Jeff Garzik | b453872 | 2005-05-12 22:48:20 -0400 | [diff] [blame] | 1 | /****************************************************************************** |
| 2 | |
| 3 | Copyright(c) 2003 - 2004 Intel Corporation. All rights reserved. |
| 4 | |
| 5 | This program is free software; you can redistribute it and/or modify it |
| 6 | under the terms of version 2 of the GNU General Public License as |
| 7 | published by the Free Software Foundation. |
| 8 | |
| 9 | This program is distributed in the hope that it will be useful, but WITHOUT |
| 10 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 11 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 12 | more details. |
| 13 | |
| 14 | You should have received a copy of the GNU General Public License along with |
| 15 | this program; if not, write to the Free Software Foundation, Inc., 59 |
| 16 | Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 17 | |
| 18 | The full GNU General Public License is included in this distribution in the |
| 19 | file called LICENSE. |
| 20 | |
| 21 | Contact Information: |
| 22 | James P. Ketrenos <ipw2100-admin@linux.intel.com> |
| 23 | Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497 |
| 24 | |
| 25 | ******************************************************************************/ |
| 26 | #include <linux/compiler.h> |
| 27 | #include <linux/config.h> |
| 28 | #include <linux/errno.h> |
| 29 | #include <linux/if_arp.h> |
| 30 | #include <linux/in6.h> |
| 31 | #include <linux/in.h> |
| 32 | #include <linux/ip.h> |
| 33 | #include <linux/kernel.h> |
| 34 | #include <linux/module.h> |
| 35 | #include <linux/netdevice.h> |
Jeff Garzik | b453872 | 2005-05-12 22:48:20 -0400 | [diff] [blame] | 36 | #include <linux/proc_fs.h> |
| 37 | #include <linux/skbuff.h> |
| 38 | #include <linux/slab.h> |
| 39 | #include <linux/tcp.h> |
| 40 | #include <linux/types.h> |
| 41 | #include <linux/version.h> |
| 42 | #include <linux/wireless.h> |
| 43 | #include <linux/etherdevice.h> |
| 44 | #include <asm/uaccess.h> |
| 45 | |
| 46 | #include <net/ieee80211.h> |
| 47 | |
| 48 | |
| 49 | /* |
| 50 | |
| 51 | |
| 52 | 802.11 Data Frame |
| 53 | |
| 54 | ,-------------------------------------------------------------------. |
| 55 | Bytes | 2 | 2 | 6 | 6 | 6 | 2 | 0..2312 | 4 | |
| 56 | |------|------|---------|---------|---------|------|---------|------| |
| 57 | Desc. | ctrl | dura | DA/RA | TA | SA | Sequ | Frame | fcs | |
| 58 | | | tion | (BSSID) | | | ence | data | | |
| 59 | `--------------------------------------------------| |------' |
| 60 | Total: 28 non-data bytes `----.----' |
| 61 | | |
| 62 | .- 'Frame data' expands to <---------------------------' |
| 63 | | |
| 64 | V |
| 65 | ,---------------------------------------------------. |
| 66 | Bytes | 1 | 1 | 1 | 3 | 2 | 0-2304 | |
| 67 | |------|------|---------|----------|------|---------| |
| 68 | Desc. | SNAP | SNAP | Control |Eth Tunnel| Type | IP | |
| 69 | | DSAP | SSAP | | | | Packet | |
| 70 | | 0xAA | 0xAA |0x03 (UI)|0x00-00-F8| | | |
| 71 | `-----------------------------------------| | |
| 72 | Total: 8 non-data bytes `----.----' |
| 73 | | |
| 74 | .- 'IP Packet' expands, if WEP enabled, to <--' |
| 75 | | |
| 76 | V |
| 77 | ,-----------------------. |
| 78 | Bytes | 4 | 0-2296 | 4 | |
| 79 | |-----|-----------|-----| |
| 80 | Desc. | IV | Encrypted | ICV | |
| 81 | | | IP Packet | | |
| 82 | `-----------------------' |
| 83 | Total: 8 non-data bytes |
| 84 | |
| 85 | |
| 86 | 802.3 Ethernet Data Frame |
| 87 | |
| 88 | ,-----------------------------------------. |
| 89 | Bytes | 6 | 6 | 2 | Variable | 4 | |
| 90 | |-------|-------|------|-----------|------| |
| 91 | Desc. | Dest. | Source| Type | IP Packet | fcs | |
| 92 | | MAC | MAC | | | | |
| 93 | `-----------------------------------------' |
| 94 | Total: 18 non-data bytes |
| 95 | |
| 96 | In the event that fragmentation is required, the incoming payload is split into |
| 97 | N parts of size ieee->fts. The first fragment contains the SNAP header and the |
| 98 | remaining packets are just data. |
| 99 | |
| 100 | If encryption is enabled, each fragment payload size is reduced by enough space |
| 101 | to add the prefix and postfix (IV and ICV totalling 8 bytes in the case of WEP) |
| 102 | So if you have 1500 bytes of payload with ieee->fts set to 500 without |
| 103 | encryption it will take 3 frames. With WEP it will take 4 frames as the |
| 104 | payload of each frame is reduced to 492 bytes. |
| 105 | |
| 106 | * SKB visualization |
| 107 | * |
| 108 | * ,- skb->data |
| 109 | * | |
| 110 | * | ETHERNET HEADER ,-<-- PAYLOAD |
| 111 | * | | 14 bytes from skb->data |
| 112 | * | 2 bytes for Type --> ,T. | (sizeof ethhdr) |
| 113 | * | | | | |
| 114 | * |,-Dest.--. ,--Src.---. | | | |
| 115 | * | 6 bytes| | 6 bytes | | | | |
| 116 | * v | | | | | | |
| 117 | * 0 | v 1 | v | v 2 |
| 118 | * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 |
| 119 | * ^ | ^ | ^ | |
| 120 | * | | | | | | |
| 121 | * | | | | `T' <---- 2 bytes for Type |
| 122 | * | | | | |
| 123 | * | | '---SNAP--' <-------- 6 bytes for SNAP |
| 124 | * | | |
| 125 | * `-IV--' <-------------------- 4 bytes for IV (WEP) |
| 126 | * |
| 127 | * SNAP HEADER |
| 128 | * |
| 129 | */ |
| 130 | |
| 131 | static u8 P802_1H_OUI[P80211_OUI_LEN] = { 0x00, 0x00, 0xf8 }; |
| 132 | static u8 RFC1042_OUI[P80211_OUI_LEN] = { 0x00, 0x00, 0x00 }; |
| 133 | |
| 134 | static inline int ieee80211_put_snap(u8 *data, u16 h_proto) |
| 135 | { |
| 136 | struct ieee80211_snap_hdr *snap; |
| 137 | u8 *oui; |
| 138 | |
| 139 | snap = (struct ieee80211_snap_hdr *)data; |
| 140 | snap->dsap = 0xaa; |
| 141 | snap->ssap = 0xaa; |
| 142 | snap->ctrl = 0x03; |
| 143 | |
| 144 | if (h_proto == 0x8137 || h_proto == 0x80f3) |
| 145 | oui = P802_1H_OUI; |
| 146 | else |
| 147 | oui = RFC1042_OUI; |
| 148 | snap->oui[0] = oui[0]; |
| 149 | snap->oui[1] = oui[1]; |
| 150 | snap->oui[2] = oui[2]; |
| 151 | |
| 152 | *(u16 *)(data + SNAP_SIZE) = htons(h_proto); |
| 153 | |
| 154 | return SNAP_SIZE + sizeof(u16); |
| 155 | } |
| 156 | |
| 157 | static inline int ieee80211_encrypt_fragment( |
| 158 | struct ieee80211_device *ieee, |
| 159 | struct sk_buff *frag, |
| 160 | int hdr_len) |
| 161 | { |
| 162 | struct ieee80211_crypt_data* crypt = ieee->crypt[ieee->tx_keyidx]; |
| 163 | int res; |
| 164 | |
| 165 | #ifdef CONFIG_IEEE80211_CRYPT_TKIP |
| 166 | struct ieee80211_hdr *header; |
| 167 | |
| 168 | if (ieee->tkip_countermeasures && |
| 169 | crypt && crypt->ops && strcmp(crypt->ops->name, "TKIP") == 0) { |
| 170 | header = (struct ieee80211_hdr *) frag->data; |
| 171 | if (net_ratelimit()) { |
| 172 | printk(KERN_DEBUG "%s: TKIP countermeasures: dropped " |
| 173 | "TX packet to " MAC_FMT "\n", |
| 174 | ieee->dev->name, MAC_ARG(header->addr1)); |
| 175 | } |
| 176 | return -1; |
| 177 | } |
| 178 | #endif |
| 179 | /* To encrypt, frame format is: |
| 180 | * IV (4 bytes), clear payload (including SNAP), ICV (4 bytes) */ |
| 181 | |
| 182 | // PR: FIXME: Copied from hostap. Check fragmentation/MSDU/MPDU encryption. |
| 183 | /* Host-based IEEE 802.11 fragmentation for TX is not yet supported, so |
| 184 | * call both MSDU and MPDU encryption functions from here. */ |
| 185 | atomic_inc(&crypt->refcnt); |
| 186 | res = 0; |
| 187 | if (crypt->ops->encrypt_msdu) |
| 188 | res = crypt->ops->encrypt_msdu(frag, hdr_len, crypt->priv); |
| 189 | if (res == 0 && crypt->ops->encrypt_mpdu) |
| 190 | res = crypt->ops->encrypt_mpdu(frag, hdr_len, crypt->priv); |
| 191 | |
| 192 | atomic_dec(&crypt->refcnt); |
| 193 | if (res < 0) { |
| 194 | printk(KERN_INFO "%s: Encryption failed: len=%d.\n", |
| 195 | ieee->dev->name, frag->len); |
| 196 | ieee->ieee_stats.tx_discards++; |
| 197 | return -1; |
| 198 | } |
| 199 | |
| 200 | return 0; |
| 201 | } |
| 202 | |
| 203 | |
| 204 | void ieee80211_txb_free(struct ieee80211_txb *txb) { |
| 205 | int i; |
| 206 | if (unlikely(!txb)) |
| 207 | return; |
| 208 | for (i = 0; i < txb->nr_frags; i++) |
| 209 | if (txb->fragments[i]) |
| 210 | dev_kfree_skb_any(txb->fragments[i]); |
| 211 | kfree(txb); |
| 212 | } |
| 213 | |
Adrian Bunk | e157249 | 2005-05-06 23:32:39 +0200 | [diff] [blame] | 214 | static struct ieee80211_txb *ieee80211_alloc_txb(int nr_frags, int txb_size, |
| 215 | int gfp_mask) |
Jeff Garzik | b453872 | 2005-05-12 22:48:20 -0400 | [diff] [blame] | 216 | { |
| 217 | struct ieee80211_txb *txb; |
| 218 | int i; |
| 219 | txb = kmalloc( |
| 220 | sizeof(struct ieee80211_txb) + (sizeof(u8*) * nr_frags), |
| 221 | gfp_mask); |
| 222 | if (!txb) |
| 223 | return NULL; |
| 224 | |
Adrian Bunk | 0a989b2 | 2005-04-11 16:52:15 -0700 | [diff] [blame] | 225 | memset(txb, 0, sizeof(struct ieee80211_txb)); |
Jeff Garzik | b453872 | 2005-05-12 22:48:20 -0400 | [diff] [blame] | 226 | txb->nr_frags = nr_frags; |
| 227 | txb->frag_size = txb_size; |
| 228 | |
| 229 | for (i = 0; i < nr_frags; i++) { |
| 230 | txb->fragments[i] = dev_alloc_skb(txb_size); |
| 231 | if (unlikely(!txb->fragments[i])) { |
| 232 | i--; |
| 233 | break; |
| 234 | } |
| 235 | } |
| 236 | if (unlikely(i != nr_frags)) { |
| 237 | while (i >= 0) |
| 238 | dev_kfree_skb_any(txb->fragments[i--]); |
| 239 | kfree(txb); |
| 240 | return NULL; |
| 241 | } |
| 242 | return txb; |
| 243 | } |
| 244 | |
| 245 | /* SKBs are added to the ieee->tx_queue. */ |
| 246 | int ieee80211_xmit(struct sk_buff *skb, |
| 247 | struct net_device *dev) |
| 248 | { |
| 249 | struct ieee80211_device *ieee = netdev_priv(dev); |
| 250 | struct ieee80211_txb *txb = NULL; |
| 251 | struct ieee80211_hdr *frag_hdr; |
| 252 | int i, bytes_per_frag, nr_frags, bytes_last_frag, frag_size; |
| 253 | unsigned long flags; |
| 254 | struct net_device_stats *stats = &ieee->stats; |
| 255 | int ether_type, encrypt; |
| 256 | int bytes, fc, hdr_len; |
| 257 | struct sk_buff *skb_frag; |
| 258 | struct ieee80211_hdr header = { /* Ensure zero initialized */ |
| 259 | .duration_id = 0, |
| 260 | .seq_ctl = 0 |
| 261 | }; |
| 262 | u8 dest[ETH_ALEN], src[ETH_ALEN]; |
| 263 | |
| 264 | struct ieee80211_crypt_data* crypt; |
| 265 | |
| 266 | spin_lock_irqsave(&ieee->lock, flags); |
| 267 | |
| 268 | /* If there is no driver handler to take the TXB, dont' bother |
| 269 | * creating it... */ |
| 270 | if (!ieee->hard_start_xmit) { |
| 271 | printk(KERN_WARNING "%s: No xmit handler.\n", |
| 272 | ieee->dev->name); |
| 273 | goto success; |
| 274 | } |
| 275 | |
| 276 | if (unlikely(skb->len < SNAP_SIZE + sizeof(u16))) { |
| 277 | printk(KERN_WARNING "%s: skb too small (%d).\n", |
| 278 | ieee->dev->name, skb->len); |
| 279 | goto success; |
| 280 | } |
| 281 | |
| 282 | ether_type = ntohs(((struct ethhdr *)skb->data)->h_proto); |
| 283 | |
| 284 | crypt = ieee->crypt[ieee->tx_keyidx]; |
| 285 | |
| 286 | encrypt = !(ether_type == ETH_P_PAE && ieee->ieee802_1x) && |
| 287 | ieee->host_encrypt && crypt && crypt->ops; |
| 288 | |
| 289 | if (!encrypt && ieee->ieee802_1x && |
| 290 | ieee->drop_unencrypted && ether_type != ETH_P_PAE) { |
| 291 | stats->tx_dropped++; |
| 292 | goto success; |
| 293 | } |
| 294 | |
| 295 | #ifdef CONFIG_IEEE80211_DEBUG |
| 296 | if (crypt && !encrypt && ether_type == ETH_P_PAE) { |
| 297 | struct eapol *eap = (struct eapol *)(skb->data + |
| 298 | sizeof(struct ethhdr) - SNAP_SIZE - sizeof(u16)); |
| 299 | IEEE80211_DEBUG_EAP("TX: IEEE 802.11 EAPOL frame: %s\n", |
| 300 | eap_get_type(eap->type)); |
| 301 | } |
| 302 | #endif |
| 303 | |
| 304 | /* Save source and destination addresses */ |
| 305 | memcpy(&dest, skb->data, ETH_ALEN); |
| 306 | memcpy(&src, skb->data+ETH_ALEN, ETH_ALEN); |
| 307 | |
| 308 | /* Advance the SKB to the start of the payload */ |
| 309 | skb_pull(skb, sizeof(struct ethhdr)); |
| 310 | |
| 311 | /* Determine total amount of storage required for TXB packets */ |
| 312 | bytes = skb->len + SNAP_SIZE + sizeof(u16); |
| 313 | |
| 314 | if (encrypt) |
| 315 | fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA | |
| 316 | IEEE80211_FCTL_WEP; |
| 317 | else |
| 318 | fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA; |
| 319 | |
| 320 | if (ieee->iw_mode == IW_MODE_INFRA) { |
| 321 | fc |= IEEE80211_FCTL_TODS; |
| 322 | /* To DS: Addr1 = BSSID, Addr2 = SA, |
| 323 | Addr3 = DA */ |
| 324 | memcpy(&header.addr1, ieee->bssid, ETH_ALEN); |
| 325 | memcpy(&header.addr2, &src, ETH_ALEN); |
| 326 | memcpy(&header.addr3, &dest, ETH_ALEN); |
| 327 | } else if (ieee->iw_mode == IW_MODE_ADHOC) { |
| 328 | /* not From/To DS: Addr1 = DA, Addr2 = SA, |
| 329 | Addr3 = BSSID */ |
| 330 | memcpy(&header.addr1, dest, ETH_ALEN); |
| 331 | memcpy(&header.addr2, src, ETH_ALEN); |
| 332 | memcpy(&header.addr3, ieee->bssid, ETH_ALEN); |
| 333 | } |
| 334 | header.frame_ctl = cpu_to_le16(fc); |
| 335 | hdr_len = IEEE80211_3ADDR_LEN; |
| 336 | |
| 337 | /* Determine fragmentation size based on destination (multicast |
| 338 | * and broadcast are not fragmented) */ |
| 339 | if (is_multicast_ether_addr(dest) || |
| 340 | is_broadcast_ether_addr(dest)) |
| 341 | frag_size = MAX_FRAG_THRESHOLD; |
| 342 | else |
| 343 | frag_size = ieee->fts; |
| 344 | |
| 345 | /* Determine amount of payload per fragment. Regardless of if |
| 346 | * this stack is providing the full 802.11 header, one will |
| 347 | * eventually be affixed to this fragment -- so we must account for |
| 348 | * it when determining the amount of payload space. */ |
| 349 | bytes_per_frag = frag_size - IEEE80211_3ADDR_LEN; |
| 350 | if (ieee->config & |
| 351 | (CFG_IEEE80211_COMPUTE_FCS | CFG_IEEE80211_RESERVE_FCS)) |
| 352 | bytes_per_frag -= IEEE80211_FCS_LEN; |
| 353 | |
| 354 | /* Each fragment may need to have room for encryptiong pre/postfix */ |
| 355 | if (encrypt) |
| 356 | bytes_per_frag -= crypt->ops->extra_prefix_len + |
| 357 | crypt->ops->extra_postfix_len; |
| 358 | |
| 359 | /* Number of fragments is the total bytes_per_frag / |
| 360 | * payload_per_fragment */ |
| 361 | nr_frags = bytes / bytes_per_frag; |
| 362 | bytes_last_frag = bytes % bytes_per_frag; |
| 363 | if (bytes_last_frag) |
| 364 | nr_frags++; |
| 365 | else |
| 366 | bytes_last_frag = bytes_per_frag; |
| 367 | |
| 368 | /* When we allocate the TXB we allocate enough space for the reserve |
| 369 | * and full fragment bytes (bytes_per_frag doesn't include prefix, |
| 370 | * postfix, header, FCS, etc.) */ |
| 371 | txb = ieee80211_alloc_txb(nr_frags, frag_size, GFP_ATOMIC); |
| 372 | if (unlikely(!txb)) { |
| 373 | printk(KERN_WARNING "%s: Could not allocate TXB\n", |
| 374 | ieee->dev->name); |
| 375 | goto failed; |
| 376 | } |
| 377 | txb->encrypted = encrypt; |
| 378 | txb->payload_size = bytes; |
| 379 | |
| 380 | for (i = 0; i < nr_frags; i++) { |
| 381 | skb_frag = txb->fragments[i]; |
| 382 | |
| 383 | if (encrypt) |
| 384 | skb_reserve(skb_frag, crypt->ops->extra_prefix_len); |
| 385 | |
| 386 | frag_hdr = (struct ieee80211_hdr *)skb_put(skb_frag, hdr_len); |
| 387 | memcpy(frag_hdr, &header, hdr_len); |
| 388 | |
| 389 | /* If this is not the last fragment, then add the MOREFRAGS |
| 390 | * bit to the frame control */ |
| 391 | if (i != nr_frags - 1) { |
| 392 | frag_hdr->frame_ctl = cpu_to_le16( |
| 393 | fc | IEEE80211_FCTL_MOREFRAGS); |
| 394 | bytes = bytes_per_frag; |
| 395 | } else { |
| 396 | /* The last fragment takes the remaining length */ |
| 397 | bytes = bytes_last_frag; |
| 398 | } |
| 399 | |
| 400 | /* Put a SNAP header on the first fragment */ |
| 401 | if (i == 0) { |
| 402 | ieee80211_put_snap( |
| 403 | skb_put(skb_frag, SNAP_SIZE + sizeof(u16)), |
| 404 | ether_type); |
| 405 | bytes -= SNAP_SIZE + sizeof(u16); |
| 406 | } |
| 407 | |
| 408 | memcpy(skb_put(skb_frag, bytes), skb->data, bytes); |
| 409 | |
| 410 | /* Advance the SKB... */ |
| 411 | skb_pull(skb, bytes); |
| 412 | |
| 413 | /* Encryption routine will move the header forward in order |
| 414 | * to insert the IV between the header and the payload */ |
| 415 | if (encrypt) |
| 416 | ieee80211_encrypt_fragment(ieee, skb_frag, hdr_len); |
| 417 | if (ieee->config & |
| 418 | (CFG_IEEE80211_COMPUTE_FCS | CFG_IEEE80211_RESERVE_FCS)) |
| 419 | skb_put(skb_frag, 4); |
| 420 | } |
| 421 | |
| 422 | |
| 423 | success: |
| 424 | spin_unlock_irqrestore(&ieee->lock, flags); |
| 425 | |
| 426 | dev_kfree_skb_any(skb); |
| 427 | |
| 428 | if (txb) { |
| 429 | if ((*ieee->hard_start_xmit)(txb, dev) == 0) { |
| 430 | stats->tx_packets++; |
| 431 | stats->tx_bytes += txb->payload_size; |
| 432 | return 0; |
| 433 | } |
| 434 | ieee80211_txb_free(txb); |
| 435 | } |
| 436 | |
| 437 | return 0; |
| 438 | |
| 439 | failed: |
| 440 | spin_unlock_irqrestore(&ieee->lock, flags); |
| 441 | netif_stop_queue(dev); |
| 442 | stats->tx_errors++; |
| 443 | return 1; |
| 444 | |
| 445 | } |
| 446 | |
| 447 | EXPORT_SYMBOL(ieee80211_txb_free); |