Subject: Re: [RFC PATCH bridge 2/5] bridge: Add vlan to unicast fdb entries

From: "Michael S. Tsirkin" <[email-masked]>
Date: Thu, 30 Aug 2012 17:33:03 +0300

On Thu, Aug 23, 2012 at 03:29:52PM -0400, Vlad Yasevich wrote:
> This patch adds vlan to unicast fdb entries that are created for
> learned addresses (not the manually configured ones).  It adds
> vlan id into the hash mix and uses vlan as an addditional parameter
> for an entry match.
> 
> Signed-off-by: Vlad Yasevich <[email-masked]>

I wonder whether this conflicts with Eric's
05423b241311c9380b7280179295bac7794281b6
which allowed null vid.

Specifically this calls vlan_tx_tag_get without
checking vlan_tx_tag_present. Why is this OK?

> ---
>  include/linux/if_bridge.h |    1 +
>  net/bridge/br_device.c    |    2 +-
>  net/bridge/br_fdb.c       |   71 ++++++++++++++++++++++++++------------------
>  net/bridge/br_input.c     |   14 ++++++---
>  net/bridge/br_private.h   |    7 +++-
>  5 files changed, 58 insertions(+), 37 deletions(-)
> 
> diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h
> index dd3f201..288ff10 100644
> --- a/include/linux/if_bridge.h
> +++ b/include/linux/if_bridge.h
> @@ -95,6 +95,7 @@ struct __fdb_entry {
>  	__u8 port_hi;
>  	__u8 pad0;
>  	__u16 unused;
> +#define fdb_vid unused
>  };
>  
>  #ifdef __KERNEL__
> diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
> index 3334845..e321b9d 100644
> --- a/net/bridge/br_device.c
> +++ b/net/bridge/br_device.c
> @@ -66,7 +66,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
>  			br_multicast_deliver(mdst, skb);
>  		else
>  			br_flood_deliver(br, skb);
> -	} else if ((dst = __br_fdb_get(br, dest)) != NULL)
> +	} else if ((dst = __br_fdb_get(br, dest, vlan_tx_tag_get(skb))) != NULL)
>  		br_deliver(dst->dst, skb);
>  	else
>  		br_flood_deliver(br, skb);
> diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
> index d21f323..478ca1d 100644
> --- a/net/bridge/br_fdb.c
> +++ b/net/bridge/br_fdb.c
> @@ -23,6 +23,7 @@
>  #include <linux/slab.h>
>  #include <linux/atomic.h>
>  #include <asm/unaligned.h>
> +#include <linux/if_vlan.h>
>  #include "br_private.h"
>  
>  static struct kmem_cache *br_fdb_cache __read_mostly;
> @@ -67,11 +68,12 @@ static inline int has_expired(const struct net_bridge *br,
>  		time_before_eq(fdb->updated + hold_time(br), jiffies);
>  }
>  
> -static inline int br_mac_hash(const unsigned char *mac)
> +static inline int br_mac_hash(const unsigned char *mac, __u16 vlan_tci)
>  {
> -	/* use 1 byte of OUI cnd 3 bytes of NIC */
> +	/* use 1 byte of OUI and 3 bytes of NIC */
>  	u32 key = get_unaligned((u32 *)(mac + 2));
> -	return jhash_1word(key, fdb_salt) & (BR_HASH_SIZE - 1);
> +	return jhash_2words(key, (vlan_tci & VLAN_VID_MASK),
> +				fdb_salt) & (BR_HASH_SIZE - 1);
>  }
>  
>  static void fdb_rcu_free(struct rcu_head *head)
> @@ -132,7 +134,7 @@ void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
>  	struct net_bridge_fdb_entry *f;
>  
>  	/* If old entry was unassociated with any port, then delete it. */
> -	f = __br_fdb_get(br, br->dev->dev_addr);
> +	f = __br_fdb_get(br, br->dev->dev_addr, 0);
>  	if (f && f->is_local && !f->dst)
>  		fdb_delete(br, f);
>  
> @@ -231,13 +233,16 @@ void br_fdb_delete_by_port(struct net_bridge *br,
>  
>  /* No locking or refcounting, assumes caller has rcu_read_lock */
>  struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
> -					  const unsigned char *addr)
> +					  const unsigned char *addr,
> +					  __u16 vlan_tci)
>  {
>  	struct hlist_node *h;
>  	struct net_bridge_fdb_entry *fdb;
>  
> -	hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) {
> -		if (ether_addr_equal(fdb->addr.addr, addr)) {
> +	hlist_for_each_entry_rcu(fdb, h,
> +				&br->hash[br_mac_hash(addr, vlan_tci)], hlist) {
> +		if (ether_addr_equal(fdb->addr.addr, addr) &&
> +		    fdb->vlan_id == (vlan_tci & VLAN_VID_MASK) ) {
>  			if (unlikely(has_expired(br, fdb)))
>  				break;
>  			return fdb;
> @@ -261,7 +266,7 @@ int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
>  	if (!port)
>  		ret = 0;
>  	else {
> -		fdb = __br_fdb_get(port->br, addr);
> +		fdb = __br_fdb_get(port->br, addr, 0);
>  		ret = fdb && fdb->dst && fdb->dst->dev != dev &&
>  			fdb->dst->state == BR_STATE_FORWARDING;
>  	}
> @@ -313,6 +318,7 @@ int br_fdb_fillbuf(struct net_bridge *br, void *buf,
>  			fe->is_local = f->is_local;
>  			if (!f->is_static)
>  				fe->ageing_timer_value = jiffies_to_clock_t(jiffies - f->updated);
> +			fe->fdb_vid = f->vlan_id;
>  			++fe;
>  			++num;
>  		}
> @@ -325,26 +331,30 @@ int br_fdb_fillbuf(struct net_bridge *br, void *buf,
>  }
>  
>  static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
> -					     const unsigned char *addr)
> +					     const unsigned char *addr,
> +					     __u16 vlan_tci)
>  {
>  	struct hlist_node *h;
>  	struct net_bridge_fdb_entry *fdb;
>  
>  	hlist_for_each_entry(fdb, h, head, hlist) {
> -		if (ether_addr_equal(fdb->addr.addr, addr))
> +		if (ether_addr_equal(fdb->addr.addr, addr) &&
> +		    fdb->vlan_id == (vlan_tci & VLAN_VID_MASK))
>  			return fdb;
>  	}
>  	return NULL;
>  }
>  
>  static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
> -						 const unsigned char *addr)
> +						 const unsigned char *addr,
> +						 __u16 vlan_tci)
>  {
>  	struct hlist_node *h;
>  	struct net_bridge_fdb_entry *fdb;
>  
>  	hlist_for_each_entry_rcu(fdb, h, head, hlist) {
> -		if (ether_addr_equal(fdb->addr.addr, addr))
> +		if (ether_addr_equal(fdb->addr.addr, addr) &&
> +		    fdb->vlan_id == (vlan_tci & VLAN_VID_MASK))
>  			return fdb;
>  	}
>  	return NULL;
> @@ -352,7 +362,8 @@ static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
>  
>  static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
>  					       struct net_bridge_port *source,
> -					       const unsigned char *addr)
> +					       const unsigned char *addr,
> +					       __u16 vlan_tci)
>  {
>  	struct net_bridge_fdb_entry *fdb;
>  
> @@ -360,6 +371,7 @@ static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
>  	if (fdb) {
>  		memcpy(fdb->addr.addr, addr, ETH_ALEN);
>  		fdb->dst = source;
> +		fdb->vlan_id = (vlan_tci & VLAN_VID_MASK);
>  		fdb->is_local = 0;
>  		fdb->is_static = 0;
>  		fdb->updated = fdb->used = jiffies;
> @@ -371,13 +383,13 @@ static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
>  static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
>  		  const unsigned char *addr)
>  {
> -	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
> +	struct hlist_head *head = &br->hash[br_mac_hash(addr, 0)];
>  	struct net_bridge_fdb_entry *fdb;
>  
>  	if (!is_valid_ether_addr(addr))
>  		return -EINVAL;
>  
> -	fdb = fdb_find(head, addr);
> +	fdb = fdb_find(head, addr, 0);
>  	if (fdb) {
>  		/* it is okay to have multiple ports with same
>  		 * address, just use the first one.
> @@ -390,7 +402,7 @@ static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
>  		fdb_delete(br, fdb);
>  	}
>  
> -	fdb = fdb_create(head, source, addr);
> +	fdb = fdb_create(head, source, addr, 0);
>  	if (!fdb)
>  		return -ENOMEM;
>  
> @@ -412,9 +424,9 @@ int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
>  }
>  
>  void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
> -		   const unsigned char *addr)
> +		   const unsigned char *addr, __u16 vlan_tci)
>  {
> -	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
> +	struct hlist_head *head = &br->hash[br_mac_hash(addr, vlan_tci)];
>  	struct net_bridge_fdb_entry *fdb;
>  
>  	/* some users want to always flood. */
> @@ -426,7 +438,7 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
>  	      source->state == BR_STATE_FORWARDING))
>  		return;
>  
> -	fdb = fdb_find_rcu(head, addr);
> +	fdb = fdb_find_rcu(head, addr, vlan_tci);
>  	if (likely(fdb)) {
>  		/* attempt to update an entry for a local interface */
>  		if (unlikely(fdb->is_local)) {
> @@ -441,8 +453,8 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
>  		}
>  	} else {
>  		spin_lock(&br->hash_lock);
> -		if (likely(!fdb_find(head, addr))) {
> -			fdb = fdb_create(head, source, addr);
> +		if (likely(!fdb_find(head, addr, vlan_tci))) {
> +			fdb = fdb_create(head, source, addr, vlan_tci);
>  			if (fdb)
>  				fdb_notify(br, fdb, RTM_NEWNEIGH);
>  		}
> @@ -571,18 +583,18 @@ out:
>  
>  /* Update (create or replace) forwarding database entry */
>  static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
> -			 __u16 state, __u16 flags)
> +			 __u16 state, __u16 flags, __u16 vlan_tci)
>  {
>  	struct net_bridge *br = source->br;
> -	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
> +	struct hlist_head *head = &br->hash[br_mac_hash(addr, vlan_tci)];
>  	struct net_bridge_fdb_entry *fdb;
>  
> -	fdb = fdb_find(head, addr);
> +	fdb = fdb_find(head, addr, vlan_tci);
>  	if (fdb == NULL) {
>  		if (!(flags & NLM_F_CREATE))
>  			return -ENOENT;
>  
> -		fdb = fdb_create(head, source, addr);
> +		fdb = fdb_create(head, source, addr, vlan_tci);
>  		if (!fdb)
>  			return -ENOMEM;
>  		fdb_notify(br, fdb, RTM_NEWNEIGH);
> @@ -628,11 +640,12 @@ int br_fdb_add(struct ndmsg *ndm, struct net_device *dev,
>  
>  	if (ndm->ndm_flags & NTF_USE) {
>  		rcu_read_lock();
> -		br_fdb_update(p->br, p, addr);
> +		br_fdb_update(p->br, p, addr, 0);
>  		rcu_read_unlock();
>  	} else {
>  		spin_lock_bh(&p->br->hash_lock);
> -		err = fdb_add_entry(p, addr, ndm->ndm_state, nlh_flags);
> +		err = fdb_add_entry(p, addr, ndm->ndm_state, nlh_flags,
> +				0);
>  		spin_unlock_bh(&p->br->hash_lock);
>  	}
>  
> @@ -642,10 +655,10 @@ int br_fdb_add(struct ndmsg *ndm, struct net_device *dev,
>  static int fdb_delete_by_addr(struct net_bridge_port *p, u8 *addr)
>  {
>  	struct net_bridge *br = p->br;
> -	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
> +	struct hlist_head *head = &br->hash[br_mac_hash(addr, 0)];
>  	struct net_bridge_fdb_entry *fdb;
>  
> -	fdb = fdb_find(head, addr);
> +	fdb = fdb_find(head, addr, 0);
>  	if (!fdb)
>  		return -ENOENT;
>  
> diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
> index b7ca3b3..a4579ee 100644
> --- a/net/bridge/br_input.c
> +++ b/net/bridge/br_input.c
> @@ -62,12 +62,15 @@ int br_handle_frame_finish(struct sk_buff *skb)
>  	 * only traffic matching the VLAN filter.
>  	 */
>  	vlan_map = rcu_dereference(p->vlan_map);
> -	if (vlan_map && !test_bit((skb->vlan_tci & VLAN_VID_MASK), vlan_map))
> -		goto drop;
> +	if (vlan_map && vlan_tx_tag_present(skb)) {
> +		unsigned short vid = vlan_tx_tag_get(skb) & VLAN_VID_MASK;
> +		if (!test_bit(vid+1, vlan_map))
> +			goto drop;
> +	}
>  
>  	/* insert into forwarding database after filtering to avoid spoofing */
>  	br = p->br;
> -	br_fdb_update(br, p, eth_hdr(skb)->h_source);
> +	br_fdb_update(br, p, eth_hdr(skb)->h_source, vlan_tx_tag_get(skb));
>  
>  	if (!is_broadcast_ether_addr(dest) && is_multicast_ether_addr(dest) &&
>  	    br_multicast_rcv(br, p, skb))
> @@ -102,7 +105,8 @@ int br_handle_frame_finish(struct sk_buff *skb)
>  			skb2 = skb;
>  
>  		br->dev->stats.multicast++;
> -	} else if ((dst = __br_fdb_get(br, dest)) && dst->is_local) {
> +	} else if ((dst = __br_fdb_get(br, dest, vlan_tx_tag_get(skb))) &&
> +			dst->is_local) {
>  		skb2 = skb;
>  		/* Do not forward the packet since it's local. */
>  		skb = NULL;
> @@ -131,7 +135,7 @@ static int br_handle_local_finish(struct sk_buff *skb)
>  {
>  	struct net_bridge_port *p = br_port_get_rcu(skb->dev);
>  
> -	br_fdb_update(p->br, p, eth_hdr(skb)->h_source);
> +	br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vlan_tx_tag_get(skb));
>  	return 0;	 /* process further */
>  }
>  
> diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
> index 8da90e8..921b927 100644
> --- a/net/bridge/br_private.h
> +++ b/net/bridge/br_private.h
> @@ -72,6 +72,7 @@ struct net_bridge_fdb_entry
>  	unsigned long			updated;
>  	unsigned long			used;
>  	mac_addr			addr;
> +	__u16				vlan_id;
>  	unsigned char			is_local;
>  	unsigned char			is_static;
>  };
> @@ -352,7 +353,8 @@ extern void br_fdb_cleanup(unsigned long arg);
>  extern void br_fdb_delete_by_port(struct net_bridge *br,
>  				  const struct net_bridge_port *p, int do_all);
>  extern struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
> -						 const unsigned char *addr);
> +						 const unsigned char *addr,
> +						 __u16 vlan_tci);
>  extern int br_fdb_test_addr(struct net_device *dev, unsigned char *addr);
>  extern int br_fdb_fillbuf(struct net_bridge *br, void *buf,
>  			  unsigned long count, unsigned long off);
> @@ -361,7 +363,8 @@ extern int br_fdb_insert(struct net_bridge *br,
>  			 const unsigned char *addr);
>  extern void br_fdb_update(struct net_bridge *br,
>  			  struct net_bridge_port *source,
> -			  const unsigned char *addr);
> +			  const unsigned char *addr,
> +			  __u16 vlan_tci);
>  
>  extern int br_fdb_delete(struct ndmsg *ndm,
>  			 struct net_device *dev,
> -- 
> 1.7.7.6
> 
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