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