ieee80211_output.c

madwifi上的atheros无线网卡驱动源码

/*-
 * Copyright (c) 2001 Atsushi Onoe
 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
 * 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.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * 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_output.c 3058 2007-12-13 06:21:32Z br1 $
 */
#ifndef EXPORT_SYMTAB
#define	EXPORT_SYMTAB
#endif

/*
 * IEEE 802.11 output handling.
 */
#ifndef AUTOCONF_INCLUDED
#include <linux/config.h>
#endif
#include <linux/version.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/if_vlan.h>

#include <linux/ip.h>			/* XXX for TOS */

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

#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_monitor.h>
#include <net80211/if_athproto.h>

#ifdef IEEE80211_DEBUG
/*
 * Decide if an outbound management frame should be
 * printed when debugging is enabled.  This filters some
 * of the less interesting frames that come frequently
 * (e.g. beacons).
 */
static __inline int
doprint(struct ieee80211vap *vap, int subtype)
{
	if (subtype == IEEE80211_FC0_SUBTYPE_PROBE_RESP)
		return (vap->iv_opmode == IEEE80211_M_IBSS);
	return 1;
}
#endif


/*
 * Determine the priority based on VLAN and/or IP TOS. Priority is
 * written into the skb->priority field. On success, returns 0. Failure
 * due to bad or mis-matched vlan tag is indicated by non-zero return.
 */
static int 
ieee80211_classify(struct ieee80211_node *ni, struct sk_buff *skb)
{
	struct ieee80211vap *vap = ni->ni_vap;
	struct ether_header *eh = (struct ether_header *) skb->data;
	int v_wme_ac = 0, d_wme_ac = 0;

	/* default priority */
	skb->priority = WME_AC_BE;

	if (!(ni->ni_flags & IEEE80211_NODE_QOS)) 
		return 0;

	/* 
	 * If node has a vlan tag then all traffic
	 * to it must have a matching vlan id.
	 */
	if (ni->ni_vlan != 0 && vlan_tx_tag_present(skb)) {
		u_int32_t tag=0;
		int v_pri;

		if (vap->iv_vlgrp == NULL) {
			IEEE80211_NODE_STAT(ni, tx_novlantag);
			ni->ni_stats.ns_tx_novlantag++;
			return 1;
		}
		if (((tag = vlan_tx_tag_get(skb)) & VLAN_VID_MASK) != 
		    (ni->ni_vlan & VLAN_VID_MASK)) {
			IEEE80211_NODE_STAT(ni, tx_vlanmismatch);
			ni->ni_stats.ns_tx_vlanmismatch++;
			return 1;
		}
		if (ni->ni_flags & IEEE80211_NODE_QOS) {
			v_pri = (tag >> VLAN_PRI_SHIFT) & VLAN_PRI_MASK;
			switch (v_pri) {
			case 1:
			case 2:		/* Background (BK) */
				v_wme_ac = WME_AC_BK;
				break;
			case 0:
			case 3:		/* Best Effort (BE) */
				v_wme_ac = WME_AC_BE;
				break;
			case 4:
			case 5:		/* Video (VI) */
				v_wme_ac = WME_AC_VI;
				break;
			case 6:
			case 7:		/* Voice (VO) */
				v_wme_ac = WME_AC_VO;
				break;
			}
		}
	}

	if (eh->ether_type == __constant_htons(ETHERTYPE_IP)) {
		const struct iphdr *ip = (struct iphdr *)
			(skb->data + sizeof (struct ether_header));
		/*
		 * IP frame, map the TOS field.
		 *
		 * XXX: fill out these mappings???
		 */
		switch(ip->tos) {
		case 0x08:				/* Background */
		case 0x20:
			d_wme_ac = WME_AC_BK;
			break;
		case 0x28:				/* Video */
		case 0xa0:
			d_wme_ac = WME_AC_VI;
			break;
		case 0x30:				/* Voice */
		case 0xe0:
		case 0x88:				/* XXX UPSD */
		case 0xb8:
			d_wme_ac = WME_AC_VO;
			break;
		default:				/* All others */
			d_wme_ac = WME_AC_BE;
			break;
		}
	} else {
		d_wme_ac = WME_AC_BE;
	}
	skb->priority = d_wme_ac;
	if (v_wme_ac > d_wme_ac)
		skb->priority = v_wme_ac;

	/* Applying ACM policy */
	if (vap->iv_opmode == IEEE80211_M_STA) {
		struct ieee80211com *ic = ni->ni_ic;

		while (skb->priority != WME_AC_BK &&
		    ic->ic_wme.wme_wmeBssChanParams.cap_wmeParams[skb->priority].wmep_acm) {
			switch (skb->priority) {
			case WME_AC_BE:
				skb->priority = WME_AC_BK;
				break;
			case WME_AC_VI:
				skb->priority = WME_AC_BE;
				break;
			case WME_AC_VO:
				skb->priority = WME_AC_VI;
				break;
			default:
				skb->priority = WME_AC_BK;
				break;
			}
		}
	}
	
	return 0;
}

/*
 * Context: process context (BH's disabled)
 */
int
ieee80211_hardstart(struct sk_buff *skb, struct net_device *dev)
{
	struct ieee80211vap *vap = dev->priv;
	struct ieee80211com *ic = vap->iv_ic;
	struct net_device *parent = ic->ic_dev;
	struct ieee80211_node *ni = NULL;
	struct ieee80211_cb *cb;
	struct ether_header *eh;

	/* NB: parent must be up and running */
	if ((parent->flags & (IFF_RUNNING|IFF_UP)) != (IFF_RUNNING|IFF_UP))
		goto bad;
	/*
	 * No data frames go out unless we're running.
	 */
	if (vap->iv_state != IEEE80211_S_RUN) {
		IEEE80211_DPRINTF(vap, IEEE80211_MSG_OUTPUT,
			"%s: ignore data packet, state %u\n",
			__func__, vap->iv_state);
#if 0
		vap->iv_stats.ist_tx_discard++;
#endif
		goto bad;
	}

	cb = (struct ieee80211_cb *) skb->cb;
	memset(cb, 0, sizeof(struct ieee80211_cb));
	
        if (vap->iv_opmode == IEEE80211_M_MONITOR) {
		ieee80211_monitor_encap(vap, skb);
                ieee80211_parent_queue_xmit(skb);
                return 0;
        }
	if (ic->ic_flags & IEEE80211_F_SCAN)		/* cancel bg scan */
		ieee80211_cancel_scan(vap);
	/* 
	 * Find the node for the destination so we can do
	 * things like power save.
	 */
	eh = (struct ether_header *)skb->data;
	if (vap->iv_opmode == IEEE80211_M_WDS)
		ni = ieee80211_find_txnode(vap, vap->wds_mac);
	else
		ni = ieee80211_find_txnode(vap, eh->ether_dhost);

	if (ni == NULL) {
		/* NB: ieee80211_find_txnode does stat+msg */
		goto bad;
	}
	/* calculate priority so drivers can find the TX queue */
	if (ieee80211_classify(ni, skb)) {
		IEEE80211_NOTE(vap, IEEE80211_MSG_OUTPUT, ni,
			"%s: discard, classification failure", __func__);
		goto bad;
	}
	
	cb->ni = ni;
	
	/* power-save checks */
	if (WME_UAPSD_AC_CAN_TRIGGER(skb->priority, ni)) {
		/* U-APSD power save queue */
		/* XXXAPSD: assuming triggerable means deliverable */
		M_FLAG_SET(skb, M_UAPSD);
	} else if ((ni->ni_flags & IEEE80211_NODE_PWR_MGT)) {
		/*
		 * Station in power save mode; stick the frame
		 * on the sta's power save queue and continue.
		 * We'll get the frame back when the time is right.
		 */
		ieee80211_pwrsave(ni, skb);
		return 0;
	}

#ifdef ATH_SUPERG_XR
	/* 
	 * broadcast/multicast  packets need to be sent on XR vap in addition to
	 * normal vap.
	 */

	/* FIXME: ieee80211_parent_queue_xmit */
	if (vap->iv_xrvap && ni == vap->iv_bss &&
	    vap->iv_xrvap->iv_sta_assoc) {
		struct sk_buff *skb1;
		ni = ieee80211_find_txnode(vap->iv_xrvap, eh->ether_dhost);
		skb1 = skb_clone(skb,GFP_ATOMIC);
		if (skb1) {
			cb = (struct ieee80211_cb *) skb1->cb;
			cb->ni = ni;
			cb->flags = 0;
			cb->next = NULL;
			(void) dev_queue_xmit(skb1);
		}
	}
#endif
	ieee80211_parent_queue_xmit(skb);
	return 0;

bad:
	if (skb != NULL)
		dev_kfree_skb(skb);
	if (ni != NULL)
		ieee80211_free_node(ni);
	return 0;
}

void ieee80211_parent_queue_xmit(struct sk_buff *skb) {
	struct ieee80211vap *vap = skb->dev->priv;

	vap->iv_devstats.tx_packets++;
	vap->iv_devstats.tx_bytes += skb->len;
	vap->iv_ic->ic_lastdata = jiffies;

	// Dispatch the packet to the parent device
	skb->dev = vap->iv_ic->ic_dev;
	(void) dev_queue_xmit(skb);
}

/*
 * Set the direction field and address fields of an outgoing
 * non-QoS frame.  Note this should be called early on in
 * constructing a frame as it sets i_fc[1]; other bits can
 * then be or'd in.
 */
static void
ieee80211_send_setup(struct ieee80211vap *vap,
	struct ieee80211_node *ni,
	struct ieee80211_frame *wh,
	int type,
	const u_int8_t sa[IEEE80211_ADDR_LEN],
	const u_int8_t da[IEEE80211_ADDR_LEN],
	const u_int8_t bssid[IEEE80211_ADDR_LEN])
{
#define	WH4(wh)	((struct ieee80211_frame_addr4 *)wh)

	wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | type;
	if ((type & IEEE80211_FC0_TYPE_MASK) == IEEE80211_FC0_TYPE_DATA) {
		switch (vap->iv_opmode) {
		case IEEE80211_M_STA:
			wh->i_fc[1] = IEEE80211_FC1_DIR_TODS;
			IEEE80211_ADDR_COPY(wh->i_addr1, bssid);
			IEEE80211_ADDR_COPY(wh->i_addr2, sa);
			IEEE80211_ADDR_COPY(wh->i_addr3, da);
			break;
		case IEEE80211_M_IBSS:
		case IEEE80211_M_AHDEMO:
			wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
			IEEE80211_ADDR_COPY(wh->i_addr1, da);
			IEEE80211_ADDR_COPY(wh->i_addr2, sa);
			IEEE80211_ADDR_COPY(wh->i_addr3, bssid);
			break;
		case IEEE80211_M_HOSTAP:
			wh->i_fc[1] = IEEE80211_FC1_DIR_FROMDS;
			IEEE80211_ADDR_COPY(wh->i_addr1, da);
			IEEE80211_ADDR_COPY(wh->i_addr2, bssid);
			IEEE80211_ADDR_COPY(wh->i_addr3, sa);
			break;
		case IEEE80211_M_WDS:
			wh->i_fc[1] = IEEE80211_FC1_DIR_DSTODS;
			/* XXX cheat, bssid holds RA */
			IEEE80211_ADDR_COPY(wh->i_addr1, bssid);
			IEEE80211_ADDR_COPY(wh->i_addr2, vap->iv_myaddr);
			IEEE80211_ADDR_COPY(wh->i_addr3, da);
			IEEE80211_ADDR_COPY(WH4(wh)->i_addr4, sa);
			break;
		case IEEE80211_M_MONITOR:	/* NB: to quiet compiler */
			break;
		}
	} else {
		wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
		IEEE80211_ADDR_COPY(wh->i_addr1, da);
		IEEE80211_ADDR_COPY(wh->i_addr2, sa);
		IEEE80211_ADDR_COPY(wh->i_addr3, bssid);
	}
	wh->i_dur = 0;
	/* NB: use non-QoS tid */
	*(__le16 *)&wh->i_seq[0] =
	    htole16(ni->ni_txseqs[0] << IEEE80211_SEQ_SEQ_SHIFT);
	ni->ni_txseqs[0]++;
#undef WH4
}

/*
 * Send a management frame to the specified node.  The node pointer
 * must have a reference as the pointer will be passed to the driver
 * and potentially held for a long time.  If the frame is successfully
 * dispatched to the driver, then it is responsible for freeing the
 * reference (and potentially freeing up any associated storage).
 */
static void
ieee80211_mgmt_output(struct ieee80211_node *ni, struct sk_buff *skb, int type)
{
	struct ieee80211vap *vap = ni->ni_vap;
	struct ieee80211com *ic = ni->ni_ic;
	struct ieee80211_frame *wh;
	struct ieee80211_cb *cb = (struct ieee80211_cb *)skb->cb;

	KASSERT(ni != NULL, ("null node"));

	cb->ni = ni;

	wh = (struct ieee80211_frame *)
		skb_push(skb, sizeof(struct ieee80211_frame));
	ieee80211_send_setup(vap, ni, wh, 
		IEEE80211_FC0_TYPE_MGT | type,
		vap->iv_myaddr, ni->ni_macaddr, vap->iv_bss->ni_bssid);
	/* XXX power management */

	if ((cb->flags & M_LINK0) != 0 && ni->ni_challenge != NULL) {
		cb->flags &= ~M_LINK0;
		IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_AUTH, wh->i_addr1,
			"encrypting frame (%s)", __func__);
		wh->i_fc[1] |= IEEE80211_FC1_PROT;
	}

	if (IEEE80211_VAP_IS_SLEEPING(ni->ni_vap))
		wh->i_fc[1] |= IEEE80211_FC1_PWR_MGT;

#ifdef IEEE80211_DEBUG
	/* avoid printing too many frames */
	if ((ieee80211_msg_debug(vap) && doprint(vap, type)) ||
	    ieee80211_msg_dumppkts(vap)) {
		printf("[%s] send %s on channel %u\n",
			ether_sprintf(wh->i_addr1),
			ieee80211_mgt_subtype_name[
				(type & IEEE80211_FC0_SUBTYPE_MASK) >>
					IEEE80211_FC0_SUBTYPE_SHIFT],
		    	ieee80211_chan2ieee(ic, ic->ic_curchan));
	}
#endif
	IEEE80211_NODE_STAT(ni, tx_mgmt);

	(void) ic->ic_mgtstart(ic, skb);
}

/*
 * Send a null data frame to the specified node.
 *
 * NB: the caller is assumed to have setup a node reference
 *     for use; this is necessary to deal with a race condition
 *     when probing for inactive stations.
 */
int
ieee80211_send_nulldata(struct ieee80211_node *ni)
{
	struct ieee80211vap *vap = ni->ni_vap;
	struct ieee80211com *ic = ni->ni_ic;
	struct sk_buff *skb;
	struct ieee80211_cb *cb;
	struct ieee80211_frame *wh;
	u_int8_t *frm;

	skb = ieee80211_getmgtframe(&frm, 0);
	if (skb == NULL) {
		/* XXX debug msg */