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
97	case IEEE802154_CMD_ASSOCIATION_RESP:
98		dev_dbg(&mac_pkt->sdata->dev->dev, "processing ASSOC RESP\n");
99		if (!mac802154_is_associating(local))
100			break;
101
102		mac802154_process_association_resp(mac_pkt->sdata, mac_pkt->skb);
103		break;
104
105	case IEEE802154_CMD_ASSOCIATION_REQ:
106		dev_dbg(&mac_pkt->sdata->dev->dev, "processing ASSOC REQ\n");
107		if (mac_pkt->sdata->wpan_dev.iftype != NL802154_IFTYPE_COORD)
108			break;
109
110		mac802154_process_association_req(mac_pkt->sdata, mac_pkt->skb);
111		break;
112
113	case IEEE802154_CMD_DISASSOCIATION_NOTIFY:
114		dev_dbg(&mac_pkt->sdata->dev->dev, "processing DISASSOC NOTIF\n");
115		if (mac_pkt->sdata->wpan_dev.iftype != NL802154_IFTYPE_COORD)
116			break;
117
118		mac802154_process_disassociation_notif(mac_pkt->sdata, mac_pkt->skb);
119		break;
120
121	default:
122		break;
123	}
124
125out:
126	list_del(&mac_pkt->node);
127	kfree_skb(mac_pkt->skb);
128	kfree(mac_pkt);
129}
130
131static int
132ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata,
133		       struct sk_buff *skb, const struct ieee802154_hdr *hdr)
134{
135	struct wpan_phy *wpan_phy = sdata->local->hw.phy;
136	struct wpan_dev *wpan_dev = &sdata->wpan_dev;
137	struct cfg802154_mac_pkt *mac_pkt;
138	__le16 span, sshort;
139	int rc;
140
141	pr_debug("getting packet via slave interface %s\n", sdata->dev->name);
142
143	span = wpan_dev->pan_id;
144	sshort = wpan_dev->short_addr;
145
146	/* Level 3 filtering: Only beacons are accepted during scans */
147	if (sdata->required_filtering == IEEE802154_FILTERING_3_SCAN &&
148	    sdata->required_filtering > wpan_phy->filtering) {
149		if (mac_cb(skb)->type != IEEE802154_FC_TYPE_BEACON) {
150			dev_dbg(&sdata->dev->dev,
151				"drop non-beacon frame (0x%x) during scan\n",
152				mac_cb(skb)->type);
153			goto fail;
154		}
155	}
156
157	switch (mac_cb(skb)->dest.mode) {
158	case IEEE802154_ADDR_NONE:
159		if (hdr->source.mode == IEEE802154_ADDR_NONE)
160			/* ACK comes with both addresses empty */
161			skb->pkt_type = PACKET_HOST;
162		else if (!wpan_dev->parent)
163			/* No dest means PAN coordinator is the recipient */
164			skb->pkt_type = PACKET_HOST;
165		else
166			/* We are not the PAN coordinator, just relaying */
167			skb->pkt_type = PACKET_OTHERHOST;
168		break;
169	case IEEE802154_ADDR_LONG:
170		if (mac_cb(skb)->dest.pan_id != span &&
171		    mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
172			skb->pkt_type = PACKET_OTHERHOST;
173		else if (mac_cb(skb)->dest.extended_addr == wpan_dev->extended_addr)
174			skb->pkt_type = PACKET_HOST;
175		else
176			skb->pkt_type = PACKET_OTHERHOST;
177		break;
178	case IEEE802154_ADDR_SHORT:
179		if (mac_cb(skb)->dest.pan_id != span &&
180		    mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
181			skb->pkt_type = PACKET_OTHERHOST;
182		else if (mac_cb(skb)->dest.short_addr == sshort)
183			skb->pkt_type = PACKET_HOST;
184		else if (mac_cb(skb)->dest.short_addr ==
185			  cpu_to_le16(IEEE802154_ADDR_BROADCAST))
186			skb->pkt_type = PACKET_BROADCAST;
187		else
188			skb->pkt_type = PACKET_OTHERHOST;
189		break;
190	default:
191		pr_debug("invalid dest mode\n");
192		goto fail;
193	}
194
195	skb->dev = sdata->dev;
196
197	/* TODO this should be moved after netif_receive_skb call, otherwise
198	 * wireshark will show a mac header with security fields and the
199	 * payload is already decrypted.
200	 */
201	rc = mac802154_llsec_decrypt(&sdata->sec, skb);
202	if (rc) {
203		pr_debug("decryption failed: %i\n", rc);
204		goto fail;
205	}
206
207	sdata->dev->stats.rx_packets++;
208	sdata->dev->stats.rx_bytes += skb->len;
209
210	switch (mac_cb(skb)->type) {
211	case IEEE802154_FC_TYPE_BEACON:
212		dev_dbg(&sdata->dev->dev, "BEACON received\n");
213		if (!mac802154_is_scanning(sdata->local))
214			goto fail;
215
216		mac_pkt = kzalloc(sizeof(*mac_pkt), GFP_ATOMIC);
217		if (!mac_pkt)
218			goto fail;
219
220		mac_pkt->skb = skb_get(skb);
221		mac_pkt->sdata = sdata;
222		mac_pkt->page = sdata->local->scan_page;
223		mac_pkt->channel = sdata->local->scan_channel;
224		list_add_tail(&mac_pkt->node, &sdata->local->rx_beacon_list);
225		queue_work(sdata->local->mac_wq, &sdata->local->rx_beacon_work);
226		return NET_RX_SUCCESS;
227
228	case IEEE802154_FC_TYPE_MAC_CMD:
229		dev_dbg(&sdata->dev->dev, "MAC COMMAND received\n");
230		mac_pkt = kzalloc(sizeof(*mac_pkt), GFP_ATOMIC);
231		if (!mac_pkt)
232			goto fail;
233
234		mac_pkt->skb = skb_get(skb);
235		mac_pkt->sdata = sdata;
236		list_add_tail(&mac_pkt->node, &sdata->local->rx_mac_cmd_list);
237		queue_work(sdata->local->mac_wq, &sdata->local->rx_mac_cmd_work);
238		return NET_RX_SUCCESS;
239
240	case IEEE802154_FC_TYPE_ACK:
241		goto fail;
242
243	case IEEE802154_FC_TYPE_DATA:
244		return ieee802154_deliver_skb(skb);
245	default:
246		pr_warn_ratelimited("ieee802154: bad frame received "
247				    "(type = %d)\n", mac_cb(skb)->type);
248		goto fail;
249	}
250
251fail:
252	kfree_skb(skb);
253	return NET_RX_DROP;
254}
255
256static void
257ieee802154_print_addr(const char *name, const struct ieee802154_addr *addr)
258{
259	if (addr->mode == IEEE802154_ADDR_NONE) {
260		pr_debug("%s not present\n", name);
261		return;
262	}
263
264	pr_debug("%s PAN ID: %04x\n", name, le16_to_cpu(addr->pan_id));
265	if (addr->mode == IEEE802154_ADDR_SHORT) {
266		pr_debug("%s is short: %04x\n", name,
267			 le16_to_cpu(addr->short_addr));
268	} else {
269		u64 hw = swab64((__force u64)addr->extended_addr);
270
271		pr_debug("%s is hardware: %8phC\n", name, &hw);
272	}
273}
274
275static int
276ieee802154_parse_frame_start(struct sk_buff *skb, struct ieee802154_hdr *hdr)
277{
278	int hlen;
279	struct ieee802154_mac_cb *cb = mac_cb(skb);
280
281	skb_reset_mac_header(skb);
282
283	hlen = ieee802154_hdr_pull(skb, hdr);
284	if (hlen < 0)
285		return -EINVAL;
286
287	skb->mac_len = hlen;
288
289	pr_debug("fc: %04x dsn: %02x\n", le16_to_cpup((__le16 *)&hdr->fc),
290		 hdr->seq);
291
292	cb->type = hdr->fc.type;
293	cb->ackreq = hdr->fc.ack_request;
294	cb->secen = hdr->fc.security_enabled;
295
296	ieee802154_print_addr("destination", &hdr->dest);
297	ieee802154_print_addr("source", &hdr->source);
298
299	cb->source = hdr->source;
300	cb->dest = hdr->dest;
301
302	if (hdr->fc.security_enabled) {
303		u64 key;
304
305		pr_debug("seclevel %i\n", hdr->sec.level);
306
307		switch (hdr->sec.key_id_mode) {
308		case IEEE802154_SCF_KEY_IMPLICIT:
309			pr_debug("implicit key\n");
310			break;
311
312		case IEEE802154_SCF_KEY_INDEX:
313			pr_debug("key %02x\n", hdr->sec.key_id);
314			break;
315
316		case IEEE802154_SCF_KEY_SHORT_INDEX:
317			pr_debug("key %04x:%04x %02x\n",
318				 le32_to_cpu(hdr->sec.short_src) >> 16,
319				 le32_to_cpu(hdr->sec.short_src) & 0xffff,
320				 hdr->sec.key_id);
321			break;
322
323		case IEEE802154_SCF_KEY_HW_INDEX:
324			key = swab64((__force u64)hdr->sec.extended_src);
325			pr_debug("key source %8phC %02x\n", &key,
326				 hdr->sec.key_id);
327			break;
328		}
329	}
330
331	return 0;
332}
333
334static void
335__ieee802154_rx_handle_packet(struct ieee802154_local *local,
336			      struct sk_buff *skb)
337{
338	int ret;
339	struct ieee802154_sub_if_data *sdata;
340	struct ieee802154_hdr hdr;
341	struct sk_buff *skb2;
342
343	ret = ieee802154_parse_frame_start(skb, &hdr);
344	if (ret) {
345		pr_debug("got invalid frame\n");
346		return;
347	}
348
349	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
350		if (sdata->wpan_dev.iftype == NL802154_IFTYPE_MONITOR)
351			continue;
352
353		if (!ieee802154_sdata_running(sdata))
354			continue;
355
356		/* Do not deliver packets received on interfaces expecting
357		 * AACK=1 if the address filters where disabled.
358		 */
359		if (local->hw.phy->filtering < IEEE802154_FILTERING_4_FRAME_FIELDS &&
360		    sdata->required_filtering == IEEE802154_FILTERING_4_FRAME_FIELDS)
361			continue;
362
363		skb2 = skb_clone(skb, GFP_ATOMIC);
364		if (skb2) {
365			skb2->dev = sdata->dev;
366			ieee802154_subif_frame(sdata, skb2, &hdr);
367		}
368	}
369}
370
371static void
372ieee802154_monitors_rx(struct ieee802154_local *local, struct sk_buff *skb)
373{
374	struct sk_buff *skb2;
375	struct ieee802154_sub_if_data *sdata;
376
377	skb_reset_mac_header(skb);
378	skb->ip_summed = CHECKSUM_UNNECESSARY;
379	skb->pkt_type = PACKET_OTHERHOST;
380	skb->protocol = htons(ETH_P_IEEE802154);
381
382	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
383		if (sdata->wpan_dev.iftype != NL802154_IFTYPE_MONITOR)
384			continue;
385
386		if (!ieee802154_sdata_running(sdata))
387			continue;
388
389		skb2 = skb_clone(skb, GFP_ATOMIC);
390		if (skb2) {
391			skb2->dev = sdata->dev;
392			ieee802154_deliver_skb(skb2);
393
394			sdata->dev->stats.rx_packets++;
395			sdata->dev->stats.rx_bytes += skb->len;
396		}
397	}
398}
399
400void ieee802154_rx(struct ieee802154_local *local, struct sk_buff *skb)
401{
402	u16 crc;
403
404	WARN_ON_ONCE(softirq_count() == 0);
405
406	if (local->suspended)
407		goto free_skb;
408
409	/* TODO: When a transceiver omits the checksum here, we
410	 * add an own calculated one. This is currently an ugly
411	 * solution because the monitor needs a crc here.
412	 */
413	if (local->hw.flags & IEEE802154_HW_RX_OMIT_CKSUM) {
414		crc = crc_ccitt(0, skb->data, skb->len);
415		put_unaligned_le16(crc, skb_put(skb, 2));
416	}
417
418	rcu_read_lock();
419
420	ieee802154_monitors_rx(local, skb);
421
422	/* Level 1 filtering: Check the FCS by software when relevant */
423	if (local->hw.phy->filtering == IEEE802154_FILTERING_NONE) {
424		crc = crc_ccitt(0, skb->data, skb->len);
425		if (crc)
426			goto drop;
427	}
428	/* remove crc */
429	skb_trim(skb, skb->len - 2);
430
431	__ieee802154_rx_handle_packet(local, skb);
432
433drop:
434	rcu_read_unlock();
435free_skb:
436	kfree_skb(skb);
437}
438
439void
440ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb, u8 lqi)
441{
442	struct ieee802154_local *local = hw_to_local(hw);
443	struct ieee802154_mac_cb *cb = mac_cb_init(skb);
444
445	cb->lqi = lqi;
446	skb->pkt_type = IEEE802154_RX_MSG;
447	skb_queue_tail(&local->skb_queue, skb);
448	tasklet_schedule(&local->tasklet);
449}
450EXPORT_SYMBOL(ieee802154_rx_irqsafe);
451