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drm/amd/powerplay: incorrectly use of the function return value
[linux-2.6-block.git] / net / 6lowpan / iphc.c
CommitLineData
8df8c56a
JR		 1/*
2 * Copyright 2011, Siemens AG
3 * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
4 */
5
4710d806 6/* Based on patches from Jon Smirl <jonsmirl@gmail.com>
8df8c56a
JR		 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 *
8df8c56a
JR		 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>
8911d774 52
cefc8c8a 53#include <net/6lowpan.h>
8df8c56a 54#include <net/ipv6.h>
8911d774 55
5609c185 56#include "6lowpan_i.h"
cc6ed268
AA		 57#include "nhc.h"
58
c8a3e7eb
AA		 59/* Values of fields within the IPHC encoding first byte */
60#define LOWPAN_IPHC_TF_MASK 0x18
61#define LOWPAN_IPHC_TF_00 0x00
62#define LOWPAN_IPHC_TF_01 0x08
63#define LOWPAN_IPHC_TF_10 0x10
64#define LOWPAN_IPHC_TF_11 0x18
65
66#define LOWPAN_IPHC_NH 0x04
6350047e 67
c8a3e7eb
AA		 68#define LOWPAN_IPHC_HLIM_MASK 0x03
69#define LOWPAN_IPHC_HLIM_00 0x00
70#define LOWPAN_IPHC_HLIM_01 0x01
71#define LOWPAN_IPHC_HLIM_10 0x02
72#define LOWPAN_IPHC_HLIM_11 0x03
6350047e
AA		 73
74/* Values of fields within the IPHC encoding second byte */
75#define LOWPAN_IPHC_CID 0x80
76
6350047e 77#define LOWPAN_IPHC_SAC 0x40
6350047e 78
c8a3e7eb
AA		 79#define LOWPAN_IPHC_SAM_MASK 0x30
80#define LOWPAN_IPHC_SAM_00 0x00
81#define LOWPAN_IPHC_SAM_01 0x10
82#define LOWPAN_IPHC_SAM_10 0x20
83#define LOWPAN_IPHC_SAM_11 0x30
6350047e
AA		 84
85#define LOWPAN_IPHC_M 0x08
c8a3e7eb 86
6350047e 87#define LOWPAN_IPHC_DAC 0x04
c8a3e7eb
AA		 88
89#define LOWPAN_IPHC_DAM_MASK 0x03
6350047e
AA		 90#define LOWPAN_IPHC_DAM_00 0x00
91#define LOWPAN_IPHC_DAM_01 0x01
92#define LOWPAN_IPHC_DAM_10 0x02
93#define LOWPAN_IPHC_DAM_11 0x03
94
6350047e
AA		 95/* ipv6 address based on mac
96 * second bit-flip (Universe/Local) is done according RFC2464
97 */
98#define is_addr_mac_addr_based(a, m) \
99 ((((a)->s6_addr[8]) == (((m)[0]) ^ 0x02)) && \
100 (((a)->s6_addr[9]) == (m)[1]) && \
101 (((a)->s6_addr[10]) == (m)[2]) && \
102 (((a)->s6_addr[11]) == (m)[3]) && \
103 (((a)->s6_addr[12]) == (m)[4]) && \
104 (((a)->s6_addr[13]) == (m)[5]) && \
105 (((a)->s6_addr[14]) == (m)[6]) && \
106 (((a)->s6_addr[15]) == (m)[7]))
107
108/* check whether we can compress the IID to 16 bits,
109 * it's possible for unicast addresses with first 49 bits are zero only.
110 */
111#define lowpan_is_iid_16_bit_compressable(a) \
112 ((((a)->s6_addr16[4]) == 0) && \
113 (((a)->s6_addr[10]) == 0) && \
114 (((a)->s6_addr[11]) == 0xff) && \
115 (((a)->s6_addr[12]) == 0xfe) && \
116 (((a)->s6_addr[13]) == 0))
117
118/* check whether the 112-bit gid of the multicast address is mappable to: */
119
120/* 48 bits, FFXX::00XX:XXXX:XXXX */
121#define lowpan_is_mcast_addr_compressable48(a) \
122 ((((a)->s6_addr16[1]) == 0) && \
123 (((a)->s6_addr16[2]) == 0) && \
124 (((a)->s6_addr16[3]) == 0) && \
125 (((a)->s6_addr16[4]) == 0) && \
126 (((a)->s6_addr[10]) == 0))
127
128/* 32 bits, FFXX::00XX:XXXX */
129#define lowpan_is_mcast_addr_compressable32(a) \
130 ((((a)->s6_addr16[1]) == 0) && \
131 (((a)->s6_addr16[2]) == 0) && \
132 (((a)->s6_addr16[3]) == 0) && \
133 (((a)->s6_addr16[4]) == 0) && \
134 (((a)->s6_addr16[5]) == 0) && \
135 (((a)->s6_addr[12]) == 0))
136
137/* 8 bits, FF02::00XX */
138#define lowpan_is_mcast_addr_compressable8(a) \
139 ((((a)->s6_addr[1]) == 2) && \
140 (((a)->s6_addr16[1]) == 0) && \
141 (((a)->s6_addr16[2]) == 0) && \
142 (((a)->s6_addr16[3]) == 0) && \
143 (((a)->s6_addr16[4]) == 0) && \
144 (((a)->s6_addr16[5]) == 0) && \
145 (((a)->s6_addr16[6]) == 0) && \
146 (((a)->s6_addr[14]) == 0))
147
feb2add3
AA		 148#define lowpan_is_linklocal_zero_padded(a) \
149 (!(hdr->saddr.s6_addr[1] & 0x3f) && \
150 !hdr->saddr.s6_addr16[1] && \
151 !hdr->saddr.s6_addr32[1])
152
5609c185
AA		 153#define LOWPAN_IPHC_CID_DCI(cid) (cid & 0x0f)
154#define LOWPAN_IPHC_CID_SCI(cid) ((cid & 0xf0) >> 4)
155
7115a968
AA		 156static inline void
157lowpan_iphc_uncompress_802154_lladdr(struct in6_addr *ipaddr,
158 const void *lladdr)
8911d774
AA		 159{
160 const struct ieee802154_addr *addr = lladdr;
2bc068c3 161 u8 eui64[EUI64_ADDR_LEN];
8911d774
AA		 162
163 switch (addr->mode) {
164 case IEEE802154_ADDR_LONG:
165 ieee802154_le64_to_be64(eui64, &addr->extended_addr);
7115a968 166 lowpan_iphc_uncompress_eui64_lladdr(ipaddr, eui64);
8911d774
AA		 167 break;
168 case IEEE802154_ADDR_SHORT:
169 /* fe:80::ff:fe00:XXXX
170 * \__/
171 * short_addr
172 *
173 * Universe/Local bit is zero.
174 */
175 ipaddr->s6_addr[0] = 0xFE;
176 ipaddr->s6_addr[1] = 0x80;
177 ipaddr->s6_addr[11] = 0xFF;
178 ipaddr->s6_addr[12] = 0xFE;
179 ieee802154_le16_to_be16(&ipaddr->s6_addr16[7],
180 &addr->short_addr);
181 break;
182 default:
183 /* should never handled and filtered by 802154 6lowpan */
184 WARN_ON_ONCE(1);
185 break;
186 }
187}
188
5609c185
AA		 189static struct lowpan_iphc_ctx *
190lowpan_iphc_ctx_get_by_id(const struct net_device *dev, u8 id)
191{
2e4d60cb 192 struct lowpan_iphc_ctx *ret = &lowpan_dev(dev)->ctx.table[id];
5609c185
AA		 193
194 if (!lowpan_iphc_ctx_is_active(ret))
195 return NULL;
196
197 return ret;
198}
199
200static struct lowpan_iphc_ctx *
201lowpan_iphc_ctx_get_by_addr(const struct net_device *dev,
202 const struct in6_addr *addr)
203{
2e4d60cb 204 struct lowpan_iphc_ctx *table = lowpan_dev(dev)->ctx.table;
5609c185
AA		 205 struct lowpan_iphc_ctx *ret = NULL;
206 struct in6_addr addr_pfx;
207 u8 addr_plen;
208 int i;
209
210 for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++) {
211 /* Check if context is valid. A context that is not valid
212 * MUST NOT be used for compression.
213 */
214 if (!lowpan_iphc_ctx_is_active(&table[i]) ||
215 !lowpan_iphc_ctx_is_compression(&table[i]))
216 continue;
217
218 ipv6_addr_prefix(&addr_pfx, addr, table[i].plen);
219
220 /* if prefix len < 64, the remaining bits until 64th bit is
221 * zero. Otherwise we use table[i]->plen.
222 */
223 if (table[i].plen < 64)
224 addr_plen = 64;
225 else
226 addr_plen = table[i].plen;
227
228 if (ipv6_prefix_equal(&addr_pfx, &table[i].pfx, addr_plen)) {
229 /* remember first match */
230 if (!ret) {
231 ret = &table[i];
232 continue;
233 }
234
235 /* get the context with longest prefix len */
236 if (table[i].plen > ret->plen)
237 ret = &table[i];
238 }
239 }
240
241 return ret;
242}
243
244static struct lowpan_iphc_ctx *
245lowpan_iphc_ctx_get_by_mcast_addr(const struct net_device *dev,
246 const struct in6_addr *addr)
247{
2e4d60cb 248 struct lowpan_iphc_ctx *table = lowpan_dev(dev)->ctx.table;
5609c185
AA		 249 struct lowpan_iphc_ctx *ret = NULL;
250 struct in6_addr addr_mcast, network_pfx = {};
251 int i;
252
253 /* init mcast address with */
254 memcpy(&addr_mcast, addr, sizeof(*addr));
255
256 for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++) {
257 /* Check if context is valid. A context that is not valid
258 * MUST NOT be used for compression.
259 */
260 if (!lowpan_iphc_ctx_is_active(&table[i]) ||
261 !lowpan_iphc_ctx_is_compression(&table[i]))
262 continue;
263
264 /* setting plen */
265 addr_mcast.s6_addr[3] = table[i].plen;
266 /* get network prefix to copy into multicast address */
267 ipv6_addr_prefix(&network_pfx, &table[i].pfx,
268 table[i].plen);
269 /* setting network prefix */
270 memcpy(&addr_mcast.s6_addr[4], &network_pfx, 8);
271
272 if (ipv6_addr_equal(addr, &addr_mcast)) {
273 ret = &table[i];
274 break;
275 }
276 }
277
278 return ret;
279}
280
4710d806 281/* Uncompress address function for source and
8df8c56a
JR		 282 * destination address(non-multicast).
283 *
c8a3e7eb 284 * address_mode is the masked value for sam or dam value
8df8c56a 285 */
7115a968
AA		 286static int lowpan_iphc_uncompress_addr(struct sk_buff *skb,
287 const struct net_device *dev,
288 struct in6_addr *ipaddr,
289 u8 address_mode, const void *lladdr)
8df8c56a
JR		 290{
291 bool fail;
292
293 switch (address_mode) {
c8a3e7eb
AA		 294 /* SAM and DAM are the same here */
295 case LOWPAN_IPHC_DAM_00:
8df8c56a
JR		 296 /* for global link addresses */
297 fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
298 break;
c8a3e7eb
AA		 299 case LOWPAN_IPHC_SAM_01:
300 case LOWPAN_IPHC_DAM_01:
8df8c56a
JR		 301 /* fe:80::XXXX:XXXX:XXXX:XXXX */
302 ipaddr->s6_addr[0] = 0xFE;
303 ipaddr->s6_addr[1] = 0x80;
304 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[8], 8);
305 break;
c8a3e7eb
AA		 306 case LOWPAN_IPHC_SAM_10:
307 case LOWPAN_IPHC_DAM_10:
8df8c56a
JR		 308 /* fe:80::ff:fe00:XXXX */
309 ipaddr->s6_addr[0] = 0xFE;
310 ipaddr->s6_addr[1] = 0x80;
311 ipaddr->s6_addr[11] = 0xFF;
312 ipaddr->s6_addr[12] = 0xFE;
313 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2);
314 break;
c8a3e7eb
AA		 315 case LOWPAN_IPHC_SAM_11:
316 case LOWPAN_IPHC_DAM_11:
8df8c56a 317 fail = false;
2e4d60cb 318 switch (lowpan_dev(dev)->lltype) {
8911d774 319 case LOWPAN_LLTYPE_IEEE802154:
7115a968 320 lowpan_iphc_uncompress_802154_lladdr(ipaddr, lladdr);
8df8c56a
JR		 321 break;
322 default:
7115a968 323 lowpan_iphc_uncompress_eui64_lladdr(ipaddr, lladdr);
8911d774 324 break;
8df8c56a
JR		 325 }
326 break;
327 default:
328 pr_debug("Invalid address mode value: 0x%x\n", address_mode);
329 return -EINVAL;
330 }
331
332 if (fail) {
333 pr_debug("Failed to fetch skb data\n");
334 return -EIO;
335 }
336
337 raw_dump_inline(NULL, "Reconstructed ipv6 addr is",
338 ipaddr->s6_addr, 16);
339
340 return 0;
341}
342
4710d806 343/* Uncompress address function for source context
8df8c56a
JR		 344 * based address(non-multicast).
345 */
7115a968
AA		 346static int lowpan_iphc_uncompress_ctx_addr(struct sk_buff *skb,
347 const struct net_device *dev,
348 const struct lowpan_iphc_ctx *ctx,
349 struct in6_addr *ipaddr,
350 u8 address_mode, const void *lladdr)
8df8c56a 351{
5609c185
AA		 352 bool fail;
353
c8a3e7eb 354 switch (address_mode) {
5609c185
AA		 355 /* SAM and DAM are the same here */
356 case LOWPAN_IPHC_DAM_00:
357 fail = false;
358 /* SAM_00 -> unspec address ::
8df8c56a 359 * Do nothing, address is already ::
5609c185
AA		 360 *
361 * DAM 00 -> reserved should never occur.
8df8c56a
JR		 362 */
363 break;
c8a3e7eb 364 case LOWPAN_IPHC_SAM_01:
5609c185
AA		 365 case LOWPAN_IPHC_DAM_01:
366 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[8], 8);
367 ipv6_addr_prefix_copy(ipaddr, &ctx->pfx, ctx->plen);
368 break;
c8a3e7eb 369 case LOWPAN_IPHC_SAM_10:
5609c185
AA		 370 case LOWPAN_IPHC_DAM_10:
371 ipaddr->s6_addr[11] = 0xFF;
372 ipaddr->s6_addr[12] = 0xFE;
373 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2);
374 ipv6_addr_prefix_copy(ipaddr, &ctx->pfx, ctx->plen);
375 break;
c8a3e7eb 376 case LOWPAN_IPHC_SAM_11:
5609c185
AA		 377 case LOWPAN_IPHC_DAM_11:
378 fail = false;
2e4d60cb 379 switch (lowpan_dev(dev)->lltype) {
5609c185 380 case LOWPAN_LLTYPE_IEEE802154:
7115a968 381 lowpan_iphc_uncompress_802154_lladdr(ipaddr, lladdr);
5609c185
AA		 382 break;
383 default:
7115a968 384 lowpan_iphc_uncompress_eui64_lladdr(ipaddr, lladdr);
5609c185
AA		 385 break;
386 }
387 ipv6_addr_prefix_copy(ipaddr, &ctx->pfx, ctx->plen);
388 break;
8df8c56a 389 default:
c8a3e7eb 390 pr_debug("Invalid sam value: 0x%x\n", address_mode);
8df8c56a
JR		 391 return -EINVAL;
392 }
393
5609c185
AA		 394 if (fail) {
395 pr_debug("Failed to fetch skb data\n");
396 return -EIO;
397 }
398
8df8c56a
JR		 399 raw_dump_inline(NULL,
400 "Reconstructed context based ipv6 src addr is",
401 ipaddr->s6_addr, 16);
402
403 return 0;
404}
405
8df8c56a
JR		 406/* Uncompress function for multicast destination address,
407 * when M bit is set.
408 */
7fc4cfda
MH		 409static int lowpan_uncompress_multicast_daddr(struct sk_buff *skb,
410 struct in6_addr *ipaddr,
c8a3e7eb 411 u8 address_mode)
8df8c56a
JR		 412{
413 bool fail;
414
c8a3e7eb 415 switch (address_mode) {
8df8c56a
JR		 416 case LOWPAN_IPHC_DAM_00:
417 /* 00: 128 bits. The full address
418 * is carried in-line.
419 */
420 fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
421 break;
422 case LOWPAN_IPHC_DAM_01:
423 /* 01: 48 bits. The address takes
424 * the form ffXX::00XX:XXXX:XXXX.
425 */
426 ipaddr->s6_addr[0] = 0xFF;
427 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
428 fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[11], 5);
429 break;
430 case LOWPAN_IPHC_DAM_10:
431 /* 10: 32 bits. The address takes
432 * the form ffXX::00XX:XXXX.
433 */
434 ipaddr->s6_addr[0] = 0xFF;
435 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
436 fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[13], 3);
437 break;
438 case LOWPAN_IPHC_DAM_11:
439 /* 11: 8 bits. The address takes
440 * the form ff02::00XX.
441 */
442 ipaddr->s6_addr[0] = 0xFF;
443 ipaddr->s6_addr[1] = 0x02;
444 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[15], 1);
445 break;
446 default:
c8a3e7eb 447 pr_debug("DAM value has a wrong value: 0x%x\n", address_mode);
8df8c56a
JR		 448 return -EINVAL;
449 }
450
451 if (fail) {
452 pr_debug("Failed to fetch skb data\n");
453 return -EIO;
454 }
455
456 raw_dump_inline(NULL, "Reconstructed ipv6 multicast addr is",
7fc4cfda 457 ipaddr->s6_addr, 16);
8df8c56a
JR		 458
459 return 0;
460}
461
5609c185
AA		 462static int lowpan_uncompress_multicast_ctx_daddr(struct sk_buff *skb,
463 struct lowpan_iphc_ctx *ctx,
464 struct in6_addr *ipaddr,
465 u8 address_mode)
466{
467 struct in6_addr network_pfx = {};
468 bool fail;
469
470 ipaddr->s6_addr[0] = 0xFF;
471 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 2);
472 fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[12], 4);
4c23d874 473 if (fail)
5609c185
AA		 474 return -EIO;
475
476 /* take prefix_len and network prefix from the context */
477 ipaddr->s6_addr[3] = ctx->plen;
478 /* get network prefix to copy into multicast address */
479 ipv6_addr_prefix(&network_pfx, &ctx->pfx, ctx->plen);
480 /* setting network prefix */
481 memcpy(&ipaddr->s6_addr[4], &network_pfx, 8);
482
483 return 0;
484}
485
b5af9bdb
AA		 486/* get the ecn values from iphc tf format and set it to ipv6hdr */
487static inline void lowpan_iphc_tf_set_ecn(struct ipv6hdr *hdr, const u8 *tf)
488{
489 /* get the two higher bits which is ecn */
490 u8 ecn = tf[0] & 0xc0;
491
492 /* ECN takes 0x30 in hdr->flow_lbl[0] */
493 hdr->flow_lbl[0] |= (ecn >> 2);
494}
495
496/* get the dscp values from iphc tf format and set it to ipv6hdr */
497static inline void lowpan_iphc_tf_set_dscp(struct ipv6hdr *hdr, const u8 *tf)
498{
499 /* DSCP is at place after ECN */
500 u8 dscp = tf[0] & 0x3f;
501
502 /* The four highest bits need to be set at hdr->priority */
503 hdr->priority |= ((dscp & 0x3c) >> 2);
504 /* The two lower bits is part of hdr->flow_lbl[0] */
505 hdr->flow_lbl[0] |= ((dscp & 0x03) << 6);
506}
507
508/* get the flow label values from iphc tf format and set it to ipv6hdr */
509static inline void lowpan_iphc_tf_set_lbl(struct ipv6hdr *hdr, const u8 *lbl)
510{
511 /* flow label is always some array started with lower nibble of
512 * flow_lbl[0] and followed with two bytes afterwards. Inside inline
513 * data the flow_lbl position can be different, which will be handled
514 * by lbl pointer. E.g. case "01" vs "00" the traffic class is 8 bit
515 * shifted, the different lbl pointer will handle that.
516 *
517 * The flow label will started at lower nibble of flow_lbl[0], the
518 * higher nibbles are part of DSCP + ECN.
519 */
520 hdr->flow_lbl[0] |= lbl[0] & 0x0f;
521 memcpy(&hdr->flow_lbl[1], &lbl[1], 2);
522}
523
524/* lowpan_iphc_tf_decompress - decompress the traffic class.
525 * This function will return zero on success, a value lower than zero if
526 * failed.
527 */
528static int lowpan_iphc_tf_decompress(struct sk_buff *skb, struct ipv6hdr *hdr,
529 u8 val)
530{
531 u8 tf[4];
532
533 /* Traffic Class and Flow Label */
534 switch (val) {
535 case LOWPAN_IPHC_TF_00:
536 /* ECN + DSCP + 4-bit Pad + Flow Label (4 bytes) */
537 if (lowpan_fetch_skb(skb, tf, 4))
538 return -EINVAL;
539
540 /* 1 2 3
541 * 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
542 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
543 * |ECN| DSCP | rsv | Flow Label |
544 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
545 */
546 lowpan_iphc_tf_set_ecn(hdr, tf);
547 lowpan_iphc_tf_set_dscp(hdr, tf);
548 lowpan_iphc_tf_set_lbl(hdr, &tf[1]);
549 break;
550 case LOWPAN_IPHC_TF_01:
551 /* ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided. */
552 if (lowpan_fetch_skb(skb, tf, 3))
553 return -EINVAL;
554
555 /* 1 2
556 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
557 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
558 * |ECN|rsv| Flow Label |
559 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
560 */
561 lowpan_iphc_tf_set_ecn(hdr, tf);
562 lowpan_iphc_tf_set_lbl(hdr, &tf[0]);
563 break;
564 case LOWPAN_IPHC_TF_10:
565 /* ECN + DSCP (1 byte), Flow Label is elided. */
566 if (lowpan_fetch_skb(skb, tf, 1))
567 return -EINVAL;
568
569 /* 0 1 2 3 4 5 6 7
570 * +-+-+-+-+-+-+-+-+
571 * |ECN| DSCP |
572 * +-+-+-+-+-+-+-+-+
573 */
574 lowpan_iphc_tf_set_ecn(hdr, tf);
575 lowpan_iphc_tf_set_dscp(hdr, tf);
576 break;
577 case LOWPAN_IPHC_TF_11:
578 /* Traffic Class and Flow Label are elided */
579 break;
580 default:
581 WARN_ON_ONCE(1);
582 return -EINVAL;
583 }
584
585 return 0;
586}
587
8df8c56a 588/* TTL uncompression values */
c8a3e7eb
AA		 589static const u8 lowpan_ttl_values[] = {
590 [LOWPAN_IPHC_HLIM_01] = 1,
591 [LOWPAN_IPHC_HLIM_10] = 64,
592 [LOWPAN_IPHC_HLIM_11] = 255,
593};
8df8c56a 594
8911d774
AA		 595int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev,
596 const void *daddr, const void *saddr)
8df8c56a
JR		 597{
598 struct ipv6hdr hdr = {};
5609c185
AA		 599 struct lowpan_iphc_ctx *ci;
600 u8 iphc0, iphc1, cid = 0;
8df8c56a
JR		 601 int err;
602
603 raw_dump_table(__func__, "raw skb data dump uncompressed",
4710d806 604 skb->data, skb->len);
8df8c56a 605
478208e3
AA		 606 if (lowpan_fetch_skb(skb, &iphc0, sizeof(iphc0)) ||
607 lowpan_fetch_skb(skb, &iphc1, sizeof(iphc1)))
8911d774
AA		 608 return -EINVAL;
609
8df8c56a
JR		 610 hdr.version = 6;
611
5609c185
AA		 612 /* default CID = 0, another if the CID flag is set */
613 if (iphc1 & LOWPAN_IPHC_CID) {
614 if (lowpan_fetch_skb(skb, &cid, sizeof(cid)))
615 return -EINVAL;
616 }
617
b5af9bdb
AA		 618 err = lowpan_iphc_tf_decompress(skb, &hdr,
619 iphc0 & LOWPAN_IPHC_TF_MASK);
620 if (err < 0)
621 return err;
8df8c56a
JR		 622
623 /* Next Header */
c8a3e7eb 624 if (!(iphc0 & LOWPAN_IPHC_NH)) {
8df8c56a 625 /* Next header is carried inline */
4ebc960f 626 if (lowpan_fetch_skb(skb, &hdr.nexthdr, sizeof(hdr.nexthdr)))
56b2c3ee 627 return -EINVAL;
8df8c56a
JR		 628
629 pr_debug("NH flag is set, next header carried inline: %02x\n",
630 hdr.nexthdr);
631 }
632
633 /* Hop Limit */
c8a3e7eb
AA		 634 if ((iphc0 & LOWPAN_IPHC_HLIM_MASK) != LOWPAN_IPHC_HLIM_00) {
635 hdr.hop_limit = lowpan_ttl_values[iphc0 & LOWPAN_IPHC_HLIM_MASK];
4710d806 636 } else {
4ebc960f
AA		 637 if (lowpan_fetch_skb(skb, &hdr.hop_limit,
638 sizeof(hdr.hop_limit)))
56b2c3ee 639 return -EINVAL;
8df8c56a
JR		 640 }
641
8df8c56a 642 if (iphc1 & LOWPAN_IPHC_SAC) {
2e4d60cb 643 spin_lock_bh(&lowpan_dev(dev)->ctx.lock);
5609c185
AA		 644 ci = lowpan_iphc_ctx_get_by_id(dev, LOWPAN_IPHC_CID_SCI(cid));
645 if (!ci) {
2e4d60cb 646 spin_unlock_bh(&lowpan_dev(dev)->ctx.lock);
5609c185
AA		 647 return -EINVAL;
648 }
649
8df8c56a 650 pr_debug("SAC bit is set. Handle context based source address.\n");
7115a968
AA		 651 err = lowpan_iphc_uncompress_ctx_addr(skb, dev, ci, &hdr.saddr,
652 iphc1 & LOWPAN_IPHC_SAM_MASK,
653 saddr);
2e4d60cb 654 spin_unlock_bh(&lowpan_dev(dev)->ctx.lock);
8df8c56a
JR		 655 } else {
656 /* Source address uncompression */
657 pr_debug("source address stateless compression\n");
7115a968
AA		 658 err = lowpan_iphc_uncompress_addr(skb, dev, &hdr.saddr,
659 iphc1 & LOWPAN_IPHC_SAM_MASK,
660 saddr);
8df8c56a
JR		 661 }
662
663 /* Check on error of previous branch */
664 if (err)
56b2c3ee 665 return -EINVAL;
8df8c56a 666
5609c185
AA		 667 switch (iphc1 & (LOWPAN_IPHC_M | LOWPAN_IPHC_DAC)) {
668 case LOWPAN_IPHC_M | LOWPAN_IPHC_DAC:
2e4d60cb 669 spin_lock_bh(&lowpan_dev(dev)->ctx.lock);
5609c185
AA		 670 ci = lowpan_iphc_ctx_get_by_id(dev, LOWPAN_IPHC_CID_DCI(cid));
671 if (!ci) {
2e4d60cb 672 spin_unlock_bh(&lowpan_dev(dev)->ctx.lock);
5609c185
AA		 673 return -EINVAL;
674 }
7fc4cfda 675
5609c185
AA		 676 /* multicast with context */
677 pr_debug("dest: context-based mcast compression\n");
678 err = lowpan_uncompress_multicast_ctx_daddr(skb, ci,
679 &hdr.daddr,
680 iphc1 & LOWPAN_IPHC_DAM_MASK);
2e4d60cb 681 spin_unlock_bh(&lowpan_dev(dev)->ctx.lock);
5609c185
AA		 682 break;
683 case LOWPAN_IPHC_M:
684 /* multicast */
685 err = lowpan_uncompress_multicast_daddr(skb, &hdr.daddr,
686 iphc1 & LOWPAN_IPHC_DAM_MASK);
687 break;
688 case LOWPAN_IPHC_DAC:
2e4d60cb 689 spin_lock_bh(&lowpan_dev(dev)->ctx.lock);
5609c185
AA		 690 ci = lowpan_iphc_ctx_get_by_id(dev, LOWPAN_IPHC_CID_DCI(cid));
691 if (!ci) {
2e4d60cb 692 spin_unlock_bh(&lowpan_dev(dev)->ctx.lock);
5609c185 693 return -EINVAL;
8df8c56a 694 }
5609c185
AA		 695
696 /* Destination address context based uncompression */
697 pr_debug("DAC bit is set. Handle context based destination address.\n");
7115a968
AA		 698 err = lowpan_iphc_uncompress_ctx_addr(skb, dev, ci, &hdr.daddr,
699 iphc1 & LOWPAN_IPHC_DAM_MASK,
700 daddr);
2e4d60cb 701 spin_unlock_bh(&lowpan_dev(dev)->ctx.lock);
5609c185
AA		 702 break;
703 default:
7115a968
AA		 704 err = lowpan_iphc_uncompress_addr(skb, dev, &hdr.daddr,
705 iphc1 & LOWPAN_IPHC_DAM_MASK,
706 daddr);
8df8c56a 707 pr_debug("dest: stateless compression mode %d dest %pI6c\n",
c8a3e7eb 708 iphc1 & LOWPAN_IPHC_DAM_MASK, &hdr.daddr);
5609c185 709 break;
8df8c56a
JR		 710 }
711
5609c185
AA		 712 if (err)
713 return -EINVAL;
714
cc6ed268 715 /* Next header data uncompression */
c8a3e7eb 716 if (iphc0 & LOWPAN_IPHC_NH) {
cc6ed268
AA		 717 err = lowpan_nhc_do_uncompression(skb, dev, &hdr);
718 if (err < 0)
11e3ff70 719 return err;
11e3ff70
MT		 720 } else {
721 err = skb_cow(skb, sizeof(hdr));
56b2c3ee 722 if (unlikely(err))
11e3ff70 723 return err;
8df8c56a
JR		 724 }
725
2e4d60cb 726 switch (lowpan_dev(dev)->lltype) {
72a5e6bb
AA		 727 case LOWPAN_LLTYPE_IEEE802154:
728 if (lowpan_802154_cb(skb)->d_size)
729 hdr.payload_len = htons(lowpan_802154_cb(skb)->d_size -
730 sizeof(struct ipv6hdr));
731 else
732 hdr.payload_len = htons(skb->len);
733 break;
734 default:
735 hdr.payload_len = htons(skb->len);
736 break;
737 }
8df8c56a
JR		 738
739 pr_debug("skb headroom size = %d, data length = %d\n",
740 skb_headroom(skb), skb->len);
741
742 pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n\t"
743 "nexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n",
744 hdr.version, ntohs(hdr.payload_len), hdr.nexthdr,
745 hdr.hop_limit, &hdr.daddr);
746
f8b36176
MT		 747 skb_push(skb, sizeof(hdr));
748 skb_reset_network_header(skb);
749 skb_copy_to_linear_data(skb, &hdr, sizeof(hdr));
8df8c56a 750
f8b36176 751 raw_dump_table(__func__, "raw header dump", (u8 *)&hdr, sizeof(hdr));
8df8c56a 752
f8b36176 753 return 0;
8df8c56a 754}
01141234 755EXPORT_SYMBOL_GPL(lowpan_header_decompress);
8df8c56a 756
c8a3e7eb
AA		 757static const u8 lowpan_iphc_dam_to_sam_value[] = {
758 [LOWPAN_IPHC_DAM_00] = LOWPAN_IPHC_SAM_00,
759 [LOWPAN_IPHC_DAM_01] = LOWPAN_IPHC_SAM_01,
760 [LOWPAN_IPHC_DAM_10] = LOWPAN_IPHC_SAM_10,
761 [LOWPAN_IPHC_DAM_11] = LOWPAN_IPHC_SAM_11,
762};
763
5609c185
AA		 764static u8 lowpan_compress_ctx_addr(u8 **hc_ptr, const struct in6_addr *ipaddr,
765 const struct lowpan_iphc_ctx *ctx,
766 const unsigned char *lladdr, bool sam)
767{
768 struct in6_addr tmp = {};
769 u8 dam;
770
771 /* check for SAM/DAM = 11 */
772 memcpy(&tmp.s6_addr[8], lladdr, 8);
773 /* second bit-flip (Universe/Local) is done according RFC2464 */
774 tmp.s6_addr[8] ^= 0x02;
775 /* context information are always used */
776 ipv6_addr_prefix_copy(&tmp, &ctx->pfx, ctx->plen);
777 if (ipv6_addr_equal(&tmp, ipaddr)) {
778 dam = LOWPAN_IPHC_DAM_11;
779 goto out;
780 }
781
782 memset(&tmp, 0, sizeof(tmp));
24c4a81d 783 /* check for SAM/DAM = 10 */
5609c185
AA		 784 tmp.s6_addr[11] = 0xFF;
785 tmp.s6_addr[12] = 0xFE;
786 memcpy(&tmp.s6_addr[14], &ipaddr->s6_addr[14], 2);
787 /* context information are always used */
788 ipv6_addr_prefix_copy(&tmp, &ctx->pfx, ctx->plen);
789 if (ipv6_addr_equal(&tmp, ipaddr)) {
790 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[14], 2);
791 dam = LOWPAN_IPHC_DAM_10;
792 goto out;
793 }
794
795 memset(&tmp, 0, sizeof(tmp));
24c4a81d 796 /* check for SAM/DAM = 01, should always match */
5609c185
AA		 797 memcpy(&tmp.s6_addr[8], &ipaddr->s6_addr[8], 8);
798 /* context information are always used */
799 ipv6_addr_prefix_copy(&tmp, &ctx->pfx, ctx->plen);
800 if (ipv6_addr_equal(&tmp, ipaddr)) {
801 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[8], 8);
802 dam = LOWPAN_IPHC_DAM_01;
803 goto out;
804 }
805
2306f656
AA		 806 WARN_ONCE(1, "context found but no address mode matched\n");
807 return LOWPAN_IPHC_DAM_00;
5609c185
AA		 808out:
809
810 if (sam)
811 return lowpan_iphc_dam_to_sam_value[dam];
812 else
813 return dam;
814}
815
c8a3e7eb
AA		 816static u8 lowpan_compress_addr_64(u8 **hc_ptr, const struct in6_addr *ipaddr,
817 const unsigned char *lladdr, bool sam)
8df8c56a 818{
c8a3e7eb 819 u8 dam = LOWPAN_IPHC_DAM_00;
8df8c56a
JR		 820
821 if (is_addr_mac_addr_based(ipaddr, lladdr)) {
c8a3e7eb 822 dam = LOWPAN_IPHC_DAM_11; /* 0-bits */
8df8c56a
JR		 823 pr_debug("address compression 0 bits\n");
824 } else if (lowpan_is_iid_16_bit_compressable(ipaddr)) {
825 /* compress IID to 16 bits xxxx::XXXX */
85c71240 826 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[7], 2);
c8a3e7eb 827 dam = LOWPAN_IPHC_DAM_10; /* 16-bits */
8df8c56a 828 raw_dump_inline(NULL, "Compressed ipv6 addr is (16 bits)",
84ca5e03 829 *hc_ptr - 2, 2);
8df8c56a
JR		 830 } else {
831 /* do not compress IID => xxxx::IID */
85c71240 832 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[4], 8);
c8a3e7eb 833 dam = LOWPAN_IPHC_DAM_01; /* 64-bits */
8df8c56a 834 raw_dump_inline(NULL, "Compressed ipv6 addr is (64 bits)",
84ca5e03 835 *hc_ptr - 8, 8);
8df8c56a
JR		 836 }
837
c8a3e7eb
AA		 838 if (sam)
839 return lowpan_iphc_dam_to_sam_value[dam];
840 else
841 return dam;
8df8c56a
JR		 842}
843
b5af9bdb
AA		 844/* lowpan_iphc_get_tc - get the ECN + DCSP fields in hc format */
845static inline u8 lowpan_iphc_get_tc(const struct ipv6hdr *hdr)
846{
847 u8 dscp, ecn;
848
849 /* hdr->priority contains the higher bits of dscp, lower are part of
850 * flow_lbl[0]. Note ECN, DCSP is swapped in ipv6 hdr.
851 */
852 dscp = (hdr->priority << 2) | ((hdr->flow_lbl[0] & 0xc0) >> 6);
853 /* ECN is at the two lower bits from first nibble of flow_lbl[0] */
854 ecn = (hdr->flow_lbl[0] & 0x30);
855 /* for pretty debug output, also shift ecn to get the ecn value */
856 pr_debug("ecn 0x%02x dscp 0x%02x\n", ecn >> 4, dscp);
857 /* ECN is at 0x30 now, shift it to have ECN + DCSP */
858 return (ecn << 2) | dscp;
859}
860
861/* lowpan_iphc_is_flow_lbl_zero - check if flow label is zero */
862static inline bool lowpan_iphc_is_flow_lbl_zero(const struct ipv6hdr *hdr)
863{
864 return ((!(hdr->flow_lbl[0] & 0x0f)) &&
865 !hdr->flow_lbl[1] && !hdr->flow_lbl[2]);
866}
867
868/* lowpan_iphc_tf_compress - compress the traffic class which is set by
869 * ipv6hdr. Return the corresponding format identifier which is used.
870 */
871static u8 lowpan_iphc_tf_compress(u8 **hc_ptr, const struct ipv6hdr *hdr)
872{
873 /* get ecn dscp data in a byteformat as: ECN(hi) + DSCP(lo) */
874 u8 tc = lowpan_iphc_get_tc(hdr), tf[4], val;
875
876 /* printout the traffic class in hc format */
877 pr_debug("tc 0x%02x\n", tc);
878
879 if (lowpan_iphc_is_flow_lbl_zero(hdr)) {
880 if (!tc) {
881 /* 11: Traffic Class and Flow Label are elided. */
882 val = LOWPAN_IPHC_TF_11;
883 } else {
884 /* 10: ECN + DSCP (1 byte), Flow Label is elided.
885 *
886 * 0 1 2 3 4 5 6 7
887 * +-+-+-+-+-+-+-+-+
888 * |ECN| DSCP |
889 * +-+-+-+-+-+-+-+-+
890 */
891 lowpan_push_hc_data(hc_ptr, &tc, sizeof(tc));
892 val = LOWPAN_IPHC_TF_10;
893 }
894 } else {
895 /* check if dscp is zero, it's after the first two bit */
896 if (!(tc & 0x3f)) {
897 /* 01: ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
898 *
899 * 1 2
900 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
901 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
902 * |ECN|rsv| Flow Label |
903 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
904 */
905 memcpy(&tf[0], &hdr->flow_lbl[0], 3);
906 /* zero the highest 4-bits, contains DCSP + ECN */
907 tf[0] &= ~0xf0;
908 /* set ECN */
909 tf[0] |= (tc & 0xc0);
910
911 lowpan_push_hc_data(hc_ptr, tf, 3);
912 val = LOWPAN_IPHC_TF_01;
913 } else {
914 /* 00: ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
915 *
916 * 1 2 3
917 * 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
918 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
919 * |ECN| DSCP | rsv | Flow Label |
920 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
921 */
922 memcpy(&tf[0], &tc, sizeof(tc));
923 /* highest nibble of flow_lbl[0] is part of DSCP + ECN
924 * which will be the 4-bit pad and will be filled with
925 * zeros afterwards.
926 */
927 memcpy(&tf[1], &hdr->flow_lbl[0], 3);
928 /* zero the 4-bit pad, which is reserved */
929 tf[1] &= ~0xf0;
930
931 lowpan_push_hc_data(hc_ptr, tf, 4);
932 val = LOWPAN_IPHC_TF_00;
933 }
934 }
935
936 return val;
937}
938
5609c185
AA		 939static u8 lowpan_iphc_mcast_ctx_addr_compress(u8 **hc_ptr,
940 const struct lowpan_iphc_ctx *ctx,
941 const struct in6_addr *ipaddr)
942{
943 u8 data[6];
944
945 /* flags/scope, reserved (RIID) */
946 memcpy(data, &ipaddr->s6_addr[1], 2);
947 /* group ID */
948 memcpy(&data[1], &ipaddr->s6_addr[11], 4);
949 lowpan_push_hc_data(hc_ptr, data, 6);
950
951 return LOWPAN_IPHC_DAM_00;
952}
953
09bf420f
AA		 954static u8 lowpan_iphc_mcast_addr_compress(u8 **hc_ptr,
955 const struct in6_addr *ipaddr)
956{
957 u8 val;
958
959 if (lowpan_is_mcast_addr_compressable8(ipaddr)) {
960 pr_debug("compressed to 1 octet\n");
961 /* use last byte */
962 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[15], 1);
963 val = LOWPAN_IPHC_DAM_11;
964 } else if (lowpan_is_mcast_addr_compressable32(ipaddr)) {
965 pr_debug("compressed to 4 octets\n");
966 /* second byte + the last three */
967 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[1], 1);
968 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[13], 3);
969 val = LOWPAN_IPHC_DAM_10;
970 } else if (lowpan_is_mcast_addr_compressable48(ipaddr)) {
971 pr_debug("compressed to 6 octets\n");
972 /* second byte + the last five */
973 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[1], 1);
974 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[11], 5);
975 val = LOWPAN_IPHC_DAM_01;
976 } else {
977 pr_debug("using full address\n");
978 lowpan_push_hc_data(hc_ptr, ipaddr->s6_addr, 16);
979 val = LOWPAN_IPHC_DAM_00;
980 }
981
982 return val;
983}
984
a6f77389
AA		 985int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
986 const void *daddr, const void *saddr)
8df8c56a 987{
5609c185 988 u8 iphc0, iphc1, *hc_ptr, cid = 0;
8df8c56a 989 struct ipv6hdr *hdr;
bf513fd6 990 u8 head[LOWPAN_IPHC_MAX_HC_BUF_LEN] = {};
5609c185
AA		 991 struct lowpan_iphc_ctx *dci, *sci, dci_entry, sci_entry;
992 int ret, ipv6_daddr_type, ipv6_saddr_type;
8df8c56a 993
a6f77389 994 if (skb->protocol != htons(ETH_P_IPV6))
8df8c56a
JR		 995 return -EINVAL;
996
997 hdr = ipv6_hdr(skb);
84ca5e03 998 hc_ptr = head + 2;
8df8c56a
JR		 999
1000 pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n"
1001 "\tnexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n",
4710d806
VB		 1002 hdr->version, ntohs(hdr->payload_len), hdr->nexthdr,
1003 hdr->hop_limit, &hdr->daddr);
8df8c56a
JR		 1004
1005 raw_dump_table(__func__, "raw skb network header dump",
4710d806 1006 skb_network_header(skb), sizeof(struct ipv6hdr));
8df8c56a 1007
4710d806 1008 /* As we copy some bit-length fields, in the IPHC encoding bytes,
8df8c56a
JR		 1009 * we sometimes use |=
1010 * If the field is 0, and the current bit value in memory is 1,
1011 * this does not work. We therefore reset the IPHC encoding here
1012 */
1013 iphc0 = LOWPAN_DISPATCH_IPHC;
1014 iphc1 = 0;
1015
a6f77389
AA		 1016 raw_dump_inline(__func__, "saddr", saddr, EUI64_ADDR_LEN);
1017 raw_dump_inline(__func__, "daddr", daddr, EUI64_ADDR_LEN);
8df8c56a 1018
7fc4cfda 1019 raw_dump_table(__func__, "sending raw skb network uncompressed packet",
4710d806 1020 skb->data, skb->len);
8df8c56a 1021
5609c185 1022 ipv6_daddr_type = ipv6_addr_type(&hdr->daddr);
2e4d60cb 1023 spin_lock_bh(&lowpan_dev(dev)->ctx.lock);
5609c185
AA		 1024 if (ipv6_daddr_type & IPV6_ADDR_MULTICAST)
1025 dci = lowpan_iphc_ctx_get_by_mcast_addr(dev, &hdr->daddr);
1026 else
1027 dci = lowpan_iphc_ctx_get_by_addr(dev, &hdr->daddr);
1028 if (dci) {
1029 memcpy(&dci_entry, dci, sizeof(*dci));
1030 cid |= dci->id;
1031 }
2e4d60cb 1032 spin_unlock_bh(&lowpan_dev(dev)->ctx.lock);
5609c185 1033
2e4d60cb 1034 spin_lock_bh(&lowpan_dev(dev)->ctx.lock);
5609c185
AA		 1035 sci = lowpan_iphc_ctx_get_by_addr(dev, &hdr->saddr);
1036 if (sci) {
1037 memcpy(&sci_entry, sci, sizeof(*sci));
1038 cid |= (sci->id << 4);
1039 }
2e4d60cb 1040 spin_unlock_bh(&lowpan_dev(dev)->ctx.lock);
5609c185
AA		 1041
1042 /* if cid is zero it will be compressed */
1043 if (cid) {
1044 iphc1 |= LOWPAN_IPHC_CID;
1045 lowpan_push_hc_data(&hc_ptr, &cid, sizeof(cid));
1046 }
1047
b5af9bdb
AA		 1048 /* Traffic Class, Flow Label compression */
1049 iphc0 |= lowpan_iphc_tf_compress(&hc_ptr, hdr);
8df8c56a
JR		 1050
1051 /* NOTE: payload length is always compressed */
1052
cc6ed268
AA		 1053 /* Check if we provide the nhc format for nexthdr and compression
1054 * functionality. If not nexthdr is handled inline and not compressed.
1055 */
607b0bd3
AA		 1056 ret = lowpan_nhc_check_compression(skb, hdr, &hc_ptr);
1057 if (ret == -ENOENT)
1058 lowpan_push_hc_data(&hc_ptr, &hdr->nexthdr,
1059 sizeof(hdr->nexthdr));
1060 else
c8a3e7eb 1061 iphc0 |= LOWPAN_IPHC_NH;
8df8c56a 1062
4710d806 1063 /* Hop limit
8df8c56a
JR		 1064 * if 1: compress, encoding is 01
1065 * if 64: compress, encoding is 10
1066 * if 255: compress, encoding is 11
1067 * else do not compress
1068 */
1069 switch (hdr->hop_limit) {
1070 case 1:
c8a3e7eb 1071 iphc0 |= LOWPAN_IPHC_HLIM_01;
8df8c56a
JR		 1072 break;
1073 case 64:
c8a3e7eb 1074 iphc0 |= LOWPAN_IPHC_HLIM_10;
8df8c56a
JR		 1075 break;
1076 case 255:
c8a3e7eb 1077 iphc0 |= LOWPAN_IPHC_HLIM_11;
8df8c56a
JR		 1078 break;
1079 default:
85c71240
AA		 1080 lowpan_push_hc_data(&hc_ptr, &hdr->hop_limit,
1081 sizeof(hdr->hop_limit));
8df8c56a
JR		 1082 }
1083
5609c185 1084 ipv6_saddr_type = ipv6_addr_type(&hdr->saddr);
8df8c56a 1085 /* source address compression */
5609c185 1086 if (ipv6_saddr_type == IPV6_ADDR_ANY) {
8df8c56a
JR		 1087 pr_debug("source address is unspecified, setting SAC\n");
1088 iphc1 |= LOWPAN_IPHC_SAC;
8df8c56a 1089 } else {
5609c185
AA		 1090 if (sci) {
1091 iphc1 |= lowpan_compress_ctx_addr(&hc_ptr, &hdr->saddr,
1092 &sci_entry, saddr,
1093 true);
1094 iphc1 |= LOWPAN_IPHC_SAC;
556a5bfc 1095 } else {
feb2add3
AA		 1096 if (ipv6_saddr_type & IPV6_ADDR_LINKLOCAL &&
1097 lowpan_is_linklocal_zero_padded(hdr->saddr)) {
5609c185
AA		 1098 iphc1 |= lowpan_compress_addr_64(&hc_ptr,
1099 &hdr->saddr,
1100 saddr, true);
1101 pr_debug("source address unicast link-local %pI6c iphc1 0x%02x\n",
1102 &hdr->saddr, iphc1);
1103 } else {
1104 pr_debug("send the full source address\n");
1105 lowpan_push_hc_data(&hc_ptr,
1106 hdr->saddr.s6_addr, 16);
1107 }
556a5bfc 1108 }
8df8c56a
JR		 1109 }
1110
1111 /* destination address compression */
5609c185 1112 if (ipv6_daddr_type & IPV6_ADDR_MULTICAST) {
8df8c56a 1113 pr_debug("destination address is multicast: ");
8790404d 1114 iphc1 |= LOWPAN_IPHC_M;
5609c185
AA		 1115 if (dci) {
1116 iphc1 |= lowpan_iphc_mcast_ctx_addr_compress(&hc_ptr,
1117 &dci_entry,
1118 &hdr->daddr);
8790404d 1119 iphc1 |= LOWPAN_IPHC_DAC;
5609c185 1120 } else {
5609c185
AA		 1121 iphc1 |= lowpan_iphc_mcast_addr_compress(&hc_ptr,
1122 &hdr->daddr);
1123 }
8df8c56a 1124 } else {
5609c185
AA		 1125 if (dci) {
1126 iphc1 |= lowpan_compress_ctx_addr(&hc_ptr, &hdr->daddr,
1127 &dci_entry, daddr,
1128 false);
1129 iphc1 |= LOWPAN_IPHC_DAC;
8df8c56a 1130 } else {
feb2add3
AA		 1131 if (ipv6_daddr_type & IPV6_ADDR_LINKLOCAL &&
1132 lowpan_is_linklocal_zero_padded(hdr->daddr)) {
5609c185
AA		 1133 iphc1 |= lowpan_compress_addr_64(&hc_ptr,
1134 &hdr->daddr,
1135 daddr, false);
1136 pr_debug("dest address unicast link-local %pI6c iphc1 0x%02x\n",
1137 &hdr->daddr, iphc1);
1138 } else {
1139 pr_debug("dest address unicast %pI6c\n",
1140 &hdr->daddr);
1141 lowpan_push_hc_data(&hc_ptr,
1142 hdr->daddr.s6_addr, 16);
1143 }
8df8c56a
JR		 1144 }
1145 }
1146
cc6ed268 1147 /* next header compression */
c8a3e7eb 1148 if (iphc0 & LOWPAN_IPHC_NH) {
cc6ed268
AA		 1149 ret = lowpan_nhc_do_compression(skb, hdr, &hc_ptr);
1150 if (ret < 0)
1151 return ret;
1152 }
8df8c56a
JR		 1153
1154 head[0] = iphc0;
1155 head[1] = iphc1;
1156
1157 skb_pull(skb, sizeof(struct ipv6hdr));
1158 skb_reset_transport_header(skb);
84ca5e03 1159 memcpy(skb_push(skb, hc_ptr - head), head, hc_ptr - head);
8df8c56a
JR		 1160 skb_reset_network_header(skb);
1161
84ca5e03 1162 pr_debug("header len %d skb %u\n", (int)(hc_ptr - head), skb->len);
8df8c56a
JR		 1163
1164 raw_dump_table(__func__, "raw skb data dump compressed",
4710d806 1165 skb->data, skb->len);
8df8c56a
JR		 1166 return 0;
1167}
1168EXPORT_SYMBOL_GPL(lowpan_header_compress);
Linux 6.x block layer and io_uring tree(s)