xref: /openbmc/linux/net/mac802154/rx.c (revision ecfb9f40) 
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 static int
33 ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata,
34 		       struct sk_buff *skb, const struct ieee802154_hdr *hdr)
35 {
36 	struct wpan_dev *wpan_dev = &sdata->wpan_dev;
37 	struct wpan_phy *wpan_phy = sdata->local->hw.phy;
38 	__le16 span, sshort;
39 	int rc;
40 
41 	pr_debug("getting packet via slave interface %s\n", sdata->dev->name);
42 
43 	span = wpan_dev->pan_id;
44 	sshort = wpan_dev->short_addr;
45 
46 	/* Level 3 filtering: Only beacons are accepted during scans */
47 	if (sdata->required_filtering == IEEE802154_FILTERING_3_SCAN &&
48 	    sdata->required_filtering > wpan_phy->filtering) {
49 		if (mac_cb(skb)->type != IEEE802154_FC_TYPE_BEACON) {
50 			dev_dbg(&sdata->dev->dev,
51 				"drop non-beacon frame (0x%x) during scan\n",
52 				mac_cb(skb)->type);
53 			goto fail;
54 		}
55 	}
56 
57 	switch (mac_cb(skb)->dest.mode) {
58 	case IEEE802154_ADDR_NONE:
59 		if (hdr->source.mode != IEEE802154_ADDR_NONE)
60 			/* FIXME: check if we are PAN coordinator */
61 			skb->pkt_type = PACKET_OTHERHOST;
62 		else
63 			/* ACK comes with both addresses empty */
64 			skb->pkt_type = PACKET_HOST;
65 		break;
66 	case IEEE802154_ADDR_LONG:
67 		if (mac_cb(skb)->dest.pan_id != span &&
68 		    mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
69 			skb->pkt_type = PACKET_OTHERHOST;
70 		else if (mac_cb(skb)->dest.extended_addr == wpan_dev->extended_addr)
71 			skb->pkt_type = PACKET_HOST;
72 		else
73 			skb->pkt_type = PACKET_OTHERHOST;
74 		break;
75 	case IEEE802154_ADDR_SHORT:
76 		if (mac_cb(skb)->dest.pan_id != span &&
77 		    mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
78 			skb->pkt_type = PACKET_OTHERHOST;
79 		else if (mac_cb(skb)->dest.short_addr == sshort)
80 			skb->pkt_type = PACKET_HOST;
81 		else if (mac_cb(skb)->dest.short_addr ==
82 			  cpu_to_le16(IEEE802154_ADDR_BROADCAST))
83 			skb->pkt_type = PACKET_BROADCAST;
84 		else
85 			skb->pkt_type = PACKET_OTHERHOST;
86 		break;
87 	default:
88 		pr_debug("invalid dest mode\n");
89 		goto fail;
90 	}
91 
92 	skb->dev = sdata->dev;
93 
94 	/* TODO this should be moved after netif_receive_skb call, otherwise
95 	 * wireshark will show a mac header with security fields and the
96 	 * payload is already decrypted.
97 	 */
98 	rc = mac802154_llsec_decrypt(&sdata->sec, skb);
99 	if (rc) {
100 		pr_debug("decryption failed: %i\n", rc);
101 		goto fail;
102 	}
103 
104 	sdata->dev->stats.rx_packets++;
105 	sdata->dev->stats.rx_bytes += skb->len;
106 
107 	switch (mac_cb(skb)->type) {
108 	case IEEE802154_FC_TYPE_BEACON:
109 	case IEEE802154_FC_TYPE_ACK:
110 	case IEEE802154_FC_TYPE_MAC_CMD:
111 		goto fail;
112 
113 	case IEEE802154_FC_TYPE_DATA:
114 		return ieee802154_deliver_skb(skb);
115 	default:
116 		pr_warn_ratelimited("ieee802154: bad frame received "
117 				    "(type = %d)\n", mac_cb(skb)->type);
118 		goto fail;
119 	}
120 
121 fail:
122 	kfree_skb(skb);
123 	return NET_RX_DROP;
124 }
125 
126 static void
127 ieee802154_print_addr(const char *name, const struct ieee802154_addr *addr)
128 {
129 	if (addr->mode == IEEE802154_ADDR_NONE) {
130 		pr_debug("%s not present\n", name);
131 		return;
132 	}
133 
134 	pr_debug("%s PAN ID: %04x\n", name, le16_to_cpu(addr->pan_id));
135 	if (addr->mode == IEEE802154_ADDR_SHORT) {
136 		pr_debug("%s is short: %04x\n", name,
137 			 le16_to_cpu(addr->short_addr));
138 	} else {
139 		u64 hw = swab64((__force u64)addr->extended_addr);
140 
141 		pr_debug("%s is hardware: %8phC\n", name, &hw);
142 	}
143 }
144 
145 static int
146 ieee802154_parse_frame_start(struct sk_buff *skb, struct ieee802154_hdr *hdr)
147 {
148 	int hlen;
149 	struct ieee802154_mac_cb *cb = mac_cb(skb);
150 
151 	skb_reset_mac_header(skb);
152 
153 	hlen = ieee802154_hdr_pull(skb, hdr);
154 	if (hlen < 0)
155 		return -EINVAL;
156 
157 	skb->mac_len = hlen;
158 
159 	pr_debug("fc: %04x dsn: %02x\n", le16_to_cpup((__le16 *)&hdr->fc),
160 		 hdr->seq);
161 
162 	cb->type = hdr->fc.type;
163 	cb->ackreq = hdr->fc.ack_request;
164 	cb->secen = hdr->fc.security_enabled;
165 
166 	ieee802154_print_addr("destination", &hdr->dest);
167 	ieee802154_print_addr("source", &hdr->source);
168 
169 	cb->source = hdr->source;
170 	cb->dest = hdr->dest;
171 
172 	if (hdr->fc.security_enabled) {
173 		u64 key;
174 
175 		pr_debug("seclevel %i\n", hdr->sec.level);
176 
177 		switch (hdr->sec.key_id_mode) {
178 		case IEEE802154_SCF_KEY_IMPLICIT:
179 			pr_debug("implicit key\n");
180 			break;
181 
182 		case IEEE802154_SCF_KEY_INDEX:
183 			pr_debug("key %02x\n", hdr->sec.key_id);
184 			break;
185 
186 		case IEEE802154_SCF_KEY_SHORT_INDEX:
187 			pr_debug("key %04x:%04x %02x\n",
188 				 le32_to_cpu(hdr->sec.short_src) >> 16,
189 				 le32_to_cpu(hdr->sec.short_src) & 0xffff,
190 				 hdr->sec.key_id);
191 			break;
192 
193 		case IEEE802154_SCF_KEY_HW_INDEX:
194 			key = swab64((__force u64)hdr->sec.extended_src);
195 			pr_debug("key source %8phC %02x\n", &key,
196 				 hdr->sec.key_id);
197 			break;
198 		}
199 	}
200 
201 	return 0;
202 }
203 
204 static void
205 __ieee802154_rx_handle_packet(struct ieee802154_local *local,
206 			      struct sk_buff *skb)
207 {
208 	int ret;
209 	struct ieee802154_sub_if_data *sdata;
210 	struct ieee802154_hdr hdr;
211 	struct sk_buff *skb2;
212 
213 	ret = ieee802154_parse_frame_start(skb, &hdr);
214 	if (ret) {
215 		pr_debug("got invalid frame\n");
216 		kfree_skb(skb);
217 		return;
218 	}
219 
220 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
221 		if (sdata->wpan_dev.iftype == NL802154_IFTYPE_MONITOR)
222 			continue;
223 
224 		if (!ieee802154_sdata_running(sdata))
225 			continue;
226 
227 		/* Do not deliver packets received on interfaces expecting
228 		 * AACK=1 if the address filters where disabled.
229 		 */
230 		if (local->hw.phy->filtering < IEEE802154_FILTERING_4_FRAME_FIELDS &&
231 		    sdata->required_filtering == IEEE802154_FILTERING_4_FRAME_FIELDS)
232 			continue;
233 
234 		skb2 = skb_clone(skb, GFP_ATOMIC);
235 		if (skb2) {
236 			skb2->dev = sdata->dev;
237 			ieee802154_subif_frame(sdata, skb2, &hdr);
238 		}
239 	}
240 }
241 
242 static void
243 ieee802154_monitors_rx(struct ieee802154_local *local, struct sk_buff *skb)
244 {
245 	struct sk_buff *skb2;
246 	struct ieee802154_sub_if_data *sdata;
247 
248 	skb_reset_mac_header(skb);
249 	skb->ip_summed = CHECKSUM_UNNECESSARY;
250 	skb->pkt_type = PACKET_OTHERHOST;
251 	skb->protocol = htons(ETH_P_IEEE802154);
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 		skb2 = skb_clone(skb, GFP_ATOMIC);
261 		if (skb2) {
262 			skb2->dev = sdata->dev;
263 			ieee802154_deliver_skb(skb2);
264 
265 			sdata->dev->stats.rx_packets++;
266 			sdata->dev->stats.rx_bytes += skb->len;
267 		}
268 	}
269 }
270 
271 void ieee802154_rx(struct ieee802154_local *local, struct sk_buff *skb)
272 {
273 	u16 crc;
274 
275 	WARN_ON_ONCE(softirq_count() == 0);
276 
277 	if (local->suspended)
278 		goto free_skb;
279 
280 	/* TODO: When a transceiver omits the checksum here, we
281 	 * add an own calculated one. This is currently an ugly
282 	 * solution because the monitor needs a crc here.
283 	 */
284 	if (local->hw.flags & IEEE802154_HW_RX_OMIT_CKSUM) {
285 		crc = crc_ccitt(0, skb->data, skb->len);
286 		put_unaligned_le16(crc, skb_put(skb, 2));
287 	}
288 
289 	rcu_read_lock();
290 
291 	ieee802154_monitors_rx(local, skb);
292 
293 	/* Level 1 filtering: Check the FCS by software when relevant */
294 	if (local->hw.phy->filtering == IEEE802154_FILTERING_NONE) {
295 		crc = crc_ccitt(0, skb->data, skb->len);
296 		if (crc)
297 			goto drop;
298 	}
299 	/* remove crc */
300 	skb_trim(skb, skb->len - 2);
301 
302 	__ieee802154_rx_handle_packet(local, skb);
303 
304 drop:
305 	rcu_read_unlock();
306 free_skb:
307 	kfree_skb(skb);
308 }
309 
310 void
311 ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb, u8 lqi)
312 {
313 	struct ieee802154_local *local = hw_to_local(hw);
314 	struct ieee802154_mac_cb *cb = mac_cb_init(skb);
315 
316 	cb->lqi = lqi;
317 	skb->pkt_type = IEEE802154_RX_MSG;
318 	skb_queue_tail(&local->skb_queue, skb);
319 	tasklet_schedule(&local->tasklet);
320 }
321 EXPORT_SYMBOL(ieee802154_rx_irqsafe);
322