xref: /linux/include/net/6lowpan.h (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
1 /*
2  * Copyright 2011, Siemens AG
3  * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
4  */
5 
6 /*
7  * Based on patches from Jon Smirl <jonsmirl@gmail.com>
8  * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2
12  * as published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License along
20  * with this program; if not, write to the Free Software Foundation, Inc.,
21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
22  */
23 
24 /* Jon's code is based on 6lowpan implementation for Contiki which is:
25  * Copyright (c) 2008, Swedish Institute of Computer Science.
26  * All rights reserved.
27  *
28  * Redistribution and use in source and binary forms, with or without
29  * modification, are permitted provided that the following conditions
30  * are met:
31  * 1. Redistributions of source code must retain the above copyright
32  *    notice, this list of conditions and the following disclaimer.
33  * 2. Redistributions in binary form must reproduce the above copyright
34  *    notice, this list of conditions and the following disclaimer in the
35  *    documentation and/or other materials provided with the distribution.
36  * 3. Neither the name of the Institute nor the names of its contributors
37  *    may be used to endorse or promote products derived from this software
38  *    without specific prior written permission.
39  *
40  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  */
52 
53 #ifndef __6LOWPAN_H__
54 #define __6LOWPAN_H__
55 
56 #include <net/ipv6.h>
57 #include <net/net_namespace.h>
58 
59 #define UIP_802154_SHORTADDR_LEN	2  /* compressed ipv6 address length */
60 #define UIP_IPH_LEN			40 /* ipv6 fixed header size */
61 #define UIP_PROTO_UDP			17 /* ipv6 next header value for UDP */
62 #define UIP_FRAGH_LEN			8  /* ipv6 fragment header size */
63 
64 /*
65  * ipv6 address based on mac
66  * second bit-flip (Universe/Local) is done according RFC2464
67  */
68 #define is_addr_mac_addr_based(a, m) \
69 	((((a)->s6_addr[8])  == (((m)[0]) ^ 0x02)) &&	\
70 	 (((a)->s6_addr[9])  == (m)[1]) &&		\
71 	 (((a)->s6_addr[10]) == (m)[2]) &&		\
72 	 (((a)->s6_addr[11]) == (m)[3]) &&		\
73 	 (((a)->s6_addr[12]) == (m)[4]) &&		\
74 	 (((a)->s6_addr[13]) == (m)[5]) &&		\
75 	 (((a)->s6_addr[14]) == (m)[6]) &&		\
76 	 (((a)->s6_addr[15]) == (m)[7]))
77 
78 /*
79  * check whether we can compress the IID to 16 bits,
80  * it's possible for unicast adresses with first 49 bits are zero only.
81  */
82 #define lowpan_is_iid_16_bit_compressable(a)	\
83 	((((a)->s6_addr16[4]) == 0) &&		\
84 	 (((a)->s6_addr[10]) == 0) &&		\
85 	 (((a)->s6_addr[11]) == 0xff) &&	\
86 	 (((a)->s6_addr[12]) == 0xfe) &&	\
87 	 (((a)->s6_addr[13]) == 0))
88 
89 /* check whether the 112-bit gid of the multicast address is mappable to: */
90 
91 /* 48 bits, FFXX::00XX:XXXX:XXXX */
92 #define lowpan_is_mcast_addr_compressable48(a)	\
93 	((((a)->s6_addr16[1]) == 0) &&		\
94 	 (((a)->s6_addr16[2]) == 0) &&		\
95 	 (((a)->s6_addr16[3]) == 0) &&		\
96 	 (((a)->s6_addr16[4]) == 0) &&		\
97 	 (((a)->s6_addr[10]) == 0))
98 
99 /* 32 bits, FFXX::00XX:XXXX */
100 #define lowpan_is_mcast_addr_compressable32(a)	\
101 	((((a)->s6_addr16[1]) == 0) &&		\
102 	 (((a)->s6_addr16[2]) == 0) &&		\
103 	 (((a)->s6_addr16[3]) == 0) &&		\
104 	 (((a)->s6_addr16[4]) == 0) &&		\
105 	 (((a)->s6_addr16[5]) == 0) &&		\
106 	 (((a)->s6_addr[12]) == 0))
107 
108 /* 8 bits, FF02::00XX */
109 #define lowpan_is_mcast_addr_compressable8(a)	\
110 	((((a)->s6_addr[1])  == 2) &&		\
111 	 (((a)->s6_addr16[1]) == 0) &&		\
112 	 (((a)->s6_addr16[2]) == 0) &&		\
113 	 (((a)->s6_addr16[3]) == 0) &&		\
114 	 (((a)->s6_addr16[4]) == 0) &&		\
115 	 (((a)->s6_addr16[5]) == 0) &&		\
116 	 (((a)->s6_addr16[6]) == 0) &&		\
117 	 (((a)->s6_addr[14]) == 0))
118 
119 #define lowpan_is_addr_broadcast(a)	\
120 	((((a)[0]) == 0xFF) &&	\
121 	 (((a)[1]) == 0xFF) &&	\
122 	 (((a)[2]) == 0xFF) &&	\
123 	 (((a)[3]) == 0xFF) &&	\
124 	 (((a)[4]) == 0xFF) &&	\
125 	 (((a)[5]) == 0xFF) &&	\
126 	 (((a)[6]) == 0xFF) &&	\
127 	 (((a)[7]) == 0xFF))
128 
129 #define LOWPAN_DISPATCH_IPV6	0x41 /* 01000001 = 65 */
130 #define LOWPAN_DISPATCH_HC1	0x42 /* 01000010 = 66 */
131 #define LOWPAN_DISPATCH_IPHC	0x60 /* 011xxxxx = ... */
132 #define LOWPAN_DISPATCH_FRAG1	0xc0 /* 11000xxx */
133 #define LOWPAN_DISPATCH_FRAGN	0xe0 /* 11100xxx */
134 
135 #define LOWPAN_DISPATCH_MASK	0xf8 /* 11111000 */
136 
137 #define LOWPAN_FRAG_TIMEOUT	(HZ * 60)	/* time-out 60 sec */
138 
139 #define LOWPAN_FRAG1_HEAD_SIZE	0x4
140 #define LOWPAN_FRAGN_HEAD_SIZE	0x5
141 
142 /*
143  * Values of fields within the IPHC encoding first byte
144  * (C stands for compressed and I for inline)
145  */
146 #define LOWPAN_IPHC_TF		0x18
147 
148 #define LOWPAN_IPHC_FL_C	0x10
149 #define LOWPAN_IPHC_TC_C	0x08
150 #define LOWPAN_IPHC_NH_C	0x04
151 #define LOWPAN_IPHC_TTL_1	0x01
152 #define LOWPAN_IPHC_TTL_64	0x02
153 #define LOWPAN_IPHC_TTL_255	0x03
154 #define LOWPAN_IPHC_TTL_I	0x00
155 
156 
157 /* Values of fields within the IPHC encoding second byte */
158 #define LOWPAN_IPHC_CID		0x80
159 
160 #define LOWPAN_IPHC_ADDR_00	0x00
161 #define LOWPAN_IPHC_ADDR_01	0x01
162 #define LOWPAN_IPHC_ADDR_02	0x02
163 #define LOWPAN_IPHC_ADDR_03	0x03
164 
165 #define LOWPAN_IPHC_SAC		0x40
166 #define LOWPAN_IPHC_SAM		0x30
167 
168 #define LOWPAN_IPHC_SAM_BIT	4
169 
170 #define LOWPAN_IPHC_M		0x08
171 #define LOWPAN_IPHC_DAC		0x04
172 #define LOWPAN_IPHC_DAM_00	0x00
173 #define LOWPAN_IPHC_DAM_01	0x01
174 #define LOWPAN_IPHC_DAM_10	0x02
175 #define LOWPAN_IPHC_DAM_11	0x03
176 
177 #define LOWPAN_IPHC_DAM_BIT	0
178 /*
179  * LOWPAN_UDP encoding (works together with IPHC)
180  */
181 #define LOWPAN_NHC_UDP_MASK		0xF8
182 #define LOWPAN_NHC_UDP_ID		0xF0
183 #define LOWPAN_NHC_UDP_CHECKSUMC	0x04
184 #define LOWPAN_NHC_UDP_CHECKSUMI	0x00
185 
186 #define LOWPAN_NHC_UDP_4BIT_PORT	0xF0B0
187 #define LOWPAN_NHC_UDP_4BIT_MASK	0xFFF0
188 #define LOWPAN_NHC_UDP_8BIT_PORT	0xF000
189 #define LOWPAN_NHC_UDP_8BIT_MASK	0xFF00
190 
191 /* values for port compression, _with checksum_ ie bit 5 set to 0 */
192 #define LOWPAN_NHC_UDP_CS_P_00	0xF0 /* all inline */
193 #define LOWPAN_NHC_UDP_CS_P_01	0xF1 /* source 16bit inline,
194 					dest = 0xF0 + 8 bit inline */
195 #define LOWPAN_NHC_UDP_CS_P_10	0xF2 /* source = 0xF0 + 8bit inline,
196 					dest = 16 bit inline */
197 #define LOWPAN_NHC_UDP_CS_P_11	0xF3 /* source & dest = 0xF0B + 4bit inline */
198 #define LOWPAN_NHC_UDP_CS_C	0x04 /* checksum elided */
199 
200 #ifdef DEBUG
201 /* print data in line */
202 static inline void raw_dump_inline(const char *caller, char *msg,
203 				   unsigned char *buf, int len)
204 {
205 	if (msg)
206 		pr_debug("%s():%s: ", caller, msg);
207 
208 	print_hex_dump_debug("", DUMP_PREFIX_NONE, 16, 1, buf, len, false);
209 }
210 
211 /* print data in a table format:
212  *
213  * addr: xx xx xx xx xx xx
214  * addr: xx xx xx xx xx xx
215  * ...
216  */
217 static inline void raw_dump_table(const char *caller, char *msg,
218 				  unsigned char *buf, int len)
219 {
220 	if (msg)
221 		pr_debug("%s():%s:\n", caller, msg);
222 
223 	print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET, 16, 1, buf, len, false);
224 }
225 #else
226 static inline void raw_dump_table(const char *caller, char *msg,
227 				  unsigned char *buf, int len) { }
228 static inline void raw_dump_inline(const char *caller, char *msg,
229 				   unsigned char *buf, int len) { }
230 #endif
231 
232 static inline int lowpan_fetch_skb_u8(struct sk_buff *skb, u8 *val)
233 {
234 	if (unlikely(!pskb_may_pull(skb, 1)))
235 		return -EINVAL;
236 
237 	*val = skb->data[0];
238 	skb_pull(skb, 1);
239 
240 	return 0;
241 }
242 
243 static inline bool lowpan_fetch_skb(struct sk_buff *skb,
244 		void *data, const unsigned int len)
245 {
246 	if (unlikely(!pskb_may_pull(skb, len)))
247 		return true;
248 
249 	skb_copy_from_linear_data(skb, data, len);
250 	skb_pull(skb, len);
251 
252 	return false;
253 }
254 
255 static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data,
256 				       const size_t len)
257 {
258 	memcpy(*hc_ptr, data, len);
259 	*hc_ptr += len;
260 }
261 
262 static inline u8 lowpan_addr_mode_size(const u8 addr_mode)
263 {
264 	static const u8 addr_sizes[] = {
265 		[LOWPAN_IPHC_ADDR_00] = 16,
266 		[LOWPAN_IPHC_ADDR_01] = 8,
267 		[LOWPAN_IPHC_ADDR_02] = 2,
268 		[LOWPAN_IPHC_ADDR_03] = 0,
269 	};
270 	return addr_sizes[addr_mode];
271 }
272 
273 static inline u8 lowpan_next_hdr_size(const u8 h_enc, u16 *uncomp_header)
274 {
275 	u8 ret = 1;
276 
277 	if ((h_enc & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
278 		*uncomp_header += sizeof(struct udphdr);
279 
280 		switch (h_enc & LOWPAN_NHC_UDP_CS_P_11) {
281 		case LOWPAN_NHC_UDP_CS_P_00:
282 			ret += 4;
283 			break;
284 		case LOWPAN_NHC_UDP_CS_P_01:
285 		case LOWPAN_NHC_UDP_CS_P_10:
286 			ret += 3;
287 			break;
288 		case LOWPAN_NHC_UDP_CS_P_11:
289 			ret++;
290 			break;
291 		default:
292 			break;
293 		}
294 
295 		if (!(h_enc & LOWPAN_NHC_UDP_CS_C))
296 			ret += 2;
297 	}
298 
299 	return ret;
300 }
301 
302 /**
303  *	lowpan_uncompress_size - returns skb->len size with uncompressed header
304  *	@skb: sk_buff with 6lowpan header inside
305  *	@datagram_offset: optional to get the datagram_offset value
306  *
307  *	Returns the skb->len with uncompressed header
308  */
309 static inline u16
310 lowpan_uncompress_size(const struct sk_buff *skb, u16 *dgram_offset)
311 {
312 	u16 ret = 2, uncomp_header = sizeof(struct ipv6hdr);
313 	u8 iphc0, iphc1, h_enc;
314 
315 	iphc0 = skb_network_header(skb)[0];
316 	iphc1 = skb_network_header(skb)[1];
317 
318 	switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
319 	case 0:
320 		ret += 4;
321 		break;
322 	case 1:
323 		ret += 3;
324 		break;
325 	case 2:
326 		ret++;
327 		break;
328 	default:
329 		break;
330 	}
331 
332 	if (!(iphc0 & LOWPAN_IPHC_NH_C))
333 		ret++;
334 
335 	if (!(iphc0 & 0x03))
336 		ret++;
337 
338 	ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_SAM) >>
339 				     LOWPAN_IPHC_SAM_BIT);
340 
341 	if (iphc1 & LOWPAN_IPHC_M) {
342 		switch ((iphc1 & LOWPAN_IPHC_DAM_11) >>
343 			LOWPAN_IPHC_DAM_BIT) {
344 		case LOWPAN_IPHC_DAM_00:
345 			ret += 16;
346 			break;
347 		case LOWPAN_IPHC_DAM_01:
348 			ret += 6;
349 			break;
350 		case LOWPAN_IPHC_DAM_10:
351 			ret += 4;
352 			break;
353 		case LOWPAN_IPHC_DAM_11:
354 			ret++;
355 			break;
356 		default:
357 			break;
358 		}
359 	} else {
360 		ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_DAM_11) >>
361 					     LOWPAN_IPHC_DAM_BIT);
362 	}
363 
364 	if (iphc0 & LOWPAN_IPHC_NH_C) {
365 		h_enc = skb_network_header(skb)[ret];
366 		ret += lowpan_next_hdr_size(h_enc, &uncomp_header);
367 	}
368 
369 	if (dgram_offset)
370 		*dgram_offset = uncomp_header;
371 
372 	return skb->len + uncomp_header - ret;
373 }
374 
375 typedef int (*skb_delivery_cb)(struct sk_buff *skb, struct net_device *dev);
376 
377 int lowpan_process_data(struct sk_buff *skb, struct net_device *dev,
378 		const u8 *saddr, const u8 saddr_type, const u8 saddr_len,
379 		const u8 *daddr, const u8 daddr_type, const u8 daddr_len,
380 		u8 iphc0, u8 iphc1, skb_delivery_cb skb_deliver);
381 int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
382 			unsigned short type, const void *_daddr,
383 			const void *_saddr, unsigned int len);
384 
385 #endif /* __6LOWPAN_H__ */
386