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 int
  51 ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata,
  52                        struct sk_buff *skb, const struct ieee802154_hdr *hdr)
  53 {
  54         struct wpan_phy *wpan_phy = sdata->local->hw.phy;
  55         struct wpan_dev *wpan_dev = &sdata->wpan_dev;
  56         struct cfg802154_mac_pkt *mac_pkt;
  57         __le16 span, sshort;
  58         int rc;
  59
  60         pr_debug("getting packet via slave interface %s\n", sdata->dev->name);
  61
  62         span = wpan_dev->pan_id;
  63         sshort = wpan_dev->short_addr;
  64
  65         /* Level 3 filtering: Only beacons are accepted during scans */
  66         if (sdata->required_filtering == IEEE802154_FILTERING_3_SCAN &&
  67             sdata->required_filtering > wpan_phy->filtering) {
  68                 if (mac_cb(skb)->type != IEEE802154_FC_TYPE_BEACON) {
  69                         dev_dbg(&sdata->dev->dev,
  70                                 "drop non-beacon frame (0x%x) during scan\n",
  71                                 mac_cb(skb)->type);
  72                         goto fail;
  73                 }
  74         }
  75
  76         switch (mac_cb(skb)->dest.mode) {
  77         case IEEE802154_ADDR_NONE:
  78                 if (hdr->source.mode != IEEE802154_ADDR_NONE)
  79                         /* FIXME: check if we are PAN coordinator */
  80                         skb->pkt_type = PACKET_OTHERHOST;
  81                 else
  82                         /* ACK comes with both addresses empty */
  83                         skb->pkt_type = PACKET_HOST;
  84                 break;
  85         case IEEE802154_ADDR_LONG:
  86                 if (mac_cb(skb)->dest.pan_id != span &&
  87                     mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
  88                         skb->pkt_type = PACKET_OTHERHOST;
  89                 else if (mac_cb(skb)->dest.extended_addr == wpan_dev->extended_addr)
  90                         skb->pkt_type = PACKET_HOST;
  91                 else
  92                         skb->pkt_type = PACKET_OTHERHOST;
  93                 break;
  94         case IEEE802154_ADDR_SHORT:
  95                 if (mac_cb(skb)->dest.pan_id != span &&
  96                     mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
  97                         skb->pkt_type = PACKET_OTHERHOST;
  98                 else if (mac_cb(skb)->dest.short_addr == sshort)
  99                         skb->pkt_type = PACKET_HOST;
 100                 else if (mac_cb(skb)->dest.short_addr ==
 101                           cpu_to_le16(IEEE802154_ADDR_BROADCAST))
 102                         skb->pkt_type = PACKET_BROADCAST;
 103                 else
 104                         skb->pkt_type = PACKET_OTHERHOST;
 105                 break;
 106         default:
 107                 pr_debug("invalid dest mode\n");
 108                 goto fail;
 109         }
 110
 111         skb->dev = sdata->dev;
 112
 113         /* TODO this should be moved after netif_receive_skb call, otherwise
 114          * wireshark will show a mac header with security fields and the
 115          * payload is already decrypted.
 116          */
 117         rc = mac802154_llsec_decrypt(&sdata->sec, skb);
 118         if (rc) {
 119                 pr_debug("decryption failed: %i\n", rc);
 120                 goto fail;
 121         }
 122
 123         sdata->dev->stats.rx_packets++;
 124         sdata->dev->stats.rx_bytes += skb->len;
 125
 126         switch (mac_cb(skb)->type) {
 127         case IEEE802154_FC_TYPE_BEACON:
 128                 dev_dbg(&sdata->dev->dev, "BEACON received\n");
 129                 if (!mac802154_is_scanning(sdata->local))
 130                         goto fail;
 131
 132                 mac_pkt = kzalloc(sizeof(*mac_pkt), GFP_ATOMIC);
 133                 if (!mac_pkt)
 134                         goto fail;
 135
 136                 mac_pkt->skb = skb_get(skb);
 137                 mac_pkt->sdata = sdata;
 138                 mac_pkt->page = sdata->local->scan_page;
 139                 mac_pkt->channel = sdata->local->scan_channel;
 140                 list_add_tail(&mac_pkt->node, &sdata->local->rx_beacon_list);
 141                 queue_work(sdata->local->mac_wq, &sdata->local->rx_beacon_work);
 142                 return NET_RX_SUCCESS;
 143         case IEEE802154_FC_TYPE_ACK:
 144         case IEEE802154_FC_TYPE_MAC_CMD:
 145                 goto fail;
 146
 147         case IEEE802154_FC_TYPE_DATA:
 148                 return ieee802154_deliver_skb(skb);
 149         default:
 150                 pr_warn_ratelimited("ieee802154: bad frame received "
 151                                     "(type = %d)\n", mac_cb(skb)->type);
 152                 goto fail;
 153         }
 154
 155 fail:
 156         kfree_skb(skb);
 157         return NET_RX_DROP;
 158 }
 159
 160 static void
 161 ieee802154_print_addr(const char *name, const struct ieee802154_addr *addr)
 162 {
 163         if (addr->mode == IEEE802154_ADDR_NONE) {
 164                 pr_debug("%s not present\n", name);
 165                 return;
 166         }
 167
 168         pr_debug("%s PAN ID: %04x\n", name, le16_to_cpu(addr->pan_id));
 169         if (addr->mode == IEEE802154_ADDR_SHORT) {
 170                 pr_debug("%s is short: %04x\n", name,
 171                          le16_to_cpu(addr->short_addr));
 172         } else {
 173                 u64 hw = swab64((__force u64)addr->extended_addr);
 174
 175                 pr_debug("%s is hardware: %8phC\n", name, &hw);
 176         }
 177 }
 178
 179 static int
 180 ieee802154_parse_frame_start(struct sk_buff *skb, struct ieee802154_hdr *hdr)
 181 {
 182         int hlen;
 183         struct ieee802154_mac_cb *cb = mac_cb(skb);
 184
 185         skb_reset_mac_header(skb);
 186
 187         hlen = ieee802154_hdr_pull(skb, hdr);
 188         if (hlen < 0)
 189                 return -EINVAL;
 190
 191         skb->mac_len = hlen;
 192
 193         pr_debug("fc: %04x dsn: %02x\n", le16_to_cpup((__le16 *)&hdr->fc),
 194                  hdr->seq);
 195
 196         cb->type = hdr->fc.type;
 197         cb->ackreq = hdr->fc.ack_request;
 198         cb->secen = hdr->fc.security_enabled;
 199
 200         ieee802154_print_addr("destination", &hdr->dest);
 201         ieee802154_print_addr("source", &hdr->source);
 202
 203         cb->source = hdr->source;
 204         cb->dest = hdr->dest;
 205
 206         if (hdr->fc.security_enabled) {
 207                 u64 key;
 208
 209                 pr_debug("seclevel %i\n", hdr->sec.level);
 210
 211                 switch (hdr->sec.key_id_mode) {
 212                 case IEEE802154_SCF_KEY_IMPLICIT:
 213                         pr_debug("implicit key\n");
 214                         break;
 215
 216                 case IEEE802154_SCF_KEY_INDEX:
 217                         pr_debug("key %02x\n", hdr->sec.key_id);
 218                         break;
 219
 220                 case IEEE802154_SCF_KEY_SHORT_INDEX:
 221                         pr_debug("key %04x:%04x %02x\n",
 222                                  le32_to_cpu(hdr->sec.short_src) >> 16,
 223                                  le32_to_cpu(hdr->sec.short_src) & 0xffff,
 224                                  hdr->sec.key_id);
 225                         break;
 226
 227                 case IEEE802154_SCF_KEY_HW_INDEX:
 228                         key = swab64((__force u64)hdr->sec.extended_src);
 229                         pr_debug("key source %8phC %02x\n", &key,
 230                                  hdr->sec.key_id);
 231                         break;
 232                 }
 233         }
 234
 235         return 0;
 236 }
 237
 238 static void
 239 __ieee802154_rx_handle_packet(struct ieee802154_local *local,
 240                               struct sk_buff *skb)
 241 {
 242         int ret;
 243         struct ieee802154_sub_if_data *sdata;
 244         struct ieee802154_hdr hdr;
 245         struct sk_buff *skb2;
 246
 247         ret = ieee802154_parse_frame_start(skb, &hdr);
 248         if (ret) {
 249                 pr_debug("got invalid frame\n");
 250                 return;
 251         }
 252
 253         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 254                 if (sdata->wpan_dev.iftype == NL802154_IFTYPE_MONITOR)
 255                         continue;
 256
 257                 if (!ieee802154_sdata_running(sdata))
 258                         continue;
 259
 260                 /* Do not deliver packets received on interfaces expecting
 261                  * AACK=1 if the address filters where disabled.
 262                  */
 263                 if (local->hw.phy->filtering < IEEE802154_FILTERING_4_FRAME_FIELDS &&
 264                     sdata->required_filtering == IEEE802154_FILTERING_4_FRAME_FIELDS)
 265                         continue;
 266
 267                 skb2 = skb_clone(skb, GFP_ATOMIC);
 268                 if (skb2) {
 269                         skb2->dev = sdata->dev;
 270                         ieee802154_subif_frame(sdata, skb2, &hdr);
 271                 }
 272         }
 273 }
 274
 275 static void
 276 ieee802154_monitors_rx(struct ieee802154_local *local, struct sk_buff *skb)
 277 {
 278         struct sk_buff *skb2;
 279         struct ieee802154_sub_if_data *sdata;
 280
 281         skb_reset_mac_header(skb);
 282         skb->ip_summed = CHECKSUM_UNNECESSARY;
 283         skb->pkt_type = PACKET_OTHERHOST;
 284         skb->protocol = htons(ETH_P_IEEE802154);
 285
 286         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 287                 if (sdata->wpan_dev.iftype != NL802154_IFTYPE_MONITOR)
 288                         continue;
 289
 290                 if (!ieee802154_sdata_running(sdata))
 291                         continue;
 292
 293                 skb2 = skb_clone(skb, GFP_ATOMIC);
 294                 if (skb2) {
 295                         skb2->dev = sdata->dev;
 296                         ieee802154_deliver_skb(skb2);
 297
 298                         sdata->dev->stats.rx_packets++;
 299                         sdata->dev->stats.rx_bytes += skb->len;
 300                 }
 301         }
 302 }
 303
 304 void ieee802154_rx(struct ieee802154_local *local, struct sk_buff *skb)
 305 {
 306         u16 crc;
 307
 308         WARN_ON_ONCE(softirq_count() == 0);
 309
 310         if (local->suspended)
 311                 goto free_skb;
 312
 313         /* TODO: When a transceiver omits the checksum here, we
 314          * add an own calculated one. This is currently an ugly
 315          * solution because the monitor needs a crc here.
 316          */
 317         if (local->hw.flags & IEEE802154_HW_RX_OMIT_CKSUM) {
 318                 crc = crc_ccitt(0, skb->data, skb->len);
 319                 put_unaligned_le16(crc, skb_put(skb, 2));
 320         }
 321
 322         rcu_read_lock();
 323
 324         ieee802154_monitors_rx(local, skb);
 325
 326         /* Level 1 filtering: Check the FCS by software when relevant */
 327         if (local->hw.phy->filtering == IEEE802154_FILTERING_NONE) {
 328                 crc = crc_ccitt(0, skb->data, skb->len);
 329                 if (crc)
 330                         goto drop;
 331         }
 332         /* remove crc */
 333         skb_trim(skb, skb->len - 2);
 334
 335         __ieee802154_rx_handle_packet(local, skb);
 336
 337 drop:
 338         rcu_read_unlock();
 339 free_skb:
 340         kfree_skb(skb);
 341 }
 342
 343 void
 344 ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb, u8 lqi)
 345 {
 346         struct ieee802154_local *local = hw_to_local(hw);
 347         struct ieee802154_mac_cb *cb = mac_cb_init(skb);
 348
 349         cb->lqi = lqi;
 350         skb->pkt_type = IEEE802154_RX_MSG;
 351         skb_queue_tail(&local->skb_queue, skb);
 352         tasklet_schedule(&local->tasklet);
 353 }
 354 EXPORT_SYMBOL(ieee802154_rx_irqsafe);