[B.A.T.M.A.N.] [PATCH 3/3] batman-adv: Modified forwarding behaviour for multicast packets

[B.A.T.M.A.N.] [PATCH 3/3] batman-adv: Modified forwarding behaviour for multicast packets

[Linus Lüssing]

With this patch a multicast packet is not always simply flooded anymore,
the bevahiour for the following cases is changed to reduce
unnecessary overhead:

If all nodes within the horizon of a certain node have signalized
multicast listener announcement capability
(BATADV_MCAST_LISTENER_ANNOUNCEMENT) then an IPv6 multicast packet
with a destination of IPv6 link-local scope coming from the upstream
of this node...

* ...is dropped if there is no according multicast listener in the
  translation table.
* ...is forwarded via unicast if there is a single node with interested
  multicast listeners.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
---
 multicast.c         |   42 ++++++++++++++++++++++++++++++++++++++++++
 multicast.h         |    8 ++++++++
 soft-interface.c    |   10 ++++++++++
 translation-table.c |   44 ++++++++++++++++++++++++++++++++++++++++++++
 translation-table.h |    1 +
 5 files changed, 105 insertions(+)

diff --git a/multicast.c b/multicast.c
index 95beac4..673d5f1 100644
--- a/multicast.c
+++ b/multicast.c
@@ -218,6 +218,48 @@ out:
 }
 
 /**
+ * batadv_mcast_flood - Checks on how to forward a multicast packet
+ * @skb: The multicast packet to check
+ * @bat_priv: the bat priv with all the soft interface information
+ *
+ * Returns 1 if the packet should be flooded, 0 if it should be forwarded
+ * via unicast or -1 if it should be drooped.
+ */
+int batadv_mcast_flood(struct sk_buff *skb, struct batadv_priv *bat_priv)
+{
+	struct ethhdr *ethhdr = (struct ethhdr *)(skb->data);
+	struct ipv6hdr *ip6hdr;
+	int count, ret = 1;
+
+	if (atomic_read(&bat_priv->mcast_group_awareness) &&
+	    !atomic_read(&bat_priv->mcast_num_non_aware) &&
+	    ntohs(ethhdr->h_proto) == ETH_P_IPV6) {
+		if (!pskb_may_pull(skb, sizeof(*ethhdr) + sizeof(*ip6hdr))) {
+			ret = -1;
+			goto out;
+		}
+
+		ip6hdr = ipv6_hdr(skb);
+
+		/* TODO: Implement Multicast Router Discovery, then add
+		 * scope >= IPV6_ADDR_SCOPE_LINKLOCAL, too */
+		if (IPV6_ADDR_MC_SCOPE(&ip6hdr->daddr) !=
+		    IPV6_ADDR_SCOPE_LINKLOCAL)
+			goto out;
+
+		count = batadv_tt_global_hash_count(bat_priv, ethhdr->h_dest);
+
+		if (!count)
+			ret = -1;
+		else if (count == 1)
+			ret = 0;
+	}
+
+out:
+	return ret;
+}
+
+/**
  * batadv_mcast_tvlv_ogm_handler_v1 - process incoming multicast tvlv container
  * @bat_priv: the bat priv with all the soft interface information
  * @orig: the orig_node of the ogm
diff --git a/multicast.h b/multicast.h
index 9955a18..0c2baad 100644
--- a/multicast.h
+++ b/multicast.h
@@ -24,6 +24,8 @@
 
 void batadv_mcast_mla_tt_update(struct batadv_priv *bat_priv);
 
+int batadv_mcast_flood(struct sk_buff *skb, struct batadv_priv *bat_priv);
+
 int batadv_mcast_init(struct batadv_priv *bat_priv);
 
 void batadv_mcast_free(struct batadv_priv *bat_priv);
@@ -35,6 +37,12 @@ static inline void batadv_mcast_mla_tt_update(struct batadv_priv *bat_priv)
 	return;
 }
 
+static inline int batadv_mcast_flood(struct sk_buff *skb,
+				     struct batadv_priv *bat_priv)
+{
+	return 1;
+}
+
 static inline int batadv_mcast_init(struct batadv_priv *bat_priv)
 {
 	return 0;
diff --git a/soft-interface.c b/soft-interface.c
index c1142c2..831a618 100644
--- a/soft-interface.c
+++ b/soft-interface.c
@@ -36,6 +36,7 @@
 #include <linux/if_vlan.h>
 #include <linux/if_ether.h>
 #include "unicast.h"
+#include "multicast.h"
 #include "bridge_loop_avoidance.h"
 #include "network-coding.h"
 
@@ -222,6 +223,15 @@ static int batadv_interface_tx(struct sk_buff *skb,
 		}
 	}
 
+	if (do_bcast && !is_broadcast_ether_addr(ethhdr->h_dest)) {
+		ret = batadv_mcast_flood(skb, bat_priv);
+		if (ret < 0)
+			goto dropped;
+
+		if (!ret)
+			do_bcast = false;
+	}
+
 	/* ethernet packet should be broadcasted */
 	if (do_bcast) {
 		primary_if = batadv_primary_if_get_selected(bat_priv);
diff --git a/translation-table.c b/translation-table.c
index 37e7d47..1d2d618 100644
--- a/translation-table.c
+++ b/translation-table.c
@@ -83,6 +83,40 @@ batadv_tt_hash_find(struct batadv_hashtable *hash, const void *data)
 	return tt_common_entry_tmp;
 }
 
+/**
+ * batadv_tt_hash_count - Counts the number of tt entries for the given data
+ * @hash: hash table containing the tt entries
+ * @data: The data to count entries for
+ */
+static int batadv_tt_hash_count(struct batadv_hashtable *hash, const void *data)
+{
+	struct hlist_head *head;
+	struct batadv_tt_common_entry *tt_common_entry;
+	uint32_t index;
+	int count = 0;
+
+	if (!hash)
+		goto out;
+
+	index = batadv_choose_orig(data, hash->size);
+	head = &hash->table[index];
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(tt_common_entry, head, hash_entry) {
+		if (!batadv_compare_eth(tt_common_entry, data))
+			continue;
+
+		if (!atomic_read(&tt_common_entry->refcount))
+			continue;
+
+		count++;
+	}
+	rcu_read_unlock();
+
+out:
+	return count;
+}
+
 static struct batadv_tt_local_entry *
 batadv_tt_local_hash_find(struct batadv_priv *bat_priv, const void *data)
 {
@@ -111,6 +145,16 @@ batadv_tt_global_hash_find(struct batadv_priv *bat_priv, const void *data)
 	return tt_global_entry;
 }
 
+/**
+ * batadv_tt_hash_count - Counts the number of global tt entries for some data
+ * @bat_priv: the bat priv with all the soft interface information
+ * @data: The data to count entries for
+ */
+int batadv_tt_global_hash_count(struct batadv_priv *bat_priv, const void *data)
+{
+	return batadv_tt_hash_count(bat_priv->tt.global_hash, data);
+}
+
 static void
 batadv_tt_local_entry_free_ref(struct batadv_tt_local_entry *tt_local_entry)
 {
diff --git a/translation-table.h b/translation-table.h
index 015d8b9..5986c57 100644
--- a/translation-table.h
+++ b/translation-table.h
@@ -31,6 +31,7 @@ int batadv_tt_global_seq_print_text(struct seq_file *seq, void *offset);
 void batadv_tt_global_del_orig(struct batadv_priv *bat_priv,
 			       struct batadv_orig_node *orig_node,
 			       const char *message);
+int batadv_tt_global_hash_count(struct batadv_priv *bat_priv, const void *data);
 struct batadv_orig_node *batadv_transtable_search(struct batadv_priv *bat_priv,
 						  const uint8_t *src,
 						  const uint8_t *addr);
-- 
1.7.10.4

Re: [B.A.T.M.A.N.] [PATCH 3/3] batman-adv: Modified forwarding behaviour for multicast packets

[Antonio Quartulli]

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On Sat, May 11, 2013 at 07:23:27PM +0200, Linus Lüssing wrote:
> With this patch a multicast packet is not always simply flooded anymore,
> the bevahiour for the following cases is changed to reduce
> unnecessary overhead:
> 
> If all nodes within the horizon of a certain node have signalized
> multicast listener announcement capability
> (BATADV_MCAST_LISTENER_ANNOUNCEMENT) then an IPv6 multicast packet
> with a destination of IPv6 link-local scope coming from the upstream
> of this node...
> 
> * ...is dropped if there is no according multicast listener in the
>   translation table.
> * ...is forwarded via unicast if there is a single node with interested
>   multicast listeners.
> 

othwerwise? Does it get flooded like now if there is more than one receiver?

>  
>  /**
> + * batadv_mcast_flood - Checks on how to forward a multicast packet
> + * @skb: The multicast packet to check
> + * @bat_priv: the bat priv with all the soft interface information
> + *
> + * Returns 1 if the packet should be flooded, 0 if it should be forwarded
> + * via unicast or -1 if it should be drooped.
> + */
> +int batadv_mcast_flood(struct sk_buff *skb, struct batadv_priv *bat_priv)
> +{
> +	struct ethhdr *ethhdr = (struct ethhdr *)(skb->data);
> +	struct ipv6hdr *ip6hdr;
> +	int count, ret = 1;
> +
> +	if (atomic_read(&bat_priv->mcast_group_awareness) &&
> +	    !atomic_read(&bat_priv->mcast_num_non_aware) &&
> +	    ntohs(ethhdr->h_proto) == ETH_P_IPV6) {

mh..this would not work for VLANs..did you plan to introduce support for VLANs
later? or you simply overlooked it? :)

> +		if (!pskb_may_pull(skb, sizeof(*ethhdr) + sizeof(*ip6hdr))) {
> +			ret = -1;
> +			goto out;
> +		}
> +
> +		ip6hdr = ipv6_hdr(skb);
> +
> +		/* TODO: Implement Multicast Router Discovery, then add
> +		 * scope >= IPV6_ADDR_SCOPE_LINKLOCAL, too */
> +		if (IPV6_ADDR_MC_SCOPE(&ip6hdr->daddr) !=
> +		    IPV6_ADDR_SCOPE_LINKLOCAL)
> +			goto out;
> +
> +		count = batadv_tt_global_hash_count(bat_priv, ethhdr->h_dest);
> +
> +		if (!count)
> +			ret = -1;
> +		else if (count == 1)
> +			ret = 0;

how can this function return more than one?
When there is more than one originator announcing the same MAC address then we
have _a single_ global entry having a list of orig_entry. but stil only one
global entry.

so you may want to count the orig_entries rather than the global_entries?

> diff --git a/translation-table.c b/translation-table.c
> index 37e7d47..1d2d618 100644
> --- a/translation-table.c
> +++ b/translation-table.c
> @@ -83,6 +83,40 @@ batadv_tt_hash_find(struct batadv_hashtable *hash, const void *data)
>  	return tt_common_entry_tmp;
>  }
>  
> +/**
> + * batadv_tt_hash_count - Counts the number of tt entries for the given data
> + * @hash: hash table containing the tt entries
> + * @data: The data to count entries for

One line saying what you are returning would be nice :)

> + */
> +static int batadv_tt_hash_count(struct batadv_hashtable *hash, const void *data)
> +{
> +	struct hlist_head *head;
> +	struct batadv_tt_common_entry *tt_common_entry;
> +	uint32_t index;
> +	int count = 0;
> +
> +	if (!hash)
> +		goto out;
> +
> +	index = batadv_choose_orig(data, hash->size);
> +	head = &hash->table[index];
> +
> +	rcu_read_lock();
> +	hlist_for_each_entry_rcu(tt_common_entry, head, hash_entry) {
> +		if (!batadv_compare_eth(tt_common_entry, data))
> +			continue;
> +
> +		if (!atomic_read(&tt_common_entry->refcount))
> +			continue;
> +
> +		count++;
> +	}
> +	rcu_read_unlock();
> +
> +out:
> +	return count;
> +}

as I asked before: this function cannot return >1 because the same address is
never stored twice.


Nice job so far!
Thanks for working on this cool feature!

Cheers,

-- 
Antonio Quartulli

..each of us alone is worth nothing..
Ernesto "Che" Guevara

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Re: [B.A.T.M.A.N.] [PATCH 3/3] batman-adv: Modified forwarding behaviour for multicast packets

[Linus Lüssing]

On Sun, May 12, 2013 at 01:29:29AM +0200, Antonio Quartulli wrote:
> On Sat, May 11, 2013 at 07:23:27PM +0200, Linus Lüssing wrote:
> > With this patch a multicast packet is not always simply flooded anymore,
> > the bevahiour for the following cases is changed to reduce
> > unnecessary overhead:
> > 
> > If all nodes within the horizon of a certain node have signalized
> > multicast listener announcement capability
> > (BATADV_MCAST_LISTENER_ANNOUNCEMENT) then an IPv6 multicast packet
> > with a destination of IPv6 link-local scope coming from the upstream
> > of this node...
> > 
> > * ...is dropped if there is no according multicast listener in the
> >   translation table.
> > * ...is forwarded via unicast if there is a single node with interested
> >   multicast listeners.
> > 
> 
> othwerwise? Does it get flooded like now if there is more than one receiver?

Yes, it will get flooded. Thought it was clear because I was
saying "for the following cases is changed", trying to imply that
for anything else it'll still get flooded. But ok, I can make it
more explicit.

> 
> >  
> >  /**
> > + * batadv_mcast_flood - Checks on how to forward a multicast packet
> > + * @skb: The multicast packet to check
> > + * @bat_priv: the bat priv with all the soft interface information
> > + *
> > + * Returns 1 if the packet should be flooded, 0 if it should be forwarded
> > + * via unicast or -1 if it should be drooped.
> > + */
> > +int batadv_mcast_flood(struct sk_buff *skb, struct batadv_priv *bat_priv)
> > +{
> > +	struct ethhdr *ethhdr = (struct ethhdr *)(skb->data);
> > +	struct ipv6hdr *ip6hdr;
> > +	int count, ret = 1;
> > +
> > +	if (atomic_read(&bat_priv->mcast_group_awareness) &&
> > +	    !atomic_read(&bat_priv->mcast_num_non_aware) &&
> > +	    ntohs(ethhdr->h_proto) == ETH_P_IPV6) {
> 
> mh..this would not work for VLANs..did you plan to introduce support for VLANs
> later? or you simply overlooked it? :)

I guess I overlooked, will try to add that in the same patch, too.

> 
> > +		if (!pskb_may_pull(skb, sizeof(*ethhdr) + sizeof(*ip6hdr))) {
> > +			ret = -1;
> > +			goto out;
> > +		}
> > +
> > +		ip6hdr = ipv6_hdr(skb);
> > +
> > +		/* TODO: Implement Multicast Router Discovery, then add
> > +		 * scope >= IPV6_ADDR_SCOPE_LINKLOCAL, too */
> > +		if (IPV6_ADDR_MC_SCOPE(&ip6hdr->daddr) !=
> > +		    IPV6_ADDR_SCOPE_LINKLOCAL)
> > +			goto out;
> > +
> > +		count = batadv_tt_global_hash_count(bat_priv, ethhdr->h_dest);
> > +
> > +		if (!count)
> > +			ret = -1;
> > +		else if (count == 1)
> > +			ret = 0;
> 
> how can this function return more than one?
> When there is more than one originator announcing the same MAC address then we
> have _a single_ global entry having a list of orig_entry. but stil only one
> global entry.
> 
> so you may want to count the orig_entries rather than the global_entries?

You are right, looks like I only tested dropping vs. unicast, not
unicast vs. flooding behaviour in my VMs.

> 
> > diff --git a/translation-table.c b/translation-table.c
> > index 37e7d47..1d2d618 100644
> > --- a/translation-table.c
> > +++ b/translation-table.c
> > @@ -83,6 +83,40 @@ batadv_tt_hash_find(struct batadv_hashtable *hash, const void *data)
> >  	return tt_common_entry_tmp;
> >  }
> >  
> > +/**
> > + * batadv_tt_hash_count - Counts the number of tt entries for the given data
> > + * @hash: hash table containing the tt entries
> > + * @data: The data to count entries for
> 
> One line saying what you are returning would be nice :)

ok

> 
> > + */
> > +static int batadv_tt_hash_count(struct batadv_hashtable *hash, const void *data)
> > +{
> > +	struct hlist_head *head;
> > +	struct batadv_tt_common_entry *tt_common_entry;
> > +	uint32_t index;
> > +	int count = 0;
> > +
> > +	if (!hash)
> > +		goto out;
> > +
> > +	index = batadv_choose_orig(data, hash->size);
> > +	head = &hash->table[index];
> > +
> > +	rcu_read_lock();
> > +	hlist_for_each_entry_rcu(tt_common_entry, head, hash_entry) {
> > +		if (!batadv_compare_eth(tt_common_entry, data))
> > +			continue;
> > +
> > +		if (!atomic_read(&tt_common_entry->refcount))
> > +			continue;
> > +
> > +		count++;
> > +	}
> > +	rcu_read_unlock();
> > +
> > +out:
> > +	return count;
> > +}
> 
> as I asked before: this function cannot return >1 because the same address is
> never stored twice.
> 
> 
> Nice job so far!
> Thanks for working on this cool feature!
> 
> Cheers,
> 
> -- 
> Antonio Quartulli
> 
> ..each of us alone is worth nothing..
> Ernesto "Che" Guevara

Cheers, Linus

Re: [B.A.T.M.A.N.] [PATCH 3/3] batman-adv: Modified forwarding behaviour for multicast packets

[Antonio Quartulli]

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On Thu, May 16, 2013 at 08:22:25PM +0200, Linus Lüssing wrote:
> On Sun, May 12, 2013 at 01:29:29AM +0200, Antonio Quartulli wrote:
> > On Sat, May 11, 2013 at 07:23:27PM +0200, Linus Lüssing wrote:
> > > With this patch a multicast packet is not always simply flooded anymore,
> > > the bevahiour for the following cases is changed to reduce
> > > unnecessary overhead:
> > > 
> > > If all nodes within the horizon of a certain node have signalized
> > > multicast listener announcement capability
> > > (BATADV_MCAST_LISTENER_ANNOUNCEMENT) then an IPv6 multicast packet
> > > with a destination of IPv6 link-local scope coming from the upstream
> > > of this node...
> > > 
> > > * ...is dropped if there is no according multicast listener in the
> > >   translation table.
> > > * ...is forwarded via unicast if there is a single node with interested
> > >   multicast listeners.
> > > 
> > 
> > othwerwise? Does it get flooded like now if there is more than one receiver?
> 
> Yes, it will get flooded. Thought it was clear because I was
> saying "for the following cases is changed", trying to imply that
> for anything else it'll still get flooded. But ok, I can make it
> more explicit.

Yes, please

Cheers,

-- 
Antonio Quartulli

..each of us alone is worth nothing..
Ernesto "Che" Guevara

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[B.A.T.M.A.N.] Basic Multicast Optimizations

[Linus Lüssing]

This is the third revision of the basic multicast optimization patches.
It includes one functional and some compat fixes, and some style improvements,
thanks to Simons feedback:

PATCHv3 1/3:
* the pmc_rcu functions got removed - they weren't actually used in the
  submitted revision - so there's no more patch for net to export
  for_each_pmc_rcu() needed anymore. Should also fix Simon's compat error.
* Compat code for netdev_for_each_mc_addr() added.
  (I needed to introduce a batadv_hw_addr because I wasn't able to achieve
  backwards compatibility with a netdev_hw_addr - my "official reasoning" will
  be that netdev_hw_addr is unnecessarily bloated, struct batadv_hw_addr
  has just the right size to do the job)
* Compat fix for IFF_BRIDGE_PORT
* Removed primary_if->soft_iface in batadv_mcast_mla_tt_update() as we
  can always use bat_priv->soft_iface instead.

PATCHv3 2/3
* Renamed num_non_aware to a more specific num_no_mla - because we will need
  things like a num_no_tracker for instance with the multicast tracker feature
  in the future.
* Fixed removal of orig_node's without BATADV_MCAST_LISTENER_ANNOUNCEMENT
  flag, update num_no_mla properly now.

PATCHv3 3/3
* Renamed batadv_mcast_flood() to batadv_mcast_forw_mode() because it does not
  only show whether to flood or not (=drop), but also whether to forward via
  unicast. In the future with the multicast tracker feature a fourth return value
  is going to be added, making the name "batadv_mcast_flood()" even less fitting.
* Simon's style suggestions for batadv_mcast_forw_mode() and
  batadv_interface_tx().
* batadv_mcast_forw_mode() now returns an enum (thanks to Marek and Antonio for
  the suggestion).

I did not change:
> I don't quite understand why you return -1, maybe the packet could still
> be forwarded even if it could not be pulled?

Because if it returns -1 then something is wrong, for instance we could be
out of memory. If we are out of memory then we probably won't be able to
forward any packet. Also we shouldn't allocate any more memory for one thing
but I think it is also better to drop/free packets to save some memory
to increase the possibility of the system to recover without crashing.

Cheers, Linus

[B.A.T.M.A.N.] [PATCH 1/3] batman-adv: Multicast Listener Announcements via Translation Table

[Linus Lüssing]

With this patch a node which has no bridge interface on top of its soft
interface announces its local multicast listeners via the translation
table.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
---
 Makefile               |    2 +
 Makefile.kbuild        |    1 +
 compat.h               |   20 ++++-
 gen-compat-autoconf.sh |    1 +
 main.c                 |    6 ++
 main.h                 |    1 +
 multicast.c            |  209 ++++++++++++++++++++++++++++++++++++++++++++++++
 multicast.h            |   43 ++++++++++
 soft-interface.c       |    3 +
 sysfs.c                |    6 ++
 translation-table.c    |   22 ++++-
 types.h                |   12 +++
 12 files changed, 321 insertions(+), 5 deletions(-)
 create mode 100644 multicast.c
 create mode 100644 multicast.h

diff --git a/Makefile b/Makefile
index 407cdc4..d7c6fa6 100644
--- a/Makefile
+++ b/Makefile
@@ -27,6 +27,8 @@ export CONFIG_BATMAN_ADV_BLA=y
 export CONFIG_BATMAN_ADV_DAT=y
 # B.A.T.M.A.N network coding (catwoman):
 export CONFIG_BATMAN_ADV_NC=n
+# B.A.T.M.A.N. multicast optimizations:
+export CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS=y
 
 PWD:=$(shell pwd)
 KERNELPATH ?= /lib/modules/$(shell uname -r)/build
diff --git a/Makefile.kbuild b/Makefile.kbuild
index 4f4aabb..f154c5b 100644
--- a/Makefile.kbuild
+++ b/Makefile.kbuild
@@ -38,3 +38,4 @@ batman-adv-y += send.o
 batman-adv-y += soft-interface.o
 batman-adv-y += sysfs.o
 batman-adv-y += translation-table.o
+batman-adv-$(CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS) += multicast.o
diff --git a/compat.h b/compat.h
index dbf1926..ddc1b29 100644
--- a/compat.h
+++ b/compat.h
@@ -103,13 +103,31 @@ static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
 
 #define pr_warn pr_warning
 
+#undef  netdev_for_each_mc_addr
+#define netdev_for_each_mc_addr(mclist, dev) \
+	for (mclist = (struct bat_dev_addr_list *)dev->mc_list; mclist; \
+	     mclist = (struct bat_dev_addr_list *)mclist->next)
+
+/* Note, that this breaks the usage of the normal 'struct netdev_hw_addr'
+ * for kernels < 2.6.35 in batman-adv!
+ */
+#define netdev_hw_addr batadv_dev_addr_list
+struct batadv_dev_addr_list {
+	struct dev_addr_list *next;
+	u8  addr[MAX_ADDR_LEN];
+	u8  da_addrlen;
+	u8  da_synced;
+	int da_users;
+	int da_gusers;
+};
+
 #endif /* < KERNEL_VERSION(2, 6, 35) */
 
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 36)
 
 #define __rcu
-#define IFF_BRIDGE_PORT  0 || (hard_iface->net_dev->br_port ? 1 : 0)
+#define IFF_BRIDGE_PORT  0 || (soft_iface->br_port ? 1 : 0)
 
 struct kernel_param_ops {
 	/* Returns 0, or -errno.  arg is in kp->arg. */
diff --git a/gen-compat-autoconf.sh b/gen-compat-autoconf.sh
index 78573e4..b56ac29 100755
--- a/gen-compat-autoconf.sh
+++ b/gen-compat-autoconf.sh
@@ -39,6 +39,7 @@ gen_config() {
 gen_config 'CONFIG_BATMAN_ADV_DEBUG' ${CONFIG_BATMAN_ADV_DEBUG:="n"} >> "${TMP}"
 gen_config 'CONFIG_BATMAN_ADV_BLA' ${CONFIG_BATMAN_ADV_BLA:="y"} >> "${TMP}"
 gen_config 'CONFIG_BATMAN_ADV_DAT' ${CONFIG_BATMAN_ADV_DAT:="y"} >> "${TMP}"
+gen_config 'CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS' ${CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS:="y"} >> "${TMP}"
 gen_config 'CONFIG_BATMAN_ADV_NC' ${CONFIG_BATMAN_ADV_NC:="n"} >> "${TMP}"
 
 # only regenerate compat-autoconf.h when config was changed
diff --git a/main.c b/main.c
index 5d30fe0..fc5789c 100644
--- a/main.c
+++ b/main.c
@@ -32,6 +32,7 @@
 #include "gateway_client.h"
 #include "bridge_loop_avoidance.h"
 #include "distributed-arp-table.h"
+#include "multicast.h"
 #include "gateway_common.h"
 #include "hash.h"
 #include "bat_algo.h"
@@ -115,6 +116,9 @@ int batadv_mesh_init(struct net_device *soft_iface)
 	INIT_LIST_HEAD(&bat_priv->tt.changes_list);
 	INIT_LIST_HEAD(&bat_priv->tt.req_list);
 	INIT_LIST_HEAD(&bat_priv->tt.roam_list);
+#ifdef CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS
+	INIT_LIST_HEAD(&bat_priv->mcast.mla_list);
+#endif
 	INIT_HLIST_HEAD(&bat_priv->tvlv.container_list);
 	INIT_HLIST_HEAD(&bat_priv->tvlv.handler_list);
 
@@ -168,6 +172,8 @@ void batadv_mesh_free(struct net_device *soft_iface)
 	batadv_dat_free(bat_priv);
 	batadv_bla_free(bat_priv);
 
+	batadv_mcast_free(bat_priv);
+
 	/* Free the TT and the originator tables only after having terminated
 	 * all the other depending components which may use these structures for
 	 * their purposes.
diff --git a/main.h b/main.h
index 1f0b135..87db514 100644
--- a/main.h
+++ b/main.h
@@ -164,6 +164,7 @@ enum batadv_uev_type {
 #include <linux/percpu.h>
 #include <linux/slab.h>
 #include <net/sock.h>		/* struct sock */
+#include <net/addrconf.h>	/* ipv6 address stuff */
 #include <net/rtnetlink.h>
 #include <linux/jiffies.h>
 #include <linux/seq_file.h>
diff --git a/multicast.c b/multicast.c
new file mode 100644
index 0000000..d6d8b62
--- /dev/null
+++ b/multicast.c
@@ -0,0 +1,209 @@
+/* Copyright (C) 2013 B.A.T.M.A.N. contributors:
+ *
+ * Linus Lüssing
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA
+ */
+
+#include "main.h"
+#include "originator.h"
+#include "hard-interface.h"
+#include "translation-table.h"
+
+struct batadv_hw_addr {
+	struct list_head	list;
+	unsigned char addr[ETH_ALEN];
+};
+
+/**
+ * batadv_mcast_mla_local_collect - collect local multicast listeners
+ * @dev: the device to collect multicast addresses from
+ * @mcast_list: a list to put found addresses into
+ *
+ * Collect multicast addresses of the local multicast listeners
+ * on the given interface, dev, in the given mcast_list.
+ *
+ * Return -ENOMEM on memory allocation error or the number of
+ * items added to the mcast_list otherwise.
+ */
+static int batadv_mcast_mla_local_collect(struct net_device *dev,
+					  struct list_head *mcast_list)
+{
+	struct netdev_hw_addr *mc_list_entry;
+	struct batadv_hw_addr *new;
+	int ret = 0;
+
+	netif_addr_lock_bh(dev);
+	netdev_for_each_mc_addr(mc_list_entry, dev) {
+		new = kmalloc(sizeof(*new), GFP_ATOMIC);
+		if (!new) {
+			ret = -ENOMEM;
+			break;
+		}
+
+		memcpy(&new->addr, &mc_list_entry->addr, ETH_ALEN);
+		list_add(&new->list, mcast_list);
+		ret++;
+	}
+	netif_addr_unlock_bh(dev);
+
+	return ret;
+}
+
+/**
+ * batadv_mcast_mla_is_duplicate - check whether an address is in a list
+ * @mcast_addr: the multicast address to check
+ * @mcast_list: the list with multicast addresses to search in
+ *
+ * Return true if the given address is already in the given list.
+ * Otherwise returns false.
+ */
+static bool batadv_mcast_mla_is_duplicate(uint8_t *mcast_addr,
+					  struct list_head *mcast_list)
+{
+	struct batadv_hw_addr *mcast_entry;
+
+	list_for_each_entry(mcast_entry, mcast_list, list)
+		if (batadv_compare_eth(mcast_entry->addr, mcast_addr))
+			return true;
+
+	return false;
+}
+
+/**
+ * batadv_mcast_mla_collect_free - free a list of multicast addresses
+ * @mcast_list: the list to free
+ *
+ * Remove and free all items in the given mcast_list.
+ */
+void batadv_mcast_mla_collect_free(struct list_head *mcast_list)
+{
+	struct batadv_hw_addr *mcast_entry, *tmp;
+
+	list_for_each_entry_safe(mcast_entry, tmp, mcast_list, list) {
+		list_del(&mcast_entry->list);
+		kfree(mcast_entry);
+	}
+}
+
+/**
+ * batadv_mcast_mla_tt_clean - clean up multicast listener announcements
+ * @bat_priv: the bat priv with all the soft interface information
+ * @mcast_list: a list of addresses which should _not_ be removed
+ *
+ * Retract the announcement of any multicast listener from the
+ * translation table except the ones listed in the given mcast_list.
+ *
+ * If mcast_list is NULL then all are retracted.
+ */
+static void batadv_mcast_mla_tt_clean(struct batadv_priv *bat_priv,
+				      struct list_head *mcast_list)
+{
+	struct batadv_hw_addr *mcast_entry, *tmp;
+
+	list_for_each_entry_safe(mcast_entry, tmp, &bat_priv->mcast.mla_list,
+				 list) {
+		if (mcast_list &&
+		    batadv_mcast_mla_is_duplicate(mcast_entry->addr,
+						  mcast_list))
+			continue;
+
+		batadv_tt_local_remove(bat_priv, mcast_entry->addr,
+				       "mcast TT outdated", false);
+
+		list_del(&mcast_entry->list);
+		kfree(mcast_entry);
+	}
+}
+
+/**
+ * batadv_mcast_mla_tt_add - add multicast listener announcements
+ * @bat_priv: the bat priv with all the soft interface information
+ * @mcast_list: a list of addresses which are going to get added
+ *
+ * Add multicast listener announcements from the given mcast_list to the
+ * translation table if they have not been added yet.
+ */
+static void batadv_mcast_mla_tt_add(struct batadv_priv *bat_priv,
+				    struct list_head *mcast_list)
+{
+	struct batadv_hw_addr *mcast_entry, *tmp;
+
+	if (!mcast_list)
+		return;
+
+	list_for_each_entry_safe(mcast_entry, tmp, mcast_list, list) {
+		if (batadv_mcast_mla_is_duplicate(mcast_entry->addr,
+						  &bat_priv->mcast.mla_list))
+			continue;
+
+		batadv_tt_local_add(bat_priv->soft_iface, mcast_entry->addr,
+				    BATADV_NULL_IFINDEX);
+		list_move_tail(&mcast_entry->list, &bat_priv->mcast.mla_list);
+	}
+}
+
+/**
+ * batadv_mcast_mla_tt_update - update the own MLAs
+ * @bat_priv: the bat priv with all the soft interface information
+ *
+ * Update the own multicast listener announcements in the translation
+ * table. Also take care of registering or unregistering the multicast
+ * tvlv depending on whether the user activated or deactivated
+ * multicast optimizations.
+ */
+void batadv_mcast_mla_tt_update(struct batadv_priv *bat_priv)
+{
+	struct net_device *soft_iface = bat_priv->soft_iface;
+	struct list_head mcast_list;
+	int ret;
+	static bool enabled;
+
+	INIT_LIST_HEAD(&mcast_list);
+
+	/* Avoid attaching MLAs, if multicast optimization is disabled
+	 * or there is a bridge on top of our soft interface (TODO)
+	 */
+	if (!atomic_read(&bat_priv->mcast_group_awareness) ||
+	    bat_priv->soft_iface->priv_flags & IFF_BRIDGE_PORT) {
+		if (enabled)
+			enabled = false;
+
+		goto update;
+	}
+
+	if (!enabled)
+		enabled = true;
+
+	ret = batadv_mcast_mla_local_collect(soft_iface, &mcast_list);
+	if (ret < 0)
+		goto out;
+
+update:
+	batadv_mcast_mla_tt_clean(bat_priv, &mcast_list);
+	batadv_mcast_mla_tt_add(bat_priv, &mcast_list);
+
+out:
+	batadv_mcast_mla_collect_free(&mcast_list);
+}
+
+/**
+ * batadv_mcast_free - free the multicast optimizations structures
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+void batadv_mcast_free(struct batadv_priv *bat_priv)
+{
+	batadv_mcast_mla_tt_clean(bat_priv, NULL);
+}
diff --git a/multicast.h b/multicast.h
new file mode 100644
index 0000000..3b68e3b
--- /dev/null
+++ b/multicast.h
@@ -0,0 +1,43 @@
+/* Copyright (C) 2013 B.A.T.M.A.N. contributors:
+ *
+ * Linus Lüssing
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA
+ */
+
+#ifndef _NET_BATMAN_ADV_MULTICAST_H_
+#define _NET_BATMAN_ADV_MULTICAST_H_
+
+#ifdef CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS
+
+void batadv_mcast_mla_tt_update(struct batadv_priv *bat_priv);
+
+void batadv_mcast_free(struct batadv_priv *bat_priv);
+
+#else
+
+static inline void batadv_mcast_mla_tt_update(struct batadv_priv *bat_priv)
+{
+	return;
+}
+
+static inline void batadv_mcast_free(struct batadv_priv *bat_priv)
+{
+	return;
+}
+
+#endif /* CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS */
+
+#endif /* _NET_BATMAN_ADV_MULTICAST_H_ */
diff --git a/soft-interface.c b/soft-interface.c
index d4fdc61..52244b0 100644
--- a/soft-interface.c
+++ b/soft-interface.c
@@ -456,6 +456,9 @@ static int batadv_softif_init_late(struct net_device *dev)
 #ifdef CONFIG_BATMAN_ADV_DAT
 	atomic_set(&bat_priv->distributed_arp_table, 1);
 #endif
+#ifdef CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS
+	atomic_set(&bat_priv->mcast_group_awareness, 1);
+#endif
 	atomic_set(&bat_priv->ap_isolation, 0);
 	atomic_set(&bat_priv->gw_mode, BATADV_GW_MODE_OFF);
 	atomic_set(&bat_priv->gw_sel_class, 20);
diff --git a/sysfs.c b/sysfs.c
index b70ae52..cc4e7e5 100644
--- a/sysfs.c
+++ b/sysfs.c
@@ -369,6 +369,9 @@ BATADV_ATTR_SIF_UINT(gw_sel_class, S_IRUGO | S_IWUSR, 1, BATADV_TQ_MAX_VALUE,
 		     batadv_post_gw_deselect);
 static BATADV_ATTR(gw_bandwidth, S_IRUGO | S_IWUSR, batadv_show_gw_bwidth,
 		   batadv_store_gw_bwidth);
+#ifdef CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS
+BATADV_ATTR_SIF_BOOL(mcast_group_awareness, S_IRUGO | S_IWUSR, NULL);
+#endif
 #ifdef CONFIG_BATMAN_ADV_DEBUG
 BATADV_ATTR_SIF_UINT(log_level, S_IRUGO | S_IWUSR, 0, BATADV_DBG_ALL, NULL);
 #endif
@@ -386,6 +389,9 @@ static struct batadv_attribute *batadv_mesh_attrs[] = {
 #ifdef CONFIG_BATMAN_ADV_DAT
 	&batadv_attr_distributed_arp_table,
 #endif
+#ifdef CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS
+	&batadv_attr_mcast_group_awareness,
+#endif
 	&batadv_attr_fragmentation,
 	&batadv_attr_ap_isolation,
 	&batadv_attr_routing_algo,
diff --git a/translation-table.c b/translation-table.c
index 7580ee5..0be7b15 100644
--- a/translation-table.c
+++ b/translation-table.c
@@ -26,6 +26,7 @@
 #include "originator.h"
 #include "routing.h"
 #include "bridge_loop_avoidance.h"
+#include "multicast.h"
 
 #include <linux/crc32c.h>
 
@@ -277,14 +278,16 @@ void batadv_tt_local_add(struct net_device *soft_iface, const uint8_t *addr,
 {
 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
 	struct batadv_tt_local_entry *tt_local;
-	struct batadv_tt_global_entry *tt_global;
+	struct batadv_tt_global_entry *tt_global = NULL;
 	struct hlist_head *head;
 	struct batadv_tt_orig_list_entry *orig_entry;
 	int hash_added;
 	bool roamed_back = false;
 
 	tt_local = batadv_tt_local_hash_find(bat_priv, addr);
-	tt_global = batadv_tt_global_hash_find(bat_priv, addr);
+
+	if (!is_multicast_ether_addr(addr))
+		tt_global = batadv_tt_global_hash_find(bat_priv, addr);
 
 	if (tt_local) {
 		tt_local->last_seen = jiffies;
@@ -335,8 +338,11 @@ void batadv_tt_local_add(struct net_device *soft_iface, const uint8_t *addr,
 	tt_local->last_seen = jiffies;
 	tt_local->common.added_at = tt_local->last_seen;
 
-	/* the batman interface mac address should never be purged */
-	if (batadv_compare_eth(addr, soft_iface->dev_addr))
+	/* the batman interface mac and multicast addresses should never be
+	 * purged
+	 */
+	if (batadv_compare_eth(addr, soft_iface->dev_addr) ||
+	    is_multicast_ether_addr(addr))
 		tt_local->common.flags |= BATADV_TT_CLIENT_NOPURGE;
 
 	hash_added = batadv_hash_add(bat_priv->tt.local_hash, batadv_compare_tt,
@@ -922,6 +928,11 @@ add_orig_entry:
 	ret = true;
 
 out_remove:
+	/* Do not remove multicast addresses from the local hash on
+	 * global additions
+	 */
+	if (is_multicast_ether_addr(tt_addr))
+		goto out;
 
 	/* remove address from local hash if present */
 	local_flags = batadv_tt_local_remove(bat_priv, tt_addr,
@@ -2348,6 +2359,9 @@ void batadv_tt_local_commit_changes(struct batadv_priv *bat_priv)
 {
 	uint16_t changed_num = 0;
 
+	/* Update multicast addresses in local translation table */
+	batadv_mcast_mla_tt_update(bat_priv);
+
 	if (atomic_read(&bat_priv->tt.local_changes) < 1) {
 		if (!batadv_atomic_dec_not_zero(&bat_priv->tt.ogm_append_cnt))
 			batadv_tt_tvlv_container_update(bat_priv);
diff --git a/types.h b/types.h
index 304f3d0..8175424 100644
--- a/types.h
+++ b/types.h
@@ -501,6 +501,12 @@ struct batadv_priv_dat {
 };
 #endif
 
+#ifdef CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS
+struct batadv_priv_mcast {
+	struct list_head mla_list;
+};
+#endif
+
 /**
  * struct batadv_priv_nc - per mesh interface network coding private data
  * @work: work queue callback item for cleanup
@@ -591,6 +597,9 @@ struct batadv_priv {
 #ifdef CONFIG_BATMAN_ADV_DAT
 	atomic_t distributed_arp_table;
 #endif
+#ifdef CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS
+	atomic_t mcast_group_awareness;
+#endif
 	atomic_t gw_mode;
 	atomic_t gw_sel_class;
 	atomic_t orig_interval;
@@ -625,6 +634,9 @@ struct batadv_priv {
 #ifdef CONFIG_BATMAN_ADV_DAT
 	struct batadv_priv_dat dat;
 #endif
+#ifdef CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS
+	struct batadv_priv_mcast mcast;
+#endif
 #ifdef CONFIG_BATMAN_ADV_NC
 	atomic_t network_coding;
 	struct batadv_priv_nc nc;
-- 
1.7.10.4

[B.A.T.M.A.N.] [PATCH 2/3] batman-adv: Announce new capability via multicast TVLV

[Linus Lüssing]

If the soft interface of a node is not part of a bridge then a node
announces a new multicast TVLV: The according flag
(BATADV_MCAST_LISTENER_ANNOUNCEMENT) signalizes that this node is
announcing all of its multicast listeners via the translation table
infrastructure. More precisely, all multicast listeners of scope greater
than link-local for IPv4 and of scope greater
or equal to link-local for IPv6.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
---
 main.c           |    4 ++++
 multicast.c      |   68 ++++++++++++++++++++++++++++++++++++++++++++++++++++--
 multicast.h      |   14 +++++++++++
 originator.c     |    6 +++++
 packet.h         |    7 ++++++
 soft-interface.c |    1 +
 types.h          |    4 ++++
 7 files changed, 102 insertions(+), 2 deletions(-)

diff --git a/main.c b/main.c
index fc5789c..968f77a 100644
--- a/main.c
+++ b/main.c
@@ -145,6 +145,10 @@ int batadv_mesh_init(struct net_device *soft_iface)
 	if (ret < 0)
 		goto err;
 
+	ret = batadv_mcast_init(bat_priv);
+	if (ret < 0)
+		goto err;
+
 	ret = batadv_gw_init(bat_priv);
 	if (ret < 0)
 		goto err;
diff --git a/multicast.c b/multicast.c
index d6d8b62..6375347 100644
--- a/multicast.c
+++ b/multicast.c
@@ -170,6 +170,7 @@ void batadv_mcast_mla_tt_update(struct batadv_priv *bat_priv)
 	struct list_head mcast_list;
 	int ret;
 	static bool enabled;
+	uint8_t mcast_flags;
 
 	INIT_LIST_HEAD(&mcast_list);
 
@@ -178,14 +179,22 @@ void batadv_mcast_mla_tt_update(struct batadv_priv *bat_priv)
 	 */
 	if (!atomic_read(&bat_priv->mcast_group_awareness) ||
 	    bat_priv->soft_iface->priv_flags & IFF_BRIDGE_PORT) {
-		if (enabled)
+		if (enabled) {
+			batadv_tvlv_container_unregister(bat_priv,
+							 BATADV_TVLV_MCAST, 1);
 			enabled = false;
+		}
 
 		goto update;
 	}
 
-	if (!enabled)
+	if (!enabled) {
+		mcast_flags = BATADV_MCAST_LISTENER_ANNOUNCEMENT;
+		batadv_tvlv_container_register(bat_priv, BATADV_TVLV_MCAST, 1,
+					       &mcast_flags,
+					       sizeof(mcast_flags));
 		enabled = true;
+	}
 
 	ret = batadv_mcast_mla_local_collect(soft_iface, &mcast_list);
 	if (ret < 0)
@@ -200,10 +209,65 @@ out:
 }
 
 /**
+ * batadv_mcast_tvlv_ogm_handler_v1 - process incoming multicast tvlv container
+ * @bat_priv: the bat priv with all the soft interface information
+ * @orig: the orig_node of the ogm
+ * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
+ * @tvlv_value: tvlv buffer containing the multicast data
+ * @tvlv_value_len: tvlv buffer length
+ */
+static void batadv_mcast_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
+					     struct batadv_orig_node *orig,
+					     uint8_t flags,
+					     void *tvlv_value,
+					     uint16_t tvlv_value_len)
+{
+	uint8_t mcast_flags = BATADV_NO_FLAGS;
+
+	/* only fetch the tvlv value if the handler wasn't called via the
+	 * CIFNOTFND flag and if there is data to fetch
+	 */
+	if (!(flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND) &&
+	    (tvlv_value) && (tvlv_value_len == sizeof(mcast_flags)))
+		mcast_flags = *(uint8_t *)tvlv_value;
+
+	if (!(mcast_flags & BATADV_MCAST_LISTENER_ANNOUNCEMENT) &&
+	    orig->mcast_flags & BATADV_MCAST_LISTENER_ANNOUNCEMENT) {
+		atomic_inc(&bat_priv->mcast.num_no_mla);
+	} else if (mcast_flags & BATADV_MCAST_LISTENER_ANNOUNCEMENT &&
+		   !(orig->mcast_flags & BATADV_MCAST_LISTENER_ANNOUNCEMENT)) {
+		atomic_dec(&bat_priv->mcast.num_no_mla);
+	}
+
+	orig->mcast_flags = mcast_flags;
+}
+
+/**
+ * batadv_mcast_init - initialize the multicast optimizations structures
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+int batadv_mcast_init(struct batadv_priv *bat_priv)
+{
+	batadv_tvlv_handler_register(bat_priv, batadv_mcast_tvlv_ogm_handler_v1,
+				     NULL, BATADV_TVLV_MCAST, 1,
+				     BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
+	return 0;
+}
+
+/**
  * batadv_mcast_free - free the multicast optimizations structures
  * @bat_priv: the bat priv with all the soft interface information
  */
 void batadv_mcast_free(struct batadv_priv *bat_priv)
 {
+	batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_MCAST, 1);
+	batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_MCAST, 1);
+
 	batadv_mcast_mla_tt_clean(bat_priv, NULL);
 }
+
+void batadv_mcast_purge_orig(struct batadv_orig_node *orig_node)
+{
+	if (!(orig_node->mcast_flags & BATADV_MCAST_LISTENER_ANNOUNCEMENT))
+		atomic_dec(&orig_node->bat_priv->mcast.num_no_mla);
+}
diff --git a/multicast.h b/multicast.h
index 3b68e3b..aa58e4b 100644
--- a/multicast.h
+++ b/multicast.h
@@ -24,8 +24,12 @@
 
 void batadv_mcast_mla_tt_update(struct batadv_priv *bat_priv);
 
+int batadv_mcast_init(struct batadv_priv *bat_priv);
+
 void batadv_mcast_free(struct batadv_priv *bat_priv);
 
+void batadv_mcast_purge_orig(struct batadv_orig_node *orig_node);
+
 #else
 
 static inline void batadv_mcast_mla_tt_update(struct batadv_priv *bat_priv)
@@ -33,11 +37,21 @@ static inline void batadv_mcast_mla_tt_update(struct batadv_priv *bat_priv)
 	return;
 }
 
+static inline int batadv_mcast_init(struct batadv_priv *bat_priv)
+{
+	return 0;
+}
+
 static inline void batadv_mcast_free(struct batadv_priv *bat_priv)
 {
 	return;
 }
 
+static inline void batadv_mcast_purge_orig(struct batadv_orig_node *orig_node)
+{
+	return;
+}
+
 #endif /* CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS */
 
 #endif /* _NET_BATMAN_ADV_MULTICAST_H_ */
diff --git a/originator.c b/originator.c
index a591dc5..5e827fa 100644
--- a/originator.c
+++ b/originator.c
@@ -29,6 +29,7 @@
 #include "bridge_loop_avoidance.h"
 #include "network-coding.h"
 #include "fragmentation.h"
+#include "multicast.h"
 
 /* hash class keys */
 static struct lock_class_key batadv_orig_hash_lock_class_key;
@@ -143,6 +144,8 @@ static void batadv_orig_node_free_rcu(struct rcu_head *rcu)
 
 	spin_unlock_bh(&orig_node->neigh_list_lock);
 
+	batadv_mcast_purge_orig(orig_node);
+
 	/* Free nc_nodes */
 	batadv_nc_purge_orig(orig_node->bat_priv, orig_node, NULL);
 
@@ -258,6 +261,9 @@ struct batadv_orig_node *batadv_get_orig_node(struct batadv_priv *bat_priv,
 	reset_time = jiffies - 1 - msecs_to_jiffies(BATADV_RESET_PROTECTION_MS);
 	orig_node->bcast_seqno_reset = reset_time;
 	orig_node->batman_seqno_reset = reset_time;
+#ifdef CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS
+	orig_node->mcast_flags = BATADV_MCAST_LISTENER_ANNOUNCEMENT;
+#endif
 
 	atomic_set(&orig_node->bond_candidates, 0);
 
diff --git a/packet.h b/packet.h
index e3ae41a..0d616f9 100644
--- a/packet.h
+++ b/packet.h
@@ -91,6 +91,11 @@ enum batadv_icmp_packettype {
 	BATADV_PARAMETER_PROBLEM       = 12,
 };
 
+/* multicast capabilities */
+enum batadv_mcast_flags {
+	BATADV_MCAST_LISTENER_ANNOUNCEMENT = BIT(0),
+};
+
 /* tt data subtypes */
 #define BATADV_TT_DATA_TYPE_MASK 0x0F
 
@@ -137,6 +142,7 @@ enum batadv_bla_claimframe {
  * @BATADV_TVLV_NC: network coding tvlv
  * @BATADV_TVLV_TT: translation table tvlv
  * @BATADV_TVLV_ROAM: roaming advertisement tvlv
+ * @BATADV_TVLV_MCAST: multicast capability tvlv
  */
 enum batadv_tvlv_type {
 	BATADV_TVLV_GW		= 0x01,
@@ -144,6 +150,7 @@ enum batadv_tvlv_type {
 	BATADV_TVLV_NC		= 0x03,
 	BATADV_TVLV_TT		= 0x04,
 	BATADV_TVLV_ROAM	= 0x05,
+	BATADV_TVLV_MCAST	= 0x06,
 };
 
 /* the destination hardware field in the ARP frame is used to
diff --git a/soft-interface.c b/soft-interface.c
index 52244b0..bc0cc35 100644
--- a/soft-interface.c
+++ b/soft-interface.c
@@ -458,6 +458,7 @@ static int batadv_softif_init_late(struct net_device *dev)
 #endif
 #ifdef CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS
 	atomic_set(&bat_priv->mcast_group_awareness, 1);
+	atomic_set(&bat_priv->mcast.num_no_mla, 0);
 #endif
 	atomic_set(&bat_priv->ap_isolation, 0);
 	atomic_set(&bat_priv->gw_mode, BATADV_GW_MODE_OFF);
diff --git a/types.h b/types.h
index 8175424..0586693 100644
--- a/types.h
+++ b/types.h
@@ -163,6 +163,9 @@ struct batadv_orig_node {
 	unsigned long last_seen;
 	unsigned long bcast_seqno_reset;
 	unsigned long batman_seqno_reset;
+#ifdef CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS
+	uint8_t mcast_flags;
+#endif
 	uint8_t capabilities;
 	atomic_t last_ttvn;
 	uint32_t tt_crc;
@@ -504,6 +507,7 @@ struct batadv_priv_dat {
 #ifdef CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS
 struct batadv_priv_mcast {
 	struct list_head mla_list;
+	atomic_t num_no_mla;
 };
 #endif
 
-- 
1.7.10.4

[B.A.T.M.A.N.] [PATCH 3/3] batman-adv: Modified forwarding behaviour for multicast packets

[Linus Lüssing]

With this patch a multicast packet is not always simply flooded anymore,
the bevahiour for the following cases is changed to reduce
unnecessary overhead:

If all nodes within the horizon of a certain node have signalized
multicast listener announcement capability
(BATADV_MCAST_LISTENER_ANNOUNCEMENT) then an IPv6 multicast packet
with a destination of IPv6 link-local scope coming from the upstream
of this node...

* ...is dropped if there is no according multicast listener in the
  translation table,
* ...is forwarded via unicast if there is a single node with interested
  multicast listeners
* ...and otherwise still gets flooded.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
---
 multicast.c         |   49 ++++++++++++++++++++++++++++++++++++++
 multicast.h         |   23 ++++++++++++++++++
 soft-interface.c    |   11 +++++++++
 translation-table.c |   66 +++++++++++++++++++++++++++++++++++++++++++++++++++
 translation-table.h |    1 +
 5 files changed, 150 insertions(+)

diff --git a/multicast.c b/multicast.c
index 6375347..e4bcdb2 100644
--- a/multicast.c
+++ b/multicast.c
@@ -21,6 +21,7 @@
 #include "originator.h"
 #include "hard-interface.h"
 #include "translation-table.h"
+#include "multicast.h"
 
 struct batadv_hw_addr {
 	struct list_head	list;
@@ -209,6 +210,54 @@ out:
 }
 
 /**
+ * batadv_mcast_forw_mode - check on how to forward a multicast packet
+ * @skb: The multicast packet to check
+ * @bat_priv: the bat priv with all the soft interface information
+ *
+ * Return the forwarding mode as enum batadv_forw_mode.
+ */
+enum batadv_forw_mode
+batadv_mcast_forw_mode(struct sk_buff *skb, struct batadv_priv *bat_priv)
+{
+	struct ethhdr *ethhdr = (struct ethhdr *)(skb->data);
+	struct ipv6hdr *ip6hdr;
+	int count;
+
+	if (!atomic_read(&bat_priv->mcast_group_awareness))
+		return BATADV_FORW_ALL;
+
+	if (atomic_read(&bat_priv->mcast.num_no_mla))
+		return BATADV_FORW_ALL;
+
+	if (ntohs(ethhdr->h_proto) != ETH_P_IPV6)
+		return BATADV_FORW_ALL;
+
+	/* We might fail due to out-of-memory -> drop it */
+	if (!pskb_may_pull(skb, sizeof(*ethhdr) + sizeof(*ip6hdr)))
+		return BATADV_FORW_NONE;
+
+	ip6hdr = ipv6_hdr(skb);
+
+	/* TODO: Implement Multicast Router Discovery, then add
+	 * scope >= IPV6_ADDR_SCOPE_LINKLOCAL, too
+	 */
+	if (IPV6_ADDR_MC_SCOPE(&ip6hdr->daddr) !=
+	    IPV6_ADDR_SCOPE_LINKLOCAL)
+		return BATADV_FORW_ALL;
+
+	count = batadv_tt_global_hash_count(bat_priv, ethhdr->h_dest);
+
+	switch (count) {
+	case 0:
+		return BATADV_FORW_NONE;
+	case 1:
+		return BATADV_FORW_SINGLE;
+	default:
+		return BATADV_FORW_ALL;
+	}
+}
+
+/**
  * batadv_mcast_tvlv_ogm_handler_v1 - process incoming multicast tvlv container
  * @bat_priv: the bat priv with all the soft interface information
  * @orig: the orig_node of the ogm
diff --git a/multicast.h b/multicast.h
index aa58e4b..6388793 100644
--- a/multicast.h
+++ b/multicast.h
@@ -20,10 +20,27 @@
 #ifndef _NET_BATMAN_ADV_MULTICAST_H_
 #define _NET_BATMAN_ADV_MULTICAST_H_
 
+/**
+ * batadv_forw_mode - the way a packet should be forwarded as
+ * @BATADV_FORW_ALL: forward the packet to all nodes
+ *  (currently via classic flooding)
+ * @BATADV_FORW_SINGLE: forward the packet to a single node
+ *  (currently via the BATMAN_IV unicast routing protocol)
+ * @BATADV_FORW_NONE: don't forward, drop it
+ */
+enum batadv_forw_mode {
+	BATADV_FORW_ALL,
+	BATADV_FORW_SINGLE,
+	BATADV_FORW_NONE,
+};
+
 #ifdef CONFIG_BATMAN_ADV_MCAST_OPTIMIZATIONS
 
 void batadv_mcast_mla_tt_update(struct batadv_priv *bat_priv);
 
+enum batadv_forw_mode
+batadv_mcast_forw_mode(struct sk_buff *skb, struct batadv_priv *bat_priv);
+
 int batadv_mcast_init(struct batadv_priv *bat_priv);
 
 void batadv_mcast_free(struct batadv_priv *bat_priv);
@@ -37,6 +54,12 @@ static inline void batadv_mcast_mla_tt_update(struct batadv_priv *bat_priv)
 	return;
 }
 
+static inline batadv_forw_mode
+batadv_mcast_forw_mode(struct sk_buff *skb, struct batadv_priv *bat_priv)
+{
+	return BATADV_FORW_ALL;
+}
+
 static inline int batadv_mcast_init(struct batadv_priv *bat_priv)
 {
 	return 0;
diff --git a/soft-interface.c b/soft-interface.c
index bc0cc35..7ff5a02 100644
--- a/soft-interface.c
+++ b/soft-interface.c
@@ -34,6 +34,7 @@
 #include <linux/ethtool.h>
 #include <linux/etherdevice.h>
 #include <linux/if_vlan.h>
+#include "multicast.h"
 #include "bridge_loop_avoidance.h"
 #include "network-coding.h"
 
@@ -156,6 +157,7 @@ static int batadv_interface_tx(struct sk_buff *skb,
 	bool do_bcast = false;
 	uint32_t seqno;
 	unsigned long brd_delay = 1;
+	enum batadv_forw_mode mode;
 
 	if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
 		goto dropped;
@@ -218,6 +220,15 @@ static int batadv_interface_tx(struct sk_buff *skb,
 		default:
 			break;
 		}
+
+		if (do_bcast && !is_broadcast_ether_addr(ethhdr->h_dest)) {
+			mode = batadv_mcast_forw_mode(skb, bat_priv);
+			if (mode == BATADV_FORW_NONE)
+				goto dropped;
+
+			if (mode == BATADV_FORW_SINGLE)
+				do_bcast = false;
+		}
 	}
 
 	/* ethernet packet should be broadcasted */
diff --git a/translation-table.c b/translation-table.c
index 0be7b15..d14ee64 100644
--- a/translation-table.c
+++ b/translation-table.c
@@ -83,6 +83,72 @@ batadv_tt_hash_find(struct batadv_hashtable *hash, const void *data)
 	return tt_common_entry_tmp;
 }
 
+/**
+ * batadv_tt_orig_entries_count - count the number of originators
+ * @head: a list of originators
+ *
+ * Return the number of originator entries in the given list.
+ *
+ * The caller needs to hold the rcu_read_lock().
+ */
+static int batadv_tt_orig_entries_count(struct hlist_head *head)
+{
+	struct batadv_tt_orig_list_entry *orig_entry;
+	int count = 0;
+
+	hlist_for_each_entry_rcu(orig_entry, head, list) {
+		if (!atomic_read(&orig_entry->refcount))
+			continue;
+
+		count++;
+	}
+
+	return count;
+}
+
+/**
+ * batadv_tt_global_hash_count - count the number of orig entries
+ * @hash: hash table containing the tt entries
+ * @data: the data to count entries for
+ *
+ * Return the number of originators advertising the given address/data
+ * (excluding ourself).
+ */
+int batadv_tt_global_hash_count(struct batadv_priv *bat_priv, const void *data)
+{
+	struct hlist_head *head, *orig_list;
+	struct batadv_tt_common_entry *tt_common_entry;
+	struct batadv_tt_global_entry *tt_global_entry;
+	uint32_t index;
+	int count = 0;
+
+	if (!bat_priv->tt.global_hash)
+		goto out;
+
+	index = batadv_choose_orig(data, bat_priv->tt.global_hash->size);
+	head = &bat_priv->tt.global_hash->table[index];
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(tt_common_entry, head, hash_entry) {
+		if (!batadv_compare_eth(tt_common_entry, data))
+			continue;
+
+		if (!atomic_read(&tt_common_entry->refcount))
+			continue;
+
+		tt_global_entry = container_of(tt_common_entry,
+					       struct batadv_tt_global_entry,
+					       common);
+		orig_list = &tt_global_entry->orig_list;
+		count = batadv_tt_orig_entries_count(orig_list);
+		break;
+	}
+	rcu_read_unlock();
+
+out:
+	return count;
+}
+
 static struct batadv_tt_local_entry *
 batadv_tt_local_hash_find(struct batadv_priv *bat_priv, const void *data)
 {
diff --git a/translation-table.h b/translation-table.h
index 015d8b9..5986c57 100644
--- a/translation-table.h
+++ b/translation-table.h
@@ -31,6 +31,7 @@ int batadv_tt_global_seq_print_text(struct seq_file *seq, void *offset);
 void batadv_tt_global_del_orig(struct batadv_priv *bat_priv,
 			       struct batadv_orig_node *orig_node,
 			       const char *message);
+int batadv_tt_global_hash_count(struct batadv_priv *bat_priv, const void *data);
 struct batadv_orig_node *batadv_transtable_search(struct batadv_priv *bat_priv,
 						  const uint8_t *src,
 						  const uint8_t *addr);
-- 
1.7.10.4

Re: [B.A.T.M.A.N.] Basic Multicast Optimizations

[Linus Lüssing]

Hrm, forgot to add the v3 an the patch naming. And forgot to
actually add
-static inline batadv_forw_mode
+static inline enum batadv_forw_mode
to the according commit.

Will send a v4 in a sec.

Cheers, Linus

On Mon, Jun 10, 2013 at 08:28:18AM +0200, Linus Lüssing wrote:
> This is the third revision of the basic multicast optimization patches.
> It includes one functional and some compat fixes, and some style improvements,
> thanks to Simons feedback:
> 
> PATCHv3 1/3:
> * the pmc_rcu functions got removed - they weren't actually used in the
>   submitted revision - so there's no more patch for net to export
>   for_each_pmc_rcu() needed anymore. Should also fix Simon's compat error.
> * Compat code for netdev_for_each_mc_addr() added.
>   (I needed to introduce a batadv_hw_addr because I wasn't able to achieve
>   backwards compatibility with a netdev_hw_addr - my "official reasoning" will
>   be that netdev_hw_addr is unnecessarily bloated, struct batadv_hw_addr
>   has just the right size to do the job)
> * Compat fix for IFF_BRIDGE_PORT
> * Removed primary_if->soft_iface in batadv_mcast_mla_tt_update() as we
>   can always use bat_priv->soft_iface instead.
> 
> PATCHv3 2/3
> * Renamed num_non_aware to a more specific num_no_mla - because we will need
>   things like a num_no_tracker for instance with the multicast tracker feature
>   in the future.
> * Fixed removal of orig_node's without BATADV_MCAST_LISTENER_ANNOUNCEMENT
>   flag, update num_no_mla properly now.
> 
> PATCHv3 3/3
> * Renamed batadv_mcast_flood() to batadv_mcast_forw_mode() because it does not
>   only show whether to flood or not (=drop), but also whether to forward via
>   unicast. In the future with the multicast tracker feature a fourth return value
>   is going to be added, making the name "batadv_mcast_flood()" even less fitting.
> * Simon's style suggestions for batadv_mcast_forw_mode() and
>   batadv_interface_tx().
> * batadv_mcast_forw_mode() now returns an enum (thanks to Marek and Antonio for
>   the suggestion).
> 
> I did not change:
> > I don't quite understand why you return -1, maybe the packet could still
> > be forwarded even if it could not be pulled?
> 
> Because if it returns -1 then something is wrong, for instance we could be
> out of memory. If we are out of memory then we probably won't be able to
> forward any packet. Also we shouldn't allocate any more memory for one thing
> but I think it is also better to drop/free packets to save some memory
> to increase the possibility of the system to recover without crashing.
> 
> Cheers, Linus
>