cregit-Linux how code gets into the kernel

Release 4.8 net/6lowpan/iphc.c

Directory: net/6lowpan
/*
 * 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; } }

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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; }

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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; }

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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; }

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/* 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_eui64_lladdr(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; }

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/* 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_eui64_lladdr(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; }

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/* 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; }

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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; }

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martin townsendmartin townsend43.03%120.00%
Total132100.00%5100.00%

/* 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); }

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/* 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); }

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/* 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); }

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/* 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; }

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Total170100.00%1100.00%

/* 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: 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: /* multicast */ err = lowpan_uncompress_multicast_daddr(skb, &hdr.daddr, iphc1 & LOWPAN_IPHC_DAM_MASK); break; case LOWPAN_IPHC_DAC: 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: 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_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; }

Contributors

PersonTokensPropCommitsCommitProp
alexander aringalexander aring84798.03%571.43%
jukka rissanenjukka rissanen91.04%114.29%
simon vincentsimon vincent80.93%114.29%
Total864100.00%7100.00%

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, };