1 /* 2 * Copyright (C) 2007-2012 Siemens AG 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 6 * as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public License along 14 * with this program; if not, write to the Free Software Foundation, Inc., 15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 16 * 17 * Written by: 18 * Pavel Smolenskiy <pavel.smolenskiy@gmail.com> 19 * Maxim Gorbachyov <maxim.gorbachev@siemens.com> 20 * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> 21 * Alexander Smirnov <alex.bluesman.smirnov@gmail.com> 22 */ 23 24 #include <linux/kernel.h> 25 #include <linux/module.h> 26 #include <linux/workqueue.h> 27 #include <linux/netdevice.h> 28 #include <linux/crc-ccitt.h> 29 30 #include <net/mac802154.h> 31 #include <net/ieee802154_netdev.h> 32 33 #include "mac802154.h" 34 35 /* The IEEE 802.15.4 standard defines 4 MAC packet types: 36 * - beacon frame 37 * - MAC command frame 38 * - acknowledgement frame 39 * - data frame 40 * 41 * and only the data frame should be pushed to the upper layers, other types 42 * are just internal MAC layer management information. So only data packets 43 * are going to be sent to the networking queue, all other will be processed 44 * right here by using the device workqueue. 45 */ 46 struct rx_work { 47 struct sk_buff *skb; 48 struct work_struct work; 49 struct ieee802154_dev *dev; 50 u8 lqi; 51 }; 52 53 static void 54 mac802154_subif_rx(struct ieee802154_dev *hw, struct sk_buff *skb, u8 lqi) 55 { 56 struct mac802154_priv *priv = mac802154_to_priv(hw); 57 58 mac_cb(skb)->lqi = lqi; 59 skb->protocol = htons(ETH_P_IEEE802154); 60 skb_reset_mac_header(skb); 61 62 BUILD_BUG_ON(sizeof(struct ieee802154_mac_cb) > sizeof(skb->cb)); 63 64 if (!(priv->hw.flags & IEEE802154_HW_OMIT_CKSUM)) { 65 u16 crc; 66 67 if (skb->len < 2) { 68 pr_debug("got invalid frame\n"); 69 goto out; 70 } 71 crc = crc_ccitt(0, skb->data, skb->len); 72 if (crc) { 73 pr_debug("CRC mismatch\n"); 74 goto out; 75 } 76 skb_trim(skb, skb->len - 2); /* CRC */ 77 } 78 79 mac802154_monitors_rx(priv, skb); 80 mac802154_wpans_rx(priv, skb); 81 out: 82 dev_kfree_skb(skb); 83 } 84 85 static void mac802154_rx_worker(struct work_struct *work) 86 { 87 struct rx_work *rw = container_of(work, struct rx_work, work); 88 struct sk_buff *skb = rw->skb; 89 90 mac802154_subif_rx(rw->dev, skb, rw->lqi); 91 kfree(rw); 92 } 93 94 void 95 ieee802154_rx_irqsafe(struct ieee802154_dev *dev, struct sk_buff *skb, u8 lqi) 96 { 97 struct mac802154_priv *priv = mac802154_to_priv(dev); 98 struct rx_work *work; 99 100 if (!skb) 101 return; 102 103 work = kzalloc(sizeof(struct rx_work), GFP_ATOMIC); 104 if (!work) 105 return; 106 107 INIT_WORK(&work->work, mac802154_rx_worker); 108 work->skb = skb; 109 work->dev = dev; 110 work->lqi = lqi; 111 112 queue_work(priv->dev_workqueue, &work->work); 113 } 114 EXPORT_SYMBOL(ieee802154_rx_irqsafe); 115