/* * Copyright 2011, Siemens AG * written by Alexander Smirnov */ /* * Based on patches from Jon Smirl * Copyright (c) 2011 Jon Smirl * * 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 #include #include #include #include #include #include #include #include #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 */ 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); static DEFINE_SPINLOCK(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_ADDR_LEN); /* 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_ADDR_LEN); 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("uncompressing %d + %d => ", 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); if (((uh->source & LOWPAN_NHC_UDP_4BIT_MASK) == LOWPAN_NHC_UDP_4BIT_PORT) && ((uh->dest & LOWPAN_NHC_UDP_4BIT_MASK) == LOWPAN_NHC_UDP_4BIT_PORT)) { pr_debug("UDP header: both ports compression to 4 bits\n"); **hc06_ptr = LOWPAN_NHC_UDP_CS_P_11; **(hc06_ptr + 1) = /* subtraction is faster */ (u8)((uh->dest - LOWPAN_NHC_UDP_4BIT_PORT) + ((uh->source & LOWPAN_NHC_UDP_4BIT_PORT) << 4)); *hc06_ptr += 2; } else if ((uh->dest & LOWPAN_NHC_UDP_8BIT_MASK) == LOWPAN_NHC_UDP_8BIT_PORT) { pr_debug("UDP header: remove 8 bits of dest\n"); **hc06_ptr = LOWPAN_NHC_UDP_CS_P_01; memcpy(*hc06_ptr + 1, &uh->source, 2); **(hc06_ptr + 3) = (u8)(uh->dest - LOWPAN_NHC_UDP_8BIT_PORT); *hc06_ptr += 4; } else if ((uh->source & LOWPAN_NHC_UDP_8BIT_MASK) == LOWPAN_NHC_UDP_8BIT_PORT) { pr_debug("UDP header: remove 8 bits of source\n"); **hc06_ptr = LOWPAN_NHC_UDP_CS_P_10; memcpy(*hc06_ptr + 1, &uh->dest, 2); **(hc06_ptr + 3) = (u8)(uh->source - LOWPAN_NHC_UDP_8BIT_PORT); *hc06_ptr += 4; } else { pr_debug("UDP header: can't compress\n"); **hc06_ptr = LOWPAN_NHC_UDP_CS_P_00; memcpy(*hc06_ptr + 1, &uh->source, 2); memcpy(*hc06_ptr + 3, &uh->dest, 2); *hc06_ptr += 5; } /* checksum is always inline */ memcpy(*hc06_ptr, &uh->check, 2); *hc06_ptr += 2; } static inline int lowpan_fetch_skb_u8(struct sk_buff *skb, u8 *val) { if (unlikely(!pskb_may_pull(skb, 1))) return -EINVAL; *val = skb->data[0]; skb_pull(skb, 1); return 0; } static inline int lowpan_fetch_skb_u16(struct sk_buff *skb, u16 *val) { if (unlikely(!pskb_may_pull(skb, 2))) return -EINVAL; *val = (skb->data[0] << 8) | skb->data[1]; skb_pull(skb, 2); return 0; } static int lowpan_uncompress_udp_header(struct sk_buff *skb) { struct udphdr *uh = udp_hdr(skb); u8 tmp; if (!uh) goto err; if (lowpan_fetch_skb_u8(skb, &tmp)) goto err; if ((tmp & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) { pr_debug("UDP header uncompression\n"); switch (tmp & LOWPAN_NHC_UDP_CS_P_11) { case LOWPAN_NHC_UDP_CS_P_00: memcpy(&uh->source, &skb->data[0], 2); memcpy(&uh->dest, &skb->data[2], 2); skb_pull(skb, 4); break; case LOWPAN_NHC_UDP_CS_P_01: memcpy(&uh->source, &skb->data[0], 2); uh->dest = skb->data[2] + LOWPAN_NHC_UDP_8BIT_PORT; skb_pull(skb, 3); break; case LOWPAN_NHC_UDP_CS_P_10: uh->source = skb->data[0] + LOWPAN_NHC_UDP_8BIT_PORT; memcpy(&uh->dest, &skb->data[1], 2); skb_pull(skb, 3); break; case LOWPAN_NHC_UDP_CS_P_11: uh->source = LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] >> 4); uh->dest = LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] & 0x0f); skb_pull(skb, 1); break; default: pr_debug("ERROR: unknown UDP format\n"); goto err; break; } pr_debug("uncompressed UDP ports: src = %d, dst = %d\n", uh->source, uh->dest); /* copy checksum */ memcpy(&uh->check, &skb->data[0], 2); skb_pull(skb, 2); } else { pr_debug("ERROR: unsupported NH format\n"); 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 int len) { u8 tmp, iphc0, iphc1, *hc06_ptr; struct ipv6hdr *hdr; const u8 *saddr = _saddr; const u8 *daddr = _daddr; u8 head[100]; struct ieee802154_addr sa, da; /* TODO: * if this package isn't ipv6 one, where should it be routed? */ if (type != ETH_P_IPV6) return 0; 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", 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; 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)) { pr_debug("source address is link-local\n"); iphc1 |= lowpan_compress_addr_64(&hc06_ptr, LOWPAN_IPHC_SAM_BIT, &hdr->saddr, saddr); } 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)) { pr_debug("dest address is unicast and link-local\n"); iphc1 |= lowpan_compress_addr_64(&hc06_ptr, LOWPAN_IPHC_DAM_BIT, &hdr->daddr, daddr); } else { pr_debug("dest address is unicast: using full one\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); 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 */ { mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA; /* prepare wpan address data */ sa.addr_type = IEEE802154_ADDR_LONG; sa.pan_id = 0xff; memcpy(&(sa.hwaddr), saddr, 8); da.pan_id = 0xff; /* * if the destination address is the broadcast address, use the * corresponding short address */ if (lowpan_is_addr_broadcast(daddr)) { da.addr_type = IEEE802154_ADDR_SHORT; da.short_addr = IEEE802154_ADDR_BROADCAST; } else { da.addr_type = IEEE802154_ADDR_LONG; memcpy(&(da.hwaddr), daddr, 8); /* request acknowledgment */ mac_cb(skb)->flags |= MAC_CB_FLAG_ACKREQ; } return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev, type, (void *)&da, (void *)&sa, skb->len); } } static int lowpan_give_skb_to_devices(struct sk_buff *skb) { struct lowpan_dev_record *entry; struct sk_buff *skb_cp; int stat = NET_RX_SUCCESS; rcu_read_lock(); list_for_each_entry_rcu(entry, &lowpan_devices, list) if (lowpan_dev_info(entry->ldev)->real_dev == skb->dev) { skb_cp = skb_copy(skb, GFP_ATOMIC); if (!skb_cp) { stat = -ENOMEM; break; } skb_cp->dev = entry->ldev; stat = netif_rx(skb_cp); } rcu_read_unlock(); return stat; } static int lowpan_skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr) { struct sk_buff *new; 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; stat = lowpan_give_skb_to_devices(new); 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("timer expired for frame with tag %d\n", entry->tag); list_del(&entry->list); dev_kfree_skb(entry->skb); kfree(entry); } static struct lowpan_fragment * lowpan_alloc_new_frame(struct sk_buff *skb, u8 len, u16 tag) { struct lowpan_fragment *frame; frame = kzalloc(sizeof(struct lowpan_fragment), GFP_ATOMIC); if (!frame) goto frame_err; INIT_LIST_HEAD(&frame->list); frame->length = len; frame->tag = tag; /* allocate buffer for frame assembling */ frame->skb = netdev_alloc_skb_ip_align(skb->dev, frame->length + sizeof(struct ipv6hdr)); if (!frame->skb) goto skb_err; 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); return frame; skb_err: kfree(frame); frame_err: return NULL; } 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; if (lowpan_fetch_skb_u8(skb, &iphc0)) goto drop; /* fragments assembling */ switch (iphc0 & LOWPAN_DISPATCH_MASK) { case LOWPAN_DISPATCH_FRAG1: case LOWPAN_DISPATCH_FRAGN: { struct lowpan_fragment *frame; /* slen stores the rightmost 8 bits of the 11 bits length */ u8 slen, offset; u16 len, tag; bool found = false; if (lowpan_fetch_skb_u8(skb, &slen) || /* frame length */ lowpan_fetch_skb_u16(skb, &tag)) /* fragment tag */ goto drop; /* adds the 3 MSB to the 8 LSB to retrieve the 11 bits length */ len = ((iphc0 & 7) << 8) | slen; /* * check if frame assembling with the same tag is * already in progress */ spin_lock_bh(&flist_lock); list_for_each_entry(frame, &lowpan_fragments, list) if (frame->tag == tag) { found = true; break; } /* alloc new frame structure */ if (!found) { frame = lowpan_alloc_new_frame(skb, len, tag); if (!frame) goto unlock_and_drop; } if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1) goto unlock_and_drop; if (lowpan_fetch_skb_u8(skb, &offset)) /* fetch offset */ goto unlock_and_drop; /* 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_sync(&frame->timer); list_del(&frame->list); spin_unlock_bh(&flist_lock); dev_kfree_skb(skb); skb = frame->skb; kfree(frame); if (lowpan_fetch_skb_u8(skb, &iphc0)) goto drop; break; } spin_unlock_bh(&flist_lock); return kfree_skb(skb), 0; } default: break; } if (lowpan_fetch_skb_u8(skb, &iphc1)) goto drop; _saddr = mac_cb(skb)->sa.hwaddr; _daddr = mac_cb(skb)->da.hwaddr; pr_debug("iphc0 = %02x, iphc1 = %02x\n", iphc0, iphc1); /* 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 1: /* 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); 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 (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 */ 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 (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; /* Source address uncompression */ pr_debug("source address stateless compression\n"); 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("dest: context-based mcast compression\n"); /* TODO: implement this */ } else { u8 prefix[] = {0xff, 0x02}; pr_debug("dest: non context-based mcast compression\n"); if (0 < tmp && tmp < 3) { if (lowpan_fetch_skb_u8(skb, &prefix[1])) goto drop; } err = lowpan_uncompress_addr(skb, &hdr.daddr, prefix, lowpan_unc_mxconf[tmp], NULL); if (err) goto drop; } } else { pr_debug("dest: stateless compression\n"); 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; hdr.nexthdr = UIP_PROTO_UDP; } /* Not fragmented package */ 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", 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_bh(&flist_lock); drop: kfree_skb(skb); return -EINVAL; } static int lowpan_set_address(struct net_device *dev, void *p) { struct sockaddr *sa = p; if (netif_running(dev)) return -EBUSY; /* TODO: validate addr */ memcpy(dev->dev_addr, sa->sa_data, dev->addr_len); return 0; } 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 >> 8) & 0x7); head[1] = payload_length & 0xff; head[2] = tag >> 8; head[3] = tag & 0xff; 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("package xmit\n"); skb->dev = lowpan_dev_info(dev)->real_dev; if (skb->dev == NULL) { pr_debug("ERROR: no real wpan device found\n"); goto error; } /* Send directly if less than the MTU minus the 2 checksum bytes. */ if (skb->len <= IEEE802154_MTU - IEEE802154_MFR_SIZE) { err = dev_queue_xmit(skb); goto out; } pr_debug("frame is too big, fragmentation is needed\n"); err = lowpan_skb_fragmentation(skb); error: dev_kfree_skb(skb); out: if (err < 0) pr_debug("ERROR: xmit failed\n"); return (err < 0 ? NETDEV_TX_BUSY : NETDEV_TX_OK); } 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 = lowpan_set_address, }; 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) { 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 = free_netdev; } static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[]) { 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) { struct sk_buff *local_skb; if (!netif_running(dev)) goto drop; if (dev->type != ARPHRD_IEEE802154) goto drop; /* check that it's our buffer */ if (skb->data[0] == LOWPAN_DISPATCH_IPV6) { /* Copy the packet so that the IPv6 header is * properly aligned. */ local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1, skb_tailroom(skb), GFP_ATOMIC); if (!local_skb) goto drop; local_skb->protocol = htons(ETH_P_IPV6); local_skb->pkt_type = PACKET_HOST; /* Pull off the 1-byte of 6lowpan header. */ skb_pull(local_skb, 1); skb_reset_network_header(local_skb); skb_set_transport_header(local_skb, sizeof(struct ipv6hdr)); lowpan_give_skb_to_devices(local_skb); kfree_skb(local_skb); kfree_skb(skb); } else { 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 */ local_skb = skb_clone(skb, GFP_ATOMIC); if (!local_skb) goto drop; lowpan_process_data(local_skb); kfree_skb(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("adding new link\n"); 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); 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; ASSERT_RTNL(); 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 lowpan_netlink_fini(void) { rtnl_link_unregister(&lowpan_link_ops); } static int lowpan_device_event(struct notifier_block *unused, unsigned long event, void *ptr) { struct net_device *dev = ptr; LIST_HEAD(del_list); struct lowpan_dev_record *entry, *tmp; if (dev->type != ARPHRD_IEEE802154) goto out; if (event == NETDEV_UNREGISTER) { list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) { if (lowpan_dev_info(entry->ldev)->real_dev == dev) lowpan_dellink(entry->ldev, &del_list); } unregister_netdevice_many(&del_list); } out: return NOTIFY_DONE; } static struct notifier_block lowpan_dev_notifier = { .notifier_call = lowpan_device_event, }; 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; err = lowpan_netlink_init(); if (err < 0) goto out; dev_add_pack(&lowpan_packet_type); err = register_netdevice_notifier(&lowpan_dev_notifier); if (err < 0) { dev_remove_pack(&lowpan_packet_type); lowpan_netlink_fini(); } out: return err; } static void __exit lowpan_cleanup_module(void) { struct lowpan_fragment *frame, *tframe; lowpan_netlink_fini(); dev_remove_pack(&lowpan_packet_type); unregister_netdevice_notifier(&lowpan_dev_notifier); /* Now 6lowpan packet_type is removed, so no new fragments are * expected on RX, therefore that's the time to clean incomplete * fragments. */ spin_lock_bh(&flist_lock); list_for_each_entry_safe(frame, tframe, &lowpan_fragments, list) { del_timer_sync(&frame->timer); list_del(&frame->list); dev_kfree_skb(frame->skb); kfree(frame); } spin_unlock_bh(&flist_lock); } module_init(lowpan_init_module); module_exit(lowpan_cleanup_module); MODULE_LICENSE("GPL"); MODULE_ALIAS_RTNL_LINK("lowpan");