--- /dev/null
+/*
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/* 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/ipv6.h>
+#include <net/af_ieee802154.h>
+
+#include "6lowpan.h"
+
+/* print data in line */
+static inline void raw_dump_inline(const char *caller, char *msg,
+ unsigned char *buf, int len)
+{
+ if (msg)
+ pr_debug("%s():%s: ", caller, msg);
+ print_hex_dump_debug("", DUMP_PREFIX_NONE,
+ 16, 1, buf, len, false);
+}
+
+/*
+ * print data in a table format:
+ *
+ * addr: xx xx xx xx xx xx
+ * addr: xx xx xx xx xx xx
+ * ...
+ */
+static inline void raw_dump_table(const char *caller, char *msg,
+ unsigned char *buf, int len)
+{
+ if (msg)
+ pr_debug("%s():%s:\n", caller, msg);
+ print_hex_dump_debug("\t", DUMP_PREFIX_OFFSET,
+ 16, 1, buf, len, false);
+}
+
+/*
+ * Uncompress address function for source and
+ * destination address(non-multicast).
+ *
+ * address_mode is sam value or dam value.
+ */
+static int uncompress_addr(struct sk_buff *skb,
+ struct in6_addr *ipaddr, const u8 address_mode,
+ const u8 *lladdr, const u8 addr_type,
+ const u8 addr_len)
+{
+ bool fail;
+
+ switch (address_mode) {
+ case LOWPAN_IPHC_ADDR_00:
+ /* for global link addresses */
+ fail = lowpan_fetch_skb(skb, ipaddr->s6_addr, 16);
+ break;
+ case LOWPAN_IPHC_ADDR_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_ADDR_02:
+ /* 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_ADDR_03:
+ fail = false;
+ switch (addr_type) {
+ case IEEE802154_ADDR_LONG:
+ /* fe:80::XXXX:XXXX:XXXX:XXXX
+ * \_________________/
+ * hwaddr
+ */
+ ipaddr->s6_addr[0] = 0xFE;
+ ipaddr->s6_addr[1] = 0x80;
+ memcpy(&ipaddr->s6_addr[8], lladdr, addr_len);
+ /* second bit-flip (Universe/Local)
+ * is done according RFC2464
+ */
+ ipaddr->s6_addr[8] ^= 0x02;
+ 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;
+ ipaddr->s6_addr16[7] = htons(*((u16 *)lladdr));
+ break;
+ default:
+ pr_debug("Invalid addr_type set\n");
+ return -EINVAL;
+ }
+ 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 uncompress_context_based_src_addr(struct sk_buff *skb,
+ struct in6_addr *ipaddr,
+ const u8 sam)
+{
+ switch (sam) {
+ case LOWPAN_IPHC_ADDR_00:
+ /* unspec address ::
+ * Do nothing, address is already ::
+ */
+ break;
+ case LOWPAN_IPHC_ADDR_01:
+ /* TODO */
+ case LOWPAN_IPHC_ADDR_02:
+ /* TODO */
+ case LOWPAN_IPHC_ADDR_03:
+ /* TODO */
+ netdev_warn(skb->dev, "SAM value 0x%x not supported\n", sam);
+ return -EINVAL;
+ default:
+ pr_debug("Invalid sam value: 0x%x\n", sam);
+ return -EINVAL;
+ }
+
+ raw_dump_inline(NULL,
+ "Reconstructed context based ipv6 src addr is",
+ ipaddr->s6_addr, 16);
+
+ return 0;
+}
+
+static int skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr,
+ struct net_device *dev, skb_delivery_cb deliver_skb)
+{
+ struct sk_buff *new;
+ int stat;
+
+ new = skb_copy_expand(skb, sizeof(struct ipv6hdr), skb_tailroom(skb),
+ GFP_ATOMIC);
+ kfree_skb(skb);
+
+ if (!new)
+ return -ENOMEM;
+
+ skb_push(new, sizeof(struct ipv6hdr));
+ skb_reset_network_header(new);
+ skb_copy_to_linear_data(new, hdr, sizeof(struct ipv6hdr));
+
+ new->protocol = htons(ETH_P_IPV6);
+ new->pkt_type = PACKET_HOST;
+ new->dev = dev;
+
+ raw_dump_table(__func__, "raw skb data dump before receiving",
+ new->data, new->len);
+
+ stat = deliver_skb(new, dev);
+
+ kfree_skb(new);
+
+ return stat;
+}
+
+/* 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,
+ const u8 dam)
+{
+ bool fail;
+
+ switch (dam) {
+ 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", dam);
+ 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
+uncompress_udp_header(struct sk_buff *skb, struct udphdr *uh)
+{
+ u8 tmp;
+
+ if (!uh)
+ goto err;
+
+ if (lowpan_fetch_skb_u8(skb, &tmp))
+ goto err;
+
+ if ((tmp & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
+ pr_debug("UDP header uncompression\n");
+ switch (tmp & LOWPAN_NHC_UDP_CS_P_11) {
+ case LOWPAN_NHC_UDP_CS_P_00:
+ memcpy(&uh->source, &skb->data[0], 2);
+ memcpy(&uh->dest, &skb->data[2], 2);
+ skb_pull(skb, 4);
+ break;
+ case LOWPAN_NHC_UDP_CS_P_01:
+ memcpy(&uh->source, &skb->data[0], 2);
+ uh->dest =
+ skb->data[2] + LOWPAN_NHC_UDP_8BIT_PORT;
+ skb_pull(skb, 3);
+ break;
+ case LOWPAN_NHC_UDP_CS_P_10:
+ uh->source = skb->data[0] + LOWPAN_NHC_UDP_8BIT_PORT;
+ memcpy(&uh->dest, &skb->data[1], 2);
+ skb_pull(skb, 3);
+ break;
+ case LOWPAN_NHC_UDP_CS_P_11:
+ uh->source =
+ LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] >> 4);
+ uh->dest =
+ LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] & 0x0f);
+ skb_pull(skb, 1);
+ break;
+ default:
+ pr_debug("ERROR: unknown UDP format\n");
+ goto err;
+ break;
+ }
+
+ pr_debug("uncompressed UDP ports: src = %d, dst = %d\n",
+ uh->source, uh->dest);
+
+ /* copy checksum */
+ memcpy(&uh->check, &skb->data[0], 2);
+ skb_pull(skb, 2);
+
+ /*
+ * UDP lenght needs to be infered from the lower layers
+ * here, we obtain the hint from the remaining size of the
+ * frame
+ */
+ uh->len = htons(skb->len + sizeof(struct udphdr));
+ pr_debug("uncompressed UDP length: src = %d", uh->len);
+ } else {
+ pr_debug("ERROR: unsupported NH format\n");
+ goto err;
+ }
+
+ return 0;
+err:
+ return -EINVAL;
+}
+
+/* TTL uncompression values */
+static const u8 lowpan_ttl_values[] = { 0, 1, 64, 255 };
+
+int lowpan_process_data(struct sk_buff *skb, struct net_device *dev,
+ const u8 *saddr, const u8 saddr_type, const u8 saddr_len,
+ const u8 *daddr, const u8 daddr_type, const u8 daddr_len,
+ u8 iphc0, u8 iphc1, skb_delivery_cb deliver_skb)
+{
+ struct ipv6hdr hdr = {};
+ u8 tmp, num_context = 0;
+ int err;
+
+ raw_dump_table(__func__, "raw skb data dump uncompressed",
+ skb->data, skb->len);
+
+ /* another if the CID flag is set */
+ if (iphc1 & LOWPAN_IPHC_CID) {
+ pr_debug("CID flag is set, increase header with one\n");
+ if (lowpan_fetch_skb_u8(skb, &num_context))
+ goto drop;
+ }
+
+ hdr.version = 6;
+
+ /* Traffic Class and Flow Label */
+ switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) {
+ /*
+ * Traffic Class and FLow Label carried in-line
+ * ECN + DSCP + 4-bit Pad + Flow Label (4 bytes)
+ */
+ case 0: /* 00b */
+ if (lowpan_fetch_skb_u8(skb, &tmp))
+ goto drop;
+
+ memcpy(&hdr.flow_lbl, &skb->data[0], 3);
+ skb_pull(skb, 3);
+ hdr.priority = ((tmp >> 2) & 0x0f);
+ hdr.flow_lbl[0] = ((tmp >> 2) & 0x30) | (tmp << 6) |
+ (hdr.flow_lbl[0] & 0x0f);
+ break;
+ /*
+ * Traffic class carried in-line
+ * ECN + DSCP (1 byte), Flow Label is elided
+ */
+ case 2: /* 10b */
+ if (lowpan_fetch_skb_u8(skb, &tmp))
+ goto drop;
+
+ hdr.priority = ((tmp >> 2) & 0x0f);
+ hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30);
+ break;
+ /*
+ * Flow Label carried in-line
+ * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided
+ */
+ case 1: /* 01b */
+ if (lowpan_fetch_skb_u8(skb, &tmp))
+ goto drop;
+
+ hdr.flow_lbl[0] = (skb->data[0] & 0x0F) | ((tmp >> 2) & 0x30);
+ memcpy(&hdr.flow_lbl[1], &skb->data[0], 2);
+ skb_pull(skb, 2);
+ break;
+ /* Traffic Class and Flow Label are elided */
+ case 3: /* 11b */
+ break;
+ default:
+ break;
+ }
+
+ /* Next Header */
+ if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
+ /* Next header is carried inline */
+ if (lowpan_fetch_skb_u8(skb, &(hdr.nexthdr)))
+ goto drop;
+
+ pr_debug("NH flag is set, next header carried inline: %02x\n",
+ hdr.nexthdr);
+ }
+
+ /* Hop Limit */
+ if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I)
+ hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03];
+ else {
+ if (lowpan_fetch_skb_u8(skb, &(hdr.hop_limit)))
+ goto drop;
+ }
+
+ /* Extract SAM to the tmp variable */
+ tmp = ((iphc1 & LOWPAN_IPHC_SAM) >> LOWPAN_IPHC_SAM_BIT) & 0x03;
+
+ if (iphc1 & LOWPAN_IPHC_SAC) {
+ /* Source address context based uncompression */
+ pr_debug("SAC bit is set. Handle context based source address.\n");
+ err = uncompress_context_based_src_addr(
+ skb, &hdr.saddr, tmp);
+ } else {
+ /* Source address uncompression */
+ pr_debug("source address stateless compression\n");
+ err = uncompress_addr(skb, &hdr.saddr, tmp, saddr,
+ saddr_type, saddr_len);
+ }
+
+ /* Check on error of previous branch */
+ if (err)
+ goto drop;
+
+ /* Extract DAM to the tmp variable */
+ tmp = ((iphc1 & LOWPAN_IPHC_DAM_11) >> LOWPAN_IPHC_DAM_BIT) & 0x03;
+
+ /* check for Multicast Compression */
+ if (iphc1 & LOWPAN_IPHC_M) {
+ if (iphc1 & LOWPAN_IPHC_DAC) {
+ pr_debug("dest: context-based mcast compression\n");
+ /* TODO: implement this */
+ } else {
+ err = lowpan_uncompress_multicast_daddr(
+ skb, &hdr.daddr, tmp);
+ if (err)
+ goto drop;
+ }
+ } else {
+ err = uncompress_addr(skb, &hdr.daddr, tmp, daddr,
+ daddr_type, daddr_len);
+ pr_debug("dest: stateless compression mode %d dest %pI6c\n",
+ tmp, &hdr.daddr);
+ if (err)
+ goto drop;
+ }
+
+ /* UDP data uncompression */
+ if (iphc0 & LOWPAN_IPHC_NH_C) {
+ struct udphdr uh;
+ struct sk_buff *new;
+ if (uncompress_udp_header(skb, &uh))
+ goto drop;
+
+ /*
+ * replace the compressed UDP head by the uncompressed UDP
+ * header
+ */
+ new = skb_copy_expand(skb, sizeof(struct udphdr),
+ skb_tailroom(skb), GFP_ATOMIC);
+ kfree_skb(skb);
+
+ if (!new)
+ return -ENOMEM;
+
+ skb = new;
+
+ skb_push(skb, sizeof(struct udphdr));
+ skb_reset_transport_header(skb);
+ skb_copy_to_linear_data(skb, &uh, sizeof(struct udphdr));
+
+ raw_dump_table(__func__, "raw UDP header dump",
+ (u8 *)&uh, sizeof(uh));
+
+ hdr.nexthdr = UIP_PROTO_UDP;
+ }
+
+ hdr.payload_len = htons(skb->len);
+
+ 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);
+
+ raw_dump_table(__func__, "raw header dump", (u8 *)&hdr,
+ sizeof(hdr));
+
+ return skb_deliver(skb, &hdr, dev, deliver_skb);
+
+drop:
+ kfree_skb(skb);
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(lowpan_process_data);
+
+static u8 lowpan_compress_addr_64(u8 **hc06_ptr, u8 shift,
+ const struct in6_addr *ipaddr,
+ const unsigned char *lladdr)
+{
+ u8 val = 0;
+
+ if (is_addr_mac_addr_based(ipaddr, lladdr)) {
+ val = 3; /* 0-bits */
+ pr_debug("address compression 0 bits\n");
+ } else if (lowpan_is_iid_16_bit_compressable(ipaddr)) {
+ /* compress IID to 16 bits xxxx::XXXX */
+ memcpy(*hc06_ptr, &ipaddr->s6_addr16[7], 2);
+ *hc06_ptr += 2;
+ val = 2; /* 16-bits */
+ raw_dump_inline(NULL, "Compressed ipv6 addr is (16 bits)",
+ *hc06_ptr - 2, 2);
+ } else {
+ /* do not compress IID => xxxx::IID */
+ memcpy(*hc06_ptr, &ipaddr->s6_addr16[4], 8);
+ *hc06_ptr += 8;
+ val = 1; /* 64-bits */
+ raw_dump_inline(NULL, "Compressed ipv6 addr is (64 bits)",
+ *hc06_ptr - 8, 8);
+ }
+
+ return rol8(val, shift);
+}
+
+static void compress_udp_header(u8 **hc06_ptr, struct sk_buff *skb)
+{
+ struct udphdr *uh = udp_hdr(skb);
+
+ if (((uh->source & LOWPAN_NHC_UDP_4BIT_MASK) ==
+ LOWPAN_NHC_UDP_4BIT_PORT) &&
+ ((uh->dest & LOWPAN_NHC_UDP_4BIT_MASK) ==
+ LOWPAN_NHC_UDP_4BIT_PORT)) {
+ pr_debug("UDP header: both ports compression to 4 bits\n");
+ **hc06_ptr = LOWPAN_NHC_UDP_CS_P_11;
+ **(hc06_ptr + 1) = /* subtraction is faster */
+ (u8)((uh->dest - LOWPAN_NHC_UDP_4BIT_PORT) +
+ ((uh->source & LOWPAN_NHC_UDP_4BIT_PORT) << 4));
+ *hc06_ptr += 2;
+ } else if ((uh->dest & LOWPAN_NHC_UDP_8BIT_MASK) ==
+ LOWPAN_NHC_UDP_8BIT_PORT) {
+ pr_debug("UDP header: remove 8 bits of dest\n");
+ **hc06_ptr = LOWPAN_NHC_UDP_CS_P_01;
+ memcpy(*hc06_ptr + 1, &uh->source, 2);
+ **(hc06_ptr + 3) = (u8)(uh->dest - LOWPAN_NHC_UDP_8BIT_PORT);
+ *hc06_ptr += 4;
+ } else if ((uh->source & LOWPAN_NHC_UDP_8BIT_MASK) ==
+ LOWPAN_NHC_UDP_8BIT_PORT) {
+ pr_debug("UDP header: remove 8 bits of source\n");
+ **hc06_ptr = LOWPAN_NHC_UDP_CS_P_10;
+ memcpy(*hc06_ptr + 1, &uh->dest, 2);
+ **(hc06_ptr + 3) = (u8)(uh->source - LOWPAN_NHC_UDP_8BIT_PORT);
+ *hc06_ptr += 4;
+ } else {
+ pr_debug("UDP header: can't compress\n");
+ **hc06_ptr = LOWPAN_NHC_UDP_CS_P_00;
+ memcpy(*hc06_ptr + 1, &uh->source, 2);
+ memcpy(*hc06_ptr + 3, &uh->dest, 2);
+ *hc06_ptr += 5;
+ }
+
+ /* checksum is always inline */
+ memcpy(*hc06_ptr, &uh->check, 2);
+ *hc06_ptr += 2;
+
+ /* skip the UDP header */
+ skb_pull(skb, sizeof(struct udphdr));
+}
+
+int lowpan_header_compress(struct sk_buff *skb, struct net_device *dev,
+ unsigned short type, const void *_daddr,
+ const void *_saddr, unsigned int len)
+{
+ u8 tmp, iphc0, iphc1, *hc06_ptr;
+ struct ipv6hdr *hdr;
+ u8 head[100] = {};
+
+ if (type != ETH_P_IPV6)
+ return -EINVAL;
+
+ hdr = ipv6_hdr(skb);
+ hc06_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;
+
+ /* TODO: context lookup */
+
+ raw_dump_inline(__func__, "saddr",
+ (unsigned char *)_saddr, IEEE802154_ADDR_LEN);
+ raw_dump_inline(__func__, "daddr",
+ (unsigned char *)_daddr, IEEE802154_ADDR_LEN);
+
+ raw_dump_table(__func__,
+ "sending raw skb network uncompressed packet",
+ skb->data, skb->len);
+
+ /*
+ * Traffic class, flow label
+ * If flow label is 0, compress it. If traffic class is 0, compress it
+ * We have to process both in the same time as the offset of traffic
+ * class depends on the presence of version and flow label
+ */
+
+ /* hc06 format of TC is ECN | DSCP , original one is DSCP | ECN */
+ tmp = (hdr->priority << 4) | (hdr->flow_lbl[0] >> 4);
+ tmp = ((tmp & 0x03) << 6) | (tmp >> 2);
+
+ if (((hdr->flow_lbl[0] & 0x0F) == 0) &&
+ (hdr->flow_lbl[1] == 0) && (hdr->flow_lbl[2] == 0)) {
+ /* flow label can be compressed */
+ iphc0 |= LOWPAN_IPHC_FL_C;
+ if ((hdr->priority == 0) &&
+ ((hdr->flow_lbl[0] & 0xF0) == 0)) {
+ /* compress (elide) all */
+ iphc0 |= LOWPAN_IPHC_TC_C;
+ } else {
+ /* compress only the flow label */
+ *hc06_ptr = tmp;
+ hc06_ptr += 1;
+ }
+ } else {
+ /* Flow label cannot be compressed */
+ if ((hdr->priority == 0) &&
+ ((hdr->flow_lbl[0] & 0xF0) == 0)) {
+ /* compress only traffic class */
+ iphc0 |= LOWPAN_IPHC_TC_C;
+ *hc06_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F);
+ memcpy(hc06_ptr + 1, &hdr->flow_lbl[1], 2);
+ hc06_ptr += 3;
+ } else {
+ /* compress nothing */
+ memcpy(hc06_ptr, &hdr, 4);
+ /* replace the top byte with new ECN | DSCP format */
+ *hc06_ptr = tmp;
+ hc06_ptr += 4;
+ }
+ }
+
+ /* NOTE: payload length is always compressed */
+
+ /* Next Header is compress if UDP */
+ if (hdr->nexthdr == UIP_PROTO_UDP)
+ iphc0 |= LOWPAN_IPHC_NH_C;
+
+ if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
+ *hc06_ptr = hdr->nexthdr;
+ hc06_ptr += 1;
+ }
+
+ /*
+ * 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_TTL_1;
+ break;
+ case 64:
+ iphc0 |= LOWPAN_IPHC_TTL_64;
+ break;
+ case 255:
+ iphc0 |= LOWPAN_IPHC_TTL_255;
+ break;
+ default:
+ *hc06_ptr = hdr->hop_limit;
+ hc06_ptr += 1;
+ break;
+ }
+
+ /* source address compression */
+ if (is_addr_unspecified(&hdr->saddr)) {
+ pr_debug("source address is unspecified, setting SAC\n");
+ iphc1 |= LOWPAN_IPHC_SAC;
+ /* TODO: context lookup */
+ } else if (is_addr_link_local(&hdr->saddr)) {
+ iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
+ LOWPAN_IPHC_SAM_BIT, &hdr->saddr, _saddr);
+ pr_debug("source address unicast link-local %pI6c "
+ "iphc1 0x%02x\n", &hdr->saddr, iphc1);
+ } else {
+ pr_debug("send the full source address\n");
+ memcpy(hc06_ptr, &hdr->saddr.s6_addr16[0], 16);
+ hc06_ptr += 16;
+ }
+
+ /* destination address compression */
+ if (is_addr_mcast(&hdr->daddr)) {
+ pr_debug("destination address is multicast: ");
+ iphc1 |= LOWPAN_IPHC_M;
+ if (lowpan_is_mcast_addr_compressable8(&hdr->daddr)) {
+ pr_debug("compressed to 1 octet\n");
+ iphc1 |= LOWPAN_IPHC_DAM_11;
+ /* use last byte */
+ *hc06_ptr = hdr->daddr.s6_addr[15];
+ hc06_ptr += 1;
+ } else if (lowpan_is_mcast_addr_compressable32(&hdr->daddr)) {
+ pr_debug("compressed to 4 octets\n");
+ iphc1 |= LOWPAN_IPHC_DAM_10;
+ /* second byte + the last three */
+ *hc06_ptr = hdr->daddr.s6_addr[1];
+ memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[13], 3);
+ hc06_ptr += 4;
+ } else if (lowpan_is_mcast_addr_compressable48(&hdr->daddr)) {
+ pr_debug("compressed to 6 octets\n");
+ iphc1 |= LOWPAN_IPHC_DAM_01;
+ /* second byte + the last five */
+ *hc06_ptr = hdr->daddr.s6_addr[1];
+ memcpy(hc06_ptr + 1, &hdr->daddr.s6_addr[11], 5);
+ hc06_ptr += 6;
+ } else {
+ pr_debug("using full address\n");
+ iphc1 |= LOWPAN_IPHC_DAM_00;
+ memcpy(hc06_ptr, &hdr->daddr.s6_addr[0], 16);
+ hc06_ptr += 16;
+ }
+ } else {
+ /* TODO: context lookup */
+ if (is_addr_link_local(&hdr->daddr)) {
+ iphc1 |= lowpan_compress_addr_64(&hc06_ptr,
+ LOWPAN_IPHC_DAM_BIT, &hdr->daddr, _daddr);
+ 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);
+ memcpy(hc06_ptr, &hdr->daddr.s6_addr16[0], 16);
+ hc06_ptr += 16;
+ }
+ }
+
+ /* UDP header compression */
+ if (hdr->nexthdr == UIP_PROTO_UDP)
+ compress_udp_header(&hc06_ptr, skb);
+
+ head[0] = iphc0;
+ head[1] = iphc1;
+
+ skb_pull(skb, sizeof(struct ipv6hdr));
+ skb_reset_transport_header(skb);
+ memcpy(skb_push(skb, hc06_ptr - head), head, hc06_ptr - head);
+ skb_reset_network_header(skb);
+
+ pr_debug("header len %d skb %u\n", (int)(hc06_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);
projects / ~andy / linux / blobdiff