diff options
Diffstat (limited to 'net/ieee802154/6lowpan_rtnl.c')
| -rw-r--r-- | net/ieee802154/6lowpan_rtnl.c | 674 |
1 files changed, 674 insertions, 0 deletions
diff --git a/net/ieee802154/6lowpan_rtnl.c b/net/ieee802154/6lowpan_rtnl.c new file mode 100644 index 00000000000..0f5a69ed746 --- /dev/null +++ b/net/ieee802154/6lowpan_rtnl.c @@ -0,0 +1,674 @@ +/* Copyright 2011, Siemens AG + * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com> + */ + +/* Based on patches from Jon Smirl <jonsmirl@gmail.com> + * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +/* Jon's code is based on 6lowpan implementation for Contiki which is: + * Copyright (c) 2008, Swedish Institute of Computer Science. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <linux/bitops.h> +#include <linux/if_arp.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/netdevice.h> +#include <net/af_ieee802154.h> +#include <net/ieee802154.h> +#include <net/ieee802154_netdev.h> +#include <net/6lowpan.h> +#include <net/ipv6.h> + +#include "reassembly.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 */ + __be16 fragment_tag; +}; + +struct lowpan_dev_record { + struct net_device *ldev; + struct list_head list; +}; + +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.mode = IEEE802154_ADDR_LONG; + sa.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev); + sa.extended_addr = ieee802154_devaddr_from_raw(saddr); + + /* intra-PAN communications */ + da.pan_id = sa.pan_id; + + /* if the destination address is the broadcast address, use the + * corresponding short address + */ + if (lowpan_is_addr_broadcast(daddr)) { + da.mode = IEEE802154_ADDR_SHORT; + da.short_addr = cpu_to_le16(IEEE802154_ADDR_BROADCAST); + } else { + da.mode = IEEE802154_ADDR_LONG; + da.extended_addr = ieee802154_devaddr_from_raw(daddr); + + /* 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, 0); +} + +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 int process_data(struct sk_buff *skb, const struct ieee802154_hdr *hdr) +{ + u8 iphc0, iphc1; + struct ieee802154_addr_sa sa, da; + void *sap, *dap; + + 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; + + if (lowpan_fetch_skb_u8(skb, &iphc1)) + goto drop; + + ieee802154_addr_to_sa(&sa, &hdr->source); + ieee802154_addr_to_sa(&da, &hdr->dest); + + if (sa.addr_type == IEEE802154_ADDR_SHORT) + sap = &sa.short_addr; + else + sap = &sa.hwaddr; + + if (da.addr_type == IEEE802154_ADDR_SHORT) + dap = &da.short_addr; + else + dap = &da.hwaddr; + + return lowpan_process_data(skb, skb->dev, sap, sa.addr_type, + IEEE802154_ADDR_LEN, dap, da.addr_type, + IEEE802154_ADDR_LEN, iphc0, iphc1, + lowpan_give_skb_to_devices); + +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; + u16 dgram_offset, dgram_size, payload_length, header_length, + lowpan_size, frag_plen, offset; + __be16 tag; + u8 head[5]; + + header_length = skb->mac_len; + payload_length = skb->len - header_length; + tag = lowpan_dev_info(dev)->fragment_tag++; + lowpan_size = skb_network_header_len(skb); + dgram_size = lowpan_uncompress_size(skb, &dgram_offset) - + header_length; + + /* first fragment header */ + head[0] = LOWPAN_DISPATCH_FRAG1 | ((dgram_size >> 8) & 0x7); + head[1] = dgram_size & 0xff; + memcpy(head + 2, &tag, sizeof(tag)); + + /* calc the nearest payload length(divided to 8) for first fragment + * which fits into a IEEE802154_MTU + */ + frag_plen = round_down(IEEE802154_MTU - header_length - + LOWPAN_FRAG1_HEAD_SIZE - lowpan_size - + IEEE802154_MFR_SIZE, 8); + + err = lowpan_fragment_xmit(skb, head, header_length, + frag_plen + lowpan_size, 0, + LOWPAN_DISPATCH_FRAG1); + if (err) { + pr_debug("%s unable to send FRAG1 packet (tag: %d)", + __func__, tag); + goto exit; + } + + offset = lowpan_size + frag_plen; + dgram_offset += frag_plen; + + /* next fragment header */ + head[0] &= ~LOWPAN_DISPATCH_FRAG1; + head[0] |= LOWPAN_DISPATCH_FRAGN; + + frag_plen = round_down(IEEE802154_MTU - header_length - + LOWPAN_FRAGN_HEAD_SIZE - IEEE802154_MFR_SIZE, 8); + + while (payload_length - offset > 0) { + int len = frag_plen; + + head[4] = dgram_offset >> 3; + + 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 FRAGN packet. (tag: %d, offset: %d)\n", + __func__, tag, offset); + goto exit; + } + + offset += len; + dgram_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 __le16 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 __le16 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 struct lock_class_key lowpan_tx_busylock; +static struct lock_class_key lowpan_netdev_xmit_lock_key; + +static void lowpan_set_lockdep_class_one(struct net_device *dev, + struct netdev_queue *txq, + void *_unused) +{ + lockdep_set_class(&txq->_xmit_lock, + &lowpan_netdev_xmit_lock_key); +} + + +static int lowpan_dev_init(struct net_device *dev) +{ + netdev_for_each_tx_queue(dev, lowpan_set_lockdep_class_one, NULL); + dev->qdisc_tx_busylock = &lowpan_tx_busylock; + return 0; +} + +static const struct net_device_ops lowpan_netdev_ops = { + .ndo_init = lowpan_dev_init, + .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 ieee802154_hdr hdr; + int ret; + + skb = skb_share_check(skb, GFP_ATOMIC); + if (!skb) + goto drop; + + if (!netif_running(dev)) + goto drop_skb; + + if (dev->type != ARPHRD_IEEE802154) + goto drop_skb; + + if (ieee802154_hdr_peek_addrs(skb, &hdr) < 0) + goto drop_skb; + + /* check that it's our buffer */ + if (skb->data[0] == LOWPAN_DISPATCH_IPV6) { + skb->protocol = htons(ETH_P_IPV6); + skb->pkt_type = PACKET_HOST; + + /* Pull off the 1-byte of 6lowpan header. */ + skb_pull(skb, 1); + + ret = lowpan_give_skb_to_devices(skb, NULL); + if (ret == NET_RX_DROP) + goto drop; + } else { + switch (skb->data[0] & 0xe0) { + case LOWPAN_DISPATCH_IPHC: /* ipv6 datagram */ + ret = process_data(skb, &hdr); + if (ret == NET_RX_DROP) + goto drop; + break; + case LOWPAN_DISPATCH_FRAG1: /* first fragment header */ + ret = lowpan_frag_rcv(skb, LOWPAN_DISPATCH_FRAG1); + if (ret == 1) { + ret = process_data(skb, &hdr); + if (ret == NET_RX_DROP) + goto drop; + } + break; + case LOWPAN_DISPATCH_FRAGN: /* next fragments headers */ + ret = lowpan_frag_rcv(skb, LOWPAN_DISPATCH_FRAGN); + if (ret == 1) { + ret = process_data(skb, &hdr); + if (ret == NET_RX_DROP) + goto drop; + } + break; + default: + break; + } + } + + return NET_RX_SUCCESS; +drop_skb: + kfree_skb(skb); +drop: + 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; + mutex_init(&lowpan_dev_info(dev)->dev_list_mtx); + + entry = kzalloc(sizeof(*entry), 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 = htons(ETH_P_IEEE802154), + .func = lowpan_rcv, +}; + +static int __init lowpan_init_module(void) +{ + int err = 0; + + err = lowpan_net_frag_init(); + if (err < 0) + goto out; + + err = lowpan_netlink_init(); + if (err < 0) + goto out_frag; + + dev_add_pack(&lowpan_packet_type); + + err = register_netdevice_notifier(&lowpan_dev_notifier); + if (err < 0) + goto out_pack; + + return 0; + +out_pack: + dev_remove_pack(&lowpan_packet_type); + lowpan_netlink_fini(); +out_frag: + lowpan_net_frag_exit(); +out: + return err; +} + +static void __exit lowpan_cleanup_module(void) +{ + lowpan_netlink_fini(); + + dev_remove_pack(&lowpan_packet_type); + + lowpan_net_frag_exit(); + + unregister_netdevice_notifier(&lowpan_dev_notifier); +} + +module_init(lowpan_init_module); +module_exit(lowpan_cleanup_module); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_RTNL_LINK("lowpan"); |