summaryrefslogtreecommitdiff
path: root/net/mac802154/rx.c
blob: c2aae2a6d6a6ba98b5513980f8ee97946cde0810 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2007-2012 Siemens AG
 *
 * Written by:
 * Pavel Smolenskiy <pavel.smolenskiy@gmail.com>
 * Maxim Gorbachyov <maxim.gorbachev@siemens.com>
 * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
 * Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
 */

#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;
	struct wpan_phy *wpan_phy = sdata->local->hw.phy;
	__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;

	/* Level 3 filtering: Only beacons are accepted during scans */
	if (sdata->required_filtering == IEEE802154_FILTERING_3_SCAN &&
	    sdata->required_filtering > wpan_phy->filtering) {
		if (mac_cb(skb)->type != IEEE802154_FC_TYPE_BEACON) {
			dev_dbg(&sdata->dev->dev,
				"drop non-beacon frame (0x%x) during scan\n",
				mac_cb(skb)->type);
			goto fail;
		}
	}

	switch (mac_cb(skb)->dest.mode) {
	case IEEE802154_ADDR_NONE:
		if (hdr->source.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);
		return;
	}

	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(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;
	struct sk_buff *skb2;

	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_MONITOR)
			continue;

		if (!ieee802154_sdata_running(sdata))
			continue;

		/* Do not deliver packets received on interfaces expecting
		 * AACK=1 if the address filters where disabled.
		 */
		if (local->hw.phy->filtering < IEEE802154_FILTERING_4_FRAME_FIELDS &&
		    sdata->required_filtering == IEEE802154_FILTERING_4_FRAME_FIELDS)
			continue;

		skb2 = skb_clone(skb, GFP_ATOMIC);
		if (skb2) {
			skb2->dev = sdata->dev;
			ieee802154_subif_frame(sdata, skb2, &hdr);
		}
	}
}

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 free_skb;

	/* 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);

	/* Level 1 filtering: Check the FCS by software when relevant */
	if (local->hw.phy->filtering == IEEE802154_FILTERING_NONE) {
		crc = crc_ccitt(0, skb->data, skb->len);
		if (crc)
			goto drop;
	}
	/* remove crc */
	skb_trim(skb, skb->len - 2);

	__ieee802154_rx_handle_packet(local, skb);

drop:
	rcu_read_unlock();
free_skb:
	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);
	struct ieee802154_mac_cb *cb = mac_cb_init(skb);

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