2 * Copyright 2011, Siemens AG
3 * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
7 * Based on patches from Jon Smirl <jonsmirl@gmail.com>
8 * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com>
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.
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.
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.
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.
28 * Redistribution and use in source and binary forms, with or without
29 * modification, are permitted provided that the following conditions
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.
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
53 #include <linux/bitops.h>
54 #include <linux/if_arp.h>
55 #include <linux/module.h>
56 #include <linux/netdevice.h>
57 #include <net/6lowpan.h>
59 #include <net/af_ieee802154.h>
62 * Uncompress address function for source and
63 * destination address(non-multicast).
65 * address_mode is sam value or dam value.
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,
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);
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);
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);
93 case LOWPAN_IPHC_ADDR_03:
96 case IEEE802154_ADDR_LONG:
97 /* fe:80::XXXX:XXXX:XXXX:XXXX
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
107 ipaddr->s6_addr[8] ^= 0x02;
109 case IEEE802154_ADDR_SHORT:
110 /* fe:80::ff:fe00:XXXX
114 * Universe/Local bit is zero.
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));
123 pr_debug("Invalid addr_type set\n");
128 pr_debug("Invalid address mode value: 0x%x\n", address_mode);
133 pr_debug("Failed to fetch skb data\n");
137 raw_dump_inline(NULL, "Reconstructed ipv6 addr is",
138 ipaddr->s6_addr, 16);
144 * Uncompress address function for source context
145 * based address(non-multicast).
147 static int uncompress_context_based_src_addr(struct sk_buff *skb,
148 struct in6_addr *ipaddr,
152 case LOWPAN_IPHC_ADDR_00:
154 * Do nothing, address is already ::
157 case LOWPAN_IPHC_ADDR_01:
159 case LOWPAN_IPHC_ADDR_02:
161 case LOWPAN_IPHC_ADDR_03:
163 netdev_warn(skb->dev, "SAM value 0x%x not supported\n", sam);
166 pr_debug("Invalid sam value: 0x%x\n", sam);
170 raw_dump_inline(NULL,
171 "Reconstructed context based ipv6 src addr is",
172 ipaddr->s6_addr, 16);
177 static int skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr,
178 struct net_device *dev, skb_delivery_cb deliver_skb)
183 new = skb_copy_expand(skb, sizeof(struct ipv6hdr), skb_tailroom(skb),
190 skb_push(new, sizeof(struct ipv6hdr));
191 skb_reset_network_header(new);
192 skb_copy_to_linear_data(new, hdr, sizeof(struct ipv6hdr));
194 new->protocol = htons(ETH_P_IPV6);
195 new->pkt_type = PACKET_HOST;
198 raw_dump_table(__func__, "raw skb data dump before receiving",
199 new->data, new->len);
201 stat = deliver_skb(new, dev);
208 /* Uncompress function for multicast destination address,
212 lowpan_uncompress_multicast_daddr(struct sk_buff *skb,
213 struct in6_addr *ipaddr,
219 case LOWPAN_IPHC_DAM_00:
220 /* 00: 128 bits. The full address
221 * is carried in-line.
223 fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
225 case LOWPAN_IPHC_DAM_01:
226 /* 01: 48 bits. The address takes
227 * the form ffXX::00XX:XXXX:XXXX.
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);
233 case LOWPAN_IPHC_DAM_10:
234 /* 10: 32 bits. The address takes
235 * the form ffXX::00XX:XXXX.
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);
241 case LOWPAN_IPHC_DAM_11:
242 /* 11: 8 bits. The address takes
243 * the form ff02::00XX.
245 ipaddr->s6_addr[0] = 0xFF;
246 ipaddr->s6_addr[1] = 0x02;
247 fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[15], 1);
250 pr_debug("DAM value has a wrong value: 0x%x\n", dam);
255 pr_debug("Failed to fetch skb data\n");
259 raw_dump_inline(NULL, "Reconstructed ipv6 multicast addr is",
260 ipaddr->s6_addr, 16);
266 uncompress_udp_header(struct sk_buff *skb, struct udphdr *uh)
274 fail = lowpan_fetch_skb(skb, &tmp, sizeof(tmp));
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 fail |= lowpan_fetch_skb(skb, &uh->source,
282 fail |= lowpan_fetch_skb(skb, &uh->dest,
285 case LOWPAN_NHC_UDP_CS_P_01:
286 fail |= lowpan_fetch_skb(skb, &uh->source,
288 fail |= lowpan_fetch_skb(skb, &val, sizeof(val));
289 uh->dest = htons(val + LOWPAN_NHC_UDP_8BIT_PORT);
291 case LOWPAN_NHC_UDP_CS_P_10:
292 fail |= lowpan_fetch_skb(skb, &val, sizeof(val));
293 uh->source = htons(val + LOWPAN_NHC_UDP_8BIT_PORT);
294 fail |= lowpan_fetch_skb(skb, &uh->dest,
297 case LOWPAN_NHC_UDP_CS_P_11:
298 fail |= lowpan_fetch_skb(skb, &val, sizeof(val));
299 uh->source = htons(LOWPAN_NHC_UDP_4BIT_PORT +
301 uh->dest = htons(LOWPAN_NHC_UDP_4BIT_PORT +
305 pr_debug("ERROR: unknown UDP format\n");
310 pr_debug("uncompressed UDP ports: src = %d, dst = %d\n",
311 ntohs(uh->source), ntohs(uh->dest));
314 if (tmp & LOWPAN_NHC_UDP_CS_C) {
315 pr_debug_ratelimited("checksum elided currently not supported\n");
318 fail |= lowpan_fetch_skb(skb, &uh->check,
323 * UDP lenght needs to be infered from the lower layers
324 * here, we obtain the hint from the remaining size of the
327 uh->len = htons(skb->len + sizeof(struct udphdr));
328 pr_debug("uncompressed UDP length: src = %d", ntohs(uh->len));
330 pr_debug("ERROR: unsupported NH format\n");
342 /* TTL uncompression values */
343 static const u8 lowpan_ttl_values[] = { 0, 1, 64, 255 };
345 int 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)
350 struct ipv6hdr hdr = {};
351 u8 tmp, num_context = 0;
354 raw_dump_table(__func__, "raw skb data dump uncompressed",
355 skb->data, skb->len);
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");
360 if (lowpan_fetch_skb(skb, &num_context, sizeof(num_context)))
366 /* Traffic Class and Flow Label */
367 switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
369 * Traffic Class and FLow Label carried in-line
370 * ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
373 if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp)))
376 memcpy(&hdr.flow_lbl, &skb->data[0], 3);
378 hdr.priority = ((tmp >> 2) & 0x0f);
379 hdr.flow_lbl[0] = ((tmp >> 2) & 0x30) | (tmp << 6) |
380 (hdr.flow_lbl[0] & 0x0f);
383 * Traffic class carried in-line
384 * ECN + DSCP (1 byte), Flow Label is elided
387 if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp)))
390 hdr.priority = ((tmp >> 2) & 0x0f);
391 hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30);
394 * Flow Label carried in-line
395 * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
398 if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp)))
401 hdr.flow_lbl[0] = (skb->data[0] & 0x0F) | ((tmp >> 2) & 0x30);
402 memcpy(&hdr.flow_lbl[1], &skb->data[0], 2);
405 /* Traffic Class and Flow Label are elided */
413 if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
414 /* Next header is carried inline */
415 if (lowpan_fetch_skb(skb, &hdr.nexthdr, sizeof(hdr.nexthdr)))
418 pr_debug("NH flag is set, next header carried inline: %02x\n",
423 if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I)
424 hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03];
426 if (lowpan_fetch_skb(skb, &hdr.hop_limit,
427 sizeof(hdr.hop_limit)))
431 /* Extract SAM to the tmp variable */
432 tmp = ((iphc1 & LOWPAN_IPHC_SAM) >> LOWPAN_IPHC_SAM_BIT) & 0x03;
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);
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);
446 /* Check on error of previous branch */
450 /* Extract DAM to the tmp variable */
451 tmp = ((iphc1 & LOWPAN_IPHC_DAM_11) >> LOWPAN_IPHC_DAM_BIT) & 0x03;
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 */
459 err = lowpan_uncompress_multicast_daddr(
460 skb, &hdr.daddr, tmp);
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",
473 /* UDP data uncompression */
474 if (iphc0 & LOWPAN_IPHC_NH_C) {
477 if (uncompress_udp_header(skb, &uh))
481 * replace the compressed UDP head by the uncompressed UDP
484 new = skb_copy_expand(skb, sizeof(struct udphdr),
485 skb_tailroom(skb), GFP_ATOMIC);
493 skb_push(skb, sizeof(struct udphdr));
494 skb_reset_transport_header(skb);
495 skb_copy_to_linear_data(skb, &uh, sizeof(struct udphdr));
497 raw_dump_table(__func__, "raw UDP header dump",
498 (u8 *)&uh, sizeof(uh));
500 hdr.nexthdr = UIP_PROTO_UDP;
503 hdr.payload_len = htons(skb->len);
505 pr_debug("skb headroom size = %d, data length = %d\n",
506 skb_headroom(skb), skb->len);
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);
513 raw_dump_table(__func__, "raw header dump", (u8 *)&hdr,
516 return skb_deliver(skb, &hdr, dev, deliver_skb);
522 EXPORT_SYMBOL_GPL(lowpan_process_data);
524 static u8 lowpan_compress_addr_64(u8 **hc_ptr, u8 shift,
525 const struct in6_addr *ipaddr,
526 const unsigned char *lladdr)
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 */
535 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[7], 2);
536 val = 2; /* 16-bits */
537 raw_dump_inline(NULL, "Compressed ipv6 addr is (16 bits)",
540 /* do not compress IID => xxxx::IID */
541 lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[4], 8);
542 val = 1; /* 64-bits */
543 raw_dump_inline(NULL, "Compressed ipv6 addr is (64 bits)",
547 return rol8(val, shift);
550 static void compress_udp_header(u8 **hc_ptr, struct sk_buff *skb)
552 struct udphdr *uh = udp_hdr(skb);
555 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)) {
559 pr_debug("UDP header: both ports compression to 4 bits\n");
560 /* compression value */
561 tmp = LOWPAN_NHC_UDP_CS_P_11;
562 lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
563 /* source and destination port */
564 tmp = ntohs(uh->dest) - LOWPAN_NHC_UDP_4BIT_PORT +
565 ((ntohs(uh->source) - LOWPAN_NHC_UDP_4BIT_PORT) << 4);
566 lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
567 } else if ((ntohs(uh->dest) & LOWPAN_NHC_UDP_8BIT_MASK) ==
568 LOWPAN_NHC_UDP_8BIT_PORT) {
569 pr_debug("UDP header: remove 8 bits of dest\n");
570 /* compression value */
571 tmp = LOWPAN_NHC_UDP_CS_P_01;
572 lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
574 lowpan_push_hc_data(hc_ptr, &uh->source, sizeof(uh->source));
575 /* destination port */
576 tmp = ntohs(uh->dest) - LOWPAN_NHC_UDP_8BIT_PORT;
577 lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
578 } else if ((ntohs(uh->source) & LOWPAN_NHC_UDP_8BIT_MASK) ==
579 LOWPAN_NHC_UDP_8BIT_PORT) {
580 pr_debug("UDP header: remove 8 bits of source\n");
581 /* compression value */
582 tmp = LOWPAN_NHC_UDP_CS_P_10;
583 lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
585 tmp = ntohs(uh->source) - LOWPAN_NHC_UDP_8BIT_PORT;
586 lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
587 /* destination port */
588 lowpan_push_hc_data(hc_ptr, &uh->dest, sizeof(uh->dest));
590 pr_debug("UDP header: can't compress\n");
591 /* compression value */
592 tmp = LOWPAN_NHC_UDP_CS_P_00;
593 lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp));
595 lowpan_push_hc_data(hc_ptr, &uh->source, sizeof(uh->source));
596 /* destination port */
597 lowpan_push_hc_data(hc_ptr, &uh->dest, sizeof(uh->dest));
600 /* checksum is always inline */
601 lowpan_push_hc_data(hc_ptr, &uh->check, sizeof(uh->check));
603 /* skip the UDP header */
604 skb_pull(skb, sizeof(struct udphdr));
607 int 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)
611 u8 tmp, iphc0, iphc1, *hc_ptr;
615 if (type != ETH_P_IPV6)
621 pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n"
622 "\tnexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n",
623 hdr->version, ntohs(hdr->payload_len), hdr->nexthdr,
624 hdr->hop_limit, &hdr->daddr);
626 raw_dump_table(__func__, "raw skb network header dump",
627 skb_network_header(skb), sizeof(struct ipv6hdr));
630 * As we copy some bit-length fields, in the IPHC encoding bytes,
631 * we sometimes use |=
632 * If the field is 0, and the current bit value in memory is 1,
633 * this does not work. We therefore reset the IPHC encoding here
635 iphc0 = LOWPAN_DISPATCH_IPHC;
638 /* TODO: context lookup */
640 raw_dump_inline(__func__, "saddr",
641 (unsigned char *)_saddr, IEEE802154_ADDR_LEN);
642 raw_dump_inline(__func__, "daddr",
643 (unsigned char *)_daddr, IEEE802154_ADDR_LEN);
645 raw_dump_table(__func__,
646 "sending raw skb network uncompressed packet",
647 skb->data, skb->len);
650 * Traffic class, flow label
651 * If flow label is 0, compress it. If traffic class is 0, compress it
652 * We have to process both in the same time as the offset of traffic
653 * class depends on the presence of version and flow label
656 /* hc format of TC is ECN | DSCP , original one is DSCP | ECN */
657 tmp = (hdr->priority << 4) | (hdr->flow_lbl[0] >> 4);
658 tmp = ((tmp & 0x03) << 6) | (tmp >> 2);
660 if (((hdr->flow_lbl[0] & 0x0F) == 0) &&
661 (hdr->flow_lbl[1] == 0) && (hdr->flow_lbl[2] == 0)) {
662 /* flow label can be compressed */
663 iphc0 |= LOWPAN_IPHC_FL_C;
664 if ((hdr->priority == 0) &&
665 ((hdr->flow_lbl[0] & 0xF0) == 0)) {
666 /* compress (elide) all */
667 iphc0 |= LOWPAN_IPHC_TC_C;
669 /* compress only the flow label */
674 /* Flow label cannot be compressed */
675 if ((hdr->priority == 0) &&
676 ((hdr->flow_lbl[0] & 0xF0) == 0)) {
677 /* compress only traffic class */
678 iphc0 |= LOWPAN_IPHC_TC_C;
679 *hc_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F);
680 memcpy(hc_ptr + 1, &hdr->flow_lbl[1], 2);
683 /* compress nothing */
684 memcpy(hc_ptr, hdr, 4);
685 /* replace the top byte with new ECN | DSCP format */
691 /* NOTE: payload length is always compressed */
693 /* Next Header is compress if UDP */
694 if (hdr->nexthdr == UIP_PROTO_UDP)
695 iphc0 |= LOWPAN_IPHC_NH_C;
697 if ((iphc0 & LOWPAN_IPHC_NH_C) == 0)
698 lowpan_push_hc_data(&hc_ptr, &hdr->nexthdr,
699 sizeof(hdr->nexthdr));
703 * if 1: compress, encoding is 01
704 * if 64: compress, encoding is 10
705 * if 255: compress, encoding is 11
706 * else do not compress
708 switch (hdr->hop_limit) {
710 iphc0 |= LOWPAN_IPHC_TTL_1;
713 iphc0 |= LOWPAN_IPHC_TTL_64;
716 iphc0 |= LOWPAN_IPHC_TTL_255;
719 lowpan_push_hc_data(&hc_ptr, &hdr->hop_limit,
720 sizeof(hdr->hop_limit));
723 /* source address compression */
724 if (is_addr_unspecified(&hdr->saddr)) {
725 pr_debug("source address is unspecified, setting SAC\n");
726 iphc1 |= LOWPAN_IPHC_SAC;
727 /* TODO: context lookup */
728 } else if (is_addr_link_local(&hdr->saddr)) {
729 iphc1 |= lowpan_compress_addr_64(&hc_ptr,
730 LOWPAN_IPHC_SAM_BIT, &hdr->saddr, _saddr);
731 pr_debug("source address unicast link-local %pI6c "
732 "iphc1 0x%02x\n", &hdr->saddr, iphc1);
734 pr_debug("send the full source address\n");
735 lowpan_push_hc_data(&hc_ptr, &hdr->saddr.s6_addr[0], 16);
738 /* destination address compression */
739 if (is_addr_mcast(&hdr->daddr)) {
740 pr_debug("destination address is multicast: ");
741 iphc1 |= LOWPAN_IPHC_M;
742 if (lowpan_is_mcast_addr_compressable8(&hdr->daddr)) {
743 pr_debug("compressed to 1 octet\n");
744 iphc1 |= LOWPAN_IPHC_DAM_11;
746 lowpan_push_hc_data(&hc_ptr,
747 &hdr->daddr.s6_addr[15], 1);
748 } else if (lowpan_is_mcast_addr_compressable32(&hdr->daddr)) {
749 pr_debug("compressed to 4 octets\n");
750 iphc1 |= LOWPAN_IPHC_DAM_10;
751 /* second byte + the last three */
752 lowpan_push_hc_data(&hc_ptr,
753 &hdr->daddr.s6_addr[1], 1);
754 lowpan_push_hc_data(&hc_ptr,
755 &hdr->daddr.s6_addr[13], 3);
756 } else if (lowpan_is_mcast_addr_compressable48(&hdr->daddr)) {
757 pr_debug("compressed to 6 octets\n");
758 iphc1 |= LOWPAN_IPHC_DAM_01;
759 /* second byte + the last five */
760 lowpan_push_hc_data(&hc_ptr,
761 &hdr->daddr.s6_addr[1], 1);
762 lowpan_push_hc_data(&hc_ptr,
763 &hdr->daddr.s6_addr[11], 5);
765 pr_debug("using full address\n");
766 iphc1 |= LOWPAN_IPHC_DAM_00;
767 lowpan_push_hc_data(&hc_ptr, hdr->daddr.s6_addr, 16);
770 /* TODO: context lookup */
771 if (is_addr_link_local(&hdr->daddr)) {
772 iphc1 |= lowpan_compress_addr_64(&hc_ptr,
773 LOWPAN_IPHC_DAM_BIT, &hdr->daddr, _daddr);
774 pr_debug("dest address unicast link-local %pI6c "
775 "iphc1 0x%02x\n", &hdr->daddr, iphc1);
777 pr_debug("dest address unicast %pI6c\n", &hdr->daddr);
778 lowpan_push_hc_data(&hc_ptr, hdr->daddr.s6_addr, 16);
782 /* UDP header compression */
783 if (hdr->nexthdr == UIP_PROTO_UDP)
784 compress_udp_header(&hc_ptr, skb);
789 skb_pull(skb, sizeof(struct ipv6hdr));
790 skb_reset_transport_header(skb);
791 memcpy(skb_push(skb, hc_ptr - head), head, hc_ptr - head);
792 skb_reset_network_header(skb);
794 pr_debug("header len %d skb %u\n", (int)(hc_ptr - head), skb->len);
796 raw_dump_table(__func__, "raw skb data dump compressed",
797 skb->data, skb->len);
800 EXPORT_SYMBOL_GPL(lowpan_header_compress);
802 MODULE_LICENSE("GPL");