drivers/staging/wlan-ng/p80211conv.c

/* 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/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 <linux/if_ether.h>

#include <asm/byteorder.h>

#include "wlan_compat.h"

/*================================================================*/
/* Project Includes */

#include "p80211types.h"
#include "p80211hdr.h"
#include "p80211conv.h"
#include "p80211mgmt.h"
#include "p80211msg.h"
#include "p80211netdev.h"
#include "p80211ioctl.h"
#include "p80211req.h"


/*================================================================*/
/* Local Constants */

/*================================================================*/
/* Local Macros */


/*================================================================*/
/* Local Types */


/*================================================================*/
/* Local Static Definitions */

static u8	oui_rfc1042[] = {0x00, 0x00, 0x00};
static u8	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, u32 ethconv, struct sk_buff *skb, p80211_hdr_t *p80211_hdr, p80211_metawep_t *p80211_wep)
{

	u16          fc;
	u16          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_DEBUG(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_ERROR("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;
}

/* jkriegl: from orinoco, modified */
static void orinoco_spy_gather(wlandevice_t *wlandev, char *mac,
			       p80211_rxmeta_t *rxmeta)
{
        int i;

        /* Gather wireless spy statistics: for each packet, compare the
         * source address with out list, and if match, get the stats... */

        for (i = 0; i < wlandev->spy_number; i++) {

                if (!memcmp(wlandev->spy_address[i], mac, ETH_ALEN)) {
			memcpy(wlandev->spy_address[i], mac, ETH_ALEN);
                        wlandev->spy_stat[i].level = rxmeta->signal;
                        wlandev->spy_stat[i].noise = rxmeta->noise;
                        wlandev->spy_stat[i].qual = (rxmeta->signal > rxmeta->noise) ? \
                                                     (rxmeta->signal - rxmeta->noise) : 0;
                        wlandev->spy_stat[i].updated = 0x7;
                }
        }
}

/*----------------------------------------------------------------
* 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, u32 ethconv, struct sk_buff *skb)
{
	netdevice_t     *netdev = wlandev->netdev;
	u16          fc;
	unsigned int            payload_length;
	unsigned int            payload_offset;
	u8		daddr[WLAN_ETHADDR_LEN];
	u8		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_ERROR("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 */

		/* 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 */

		/* 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 */

		/* 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 */

		/* 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, netdev);
	skb_reset_mac_header(skb);

        /* jkriegl: process signal and noise as set in hfa384x_int_rx() */
	/* jkriegl: only process signal/noise if requested by iwspy */
        if (wlandev->spy_number)
                orinoco_spy_gather(wlandev, eth_hdr(skb)->h_source, P80211SKB_RXMETA(skb));

	/* Free the metadata */
	p80211skb_rxmeta_detach(skb);

	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(u16 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;
}

/*----------------------------------------------------------------
* p80211skb_rxmeta_detach
*
* Disconnects the frmmeta and rxmeta from an skb.
*
* Arguments:
*	wlandev		The wlandev this skb belongs to.
*	skb		The skb we're attaching to.
*
* Returns:
*	0 on success, non-zero otherwise
*
* Call context:
*	May be called in interrupt or non-interrupt context
----------------------------------------------------------------*/
void
p80211skb_rxmeta_detach(struct sk_buff *skb)
{
	p80211_rxmeta_t		*rxmeta;
	p80211_frmmeta_t	*frmmeta;

	DBFENTER;
	/* Sanity checks */
	if ( skb==NULL ) {			/* bad skb */
		WLAN_LOG_DEBUG(1, "Called w/ null skb.\n");
		goto exit;
	}
	frmmeta = P80211SKB_FRMMETA(skb);
	if ( frmmeta == NULL ) { 		/* no magic */
		WLAN_LOG_DEBUG(1, "Called w/ bad frmmeta magic.\n");
		goto exit;
	}
	rxmeta = frmmeta->rx;
	if ( rxmeta == NULL ) {			/* bad meta ptr */
		WLAN_LOG_DEBUG(1, "Called w/ bad rxmeta ptr.\n");
		goto exit;
	}

	/* Free rxmeta */
	kfree(rxmeta);

	/* Clear skb->cb */
	memset(skb->cb, 0, sizeof(skb->cb));
exit:
	DBFEXIT;
	return;
}

/*----------------------------------------------------------------
* p80211skb_rxmeta_attach
*
* Allocates a p80211rxmeta structure, initializes it, and attaches
* it to an skb.
*
* Arguments:
*	wlandev		The wlandev this skb belongs to.
*	skb		The skb we're attaching to.
*
* Returns:
*	0 on success, non-zero otherwise
*
* Call context:
*	May be called in interrupt or non-interrupt context
----------------------------------------------------------------*/
int
p80211skb_rxmeta_attach(struct wlandevice *wlandev, struct sk_buff *skb)
{
	int			result = 0;
	p80211_rxmeta_t		*rxmeta;
	p80211_frmmeta_t	*frmmeta;

	DBFENTER;

	/* If these already have metadata, we error out! */
	if (P80211SKB_RXMETA(skb) != NULL) {
		WLAN_LOG_ERROR("%s: RXmeta already attached!\n",
				wlandev->name);
		result = 0;
		goto exit;
	}

	/* Allocate the rxmeta */
	rxmeta = kmalloc(sizeof(p80211_rxmeta_t), GFP_ATOMIC);

	if ( rxmeta == NULL ) {
		WLAN_LOG_ERROR("%s: Failed to allocate rxmeta.\n",
				wlandev->name);
		result = 1;
		goto exit;
	}

	/* Initialize the rxmeta */
	memset(rxmeta, 0, sizeof(p80211_rxmeta_t));
	rxmeta->wlandev = wlandev;
	rxmeta->hosttime = jiffies;

	/* Overlay a frmmeta_t onto skb->cb */
	memset(skb->cb, 0, sizeof(p80211_frmmeta_t));
	frmmeta = (p80211_frmmeta_t*)(skb->cb);
	frmmeta->magic = P80211_FRMMETA_MAGIC;
	frmmeta->rx = rxmeta;
exit:
	DBFEXIT;
	return result;
}

/*----------------------------------------------------------------
* p80211skb_free
*
* Frees an entire p80211skb by checking and freeing the meta struct
* and then freeing the skb.
*
* Arguments:
*	wlandev		The wlandev this skb belongs to.
*	skb		The skb we're attaching to.
*
* Returns:
*	0 on success, non-zero otherwise
*
* Call context:
*	May be called in interrupt or non-interrupt context
----------------------------------------------------------------*/
void
p80211skb_free(struct wlandevice *wlandev, struct sk_buff *skb)
{
	p80211_frmmeta_t	*meta;
	DBFENTER;
	meta = P80211SKB_FRMMETA(skb);
	if ( meta && meta->rx) {
		p80211skb_rxmeta_detach(skb);
	} else {
		WLAN_LOG_ERROR("Freeing an skb (%p) w/ no frmmeta.\n", skb);
	}

	dev_kfree_skb(skb);
	DBFEXIT;
	return;
}