2 * Copyright 2011, Siemens AG
3 * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
6 /* Based on patches from Jon Smirl <jonsmirl@gmail.com>
7 * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
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.
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.
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
23 /* Jon's code is based on 6lowpan implementation for Contiki which is:
24 * Copyright (c) 2008, Swedish Institute of Computer Science.
25 * All rights reserved.
27 * Redistribution and use in source and binary forms, with or without
28 * modification, are permitted provided that the following conditions
30 * 1. Redistributions of source code must retain the above copyright
31 * notice, this list of conditions and the following disclaimer.
32 * 2. Redistributions in binary form must reproduce the above copyright
33 * notice, this list of conditions and the following disclaimer in the
34 * documentation and/or other materials provided with the distribution.
35 * 3. Neither the name of the Institute nor the names of its contributors
36 * may be used to endorse or promote products derived from this software
37 * without specific prior written permission.
39 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
40 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
42 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
43 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
44 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
45 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
46 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
47 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
48 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52 #include <linux/bitops.h>
53 #include <linux/if_arp.h>
54 #include <linux/module.h>
55 #include <linux/netdevice.h>
56 #include <net/6lowpan.h>
58 #include <net/af_ieee802154.h>
60 /* Uncompress address function for source and
61 * destination address(non-multicast).
63 * address_mode is sam value or dam value.
65 static int uncompress_addr(struct sk_buff
*skb
,
66 struct in6_addr
*ipaddr
, const u8 address_mode
,
67 const u8
*lladdr
, const u8 addr_type
,
72 switch (address_mode
) {
73 case LOWPAN_IPHC_ADDR_00
:
74 /* for global link addresses */
75 fail
= lowpan_fetch_skb(skb
, ipaddr
->s6_addr
, 16);
77 case LOWPAN_IPHC_ADDR_01
:
78 /* fe:80::XXXX:XXXX:XXXX:XXXX */
79 ipaddr
->s6_addr
[0] = 0xFE;
80 ipaddr
->s6_addr
[1] = 0x80;
81 fail
= lowpan_fetch_skb(skb
, &ipaddr
->s6_addr
[8], 8);
83 case LOWPAN_IPHC_ADDR_02
:
84 /* fe:80::ff:fe00:XXXX */
85 ipaddr
->s6_addr
[0] = 0xFE;
86 ipaddr
->s6_addr
[1] = 0x80;
87 ipaddr
->s6_addr
[11] = 0xFF;
88 ipaddr
->s6_addr
[12] = 0xFE;
89 fail
= lowpan_fetch_skb(skb
, &ipaddr
->s6_addr
[14], 2);
91 case LOWPAN_IPHC_ADDR_03
:
94 case IEEE802154_ADDR_LONG
:
95 /* fe:80::XXXX:XXXX:XXXX:XXXX
99 ipaddr
->s6_addr
[0] = 0xFE;
100 ipaddr
->s6_addr
[1] = 0x80;
101 memcpy(&ipaddr
->s6_addr
[8], lladdr
, addr_len
);
102 /* second bit-flip (Universe/Local)
103 * is done according RFC2464
105 ipaddr
->s6_addr
[8] ^= 0x02;
107 case IEEE802154_ADDR_SHORT
:
108 /* fe:80::ff:fe00:XXXX
112 * Universe/Local bit is zero.
114 ipaddr
->s6_addr
[0] = 0xFE;
115 ipaddr
->s6_addr
[1] = 0x80;
116 ipaddr
->s6_addr
[11] = 0xFF;
117 ipaddr
->s6_addr
[12] = 0xFE;
118 ipaddr
->s6_addr16
[7] = htons(*((u16
*)lladdr
));
121 pr_debug("Invalid addr_type set\n");
126 pr_debug("Invalid address mode value: 0x%x\n", address_mode
);
131 pr_debug("Failed to fetch skb data\n");
135 raw_dump_inline(NULL
, "Reconstructed ipv6 addr is",
136 ipaddr
->s6_addr
, 16);
141 /* Uncompress address function for source context
142 * based address(non-multicast).
144 static int uncompress_context_based_src_addr(struct sk_buff
*skb
,
145 struct in6_addr
*ipaddr
,
149 case LOWPAN_IPHC_ADDR_00
:
151 * Do nothing, address is already ::
154 case LOWPAN_IPHC_ADDR_01
:
156 case LOWPAN_IPHC_ADDR_02
:
158 case LOWPAN_IPHC_ADDR_03
:
160 netdev_warn(skb
->dev
, "SAM value 0x%x not supported\n", sam
);
163 pr_debug("Invalid sam value: 0x%x\n", sam
);
167 raw_dump_inline(NULL
,
168 "Reconstructed context based ipv6 src addr is",
169 ipaddr
->s6_addr
, 16);
174 static int skb_deliver(struct sk_buff
*skb
, struct ipv6hdr
*hdr
,
175 struct net_device
*dev
, skb_delivery_cb deliver_skb
)
180 new = skb_copy_expand(skb
, sizeof(struct ipv6hdr
),
181 skb_tailroom(skb
), GFP_ATOMIC
);
187 skb_push(new, sizeof(struct ipv6hdr
));
188 skb_reset_network_header(new);
189 skb_copy_to_linear_data(new, hdr
, sizeof(struct ipv6hdr
));
191 new->protocol
= htons(ETH_P_IPV6
);
192 new->pkt_type
= PACKET_HOST
;
195 raw_dump_table(__func__
, "raw skb data dump before receiving",
196 new->data
, new->len
);
198 stat
= deliver_skb(new, dev
);
205 /* Uncompress function for multicast destination address,
209 lowpan_uncompress_multicast_daddr(struct sk_buff
*skb
,
210 struct in6_addr
*ipaddr
,
216 case LOWPAN_IPHC_DAM_00
:
217 /* 00: 128 bits. The full address
218 * is carried in-line.
220 fail
= lowpan_fetch_skb(skb
, ipaddr
->s6_addr
, 16);
222 case LOWPAN_IPHC_DAM_01
:
223 /* 01: 48 bits. The address takes
224 * the form ffXX::00XX:XXXX:XXXX.
226 ipaddr
->s6_addr
[0] = 0xFF;
227 fail
= lowpan_fetch_skb(skb
, &ipaddr
->s6_addr
[1], 1);
228 fail
|= lowpan_fetch_skb(skb
, &ipaddr
->s6_addr
[11], 5);
230 case LOWPAN_IPHC_DAM_10
:
231 /* 10: 32 bits. The address takes
232 * the form ffXX::00XX:XXXX.
234 ipaddr
->s6_addr
[0] = 0xFF;
235 fail
= lowpan_fetch_skb(skb
, &ipaddr
->s6_addr
[1], 1);
236 fail
|= lowpan_fetch_skb(skb
, &ipaddr
->s6_addr
[13], 3);
238 case LOWPAN_IPHC_DAM_11
:
239 /* 11: 8 bits. The address takes
240 * the form ff02::00XX.
242 ipaddr
->s6_addr
[0] = 0xFF;
243 ipaddr
->s6_addr
[1] = 0x02;
244 fail
= lowpan_fetch_skb(skb
, &ipaddr
->s6_addr
[15], 1);
247 pr_debug("DAM value has a wrong value: 0x%x\n", dam
);
252 pr_debug("Failed to fetch skb data\n");
256 raw_dump_inline(NULL
, "Reconstructed ipv6 multicast addr is",
257 ipaddr
->s6_addr
, 16);
263 uncompress_udp_header(struct sk_buff
*skb
, struct udphdr
*uh
)
271 fail
= lowpan_fetch_skb(skb
, &tmp
, 1);
273 if ((tmp
& LOWPAN_NHC_UDP_MASK
) == LOWPAN_NHC_UDP_ID
) {
274 pr_debug("UDP header uncompression\n");
275 switch (tmp
& LOWPAN_NHC_UDP_CS_P_11
) {
276 case LOWPAN_NHC_UDP_CS_P_00
:
277 fail
|= lowpan_fetch_skb(skb
, &uh
->source
, 2);
278 fail
|= lowpan_fetch_skb(skb
, &uh
->dest
, 2);
280 case LOWPAN_NHC_UDP_CS_P_01
:
281 fail
|= lowpan_fetch_skb(skb
, &uh
->source
, 2);
282 fail
|= lowpan_fetch_skb(skb
, &val
, 1);
283 uh
->dest
= htons(val
+ LOWPAN_NHC_UDP_8BIT_PORT
);
285 case LOWPAN_NHC_UDP_CS_P_10
:
286 fail
|= lowpan_fetch_skb(skb
, &val
, 1);
287 uh
->source
= htons(val
+ LOWPAN_NHC_UDP_8BIT_PORT
);
288 fail
|= lowpan_fetch_skb(skb
, &uh
->dest
, 2);
290 case LOWPAN_NHC_UDP_CS_P_11
:
291 fail
|= lowpan_fetch_skb(skb
, &val
, 1);
292 uh
->source
= htons(LOWPAN_NHC_UDP_4BIT_PORT
+
294 uh
->dest
= htons(LOWPAN_NHC_UDP_4BIT_PORT
+
298 pr_debug("ERROR: unknown UDP format\n");
303 pr_debug("uncompressed UDP ports: src = %d, dst = %d\n",
304 ntohs(uh
->source
), ntohs(uh
->dest
));
307 if (tmp
& LOWPAN_NHC_UDP_CS_C
) {
308 pr_debug_ratelimited("checksum elided currently not supported\n");
311 fail
|= lowpan_fetch_skb(skb
, &uh
->check
, 2);
314 /* UDP lenght needs to be infered from the lower layers
315 * here, we obtain the hint from the remaining size of the
318 uh
->len
= htons(skb
->len
+ sizeof(struct udphdr
));
319 pr_debug("uncompressed UDP length: src = %d", ntohs(uh
->len
));
321 pr_debug("ERROR: unsupported NH format\n");
333 /* TTL uncompression values */
334 static const u8 lowpan_ttl_values
[] = { 0, 1, 64, 255 };
336 int lowpan_process_data(struct sk_buff
*skb
, struct net_device
*dev
,
337 const u8
*saddr
, const u8 saddr_type
,
338 const u8 saddr_len
, const u8
*daddr
,
339 const u8 daddr_type
, const u8 daddr_len
,
340 u8 iphc0
, u8 iphc1
, skb_delivery_cb deliver_skb
)
342 struct ipv6hdr hdr
= {};
343 u8 tmp
, num_context
= 0;
346 raw_dump_table(__func__
, "raw skb data dump uncompressed",
347 skb
->data
, skb
->len
);
349 /* another if the CID flag is set */
350 if (iphc1
& LOWPAN_IPHC_CID
) {
351 pr_debug("CID flag is set, increase header with one\n");
352 if (lowpan_fetch_skb_u8(skb
, &num_context
))
358 /* Traffic Class and Flow Label */
359 switch ((iphc0
& LOWPAN_IPHC_TF
) >> 3) {
360 /* Traffic Class and FLow Label carried in-line
361 * ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
364 if (lowpan_fetch_skb_u8(skb
, &tmp
))
367 memcpy(&hdr
.flow_lbl
, &skb
->data
[0], 3);
369 hdr
.priority
= ((tmp
>> 2) & 0x0f);
370 hdr
.flow_lbl
[0] = ((tmp
>> 2) & 0x30) | (tmp
<< 6) |
371 (hdr
.flow_lbl
[0] & 0x0f);
373 /* Traffic class carried in-line
374 * ECN + DSCP (1 byte), Flow Label is elided
377 if (lowpan_fetch_skb_u8(skb
, &tmp
))
380 hdr
.priority
= ((tmp
>> 2) & 0x0f);
381 hdr
.flow_lbl
[0] = ((tmp
<< 6) & 0xC0) | ((tmp
>> 2) & 0x30);
383 /* Flow Label carried in-line
384 * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
387 if (lowpan_fetch_skb_u8(skb
, &tmp
))
390 hdr
.flow_lbl
[0] = (skb
->data
[0] & 0x0F) | ((tmp
>> 2) & 0x30);
391 memcpy(&hdr
.flow_lbl
[1], &skb
->data
[0], 2);
394 /* Traffic Class and Flow Label are elided */
402 if ((iphc0
& LOWPAN_IPHC_NH_C
) == 0) {
403 /* Next header is carried inline */
404 if (lowpan_fetch_skb_u8(skb
, &(hdr
.nexthdr
)))
407 pr_debug("NH flag is set, next header carried inline: %02x\n",
412 if ((iphc0
& 0x03) != LOWPAN_IPHC_TTL_I
) {
413 hdr
.hop_limit
= lowpan_ttl_values
[iphc0
& 0x03];
415 if (lowpan_fetch_skb_u8(skb
, &(hdr
.hop_limit
)))
419 /* Extract SAM to the tmp variable */
420 tmp
= ((iphc1
& LOWPAN_IPHC_SAM
) >> LOWPAN_IPHC_SAM_BIT
) & 0x03;
422 if (iphc1
& LOWPAN_IPHC_SAC
) {
423 /* Source address context based uncompression */
424 pr_debug("SAC bit is set. Handle context based source address.\n");
425 err
= uncompress_context_based_src_addr(
426 skb
, &hdr
.saddr
, tmp
);
428 /* Source address uncompression */
429 pr_debug("source address stateless compression\n");
430 err
= uncompress_addr(skb
, &hdr
.saddr
, tmp
, saddr
,
431 saddr_type
, saddr_len
);
434 /* Check on error of previous branch */
438 /* Extract DAM to the tmp variable */
439 tmp
= ((iphc1
& LOWPAN_IPHC_DAM_11
) >> LOWPAN_IPHC_DAM_BIT
) & 0x03;
441 /* check for Multicast Compression */
442 if (iphc1
& LOWPAN_IPHC_M
) {
443 if (iphc1
& LOWPAN_IPHC_DAC
) {
444 pr_debug("dest: context-based mcast compression\n");
445 /* TODO: implement this */
447 err
= lowpan_uncompress_multicast_daddr(
448 skb
, &hdr
.daddr
, tmp
);
453 err
= uncompress_addr(skb
, &hdr
.daddr
, tmp
, daddr
,
454 daddr_type
, daddr_len
);
455 pr_debug("dest: stateless compression mode %d dest %pI6c\n",
461 /* UDP data uncompression */
462 if (iphc0
& LOWPAN_IPHC_NH_C
) {
466 if (uncompress_udp_header(skb
, &uh
))
469 /* replace the compressed UDP head by the uncompressed UDP
472 new = skb_copy_expand(skb
, sizeof(struct udphdr
),
473 skb_tailroom(skb
), GFP_ATOMIC
);
481 skb_push(skb
, sizeof(struct udphdr
));
482 skb_reset_transport_header(skb
);
483 skb_copy_to_linear_data(skb
, &uh
, sizeof(struct udphdr
));
485 raw_dump_table(__func__
, "raw UDP header dump",
486 (u8
*)&uh
, sizeof(uh
));
488 hdr
.nexthdr
= UIP_PROTO_UDP
;
491 hdr
.payload_len
= htons(skb
->len
);
493 pr_debug("skb headroom size = %d, data length = %d\n",
494 skb_headroom(skb
), skb
->len
);
496 pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n\t"
497 "nexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n",
498 hdr
.version
, ntohs(hdr
.payload_len
), hdr
.nexthdr
,
499 hdr
.hop_limit
, &hdr
.daddr
);
501 raw_dump_table(__func__
, "raw header dump",
502 (u8
*)&hdr
, sizeof(hdr
));
504 return skb_deliver(skb
, &hdr
, dev
, deliver_skb
);
510 EXPORT_SYMBOL_GPL(lowpan_process_data
);
512 static u8
lowpan_compress_addr_64(u8
**hc06_ptr
, u8 shift
,
513 const struct in6_addr
*ipaddr
,
514 const unsigned char *lladdr
)
518 if (is_addr_mac_addr_based(ipaddr
, lladdr
)) {
519 val
= 3; /* 0-bits */
520 pr_debug("address compression 0 bits\n");
521 } else if (lowpan_is_iid_16_bit_compressable(ipaddr
)) {
522 /* compress IID to 16 bits xxxx::XXXX */
523 memcpy(*hc06_ptr
, &ipaddr
->s6_addr16
[7], 2);
525 val
= 2; /* 16-bits */
526 raw_dump_inline(NULL
, "Compressed ipv6 addr is (16 bits)",
529 /* do not compress IID => xxxx::IID */
530 memcpy(*hc06_ptr
, &ipaddr
->s6_addr16
[4], 8);
532 val
= 1; /* 64-bits */
533 raw_dump_inline(NULL
, "Compressed ipv6 addr is (64 bits)",
537 return rol8(val
, shift
);
540 static void compress_udp_header(u8
**hc06_ptr
, struct sk_buff
*skb
)
542 struct udphdr
*uh
= udp_hdr(skb
);
545 if (((ntohs(uh
->source
) & LOWPAN_NHC_UDP_4BIT_MASK
) ==
546 LOWPAN_NHC_UDP_4BIT_PORT
) &&
547 ((ntohs(uh
->dest
) & LOWPAN_NHC_UDP_4BIT_MASK
) ==
548 LOWPAN_NHC_UDP_4BIT_PORT
)) {
549 pr_debug("UDP header: both ports compression to 4 bits\n");
550 /* compression value */
551 tmp
= LOWPAN_NHC_UDP_CS_P_11
;
552 lowpan_push_hc_data(hc06_ptr
, &tmp
, sizeof(tmp
));
553 /* source and destination port */
554 tmp
= ntohs(uh
->dest
) - LOWPAN_NHC_UDP_4BIT_PORT
+
555 ((ntohs(uh
->source
) - LOWPAN_NHC_UDP_4BIT_PORT
) << 4);
556 lowpan_push_hc_data(hc06_ptr
, &tmp
, sizeof(tmp
));
557 } else if ((ntohs(uh
->dest
) & LOWPAN_NHC_UDP_8BIT_MASK
) ==
558 LOWPAN_NHC_UDP_8BIT_PORT
) {
559 pr_debug("UDP header: remove 8 bits of dest\n");
560 /* compression value */
561 tmp
= LOWPAN_NHC_UDP_CS_P_01
;
562 lowpan_push_hc_data(hc06_ptr
, &tmp
, sizeof(tmp
));
564 lowpan_push_hc_data(hc06_ptr
, &uh
->source
, sizeof(uh
->source
));
565 /* destination port */
566 tmp
= ntohs(uh
->dest
) - LOWPAN_NHC_UDP_8BIT_PORT
;
567 lowpan_push_hc_data(hc06_ptr
, &tmp
, sizeof(tmp
));
568 } else if ((ntohs(uh
->source
) & LOWPAN_NHC_UDP_8BIT_MASK
) ==
569 LOWPAN_NHC_UDP_8BIT_PORT
) {
570 pr_debug("UDP header: remove 8 bits of source\n");
571 /* compression value */
572 tmp
= LOWPAN_NHC_UDP_CS_P_10
;
573 lowpan_push_hc_data(hc06_ptr
, &tmp
, sizeof(tmp
));
575 tmp
= ntohs(uh
->source
) - LOWPAN_NHC_UDP_8BIT_PORT
;
576 lowpan_push_hc_data(hc06_ptr
, &tmp
, sizeof(tmp
));
577 /* destination port */
578 lowpan_push_hc_data(hc06_ptr
, &uh
->dest
, sizeof(uh
->dest
));
580 pr_debug("UDP header: can't compress\n");
581 /* compression value */
582 tmp
= LOWPAN_NHC_UDP_CS_P_00
;
583 lowpan_push_hc_data(hc06_ptr
, &tmp
, sizeof(tmp
));
585 lowpan_push_hc_data(hc06_ptr
, &uh
->source
, sizeof(uh
->source
));
586 /* destination port */
587 lowpan_push_hc_data(hc06_ptr
, &uh
->dest
, sizeof(uh
->dest
));
590 /* checksum is always inline */
591 lowpan_push_hc_data(hc06_ptr
, &uh
->check
, sizeof(uh
->check
));
593 /* skip the UDP header */
594 skb_pull(skb
, sizeof(struct udphdr
));
597 int lowpan_header_compress(struct sk_buff
*skb
, struct net_device
*dev
,
598 unsigned short type
, const void *_daddr
,
599 const void *_saddr
, unsigned int len
)
601 u8 tmp
, iphc0
, iphc1
, *hc06_ptr
;
605 if (type
!= ETH_P_IPV6
)
611 pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n"
612 "\tnexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n",
613 hdr
->version
, ntohs(hdr
->payload_len
), hdr
->nexthdr
,
614 hdr
->hop_limit
, &hdr
->daddr
);
616 raw_dump_table(__func__
, "raw skb network header dump",
617 skb_network_header(skb
), sizeof(struct ipv6hdr
));
619 /* As we copy some bit-length fields, in the IPHC encoding bytes,
620 * we sometimes use |=
621 * If the field is 0, and the current bit value in memory is 1,
622 * this does not work. We therefore reset the IPHC encoding here
624 iphc0
= LOWPAN_DISPATCH_IPHC
;
627 /* TODO: context lookup */
629 raw_dump_inline(__func__
, "saddr",
630 (unsigned char *)_saddr
, IEEE802154_ADDR_LEN
);
631 raw_dump_inline(__func__
, "daddr",
632 (unsigned char *)_daddr
, IEEE802154_ADDR_LEN
);
634 raw_dump_table(__func__
,
635 "sending raw skb network uncompressed packet",
636 skb
->data
, skb
->len
);
638 /* Traffic class, flow label
639 * If flow label is 0, compress it. If traffic class is 0, compress it
640 * We have to process both in the same time as the offset of traffic
641 * class depends on the presence of version and flow label
644 /* hc06 format of TC is ECN | DSCP , original one is DSCP | ECN */
645 tmp
= (hdr
->priority
<< 4) | (hdr
->flow_lbl
[0] >> 4);
646 tmp
= ((tmp
& 0x03) << 6) | (tmp
>> 2);
648 if (((hdr
->flow_lbl
[0] & 0x0F) == 0) &&
649 (hdr
->flow_lbl
[1] == 0) && (hdr
->flow_lbl
[2] == 0)) {
650 /* flow label can be compressed */
651 iphc0
|= LOWPAN_IPHC_FL_C
;
652 if ((hdr
->priority
== 0) &&
653 ((hdr
->flow_lbl
[0] & 0xF0) == 0)) {
654 /* compress (elide) all */
655 iphc0
|= LOWPAN_IPHC_TC_C
;
657 /* compress only the flow label */
662 /* Flow label cannot be compressed */
663 if ((hdr
->priority
== 0) &&
664 ((hdr
->flow_lbl
[0] & 0xF0) == 0)) {
665 /* compress only traffic class */
666 iphc0
|= LOWPAN_IPHC_TC_C
;
667 *hc06_ptr
= (tmp
& 0xc0) | (hdr
->flow_lbl
[0] & 0x0F);
668 memcpy(hc06_ptr
+ 1, &hdr
->flow_lbl
[1], 2);
671 /* compress nothing */
672 memcpy(hc06_ptr
, hdr
, 4);
673 /* replace the top byte with new ECN | DSCP format */
679 /* NOTE: payload length is always compressed */
681 /* Next Header is compress if UDP */
682 if (hdr
->nexthdr
== UIP_PROTO_UDP
)
683 iphc0
|= LOWPAN_IPHC_NH_C
;
685 if ((iphc0
& LOWPAN_IPHC_NH_C
) == 0) {
686 *hc06_ptr
= hdr
->nexthdr
;
691 * if 1: compress, encoding is 01
692 * if 64: compress, encoding is 10
693 * if 255: compress, encoding is 11
694 * else do not compress
696 switch (hdr
->hop_limit
) {
698 iphc0
|= LOWPAN_IPHC_TTL_1
;
701 iphc0
|= LOWPAN_IPHC_TTL_64
;
704 iphc0
|= LOWPAN_IPHC_TTL_255
;
707 *hc06_ptr
= hdr
->hop_limit
;
712 /* source address compression */
713 if (is_addr_unspecified(&hdr
->saddr
)) {
714 pr_debug("source address is unspecified, setting SAC\n");
715 iphc1
|= LOWPAN_IPHC_SAC
;
716 /* TODO: context lookup */
717 } else if (is_addr_link_local(&hdr
->saddr
)) {
718 iphc1
|= lowpan_compress_addr_64(&hc06_ptr
,
719 LOWPAN_IPHC_SAM_BIT
, &hdr
->saddr
, _saddr
);
720 pr_debug("source address unicast link-local %pI6c "
721 "iphc1 0x%02x\n", &hdr
->saddr
, iphc1
);
723 pr_debug("send the full source address\n");
724 memcpy(hc06_ptr
, &hdr
->saddr
.s6_addr16
[0], 16);
728 /* destination address compression */
729 if (is_addr_mcast(&hdr
->daddr
)) {
730 pr_debug("destination address is multicast: ");
731 iphc1
|= LOWPAN_IPHC_M
;
732 if (lowpan_is_mcast_addr_compressable8(&hdr
->daddr
)) {
733 pr_debug("compressed to 1 octet\n");
734 iphc1
|= LOWPAN_IPHC_DAM_11
;
736 *hc06_ptr
= hdr
->daddr
.s6_addr
[15];
738 } else if (lowpan_is_mcast_addr_compressable32(&hdr
->daddr
)) {
739 pr_debug("compressed to 4 octets\n");
740 iphc1
|= LOWPAN_IPHC_DAM_10
;
741 /* second byte + the last three */
742 *hc06_ptr
= hdr
->daddr
.s6_addr
[1];
743 memcpy(hc06_ptr
+ 1, &hdr
->daddr
.s6_addr
[13], 3);
745 } else if (lowpan_is_mcast_addr_compressable48(&hdr
->daddr
)) {
746 pr_debug("compressed to 6 octets\n");
747 iphc1
|= LOWPAN_IPHC_DAM_01
;
748 /* second byte + the last five */
749 *hc06_ptr
= hdr
->daddr
.s6_addr
[1];
750 memcpy(hc06_ptr
+ 1, &hdr
->daddr
.s6_addr
[11], 5);
753 pr_debug("using full address\n");
754 iphc1
|= LOWPAN_IPHC_DAM_00
;
755 memcpy(hc06_ptr
, &hdr
->daddr
.s6_addr
[0], 16);
759 /* TODO: context lookup */
760 if (is_addr_link_local(&hdr
->daddr
)) {
761 iphc1
|= lowpan_compress_addr_64(&hc06_ptr
,
762 LOWPAN_IPHC_DAM_BIT
, &hdr
->daddr
, _daddr
);
763 pr_debug("dest address unicast link-local %pI6c "
764 "iphc1 0x%02x\n", &hdr
->daddr
, iphc1
);
766 pr_debug("dest address unicast %pI6c\n", &hdr
->daddr
);
767 memcpy(hc06_ptr
, &hdr
->daddr
.s6_addr16
[0], 16);
772 /* UDP header compression */
773 if (hdr
->nexthdr
== UIP_PROTO_UDP
)
774 compress_udp_header(&hc06_ptr
, skb
);
779 skb_pull(skb
, sizeof(struct ipv6hdr
));
780 skb_reset_transport_header(skb
);
781 memcpy(skb_push(skb
, hc06_ptr
- head
), head
, hc06_ptr
- head
);
782 skb_reset_network_header(skb
);
784 pr_debug("header len %d skb %u\n", (int)(hc06_ptr
- head
), skb
->len
);
786 raw_dump_table(__func__
, "raw skb data dump compressed",
787 skb
->data
, skb
->len
);
790 EXPORT_SYMBOL_GPL(lowpan_header_compress
);
792 MODULE_LICENSE("GPL");