ieee80211_monitor.c

madwifi上的atheros无线网卡驱动源码

/*-
 * Copyright (c) 2005 John Bicket
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * $Id: ieee80211_monitor.c 3298 2008-01-29 02:21:47Z br1 $
 */

#ifndef EXPORT_SYMTAB
#define	EXPORT_SYMTAB
#endif

/*
 * IEEE 802.11 monitor mode 
 */
#ifndef AUTOCONF_INCLUDED
#include <linux/config.h>
#endif
#include <linux/version.h>
#include <linux/module.h>
#include <linux/kmod.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/sysctl.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/if_vlan.h>

#include <net/iw_handler.h>
#include <linux/wireless.h>
#include <linux/if_arp.h>		/* XXX for ARPHRD_* */

#include <asm/uaccess.h>

#include "if_media.h"
#include "if_ethersubr.h"

#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_monitor.h>
#include <ath/if_athvar.h>



static int
ratecode_to_dot11(int ratecode)
{
        switch (ratecode) {
                /* a */
        case 0x0b: return 12;
        case 0x0f: return 18;
        case 0x0a: return 24;
        case 0x0e: return 36;
        case 0x09: return 48;
        case 0x0d: return 72;
        case 0x08: return 96;
        case 0x0c: return 108;

        case 0x1b: return 2;
        case 0x1a: return 4;
        case 0x1e: return 4;
        case 0x19: return 11;
        case 0x1d: return 11;
        case 0x18: return 22;
        case 0x1c: return 22;
        }
        return 0;
}

struct ar5212_openbsd_desc {
	/*
	 * tx_control_0
	 */
	u_int32_t frame_len:12;
	u_int32_t reserved_12_15:4;
	u_int32_t xmit_power:6;
	u_int32_t rts_cts_enable:1;
	u_int32_t veol:1;
	u_int32_t clear_dest_mask:1;
	u_int32_t ant_mode_xmit:4;
	u_int32_t inter_req:1;
	u_int32_t encrypt_key_valid:1;
	u_int32_t cts_enable:1;

	u_int32_t r1;

	/*
	 * tx_control_2
	 */
	u_int32_t rts_duration:15;
	u_int32_t duration_update_enable:1;
	u_int32_t xmit_tries0:4;
	u_int32_t xmit_tries1:4;
	u_int32_t xmit_tries2:4;
	u_int32_t xmit_tries3:4;

	/*
	 * tx_control_3
	 */
	u_int32_t xmit_rate0:5;
	u_int32_t xmit_rate1:5;
	u_int32_t xmit_rate2:5;
	u_int32_t xmit_rate3:5;
	u_int32_t rts_cts_rate:5;
	u_int32_t reserved_25_31:7;
};

void
ieee80211_monitor_encap(struct ieee80211vap *vap, struct sk_buff *skb) 
{
	struct ieee80211_cb *cb = (struct ieee80211_cb *) skb->cb;
	struct ieee80211_phy_params *ph =
		(struct ieee80211_phy_params *) (skb->cb + sizeof(struct ieee80211_cb));
	cb->flags = M_RAW;
	cb->ni = NULL;
	cb->next = NULL;
	memset(ph, 0, sizeof(struct ieee80211_phy_params));

	/* send at a static rate if it is configured */
	ph->rate0 = vap->iv_fixed_rate > 0 ? vap->iv_fixed_rate : 2;
	/* don't retry control packets */
	ph->try0 = 11;
	ph->power = 60;

	switch (skb->dev->type) {
	case ARPHRD_IEEE80211: {
		struct ieee80211_frame *wh = (struct ieee80211_frame *) skb->data;
		if ((wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) == IEEE80211_FC0_TYPE_CTL) 
			ph->try0 = 1;
		break;
	}
	case ARPHRD_IEEE80211_PRISM: {
		struct ieee80211_frame *wh = NULL;
		wlan_ng_prism2_header *p2h = 
			(wlan_ng_prism2_header *) skb->data;
		/* does it look like there is a prism header here? */
		if (skb->len > sizeof (wlan_ng_prism2_header) &&
                    p2h->msgcode == DIDmsg_lnxind_wlansniffrm &&
		    p2h->rate.did == DIDmsg_lnxind_wlansniffrm_rate) {
                        ph->rate0 = p2h->rate.data;
                        skb_pull(skb, sizeof(wlan_ng_prism2_header));
		}
		wh = (struct ieee80211_frame *) skb->data;
		if ((wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) == IEEE80211_FC0_TYPE_CTL) 
			ph->try0 = 1;
                break;
	}
	case ARPHRD_IEEE80211_RADIOTAP: {
		struct ieee80211_frame *wh = NULL;
		struct ieee80211_radiotap_header *rh =
			(struct ieee80211_radiotap_header *)skb->data;
		u_int32_t present, present_ext;
		u_int16_t len;
		u_int8_t *start = skb->data + sizeof(struct ieee80211_radiotap_header);
		u_int8_t *p = start;
		u_int8_t *end = skb->data + skb->len;
		u_int8_t bit, flags = 0;

		if (skb->len < sizeof(*rh) || rh->it_version != 0)
			break;

		present_ext = present = le32_to_cpu(rh->it_present);
		len = le16_to_cpu(rh->it_len);

		if (skb->len < len)
			break;

		/* skip the chain of additional bitmaps following it_present */
		while (present_ext & (1 << IEEE80211_RADIOTAP_EXT)) {
			if (p+4 > end) {
				/* An extended bitmap would now follow, but there is 
				 * no place for it. Stop parsing. */
				present = 0;
				break;
			}
			present_ext = le32_to_cpu(*(__le32 *)p);
			p += 4;
		}

		for (bit = 0; present && p < end; present >>= 1, bit++) {
			if ((present & 1) == 0)
				continue;
			switch (bit) {
				case IEEE80211_RADIOTAP_RATE:
					ph->rate0 = *p;
					p++;
					break;

				case IEEE80211_RADIOTAP_DBM_TX_POWER:
					ph->power = *p;
					p++;
					break;

				case IEEE80211_RADIOTAP_FLAGS:
					flags = *p;
					p++;
					break;

				case IEEE80211_RADIOTAP_DB_ANTSIGNAL:
				case IEEE80211_RADIOTAP_DB_ANTNOISE:
				case IEEE80211_RADIOTAP_ANTENNA:
				case IEEE80211_RADIOTAP_DBM_ANTSIGNAL:
				case IEEE80211_RADIOTAP_DBM_ANTNOISE:
					/* 8-bit */
					p++;
					break;

				case IEEE80211_RADIOTAP_FHSS:
					/* 2 x 8-bit */
					p += 2;
					break;

				case IEEE80211_RADIOTAP_LOCK_QUALITY:
				case IEEE80211_RADIOTAP_TX_ATTENUATION:
				case IEEE80211_RADIOTAP_DB_TX_ATTENUATION:
					/* 16-bit */
					p = start + roundup(p - start, 2) + 2;
					break;

				case IEEE80211_RADIOTAP_CHANNEL:
					/* 2 x 16-bit */
					p = start + roundup(p - start, 2) + 4;
					break;

				case IEEE80211_RADIOTAP_TSFT:
					/* 64-bit */
					p = start + roundup(p - start, 8) + 8;
					break;

				case IEEE80211_RADIOTAP_DATA_RETRIES:
					ph->try0 = *p + 1;
					p++;
					break;

				default:
					present = 0;
					break;
			}
		}
		skb_pull(skb, len);
		if (flags & IEEE80211_RADIOTAP_F_FCS)
			/* Remove FCS from the end of frames to transmit */
			skb_trim(skb, skb->len - IEEE80211_CRC_LEN);
		wh = (struct ieee80211_frame *)skb->data;

		if (!ph->try0 &&
		    (wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) == IEEE80211_FC0_TYPE_CTL)
			ph->try0 = 1;
                break;
	}
	case ARPHRD_IEEE80211_ATHDESC: {
		if (skb->len > ATHDESC_HEADER_SIZE) {
			struct ar5212_openbsd_desc *desc =
				(struct ar5212_openbsd_desc *) (skb->data + 8);
			ph->power = desc->xmit_power;
			ph->rate0 = ratecode_to_dot11(desc->xmit_rate0);
			ph->rate1 = ratecode_to_dot11(desc->xmit_rate1);
			ph->rate2 = ratecode_to_dot11(desc->xmit_rate2);
			ph->rate3 = ratecode_to_dot11(desc->xmit_rate3);
			ph->try0 = desc->xmit_tries0;
			ph->try1 = desc->xmit_tries1;
			ph->try2 = desc->xmit_tries2;
			ph->try3 = desc->xmit_tries3;
			skb_pull(skb, ATHDESC_HEADER_SIZE);
		}
		break;
	}	
	default:
		break;
	}