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