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         span = wpan_dev->pan_id;
  51         sshort = wpan_dev->short_addr;
  52
  53         switch (mac_cb(skb)->dest.mode) {
  54         case IEEE802154_ADDR_NONE:
  55                 if (mac_cb(skb)->dest.mode != IEEE802154_ADDR_NONE)
  56                         /* FIXME: check if we are PAN coordinator */
  57                         skb->pkt_type = PACKET_OTHERHOST;
  58                 else
  59                         /* ACK comes with both addresses empty */
  60                         skb->pkt_type = PACKET_HOST;
  61                 break;
  62         case IEEE802154_ADDR_LONG:
  63                 if (mac_cb(skb)->dest.pan_id != span &&
  64                     mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
  65                         skb->pkt_type = PACKET_OTHERHOST;
  66                 else if (mac_cb(skb)->dest.extended_addr == wpan_dev->extended_addr)
  67                         skb->pkt_type = PACKET_HOST;
  68                 else
  69                         skb->pkt_type = PACKET_OTHERHOST;
  70                 break;
  71         case IEEE802154_ADDR_SHORT:
  72                 if (mac_cb(skb)->dest.pan_id != span &&
  73                     mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
  74                         skb->pkt_type = PACKET_OTHERHOST;
  75                 else if (mac_cb(skb)->dest.short_addr == sshort)
  76                         skb->pkt_type = PACKET_HOST;
  77                 else if (mac_cb(skb)->dest.short_addr ==
  78                           cpu_to_le16(IEEE802154_ADDR_BROADCAST))
  79                         skb->pkt_type = PACKET_BROADCAST;
  80                 else
  81                         skb->pkt_type = PACKET_OTHERHOST;
  82                 break;
  83         default:
  84                 pr_debug("invalid dest mode\n");
  85                 goto fail;
  86         }
  87
  88         skb->dev = sdata->dev;
  89
  90         rc = mac802154_llsec_decrypt(&sdata->sec, skb);
  91         if (rc) {
  92                 pr_debug("decryption failed: %i\n", rc);
  93                 goto fail;
  94         }
  95
  96         sdata->dev->stats.rx_packets++;
  97         sdata->dev->stats.rx_bytes += skb->len;
  98
  99         switch (mac_cb(skb)->type) {
 100         case IEEE802154_FC_TYPE_DATA:
 101                 return ieee802154_deliver_skb(skb);
 102         default:
 103                 pr_warn("ieee802154: bad frame received (type = %d)\n",
 104                         mac_cb(skb)->type);
 105                 goto fail;
 106         }
 107
 108 fail:
 109         kfree_skb(skb);
 110         return NET_RX_DROP;
 111 }
 112
 113 static void
 114 ieee802154_print_addr(const char *name, const struct ieee802154_addr *addr)
 115 {
 116         if (addr->mode == IEEE802154_ADDR_NONE)
 117                 pr_debug("%s not present\n", name);
 118
 119         pr_debug("%s PAN ID: %04x\n", name, le16_to_cpu(addr->pan_id));
 120         if (addr->mode == IEEE802154_ADDR_SHORT) {
 121                 pr_debug("%s is short: %04x\n", name,
 122                          le16_to_cpu(addr->short_addr));
 123         } else {
 124                 u64 hw = swab64((__force u64)addr->extended_addr);
 125
 126                 pr_debug("%s is hardware: %8phC\n", name, &hw);
 127         }
 128 }
 129
 130 static int
 131 ieee802154_parse_frame_start(struct sk_buff *skb, struct ieee802154_hdr *hdr)
 132 {
 133         int hlen;
 134         struct ieee802154_mac_cb *cb = mac_cb_init(skb);
 135
 136         skb_reset_mac_header(skb);
 137
 138         hlen = ieee802154_hdr_pull(skb, hdr);
 139         if (hlen < 0)
 140                 return -EINVAL;
 141
 142         skb->mac_len = hlen;
 143
 144         pr_debug("fc: %04x dsn: %02x\n", le16_to_cpup((__le16 *)&hdr->fc),
 145                  hdr->seq);
 146
 147         cb->type = hdr->fc.type;
 148         cb->ackreq = hdr->fc.ack_request;
 149         cb->secen = hdr->fc.security_enabled;
 150
 151         ieee802154_print_addr("destination", &hdr->dest);
 152         ieee802154_print_addr("source", &hdr->source);
 153
 154         cb->source = hdr->source;
 155         cb->dest = hdr->dest;
 156
 157         if (hdr->fc.security_enabled) {
 158                 u64 key;
 159
 160                 pr_debug("seclevel %i\n", hdr->sec.level);
 161
 162                 switch (hdr->sec.key_id_mode) {
 163                 case IEEE802154_SCF_KEY_IMPLICIT:
 164                         pr_debug("implicit key\n");
 165                         break;
 166
 167                 case IEEE802154_SCF_KEY_INDEX:
 168                         pr_debug("key %02x\n", hdr->sec.key_id);
 169                         break;
 170
 171                 case IEEE802154_SCF_KEY_SHORT_INDEX:
 172                         pr_debug("key %04x:%04x %02x\n",
 173                                  le32_to_cpu(hdr->sec.short_src) >> 16,
 174                                  le32_to_cpu(hdr->sec.short_src) & 0xffff,
 175                                  hdr->sec.key_id);
 176                         break;
 177
 178                 case IEEE802154_SCF_KEY_HW_INDEX:
 179                         key = swab64((__force u64)hdr->sec.extended_src);
 180                         pr_debug("key source %8phC %02x\n", &key,
 181                                  hdr->sec.key_id);
 182                         break;
 183                 }
 184         }
 185
 186         return 0;
 187 }
 188
 189 static void
 190 __ieee802154_rx_handle_packet(struct ieee802154_local *local,
 191                               struct sk_buff *skb)
 192 {
 193         int ret;
 194         struct ieee802154_sub_if_data *sdata;
 195         struct ieee802154_hdr hdr;
 196
 197         ret = ieee802154_parse_frame_start(skb, &hdr);
 198         if (ret) {
 199                 pr_debug("got invalid frame\n");
 200                 kfree_skb(skb);
 201                 return;
 202         }
 203
 204         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 205                 if (sdata->wpan_dev.iftype != NL802154_IFTYPE_NODE)
 206                         continue;
 207
 208                 if (!ieee802154_sdata_running(sdata))
 209                         continue;
 210
 211                 ieee802154_subif_frame(sdata, skb, &hdr);
 212                 skb = NULL;
 213                 break;
 214         }
 215
 216         if (skb)
 217                 kfree_skb(skb);
 218 }
 219
 220 static void
 221 ieee802154_monitors_rx(struct ieee802154_local *local, struct sk_buff *skb)
 222 {
 223         struct sk_buff *skb2;
 224         struct ieee802154_sub_if_data *sdata;
 225
 226         skb_reset_mac_header(skb);
 227         skb->ip_summed = CHECKSUM_UNNECESSARY;
 228         skb->pkt_type = PACKET_OTHERHOST;
 229         skb->protocol = htons(ETH_P_IEEE802154);
 230
 231         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 232                 if (sdata->wpan_dev.iftype != NL802154_IFTYPE_MONITOR)
 233                         continue;
 234
 235                 if (!ieee802154_sdata_running(sdata))
 236                         continue;
 237
 238                 skb2 = skb_clone(skb, GFP_ATOMIC);
 239                 if (skb2) {
 240                         skb2->dev = sdata->dev;
 241                         ieee802154_deliver_skb(skb2);
 242
 243                         sdata->dev->stats.rx_packets++;
 244                         sdata->dev->stats.rx_bytes += skb->len;
 245                 }
 246         }
 247 }
 248
 249 void ieee802154_rx(struct ieee802154_hw *hw, struct sk_buff *skb)
 250 {
 251         struct ieee802154_local *local = hw_to_local(hw);
 252         u16 crc;
 253
 254         WARN_ON_ONCE(softirq_count() == 0);
 255
 256         /* TODO: When a transceiver omits the checksum here, we
 257          * add an own calculated one. This is currently an ugly
 258          * solution because the monitor needs a crc here.
 259          */
 260         if (local->hw.flags & IEEE802154_HW_RX_OMIT_CKSUM) {
 261                 crc = crc_ccitt(0, skb->data, skb->len);
 262                 put_unaligned_le16(crc, skb_put(skb, 2));
 263         }
 264
 265         rcu_read_lock();
 266
 267         ieee802154_monitors_rx(local, skb);
 268
 269         /* Check if transceiver doesn't validate the checksum.
 270          * If not we validate the checksum here.
 271          */
 272         if (local->hw.flags & IEEE802154_HW_RX_DROP_BAD_CKSUM) {
 273                 crc = crc_ccitt(0, skb->data, skb->len);
 274                 if (crc) {
 275                         rcu_read_unlock();
 276                         kfree_skb(skb);
 277                         return;
 278                 }
 279         }
 280         /* remove crc */
 281         skb_trim(skb, skb->len - 2);
 282
 283         __ieee802154_rx_handle_packet(local, skb);
 284
 285         rcu_read_unlock();
 286 }
 287 EXPORT_SYMBOL(ieee802154_rx);
 288
 289 void
 290 ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb, u8 lqi)
 291 {
 292         struct ieee802154_local *local = hw_to_local(hw);
 293
 294         mac_cb(skb)->lqi = lqi;
 295         skb->pkt_type = IEEE802154_RX_MSG;
 296         skb_queue_tail(&local->skb_queue, skb);
 297         tasklet_schedule(&local->tasklet);
 298 }
 299 EXPORT_SYMBOL(ieee802154_rx_irqsafe);