Commit | Line | Data |
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8df8c56a JR |
1 | /* |
2 | * Copyright 2011, Siemens AG | |
3 | * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com> | |
4 | */ | |
5 | ||
6 | /* | |
7 | * Based on patches from Jon Smirl <jonsmirl@gmail.com> | |
8 | * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com> | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License version 2 | |
12 | * as published by the Free Software Foundation. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License along | |
20 | * with this program; if not, write to the Free Software Foundation, Inc., | |
21 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
22 | */ | |
23 | ||
24 | /* Jon's code is based on 6lowpan implementation for Contiki which is: | |
25 | * Copyright (c) 2008, Swedish Institute of Computer Science. | |
26 | * All rights reserved. | |
27 | * | |
28 | * Redistribution and use in source and binary forms, with or without | |
29 | * modification, are permitted provided that the following conditions | |
30 | * are met: | |
31 | * 1. Redistributions of source code must retain the above copyright | |
32 | * notice, this list of conditions and the following disclaimer. | |
33 | * 2. Redistributions in binary form must reproduce the above copyright | |
34 | * notice, this list of conditions and the following disclaimer in the | |
35 | * documentation and/or other materials provided with the distribution. | |
36 | * 3. Neither the name of the Institute nor the names of its contributors | |
37 | * may be used to endorse or promote products derived from this software | |
38 | * without specific prior written permission. | |
39 | * | |
40 | * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND | |
41 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
42 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
43 | * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE | |
44 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
45 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
46 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
47 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
48 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
49 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
50 | * SUCH DAMAGE. | |
51 | */ | |
52 | ||
53 | #include <linux/bitops.h> | |
54 | #include <linux/if_arp.h> | |
55 | #include <linux/netdevice.h> | |
56 | #include <net/ipv6.h> | |
57 | #include <net/af_ieee802154.h> | |
58 | ||
59 | #include "6lowpan.h" | |
60 | ||
8df8c56a JR |
61 | /* |
62 | * Uncompress address function for source and | |
63 | * destination address(non-multicast). | |
64 | * | |
65 | * address_mode is sam value or dam value. | |
66 | */ | |
67 | static 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 | */ | |
147 | static 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 | ||
177 | static 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 | */ | |
211 | static int | |
212 | lowpan_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 | ||
265 | static int | |
266 | uncompress_udp_header(struct sk_buff *skb, struct udphdr *uh) | |
267 | { | |
268 | u8 tmp; | |
269 | ||
270 | if (!uh) | |
271 | goto err; | |
272 | ||
273 | if (lowpan_fetch_skb_u8(skb, &tmp)) | |
274 | goto err; | |
275 | ||
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: | |
280 | memcpy(&uh->source, &skb->data[0], 2); | |
281 | memcpy(&uh->dest, &skb->data[2], 2); | |
282 | skb_pull(skb, 4); | |
283 | break; | |
284 | case LOWPAN_NHC_UDP_CS_P_01: | |
285 | memcpy(&uh->source, &skb->data[0], 2); | |
286 | uh->dest = | |
287 | skb->data[2] + LOWPAN_NHC_UDP_8BIT_PORT; | |
288 | skb_pull(skb, 3); | |
289 | break; | |
290 | case LOWPAN_NHC_UDP_CS_P_10: | |
291 | uh->source = skb->data[0] + LOWPAN_NHC_UDP_8BIT_PORT; | |
292 | memcpy(&uh->dest, &skb->data[1], 2); | |
293 | skb_pull(skb, 3); | |
294 | break; | |
295 | case LOWPAN_NHC_UDP_CS_P_11: | |
296 | uh->source = | |
297 | LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] >> 4); | |
298 | uh->dest = | |
299 | LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] & 0x0f); | |
300 | skb_pull(skb, 1); | |
301 | break; | |
302 | default: | |
303 | pr_debug("ERROR: unknown UDP format\n"); | |
304 | goto err; | |
305 | break; | |
306 | } | |
307 | ||
308 | pr_debug("uncompressed UDP ports: src = %d, dst = %d\n", | |
309 | uh->source, uh->dest); | |
310 | ||
311 | /* copy checksum */ | |
312 | memcpy(&uh->check, &skb->data[0], 2); | |
313 | skb_pull(skb, 2); | |
314 | ||
315 | /* | |
316 | * UDP lenght needs to be infered from the lower layers | |
317 | * here, we obtain the hint from the remaining size of the | |
318 | * frame | |
319 | */ | |
320 | uh->len = htons(skb->len + sizeof(struct udphdr)); | |
321 | pr_debug("uncompressed UDP length: src = %d", uh->len); | |
322 | } else { | |
323 | pr_debug("ERROR: unsupported NH format\n"); | |
324 | goto err; | |
325 | } | |
326 | ||
327 | return 0; | |
328 | err: | |
329 | return -EINVAL; | |
330 | } | |
331 | ||
332 | /* TTL uncompression values */ | |
333 | static const u8 lowpan_ttl_values[] = { 0, 1, 64, 255 }; | |
334 | ||
335 | int lowpan_process_data(struct sk_buff *skb, struct net_device *dev, | |
336 | const u8 *saddr, const u8 saddr_type, const u8 saddr_len, | |
337 | const u8 *daddr, const u8 daddr_type, const u8 daddr_len, | |
338 | u8 iphc0, u8 iphc1, skb_delivery_cb deliver_skb) | |
339 | { | |
340 | struct ipv6hdr hdr = {}; | |
341 | u8 tmp, num_context = 0; | |
342 | int err; | |
343 | ||
344 | raw_dump_table(__func__, "raw skb data dump uncompressed", | |
345 | skb->data, skb->len); | |
346 | ||
347 | /* another if the CID flag is set */ | |
348 | if (iphc1 & LOWPAN_IPHC_CID) { | |
349 | pr_debug("CID flag is set, increase header with one\n"); | |
350 | if (lowpan_fetch_skb_u8(skb, &num_context)) | |
351 | goto drop; | |
352 | } | |
353 | ||
354 | hdr.version = 6; | |
355 | ||
356 | /* Traffic Class and Flow Label */ | |
357 | switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) { | |
358 | /* | |
359 | * Traffic Class and FLow Label carried in-line | |
360 | * ECN + DSCP + 4-bit Pad + Flow Label (4 bytes) | |
361 | */ | |
362 | case 0: /* 00b */ | |
363 | if (lowpan_fetch_skb_u8(skb, &tmp)) | |
364 | goto drop; | |
365 | ||
366 | memcpy(&hdr.flow_lbl, &skb->data[0], 3); | |
367 | skb_pull(skb, 3); | |
368 | hdr.priority = ((tmp >> 2) & 0x0f); | |
369 | hdr.flow_lbl[0] = ((tmp >> 2) & 0x30) | (tmp << 6) | | |
370 | (hdr.flow_lbl[0] & 0x0f); | |
371 | break; | |
372 | /* | |
373 | * Traffic class carried in-line | |
374 | * ECN + DSCP (1 byte), Flow Label is elided | |
375 | */ | |
376 | case 2: /* 10b */ | |
377 | if (lowpan_fetch_skb_u8(skb, &tmp)) | |
378 | goto drop; | |
379 | ||
380 | hdr.priority = ((tmp >> 2) & 0x0f); | |
381 | hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30); | |
382 | break; | |
383 | /* | |
384 | * Flow Label carried in-line | |
385 | * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided | |
386 | */ | |
387 | case 1: /* 01b */ | |
388 | if (lowpan_fetch_skb_u8(skb, &tmp)) | |
389 | goto drop; | |
390 | ||
391 | hdr.flow_lbl[0] = (skb->data[0] & 0x0F) | ((tmp >> 2) & 0x30); | |
392 | memcpy(&hdr.flow_lbl[1], &skb->data[0], 2); | |
393 | skb_pull(skb, 2); | |
394 | break; | |
395 | /* Traffic Class and Flow Label are elided */ | |
396 | case 3: /* 11b */ | |
397 | break; | |
398 | default: | |
399 | break; | |
400 | } | |
401 | ||
402 | /* Next Header */ | |
403 | if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) { | |
404 | /* Next header is carried inline */ | |
405 | if (lowpan_fetch_skb_u8(skb, &(hdr.nexthdr))) | |
406 | goto drop; | |
407 | ||
408 | pr_debug("NH flag is set, next header carried inline: %02x\n", | |
409 | hdr.nexthdr); | |
410 | } | |
411 | ||
412 | /* Hop Limit */ | |
413 | if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I) | |
414 | hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03]; | |
415 | else { | |
416 | if (lowpan_fetch_skb_u8(skb, &(hdr.hop_limit))) | |
417 | goto drop; | |
418 | } | |
419 | ||
420 | /* Extract SAM to the tmp variable */ | |
421 | tmp = ((iphc1 & LOWPAN_IPHC_SAM) >> LOWPAN_IPHC_SAM_BIT) & 0x03; | |
422 | ||
423 | if (iphc1 & LOWPAN_IPHC_SAC) { | |
424 | /* Source address context based uncompression */ | |
425 | pr_debug("SAC bit is set. Handle context based source address.\n"); | |
426 | err = uncompress_context_based_src_addr( | |
427 | skb, &hdr.saddr, tmp); | |
428 | } else { | |
429 | /* Source address uncompression */ | |
430 | pr_debug("source address stateless compression\n"); | |
431 | err = uncompress_addr(skb, &hdr.saddr, tmp, saddr, | |
432 | saddr_type, saddr_len); | |
433 | } | |
434 | ||
435 | /* Check on error of previous branch */ | |
436 | if (err) | |
437 | goto drop; | |
438 | ||
439 | /* Extract DAM to the tmp variable */ | |
440 | tmp = ((iphc1 & LOWPAN_IPHC_DAM_11) >> LOWPAN_IPHC_DAM_BIT) & 0x03; | |
441 | ||
442 | /* check for Multicast Compression */ | |
443 | if (iphc1 & LOWPAN_IPHC_M) { | |
444 | if (iphc1 & LOWPAN_IPHC_DAC) { | |
445 | pr_debug("dest: context-based mcast compression\n"); | |
446 | /* TODO: implement this */ | |
447 | } else { | |
448 | err = lowpan_uncompress_multicast_daddr( | |
449 | skb, &hdr.daddr, tmp); | |
450 | if (err) | |
451 | goto drop; | |
452 | } | |
453 | } else { | |
454 | err = uncompress_addr(skb, &hdr.daddr, tmp, daddr, | |
455 | daddr_type, daddr_len); | |
456 | pr_debug("dest: stateless compression mode %d dest %pI6c\n", | |
457 | tmp, &hdr.daddr); | |
458 | if (err) | |
459 | goto drop; | |
460 | } | |
461 | ||
462 | /* UDP data uncompression */ | |
463 | if (iphc0 & LOWPAN_IPHC_NH_C) { | |
464 | struct udphdr uh; | |
465 | struct sk_buff *new; | |
466 | if (uncompress_udp_header(skb, &uh)) | |
467 | goto drop; | |
468 | ||
469 | /* | |
470 | * replace the compressed UDP head by the uncompressed UDP | |
471 | * header | |
472 | */ | |
473 | new = skb_copy_expand(skb, sizeof(struct udphdr), | |
474 | skb_tailroom(skb), GFP_ATOMIC); | |
475 | kfree_skb(skb); | |
476 | ||
477 | if (!new) | |
478 | return -ENOMEM; | |
479 | ||
480 | skb = new; | |
481 | ||
482 | skb_push(skb, sizeof(struct udphdr)); | |
483 | skb_reset_transport_header(skb); | |
484 | skb_copy_to_linear_data(skb, &uh, sizeof(struct udphdr)); | |
485 | ||
486 | raw_dump_table(__func__, "raw UDP header dump", | |
487 | (u8 *)&uh, sizeof(uh)); | |
488 | ||
489 | hdr.nexthdr = UIP_PROTO_UDP; | |
490 | } | |
491 | ||
492 | hdr.payload_len = htons(skb->len); | |
493 | ||
494 | pr_debug("skb headroom size = %d, data length = %d\n", | |
495 | skb_headroom(skb), skb->len); | |
496 | ||
497 | pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n\t" | |
498 | "nexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n", | |
499 | hdr.version, ntohs(hdr.payload_len), hdr.nexthdr, | |
500 | hdr.hop_limit, &hdr.daddr); | |
501 | ||
502 | raw_dump_table(__func__, "raw header dump", (u8 *)&hdr, | |
503 | sizeof(hdr)); | |
504 | ||
505 | return skb_deliver(skb, &hdr, dev, deliver_skb); | |
506 | ||
507 | drop: | |
508 | kfree_skb(skb); | |
509 | return -EINVAL; | |
510 | } | |
511 | EXPORT_SYMBOL_GPL(lowpan_process_data); | |
512 | ||
513 | static u8 lowpan_compress_addr_64(u8 **hc06_ptr, u8 shift, | |
514 | const struct in6_addr *ipaddr, | |
515 | const unsigned char *lladdr) | |
516 | { | |
517 | u8 val = 0; | |
518 | ||
519 | if (is_addr_mac_addr_based(ipaddr, lladdr)) { | |
520 | val = 3; /* 0-bits */ | |
521 | pr_debug("address compression 0 bits\n"); | |
522 | } else if (lowpan_is_iid_16_bit_compressable(ipaddr)) { | |
523 | /* compress IID to 16 bits xxxx::XXXX */ | |
524 | memcpy(*hc06_ptr, &ipaddr->s6_addr16[7], 2); | |
525 | *hc06_ptr += 2; | |
526 | val = 2; /* 16-bits */ | |
527 | raw_dump_inline(NULL, "Compressed ipv6 addr is (16 bits)", | |
528 | *hc06_ptr - 2, 2); | |
529 | } else { | |
530 | /* do not compress IID => xxxx::IID */ | |
531 | memcpy(*hc06_ptr, &ipaddr->s6_addr16[4], 8); | |
532 | *hc06_ptr += 8; | |
533 | val = 1; /* 64-bits */ | |
534 | raw_dump_inline(NULL, "Compressed ipv6 addr is (64 bits)", | |
535 | *hc06_ptr - 8, 8); | |
536 | } | |
537 | ||
538 | return rol8(val, shift); | |
539 | } | |
540 | ||
541 | static void compress_udp_header(u8 **hc06_ptr, struct sk_buff *skb) | |
542 | { | |
543 | struct udphdr *uh = udp_hdr(skb); | |
5cede84c | 544 | u8 tmp; |
8df8c56a JR |
545 | |
546 | if (((uh->source & LOWPAN_NHC_UDP_4BIT_MASK) == | |
547 | LOWPAN_NHC_UDP_4BIT_PORT) && | |
548 | ((uh->dest & LOWPAN_NHC_UDP_4BIT_MASK) == | |
549 | LOWPAN_NHC_UDP_4BIT_PORT)) { | |
550 | pr_debug("UDP header: both ports compression to 4 bits\n"); | |
5cede84c AA |
551 | tmp = LOWPAN_NHC_UDP_CS_P_11; |
552 | lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp)); | |
553 | tmp = /* subtraction is faster */ | |
8df8c56a JR |
554 | (u8)((uh->dest - LOWPAN_NHC_UDP_4BIT_PORT) + |
555 | ((uh->source & LOWPAN_NHC_UDP_4BIT_PORT) << 4)); | |
5cede84c | 556 | lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp)); |
8df8c56a JR |
557 | } else if ((uh->dest & LOWPAN_NHC_UDP_8BIT_MASK) == |
558 | LOWPAN_NHC_UDP_8BIT_PORT) { | |
559 | pr_debug("UDP header: remove 8 bits of dest\n"); | |
5cede84c AA |
560 | tmp = LOWPAN_NHC_UDP_CS_P_01; |
561 | lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp)); | |
562 | lowpan_push_hc_data(hc06_ptr, &uh->source, sizeof(uh->source)); | |
563 | tmp = (u8)(uh->dest - LOWPAN_NHC_UDP_8BIT_PORT); | |
564 | lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp)); | |
8df8c56a JR |
565 | } else if ((uh->source & LOWPAN_NHC_UDP_8BIT_MASK) == |
566 | LOWPAN_NHC_UDP_8BIT_PORT) { | |
567 | pr_debug("UDP header: remove 8 bits of source\n"); | |
5cede84c AA |
568 | tmp = LOWPAN_NHC_UDP_CS_P_10; |
569 | lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp)); | |
570 | lowpan_push_hc_data(hc06_ptr, &uh->dest, sizeof(uh->dest)); | |
571 | tmp = (u8)(uh->source - LOWPAN_NHC_UDP_8BIT_PORT); | |
572 | lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp)); | |
8df8c56a JR |
573 | } else { |
574 | pr_debug("UDP header: can't compress\n"); | |
5cede84c AA |
575 | tmp = LOWPAN_NHC_UDP_CS_P_00; |
576 | lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp)); | |
577 | lowpan_push_hc_data(hc06_ptr, &uh->source, sizeof(uh->source)); | |
578 | lowpan_push_hc_data(hc06_ptr, &uh->dest, sizeof(uh->dest)); | |
8df8c56a JR |
579 | } |
580 | ||
581 | /* checksum is always inline */ | |
5cede84c | 582 | lowpan_push_hc_data(hc06_ptr, &uh->check, sizeof(uh->check)); |
8df8c56a JR |
583 | |
584 | /* skip the UDP header */ | |
585 | skb_pull(skb, sizeof(struct udphdr)); | |
586 | } | |
587 | ||
588 | int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev, | |
589 | unsigned short type, const void *_daddr, | |
590 | const void *_saddr, unsigned int len) | |
591 | { | |
592 | u8 tmp, iphc0, iphc1, *hc06_ptr; | |
593 | struct ipv6hdr *hdr; | |
594 | u8 head[100] = {}; | |
595 | ||
596 | if (type != ETH_P_IPV6) | |
597 | return -EINVAL; | |
598 | ||
599 | hdr = ipv6_hdr(skb); | |
600 | hc06_ptr = head + 2; | |
601 | ||
602 | pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n" | |
603 | "\tnexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n", | |
604 | hdr->version, ntohs(hdr->payload_len), hdr->nexthdr, | |
605 | hdr->hop_limit, &hdr->daddr); | |
606 | ||
607 | raw_dump_table(__func__, "raw skb network header dump", | |
608 | skb_network_header(skb), sizeof(struct ipv6hdr)); | |
609 | ||
610 | /* | |
611 | * As we copy some bit-length fields, in the IPHC encoding bytes, | |
612 | * we sometimes use |= | |
613 | * If the field is 0, and the current bit value in memory is 1, | |
614 | * this does not work. We therefore reset the IPHC encoding here | |
615 | */ | |
616 | iphc0 = LOWPAN_DISPATCH_IPHC; | |
617 | iphc1 = 0; | |
618 | ||
619 | /* TODO: context lookup */ | |
620 | ||
621 | raw_dump_inline(__func__, "saddr", | |
622 | (unsigned char *)_saddr, IEEE802154_ADDR_LEN); | |
623 | raw_dump_inline(__func__, "daddr", | |
624 | (unsigned char *)_daddr, IEEE802154_ADDR_LEN); | |
625 | ||
626 | raw_dump_table(__func__, | |
627 | "sending raw skb network uncompressed packet", | |
628 | skb->data, skb->len); | |
629 | ||
630 | /* | |
631 | * Traffic class, flow label | |
632 | * If flow label is 0, compress it. If traffic class is 0, compress it | |
633 | * We have to process both in the same time as the offset of traffic | |
634 | * class depends on the presence of version and flow label | |
635 | */ | |
636 | ||
637 | /* hc06 format of TC is ECN | DSCP , original one is DSCP | ECN */ | |
638 | tmp = (hdr->priority << 4) | (hdr->flow_lbl[0] >> 4); | |
639 | tmp = ((tmp & 0x03) << 6) | (tmp >> 2); | |
640 | ||
641 | if (((hdr->flow_lbl[0] & 0x0F) == 0) && | |
642 | (hdr->flow_lbl[1] == 0) && (hdr->flow_lbl[2] == 0)) { | |
643 | /* flow label can be compressed */ | |
644 | iphc0 |= LOWPAN_IPHC_FL_C; | |
645 | if ((hdr->priority == 0) && | |
646 | ((hdr->flow_lbl[0] & 0xF0) == 0)) { | |
647 | /* compress (elide) all */ | |
648 | iphc0 |= LOWPAN_IPHC_TC_C; | |
649 | } else { | |
650 | /* compress only the flow label */ | |
651 | *hc06_ptr = tmp; | |
652 | hc06_ptr += 1; | |
653 | } | |
654 | } else { | |
655 | /* Flow label cannot be compressed */ | |
656 | if ((hdr->priority == 0) && | |
657 | ((hdr->flow_lbl[0] & 0xF0) == 0)) { | |
658 | /* compress only traffic class */ | |
659 | iphc0 |= LOWPAN_IPHC_TC_C; | |
660 | *hc06_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F); | |
661 | memcpy(hc06_ptr + 1, &hdr->flow_lbl[1], 2); | |
662 | hc06_ptr += 3; | |
663 | } else { | |
664 | /* compress nothing */ | |
665 | memcpy(hc06_ptr, &hdr, 4); | |
666 | /* replace the top byte with new ECN | DSCP format */ | |
667 | *hc06_ptr = tmp; | |
668 | hc06_ptr += 4; | |
669 | } | |
670 | } | |
671 | ||
672 | /* NOTE: payload length is always compressed */ | |
673 | ||
674 | /* Next Header is compress if UDP */ | |
675 | if (hdr->nexthdr == UIP_PROTO_UDP) | |
676 | iphc0 |= LOWPAN_IPHC_NH_C; | |
677 | ||
678 | if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) { | |
679 | *hc06_ptr = hdr->nexthdr; | |
680 | hc06_ptr += 1; | |
681 | } | |
682 | ||
683 | /* | |
684 | * Hop limit | |
685 | * if 1: compress, encoding is 01 | |
686 | * if 64: compress, encoding is 10 | |
687 | * if 255: compress, encoding is 11 | |
688 | * else do not compress | |
689 | */ | |
690 | switch (hdr->hop_limit) { | |
691 | case 1: | |
692 | iphc0 |= LOWPAN_IPHC_TTL_1; | |
693 | break; | |
694 | case 64: | |
695 | iphc0 |= LOWPAN_IPHC_TTL_64; | |
696 | break; | |
697 | case 255: | |
698 | iphc0 |= LOWPAN_IPHC_TTL_255; | |
699 | break; | |
700 | default: | |
701 | *hc06_ptr = hdr->hop_limit; | |
702 | hc06_ptr += 1; | |
703 | break; | |
704 | } | |
705 | ||
706 | /* source address compression */ | |
707 | if (is_addr_unspecified(&hdr->saddr)) { | |
708 | pr_debug("source address is unspecified, setting SAC\n"); | |
709 | iphc1 |= LOWPAN_IPHC_SAC; | |
710 | /* TODO: context lookup */ | |
711 | } else if (is_addr_link_local(&hdr->saddr)) { | |
712 | iphc1 |= lowpan_compress_addr_64(&hc06_ptr, | |
713 | LOWPAN_IPHC_SAM_BIT, &hdr->saddr, _saddr); | |
714 | pr_debug("source address unicast link-local %pI6c " | |
715 | "iphc1 0x%02x\n", &hdr->saddr, iphc1); | |
716 | } else { | |
717 | pr_debug("send the full source address\n"); | |
718 | memcpy(hc06_ptr, &hdr->saddr.s6_addr16[0], 16); | |
719 | hc06_ptr += 16; | |
720 | } | |
721 | ||
722 | /* destination address compression */ | |
723 | if (is_addr_mcast(&hdr->daddr)) { | |
724 | pr_debug("destination address is multicast: "); | |
725 | iphc1 |= LOWPAN_IPHC_M; | |
726 | if (lowpan_is_mcast_addr_compressable8(&hdr->daddr)) { | |
727 | pr_debug("compressed to 1 octet\n"); | |
728 | iphc1 |= LOWPAN_IPHC_DAM_11; | |
729 | /* use last byte */ | |
730 | *hc06_ptr = hdr->daddr.s6_addr[15]; | |
731 | hc06_ptr += 1; | |
732 | } else if (lowpan_is_mcast_addr_compressable32(&hdr->daddr)) { | |
733 | pr_debug("compressed to 4 octets\n"); | |
734 | iphc1 |= LOWPAN_IPHC_DAM_10; | |
735 | /* second byte + the last three */ | |
736 | *hc06_ptr = hdr->daddr.s6_addr[1]; | |
737 | memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[13], 3); | |
738 | hc06_ptr += 4; | |
739 | } else if (lowpan_is_mcast_addr_compressable48(&hdr->daddr)) { | |
740 | pr_debug("compressed to 6 octets\n"); | |
741 | iphc1 |= LOWPAN_IPHC_DAM_01; | |
742 | /* second byte + the last five */ | |
743 | *hc06_ptr = hdr->daddr.s6_addr[1]; | |
744 | memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[11], 5); | |
745 | hc06_ptr += 6; | |
746 | } else { | |
747 | pr_debug("using full address\n"); | |
748 | iphc1 |= LOWPAN_IPHC_DAM_00; | |
749 | memcpy(hc06_ptr, &hdr->daddr.s6_addr[0], 16); | |
750 | hc06_ptr += 16; | |
751 | } | |
752 | } else { | |
753 | /* TODO: context lookup */ | |
754 | if (is_addr_link_local(&hdr->daddr)) { | |
755 | iphc1 |= lowpan_compress_addr_64(&hc06_ptr, | |
756 | LOWPAN_IPHC_DAM_BIT, &hdr->daddr, _daddr); | |
757 | pr_debug("dest address unicast link-local %pI6c " | |
758 | "iphc1 0x%02x\n", &hdr->daddr, iphc1); | |
759 | } else { | |
760 | pr_debug("dest address unicast %pI6c\n", &hdr->daddr); | |
761 | memcpy(hc06_ptr, &hdr->daddr.s6_addr16[0], 16); | |
762 | hc06_ptr += 16; | |
763 | } | |
764 | } | |
765 | ||
766 | /* UDP header compression */ | |
767 | if (hdr->nexthdr == UIP_PROTO_UDP) | |
768 | compress_udp_header(&hc06_ptr, skb); | |
769 | ||
770 | head[0] = iphc0; | |
771 | head[1] = iphc1; | |
772 | ||
773 | skb_pull(skb, sizeof(struct ipv6hdr)); | |
774 | skb_reset_transport_header(skb); | |
775 | memcpy(skb_push(skb, hc06_ptr - head), head, hc06_ptr - head); | |
776 | skb_reset_network_header(skb); | |
777 | ||
778 | pr_debug("header len %d skb %u\n", (int)(hc06_ptr - head), skb->len); | |
779 | ||
780 | raw_dump_table(__func__, "raw skb data dump compressed", | |
781 | skb->data, skb->len); | |
782 | return 0; | |
783 | } | |
784 | EXPORT_SYMBOL_GPL(lowpan_header_compress); |