net/mac802154/rx.c - kernel/common - Git at Google

 /*
  * Copyright (C) 2007-2012 Siemens AG
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2
  * as published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * Written by:
  * Pavel Smolenskiy <[email protected]>
  * Maxim Gorbachyov <[email protected]>
  * Dmitry Eremin-Solenikov <[email protected]>
  * Alexander Smirnov <[email protected]>
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/netdevice.h>
 #include <linux/crc-ccitt.h>
 #include <asm/unaligned.h>

 #include <net/mac802154.h>
 #include <net/ieee802154_netdev.h>
 #include <net/nl802154.h>

 #include "ieee802154_i.h"

 static int ieee802154_deliver_skb(struct sk_buff *skb)
 {
 	skb->ip_summed = CHECKSUM_UNNECESSARY;
 	skb->protocol = htons(ETH_P_IEEE802154);

 	return netif_receive_skb(skb);
 }

 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;
 	__le16 span, sshort;
 	int rc;

 	pr_debug("getting packet via slave interface %s\n", sdata->dev->name);

 	span = wpan_dev->pan_id;
 	sshort = wpan_dev->short_addr;

 	switch (mac_cb(skb)->dest.mode) {
 	case IEEE802154_ADDR_NONE:
 		if (mac_cb(skb)->dest.mode != IEEE802154_ADDR_NONE)
 			/* FIXME: check if we are PAN coordinator */
 			skb->pkt_type = PACKET_OTHERHOST;
 		else
 			/* ACK comes with both addresses empty */
 			skb->pkt_type = PACKET_HOST;
 		break;
 	case IEEE802154_ADDR_LONG:
 		if (mac_cb(skb)->dest.pan_id != span &&
 		    mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
 			skb->pkt_type = PACKET_OTHERHOST;
 		else if (mac_cb(skb)->dest.extended_addr == wpan_dev->extended_addr)
 			skb->pkt_type = PACKET_HOST;
 		else
 			skb->pkt_type = PACKET_OTHERHOST;
 		break;
 	case IEEE802154_ADDR_SHORT:
 		if (mac_cb(skb)->dest.pan_id != span &&
 		    mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
 			skb->pkt_type = PACKET_OTHERHOST;
 		else if (mac_cb(skb)->dest.short_addr == sshort)
 			skb->pkt_type = PACKET_HOST;
 		else if (mac_cb(skb)->dest.short_addr ==
 			  cpu_to_le16(IEEE802154_ADDR_BROADCAST))
 			skb->pkt_type = PACKET_BROADCAST;
 		else
 			skb->pkt_type = PACKET_OTHERHOST;
 		break;
 	default:
 		pr_debug("invalid dest mode\n");
 		goto fail;
 	}

 	skb->dev = sdata->dev;

 	/* TODO this should be moved after netif_receive_skb call, otherwise
 	 * wireshark will show a mac header with security fields and the
 	 * payload is already decrypted.
 	 */
 	rc = mac802154_llsec_decrypt(&sdata->sec, skb);
 	if (rc) {
 		pr_debug("decryption failed: %i\n", rc);
 		goto fail;
 	}

 	sdata->dev->stats.rx_packets++;
 	sdata->dev->stats.rx_bytes += skb->len;

 	switch (mac_cb(skb)->type) {
 	case IEEE802154_FC_TYPE_BEACON:
 	case IEEE802154_FC_TYPE_ACK:
 	case IEEE802154_FC_TYPE_MAC_CMD:
 		goto fail;

 	case IEEE802154_FC_TYPE_DATA:
 		return ieee802154_deliver_skb(skb);
 	default:
 		pr_warn_ratelimited("ieee802154: bad frame received "
 				    "(type = %d)\n", mac_cb(skb)->type);
 		goto fail;
 	}

 fail:
 	kfree_skb(skb);
 	return NET_RX_DROP;
 }

 static void
 ieee802154_print_addr(const char *name, const struct ieee802154_addr *addr)
 {
 	if (addr->mode == IEEE802154_ADDR_NONE)
 		pr_debug("%s not present\n", name);

 	pr_debug("%s PAN ID: %04x\n", name, le16_to_cpu(addr->pan_id));
 	if (addr->mode == IEEE802154_ADDR_SHORT) {
 		pr_debug("%s is short: %04x\n", name,
 			 le16_to_cpu(addr->short_addr));
 	} else {
 		u64 hw = swab64((__force u64)addr->extended_addr);

 		pr_debug("%s is hardware: %8phC\n", name, &hw);
 	}
 }

 static int
 ieee802154_parse_frame_start(struct sk_buff *skb, struct ieee802154_hdr *hdr)
 {
 	int hlen;
 	struct ieee802154_mac_cb *cb = mac_cb_init(skb);

 	skb_reset_mac_header(skb);

 	hlen = ieee802154_hdr_pull(skb, hdr);
 	if (hlen < 0)
 		return -EINVAL;

 	skb->mac_len = hlen;

 	pr_debug("fc: %04x dsn: %02x\n", le16_to_cpup((__le16 *)&hdr->fc),
 		 hdr->seq);

 	cb->type = hdr->fc.type;
 	cb->ackreq = hdr->fc.ack_request;
 	cb->secen = hdr->fc.security_enabled;

 	ieee802154_print_addr("destination", &hdr->dest);
 	ieee802154_print_addr("source", &hdr->source);

 	cb->source = hdr->source;
 	cb->dest = hdr->dest;

 	if (hdr->fc.security_enabled) {
 		u64 key;

 		pr_debug("seclevel %i\n", hdr->sec.level);

 		switch (hdr->sec.key_id_mode) {
 		case IEEE802154_SCF_KEY_IMPLICIT:
 			pr_debug("implicit key\n");
 			break;

 		case IEEE802154_SCF_KEY_INDEX:
 			pr_debug("key %02x\n", hdr->sec.key_id);
 			break;

 		case IEEE802154_SCF_KEY_SHORT_INDEX:
 			pr_debug("key %04x:%04x %02x\n",
 				 le32_to_cpu(hdr->sec.short_src) >> 16,
 				 le32_to_cpu(hdr->sec.short_src) & 0xffff,
 				 hdr->sec.key_id);
 			break;

 		case IEEE802154_SCF_KEY_HW_INDEX:
 			key = swab64((__force u64)hdr->sec.extended_src);
 			pr_debug("key source %8phC %02x\n", &key,
 				 hdr->sec.key_id);
 			break;
 		}
 	}

 	return 0;
 }

 static void
 __ieee802154_rx_handle_packet(struct ieee802154_local *local,
 			      struct sk_buff *skb)
 {
 	int ret;
 	struct ieee802154_sub_if_data *sdata;
 	struct ieee802154_hdr hdr;

 	ret = ieee802154_parse_frame_start(skb, &hdr);
 	if (ret) {
 		pr_debug("got invalid frame\n");
 		kfree_skb(skb);
 		return;
 	}

 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 		if (sdata->wpan_dev.iftype != NL802154_IFTYPE_NODE)
 			continue;

 		if (!ieee802154_sdata_running(sdata))
 			continue;

 		ieee802154_subif_frame(sdata, skb, &hdr);
 		skb = NULL;
 		break;
 	}

 	kfree_skb(skb);
 }

 static void
 ieee802154_monitors_rx(struct ieee802154_local *local, struct sk_buff *skb)
 {
 	struct sk_buff *skb2;
 	struct ieee802154_sub_if_data *sdata;

 	skb_reset_mac_header(skb);
 	skb->ip_summed = CHECKSUM_UNNECESSARY;
 	skb->pkt_type = PACKET_OTHERHOST;
 	skb->protocol = htons(ETH_P_IEEE802154);

 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 		if (sdata->wpan_dev.iftype != NL802154_IFTYPE_MONITOR)
 			continue;

 		if (!ieee802154_sdata_running(sdata))
 			continue;

 		skb2 = skb_clone(skb, GFP_ATOMIC);
 		if (skb2) {
 			skb2->dev = sdata->dev;
 			ieee802154_deliver_skb(skb2);

 			sdata->dev->stats.rx_packets++;
 			sdata->dev->stats.rx_bytes += skb->len;
 		}
 	}
 }

 void ieee802154_rx(struct ieee802154_local *local, struct sk_buff *skb)
 {
 	u16 crc;

 	WARN_ON_ONCE(softirq_count() == 0);

 	if (local->suspended)
 		goto drop;

 	/* TODO: When a transceiver omits the checksum here, we
 	 * add an own calculated one. This is currently an ugly
 	 * solution because the monitor needs a crc here.
 	 */
 	if (local->hw.flags & IEEE802154_HW_RX_OMIT_CKSUM) {
 		crc = crc_ccitt(0, skb->data, skb->len);
 		put_unaligned_le16(crc, skb_put(skb, 2));
 	}

 	rcu_read_lock();

 	ieee802154_monitors_rx(local, skb);

 	/* Check if transceiver doesn't validate the checksum.
 	 * If not we validate the checksum here.
 	 */
 	if (local->hw.flags & IEEE802154_HW_RX_DROP_BAD_CKSUM) {
 		crc = crc_ccitt(0, skb->data, skb->len);
 		if (crc) {
 			rcu_read_unlock();
 			goto drop;
 		}
 	}
 	/* remove crc */
 	skb_trim(skb, skb->len - 2);

 	__ieee802154_rx_handle_packet(local, skb);

 	rcu_read_unlock();

 	return;
 drop:
 	kfree_skb(skb);
 }

 void
 ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb, u8 lqi)
 {
 	struct ieee802154_local *local = hw_to_local(hw);

 	mac_cb(skb)->lqi = lqi;
 	skb->pkt_type = IEEE802154_RX_MSG;
 	skb_queue_tail(&local->skb_queue, skb);
 	tasklet_schedule(&local->tasklet);
 }
 EXPORT_SYMBOL(ieee802154_rx_irqsafe);
	/*
	* Copyright (C) 2007-2012 Siemens AG
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2
	* as published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* Written by:
	* Pavel Smolenskiy <[email protected]>
	* Maxim Gorbachyov <[email protected]>
	* Dmitry Eremin-Solenikov <[email protected]>
	* Alexander Smirnov <[email protected]>
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/netdevice.h>
	#include <linux/crc-ccitt.h>
	#include <asm/unaligned.h>

	#include <net/mac802154.h>
	#include <net/ieee802154_netdev.h>
	#include <net/nl802154.h>

	#include "ieee802154_i.h"

	static int ieee802154_deliver_skb(struct sk_buff *skb)
	{
	skb->ip_summed = CHECKSUM_UNNECESSARY;
	skb->protocol = htons(ETH_P_IEEE802154);

	return netif_receive_skb(skb);
	}

	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;
	__le16 span, sshort;
	int rc;

	pr_debug("getting packet via slave interface %s\n", sdata->dev->name);

	span = wpan_dev->pan_id;
	sshort = wpan_dev->short_addr;

	switch (mac_cb(skb)->dest.mode) {
	case IEEE802154_ADDR_NONE:
	if (mac_cb(skb)->dest.mode != IEEE802154_ADDR_NONE)
	/* FIXME: check if we are PAN coordinator */
	skb->pkt_type = PACKET_OTHERHOST;
	else
	/* ACK comes with both addresses empty */
	skb->pkt_type = PACKET_HOST;
	break;
	case IEEE802154_ADDR_LONG:
	if (mac_cb(skb)->dest.pan_id != span &&
	mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
	skb->pkt_type = PACKET_OTHERHOST;
	else if (mac_cb(skb)->dest.extended_addr == wpan_dev->extended_addr)
	skb->pkt_type = PACKET_HOST;
	else
	skb->pkt_type = PACKET_OTHERHOST;
	break;
	case IEEE802154_ADDR_SHORT:
	if (mac_cb(skb)->dest.pan_id != span &&
	mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
	skb->pkt_type = PACKET_OTHERHOST;
	else if (mac_cb(skb)->dest.short_addr == sshort)
	skb->pkt_type = PACKET_HOST;
	else if (mac_cb(skb)->dest.short_addr ==
	cpu_to_le16(IEEE802154_ADDR_BROADCAST))
	skb->pkt_type = PACKET_BROADCAST;
	else
	skb->pkt_type = PACKET_OTHERHOST;
	break;
	default:
	pr_debug("invalid dest mode\n");
	goto fail;
	}

	skb->dev = sdata->dev;

	/* TODO this should be moved after netif_receive_skb call, otherwise
	* wireshark will show a mac header with security fields and the
	* payload is already decrypted.
	*/
	rc = mac802154_llsec_decrypt(&sdata->sec, skb);
	if (rc) {
	pr_debug("decryption failed: %i\n", rc);
	goto fail;
	}

	sdata->dev->stats.rx_packets++;
	sdata->dev->stats.rx_bytes += skb->len;

	switch (mac_cb(skb)->type) {
	case IEEE802154_FC_TYPE_BEACON:
	case IEEE802154_FC_TYPE_ACK:
	case IEEE802154_FC_TYPE_MAC_CMD:
	goto fail;

	case IEEE802154_FC_TYPE_DATA:
	return ieee802154_deliver_skb(skb);
	default:
	pr_warn_ratelimited("ieee802154: bad frame received "
	"(type = %d)\n", mac_cb(skb)->type);
	goto fail;
	}

	fail:
	kfree_skb(skb);
	return NET_RX_DROP;
	}

	static void
	ieee802154_print_addr(const char name, const struct ieee802154_addr addr)
	{
	if (addr->mode == IEEE802154_ADDR_NONE)
	pr_debug("%s not present\n", name);

	pr_debug("%s PAN ID: %04x\n", name, le16_to_cpu(addr->pan_id));
	if (addr->mode == IEEE802154_ADDR_SHORT) {
	pr_debug("%s is short: %04x\n", name,
	le16_to_cpu(addr->short_addr));
	} else {
	u64 hw = swab64((__force u64)addr->extended_addr);

	pr_debug("%s is hardware: %8phC\n", name, &hw);
	}
	}

	static int
	ieee802154_parse_frame_start(struct sk_buff skb, struct ieee802154_hdr hdr)
	{
	int hlen;
	struct ieee802154_mac_cb *cb = mac_cb_init(skb);

	skb_reset_mac_header(skb);

	hlen = ieee802154_hdr_pull(skb, hdr);
	if (hlen < 0)
	return -EINVAL;

	skb->mac_len = hlen;

	pr_debug("fc: %04x dsn: %02x\n", le16_to_cpup((__le16 *)&hdr->fc),
	hdr->seq);

	cb->type = hdr->fc.type;
	cb->ackreq = hdr->fc.ack_request;
	cb->secen = hdr->fc.security_enabled;

	ieee802154_print_addr("destination", &hdr->dest);
	ieee802154_print_addr("source", &hdr->source);

	cb->source = hdr->source;
	cb->dest = hdr->dest;

	if (hdr->fc.security_enabled) {
	u64 key;

	pr_debug("seclevel %i\n", hdr->sec.level);

	switch (hdr->sec.key_id_mode) {
	case IEEE802154_SCF_KEY_IMPLICIT:
	pr_debug("implicit key\n");
	break;

	case IEEE802154_SCF_KEY_INDEX:
	pr_debug("key %02x\n", hdr->sec.key_id);
	break;

	case IEEE802154_SCF_KEY_SHORT_INDEX:
	pr_debug("key %04x:%04x %02x\n",
	le32_to_cpu(hdr->sec.short_src) >> 16,
	le32_to_cpu(hdr->sec.short_src) & 0xffff,
	hdr->sec.key_id);
	break;

	case IEEE802154_SCF_KEY_HW_INDEX:
	key = swab64((__force u64)hdr->sec.extended_src);
	pr_debug("key source %8phC %02x\n", &key,
	hdr->sec.key_id);
	break;
	}
	}

	return 0;
	}

	static void
	__ieee802154_rx_handle_packet(struct ieee802154_local *local,
	struct sk_buff *skb)
	{
	int ret;
	struct ieee802154_sub_if_data *sdata;
	struct ieee802154_hdr hdr;

	ret = ieee802154_parse_frame_start(skb, &hdr);
	if (ret) {
	pr_debug("got invalid frame\n");
	kfree_skb(skb);
	return;
	}

	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
	if (sdata->wpan_dev.iftype != NL802154_IFTYPE_NODE)
	continue;

	if (!ieee802154_sdata_running(sdata))
	continue;

	ieee802154_subif_frame(sdata, skb, &hdr);
	skb = NULL;
	break;
	}

	kfree_skb(skb);
	}

	static void
	ieee802154_monitors_rx(struct ieee802154_local local, struct sk_buff skb)
	{
	struct sk_buff *skb2;
	struct ieee802154_sub_if_data *sdata;

	skb_reset_mac_header(skb);
	skb->ip_summed = CHECKSUM_UNNECESSARY;
	skb->pkt_type = PACKET_OTHERHOST;
	skb->protocol = htons(ETH_P_IEEE802154);

	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
	if (sdata->wpan_dev.iftype != NL802154_IFTYPE_MONITOR)
	continue;

	if (!ieee802154_sdata_running(sdata))
	continue;

	skb2 = skb_clone(skb, GFP_ATOMIC);
	if (skb2) {
	skb2->dev = sdata->dev;
	ieee802154_deliver_skb(skb2);

	sdata->dev->stats.rx_packets++;
	sdata->dev->stats.rx_bytes += skb->len;
	}
	}
	}

	void ieee802154_rx(struct ieee802154_local local, struct sk_buff skb)
	{
	u16 crc;

	WARN_ON_ONCE(softirq_count() == 0);

	if (local->suspended)
	goto drop;

	/* TODO: When a transceiver omits the checksum here, we
	* add an own calculated one. This is currently an ugly
	* solution because the monitor needs a crc here.
	*/
	if (local->hw.flags & IEEE802154_HW_RX_OMIT_CKSUM) {
	crc = crc_ccitt(0, skb->data, skb->len);
	put_unaligned_le16(crc, skb_put(skb, 2));
	}

	rcu_read_lock();

	ieee802154_monitors_rx(local, skb);

	/* Check if transceiver doesn't validate the checksum.
	* If not we validate the checksum here.
	*/
	if (local->hw.flags & IEEE802154_HW_RX_DROP_BAD_CKSUM) {
	crc = crc_ccitt(0, skb->data, skb->len);
	if (crc) {
	rcu_read_unlock();
	goto drop;
	}
	}
	/* remove crc */
	skb_trim(skb, skb->len - 2);

	__ieee802154_rx_handle_packet(local, skb);

	rcu_read_unlock();

	return;
	drop:
	kfree_skb(skb);
	}

	void
	ieee802154_rx_irqsafe(struct ieee802154_hw hw, struct sk_buff skb, u8 lqi)
	{
	struct ieee802154_local *local = hw_to_local(hw);

	mac_cb(skb)->lqi = lqi;
	skb->pkt_type = IEEE802154_RX_MSG;
	skb_queue_tail(&local->skb_queue, skb);
	tasklet_schedule(&local->tasklet);
	}
	EXPORT_SYMBOL(ieee802154_rx_irqsafe);