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Diffstat (limited to '')
| -rw-r--r-- | net/6lowpan/iphc.c | 1313 |
1 files changed, 1313 insertions, 0 deletions
diff --git a/net/6lowpan/iphc.c b/net/6lowpan/iphc.c new file mode 100644 index 000000000..52fad5dad --- /dev/null +++ b/net/6lowpan/iphc.c @@ -0,0 +1,1313 @@ +/* + * Copyright 2011, Siemens AG + * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com> + */ + +/* Based on patches from Jon Smirl <jonsmirl@gmail.com> + * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +/* Jon's code is based on 6lowpan implementation for Contiki which is: + * Copyright (c) 2008, Swedish Institute of Computer Science. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <linux/bitops.h> +#include <linux/if_arp.h> +#include <linux/netdevice.h> + +#include <net/6lowpan.h> +#include <net/ipv6.h> + +#include "6lowpan_i.h" +#include "nhc.h" + +/* Values of fields within the IPHC encoding first byte */ +#define LOWPAN_IPHC_TF_MASK 0x18 +#define LOWPAN_IPHC_TF_00 0x00 +#define LOWPAN_IPHC_TF_01 0x08 +#define LOWPAN_IPHC_TF_10 0x10 +#define LOWPAN_IPHC_TF_11 0x18 + +#define LOWPAN_IPHC_NH 0x04 + +#define LOWPAN_IPHC_HLIM_MASK 0x03 +#define LOWPAN_IPHC_HLIM_00 0x00 +#define LOWPAN_IPHC_HLIM_01 0x01 +#define LOWPAN_IPHC_HLIM_10 0x02 +#define LOWPAN_IPHC_HLIM_11 0x03 + +/* Values of fields within the IPHC encoding second byte */ +#define LOWPAN_IPHC_CID 0x80 + +#define LOWPAN_IPHC_SAC 0x40 + +#define LOWPAN_IPHC_SAM_MASK 0x30 +#define LOWPAN_IPHC_SAM_00 0x00 +#define LOWPAN_IPHC_SAM_01 0x10 +#define LOWPAN_IPHC_SAM_10 0x20 +#define LOWPAN_IPHC_SAM_11 0x30 + +#define LOWPAN_IPHC_M 0x08 + +#define LOWPAN_IPHC_DAC 0x04 + +#define LOWPAN_IPHC_DAM_MASK 0x03 +#define LOWPAN_IPHC_DAM_00 0x00 +#define LOWPAN_IPHC_DAM_01 0x01 +#define LOWPAN_IPHC_DAM_10 0x02 +#define LOWPAN_IPHC_DAM_11 0x03 + +/* ipv6 address based on mac + * second bit-flip (Universe/Local) is done according RFC2464 + */ +#define is_addr_mac_addr_based(a, m) \ + ((((a)->s6_addr[8]) == (((m)[0]) ^ 0x02)) && \ + (((a)->s6_addr[9]) == (m)[1]) && \ + (((a)->s6_addr[10]) == (m)[2]) && \ + (((a)->s6_addr[11]) == (m)[3]) && \ + (((a)->s6_addr[12]) == (m)[4]) && \ + (((a)->s6_addr[13]) == (m)[5]) && \ + (((a)->s6_addr[14]) == (m)[6]) && \ + (((a)->s6_addr[15]) == (m)[7])) + +/* check whether we can compress the IID to 16 bits, + * it's possible for unicast addresses with first 49 bits are zero only. + */ +#define lowpan_is_iid_16_bit_compressable(a) \ + ((((a)->s6_addr16[4]) == 0) && \ + (((a)->s6_addr[10]) == 0) && \ + (((a)->s6_addr[11]) == 0xff) && \ + (((a)->s6_addr[12]) == 0xfe) && \ + (((a)->s6_addr[13]) == 0)) + +/* check whether the 112-bit gid of the multicast address is mappable to: */ + +/* 48 bits, FFXX::00XX:XXXX:XXXX */ +#define lowpan_is_mcast_addr_compressable48(a) \ + ((((a)->s6_addr16[1]) == 0) && \ + (((a)->s6_addr16[2]) == 0) && \ + (((a)->s6_addr16[3]) == 0) && \ + (((a)->s6_addr16[4]) == 0) && \ + (((a)->s6_addr[10]) == 0)) + +/* 32 bits, FFXX::00XX:XXXX */ +#define lowpan_is_mcast_addr_compressable32(a) \ + ((((a)->s6_addr16[1]) == 0) && \ + (((a)->s6_addr16[2]) == 0) && \ + (((a)->s6_addr16[3]) == 0) && \ + (((a)->s6_addr16[4]) == 0) && \ + (((a)->s6_addr16[5]) == 0) && \ + (((a)->s6_addr[12]) == 0)) + +/* 8 bits, FF02::00XX */ +#define lowpan_is_mcast_addr_compressable8(a) \ + ((((a)->s6_addr[1]) == 2) && \ + (((a)->s6_addr16[1]) == 0) && \ + (((a)->s6_addr16[2]) == 0) && \ + (((a)->s6_addr16[3]) == 0) && \ + (((a)->s6_addr16[4]) == 0) && \ + (((a)->s6_addr16[5]) == 0) && \ + (((a)->s6_addr16[6]) == 0) && \ + (((a)->s6_addr[14]) == 0)) + +#define lowpan_is_linklocal_zero_padded(a) \ + (!(hdr->saddr.s6_addr[1] & 0x3f) && \ + !hdr->saddr.s6_addr16[1] && \ + !hdr->saddr.s6_addr32[1]) + +#define LOWPAN_IPHC_CID_DCI(cid) (cid & 0x0f) +#define LOWPAN_IPHC_CID_SCI(cid) ((cid & 0xf0) >> 4) + +static inline void +lowpan_iphc_uncompress_802154_lladdr(struct in6_addr *ipaddr, + const void *lladdr) +{ + const struct ieee802154_addr *addr = lladdr; + u8 eui64[EUI64_ADDR_LEN]; + + switch (addr->mode) { + case IEEE802154_ADDR_LONG: + ieee802154_le64_to_be64(eui64, &addr->extended_addr); + lowpan_iphc_uncompress_eui64_lladdr(ipaddr, eui64); + break; + case IEEE802154_ADDR_SHORT: + /* fe:80::ff:fe00:XXXX + * \__/ + * short_addr + * + * Universe/Local bit is zero. + */ + ipaddr->s6_addr[0] = 0xFE; + ipaddr->s6_addr[1] = 0x80; + ipaddr->s6_addr[11] = 0xFF; + ipaddr->s6_addr[12] = 0xFE; + ieee802154_le16_to_be16(&ipaddr->s6_addr16[7], + &addr->short_addr); + break; + default: + /* should never handled and filtered by 802154 6lowpan */ + WARN_ON_ONCE(1); + break; + } +} + +static struct lowpan_iphc_ctx * +lowpan_iphc_ctx_get_by_id(const struct net_device *dev, u8 id) +{ + struct lowpan_iphc_ctx *ret = &lowpan_dev(dev)->ctx.table[id]; + + if (!lowpan_iphc_ctx_is_active(ret)) + return NULL; + + return ret; +} + +static struct lowpan_iphc_ctx * +lowpan_iphc_ctx_get_by_addr(const struct net_device *dev, + const struct in6_addr *addr) +{ + struct lowpan_iphc_ctx *table = lowpan_dev(dev)->ctx.table; + struct lowpan_iphc_ctx *ret = NULL; + struct in6_addr addr_pfx; + u8 addr_plen; + int i; + + for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++) { + /* Check if context is valid. A context that is not valid + * MUST NOT be used for compression. + */ + if (!lowpan_iphc_ctx_is_active(&table[i]) || + !lowpan_iphc_ctx_is_compression(&table[i])) + continue; + + ipv6_addr_prefix(&addr_pfx, addr, table[i].plen); + + /* if prefix len < 64, the remaining bits until 64th bit is + * zero. Otherwise we use table[i]->plen. + */ + if (table[i].plen < 64) + addr_plen = 64; + else + addr_plen = table[i].plen; + + if (ipv6_prefix_equal(&addr_pfx, &table[i].pfx, addr_plen)) { + /* remember first match */ + if (!ret) { + ret = &table[i]; + continue; + } + + /* get the context with longest prefix len */ + if (table[i].plen > ret->plen) + ret = &table[i]; + } + } + + return ret; +} + +static struct lowpan_iphc_ctx * +lowpan_iphc_ctx_get_by_mcast_addr(const struct net_device *dev, + const struct in6_addr *addr) +{ + struct lowpan_iphc_ctx *table = lowpan_dev(dev)->ctx.table; + struct lowpan_iphc_ctx *ret = NULL; + struct in6_addr addr_mcast, network_pfx = {}; + int i; + + /* init mcast address with */ + memcpy(&addr_mcast, addr, sizeof(*addr)); + + for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++) { + /* Check if context is valid. A context that is not valid + * MUST NOT be used for compression. + */ + if (!lowpan_iphc_ctx_is_active(&table[i]) || + !lowpan_iphc_ctx_is_compression(&table[i])) + continue; + + /* setting plen */ + addr_mcast.s6_addr[3] = table[i].plen; + /* get network prefix to copy into multicast address */ + ipv6_addr_prefix(&network_pfx, &table[i].pfx, + table[i].plen); + /* setting network prefix */ + memcpy(&addr_mcast.s6_addr[4], &network_pfx, 8); + + if (ipv6_addr_equal(addr, &addr_mcast)) { + ret = &table[i]; + break; + } + } + + return ret; +} + +static void lowpan_iphc_uncompress_lladdr(const struct net_device *dev, + struct in6_addr *ipaddr, + const void *lladdr) +{ + switch (dev->addr_len) { + case ETH_ALEN: + lowpan_iphc_uncompress_eui48_lladdr(ipaddr, lladdr); + break; + case EUI64_ADDR_LEN: + lowpan_iphc_uncompress_eui64_lladdr(ipaddr, lladdr); + break; + default: + WARN_ON_ONCE(1); + break; + } +} + +/* Uncompress address function for source and + * destination address(non-multicast). + * + * address_mode is the masked value for sam or dam value + */ +static int lowpan_iphc_uncompress_addr(struct sk_buff *skb, + const struct net_device *dev, + struct in6_addr *ipaddr, + u8 address_mode, const void *lladdr) +{ + bool fail; + + switch (address_mode) { + /* SAM and DAM are the same here */ + case LOWPAN_IPHC_DAM_00: + /* for global link addresses */ + fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16); + break; + case LOWPAN_IPHC_SAM_01: + case LOWPAN_IPHC_DAM_01: + /* fe:80::XXXX:XXXX:XXXX:XXXX */ + ipaddr->s6_addr[0] = 0xFE; + ipaddr->s6_addr[1] = 0x80; + fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[8], 8); + break; + case LOWPAN_IPHC_SAM_10: + case LOWPAN_IPHC_DAM_10: + /* fe:80::ff:fe00:XXXX */ + ipaddr->s6_addr[0] = 0xFE; + ipaddr->s6_addr[1] = 0x80; + ipaddr->s6_addr[11] = 0xFF; + ipaddr->s6_addr[12] = 0xFE; + fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2); + break; + case LOWPAN_IPHC_SAM_11: + case LOWPAN_IPHC_DAM_11: + fail = false; + switch (lowpan_dev(dev)->lltype) { + case LOWPAN_LLTYPE_IEEE802154: + lowpan_iphc_uncompress_802154_lladdr(ipaddr, lladdr); + break; + default: + lowpan_iphc_uncompress_lladdr(dev, ipaddr, lladdr); + break; + } + break; + default: + pr_debug("Invalid address mode value: 0x%x\n", address_mode); + return -EINVAL; + } + + if (fail) { + pr_debug("Failed to fetch skb data\n"); + return -EIO; + } + + raw_dump_inline(NULL, "Reconstructed ipv6 addr is", + ipaddr->s6_addr, 16); + + return 0; +} + +/* Uncompress address function for source context + * based address(non-multicast). + */ +static int lowpan_iphc_uncompress_ctx_addr(struct sk_buff *skb, + const struct net_device *dev, + const struct lowpan_iphc_ctx *ctx, + struct in6_addr *ipaddr, + u8 address_mode, const void *lladdr) +{ + bool fail; + + switch (address_mode) { + /* SAM and DAM are the same here */ + case LOWPAN_IPHC_DAM_00: + fail = false; + /* SAM_00 -> unspec address :: + * Do nothing, address is already :: + * + * DAM 00 -> reserved should never occur. + */ + break; + case LOWPAN_IPHC_SAM_01: + case LOWPAN_IPHC_DAM_01: + fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[8], 8); + ipv6_addr_prefix_copy(ipaddr, &ctx->pfx, ctx->plen); + break; + case LOWPAN_IPHC_SAM_10: + case LOWPAN_IPHC_DAM_10: + ipaddr->s6_addr[11] = 0xFF; + ipaddr->s6_addr[12] = 0xFE; + fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[14], 2); + ipv6_addr_prefix_copy(ipaddr, &ctx->pfx, ctx->plen); + break; + case LOWPAN_IPHC_SAM_11: + case LOWPAN_IPHC_DAM_11: + fail = false; + switch (lowpan_dev(dev)->lltype) { + case LOWPAN_LLTYPE_IEEE802154: + lowpan_iphc_uncompress_802154_lladdr(ipaddr, lladdr); + break; + default: + lowpan_iphc_uncompress_lladdr(dev, ipaddr, lladdr); + break; + } + ipv6_addr_prefix_copy(ipaddr, &ctx->pfx, ctx->plen); + break; + default: + pr_debug("Invalid sam value: 0x%x\n", address_mode); + return -EINVAL; + } + + if (fail) { + pr_debug("Failed to fetch skb data\n"); + return -EIO; + } + + raw_dump_inline(NULL, + "Reconstructed context based ipv6 src addr is", + ipaddr->s6_addr, 16); + + return 0; +} + +/* Uncompress function for multicast destination address, + * when M bit is set. + */ +static int lowpan_uncompress_multicast_daddr(struct sk_buff *skb, + struct in6_addr *ipaddr, + u8 address_mode) +{ + bool fail; + + switch (address_mode) { + case LOWPAN_IPHC_DAM_00: + /* 00: 128 bits. The full address + * is carried in-line. + */ + fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16); + break; + case LOWPAN_IPHC_DAM_01: + /* 01: 48 bits. The address takes + * the form ffXX::00XX:XXXX:XXXX. + */ + ipaddr->s6_addr[0] = 0xFF; + fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1); + fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[11], 5); + break; + case LOWPAN_IPHC_DAM_10: + /* 10: 32 bits. The address takes + * the form ffXX::00XX:XXXX. + */ + ipaddr->s6_addr[0] = 0xFF; + fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 1); + fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[13], 3); + break; + case LOWPAN_IPHC_DAM_11: + /* 11: 8 bits. The address takes + * the form ff02::00XX. + */ + ipaddr->s6_addr[0] = 0xFF; + ipaddr->s6_addr[1] = 0x02; + fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[15], 1); + break; + default: + pr_debug("DAM value has a wrong value: 0x%x\n", address_mode); + return -EINVAL; + } + + if (fail) { + pr_debug("Failed to fetch skb data\n"); + return -EIO; + } + + raw_dump_inline(NULL, "Reconstructed ipv6 multicast addr is", + ipaddr->s6_addr, 16); + + return 0; +} + +static int lowpan_uncompress_multicast_ctx_daddr(struct sk_buff *skb, + struct lowpan_iphc_ctx *ctx, + struct in6_addr *ipaddr, + u8 address_mode) +{ + struct in6_addr network_pfx = {}; + bool fail; + + ipaddr->s6_addr[0] = 0xFF; + fail = lowpan_fetch_skb(skb, &ipaddr->s6_addr[1], 2); + fail |= lowpan_fetch_skb(skb, &ipaddr->s6_addr[12], 4); + if (fail) + return -EIO; + + /* take prefix_len and network prefix from the context */ + ipaddr->s6_addr[3] = ctx->plen; + /* get network prefix to copy into multicast address */ + ipv6_addr_prefix(&network_pfx, &ctx->pfx, ctx->plen); + /* setting network prefix */ + memcpy(&ipaddr->s6_addr[4], &network_pfx, 8); + + return 0; +} + +/* get the ecn values from iphc tf format and set it to ipv6hdr */ +static inline void lowpan_iphc_tf_set_ecn(struct ipv6hdr *hdr, const u8 *tf) +{ + /* get the two higher bits which is ecn */ + u8 ecn = tf[0] & 0xc0; + + /* ECN takes 0x30 in hdr->flow_lbl[0] */ + hdr->flow_lbl[0] |= (ecn >> 2); +} + +/* get the dscp values from iphc tf format and set it to ipv6hdr */ +static inline void lowpan_iphc_tf_set_dscp(struct ipv6hdr *hdr, const u8 *tf) +{ + /* DSCP is at place after ECN */ + u8 dscp = tf[0] & 0x3f; + + /* The four highest bits need to be set at hdr->priority */ + hdr->priority |= ((dscp & 0x3c) >> 2); + /* The two lower bits is part of hdr->flow_lbl[0] */ + hdr->flow_lbl[0] |= ((dscp & 0x03) << 6); +} + +/* get the flow label values from iphc tf format and set it to ipv6hdr */ +static inline void lowpan_iphc_tf_set_lbl(struct ipv6hdr *hdr, const u8 *lbl) +{ + /* flow label is always some array started with lower nibble of + * flow_lbl[0] and followed with two bytes afterwards. Inside inline + * data the flow_lbl position can be different, which will be handled + * by lbl pointer. E.g. case "01" vs "00" the traffic class is 8 bit + * shifted, the different lbl pointer will handle that. + * + * The flow label will started at lower nibble of flow_lbl[0], the + * higher nibbles are part of DSCP + ECN. + */ + hdr->flow_lbl[0] |= lbl[0] & 0x0f; + memcpy(&hdr->flow_lbl[1], &lbl[1], 2); +} + +/* lowpan_iphc_tf_decompress - decompress the traffic class. + * This function will return zero on success, a value lower than zero if + * failed. + */ +static int lowpan_iphc_tf_decompress(struct sk_buff *skb, struct ipv6hdr *hdr, + u8 val) +{ + u8 tf[4]; + + /* Traffic Class and Flow Label */ + switch (val) { + case LOWPAN_IPHC_TF_00: + /* ECN + DSCP + 4-bit Pad + Flow Label (4 bytes) */ + if (lowpan_fetch_skb(skb, tf, 4)) + return -EINVAL; + + /* 1 2 3 + * 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 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |ECN| DSCP | rsv | Flow Label | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + */ + lowpan_iphc_tf_set_ecn(hdr, tf); + lowpan_iphc_tf_set_dscp(hdr, tf); + lowpan_iphc_tf_set_lbl(hdr, &tf[1]); + break; + case LOWPAN_IPHC_TF_01: + /* ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided. */ + if (lowpan_fetch_skb(skb, tf, 3)) + return -EINVAL; + + /* 1 2 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |ECN|rsv| Flow Label | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + */ + lowpan_iphc_tf_set_ecn(hdr, tf); + lowpan_iphc_tf_set_lbl(hdr, &tf[0]); + break; + case LOWPAN_IPHC_TF_10: + /* ECN + DSCP (1 byte), Flow Label is elided. */ + if (lowpan_fetch_skb(skb, tf, 1)) + return -EINVAL; + + /* 0 1 2 3 4 5 6 7 + * +-+-+-+-+-+-+-+-+ + * |ECN| DSCP | + * +-+-+-+-+-+-+-+-+ + */ + lowpan_iphc_tf_set_ecn(hdr, tf); + lowpan_iphc_tf_set_dscp(hdr, tf); + break; + case LOWPAN_IPHC_TF_11: + /* Traffic Class and Flow Label are elided */ + break; + default: + WARN_ON_ONCE(1); + return -EINVAL; + } + + return 0; +} + +/* TTL uncompression values */ +static const u8 lowpan_ttl_values[] = { + [LOWPAN_IPHC_HLIM_01] = 1, + [LOWPAN_IPHC_HLIM_10] = 64, + [LOWPAN_IPHC_HLIM_11] = 255, +}; + +int lowpan_header_decompress(struct sk_buff *skb, const struct net_device *dev, + const void *daddr, const void *saddr) +{ + struct ipv6hdr hdr = {}; + struct lowpan_iphc_ctx *ci; + u8 iphc0, iphc1, cid = 0; + int err; + + raw_dump_table(__func__, "raw skb data dump uncompressed", + skb->data, skb->len); + + if (lowpan_fetch_skb(skb, &iphc0, sizeof(iphc0)) || + lowpan_fetch_skb(skb, &iphc1, sizeof(iphc1))) + return -EINVAL; + + hdr.version = 6; + + /* default CID = 0, another if the CID flag is set */ + if (iphc1 & LOWPAN_IPHC_CID) { + if (lowpan_fetch_skb(skb, &cid, sizeof(cid))) + return -EINVAL; + } + + err = lowpan_iphc_tf_decompress(skb, &hdr, + iphc0 & LOWPAN_IPHC_TF_MASK); + if (err < 0) + return err; + + /* Next Header */ + if (!(iphc0 & LOWPAN_IPHC_NH)) { + /* Next header is carried inline */ + if (lowpan_fetch_skb(skb, &hdr.nexthdr, sizeof(hdr.nexthdr))) + return -EINVAL; + + pr_debug("NH flag is set, next header carried inline: %02x\n", + hdr.nexthdr); + } + + /* Hop Limit */ + if ((iphc0 & LOWPAN_IPHC_HLIM_MASK) != LOWPAN_IPHC_HLIM_00) { + hdr.hop_limit = lowpan_ttl_values[iphc0 & LOWPAN_IPHC_HLIM_MASK]; + } else { + if (lowpan_fetch_skb(skb, &hdr.hop_limit, + sizeof(hdr.hop_limit))) + return -EINVAL; + } + + if (iphc1 & LOWPAN_IPHC_SAC) { + spin_lock_bh(&lowpan_dev(dev)->ctx.lock); + ci = lowpan_iphc_ctx_get_by_id(dev, LOWPAN_IPHC_CID_SCI(cid)); + if (!ci) { + spin_unlock_bh(&lowpan_dev(dev)->ctx.lock); + return -EINVAL; + } + + pr_debug("SAC bit is set. Handle context based source address.\n"); + err = lowpan_iphc_uncompress_ctx_addr(skb, dev, ci, &hdr.saddr, + iphc1 & LOWPAN_IPHC_SAM_MASK, + saddr); + spin_unlock_bh(&lowpan_dev(dev)->ctx.lock); + } else { + /* Source address uncompression */ + pr_debug("source address stateless compression\n"); + err = lowpan_iphc_uncompress_addr(skb, dev, &hdr.saddr, + iphc1 & LOWPAN_IPHC_SAM_MASK, + saddr); + } + + /* Check on error of previous branch */ + if (err) + return -EINVAL; + + switch (iphc1 & (LOWPAN_IPHC_M | LOWPAN_IPHC_DAC)) { + case LOWPAN_IPHC_M | LOWPAN_IPHC_DAC: + skb->pkt_type = PACKET_BROADCAST; + + spin_lock_bh(&lowpan_dev(dev)->ctx.lock); + ci = lowpan_iphc_ctx_get_by_id(dev, LOWPAN_IPHC_CID_DCI(cid)); + if (!ci) { + spin_unlock_bh(&lowpan_dev(dev)->ctx.lock); + return -EINVAL; + } + + /* multicast with context */ + pr_debug("dest: context-based mcast compression\n"); + err = lowpan_uncompress_multicast_ctx_daddr(skb, ci, + &hdr.daddr, + iphc1 & LOWPAN_IPHC_DAM_MASK); + spin_unlock_bh(&lowpan_dev(dev)->ctx.lock); + break; + case LOWPAN_IPHC_M: + skb->pkt_type = PACKET_BROADCAST; + + /* multicast */ + err = lowpan_uncompress_multicast_daddr(skb, &hdr.daddr, + iphc1 & LOWPAN_IPHC_DAM_MASK); + break; + case LOWPAN_IPHC_DAC: + skb->pkt_type = PACKET_HOST; + + spin_lock_bh(&lowpan_dev(dev)->ctx.lock); + ci = lowpan_iphc_ctx_get_by_id(dev, LOWPAN_IPHC_CID_DCI(cid)); + if (!ci) { + spin_unlock_bh(&lowpan_dev(dev)->ctx.lock); + return -EINVAL; + } + + /* Destination address context based uncompression */ + pr_debug("DAC bit is set. Handle context based destination address.\n"); + err = lowpan_iphc_uncompress_ctx_addr(skb, dev, ci, &hdr.daddr, + iphc1 & LOWPAN_IPHC_DAM_MASK, + daddr); + spin_unlock_bh(&lowpan_dev(dev)->ctx.lock); + break; + default: + skb->pkt_type = PACKET_HOST; + + err = lowpan_iphc_uncompress_addr(skb, dev, &hdr.daddr, + iphc1 & LOWPAN_IPHC_DAM_MASK, + daddr); + pr_debug("dest: stateless compression mode %d dest %pI6c\n", + iphc1 & LOWPAN_IPHC_DAM_MASK, &hdr.daddr); + break; + } + + if (err) + return -EINVAL; + + /* Next header data uncompression */ + if (iphc0 & LOWPAN_IPHC_NH) { + err = lowpan_nhc_do_uncompression(skb, dev, &hdr); + if (err < 0) + return err; + } else { + err = skb_cow(skb, sizeof(hdr)); + if (unlikely(err)) + return err; + } + + switch (lowpan_dev(dev)->lltype) { + case LOWPAN_LLTYPE_IEEE802154: + if (lowpan_802154_cb(skb)->d_size) + hdr.payload_len = htons(lowpan_802154_cb(skb)->d_size - + sizeof(struct ipv6hdr)); + else + hdr.payload_len = htons(skb->len); + break; + default: + hdr.payload_len = htons(skb->len); + break; + } + + pr_debug("skb headroom size = %d, data length = %d\n", + skb_headroom(skb), skb->len); + + pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n\t" + "nexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n", + hdr.version, ntohs(hdr.payload_len), hdr.nexthdr, + hdr.hop_limit, &hdr.daddr); + + skb_push(skb, sizeof(hdr)); + skb_reset_mac_header(skb); + skb_reset_network_header(skb); + skb_copy_to_linear_data(skb, &hdr, sizeof(hdr)); + + raw_dump_table(__func__, "raw header dump", (u8 *)&hdr, sizeof(hdr)); + + return 0; +} +EXPORT_SYMBOL_GPL(lowpan_header_decompress); + +static const u8 lowpan_iphc_dam_to_sam_value[] = { + [LOWPAN_IPHC_DAM_00] = LOWPAN_IPHC_SAM_00, + [LOWPAN_IPHC_DAM_01] = LOWPAN_IPHC_SAM_01, + [LOWPAN_IPHC_DAM_10] = LOWPAN_IPHC_SAM_10, + [LOWPAN_IPHC_DAM_11] = LOWPAN_IPHC_SAM_11, +}; + +static inline bool +lowpan_iphc_compress_ctx_802154_lladdr(const struct in6_addr *ipaddr, + const struct lowpan_iphc_ctx *ctx, + const void *lladdr) +{ + const struct ieee802154_addr *addr = lladdr; + unsigned char extended_addr[EUI64_ADDR_LEN]; + bool lladdr_compress = false; + struct in6_addr tmp = {}; + + switch (addr->mode) { + case IEEE802154_ADDR_LONG: + ieee802154_le64_to_be64(&extended_addr, &addr->extended_addr); + /* check for SAM/DAM = 11 */ + memcpy(&tmp.s6_addr[8], &extended_addr, EUI64_ADDR_LEN); + /* second bit-flip (Universe/Local) is done according RFC2464 */ + tmp.s6_addr[8] ^= 0x02; + /* context information are always used */ + ipv6_addr_prefix_copy(&tmp, &ctx->pfx, ctx->plen); + if (ipv6_addr_equal(&tmp, ipaddr)) + lladdr_compress = true; + break; + case IEEE802154_ADDR_SHORT: + tmp.s6_addr[11] = 0xFF; + tmp.s6_addr[12] = 0xFE; + ieee802154_le16_to_be16(&tmp.s6_addr16[7], + &addr->short_addr); + /* context information are always used */ + ipv6_addr_prefix_copy(&tmp, &ctx->pfx, ctx->plen); + if (ipv6_addr_equal(&tmp, ipaddr)) + lladdr_compress = true; + break; + default: + /* should never handled and filtered by 802154 6lowpan */ + WARN_ON_ONCE(1); + break; + } + + return lladdr_compress; +} + +static bool lowpan_iphc_addr_equal(const struct net_device *dev, + const struct lowpan_iphc_ctx *ctx, + const struct in6_addr *ipaddr, + const void *lladdr) +{ + struct in6_addr tmp = {}; + + lowpan_iphc_uncompress_lladdr(dev, &tmp, lladdr); + + if (ctx) + ipv6_addr_prefix_copy(&tmp, &ctx->pfx, ctx->plen); + + return ipv6_addr_equal(&tmp, ipaddr); +} + +static u8 lowpan_compress_ctx_addr(u8 **hc_ptr, const struct net_device *dev, + const struct in6_addr *ipaddr, + const struct lowpan_iphc_ctx *ctx, + const unsigned char *lladdr, bool sam) +{ + struct in6_addr tmp = {}; + u8 dam; + + switch (lowpan_dev(dev)->lltype) { + case LOWPAN_LLTYPE_IEEE802154: + if (lowpan_iphc_compress_ctx_802154_lladdr(ipaddr, ctx, + lladdr)) { + dam = LOWPAN_IPHC_DAM_11; + goto out; + } + break; + default: + if (lowpan_iphc_addr_equal(dev, ctx, ipaddr, lladdr)) { + dam = LOWPAN_IPHC_DAM_11; + goto out; + } + break; + } + + memset(&tmp, 0, sizeof(tmp)); + /* check for SAM/DAM = 10 */ + tmp.s6_addr[11] = 0xFF; + tmp.s6_addr[12] = 0xFE; + memcpy(&tmp.s6_addr[14], &ipaddr->s6_addr[14], 2); + /* context information are always used */ + ipv6_addr_prefix_copy(&tmp, &ctx->pfx, ctx->plen); + if (ipv6_addr_equal(&tmp, ipaddr)) { + lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[14], 2); + dam = LOWPAN_IPHC_DAM_10; + goto out; + } + + memset(&tmp, 0, sizeof(tmp)); + /* check for SAM/DAM = 01, should always match */ + memcpy(&tmp.s6_addr[8], &ipaddr->s6_addr[8], 8); + /* context information are always used */ + ipv6_addr_prefix_copy(&tmp, &ctx->pfx, ctx->plen); + if (ipv6_addr_equal(&tmp, ipaddr)) { + lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[8], 8); + dam = LOWPAN_IPHC_DAM_01; + goto out; + } + + WARN_ONCE(1, "context found but no address mode matched\n"); + return LOWPAN_IPHC_DAM_00; +out: + + if (sam) + return lowpan_iphc_dam_to_sam_value[dam]; + else + return dam; +} + +static inline bool +lowpan_iphc_compress_802154_lladdr(const struct in6_addr *ipaddr, + const void *lladdr) +{ + const struct ieee802154_addr *addr = lladdr; + unsigned char extended_addr[EUI64_ADDR_LEN]; + bool lladdr_compress = false; + struct in6_addr tmp = {}; + + switch (addr->mode) { + case IEEE802154_ADDR_LONG: + ieee802154_le64_to_be64(&extended_addr, &addr->extended_addr); + if (is_addr_mac_addr_based(ipaddr, extended_addr)) + lladdr_compress = true; + break; + case IEEE802154_ADDR_SHORT: + /* fe:80::ff:fe00:XXXX + * \__/ + * short_addr + * + * Universe/Local bit is zero. + */ + tmp.s6_addr[0] = 0xFE; + tmp.s6_addr[1] = 0x80; + tmp.s6_addr[11] = 0xFF; + tmp.s6_addr[12] = 0xFE; + ieee802154_le16_to_be16(&tmp.s6_addr16[7], + &addr->short_addr); + if (ipv6_addr_equal(&tmp, ipaddr)) + lladdr_compress = true; + break; + default: + /* should never handled and filtered by 802154 6lowpan */ + WARN_ON_ONCE(1); + break; + } + + return lladdr_compress; +} + +static u8 lowpan_compress_addr_64(u8 **hc_ptr, const struct net_device *dev, + const struct in6_addr *ipaddr, + const unsigned char *lladdr, bool sam) +{ + u8 dam = LOWPAN_IPHC_DAM_01; + + switch (lowpan_dev(dev)->lltype) { + case LOWPAN_LLTYPE_IEEE802154: + if (lowpan_iphc_compress_802154_lladdr(ipaddr, lladdr)) { + dam = LOWPAN_IPHC_DAM_11; /* 0-bits */ + pr_debug("address compression 0 bits\n"); + goto out; + } + break; + default: + if (lowpan_iphc_addr_equal(dev, NULL, ipaddr, lladdr)) { + dam = LOWPAN_IPHC_DAM_11; + pr_debug("address compression 0 bits\n"); + goto out; + } + + break; + } + + if (lowpan_is_iid_16_bit_compressable(ipaddr)) { + /* compress IID to 16 bits xxxx::XXXX */ + lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[7], 2); + dam = LOWPAN_IPHC_DAM_10; /* 16-bits */ + raw_dump_inline(NULL, "Compressed ipv6 addr is (16 bits)", + *hc_ptr - 2, 2); + goto out; + } + + /* do not compress IID => xxxx::IID */ + lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[4], 8); + raw_dump_inline(NULL, "Compressed ipv6 addr is (64 bits)", + *hc_ptr - 8, 8); + +out: + + if (sam) + return lowpan_iphc_dam_to_sam_value[dam]; + else + return dam; +} + +/* lowpan_iphc_get_tc - get the ECN + DCSP fields in hc format */ +static inline u8 lowpan_iphc_get_tc(const struct ipv6hdr *hdr) +{ + u8 dscp, ecn; + + /* hdr->priority contains the higher bits of dscp, lower are part of + * flow_lbl[0]. Note ECN, DCSP is swapped in ipv6 hdr. + */ + dscp = (hdr->priority << 2) | ((hdr->flow_lbl[0] & 0xc0) >> 6); + /* ECN is at the two lower bits from first nibble of flow_lbl[0] */ + ecn = (hdr->flow_lbl[0] & 0x30); + /* for pretty debug output, also shift ecn to get the ecn value */ + pr_debug("ecn 0x%02x dscp 0x%02x\n", ecn >> 4, dscp); + /* ECN is at 0x30 now, shift it to have ECN + DCSP */ + return (ecn << 2) | dscp; +} + +/* lowpan_iphc_is_flow_lbl_zero - check if flow label is zero */ +static inline bool lowpan_iphc_is_flow_lbl_zero(const struct ipv6hdr *hdr) +{ + return ((!(hdr->flow_lbl[0] & 0x0f)) && + !hdr->flow_lbl[1] && !hdr->flow_lbl[2]); +} + +/* lowpan_iphc_tf_compress - compress the traffic class which is set by + * ipv6hdr. Return the corresponding format identifier which is used. + */ +static u8 lowpan_iphc_tf_compress(u8 **hc_ptr, const struct ipv6hdr *hdr) +{ + /* get ecn dscp data in a byteformat as: ECN(hi) + DSCP(lo) */ + u8 tc = lowpan_iphc_get_tc(hdr), tf[4], val; + + /* printout the traffic class in hc format */ + pr_debug("tc 0x%02x\n", tc); + + if (lowpan_iphc_is_flow_lbl_zero(hdr)) { + if (!tc) { + /* 11: Traffic Class and Flow Label are elided. */ + val = LOWPAN_IPHC_TF_11; + } else { + /* 10: ECN + DSCP (1 byte), Flow Label is elided. + * + * 0 1 2 3 4 5 6 7 + * +-+-+-+-+-+-+-+-+ + * |ECN| DSCP | + * +-+-+-+-+-+-+-+-+ + */ + lowpan_push_hc_data(hc_ptr, &tc, sizeof(tc)); + val = LOWPAN_IPHC_TF_10; + } + } else { + /* check if dscp is zero, it's after the first two bit */ + if (!(tc & 0x3f)) { + /* 01: ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided + * + * 1 2 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |ECN|rsv| Flow Label | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + */ + memcpy(&tf[0], &hdr->flow_lbl[0], 3); + /* zero the highest 4-bits, contains DCSP + ECN */ + tf[0] &= ~0xf0; + /* set ECN */ + tf[0] |= (tc & 0xc0); + + lowpan_push_hc_data(hc_ptr, tf, 3); + val = LOWPAN_IPHC_TF_01; + } else { + /* 00: ECN + DSCP + 4-bit Pad + Flow Label (4 bytes) + * + * 1 2 3 + * 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 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |ECN| DSCP | rsv | Flow Label | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + */ + memcpy(&tf[0], &tc, sizeof(tc)); + /* highest nibble of flow_lbl[0] is part of DSCP + ECN + * which will be the 4-bit pad and will be filled with + * zeros afterwards. + */ + memcpy(&tf[1], &hdr->flow_lbl[0], 3); + /* zero the 4-bit pad, which is reserved */ + tf[1] &= ~0xf0; + + lowpan_push_hc_data(hc_ptr, tf, 4); + val = LOWPAN_IPHC_TF_00; + } + } + + return val; +} + +static u8 lowpan_iphc_mcast_ctx_addr_compress(u8 **hc_ptr, + const struct lowpan_iphc_ctx *ctx, + const struct in6_addr *ipaddr) +{ + u8 data[6]; + + /* flags/scope, reserved (RIID) */ + memcpy(data, &ipaddr->s6_addr[1], 2); + /* group ID */ + memcpy(&data[1], &ipaddr->s6_addr[11], 4); + lowpan_push_hc_data(hc_ptr, data, 6); + + return LOWPAN_IPHC_DAM_00; +} + +static u8 lowpan_iphc_mcast_addr_compress(u8 **hc_ptr, + const struct in6_addr *ipaddr) +{ + u8 val; + + if (lowpan_is_mcast_addr_compressable8(ipaddr)) { + pr_debug("compressed to 1 octet\n"); + /* use last byte */ + lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[15], 1); + val = LOWPAN_IPHC_DAM_11; + } else if (lowpan_is_mcast_addr_compressable32(ipaddr)) { + pr_debug("compressed to 4 octets\n"); + /* second byte + the last three */ + lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[1], 1); + lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[13], 3); + val = LOWPAN_IPHC_DAM_10; + } else if (lowpan_is_mcast_addr_compressable48(ipaddr)) { + pr_debug("compressed to 6 octets\n"); + /* second byte + the last five */ + lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[1], 1); + lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[11], 5); + val = LOWPAN_IPHC_DAM_01; + } else { + pr_debug("using full address\n"); + lowpan_push_hc_data(hc_ptr, ipaddr->s6_addr, 16); + val = LOWPAN_IPHC_DAM_00; + } + + return val; +} + +int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev, + const void *daddr, const void *saddr) +{ + u8 iphc0, iphc1, *hc_ptr, cid = 0; + struct ipv6hdr *hdr; + u8 head[LOWPAN_IPHC_MAX_HC_BUF_LEN] = {}; + struct lowpan_iphc_ctx *dci, *sci, dci_entry, sci_entry; + int ret, ipv6_daddr_type, ipv6_saddr_type; + + if (skb->protocol != htons(ETH_P_IPV6)) + return -EINVAL; + + hdr = ipv6_hdr(skb); + hc_ptr = head + 2; + + pr_debug("IPv6 header dump:\n\tversion = %d\n\tlength = %d\n" + "\tnexthdr = 0x%02x\n\thop_lim = %d\n\tdest = %pI6c\n", + hdr->version, ntohs(hdr->payload_len), hdr->nexthdr, + hdr->hop_limit, &hdr->daddr); + + raw_dump_table(__func__, "raw skb network header dump", + skb_network_header(skb), sizeof(struct ipv6hdr)); + + /* As we copy some bit-length fields, in the IPHC encoding bytes, + * we sometimes use |= + * If the field is 0, and the current bit value in memory is 1, + * this does not work. We therefore reset the IPHC encoding here + */ + iphc0 = LOWPAN_DISPATCH_IPHC; + iphc1 = 0; + + raw_dump_table(__func__, "sending raw skb network uncompressed packet", + skb->data, skb->len); + + ipv6_daddr_type = ipv6_addr_type(&hdr->daddr); + spin_lock_bh(&lowpan_dev(dev)->ctx.lock); + if (ipv6_daddr_type & IPV6_ADDR_MULTICAST) + dci = lowpan_iphc_ctx_get_by_mcast_addr(dev, &hdr->daddr); + else + dci = lowpan_iphc_ctx_get_by_addr(dev, &hdr->daddr); + if (dci) { + memcpy(&dci_entry, dci, sizeof(*dci)); + cid |= dci->id; + } + spin_unlock_bh(&lowpan_dev(dev)->ctx.lock); + + spin_lock_bh(&lowpan_dev(dev)->ctx.lock); + sci = lowpan_iphc_ctx_get_by_addr(dev, &hdr->saddr); + if (sci) { + memcpy(&sci_entry, sci, sizeof(*sci)); + cid |= (sci->id << 4); + } + spin_unlock_bh(&lowpan_dev(dev)->ctx.lock); + + /* if cid is zero it will be compressed */ + if (cid) { + iphc1 |= LOWPAN_IPHC_CID; + lowpan_push_hc_data(&hc_ptr, &cid, sizeof(cid)); + } + + /* Traffic Class, Flow Label compression */ + iphc0 |= lowpan_iphc_tf_compress(&hc_ptr, hdr); + + /* NOTE: payload length is always compressed */ + + /* Check if we provide the nhc format for nexthdr and compression + * functionality. If not nexthdr is handled inline and not compressed. + */ + ret = lowpan_nhc_check_compression(skb, hdr, &hc_ptr); + if (ret == -ENOENT) + lowpan_push_hc_data(&hc_ptr, &hdr->nexthdr, + sizeof(hdr->nexthdr)); + else + iphc0 |= LOWPAN_IPHC_NH; + + /* Hop limit + * if 1: compress, encoding is 01 + * if 64: compress, encoding is 10 + * if 255: compress, encoding is 11 + * else do not compress + */ + switch (hdr->hop_limit) { + case 1: + iphc0 |= LOWPAN_IPHC_HLIM_01; + break; + case 64: + iphc0 |= LOWPAN_IPHC_HLIM_10; + break; + case 255: + iphc0 |= LOWPAN_IPHC_HLIM_11; + break; + default: + lowpan_push_hc_data(&hc_ptr, &hdr->hop_limit, + sizeof(hdr->hop_limit)); + } + + ipv6_saddr_type = ipv6_addr_type(&hdr->saddr); + /* source address compression */ + if (ipv6_saddr_type == IPV6_ADDR_ANY) { + pr_debug("source address is unspecified, setting SAC\n"); + iphc1 |= LOWPAN_IPHC_SAC; + } else { + if (sci) { + iphc1 |= lowpan_compress_ctx_addr(&hc_ptr, dev, + &hdr->saddr, + &sci_entry, saddr, + true); + iphc1 |= LOWPAN_IPHC_SAC; + } else { + if (ipv6_saddr_type & IPV6_ADDR_LINKLOCAL && + lowpan_is_linklocal_zero_padded(hdr->saddr)) { + iphc1 |= lowpan_compress_addr_64(&hc_ptr, dev, + &hdr->saddr, + saddr, true); + pr_debug("source address unicast link-local %pI6c iphc1 0x%02x\n", + &hdr->saddr, iphc1); + } else { + pr_debug("send the full source address\n"); + lowpan_push_hc_data(&hc_ptr, + hdr->saddr.s6_addr, 16); + } + } + } + + /* destination address compression */ + if (ipv6_daddr_type & IPV6_ADDR_MULTICAST) { + pr_debug("destination address is multicast: "); + iphc1 |= LOWPAN_IPHC_M; + if (dci) { + iphc1 |= lowpan_iphc_mcast_ctx_addr_compress(&hc_ptr, + &dci_entry, + &hdr->daddr); + iphc1 |= LOWPAN_IPHC_DAC; + } else { + iphc1 |= lowpan_iphc_mcast_addr_compress(&hc_ptr, + &hdr->daddr); + } + } else { + if (dci) { + iphc1 |= lowpan_compress_ctx_addr(&hc_ptr, dev, + &hdr->daddr, + &dci_entry, daddr, + false); + iphc1 |= LOWPAN_IPHC_DAC; + } else { + if (ipv6_daddr_type & IPV6_ADDR_LINKLOCAL && + lowpan_is_linklocal_zero_padded(hdr->daddr)) { + iphc1 |= lowpan_compress_addr_64(&hc_ptr, dev, + &hdr->daddr, + daddr, false); + pr_debug("dest address unicast link-local %pI6c iphc1 0x%02x\n", + &hdr->daddr, iphc1); + } else { + pr_debug("dest address unicast %pI6c\n", + &hdr->daddr); + lowpan_push_hc_data(&hc_ptr, + hdr->daddr.s6_addr, 16); + } + } + } + + /* next header compression */ + if (iphc0 & LOWPAN_IPHC_NH) { + ret = lowpan_nhc_do_compression(skb, hdr, &hc_ptr); + if (ret < 0) + return ret; + } + + head[0] = iphc0; + head[1] = iphc1; + + skb_pull(skb, sizeof(struct ipv6hdr)); + skb_reset_transport_header(skb); + memcpy(skb_push(skb, hc_ptr - head), head, hc_ptr - head); + skb_reset_network_header(skb); + + pr_debug("header len %d skb %u\n", (int)(hc_ptr - head), skb->len); + + raw_dump_table(__func__, "raw skb data dump compressed", + skb->data, skb->len); + return 0; +} +EXPORT_SYMBOL_GPL(lowpan_header_compress); |