diff options
Diffstat (limited to 'net/ieee802154/6lowpan_iphc.c')
| -rw-r--r-- | net/ieee802154/6lowpan_iphc.c | 801 |
1 files changed, 0 insertions, 801 deletions
diff --git a/net/ieee802154/6lowpan_iphc.c b/net/ieee802154/6lowpan_iphc.c deleted file mode 100644 index 211b568..0000000 --- a/net/ieee802154/6lowpan_iphc.c +++ /dev/null @@ -1,801 +0,0 @@ -/* - * 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/module.h> -#include <linux/netdevice.h> -#include <net/6lowpan.h> -#include <net/ipv6.h> -#include <net/af_ieee802154.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; -} - -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) -{ - bool fail; - u8 tmp = 0, val = 0; - - if (!uh) - goto err; - - fail = lowpan_fetch_skb(skb, &tmp, 1); - - 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: - fail |= lowpan_fetch_skb(skb, &uh->source, 2); - fail |= lowpan_fetch_skb(skb, &uh->dest, 2); - break; - case LOWPAN_NHC_UDP_CS_P_01: - fail |= lowpan_fetch_skb(skb, &uh->source, 2); - fail |= lowpan_fetch_skb(skb, &val, 1); - uh->dest = htons(val + LOWPAN_NHC_UDP_8BIT_PORT); - break; - case LOWPAN_NHC_UDP_CS_P_10: - fail |= lowpan_fetch_skb(skb, &val, 1); - uh->source = htons(val + LOWPAN_NHC_UDP_8BIT_PORT); - fail |= lowpan_fetch_skb(skb, &uh->dest, 2); - break; - case LOWPAN_NHC_UDP_CS_P_11: - fail |= lowpan_fetch_skb(skb, &val, 1); - uh->source = htons(LOWPAN_NHC_UDP_4BIT_PORT + - (val >> 4)); - uh->dest = htons(LOWPAN_NHC_UDP_4BIT_PORT + - (val & 0x0f)); - break; - default: - pr_debug("ERROR: unknown UDP format\n"); - goto err; - break; - } - - 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"); - goto err; - } else { - fail |= lowpan_fetch_skb(skb, &uh->check, 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", ntohs(uh->len)); - } else { - pr_debug("ERROR: unsupported NH format\n"); - goto err; - } - - if (fail) - 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); - 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(hc06_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(hc06_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(hc06_ptr, &tmp, sizeof(tmp)); - /* source port */ - lowpan_push_hc_data(hc06_ptr, &uh->source, sizeof(uh->source)); - /* destination port */ - tmp = ntohs(uh->dest) - LOWPAN_NHC_UDP_8BIT_PORT; - lowpan_push_hc_data(hc06_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(hc06_ptr, &tmp, sizeof(tmp)); - /* source port */ - tmp = ntohs(uh->source) - LOWPAN_NHC_UDP_8BIT_PORT; - lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp)); - /* destination port */ - lowpan_push_hc_data(hc06_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(hc06_ptr, &tmp, sizeof(tmp)); - /* source port */ - lowpan_push_hc_data(hc06_ptr, &uh->source, sizeof(uh->source)); - /* destination port */ - lowpan_push_hc_data(hc06_ptr, &uh->dest, sizeof(uh->dest)); - } - - /* checksum is always inline */ - lowpan_push_hc_data(hc06_ptr, &uh->check, sizeof(uh->check)); - - /* 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); - -MODULE_LICENSE("GPL"); |
