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 /* TODO this should be moved after netif_receive_skb call, otherwise 91 * wireshark will show a mac header with security fields and the 92 * payload is already decrypted. 93 */ 94 rc = mac802154_llsec_decrypt(&sdata->sec, skb); 95 if (rc) { 96 pr_debug("decryption failed: %i\n", rc); 97 goto fail; 98 } 99 100 sdata->dev->stats.rx_packets++; 101 sdata->dev->stats.rx_bytes += skb->len; 102 103 switch (mac_cb(skb)->type) { 104 case IEEE802154_FC_TYPE_BEACON: 105 case IEEE802154_FC_TYPE_ACK: 106 case IEEE802154_FC_TYPE_MAC_CMD: 107 goto fail; 108 109 case IEEE802154_FC_TYPE_DATA: 110 return ieee802154_deliver_skb(skb); 111 default: 112 pr_warn_ratelimited("ieee802154: bad frame received " 113 "(type = %d)\n", mac_cb(skb)->type); 114 goto fail; 115 } 116 117 fail: 118 kfree_skb(skb); 119 return NET_RX_DROP; 120 } 121 122 static void 123 ieee802154_print_addr(const char *name, const struct ieee802154_addr *addr) 124 { 125 if (addr->mode == IEEE802154_ADDR_NONE) 126 pr_debug("%s not present\n", name); 127 128 pr_debug("%s PAN ID: %04x\n", name, le16_to_cpu(addr->pan_id)); 129 if (addr->mode == IEEE802154_ADDR_SHORT) { 130 pr_debug("%s is short: %04x\n", name, 131 le16_to_cpu(addr->short_addr)); 132 } else { 133 u64 hw = swab64((__force u64)addr->extended_addr); 134 135 pr_debug("%s is hardware: %8phC\n", name, &hw); 136 } 137 } 138 139 static int 140 ieee802154_parse_frame_start(struct sk_buff *skb, struct ieee802154_hdr *hdr) 141 { 142 int hlen; 143 struct ieee802154_mac_cb *cb = mac_cb_init(skb); 144 145 skb_reset_mac_header(skb); 146 147 hlen = ieee802154_hdr_pull(skb, hdr); 148 if (hlen < 0) 149 return -EINVAL; 150 151 skb->mac_len = hlen; 152 153 pr_debug("fc: %04x dsn: %02x\n", le16_to_cpup((__le16 *)&hdr->fc), 154 hdr->seq); 155 156 cb->type = hdr->fc.type; 157 cb->ackreq = hdr->fc.ack_request; 158 cb->secen = hdr->fc.security_enabled; 159 160 ieee802154_print_addr("destination", &hdr->dest); 161 ieee802154_print_addr("source", &hdr->source); 162 163 cb->source = hdr->source; 164 cb->dest = hdr->dest; 165 166 if (hdr->fc.security_enabled) { 167 u64 key; 168 169 pr_debug("seclevel %i\n", hdr->sec.level); 170 171 switch (hdr->sec.key_id_mode) { 172 case IEEE802154_SCF_KEY_IMPLICIT: 173 pr_debug("implicit key\n"); 174 break; 175 176 case IEEE802154_SCF_KEY_INDEX: 177 pr_debug("key %02x\n", hdr->sec.key_id); 178 break; 179 180 case IEEE802154_SCF_KEY_SHORT_INDEX: 181 pr_debug("key %04x:%04x %02x\n", 182 le32_to_cpu(hdr->sec.short_src) >> 16, 183 le32_to_cpu(hdr->sec.short_src) & 0xffff, 184 hdr->sec.key_id); 185 break; 186 187 case IEEE802154_SCF_KEY_HW_INDEX: 188 key = swab64((__force u64)hdr->sec.extended_src); 189 pr_debug("key source %8phC %02x\n", &key, 190 hdr->sec.key_id); 191 break; 192 } 193 } 194 195 return 0; 196 } 197 198 static void 199 __ieee802154_rx_handle_packet(struct ieee802154_local *local, 200 struct sk_buff *skb) 201 { 202 int ret; 203 struct ieee802154_sub_if_data *sdata; 204 struct ieee802154_hdr hdr; 205 206 ret = ieee802154_parse_frame_start(skb, &hdr); 207 if (ret) { 208 pr_debug("got invalid frame\n"); 209 kfree_skb(skb); 210 return; 211 } 212 213 list_for_each_entry_rcu(sdata, &local->interfaces, list) { 214 if (sdata->wpan_dev.iftype != NL802154_IFTYPE_NODE) 215 continue; 216 217 if (!ieee802154_sdata_running(sdata)) 218 continue; 219 220 ieee802154_subif_frame(sdata, skb, &hdr); 221 skb = NULL; 222 break; 223 } 224 225 kfree_skb(skb); 226 } 227 228 static void 229 ieee802154_monitors_rx(struct ieee802154_local *local, struct sk_buff *skb) 230 { 231 struct sk_buff *skb2; 232 struct ieee802154_sub_if_data *sdata; 233 234 skb_reset_mac_header(skb); 235 skb->ip_summed = CHECKSUM_UNNECESSARY; 236 skb->pkt_type = PACKET_OTHERHOST; 237 skb->protocol = htons(ETH_P_IEEE802154); 238 239 list_for_each_entry_rcu(sdata, &local->interfaces, list) { 240 if (sdata->wpan_dev.iftype != NL802154_IFTYPE_MONITOR) 241 continue; 242 243 if (!ieee802154_sdata_running(sdata)) 244 continue; 245 246 skb2 = skb_clone(skb, GFP_ATOMIC); 247 if (skb2) { 248 skb2->dev = sdata->dev; 249 ieee802154_deliver_skb(skb2); 250 251 sdata->dev->stats.rx_packets++; 252 sdata->dev->stats.rx_bytes += skb->len; 253 } 254 } 255 } 256 257 void ieee802154_rx(struct ieee802154_local *local, struct sk_buff *skb) 258 { 259 u16 crc; 260 261 WARN_ON_ONCE(softirq_count() == 0); 262 263 if (local->suspended) 264 goto drop; 265 266 /* TODO: When a transceiver omits the checksum here, we 267 * add an own calculated one. This is currently an ugly 268 * solution because the monitor needs a crc here. 269 */ 270 if (local->hw.flags & IEEE802154_HW_RX_OMIT_CKSUM) { 271 crc = crc_ccitt(0, skb->data, skb->len); 272 put_unaligned_le16(crc, skb_put(skb, 2)); 273 } 274 275 rcu_read_lock(); 276 277 ieee802154_monitors_rx(local, skb); 278 279 /* Check if transceiver doesn't validate the checksum. 280 * If not we validate the checksum here. 281 */ 282 if (local->hw.flags & IEEE802154_HW_RX_DROP_BAD_CKSUM) { 283 crc = crc_ccitt(0, skb->data, skb->len); 284 if (crc) { 285 rcu_read_unlock(); 286 goto drop; 287 } 288 } 289 /* remove crc */ 290 skb_trim(skb, skb->len - 2); 291 292 __ieee802154_rx_handle_packet(local, skb); 293 294 rcu_read_unlock(); 295 296 return; 297 drop: 298 kfree_skb(skb); 299 } 300 301 void 302 ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb, u8 lqi) 303 { 304 struct ieee802154_local *local = hw_to_local(hw); 305 306 mac_cb(skb)->lqi = lqi; 307 skb->pkt_type = IEEE802154_RX_MSG; 308 skb_queue_tail(&local->skb_queue, skb); 309 tasklet_schedule(&local->tasklet); 310 } 311 EXPORT_SYMBOL(ieee802154_rx_irqsafe); 312