net/mac802154/rx.c

   1 /*
   2  * Copyright (C) 2007-2012 Siemens AG
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * Written by:
  14  * Pavel Smolenskiy <pavel.smolenskiy@gmail.com>
  15  * Maxim Gorbachyov <maxim.gorbachev@siemens.com>
  16  * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
  17  * Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
  18  */
  19
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/crc-ccitt.h>
  24 #include <asm/unaligned.h>
  25
  26 #include <net/mac802154.h>
  27 #include <net/ieee802154_netdev.h>
  28 #include <net/nl802154.h>
  29
  30 #include "ieee802154_i.h"
  31
  32 static int ieee802154_deliver_skb(struct sk_buff *skb)
  33 {
  34         skb->ip_summed = CHECKSUM_UNNECESSARY;
  35         skb->protocol = htons(ETH_P_IEEE802154);
  36
  37         return netif_receive_skb(skb);
  38 }
  39
  40 static int
  41 ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata,
  42                        struct sk_buff *skb, const struct ieee802154_hdr *hdr)
  43 {
  44         struct wpan_dev *wpan_dev = &sdata->wpan_dev;
  45         __le16 span, sshort;
  46         int rc;
  47
  48         pr_debug("getting packet via slave interface %s\n", sdata->dev->name);
  49
  50         spin_lock_bh(&sdata->mib_lock);
  51
  52         span = wpan_dev->pan_id;
  53         sshort = wpan_dev->short_addr;
  54
  55         switch (mac_cb(skb)->dest.mode) {
  56         case IEEE802154_ADDR_NONE:
  57                 if (mac_cb(skb)->dest.mode != IEEE802154_ADDR_NONE)
  58                         /* FIXME: check if we are PAN coordinator */
  59                         skb->pkt_type = PACKET_OTHERHOST;
  60                 else
  61                         /* ACK comes with both addresses empty */
  62                         skb->pkt_type = PACKET_HOST;
  63                 break;
  64         case IEEE802154_ADDR_LONG:
  65                 if (mac_cb(skb)->dest.pan_id != span &&
  66                     mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
  67                         skb->pkt_type = PACKET_OTHERHOST;
  68                 else if (mac_cb(skb)->dest.extended_addr == wpan_dev->extended_addr)
  69                         skb->pkt_type = PACKET_HOST;
  70                 else
  71                         skb->pkt_type = PACKET_OTHERHOST;
  72                 break;
  73         case IEEE802154_ADDR_SHORT:
  74                 if (mac_cb(skb)->dest.pan_id != span &&
  75                     mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
  76                         skb->pkt_type = PACKET_OTHERHOST;
  77                 else if (mac_cb(skb)->dest.short_addr == sshort)
  78                         skb->pkt_type = PACKET_HOST;
  79                 else if (mac_cb(skb)->dest.short_addr ==
  80                           cpu_to_le16(IEEE802154_ADDR_BROADCAST))
  81                         skb->pkt_type = PACKET_BROADCAST;
  82                 else
  83                         skb->pkt_type = PACKET_OTHERHOST;
  84                 break;
  85         default:
  86                 spin_unlock_bh(&sdata->mib_lock);
  87                 pr_debug("invalid dest mode\n");
  88                 goto fail;
  89         }
  90
  91         spin_unlock_bh(&sdata->mib_lock);
  92
  93         skb->dev = sdata->dev;
  94
  95         rc = mac802154_llsec_decrypt(&sdata->sec, skb);
  96         if (rc) {
  97                 pr_debug("decryption failed: %i\n", rc);
  98                 goto fail;
  99         }
 100
 101         sdata->dev->stats.rx_packets++;
 102         sdata->dev->stats.rx_bytes += skb->len;
 103
 104         switch (mac_cb(skb)->type) {
 105         case IEEE802154_FC_TYPE_DATA:
 106                 return ieee802154_deliver_skb(skb);
 107         default:
 108                 pr_warn("ieee802154: bad frame received (type = %d)\n",
 109                         mac_cb(skb)->type);
 110                 goto fail;
 111         }
 112
 113 fail:
 114         kfree_skb(skb);
 115         return NET_RX_DROP;
 116 }
 117
 118 static void
 119 ieee802154_print_addr(const char *name, const struct ieee802154_addr *addr)
 120 {
 121         if (addr->mode == IEEE802154_ADDR_NONE)
 122                 pr_debug("%s not present\n", name);
 123
 124         pr_debug("%s PAN ID: %04x\n", name, le16_to_cpu(addr->pan_id));
 125         if (addr->mode == IEEE802154_ADDR_SHORT) {
 126                 pr_debug("%s is short: %04x\n", name,
 127                          le16_to_cpu(addr->short_addr));
 128         } else {
 129                 u64 hw = swab64((__force u64)addr->extended_addr);
 130
 131                 pr_debug("%s is hardware: %8phC\n", name, &hw);
 132         }
 133 }
 134
 135 static int
 136 ieee802154_parse_frame_start(struct sk_buff *skb, struct ieee802154_hdr *hdr)
 137 {
 138         int hlen;
 139         struct ieee802154_mac_cb *cb = mac_cb_init(skb);
 140
 141         skb_reset_mac_header(skb);
 142
 143         hlen = ieee802154_hdr_pull(skb, hdr);
 144         if (hlen < 0)
 145                 return -EINVAL;
 146
 147         skb->mac_len = hlen;
 148
 149         pr_debug("fc: %04x dsn: %02x\n", le16_to_cpup((__le16 *)&hdr->fc),
 150                  hdr->seq);
 151
 152         cb->type = hdr->fc.type;
 153         cb->ackreq = hdr->fc.ack_request;
 154         cb->secen = hdr->fc.security_enabled;
 155
 156         ieee802154_print_addr("destination", &hdr->dest);
 157         ieee802154_print_addr("source", &hdr->source);
 158
 159         cb->source = hdr->source;
 160         cb->dest = hdr->dest;
 161
 162         if (hdr->fc.security_enabled) {
 163                 u64 key;
 164
 165                 pr_debug("seclevel %i\n", hdr->sec.level);
 166
 167                 switch (hdr->sec.key_id_mode) {
 168                 case IEEE802154_SCF_KEY_IMPLICIT:
 169                         pr_debug("implicit key\n");
 170                         break;
 171
 172                 case IEEE802154_SCF_KEY_INDEX:
 173                         pr_debug("key %02x\n", hdr->sec.key_id);
 174                         break;
 175
 176                 case IEEE802154_SCF_KEY_SHORT_INDEX:
 177                         pr_debug("key %04x:%04x %02x\n",
 178                                  le32_to_cpu(hdr->sec.short_src) >> 16,
 179                                  le32_to_cpu(hdr->sec.short_src) & 0xffff,
 180                                  hdr->sec.key_id);
 181                         break;
 182
 183                 case IEEE802154_SCF_KEY_HW_INDEX:
 184                         key = swab64((__force u64)hdr->sec.extended_src);
 185                         pr_debug("key source %8phC %02x\n", &key,
 186                                  hdr->sec.key_id);
 187                         break;
 188                 }
 189         }
 190
 191         return 0;
 192 }
 193
 194 static void
 195 __ieee802154_rx_handle_packet(struct ieee802154_local *local,
 196                               struct sk_buff *skb)
 197 {
 198         int ret;
 199         struct ieee802154_sub_if_data *sdata;
 200         struct ieee802154_hdr hdr;
 201
 202         ret = ieee802154_parse_frame_start(skb, &hdr);
 203         if (ret) {
 204                 pr_debug("got invalid frame\n");
 205                 kfree_skb(skb);
 206                 return;
 207         }
 208
 209         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 210                 if (sdata->vif.type != NL802154_IFTYPE_NODE ||
 211                     !netif_running(sdata->dev))
 212                         continue;
 213
 214                 ieee802154_subif_frame(sdata, skb, &hdr);
 215                 skb = NULL;
 216                 break;
 217         }
 218
 219         if (skb)
 220                 kfree_skb(skb);
 221 }
 222
 223 static void
 224 ieee802154_monitors_rx(struct ieee802154_local *local, struct sk_buff *skb)
 225 {
 226         struct sk_buff *skb2;
 227         struct ieee802154_sub_if_data *sdata;
 228
 229         skb_reset_mac_header(skb);
 230         skb->ip_summed = CHECKSUM_UNNECESSARY;
 231         skb->pkt_type = PACKET_OTHERHOST;
 232         skb->protocol = htons(ETH_P_IEEE802154);
 233
 234         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 235                 if (sdata->vif.type != NL802154_IFTYPE_MONITOR)
 236                         continue;
 237
 238                 if (!ieee802154_sdata_running(sdata))
 239                         continue;
 240
 241                 skb2 = skb_clone(skb, GFP_ATOMIC);
 242                 if (skb2) {
 243                         skb2->dev = sdata->dev;
 244                         ieee802154_deliver_skb(skb2);
 245
 246                         sdata->dev->stats.rx_packets++;
 247                         sdata->dev->stats.rx_bytes += skb->len;
 248                 }
 249         }
 250 }
 251
 252 void ieee802154_rx(struct ieee802154_hw *hw, struct sk_buff *skb)
 253 {
 254         struct ieee802154_local *local = hw_to_local(hw);
 255         u16 crc;
 256
 257         WARN_ON_ONCE(softirq_count() == 0);
 258
 259         /* TODO: When a transceiver omits the checksum here, we
 260          * add an own calculated one. This is currently an ugly
 261          * solution because the monitor needs a crc here.
 262          */
 263         if (local->hw.flags & IEEE802154_HW_RX_OMIT_CKSUM) {
 264                 crc = crc_ccitt(0, skb->data, skb->len);
 265                 put_unaligned_le16(crc, skb_put(skb, 2));
 266         }
 267
 268         rcu_read_lock();
 269
 270         ieee802154_monitors_rx(local, skb);
 271
 272         /* Check if transceiver doesn't validate the checksum.
 273          * If not we validate the checksum here.
 274          */
 275         if (local->hw.flags & IEEE802154_HW_RX_DROP_BAD_CKSUM) {
 276                 crc = crc_ccitt(0, skb->data, skb->len);
 277                 if (crc) {
 278                         rcu_read_unlock();
 279                         kfree_skb(skb);
 280                         return;
 281                 }
 282         }
 283         /* remove crc */
 284         skb_trim(skb, skb->len - 2);
 285
 286         __ieee802154_rx_handle_packet(local, skb);
 287
 288         rcu_read_unlock();
 289 }
 290 EXPORT_SYMBOL(ieee802154_rx);
 291
 292 void
 293 ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb, u8 lqi)
 294 {
 295         struct ieee802154_local *local = hw_to_local(hw);
 296
 297         mac_cb(skb)->lqi = lqi;
 298         skb->pkt_type = IEEE802154_RX_MSG;
 299         skb_queue_tail(&local->skb_queue, skb);
 300         tasklet_schedule(&local->tasklet);
 301 }
 302 EXPORT_SYMBOL(ieee802154_rx_irqsafe);