/* * 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" static LIST_HEAD(lowpan_devices); /* 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 */ unsigned short fragment_tag; }; 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 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]; } 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) { const u8 *saddr = _saddr; const u8 *daddr = _daddr; 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; if (!saddr) saddr = dev->dev_addr; raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8); raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8); lowpan_header_compress(skb, dev, type, daddr, saddr, 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; mac_cb(skb)->seq = ieee802154_mlme_ops(dev)->get_dsn(dev); /* prepare wpan address data */ sa.addr_type = IEEE802154_ADDR_LONG; sa.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev); memcpy(&(sa.hwaddr), saddr, 8); /* intra-PAN communications */ da.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev); /* * 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, IEEE802154_ADDR_LEN); /* 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 net_device *dev) { 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 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, u16 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; /* reserve headroom for uncompressed ipv6 header */ skb_reserve(frame->skb, sizeof(struct ipv6hdr)); skb_put(frame->skb, frame->length); /* copy the first control block to keep a * trace of the link-layer addresses in case * of a link-local compressed address */ memcpy(frame->skb->cb, skb->cb, sizeof(skb->cb)); 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 process_data(struct sk_buff *skb) { u8 iphc0, iphc1; const struct ieee802154_addr *_saddr, *_daddr; 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 = 0; 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; if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1) { pr_debug("%s received a FRAG1 packet (tag: %d, " "size of the entire IP packet: %d)", __func__, tag, len); } else { /* FRAGN */ if (lowpan_fetch_skb_u8(skb, &offset)) goto unlock_and_drop; pr_debug("%s received a FRAGN packet (tag: %d, " "size of the entire IP packet: %d, " "offset: %d)", __func__, tag, len, offset * 8); } /* * 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) { pr_debug("%s first fragment received for tag %d, " "begin packet reassembly", __func__, tag); frame = lowpan_alloc_new_frame(skb, len, tag); if (!frame) 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); pr_debug("%s successfully reassembled fragment " "(tag %d)", __func__, tag); 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; _daddr = &mac_cb(skb)->da; return lowpan_process_data(skb, skb->dev, (u8 *)_saddr->hwaddr, _saddr->addr_type, IEEE802154_ADDR_LEN, (u8 *)_daddr->hwaddr, _daddr->addr_type, IEEE802154_ADDR_LEN, iphc0, iphc1, lowpan_give_skb_to_devices); 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_fragment_xmit(struct sk_buff *skb, u8 *head, int mlen, int plen, int offset, int type) { struct sk_buff *frag; int hlen; hlen = (type == LOWPAN_DISPATCH_FRAG1) ? LOWPAN_FRAG1_HEAD_SIZE : LOWPAN_FRAGN_HEAD_SIZE; raw_dump_inline(__func__, "6lowpan fragment header", head, hlen); frag = netdev_alloc_skb(skb->dev, hlen + mlen + plen + IEEE802154_MFR_SIZE); if (!frag) return -ENOMEM; frag->priority = skb->priority; /* copy header, MFR and payload */ skb_put(frag, mlen); skb_copy_to_linear_data(frag, skb_mac_header(skb), mlen); skb_put(frag, hlen); skb_copy_to_linear_data_offset(frag, mlen, head, hlen); skb_put(frag, plen); skb_copy_to_linear_data_offset(frag, mlen + hlen, skb_network_header(skb) + offset, plen); raw_dump_table(__func__, " raw fragment dump", frag->data, frag->len); return dev_queue_xmit(frag); } static int lowpan_skb_fragmentation(struct sk_buff *skb, struct net_device *dev) { int err, header_length, payload_length, tag, offset = 0; u8 head[5]; header_length = skb->mac_len; payload_length = skb->len - header_length; tag = lowpan_dev_info(dev)->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, LOWPAN_FRAG_SIZE, 0, LOWPAN_DISPATCH_FRAG1); if (err) { pr_debug("%s unable to send FRAG1 packet (tag: %d)", __func__, tag); goto exit; } offset = LOWPAN_FRAG_SIZE; /* next fragment header */ head[0] &= ~LOWPAN_DISPATCH_FRAG1; head[0] |= LOWPAN_DISPATCH_FRAGN; while (payload_length - offset > 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, LOWPAN_DISPATCH_FRAGN); if (err) { pr_debug("%s unable to send a subsequent FRAGN packet " "(tag: %d, offset: %d", __func__, tag, offset); goto exit; } offset += len; } exit: 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, dev); error: dev_kfree_skb(skb); out: if (err) pr_debug("ERROR: xmit failed\n"); return (err < 0) ? NET_XMIT_DROP : err; } 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 u8 lowpan_get_dsn(const struct net_device *dev) { struct net_device *real_dev = lowpan_dev_info(dev)->real_dev; return ieee802154_mlme_ops(real_dev)->get_dsn(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, .get_dsn = lowpan_get_dsn, }; 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); lowpan_give_skb_to_devices(local_skb, NULL); 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; 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; if (real_dev->type != ARPHRD_IEEE802154) { dev_put(real_dev); return -EINVAL; } lowpan_dev_info(dev)->real_dev = real_dev; lowpan_dev_info(dev)->fragment_tag = 0; 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; /* Set the lowpan harware address to the wpan hardware address. */ memcpy(dev->dev_addr, real_dev->dev_addr, IEEE802154_ADDR_LEN); 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 = netdev_notifier_info_to_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");