net/mac802154/rx.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2007-2012 Siemens AG
   4  *
   5  * Written by:
   6  * Pavel Smolenskiy <pavel.smolenskiy@gmail.com>
   7  * Maxim Gorbachyov <maxim.gorbachev@siemens.com>
   8  * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
   9  * Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/netdevice.h>
  15 #include <linux/crc-ccitt.h>
  16 #include <asm/unaligned.h>
  17
  18 #include <net/mac802154.h>
  19 #include <net/ieee802154_netdev.h>
  20 #include <net/nl802154.h>
  21
  22 #include "ieee802154_i.h"
  23
  24 static int ieee802154_deliver_skb(struct sk_buff *skb)
  25 {
  26         skb->ip_summed = CHECKSUM_UNNECESSARY;
  27         skb->protocol = htons(ETH_P_IEEE802154);
  28
  29         return netif_receive_skb(skb);
  30 }
  31
  32 void mac802154_rx_beacon_worker(struct work_struct *work)
  33 {
  34         struct ieee802154_local *local =
  35                 container_of(work, struct ieee802154_local, rx_beacon_work);
  36         struct cfg802154_mac_pkt *mac_pkt;
  37
  38         mac_pkt = list_first_entry_or_null(&local->rx_beacon_list,
  39                                            struct cfg802154_mac_pkt, node);
  40         if (!mac_pkt)
  41                 return;
  42
  43         mac802154_process_beacon(local, mac_pkt->skb, mac_pkt->page, mac_pkt->channel);
  44
  45         list_del(&mac_pkt->node);
  46         kfree_skb(mac_pkt->skb);
  47         kfree(mac_pkt);
  48 }
  49
  50 static bool mac802154_should_answer_beacon_req(struct ieee802154_local *local)
  51 {
  52         struct cfg802154_beacon_request *beacon_req;
  53         unsigned int interval;
  54
  55         rcu_read_lock();
  56         beacon_req = rcu_dereference(local->beacon_req);
  57         if (!beacon_req) {
  58                 rcu_read_unlock();
  59                 return false;
  60         }
  61
  62         interval = beacon_req->interval;
  63         rcu_read_unlock();
  64
  65         if (!mac802154_is_beaconing(local))
  66                 return false;
  67
  68         return interval == IEEE802154_ACTIVE_SCAN_DURATION;
  69 }
  70
  71 void mac802154_rx_mac_cmd_worker(struct work_struct *work)
  72 {
  73         struct ieee802154_local *local =
  74                 container_of(work, struct ieee802154_local, rx_mac_cmd_work);
  75         struct cfg802154_mac_pkt *mac_pkt;
  76         u8 mac_cmd;
  77         int rc;
  78
  79         mac_pkt = list_first_entry_or_null(&local->rx_mac_cmd_list,
  80                                            struct cfg802154_mac_pkt, node);
  81         if (!mac_pkt)
  82                 return;
  83
  84         rc = ieee802154_get_mac_cmd(mac_pkt->skb, &mac_cmd);
  85         if (rc)
  86                 goto out;
  87
  88         switch (mac_cmd) {
  89         case IEEE802154_CMD_BEACON_REQ:
  90                 dev_dbg(&mac_pkt->sdata->dev->dev, "processing BEACON REQ\n");
  91                 if (!mac802154_should_answer_beacon_req(local))
  92                         break;
  93
  94                 queue_delayed_work(local->mac_wq, &local->beacon_work, 0);
  95                 break;
  96         default:
  97                 break;
  98         }
  99
 100 out:
 101         list_del(&mac_pkt->node);
 102         kfree_skb(mac_pkt->skb);
 103         kfree(mac_pkt);
 104 }
 105
 106 static int
 107 ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata,
 108                        struct sk_buff *skb, const struct ieee802154_hdr *hdr)
 109 {
 110         struct wpan_phy *wpan_phy = sdata->local->hw.phy;
 111         struct wpan_dev *wpan_dev = &sdata->wpan_dev;
 112         struct cfg802154_mac_pkt *mac_pkt;
 113         __le16 span, sshort;
 114         int rc;
 115
 116         pr_debug("getting packet via slave interface %s\n", sdata->dev->name);
 117
 118         span = wpan_dev->pan_id;
 119         sshort = wpan_dev->short_addr;
 120
 121         /* Level 3 filtering: Only beacons are accepted during scans */
 122         if (sdata->required_filtering == IEEE802154_FILTERING_3_SCAN &&
 123             sdata->required_filtering > wpan_phy->filtering) {
 124                 if (mac_cb(skb)->type != IEEE802154_FC_TYPE_BEACON) {
 125                         dev_dbg(&sdata->dev->dev,
 126                                 "drop non-beacon frame (0x%x) during scan\n",
 127                                 mac_cb(skb)->type);
 128                         goto fail;
 129                 }
 130         }
 131
 132         switch (mac_cb(skb)->dest.mode) {
 133         case IEEE802154_ADDR_NONE:
 134                 if (hdr->source.mode != IEEE802154_ADDR_NONE)
 135                         /* FIXME: check if we are PAN coordinator */
 136                         skb->pkt_type = PACKET_OTHERHOST;
 137                 else
 138                         /* ACK comes with both addresses empty */
 139                         skb->pkt_type = PACKET_HOST;
 140                 break;
 141         case IEEE802154_ADDR_LONG:
 142                 if (mac_cb(skb)->dest.pan_id != span &&
 143                     mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
 144                         skb->pkt_type = PACKET_OTHERHOST;
 145                 else if (mac_cb(skb)->dest.extended_addr == wpan_dev->extended_addr)
 146                         skb->pkt_type = PACKET_HOST;
 147                 else
 148                         skb->pkt_type = PACKET_OTHERHOST;
 149                 break;
 150         case IEEE802154_ADDR_SHORT:
 151                 if (mac_cb(skb)->dest.pan_id != span &&
 152                     mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
 153                         skb->pkt_type = PACKET_OTHERHOST;
 154                 else if (mac_cb(skb)->dest.short_addr == sshort)
 155                         skb->pkt_type = PACKET_HOST;
 156                 else if (mac_cb(skb)->dest.short_addr ==
 157                           cpu_to_le16(IEEE802154_ADDR_BROADCAST))
 158                         skb->pkt_type = PACKET_BROADCAST;
 159                 else
 160                         skb->pkt_type = PACKET_OTHERHOST;
 161                 break;
 162         default:
 163                 pr_debug("invalid dest mode\n");
 164                 goto fail;
 165         }
 166
 167         skb->dev = sdata->dev;
 168
 169         /* TODO this should be moved after netif_receive_skb call, otherwise
 170          * wireshark will show a mac header with security fields and the
 171          * payload is already decrypted.
 172          */
 173         rc = mac802154_llsec_decrypt(&sdata->sec, skb);
 174         if (rc) {
 175                 pr_debug("decryption failed: %i\n", rc);
 176                 goto fail;
 177         }
 178
 179         sdata->dev->stats.rx_packets++;
 180         sdata->dev->stats.rx_bytes += skb->len;
 181
 182         switch (mac_cb(skb)->type) {
 183         case IEEE802154_FC_TYPE_BEACON:
 184                 dev_dbg(&sdata->dev->dev, "BEACON received\n");
 185                 if (!mac802154_is_scanning(sdata->local))
 186                         goto fail;
 187
 188                 mac_pkt = kzalloc(sizeof(*mac_pkt), GFP_ATOMIC);
 189                 if (!mac_pkt)
 190                         goto fail;
 191
 192                 mac_pkt->skb = skb_get(skb);
 193                 mac_pkt->sdata = sdata;
 194                 mac_pkt->page = sdata->local->scan_page;
 195                 mac_pkt->channel = sdata->local->scan_channel;
 196                 list_add_tail(&mac_pkt->node, &sdata->local->rx_beacon_list);
 197                 queue_work(sdata->local->mac_wq, &sdata->local->rx_beacon_work);
 198                 return NET_RX_SUCCESS;
 199
 200         case IEEE802154_FC_TYPE_MAC_CMD:
 201                 dev_dbg(&sdata->dev->dev, "MAC COMMAND received\n");
 202                 mac_pkt = kzalloc(sizeof(*mac_pkt), GFP_ATOMIC);
 203                 if (!mac_pkt)
 204                         goto fail;
 205
 206                 mac_pkt->skb = skb_get(skb);
 207                 mac_pkt->sdata = sdata;
 208                 list_add_tail(&mac_pkt->node, &sdata->local->rx_mac_cmd_list);
 209                 queue_work(sdata->local->mac_wq, &sdata->local->rx_mac_cmd_work);
 210                 return NET_RX_SUCCESS;
 211
 212         case IEEE802154_FC_TYPE_ACK:
 213                 goto fail;
 214
 215         case IEEE802154_FC_TYPE_DATA:
 216                 return ieee802154_deliver_skb(skb);
 217         default:
 218                 pr_warn_ratelimited("ieee802154: bad frame received "
 219                                     "(type = %d)\n", mac_cb(skb)->type);
 220                 goto fail;
 221         }
 222
 223 fail:
 224         kfree_skb(skb);
 225         return NET_RX_DROP;
 226 }
 227
 228 static void
 229 ieee802154_print_addr(const char *name, const struct ieee802154_addr *addr)
 230 {
 231         if (addr->mode == IEEE802154_ADDR_NONE) {
 232                 pr_debug("%s not present\n", name);
 233                 return;
 234         }
 235
 236         pr_debug("%s PAN ID: %04x\n", name, le16_to_cpu(addr->pan_id));
 237         if (addr->mode == IEEE802154_ADDR_SHORT) {
 238                 pr_debug("%s is short: %04x\n", name,
 239                          le16_to_cpu(addr->short_addr));
 240         } else {
 241                 u64 hw = swab64((__force u64)addr->extended_addr);
 242
 243                 pr_debug("%s is hardware: %8phC\n", name, &hw);
 244         }
 245 }
 246
 247 static int
 248 ieee802154_parse_frame_start(struct sk_buff *skb, struct ieee802154_hdr *hdr)
 249 {
 250         int hlen;
 251         struct ieee802154_mac_cb *cb = mac_cb(skb);
 252
 253         skb_reset_mac_header(skb);
 254
 255         hlen = ieee802154_hdr_pull(skb, hdr);
 256         if (hlen < 0)
 257                 return -EINVAL;
 258
 259         skb->mac_len = hlen;
 260
 261         pr_debug("fc: %04x dsn: %02x\n", le16_to_cpup((__le16 *)&hdr->fc),
 262                  hdr->seq);
 263
 264         cb->type = hdr->fc.type;
 265         cb->ackreq = hdr->fc.ack_request;
 266         cb->secen = hdr->fc.security_enabled;
 267
 268         ieee802154_print_addr("destination", &hdr->dest);
 269         ieee802154_print_addr("source", &hdr->source);
 270
 271         cb->source = hdr->source;
 272         cb->dest = hdr->dest;
 273
 274         if (hdr->fc.security_enabled) {
 275                 u64 key;
 276
 277                 pr_debug("seclevel %i\n", hdr->sec.level);
 278
 279                 switch (hdr->sec.key_id_mode) {
 280                 case IEEE802154_SCF_KEY_IMPLICIT:
 281                         pr_debug("implicit key\n");
 282                         break;
 283
 284                 case IEEE802154_SCF_KEY_INDEX:
 285                         pr_debug("key %02x\n", hdr->sec.key_id);
 286                         break;
 287
 288                 case IEEE802154_SCF_KEY_SHORT_INDEX:
 289                         pr_debug("key %04x:%04x %02x\n",
 290                                  le32_to_cpu(hdr->sec.short_src) >> 16,
 291                                  le32_to_cpu(hdr->sec.short_src) & 0xffff,
 292                                  hdr->sec.key_id);
 293                         break;
 294
 295                 case IEEE802154_SCF_KEY_HW_INDEX:
 296                         key = swab64((__force u64)hdr->sec.extended_src);
 297                         pr_debug("key source %8phC %02x\n", &key,
 298                                  hdr->sec.key_id);
 299                         break;
 300                 }
 301         }
 302
 303         return 0;
 304 }
 305
 306 static void
 307 __ieee802154_rx_handle_packet(struct ieee802154_local *local,
 308                               struct sk_buff *skb)
 309 {
 310         int ret;
 311         struct ieee802154_sub_if_data *sdata;
 312         struct ieee802154_hdr hdr;
 313         struct sk_buff *skb2;
 314
 315         ret = ieee802154_parse_frame_start(skb, &hdr);
 316         if (ret) {
 317                 pr_debug("got invalid frame\n");
 318                 return;
 319         }
 320
 321         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 322                 if (sdata->wpan_dev.iftype == NL802154_IFTYPE_MONITOR)
 323                         continue;
 324
 325                 if (!ieee802154_sdata_running(sdata))
 326                         continue;
 327
 328                 /* Do not deliver packets received on interfaces expecting
 329                  * AACK=1 if the address filters where disabled.
 330                  */
 331                 if (local->hw.phy->filtering < IEEE802154_FILTERING_4_FRAME_FIELDS &&
 332                     sdata->required_filtering == IEEE802154_FILTERING_4_FRAME_FIELDS)
 333                         continue;
 334
 335                 skb2 = skb_clone(skb, GFP_ATOMIC);
 336                 if (skb2) {
 337                         skb2->dev = sdata->dev;
 338                         ieee802154_subif_frame(sdata, skb2, &hdr);
 339                 }
 340         }
 341 }
 342
 343 static void
 344 ieee802154_monitors_rx(struct ieee802154_local *local, struct sk_buff *skb)
 345 {
 346         struct sk_buff *skb2;
 347         struct ieee802154_sub_if_data *sdata;
 348
 349         skb_reset_mac_header(skb);
 350         skb->ip_summed = CHECKSUM_UNNECESSARY;
 351         skb->pkt_type = PACKET_OTHERHOST;
 352         skb->protocol = htons(ETH_P_IEEE802154);
 353
 354         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 355                 if (sdata->wpan_dev.iftype != NL802154_IFTYPE_MONITOR)
 356                         continue;
 357
 358                 if (!ieee802154_sdata_running(sdata))
 359                         continue;
 360
 361                 skb2 = skb_clone(skb, GFP_ATOMIC);
 362                 if (skb2) {
 363                         skb2->dev = sdata->dev;
 364                         ieee802154_deliver_skb(skb2);
 365
 366                         sdata->dev->stats.rx_packets++;
 367                         sdata->dev->stats.rx_bytes += skb->len;
 368                 }
 369         }
 370 }
 371
 372 void ieee802154_rx(struct ieee802154_local *local, struct sk_buff *skb)
 373 {
 374         u16 crc;
 375
 376         WARN_ON_ONCE(softirq_count() == 0);
 377
 378         if (local->suspended)
 379                 goto free_skb;
 380
 381         /* TODO: When a transceiver omits the checksum here, we
 382          * add an own calculated one. This is currently an ugly
 383          * solution because the monitor needs a crc here.
 384          */
 385         if (local->hw.flags & IEEE802154_HW_RX_OMIT_CKSUM) {
 386                 crc = crc_ccitt(0, skb->data, skb->len);
 387                 put_unaligned_le16(crc, skb_put(skb, 2));
 388         }
 389
 390         rcu_read_lock();
 391
 392         ieee802154_monitors_rx(local, skb);
 393
 394         /* Level 1 filtering: Check the FCS by software when relevant */
 395         if (local->hw.phy->filtering == IEEE802154_FILTERING_NONE) {
 396                 crc = crc_ccitt(0, skb->data, skb->len);
 397                 if (crc)
 398                         goto drop;
 399         }
 400         /* remove crc */
 401         skb_trim(skb, skb->len - 2);
 402
 403         __ieee802154_rx_handle_packet(local, skb);
 404
 405 drop:
 406         rcu_read_unlock();
 407 free_skb:
 408         kfree_skb(skb);
 409 }
 410
 411 void
 412 ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb, u8 lqi)
 413 {
 414         struct ieee802154_local *local = hw_to_local(hw);
 415         struct ieee802154_mac_cb *cb = mac_cb_init(skb);
 416
 417         cb->lqi = lqi;
 418         skb->pkt_type = IEEE802154_RX_MSG;
 419         skb_queue_tail(&local->skb_queue, skb);
 420         tasklet_schedule(&local->tasklet);
 421 }
 422 EXPORT_SYMBOL(ieee802154_rx_irqsafe);