drivers/staging/wlan-ng/p80211conv.c

   1 /* src/p80211/p80211conv.c
   2 *
   3 * Ether/802.11 conversions and packet buffer routines
   4 *
   5 * Copyright (C) 1999 AbsoluteValue Systems, Inc.  All Rights Reserved.
   6 * --------------------------------------------------------------------
   7 *
   8 * linux-wlan
   9 *
  10 *   The contents of this file are subject to the Mozilla Public
  11 *   License Version 1.1 (the "License"); you may not use this file
  12 *   except in compliance with the License. You may obtain a copy of
  13 *   the License at http://www.mozilla.org/MPL/
  14 *
  15 *   Software distributed under the License is distributed on an "AS
  16 *   IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
  17 *   implied. See the License for the specific language governing
  18 *   rights and limitations under the License.
  19 *
  20 *   Alternatively, the contents of this file may be used under the
  21 *   terms of the GNU Public License version 2 (the "GPL"), in which
  22 *   case the provisions of the GPL are applicable instead of the
  23 *   above.  If you wish to allow the use of your version of this file
  24 *   only under the terms of the GPL and not to allow others to use
  25 *   your version of this file under the MPL, indicate your decision
  26 *   by deleting the provisions above and replace them with the notice
  27 *   and other provisions required by the GPL.  If you do not delete
  28 *   the provisions above, a recipient may use your version of this
  29 *   file under either the MPL or the GPL.
  30 *
  31 * --------------------------------------------------------------------
  32 *
  33 * Inquiries regarding the linux-wlan Open Source project can be
  34 * made directly to:
  35 *
  36 * AbsoluteValue Systems Inc.
  37 * info@linux-wlan.com
  38 * http://www.linux-wlan.com
  39 *
  40 * --------------------------------------------------------------------
  41 *
  42 * Portions of the development of this software were funded by
  43 * Intersil Corporation as part of PRISM(R) chipset product development.
  44 *
  45 * --------------------------------------------------------------------
  46 *
  47 * This file defines the functions that perform Ethernet to/from
  48 * 802.11 frame conversions.
  49 *
  50 * --------------------------------------------------------------------
  51 *
  52 *================================================================ */
  53
  54 #include <linux/module.h>
  55 #include <linux/kernel.h>
  56 #include <linux/sched.h>
  57 #include <linux/types.h>
  58 #include <linux/skbuff.h>
  59 #include <linux/slab.h>
  60 #include <linux/wireless.h>
  61 #include <linux/netdevice.h>
  62 #include <linux/etherdevice.h>
  63 #include <linux/if_ether.h>
  64 #include <linux/byteorder/generic.h>
  65
  66 #include <asm/byteorder.h>
  67
  68 #include "p80211types.h"
  69 #include "p80211hdr.h"
  70 #include "p80211conv.h"
  71 #include "p80211mgmt.h"
  72 #include "p80211msg.h"
  73 #include "p80211netdev.h"
  74 #include "p80211ioctl.h"
  75 #include "p80211req.h"
  76
  77 static u8 oui_rfc1042[] = { 0x00, 0x00, 0x00 };
  78 static u8 oui_8021h[] = { 0x00, 0x00, 0xf8 };
  79
  80 /*----------------------------------------------------------------
  81 * p80211pb_ether_to_80211
  82 *
  83 * Uses the contents of the ether frame and the etherconv setting
  84 * to build the elements of the 802.11 frame.
  85 *
  86 * We don't actually set
  87 * up the frame header here.  That's the MAC's job.  We're only handling
  88 * conversion of DIXII or 802.3+LLC frames to something that works
  89 * with 802.11.
  90 *
  91 * Note -- 802.11 header is NOT part of the skb.  Likewise, the 802.11
  92 *         FCS is also not present and will need to be added elsewhere.
  93 *
  94 * Arguments:
  95 *       ethconv         Conversion type to perform
  96 *       skb             skbuff containing the ether frame
  97 *       p80211_hdr      802.11 header
  98 *
  99 * Returns:
 100 *       0 on success, non-zero otherwise
 101 *
 102 * Call context:
 103 *       May be called in interrupt or non-interrupt context
 104 ----------------------------------------------------------------*/
 105 int skb_ether_to_p80211(wlandevice_t *wlandev, u32 ethconv,
 106                         struct sk_buff *skb, union p80211_hdr *p80211_hdr,
 107                         struct p80211_metawep *p80211_wep)
 108 {
 109
 110         u16 fc;
 111         u16 proto;
 112         struct wlan_ethhdr e_hdr;
 113         struct wlan_llc *e_llc;
 114         struct wlan_snap *e_snap;
 115         int foo;
 116
 117         memcpy(&e_hdr, skb->data, sizeof(e_hdr));
 118
 119         if (skb->len <= 0) {
 120                 pr_debug("zero-length skb!\n");
 121                 return 1;
 122         }
 123
 124         if (ethconv == WLAN_ETHCONV_ENCAP) {    /* simplest case */
 125                 pr_debug("ENCAP len: %d\n", skb->len);
 126                 /* here, we don't care what kind of ether frm. Just stick it */
 127                 /*  in the 80211 payload */
 128                 /* which is to say, leave the skb alone. */
 129         } else {
 130                 /* step 1: classify ether frame, DIX or 802.3? */
 131                 proto = ntohs(e_hdr.type);
 132                 if (proto <= 1500) {
 133                         pr_debug("802.3 len: %d\n", skb->len);
 134                         /* codes <= 1500 reserved for 802.3 lengths */
 135                         /* it's 802.3, pass ether payload unchanged,  */
 136
 137                         /* trim off ethernet header */
 138                         skb_pull(skb, WLAN_ETHHDR_LEN);
 139
 140                         /*   leave off any PAD octets.  */
 141                         skb_trim(skb, proto);
 142                 } else {
 143                         pr_debug("DIXII len: %d\n", skb->len);
 144                         /* it's DIXII, time for some conversion */
 145
 146                         /* trim off ethernet header */
 147                         skb_pull(skb, WLAN_ETHHDR_LEN);
 148
 149                         /* tack on SNAP */
 150                         e_snap =
 151                             (struct wlan_snap *) skb_push(skb,
 152                                 sizeof(struct wlan_snap));
 153                         e_snap->type = htons(proto);
 154                         if (ethconv == WLAN_ETHCONV_8021h
 155                             && p80211_stt_findproto(proto)) {
 156                                 memcpy(e_snap->oui, oui_8021h,
 157                                        WLAN_IEEE_OUI_LEN);
 158                         } else {
 159                                 memcpy(e_snap->oui, oui_rfc1042,
 160                                        WLAN_IEEE_OUI_LEN);
 161                         }
 162
 163                         /* tack on llc */
 164                         e_llc =
 165                             (struct wlan_llc *) skb_push(skb,
 166                                 sizeof(struct wlan_llc));
 167                         e_llc->dsap = 0xAA;     /* SNAP, see IEEE 802 */
 168                         e_llc->ssap = 0xAA;
 169                         e_llc->ctl = 0x03;
 170
 171                 }
 172         }
 173
 174         /* Set up the 802.11 header */
 175         /* It's a data frame */
 176         fc = cpu_to_le16(WLAN_SET_FC_FTYPE(WLAN_FTYPE_DATA) |
 177                          WLAN_SET_FC_FSTYPE(WLAN_FSTYPE_DATAONLY));
 178
 179         switch (wlandev->macmode) {
 180         case WLAN_MACMODE_IBSS_STA:
 181                 memcpy(p80211_hdr->a3.a1, &e_hdr.daddr, ETH_ALEN);
 182                 memcpy(p80211_hdr->a3.a2, wlandev->netdev->dev_addr, ETH_ALEN);
 183                 memcpy(p80211_hdr->a3.a3, wlandev->bssid, ETH_ALEN);
 184                 break;
 185         case WLAN_MACMODE_ESS_STA:
 186                 fc |= cpu_to_le16(WLAN_SET_FC_TODS(1));
 187                 memcpy(p80211_hdr->a3.a1, wlandev->bssid, ETH_ALEN);
 188                 memcpy(p80211_hdr->a3.a2, wlandev->netdev->dev_addr, ETH_ALEN);
 189                 memcpy(p80211_hdr->a3.a3, &e_hdr.daddr, ETH_ALEN);
 190                 break;
 191         case WLAN_MACMODE_ESS_AP:
 192                 fc |= cpu_to_le16(WLAN_SET_FC_FROMDS(1));
 193                 memcpy(p80211_hdr->a3.a1, &e_hdr.daddr, ETH_ALEN);
 194                 memcpy(p80211_hdr->a3.a2, wlandev->bssid, ETH_ALEN);
 195                 memcpy(p80211_hdr->a3.a3, &e_hdr.saddr, ETH_ALEN);
 196                 break;
 197         default:
 198                 printk(KERN_ERR
 199                        "Error: Converting eth to wlan in unknown mode.\n");
 200                 return 1;
 201                 break;
 202         }
 203
 204         p80211_wep->data = NULL;
 205
 206         if ((wlandev->hostwep & HOSTWEP_PRIVACYINVOKED)
 207             && (wlandev->hostwep & HOSTWEP_ENCRYPT)) {
 208                 /* XXXX need to pick keynum other than default? */
 209
 210                 p80211_wep->data = kmalloc(skb->len, GFP_ATOMIC);
 211                 foo = wep_encrypt(wlandev, skb->data, p80211_wep->data,
 212                                   skb->len,
 213                                   (wlandev->hostwep & HOSTWEP_DEFAULTKEY_MASK),
 214                                   p80211_wep->iv, p80211_wep->icv);
 215                 if (foo) {
 216                         printk(KERN_WARNING
 217                                "Host en-WEP failed, dropping frame (%d).\n",
 218                                foo);
 219                         return 2;
 220                 }
 221                 fc |= cpu_to_le16(WLAN_SET_FC_ISWEP(1));
 222         }
 223
 224         /*      skb->nh.raw = skb->data; */
 225
 226         p80211_hdr->a3.fc = fc;
 227         p80211_hdr->a3.dur = 0;
 228         p80211_hdr->a3.seq = 0;
 229
 230         return 0;
 231 }
 232
 233 /* jkriegl: from orinoco, modified */
 234 static void orinoco_spy_gather(wlandevice_t *wlandev, char *mac,
 235                                struct p80211_rxmeta *rxmeta)
 236 {
 237         int i;
 238
 239         /* Gather wireless spy statistics: for each packet, compare the
 240          * source address with out list, and if match, get the stats... */
 241
 242         for (i = 0; i < wlandev->spy_number; i++) {
 243
 244                 if (!memcmp(wlandev->spy_address[i], mac, ETH_ALEN)) {
 245                         memcpy(wlandev->spy_address[i], mac, ETH_ALEN);
 246                         wlandev->spy_stat[i].level = rxmeta->signal;
 247                         wlandev->spy_stat[i].noise = rxmeta->noise;
 248                         wlandev->spy_stat[i].qual =
 249                             (rxmeta->signal >
 250                              rxmeta->noise) ? (rxmeta->signal -
 251                                                rxmeta->noise) : 0;
 252                         wlandev->spy_stat[i].updated = 0x7;
 253                 }
 254         }
 255 }
 256
 257 /*----------------------------------------------------------------
 258 * p80211pb_80211_to_ether
 259 *
 260 * Uses the contents of a received 802.11 frame and the etherconv
 261 * setting to build an ether frame.
 262 *
 263 * This function extracts the src and dest address from the 802.11
 264 * frame to use in the construction of the eth frame.
 265 *
 266 * Arguments:
 267 *       ethconv         Conversion type to perform
 268 *       skb             Packet buffer containing the 802.11 frame
 269 *
 270 * Returns:
 271 *       0 on success, non-zero otherwise
 272 *
 273 * Call context:
 274 *       May be called in interrupt or non-interrupt context
 275 ----------------------------------------------------------------*/
 276 int skb_p80211_to_ether(wlandevice_t *wlandev, u32 ethconv,
 277                         struct sk_buff *skb)
 278 {
 279         netdevice_t *netdev = wlandev->netdev;
 280         u16 fc;
 281         unsigned int payload_length;
 282         unsigned int payload_offset;
 283         u8 daddr[WLAN_ETHADDR_LEN];
 284         u8 saddr[WLAN_ETHADDR_LEN];
 285         union p80211_hdr *w_hdr;
 286         struct wlan_ethhdr *e_hdr;
 287         struct wlan_llc *e_llc;
 288         struct wlan_snap *e_snap;
 289
 290         int foo;
 291
 292         payload_length = skb->len - WLAN_HDR_A3_LEN - WLAN_CRC_LEN;
 293         payload_offset = WLAN_HDR_A3_LEN;
 294
 295         w_hdr = (union p80211_hdr *) skb->data;
 296
 297         /* setup some vars for convenience */
 298         fc = le16_to_cpu(w_hdr->a3.fc);
 299         if ((WLAN_GET_FC_TODS(fc) == 0) && (WLAN_GET_FC_FROMDS(fc) == 0)) {
 300                 memcpy(daddr, w_hdr->a3.a1, WLAN_ETHADDR_LEN);
 301                 memcpy(saddr, w_hdr->a3.a2, WLAN_ETHADDR_LEN);
 302         } else if ((WLAN_GET_FC_TODS(fc) == 0)
 303                         && (WLAN_GET_FC_FROMDS(fc) == 1)) {
 304                 memcpy(daddr, w_hdr->a3.a1, WLAN_ETHADDR_LEN);
 305                 memcpy(saddr, w_hdr->a3.a3, WLAN_ETHADDR_LEN);
 306         } else if ((WLAN_GET_FC_TODS(fc) == 1)
 307                         && (WLAN_GET_FC_FROMDS(fc) == 0)) {
 308                 memcpy(daddr, w_hdr->a3.a3, WLAN_ETHADDR_LEN);
 309                 memcpy(saddr, w_hdr->a3.a2, WLAN_ETHADDR_LEN);
 310         } else {
 311                 payload_offset = WLAN_HDR_A4_LEN;
 312                 if (payload_length < WLAN_HDR_A4_LEN - WLAN_HDR_A3_LEN) {
 313                         printk(KERN_ERR "A4 frame too short!\n");
 314                         return 1;
 315                 }
 316                 payload_length -= (WLAN_HDR_A4_LEN - WLAN_HDR_A3_LEN);
 317                 memcpy(daddr, w_hdr->a4.a3, WLAN_ETHADDR_LEN);
 318                 memcpy(saddr, w_hdr->a4.a4, WLAN_ETHADDR_LEN);
 319         }
 320
 321         /* perform de-wep if necessary.. */
 322         if ((wlandev->hostwep & HOSTWEP_PRIVACYINVOKED) && WLAN_GET_FC_ISWEP(fc)
 323             && (wlandev->hostwep & HOSTWEP_DECRYPT)) {
 324                 if (payload_length <= 8) {
 325                         printk(KERN_ERR "WEP frame too short (%u).\n",
 326                                skb->len);
 327                         return 1;
 328                 }
 329                 foo = wep_decrypt(wlandev, skb->data + payload_offset + 4,
 330                                        payload_length - 8, -1,
 331                                        skb->data + payload_offset,
 332                                        skb->data + payload_offset +
 333                                        payload_length - 4);
 334                 if (foo) {
 335                         /* de-wep failed, drop skb. */
 336                         pr_debug("Host de-WEP failed, dropping frame (%d).\n",
 337                                  foo);
 338                         wlandev->rx.decrypt_err++;
 339                         return 2;
 340                 }
 341
 342                 /* subtract the IV+ICV length off the payload */
 343                 payload_length -= 8;
 344                 /* chop off the IV */
 345                 skb_pull(skb, 4);
 346                 /* chop off the ICV. */
 347                 skb_trim(skb, skb->len - 4);
 348
 349                 wlandev->rx.decrypt++;
 350         }
 351
 352         e_hdr = (struct wlan_ethhdr *) (skb->data + payload_offset);
 353
 354         e_llc = (struct wlan_llc *) (skb->data + payload_offset);
 355         e_snap =
 356             (struct wlan_snap *) (skb->data + payload_offset +
 357                 sizeof(struct wlan_llc));
 358
 359         /* Test for the various encodings */
 360         if ((payload_length >= sizeof(struct wlan_ethhdr)) &&
 361             (e_llc->dsap != 0xaa || e_llc->ssap != 0xaa) &&
 362             ((memcmp(daddr, e_hdr->daddr, WLAN_ETHADDR_LEN) == 0) ||
 363              (memcmp(saddr, e_hdr->saddr, WLAN_ETHADDR_LEN) == 0))) {
 364                 pr_debug("802.3 ENCAP len: %d\n", payload_length);
 365                 /* 802.3 Encapsulated */
 366                 /* Test for an overlength frame */
 367                 if (payload_length > (netdev->mtu + WLAN_ETHHDR_LEN)) {
 368                         /* A bogus length ethfrm has been encap'd. */
 369                         /* Is someone trying an oflow attack? */
 370                         printk(KERN_ERR "ENCAP frame too large (%d > %d)\n",
 371                                payload_length, netdev->mtu + WLAN_ETHHDR_LEN);
 372                         return 1;
 373                 }
 374
 375                 /* Chop off the 802.11 header.  it's already sane. */
 376                 skb_pull(skb, payload_offset);
 377                 /* chop off the 802.11 CRC */
 378                 skb_trim(skb, skb->len - WLAN_CRC_LEN);
 379
 380         } else if ((payload_length >= sizeof(struct wlan_llc) +
 381                 sizeof(struct wlan_snap))
 382                 && (e_llc->dsap == 0xaa)
 383                 && (e_llc->ssap == 0xaa)
 384                 && (e_llc->ctl == 0x03)
 385                    &&
 386                    (((memcmp(e_snap->oui, oui_rfc1042, WLAN_IEEE_OUI_LEN) == 0)
 387                      && (ethconv == WLAN_ETHCONV_8021h)
 388                      && (p80211_stt_findproto(le16_to_cpu(e_snap->type))))
 389                     || (memcmp(e_snap->oui, oui_rfc1042, WLAN_IEEE_OUI_LEN) !=
 390                         0))) {
 391                 pr_debug("SNAP+RFC1042 len: %d\n", payload_length);
 392                 /* it's a SNAP + RFC1042 frame && protocol is in STT */
 393                 /* build 802.3 + RFC1042 */
 394
 395                 /* Test for an overlength frame */
 396                 if (payload_length > netdev->mtu) {
 397                         /* A bogus length ethfrm has been sent. */
 398                         /* Is someone trying an oflow attack? */
 399                         printk(KERN_ERR "SNAP frame too large (%d > %d)\n",
 400                                payload_length, netdev->mtu);
 401                         return 1;
 402                 }
 403
 404                 /* chop 802.11 header from skb. */
 405                 skb_pull(skb, payload_offset);
 406
 407                 /* create 802.3 header at beginning of skb. */
 408                 e_hdr = (struct wlan_ethhdr *) skb_push(skb, WLAN_ETHHDR_LEN);
 409                 memcpy(e_hdr->daddr, daddr, WLAN_ETHADDR_LEN);
 410                 memcpy(e_hdr->saddr, saddr, WLAN_ETHADDR_LEN);
 411                 e_hdr->type = htons(payload_length);
 412
 413                 /* chop off the 802.11 CRC */
 414                 skb_trim(skb, skb->len - WLAN_CRC_LEN);
 415
 416         } else if ((payload_length >= sizeof(struct wlan_llc) +
 417                 sizeof(struct wlan_snap))
 418                 && (e_llc->dsap == 0xaa)
 419                 && (e_llc->ssap == 0xaa)
 420                 && (e_llc->ctl == 0x03)) {
 421                 pr_debug("802.1h/RFC1042 len: %d\n", payload_length);
 422                 /* it's an 802.1h frame || (an RFC1042 && protocol not in STT)
 423                    build a DIXII + RFC894 */
 424
 425                 /* Test for an overlength frame */
 426                 if ((payload_length - sizeof(struct wlan_llc) -
 427                         sizeof(struct wlan_snap))
 428                         > netdev->mtu) {
 429                         /* A bogus length ethfrm has been sent. */
 430                         /* Is someone trying an oflow attack? */
 431                         printk(KERN_ERR "DIXII frame too large (%ld > %d)\n",
 432                                (long int)(payload_length -
 433                                         sizeof(struct wlan_llc) -
 434                                         sizeof(struct wlan_snap)), netdev->mtu);
 435                         return 1;
 436                 }
 437
 438                 /* chop 802.11 header from skb. */
 439                 skb_pull(skb, payload_offset);
 440
 441                 /* chop llc header from skb. */
 442                 skb_pull(skb, sizeof(struct wlan_llc));
 443
 444                 /* chop snap header from skb. */
 445                 skb_pull(skb, sizeof(struct wlan_snap));
 446
 447                 /* create 802.3 header at beginning of skb. */
 448                 e_hdr = (struct wlan_ethhdr *) skb_push(skb, WLAN_ETHHDR_LEN);
 449                 e_hdr->type = e_snap->type;
 450                 memcpy(e_hdr->daddr, daddr, WLAN_ETHADDR_LEN);
 451                 memcpy(e_hdr->saddr, saddr, WLAN_ETHADDR_LEN);
 452
 453                 /* chop off the 802.11 CRC */
 454                 skb_trim(skb, skb->len - WLAN_CRC_LEN);
 455         } else {
 456                 pr_debug("NON-ENCAP len: %d\n", payload_length);
 457                 /* any NON-ENCAP */
 458                 /* it's a generic 80211+LLC or IPX 'Raw 802.3' */
 459                 /*  build an 802.3 frame */
 460                 /* allocate space and setup hostbuf */
 461
 462                 /* Test for an overlength frame */
 463                 if (payload_length > netdev->mtu) {
 464                         /* A bogus length ethfrm has been sent. */
 465                         /* Is someone trying an oflow attack? */
 466                         printk(KERN_ERR "OTHER frame too large (%d > %d)\n",
 467                                payload_length, netdev->mtu);
 468                         return 1;
 469                 }
 470
 471                 /* Chop off the 802.11 header. */
 472                 skb_pull(skb, payload_offset);
 473
 474                 /* create 802.3 header at beginning of skb. */
 475                 e_hdr = (struct wlan_ethhdr *) skb_push(skb, WLAN_ETHHDR_LEN);
 476                 memcpy(e_hdr->daddr, daddr, WLAN_ETHADDR_LEN);
 477                 memcpy(e_hdr->saddr, saddr, WLAN_ETHADDR_LEN);
 478                 e_hdr->type = htons(payload_length);
 479
 480                 /* chop off the 802.11 CRC */
 481                 skb_trim(skb, skb->len - WLAN_CRC_LEN);
 482
 483         }
 484
 485         /*
 486          * Note that eth_type_trans() expects an skb w/ skb->data pointing
 487          * at the MAC header, it then sets the following skb members:
 488          * skb->mac_header,
 489          * skb->data, and
 490          * skb->pkt_type.
 491          * It then _returns_ the value that _we're_ supposed to stuff in
 492          * skb->protocol.  This is nuts.
 493          */
 494         skb->protocol = eth_type_trans(skb, netdev);
 495
 496         /* jkriegl: process signal and noise as set in hfa384x_int_rx() */
 497         /* jkriegl: only process signal/noise if requested by iwspy */
 498         if (wlandev->spy_number)
 499                 orinoco_spy_gather(wlandev, eth_hdr(skb)->h_source,
 500                                    P80211SKB_RXMETA(skb));
 501
 502         /* Free the metadata */
 503         p80211skb_rxmeta_detach(skb);
 504
 505         return 0;
 506 }
 507
 508 /*----------------------------------------------------------------
 509 * p80211_stt_findproto
 510 *
 511 * Searches the 802.1h Selective Translation Table for a given
 512 * protocol.
 513 *
 514 * Arguments:
 515 *       proto   protocl number (in host order) to search for.
 516 *
 517 * Returns:
 518 *       1 - if the table is empty or a match is found.
 519 *       0 - if the table is non-empty and a match is not found.
 520 *
 521 * Call context:
 522 *       May be called in interrupt or non-interrupt context
 523 ----------------------------------------------------------------*/
 524 int p80211_stt_findproto(u16 proto)
 525 {
 526         /* Always return found for now.  This is the behavior used by the */
 527         /*  Zoom Win95 driver when 802.1h mode is selected */
 528         /* TODO: If necessary, add an actual search we'll probably
 529            need this to match the CMAC's way of doing things.
 530            Need to do some testing to confirm.
 531          */
 532
 533         if (proto == 0x80f3)    /* APPLETALK */
 534                 return 1;
 535
 536         return 0;
 537 }
 538
 539 /*----------------------------------------------------------------
 540 * p80211skb_rxmeta_detach
 541 *
 542 * Disconnects the frmmeta and rxmeta from an skb.
 543 *
 544 * Arguments:
 545 *       wlandev         The wlandev this skb belongs to.
 546 *       skb             The skb we're attaching to.
 547 *
 548 * Returns:
 549 *       0 on success, non-zero otherwise
 550 *
 551 * Call context:
 552 *       May be called in interrupt or non-interrupt context
 553 ----------------------------------------------------------------*/
 554 void p80211skb_rxmeta_detach(struct sk_buff *skb)
 555 {
 556         struct p80211_rxmeta *rxmeta;
 557         struct p80211_frmmeta *frmmeta;
 558
 559         /* Sanity checks */
 560         if (skb == NULL) {      /* bad skb */
 561                 pr_debug("Called w/ null skb.\n");
 562                 return;
 563         }
 564         frmmeta = P80211SKB_FRMMETA(skb);
 565         if (frmmeta == NULL) {  /* no magic */
 566                 pr_debug("Called w/ bad frmmeta magic.\n");
 567                 return;
 568         }
 569         rxmeta = frmmeta->rx;
 570         if (rxmeta == NULL) {   /* bad meta ptr */
 571                 pr_debug("Called w/ bad rxmeta ptr.\n");
 572                 return;
 573         }
 574
 575         /* Free rxmeta */
 576         kfree(rxmeta);
 577
 578         /* Clear skb->cb */
 579         memset(skb->cb, 0, sizeof(skb->cb));
 580 }
 581
 582 /*----------------------------------------------------------------
 583 * p80211skb_rxmeta_attach
 584 *
 585 * Allocates a p80211rxmeta structure, initializes it, and attaches
 586 * it to an skb.
 587 *
 588 * Arguments:
 589 *       wlandev         The wlandev this skb belongs to.
 590 *       skb             The skb we're attaching to.
 591 *
 592 * Returns:
 593 *       0 on success, non-zero otherwise
 594 *
 595 * Call context:
 596 *       May be called in interrupt or non-interrupt context
 597 ----------------------------------------------------------------*/
 598 int p80211skb_rxmeta_attach(struct wlandevice *wlandev, struct sk_buff *skb)
 599 {
 600         int result = 0;
 601         struct p80211_rxmeta *rxmeta;
 602         struct p80211_frmmeta *frmmeta;
 603
 604         /* If these already have metadata, we error out! */
 605         if (P80211SKB_RXMETA(skb) != NULL) {
 606                 printk(KERN_ERR "%s: RXmeta already attached!\n",
 607                        wlandev->name);
 608                 result = 0;
 609                 goto exit;
 610         }
 611
 612         /* Allocate the rxmeta */
 613         rxmeta = kzalloc(sizeof(struct p80211_rxmeta), GFP_ATOMIC);
 614
 615         if (rxmeta == NULL) {
 616                 printk(KERN_ERR "%s: Failed to allocate rxmeta.\n",
 617                        wlandev->name);
 618                 result = 1;
 619                 goto exit;
 620         }
 621
 622         /* Initialize the rxmeta */
 623         rxmeta->wlandev = wlandev;
 624         rxmeta->hosttime = jiffies;
 625
 626         /* Overlay a frmmeta_t onto skb->cb */
 627         memset(skb->cb, 0, sizeof(struct p80211_frmmeta));
 628         frmmeta = (struct p80211_frmmeta *) (skb->cb);
 629         frmmeta->magic = P80211_FRMMETA_MAGIC;
 630         frmmeta->rx = rxmeta;
 631 exit:
 632         return result;
 633 }
 634
 635 /*----------------------------------------------------------------
 636 * p80211skb_free
 637 *
 638 * Frees an entire p80211skb by checking and freeing the meta struct
 639 * and then freeing the skb.
 640 *
 641 * Arguments:
 642 *       wlandev         The wlandev this skb belongs to.
 643 *       skb             The skb we're attaching to.
 644 *
 645 * Returns:
 646 *       0 on success, non-zero otherwise
 647 *
 648 * Call context:
 649 *       May be called in interrupt or non-interrupt context
 650 ----------------------------------------------------------------*/
 651 void p80211skb_free(struct wlandevice *wlandev, struct sk_buff *skb)
 652 {
 653         struct p80211_frmmeta *meta;
 654
 655         meta = P80211SKB_FRMMETA(skb);
 656         if (meta && meta->rx)
 657                 p80211skb_rxmeta_detach(skb);
 658         else
 659                 printk(KERN_ERR "Freeing an skb (%p) w/ no frmmeta.\n", skb);
 660         dev_kfree_skb(skb);
 661 }