diff options
Diffstat (limited to 'net/6lowpan')
| -rw-r--r-- | net/6lowpan/Kconfig | 61 | ||||
| -rw-r--r-- | net/6lowpan/Makefile | 12 | ||||
| -rw-r--r-- | net/6lowpan/iphc.c | 628 | ||||
| -rw-r--r-- | net/6lowpan/nhc.c | 241 | ||||
| -rw-r--r-- | net/6lowpan/nhc.h | 146 | ||||
| -rw-r--r-- | net/6lowpan/nhc_dest.c | 28 | ||||
| -rw-r--r-- | net/6lowpan/nhc_fragment.c | 27 | ||||
| -rw-r--r-- | net/6lowpan/nhc_hop.c | 27 | ||||
| -rw-r--r-- | net/6lowpan/nhc_ipv6.c | 27 | ||||
| -rw-r--r-- | net/6lowpan/nhc_mobility.c | 27 | ||||
| -rw-r--r-- | net/6lowpan/nhc_routing.c | 27 | ||||
| -rw-r--r-- | net/6lowpan/nhc_udp.c | 157 |
12 files changed, 1408 insertions, 0 deletions
diff --git a/net/6lowpan/Kconfig b/net/6lowpan/Kconfig new file mode 100644 index 000000000..7fa0f382e --- /dev/null +++ b/net/6lowpan/Kconfig @@ -0,0 +1,61 @@ +menuconfig 6LOWPAN + tristate "6LoWPAN Support" + depends on IPV6 + ---help--- + This enables IPv6 over Low power Wireless Personal Area Network - + "6LoWPAN" which is supported by IEEE 802.15.4 or Bluetooth stacks. + +menuconfig 6LOWPAN_NHC + tristate "Next Header Compression Support" + depends on 6LOWPAN + default y + ---help--- + Support for next header compression. + +if 6LOWPAN_NHC + +config 6LOWPAN_NHC_DEST + tristate "Destination Options Header Support" + default y + ---help--- + 6LoWPAN IPv6 Destination Options Header compression according to + RFC6282. + +config 6LOWPAN_NHC_FRAGMENT + tristate "Fragment Header Support" + default y + ---help--- + 6LoWPAN IPv6 Fragment Header compression according to RFC6282. + +config 6LOWPAN_NHC_HOP + tristate "Hop-by-Hop Options Header Support" + default y + ---help--- + 6LoWPAN IPv6 Hop-by-Hop Options Header compression according to + RFC6282. + +config 6LOWPAN_NHC_IPV6 + tristate "IPv6 Header Support" + default y + ---help--- + 6LoWPAN IPv6 Header compression according to RFC6282. + +config 6LOWPAN_NHC_MOBILITY + tristate "Mobility Header Support" + default y + ---help--- + 6LoWPAN IPv6 Mobility Header compression according to RFC6282. + +config 6LOWPAN_NHC_ROUTING + tristate "Routing Header Support" + default y + ---help--- + 6LoWPAN IPv6 Routing Header compression according to RFC6282. + +config 6LOWPAN_NHC_UDP + tristate "UDP Header Support" + default y + ---help--- + 6LoWPAN IPv6 UDP Header compression according to RFC6282. + +endif diff --git a/net/6lowpan/Makefile b/net/6lowpan/Makefile new file mode 100644 index 000000000..eb8baa72a --- /dev/null +++ b/net/6lowpan/Makefile @@ -0,0 +1,12 @@ +obj-$(CONFIG_6LOWPAN) += 6lowpan.o + +6lowpan-y := iphc.o nhc.o + +#rfc6282 nhcs +obj-$(CONFIG_6LOWPAN_NHC_DEST) += nhc_dest.o +obj-$(CONFIG_6LOWPAN_NHC_FRAGMENT) += nhc_fragment.o +obj-$(CONFIG_6LOWPAN_NHC_HOP) += nhc_hop.o +obj-$(CONFIG_6LOWPAN_NHC_IPV6) += nhc_ipv6.o +obj-$(CONFIG_6LOWPAN_NHC_MOBILITY) += nhc_mobility.o +obj-$(CONFIG_6LOWPAN_NHC_ROUTING) += nhc_routing.o +obj-$(CONFIG_6LOWPAN_NHC_UDP) += nhc_udp.o diff --git a/net/6lowpan/iphc.c b/net/6lowpan/iphc.c new file mode 100644 index 000000000..94a375c04 --- /dev/null +++ b/net/6lowpan/iphc.c @@ -0,0 +1,628 @@ +/* + * 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/module.h> +#include <linux/netdevice.h> +#include <net/6lowpan.h> +#include <net/ipv6.h> +#include <net/af_ieee802154.h> + +#include "nhc.h" + +/* 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; +} + +/* 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; +} + +/* TTL uncompression values */ +static const u8 lowpan_ttl_values[] = { 0, 1, 64, 255 }; + +int +lowpan_header_decompress(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) +{ + 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(skb, &num_context, sizeof(num_context))) + return -EINVAL; + } + + 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(skb, &tmp, sizeof(tmp))) + return -EINVAL; + + 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(skb, &tmp, sizeof(tmp))) + return -EINVAL; + + 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(skb, &tmp, sizeof(tmp))) + return -EINVAL; + + 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(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 & 0x03) != LOWPAN_IPHC_TTL_I) { + hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03]; + } else { + if (lowpan_fetch_skb(skb, &hdr.hop_limit, + sizeof(hdr.hop_limit))) + return -EINVAL; + } + + /* 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) + return -EINVAL; + + /* 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) + return -EINVAL; + } + } 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) + return -EINVAL; + } + + /* Next header data uncompression */ + if (iphc0 & LOWPAN_IPHC_NH_C) { + 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; + } + + 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); + + 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; +} +EXPORT_SYMBOL_GPL(lowpan_header_decompress); + +static u8 lowpan_compress_addr_64(u8 **hc_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 */ + lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[7], 2); + val = 2; /* 16-bits */ + raw_dump_inline(NULL, "Compressed ipv6 addr is (16 bits)", + *hc_ptr - 2, 2); + } else { + /* do not compress IID => xxxx::IID */ + lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr16[4], 8); + val = 1; /* 64-bits */ + raw_dump_inline(NULL, "Compressed ipv6 addr is (64 bits)", + *hc_ptr - 8, 8); + } + + return rol8(val, shift); +} + +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, *hc_ptr; + struct ipv6hdr *hdr; + u8 head[100] = {}; + int ret, addr_type; + + if (type != 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; + + /* 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 + */ + + /* hc 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 */ + *hc_ptr = tmp; + hc_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; + *hc_ptr = (tmp & 0xc0) | (hdr->flow_lbl[0] & 0x0F); + memcpy(hc_ptr + 1, &hdr->flow_lbl[1], 2); + hc_ptr += 3; + } else { + /* compress nothing */ + memcpy(hc_ptr, hdr, 4); + /* replace the top byte with new ECN | DSCP format */ + *hc_ptr = tmp; + hc_ptr += 4; + } + } + + /* 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, &iphc0); + if (ret < 0) + return ret; + + /* 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: + lowpan_push_hc_data(&hc_ptr, &hdr->hop_limit, + sizeof(hdr->hop_limit)); + } + + addr_type = ipv6_addr_type(&hdr->saddr); + /* source address compression */ + if (addr_type == IPV6_ADDR_ANY) { + pr_debug("source address is unspecified, setting SAC\n"); + iphc1 |= LOWPAN_IPHC_SAC; + } else { + if (addr_type & IPV6_ADDR_LINKLOCAL) { + iphc1 |= lowpan_compress_addr_64(&hc_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"); + lowpan_push_hc_data(&hc_ptr, hdr->saddr.s6_addr, 16); + } + } + + addr_type = ipv6_addr_type(&hdr->daddr); + /* destination address compression */ + if (addr_type & IPV6_ADDR_MULTICAST) { + 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 */ + lowpan_push_hc_data(&hc_ptr, + &hdr->daddr.s6_addr[15], 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 */ + lowpan_push_hc_data(&hc_ptr, + &hdr->daddr.s6_addr[1], 1); + lowpan_push_hc_data(&hc_ptr, + &hdr->daddr.s6_addr[13], 3); + } 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 */ + lowpan_push_hc_data(&hc_ptr, + &hdr->daddr.s6_addr[1], 1); + lowpan_push_hc_data(&hc_ptr, + &hdr->daddr.s6_addr[11], 5); + } else { + pr_debug("using full address\n"); + iphc1 |= LOWPAN_IPHC_DAM_00; + lowpan_push_hc_data(&hc_ptr, hdr->daddr.s6_addr, 16); + } + } else { + if (addr_type & IPV6_ADDR_LINKLOCAL) { + /* TODO: context lookup */ + iphc1 |= lowpan_compress_addr_64(&hc_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); + lowpan_push_hc_data(&hc_ptr, hdr->daddr.s6_addr, 16); + } + } + + /* next header compression */ + if (iphc0 & LOWPAN_IPHC_NH_C) { + 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); + +static int __init lowpan_module_init(void) +{ + request_module_nowait("nhc_dest"); + request_module_nowait("nhc_fragment"); + request_module_nowait("nhc_hop"); + request_module_nowait("nhc_ipv6"); + request_module_nowait("nhc_mobility"); + request_module_nowait("nhc_routing"); + request_module_nowait("nhc_udp"); + + return 0; +} +module_init(lowpan_module_init); + +MODULE_LICENSE("GPL"); diff --git a/net/6lowpan/nhc.c b/net/6lowpan/nhc.c new file mode 100644 index 000000000..fd20fc51a --- /dev/null +++ b/net/6lowpan/nhc.c @@ -0,0 +1,241 @@ +/* + * 6LoWPAN next header compression + * + * + * Authors: + * Alexander Aring <aar@pengutronix.de> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/netdevice.h> + +#include <net/ipv6.h> + +#include "nhc.h" + +static struct rb_root rb_root = RB_ROOT; +static struct lowpan_nhc *lowpan_nexthdr_nhcs[NEXTHDR_MAX]; +static DEFINE_SPINLOCK(lowpan_nhc_lock); + +static int lowpan_nhc_insert(struct lowpan_nhc *nhc) +{ + struct rb_node **new = &rb_root.rb_node, *parent = NULL; + + /* Figure out where to put new node */ + while (*new) { + struct lowpan_nhc *this = container_of(*new, struct lowpan_nhc, + node); + int result, len_dif, len; + + len_dif = nhc->idlen - this->idlen; + + if (nhc->idlen < this->idlen) + len = nhc->idlen; + else + len = this->idlen; + + result = memcmp(nhc->id, this->id, len); + if (!result) + result = len_dif; + + parent = *new; + if (result < 0) + new = &((*new)->rb_left); + else if (result > 0) + new = &((*new)->rb_right); + else + return -EEXIST; + } + + /* Add new node and rebalance tree. */ + rb_link_node(&nhc->node, parent, new); + rb_insert_color(&nhc->node, &rb_root); + + return 0; +} + +static void lowpan_nhc_remove(struct lowpan_nhc *nhc) +{ + rb_erase(&nhc->node, &rb_root); +} + +static struct lowpan_nhc *lowpan_nhc_by_nhcid(const struct sk_buff *skb) +{ + struct rb_node *node = rb_root.rb_node; + const u8 *nhcid_skb_ptr = skb->data; + + while (node) { + struct lowpan_nhc *nhc = container_of(node, struct lowpan_nhc, + node); + u8 nhcid_skb_ptr_masked[LOWPAN_NHC_MAX_ID_LEN]; + int result, i; + + if (nhcid_skb_ptr + nhc->idlen > skb->data + skb->len) + return NULL; + + /* copy and mask afterwards the nhid value from skb */ + memcpy(nhcid_skb_ptr_masked, nhcid_skb_ptr, nhc->idlen); + for (i = 0; i < nhc->idlen; i++) + nhcid_skb_ptr_masked[i] &= nhc->idmask[i]; + + result = memcmp(nhcid_skb_ptr_masked, nhc->id, nhc->idlen); + if (result < 0) + node = node->rb_left; + else if (result > 0) + node = node->rb_right; + else + return nhc; + } + + return NULL; +} + +int lowpan_nhc_check_compression(struct sk_buff *skb, + const struct ipv6hdr *hdr, u8 **hc_ptr, + u8 *iphc0) +{ + struct lowpan_nhc *nhc; + + spin_lock_bh(&lowpan_nhc_lock); + + nhc = lowpan_nexthdr_nhcs[hdr->nexthdr]; + if (nhc && nhc->compress) + *iphc0 |= LOWPAN_IPHC_NH_C; + else + lowpan_push_hc_data(hc_ptr, &hdr->nexthdr, + sizeof(hdr->nexthdr)); + + spin_unlock_bh(&lowpan_nhc_lock); + + return 0; +} + +int lowpan_nhc_do_compression(struct sk_buff *skb, const struct ipv6hdr *hdr, + u8 **hc_ptr) +{ + int ret; + struct lowpan_nhc *nhc; + + spin_lock_bh(&lowpan_nhc_lock); + + nhc = lowpan_nexthdr_nhcs[hdr->nexthdr]; + /* check if the nhc module was removed in unlocked part. + * TODO: this is a workaround we should prevent unloading + * of nhc modules while unlocked part, this will always drop + * the lowpan packet but it's very unlikely. + * + * Solution isn't easy because we need to decide at + * lowpan_nhc_check_compression if we do a compression or not. + * Because the inline data which is added to skb, we can't move this + * handling. + */ + if (unlikely(!nhc || !nhc->compress)) { + ret = -EINVAL; + goto out; + } + + /* In the case of RAW sockets the transport header is not set by + * the ip6 stack so we must set it ourselves + */ + if (skb->transport_header == skb->network_header) + skb_set_transport_header(skb, sizeof(struct ipv6hdr)); + + ret = nhc->compress(skb, hc_ptr); + if (ret < 0) + goto out; + + /* skip the transport header */ + skb_pull(skb, nhc->nexthdrlen); + +out: + spin_unlock_bh(&lowpan_nhc_lock); + + return ret; +} + +int lowpan_nhc_do_uncompression(struct sk_buff *skb, struct net_device *dev, + struct ipv6hdr *hdr) +{ + struct lowpan_nhc *nhc; + int ret; + + spin_lock_bh(&lowpan_nhc_lock); + + nhc = lowpan_nhc_by_nhcid(skb); + if (nhc) { + if (nhc->uncompress) { + ret = nhc->uncompress(skb, sizeof(struct ipv6hdr) + + nhc->nexthdrlen); + if (ret < 0) { + spin_unlock_bh(&lowpan_nhc_lock); + return ret; + } + } else { + spin_unlock_bh(&lowpan_nhc_lock); + netdev_warn(dev, "received nhc id for %s which is not implemented.\n", + nhc->name); + return -ENOTSUPP; + } + } else { + spin_unlock_bh(&lowpan_nhc_lock); + netdev_warn(dev, "received unknown nhc id which was not found.\n"); + return -ENOENT; + } + + hdr->nexthdr = nhc->nexthdr; + skb_reset_transport_header(skb); + raw_dump_table(__func__, "raw transport header dump", + skb_transport_header(skb), nhc->nexthdrlen); + + spin_unlock_bh(&lowpan_nhc_lock); + + return 0; +} + +int lowpan_nhc_add(struct lowpan_nhc *nhc) +{ + int ret; + + if (!nhc->idlen || !nhc->idsetup) + return -EINVAL; + + WARN_ONCE(nhc->idlen > LOWPAN_NHC_MAX_ID_LEN, + "LOWPAN_NHC_MAX_ID_LEN should be updated to %zd.\n", + nhc->idlen); + + nhc->idsetup(nhc); + + spin_lock_bh(&lowpan_nhc_lock); + + if (lowpan_nexthdr_nhcs[nhc->nexthdr]) { + ret = -EEXIST; + goto out; + } + + ret = lowpan_nhc_insert(nhc); + if (ret < 0) + goto out; + + lowpan_nexthdr_nhcs[nhc->nexthdr] = nhc; +out: + spin_unlock_bh(&lowpan_nhc_lock); + return ret; +} +EXPORT_SYMBOL(lowpan_nhc_add); + +void lowpan_nhc_del(struct lowpan_nhc *nhc) +{ + spin_lock_bh(&lowpan_nhc_lock); + + lowpan_nhc_remove(nhc); + lowpan_nexthdr_nhcs[nhc->nexthdr] = NULL; + + spin_unlock_bh(&lowpan_nhc_lock); + + synchronize_net(); +} +EXPORT_SYMBOL(lowpan_nhc_del); diff --git a/net/6lowpan/nhc.h b/net/6lowpan/nhc.h new file mode 100644 index 000000000..ed44938eb --- /dev/null +++ b/net/6lowpan/nhc.h @@ -0,0 +1,146 @@ +#ifndef __6LOWPAN_NHC_H +#define __6LOWPAN_NHC_H + +#include <linux/skbuff.h> +#include <linux/rbtree.h> +#include <linux/module.h> + +#include <net/6lowpan.h> +#include <net/ipv6.h> + +#define LOWPAN_NHC_MAX_ID_LEN 1 + +/** + * LOWPAN_NHC - helper macro to generate nh id fields and lowpan_nhc struct + * + * @__nhc: variable name of the lowpan_nhc struct. + * @_name: const char * of common header compression name. + * @_nexthdr: ipv6 nexthdr field for the header compression. + * @_nexthdrlen: ipv6 nexthdr len for the reserved space. + * @_idsetup: callback to setup id and mask values. + * @_idlen: len for the next header id and mask, should be always the same. + * @_uncompress: callback for uncompression call. + * @_compress: callback for compression call. + */ +#define LOWPAN_NHC(__nhc, _name, _nexthdr, \ + _hdrlen, _idsetup, _idlen, \ + _uncompress, _compress) \ +static u8 __nhc##_val[_idlen]; \ +static u8 __nhc##_mask[_idlen]; \ +static struct lowpan_nhc __nhc = { \ + .name = _name, \ + .nexthdr = _nexthdr, \ + .nexthdrlen = _hdrlen, \ + .id = __nhc##_val, \ + .idmask = __nhc##_mask, \ + .idlen = _idlen, \ + .idsetup = _idsetup, \ + .uncompress = _uncompress, \ + .compress = _compress, \ +} + +#define module_lowpan_nhc(__nhc) \ +static int __init __nhc##_init(void) \ +{ \ + return lowpan_nhc_add(&(__nhc)); \ +} \ +module_init(__nhc##_init); \ +static void __exit __nhc##_exit(void) \ +{ \ + lowpan_nhc_del(&(__nhc)); \ +} \ +module_exit(__nhc##_exit); + +/** + * struct lowpan_nhc - hold 6lowpan next hdr compression ifnformation + * + * @node: holder for the rbtree. + * @name: name of the specific next header compression + * @nexthdr: next header value of the protocol which should be compressed. + * @nexthdrlen: ipv6 nexthdr len for the reserved space. + * @id: array for nhc id. Note this need to be in network byteorder. + * @mask: array for nhc id mask. Note this need to be in network byteorder. + * @len: the length of the next header id and mask. + * @setup: callback to setup fill the next header id value and mask. + * @compress: callback to do the header compression. + * @uncompress: callback to do the header uncompression. + */ +struct lowpan_nhc { + struct rb_node node; + const char *name; + const u8 nexthdr; + const size_t nexthdrlen; + u8 *id; + u8 *idmask; + const size_t idlen; + + void (*idsetup)(struct lowpan_nhc *nhc); + int (*uncompress)(struct sk_buff *skb, size_t needed); + int (*compress)(struct sk_buff *skb, u8 **hc_ptr); +}; + +/** + * lowpan_nhc_by_nexthdr - return the 6lowpan nhc by ipv6 nexthdr. + * + * @nexthdr: ipv6 nexthdr value. + */ +struct lowpan_nhc *lowpan_nhc_by_nexthdr(u8 nexthdr); + +/** + * lowpan_nhc_check_compression - checks if we support compression format. If + * we support the nhc by nexthdr field, the 6LoWPAN iphc NHC bit will be + * set. If we don't support nexthdr will be added as inline data to the + * 6LoWPAN header. + * + * @skb: skb of 6LoWPAN header to read nhc and replace header. + * @hdr: ipv6hdr to check the nexthdr value + * @hc_ptr: pointer for 6LoWPAN header which should increment at the end of + * replaced header. + * @iphc0: iphc0 pointer to set the 6LoWPAN NHC bit + */ +int lowpan_nhc_check_compression(struct sk_buff *skb, + const struct ipv6hdr *hdr, u8 **hc_ptr, + u8 *iphc0); + +/** + * lowpan_nhc_do_compression - calling compress callback for nhc + * + * @skb: skb of 6LoWPAN header to read nhc and replace header. + * @hdr: ipv6hdr to set the nexthdr value + * @hc_ptr: pointer for 6LoWPAN header which should increment at the end of + * replaced header. + */ +int lowpan_nhc_do_compression(struct sk_buff *skb, const struct ipv6hdr *hdr, + u8 **hc_ptr); + +/** + * lowpan_nhc_do_uncompression - calling uncompress callback for nhc + * + * @nhc: 6LoWPAN nhc context, get by lowpan_nhc_by_ functions. + * @skb: skb of 6LoWPAN header, skb->data should be pointed to nhc id value. + * @dev: netdevice for print logging information. + * @hdr: ipv6hdr for setting nexthdr value. + */ +int lowpan_nhc_do_uncompression(struct sk_buff *skb, struct net_device *dev, + struct ipv6hdr *hdr); + +/** + * lowpan_nhc_add - register a next header compression to framework + * + * @nhc: nhc which should be add. + */ +int lowpan_nhc_add(struct lowpan_nhc *nhc); + +/** + * lowpan_nhc_del - delete a next header compression from framework + * + * @nhc: nhc which should be delete. + */ +void lowpan_nhc_del(struct lowpan_nhc *nhc); + +/** + * lowpan_nhc_init - adding all default nhcs + */ +void lowpan_nhc_init(void); + +#endif /* __6LOWPAN_NHC_H */ diff --git a/net/6lowpan/nhc_dest.c b/net/6lowpan/nhc_dest.c new file mode 100644 index 000000000..0b292c964 --- /dev/null +++ b/net/6lowpan/nhc_dest.c @@ -0,0 +1,28 @@ +/* + * 6LoWPAN IPv6 Destination Options Header compression according to + * RFC6282 + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include "nhc.h" + +#define LOWPAN_NHC_DEST_IDLEN 1 +#define LOWPAN_NHC_DEST_ID_0 0xe6 +#define LOWPAN_NHC_DEST_MASK_0 0xfe + +static void dest_nhid_setup(struct lowpan_nhc *nhc) +{ + nhc->id[0] = LOWPAN_NHC_DEST_ID_0; + nhc->idmask[0] = LOWPAN_NHC_DEST_MASK_0; +} + +LOWPAN_NHC(nhc_dest, "RFC6282 Destination Options", NEXTHDR_DEST, 0, + dest_nhid_setup, LOWPAN_NHC_DEST_IDLEN, NULL, NULL); + +module_lowpan_nhc(nhc_dest); +MODULE_DESCRIPTION("6LoWPAN next header RFC6282 Destination Options compression"); +MODULE_LICENSE("GPL"); diff --git a/net/6lowpan/nhc_fragment.c b/net/6lowpan/nhc_fragment.c new file mode 100644 index 000000000..473dbc58e --- /dev/null +++ b/net/6lowpan/nhc_fragment.c @@ -0,0 +1,27 @@ +/* + * 6LoWPAN IPv6 Fragment Header compression according to RFC6282 + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include "nhc.h" + +#define LOWPAN_NHC_FRAGMENT_IDLEN 1 +#define LOWPAN_NHC_FRAGMENT_ID_0 0xe4 +#define LOWPAN_NHC_FRAGMENT_MASK_0 0xfe + +static void fragment_nhid_setup(struct lowpan_nhc *nhc) +{ + nhc->id[0] = LOWPAN_NHC_FRAGMENT_ID_0; + nhc->idmask[0] = LOWPAN_NHC_FRAGMENT_MASK_0; +} + +LOWPAN_NHC(nhc_fragment, "RFC6282 Fragment", NEXTHDR_FRAGMENT, 0, + fragment_nhid_setup, LOWPAN_NHC_FRAGMENT_IDLEN, NULL, NULL); + +module_lowpan_nhc(nhc_fragment); +MODULE_DESCRIPTION("6LoWPAN next header RFC6282 Fragment compression"); +MODULE_LICENSE("GPL"); diff --git a/net/6lowpan/nhc_hop.c b/net/6lowpan/nhc_hop.c new file mode 100644 index 000000000..1eb66be16 --- /dev/null +++ b/net/6lowpan/nhc_hop.c @@ -0,0 +1,27 @@ +/* + * 6LoWPAN IPv6 Hop-by-Hop Options Header compression according to RFC6282 + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include "nhc.h" + +#define LOWPAN_NHC_HOP_IDLEN 1 +#define LOWPAN_NHC_HOP_ID_0 0xe0 +#define LOWPAN_NHC_HOP_MASK_0 0xfe + +static void hop_nhid_setup(struct lowpan_nhc *nhc) +{ + nhc->id[0] = LOWPAN_NHC_HOP_ID_0; + nhc->idmask[0] = LOWPAN_NHC_HOP_MASK_0; +} + +LOWPAN_NHC(nhc_hop, "RFC6282 Hop-by-Hop Options", NEXTHDR_HOP, 0, + hop_nhid_setup, LOWPAN_NHC_HOP_IDLEN, NULL, NULL); + +module_lowpan_nhc(nhc_hop); +MODULE_DESCRIPTION("6LoWPAN next header RFC6282 Hop-by-Hop Options compression"); +MODULE_LICENSE("GPL"); diff --git a/net/6lowpan/nhc_ipv6.c b/net/6lowpan/nhc_ipv6.c new file mode 100644 index 000000000..2313d1600 --- /dev/null +++ b/net/6lowpan/nhc_ipv6.c @@ -0,0 +1,27 @@ +/* + * 6LoWPAN IPv6 Header compression according to RFC6282 + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include "nhc.h" + +#define LOWPAN_NHC_IPV6_IDLEN 1 +#define LOWPAN_NHC_IPV6_ID_0 0xee +#define LOWPAN_NHC_IPV6_MASK_0 0xfe + +static void ipv6_nhid_setup(struct lowpan_nhc *nhc) +{ + nhc->id[0] = LOWPAN_NHC_IPV6_ID_0; + nhc->idmask[0] = LOWPAN_NHC_IPV6_MASK_0; +} + +LOWPAN_NHC(nhc_ipv6, "RFC6282 IPv6", NEXTHDR_IPV6, 0, ipv6_nhid_setup, + LOWPAN_NHC_IPV6_IDLEN, NULL, NULL); + +module_lowpan_nhc(nhc_ipv6); +MODULE_DESCRIPTION("6LoWPAN next header RFC6282 IPv6 compression"); +MODULE_LICENSE("GPL"); diff --git a/net/6lowpan/nhc_mobility.c b/net/6lowpan/nhc_mobility.c new file mode 100644 index 000000000..60d3f3886 --- /dev/null +++ b/net/6lowpan/nhc_mobility.c @@ -0,0 +1,27 @@ +/* + * 6LoWPAN IPv6 Mobility Header compression according to RFC6282 + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include "nhc.h" + +#define LOWPAN_NHC_MOBILITY_IDLEN 1 +#define LOWPAN_NHC_MOBILITY_ID_0 0xe8 +#define LOWPAN_NHC_MOBILITY_MASK_0 0xfe + +static void mobility_nhid_setup(struct lowpan_nhc *nhc) +{ + nhc->id[0] = LOWPAN_NHC_MOBILITY_ID_0; + nhc->idmask[0] = LOWPAN_NHC_MOBILITY_MASK_0; +} + +LOWPAN_NHC(nhc_mobility, "RFC6282 Mobility", NEXTHDR_MOBILITY, 0, + mobility_nhid_setup, LOWPAN_NHC_MOBILITY_IDLEN, NULL, NULL); + +module_lowpan_nhc(nhc_mobility); +MODULE_DESCRIPTION("6LoWPAN next header RFC6282 Mobility compression"); +MODULE_LICENSE("GPL"); diff --git a/net/6lowpan/nhc_routing.c b/net/6lowpan/nhc_routing.c new file mode 100644 index 000000000..c393280f1 --- /dev/null +++ b/net/6lowpan/nhc_routing.c @@ -0,0 +1,27 @@ +/* + * 6LoWPAN IPv6 Routing Header compression according to RFC6282 + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include "nhc.h" + +#define LOWPAN_NHC_ROUTING_IDLEN 1 +#define LOWPAN_NHC_ROUTING_ID_0 0xe2 +#define LOWPAN_NHC_ROUTING_MASK_0 0xfe + +static void routing_nhid_setup(struct lowpan_nhc *nhc) +{ + nhc->id[0] = LOWPAN_NHC_ROUTING_ID_0; + nhc->idmask[0] = LOWPAN_NHC_ROUTING_MASK_0; +} + +LOWPAN_NHC(nhc_routing, "RFC6282 Routing", NEXTHDR_ROUTING, 0, + routing_nhid_setup, LOWPAN_NHC_ROUTING_IDLEN, NULL, NULL); + +module_lowpan_nhc(nhc_routing); +MODULE_DESCRIPTION("6LoWPAN next header RFC6282 Routing compression"); +MODULE_LICENSE("GPL"); diff --git a/net/6lowpan/nhc_udp.c b/net/6lowpan/nhc_udp.c new file mode 100644 index 000000000..c6bcaeb42 --- /dev/null +++ b/net/6lowpan/nhc_udp.c @@ -0,0 +1,157 @@ +/* + * 6LoWPAN IPv6 UDP compression according to RFC6282 + * + * + * Authors: + * Alexander Aring <aar@pengutronix.de> + * + * Orignal written by: + * Alexander Smirnov <alex.bluesman.smirnov@gmail.com> + * 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 + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include "nhc.h" + +#define LOWPAN_NHC_UDP_IDLEN 1 + +static int udp_uncompress(struct sk_buff *skb, size_t needed) +{ + u8 tmp = 0, val = 0; + struct udphdr uh; + bool fail; + int err; + + fail = lowpan_fetch_skb(skb, &tmp, sizeof(tmp)); + + pr_debug("UDP header uncompression\n"); + switch (tmp & LOWPAN_NHC_UDP_CS_P_11) { + case LOWPAN_NHC_UDP_CS_P_00: + fail |= lowpan_fetch_skb(skb, &uh.source, sizeof(uh.source)); + fail |= lowpan_fetch_skb(skb, &uh.dest, sizeof(uh.dest)); + break; + case LOWPAN_NHC_UDP_CS_P_01: + fail |= lowpan_fetch_skb(skb, &uh.source, sizeof(uh.source)); + fail |= lowpan_fetch_skb(skb, &val, sizeof(val)); + uh.dest = htons(val + LOWPAN_NHC_UDP_8BIT_PORT); + break; + case LOWPAN_NHC_UDP_CS_P_10: + fail |= lowpan_fetch_skb(skb, &val, sizeof(val)); + uh.source = htons(val + LOWPAN_NHC_UDP_8BIT_PORT); + fail |= lowpan_fetch_skb(skb, &uh.dest, sizeof(uh.dest)); + break; + case LOWPAN_NHC_UDP_CS_P_11: + fail |= lowpan_fetch_skb(skb, &val, sizeof(val)); + uh.source = htons(LOWPAN_NHC_UDP_4BIT_PORT + (val >> 4)); + uh.dest = htons(LOWPAN_NHC_UDP_4BIT_PORT + (val & 0x0f)); + break; + default: + BUG(); + } + + pr_debug("uncompressed UDP ports: src = %d, dst = %d\n", + ntohs(uh.source), ntohs(uh.dest)); + + /* checksum */ + if (tmp & LOWPAN_NHC_UDP_CS_C) { + pr_debug_ratelimited("checksum elided currently not supported\n"); + fail = true; + } else { + fail |= lowpan_fetch_skb(skb, &uh.check, sizeof(uh.check)); + } + + if (fail) + return -EINVAL; + + /* UDP length 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", ntohs(uh.len)); + + /* replace the compressed UDP head by the uncompressed UDP + * header + */ + err = skb_cow(skb, needed); + if (unlikely(err)) + return err; + + skb_push(skb, sizeof(struct udphdr)); + skb_copy_to_linear_data(skb, &uh, sizeof(struct udphdr)); + + return 0; +} + +static int udp_compress(struct sk_buff *skb, u8 **hc_ptr) +{ + const struct udphdr *uh = udp_hdr(skb); + u8 tmp; + + if (((ntohs(uh->source) & LOWPAN_NHC_UDP_4BIT_MASK) == + LOWPAN_NHC_UDP_4BIT_PORT) && + ((ntohs(uh->dest) & LOWPAN_NHC_UDP_4BIT_MASK) == + LOWPAN_NHC_UDP_4BIT_PORT)) { + pr_debug("UDP header: both ports compression to 4 bits\n"); + /* compression value */ + tmp = LOWPAN_NHC_UDP_CS_P_11; + lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); + /* source and destination port */ + tmp = ntohs(uh->dest) - LOWPAN_NHC_UDP_4BIT_PORT + + ((ntohs(uh->source) - LOWPAN_NHC_UDP_4BIT_PORT) << 4); + lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); + } else if ((ntohs(uh->dest) & LOWPAN_NHC_UDP_8BIT_MASK) == + LOWPAN_NHC_UDP_8BIT_PORT) { + pr_debug("UDP header: remove 8 bits of dest\n"); + /* compression value */ + tmp = LOWPAN_NHC_UDP_CS_P_01; + lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); + /* source port */ + lowpan_push_hc_data(hc_ptr, &uh->source, sizeof(uh->source)); + /* destination port */ + tmp = ntohs(uh->dest) - LOWPAN_NHC_UDP_8BIT_PORT; + lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); + } else if ((ntohs(uh->source) & LOWPAN_NHC_UDP_8BIT_MASK) == + LOWPAN_NHC_UDP_8BIT_PORT) { + pr_debug("UDP header: remove 8 bits of source\n"); + /* compression value */ + tmp = LOWPAN_NHC_UDP_CS_P_10; + lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); + /* source port */ + tmp = ntohs(uh->source) - LOWPAN_NHC_UDP_8BIT_PORT; + lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); + /* destination port */ + lowpan_push_hc_data(hc_ptr, &uh->dest, sizeof(uh->dest)); + } else { + pr_debug("UDP header: can't compress\n"); + /* compression value */ + tmp = LOWPAN_NHC_UDP_CS_P_00; + lowpan_push_hc_data(hc_ptr, &tmp, sizeof(tmp)); + /* source port */ + lowpan_push_hc_data(hc_ptr, &uh->source, sizeof(uh->source)); + /* destination port */ + lowpan_push_hc_data(hc_ptr, &uh->dest, sizeof(uh->dest)); + } + + /* checksum is always inline */ + lowpan_push_hc_data(hc_ptr, &uh->check, sizeof(uh->check)); + + return 0; +} + +static void udp_nhid_setup(struct lowpan_nhc *nhc) +{ + nhc->id[0] = LOWPAN_NHC_UDP_ID; + nhc->idmask[0] = LOWPAN_NHC_UDP_MASK; +} + +LOWPAN_NHC(nhc_udp, "RFC6282 UDP", NEXTHDR_UDP, sizeof(struct udphdr), + udp_nhid_setup, LOWPAN_NHC_UDP_IDLEN, udp_uncompress, udp_compress); + +module_lowpan_nhc(nhc_udp); +MODULE_DESCRIPTION("6LoWPAN next header RFC6282 UDP compression"); +MODULE_LICENSE("GPL"); |