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6lowpan: debugfs: add missing static
[GitHub/LineageOS/android_kernel_motorola_exynos9610.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_IPHC_CID_DCI(cid) (cid & 0x0f)
152 #define LOWPAN_IPHC_CID_SCI(cid) ((cid & 0xf0) >> 4)
153
154 static inline void iphc_uncompress_eui64_lladdr(struct in6_addr *ipaddr,
155 const void *lladdr)
156 {
157 /* fe:80::XXXX:XXXX:XXXX:XXXX
158 * \_________________/
159 * hwaddr
160 */
161 ipaddr->s6_addr[0] = 0xFE;
162 ipaddr->s6_addr[1] = 0x80;
163 memcpy(&ipaddr->s6_addr[8], lladdr, EUI64_ADDR_LEN);
164 /* second bit-flip (Universe/Local)
165 * is done according RFC2464
166 */
167 ipaddr->s6_addr[8] ^= 0x02;
168 }
169
170 static inline void iphc_uncompress_802154_lladdr(struct in6_addr *ipaddr,
171 const void *lladdr)
172 {
173 const struct ieee802154_addr *addr = lladdr;
174 u8 eui64[EUI64_ADDR_LEN] = { };
175
176 switch (addr->mode) {
177 case IEEE802154_ADDR_LONG:
178 ieee802154_le64_to_be64(eui64, &addr->extended_addr);
179 iphc_uncompress_eui64_lladdr(ipaddr, eui64);
180 break;
181 case IEEE802154_ADDR_SHORT:
182 /* fe:80::ff:fe00:XXXX
183 * \__/
184 * short_addr
185 *
186 * Universe/Local bit is zero.
187 */
188 ipaddr->s6_addr[0] = 0xFE;
189 ipaddr->s6_addr[1] = 0x80;
190 ipaddr->s6_addr[11] = 0xFF;
191 ipaddr->s6_addr[12] = 0xFE;
192 ieee802154_le16_to_be16(&ipaddr->s6_addr16[7],
193 &addr->short_addr);
194 break;
195 default:
196 /* should never handled and filtered by 802154 6lowpan */
197 WARN_ON_ONCE(1);
198 break;
199 }
200 }
201
202 static struct lowpan_iphc_ctx *
203 lowpan_iphc_ctx_get_by_id(const struct net_device *dev, u8 id)
204 {
205 struct lowpan_iphc_ctx *ret = &lowpan_priv(dev)->ctx.table[id];
206
207 if (!lowpan_iphc_ctx_is_active(ret))
208 return NULL;
209
210 return ret;
211 }
212
213 static struct lowpan_iphc_ctx *
214 lowpan_iphc_ctx_get_by_addr(const struct net_device *dev,
215 const struct in6_addr *addr)
216 {
217 struct lowpan_iphc_ctx *table = lowpan_priv(dev)->ctx.table;
218 struct lowpan_iphc_ctx *ret = NULL;
219 struct in6_addr addr_pfx;
220 u8 addr_plen;
221 int i;
222
223 for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++) {
224 /* Check if context is valid. A context that is not valid
225 * MUST NOT be used for compression.
226 */
227 if (!lowpan_iphc_ctx_is_active(&table[i]) ||
228 !lowpan_iphc_ctx_is_compression(&table[i]))
229 continue;
230
231 ipv6_addr_prefix(&addr_pfx, addr, table[i].plen);
232
233 /* if prefix len < 64, the remaining bits until 64th bit is
234 * zero. Otherwise we use table[i]->plen.
235 */
236 if (table[i].plen < 64)
237 addr_plen = 64;
238 else
239 addr_plen = table[i].plen;
240
241 if (ipv6_prefix_equal(&addr_pfx, &table[i].pfx, addr_plen)) {
242 /* remember first match */
243 if (!ret) {
244 ret = &table[i];
245 continue;
246 }
247
248 /* get the context with longest prefix len */
249 if (table[i].plen > ret->plen)
250 ret = &table[i];
251 }
252 }
253
254 return ret;
255 }
256
257 static struct lowpan_iphc_ctx *
258 lowpan_iphc_ctx_get_by_mcast_addr(const struct net_device *dev,
259 const struct in6_addr *addr)
260 {
261 struct lowpan_iphc_ctx *table = lowpan_priv(dev)->ctx.table;
262 struct lowpan_iphc_ctx *ret = NULL;
263 struct in6_addr addr_mcast, network_pfx = {};
264 int i;
265
266 /* init mcast address with */
267 memcpy(&addr_mcast, addr, sizeof(*addr));
268
269 for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++) {
270 /* Check if context is valid. A context that is not valid
271 * MUST NOT be used for compression.
272 */
273 if (!lowpan_iphc_ctx_is_active(&table[i]) ||
274 !lowpan_iphc_ctx_is_compression(&table[i]))
275 continue;
276
277 /* setting plen */
278 addr_mcast.s6_addr[3] = table[i].plen;
279 /* get network prefix to copy into multicast address */
280 ipv6_addr_prefix(&network_pfx, &table[i].pfx,
281 table[i].plen);
282 /* setting network prefix */
283 memcpy(&addr_mcast.s6_addr[4], &network_pfx, 8);
284
285 if (ipv6_addr_equal(addr, &addr_mcast)) {
286 ret = &table[i];
287 break;
288 }
289 }
290
291 return ret;
292 }
293
294 /* Uncompress address function for source and
295 * destination address(non-multicast).
296 *
297 * address_mode is the masked value for sam or dam value
298 */
299 static int uncompress_addr(struct sk_buff *skb, const struct net_device *dev,
300 struct in6_addr *ipaddr, u8 address_mode,
301 const void *lladdr)
302 {
303 bool fail;
304
305 switch (address_mode) {
306 /* SAM and DAM are the same here */
307 case LOWPAN_IPHC_DAM_00:
308 /* for global link addresses */
309 fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
310 break;
311 case LOWPAN_IPHC_SAM_01:
312 case LOWPAN_IPHC_DAM_01:
313 /* fe:80::XXXX:XXXX:XXXX:XXXX */
314 ipaddr->s6_addr[0] = 0xFE;
315 ipaddr->s6_addr[1] = 0x80;
316 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[8], 8);
317 break;
318 case LOWPAN_IPHC_SAM_10:
319 case LOWPAN_IPHC_DAM_10:
320 /* fe:80::ff:fe00:XXXX */
321 ipaddr->s6_addr[0] = 0xFE;
322 ipaddr->s6_addr[1] = 0x80;
323 ipaddr->s6_addr[11] = 0xFF;
324 ipaddr->s6_addr[12] = 0xFE;
325 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2);
326 break;
327 case LOWPAN_IPHC_SAM_11:
328 case LOWPAN_IPHC_DAM_11:
329 fail = false;
330 switch (lowpan_priv(dev)->lltype) {
331 case LOWPAN_LLTYPE_IEEE802154:
332 iphc_uncompress_802154_lladdr(ipaddr, lladdr);
333 break;
334 default:
335 iphc_uncompress_eui64_lladdr(ipaddr, lladdr);
336 break;
337 }
338 break;
339 default:
340 pr_debug("Invalid address mode value: 0x%x\n", address_mode);
341 return -EINVAL;
342 }
343
344 if (fail) {
345 pr_debug("Failed to fetch skb data\n");
346 return -EIO;
347 }
348
349 raw_dump_inline(NULL, "Reconstructed ipv6 addr is",
350 ipaddr->s6_addr, 16);
351
352 return 0;
353 }
354
355 /* Uncompress address function for source context
356 * based address(non-multicast).
357 */
358 static int uncompress_ctx_addr(struct sk_buff *skb,
359 const struct net_device *dev,
360 const struct lowpan_iphc_ctx *ctx,
361 struct in6_addr *ipaddr, u8 address_mode,
362 const void *lladdr)
363 {
364 bool fail;
365
366 switch (address_mode) {
367 /* SAM and DAM are the same here */
368 case LOWPAN_IPHC_DAM_00:
369 fail = false;
370 /* SAM_00 -> unspec address ::
371 * Do nothing, address is already ::
372 *
373 * DAM 00 -> reserved should never occur.
374 */
375 break;
376 case LOWPAN_IPHC_SAM_01:
377 case LOWPAN_IPHC_DAM_01:
378 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[8], 8);
379 ipv6_addr_prefix_copy(ipaddr, &ctx->pfx, ctx->plen);
380 break;
381 case LOWPAN_IPHC_SAM_10:
382 case LOWPAN_IPHC_DAM_10:
383 ipaddr->s6_addr[11] = 0xFF;
384 ipaddr->s6_addr[12] = 0xFE;
385 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2);
386 ipv6_addr_prefix_copy(ipaddr, &ctx->pfx, ctx->plen);
387 break;
388 case LOWPAN_IPHC_SAM_11:
389 case LOWPAN_IPHC_DAM_11:
390 fail = false;
391 switch (lowpan_priv(dev)->lltype) {
392 case LOWPAN_LLTYPE_IEEE802154:
393 iphc_uncompress_802154_lladdr(ipaddr, lladdr);
394 break;
395 default:
396 iphc_uncompress_eui64_lladdr(ipaddr, lladdr);
397 break;
398 }
399 ipv6_addr_prefix_copy(ipaddr, &ctx->pfx, ctx->plen);
400 break;
401 default:
402 pr_debug("Invalid sam value: 0x%x\n", address_mode);
403 return -EINVAL;
404 }
405
406 if (fail) {
407 pr_debug("Failed to fetch skb data\n");
408 return -EIO;
409 }
410
411 raw_dump_inline(NULL,
412 "Reconstructed context based ipv6 src addr is",
413 ipaddr->s6_addr, 16);
414
415 return 0;
416 }
417
418 /* Uncompress function for multicast destination address,
419 * when M bit is set.
420 */
421 static int lowpan_uncompress_multicast_daddr(struct sk_buff *skb,
422 struct in6_addr *ipaddr,
423 u8 address_mode)
424 {
425 bool fail;
426
427 switch (address_mode) {
428 case LOWPAN_IPHC_DAM_00:
429 /* 00: 128 bits. The full address
430 * is carried in-line.
431 */
432 fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
433 break;
434 case LOWPAN_IPHC_DAM_01:
435 /* 01: 48 bits. The address takes
436 * the form ffXX::00XX:XXXX:XXXX.
437 */
438 ipaddr->s6_addr[0] = 0xFF;
439 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
440 fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[11], 5);
441 break;
442 case LOWPAN_IPHC_DAM_10:
443 /* 10: 32 bits. The address takes
444 * the form ffXX::00XX:XXXX.
445 */
446 ipaddr->s6_addr[0] = 0xFF;
447 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
448 fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[13], 3);
449 break;
450 case LOWPAN_IPHC_DAM_11:
451 /* 11: 8 bits. The address takes
452 * the form ff02::00XX.
453 */
454 ipaddr->s6_addr[0] = 0xFF;
455 ipaddr->s6_addr[1] = 0x02;
456 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[15], 1);
457 break;
458 default:
459 pr_debug("DAM value has a wrong value: 0x%x\n", address_mode);
460 return -EINVAL;
461 }
462
463 if (fail) {
464 pr_debug("Failed to fetch skb data\n");
465 return -EIO;
466 }
467
468 raw_dump_inline(NULL, "Reconstructed ipv6 multicast addr is",
469 ipaddr->s6_addr, 16);
470
471 return 0;
472 }
473
474 static int lowpan_uncompress_multicast_ctx_daddr(struct sk_buff *skb,
475 struct lowpan_iphc_ctx *ctx,
476 struct in6_addr *ipaddr,
477 u8 address_mode)
478 {
479 struct in6_addr network_pfx = {};
480 bool fail;
481
482 ipaddr->s6_addr[0] = 0xFF;
483 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 2);
484 fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[12], 4);
485 if (fail)
486 return -EIO;
487
488 /* take prefix_len and network prefix from the context */
489 ipaddr->s6_addr[3] = ctx->plen;
490 /* get network prefix to copy into multicast address */
491 ipv6_addr_prefix(&network_pfx, &ctx->pfx, ctx->plen);
492 /* setting network prefix */
493 memcpy(&ipaddr->s6_addr[4], &network_pfx, 8);
494
495 return 0;
496 }
497
498 /* get the ecn values from iphc tf format and set it to ipv6hdr */
499 static inline void lowpan_iphc_tf_set_ecn(struct ipv6hdr *hdr, const u8 *tf)
500 {
501 /* get the two higher bits which is ecn */
502 u8 ecn = tf[0] & 0xc0;
503
504 /* ECN takes 0x30 in hdr->flow_lbl[0] */
505 hdr->flow_lbl[0] |= (ecn >> 2);
506 }
507
508 /* get the dscp values from iphc tf format and set it to ipv6hdr */
509 static inline void lowpan_iphc_tf_set_dscp(struct ipv6hdr *hdr, const u8 *tf)
510 {
511 /* DSCP is at place after ECN */
512 u8 dscp = tf[0] & 0x3f;
513
514 /* The four highest bits need to be set at hdr->priority */
515 hdr->priority |= ((dscp & 0x3c) >> 2);
516 /* The two lower bits is part of hdr->flow_lbl[0] */
517 hdr->flow_lbl[0] |= ((dscp & 0x03) << 6);
518 }
519
520 /* get the flow label values from iphc tf format and set it to ipv6hdr */
521 static inline void lowpan_iphc_tf_set_lbl(struct ipv6hdr *hdr, const u8 *lbl)
522 {
523 /* flow label is always some array started with lower nibble of
524 * flow_lbl[0] and followed with two bytes afterwards. Inside inline
525 * data the flow_lbl position can be different, which will be handled
526 * by lbl pointer. E.g. case "01" vs "00" the traffic class is 8 bit
527 * shifted, the different lbl pointer will handle that.
528 *
529 * The flow label will started at lower nibble of flow_lbl[0], the
530 * higher nibbles are part of DSCP + ECN.
531 */
532 hdr->flow_lbl[0] |= lbl[0] & 0x0f;
533 memcpy(&hdr->flow_lbl[1], &lbl[1], 2);
534 }
535
536 /* lowpan_iphc_tf_decompress - decompress the traffic class.
537 * This function will return zero on success, a value lower than zero if
538 * failed.
539 */
540 static int lowpan_iphc_tf_decompress(struct sk_buff *skb, struct ipv6hdr *hdr,
541 u8 val)
542 {
543 u8 tf[4];
544
545 /* Traffic Class and Flow Label */
546 switch (val) {
547 case LOWPAN_IPHC_TF_00:
548 /* ECN + DSCP + 4-bit Pad + Flow Label (4 bytes) */
549 if (lowpan_fetch_skb(skb, tf, 4))
550 return -EINVAL;
551
552 /* 1 2 3
553 * 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
554 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
555 * |ECN| DSCP | rsv | Flow Label |
556 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
557 */
558 lowpan_iphc_tf_set_ecn(hdr, tf);
559 lowpan_iphc_tf_set_dscp(hdr, tf);
560 lowpan_iphc_tf_set_lbl(hdr, &tf[1]);
561 break;
562 case LOWPAN_IPHC_TF_01:
563 /* ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided. */
564 if (lowpan_fetch_skb(skb, tf, 3))
565 return -EINVAL;
566
567 /* 1 2
568 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
569 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
570 * |ECN|rsv| Flow Label |
571 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
572 */
573 lowpan_iphc_tf_set_ecn(hdr, tf);
574 lowpan_iphc_tf_set_lbl(hdr, &tf[0]);
575 break;
576 case LOWPAN_IPHC_TF_10:
577 /* ECN + DSCP (1 byte), Flow Label is elided. */
578 if (lowpan_fetch_skb(skb, tf, 1))
579 return -EINVAL;
580
581 /* 0 1 2 3 4 5 6 7
582 * +-+-+-+-+-+-+-+-+
583 * |ECN| DSCP |
584 * +-+-+-+-+-+-+-+-+
585 */
586 lowpan_iphc_tf_set_ecn(hdr, tf);
587 lowpan_iphc_tf_set_dscp(hdr, tf);
588 break;
589 case LOWPAN_IPHC_TF_11:
590 /* Traffic Class and Flow Label are elided */
591 break;
592 default:
593 WARN_ON_ONCE(1);
594 return -EINVAL;
595 }
596
597 return 0;
598 }
599
600 /* TTL uncompression values */
601 static const u8 lowpan_ttl_values[] = {
602 [LOWPAN_IPHC_HLIM_01] = 1,
603 [LOWPAN_IPHC_HLIM_10] = 64,
604 [LOWPAN_IPHC_HLIM_11] = 255,
605 };
606
607 int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev,
608 const void *daddr, const void *saddr)
609 {
610 struct ipv6hdr hdr = {};
611 struct lowpan_iphc_ctx *ci;
612 u8 iphc0, iphc1, cid = 0;
613 int err;
614
615 raw_dump_table(__func__, "raw skb data dump uncompressed",
616 skb->data, skb->len);
617
618 if (lowpan_fetch_skb(skb, &iphc0, sizeof(iphc0)) ||
619 lowpan_fetch_skb(skb, &iphc1, sizeof(iphc1)))
620 return -EINVAL;
621
622 hdr.version = 6;
623
624 /* default CID = 0, another if the CID flag is set */
625 if (iphc1 & LOWPAN_IPHC_CID) {
626 if (lowpan_fetch_skb(skb, &cid, sizeof(cid)))
627 return -EINVAL;
628 }
629
630 err = lowpan_iphc_tf_decompress(skb, &hdr,
631 iphc0 & LOWPAN_IPHC_TF_MASK);
632 if (err < 0)
633 return err;
634
635 /* Next Header */
636 if (!(iphc0 & LOWPAN_IPHC_NH)) {
637 /* Next header is carried inline */
638 if (lowpan_fetch_skb(skb, &hdr.nexthdr, sizeof(hdr.nexthdr)))
639 return -EINVAL;
640
641 pr_debug("NH flag is set, next header carried inline: %02x\n",
642 hdr.nexthdr);
643 }
644
645 /* Hop Limit */
646 if ((iphc0 & LOWPAN_IPHC_HLIM_MASK) != LOWPAN_IPHC_HLIM_00) {
647 hdr.hop_limit = lowpan_ttl_values[iphc0 & LOWPAN_IPHC_HLIM_MASK];
648 } else {
649 if (lowpan_fetch_skb(skb, &hdr.hop_limit,
650 sizeof(hdr.hop_limit)))
651 return -EINVAL;
652 }
653
654 if (iphc1 & LOWPAN_IPHC_SAC) {
655 spin_lock_bh(&lowpan_priv(dev)->ctx.lock);
656 ci = lowpan_iphc_ctx_get_by_id(dev, LOWPAN_IPHC_CID_SCI(cid));
657 if (!ci) {
658 spin_unlock_bh(&lowpan_priv(dev)->ctx.lock);
659 return -EINVAL;
660 }
661
662 pr_debug("SAC bit is set. Handle context based source address.\n");
663 err = uncompress_ctx_addr(skb, dev, ci, &hdr.saddr,
664 iphc1 & LOWPAN_IPHC_SAM_MASK, saddr);
665 spin_unlock_bh(&lowpan_priv(dev)->ctx.lock);
666 } else {
667 /* Source address uncompression */
668 pr_debug("source address stateless compression\n");
669 err = uncompress_addr(skb, dev, &hdr.saddr,
670 iphc1 & LOWPAN_IPHC_SAM_MASK, saddr);
671 }
672
673 /* Check on error of previous branch */
674 if (err)
675 return -EINVAL;
676
677 switch (iphc1 & (LOWPAN_IPHC_M | LOWPAN_IPHC_DAC)) {
678 case LOWPAN_IPHC_M | LOWPAN_IPHC_DAC:
679 spin_lock_bh(&lowpan_priv(dev)->ctx.lock);
680 ci = lowpan_iphc_ctx_get_by_id(dev, LOWPAN_IPHC_CID_DCI(cid));
681 if (!ci) {
682 spin_unlock_bh(&lowpan_priv(dev)->ctx.lock);
683 return -EINVAL;
684 }
685
686 /* multicast with context */
687 pr_debug("dest: context-based mcast compression\n");
688 err = lowpan_uncompress_multicast_ctx_daddr(skb, ci,
689 &hdr.daddr,
690 iphc1 & LOWPAN_IPHC_DAM_MASK);
691 spin_unlock_bh(&lowpan_priv(dev)->ctx.lock);
692 break;
693 case LOWPAN_IPHC_M:
694 /* multicast */
695 err = lowpan_uncompress_multicast_daddr(skb, &hdr.daddr,
696 iphc1 & LOWPAN_IPHC_DAM_MASK);
697 break;
698 case LOWPAN_IPHC_DAC:
699 spin_lock_bh(&lowpan_priv(dev)->ctx.lock);
700 ci = lowpan_iphc_ctx_get_by_id(dev, LOWPAN_IPHC_CID_DCI(cid));
701 if (!ci) {
702 spin_unlock_bh(&lowpan_priv(dev)->ctx.lock);
703 return -EINVAL;
704 }
705
706 /* Destination address context based uncompression */
707 pr_debug("DAC bit is set. Handle context based destination address.\n");
708 err = uncompress_ctx_addr(skb, dev, ci, &hdr.daddr,
709 iphc1 & LOWPAN_IPHC_DAM_MASK, daddr);
710 spin_unlock_bh(&lowpan_priv(dev)->ctx.lock);
711 break;
712 default:
713 err = uncompress_addr(skb, dev, &hdr.daddr,
714 iphc1 & LOWPAN_IPHC_DAM_MASK, daddr);
715 pr_debug("dest: stateless compression mode %d dest %pI6c\n",
716 iphc1 & LOWPAN_IPHC_DAM_MASK, &hdr.daddr);
717 break;
718 }
719
720 if (err)
721 return -EINVAL;
722
723 /* Next header data uncompression */
724 if (iphc0 & LOWPAN_IPHC_NH) {
725 err = lowpan_nhc_do_uncompression(skb, dev, &hdr);
726 if (err < 0)
727 return err;
728 } else {
729 err = skb_cow(skb, sizeof(hdr));
730 if (unlikely(err))
731 return err;
732 }
733
734 switch (lowpan_priv(dev)->lltype) {
735 case LOWPAN_LLTYPE_IEEE802154:
736 if (lowpan_802154_cb(skb)->d_size)
737 hdr.payload_len = htons(lowpan_802154_cb(skb)->d_size -
738 sizeof(struct ipv6hdr));
739 else
740 hdr.payload_len = htons(skb->len);
741 break;
742 default:
743 hdr.payload_len = htons(skb->len);
744 break;
745 }
746
747 pr_debug("skb headroom size = %d, data length = %d\n",
748 skb_headroom(skb), skb->len);
749
750 pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n\t"
751 "nexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n",
752 hdr.version, ntohs(hdr.payload_len), hdr.nexthdr,
753 hdr.hop_limit, &hdr.daddr);
754
755 skb_push(skb, sizeof(hdr));
756 skb_reset_network_header(skb);
757 skb_copy_to_linear_data(skb, &hdr, sizeof(hdr));
758
759 raw_dump_table(__func__, "raw header dump", (u8 *)&hdr, sizeof(hdr));
760
761 return 0;
762 }
763 EXPORT_SYMBOL_GPL(lowpan_header_decompress);
764
765 static const u8 lowpan_iphc_dam_to_sam_value[] = {
766 [LOWPAN_IPHC_DAM_00] = LOWPAN_IPHC_SAM_00,
767 [LOWPAN_IPHC_DAM_01] = LOWPAN_IPHC_SAM_01,
768 [LOWPAN_IPHC_DAM_10] = LOWPAN_IPHC_SAM_10,
769 [LOWPAN_IPHC_DAM_11] = LOWPAN_IPHC_SAM_11,
770 };
771
772 static u8 lowpan_compress_ctx_addr(u8 **hc_ptr, const struct in6_addr *ipaddr,
773 const struct lowpan_iphc_ctx *ctx,
774 const unsigned char *lladdr, bool sam)
775 {
776 struct in6_addr tmp = {};
777 u8 dam;
778
779 /* check for SAM/DAM = 11 */
780 memcpy(&tmp.s6_addr[8], lladdr, 8);
781 /* second bit-flip (Universe/Local) is done according RFC2464 */
782 tmp.s6_addr[8] ^= 0x02;
783 /* context information are always used */
784 ipv6_addr_prefix_copy(&tmp, &ctx->pfx, ctx->plen);
785 if (ipv6_addr_equal(&tmp, ipaddr)) {
786 dam = LOWPAN_IPHC_DAM_11;
787 goto out;
788 }
789
790 memset(&tmp, 0, sizeof(tmp));
791 /* check for SAM/DAM = 01 */
792 tmp.s6_addr[11] = 0xFF;
793 tmp.s6_addr[12] = 0xFE;
794 memcpy(&tmp.s6_addr[14], &ipaddr->s6_addr[14], 2);
795 /* context information are always used */
796 ipv6_addr_prefix_copy(&tmp, &ctx->pfx, ctx->plen);
797 if (ipv6_addr_equal(&tmp, ipaddr)) {
798 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[14], 2);
799 dam = LOWPAN_IPHC_DAM_10;
800 goto out;
801 }
802
803 memset(&tmp, 0, sizeof(tmp));
804 /* check for SAM/DAM = 10, should always match */
805 memcpy(&tmp.s6_addr[8], &ipaddr->s6_addr[8], 8);
806 /* context information are always used */
807 ipv6_addr_prefix_copy(&tmp, &ctx->pfx, ctx->plen);
808 if (ipv6_addr_equal(&tmp, ipaddr)) {
809 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[8], 8);
810 dam = LOWPAN_IPHC_DAM_01;
811 goto out;
812 }
813
814 WARN_ONCE(1, "context found but no address mode matched\n");
815 return LOWPAN_IPHC_DAM_00;
816 out:
817
818 if (sam)
819 return lowpan_iphc_dam_to_sam_value[dam];
820 else
821 return dam;
822 }
823
824 static u8 lowpan_compress_addr_64(u8 **hc_ptr, const struct in6_addr *ipaddr,
825 const unsigned char *lladdr, bool sam)
826 {
827 u8 dam = LOWPAN_IPHC_DAM_00;
828
829 if (is_addr_mac_addr_based(ipaddr, lladdr)) {
830 dam = LOWPAN_IPHC_DAM_11; /* 0-bits */
831 pr_debug("address compression 0 bits\n");
832 } else if (lowpan_is_iid_16_bit_compressable(ipaddr)) {
833 /* compress IID to 16 bits xxxx::XXXX */
834 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[7], 2);
835 dam = LOWPAN_IPHC_DAM_10; /* 16-bits */
836 raw_dump_inline(NULL, "Compressed ipv6 addr is (16 bits)",
837 *hc_ptr - 2, 2);
838 } else {
839 /* do not compress IID => xxxx::IID */
840 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[4], 8);
841 dam = LOWPAN_IPHC_DAM_01; /* 64-bits */
842 raw_dump_inline(NULL, "Compressed ipv6 addr is (64 bits)",
843 *hc_ptr - 8, 8);
844 }
845
846 if (sam)
847 return lowpan_iphc_dam_to_sam_value[dam];
848 else
849 return dam;
850 }
851
852 /* lowpan_iphc_get_tc - get the ECN + DCSP fields in hc format */
853 static inline u8 lowpan_iphc_get_tc(const struct ipv6hdr *hdr)
854 {
855 u8 dscp, ecn;
856
857 /* hdr->priority contains the higher bits of dscp, lower are part of
858 * flow_lbl[0]. Note ECN, DCSP is swapped in ipv6 hdr.
859 */
860 dscp = (hdr->priority << 2) | ((hdr->flow_lbl[0] & 0xc0) >> 6);
861 /* ECN is at the two lower bits from first nibble of flow_lbl[0] */
862 ecn = (hdr->flow_lbl[0] & 0x30);
863 /* for pretty debug output, also shift ecn to get the ecn value */
864 pr_debug("ecn 0x%02x dscp 0x%02x\n", ecn >> 4, dscp);
865 /* ECN is at 0x30 now, shift it to have ECN + DCSP */
866 return (ecn << 2) | dscp;
867 }
868
869 /* lowpan_iphc_is_flow_lbl_zero - check if flow label is zero */
870 static inline bool lowpan_iphc_is_flow_lbl_zero(const struct ipv6hdr *hdr)
871 {
872 return ((!(hdr->flow_lbl[0] & 0x0f)) &&
873 !hdr->flow_lbl[1] && !hdr->flow_lbl[2]);
874 }
875
876 /* lowpan_iphc_tf_compress - compress the traffic class which is set by
877 * ipv6hdr. Return the corresponding format identifier which is used.
878 */
879 static u8 lowpan_iphc_tf_compress(u8 **hc_ptr, const struct ipv6hdr *hdr)
880 {
881 /* get ecn dscp data in a byteformat as: ECN(hi) + DSCP(lo) */
882 u8 tc = lowpan_iphc_get_tc(hdr), tf[4], val;
883
884 /* printout the traffic class in hc format */
885 pr_debug("tc 0x%02x\n", tc);
886
887 if (lowpan_iphc_is_flow_lbl_zero(hdr)) {
888 if (!tc) {
889 /* 11: Traffic Class and Flow Label are elided. */
890 val = LOWPAN_IPHC_TF_11;
891 } else {
892 /* 10: ECN + DSCP (1 byte), Flow Label is elided.
893 *
894 * 0 1 2 3 4 5 6 7
895 * +-+-+-+-+-+-+-+-+
896 * |ECN| DSCP |
897 * +-+-+-+-+-+-+-+-+
898 */
899 lowpan_push_hc_data(hc_ptr, &tc, sizeof(tc));
900 val = LOWPAN_IPHC_TF_10;
901 }
902 } else {
903 /* check if dscp is zero, it's after the first two bit */
904 if (!(tc & 0x3f)) {
905 /* 01: ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
906 *
907 * 1 2
908 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
909 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
910 * |ECN|rsv| Flow Label |
911 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
912 */
913 memcpy(&tf[0], &hdr->flow_lbl[0], 3);
914 /* zero the highest 4-bits, contains DCSP + ECN */
915 tf[0] &= ~0xf0;
916 /* set ECN */
917 tf[0] |= (tc & 0xc0);
918
919 lowpan_push_hc_data(hc_ptr, tf, 3);
920 val = LOWPAN_IPHC_TF_01;
921 } else {
922 /* 00: ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
923 *
924 * 1 2 3
925 * 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
926 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
927 * |ECN| DSCP | rsv | Flow Label |
928 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
929 */
930 memcpy(&tf[0], &tc, sizeof(tc));
931 /* highest nibble of flow_lbl[0] is part of DSCP + ECN
932 * which will be the 4-bit pad and will be filled with
933 * zeros afterwards.
934 */
935 memcpy(&tf[1], &hdr->flow_lbl[0], 3);
936 /* zero the 4-bit pad, which is reserved */
937 tf[1] &= ~0xf0;
938
939 lowpan_push_hc_data(hc_ptr, tf, 4);
940 val = LOWPAN_IPHC_TF_00;
941 }
942 }
943
944 return val;
945 }
946
947 static u8 lowpan_iphc_mcast_ctx_addr_compress(u8 **hc_ptr,
948 const struct lowpan_iphc_ctx *ctx,
949 const struct in6_addr *ipaddr)
950 {
951 u8 data[6];
952
953 /* flags/scope, reserved (RIID) */
954 memcpy(data, &ipaddr->s6_addr[1], 2);
955 /* group ID */
956 memcpy(&data[1], &ipaddr->s6_addr[11], 4);
957 lowpan_push_hc_data(hc_ptr, data, 6);
958
959 return LOWPAN_IPHC_DAM_00;
960 }
961
962 static u8 lowpan_iphc_mcast_addr_compress(u8 **hc_ptr,
963 const struct in6_addr *ipaddr)
964 {
965 u8 val;
966
967 if (lowpan_is_mcast_addr_compressable8(ipaddr)) {
968 pr_debug("compressed to 1 octet\n");
969 /* use last byte */
970 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[15], 1);
971 val = LOWPAN_IPHC_DAM_11;
972 } else if (lowpan_is_mcast_addr_compressable32(ipaddr)) {
973 pr_debug("compressed to 4 octets\n");
974 /* second byte + the last three */
975 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[1], 1);
976 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[13], 3);
977 val = LOWPAN_IPHC_DAM_10;
978 } else if (lowpan_is_mcast_addr_compressable48(ipaddr)) {
979 pr_debug("compressed to 6 octets\n");
980 /* second byte + the last five */
981 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[1], 1);
982 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[11], 5);
983 val = LOWPAN_IPHC_DAM_01;
984 } else {
985 pr_debug("using full address\n");
986 lowpan_push_hc_data(hc_ptr, ipaddr->s6_addr, 16);
987 val = LOWPAN_IPHC_DAM_00;
988 }
989
990 return val;
991 }
992
993 int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
994 const void *daddr, const void *saddr)
995 {
996 u8 iphc0, iphc1, *hc_ptr, cid = 0;
997 struct ipv6hdr *hdr;
998 u8 head[LOWPAN_IPHC_MAX_HC_BUF_LEN] = {};
999 struct lowpan_iphc_ctx *dci, *sci, dci_entry, sci_entry;
1000 int ret, ipv6_daddr_type, ipv6_saddr_type;
1001
1002 if (skb->protocol != htons(ETH_P_IPV6))
1003 return -EINVAL;
1004
1005 hdr = ipv6_hdr(skb);
1006 hc_ptr = head + 2;
1007
1008 pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n"
1009 "\tnexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n",
1010 hdr->version, ntohs(hdr->payload_len), hdr->nexthdr,
1011 hdr->hop_limit, &hdr->daddr);
1012
1013 raw_dump_table(__func__, "raw skb network header dump",
1014 skb_network_header(skb), sizeof(struct ipv6hdr));
1015
1016 /* As we copy some bit-length fields, in the IPHC encoding bytes,
1017 * we sometimes use |=
1018 * If the field is 0, and the current bit value in memory is 1,
1019 * this does not work. We therefore reset the IPHC encoding here
1020 */
1021 iphc0 = LOWPAN_DISPATCH_IPHC;
1022 iphc1 = 0;
1023
1024 raw_dump_inline(__func__, "saddr", saddr, EUI64_ADDR_LEN);
1025 raw_dump_inline(__func__, "daddr", daddr, EUI64_ADDR_LEN);
1026
1027 raw_dump_table(__func__, "sending raw skb network uncompressed packet",
1028 skb->data, skb->len);
1029
1030 ipv6_daddr_type = ipv6_addr_type(&hdr->daddr);
1031 spin_lock_bh(&lowpan_priv(dev)->ctx.lock);
1032 if (ipv6_daddr_type & IPV6_ADDR_MULTICAST)
1033 dci = lowpan_iphc_ctx_get_by_mcast_addr(dev, &hdr->daddr);
1034 else
1035 dci = lowpan_iphc_ctx_get_by_addr(dev, &hdr->daddr);
1036 if (dci) {
1037 memcpy(&dci_entry, dci, sizeof(*dci));
1038 cid |= dci->id;
1039 }
1040 spin_unlock_bh(&lowpan_priv(dev)->ctx.lock);
1041
1042 spin_lock_bh(&lowpan_priv(dev)->ctx.lock);
1043 sci = lowpan_iphc_ctx_get_by_addr(dev, &hdr->saddr);
1044 if (sci) {
1045 memcpy(&sci_entry, sci, sizeof(*sci));
1046 cid |= (sci->id << 4);
1047 }
1048 spin_unlock_bh(&lowpan_priv(dev)->ctx.lock);
1049
1050 /* if cid is zero it will be compressed */
1051 if (cid) {
1052 iphc1 |= LOWPAN_IPHC_CID;
1053 lowpan_push_hc_data(&hc_ptr, &cid, sizeof(cid));
1054 }
1055
1056 /* Traffic Class, Flow Label compression */
1057 iphc0 |= lowpan_iphc_tf_compress(&hc_ptr, hdr);
1058
1059 /* NOTE: payload length is always compressed */
1060
1061 /* Check if we provide the nhc format for nexthdr and compression
1062 * functionality. If not nexthdr is handled inline and not compressed.
1063 */
1064 ret = lowpan_nhc_check_compression(skb, hdr, &hc_ptr);
1065 if (ret == -ENOENT)
1066 lowpan_push_hc_data(&hc_ptr, &hdr->nexthdr,
1067 sizeof(hdr->nexthdr));
1068 else
1069 iphc0 |= LOWPAN_IPHC_NH;
1070
1071 /* Hop limit
1072 * if 1: compress, encoding is 01
1073 * if 64: compress, encoding is 10
1074 * if 255: compress, encoding is 11
1075 * else do not compress
1076 */
1077 switch (hdr->hop_limit) {
1078 case 1:
1079 iphc0 |= LOWPAN_IPHC_HLIM_01;
1080 break;
1081 case 64:
1082 iphc0 |= LOWPAN_IPHC_HLIM_10;
1083 break;
1084 case 255:
1085 iphc0 |= LOWPAN_IPHC_HLIM_11;
1086 break;
1087 default:
1088 lowpan_push_hc_data(&hc_ptr, &hdr->hop_limit,
1089 sizeof(hdr->hop_limit));
1090 }
1091
1092 ipv6_saddr_type = ipv6_addr_type(&hdr->saddr);
1093 /* source address compression */
1094 if (ipv6_saddr_type == IPV6_ADDR_ANY) {
1095 pr_debug("source address is unspecified, setting SAC\n");
1096 iphc1 |= LOWPAN_IPHC_SAC;
1097 } else {
1098 if (sci) {
1099 iphc1 |= lowpan_compress_ctx_addr(&hc_ptr, &hdr->saddr,
1100 &sci_entry, saddr,
1101 true);
1102 iphc1 |= LOWPAN_IPHC_SAC;
1103 } else {
1104 if (ipv6_saddr_type & IPV6_ADDR_LINKLOCAL) {
1105 iphc1 |= lowpan_compress_addr_64(&hc_ptr,
1106 &hdr->saddr,
1107 saddr, true);
1108 pr_debug("source address unicast link-local %pI6c iphc1 0x%02x\n",
1109 &hdr->saddr, iphc1);
1110 } else {
1111 pr_debug("send the full source address\n");
1112 lowpan_push_hc_data(&hc_ptr,
1113 hdr->saddr.s6_addr, 16);
1114 }
1115 }
1116 }
1117
1118 /* destination address compression */
1119 if (ipv6_daddr_type & IPV6_ADDR_MULTICAST) {
1120 pr_debug("destination address is multicast: ");
1121 iphc1 |= LOWPAN_IPHC_M;
1122 if (dci) {
1123 iphc1 |= lowpan_iphc_mcast_ctx_addr_compress(&hc_ptr,
1124 &dci_entry,
1125 &hdr->daddr);
1126 iphc1 |= LOWPAN_IPHC_DAC;
1127 } else {
1128 iphc1 |= lowpan_iphc_mcast_addr_compress(&hc_ptr,
1129 &hdr->daddr);
1130 }
1131 } else {
1132 if (dci) {
1133 iphc1 |= lowpan_compress_ctx_addr(&hc_ptr, &hdr->daddr,
1134 &dci_entry, daddr,
1135 false);
1136 iphc1 |= LOWPAN_IPHC_DAC;
1137 } else {
1138 if (ipv6_daddr_type & IPV6_ADDR_LINKLOCAL) {
1139 iphc1 |= lowpan_compress_addr_64(&hc_ptr,
1140 &hdr->daddr,
1141 daddr, false);
1142 pr_debug("dest address unicast link-local %pI6c iphc1 0x%02x\n",
1143 &hdr->daddr, iphc1);
1144 } else {
1145 pr_debug("dest address unicast %pI6c\n",
1146 &hdr->daddr);
1147 lowpan_push_hc_data(&hc_ptr,
1148 hdr->daddr.s6_addr, 16);
1149 }
1150 }
1151 }
1152
1153 /* next header compression */
1154 if (iphc0 & LOWPAN_IPHC_NH) {
1155 ret = lowpan_nhc_do_compression(skb, hdr, &hc_ptr);
1156 if (ret < 0)
1157 return ret;
1158 }
1159
1160 head[0] = iphc0;
1161 head[1] = iphc1;
1162
1163 skb_pull(skb, sizeof(struct ipv6hdr));
1164 skb_reset_transport_header(skb);
1165 memcpy(skb_push(skb, hc_ptr - head), head, hc_ptr - head);
1166 skb_reset_network_header(skb);
1167
1168 pr_debug("header len %d skb %u\n", (int)(hc_ptr - head), skb->len);
1169
1170 raw_dump_table(__func__, "raw skb data dump compressed",
1171 skb->data, skb->len);
1172 return 0;
1173 }
1174 EXPORT_SYMBOL_GPL(lowpan_header_compress);