xref: /kernel/linux/linux-6.6/net/mac802154/rx.c (revision 62306a36)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2007-2012 Siemens AG
4 *
5 * Written by:
6 * Pavel Smolenskiy <pavel.smolenskiy@gmail.com>
7 * Maxim Gorbachyov <maxim.gorbachev@siemens.com>
8 * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
9 * Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
10 */
11
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/netdevice.h>
15#include <linux/crc-ccitt.h>
16#include <asm/unaligned.h>
17
18#include <net/mac802154.h>
19#include <net/ieee802154_netdev.h>
20#include <net/nl802154.h>
21
22#include "ieee802154_i.h"
23
24static int ieee802154_deliver_skb(struct sk_buff *skb)
25{
26	skb->ip_summed = CHECKSUM_UNNECESSARY;
27	skb->protocol = htons(ETH_P_IEEE802154);
28
29	return netif_receive_skb(skb);
30}
31
32void mac802154_rx_beacon_worker(struct work_struct *work)
33{
34	struct ieee802154_local *local =
35		container_of(work, struct ieee802154_local, rx_beacon_work);
36	struct cfg802154_mac_pkt *mac_pkt;
37
38	mac_pkt = list_first_entry_or_null(&local->rx_beacon_list,
39					   struct cfg802154_mac_pkt, node);
40	if (!mac_pkt)
41		return;
42
43	mac802154_process_beacon(local, mac_pkt->skb, mac_pkt->page, mac_pkt->channel);
44
45	list_del(&mac_pkt->node);
46	kfree_skb(mac_pkt->skb);
47	kfree(mac_pkt);
48}
49
50static bool mac802154_should_answer_beacon_req(struct ieee802154_local *local)
51{
52	struct cfg802154_beacon_request *beacon_req;
53	unsigned int interval;
54
55	rcu_read_lock();
56	beacon_req = rcu_dereference(local->beacon_req);
57	if (!beacon_req) {
58		rcu_read_unlock();
59		return false;
60	}
61
62	interval = beacon_req->interval;
63	rcu_read_unlock();
64
65	if (!mac802154_is_beaconing(local))
66		return false;
67
68	return interval == IEEE802154_ACTIVE_SCAN_DURATION;
69}
70
71void mac802154_rx_mac_cmd_worker(struct work_struct *work)
72{
73	struct ieee802154_local *local =
74		container_of(work, struct ieee802154_local, rx_mac_cmd_work);
75	struct cfg802154_mac_pkt *mac_pkt;
76	u8 mac_cmd;
77	int rc;
78
79	mac_pkt = list_first_entry_or_null(&local->rx_mac_cmd_list,
80					   struct cfg802154_mac_pkt, node);
81	if (!mac_pkt)
82		return;
83
84	rc = ieee802154_get_mac_cmd(mac_pkt->skb, &mac_cmd);
85	if (rc)
86		goto out;
87
88	switch (mac_cmd) {
89	case IEEE802154_CMD_BEACON_REQ:
90		dev_dbg(&mac_pkt->sdata->dev->dev, "processing BEACON REQ\n");
91		if (!mac802154_should_answer_beacon_req(local))
92			break;
93
94		queue_delayed_work(local->mac_wq, &local->beacon_work, 0);
95		break;
96	default:
97		break;
98	}
99
100out:
101	list_del(&mac_pkt->node);
102	kfree_skb(mac_pkt->skb);
103	kfree(mac_pkt);
104}
105
106static int
107ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata,
108		       struct sk_buff *skb, const struct ieee802154_hdr *hdr)
109{
110	struct wpan_phy *wpan_phy = sdata->local->hw.phy;
111	struct wpan_dev *wpan_dev = &sdata->wpan_dev;
112	struct cfg802154_mac_pkt *mac_pkt;
113	__le16 span, sshort;
114	int rc;
115
116	pr_debug("getting packet via slave interface %s\n", sdata->dev->name);
117
118	span = wpan_dev->pan_id;
119	sshort = wpan_dev->short_addr;
120
121	/* Level 3 filtering: Only beacons are accepted during scans */
122	if (sdata->required_filtering == IEEE802154_FILTERING_3_SCAN &&
123	    sdata->required_filtering > wpan_phy->filtering) {
124		if (mac_cb(skb)->type != IEEE802154_FC_TYPE_BEACON) {
125			dev_dbg(&sdata->dev->dev,
126				"drop non-beacon frame (0x%x) during scan\n",
127				mac_cb(skb)->type);
128			goto fail;
129		}
130	}
131
132	switch (mac_cb(skb)->dest.mode) {
133	case IEEE802154_ADDR_NONE:
134		if (hdr->source.mode != IEEE802154_ADDR_NONE)
135			/* FIXME: check if we are PAN coordinator */
136			skb->pkt_type = PACKET_OTHERHOST;
137		else
138			/* ACK comes with both addresses empty */
139			skb->pkt_type = PACKET_HOST;
140		break;
141	case IEEE802154_ADDR_LONG:
142		if (mac_cb(skb)->dest.pan_id != span &&
143		    mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
144			skb->pkt_type = PACKET_OTHERHOST;
145		else if (mac_cb(skb)->dest.extended_addr == wpan_dev->extended_addr)
146			skb->pkt_type = PACKET_HOST;
147		else
148			skb->pkt_type = PACKET_OTHERHOST;
149		break;
150	case IEEE802154_ADDR_SHORT:
151		if (mac_cb(skb)->dest.pan_id != span &&
152		    mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
153			skb->pkt_type = PACKET_OTHERHOST;
154		else if (mac_cb(skb)->dest.short_addr == sshort)
155			skb->pkt_type = PACKET_HOST;
156		else if (mac_cb(skb)->dest.short_addr ==
157			  cpu_to_le16(IEEE802154_ADDR_BROADCAST))
158			skb->pkt_type = PACKET_BROADCAST;
159		else
160			skb->pkt_type = PACKET_OTHERHOST;
161		break;
162	default:
163		pr_debug("invalid dest mode\n");
164		goto fail;
165	}
166
167	skb->dev = sdata->dev;
168
169	/* TODO this should be moved after netif_receive_skb call, otherwise
170	 * wireshark will show a mac header with security fields and the
171	 * payload is already decrypted.
172	 */
173	rc = mac802154_llsec_decrypt(&sdata->sec, skb);
174	if (rc) {
175		pr_debug("decryption failed: %i\n", rc);
176		goto fail;
177	}
178
179	sdata->dev->stats.rx_packets++;
180	sdata->dev->stats.rx_bytes += skb->len;
181
182	switch (mac_cb(skb)->type) {
183	case IEEE802154_FC_TYPE_BEACON:
184		dev_dbg(&sdata->dev->dev, "BEACON received\n");
185		if (!mac802154_is_scanning(sdata->local))
186			goto fail;
187
188		mac_pkt = kzalloc(sizeof(*mac_pkt), GFP_ATOMIC);
189		if (!mac_pkt)
190			goto fail;
191
192		mac_pkt->skb = skb_get(skb);
193		mac_pkt->sdata = sdata;
194		mac_pkt->page = sdata->local->scan_page;
195		mac_pkt->channel = sdata->local->scan_channel;
196		list_add_tail(&mac_pkt->node, &sdata->local->rx_beacon_list);
197		queue_work(sdata->local->mac_wq, &sdata->local->rx_beacon_work);
198		return NET_RX_SUCCESS;
199
200	case IEEE802154_FC_TYPE_MAC_CMD:
201		dev_dbg(&sdata->dev->dev, "MAC COMMAND received\n");
202		mac_pkt = kzalloc(sizeof(*mac_pkt), GFP_ATOMIC);
203		if (!mac_pkt)
204			goto fail;
205
206		mac_pkt->skb = skb_get(skb);
207		mac_pkt->sdata = sdata;
208		list_add_tail(&mac_pkt->node, &sdata->local->rx_mac_cmd_list);
209		queue_work(sdata->local->mac_wq, &sdata->local->rx_mac_cmd_work);
210		return NET_RX_SUCCESS;
211
212	case IEEE802154_FC_TYPE_ACK:
213		goto fail;
214
215	case IEEE802154_FC_TYPE_DATA:
216		return ieee802154_deliver_skb(skb);
217	default:
218		pr_warn_ratelimited("ieee802154: bad frame received "
219				    "(type = %d)\n", mac_cb(skb)->type);
220		goto fail;
221	}
222
223fail:
224	kfree_skb(skb);
225	return NET_RX_DROP;
226}
227
228static void
229ieee802154_print_addr(const char *name, const struct ieee802154_addr *addr)
230{
231	if (addr->mode == IEEE802154_ADDR_NONE) {
232		pr_debug("%s not present\n", name);
233		return;
234	}
235
236	pr_debug("%s PAN ID: %04x\n", name, le16_to_cpu(addr->pan_id));
237	if (addr->mode == IEEE802154_ADDR_SHORT) {
238		pr_debug("%s is short: %04x\n", name,
239			 le16_to_cpu(addr->short_addr));
240	} else {
241		u64 hw = swab64((__force u64)addr->extended_addr);
242
243		pr_debug("%s is hardware: %8phC\n", name, &hw);
244	}
245}
246
247static int
248ieee802154_parse_frame_start(struct sk_buff *skb, struct ieee802154_hdr *hdr)
249{
250	int hlen;
251	struct ieee802154_mac_cb *cb = mac_cb(skb);
252
253	skb_reset_mac_header(skb);
254
255	hlen = ieee802154_hdr_pull(skb, hdr);
256	if (hlen < 0)
257		return -EINVAL;
258
259	skb->mac_len = hlen;
260
261	pr_debug("fc: %04x dsn: %02x\n", le16_to_cpup((__le16 *)&hdr->fc),
262		 hdr->seq);
263
264	cb->type = hdr->fc.type;
265	cb->ackreq = hdr->fc.ack_request;
266	cb->secen = hdr->fc.security_enabled;
267
268	ieee802154_print_addr("destination", &hdr->dest);
269	ieee802154_print_addr("source", &hdr->source);
270
271	cb->source = hdr->source;
272	cb->dest = hdr->dest;
273
274	if (hdr->fc.security_enabled) {
275		u64 key;
276
277		pr_debug("seclevel %i\n", hdr->sec.level);
278
279		switch (hdr->sec.key_id_mode) {
280		case IEEE802154_SCF_KEY_IMPLICIT:
281			pr_debug("implicit key\n");
282			break;
283
284		case IEEE802154_SCF_KEY_INDEX:
285			pr_debug("key %02x\n", hdr->sec.key_id);
286			break;
287
288		case IEEE802154_SCF_KEY_SHORT_INDEX:
289			pr_debug("key %04x:%04x %02x\n",
290				 le32_to_cpu(hdr->sec.short_src) >> 16,
291				 le32_to_cpu(hdr->sec.short_src) & 0xffff,
292				 hdr->sec.key_id);
293			break;
294
295		case IEEE802154_SCF_KEY_HW_INDEX:
296			key = swab64((__force u64)hdr->sec.extended_src);
297			pr_debug("key source %8phC %02x\n", &key,
298				 hdr->sec.key_id);
299			break;
300		}
301	}
302
303	return 0;
304}
305
306static void
307__ieee802154_rx_handle_packet(struct ieee802154_local *local,
308			      struct sk_buff *skb)
309{
310	int ret;
311	struct ieee802154_sub_if_data *sdata;
312	struct ieee802154_hdr hdr;
313	struct sk_buff *skb2;
314
315	ret = ieee802154_parse_frame_start(skb, &hdr);
316	if (ret) {
317		pr_debug("got invalid frame\n");
318		return;
319	}
320
321	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
322		if (sdata->wpan_dev.iftype == NL802154_IFTYPE_MONITOR)
323			continue;
324
325		if (!ieee802154_sdata_running(sdata))
326			continue;
327
328		/* Do not deliver packets received on interfaces expecting
329		 * AACK=1 if the address filters where disabled.
330		 */
331		if (local->hw.phy->filtering < IEEE802154_FILTERING_4_FRAME_FIELDS &&
332		    sdata->required_filtering == IEEE802154_FILTERING_4_FRAME_FIELDS)
333			continue;
334
335		skb2 = skb_clone(skb, GFP_ATOMIC);
336		if (skb2) {
337			skb2->dev = sdata->dev;
338			ieee802154_subif_frame(sdata, skb2, &hdr);
339		}
340	}
341}
342
343static void
344ieee802154_monitors_rx(struct ieee802154_local *local, struct sk_buff *skb)
345{
346	struct sk_buff *skb2;
347	struct ieee802154_sub_if_data *sdata;
348
349	skb_reset_mac_header(skb);
350	skb->ip_summed = CHECKSUM_UNNECESSARY;
351	skb->pkt_type = PACKET_OTHERHOST;
352	skb->protocol = htons(ETH_P_IEEE802154);
353
354	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
355		if (sdata->wpan_dev.iftype != NL802154_IFTYPE_MONITOR)
356			continue;
357
358		if (!ieee802154_sdata_running(sdata))
359			continue;
360
361		skb2 = skb_clone(skb, GFP_ATOMIC);
362		if (skb2) {
363			skb2->dev = sdata->dev;
364			ieee802154_deliver_skb(skb2);
365
366			sdata->dev->stats.rx_packets++;
367			sdata->dev->stats.rx_bytes += skb->len;
368		}
369	}
370}
371
372void ieee802154_rx(struct ieee802154_local *local, struct sk_buff *skb)
373{
374	u16 crc;
375
376	WARN_ON_ONCE(softirq_count() == 0);
377
378	if (local->suspended)
379		goto free_skb;
380
381	/* TODO: When a transceiver omits the checksum here, we
382	 * add an own calculated one. This is currently an ugly
383	 * solution because the monitor needs a crc here.
384	 */
385	if (local->hw.flags & IEEE802154_HW_RX_OMIT_CKSUM) {
386		crc = crc_ccitt(0, skb->data, skb->len);
387		put_unaligned_le16(crc, skb_put(skb, 2));
388	}
389
390	rcu_read_lock();
391
392	ieee802154_monitors_rx(local, skb);
393
394	/* Level 1 filtering: Check the FCS by software when relevant */
395	if (local->hw.phy->filtering == IEEE802154_FILTERING_NONE) {
396		crc = crc_ccitt(0, skb->data, skb->len);
397		if (crc)
398			goto drop;
399	}
400	/* remove crc */
401	skb_trim(skb, skb->len - 2);
402
403	__ieee802154_rx_handle_packet(local, skb);
404
405drop:
406	rcu_read_unlock();
407free_skb:
408	kfree_skb(skb);
409}
410
411void
412ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb, u8 lqi)
413{
414	struct ieee802154_local *local = hw_to_local(hw);
415	struct ieee802154_mac_cb *cb = mac_cb_init(skb);
416
417	cb->lqi = lqi;
418	skb->pkt_type = IEEE802154_RX_MSG;
419	skb_queue_tail(&local->skb_queue, skb);
420	tasklet_schedule(&local->tasklet);
421}
422EXPORT_SYMBOL(ieee802154_rx_irqsafe);
423