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linux-wlan-ng/src/p80211/p80211conv.c

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/* src/p80211/p80211conv.c
*
* Ether/802.11 conversions and packet buffer routines
*
* Copyright (C) 1999 AbsoluteValue Systems, Inc. All Rights Reserved.
* --------------------------------------------------------------------
*
* linux-wlan
*
* The contents of this file are subject to the Mozilla Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU Public License version 2 (the "GPL"), in which
* case the provisions of the GPL are applicable instead of the
* above. If you wish to allow the use of your version of this file
* only under the terms of the GPL and not to allow others to use
* your version of this file under the MPL, indicate your decision
* by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL. If you do not delete
* the provisions above, a recipient may use your version of this
* file under either the MPL or the GPL.
*
* --------------------------------------------------------------------
*
* Inquiries regarding the linux-wlan Open Source project can be
* made directly to:
*
* AbsoluteValue Systems Inc.
* info@linux-wlan.com
* http://www.linux-wlan.com
*
* --------------------------------------------------------------------
*
* Portions of the development of this software were funded by
* Intersil Corporation as part of PRISM(R) chipset product development.
*
* --------------------------------------------------------------------
*
* This file defines the functions that perform Ethernet to/from
* 802.11 frame conversions.
*
* --------------------------------------------------------------------
*/
/*================================================================*/
/* System Includes */
#define __NO_VERSION__ /* prevent the static definition */
#include <linux/config.h>
#include <linux/version.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/wireless.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <asm/byteorder.h>
#include <wlan/wlan_compat.h>
/*================================================================*/
/* Project Includes */
#include <wlan/version.h>
#include <wlan/p80211types.h>
#include <wlan/p80211hdr.h>
#include <wlan/p80211conv.h>
#include <wlan/p80211mgmt.h>
#include <wlan/p80211msg.h>
#include <wlan/p80211netdev.h>
#include <wlan/p80211ioctl.h>
#include <wlan/p80211req.h>
/*================================================================*/
/* Local Constants */
/*================================================================*/
/* Local Macros */
/*================================================================*/
/* Local Types */
/*================================================================*/
/* Local Static Definitions */
static UINT8 oui_rfc1042[] = {0x00, 0x00, 0x00};
static UINT8 oui_8021h[] = {0x00, 0x00, 0xf8};
/*================================================================*/
/* Local Function Declarations */
/*================================================================*/
/* Function Definitions */
/*----------------------------------------------------------------
* p80211pb_ether_to_80211
*
* Uses the contents of the ether frame and the etherconv setting
* to build the elements of the 802.11 frame.
*
* We don't actually set
* up the frame header here. That's the MAC's job. We're only handling
* conversion of DIXII or 802.3+LLC frames to something that works
* with 802.11.
*
* Note -- 802.11 header is NOT part of the skb. Likewise, the 802.11
* FCS is also not present and will need to be added elsewhere.
*
* Arguments:
* ethconv Conversion type to perform
* skb skbuff containing the ether frame
* p80211_hdr 802.11 header
*
* Returns:
* 0 on success, non-zero otherwise
*
* Call context:
* May be called in interrupt or non-interrupt context
----------------------------------------------------------------*/
int skb_ether_to_p80211( wlandevice_t *wlandev, UINT32 ethconv, struct sk_buff *skb, p80211_hdr_t *p80211_hdr, p80211_metawep_t *p80211_wep)
{
UINT16 fc;
UINT16 proto;
wlan_ethhdr_t e_hdr;
wlan_llc_t *e_llc;
wlan_snap_t *e_snap;
int foo;
DBFENTER;
memcpy(&e_hdr, skb->data, sizeof(e_hdr));
if (skb->len <= 0) {
WLAN_LOG_DEBUG0(1, "zero-length skb!\n");
return 1;
}
if ( ethconv == WLAN_ETHCONV_ENCAP ) { /* simplest case */
WLAN_LOG_DEBUG(3, "ENCAP len: %d\n", skb->len);
/* here, we don't care what kind of ether frm. Just stick it */
/* in the 80211 payload */
/* which is to say, leave the skb alone. */
} else {
/* step 1: classify ether frame, DIX or 802.3? */
proto = ntohs(e_hdr.type);
if ( proto <= 1500 ) {
WLAN_LOG_DEBUG(3, "802.3 len: %d\n", skb->len);
/* codes <= 1500 reserved for 802.3 lengths */
/* it's 802.3, pass ether payload unchanged, */
/* trim off ethernet header */
skb_pull(skb, WLAN_ETHHDR_LEN);
/* leave off any PAD octets. */
skb_trim(skb, proto);
} else {
WLAN_LOG_DEBUG(3, "DIXII len: %d\n", skb->len);
/* it's DIXII, time for some conversion */
/* trim off ethernet header */
skb_pull(skb, WLAN_ETHHDR_LEN);
/* tack on SNAP */
e_snap = (wlan_snap_t *) skb_push(skb, sizeof(wlan_snap_t));
e_snap->type = htons(proto);
if ( ethconv == WLAN_ETHCONV_8021h && p80211_stt_findproto(proto) ) {
memcpy( e_snap->oui, oui_8021h, WLAN_IEEE_OUI_LEN);
} else {
memcpy( e_snap->oui, oui_rfc1042, WLAN_IEEE_OUI_LEN);
}
/* tack on llc */
e_llc = (wlan_llc_t *) skb_push(skb, sizeof(wlan_llc_t));
e_llc->dsap = 0xAA; /* SNAP, see IEEE 802 */
e_llc->ssap = 0xAA;
e_llc->ctl = 0x03;
}
}
/* Set up the 802.11 header */
/* It's a data frame */
fc = host2ieee16( WLAN_SET_FC_FTYPE(WLAN_FTYPE_DATA) |
WLAN_SET_FC_FSTYPE(WLAN_FSTYPE_DATAONLY));
switch ( wlandev->macmode ) {
case WLAN_MACMODE_IBSS_STA:
memcpy(p80211_hdr->a3.a1, &e_hdr.daddr, WLAN_ADDR_LEN);
memcpy(p80211_hdr->a3.a2, wlandev->netdev->dev_addr, WLAN_ADDR_LEN);
memcpy(p80211_hdr->a3.a3, wlandev->bssid, WLAN_ADDR_LEN);
break;
case WLAN_MACMODE_ESS_STA:
fc |= host2ieee16(WLAN_SET_FC_TODS(1));
memcpy(p80211_hdr->a3.a1, wlandev->bssid, WLAN_ADDR_LEN);
memcpy(p80211_hdr->a3.a2, wlandev->netdev->dev_addr, WLAN_ADDR_LEN);
memcpy(p80211_hdr->a3.a3, &e_hdr.daddr, WLAN_ADDR_LEN);
break;
case WLAN_MACMODE_ESS_AP:
fc |= host2ieee16(WLAN_SET_FC_FROMDS(1));
memcpy(p80211_hdr->a3.a1, &e_hdr.daddr, WLAN_ADDR_LEN);
memcpy(p80211_hdr->a3.a2, wlandev->bssid, WLAN_ADDR_LEN);
memcpy(p80211_hdr->a3.a3, &e_hdr.saddr, WLAN_ADDR_LEN);
break;
default:
WLAN_LOG_ERROR0("Error: Converting eth to wlan in unknown mode.\n");
return 1;
break;
}
p80211_wep->data = NULL;
if ((wlandev->hostwep & HOSTWEP_PRIVACYINVOKED) && (wlandev->hostwep & HOSTWEP_ENCRYPT)) {
// XXXX need to pick keynum other than default?
#if 1
p80211_wep->data = kmalloc(skb->len, GFP_ATOMIC);
#else
p80211_wep->data = skb->data;
#endif
if ((foo = wep_encrypt(wlandev, skb->data, p80211_wep->data,
skb->len,
(wlandev->hostwep & HOSTWEP_DEFAULTKEY_MASK),
p80211_wep->iv, p80211_wep->icv))) {
WLAN_LOG_WARNING("Host en-WEP failed, dropping frame (%d).\n", foo);
return 2;
}
fc |= host2ieee16(WLAN_SET_FC_ISWEP(1));
}
// skb->nh.raw = skb->data;
p80211_hdr->a3.fc = fc;
p80211_hdr->a3.dur = 0;
p80211_hdr->a3.seq = 0;
DBFEXIT;
return 0;
}
/*----------------------------------------------------------------
* p80211pb_80211_to_ether
*
* Uses the contents of a received 802.11 frame and the etherconv
* setting to build an ether frame.
*
* This function extracts the src and dest address from the 802.11
* frame to use in the construction of the eth frame.
*
* Arguments:
* ethconv Conversion type to perform
* skb Packet buffer containing the 802.11 frame
*
* Returns:
* 0 on success, non-zero otherwise
*
* Call context:
* May be called in interrupt or non-interrupt context
----------------------------------------------------------------*/
int skb_p80211_to_ether( wlandevice_t *wlandev, UINT32 ethconv, struct sk_buff *skb)
{
netdevice_t *dev = wlandev->netdev;
UINT16 fc;
UINT payload_length;
UINT payload_offset;
UINT8 daddr[WLAN_ETHADDR_LEN];
UINT8 saddr[WLAN_ETHADDR_LEN];
p80211_hdr_t *w_hdr;
wlan_ethhdr_t *e_hdr;
wlan_llc_t *e_llc;
wlan_snap_t *e_snap;
int foo;
DBFENTER;
payload_length = skb->len - WLAN_HDR_A3_LEN - WLAN_CRC_LEN;
payload_offset = WLAN_HDR_A3_LEN;
w_hdr = (p80211_hdr_t *) skb->data;
/* setup some vars for convenience */
fc = ieee2host16(w_hdr->a3.fc);
if ( (WLAN_GET_FC_TODS(fc) == 0) && (WLAN_GET_FC_FROMDS(fc) == 0) ) {
memcpy(daddr, w_hdr->a3.a1, WLAN_ETHADDR_LEN);
memcpy(saddr, w_hdr->a3.a2, WLAN_ETHADDR_LEN);
} else if( (WLAN_GET_FC_TODS(fc) == 0) && (WLAN_GET_FC_FROMDS(fc) == 1) ) {
memcpy(daddr, w_hdr->a3.a1, WLAN_ETHADDR_LEN);
memcpy(saddr, w_hdr->a3.a3, WLAN_ETHADDR_LEN);
} else if( (WLAN_GET_FC_TODS(fc) == 1) && (WLAN_GET_FC_FROMDS(fc) == 0) ) {
memcpy(daddr, w_hdr->a3.a3, WLAN_ETHADDR_LEN);
memcpy(saddr, w_hdr->a3.a2, WLAN_ETHADDR_LEN);
} else {
payload_offset = WLAN_HDR_A4_LEN;
payload_length -= ( WLAN_HDR_A4_LEN - WLAN_HDR_A3_LEN );
if (payload_length < 0 ) {
WLAN_LOG_ERROR0("A4 frame too short!\n");
return 1;
}
memcpy(daddr, w_hdr->a4.a3, WLAN_ETHADDR_LEN);
memcpy(saddr, w_hdr->a4.a4, WLAN_ETHADDR_LEN);
}
/* perform de-wep if necessary.. */
if ((wlandev->hostwep & HOSTWEP_PRIVACYINVOKED) && WLAN_GET_FC_ISWEP(fc) && (wlandev->hostwep & HOSTWEP_DECRYPT)) {
if (payload_length <= 8) {
WLAN_LOG_ERROR("WEP frame too short (%u).\n",
skb->len);
return 1;
}
if ((foo = wep_decrypt(wlandev, skb->data + payload_offset + 4,
payload_length - 8, -1,
skb->data + payload_offset,
skb->data + payload_offset + payload_length - 4))) {
/* de-wep failed, drop skb. */
WLAN_LOG_DEBUG(1, "Host de-WEP failed, dropping frame (%d).\n", foo);
wlandev->rx.decrypt_err++;
return 2;
}
/* subtract the IV+ICV length off the payload */
payload_length -= 8;
/* chop off the IV */
skb_pull(skb, 4);
/* chop off the ICV. */
skb_trim(skb, skb->len - 4);
wlandev->rx.decrypt++;
}
e_hdr = (wlan_ethhdr_t *) (skb->data + payload_offset);
e_llc = (wlan_llc_t *) (skb->data + payload_offset);
e_snap = (wlan_snap_t *) (skb->data + payload_offset + sizeof(wlan_llc_t));
/* Test for the various encodings */
if ( (payload_length >= sizeof(wlan_ethhdr_t)) &&
( e_llc->dsap != 0xaa || e_llc->ssap != 0xaa ) &&
((memcmp(daddr, e_hdr->daddr, WLAN_ETHADDR_LEN) == 0) ||
(memcmp(saddr, e_hdr->saddr, WLAN_ETHADDR_LEN) == 0))) {
WLAN_LOG_DEBUG(3, "802.3 ENCAP len: %d\n", payload_length);
/* 802.3 Encapsulated */
/* Test for an overlength frame */
if ( payload_length > WLAN_MAX_ETHFRM_LEN) {
/* A bogus length ethfrm has been encap'd. */
/* Is someone trying an oflow attack? */
WLAN_LOG_ERROR("ENCAP frame too large (%d > %d)\n",
payload_length, WLAN_MAX_ETHFRM_LEN);
return 1;
}
/* Chop off the 802.11 header. it's already sane. */
skb_pull(skb, payload_offset);
/* chop off the 802.11 CRC */
skb_trim(skb, skb->len - WLAN_CRC_LEN);
} else if ((payload_length >= sizeof(wlan_llc_t) + sizeof(wlan_snap_t)) &&
(e_llc->dsap == 0xaa) &&
(e_llc->ssap == 0xaa) &&
(e_llc->ctl == 0x03) &&
(((memcmp( e_snap->oui, oui_rfc1042, WLAN_IEEE_OUI_LEN)==0) &&
(ethconv == WLAN_ETHCONV_8021h) &&
(p80211_stt_findproto(ieee2host16(e_snap->type)))) ||
(memcmp( e_snap->oui, oui_rfc1042, WLAN_IEEE_OUI_LEN)!=0)))
{
WLAN_LOG_DEBUG(3, "SNAP+RFC1042 len: %d\n", payload_length);
/* it's a SNAP + RFC1042 frame && protocol is in STT */
/* build 802.3 + RFC1042 */
/* Test for an overlength frame */
if ( payload_length + WLAN_ETHHDR_LEN > WLAN_MAX_ETHFRM_LEN ) {
/* A bogus length ethfrm has been sent. */
/* Is someone trying an oflow attack? */
WLAN_LOG_ERROR("SNAP frame too large (%d > %d)\n",
payload_length, WLAN_MAX_ETHFRM_LEN);
return 1;
}
/* chop 802.11 header from skb. */
skb_pull(skb, payload_offset);
/* create 802.3 header at beginning of skb. */
e_hdr = (wlan_ethhdr_t *) skb_push(skb, WLAN_ETHHDR_LEN);
memcpy(e_hdr->daddr, daddr, WLAN_ETHADDR_LEN);
memcpy(e_hdr->saddr, saddr, WLAN_ETHADDR_LEN);
e_hdr->type = htons(payload_length);
/* chop off the 802.11 CRC */
skb_trim(skb, skb->len - WLAN_CRC_LEN);
} else if ((payload_length >= sizeof(wlan_llc_t) + sizeof(wlan_snap_t)) &&
(e_llc->dsap == 0xaa) &&
(e_llc->ssap == 0xaa) &&
(e_llc->ctl == 0x03) ) {
WLAN_LOG_DEBUG(3, "802.1h/RFC1042 len: %d\n", payload_length);
/* it's an 802.1h frame || (an RFC1042 && protocol is not in STT) */
/* build a DIXII + RFC894 */
/* Test for an overlength frame */
if ( payload_length - sizeof(wlan_llc_t) - sizeof(wlan_snap_t) + WLAN_ETHHDR_LEN > WLAN_MAX_ETHFRM_LEN) {
/* A bogus length ethfrm has been sent. */
/* Is someone trying an oflow attack? */
WLAN_LOG_ERROR("DIXII frame too large (%d > %d)\n",
payload_length - sizeof(wlan_llc_t) - sizeof(wlan_snap_t),
WLAN_MAX_ETHFRM_LEN - WLAN_ETHHDR_LEN);
return 1;
}
/* chop 802.11 header from skb. */
skb_pull(skb, payload_offset);
/* chop llc header from skb. */
skb_pull(skb, sizeof(wlan_llc_t));
/* chop snap header from skb. */
skb_pull(skb, sizeof(wlan_snap_t));
/* create 802.3 header at beginning of skb. */
e_hdr = (wlan_ethhdr_t *) skb_push(skb, WLAN_ETHHDR_LEN);
e_hdr->type = e_snap->type;
memcpy(e_hdr->daddr, daddr, WLAN_ETHADDR_LEN);
memcpy(e_hdr->saddr, saddr, WLAN_ETHADDR_LEN);
/* chop off the 802.11 CRC */
skb_trim(skb, skb->len - WLAN_CRC_LEN);
} else {
WLAN_LOG_DEBUG(3, "NON-ENCAP len: %d\n", payload_length);
/* any NON-ENCAP */
/* it's a generic 80211+LLC or IPX 'Raw 802.3' */
/* build an 802.3 frame */
/* allocate space and setup hostbuf */
/* Test for an overlength frame */
if ( payload_length + WLAN_ETHHDR_LEN > WLAN_MAX_ETHFRM_LEN) {
/* A bogus length ethfrm has been sent. */
/* Is someone trying an oflow attack? */
WLAN_LOG_ERROR("OTHER frame too large (%d > %d)\n",
payload_length,
WLAN_MAX_ETHFRM_LEN - WLAN_ETHHDR_LEN);
return 1;
}
/* Chop off the 802.11 header. */
skb_pull(skb, payload_offset);
/* create 802.3 header at beginning of skb. */
e_hdr = (wlan_ethhdr_t *) skb_push(skb, WLAN_ETHHDR_LEN);
memcpy(e_hdr->daddr, daddr, WLAN_ETHADDR_LEN);
memcpy(e_hdr->saddr, saddr, WLAN_ETHADDR_LEN);
e_hdr->type = htons(payload_length);
/* chop off the 802.11 CRC */
skb_trim(skb, skb->len - WLAN_CRC_LEN);
}
skb->protocol = eth_type_trans(skb, dev);
skb->mac.raw = (unsigned char *) e_hdr; /* new MAC header */
DBFEXIT;
return 0;
}
/*----------------------------------------------------------------
* p80211_stt_findproto
*
* Searches the 802.1h Selective Translation Table for a given
* protocol.
*
* Arguments:
* proto protocl number (in host order) to search for.
*
* Returns:
* 1 - if the table is empty or a match is found.
* 0 - if the table is non-empty and a match is not found.
*
* Call context:
* May be called in interrupt or non-interrupt context
----------------------------------------------------------------*/
int p80211_stt_findproto(UINT16 proto)
{
/* Always return found for now. This is the behavior used by the */
/* Zoom Win95 driver when 802.1h mode is selected */
/* TODO: If necessary, add an actual search we'll probably
need this to match the CMAC's way of doing things.
Need to do some testing to confirm.
*/
if (proto == 0x80f3) /* APPLETALK */
return 1;
return 0;
}
#if 0
/* MSM: This function is currently unused. Not sure if we'll ever need it. */
/*----------------------------------------------------------------
* p80211_stt_addproto
*
* Add a protocol to the 802.1h Selective Translation Table.
*
* Arguments:
* proto protocl number (in host order) to search for.
*
* Returns:
* nothing
*
* Call context:
* May be called in interrupt or non-interrupt context
----------------------------------------------------------------*/
int p80211_stt_addproto(UINT16 proto)
{
return;
}
#endif
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