xref: /linux/net/mac802154/rx.c (revision 0c7f35d26b1dc45ab27e3ea8ff7f6a8a88a18174)
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 
24 static 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 
32 void 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 
50 static int
51 ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata,
52 		       struct sk_buff *skb, const struct ieee802154_hdr *hdr)
53 {
54 	struct wpan_phy *wpan_phy = sdata->local->hw.phy;
55 	struct wpan_dev *wpan_dev = &sdata->wpan_dev;
56 	struct cfg802154_mac_pkt *mac_pkt;
57 	__le16 span, sshort;
58 	int rc;
59 
60 	pr_debug("getting packet via slave interface %s\n", sdata->dev->name);
61 
62 	span = wpan_dev->pan_id;
63 	sshort = wpan_dev->short_addr;
64 
65 	/* Level 3 filtering: Only beacons are accepted during scans */
66 	if (sdata->required_filtering == IEEE802154_FILTERING_3_SCAN &&
67 	    sdata->required_filtering > wpan_phy->filtering) {
68 		if (mac_cb(skb)->type != IEEE802154_FC_TYPE_BEACON) {
69 			dev_dbg(&sdata->dev->dev,
70 				"drop non-beacon frame (0x%x) during scan\n",
71 				mac_cb(skb)->type);
72 			goto fail;
73 		}
74 	}
75 
76 	switch (mac_cb(skb)->dest.mode) {
77 	case IEEE802154_ADDR_NONE:
78 		if (hdr->source.mode != IEEE802154_ADDR_NONE)
79 			/* FIXME: check if we are PAN coordinator */
80 			skb->pkt_type = PACKET_OTHERHOST;
81 		else
82 			/* ACK comes with both addresses empty */
83 			skb->pkt_type = PACKET_HOST;
84 		break;
85 	case IEEE802154_ADDR_LONG:
86 		if (mac_cb(skb)->dest.pan_id != span &&
87 		    mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
88 			skb->pkt_type = PACKET_OTHERHOST;
89 		else if (mac_cb(skb)->dest.extended_addr == wpan_dev->extended_addr)
90 			skb->pkt_type = PACKET_HOST;
91 		else
92 			skb->pkt_type = PACKET_OTHERHOST;
93 		break;
94 	case IEEE802154_ADDR_SHORT:
95 		if (mac_cb(skb)->dest.pan_id != span &&
96 		    mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
97 			skb->pkt_type = PACKET_OTHERHOST;
98 		else if (mac_cb(skb)->dest.short_addr == sshort)
99 			skb->pkt_type = PACKET_HOST;
100 		else if (mac_cb(skb)->dest.short_addr ==
101 			  cpu_to_le16(IEEE802154_ADDR_BROADCAST))
102 			skb->pkt_type = PACKET_BROADCAST;
103 		else
104 			skb->pkt_type = PACKET_OTHERHOST;
105 		break;
106 	default:
107 		pr_debug("invalid dest mode\n");
108 		goto fail;
109 	}
110 
111 	skb->dev = sdata->dev;
112 
113 	/* TODO this should be moved after netif_receive_skb call, otherwise
114 	 * wireshark will show a mac header with security fields and the
115 	 * payload is already decrypted.
116 	 */
117 	rc = mac802154_llsec_decrypt(&sdata->sec, skb);
118 	if (rc) {
119 		pr_debug("decryption failed: %i\n", rc);
120 		goto fail;
121 	}
122 
123 	sdata->dev->stats.rx_packets++;
124 	sdata->dev->stats.rx_bytes += skb->len;
125 
126 	switch (mac_cb(skb)->type) {
127 	case IEEE802154_FC_TYPE_BEACON:
128 		dev_dbg(&sdata->dev->dev, "BEACON received\n");
129 		if (!mac802154_is_scanning(sdata->local))
130 			goto fail;
131 
132 		mac_pkt = kzalloc(sizeof(*mac_pkt), GFP_ATOMIC);
133 		if (!mac_pkt)
134 			goto fail;
135 
136 		mac_pkt->skb = skb_get(skb);
137 		mac_pkt->sdata = sdata;
138 		mac_pkt->page = sdata->local->scan_page;
139 		mac_pkt->channel = sdata->local->scan_channel;
140 		list_add_tail(&mac_pkt->node, &sdata->local->rx_beacon_list);
141 		queue_work(sdata->local->mac_wq, &sdata->local->rx_beacon_work);
142 		return NET_RX_SUCCESS;
143 	case IEEE802154_FC_TYPE_ACK:
144 	case IEEE802154_FC_TYPE_MAC_CMD:
145 		goto fail;
146 
147 	case IEEE802154_FC_TYPE_DATA:
148 		return ieee802154_deliver_skb(skb);
149 	default:
150 		pr_warn_ratelimited("ieee802154: bad frame received "
151 				    "(type = %d)\n", mac_cb(skb)->type);
152 		goto fail;
153 	}
154 
155 fail:
156 	kfree_skb(skb);
157 	return NET_RX_DROP;
158 }
159 
160 static void
161 ieee802154_print_addr(const char *name, const struct ieee802154_addr *addr)
162 {
163 	if (addr->mode == IEEE802154_ADDR_NONE) {
164 		pr_debug("%s not present\n", name);
165 		return;
166 	}
167 
168 	pr_debug("%s PAN ID: %04x\n", name, le16_to_cpu(addr->pan_id));
169 	if (addr->mode == IEEE802154_ADDR_SHORT) {
170 		pr_debug("%s is short: %04x\n", name,
171 			 le16_to_cpu(addr->short_addr));
172 	} else {
173 		u64 hw = swab64((__force u64)addr->extended_addr);
174 
175 		pr_debug("%s is hardware: %8phC\n", name, &hw);
176 	}
177 }
178 
179 static int
180 ieee802154_parse_frame_start(struct sk_buff *skb, struct ieee802154_hdr *hdr)
181 {
182 	int hlen;
183 	struct ieee802154_mac_cb *cb = mac_cb(skb);
184 
185 	skb_reset_mac_header(skb);
186 
187 	hlen = ieee802154_hdr_pull(skb, hdr);
188 	if (hlen < 0)
189 		return -EINVAL;
190 
191 	skb->mac_len = hlen;
192 
193 	pr_debug("fc: %04x dsn: %02x\n", le16_to_cpup((__le16 *)&hdr->fc),
194 		 hdr->seq);
195 
196 	cb->type = hdr->fc.type;
197 	cb->ackreq = hdr->fc.ack_request;
198 	cb->secen = hdr->fc.security_enabled;
199 
200 	ieee802154_print_addr("destination", &hdr->dest);
201 	ieee802154_print_addr("source", &hdr->source);
202 
203 	cb->source = hdr->source;
204 	cb->dest = hdr->dest;
205 
206 	if (hdr->fc.security_enabled) {
207 		u64 key;
208 
209 		pr_debug("seclevel %i\n", hdr->sec.level);
210 
211 		switch (hdr->sec.key_id_mode) {
212 		case IEEE802154_SCF_KEY_IMPLICIT:
213 			pr_debug("implicit key\n");
214 			break;
215 
216 		case IEEE802154_SCF_KEY_INDEX:
217 			pr_debug("key %02x\n", hdr->sec.key_id);
218 			break;
219 
220 		case IEEE802154_SCF_KEY_SHORT_INDEX:
221 			pr_debug("key %04x:%04x %02x\n",
222 				 le32_to_cpu(hdr->sec.short_src) >> 16,
223 				 le32_to_cpu(hdr->sec.short_src) & 0xffff,
224 				 hdr->sec.key_id);
225 			break;
226 
227 		case IEEE802154_SCF_KEY_HW_INDEX:
228 			key = swab64((__force u64)hdr->sec.extended_src);
229 			pr_debug("key source %8phC %02x\n", &key,
230 				 hdr->sec.key_id);
231 			break;
232 		}
233 	}
234 
235 	return 0;
236 }
237 
238 static void
239 __ieee802154_rx_handle_packet(struct ieee802154_local *local,
240 			      struct sk_buff *skb)
241 {
242 	int ret;
243 	struct ieee802154_sub_if_data *sdata;
244 	struct ieee802154_hdr hdr;
245 	struct sk_buff *skb2;
246 
247 	ret = ieee802154_parse_frame_start(skb, &hdr);
248 	if (ret) {
249 		pr_debug("got invalid frame\n");
250 		return;
251 	}
252 
253 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
254 		if (sdata->wpan_dev.iftype == NL802154_IFTYPE_MONITOR)
255 			continue;
256 
257 		if (!ieee802154_sdata_running(sdata))
258 			continue;
259 
260 		/* Do not deliver packets received on interfaces expecting
261 		 * AACK=1 if the address filters where disabled.
262 		 */
263 		if (local->hw.phy->filtering < IEEE802154_FILTERING_4_FRAME_FIELDS &&
264 		    sdata->required_filtering == IEEE802154_FILTERING_4_FRAME_FIELDS)
265 			continue;
266 
267 		skb2 = skb_clone(skb, GFP_ATOMIC);
268 		if (skb2) {
269 			skb2->dev = sdata->dev;
270 			ieee802154_subif_frame(sdata, skb2, &hdr);
271 		}
272 	}
273 }
274 
275 static void
276 ieee802154_monitors_rx(struct ieee802154_local *local, struct sk_buff *skb)
277 {
278 	struct sk_buff *skb2;
279 	struct ieee802154_sub_if_data *sdata;
280 
281 	skb_reset_mac_header(skb);
282 	skb->ip_summed = CHECKSUM_UNNECESSARY;
283 	skb->pkt_type = PACKET_OTHERHOST;
284 	skb->protocol = htons(ETH_P_IEEE802154);
285 
286 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
287 		if (sdata->wpan_dev.iftype != NL802154_IFTYPE_MONITOR)
288 			continue;
289 
290 		if (!ieee802154_sdata_running(sdata))
291 			continue;
292 
293 		skb2 = skb_clone(skb, GFP_ATOMIC);
294 		if (skb2) {
295 			skb2->dev = sdata->dev;
296 			ieee802154_deliver_skb(skb2);
297 
298 			sdata->dev->stats.rx_packets++;
299 			sdata->dev->stats.rx_bytes += skb->len;
300 		}
301 	}
302 }
303 
304 void ieee802154_rx(struct ieee802154_local *local, struct sk_buff *skb)
305 {
306 	u16 crc;
307 
308 	WARN_ON_ONCE(softirq_count() == 0);
309 
310 	if (local->suspended)
311 		goto free_skb;
312 
313 	/* TODO: When a transceiver omits the checksum here, we
314 	 * add an own calculated one. This is currently an ugly
315 	 * solution because the monitor needs a crc here.
316 	 */
317 	if (local->hw.flags & IEEE802154_HW_RX_OMIT_CKSUM) {
318 		crc = crc_ccitt(0, skb->data, skb->len);
319 		put_unaligned_le16(crc, skb_put(skb, 2));
320 	}
321 
322 	rcu_read_lock();
323 
324 	ieee802154_monitors_rx(local, skb);
325 
326 	/* Level 1 filtering: Check the FCS by software when relevant */
327 	if (local->hw.phy->filtering == IEEE802154_FILTERING_NONE) {
328 		crc = crc_ccitt(0, skb->data, skb->len);
329 		if (crc)
330 			goto drop;
331 	}
332 	/* remove crc */
333 	skb_trim(skb, skb->len - 2);
334 
335 	__ieee802154_rx_handle_packet(local, skb);
336 
337 drop:
338 	rcu_read_unlock();
339 free_skb:
340 	kfree_skb(skb);
341 }
342 
343 void
344 ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb, u8 lqi)
345 {
346 	struct ieee802154_local *local = hw_to_local(hw);
347 	struct ieee802154_mac_cb *cb = mac_cb_init(skb);
348 
349 	cb->lqi = lqi;
350 	skb->pkt_type = IEEE802154_RX_MSG;
351 	skb_queue_tail(&local->skb_queue, skb);
352 	tasklet_schedule(&local->tasklet);
353 }
354 EXPORT_SYMBOL(ieee802154_rx_irqsafe);
355