12c6bed7cSAlexander Aring /* 22c6bed7cSAlexander Aring * Copyright 2011, Siemens AG 32c6bed7cSAlexander Aring * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com> 42c6bed7cSAlexander Aring */ 52c6bed7cSAlexander Aring 63fd0202aSDavid S. Miller /* Based on patches from Jon Smirl <jonsmirl@gmail.com> 72c6bed7cSAlexander Aring * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com> 82c6bed7cSAlexander Aring * 92c6bed7cSAlexander Aring * This program is free software; you can redistribute it and/or modify 102c6bed7cSAlexander Aring * it under the terms of the GNU General Public License version 2 112c6bed7cSAlexander Aring * as published by the Free Software Foundation. 122c6bed7cSAlexander Aring * 132c6bed7cSAlexander Aring * This program is distributed in the hope that it will be useful, 142c6bed7cSAlexander Aring * but WITHOUT ANY WARRANTY; without even the implied warranty of 152c6bed7cSAlexander Aring * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 162c6bed7cSAlexander Aring * GNU General Public License for more details. 172c6bed7cSAlexander Aring * 182c6bed7cSAlexander Aring */ 192c6bed7cSAlexander Aring 202c6bed7cSAlexander Aring /* Jon's code is based on 6lowpan implementation for Contiki which is: 212c6bed7cSAlexander Aring * Copyright (c) 2008, Swedish Institute of Computer Science. 222c6bed7cSAlexander Aring * All rights reserved. 232c6bed7cSAlexander Aring * 242c6bed7cSAlexander Aring * Redistribution and use in source and binary forms, with or without 252c6bed7cSAlexander Aring * modification, are permitted provided that the following conditions 262c6bed7cSAlexander Aring * are met: 272c6bed7cSAlexander Aring * 1. Redistributions of source code must retain the above copyright 282c6bed7cSAlexander Aring * notice, this list of conditions and the following disclaimer. 292c6bed7cSAlexander Aring * 2. Redistributions in binary form must reproduce the above copyright 302c6bed7cSAlexander Aring * notice, this list of conditions and the following disclaimer in the 312c6bed7cSAlexander Aring * documentation and/or other materials provided with the distribution. 322c6bed7cSAlexander Aring * 3. Neither the name of the Institute nor the names of its contributors 332c6bed7cSAlexander Aring * may be used to endorse or promote products derived from this software 342c6bed7cSAlexander Aring * without specific prior written permission. 352c6bed7cSAlexander Aring * 362c6bed7cSAlexander Aring * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 372c6bed7cSAlexander Aring * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 382c6bed7cSAlexander Aring * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 392c6bed7cSAlexander Aring * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 402c6bed7cSAlexander Aring * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 412c6bed7cSAlexander Aring * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 422c6bed7cSAlexander Aring * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 432c6bed7cSAlexander Aring * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 442c6bed7cSAlexander Aring * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 452c6bed7cSAlexander Aring * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 462c6bed7cSAlexander Aring * SUCH DAMAGE. 472c6bed7cSAlexander Aring */ 482c6bed7cSAlexander Aring 492c6bed7cSAlexander Aring #include <linux/bitops.h> 502c6bed7cSAlexander Aring #include <linux/if_arp.h> 512c6bed7cSAlexander Aring #include <linux/netdevice.h> 528911d774SAlexander Aring 532c6bed7cSAlexander Aring #include <net/6lowpan.h> 542c6bed7cSAlexander Aring #include <net/ipv6.h> 558911d774SAlexander Aring 568911d774SAlexander Aring /* special link-layer handling */ 578911d774SAlexander Aring #include <net/mac802154.h> 582c6bed7cSAlexander Aring 59cc6ed268SAlexander Aring #include "nhc.h" 60cc6ed268SAlexander Aring 61c8a3e7ebSAlexander Aring /* Values of fields within the IPHC encoding first byte */ 62c8a3e7ebSAlexander Aring #define LOWPAN_IPHC_TF_MASK 0x18 63c8a3e7ebSAlexander Aring #define LOWPAN_IPHC_TF_00 0x00 64c8a3e7ebSAlexander Aring #define LOWPAN_IPHC_TF_01 0x08 65c8a3e7ebSAlexander Aring #define LOWPAN_IPHC_TF_10 0x10 66c8a3e7ebSAlexander Aring #define LOWPAN_IPHC_TF_11 0x18 676350047eSAlexander Aring 68c8a3e7ebSAlexander Aring #define LOWPAN_IPHC_NH 0x04 69c8a3e7ebSAlexander Aring 70c8a3e7ebSAlexander Aring #define LOWPAN_IPHC_HLIM_MASK 0x03 71c8a3e7ebSAlexander Aring #define LOWPAN_IPHC_HLIM_00 0x00 72c8a3e7ebSAlexander Aring #define LOWPAN_IPHC_HLIM_01 0x01 73c8a3e7ebSAlexander Aring #define LOWPAN_IPHC_HLIM_10 0x02 74c8a3e7ebSAlexander Aring #define LOWPAN_IPHC_HLIM_11 0x03 756350047eSAlexander Aring 766350047eSAlexander Aring /* Values of fields within the IPHC encoding second byte */ 776350047eSAlexander Aring #define LOWPAN_IPHC_CID 0x80 786350047eSAlexander Aring 796350047eSAlexander Aring #define LOWPAN_IPHC_SAC 0x40 806350047eSAlexander Aring 81c8a3e7ebSAlexander Aring #define LOWPAN_IPHC_SAM_MASK 0x30 82c8a3e7ebSAlexander Aring #define LOWPAN_IPHC_SAM_00 0x00 83c8a3e7ebSAlexander Aring #define LOWPAN_IPHC_SAM_01 0x10 84c8a3e7ebSAlexander Aring #define LOWPAN_IPHC_SAM_10 0x20 85c8a3e7ebSAlexander Aring #define LOWPAN_IPHC_SAM_11 0x30 866350047eSAlexander Aring 876350047eSAlexander Aring #define LOWPAN_IPHC_M 0x08 88c8a3e7ebSAlexander Aring 896350047eSAlexander Aring #define LOWPAN_IPHC_DAC 0x04 90c8a3e7ebSAlexander Aring 91c8a3e7ebSAlexander Aring #define LOWPAN_IPHC_DAM_MASK 0x03 926350047eSAlexander Aring #define LOWPAN_IPHC_DAM_00 0x00 936350047eSAlexander Aring #define LOWPAN_IPHC_DAM_01 0x01 946350047eSAlexander Aring #define LOWPAN_IPHC_DAM_10 0x02 956350047eSAlexander Aring #define LOWPAN_IPHC_DAM_11 0x03 966350047eSAlexander Aring 976350047eSAlexander Aring /* ipv6 address based on mac 986350047eSAlexander Aring * second bit-flip (Universe/Local) is done according RFC2464 996350047eSAlexander Aring */ 1006350047eSAlexander Aring #define is_addr_mac_addr_based(a, m) \ 1016350047eSAlexander Aring ((((a)->s6_addr[8]) == (((m)[0]) ^ 0x02)) && \ 1026350047eSAlexander Aring (((a)->s6_addr[9]) == (m)[1]) && \ 1036350047eSAlexander Aring (((a)->s6_addr[10]) == (m)[2]) && \ 1046350047eSAlexander Aring (((a)->s6_addr[11]) == (m)[3]) && \ 1056350047eSAlexander Aring (((a)->s6_addr[12]) == (m)[4]) && \ 1066350047eSAlexander Aring (((a)->s6_addr[13]) == (m)[5]) && \ 1076350047eSAlexander Aring (((a)->s6_addr[14]) == (m)[6]) && \ 1086350047eSAlexander Aring (((a)->s6_addr[15]) == (m)[7])) 1096350047eSAlexander Aring 1106350047eSAlexander Aring /* check whether we can compress the IID to 16 bits, 1116350047eSAlexander Aring * it's possible for unicast addresses with first 49 bits are zero only. 1126350047eSAlexander Aring */ 1136350047eSAlexander Aring #define lowpan_is_iid_16_bit_compressable(a) \ 1146350047eSAlexander Aring ((((a)->s6_addr16[4]) == 0) && \ 1156350047eSAlexander Aring (((a)->s6_addr[10]) == 0) && \ 1166350047eSAlexander Aring (((a)->s6_addr[11]) == 0xff) && \ 1176350047eSAlexander Aring (((a)->s6_addr[12]) == 0xfe) && \ 1186350047eSAlexander Aring (((a)->s6_addr[13]) == 0)) 1196350047eSAlexander Aring 1206350047eSAlexander Aring /* check whether the 112-bit gid of the multicast address is mappable to: */ 1216350047eSAlexander Aring 1226350047eSAlexander Aring /* 48 bits, FFXX::00XX:XXXX:XXXX */ 1236350047eSAlexander Aring #define lowpan_is_mcast_addr_compressable48(a) \ 1246350047eSAlexander Aring ((((a)->s6_addr16[1]) == 0) && \ 1256350047eSAlexander Aring (((a)->s6_addr16[2]) == 0) && \ 1266350047eSAlexander Aring (((a)->s6_addr16[3]) == 0) && \ 1276350047eSAlexander Aring (((a)->s6_addr16[4]) == 0) && \ 1286350047eSAlexander Aring (((a)->s6_addr[10]) == 0)) 1296350047eSAlexander Aring 1306350047eSAlexander Aring /* 32 bits, FFXX::00XX:XXXX */ 1316350047eSAlexander Aring #define lowpan_is_mcast_addr_compressable32(a) \ 1326350047eSAlexander Aring ((((a)->s6_addr16[1]) == 0) && \ 1336350047eSAlexander Aring (((a)->s6_addr16[2]) == 0) && \ 1346350047eSAlexander Aring (((a)->s6_addr16[3]) == 0) && \ 1356350047eSAlexander Aring (((a)->s6_addr16[4]) == 0) && \ 1366350047eSAlexander Aring (((a)->s6_addr16[5]) == 0) && \ 1376350047eSAlexander Aring (((a)->s6_addr[12]) == 0)) 1386350047eSAlexander Aring 1396350047eSAlexander Aring /* 8 bits, FF02::00XX */ 1406350047eSAlexander Aring #define lowpan_is_mcast_addr_compressable8(a) \ 1416350047eSAlexander Aring ((((a)->s6_addr[1]) == 2) && \ 1426350047eSAlexander Aring (((a)->s6_addr16[1]) == 0) && \ 1436350047eSAlexander Aring (((a)->s6_addr16[2]) == 0) && \ 1446350047eSAlexander Aring (((a)->s6_addr16[3]) == 0) && \ 1456350047eSAlexander Aring (((a)->s6_addr16[4]) == 0) && \ 1466350047eSAlexander Aring (((a)->s6_addr16[5]) == 0) && \ 1476350047eSAlexander Aring (((a)->s6_addr16[6]) == 0) && \ 1486350047eSAlexander Aring (((a)->s6_addr[14]) == 0)) 1496350047eSAlexander Aring 1508911d774SAlexander Aring static inline void iphc_uncompress_eui64_lladdr(struct in6_addr *ipaddr, 1518911d774SAlexander Aring const void *lladdr) 1528911d774SAlexander Aring { 1538911d774SAlexander Aring /* fe:80::XXXX:XXXX:XXXX:XXXX 1548911d774SAlexander Aring * \_________________/ 1558911d774SAlexander Aring * hwaddr 1568911d774SAlexander Aring */ 1578911d774SAlexander Aring ipaddr->s6_addr[0] = 0xFE; 1588911d774SAlexander Aring ipaddr->s6_addr[1] = 0x80; 1598911d774SAlexander Aring memcpy(&ipaddr->s6_addr[8], lladdr, EUI64_ADDR_LEN); 1608911d774SAlexander Aring /* second bit-flip (Universe/Local) 1618911d774SAlexander Aring * is done according RFC2464 1628911d774SAlexander Aring */ 1638911d774SAlexander Aring ipaddr->s6_addr[8] ^= 0x02; 1648911d774SAlexander Aring } 1658911d774SAlexander Aring 1668911d774SAlexander Aring static inline void iphc_uncompress_802154_lladdr(struct in6_addr *ipaddr, 1678911d774SAlexander Aring const void *lladdr) 1688911d774SAlexander Aring { 1698911d774SAlexander Aring const struct ieee802154_addr *addr = lladdr; 1708911d774SAlexander Aring u8 eui64[EUI64_ADDR_LEN] = { }; 1718911d774SAlexander Aring 1728911d774SAlexander Aring switch (addr->mode) { 1738911d774SAlexander Aring case IEEE802154_ADDR_LONG: 1748911d774SAlexander Aring ieee802154_le64_to_be64(eui64, &addr->extended_addr); 1758911d774SAlexander Aring iphc_uncompress_eui64_lladdr(ipaddr, eui64); 1768911d774SAlexander Aring break; 1778911d774SAlexander Aring case IEEE802154_ADDR_SHORT: 1788911d774SAlexander Aring /* fe:80::ff:fe00:XXXX 1798911d774SAlexander Aring * \__/ 1808911d774SAlexander Aring * short_addr 1818911d774SAlexander Aring * 1828911d774SAlexander Aring * Universe/Local bit is zero. 1838911d774SAlexander Aring */ 1848911d774SAlexander Aring ipaddr->s6_addr[0] = 0xFE; 1858911d774SAlexander Aring ipaddr->s6_addr[1] = 0x80; 1868911d774SAlexander Aring ipaddr->s6_addr[11] = 0xFF; 1878911d774SAlexander Aring ipaddr->s6_addr[12] = 0xFE; 1888911d774SAlexander Aring ieee802154_le16_to_be16(&ipaddr->s6_addr16[7], 1898911d774SAlexander Aring &addr->short_addr); 1908911d774SAlexander Aring break; 1918911d774SAlexander Aring default: 1928911d774SAlexander Aring /* should never handled and filtered by 802154 6lowpan */ 1938911d774SAlexander Aring WARN_ON_ONCE(1); 1948911d774SAlexander Aring break; 1958911d774SAlexander Aring } 1968911d774SAlexander Aring } 1978911d774SAlexander Aring 1983fd0202aSDavid S. Miller /* Uncompress address function for source and 1992c6bed7cSAlexander Aring * destination address(non-multicast). 2002c6bed7cSAlexander Aring * 201c8a3e7ebSAlexander Aring * address_mode is the masked value for sam or dam value 2022c6bed7cSAlexander Aring */ 2038911d774SAlexander Aring static int uncompress_addr(struct sk_buff *skb, const struct net_device *dev, 2048911d774SAlexander Aring struct in6_addr *ipaddr, u8 address_mode, 2058911d774SAlexander Aring const void *lladdr) 2062c6bed7cSAlexander Aring { 2072c6bed7cSAlexander Aring bool fail; 2082c6bed7cSAlexander Aring 2092c6bed7cSAlexander Aring switch (address_mode) { 210c8a3e7ebSAlexander Aring /* SAM and DAM are the same here */ 211c8a3e7ebSAlexander Aring case LOWPAN_IPHC_DAM_00: 2122c6bed7cSAlexander Aring /* for global link addresses */ 2132c6bed7cSAlexander Aring fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16); 2142c6bed7cSAlexander Aring break; 215c8a3e7ebSAlexander Aring case LOWPAN_IPHC_SAM_01: 216c8a3e7ebSAlexander Aring case LOWPAN_IPHC_DAM_01: 2172c6bed7cSAlexander Aring /* fe:80::XXXX:XXXX:XXXX:XXXX */ 2182c6bed7cSAlexander Aring ipaddr->s6_addr[0] = 0xFE; 2192c6bed7cSAlexander Aring ipaddr->s6_addr[1] = 0x80; 2202c6bed7cSAlexander Aring fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[8], 8); 2212c6bed7cSAlexander Aring break; 222c8a3e7ebSAlexander Aring case LOWPAN_IPHC_SAM_10: 223c8a3e7ebSAlexander Aring case LOWPAN_IPHC_DAM_10: 2242c6bed7cSAlexander Aring /* fe:80::ff:fe00:XXXX */ 2252c6bed7cSAlexander Aring ipaddr->s6_addr[0] = 0xFE; 2262c6bed7cSAlexander Aring ipaddr->s6_addr[1] = 0x80; 2272c6bed7cSAlexander Aring ipaddr->s6_addr[11] = 0xFF; 2282c6bed7cSAlexander Aring ipaddr->s6_addr[12] = 0xFE; 2292c6bed7cSAlexander Aring fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2); 2302c6bed7cSAlexander Aring break; 231c8a3e7ebSAlexander Aring case LOWPAN_IPHC_SAM_11: 232c8a3e7ebSAlexander Aring case LOWPAN_IPHC_DAM_11: 2332c6bed7cSAlexander Aring fail = false; 2348911d774SAlexander Aring switch (lowpan_priv(dev)->lltype) { 2358911d774SAlexander Aring case LOWPAN_LLTYPE_IEEE802154: 2368911d774SAlexander Aring iphc_uncompress_802154_lladdr(ipaddr, lladdr); 2372c6bed7cSAlexander Aring break; 2382c6bed7cSAlexander Aring default: 2398911d774SAlexander Aring iphc_uncompress_eui64_lladdr(ipaddr, lladdr); 2408911d774SAlexander Aring break; 2412c6bed7cSAlexander Aring } 2422c6bed7cSAlexander Aring break; 2432c6bed7cSAlexander Aring default: 2442c6bed7cSAlexander Aring pr_debug("Invalid address mode value: 0x%x\n", address_mode); 2452c6bed7cSAlexander Aring return -EINVAL; 2462c6bed7cSAlexander Aring } 2472c6bed7cSAlexander Aring 2482c6bed7cSAlexander Aring if (fail) { 2492c6bed7cSAlexander Aring pr_debug("Failed to fetch skb data\n"); 2502c6bed7cSAlexander Aring return -EIO; 2512c6bed7cSAlexander Aring } 2522c6bed7cSAlexander Aring 2532c6bed7cSAlexander Aring raw_dump_inline(NULL, "Reconstructed ipv6 addr is", 2542c6bed7cSAlexander Aring ipaddr->s6_addr, 16); 2552c6bed7cSAlexander Aring 2562c6bed7cSAlexander Aring return 0; 2572c6bed7cSAlexander Aring } 2582c6bed7cSAlexander Aring 2593fd0202aSDavid S. Miller /* Uncompress address function for source context 2602c6bed7cSAlexander Aring * based address(non-multicast). 2612c6bed7cSAlexander Aring */ 2622c6bed7cSAlexander Aring static int uncompress_context_based_src_addr(struct sk_buff *skb, 2632c6bed7cSAlexander Aring struct in6_addr *ipaddr, 264c8a3e7ebSAlexander Aring u8 address_mode) 2652c6bed7cSAlexander Aring { 266c8a3e7ebSAlexander Aring switch (address_mode) { 267c8a3e7ebSAlexander Aring case LOWPAN_IPHC_SAM_00: 2682c6bed7cSAlexander Aring /* unspec address :: 2692c6bed7cSAlexander Aring * Do nothing, address is already :: 2702c6bed7cSAlexander Aring */ 2712c6bed7cSAlexander Aring break; 272c8a3e7ebSAlexander Aring case LOWPAN_IPHC_SAM_01: 2732c6bed7cSAlexander Aring /* TODO */ 274c8a3e7ebSAlexander Aring case LOWPAN_IPHC_SAM_10: 2752c6bed7cSAlexander Aring /* TODO */ 276c8a3e7ebSAlexander Aring case LOWPAN_IPHC_SAM_11: 2772c6bed7cSAlexander Aring /* TODO */ 278c8a3e7ebSAlexander Aring netdev_warn(skb->dev, "SAM value 0x%x not supported\n", 279c8a3e7ebSAlexander Aring address_mode); 2802c6bed7cSAlexander Aring return -EINVAL; 2812c6bed7cSAlexander Aring default: 282c8a3e7ebSAlexander Aring pr_debug("Invalid sam value: 0x%x\n", address_mode); 2832c6bed7cSAlexander Aring return -EINVAL; 2842c6bed7cSAlexander Aring } 2852c6bed7cSAlexander Aring 2862c6bed7cSAlexander Aring raw_dump_inline(NULL, 2872c6bed7cSAlexander Aring "Reconstructed context based ipv6 src addr is", 2882c6bed7cSAlexander Aring ipaddr->s6_addr, 16); 2892c6bed7cSAlexander Aring 2902c6bed7cSAlexander Aring return 0; 2912c6bed7cSAlexander Aring } 2922c6bed7cSAlexander Aring 2932c6bed7cSAlexander Aring /* Uncompress function for multicast destination address, 2942c6bed7cSAlexander Aring * when M bit is set. 2952c6bed7cSAlexander Aring */ 2967fc4cfdaSMarcel Holtmann static int lowpan_uncompress_multicast_daddr(struct sk_buff *skb, 2972c6bed7cSAlexander Aring struct in6_addr *ipaddr, 298c8a3e7ebSAlexander Aring u8 address_mode) 2992c6bed7cSAlexander Aring { 3002c6bed7cSAlexander Aring bool fail; 3012c6bed7cSAlexander Aring 302c8a3e7ebSAlexander Aring switch (address_mode) { 3032c6bed7cSAlexander Aring case LOWPAN_IPHC_DAM_00: 3042c6bed7cSAlexander Aring /* 00: 128 bits. The full address 3052c6bed7cSAlexander Aring * is carried in-line. 3062c6bed7cSAlexander Aring */ 3072c6bed7cSAlexander Aring fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16); 3082c6bed7cSAlexander Aring break; 3092c6bed7cSAlexander Aring case LOWPAN_IPHC_DAM_01: 3102c6bed7cSAlexander Aring /* 01: 48 bits. The address takes 3112c6bed7cSAlexander Aring * the form ffXX::00XX:XXXX:XXXX. 3122c6bed7cSAlexander Aring */ 3132c6bed7cSAlexander Aring ipaddr->s6_addr[0] = 0xFF; 3142c6bed7cSAlexander Aring fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1); 3152c6bed7cSAlexander Aring fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[11], 5); 3162c6bed7cSAlexander Aring break; 3172c6bed7cSAlexander Aring case LOWPAN_IPHC_DAM_10: 3182c6bed7cSAlexander Aring /* 10: 32 bits. The address takes 3192c6bed7cSAlexander Aring * the form ffXX::00XX:XXXX. 3202c6bed7cSAlexander Aring */ 3212c6bed7cSAlexander Aring ipaddr->s6_addr[0] = 0xFF; 3222c6bed7cSAlexander Aring fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1); 3232c6bed7cSAlexander Aring fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[13], 3); 3242c6bed7cSAlexander Aring break; 3252c6bed7cSAlexander Aring case LOWPAN_IPHC_DAM_11: 3262c6bed7cSAlexander Aring /* 11: 8 bits. The address takes 3272c6bed7cSAlexander Aring * the form ff02::00XX. 3282c6bed7cSAlexander Aring */ 3292c6bed7cSAlexander Aring ipaddr->s6_addr[0] = 0xFF; 3302c6bed7cSAlexander Aring ipaddr->s6_addr[1] = 0x02; 3312c6bed7cSAlexander Aring fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[15], 1); 3322c6bed7cSAlexander Aring break; 3332c6bed7cSAlexander Aring default: 334c8a3e7ebSAlexander Aring pr_debug("DAM value has a wrong value: 0x%x\n", address_mode); 3352c6bed7cSAlexander Aring return -EINVAL; 3362c6bed7cSAlexander Aring } 3372c6bed7cSAlexander Aring 3382c6bed7cSAlexander Aring if (fail) { 3392c6bed7cSAlexander Aring pr_debug("Failed to fetch skb data\n"); 3402c6bed7cSAlexander Aring return -EIO; 3412c6bed7cSAlexander Aring } 3422c6bed7cSAlexander Aring 3432c6bed7cSAlexander Aring raw_dump_inline(NULL, "Reconstructed ipv6 multicast addr is", 3442c6bed7cSAlexander Aring ipaddr->s6_addr, 16); 3452c6bed7cSAlexander Aring 3462c6bed7cSAlexander Aring return 0; 3472c6bed7cSAlexander Aring } 3482c6bed7cSAlexander Aring 349b5af9bdbSAlexander Aring /* get the ecn values from iphc tf format and set it to ipv6hdr */ 350b5af9bdbSAlexander Aring static inline void lowpan_iphc_tf_set_ecn(struct ipv6hdr *hdr, const u8 *tf) 351b5af9bdbSAlexander Aring { 352b5af9bdbSAlexander Aring /* get the two higher bits which is ecn */ 353b5af9bdbSAlexander Aring u8 ecn = tf[0] & 0xc0; 354b5af9bdbSAlexander Aring 355b5af9bdbSAlexander Aring /* ECN takes 0x30 in hdr->flow_lbl[0] */ 356b5af9bdbSAlexander Aring hdr->flow_lbl[0] |= (ecn >> 2); 357b5af9bdbSAlexander Aring } 358b5af9bdbSAlexander Aring 359b5af9bdbSAlexander Aring /* get the dscp values from iphc tf format and set it to ipv6hdr */ 360b5af9bdbSAlexander Aring static inline void lowpan_iphc_tf_set_dscp(struct ipv6hdr *hdr, const u8 *tf) 361b5af9bdbSAlexander Aring { 362b5af9bdbSAlexander Aring /* DSCP is at place after ECN */ 363b5af9bdbSAlexander Aring u8 dscp = tf[0] & 0x3f; 364b5af9bdbSAlexander Aring 365b5af9bdbSAlexander Aring /* The four highest bits need to be set at hdr->priority */ 366b5af9bdbSAlexander Aring hdr->priority |= ((dscp & 0x3c) >> 2); 367b5af9bdbSAlexander Aring /* The two lower bits is part of hdr->flow_lbl[0] */ 368b5af9bdbSAlexander Aring hdr->flow_lbl[0] |= ((dscp & 0x03) << 6); 369b5af9bdbSAlexander Aring } 370b5af9bdbSAlexander Aring 371b5af9bdbSAlexander Aring /* get the flow label values from iphc tf format and set it to ipv6hdr */ 372b5af9bdbSAlexander Aring static inline void lowpan_iphc_tf_set_lbl(struct ipv6hdr *hdr, const u8 *lbl) 373b5af9bdbSAlexander Aring { 374b5af9bdbSAlexander Aring /* flow label is always some array started with lower nibble of 375b5af9bdbSAlexander Aring * flow_lbl[0] and followed with two bytes afterwards. Inside inline 376b5af9bdbSAlexander Aring * data the flow_lbl position can be different, which will be handled 377b5af9bdbSAlexander Aring * by lbl pointer. E.g. case "01" vs "00" the traffic class is 8 bit 378b5af9bdbSAlexander Aring * shifted, the different lbl pointer will handle that. 379b5af9bdbSAlexander Aring * 380b5af9bdbSAlexander Aring * The flow label will started at lower nibble of flow_lbl[0], the 381b5af9bdbSAlexander Aring * higher nibbles are part of DSCP + ECN. 382b5af9bdbSAlexander Aring */ 383b5af9bdbSAlexander Aring hdr->flow_lbl[0] |= lbl[0] & 0x0f; 384b5af9bdbSAlexander Aring memcpy(&hdr->flow_lbl[1], &lbl[1], 2); 385b5af9bdbSAlexander Aring } 386b5af9bdbSAlexander Aring 387b5af9bdbSAlexander Aring /* lowpan_iphc_tf_decompress - decompress the traffic class. 388b5af9bdbSAlexander Aring * This function will return zero on success, a value lower than zero if 389b5af9bdbSAlexander Aring * failed. 390b5af9bdbSAlexander Aring */ 391b5af9bdbSAlexander Aring static int lowpan_iphc_tf_decompress(struct sk_buff *skb, struct ipv6hdr *hdr, 392b5af9bdbSAlexander Aring u8 val) 393b5af9bdbSAlexander Aring { 394b5af9bdbSAlexander Aring u8 tf[4]; 395b5af9bdbSAlexander Aring 396b5af9bdbSAlexander Aring /* Traffic Class and Flow Label */ 397b5af9bdbSAlexander Aring switch (val) { 398b5af9bdbSAlexander Aring case LOWPAN_IPHC_TF_00: 399b5af9bdbSAlexander Aring /* ECN + DSCP + 4-bit Pad + Flow Label (4 bytes) */ 400b5af9bdbSAlexander Aring if (lowpan_fetch_skb(skb, tf, 4)) 401b5af9bdbSAlexander Aring return -EINVAL; 402b5af9bdbSAlexander Aring 403b5af9bdbSAlexander Aring /* 1 2 3 404b5af9bdbSAlexander Aring * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 405b5af9bdbSAlexander Aring * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 406b5af9bdbSAlexander Aring * |ECN| DSCP | rsv | Flow Label | 407b5af9bdbSAlexander Aring * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 408b5af9bdbSAlexander Aring */ 409b5af9bdbSAlexander Aring lowpan_iphc_tf_set_ecn(hdr, tf); 410b5af9bdbSAlexander Aring lowpan_iphc_tf_set_dscp(hdr, tf); 411b5af9bdbSAlexander Aring lowpan_iphc_tf_set_lbl(hdr, &tf[1]); 412b5af9bdbSAlexander Aring break; 413b5af9bdbSAlexander Aring case LOWPAN_IPHC_TF_01: 414b5af9bdbSAlexander Aring /* ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided. */ 415b5af9bdbSAlexander Aring if (lowpan_fetch_skb(skb, tf, 3)) 416b5af9bdbSAlexander Aring return -EINVAL; 417b5af9bdbSAlexander Aring 418b5af9bdbSAlexander Aring /* 1 2 419b5af9bdbSAlexander Aring * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 420b5af9bdbSAlexander Aring * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 421b5af9bdbSAlexander Aring * |ECN|rsv| Flow Label | 422b5af9bdbSAlexander Aring * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 423b5af9bdbSAlexander Aring */ 424b5af9bdbSAlexander Aring lowpan_iphc_tf_set_ecn(hdr, tf); 425b5af9bdbSAlexander Aring lowpan_iphc_tf_set_lbl(hdr, &tf[0]); 426b5af9bdbSAlexander Aring break; 427b5af9bdbSAlexander Aring case LOWPAN_IPHC_TF_10: 428b5af9bdbSAlexander Aring /* ECN + DSCP (1 byte), Flow Label is elided. */ 429b5af9bdbSAlexander Aring if (lowpan_fetch_skb(skb, tf, 1)) 430b5af9bdbSAlexander Aring return -EINVAL; 431b5af9bdbSAlexander Aring 432b5af9bdbSAlexander Aring /* 0 1 2 3 4 5 6 7 433b5af9bdbSAlexander Aring * +-+-+-+-+-+-+-+-+ 434b5af9bdbSAlexander Aring * |ECN| DSCP | 435b5af9bdbSAlexander Aring * +-+-+-+-+-+-+-+-+ 436b5af9bdbSAlexander Aring */ 437b5af9bdbSAlexander Aring lowpan_iphc_tf_set_ecn(hdr, tf); 438b5af9bdbSAlexander Aring lowpan_iphc_tf_set_dscp(hdr, tf); 439b5af9bdbSAlexander Aring break; 440b5af9bdbSAlexander Aring case LOWPAN_IPHC_TF_11: 441b5af9bdbSAlexander Aring /* Traffic Class and Flow Label are elided */ 442b5af9bdbSAlexander Aring break; 443b5af9bdbSAlexander Aring default: 444b5af9bdbSAlexander Aring WARN_ON_ONCE(1); 445b5af9bdbSAlexander Aring return -EINVAL; 446b5af9bdbSAlexander Aring } 447b5af9bdbSAlexander Aring 448b5af9bdbSAlexander Aring return 0; 449b5af9bdbSAlexander Aring } 450b5af9bdbSAlexander Aring 4512c6bed7cSAlexander Aring /* TTL uncompression values */ 452c8a3e7ebSAlexander Aring static const u8 lowpan_ttl_values[] = { 453c8a3e7ebSAlexander Aring [LOWPAN_IPHC_HLIM_01] = 1, 454c8a3e7ebSAlexander Aring [LOWPAN_IPHC_HLIM_10] = 64, 455c8a3e7ebSAlexander Aring [LOWPAN_IPHC_HLIM_11] = 255, 456c8a3e7ebSAlexander Aring }; 4572c6bed7cSAlexander Aring 4588911d774SAlexander Aring int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev, 4598911d774SAlexander Aring const void *daddr, const void *saddr) 4602c6bed7cSAlexander Aring { 4612c6bed7cSAlexander Aring struct ipv6hdr hdr = {}; 462b5af9bdbSAlexander Aring u8 iphc0, iphc1; 4632c6bed7cSAlexander Aring int err; 4642c6bed7cSAlexander Aring 4652c6bed7cSAlexander Aring raw_dump_table(__func__, "raw skb data dump uncompressed", 4662c6bed7cSAlexander Aring skb->data, skb->len); 4672c6bed7cSAlexander Aring 468478208e3SAlexander Aring if (lowpan_fetch_skb(skb, &iphc0, sizeof(iphc0)) || 469478208e3SAlexander Aring lowpan_fetch_skb(skb, &iphc1, sizeof(iphc1))) 4708911d774SAlexander Aring return -EINVAL; 4718911d774SAlexander Aring 4722c6bed7cSAlexander Aring /* another if the CID flag is set */ 473c8a3e7ebSAlexander Aring if (iphc1 & LOWPAN_IPHC_CID) 474c8a3e7ebSAlexander Aring return -ENOTSUPP; 4752c6bed7cSAlexander Aring 4762c6bed7cSAlexander Aring hdr.version = 6; 4772c6bed7cSAlexander Aring 478b5af9bdbSAlexander Aring err = lowpan_iphc_tf_decompress(skb, &hdr, 479b5af9bdbSAlexander Aring iphc0 & LOWPAN_IPHC_TF_MASK); 480b5af9bdbSAlexander Aring if (err < 0) 481b5af9bdbSAlexander Aring return err; 4822c6bed7cSAlexander Aring 4832c6bed7cSAlexander Aring /* Next Header */ 484c8a3e7ebSAlexander Aring if (!(iphc0 & LOWPAN_IPHC_NH)) { 4852c6bed7cSAlexander Aring /* Next header is carried inline */ 4864ebc960fSAlexander Aring if (lowpan_fetch_skb(skb, &hdr.nexthdr, sizeof(hdr.nexthdr))) 48756b2c3eeSMartin Townsend return -EINVAL; 4882c6bed7cSAlexander Aring 4892c6bed7cSAlexander Aring pr_debug("NH flag is set, next header carried inline: %02x\n", 4902c6bed7cSAlexander Aring hdr.nexthdr); 4912c6bed7cSAlexander Aring } 4922c6bed7cSAlexander Aring 4932c6bed7cSAlexander Aring /* Hop Limit */ 494c8a3e7ebSAlexander Aring if ((iphc0 & LOWPAN_IPHC_HLIM_MASK) != LOWPAN_IPHC_HLIM_00) { 495c8a3e7ebSAlexander Aring hdr.hop_limit = lowpan_ttl_values[iphc0 & LOWPAN_IPHC_HLIM_MASK]; 4963fd0202aSDavid S. Miller } else { 4974ebc960fSAlexander Aring if (lowpan_fetch_skb(skb, &hdr.hop_limit, 4984ebc960fSAlexander Aring sizeof(hdr.hop_limit))) 49956b2c3eeSMartin Townsend return -EINVAL; 5002c6bed7cSAlexander Aring } 5012c6bed7cSAlexander Aring 5022c6bed7cSAlexander Aring if (iphc1 & LOWPAN_IPHC_SAC) { 5032c6bed7cSAlexander Aring /* Source address context based uncompression */ 5042c6bed7cSAlexander Aring pr_debug("SAC bit is set. Handle context based source address.\n"); 505c8a3e7ebSAlexander Aring err = uncompress_context_based_src_addr(skb, &hdr.saddr, 506c8a3e7ebSAlexander Aring iphc1 & LOWPAN_IPHC_SAM_MASK); 5072c6bed7cSAlexander Aring } else { 5082c6bed7cSAlexander Aring /* Source address uncompression */ 5092c6bed7cSAlexander Aring pr_debug("source address stateless compression\n"); 510c8a3e7ebSAlexander Aring err = uncompress_addr(skb, dev, &hdr.saddr, 511c8a3e7ebSAlexander Aring iphc1 & LOWPAN_IPHC_SAM_MASK, saddr); 5122c6bed7cSAlexander Aring } 5132c6bed7cSAlexander Aring 5142c6bed7cSAlexander Aring /* Check on error of previous branch */ 5152c6bed7cSAlexander Aring if (err) 51656b2c3eeSMartin Townsend return -EINVAL; 5172c6bed7cSAlexander Aring 5182c6bed7cSAlexander Aring /* check for Multicast Compression */ 5192c6bed7cSAlexander Aring if (iphc1 & LOWPAN_IPHC_M) { 5202c6bed7cSAlexander Aring if (iphc1 & LOWPAN_IPHC_DAC) { 5212c6bed7cSAlexander Aring pr_debug("dest: context-based mcast compression\n"); 5222c6bed7cSAlexander Aring /* TODO: implement this */ 5232c6bed7cSAlexander Aring } else { 5247fc4cfdaSMarcel Holtmann err = lowpan_uncompress_multicast_daddr(skb, &hdr.daddr, 525c8a3e7ebSAlexander Aring iphc1 & LOWPAN_IPHC_DAM_MASK); 5267fc4cfdaSMarcel Holtmann 5272c6bed7cSAlexander Aring if (err) 52856b2c3eeSMartin Townsend return -EINVAL; 5292c6bed7cSAlexander Aring } 5302c6bed7cSAlexander Aring } else { 531c8a3e7ebSAlexander Aring err = uncompress_addr(skb, dev, &hdr.daddr, 532c8a3e7ebSAlexander Aring iphc1 & LOWPAN_IPHC_DAM_MASK, daddr); 5332c6bed7cSAlexander Aring pr_debug("dest: stateless compression mode %d dest %pI6c\n", 534c8a3e7ebSAlexander Aring iphc1 & LOWPAN_IPHC_DAM_MASK, &hdr.daddr); 5352c6bed7cSAlexander Aring if (err) 53656b2c3eeSMartin Townsend return -EINVAL; 5372c6bed7cSAlexander Aring } 5382c6bed7cSAlexander Aring 539cc6ed268SAlexander Aring /* Next header data uncompression */ 540c8a3e7ebSAlexander Aring if (iphc0 & LOWPAN_IPHC_NH) { 541cc6ed268SAlexander Aring err = lowpan_nhc_do_uncompression(skb, dev, &hdr); 542cc6ed268SAlexander Aring if (err < 0) 54311e3ff70SMartin Townsend return err; 54411e3ff70SMartin Townsend } else { 54511e3ff70SMartin Townsend err = skb_cow(skb, sizeof(hdr)); 54656b2c3eeSMartin Townsend if (unlikely(err)) 54711e3ff70SMartin Townsend return err; 54811e3ff70SMartin Townsend } 5492c6bed7cSAlexander Aring 55072a5e6bbSAlexander Aring switch (lowpan_priv(dev)->lltype) { 55172a5e6bbSAlexander Aring case LOWPAN_LLTYPE_IEEE802154: 55272a5e6bbSAlexander Aring if (lowpan_802154_cb(skb)->d_size) 55372a5e6bbSAlexander Aring hdr.payload_len = htons(lowpan_802154_cb(skb)->d_size - 55472a5e6bbSAlexander Aring sizeof(struct ipv6hdr)); 55572a5e6bbSAlexander Aring else 5562c6bed7cSAlexander Aring hdr.payload_len = htons(skb->len); 55772a5e6bbSAlexander Aring break; 55872a5e6bbSAlexander Aring default: 55972a5e6bbSAlexander Aring hdr.payload_len = htons(skb->len); 56072a5e6bbSAlexander Aring break; 56172a5e6bbSAlexander Aring } 5622c6bed7cSAlexander Aring 5632c6bed7cSAlexander Aring pr_debug("skb headroom size = %d, data length = %d\n", 5642c6bed7cSAlexander Aring skb_headroom(skb), skb->len); 5652c6bed7cSAlexander Aring 5662c6bed7cSAlexander Aring pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n\t" 5672c6bed7cSAlexander Aring "nexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n", 5682c6bed7cSAlexander Aring hdr.version, ntohs(hdr.payload_len), hdr.nexthdr, 5692c6bed7cSAlexander Aring hdr.hop_limit, &hdr.daddr); 5702c6bed7cSAlexander Aring 571f8b36176SMartin Townsend skb_push(skb, sizeof(hdr)); 572f8b36176SMartin Townsend skb_reset_network_header(skb); 573f8b36176SMartin Townsend skb_copy_to_linear_data(skb, &hdr, sizeof(hdr)); 574f8b36176SMartin Townsend 5757fc4cfdaSMarcel Holtmann raw_dump_table(__func__, "raw header dump", (u8 *)&hdr, sizeof(hdr)); 5762c6bed7cSAlexander Aring 577f8b36176SMartin Townsend return 0; 5782c6bed7cSAlexander Aring } 57901141234SMartin Townsend EXPORT_SYMBOL_GPL(lowpan_header_decompress); 5802c6bed7cSAlexander Aring 581c8a3e7ebSAlexander Aring static const u8 lowpan_iphc_dam_to_sam_value[] = { 582c8a3e7ebSAlexander Aring [LOWPAN_IPHC_DAM_00] = LOWPAN_IPHC_SAM_00, 583c8a3e7ebSAlexander Aring [LOWPAN_IPHC_DAM_01] = LOWPAN_IPHC_SAM_01, 584c8a3e7ebSAlexander Aring [LOWPAN_IPHC_DAM_10] = LOWPAN_IPHC_SAM_10, 585c8a3e7ebSAlexander Aring [LOWPAN_IPHC_DAM_11] = LOWPAN_IPHC_SAM_11, 586c8a3e7ebSAlexander Aring }; 587c8a3e7ebSAlexander Aring 588c8a3e7ebSAlexander Aring static u8 lowpan_compress_addr_64(u8 **hc_ptr, const struct in6_addr *ipaddr, 589c8a3e7ebSAlexander Aring const unsigned char *lladdr, bool sam) 5902c6bed7cSAlexander Aring { 591c8a3e7ebSAlexander Aring u8 dam = LOWPAN_IPHC_DAM_00; 5922c6bed7cSAlexander Aring 5932c6bed7cSAlexander Aring if (is_addr_mac_addr_based(ipaddr, lladdr)) { 594c8a3e7ebSAlexander Aring dam = LOWPAN_IPHC_DAM_11; /* 0-bits */ 5952c6bed7cSAlexander Aring pr_debug("address compression 0 bits\n"); 5962c6bed7cSAlexander Aring } else if (lowpan_is_iid_16_bit_compressable(ipaddr)) { 5972c6bed7cSAlexander Aring /* compress IID to 16 bits xxxx::XXXX */ 59885c71240SAlexander Aring lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[7], 2); 599c8a3e7ebSAlexander Aring dam = LOWPAN_IPHC_DAM_10; /* 16-bits */ 6002c6bed7cSAlexander Aring raw_dump_inline(NULL, "Compressed ipv6 addr is (16 bits)", 60184ca5e03SAlexander Aring *hc_ptr - 2, 2); 6022c6bed7cSAlexander Aring } else { 6032c6bed7cSAlexander Aring /* do not compress IID => xxxx::IID */ 60485c71240SAlexander Aring lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[4], 8); 605c8a3e7ebSAlexander Aring dam = LOWPAN_IPHC_DAM_01; /* 64-bits */ 6062c6bed7cSAlexander Aring raw_dump_inline(NULL, "Compressed ipv6 addr is (64 bits)", 60784ca5e03SAlexander Aring *hc_ptr - 8, 8); 6082c6bed7cSAlexander Aring } 6092c6bed7cSAlexander Aring 610c8a3e7ebSAlexander Aring if (sam) 611c8a3e7ebSAlexander Aring return lowpan_iphc_dam_to_sam_value[dam]; 612c8a3e7ebSAlexander Aring else 613c8a3e7ebSAlexander Aring return dam; 6142c6bed7cSAlexander Aring } 6152c6bed7cSAlexander Aring 616b5af9bdbSAlexander Aring /* lowpan_iphc_get_tc - get the ECN + DCSP fields in hc format */ 617b5af9bdbSAlexander Aring static inline u8 lowpan_iphc_get_tc(const struct ipv6hdr *hdr) 618b5af9bdbSAlexander Aring { 619b5af9bdbSAlexander Aring u8 dscp, ecn; 620b5af9bdbSAlexander Aring 621b5af9bdbSAlexander Aring /* hdr->priority contains the higher bits of dscp, lower are part of 622b5af9bdbSAlexander Aring * flow_lbl[0]. Note ECN, DCSP is swapped in ipv6 hdr. 623b5af9bdbSAlexander Aring */ 624b5af9bdbSAlexander Aring dscp = (hdr->priority << 2) | ((hdr->flow_lbl[0] & 0xc0) >> 6); 625b5af9bdbSAlexander Aring /* ECN is at the two lower bits from first nibble of flow_lbl[0] */ 626b5af9bdbSAlexander Aring ecn = (hdr->flow_lbl[0] & 0x30); 627b5af9bdbSAlexander Aring /* for pretty debug output, also shift ecn to get the ecn value */ 628b5af9bdbSAlexander Aring pr_debug("ecn 0x%02x dscp 0x%02x\n", ecn >> 4, dscp); 629b5af9bdbSAlexander Aring /* ECN is at 0x30 now, shift it to have ECN + DCSP */ 630b5af9bdbSAlexander Aring return (ecn << 2) | dscp; 631b5af9bdbSAlexander Aring } 632b5af9bdbSAlexander Aring 633b5af9bdbSAlexander Aring /* lowpan_iphc_is_flow_lbl_zero - check if flow label is zero */ 634b5af9bdbSAlexander Aring static inline bool lowpan_iphc_is_flow_lbl_zero(const struct ipv6hdr *hdr) 635b5af9bdbSAlexander Aring { 636b5af9bdbSAlexander Aring return ((!(hdr->flow_lbl[0] & 0x0f)) && 637b5af9bdbSAlexander Aring !hdr->flow_lbl[1] && !hdr->flow_lbl[2]); 638b5af9bdbSAlexander Aring } 639b5af9bdbSAlexander Aring 640b5af9bdbSAlexander Aring /* lowpan_iphc_tf_compress - compress the traffic class which is set by 641b5af9bdbSAlexander Aring * ipv6hdr. Return the corresponding format identifier which is used. 642b5af9bdbSAlexander Aring */ 643b5af9bdbSAlexander Aring static u8 lowpan_iphc_tf_compress(u8 **hc_ptr, const struct ipv6hdr *hdr) 644b5af9bdbSAlexander Aring { 645b5af9bdbSAlexander Aring /* get ecn dscp data in a byteformat as: ECN(hi) + DSCP(lo) */ 646b5af9bdbSAlexander Aring u8 tc = lowpan_iphc_get_tc(hdr), tf[4], val; 647b5af9bdbSAlexander Aring 648b5af9bdbSAlexander Aring /* printout the traffic class in hc format */ 649b5af9bdbSAlexander Aring pr_debug("tc 0x%02x\n", tc); 650b5af9bdbSAlexander Aring 651b5af9bdbSAlexander Aring if (lowpan_iphc_is_flow_lbl_zero(hdr)) { 652b5af9bdbSAlexander Aring if (!tc) { 653b5af9bdbSAlexander Aring /* 11: Traffic Class and Flow Label are elided. */ 654b5af9bdbSAlexander Aring val = LOWPAN_IPHC_TF_11; 655b5af9bdbSAlexander Aring } else { 656b5af9bdbSAlexander Aring /* 10: ECN + DSCP (1 byte), Flow Label is elided. 657b5af9bdbSAlexander Aring * 658b5af9bdbSAlexander Aring * 0 1 2 3 4 5 6 7 659b5af9bdbSAlexander Aring * +-+-+-+-+-+-+-+-+ 660b5af9bdbSAlexander Aring * |ECN| DSCP | 661b5af9bdbSAlexander Aring * +-+-+-+-+-+-+-+-+ 662b5af9bdbSAlexander Aring */ 663b5af9bdbSAlexander Aring lowpan_push_hc_data(hc_ptr, &tc, sizeof(tc)); 664b5af9bdbSAlexander Aring val = LOWPAN_IPHC_TF_10; 665b5af9bdbSAlexander Aring } 666b5af9bdbSAlexander Aring } else { 667b5af9bdbSAlexander Aring /* check if dscp is zero, it's after the first two bit */ 668b5af9bdbSAlexander Aring if (!(tc & 0x3f)) { 669b5af9bdbSAlexander Aring /* 01: ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided 670b5af9bdbSAlexander Aring * 671b5af9bdbSAlexander Aring * 1 2 672b5af9bdbSAlexander Aring * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 673b5af9bdbSAlexander Aring * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 674b5af9bdbSAlexander Aring * |ECN|rsv| Flow Label | 675b5af9bdbSAlexander Aring * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 676b5af9bdbSAlexander Aring */ 677b5af9bdbSAlexander Aring memcpy(&tf[0], &hdr->flow_lbl[0], 3); 678b5af9bdbSAlexander Aring /* zero the highest 4-bits, contains DCSP + ECN */ 679b5af9bdbSAlexander Aring tf[0] &= ~0xf0; 680b5af9bdbSAlexander Aring /* set ECN */ 681b5af9bdbSAlexander Aring tf[0] |= (tc & 0xc0); 682b5af9bdbSAlexander Aring 683b5af9bdbSAlexander Aring lowpan_push_hc_data(hc_ptr, tf, 3); 684b5af9bdbSAlexander Aring val = LOWPAN_IPHC_TF_01; 685b5af9bdbSAlexander Aring } else { 686b5af9bdbSAlexander Aring /* 00: ECN + DSCP + 4-bit Pad + Flow Label (4 bytes) 687b5af9bdbSAlexander Aring * 688b5af9bdbSAlexander Aring * 1 2 3 689b5af9bdbSAlexander Aring * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 690b5af9bdbSAlexander Aring * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 691b5af9bdbSAlexander Aring * |ECN| DSCP | rsv | Flow Label | 692b5af9bdbSAlexander Aring * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 693b5af9bdbSAlexander Aring */ 694b5af9bdbSAlexander Aring memcpy(&tf[0], &tc, sizeof(tc)); 695b5af9bdbSAlexander Aring /* highest nibble of flow_lbl[0] is part of DSCP + ECN 696b5af9bdbSAlexander Aring * which will be the 4-bit pad and will be filled with 697b5af9bdbSAlexander Aring * zeros afterwards. 698b5af9bdbSAlexander Aring */ 699b5af9bdbSAlexander Aring memcpy(&tf[1], &hdr->flow_lbl[0], 3); 700b5af9bdbSAlexander Aring /* zero the 4-bit pad, which is reserved */ 701b5af9bdbSAlexander Aring tf[1] &= ~0xf0; 702b5af9bdbSAlexander Aring 703b5af9bdbSAlexander Aring lowpan_push_hc_data(hc_ptr, tf, 4); 704b5af9bdbSAlexander Aring val = LOWPAN_IPHC_TF_00; 705b5af9bdbSAlexander Aring } 706b5af9bdbSAlexander Aring } 707b5af9bdbSAlexander Aring 708b5af9bdbSAlexander Aring return val; 709b5af9bdbSAlexander Aring } 710b5af9bdbSAlexander Aring 711a6f77389SAlexander Aring int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev, 712a6f77389SAlexander Aring const void *daddr, const void *saddr) 7132c6bed7cSAlexander Aring { 714b5af9bdbSAlexander Aring u8 iphc0, iphc1, *hc_ptr; 7152c6bed7cSAlexander Aring struct ipv6hdr *hdr; 716bf513fd6SAlexander Aring u8 head[LOWPAN_IPHC_MAX_HC_BUF_LEN] = {}; 717cc6ed268SAlexander Aring int ret, addr_type; 7182c6bed7cSAlexander Aring 719a6f77389SAlexander Aring if (skb->protocol != htons(ETH_P_IPV6)) 7202c6bed7cSAlexander Aring return -EINVAL; 7212c6bed7cSAlexander Aring 7222c6bed7cSAlexander Aring hdr = ipv6_hdr(skb); 72384ca5e03SAlexander Aring hc_ptr = head + 2; 7242c6bed7cSAlexander Aring 7252c6bed7cSAlexander Aring pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n" 7262c6bed7cSAlexander Aring "\tnexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n", 7272c6bed7cSAlexander Aring hdr->version, ntohs(hdr->payload_len), hdr->nexthdr, 7282c6bed7cSAlexander Aring hdr->hop_limit, &hdr->daddr); 7292c6bed7cSAlexander Aring 7302c6bed7cSAlexander Aring raw_dump_table(__func__, "raw skb network header dump", 7312c6bed7cSAlexander Aring skb_network_header(skb), sizeof(struct ipv6hdr)); 7322c6bed7cSAlexander Aring 7333fd0202aSDavid S. Miller /* As we copy some bit-length fields, in the IPHC encoding bytes, 7342c6bed7cSAlexander Aring * we sometimes use |= 7352c6bed7cSAlexander Aring * If the field is 0, and the current bit value in memory is 1, 7362c6bed7cSAlexander Aring * this does not work. We therefore reset the IPHC encoding here 7372c6bed7cSAlexander Aring */ 7382c6bed7cSAlexander Aring iphc0 = LOWPAN_DISPATCH_IPHC; 7392c6bed7cSAlexander Aring iphc1 = 0; 7402c6bed7cSAlexander Aring 7412c6bed7cSAlexander Aring /* TODO: context lookup */ 7422c6bed7cSAlexander Aring 743a6f77389SAlexander Aring raw_dump_inline(__func__, "saddr", saddr, EUI64_ADDR_LEN); 744a6f77389SAlexander Aring raw_dump_inline(__func__, "daddr", daddr, EUI64_ADDR_LEN); 7452c6bed7cSAlexander Aring 7467fc4cfdaSMarcel Holtmann raw_dump_table(__func__, "sending raw skb network uncompressed packet", 7472c6bed7cSAlexander Aring skb->data, skb->len); 7482c6bed7cSAlexander Aring 749b5af9bdbSAlexander Aring /* Traffic Class, Flow Label compression */ 750b5af9bdbSAlexander Aring iphc0 |= lowpan_iphc_tf_compress(&hc_ptr, hdr); 7512c6bed7cSAlexander Aring 7522c6bed7cSAlexander Aring /* NOTE: payload length is always compressed */ 7532c6bed7cSAlexander Aring 754cc6ed268SAlexander Aring /* Check if we provide the nhc format for nexthdr and compression 755cc6ed268SAlexander Aring * functionality. If not nexthdr is handled inline and not compressed. 756cc6ed268SAlexander Aring */ 757607b0bd3SAlexander Aring ret = lowpan_nhc_check_compression(skb, hdr, &hc_ptr); 758607b0bd3SAlexander Aring if (ret == -ENOENT) 759607b0bd3SAlexander Aring lowpan_push_hc_data(&hc_ptr, &hdr->nexthdr, 760607b0bd3SAlexander Aring sizeof(hdr->nexthdr)); 761607b0bd3SAlexander Aring else 762c8a3e7ebSAlexander Aring iphc0 |= LOWPAN_IPHC_NH; 7632c6bed7cSAlexander Aring 7643fd0202aSDavid S. Miller /* Hop limit 7652c6bed7cSAlexander Aring * if 1: compress, encoding is 01 7662c6bed7cSAlexander Aring * if 64: compress, encoding is 10 7672c6bed7cSAlexander Aring * if 255: compress, encoding is 11 7682c6bed7cSAlexander Aring * else do not compress 7692c6bed7cSAlexander Aring */ 7702c6bed7cSAlexander Aring switch (hdr->hop_limit) { 7712c6bed7cSAlexander Aring case 1: 772c8a3e7ebSAlexander Aring iphc0 |= LOWPAN_IPHC_HLIM_01; 7732c6bed7cSAlexander Aring break; 7742c6bed7cSAlexander Aring case 64: 775c8a3e7ebSAlexander Aring iphc0 |= LOWPAN_IPHC_HLIM_10; 7762c6bed7cSAlexander Aring break; 7772c6bed7cSAlexander Aring case 255: 778c8a3e7ebSAlexander Aring iphc0 |= LOWPAN_IPHC_HLIM_11; 7792c6bed7cSAlexander Aring break; 7802c6bed7cSAlexander Aring default: 78185c71240SAlexander Aring lowpan_push_hc_data(&hc_ptr, &hdr->hop_limit, 78285c71240SAlexander Aring sizeof(hdr->hop_limit)); 7832c6bed7cSAlexander Aring } 7842c6bed7cSAlexander Aring 785556a5bfcSAlexander Aring addr_type = ipv6_addr_type(&hdr->saddr); 7862c6bed7cSAlexander Aring /* source address compression */ 787556a5bfcSAlexander Aring if (addr_type == IPV6_ADDR_ANY) { 7882c6bed7cSAlexander Aring pr_debug("source address is unspecified, setting SAC\n"); 7892c6bed7cSAlexander Aring iphc1 |= LOWPAN_IPHC_SAC; 790556a5bfcSAlexander Aring } else { 791556a5bfcSAlexander Aring if (addr_type & IPV6_ADDR_LINKLOCAL) { 792c8a3e7ebSAlexander Aring iphc1 |= lowpan_compress_addr_64(&hc_ptr, &hdr->saddr, 793c8a3e7ebSAlexander Aring saddr, true); 794556a5bfcSAlexander Aring pr_debug("source address unicast link-local %pI6c iphc1 0x%02x\n", 795556a5bfcSAlexander Aring &hdr->saddr, iphc1); 7962c6bed7cSAlexander Aring } else { 7972c6bed7cSAlexander Aring pr_debug("send the full source address\n"); 798556a5bfcSAlexander Aring lowpan_push_hc_data(&hc_ptr, hdr->saddr.s6_addr, 16); 799556a5bfcSAlexander Aring } 8002c6bed7cSAlexander Aring } 8012c6bed7cSAlexander Aring 802556a5bfcSAlexander Aring addr_type = ipv6_addr_type(&hdr->daddr); 8032c6bed7cSAlexander Aring /* destination address compression */ 804556a5bfcSAlexander Aring if (addr_type & IPV6_ADDR_MULTICAST) { 8052c6bed7cSAlexander Aring pr_debug("destination address is multicast: "); 8062c6bed7cSAlexander Aring iphc1 |= LOWPAN_IPHC_M; 8072c6bed7cSAlexander Aring if (lowpan_is_mcast_addr_compressable8(&hdr->daddr)) { 8082c6bed7cSAlexander Aring pr_debug("compressed to 1 octet\n"); 8092c6bed7cSAlexander Aring iphc1 |= LOWPAN_IPHC_DAM_11; 8102c6bed7cSAlexander Aring /* use last byte */ 81185c71240SAlexander Aring lowpan_push_hc_data(&hc_ptr, 81285c71240SAlexander Aring &hdr->daddr.s6_addr[15], 1); 8132c6bed7cSAlexander Aring } else if (lowpan_is_mcast_addr_compressable32(&hdr->daddr)) { 8142c6bed7cSAlexander Aring pr_debug("compressed to 4 octets\n"); 8152c6bed7cSAlexander Aring iphc1 |= LOWPAN_IPHC_DAM_10; 8162c6bed7cSAlexander Aring /* second byte + the last three */ 81785c71240SAlexander Aring lowpan_push_hc_data(&hc_ptr, 81885c71240SAlexander Aring &hdr->daddr.s6_addr[1], 1); 81985c71240SAlexander Aring lowpan_push_hc_data(&hc_ptr, 82085c71240SAlexander Aring &hdr->daddr.s6_addr[13], 3); 8212c6bed7cSAlexander Aring } else if (lowpan_is_mcast_addr_compressable48(&hdr->daddr)) { 8222c6bed7cSAlexander Aring pr_debug("compressed to 6 octets\n"); 8232c6bed7cSAlexander Aring iphc1 |= LOWPAN_IPHC_DAM_01; 8242c6bed7cSAlexander Aring /* second byte + the last five */ 82585c71240SAlexander Aring lowpan_push_hc_data(&hc_ptr, 82685c71240SAlexander Aring &hdr->daddr.s6_addr[1], 1); 82785c71240SAlexander Aring lowpan_push_hc_data(&hc_ptr, 82885c71240SAlexander Aring &hdr->daddr.s6_addr[11], 5); 8292c6bed7cSAlexander Aring } else { 8302c6bed7cSAlexander Aring pr_debug("using full address\n"); 8312c6bed7cSAlexander Aring iphc1 |= LOWPAN_IPHC_DAM_00; 83285c71240SAlexander Aring lowpan_push_hc_data(&hc_ptr, hdr->daddr.s6_addr, 16); 8332c6bed7cSAlexander Aring } 8342c6bed7cSAlexander Aring } else { 835556a5bfcSAlexander Aring if (addr_type & IPV6_ADDR_LINKLOCAL) { 8362c6bed7cSAlexander Aring /* TODO: context lookup */ 837c8a3e7ebSAlexander Aring iphc1 |= lowpan_compress_addr_64(&hc_ptr, &hdr->daddr, 838c8a3e7ebSAlexander Aring daddr, false); 8392c6bed7cSAlexander Aring pr_debug("dest address unicast link-local %pI6c " 8402c6bed7cSAlexander Aring "iphc1 0x%02x\n", &hdr->daddr, iphc1); 8412c6bed7cSAlexander Aring } else { 8422c6bed7cSAlexander Aring pr_debug("dest address unicast %pI6c\n", &hdr->daddr); 84385c71240SAlexander Aring lowpan_push_hc_data(&hc_ptr, hdr->daddr.s6_addr, 16); 8442c6bed7cSAlexander Aring } 8452c6bed7cSAlexander Aring } 8462c6bed7cSAlexander Aring 847cc6ed268SAlexander Aring /* next header compression */ 848c8a3e7ebSAlexander Aring if (iphc0 & LOWPAN_IPHC_NH) { 849cc6ed268SAlexander Aring ret = lowpan_nhc_do_compression(skb, hdr, &hc_ptr); 850cc6ed268SAlexander Aring if (ret < 0) 851cc6ed268SAlexander Aring return ret; 852cc6ed268SAlexander Aring } 8532c6bed7cSAlexander Aring 8542c6bed7cSAlexander Aring head[0] = iphc0; 8552c6bed7cSAlexander Aring head[1] = iphc1; 8562c6bed7cSAlexander Aring 8572c6bed7cSAlexander Aring skb_pull(skb, sizeof(struct ipv6hdr)); 8582c6bed7cSAlexander Aring skb_reset_transport_header(skb); 85984ca5e03SAlexander Aring memcpy(skb_push(skb, hc_ptr - head), head, hc_ptr - head); 8602c6bed7cSAlexander Aring skb_reset_network_header(skb); 8612c6bed7cSAlexander Aring 86284ca5e03SAlexander Aring pr_debug("header len %d skb %u\n", (int)(hc_ptr - head), skb->len); 8632c6bed7cSAlexander Aring 8642c6bed7cSAlexander Aring raw_dump_table(__func__, "raw skb data dump compressed", 8652c6bed7cSAlexander Aring skb->data, skb->len); 8662c6bed7cSAlexander Aring return 0; 8672c6bed7cSAlexander Aring } 8682c6bed7cSAlexander Aring EXPORT_SYMBOL_GPL(lowpan_header_compress); 869