| /* |
| * 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); |