo, 2021 + * Authors: + * - David Girault + * - Miquel Raynal + */ + +#include +#include +#include +#include + +#include "ieee802154_i.h" +#include "driver-ops.h" +#include "../ieee802154/nl802154.h" + +static bool mac802154_check_promiscuous(struct ieee802154_local *local) +{ + struct ieee802154_sub_if_data *sdata; + bool promiscuous_on = false; + + /* Check if one subif is already in promiscuous mode. Since the list is + * protected by its own mutex, take it here to ensure no modification + * occurs during the check. + */ + mutex_lock(&local->iflist_mtx); + list_for_each_entry(sdata, &local->interfaces, list) { + if (ieee802154_sdata_running(sdata) && + sdata->wpan_dev.promiscuous_mode) { + /* At least one is in promiscuous mode */ + promiscuous_on = true; + break; + } + } + mutex_unlock(&local->iflist_mtx); + return promiscuous_on; +} + +static int mac802154_set_promiscuous_mode(struct ieee802154_local *local, + bool state) +{ + bool promiscuous_on = mac802154_check_promiscuous(local); + int ret; + + if ((state && promiscuous_on) || (!state && !promiscuous_on)) + return 0; + + ret = drv_set_promiscuous_mode(local, state); + if (ret) + pr_err("Failed to %s promiscuous mode for SW scanning", + state ? "set" : "reset"); + + return ret; +} + +static int mac802154_send_scan_done(struct ieee802154_local *local) +{ + struct cfg802154_registered_device *rdev; + struct cfg802154_scan_request *scan_req; + struct wpan_dev *wpan_dev; + + scan_req = rcu_dereference_protected(local->scan_req, + lockdep_is_held(&local->scan_lock)); + rdev = wpan_phy_to_rdev(scan_req->wpan_phy); + wpan_dev = scan_req->wpan_dev; + + return nl802154_send_scan_done(rdev, wpan_dev); +} + +static int mac802154_end_of_scan(struct ieee802154_local *local) +{ + drv_set_channel(local, local->phy->current_page, + local->phy->current_channel); + ieee802154_set_symbol_duration(local->phy); + atomic_set(&local->scanning, 0); + mac802154_set_promiscuous_mode(local, false); + ieee802154_wake_queue(&local->hw); + + return mac802154_send_scan_done(local); +} + +int mac802154_abort_scan_locked(struct ieee802154_local *local) +{ + lockdep_assert_held(&local->scan_lock); + + if (!mac802154_scan_is_ongoing(local)) + return -ESRCH; + + cancel_delayed_work(&local->scan_work); + + return mac802154_end_of_scan(local); +} + +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)); +} + +void mac802154_scan_work(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; + bool end_of_scan = false; + unsigned long chan; + int ret; + + mutex_lock(&local->scan_lock); + + if (!mac802154_scan_is_ongoing(local)) + goto unlock_mutex; + + sdata = rcu_dereference_protected(local->scan_sdata, + lockdep_is_held(&local->scan_lock)); + scan_req = rcu_dereference_protected(local->scan_req, + lockdep_is_held(&local->scan_lock)); + + if (local->suspended || !ieee802154_sdata_running(sdata)) + goto queue_work; + + do { + chan = find_next_bit((const unsigned long *)&scan_req->channels, + IEEE802154_MAX_CHANNEL + 1, + local->scan_channel_idx + 1); + + /* If there are no more channels left, complete the scan */ + if (chan > IEEE802154_MAX_CHANNEL) { + end_of_scan = true; + goto unlock_mutex; + } + + /* Channel switch cannot be made atomic so hide the chan number + * in order to prevent beacon processing during this timeframe. + */ + local->scan_channel_idx = -1; + /* Bypass the stack on purpose */ + ret = drv_set_channel(local, scan_req->page, chan); + local->scan_channel_idx = chan; + ieee802154_set_symbol_duration(local->phy); + } while (ret); + +queue_work: + scan_duration = mac802154_scan_get_channel_time(scan_req->duration, + local->phy->symbol_duration); + pr_debug("Scan channel %lu of page %u for %ums\n", + chan, scan_req->page, jiffies_to_msecs(scan_duration)); + ieee802154_queue_delayed_work(&local->hw, &local->scan_work, + scan_duration); + +unlock_mutex: + if (end_of_scan) + mac802154_end_of_scan(local); + + mutex_unlock(&local->scan_lock); +} + +int mac802154_trigger_scan_locked(struct ieee802154_sub_if_data *sdata, + struct cfg802154_scan_request *request) +{ + struct ieee802154_local *local = sdata->local; + int ret; + + lockdep_assert_held(&local->scan_lock); + + if (mac802154_scan_is_ongoing(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); + rcu_assign_pointer(local->scan_sdata, sdata); + + /* Configure scan_addr to use net_device addr or random */ + if (request->flags & NL802154_SCAN_FLAG_RANDOM_ADDR) + get_random_bytes(&local->scan_addr, sizeof(local->scan_addr)); + else + local->scan_addr = cpu_to_le64(get_unaligned_be64(sdata->dev->dev_addr)); + + local->scan_channel_idx = -1; + atomic_set(&local->scanning, 1); + + /* Software scanning requires to set promiscuous mode, so we need to + * pause the Tx queue + */ + ieee802154_stop_queue(&local->hw); + ret = mac802154_set_promiscuous_mode(local, true); + if (ret) + return mac802154_end_of_scan(local); + + ieee802154_queue_delayed_work(&local->hw, &local->scan_work, 0); + + return 0; +} + +int mac802154_scan_process_beacon(struct ieee802154_local *local, + struct sk_buff *skb) +{ + struct ieee802154_beacon_hdr *bh = (void *)skb->data; + struct ieee802154_addr *src = &mac_cb(skb)->source; + struct cfg802154_scan_request *scan_req; + struct ieee802154_pan_desc desc = {}; + int ret; + + /* Check the validity of the frame length */ + if (skb->len < sizeof(*bh)) + return -EINVAL; + + if (unlikely(src->mode == IEEE802154_ADDR_NONE)) + return -EINVAL; + + if (unlikely(!bh->pan_coordinator)) + return -ENODEV; + + scan_req = rcu_dereference(local->scan_req); + if (unlikely(!scan_req)) + return -EINVAL; + + if (unlikely(local->scan_channel_idx < 0)) { + pr_info("Dropping beacon received during channel change\n"); + return 0; + } + + pr_debug("Beacon received on channel %d of page %d\n", + local->scan_channel_idx, scan_req->page); + + /* Parse beacon and create PAN information */ + desc.coord = src; + desc.page = scan_req->page; + desc.channel = local->scan_channel_idx; + desc.link_quality = mac_cb(skb)->lqi; + desc.superframe_spec = get_unaligned_le16(skb->data); + desc.gts_permit = bh->gts_permit; + + /* Create or update the PAN entry in the management layer */ + ret = cfg802154_record_pan(local->phy, &desc); + if (ret) { + pr_err("Failed to save PAN descriptor\n"); + return ret; + } + + return 0; +} diff --git a/net/mac802154/tx.c b/net/mac802154/tx.c index c829e4a75325..40656728c624 100644 --- a/net/mac802154/tx.c +++ b/net/mac802154/tx.c @@ -54,6 +54,9 @@ ieee802154_tx(struct ieee802154_local *local, struct sk_buff *skb) struct net_device *dev = skb->dev; int ret; + if (unlikely(mac802154_scan_is_ongoing(local))) + return NETDEV_TX_BUSY; + if (!(local->hw.flags & IEEE802154_HW_TX_OMIT_CKSUM)) { struct sk_buff *nskb; u16 crc; diff --git a/net/mac802154/util.c b/net/mac802154/util.c index f2078238718b..5ee65cb1dbcd 100644 --- a/net/mac802154/util.c +++ b/net/mac802154/util.c @@ -94,3 +94,29 @@ void ieee802154_stop_device(struct ieee802154_local *local) hrtimer_cancel(&local->ifs_timer); drv_stop(local); } + +/* Nothing should have been stuffed into the workqueue during + * the suspend->resume cycle. + */ +static bool ieee802154_can_queue_work(struct ieee802154_local *local) +{ + if (local->suspended) { + pr_warn("queueing ieee802154 work while suspended\n"); + return false; + } + + return true; +} + +void ieee802154_queue_delayed_work(struct ieee802154_hw *hw, + struct delayed_work *dwork, + unsigned long delay) +{ + struct ieee802154_local *local = hw_to_local(hw); + + if (!ieee802154_can_queue_work(local)) + return; + + queue_delayed_work(local->workqueue, dwork, delay); +} +EXPORT_SYMBOL(ieee802154_queue_delayed_work);