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Jukka Rissanen8df8c562013-12-11 17:05:34 +02001/*
2 * Copyright 2011, Siemens AG
3 * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
4 */
5
6/*
7 * Based on patches from Jon Smirl <jonsmirl@gmail.com>
8 * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2
12 * as published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
22 */
23
24/* Jon's code is based on 6lowpan implementation for Contiki which is:
25 * Copyright (c) 2008, Swedish Institute of Computer Science.
26 * All rights reserved.
27 *
28 * Redistribution and use in source and binary forms, with or without
29 * modification, are permitted provided that the following conditions
30 * are met:
31 * 1. Redistributions of source code must retain the above copyright
32 * notice, this list of conditions and the following disclaimer.
33 * 2. Redistributions in binary form must reproduce the above copyright
34 * notice, this list of conditions and the following disclaimer in the
35 * documentation and/or other materials provided with the distribution.
36 * 3. Neither the name of the Institute nor the names of its contributors
37 * may be used to endorse or promote products derived from this software
38 * without specific prior written permission.
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50 * SUCH DAMAGE.
51 */
52
53#include <linux/bitops.h>
54#include <linux/if_arp.h>
Yann Droneaud5ae5e992014-01-22 20:25:24 +010055#include <linux/module.h>
Jukka Rissanen8df8c562013-12-11 17:05:34 +020056#include <linux/netdevice.h>
Alexander Aringcefc8c82014-03-05 14:29:05 +010057#include <net/6lowpan.h>
Jukka Rissanen8df8c562013-12-11 17:05:34 +020058#include <net/ipv6.h>
59#include <net/af_ieee802154.h>
60
Jukka Rissanen8df8c562013-12-11 17:05:34 +020061/*
62 * Uncompress address function for source and
63 * destination address(non-multicast).
64 *
65 * address_mode is sam value or dam value.
66 */
67static int uncompress_addr(struct sk_buff *skb,
68 struct in6_addr *ipaddr, const u8 address_mode,
69 const u8 *lladdr, const u8 addr_type,
70 const u8 addr_len)
71{
72 bool fail;
73
74 switch (address_mode) {
75 case LOWPAN_IPHC_ADDR_00:
76 /* for global link addresses */
77 fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
78 break;
79 case LOWPAN_IPHC_ADDR_01:
80 /* fe:80::XXXX:XXXX:XXXX:XXXX */
81 ipaddr->s6_addr[0] = 0xFE;
82 ipaddr->s6_addr[1] = 0x80;
83 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[8], 8);
84 break;
85 case LOWPAN_IPHC_ADDR_02:
86 /* fe:80::ff:fe00:XXXX */
87 ipaddr->s6_addr[0] = 0xFE;
88 ipaddr->s6_addr[1] = 0x80;
89 ipaddr->s6_addr[11] = 0xFF;
90 ipaddr->s6_addr[12] = 0xFE;
91 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2);
92 break;
93 case LOWPAN_IPHC_ADDR_03:
94 fail = false;
95 switch (addr_type) {
96 case IEEE802154_ADDR_LONG:
97 /* fe:80::XXXX:XXXX:XXXX:XXXX
98 * \_________________/
99 * hwaddr
100 */
101 ipaddr->s6_addr[0] = 0xFE;
102 ipaddr->s6_addr[1] = 0x80;
103 memcpy(&ipaddr->s6_addr[8], lladdr, addr_len);
104 /* second bit-flip (Universe/Local)
105 * is done according RFC2464
106 */
107 ipaddr->s6_addr[8] ^= 0x02;
108 break;
109 case IEEE802154_ADDR_SHORT:
110 /* fe:80::ff:fe00:XXXX
111 * \__/
112 * short_addr
113 *
114 * Universe/Local bit is zero.
115 */
116 ipaddr->s6_addr[0] = 0xFE;
117 ipaddr->s6_addr[1] = 0x80;
118 ipaddr->s6_addr[11] = 0xFF;
119 ipaddr->s6_addr[12] = 0xFE;
120 ipaddr->s6_addr16[7] = htons(*((u16 *)lladdr));
121 break;
122 default:
123 pr_debug("Invalid addr_type set\n");
124 return -EINVAL;
125 }
126 break;
127 default:
128 pr_debug("Invalid address mode value: 0x%x\n", address_mode);
129 return -EINVAL;
130 }
131
132 if (fail) {
133 pr_debug("Failed to fetch skb data\n");
134 return -EIO;
135 }
136
137 raw_dump_inline(NULL, "Reconstructed ipv6 addr is",
138 ipaddr->s6_addr, 16);
139
140 return 0;
141}
142
143/*
144 * Uncompress address function for source context
145 * based address(non-multicast).
146 */
147static int uncompress_context_based_src_addr(struct sk_buff *skb,
148 struct in6_addr *ipaddr,
149 const u8 sam)
150{
151 switch (sam) {
152 case LOWPAN_IPHC_ADDR_00:
153 /* unspec address ::
154 * Do nothing, address is already ::
155 */
156 break;
157 case LOWPAN_IPHC_ADDR_01:
158 /* TODO */
159 case LOWPAN_IPHC_ADDR_02:
160 /* TODO */
161 case LOWPAN_IPHC_ADDR_03:
162 /* TODO */
163 netdev_warn(skb->dev, "SAM value 0x%x not supported\n", sam);
164 return -EINVAL;
165 default:
166 pr_debug("Invalid sam value: 0x%x\n", sam);
167 return -EINVAL;
168 }
169
170 raw_dump_inline(NULL,
171 "Reconstructed context based ipv6 src addr is",
172 ipaddr->s6_addr, 16);
173
174 return 0;
175}
176
177static int skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr,
178 struct net_device *dev, skb_delivery_cb deliver_skb)
179{
180 struct sk_buff *new;
181 int stat;
182
183 new = skb_copy_expand(skb, sizeof(struct ipv6hdr), skb_tailroom(skb),
184 GFP_ATOMIC);
185 kfree_skb(skb);
186
187 if (!new)
188 return -ENOMEM;
189
190 skb_push(new, sizeof(struct ipv6hdr));
191 skb_reset_network_header(new);
192 skb_copy_to_linear_data(new, hdr, sizeof(struct ipv6hdr));
193
194 new->protocol = htons(ETH_P_IPV6);
195 new->pkt_type = PACKET_HOST;
196 new->dev = dev;
197
198 raw_dump_table(__func__, "raw skb data dump before receiving",
199 new->data, new->len);
200
201 stat = deliver_skb(new, dev);
202
203 kfree_skb(new);
204
205 return stat;
206}
207
208/* Uncompress function for multicast destination address,
209 * when M bit is set.
210 */
211static int
212lowpan_uncompress_multicast_daddr(struct sk_buff *skb,
213 struct in6_addr *ipaddr,
214 const u8 dam)
215{
216 bool fail;
217
218 switch (dam) {
219 case LOWPAN_IPHC_DAM_00:
220 /* 00: 128 bits. The full address
221 * is carried in-line.
222 */
223 fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
224 break;
225 case LOWPAN_IPHC_DAM_01:
226 /* 01: 48 bits. The address takes
227 * the form ffXX::00XX:XXXX:XXXX.
228 */
229 ipaddr->s6_addr[0] = 0xFF;
230 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
231 fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[11], 5);
232 break;
233 case LOWPAN_IPHC_DAM_10:
234 /* 10: 32 bits. The address takes
235 * the form ffXX::00XX:XXXX.
236 */
237 ipaddr->s6_addr[0] = 0xFF;
238 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1);
239 fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[13], 3);
240 break;
241 case LOWPAN_IPHC_DAM_11:
242 /* 11: 8 bits. The address takes
243 * the form ff02::00XX.
244 */
245 ipaddr->s6_addr[0] = 0xFF;
246 ipaddr->s6_addr[1] = 0x02;
247 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[15], 1);
248 break;
249 default:
250 pr_debug("DAM value has a wrong value: 0x%x\n", dam);
251 return -EINVAL;
252 }
253
254 if (fail) {
255 pr_debug("Failed to fetch skb data\n");
256 return -EIO;
257 }
258
259 raw_dump_inline(NULL, "Reconstructed ipv6 multicast addr is",
260 ipaddr->s6_addr, 16);
261
262 return 0;
263}
264
265static int
266uncompress_udp_header(struct sk_buff *skb, struct udphdr *uh)
267{
Alexander Aring1672a362013-12-17 14:21:26 +0100268 bool fail;
269 u8 tmp = 0, val = 0;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200270
271 if (!uh)
272 goto err;
273
Alexander Aring8ec1d9b2014-07-29 23:46:59 +0200274 fail = lowpan_fetch_skb(skb, &tmp, sizeof(tmp));
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200275
276 if ((tmp & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
277 pr_debug("UDP header uncompression\n");
278 switch (tmp & LOWPAN_NHC_UDP_CS_P_11) {
279 case LOWPAN_NHC_UDP_CS_P_00:
Alexander Aring8ec1d9b2014-07-29 23:46:59 +0200280 fail |= lowpan_fetch_skb(skb, &uh->source,
281 sizeof(uh->source));
282 fail |= lowpan_fetch_skb(skb, &uh->dest,
283 sizeof(uh->dest));
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200284 break;
285 case LOWPAN_NHC_UDP_CS_P_01:
Alexander Aring8ec1d9b2014-07-29 23:46:59 +0200286 fail |= lowpan_fetch_skb(skb, &uh->source,
287 sizeof(uh->source));
288 fail |= lowpan_fetch_skb(skb, &val, sizeof(val));
Alexander Aring1672a362013-12-17 14:21:26 +0100289 uh->dest = htons(val + LOWPAN_NHC_UDP_8BIT_PORT);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200290 break;
291 case LOWPAN_NHC_UDP_CS_P_10:
Alexander Aring8ec1d9b2014-07-29 23:46:59 +0200292 fail |= lowpan_fetch_skb(skb, &val, sizeof(val));
Alexander Aring1672a362013-12-17 14:21:26 +0100293 uh->source = htons(val + LOWPAN_NHC_UDP_8BIT_PORT);
Alexander Aring8ec1d9b2014-07-29 23:46:59 +0200294 fail |= lowpan_fetch_skb(skb, &uh->dest,
295 sizeof(uh->dest));
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200296 break;
297 case LOWPAN_NHC_UDP_CS_P_11:
Alexander Aring8ec1d9b2014-07-29 23:46:59 +0200298 fail |= lowpan_fetch_skb(skb, &val, sizeof(val));
Alexander Aringe5d966ef2013-12-17 14:21:24 +0100299 uh->source = htons(LOWPAN_NHC_UDP_4BIT_PORT +
Alexander Aring1672a362013-12-17 14:21:26 +0100300 (val >> 4));
Alexander Aringe5d966ef2013-12-17 14:21:24 +0100301 uh->dest = htons(LOWPAN_NHC_UDP_4BIT_PORT +
Alexander Aring1672a362013-12-17 14:21:26 +0100302 (val & 0x0f));
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200303 break;
304 default:
305 pr_debug("ERROR: unknown UDP format\n");
306 goto err;
307 break;
308 }
309
310 pr_debug("uncompressed UDP ports: src = %d, dst = %d\n",
Alexander Aringe5d966ef2013-12-17 14:21:24 +0100311 ntohs(uh->source), ntohs(uh->dest));
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200312
Alexander Aring573701c2013-12-17 14:21:25 +0100313 /* checksum */
314 if (tmp & LOWPAN_NHC_UDP_CS_C) {
315 pr_debug_ratelimited("checksum elided currently not supported\n");
316 goto err;
317 } else {
Alexander Aring8ec1d9b2014-07-29 23:46:59 +0200318 fail |= lowpan_fetch_skb(skb, &uh->check,
319 sizeof(uh->check));
Alexander Aring573701c2013-12-17 14:21:25 +0100320 }
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200321
322 /*
323 * UDP lenght needs to be infered from the lower layers
324 * here, we obtain the hint from the remaining size of the
325 * frame
326 */
327 uh->len = htons(skb->len + sizeof(struct udphdr));
Alexander Aringe5d966ef2013-12-17 14:21:24 +0100328 pr_debug("uncompressed UDP length: src = %d", ntohs(uh->len));
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200329 } else {
330 pr_debug("ERROR: unsupported NH format\n");
331 goto err;
332 }
333
Alexander Aring1672a362013-12-17 14:21:26 +0100334 if (fail)
335 goto err;
336
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200337 return 0;
338err:
339 return -EINVAL;
340}
341
342/* TTL uncompression values */
343static const u8 lowpan_ttl_values[] = { 0, 1, 64, 255 };
344
345int lowpan_process_data(struct sk_buff *skb, struct net_device *dev,
346 const u8 *saddr, const u8 saddr_type, const u8 saddr_len,
347 const u8 *daddr, const u8 daddr_type, const u8 daddr_len,
348 u8 iphc0, u8 iphc1, skb_delivery_cb deliver_skb)
349{
350 struct ipv6hdr hdr = {};
351 u8 tmp, num_context = 0;
352 int err;
353
354 raw_dump_table(__func__, "raw skb data dump uncompressed",
355 skb->data, skb->len);
356
357 /* another if the CID flag is set */
358 if (iphc1 & LOWPAN_IPHC_CID) {
359 pr_debug("CID flag is set, increase header with one\n");
Alexander Aring4ebc9602014-07-29 23:47:00 +0200360 if (lowpan_fetch_skb(skb, &num_context, sizeof(num_context)))
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200361 goto drop;
362 }
363
364 hdr.version = 6;
365
366 /* Traffic Class and Flow Label */
367 switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
368 /*
369 * Traffic Class and FLow Label carried in-line
370 * ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
371 */
372 case 0: /* 00b */
Alexander Aring4ebc9602014-07-29 23:47:00 +0200373 if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp)))
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200374 goto drop;
375
376 memcpy(&hdr.flow_lbl, &skb->data[0], 3);
377 skb_pull(skb, 3);
378 hdr.priority = ((tmp >> 2) & 0x0f);
379 hdr.flow_lbl[0] = ((tmp >> 2) & 0x30) | (tmp << 6) |
380 (hdr.flow_lbl[0] & 0x0f);
381 break;
382 /*
383 * Traffic class carried in-line
384 * ECN + DSCP (1 byte), Flow Label is elided
385 */
386 case 2: /* 10b */
Alexander Aring4ebc9602014-07-29 23:47:00 +0200387 if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp)))
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200388 goto drop;
389
390 hdr.priority = ((tmp >> 2) & 0x0f);
391 hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30);
392 break;
393 /*
394 * Flow Label carried in-line
395 * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
396 */
397 case 1: /* 01b */
Alexander Aring4ebc9602014-07-29 23:47:00 +0200398 if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp)))
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200399 goto drop;
400
401 hdr.flow_lbl[0] = (skb->data[0] & 0x0F) | ((tmp >> 2) & 0x30);
402 memcpy(&hdr.flow_lbl[1], &skb->data[0], 2);
403 skb_pull(skb, 2);
404 break;
405 /* Traffic Class and Flow Label are elided */
406 case 3: /* 11b */
407 break;
408 default:
409 break;
410 }
411
412 /* Next Header */
413 if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
414 /* Next header is carried inline */
Alexander Aring4ebc9602014-07-29 23:47:00 +0200415 if (lowpan_fetch_skb(skb, &hdr.nexthdr, sizeof(hdr.nexthdr)))
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200416 goto drop;
417
418 pr_debug("NH flag is set, next header carried inline: %02x\n",
419 hdr.nexthdr);
420 }
421
422 /* Hop Limit */
423 if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I)
424 hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03];
425 else {
Alexander Aring4ebc9602014-07-29 23:47:00 +0200426 if (lowpan_fetch_skb(skb, &hdr.hop_limit,
427 sizeof(hdr.hop_limit)))
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200428 goto drop;
429 }
430
431 /* Extract SAM to the tmp variable */
432 tmp = ((iphc1 & LOWPAN_IPHC_SAM) >> LOWPAN_IPHC_SAM_BIT) & 0x03;
433
434 if (iphc1 & LOWPAN_IPHC_SAC) {
435 /* Source address context based uncompression */
436 pr_debug("SAC bit is set. Handle context based source address.\n");
437 err = uncompress_context_based_src_addr(
438 skb, &hdr.saddr, tmp);
439 } else {
440 /* Source address uncompression */
441 pr_debug("source address stateless compression\n");
442 err = uncompress_addr(skb, &hdr.saddr, tmp, saddr,
443 saddr_type, saddr_len);
444 }
445
446 /* Check on error of previous branch */
447 if (err)
448 goto drop;
449
450 /* Extract DAM to the tmp variable */
451 tmp = ((iphc1 & LOWPAN_IPHC_DAM_11) >> LOWPAN_IPHC_DAM_BIT) & 0x03;
452
453 /* check for Multicast Compression */
454 if (iphc1 & LOWPAN_IPHC_M) {
455 if (iphc1 & LOWPAN_IPHC_DAC) {
456 pr_debug("dest: context-based mcast compression\n");
457 /* TODO: implement this */
458 } else {
459 err = lowpan_uncompress_multicast_daddr(
460 skb, &hdr.daddr, tmp);
461 if (err)
462 goto drop;
463 }
464 } else {
465 err = uncompress_addr(skb, &hdr.daddr, tmp, daddr,
466 daddr_type, daddr_len);
467 pr_debug("dest: stateless compression mode %d dest %pI6c\n",
468 tmp, &hdr.daddr);
469 if (err)
470 goto drop;
471 }
472
473 /* UDP data uncompression */
474 if (iphc0 & LOWPAN_IPHC_NH_C) {
475 struct udphdr uh;
476 struct sk_buff *new;
477 if (uncompress_udp_header(skb, &uh))
478 goto drop;
479
480 /*
481 * replace the compressed UDP head by the uncompressed UDP
482 * header
483 */
484 new = skb_copy_expand(skb, sizeof(struct udphdr),
485 skb_tailroom(skb), GFP_ATOMIC);
486 kfree_skb(skb);
487
488 if (!new)
489 return -ENOMEM;
490
491 skb = new;
492
493 skb_push(skb, sizeof(struct udphdr));
494 skb_reset_transport_header(skb);
495 skb_copy_to_linear_data(skb, &uh, sizeof(struct udphdr));
496
497 raw_dump_table(__func__, "raw UDP header dump",
498 (u8 *)&uh, sizeof(uh));
499
500 hdr.nexthdr = UIP_PROTO_UDP;
501 }
502
503 hdr.payload_len = htons(skb->len);
504
505 pr_debug("skb headroom size = %d, data length = %d\n",
506 skb_headroom(skb), skb->len);
507
508 pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n\t"
509 "nexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n",
510 hdr.version, ntohs(hdr.payload_len), hdr.nexthdr,
511 hdr.hop_limit, &hdr.daddr);
512
513 raw_dump_table(__func__, "raw header dump", (u8 *)&hdr,
514 sizeof(hdr));
515
516 return skb_deliver(skb, &hdr, dev, deliver_skb);
517
518drop:
519 kfree_skb(skb);
520 return -EINVAL;
521}
522EXPORT_SYMBOL_GPL(lowpan_process_data);
523
Alexander Aring84ca5e02014-07-29 23:46:58 +0200524static u8 lowpan_compress_addr_64(u8 **hc_ptr, u8 shift,
525 const struct in6_addr *ipaddr,
526 const unsigned char *lladdr)
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200527{
528 u8 val = 0;
529
530 if (is_addr_mac_addr_based(ipaddr, lladdr)) {
531 val = 3; /* 0-bits */
532 pr_debug("address compression 0 bits\n");
533 } else if (lowpan_is_iid_16_bit_compressable(ipaddr)) {
534 /* compress IID to 16 bits xxxx::XXXX */
Alexander Aring85c71242014-07-29 23:47:01 +0200535 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[7], 2);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200536 val = 2; /* 16-bits */
537 raw_dump_inline(NULL, "Compressed ipv6 addr is (16 bits)",
Alexander Aring84ca5e02014-07-29 23:46:58 +0200538 *hc_ptr - 2, 2);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200539 } else {
540 /* do not compress IID => xxxx::IID */
Alexander Aring85c71242014-07-29 23:47:01 +0200541 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[4], 8);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200542 val = 1; /* 64-bits */
543 raw_dump_inline(NULL, "Compressed ipv6 addr is (64 bits)",
Alexander Aring84ca5e02014-07-29 23:46:58 +0200544 *hc_ptr - 8, 8);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200545 }
546
547 return rol8(val, shift);
548}
549
Alexander Aring84ca5e02014-07-29 23:46:58 +0200550static void compress_udp_header(u8 **hc_ptr, struct sk_buff *skb)
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200551{
552 struct udphdr *uh = udp_hdr(skb);
Alexander Aring5cede842013-12-17 14:21:22 +0100553 u8 tmp;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200554
Alexander Aringe5d966ef2013-12-17 14:21:24 +0100555 if (((ntohs(uh->source) & LOWPAN_NHC_UDP_4BIT_MASK) ==
556 LOWPAN_NHC_UDP_4BIT_PORT) &&
557 ((ntohs(uh->dest) & LOWPAN_NHC_UDP_4BIT_MASK) ==
558 LOWPAN_NHC_UDP_4BIT_PORT)) {
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200559 pr_debug("UDP header: both ports compression to 4 bits\n");
Alexander Aringc567c772013-12-17 14:21:28 +0100560 /* compression value */
Alexander Aring5cede842013-12-17 14:21:22 +0100561 tmp = LOWPAN_NHC_UDP_CS_P_11;
Alexander Aring84ca5e02014-07-29 23:46:58 +0200562 lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
Alexander Aringc567c772013-12-17 14:21:28 +0100563 /* source and destination port */
564 tmp = ntohs(uh->dest) - LOWPAN_NHC_UDP_4BIT_PORT +
565 ((ntohs(uh->source) - LOWPAN_NHC_UDP_4BIT_PORT) << 4);
Alexander Aring84ca5e02014-07-29 23:46:58 +0200566 lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
Alexander Aringe5d966ef2013-12-17 14:21:24 +0100567 } else if ((ntohs(uh->dest) & LOWPAN_NHC_UDP_8BIT_MASK) ==
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200568 LOWPAN_NHC_UDP_8BIT_PORT) {
569 pr_debug("UDP header: remove 8 bits of dest\n");
Alexander Aringc567c772013-12-17 14:21:28 +0100570 /* compression value */
Alexander Aring5cede842013-12-17 14:21:22 +0100571 tmp = LOWPAN_NHC_UDP_CS_P_01;
Alexander Aring84ca5e02014-07-29 23:46:58 +0200572 lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
Alexander Aringc567c772013-12-17 14:21:28 +0100573 /* source port */
Alexander Aring84ca5e02014-07-29 23:46:58 +0200574 lowpan_push_hc_data(hc_ptr, &uh->source, sizeof(uh->source));
Alexander Aringc567c772013-12-17 14:21:28 +0100575 /* destination port */
576 tmp = ntohs(uh->dest) - LOWPAN_NHC_UDP_8BIT_PORT;
Alexander Aring84ca5e02014-07-29 23:46:58 +0200577 lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
Alexander Aringe5d966ef2013-12-17 14:21:24 +0100578 } else if ((ntohs(uh->source) & LOWPAN_NHC_UDP_8BIT_MASK) ==
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200579 LOWPAN_NHC_UDP_8BIT_PORT) {
580 pr_debug("UDP header: remove 8 bits of source\n");
Alexander Aringc567c772013-12-17 14:21:28 +0100581 /* compression value */
Alexander Aring5cede842013-12-17 14:21:22 +0100582 tmp = LOWPAN_NHC_UDP_CS_P_10;
Alexander Aring84ca5e02014-07-29 23:46:58 +0200583 lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
Alexander Aringc567c772013-12-17 14:21:28 +0100584 /* source port */
585 tmp = ntohs(uh->source) - LOWPAN_NHC_UDP_8BIT_PORT;
Alexander Aring84ca5e02014-07-29 23:46:58 +0200586 lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
Alexander Aringc567c772013-12-17 14:21:28 +0100587 /* destination port */
Alexander Aring84ca5e02014-07-29 23:46:58 +0200588 lowpan_push_hc_data(hc_ptr, &uh->dest, sizeof(uh->dest));
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200589 } else {
590 pr_debug("UDP header: can't compress\n");
Alexander Aringc567c772013-12-17 14:21:28 +0100591 /* compression value */
Alexander Aring5cede842013-12-17 14:21:22 +0100592 tmp = LOWPAN_NHC_UDP_CS_P_00;
Alexander Aring84ca5e02014-07-29 23:46:58 +0200593 lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
Alexander Aringc567c772013-12-17 14:21:28 +0100594 /* source port */
Alexander Aring84ca5e02014-07-29 23:46:58 +0200595 lowpan_push_hc_data(hc_ptr, &uh->source, sizeof(uh->source));
Alexander Aringc567c772013-12-17 14:21:28 +0100596 /* destination port */
Alexander Aring84ca5e02014-07-29 23:46:58 +0200597 lowpan_push_hc_data(hc_ptr, &uh->dest, sizeof(uh->dest));
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200598 }
599
600 /* checksum is always inline */
Alexander Aring84ca5e02014-07-29 23:46:58 +0200601 lowpan_push_hc_data(hc_ptr, &uh->check, sizeof(uh->check));
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200602
603 /* skip the UDP header */
604 skb_pull(skb, sizeof(struct udphdr));
605}
606
607int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
608 unsigned short type, const void *_daddr,
609 const void *_saddr, unsigned int len)
610{
Alexander Aring84ca5e02014-07-29 23:46:58 +0200611 u8 tmp, iphc0, iphc1, *hc_ptr;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200612 struct ipv6hdr *hdr;
613 u8 head[100] = {};
Alexander Aring556a5bf2014-07-29 23:47:02 +0200614 int addr_type;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200615
616 if (type != ETH_P_IPV6)
617 return -EINVAL;
618
619 hdr = ipv6_hdr(skb);
Alexander Aring84ca5e02014-07-29 23:46:58 +0200620 hc_ptr = head + 2;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200621
622 pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n"
623 "\tnexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n",
624 hdr->version, ntohs(hdr->payload_len), hdr->nexthdr,
625 hdr->hop_limit, &hdr->daddr);
626
627 raw_dump_table(__func__, "raw skb network header dump",
628 skb_network_header(skb), sizeof(struct ipv6hdr));
629
630 /*
631 * As we copy some bit-length fields, in the IPHC encoding bytes,
632 * we sometimes use |=
633 * If the field is 0, and the current bit value in memory is 1,
634 * this does not work. We therefore reset the IPHC encoding here
635 */
636 iphc0 = LOWPAN_DISPATCH_IPHC;
637 iphc1 = 0;
638
639 /* TODO: context lookup */
640
641 raw_dump_inline(__func__, "saddr",
642 (unsigned char *)_saddr, IEEE802154_ADDR_LEN);
643 raw_dump_inline(__func__, "daddr",
644 (unsigned char *)_daddr, IEEE802154_ADDR_LEN);
645
646 raw_dump_table(__func__,
647 "sending raw skb network uncompressed packet",
648 skb->data, skb->len);
649
650 /*
651 * Traffic class, flow label
652 * If flow label is 0, compress it. If traffic class is 0, compress it
653 * We have to process both in the same time as the offset of traffic
654 * class depends on the presence of version and flow label
655 */
656
Alexander Aring84ca5e02014-07-29 23:46:58 +0200657 /* hc format of TC is ECN | DSCP , original one is DSCP | ECN */
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200658 tmp = (hdr->priority << 4) | (hdr->flow_lbl[0] >> 4);
659 tmp = ((tmp & 0x03) << 6) | (tmp >> 2);
660
661 if (((hdr->flow_lbl[0] & 0x0F) == 0) &&
662 (hdr->flow_lbl[1] == 0) && (hdr->flow_lbl[2] == 0)) {
663 /* flow label can be compressed */
664 iphc0 |= LOWPAN_IPHC_FL_C;
665 if ((hdr->priority == 0) &&
666 ((hdr->flow_lbl[0] & 0xF0) == 0)) {
667 /* compress (elide) all */
668 iphc0 |= LOWPAN_IPHC_TC_C;
669 } else {
670 /* compress only the flow label */
Alexander Aring84ca5e02014-07-29 23:46:58 +0200671 *hc_ptr = tmp;
672 hc_ptr += 1;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200673 }
674 } else {
675 /* Flow label cannot be compressed */
676 if ((hdr->priority == 0) &&
677 ((hdr->flow_lbl[0] & 0xF0) == 0)) {
678 /* compress only traffic class */
679 iphc0 |= LOWPAN_IPHC_TC_C;
Alexander Aring84ca5e02014-07-29 23:46:58 +0200680 *hc_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F);
681 memcpy(hc_ptr + 1, &hdr->flow_lbl[1], 2);
682 hc_ptr += 3;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200683 } else {
684 /* compress nothing */
Alexander Aring84ca5e02014-07-29 23:46:58 +0200685 memcpy(hc_ptr, hdr, 4);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200686 /* replace the top byte with new ECN | DSCP format */
Alexander Aring84ca5e02014-07-29 23:46:58 +0200687 *hc_ptr = tmp;
688 hc_ptr += 4;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200689 }
690 }
691
692 /* NOTE: payload length is always compressed */
693
694 /* Next Header is compress if UDP */
695 if (hdr->nexthdr == UIP_PROTO_UDP)
696 iphc0 |= LOWPAN_IPHC_NH_C;
697
Alexander Aring85c71242014-07-29 23:47:01 +0200698 if ((iphc0 & LOWPAN_IPHC_NH_C) == 0)
699 lowpan_push_hc_data(&hc_ptr, &hdr->nexthdr,
700 sizeof(hdr->nexthdr));
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200701
702 /*
703 * Hop limit
704 * if 1: compress, encoding is 01
705 * if 64: compress, encoding is 10
706 * if 255: compress, encoding is 11
707 * else do not compress
708 */
709 switch (hdr->hop_limit) {
710 case 1:
711 iphc0 |= LOWPAN_IPHC_TTL_1;
712 break;
713 case 64:
714 iphc0 |= LOWPAN_IPHC_TTL_64;
715 break;
716 case 255:
717 iphc0 |= LOWPAN_IPHC_TTL_255;
718 break;
719 default:
Alexander Aring85c71242014-07-29 23:47:01 +0200720 lowpan_push_hc_data(&hc_ptr, &hdr->hop_limit,
721 sizeof(hdr->hop_limit));
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200722 }
723
Alexander Aring556a5bf2014-07-29 23:47:02 +0200724 addr_type = ipv6_addr_type(&hdr->saddr);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200725 /* source address compression */
Alexander Aring556a5bf2014-07-29 23:47:02 +0200726 if (addr_type == IPV6_ADDR_ANY) {
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200727 pr_debug("source address is unspecified, setting SAC\n");
728 iphc1 |= LOWPAN_IPHC_SAC;
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200729 } else {
Alexander Aring556a5bf2014-07-29 23:47:02 +0200730 if (addr_type & IPV6_ADDR_LINKLOCAL) {
731 iphc1 |= lowpan_compress_addr_64(&hc_ptr,
732 LOWPAN_IPHC_SAM_BIT,
733 &hdr->saddr, _saddr);
734 pr_debug("source address unicast link-local %pI6c iphc1 0x%02x\n",
735 &hdr->saddr, iphc1);
736 } else {
737 pr_debug("send the full source address\n");
738 lowpan_push_hc_data(&hc_ptr, hdr->saddr.s6_addr, 16);
739 }
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200740 }
741
Alexander Aring556a5bf2014-07-29 23:47:02 +0200742 addr_type = ipv6_addr_type(&hdr->daddr);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200743 /* destination address compression */
Alexander Aring556a5bf2014-07-29 23:47:02 +0200744 if (addr_type & IPV6_ADDR_MULTICAST) {
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200745 pr_debug("destination address is multicast: ");
746 iphc1 |= LOWPAN_IPHC_M;
747 if (lowpan_is_mcast_addr_compressable8(&hdr->daddr)) {
748 pr_debug("compressed to 1 octet\n");
749 iphc1 |= LOWPAN_IPHC_DAM_11;
750 /* use last byte */
Alexander Aring85c71242014-07-29 23:47:01 +0200751 lowpan_push_hc_data(&hc_ptr,
752 &hdr->daddr.s6_addr[15], 1);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200753 } else if (lowpan_is_mcast_addr_compressable32(&hdr->daddr)) {
754 pr_debug("compressed to 4 octets\n");
755 iphc1 |= LOWPAN_IPHC_DAM_10;
756 /* second byte + the last three */
Alexander Aring85c71242014-07-29 23:47:01 +0200757 lowpan_push_hc_data(&hc_ptr,
758 &hdr->daddr.s6_addr[1], 1);
759 lowpan_push_hc_data(&hc_ptr,
760 &hdr->daddr.s6_addr[13], 3);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200761 } else if (lowpan_is_mcast_addr_compressable48(&hdr->daddr)) {
762 pr_debug("compressed to 6 octets\n");
763 iphc1 |= LOWPAN_IPHC_DAM_01;
764 /* second byte + the last five */
Alexander Aring85c71242014-07-29 23:47:01 +0200765 lowpan_push_hc_data(&hc_ptr,
766 &hdr->daddr.s6_addr[1], 1);
767 lowpan_push_hc_data(&hc_ptr,
768 &hdr->daddr.s6_addr[11], 5);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200769 } else {
770 pr_debug("using full address\n");
771 iphc1 |= LOWPAN_IPHC_DAM_00;
Alexander Aring85c71242014-07-29 23:47:01 +0200772 lowpan_push_hc_data(&hc_ptr, hdr->daddr.s6_addr, 16);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200773 }
774 } else {
Alexander Aring556a5bf2014-07-29 23:47:02 +0200775 if (addr_type & IPV6_ADDR_LINKLOCAL) {
776 /* TODO: context lookup */
Alexander Aring84ca5e02014-07-29 23:46:58 +0200777 iphc1 |= lowpan_compress_addr_64(&hc_ptr,
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200778 LOWPAN_IPHC_DAM_BIT, &hdr->daddr, _daddr);
779 pr_debug("dest address unicast link-local %pI6c "
780 "iphc1 0x%02x\n", &hdr->daddr, iphc1);
781 } else {
782 pr_debug("dest address unicast %pI6c\n", &hdr->daddr);
Alexander Aring85c71242014-07-29 23:47:01 +0200783 lowpan_push_hc_data(&hc_ptr, hdr->daddr.s6_addr, 16);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200784 }
785 }
786
787 /* UDP header compression */
788 if (hdr->nexthdr == UIP_PROTO_UDP)
Alexander Aring84ca5e02014-07-29 23:46:58 +0200789 compress_udp_header(&hc_ptr, skb);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200790
791 head[0] = iphc0;
792 head[1] = iphc1;
793
794 skb_pull(skb, sizeof(struct ipv6hdr));
795 skb_reset_transport_header(skb);
Alexander Aring84ca5e02014-07-29 23:46:58 +0200796 memcpy(skb_push(skb, hc_ptr - head), head, hc_ptr - head);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200797 skb_reset_network_header(skb);
798
Alexander Aring84ca5e02014-07-29 23:46:58 +0200799 pr_debug("header len %d skb %u\n", (int)(hc_ptr - head), skb->len);
Jukka Rissanen8df8c562013-12-11 17:05:34 +0200800
801 raw_dump_table(__func__, "raw skb data dump compressed",
802 skb->data, skb->len);
803 return 0;
804}
805EXPORT_SYMBOL_GPL(lowpan_header_compress);
Yann Droneaud5ae5e992014-01-22 20:25:24 +0100806
807MODULE_LICENSE("GPL");