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 <[email protected]>
   7  * Maxim Gorbachyov <[email protected]>
   8  * Dmitry Eremin-Solenikov <[email protected]>
   9  * Alexander Smirnov <[email protected]>
  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
  97         case IEEE802154_CMD_ASSOCIATION_RESP:
  98                 dev_dbg(&mac_pkt->sdata->dev->dev, "processing ASSOC RESP\n");
  99                 if (!mac802154_is_associating(local))
 100                         break;
 101
 102                 mac802154_process_association_resp(mac_pkt->sdata, mac_pkt->skb);
 103                 break;
 104
 105         case IEEE802154_CMD_ASSOCIATION_REQ:
 106                 dev_dbg(&mac_pkt->sdata->dev->dev, "processing ASSOC REQ\n");
 107                 if (mac_pkt->sdata->wpan_dev.iftype != NL802154_IFTYPE_COORD)
 108                         break;
 109
 110                 mac802154_process_association_req(mac_pkt->sdata, mac_pkt->skb);
 111                 break;
 112
 113         case IEEE802154_CMD_DISASSOCIATION_NOTIFY:
 114                 dev_dbg(&mac_pkt->sdata->dev->dev, "processing DISASSOC NOTIF\n");
 115                 if (mac_pkt->sdata->wpan_dev.iftype != NL802154_IFTYPE_COORD)
 116                         break;
 117
 118                 mac802154_process_disassociation_notif(mac_pkt->sdata, mac_pkt->skb);
 119                 break;
 120
 121         default:
 122                 break;
 123         }
 124
 125 out:
 126         list_del(&mac_pkt->node);
 127         kfree_skb(mac_pkt->skb);
 128         kfree(mac_pkt);
 129 }
 130
 131 static int
 132 ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata,
 133                        struct sk_buff *skb, const struct ieee802154_hdr *hdr)
 134 {
 135         struct wpan_phy *wpan_phy = sdata->local->hw.phy;
 136         struct wpan_dev *wpan_dev = &sdata->wpan_dev;
 137         struct cfg802154_mac_pkt *mac_pkt;
 138         __le16 span, sshort;
 139         int rc;
 140
 141         pr_debug("getting packet via slave interface %s\n", sdata->dev->name);
 142
 143         span = wpan_dev->pan_id;
 144         sshort = wpan_dev->short_addr;
 145
 146         /* Level 3 filtering: Only beacons are accepted during scans */
 147         if (sdata->required_filtering == IEEE802154_FILTERING_3_SCAN &&
 148             sdata->required_filtering > wpan_phy->filtering) {
 149                 if (mac_cb(skb)->type != IEEE802154_FC_TYPE_BEACON) {
 150                         dev_dbg(&sdata->dev->dev,
 151                                 "drop non-beacon frame (0x%x) during scan\n",
 152                                 mac_cb(skb)->type);
 153                         goto fail;
 154                 }
 155         }
 156
 157         switch (mac_cb(skb)->dest.mode) {
 158         case IEEE802154_ADDR_NONE:
 159                 if (hdr->source.mode == IEEE802154_ADDR_NONE)
 160                         /* ACK comes with both addresses empty */
 161                         skb->pkt_type = PACKET_HOST;
 162                 else if (!wpan_dev->parent)
 163                         /* No dest means PAN coordinator is the recipient */
 164                         skb->pkt_type = PACKET_HOST;
 165                 else
 166                         /* We are not the PAN coordinator, just relaying */
 167                         skb->pkt_type = PACKET_OTHERHOST;
 168                 break;
 169         case IEEE802154_ADDR_LONG:
 170                 if (mac_cb(skb)->dest.pan_id != span &&
 171                     mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
 172                         skb->pkt_type = PACKET_OTHERHOST;
 173                 else if (mac_cb(skb)->dest.extended_addr == wpan_dev->extended_addr)
 174                         skb->pkt_type = PACKET_HOST;
 175                 else
 176                         skb->pkt_type = PACKET_OTHERHOST;
 177                 break;
 178         case IEEE802154_ADDR_SHORT:
 179                 if (mac_cb(skb)->dest.pan_id != span &&
 180                     mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
 181                         skb->pkt_type = PACKET_OTHERHOST;
 182                 else if (mac_cb(skb)->dest.short_addr == sshort)
 183                         skb->pkt_type = PACKET_HOST;
 184                 else if (mac_cb(skb)->dest.short_addr ==
 185                           cpu_to_le16(IEEE802154_ADDR_BROADCAST))
 186                         skb->pkt_type = PACKET_BROADCAST;
 187                 else
 188                         skb->pkt_type = PACKET_OTHERHOST;
 189                 break;
 190         default:
 191                 pr_debug("invalid dest mode\n");
 192                 goto fail;
 193         }
 194
 195         skb->dev = sdata->dev;
 196
 197         /* TODO this should be moved after netif_receive_skb call, otherwise
 198          * wireshark will show a mac header with security fields and the
 199          * payload is already decrypted.
 200          */
 201         rc = mac802154_llsec_decrypt(&sdata->sec, skb);
 202         if (rc) {
 203                 pr_debug("decryption failed: %i\n", rc);
 204                 goto fail;
 205         }
 206
 207         sdata->dev->stats.rx_packets++;
 208         sdata->dev->stats.rx_bytes += skb->len;
 209
 210         switch (mac_cb(skb)->type) {
 211         case IEEE802154_FC_TYPE_BEACON:
 212                 dev_dbg(&sdata->dev->dev, "BEACON received\n");
 213                 if (!mac802154_is_scanning(sdata->local))
 214                         goto fail;
 215
 216                 mac_pkt = kzalloc(sizeof(*mac_pkt), GFP_ATOMIC);
 217                 if (!mac_pkt)
 218                         goto fail;
 219
 220                 mac_pkt->skb = skb_get(skb);
 221                 mac_pkt->sdata = sdata;
 222                 mac_pkt->page = sdata->local->scan_page;
 223                 mac_pkt->channel = sdata->local->scan_channel;
 224                 list_add_tail(&mac_pkt->node, &sdata->local->rx_beacon_list);
 225                 queue_work(sdata->local->mac_wq, &sdata->local->rx_beacon_work);
 226                 return NET_RX_SUCCESS;
 227
 228         case IEEE802154_FC_TYPE_MAC_CMD:
 229                 dev_dbg(&sdata->dev->dev, "MAC COMMAND received\n");
 230                 mac_pkt = kzalloc(sizeof(*mac_pkt), GFP_ATOMIC);
 231                 if (!mac_pkt)
 232                         goto fail;
 233
 234                 mac_pkt->skb = skb_get(skb);
 235                 mac_pkt->sdata = sdata;
 236                 list_add_tail(&mac_pkt->node, &sdata->local->rx_mac_cmd_list);
 237                 queue_work(sdata->local->mac_wq, &sdata->local->rx_mac_cmd_work);
 238                 return NET_RX_SUCCESS;
 239
 240         case IEEE802154_FC_TYPE_ACK:
 241                 goto fail;
 242
 243         case IEEE802154_FC_TYPE_DATA:
 244                 return ieee802154_deliver_skb(skb);
 245         default:
 246                 pr_warn_ratelimited("ieee802154: bad frame received "
 247                                     "(type = %d)\n", mac_cb(skb)->type);
 248                 goto fail;
 249         }
 250
 251 fail:
 252         kfree_skb(skb);
 253         return NET_RX_DROP;
 254 }
 255
 256 static void
 257 ieee802154_print_addr(const char *name, const struct ieee802154_addr *addr)
 258 {
 259         if (addr->mode == IEEE802154_ADDR_NONE) {
 260                 pr_debug("%s not present\n", name);
 261                 return;
 262         }
 263
 264         pr_debug("%s PAN ID: %04x\n", name, le16_to_cpu(addr->pan_id));
 265         if (addr->mode == IEEE802154_ADDR_SHORT) {
 266                 pr_debug("%s is short: %04x\n", name,
 267                          le16_to_cpu(addr->short_addr));
 268         } else {
 269                 u64 hw = swab64((__force u64)addr->extended_addr);
 270
 271                 pr_debug("%s is hardware: %8phC\n", name, &hw);
 272         }
 273 }
 274
 275 static int
 276 ieee802154_parse_frame_start(struct sk_buff *skb, struct ieee802154_hdr *hdr)
 277 {
 278         int hlen;
 279         struct ieee802154_mac_cb *cb = mac_cb(skb);
 280
 281         skb_reset_mac_header(skb);
 282
 283         hlen = ieee802154_hdr_pull(skb, hdr);
 284         if (hlen < 0)
 285                 return -EINVAL;
 286
 287         skb->mac_len = hlen;
 288
 289         pr_debug("fc: %04x dsn: %02x\n", le16_to_cpup((__le16 *)&hdr->fc),
 290                  hdr->seq);
 291
 292         cb->type = hdr->fc.type;
 293         cb->ackreq = hdr->fc.ack_request;
 294         cb->secen = hdr->fc.security_enabled;
 295
 296         ieee802154_print_addr("destination", &hdr->dest);
 297         ieee802154_print_addr("source", &hdr->source);
 298
 299         cb->source = hdr->source;
 300         cb->dest = hdr->dest;
 301
 302         if (hdr->fc.security_enabled) {
 303                 u64 key;
 304
 305                 pr_debug("seclevel %i\n", hdr->sec.level);
 306
 307                 switch (hdr->sec.key_id_mode) {
 308                 case IEEE802154_SCF_KEY_IMPLICIT:
 309                         pr_debug("implicit key\n");
 310                         break;
 311
 312                 case IEEE802154_SCF_KEY_INDEX:
 313                         pr_debug("key %02x\n", hdr->sec.key_id);
 314                         break;
 315
 316                 case IEEE802154_SCF_KEY_SHORT_INDEX:
 317                         pr_debug("key %04x:%04x %02x\n",
 318                                  le32_to_cpu(hdr->sec.short_src) >> 16,
 319                                  le32_to_cpu(hdr->sec.short_src) & 0xffff,
 320                                  hdr->sec.key_id);
 321                         break;
 322
 323                 case IEEE802154_SCF_KEY_HW_INDEX:
 324                         key = swab64((__force u64)hdr->sec.extended_src);
 325                         pr_debug("key source %8phC %02x\n", &key,
 326                                  hdr->sec.key_id);
 327                         break;
 328                 }
 329         }
 330
 331         return 0;
 332 }
 333
 334 static void
 335 __ieee802154_rx_handle_packet(struct ieee802154_local *local,
 336                               struct sk_buff *skb)
 337 {
 338         int ret;
 339         struct ieee802154_sub_if_data *sdata;
 340         struct ieee802154_hdr hdr;
 341         struct sk_buff *skb2;
 342
 343         ret = ieee802154_parse_frame_start(skb, &hdr);
 344         if (ret) {
 345                 pr_debug("got invalid frame\n");
 346                 return;
 347         }
 348
 349         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 350                 if (sdata->wpan_dev.iftype == NL802154_IFTYPE_MONITOR)
 351                         continue;
 352
 353                 if (!ieee802154_sdata_running(sdata))
 354                         continue;
 355
 356                 /* Do not deliver packets received on interfaces expecting
 357                  * AACK=1 if the address filters where disabled.
 358                  */
 359                 if (local->hw.phy->filtering < IEEE802154_FILTERING_4_FRAME_FIELDS &&
 360                     sdata->required_filtering == IEEE802154_FILTERING_4_FRAME_FIELDS)
 361                         continue;
 362
 363                 skb2 = skb_clone(skb, GFP_ATOMIC);
 364                 if (skb2) {
 365                         skb2->dev = sdata->dev;
 366                         ieee802154_subif_frame(sdata, skb2, &hdr);
 367                 }
 368         }
 369 }
 370
 371 static void
 372 ieee802154_monitors_rx(struct ieee802154_local *local, struct sk_buff *skb)
 373 {
 374         struct sk_buff *skb2;
 375         struct ieee802154_sub_if_data *sdata;
 376
 377         skb_reset_mac_header(skb);
 378         skb->ip_summed = CHECKSUM_UNNECESSARY;
 379         skb->pkt_type = PACKET_OTHERHOST;
 380         skb->protocol = htons(ETH_P_IEEE802154);
 381
 382         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 383                 if (sdata->wpan_dev.iftype != NL802154_IFTYPE_MONITOR)
 384                         continue;
 385
 386                 if (!ieee802154_sdata_running(sdata))
 387                         continue;
 388
 389                 skb2 = skb_clone(skb, GFP_ATOMIC);
 390                 if (skb2) {
 391                         skb2->dev = sdata->dev;
 392                         ieee802154_deliver_skb(skb2);
 393
 394                         sdata->dev->stats.rx_packets++;
 395                         sdata->dev->stats.rx_bytes += skb->len;
 396                 }
 397         }
 398 }
 399
 400 void ieee802154_rx(struct ieee802154_local *local, struct sk_buff *skb)
 401 {
 402         u16 crc;
 403
 404         WARN_ON_ONCE(softirq_count() == 0);
 405
 406         if (local->suspended)
 407                 goto free_skb;
 408
 409         /* TODO: When a transceiver omits the checksum here, we
 410          * add an own calculated one. This is currently an ugly
 411          * solution because the monitor needs a crc here.
 412          */
 413         if (local->hw.flags & IEEE802154_HW_RX_OMIT_CKSUM) {
 414                 crc = crc_ccitt(0, skb->data, skb->len);
 415                 put_unaligned_le16(crc, skb_put(skb, 2));
 416         }
 417
 418         rcu_read_lock();
 419
 420         ieee802154_monitors_rx(local, skb);
 421
 422         /* Level 1 filtering: Check the FCS by software when relevant */
 423         if (local->hw.phy->filtering == IEEE802154_FILTERING_NONE) {
 424                 crc = crc_ccitt(0, skb->data, skb->len);
 425                 if (crc)
 426                         goto drop;
 427         }
 428         /* remove crc */
 429         skb_trim(skb, skb->len - 2);
 430
 431         __ieee802154_rx_handle_packet(local, skb);
 432
 433 drop:
 434         rcu_read_unlock();
 435 free_skb:
 436         kfree_skb(skb);
 437 }
 438
 439 void
 440 ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb, u8 lqi)
 441 {
 442         struct ieee802154_local *local = hw_to_local(hw);
 443         struct ieee802154_mac_cb *cb = mac_cb_init(skb);
 444
 445         cb->lqi = lqi;
 446         skb->pkt_type = IEEE802154_RX_MSG;
 447         skb_queue_tail(&local->skb_queue, skb);
 448         tasklet_schedule(&local->tasklet);
 449 }
 450 EXPORT_SYMBOL(ieee802154_rx_irqsafe);