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/rtnetlink.h>
  29 #include <linux/nl802154.h>
  30
  31 #include "ieee802154_i.h"
  32
  33 static int ieee802154_deliver_skb(struct sk_buff *skb)
  34 {
  35         skb->ip_summed = CHECKSUM_UNNECESSARY;
  36         skb->protocol = htons(ETH_P_IEEE802154);
  37
  38         return netif_receive_skb(skb);
  39 }
  40
  41 static int
  42 ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata,
  43                        struct sk_buff *skb, const struct ieee802154_hdr *hdr)
  44 {
  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 = sdata->pan_id;
  53         sshort = sdata->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 == sdata->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                 kfree_skb(skb);
  89                 return NET_RX_DROP;
  90         }
  91
  92         spin_unlock_bh(&sdata->mib_lock);
  93
  94         skb->dev = sdata->dev;
  95
  96         rc = mac802154_llsec_decrypt(&sdata->sec, skb);
  97         if (rc) {
  98                 pr_debug("decryption failed: %i\n", rc);
  99                 goto fail;
 100         }
 101
 102         sdata->dev->stats.rx_packets++;
 103         sdata->dev->stats.rx_bytes += skb->len;
 104
 105         switch (mac_cb(skb)->type) {
 106         case IEEE802154_FC_TYPE_DATA:
 107                 return ieee802154_deliver_skb(skb);
 108         default:
 109                 pr_warn("ieee802154: bad frame received (type = %d)\n",
 110                         mac_cb(skb)->type);
 111                 goto fail;
 112         }
 113
 114 fail:
 115         kfree_skb(skb);
 116         return NET_RX_DROP;
 117 }
 118
 119 static void
 120 ieee802154_print_addr(const char *name, const struct ieee802154_addr *addr)
 121 {
 122         if (addr->mode == IEEE802154_ADDR_NONE)
 123                 pr_debug("%s not present\n", name);
 124
 125         pr_debug("%s PAN ID: %04x\n", name, le16_to_cpu(addr->pan_id));
 126         if (addr->mode == IEEE802154_ADDR_SHORT) {
 127                 pr_debug("%s is short: %04x\n", name,
 128                          le16_to_cpu(addr->short_addr));
 129         } else {
 130                 u64 hw = swab64((__force u64)addr->extended_addr);
 131
 132                 pr_debug("%s is hardware: %8phC\n", name, &hw);
 133         }
 134 }
 135
 136 static int
 137 ieee802154_parse_frame_start(struct sk_buff *skb, struct ieee802154_hdr *hdr)
 138 {
 139         int hlen;
 140         struct ieee802154_mac_cb *cb = mac_cb_init(skb);
 141
 142         skb_reset_mac_header(skb);
 143
 144         hlen = ieee802154_hdr_pull(skb, hdr);
 145         if (hlen < 0)
 146                 return -EINVAL;
 147
 148         skb->mac_len = hlen;
 149
 150         pr_debug("fc: %04x dsn: %02x\n", le16_to_cpup((__le16 *)&hdr->fc),
 151                  hdr->seq);
 152
 153         cb->type = hdr->fc.type;
 154         cb->ackreq = hdr->fc.ack_request;
 155         cb->secen = hdr->fc.security_enabled;
 156
 157         ieee802154_print_addr("destination", &hdr->dest);
 158         ieee802154_print_addr("source", &hdr->source);
 159
 160         cb->source = hdr->source;
 161         cb->dest = hdr->dest;
 162
 163         if (hdr->fc.security_enabled) {
 164                 u64 key;
 165
 166                 pr_debug("seclevel %i\n", hdr->sec.level);
 167
 168                 switch (hdr->sec.key_id_mode) {
 169                 case IEEE802154_SCF_KEY_IMPLICIT:
 170                         pr_debug("implicit key\n");
 171                         break;
 172
 173                 case IEEE802154_SCF_KEY_INDEX:
 174                         pr_debug("key %02x\n", hdr->sec.key_id);
 175                         break;
 176
 177                 case IEEE802154_SCF_KEY_SHORT_INDEX:
 178                         pr_debug("key %04x:%04x %02x\n",
 179                                  le32_to_cpu(hdr->sec.short_src) >> 16,
 180                                  le32_to_cpu(hdr->sec.short_src) & 0xffff,
 181                                  hdr->sec.key_id);
 182                         break;
 183
 184                 case IEEE802154_SCF_KEY_HW_INDEX:
 185                         key = swab64((__force u64)hdr->sec.extended_src);
 186                         pr_debug("key source %8phC %02x\n", &key,
 187                                  hdr->sec.key_id);
 188                         break;
 189                 }
 190         }
 191
 192         return 0;
 193 }
 194
 195 static void
 196 __ieee802154_rx_handle_packet(struct ieee802154_local *local,
 197                               struct sk_buff *skb)
 198 {
 199         int ret;
 200         struct ieee802154_sub_if_data *sdata;
 201         struct ieee802154_hdr hdr;
 202
 203         ret = ieee802154_parse_frame_start(skb, &hdr);
 204         if (ret) {
 205                 pr_debug("got invalid frame\n");
 206                 kfree_skb(skb);
 207                 return;
 208         }
 209
 210         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 211                 if (sdata->vif.type != IEEE802154_DEV_WPAN ||
 212                     !netif_running(sdata->dev))
 213                         continue;
 214
 215                 ieee802154_subif_frame(sdata, skb, &hdr);
 216                 skb = NULL;
 217                 break;
 218         }
 219
 220         if (skb)
 221                 kfree_skb(skb);
 222 }
 223
 224 static void
 225 ieee802154_monitors_rx(struct ieee802154_local *local, struct sk_buff *skb)
 226 {
 227         struct sk_buff *skb2;
 228         struct ieee802154_sub_if_data *sdata;
 229
 230         skb_reset_mac_header(skb);
 231         skb->ip_summed = CHECKSUM_UNNECESSARY;
 232         skb->pkt_type = PACKET_OTHERHOST;
 233         skb->protocol = htons(ETH_P_IEEE802154);
 234
 235         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 236                 if (sdata->vif.type != IEEE802154_DEV_MONITOR)
 237                         continue;
 238
 239                 if (!ieee802154_sdata_running(sdata))
 240                         continue;
 241
 242                 skb2 = skb_clone(skb, GFP_ATOMIC);
 243                 if (skb2) {
 244                         skb2->dev = sdata->dev;
 245                         ieee802154_deliver_skb(skb2);
 246
 247                         sdata->dev->stats.rx_packets++;
 248                         sdata->dev->stats.rx_bytes += skb->len;
 249                 }
 250         }
 251 }
 252
 253 void ieee802154_rx(struct ieee802154_hw *hw, struct sk_buff *skb)
 254 {
 255         struct ieee802154_local *local = hw_to_local(hw);
 256         u16 crc;
 257
 258         WARN_ON_ONCE(softirq_count() == 0);
 259
 260         /* TODO: When a transceiver omits the checksum here, we
 261          * add an own calculated one. This is currently an ugly
 262          * solution because the monitor needs a crc here.
 263          */
 264         if (local->hw.flags & IEEE802154_HW_RX_OMIT_CKSUM) {
 265                 crc = crc_ccitt(0, skb->data, skb->len);
 266                 put_unaligned_le16(crc, skb_put(skb, 2));
 267         }
 268
 269         rcu_read_lock();
 270
 271         ieee802154_monitors_rx(local, skb);
 272
 273         /* Check if transceiver doesn't validate the checksum.
 274          * If not we validate the checksum here.
 275          */
 276         if (local->hw.flags & IEEE802154_HW_RX_DROP_BAD_CKSUM) {
 277                 crc = crc_ccitt(0, skb->data, skb->len);
 278                 if (crc) {
 279                         rcu_read_unlock();
 280                         kfree_skb(skb);
 281                         return;
 282                 }
 283         }
 284         /* remove crc */
 285         skb_trim(skb, skb->len - 2);
 286
 287         __ieee802154_rx_handle_packet(local, skb);
 288
 289         rcu_read_unlock();
 290 }
 291 EXPORT_SYMBOL(ieee802154_rx);
 292
 293 void
 294 ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb, u8 lqi)
 295 {
 296         struct ieee802154_local *local = hw_to_local(hw);
 297
 298         mac_cb(skb)->lqi = lqi;
 299         skb->pkt_type = IEEE802154_RX_MSG;
 300         skb_queue_tail(&local->skb_queue, skb);
 301         tasklet_schedule(&local->tasklet);
 302 }
 303 EXPORT_SYMBOL(ieee802154_rx_irqsafe);