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[mirror_ubuntu-bionic-kernel.git] / net / 6lowpan / iphc.c
1 /*
2 * Copyright 2011, Siemens AG
3 * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
4 */
5
6 /* Based on patches from Jon Smirl <jonsmirl@gmail.com>
7 * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2
11 * as published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 */
19
20 /* Jon's code is based on 6lowpan implementation for Contiki which is:
21 * Copyright (c) 2008, Swedish Institute of Computer Science.
22 * All rights reserved.
23 *
24 * Redistribution and use in source and binary forms, with or without
25 * modification, are permitted provided that the following conditions
26 * are met:
27 * 1. Redistributions of source code must retain the above copyright
28 * notice, this list of conditions and the following disclaimer.
29 * 2. Redistributions in binary form must reproduce the above copyright
30 * notice, this list of conditions and the following disclaimer in the
31 * documentation and/or other materials provided with the distribution.
32 * 3. Neither the name of the Institute nor the names of its contributors
33 * may be used to endorse or promote products derived from this software
34 * without specific prior written permission.
35 *
36 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
37 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
39 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
40 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
41 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
42 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
44 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
45 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
46 * SUCH DAMAGE.
47 */
48
49 #include <linux/bitops.h>
50 #include <linux/if_arp.h>
51 #include <linux/netdevice.h>
52
53 #include <net/6lowpan.h>
54 #include <net/ipv6.h>
55
56 /* special link-layer handling */
57 #include <net/mac802154.h>
58
59 #include "6lowpan_i.h"
60 #include "nhc.h"
61
62 /* Values of fields within the IPHC encoding first byte */
63 #define LOWPAN_IPHC_TF_MASK 0x18
64 #define LOWPAN_IPHC_TF_00 0x00
65 #define LOWPAN_IPHC_TF_01 0x08
66 #define LOWPAN_IPHC_TF_10 0x10
67 #define LOWPAN_IPHC_TF_11 0x18
68
69 #define LOWPAN_IPHC_NH 0x04
70
71 #define LOWPAN_IPHC_HLIM_MASK 0x03
72 #define LOWPAN_IPHC_HLIM_00 0x00
73 #define LOWPAN_IPHC_HLIM_01 0x01
74 #define LOWPAN_IPHC_HLIM_10 0x02
75 #define LOWPAN_IPHC_HLIM_11 0x03
76
77 /* Values of fields within the IPHC encoding second byte */
78 #define LOWPAN_IPHC_CID 0x80
79
80 #define LOWPAN_IPHC_SAC 0x40
81
82 #define LOWPAN_IPHC_SAM_MASK 0x30
83 #define LOWPAN_IPHC_SAM_00 0x00
84 #define LOWPAN_IPHC_SAM_01 0x10
85 #define LOWPAN_IPHC_SAM_10 0x20
86 #define LOWPAN_IPHC_SAM_11 0x30
87
88 #define LOWPAN_IPHC_M 0x08
89
90 #define LOWPAN_IPHC_DAC 0x04
91
92 #define LOWPAN_IPHC_DAM_MASK 0x03
93 #define LOWPAN_IPHC_DAM_00 0x00
94 #define LOWPAN_IPHC_DAM_01 0x01
95 #define LOWPAN_IPHC_DAM_10 0x02
96 #define LOWPAN_IPHC_DAM_11 0x03
97
98 /* ipv6 address based on mac
99 * second bit-flip (Universe/Local) is done according RFC2464
100 */
101 #define is_addr_mac_addr_based(a, m) \
102 ((((a)->s6_addr[8]) == (((m)[0]) ^ 0x02)) && \
103 (((a)->s6_addr[9]) == (m)[1]) && \
104 (((a)->s6_addr[10]) == (m)[2]) && \
105 (((a)->s6_addr[11]) == (m)[3]) && \
106 (((a)->s6_addr[12]) == (m)[4]) && \
107 (((a)->s6_addr[13]) == (m)[5]) && \
108 (((a)->s6_addr[14]) == (m)[6]) && \
109 (((a)->s6_addr[15]) == (m)[7]))
110
111 /* check whether we can compress the IID to 16 bits,
112 * it's possible for unicast addresses with first 49 bits are zero only.
113 */
114 #define lowpan_is_iid_16_bit_compressable(a) \
115 ((((a)->s6_addr16[4]) == 0) && \
116 (((a)->s6_addr[10]) == 0) && \
117 (((a)->s6_addr[11]) == 0xff) && \
118 (((a)->s6_addr[12]) == 0xfe) && \
119 (((a)->s6_addr[13]) == 0))
120
121 /* check whether the 112-bit gid of the multicast address is mappable to: */
122
123 /* 48 bits, FFXX::00XX:XXXX:XXXX */
124 #define lowpan_is_mcast_addr_compressable48(a) \
125 ((((a)->s6_addr16[1]) == 0) && \
126 (((a)->s6_addr16[2]) == 0) && \
127 (((a)->s6_addr16[3]) == 0) && \
128 (((a)->s6_addr16[4]) == 0) && \
129 (((a)->s6_addr[10]) == 0))
130
131 /* 32 bits, FFXX::00XX:XXXX */
132 #define lowpan_is_mcast_addr_compressable32(a) \
133 ((((a)->s6_addr16[1]) == 0) && \
134 (((a)->s6_addr16[2]) == 0) && \
135 (((a)->s6_addr16[3]) == 0) && \
136 (((a)->s6_addr16[4]) == 0) && \
137 (((a)->s6_addr16[5]) == 0) && \
138 (((a)->s6_addr[12]) == 0))
139
140 /* 8 bits, FF02::00XX */
141 #define lowpan_is_mcast_addr_compressable8(a) \
142 ((((a)->s6_addr[1]) == 2) && \
143 (((a)->s6_addr16[1]) == 0) && \
144 (((a)->s6_addr16[2]) == 0) && \
145 (((a)->s6_addr16[3]) == 0) && \
146 (((a)->s6_addr16[4]) == 0) && \
147 (((a)->s6_addr16[5]) == 0) && \
148 (((a)->s6_addr16[6]) == 0) && \
149 (((a)->s6_addr[14]) == 0))
150
151 #define lowpan_is_linklocal_zero_padded(a) \
152 (!(hdr->saddr.s6_addr[1] & 0x3f) && \
153 !hdr->saddr.s6_addr16[1] && \
154 !hdr->saddr.s6_addr32[1])
155
156 #define LOWPAN_IPHC_CID_DCI(cid) (cid & 0x0f)
157 #define LOWPAN_IPHC_CID_SCI(cid) ((cid & 0xf0) >> 4)
158
159 static inline void iphc_uncompress_eui64_lladdr(struct in6_addr *ipaddr,
160 const void *lladdr)
161 {
162 /* fe:80::XXXX:XXXX:XXXX:XXXX
163 * \_________________/
164 * hwaddr
165 */
166 ipaddr->s6_addr[0] = 0xFE;
167 ipaddr->s6_addr[1] = 0x80;
168 memcpy(&ipaddr->s6_addr[8], lladdr, EUI64_ADDR_LEN);
169 /* second bit-flip (Universe/Local)
170 * is done according RFC2464
171 */
172 ipaddr->s6_addr[8] ^= 0x02;
173 }
174
175 static inline void iphc_uncompress_802154_lladdr(struct in6_addr *ipaddr,
176 const void *lladdr)
177 {
178 const struct ieee802154_addr *addr = lladdr;
179 u8 eui64[EUI64_ADDR_LEN] = { };
180
181 switch (addr->mode) {
182 case IEEE802154_ADDR_LONG:
183 ieee802154_le64_to_be64(eui64, &addr->extended_addr);
184 iphc_uncompress_eui64_lladdr(ipaddr, eui64);
185 break;
186 case IEEE802154_ADDR_SHORT:
187 /* fe:80::ff:fe00:XXXX
188 * \__/
189 * short_addr
190 *
191 * Universe/Local bit is zero.
192 */
193 ipaddr->s6_addr[0] = 0xFE;
194 ipaddr->s6_addr[1] = 0x80;
195 ipaddr->s6_addr[11] = 0xFF;
196 ipaddr->s6_addr[12] = 0xFE;
197 ieee802154_le16_to_be16(&ipaddr->s6_addr16[7],
198 &addr->short_addr);
199 break;
200 default:
201 /* should never handled and filtered by 802154 6lowpan */
202 WARN_ON_ONCE(1);
203 break;
204 }
205 }
206
207 static struct lowpan_iphc_ctx *
208 lowpan_iphc_ctx_get_by_id(const struct net_device *dev, u8 id)
209 {
210 struct lowpan_iphc_ctx *ret = &lowpan_dev(dev)->ctx.table[id];
211
212 if (!lowpan_iphc_ctx_is_active(ret))
213 return NULL;
214
215 return ret;
216 }
217
218 static struct lowpan_iphc_ctx *
219 lowpan_iphc_ctx_get_by_addr(const struct net_device *dev,
220 const struct in6_addr *addr)
221 {
222 struct lowpan_iphc_ctx *table = lowpan_dev(dev)->ctx.table;
223 struct lowpan_iphc_ctx *ret = NULL;
224 struct in6_addr addr_pfx;
225 u8 addr_plen;
226 int i;
227
228 for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++) {
229 /* Check if context is valid. A context that is not valid
230 * MUST NOT be used for compression.
231 */
232 if (!lowpan_iphc_ctx_is_active(&table[i]) ||
233 !lowpan_iphc_ctx_is_compression(&table[i]))
234 continue;
235
236 ipv6_addr_prefix(&addr_pfx, addr, table[i].plen);
237
238 /* if prefix len < 64, the remaining bits until 64th bit is
239 * zero. Otherwise we use table[i]->plen.
240 */
241 if (table[i].plen < 64)
242 addr_plen = 64;
243 else
244 addr_plen = table[i].plen;
245
246 if (ipv6_prefix_equal(&addr_pfx, &table[i].pfx, addr_plen)) {
247 /* remember first match */
248 if (!ret) {
249 ret = &table[i];
250 continue;
251 }
252
253 /* get the context with longest prefix len */
254 if (table[i].plen > ret->plen)
255 ret = &table[i];
256 }
257 }
258
259 return ret;
260 }
261
262 static struct lowpan_iphc_ctx *
263 lowpan_iphc_ctx_get_by_mcast_addr(const struct net_device *dev,
264 const struct in6_addr *addr)
265 {
266 struct lowpan_iphc_ctx *table = lowpan_dev(dev)->ctx.table;
267 struct lowpan_iphc_ctx *ret = NULL;
268 struct in6_addr addr_mcast, network_pfx = {};
269 int i;
270
271 /* init mcast address with */
272 memcpy(&addr_mcast, addr, sizeof(*addr));
273
274 for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++) {
275 /* Check if context is valid. A context that is not valid
276 * MUST NOT be used for compression.
277 */
278 if (!lowpan_iphc_ctx_is_active(&table[i]) ||
279 !lowpan_iphc_ctx_is_compression(&table[i]))
280 continue;
281
282 /* setting plen */
283 addr_mcast.s6_addr[3] = table[i].plen;
284 /* get network prefix to copy into multicast address */
285 ipv6_addr_prefix(&network_pfx, &table[i].pfx,
286 table[i].plen);
287 /* setting network prefix */
288 memcpy(&addr_mcast.s6_addr[4], &network_pfx, 8);
289
290 if (ipv6_addr_equal(addr, &addr_mcast)) {
291 ret = &table[i];
292 break;
293 }
294 }
295
296 return ret;
297 }
298
299 /* Uncompress address function for source and
300 * destination address(non-multicast).
301 *
302 * address_mode is the masked value for sam or dam value
303 */
304 static int uncompress_addr(struct sk_buff *skb, const struct net_device *dev,
305 struct in6_addr *ipaddr, u8 address_mode,
306 const void *lladdr)
307 {
308 bool fail;
309
310 switch (address_mode) {
311 /* SAM and DAM are the same here */
312 case LOWPAN_IPHC_DAM_00:
313 /* for global link addresses */
314 fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
315 break;
316 case LOWPAN_IPHC_SAM_01:
317 case LOWPAN_IPHC_DAM_01:
318 /* fe:80::XXXX:XXXX:XXXX:XXXX */
319 ipaddr->s6_addr[0] = 0xFE;
320 ipaddr->s6_addr[1] = 0x80;
321 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[8], 8);
322 break;
323 case LOWPAN_IPHC_SAM_10:
324 case LOWPAN_IPHC_DAM_10:
325 /* fe:80::ff:fe00:XXXX */
326 ipaddr->s6_addr[0] = 0xFE;
327 ipaddr->s6_addr[1] = 0x80;
328 ipaddr->s6_addr[11] = 0xFF;
329 ipaddr->s6_addr[12] = 0xFE;
330 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2);
331 break;
332 case LOWPAN_IPHC_SAM_11:
333 case LOWPAN_IPHC_DAM_11:
334 fail = false;
335 switch (lowpan_dev(dev)->lltype) {
336 case LOWPAN_LLTYPE_IEEE802154:
337 iphc_uncompress_802154_lladdr(ipaddr, lladdr);
338 break;
339 default:
340 iphc_uncompress_eui64_lladdr(ipaddr, lladdr);
341 break;
342 }
343 break;
344 default:
345 pr_debug("Invalid address mode value: 0x%x\n", address_mode);
346 return -EINVAL;
347 }
348
349 if (fail) {
350 pr_debug("Failed to fetch skb data\n");
351 return -EIO;
352 }
353
354 raw_dump_inline(NULL, "Reconstructed ipv6 addr is",
355 ipaddr->s6_addr, 16);
356
357 return 0;
358 }
359
360 /* Uncompress address function for source context
361 * based address(non-multicast).
362 */
363 static int uncompress_ctx_addr(struct sk_buff *skb,
364 const struct net_device *dev,
365 const struct lowpan_iphc_ctx *ctx,
366 struct in6_addr *ipaddr, u8 address_mode,
367 const void *lladdr)
368 {
369 bool fail;
370
371 switch (address_mode) {
372 /* SAM and DAM are the same here */
373 case LOWPAN_IPHC_DAM_00:
374 fail = false;
375 /* SAM_00 -> unspec address ::
376 * Do nothing, address is already ::
377 *
378 * DAM 00 -> reserved should never occur.
379 */
380 break;
381 case LOWPAN_IPHC_SAM_01:
382 case LOWPAN_IPHC_DAM_01:
383 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[8], 8);
384 ipv6_addr_prefix_copy(ipaddr, &ctx->pfx, ctx->plen);
385 break;
386 case LOWPAN_IPHC_SAM_10:
387 case LOWPAN_IPHC_DAM_10:
388 ipaddr->s6_addr[11] = 0xFF;
389 ipaddr->s6_addr[12] = 0xFE;
390 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2);
391 ipv6_addr_prefix_copy(ipaddr, &ctx->pfx, ctx->plen);
392 break;
393 case LOWPAN_IPHC_SAM_11:
394 case LOWPAN_IPHC_DAM_11:
395 fail = false;
396 switch (lowpan_dev(dev)->lltype) {
397 case LOWPAN_LLTYPE_IEEE802154:
398 iphc_uncompress_802154_lladdr(ipaddr, lladdr);
399 break;
400 default:
401 iphc_uncompress_eui64_lladdr(ipaddr, lladdr);
402 break;
403 }
404 ipv6_addr_prefix_copy(ipaddr, &ctx->pfx, ctx->plen);
405 break;
406 default:
407 pr_debug("Invalid sam value: 0x%x\n", address_mode);
408 return -EINVAL;
409 }
410
411 if (fail) {
412 pr_debug("Failed to fetch skb data\n");
413 return -EIO;
414 }
415
416 raw_dump_inline(NULL,
417 "Reconstructed context based ipv6 src addr is",
418 ipaddr->s6_addr, 16);
419
420 return 0;
421 }
422
423 /* Uncompress function for multicast destination address,
424 * when M bit is set.
425 */
426 static int lowpan_uncompress_multicast_daddr(struct sk_buff *skb,
427 struct in6_addr *ipaddr,
428 u8 address_mode)
429 {
430 bool fail;
431
432 switch (address_mode) {
433 case LOWPAN_IPHC_DAM_00:
434 /* 00: 128 bits. The full address
435 * is carried in-line.
436 */
437 fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
438 break;
439 case LOWPAN_IPHC_DAM_01:
440 /* 01: 48 bits. The address takes
441 * the form ffXX::00XX:XXXX:XXXX.
442 */
443 ipaddr->s6_addr[0] = 0xFF;
444 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
445 fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[11], 5);
446 break;
447 case LOWPAN_IPHC_DAM_10:
448 /* 10: 32 bits. The address takes
449 * the form ffXX::00XX:XXXX.
450 */
451 ipaddr->s6_addr[0] = 0xFF;
452 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
453 fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[13], 3);
454 break;
455 case LOWPAN_IPHC_DAM_11:
456 /* 11: 8 bits. The address takes
457 * the form ff02::00XX.
458 */
459 ipaddr->s6_addr[0] = 0xFF;
460 ipaddr->s6_addr[1] = 0x02;
461 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[15], 1);
462 break;
463 default:
464 pr_debug("DAM value has a wrong value: 0x%x\n", address_mode);
465 return -EINVAL;
466 }
467
468 if (fail) {
469 pr_debug("Failed to fetch skb data\n");
470 return -EIO;
471 }
472
473 raw_dump_inline(NULL, "Reconstructed ipv6 multicast addr is",
474 ipaddr->s6_addr, 16);
475
476 return 0;
477 }
478
479 static int lowpan_uncompress_multicast_ctx_daddr(struct sk_buff *skb,
480 struct lowpan_iphc_ctx *ctx,
481 struct in6_addr *ipaddr,
482 u8 address_mode)
483 {
484 struct in6_addr network_pfx = {};
485 bool fail;
486
487 ipaddr->s6_addr[0] = 0xFF;
488 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 2);
489 fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[12], 4);
490 if (fail)
491 return -EIO;
492
493 /* take prefix_len and network prefix from the context */
494 ipaddr->s6_addr[3] = ctx->plen;
495 /* get network prefix to copy into multicast address */
496 ipv6_addr_prefix(&network_pfx, &ctx->pfx, ctx->plen);
497 /* setting network prefix */
498 memcpy(&ipaddr->s6_addr[4], &network_pfx, 8);
499
500 return 0;
501 }
502
503 /* get the ecn values from iphc tf format and set it to ipv6hdr */
504 static inline void lowpan_iphc_tf_set_ecn(struct ipv6hdr *hdr, const u8 *tf)
505 {
506 /* get the two higher bits which is ecn */
507 u8 ecn = tf[0] & 0xc0;
508
509 /* ECN takes 0x30 in hdr->flow_lbl[0] */
510 hdr->flow_lbl[0] |= (ecn >> 2);
511 }
512
513 /* get the dscp values from iphc tf format and set it to ipv6hdr */
514 static inline void lowpan_iphc_tf_set_dscp(struct ipv6hdr *hdr, const u8 *tf)
515 {
516 /* DSCP is at place after ECN */
517 u8 dscp = tf[0] & 0x3f;
518
519 /* The four highest bits need to be set at hdr->priority */
520 hdr->priority |= ((dscp & 0x3c) >> 2);
521 /* The two lower bits is part of hdr->flow_lbl[0] */
522 hdr->flow_lbl[0] |= ((dscp & 0x03) << 6);
523 }
524
525 /* get the flow label values from iphc tf format and set it to ipv6hdr */
526 static inline void lowpan_iphc_tf_set_lbl(struct ipv6hdr *hdr, const u8 *lbl)
527 {
528 /* flow label is always some array started with lower nibble of
529 * flow_lbl[0] and followed with two bytes afterwards. Inside inline
530 * data the flow_lbl position can be different, which will be handled
531 * by lbl pointer. E.g. case "01" vs "00" the traffic class is 8 bit
532 * shifted, the different lbl pointer will handle that.
533 *
534 * The flow label will started at lower nibble of flow_lbl[0], the
535 * higher nibbles are part of DSCP + ECN.
536 */
537 hdr->flow_lbl[0] |= lbl[0] & 0x0f;
538 memcpy(&hdr->flow_lbl[1], &lbl[1], 2);
539 }
540
541 /* lowpan_iphc_tf_decompress - decompress the traffic class.
542 * This function will return zero on success, a value lower than zero if
543 * failed.
544 */
545 static int lowpan_iphc_tf_decompress(struct sk_buff *skb, struct ipv6hdr *hdr,
546 u8 val)
547 {
548 u8 tf[4];
549
550 /* Traffic Class and Flow Label */
551 switch (val) {
552 case LOWPAN_IPHC_TF_00:
553 /* ECN + DSCP + 4-bit Pad + Flow Label (4 bytes) */
554 if (lowpan_fetch_skb(skb, tf, 4))
555 return -EINVAL;
556
557 /* 1 2 3
558 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
559 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
560 * |ECN| DSCP | rsv | Flow Label |
561 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
562 */
563 lowpan_iphc_tf_set_ecn(hdr, tf);
564 lowpan_iphc_tf_set_dscp(hdr, tf);
565 lowpan_iphc_tf_set_lbl(hdr, &tf[1]);
566 break;
567 case LOWPAN_IPHC_TF_01:
568 /* ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided. */
569 if (lowpan_fetch_skb(skb, tf, 3))
570 return -EINVAL;
571
572 /* 1 2
573 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
574 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
575 * |ECN|rsv| Flow Label |
576 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
577 */
578 lowpan_iphc_tf_set_ecn(hdr, tf);
579 lowpan_iphc_tf_set_lbl(hdr, &tf[0]);
580 break;
581 case LOWPAN_IPHC_TF_10:
582 /* ECN + DSCP (1 byte), Flow Label is elided. */
583 if (lowpan_fetch_skb(skb, tf, 1))
584 return -EINVAL;
585
586 /* 0 1 2 3 4 5 6 7
587 * +-+-+-+-+-+-+-+-+
588 * |ECN| DSCP |
589 * +-+-+-+-+-+-+-+-+
590 */
591 lowpan_iphc_tf_set_ecn(hdr, tf);
592 lowpan_iphc_tf_set_dscp(hdr, tf);
593 break;
594 case LOWPAN_IPHC_TF_11:
595 /* Traffic Class and Flow Label are elided */
596 break;
597 default:
598 WARN_ON_ONCE(1);
599 return -EINVAL;
600 }
601
602 return 0;
603 }
604
605 /* TTL uncompression values */
606 static const u8 lowpan_ttl_values[] = {
607 [LOWPAN_IPHC_HLIM_01] = 1,
608 [LOWPAN_IPHC_HLIM_10] = 64,
609 [LOWPAN_IPHC_HLIM_11] = 255,
610 };
611
612 int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev,
613 const void *daddr, const void *saddr)
614 {
615 struct ipv6hdr hdr = {};
616 struct lowpan_iphc_ctx *ci;
617 u8 iphc0, iphc1, cid = 0;
618 int err;
619
620 raw_dump_table(__func__, "raw skb data dump uncompressed",
621 skb->data, skb->len);
622
623 if (lowpan_fetch_skb(skb, &iphc0, sizeof(iphc0)) ||
624 lowpan_fetch_skb(skb, &iphc1, sizeof(iphc1)))
625 return -EINVAL;
626
627 hdr.version = 6;
628
629 /* default CID = 0, another if the CID flag is set */
630 if (iphc1 & LOWPAN_IPHC_CID) {
631 if (lowpan_fetch_skb(skb, &cid, sizeof(cid)))
632 return -EINVAL;
633 }
634
635 err = lowpan_iphc_tf_decompress(skb, &hdr,
636 iphc0 & LOWPAN_IPHC_TF_MASK);
637 if (err < 0)
638 return err;
639
640 /* Next Header */
641 if (!(iphc0 & LOWPAN_IPHC_NH)) {
642 /* Next header is carried inline */
643 if (lowpan_fetch_skb(skb, &hdr.nexthdr, sizeof(hdr.nexthdr)))
644 return -EINVAL;
645
646 pr_debug("NH flag is set, next header carried inline: %02x\n",
647 hdr.nexthdr);
648 }
649
650 /* Hop Limit */
651 if ((iphc0 & LOWPAN_IPHC_HLIM_MASK) != LOWPAN_IPHC_HLIM_00) {
652 hdr.hop_limit = lowpan_ttl_values[iphc0 & LOWPAN_IPHC_HLIM_MASK];
653 } else {
654 if (lowpan_fetch_skb(skb, &hdr.hop_limit,
655 sizeof(hdr.hop_limit)))
656 return -EINVAL;
657 }
658
659 if (iphc1 & LOWPAN_IPHC_SAC) {
660 spin_lock_bh(&lowpan_dev(dev)->ctx.lock);
661 ci = lowpan_iphc_ctx_get_by_id(dev, LOWPAN_IPHC_CID_SCI(cid));
662 if (!ci) {
663 spin_unlock_bh(&lowpan_dev(dev)->ctx.lock);
664 return -EINVAL;
665 }
666
667 pr_debug("SAC bit is set. Handle context based source address.\n");
668 err = uncompress_ctx_addr(skb, dev, ci, &hdr.saddr,
669 iphc1 & LOWPAN_IPHC_SAM_MASK, saddr);
670 spin_unlock_bh(&lowpan_dev(dev)->ctx.lock);
671 } else {
672 /* Source address uncompression */
673 pr_debug("source address stateless compression\n");
674 err = uncompress_addr(skb, dev, &hdr.saddr,
675 iphc1 & LOWPAN_IPHC_SAM_MASK, saddr);
676 }
677
678 /* Check on error of previous branch */
679 if (err)
680 return -EINVAL;
681
682 switch (iphc1 & (LOWPAN_IPHC_M | LOWPAN_IPHC_DAC)) {
683 case LOWPAN_IPHC_M | LOWPAN_IPHC_DAC:
684 spin_lock_bh(&lowpan_dev(dev)->ctx.lock);
685 ci = lowpan_iphc_ctx_get_by_id(dev, LOWPAN_IPHC_CID_DCI(cid));
686 if (!ci) {
687 spin_unlock_bh(&lowpan_dev(dev)->ctx.lock);
688 return -EINVAL;
689 }
690
691 /* multicast with context */
692 pr_debug("dest: context-based mcast compression\n");
693 err = lowpan_uncompress_multicast_ctx_daddr(skb, ci,
694 &hdr.daddr,
695 iphc1 & LOWPAN_IPHC_DAM_MASK);
696 spin_unlock_bh(&lowpan_dev(dev)->ctx.lock);
697 break;
698 case LOWPAN_IPHC_M:
699 /* multicast */
700 err = lowpan_uncompress_multicast_daddr(skb, &hdr.daddr,
701 iphc1 & LOWPAN_IPHC_DAM_MASK);
702 break;
703 case LOWPAN_IPHC_DAC:
704 spin_lock_bh(&lowpan_dev(dev)->ctx.lock);
705 ci = lowpan_iphc_ctx_get_by_id(dev, LOWPAN_IPHC_CID_DCI(cid));
706 if (!ci) {
707 spin_unlock_bh(&lowpan_dev(dev)->ctx.lock);
708 return -EINVAL;
709 }
710
711 /* Destination address context based uncompression */
712 pr_debug("DAC bit is set. Handle context based destination address.\n");
713 err = uncompress_ctx_addr(skb, dev, ci, &hdr.daddr,
714 iphc1 & LOWPAN_IPHC_DAM_MASK, daddr);
715 spin_unlock_bh(&lowpan_dev(dev)->ctx.lock);
716 break;
717 default:
718 err = uncompress_addr(skb, dev, &hdr.daddr,
719 iphc1 & LOWPAN_IPHC_DAM_MASK, daddr);
720 pr_debug("dest: stateless compression mode %d dest %pI6c\n",
721 iphc1 & LOWPAN_IPHC_DAM_MASK, &hdr.daddr);
722 break;
723 }
724
725 if (err)
726 return -EINVAL;
727
728 /* Next header data uncompression */
729 if (iphc0 & LOWPAN_IPHC_NH) {
730 err = lowpan_nhc_do_uncompression(skb, dev, &hdr);
731 if (err < 0)
732 return err;
733 } else {
734 err = skb_cow(skb, sizeof(hdr));
735 if (unlikely(err))
736 return err;
737 }
738
739 switch (lowpan_dev(dev)->lltype) {
740 case LOWPAN_LLTYPE_IEEE802154:
741 if (lowpan_802154_cb(skb)->d_size)
742 hdr.payload_len = htons(lowpan_802154_cb(skb)->d_size -
743 sizeof(struct ipv6hdr));
744 else
745 hdr.payload_len = htons(skb->len);
746 break;
747 default:
748 hdr.payload_len = htons(skb->len);
749 break;
750 }
751
752 pr_debug("skb headroom size = %d, data length = %d\n",
753 skb_headroom(skb), skb->len);
754
755 pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n\t"
756 "nexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n",
757 hdr.version, ntohs(hdr.payload_len), hdr.nexthdr,
758 hdr.hop_limit, &hdr.daddr);
759
760 skb_push(skb, sizeof(hdr));
761 skb_reset_network_header(skb);
762 skb_copy_to_linear_data(skb, &hdr, sizeof(hdr));
763
764 raw_dump_table(__func__, "raw header dump", (u8 *)&hdr, sizeof(hdr));
765
766 return 0;
767 }
768 EXPORT_SYMBOL_GPL(lowpan_header_decompress);
769
770 static const u8 lowpan_iphc_dam_to_sam_value[] = {
771 [LOWPAN_IPHC_DAM_00] = LOWPAN_IPHC_SAM_00,
772 [LOWPAN_IPHC_DAM_01] = LOWPAN_IPHC_SAM_01,
773 [LOWPAN_IPHC_DAM_10] = LOWPAN_IPHC_SAM_10,
774 [LOWPAN_IPHC_DAM_11] = LOWPAN_IPHC_SAM_11,
775 };
776
777 static u8 lowpan_compress_ctx_addr(u8 **hc_ptr, const struct in6_addr *ipaddr,
778 const struct lowpan_iphc_ctx *ctx,
779 const unsigned char *lladdr, bool sam)
780 {
781 struct in6_addr tmp = {};
782 u8 dam;
783
784 /* check for SAM/DAM = 11 */
785 memcpy(&tmp.s6_addr[8], lladdr, 8);
786 /* second bit-flip (Universe/Local) is done according RFC2464 */
787 tmp.s6_addr[8] ^= 0x02;
788 /* context information are always used */
789 ipv6_addr_prefix_copy(&tmp, &ctx->pfx, ctx->plen);
790 if (ipv6_addr_equal(&tmp, ipaddr)) {
791 dam = LOWPAN_IPHC_DAM_11;
792 goto out;
793 }
794
795 memset(&tmp, 0, sizeof(tmp));
796 /* check for SAM/DAM = 10 */
797 tmp.s6_addr[11] = 0xFF;
798 tmp.s6_addr[12] = 0xFE;
799 memcpy(&tmp.s6_addr[14], &ipaddr->s6_addr[14], 2);
800 /* context information are always used */
801 ipv6_addr_prefix_copy(&tmp, &ctx->pfx, ctx->plen);
802 if (ipv6_addr_equal(&tmp, ipaddr)) {
803 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[14], 2);
804 dam = LOWPAN_IPHC_DAM_10;
805 goto out;
806 }
807
808 memset(&tmp, 0, sizeof(tmp));
809 /* check for SAM/DAM = 01, should always match */
810 memcpy(&tmp.s6_addr[8], &ipaddr->s6_addr[8], 8);
811 /* context information are always used */
812 ipv6_addr_prefix_copy(&tmp, &ctx->pfx, ctx->plen);
813 if (ipv6_addr_equal(&tmp, ipaddr)) {
814 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[8], 8);
815 dam = LOWPAN_IPHC_DAM_01;
816 goto out;
817 }
818
819 WARN_ONCE(1, "context found but no address mode matched\n");
820 return LOWPAN_IPHC_DAM_00;
821 out:
822
823 if (sam)
824 return lowpan_iphc_dam_to_sam_value[dam];
825 else
826 return dam;
827 }
828
829 static u8 lowpan_compress_addr_64(u8 **hc_ptr, const struct in6_addr *ipaddr,
830 const unsigned char *lladdr, bool sam)
831 {
832 u8 dam = LOWPAN_IPHC_DAM_00;
833
834 if (is_addr_mac_addr_based(ipaddr, lladdr)) {
835 dam = LOWPAN_IPHC_DAM_11; /* 0-bits */
836 pr_debug("address compression 0 bits\n");
837 } else if (lowpan_is_iid_16_bit_compressable(ipaddr)) {
838 /* compress IID to 16 bits xxxx::XXXX */
839 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[7], 2);
840 dam = LOWPAN_IPHC_DAM_10; /* 16-bits */
841 raw_dump_inline(NULL, "Compressed ipv6 addr is (16 bits)",
842 *hc_ptr - 2, 2);
843 } else {
844 /* do not compress IID => xxxx::IID */
845 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[4], 8);
846 dam = LOWPAN_IPHC_DAM_01; /* 64-bits */
847 raw_dump_inline(NULL, "Compressed ipv6 addr is (64 bits)",
848 *hc_ptr - 8, 8);
849 }
850
851 if (sam)
852 return lowpan_iphc_dam_to_sam_value[dam];
853 else
854 return dam;
855 }
856
857 /* lowpan_iphc_get_tc - get the ECN + DCSP fields in hc format */
858 static inline u8 lowpan_iphc_get_tc(const struct ipv6hdr *hdr)
859 {
860 u8 dscp, ecn;
861
862 /* hdr->priority contains the higher bits of dscp, lower are part of
863 * flow_lbl[0]. Note ECN, DCSP is swapped in ipv6 hdr.
864 */
865 dscp = (hdr->priority << 2) | ((hdr->flow_lbl[0] & 0xc0) >> 6);
866 /* ECN is at the two lower bits from first nibble of flow_lbl[0] */
867 ecn = (hdr->flow_lbl[0] & 0x30);
868 /* for pretty debug output, also shift ecn to get the ecn value */
869 pr_debug("ecn 0x%02x dscp 0x%02x\n", ecn >> 4, dscp);
870 /* ECN is at 0x30 now, shift it to have ECN + DCSP */
871 return (ecn << 2) | dscp;
872 }
873
874 /* lowpan_iphc_is_flow_lbl_zero - check if flow label is zero */
875 static inline bool lowpan_iphc_is_flow_lbl_zero(const struct ipv6hdr *hdr)
876 {
877 return ((!(hdr->flow_lbl[0] & 0x0f)) &&
878 !hdr->flow_lbl[1] && !hdr->flow_lbl[2]);
879 }
880
881 /* lowpan_iphc_tf_compress - compress the traffic class which is set by
882 * ipv6hdr. Return the corresponding format identifier which is used.
883 */
884 static u8 lowpan_iphc_tf_compress(u8 **hc_ptr, const struct ipv6hdr *hdr)
885 {
886 /* get ecn dscp data in a byteformat as: ECN(hi) + DSCP(lo) */
887 u8 tc = lowpan_iphc_get_tc(hdr), tf[4], val;
888
889 /* printout the traffic class in hc format */
890 pr_debug("tc 0x%02x\n", tc);
891
892 if (lowpan_iphc_is_flow_lbl_zero(hdr)) {
893 if (!tc) {
894 /* 11: Traffic Class and Flow Label are elided. */
895 val = LOWPAN_IPHC_TF_11;
896 } else {
897 /* 10: ECN + DSCP (1 byte), Flow Label is elided.
898 *
899 * 0 1 2 3 4 5 6 7
900 * +-+-+-+-+-+-+-+-+
901 * |ECN| DSCP |
902 * +-+-+-+-+-+-+-+-+
903 */
904 lowpan_push_hc_data(hc_ptr, &tc, sizeof(tc));
905 val = LOWPAN_IPHC_TF_10;
906 }
907 } else {
908 /* check if dscp is zero, it's after the first two bit */
909 if (!(tc & 0x3f)) {
910 /* 01: ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
911 *
912 * 1 2
913 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
914 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
915 * |ECN|rsv| Flow Label |
916 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
917 */
918 memcpy(&tf[0], &hdr->flow_lbl[0], 3);
919 /* zero the highest 4-bits, contains DCSP + ECN */
920 tf[0] &= ~0xf0;
921 /* set ECN */
922 tf[0] |= (tc & 0xc0);
923
924 lowpan_push_hc_data(hc_ptr, tf, 3);
925 val = LOWPAN_IPHC_TF_01;
926 } else {
927 /* 00: ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
928 *
929 * 1 2 3
930 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
931 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
932 * |ECN| DSCP | rsv | Flow Label |
933 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
934 */
935 memcpy(&tf[0], &tc, sizeof(tc));
936 /* highest nibble of flow_lbl[0] is part of DSCP + ECN
937 * which will be the 4-bit pad and will be filled with
938 * zeros afterwards.
939 */
940 memcpy(&tf[1], &hdr->flow_lbl[0], 3);
941 /* zero the 4-bit pad, which is reserved */
942 tf[1] &= ~0xf0;
943
944 lowpan_push_hc_data(hc_ptr, tf, 4);
945 val = LOWPAN_IPHC_TF_00;
946 }
947 }
948
949 return val;
950 }
951
952 static u8 lowpan_iphc_mcast_ctx_addr_compress(u8 **hc_ptr,
953 const struct lowpan_iphc_ctx *ctx,
954 const struct in6_addr *ipaddr)
955 {
956 u8 data[6];
957
958 /* flags/scope, reserved (RIID) */
959 memcpy(data, &ipaddr->s6_addr[1], 2);
960 /* group ID */
961 memcpy(&data[1], &ipaddr->s6_addr[11], 4);
962 lowpan_push_hc_data(hc_ptr, data, 6);
963
964 return LOWPAN_IPHC_DAM_00;
965 }
966
967 static u8 lowpan_iphc_mcast_addr_compress(u8 **hc_ptr,
968 const struct in6_addr *ipaddr)
969 {
970 u8 val;
971
972 if (lowpan_is_mcast_addr_compressable8(ipaddr)) {
973 pr_debug("compressed to 1 octet\n");
974 /* use last byte */
975 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[15], 1);
976 val = LOWPAN_IPHC_DAM_11;
977 } else if (lowpan_is_mcast_addr_compressable32(ipaddr)) {
978 pr_debug("compressed to 4 octets\n");
979 /* second byte + the last three */
980 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[1], 1);
981 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[13], 3);
982 val = LOWPAN_IPHC_DAM_10;
983 } else if (lowpan_is_mcast_addr_compressable48(ipaddr)) {
984 pr_debug("compressed to 6 octets\n");
985 /* second byte + the last five */
986 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[1], 1);
987 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[11], 5);
988 val = LOWPAN_IPHC_DAM_01;
989 } else {
990 pr_debug("using full address\n");
991 lowpan_push_hc_data(hc_ptr, ipaddr->s6_addr, 16);
992 val = LOWPAN_IPHC_DAM_00;
993 }
994
995 return val;
996 }
997
998 int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
999 const void *daddr, const void *saddr)
1000 {
1001 u8 iphc0, iphc1, *hc_ptr, cid = 0;
1002 struct ipv6hdr *hdr;
1003 u8 head[LOWPAN_IPHC_MAX_HC_BUF_LEN] = {};
1004 struct lowpan_iphc_ctx *dci, *sci, dci_entry, sci_entry;
1005 int ret, ipv6_daddr_type, ipv6_saddr_type;
1006
1007 if (skb->protocol != htons(ETH_P_IPV6))
1008 return -EINVAL;
1009
1010 hdr = ipv6_hdr(skb);
1011 hc_ptr = head + 2;
1012
1013 pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n"
1014 "\tnexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n",
1015 hdr->version, ntohs(hdr->payload_len), hdr->nexthdr,
1016 hdr->hop_limit, &hdr->daddr);
1017
1018 raw_dump_table(__func__, "raw skb network header dump",
1019 skb_network_header(skb), sizeof(struct ipv6hdr));
1020
1021 /* As we copy some bit-length fields, in the IPHC encoding bytes,
1022 * we sometimes use |=
1023 * If the field is 0, and the current bit value in memory is 1,
1024 * this does not work. We therefore reset the IPHC encoding here
1025 */
1026 iphc0 = LOWPAN_DISPATCH_IPHC;
1027 iphc1 = 0;
1028
1029 raw_dump_inline(__func__, "saddr", saddr, EUI64_ADDR_LEN);
1030 raw_dump_inline(__func__, "daddr", daddr, EUI64_ADDR_LEN);
1031
1032 raw_dump_table(__func__, "sending raw skb network uncompressed packet",
1033 skb->data, skb->len);
1034
1035 ipv6_daddr_type = ipv6_addr_type(&hdr->daddr);
1036 spin_lock_bh(&lowpan_dev(dev)->ctx.lock);
1037 if (ipv6_daddr_type & IPV6_ADDR_MULTICAST)
1038 dci = lowpan_iphc_ctx_get_by_mcast_addr(dev, &hdr->daddr);
1039 else
1040 dci = lowpan_iphc_ctx_get_by_addr(dev, &hdr->daddr);
1041 if (dci) {
1042 memcpy(&dci_entry, dci, sizeof(*dci));
1043 cid |= dci->id;
1044 }
1045 spin_unlock_bh(&lowpan_dev(dev)->ctx.lock);
1046
1047 spin_lock_bh(&lowpan_dev(dev)->ctx.lock);
1048 sci = lowpan_iphc_ctx_get_by_addr(dev, &hdr->saddr);
1049 if (sci) {
1050 memcpy(&sci_entry, sci, sizeof(*sci));
1051 cid |= (sci->id << 4);
1052 }
1053 spin_unlock_bh(&lowpan_dev(dev)->ctx.lock);
1054
1055 /* if cid is zero it will be compressed */
1056 if (cid) {
1057 iphc1 |= LOWPAN_IPHC_CID;
1058 lowpan_push_hc_data(&hc_ptr, &cid, sizeof(cid));
1059 }
1060
1061 /* Traffic Class, Flow Label compression */
1062 iphc0 |= lowpan_iphc_tf_compress(&hc_ptr, hdr);
1063
1064 /* NOTE: payload length is always compressed */
1065
1066 /* Check if we provide the nhc format for nexthdr and compression
1067 * functionality. If not nexthdr is handled inline and not compressed.
1068 */
1069 ret = lowpan_nhc_check_compression(skb, hdr, &hc_ptr);
1070 if (ret == -ENOENT)
1071 lowpan_push_hc_data(&hc_ptr, &hdr->nexthdr,
1072 sizeof(hdr->nexthdr));
1073 else
1074 iphc0 |= LOWPAN_IPHC_NH;
1075
1076 /* Hop limit
1077 * if 1: compress, encoding is 01
1078 * if 64: compress, encoding is 10
1079 * if 255: compress, encoding is 11
1080 * else do not compress
1081 */
1082 switch (hdr->hop_limit) {
1083 case 1:
1084 iphc0 |= LOWPAN_IPHC_HLIM_01;
1085 break;
1086 case 64:
1087 iphc0 |= LOWPAN_IPHC_HLIM_10;
1088 break;
1089 case 255:
1090 iphc0 |= LOWPAN_IPHC_HLIM_11;
1091 break;
1092 default:
1093 lowpan_push_hc_data(&hc_ptr, &hdr->hop_limit,
1094 sizeof(hdr->hop_limit));
1095 }
1096
1097 ipv6_saddr_type = ipv6_addr_type(&hdr->saddr);
1098 /* source address compression */
1099 if (ipv6_saddr_type == IPV6_ADDR_ANY) {
1100 pr_debug("source address is unspecified, setting SAC\n");
1101 iphc1 |= LOWPAN_IPHC_SAC;
1102 } else {
1103 if (sci) {
1104 iphc1 |= lowpan_compress_ctx_addr(&hc_ptr, &hdr->saddr,
1105 &sci_entry, saddr,
1106 true);
1107 iphc1 |= LOWPAN_IPHC_SAC;
1108 } else {
1109 if (ipv6_saddr_type & IPV6_ADDR_LINKLOCAL &&
1110 lowpan_is_linklocal_zero_padded(hdr->saddr)) {
1111 iphc1 |= lowpan_compress_addr_64(&hc_ptr,
1112 &hdr->saddr,
1113 saddr, true);
1114 pr_debug("source address unicast link-local %pI6c iphc1 0x%02x\n",
1115 &hdr->saddr, iphc1);
1116 } else {
1117 pr_debug("send the full source address\n");
1118 lowpan_push_hc_data(&hc_ptr,
1119 hdr->saddr.s6_addr, 16);
1120 }
1121 }
1122 }
1123
1124 /* destination address compression */
1125 if (ipv6_daddr_type & IPV6_ADDR_MULTICAST) {
1126 pr_debug("destination address is multicast: ");
1127 iphc1 |= LOWPAN_IPHC_M;
1128 if (dci) {
1129 iphc1 |= lowpan_iphc_mcast_ctx_addr_compress(&hc_ptr,
1130 &dci_entry,
1131 &hdr->daddr);
1132 iphc1 |= LOWPAN_IPHC_DAC;
1133 } else {
1134 iphc1 |= lowpan_iphc_mcast_addr_compress(&hc_ptr,
1135 &hdr->daddr);
1136 }
1137 } else {
1138 if (dci) {
1139 iphc1 |= lowpan_compress_ctx_addr(&hc_ptr, &hdr->daddr,
1140 &dci_entry, daddr,
1141 false);
1142 iphc1 |= LOWPAN_IPHC_DAC;
1143 } else {
1144 if (ipv6_daddr_type & IPV6_ADDR_LINKLOCAL &&
1145 lowpan_is_linklocal_zero_padded(hdr->daddr)) {
1146 iphc1 |= lowpan_compress_addr_64(&hc_ptr,
1147 &hdr->daddr,
1148 daddr, false);
1149 pr_debug("dest address unicast link-local %pI6c iphc1 0x%02x\n",
1150 &hdr->daddr, iphc1);
1151 } else {
1152 pr_debug("dest address unicast %pI6c\n",
1153 &hdr->daddr);
1154 lowpan_push_hc_data(&hc_ptr,
1155 hdr->daddr.s6_addr, 16);
1156 }
1157 }
1158 }
1159
1160 /* next header compression */
1161 if (iphc0 & LOWPAN_IPHC_NH) {
1162 ret = lowpan_nhc_do_compression(skb, hdr, &hc_ptr);
1163 if (ret < 0)
1164 return ret;
1165 }
1166
1167 head[0] = iphc0;
1168 head[1] = iphc1;
1169
1170 skb_pull(skb, sizeof(struct ipv6hdr));
1171 skb_reset_transport_header(skb);
1172 memcpy(skb_push(skb, hc_ptr - head), head, hc_ptr - head);
1173 skb_reset_network_header(skb);
1174
1175 pr_debug("header len %d skb %u\n", (int)(hc_ptr - head), skb->len);
1176
1177 raw_dump_table(__func__, "raw skb data dump compressed",
1178 skb->data, skb->len);
1179 return 0;
1180 }
1181 EXPORT_SYMBOL_GPL(lowpan_header_compress);
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