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Commit 3c5772a5 authored by Javier Cardona's avatar Javier Cardona Committed by John W. Linville
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mac80211: Use 3-address format for mesh broadcast frames. 



The 11s task group recently changed the frame mesh multicast/broadcast frame
format to use 3-address.  This was done to avoid interactions with widely
deployed lazy-WDS access points.

This patch changes the format of group addressed frames, both mesh-originated
and proxied, to use the data format defined in draft D2.08 and forward.  The
address fields used for group addressed frames is:

In 802.11 header
 ToDS:0  FromDS:1
 addr1: DA  (broadcast/multicast address)
 addr2: TA
 addr3: Mesh SA

In address extension header:
 addr4: SA  (only present if frame was proxied)

Note that this change breaks backward compatibility with earlier mesh stack
versions.

Signed-off-by: default avatarAndrey Yurovsky <andrey@cozybit.com>
Signed-off-by: default avatarJavier Cardona <javier@cozybit.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent a9e3091b

net/mac80211/mesh.c

+58 −4
Original line number Diff line number Diff line
@@ -398,22 +398,76 @@ endgrow: 
	return NULL;

}



/**

 * ieee80211_fill_mesh_addresses - fill addresses of a locally originated mesh frame

 * @hdr:    	802.11 frame header

 * @fc:		frame control field

 * @meshda:	destination address in the mesh

 * @meshsa:	source address address in the mesh.  Same as TA, as frame is

 *              locally originated.

 *

 * Return the length of the 802.11 (does not include a mesh control header)

 */

int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc, char

		*meshda, char *meshsa) {

	if (is_multicast_ether_addr(meshda)) {

		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);

		/* DA TA SA */

		memcpy(hdr->addr1, meshda, ETH_ALEN);

		memcpy(hdr->addr2, meshsa, ETH_ALEN);

		memcpy(hdr->addr3, meshsa, ETH_ALEN);

		return 24;

	} else {

		*fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |

				IEEE80211_FCTL_TODS);

		/* RA TA DA SA */

		memset(hdr->addr1, 0, ETH_ALEN);   /* RA is resolved later */

		memcpy(hdr->addr2, meshsa, ETH_ALEN);

		memcpy(hdr->addr3, meshda, ETH_ALEN);

		memcpy(hdr->addr4, meshsa, ETH_ALEN);

		return 30;

	}

}



/**

 * ieee80211_new_mesh_header - create a new mesh header

 * @meshhdr:    uninitialized mesh header

 * @sdata:	mesh interface to be used

 * @addr4:	addr4 of the mesh frame (1st in ae header)

 *              may be NULL

 * @addr5:	addr5 of the mesh frame (1st or 2nd in ae header)

 *              may be NULL unless addr6 is present

 * @addr6:	addr6 of the mesh frame (2nd or 3rd in ae header)

 * 		may be NULL unless addr5 is present

 *

 * Return the header length.

 */

int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,

		struct ieee80211_sub_if_data *sdata)

		struct ieee80211_sub_if_data *sdata, char *addr4,

		char *addr5, char *addr6)

{

	meshhdr->flags = 0;

	int aelen = 0;

	memset(meshhdr, 0, sizeof(meshhdr));

	meshhdr->ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;

	put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &meshhdr->seqnum);

	sdata->u.mesh.mesh_seqnum++;



	return 6;

	if (addr4) {

		meshhdr->flags |= MESH_FLAGS_AE_A4;

		aelen += ETH_ALEN;

		memcpy(meshhdr->eaddr1, addr4, ETH_ALEN);

	}

	if (addr5 && addr6) {

		meshhdr->flags |= MESH_FLAGS_AE_A5_A6;

		aelen += 2 * ETH_ALEN;

		if (!addr4) {

			memcpy(meshhdr->eaddr1, addr5, ETH_ALEN);

			memcpy(meshhdr->eaddr2, addr6, ETH_ALEN);

		} else {

			memcpy(meshhdr->eaddr2, addr5, ETH_ALEN);

			memcpy(meshhdr->eaddr3, addr6, ETH_ALEN);

		}

	}

	return 6 + aelen;

}



static void ieee80211_mesh_housekeeping(struct ieee80211_sub_if_data *sdata,

net/mac80211/mesh.h

+4 −1
Original line number Diff line number Diff line
@@ -193,8 +193,11 @@ struct mesh_rmc { 


/* Public interfaces */

/* Various */

int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,

		char *da, char *sa);

int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,

		struct ieee80211_sub_if_data *sdata);

		struct ieee80211_sub_if_data *sdata, char *addr4,

		char *addr5, char *addr6);

int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,

		struct ieee80211_sub_if_data *sdata);

bool mesh_matches_local(struct ieee802_11_elems *ie,

net/mac80211/rx.c

+28 −17
Original line number Diff line number Diff line
@@ -489,13 +489,22 @@ ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx) 
{

	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;

	unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);

	char *dev_addr = rx->dev->dev_addr;



	if (ieee80211_is_data(hdr->frame_control)) {

		if (is_multicast_ether_addr(hdr->addr1)) {

			if (ieee80211_has_tods(hdr->frame_control) ||

				!ieee80211_has_fromds(hdr->frame_control))

				return RX_DROP_MONITOR;

			if (memcmp(hdr->addr3, dev_addr, ETH_ALEN) == 0)

				return RX_DROP_MONITOR;

		} else {

			if (!ieee80211_has_a4(hdr->frame_control))

				return RX_DROP_MONITOR;

		if (memcmp(hdr->addr4, rx->dev->dev_addr, ETH_ALEN) == 0)

			if (memcmp(hdr->addr4, dev_addr, ETH_ALEN) == 0)

				return RX_DROP_MONITOR;

		}

	}



	/* If there is not an established peer link and this is not a peer link

	 * establisment frame, beacon or probe, drop the frame.
@@ -527,7 +536,7 @@ ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx) 


	if (ieee80211_is_data(hdr->frame_control) &&

	    is_multicast_ether_addr(hdr->addr1) &&

	    mesh_rmc_check(hdr->addr4, msh_h_get(hdr, hdrlen), rx->sdata))

	    mesh_rmc_check(hdr->addr3, msh_h_get(hdr, hdrlen), rx->sdata))

		return RX_DROP_MONITOR;

#undef msh_h_get
@@ -1495,7 +1504,8 @@ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx) 
		/* illegal frame */

		return RX_DROP_MONITOR;



	if (mesh_hdr->flags & MESH_FLAGS_AE_A5_A6){

	if (!is_multicast_ether_addr(hdr->addr1) &&

			(mesh_hdr->flags & MESH_FLAGS_AE_A5_A6)) {

		struct mesh_path *mppath;



		rcu_read_lock();
@@ -1512,7 +1522,9 @@ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx) 
		rcu_read_unlock();

	}



	if (compare_ether_addr(rx->dev->dev_addr, hdr->addr3) == 0)

	/* Frame has reached destination.  Don't forward */

	if (!is_multicast_ether_addr(hdr->addr1) &&

			compare_ether_addr(rx->dev->dev_addr, hdr->addr3) == 0)

		return RX_CONTINUE;



	mesh_hdr->ttl--;
@@ -1532,22 +1544,21 @@ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx) 
						   rx->dev->name);



			fwd_hdr =  (struct ieee80211_hdr *) fwd_skb->data;

			/*

			 * Save TA to addr1 to send TA a path error if a

			 * suitable next hop is not found

			 */

			memcpy(fwd_hdr->addr1, fwd_hdr->addr2, ETH_ALEN);

			memcpy(fwd_hdr->addr2, rx->dev->dev_addr, ETH_ALEN);

			info = IEEE80211_SKB_CB(fwd_skb);

			memset(info, 0, sizeof(*info));

			info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;

			info->control.vif = &rx->sdata->vif;

			ieee80211_select_queue(local, fwd_skb);

			if (is_multicast_ether_addr(fwd_hdr->addr3))

				memcpy(fwd_hdr->addr1, fwd_hdr->addr3,

			if (!is_multicast_ether_addr(fwd_hdr->addr1)) {

				int err;

				/*

				 * Save TA to addr1 to send TA a path error if a

				 * suitable next hop is not found

				 */

				memcpy(fwd_hdr->addr1, fwd_hdr->addr2,

						ETH_ALEN);

			else {

				int err = mesh_nexthop_lookup(fwd_skb, sdata);

				err = mesh_nexthop_lookup(fwd_skb, sdata);

				/* Failed to immediately resolve next hop:

				 * fwded frame was dropped or will be added

				 * later to the pending skb queue.  */
@@ -1560,7 +1571,7 @@ ieee80211_rx_h_mesh_fwding(struct ieee80211_rx_data *rx) 
		}

	}



	if (is_multicast_ether_addr(hdr->addr3) ||

	if (is_multicast_ether_addr(hdr->addr1) ||

	    rx->dev->flags & IFF_PROMISC)

		return RX_CONTINUE;

	else

net/mac80211/tx.c

+34 −30
Original line number Diff line number Diff line
@@ -1414,9 +1414,7 @@ static void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, 


	if (ieee80211_vif_is_mesh(&sdata->vif) &&

	    ieee80211_is_data(hdr->frame_control)) {

		if (is_multicast_ether_addr(hdr->addr3))

			memcpy(hdr->addr1, hdr->addr3, ETH_ALEN);

		else

		if (!is_multicast_ether_addr(hdr->addr1))

			if (mesh_nexthop_lookup(skb, sdata)) {

				dev_put(sdata->dev);

				return;
@@ -1619,52 +1617,58 @@ int ieee80211_subif_start_xmit(struct sk_buff *skb, 
		break;

#ifdef CONFIG_MAC80211_MESH

	case NL80211_IFTYPE_MESH_POINT:

		fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);

		if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {

			/* Do not send frames with mesh_ttl == 0 */

			sdata->u.mesh.mshstats.dropped_frames_ttl++;

			ret = NETDEV_TX_OK;

			goto fail;

		}

		memset(&mesh_hdr, 0, sizeof(mesh_hdr));



		if (compare_ether_addr(dev->dev_addr,

					  skb->data + ETH_ALEN) == 0) {

			/* RA TA DA SA */

			memset(hdr.addr1, 0, ETH_ALEN);

			memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);

			memcpy(hdr.addr3, skb->data, ETH_ALEN);

			memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);

			meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr, sdata);

			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,

					skb->data, skb->data + ETH_ALEN);

			meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr,

					sdata, NULL, NULL, NULL);

		} else {

			/* packet from other interface */

			struct mesh_path *mppath;

			int is_mesh_mcast = 1;

			char *mesh_da;



			memset(hdr.addr1, 0, ETH_ALEN);

			memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);

			memcpy(hdr.addr4, dev->dev_addr, ETH_ALEN);



			rcu_read_lock();

			if (is_multicast_ether_addr(skb->data))

				memcpy(hdr.addr3, skb->data, ETH_ALEN);

				/* DA TA mSA AE:SA */

				mesh_da = skb->data;

			else {

				rcu_read_lock();

				mppath = mpp_path_lookup(skb->data, sdata);

				if (mppath)

					memcpy(hdr.addr3, mppath->mpp, ETH_ALEN);

				else

					memset(hdr.addr3, 0xff, ETH_ALEN);

				rcu_read_unlock();

				if (mppath) {

					/* RA TA mDA mSA AE:DA SA */

					mesh_da = mppath->mpp;

					is_mesh_mcast = 0;

				} else

					/* DA TA mSA AE:SA */

					mesh_da = dev->broadcast;

			}

			hdrlen = ieee80211_fill_mesh_addresses(&hdr, &fc,

					mesh_da, dev->dev_addr);

			rcu_read_unlock();

			if (is_mesh_mcast)

				meshhdrlen =

					ieee80211_new_mesh_header(&mesh_hdr,

							sdata,

							skb->data + ETH_ALEN,

							NULL,

							NULL);

			else

				meshhdrlen =

					ieee80211_new_mesh_header(&mesh_hdr,

							sdata,

							NULL,

							skb->data,

							skb->data + ETH_ALEN);



			mesh_hdr.flags |= MESH_FLAGS_AE_A5_A6;

			mesh_hdr.ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;

			put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &mesh_hdr.seqnum);

			memcpy(mesh_hdr.eaddr1, skb->data, ETH_ALEN);

			memcpy(mesh_hdr.eaddr2, skb->data + ETH_ALEN, ETH_ALEN);

			sdata->u.mesh.mesh_seqnum++;

			meshhdrlen = 18;

		}

		hdrlen = 30;

		break;

#endif

	case NL80211_IFTYPE_STATION:

net/wireless/util.c

+12 −4
Original line number Diff line number Diff line
@@ -274,11 +274,11 @@ static int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr) 
	switch (ae) {

	case 0:

		return 6;

	case 1:

	case MESH_FLAGS_AE_A4:

		return 12;

	case 2:

	case MESH_FLAGS_AE_A5_A6:

		return 18;

	case 3:

	case (MESH_FLAGS_AE_A4 | MESH_FLAGS_AE_A5_A6):

		return 24;

	default:

		return 6;
@@ -333,10 +333,18 @@ int ieee80211_data_to_8023(struct sk_buff *skb, u8 *addr, 
		}

		break;

	case cpu_to_le16(IEEE80211_FCTL_FROMDS):

		if (iftype != NL80211_IFTYPE_STATION ||

		if ((iftype != NL80211_IFTYPE_STATION &&

		    iftype != NL80211_IFTYPE_MESH_POINT) ||

		    (is_multicast_ether_addr(dst) &&

		     !compare_ether_addr(src, addr)))

			return -1;

		if (iftype == NL80211_IFTYPE_MESH_POINT) {

			struct ieee80211s_hdr *meshdr =

				(struct ieee80211s_hdr *) (skb->data + hdrlen);

			hdrlen += ieee80211_get_mesh_hdrlen(meshdr);

			if (meshdr->flags & MESH_FLAGS_AE_A4)

				memcpy(src, meshdr->eaddr1, ETH_ALEN);

		}

		break;

	case cpu_to_le16(0):

		if (iftype != NL80211_IFTYPE_ADHOC)