diff options
Diffstat (limited to 'net/ieee802154/6lowpan.c')
| -rw-r--r-- | net/ieee802154/6lowpan.c | 1263 |
1 files changed, 1263 insertions, 0 deletions
diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c new file mode 100644 index 00000000..840821b9 --- /dev/null +++ b/net/ieee802154/6lowpan.c @@ -0,0 +1,1263 @@ +/* + * 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/moduleparam.h> +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <net/af_ieee802154.h> +#include <net/ieee802154.h> +#include <net/ieee802154_netdev.h> +#include <net/ipv6.h> + +#include "6lowpan.h" + +/* TTL uncompression values */ +static const u8 lowpan_ttl_values[] = {0, 1, 64, 255}; + +static LIST_HEAD(lowpan_devices); + +/* + * Uncompression of linklocal: + * 0 -> 16 bytes from packet + * 1 -> 2 bytes from prefix - bunch of zeroes and 8 from packet + * 2 -> 2 bytes from prefix - zeroes + 2 from packet + * 3 -> 2 bytes from prefix - infer 8 bytes from lladdr + * + * NOTE: => the uncompress function does change 0xf to 0x10 + * NOTE: 0x00 => no-autoconfig => unspecified + */ +static const u8 lowpan_unc_llconf[] = {0x0f, 0x28, 0x22, 0x20}; + +/* + * Uncompression of ctx-based: + * 0 -> 0 bits from packet [unspecified / reserved] + * 1 -> 8 bytes from prefix - bunch of zeroes and 8 from packet + * 2 -> 8 bytes from prefix - zeroes + 2 from packet + * 3 -> 8 bytes from prefix - infer 8 bytes from lladdr + */ +static const u8 lowpan_unc_ctxconf[] = {0x00, 0x88, 0x82, 0x80}; + +/* + * Uncompression of ctx-base + * 0 -> 0 bits from packet + * 1 -> 2 bytes from prefix - bunch of zeroes 5 from packet + * 2 -> 2 bytes from prefix - zeroes + 3 from packet + * 3 -> 2 bytes from prefix - infer 1 bytes from lladdr + */ +static const u8 lowpan_unc_mxconf[] = {0x0f, 0x25, 0x23, 0x21}; + +/* Link local prefix */ +static const u8 lowpan_llprefix[] = {0xfe, 0x80}; + +/* private device info */ +struct lowpan_dev_info { + struct net_device *real_dev; /* real WPAN device ptr */ + struct mutex dev_list_mtx; /* mutex for list ops */ +}; + +struct lowpan_dev_record { + struct net_device *ldev; + struct list_head list; +}; + +struct lowpan_fragment { + struct sk_buff *skb; /* skb to be assembled */ + spinlock_t lock; /* concurency lock */ + u16 length; /* length to be assemled */ + u32 bytes_rcv; /* bytes received */ + u16 tag; /* current fragment tag */ + struct timer_list timer; /* assembling timer */ + struct list_head list; /* fragments list */ +}; + +static unsigned short fragment_tag; +static LIST_HEAD(lowpan_fragments); +spinlock_t flist_lock; + +static inline struct +lowpan_dev_info *lowpan_dev_info(const struct net_device *dev) +{ + return netdev_priv(dev); +} + +static inline void lowpan_address_flip(u8 *src, u8 *dest) +{ + int i; + for (i = 0; i < IEEE802154_ADDR_LEN; i++) + (dest)[IEEE802154_ADDR_LEN - i - 1] = (src)[i]; +} + +/* list of all 6lowpan devices, uses for package delivering */ +/* print data in line */ +static inline void lowpan_raw_dump_inline(const char *caller, char *msg, + unsigned char *buf, int len) +{ +#ifdef DEBUG + if (msg) + pr_debug("(%s) %s: ", caller, msg); + print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, + 16, 1, buf, len, false); +#endif /* DEBUG */ +} + +/* + * print data in a table format: + * + * addr: xx xx xx xx xx xx + * addr: xx xx xx xx xx xx + * ... + */ +static inline void lowpan_raw_dump_table(const char *caller, char *msg, + unsigned char *buf, int len) +{ +#ifdef DEBUG + if (msg) + pr_debug("(%s) %s:\n", caller, msg); + print_hex_dump(KERN_DEBUG, "\t", DUMP_PREFIX_OFFSET, + 16, 1, buf, len, false); +#endif /* DEBUG */ +} + +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 */ + 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 */ + } else { + /* do not compress IID => xxxx::IID */ + memcpy(*hc06_ptr, &ipaddr->s6_addr16[4], 8); + *hc06_ptr += 8; + val = 1; /* 64-bits */ + } + + return rol8(val, shift); +} + +static void +lowpan_uip_ds6_set_addr_iid(struct in6_addr *ipaddr, unsigned char *lladdr) +{ + memcpy(&ipaddr->s6_addr[8], lladdr, IEEE802154_ALEN); + /* second bit-flip (Universe/Local) is done according RFC2464 */ + ipaddr->s6_addr[8] ^= 0x02; +} + +/* + * Uncompress addresses based on a prefix and a postfix with zeroes in + * between. If the postfix is zero in length it will use the link address + * to configure the IP address (autoconf style). + * pref_post_count takes a byte where the first nibble specify prefix count + * and the second postfix count (NOTE: 15/0xf => 16 bytes copy). + */ +static int +lowpan_uncompress_addr(struct sk_buff *skb, struct in6_addr *ipaddr, + u8 const *prefix, u8 pref_post_count, unsigned char *lladdr) +{ + u8 prefcount = pref_post_count >> 4; + u8 postcount = pref_post_count & 0x0f; + + /* full nibble 15 => 16 */ + prefcount = (prefcount == 15 ? 16 : prefcount); + postcount = (postcount == 15 ? 16 : postcount); + + if (lladdr) + lowpan_raw_dump_inline(__func__, "linklocal address", + lladdr, IEEE802154_ALEN); + if (prefcount > 0) + memcpy(ipaddr, prefix, prefcount); + + if (prefcount + postcount < 16) + memset(&ipaddr->s6_addr[prefcount], 0, + 16 - (prefcount + postcount)); + + if (postcount > 0) { + memcpy(&ipaddr->s6_addr[16 - postcount], skb->data, postcount); + skb_pull(skb, postcount); + } else if (prefcount > 0) { + if (lladdr == NULL) + return -EINVAL; + + /* no IID based configuration if no prefix and no data */ + lowpan_uip_ds6_set_addr_iid(ipaddr, lladdr); + } + + pr_debug("(%s): uncompressing %d + %d => ", __func__, prefcount, + postcount); + lowpan_raw_dump_inline(NULL, NULL, ipaddr->s6_addr, 16); + + return 0; +} + +static void +lowpan_compress_udp_header(u8 **hc06_ptr, struct sk_buff *skb) +{ + struct udphdr *uh = udp_hdr(skb); + + pr_debug("(%s): UDP header compression\n", __func__); + + 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("(%s): both ports compression to 4 bits\n", __func__); + **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("(%s): remove 8 bits of dest\n", __func__); + **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("(%s): remove 8 bits of source\n", __func__); + **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("(%s): can't compress header\n", __func__); + **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; +} + +static u8 lowpan_fetch_skb_u8(struct sk_buff *skb) +{ + u8 ret; + + ret = skb->data[0]; + skb_pull(skb, 1); + + return ret; +} + +static u16 lowpan_fetch_skb_u16(struct sk_buff *skb) +{ + u16 ret; + + BUG_ON(!pskb_may_pull(skb, 2)); + + ret = skb->data[0] | (skb->data[1] << 8); + skb_pull(skb, 2); + return ret; +} + +static int +lowpan_uncompress_udp_header(struct sk_buff *skb) +{ + struct udphdr *uh = udp_hdr(skb); + u8 tmp; + + tmp = lowpan_fetch_skb_u8(skb); + + if ((tmp & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) { + pr_debug("(%s): UDP header uncompression\n", __func__); + 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("(%s) ERROR: unknown UDP format\n", __func__); + goto err; + break; + } + + pr_debug("(%s): uncompressed UDP ports: src = %d, dst = %d\n", + __func__, uh->source, uh->dest); + + /* copy checksum */ + memcpy(&uh->check, &skb->data[0], 2); + skb_pull(skb, 2); + } else { + pr_debug("(%s): ERROR: unsupported NH format\n", __func__); + goto err; + } + + return 0; +err: + return -EINVAL; +} + +static int lowpan_header_create(struct sk_buff *skb, + struct net_device *dev, + unsigned short type, const void *_daddr, + const void *_saddr, unsigned len) +{ + u8 tmp, iphc0, iphc1, *hc06_ptr; + struct ipv6hdr *hdr; + const u8 *saddr = _saddr; + const u8 *daddr = _daddr; + u8 *head; + struct ieee802154_addr sa, da; + + if (type != ETH_P_IPV6) + return 0; + /* TODO: + * if this package isn't ipv6 one, where should it be routed? + */ + head = kzalloc(100, GFP_KERNEL); + if (head == NULL) + return -ENOMEM; + + hdr = ipv6_hdr(skb); + hc06_ptr = head + 2; + + pr_debug("(%s): IPv6 header dump:\n\tversion = %d\n\tlength = %d\n" + "\tnexthdr = 0x%02x\n\thop_lim = %d\n", __func__, + hdr->version, ntohs(hdr->payload_len), hdr->nexthdr, + hdr->hop_limit); + + lowpan_raw_dump_table(__func__, "raw skb network header dump", + skb_network_header(skb), sizeof(struct ipv6hdr)); + + if (!saddr) + saddr = dev->dev_addr; + + lowpan_raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8); + + /* + * 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 */ + + lowpan_raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8); + + /* + * 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; + break; + } + + /* source address compression */ + if (is_addr_unspecified(&hdr->saddr)) { + pr_debug("(%s): source address is unspecified, setting SAC\n", + __func__); + iphc1 |= LOWPAN_IPHC_SAC; + /* TODO: context lookup */ + } else if (is_addr_link_local(&hdr->saddr)) { + pr_debug("(%s): source address is link-local\n", __func__); + iphc1 |= lowpan_compress_addr_64(&hc06_ptr, + LOWPAN_IPHC_SAM_BIT, &hdr->saddr, saddr); + } else { + pr_debug("(%s): send the full source address\n", __func__); + memcpy(hc06_ptr, &hdr->saddr.s6_addr16[0], 16); + hc06_ptr += 16; + } + + /* destination address compression */ + if (is_addr_mcast(&hdr->daddr)) { + pr_debug("(%s): destination address is multicast", __func__); + 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 { + pr_debug("(%s): destination address is unicast: ", __func__); + /* TODO: context lookup */ + if (is_addr_link_local(&hdr->daddr)) { + pr_debug("destination address is link-local\n"); + iphc1 |= lowpan_compress_addr_64(&hc06_ptr, + LOWPAN_IPHC_DAM_BIT, &hdr->daddr, daddr); + } else { + pr_debug("using full address\n"); + memcpy(hc06_ptr, &hdr->daddr.s6_addr16[0], 16); + hc06_ptr += 16; + } + } + + /* UDP header compression */ + if (hdr->nexthdr == UIP_PROTO_UDP) + lowpan_compress_udp_header(&hc06_ptr, skb); + + head[0] = iphc0; + head[1] = iphc1; + + skb_pull(skb, sizeof(struct ipv6hdr)); + memcpy(skb_push(skb, hc06_ptr - head), head, hc06_ptr - head); + + kfree(head); + + lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data, + skb->len); + + /* + * NOTE1: I'm still unsure about the fact that compression and WPAN + * header are created here and not later in the xmit. So wait for + * an opinion of net maintainers. + */ + /* + * NOTE2: to be absolutely correct, we must derive PANid information + * from MAC subif of the 'dev' and 'real_dev' network devices, but + * this isn't implemented in mainline yet, so currently we assign 0xff + */ + { + /* prepare wpan address data */ + sa.addr_type = IEEE802154_ADDR_LONG; + sa.pan_id = 0xff; + + da.addr_type = IEEE802154_ADDR_LONG; + da.pan_id = 0xff; + + memcpy(&(da.hwaddr), daddr, 8); + memcpy(&(sa.hwaddr), saddr, 8); + + mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA; + + return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev, + type, (void *)&da, (void *)&sa, skb->len); + } +} + +static int lowpan_skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr) +{ + struct sk_buff *new; + struct lowpan_dev_record *entry; + int stat = NET_RX_SUCCESS; + + 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; + + rcu_read_lock(); + list_for_each_entry_rcu(entry, &lowpan_devices, list) + if (lowpan_dev_info(entry->ldev)->real_dev == new->dev) { + skb = skb_copy(new, GFP_ATOMIC); + if (!skb) { + stat = -ENOMEM; + break; + } + + skb->dev = entry->ldev; + stat = netif_rx(skb); + } + rcu_read_unlock(); + + kfree_skb(new); + + return stat; +} + +static void lowpan_fragment_timer_expired(unsigned long entry_addr) +{ + struct lowpan_fragment *entry = (struct lowpan_fragment *)entry_addr; + + pr_debug("%s: timer expired for frame with tag %d\n", __func__, + entry->tag); + + spin_lock(&flist_lock); + list_del(&entry->list); + spin_unlock(&flist_lock); + + dev_kfree_skb(entry->skb); + kfree(entry); +} + +static int +lowpan_process_data(struct sk_buff *skb) +{ + struct ipv6hdr hdr; + u8 tmp, iphc0, iphc1, num_context = 0; + u8 *_saddr, *_daddr; + int err; + + lowpan_raw_dump_table(__func__, "raw skb data dump", skb->data, + skb->len); + /* at least two bytes will be used for the encoding */ + if (skb->len < 2) + goto drop; + iphc0 = lowpan_fetch_skb_u8(skb); + + /* fragments assembling */ + switch (iphc0 & LOWPAN_DISPATCH_MASK) { + case LOWPAN_DISPATCH_FRAG1: + case LOWPAN_DISPATCH_FRAGN: + { + struct lowpan_fragment *frame; + u8 len, offset; + u16 tag; + bool found = false; + + len = lowpan_fetch_skb_u8(skb); /* frame length */ + tag = lowpan_fetch_skb_u16(skb); + + /* + * check if frame assembling with the same tag is + * already in progress + */ + spin_lock(&flist_lock); + + list_for_each_entry(frame, &lowpan_fragments, list) + if (frame->tag == tag) { + found = true; + break; + } + + /* alloc new frame structure */ + if (!found) { + frame = kzalloc(sizeof(struct lowpan_fragment), + GFP_ATOMIC); + if (!frame) + goto unlock_and_drop; + + INIT_LIST_HEAD(&frame->list); + + frame->length = (iphc0 & 7) | (len << 3); + frame->tag = tag; + + /* allocate buffer for frame assembling */ + frame->skb = alloc_skb(frame->length + + sizeof(struct ipv6hdr), GFP_ATOMIC); + + if (!frame->skb) { + kfree(frame); + goto unlock_and_drop; + } + + frame->skb->priority = skb->priority; + frame->skb->dev = skb->dev; + + /* reserve headroom for uncompressed ipv6 header */ + skb_reserve(frame->skb, sizeof(struct ipv6hdr)); + skb_put(frame->skb, frame->length); + + init_timer(&frame->timer); + /* time out is the same as for ipv6 - 60 sec */ + frame->timer.expires = jiffies + LOWPAN_FRAG_TIMEOUT; + frame->timer.data = (unsigned long)frame; + frame->timer.function = lowpan_fragment_timer_expired; + + add_timer(&frame->timer); + + list_add_tail(&frame->list, &lowpan_fragments); + } + + if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1) + goto unlock_and_drop; + + offset = lowpan_fetch_skb_u8(skb); /* fetch offset */ + + /* if payload fits buffer, copy it */ + if (likely((offset * 8 + skb->len) <= frame->length)) + skb_copy_to_linear_data_offset(frame->skb, offset * 8, + skb->data, skb->len); + else + goto unlock_and_drop; + + frame->bytes_rcv += skb->len; + + /* frame assembling complete */ + if ((frame->bytes_rcv == frame->length) && + frame->timer.expires > jiffies) { + /* if timer haven't expired - first of all delete it */ + del_timer(&frame->timer); + list_del(&frame->list); + spin_unlock(&flist_lock); + + dev_kfree_skb(skb); + skb = frame->skb; + kfree(frame); + iphc0 = lowpan_fetch_skb_u8(skb); + break; + } + spin_unlock(&flist_lock); + + return kfree_skb(skb), 0; + } + default: + break; + } + + iphc1 = lowpan_fetch_skb_u8(skb); + + _saddr = mac_cb(skb)->sa.hwaddr; + _daddr = mac_cb(skb)->da.hwaddr; + + pr_debug("(%s): iphc0 = %02x, iphc1 = %02x\n", __func__, iphc0, iphc1); + + /* another if the CID flag is set */ + if (iphc1 & LOWPAN_IPHC_CID) { + pr_debug("(%s): CID flag is set, increase header with one\n", + __func__); + if (!skb->len) + goto drop; + num_context = lowpan_fetch_skb_u8(skb); + } + + 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 (!skb->len) + goto drop; + tmp = lowpan_fetch_skb_u8(skb); + 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 1: /* 10b */ + if (!skb->len) + goto drop; + tmp = lowpan_fetch_skb_u8(skb); + hdr.priority = ((tmp >> 2) & 0x0f); + hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30); + hdr.flow_lbl[1] = 0; + hdr.flow_lbl[2] = 0; + break; + /* + * Flow Label carried in-line + * ECN + 2-bit Pad + Flow Label (3 bytes), DSCP is elided + */ + case 2: /* 01b */ + if (!skb->len) + goto drop; + tmp = lowpan_fetch_skb_u8(skb); + 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 */ + hdr.priority = 0; + hdr.flow_lbl[0] = 0; + hdr.flow_lbl[1] = 0; + hdr.flow_lbl[2] = 0; + break; + default: + break; + } + + /* Next Header */ + if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) { + /* Next header is carried inline */ + if (!skb->len) + goto drop; + hdr.nexthdr = lowpan_fetch_skb_u8(skb); + pr_debug("(%s): NH flag is set, next header is carried " + "inline: %02x\n", __func__, hdr.nexthdr); + } + + /* Hop Limit */ + if ((iphc0 & 0x03) != LOWPAN_IPHC_TTL_I) + hdr.hop_limit = lowpan_ttl_values[iphc0 & 0x03]; + else { + if (!skb->len) + goto drop; + hdr.hop_limit = lowpan_fetch_skb_u8(skb); + } + + /* Extract SAM to the tmp variable */ + tmp = ((iphc1 & LOWPAN_IPHC_SAM) >> LOWPAN_IPHC_SAM_BIT) & 0x03; + + /* Source address uncompression */ + pr_debug("(%s): source address stateless compression\n", __func__); + err = lowpan_uncompress_addr(skb, &hdr.saddr, lowpan_llprefix, + lowpan_unc_llconf[tmp], skb->data); + 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("(%s): destination address context-based " + "multicast compression\n", __func__); + /* TODO: implement this */ + } else { + u8 prefix[] = {0xff, 0x02}; + + pr_debug("(%s): destination address non-context-based" + " multicast compression\n", __func__); + if (0 < tmp && tmp < 3) { + if (!skb->len) + goto drop; + else + prefix[1] = lowpan_fetch_skb_u8(skb); + } + + err = lowpan_uncompress_addr(skb, &hdr.daddr, prefix, + lowpan_unc_mxconf[tmp], NULL); + if (err) + goto drop; + } + } else { + pr_debug("(%s): destination address stateless compression\n", + __func__); + err = lowpan_uncompress_addr(skb, &hdr.daddr, lowpan_llprefix, + lowpan_unc_llconf[tmp], skb->data); + if (err) + goto drop; + } + + /* UDP data uncompression */ + if (iphc0 & LOWPAN_IPHC_NH_C) + if (lowpan_uncompress_udp_header(skb)) + goto drop; + + /* Not fragmented package */ + hdr.payload_len = htons(skb->len); + + pr_debug("(%s): skb headroom size = %d, data length = %d\n", __func__, + skb_headroom(skb), skb->len); + + pr_debug("(%s): IPv6 header dump:\n\tversion = %d\n\tlength = %d\n\t" + "nexthdr = 0x%02x\n\thop_lim = %d\n", __func__, hdr.version, + ntohs(hdr.payload_len), hdr.nexthdr, hdr.hop_limit); + + lowpan_raw_dump_table(__func__, "raw header dump", (u8 *)&hdr, + sizeof(hdr)); + return lowpan_skb_deliver(skb, &hdr); + +unlock_and_drop: + spin_unlock(&flist_lock); +drop: + kfree_skb(skb); + return -EINVAL; +} + +static int lowpan_get_mac_header_length(struct sk_buff *skb) +{ + /* + * Currently long addressing mode is supported only, so the overall + * header size is 21: + * FC SeqNum DPAN DA SA Sec + * 2 + 1 + 2 + 8 + 8 + 0 = 21 + */ + return 21; +} + +static int +lowpan_fragment_xmit(struct sk_buff *skb, u8 *head, + int mlen, int plen, int offset) +{ + struct sk_buff *frag; + int hlen, ret; + + /* if payload length is zero, therefore it's a first fragment */ + hlen = (plen == 0 ? LOWPAN_FRAG1_HEAD_SIZE : LOWPAN_FRAGN_HEAD_SIZE); + + lowpan_raw_dump_inline(__func__, "6lowpan fragment header", head, hlen); + + frag = dev_alloc_skb(hlen + mlen + plen + IEEE802154_MFR_SIZE); + if (!frag) + return -ENOMEM; + + frag->priority = skb->priority; + frag->dev = skb->dev; + + /* copy header, MFR and payload */ + memcpy(skb_put(frag, mlen), skb->data, mlen); + memcpy(skb_put(frag, hlen), head, hlen); + + if (plen) + skb_copy_from_linear_data_offset(skb, offset + mlen, + skb_put(frag, plen), plen); + + lowpan_raw_dump_table(__func__, " raw fragment dump", frag->data, + frag->len); + + ret = dev_queue_xmit(frag); + + return ret; +} + +static int +lowpan_skb_fragmentation(struct sk_buff *skb) +{ + int err, header_length, payload_length, tag, offset = 0; + u8 head[5]; + + header_length = lowpan_get_mac_header_length(skb); + payload_length = skb->len - header_length; + tag = fragment_tag++; + + /* first fragment header */ + head[0] = LOWPAN_DISPATCH_FRAG1 | (payload_length & 0x7); + head[1] = (payload_length >> 3) & 0xff; + head[2] = tag & 0xff; + head[3] = tag >> 8; + + err = lowpan_fragment_xmit(skb, head, header_length, 0, 0); + + /* next fragment header */ + head[0] &= ~LOWPAN_DISPATCH_FRAG1; + head[0] |= LOWPAN_DISPATCH_FRAGN; + + while ((payload_length - offset > 0) && (err >= 0)) { + int len = LOWPAN_FRAG_SIZE; + + head[4] = offset / 8; + + if (payload_length - offset < len) + len = payload_length - offset; + + err = lowpan_fragment_xmit(skb, head, header_length, + len, offset); + offset += len; + } + + return err; +} + +static netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev) +{ + int err = -1; + + pr_debug("(%s): package xmit\n", __func__); + + skb->dev = lowpan_dev_info(dev)->real_dev; + if (skb->dev == NULL) { + pr_debug("(%s) ERROR: no real wpan device found\n", __func__); + goto error; + } + + if (skb->len <= IEEE802154_MTU) { + err = dev_queue_xmit(skb); + goto out; + } + + pr_debug("(%s): frame is too big, fragmentation is needed\n", + __func__); + err = lowpan_skb_fragmentation(skb); +error: + dev_kfree_skb(skb); +out: + if (err < 0) + pr_debug("(%s): ERROR: xmit failed\n", __func__); + + return (err < 0 ? NETDEV_TX_BUSY : NETDEV_TX_OK); +} + +static void lowpan_dev_free(struct net_device *dev) +{ + dev_put(lowpan_dev_info(dev)->real_dev); + free_netdev(dev); +} + +static struct wpan_phy *lowpan_get_phy(const struct net_device *dev) +{ + struct net_device *real_dev = lowpan_dev_info(dev)->real_dev; + return ieee802154_mlme_ops(real_dev)->get_phy(real_dev); +} + +static u16 lowpan_get_pan_id(const struct net_device *dev) +{ + struct net_device *real_dev = lowpan_dev_info(dev)->real_dev; + return ieee802154_mlme_ops(real_dev)->get_pan_id(real_dev); +} + +static u16 lowpan_get_short_addr(const struct net_device *dev) +{ + struct net_device *real_dev = lowpan_dev_info(dev)->real_dev; + return ieee802154_mlme_ops(real_dev)->get_short_addr(real_dev); +} + +static struct header_ops lowpan_header_ops = { + .create = lowpan_header_create, +}; + +static const struct net_device_ops lowpan_netdev_ops = { + .ndo_start_xmit = lowpan_xmit, + .ndo_set_mac_address = eth_mac_addr, +}; + +static struct ieee802154_mlme_ops lowpan_mlme = { + .get_pan_id = lowpan_get_pan_id, + .get_phy = lowpan_get_phy, + .get_short_addr = lowpan_get_short_addr, +}; + +static void lowpan_setup(struct net_device *dev) +{ + pr_debug("(%s)\n", __func__); + + dev->addr_len = IEEE802154_ADDR_LEN; + memset(dev->broadcast, 0xff, IEEE802154_ADDR_LEN); + dev->type = ARPHRD_IEEE802154; + /* Frame Control + Sequence Number + Address fields + Security Header */ + dev->hard_header_len = 2 + 1 + 20 + 14; + dev->needed_tailroom = 2; /* FCS */ + dev->mtu = 1281; + dev->tx_queue_len = 0; + dev->flags = IFF_BROADCAST | IFF_MULTICAST; + dev->watchdog_timeo = 0; + + dev->netdev_ops = &lowpan_netdev_ops; + dev->header_ops = &lowpan_header_ops; + dev->ml_priv = &lowpan_mlme; + dev->destructor = lowpan_dev_free; +} + +static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[]) +{ + pr_debug("(%s)\n", __func__); + + if (tb[IFLA_ADDRESS]) { + if (nla_len(tb[IFLA_ADDRESS]) != IEEE802154_ADDR_LEN) + return -EINVAL; + } + return 0; +} + +static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pt, struct net_device *orig_dev) +{ + if (!netif_running(dev)) + goto drop; + + if (dev->type != ARPHRD_IEEE802154) + goto drop; + + /* check that it's our buffer */ + switch (skb->data[0] & 0xe0) { + case LOWPAN_DISPATCH_IPHC: /* ipv6 datagram */ + case LOWPAN_DISPATCH_FRAG1: /* first fragment header */ + case LOWPAN_DISPATCH_FRAGN: /* next fragments headers */ + lowpan_process_data(skb); + break; + default: + break; + } + + return NET_RX_SUCCESS; + +drop: + kfree_skb(skb); + return NET_RX_DROP; +} + +static int lowpan_newlink(struct net *src_net, struct net_device *dev, + struct nlattr *tb[], struct nlattr *data[]) +{ + struct net_device *real_dev; + struct lowpan_dev_record *entry; + + pr_debug("(%s)\n", __func__); + + if (!tb[IFLA_LINK]) + return -EINVAL; + /* find and hold real wpan device */ + real_dev = dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK])); + if (!real_dev) + return -ENODEV; + + lowpan_dev_info(dev)->real_dev = real_dev; + mutex_init(&lowpan_dev_info(dev)->dev_list_mtx); + + entry = kzalloc(sizeof(struct lowpan_dev_record), GFP_KERNEL); + if (!entry) { + dev_put(real_dev); + lowpan_dev_info(dev)->real_dev = NULL; + return -ENOMEM; + } + + entry->ldev = dev; + + mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx); + INIT_LIST_HEAD(&entry->list); + list_add_tail(&entry->list, &lowpan_devices); + mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx); + + spin_lock_init(&flist_lock); + + register_netdevice(dev); + + return 0; +} + +static void lowpan_dellink(struct net_device *dev, struct list_head *head) +{ + struct lowpan_dev_info *lowpan_dev = lowpan_dev_info(dev); + struct net_device *real_dev = lowpan_dev->real_dev; + struct lowpan_dev_record *entry, *tmp; + struct lowpan_fragment *frame, *tframe; + + ASSERT_RTNL(); + + spin_lock(&flist_lock); + list_for_each_entry_safe(frame, tframe, &lowpan_fragments, list) { + del_timer(&frame->timer); + list_del(&frame->list); + dev_kfree_skb(frame->skb); + kfree(frame); + } + spin_unlock(&flist_lock); + + mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx); + list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) { + if (entry->ldev == dev) { + list_del(&entry->list); + kfree(entry); + } + } + mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx); + + mutex_destroy(&lowpan_dev_info(dev)->dev_list_mtx); + + unregister_netdevice_queue(dev, head); + + dev_put(real_dev); +} + +static struct rtnl_link_ops lowpan_link_ops __read_mostly = { + .kind = "lowpan", + .priv_size = sizeof(struct lowpan_dev_info), + .setup = lowpan_setup, + .newlink = lowpan_newlink, + .dellink = lowpan_dellink, + .validate = lowpan_validate, +}; + +static inline int __init lowpan_netlink_init(void) +{ + return rtnl_link_register(&lowpan_link_ops); +} + +static inline void __init lowpan_netlink_fini(void) +{ + rtnl_link_unregister(&lowpan_link_ops); +} + +static struct packet_type lowpan_packet_type = { + .type = __constant_htons(ETH_P_IEEE802154), + .func = lowpan_rcv, +}; + +static int __init lowpan_init_module(void) +{ + int err = 0; + + pr_debug("(%s)\n", __func__); + + err = lowpan_netlink_init(); + if (err < 0) + goto out; + + dev_add_pack(&lowpan_packet_type); +out: + return err; +} + +static void __exit lowpan_cleanup_module(void) +{ + pr_debug("(%s)\n", __func__); + + lowpan_netlink_fini(); + + dev_remove_pack(&lowpan_packet_type); +} + +module_init(lowpan_init_module); +module_exit(lowpan_cleanup_module); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_RTNL_LINK("lowpan"); |