[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/net/6lowpan/iphc.c b/src/kernel/linux/v4.14/net/6lowpan/iphc.c
new file mode 100644
index 0000000..52fad5d
--- /dev/null
+++ b/src/kernel/linux/v4.14/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);