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batman-adv: mcast: implement multicast packet generation
Implement the preparation of a batman-adv multicast packet and use this under certain conditions. For one thing this implements the capability to push a complete batman-adv multicast packet header, including a tracker TVLV with all originator destinations that have signaled interest in it, onto a given ethernet frame with an IP multicast packet inside. For another checks are implemented to determine if encapsulating a multicast packet in this new batman-adv multicast packet type and using it is feasible. Those checks are: 1) Have all nodes signaled that they are capable of handling the new batman-adv multicast packet type? 2) Do all active hard interfaces of all nodes, including us, have an MTU of at least 1280 bytes? 3) Does a complete multicast packet header with all its destination addresses fit onto the given multicast packet / ethernet frame and does not exceed 1280 bytes? If all checks passed then the new batman-adv multicast packet type will be used for transmission and distribution. Otherwise we fall back to one or more batman-adv unicast packet transmissions, if possible. Or if not possible we will fall back to classic flooding through a batman-adv broadcast packet. Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
This commit is contained in:
Linus Lüssing
Simon Wunderlich
parent
07afe1ba28
commit
9003913322
@ -1169,17 +1169,62 @@ static int batadv_mcast_forw_rtr_count(struct batadv_priv *bat_priv,
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}
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}
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/**
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* batadv_mcast_forw_mode_by_count() - get forwarding mode by count
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* @bat_priv: the bat priv with all the soft interface information
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* @skb: the multicast packet to check
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* @vid: the vlan identifier
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* @is_routable: stores whether the destination is routable
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* @count: the number of originators the multicast packet need to be sent to
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*
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* For a multicast packet with multiple destination originators, checks which
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* mode to use. For BATADV_FORW_MCAST it also encapsulates the packet with a
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* complete batman-adv multicast header.
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*
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* Return:
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* BATADV_FORW_MCAST: If all nodes have multicast packet routing
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* capabilities and an MTU >= 1280 on all hard interfaces (including us)
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* and the encapsulated multicast packet with all destination addresses
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* would still fit into an 1280 bytes batman-adv multicast packet
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* (excluding the outer ethernet frame) and we could successfully push
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* the full batman-adv multicast packet header.
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* BATADV_FORW_UCASTS: If the packet cannot be sent in a batman-adv
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* multicast packet and the amount of batman-adv unicast packets needed
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* is smaller or equal to the configured multicast fanout.
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* BATADV_FORW_BCAST: Otherwise.
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*/
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static enum batadv_forw_mode
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batadv_mcast_forw_mode_by_count(struct batadv_priv *bat_priv,
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struct sk_buff *skb, unsigned short vid,
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int is_routable, int count)
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{
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unsigned int mcast_hdrlen = batadv_mcast_forw_packet_hdrlen(count);
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u8 own_tvlv_flags = bat_priv->mcast.mla_flags.tvlv_flags;
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if (!atomic_read(&bat_priv->mcast.num_no_mc_ptype_capa) &&
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own_tvlv_flags & BATADV_MCAST_HAVE_MC_PTYPE_CAPA &&
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skb->len + mcast_hdrlen <= IPV6_MIN_MTU &&
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batadv_mcast_forw_push(bat_priv, skb, vid, is_routable, count))
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return BATADV_FORW_MCAST;
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if (count <= atomic_read(&bat_priv->multicast_fanout))
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return BATADV_FORW_UCASTS;
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return BATADV_FORW_BCAST;
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}
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/**
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* batadv_mcast_forw_mode() - check on how to forward a multicast packet
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* @bat_priv: the bat priv with all the soft interface information
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* @skb: the multicast packet to check
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* @vid: the vlan identifier
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* @is_routable: stores whether the destination is routable
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*
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* Return: The forwarding mode as enum batadv_forw_mode.
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*/
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enum batadv_forw_mode
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batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
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int *is_routable)
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unsigned short vid, int *is_routable)
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{
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int ret, tt_count, ip_count, unsnoop_count, total_count;
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bool is_unsnoopable = false;
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@ -1209,10 +1254,8 @@ batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
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else if (unsnoop_count)
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return BATADV_FORW_BCAST;
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if (total_count <= atomic_read(&bat_priv->multicast_fanout))
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return BATADV_FORW_UCASTS;
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return BATADV_FORW_BCAST;
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return batadv_mcast_forw_mode_by_count(bat_priv, skb, vid, *is_routable,
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total_count);
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}
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/**
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@ -1772,6 +1815,31 @@ static void batadv_mcast_want_rtr6_update(struct batadv_priv *bat_priv,
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}
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}
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/**
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* batadv_mcast_have_mc_ptype_update() - update multicast packet type counter
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* @bat_priv: the bat priv with all the soft interface information
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* @orig: the orig_node which multicast state might have changed of
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* @mcast_flags: flags indicating the new multicast state
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*
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* If the BATADV_MCAST_HAVE_MC_PTYPE_CAPA flag of this originator, orig, has
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* toggled then this method updates the counter accordingly.
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*/
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static void batadv_mcast_have_mc_ptype_update(struct batadv_priv *bat_priv,
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struct batadv_orig_node *orig,
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u8 mcast_flags)
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{
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lockdep_assert_held(&orig->mcast_handler_lock);
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/* switched from flag set to unset */
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if (!(mcast_flags & BATADV_MCAST_HAVE_MC_PTYPE_CAPA) &&
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orig->mcast_flags & BATADV_MCAST_HAVE_MC_PTYPE_CAPA)
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atomic_inc(&bat_priv->mcast.num_no_mc_ptype_capa);
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/* switched from flag unset to set */
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else if (mcast_flags & BATADV_MCAST_HAVE_MC_PTYPE_CAPA &&
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!(orig->mcast_flags & BATADV_MCAST_HAVE_MC_PTYPE_CAPA))
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atomic_dec(&bat_priv->mcast.num_no_mc_ptype_capa);
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}
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/**
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* batadv_mcast_tvlv_flags_get() - get multicast flags from an OGM TVLV
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* @enabled: whether the originator has multicast TVLV support enabled
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@ -1840,6 +1908,7 @@ static void batadv_mcast_tvlv_ogm_handler(struct batadv_priv *bat_priv,
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batadv_mcast_want_ipv6_update(bat_priv, orig, mcast_flags);
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batadv_mcast_want_rtr4_update(bat_priv, orig, mcast_flags);
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batadv_mcast_want_rtr6_update(bat_priv, orig, mcast_flags);
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batadv_mcast_have_mc_ptype_update(bat_priv, orig, mcast_flags);
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orig->mcast_flags = mcast_flags;
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spin_unlock_bh(&orig->mcast_handler_lock);
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@ -11,6 +11,7 @@
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#include <linux/netlink.h>
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#include <linux/skbuff.h>
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#include <linux/types.h>
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/**
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* enum batadv_forw_mode - the way a packet should be forwarded as
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@ -28,6 +29,12 @@ enum batadv_forw_mode {
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*/
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BATADV_FORW_UCASTS,
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/**
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* @BATADV_FORW_MCAST: forward the packet to some nodes via a
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* batman-adv multicast packet
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*/
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BATADV_FORW_MCAST,
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/** @BATADV_FORW_NONE: don't forward, drop it */
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BATADV_FORW_NONE,
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};
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@ -36,7 +43,7 @@ enum batadv_forw_mode {
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enum batadv_forw_mode
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batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
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int *is_routable);
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unsigned short vid, int *is_routable);
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int batadv_mcast_forw_send(struct batadv_priv *bat_priv, struct sk_buff *skb,
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unsigned short vid, int is_routable);
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@ -57,11 +64,18 @@ void batadv_mcast_purge_orig(struct batadv_orig_node *orig_node);
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int batadv_mcast_forw_tracker_tvlv_handler(struct batadv_priv *bat_priv,
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struct sk_buff *skb);
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unsigned int batadv_mcast_forw_packet_hdrlen(unsigned int num_dests);
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bool batadv_mcast_forw_push(struct batadv_priv *bat_priv, struct sk_buff *skb,
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unsigned short vid, int is_routable, int count);
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int batadv_mcast_forw_mcsend(struct batadv_priv *bat_priv, struct sk_buff *skb);
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#else
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static inline enum batadv_forw_mode
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batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
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int *is_routable)
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unsigned short vid, int *is_routable)
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{
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return BATADV_FORW_BCAST;
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}
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@ -99,6 +113,13 @@ static inline void batadv_mcast_purge_orig(struct batadv_orig_node *orig_node)
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{
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}
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static inline int batadv_mcast_forw_mcsend(struct batadv_priv *bat_priv,
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struct sk_buff *skb)
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{
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kfree_skb(skb);
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return NET_XMIT_DROP;
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}
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#endif /* CONFIG_BATMAN_ADV_MCAST */
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#endif /* _NET_BATMAN_ADV_MULTICAST_H_ */
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@ -7,19 +7,30 @@
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#include "multicast.h"
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#include "main.h"
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#include <linux/bug.h>
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#include <linux/build_bug.h>
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#include <linux/byteorder/generic.h>
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#include <linux/compiler.h>
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#include <linux/errno.h>
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#include <linux/etherdevice.h>
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#include <linux/gfp.h>
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#include <linux/if_ether.h>
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#include <linux/if_vlan.h>
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#include <linux/ipv6.h>
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#include <linux/limits.h>
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#include <linux/netdevice.h>
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#include <linux/rculist.h>
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#include <linux/rcupdate.h>
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#include <linux/skbuff.h>
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#include <linux/stddef.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <uapi/linux/batadv_packet.h>
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#include "bridge_loop_avoidance.h"
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#include "originator.h"
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#include "send.h"
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#include "translation-table.h"
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#define batadv_mcast_forw_tracker_for_each_dest(dest, num_dests) \
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for (; num_dests; num_dests--, (dest) += ETH_ALEN)
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@ -27,6 +38,600 @@
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#define batadv_mcast_forw_tracker_for_each_dest2(dest1, dest2, num_dests) \
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for (; num_dests; num_dests--, (dest1) += ETH_ALEN, (dest2) += ETH_ALEN)
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/**
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* batadv_mcast_forw_skb_push() - skb_push and memorize amount of pushed bytes
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* @skb: the skb to push onto
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* @size: the amount of bytes to push
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* @len: stores the total amount of bytes pushed
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*
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* Performs an skb_push() onto the given skb and adds the amount of pushed bytes
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* to the given len pointer.
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*
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* Return: the return value of the skb_push() call.
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*/
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static void *batadv_mcast_forw_skb_push(struct sk_buff *skb, size_t size,
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unsigned short *len)
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{
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*len += size;
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return skb_push(skb, size);
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}
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/**
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* batadv_mcast_forw_push_padding() - push 2 padding bytes to skb's front
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* @skb: the skb to push onto
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* @tvlv_len: stores the amount of currently pushed TVLV bytes
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*
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* Pushes two padding bytes to the front of the given skb.
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*
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* Return: On success a pointer to the first byte of the two pushed padding
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* bytes within the skb. NULL otherwise.
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*/
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static char *
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batadv_mcast_forw_push_padding(struct sk_buff *skb, unsigned short *tvlv_len)
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{
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const int pad_len = 2;
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char *padding;
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if (skb_headroom(skb) < pad_len)
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return NULL;
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padding = batadv_mcast_forw_skb_push(skb, pad_len, tvlv_len);
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memset(padding, 0, pad_len);
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return padding;
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}
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/**
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* batadv_mcast_forw_push_est_padding() - push padding bytes if necessary
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* @skb: the skb to potentially push the padding onto
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* @count: the (estimated) number of originators the multicast packet needs to
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* be sent to
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* @tvlv_len: stores the amount of currently pushed TVLV bytes
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*
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* If the number of destination entries is even then this adds two
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* padding bytes to the end of the tracker TVLV.
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*
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* Return: true on success or if no padding is needed, false otherwise.
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*/
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static bool
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batadv_mcast_forw_push_est_padding(struct sk_buff *skb, int count,
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unsigned short *tvlv_len)
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{
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if (!(count % 2) && !batadv_mcast_forw_push_padding(skb, tvlv_len))
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return false;
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return true;
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}
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/**
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* batadv_mcast_forw_orig_entry() - get orig_node from an hlist node
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* @node: the hlist node to get the orig_node from
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* @entry_offset: the offset of the hlist node within the orig_node struct
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*
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* Return: The orig_node containing the hlist node on success, NULL on error.
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*/
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static struct batadv_orig_node *
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batadv_mcast_forw_orig_entry(struct hlist_node *node,
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size_t entry_offset)
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{
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/* sanity check */
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switch (entry_offset) {
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case offsetof(struct batadv_orig_node, mcast_want_all_ipv4_node):
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case offsetof(struct batadv_orig_node, mcast_want_all_ipv6_node):
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case offsetof(struct batadv_orig_node, mcast_want_all_rtr4_node):
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case offsetof(struct batadv_orig_node, mcast_want_all_rtr6_node):
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break;
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default:
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WARN_ON(1);
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return NULL;
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}
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return (struct batadv_orig_node *)((void *)node - entry_offset);
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}
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/**
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* batadv_mcast_forw_push_dest() - push an originator MAC address onto an skb
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* @bat_priv: the bat priv with all the soft interface information
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* @skb: the skb to push the destination address onto
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* @vid: the vlan identifier
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* @orig_node: the originator node to get the MAC address from
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* @num_dests: a pointer to store the number of pushed addresses in
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* @tvlv_len: stores the amount of currently pushed TVLV bytes
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*
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* If the orig_node is a BLA backbone gateway, if there is not enough skb
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* headroom available or if num_dests is already at its maximum (65535) then
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* neither the skb nor num_dests is changed. Otherwise the originator's MAC
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* address is pushed onto the given skb and num_dests incremented by one.
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*
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* Return: true if the orig_node is a backbone gateway or if an orig address
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* was pushed successfully, false otherwise.
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*/
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static bool batadv_mcast_forw_push_dest(struct batadv_priv *bat_priv,
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struct sk_buff *skb, unsigned short vid,
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struct batadv_orig_node *orig_node,
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unsigned short *num_dests,
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unsigned short *tvlv_len)
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{
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BUILD_BUG_ON(sizeof_field(struct batadv_tvlv_mcast_tracker, num_dests)
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!= sizeof(__be16));
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/* Avoid sending to other BLA gateways - they already got the frame from
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* the LAN side we share with them.
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* TODO: Refactor to take BLA into account earlier in mode check.
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*/
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if (batadv_bla_is_backbone_gw_orig(bat_priv, orig_node->orig, vid))
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return true;
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if (skb_headroom(skb) < ETH_ALEN || *num_dests == U16_MAX)
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return false;
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batadv_mcast_forw_skb_push(skb, ETH_ALEN, tvlv_len);
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ether_addr_copy(skb->data, orig_node->orig);
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(*num_dests)++;
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return true;
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}
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/**
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* batadv_mcast_forw_push_dests_list() - push originators from list onto an skb
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* @bat_priv: the bat priv with all the soft interface information
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* @skb: the skb to push the destination addresses onto
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* @vid: the vlan identifier
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* @head: the list to gather originators from
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* @entry_offset: offset of an hlist node in an orig_node structure
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* @num_dests: a pointer to store the number of pushed addresses in
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* @tvlv_len: stores the amount of currently pushed TVLV bytes
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*
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* Push the MAC addresses of all originators in the given list onto the given
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* skb.
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*
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* Return: true on success, false otherwise.
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*/
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static int batadv_mcast_forw_push_dests_list(struct batadv_priv *bat_priv,
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struct sk_buff *skb,
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unsigned short vid,
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struct hlist_head *head,
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size_t entry_offset,
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unsigned short *num_dests,
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unsigned short *tvlv_len)
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{
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struct hlist_node *node;
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struct batadv_orig_node *orig_node;
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rcu_read_lock();
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__hlist_for_each_rcu(node, head) {
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orig_node = batadv_mcast_forw_orig_entry(node, entry_offset);
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if (!orig_node ||
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!batadv_mcast_forw_push_dest(bat_priv, skb, vid, orig_node,
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num_dests, tvlv_len)) {
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rcu_read_unlock();
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return false;
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}
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}
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rcu_read_unlock();
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return true;
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}
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/**
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* batadv_mcast_forw_push_tt() - push originators with interest through TT
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* @bat_priv: the bat priv with all the soft interface information
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* @skb: the skb to push the destination addresses onto
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* @vid: the vlan identifier
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* @num_dests: a pointer to store the number of pushed addresses in
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* @tvlv_len: stores the amount of currently pushed TVLV bytes
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*
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* Push the MAC addresses of all originators which have indicated interest in
|
||||
* this multicast packet through the translation table onto the given skb.
|
||||
*
|
||||
* Return: true on success, false otherwise.
|
||||
*/
|
||||
static bool
|
||||
batadv_mcast_forw_push_tt(struct batadv_priv *bat_priv, struct sk_buff *skb,
|
||||
unsigned short vid, unsigned short *num_dests,
|
||||
unsigned short *tvlv_len)
|
||||
{
|
||||
struct batadv_tt_orig_list_entry *orig_entry;
|
||||
|
||||
struct batadv_tt_global_entry *tt_global;
|
||||
const u8 *addr = eth_hdr(skb)->h_dest;
|
||||
|
||||
/* ok */
|
||||
int ret = true;
|
||||
|
||||
tt_global = batadv_tt_global_hash_find(bat_priv, addr, vid);
|
||||
if (!tt_global)
|
||||
goto out;
|
||||
|
||||
rcu_read_lock();
|
||||
hlist_for_each_entry_rcu(orig_entry, &tt_global->orig_list, list) {
|
||||
if (!batadv_mcast_forw_push_dest(bat_priv, skb, vid,
|
||||
orig_entry->orig_node,
|
||||
num_dests, tvlv_len)) {
|
||||
ret = false;
|
||||
break;
|
||||
}
|
||||
}
|
||||
rcu_read_unlock();
|
||||
|
||||
batadv_tt_global_entry_put(tt_global);
|
||||
|
||||
out:
|
||||
return ret;
|
||||
}
|
||||
|
||||
/**
|
||||
* batadv_mcast_forw_push_want_all() - push originators with want-all flag
|
||||
* @bat_priv: the bat priv with all the soft interface information
|
||||
* @skb: the skb to push the destination addresses onto
|
||||
* @vid: the vlan identifier
|
||||
* @num_dests: a pointer to store the number of pushed addresses in
|
||||
* @tvlv_len: stores the amount of currently pushed TVLV bytes
|
||||
*
|
||||
* Push the MAC addresses of all originators which have indicated interest in
|
||||
* this multicast packet through the want-all flag onto the given skb.
|
||||
*
|
||||
* Return: true on success, false otherwise.
|
||||
*/
|
||||
static bool batadv_mcast_forw_push_want_all(struct batadv_priv *bat_priv,
|
||||
struct sk_buff *skb,
|
||||
unsigned short vid,
|
||||
unsigned short *num_dests,
|
||||
unsigned short *tvlv_len)
|
||||
{
|
||||
struct hlist_head *head = NULL;
|
||||
size_t offset;
|
||||
int ret;
|
||||
|
||||
switch (eth_hdr(skb)->h_proto) {
|
||||
case htons(ETH_P_IP):
|
||||
head = &bat_priv->mcast.want_all_ipv4_list;
|
||||
offset = offsetof(struct batadv_orig_node,
|
||||
mcast_want_all_ipv4_node);
|
||||
break;
|
||||
case htons(ETH_P_IPV6):
|
||||
head = &bat_priv->mcast.want_all_ipv6_list;
|
||||
offset = offsetof(struct batadv_orig_node,
|
||||
mcast_want_all_ipv6_node);
|
||||
break;
|
||||
default:
|
||||
return false;
|
||||
}
|
||||
|
||||
ret = batadv_mcast_forw_push_dests_list(bat_priv, skb, vid, head,
|
||||
offset, num_dests, tvlv_len);
|
||||
if (!ret)
|
||||
return false;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
/**
|
||||
* batadv_mcast_forw_push_want_rtr() - push originators with want-router flag
|
||||
* @bat_priv: the bat priv with all the soft interface information
|
||||
* @skb: the skb to push the destination addresses onto
|
||||
* @vid: the vlan identifier
|
||||
* @num_dests: a pointer to store the number of pushed addresses in
|
||||
* @tvlv_len: stores the amount of currently pushed TVLV bytes
|
||||
*
|
||||
* Push the MAC addresses of all originators which have indicated interest in
|
||||
* this multicast packet through the want-all-rtr flag onto the given skb.
|
||||
*
|
||||
* Return: true on success, false otherwise.
|
||||
*/
|
||||
static bool batadv_mcast_forw_push_want_rtr(struct batadv_priv *bat_priv,
|
||||
struct sk_buff *skb,
|
||||
unsigned short vid,
|
||||
unsigned short *num_dests,
|
||||
unsigned short *tvlv_len)
|
||||
{
|
||||
struct hlist_head *head = NULL;
|
||||
size_t offset;
|
||||
int ret;
|
||||
|
||||
switch (eth_hdr(skb)->h_proto) {
|
||||
case htons(ETH_P_IP):
|
||||
head = &bat_priv->mcast.want_all_rtr4_list;
|
||||
offset = offsetof(struct batadv_orig_node,
|
||||
mcast_want_all_rtr4_node);
|
||||
break;
|
||||
case htons(ETH_P_IPV6):
|
||||
head = &bat_priv->mcast.want_all_rtr6_list;
|
||||
offset = offsetof(struct batadv_orig_node,
|
||||
mcast_want_all_rtr6_node);
|
||||
break;
|
||||
default:
|
||||
return false;
|
||||
}
|
||||
|
||||
ret = batadv_mcast_forw_push_dests_list(bat_priv, skb, vid, head,
|
||||
offset, num_dests, tvlv_len);
|
||||
if (!ret)
|
||||
return false;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
/**
|
||||
* batadv_mcast_forw_scrape() - remove bytes within skb data
|
||||
* @skb: the skb to remove bytes from
|
||||
* @offset: the offset from the skb data from which to scrape
|
||||
* @len: the amount of bytes to scrape starting from the offset
|
||||
*
|
||||
* Scrapes/removes len bytes from the given skb at the given offset from the
|
||||
* skb data.
|
||||
*
|
||||
* Caller needs to ensure that the region from the skb data's start up
|
||||
* to/including the to be removed bytes are linearized.
|
||||
*/
|
||||
static void batadv_mcast_forw_scrape(struct sk_buff *skb,
|
||||
unsigned short offset,
|
||||
unsigned short len)
|
||||
{
|
||||
char *to, *from;
|
||||
|
||||
SKB_LINEAR_ASSERT(skb);
|
||||
|
||||
to = skb_pull(skb, len);
|
||||
from = to - len;
|
||||
|
||||
memmove(to, from, offset);
|
||||
}
|
||||
|
||||
/**
|
||||
* batadv_mcast_forw_push_scrape_padding() - remove TVLV padding
|
||||
* @skb: the skb to potentially adjust the TVLV's padding on
|
||||
* @tvlv_len: stores the amount of currently pushed TVLV bytes
|
||||
*
|
||||
* Remove two padding bytes from the end of the multicast tracker TVLV,
|
||||
* from before the payload data.
|
||||
*
|
||||
* Caller needs to ensure that the TVLV bytes are linearized.
|
||||
*/
|
||||
static void batadv_mcast_forw_push_scrape_padding(struct sk_buff *skb,
|
||||
unsigned short *tvlv_len)
|
||||
{
|
||||
const int pad_len = 2;
|
||||
|
||||
batadv_mcast_forw_scrape(skb, *tvlv_len - pad_len, pad_len);
|
||||
*tvlv_len -= pad_len;
|
||||
}
|
||||
|
||||
/**
|
||||
* batadv_mcast_forw_push_insert_padding() - insert TVLV padding
|
||||
* @skb: the skb to potentially adjust the TVLV's padding on
|
||||
* @tvlv_len: stores the amount of currently pushed TVLV bytes
|
||||
*
|
||||
* Inserts two padding bytes at the end of the multicast tracker TVLV,
|
||||
* before the payload data in the given skb.
|
||||
*
|
||||
* Return: true on success, false otherwise.
|
||||
*/
|
||||
static bool batadv_mcast_forw_push_insert_padding(struct sk_buff *skb,
|
||||
unsigned short *tvlv_len)
|
||||
{
|
||||
unsigned short offset = *tvlv_len;
|
||||
char *to, *from = skb->data;
|
||||
|
||||
to = batadv_mcast_forw_push_padding(skb, tvlv_len);
|
||||
if (!to)
|
||||
return false;
|
||||
|
||||
memmove(to, from, offset);
|
||||
memset(to + offset, 0, *tvlv_len - offset);
|
||||
return true;
|
||||
}
|
||||
|
||||
/**
|
||||
* batadv_mcast_forw_push_adjust_padding() - adjust padding if necessary
|
||||
* @skb: the skb to potentially adjust the TVLV's padding on
|
||||
* @count: the estimated number of originators the multicast packet needs to
|
||||
* be sent to
|
||||
* @num_dests_pushed: the number of originators that were actually added to the
|
||||
* multicast packet's tracker TVLV
|
||||
* @tvlv_len: stores the amount of currently pushed TVLV bytes
|
||||
*
|
||||
* Adjusts the padding in the multicast packet's tracker TVLV depending on the
|
||||
* initially estimated amount of destinations versus the amount of destinations
|
||||
* that were actually added to the tracker TVLV.
|
||||
*
|
||||
* If the initial estimate was correct or at least the oddness was the same then
|
||||
* no padding adjustment is performed.
|
||||
* If the initially estimated number was even, so padding was initially added,
|
||||
* but it turned out to be odd then padding is removed.
|
||||
* If the initially estimated number was odd, so no padding was initially added,
|
||||
* but it turned out to be even then padding is added.
|
||||
*
|
||||
* Return: true if no padding adjustment is needed or the adjustment was
|
||||
* successful, false otherwise.
|
||||
*/
|
||||
static bool
|
||||
batadv_mcast_forw_push_adjust_padding(struct sk_buff *skb, int *count,
|
||||
unsigned short num_dests_pushed,
|
||||
unsigned short *tvlv_len)
|
||||
{
|
||||
int ret = true;
|
||||
|
||||
if (likely((num_dests_pushed % 2) == (*count % 2)))
|
||||
goto out;
|
||||
|
||||
/**
|
||||
* estimated even number of destinations, but turned out to be odd
|
||||
* -> remove padding
|
||||
*/
|
||||
if (!(*count % 2) && (num_dests_pushed % 2))
|
||||
batadv_mcast_forw_push_scrape_padding(skb, tvlv_len);
|
||||
/**
|
||||
* estimated odd number of destinations, but turned out to be even
|
||||
* -> add padding
|
||||
*/
|
||||
else if ((*count % 2) && (!(num_dests_pushed % 2)))
|
||||
ret = batadv_mcast_forw_push_insert_padding(skb, tvlv_len);
|
||||
|
||||
out:
|
||||
*count = num_dests_pushed;
|
||||
return ret;
|
||||
}
|
||||
|
||||
/**
|
||||
* batadv_mcast_forw_push_dests() - push originator addresses onto an skb
|
||||
* @bat_priv: the bat priv with all the soft interface information
|
||||
* @skb: the skb to push the destination addresses onto
|
||||
* @vid: the vlan identifier
|
||||
* @is_routable: indicates whether the destination is routable
|
||||
* @count: the number of originators the multicast packet needs to be sent to
|
||||
* @tvlv_len: stores the amount of currently pushed TVLV bytes
|
||||
*
|
||||
* Push the MAC addresses of all originators which have indicated interest in
|
||||
* this multicast packet onto the given skb.
|
||||
*
|
||||
* Return: -ENOMEM if there is not enough skb headroom available. Otherwise, on
|
||||
* success 0.
|
||||
*/
|
||||
static int
|
||||
batadv_mcast_forw_push_dests(struct batadv_priv *bat_priv, struct sk_buff *skb,
|
||||
unsigned short vid, int is_routable, int *count,
|
||||
unsigned short *tvlv_len)
|
||||
{
|
||||
unsigned short num_dests = 0;
|
||||
|
||||
if (!batadv_mcast_forw_push_est_padding(skb, *count, tvlv_len))
|
||||
goto err;
|
||||
|
||||
if (!batadv_mcast_forw_push_tt(bat_priv, skb, vid, &num_dests,
|
||||
tvlv_len))
|
||||
goto err;
|
||||
|
||||
if (!batadv_mcast_forw_push_want_all(bat_priv, skb, vid, &num_dests,
|
||||
tvlv_len))
|
||||
goto err;
|
||||
|
||||
if (is_routable &&
|
||||
!batadv_mcast_forw_push_want_rtr(bat_priv, skb, vid, &num_dests,
|
||||
tvlv_len))
|
||||
goto err;
|
||||
|
||||
if (!batadv_mcast_forw_push_adjust_padding(skb, count, num_dests,
|
||||
tvlv_len))
|
||||
goto err;
|
||||
|
||||
return 0;
|
||||
err:
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
/**
|
||||
* batadv_mcast_forw_push_tracker() - push a multicast tracker TVLV header
|
||||
* @skb: the skb to push the tracker TVLV onto
|
||||
* @num_dests: the number of destination addresses to set in the header
|
||||
* @tvlv_len: stores the amount of currently pushed TVLV bytes
|
||||
*
|
||||
* Pushes a multicast tracker TVLV header onto the given skb, including the
|
||||
* generic TVLV header but excluding the destination MAC addresses.
|
||||
*
|
||||
* The provided num_dests value is taken into consideration to set the
|
||||
* num_dests field in the tracker header and to set the appropriate TVLV length
|
||||
* value fields.
|
||||
*
|
||||
* Return: -ENOMEM if there is not enough skb headroom available. Otherwise, on
|
||||
* success 0.
|
||||
*/
|
||||
static int batadv_mcast_forw_push_tracker(struct sk_buff *skb, int num_dests,
|
||||
unsigned short *tvlv_len)
|
||||
{
|
||||
struct batadv_tvlv_mcast_tracker *mcast_tracker;
|
||||
struct batadv_tvlv_hdr *tvlv_hdr;
|
||||
unsigned int tvlv_value_len;
|
||||
|
||||
if (skb_headroom(skb) < sizeof(*mcast_tracker) + sizeof(*tvlv_hdr))
|
||||
return -ENOMEM;
|
||||
|
||||
tvlv_value_len = sizeof(*mcast_tracker) + *tvlv_len;
|
||||
if (tvlv_value_len + sizeof(*tvlv_hdr) > U16_MAX)
|
||||
return -ENOMEM;
|
||||
|
||||
batadv_mcast_forw_skb_push(skb, sizeof(*mcast_tracker), tvlv_len);
|
||||
mcast_tracker = (struct batadv_tvlv_mcast_tracker *)skb->data;
|
||||
mcast_tracker->num_dests = htons(num_dests);
|
||||
|
||||
skb_reset_network_header(skb);
|
||||
|
||||
batadv_mcast_forw_skb_push(skb, sizeof(*tvlv_hdr), tvlv_len);
|
||||
tvlv_hdr = (struct batadv_tvlv_hdr *)skb->data;
|
||||
tvlv_hdr->type = BATADV_TVLV_MCAST_TRACKER;
|
||||
tvlv_hdr->version = 1;
|
||||
tvlv_hdr->len = htons(tvlv_value_len);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* batadv_mcast_forw_push_tvlvs() - push a multicast tracker TVLV onto an skb
|
||||
* @bat_priv: the bat priv with all the soft interface information
|
||||
* @skb: the skb to push the tracker TVLV onto
|
||||
* @vid: the vlan identifier
|
||||
* @is_routable: indicates whether the destination is routable
|
||||
* @count: the number of originators the multicast packet needs to be sent to
|
||||
* @tvlv_len: stores the amount of currently pushed TVLV bytes
|
||||
*
|
||||
* Pushes a multicast tracker TVLV onto the given skb, including the collected
|
||||
* destination MAC addresses and the generic TVLV header.
|
||||
*
|
||||
* Return: -ENOMEM if there is not enough skb headroom available. Otherwise, on
|
||||
* success 0.
|
||||
*/
|
||||
static int
|
||||
batadv_mcast_forw_push_tvlvs(struct batadv_priv *bat_priv, struct sk_buff *skb,
|
||||
unsigned short vid, int is_routable, int count,
|
||||
unsigned short *tvlv_len)
|
||||
{
|
||||
int ret;
|
||||
|
||||
ret = batadv_mcast_forw_push_dests(bat_priv, skb, vid, is_routable,
|
||||
&count, tvlv_len);
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
ret = batadv_mcast_forw_push_tracker(skb, count, tvlv_len);
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* batadv_mcast_forw_push_hdr() - push a multicast packet header onto an skb
|
||||
* @skb: the skb to push the header onto
|
||||
* @tvlv_len: the total TVLV length value to set in the header
|
||||
*
|
||||
* Pushes a batman-adv multicast packet header onto the given skb and sets
|
||||
* the provided total TVLV length value in it.
|
||||
*
|
||||
* Caller needs to ensure enough skb headroom is available.
|
||||
*
|
||||
* Return: -ENOMEM if there is not enough skb headroom available. Otherwise, on
|
||||
* success 0.
|
||||
*/
|
||||
static int
|
||||
batadv_mcast_forw_push_hdr(struct sk_buff *skb, unsigned short tvlv_len)
|
||||
{
|
||||
struct batadv_mcast_packet *mcast_packet;
|
||||
|
||||
if (skb_headroom(skb) < sizeof(*mcast_packet))
|
||||
return -ENOMEM;
|
||||
|
||||
skb_push(skb, sizeof(*mcast_packet));
|
||||
|
||||
mcast_packet = (struct batadv_mcast_packet *)skb->data;
|
||||
mcast_packet->version = BATADV_COMPAT_VERSION;
|
||||
mcast_packet->ttl = BATADV_TTL;
|
||||
mcast_packet->packet_type = BATADV_MCAST;
|
||||
mcast_packet->reserved = 0;
|
||||
mcast_packet->tvlv_len = htons(tvlv_len);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* batadv_mcast_forw_scrub_dests() - scrub destinations in a tracker TVLV
|
||||
* @bat_priv: the bat priv with all the soft interface information
|
||||
@ -237,3 +842,130 @@ int batadv_mcast_forw_tracker_tvlv_handler(struct batadv_priv *bat_priv,
|
||||
{
|
||||
return batadv_mcast_forw_packet(bat_priv, skb, false);
|
||||
}
|
||||
|
||||
/**
|
||||
* batadv_mcast_forw_packet_hdrlen() - multicast packet header length
|
||||
* @num_dests: number of destination nodes
|
||||
*
|
||||
* Calculates the total batman-adv multicast packet header length for a given
|
||||
* number of destination nodes (excluding the outer ethernet frame).
|
||||
*
|
||||
* Return: The calculated total batman-adv multicast packet header length.
|
||||
*/
|
||||
unsigned int batadv_mcast_forw_packet_hdrlen(unsigned int num_dests)
|
||||
{
|
||||
/**
|
||||
* If the number of destination entries is even then we need to add
|
||||
* two byte padding to the tracker TVLV.
|
||||
*/
|
||||
int padding = (!(num_dests % 2)) ? 2 : 0;
|
||||
|
||||
return padding + num_dests * ETH_ALEN +
|
||||
sizeof(struct batadv_tvlv_mcast_tracker) +
|
||||
sizeof(struct batadv_tvlv_hdr) +
|
||||
sizeof(struct batadv_mcast_packet);
|
||||
}
|
||||
|
||||
/**
|
||||
* batadv_mcast_forw_expand_head() - expand headroom for an mcast packet
|
||||
* @bat_priv: the bat priv with all the soft interface information
|
||||
* @skb: the multicast packet to send
|
||||
*
|
||||
* Tries to expand an skb's headroom so that its head to tail is 1298
|
||||
* bytes (minimum IPv6 MTU + vlan ethernet header size) large.
|
||||
*
|
||||
* Return: -EINVAL if the given skb's length is too large or -ENOMEM on memory
|
||||
* allocation failure. Otherwise, on success, zero is returned.
|
||||
*/
|
||||
static int batadv_mcast_forw_expand_head(struct batadv_priv *bat_priv,
|
||||
struct sk_buff *skb)
|
||||
{
|
||||
int hdr_size = VLAN_ETH_HLEN + IPV6_MIN_MTU - skb->len;
|
||||
|
||||
/* TODO: Could be tightened to actual number of destination nodes?
|
||||
* But it's tricky, number of destinations might have increased since
|
||||
* we last checked.
|
||||
*/
|
||||
if (hdr_size < 0) {
|
||||
/* batadv_mcast_forw_mode_check_count() should ensure we do not
|
||||
* end up here
|
||||
*/
|
||||
WARN_ON(1);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
if (skb_headroom(skb) < hdr_size &&
|
||||
pskb_expand_head(skb, hdr_size, 0, GFP_ATOMIC) < 0)
|
||||
return -ENOMEM;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* batadv_mcast_forw_push() - encapsulate skb in a batman-adv multicast packet
|
||||
* @bat_priv: the bat priv with all the soft interface information
|
||||
* @skb: the multicast packet to encapsulate and send
|
||||
* @vid: the vlan identifier
|
||||
* @is_routable: indicates whether the destination is routable
|
||||
* @count: the number of originators the multicast packet needs to be sent to
|
||||
*
|
||||
* Encapsulates the given multicast packet in a batman-adv multicast packet.
|
||||
* A multicast tracker TVLV with destination originator addresses for any node
|
||||
* that signaled interest in it, that is either via the translation table or the
|
||||
* according want-all flags, is attached accordingly.
|
||||
*
|
||||
* Return: true on success, false otherwise.
|
||||
*/
|
||||
bool batadv_mcast_forw_push(struct batadv_priv *bat_priv, struct sk_buff *skb,
|
||||
unsigned short vid, int is_routable, int count)
|
||||
{
|
||||
unsigned short tvlv_len = 0;
|
||||
int ret;
|
||||
|
||||
if (batadv_mcast_forw_expand_head(bat_priv, skb) < 0)
|
||||
goto err;
|
||||
|
||||
skb_reset_transport_header(skb);
|
||||
|
||||
ret = batadv_mcast_forw_push_tvlvs(bat_priv, skb, vid, is_routable,
|
||||
count, &tvlv_len);
|
||||
if (ret < 0)
|
||||
goto err;
|
||||
|
||||
ret = batadv_mcast_forw_push_hdr(skb, tvlv_len);
|
||||
if (ret < 0)
|
||||
goto err;
|
||||
|
||||
return true;
|
||||
|
||||
err:
|
||||
if (tvlv_len)
|
||||
skb_pull(skb, tvlv_len);
|
||||
|
||||
return false;
|
||||
}
|
||||
|
||||
/**
|
||||
* batadv_mcast_forw_mcsend() - send a self prepared batman-adv multicast packet
|
||||
* @bat_priv: the bat priv with all the soft interface information
|
||||
* @skb: the multicast packet to encapsulate and send
|
||||
*
|
||||
* Transmits a batman-adv multicast packet that was locally prepared and
|
||||
* consumes/frees it.
|
||||
*
|
||||
* Return: NET_XMIT_DROP on memory allocation failure. NET_XMIT_SUCCESS
|
||||
* otherwise.
|
||||
*/
|
||||
int batadv_mcast_forw_mcsend(struct batadv_priv *bat_priv,
|
||||
struct sk_buff *skb)
|
||||
{
|
||||
int ret = batadv_mcast_forw_packet(bat_priv, skb, true);
|
||||
|
||||
if (ret < 0) {
|
||||
kfree_skb(skb);
|
||||
return NET_XMIT_DROP;
|
||||
}
|
||||
|
||||
consume_skb(skb);
|
||||
return NET_XMIT_SUCCESS;
|
||||
}
|
||||
|
||||
@ -301,12 +301,13 @@ static netdev_tx_t batadv_interface_tx(struct sk_buff *skb,
|
||||
|
||||
send:
|
||||
if (do_bcast && !is_broadcast_ether_addr(ethhdr->h_dest)) {
|
||||
forw_mode = batadv_mcast_forw_mode(bat_priv, skb,
|
||||
forw_mode = batadv_mcast_forw_mode(bat_priv, skb, vid,
|
||||
&mcast_is_routable);
|
||||
switch (forw_mode) {
|
||||
case BATADV_FORW_BCAST:
|
||||
break;
|
||||
case BATADV_FORW_UCASTS:
|
||||
case BATADV_FORW_MCAST:
|
||||
do_bcast = false;
|
||||
break;
|
||||
case BATADV_FORW_NONE:
|
||||
@ -365,6 +366,8 @@ static netdev_tx_t batadv_interface_tx(struct sk_buff *skb,
|
||||
} else if (forw_mode == BATADV_FORW_UCASTS) {
|
||||
ret = batadv_mcast_forw_send(bat_priv, skb, vid,
|
||||
mcast_is_routable);
|
||||
} else if (forw_mode == BATADV_FORW_MCAST) {
|
||||
ret = batadv_mcast_forw_mcsend(bat_priv, skb);
|
||||
} else {
|
||||
if (batadv_dat_snoop_outgoing_arp_request(bat_priv,
|
||||
skb))
|
||||
@ -762,6 +765,7 @@ static int batadv_softif_init_late(struct net_device *dev)
|
||||
atomic_set(&bat_priv->mcast.num_want_all_unsnoopables, 0);
|
||||
atomic_set(&bat_priv->mcast.num_want_all_ipv4, 0);
|
||||
atomic_set(&bat_priv->mcast.num_want_all_ipv6, 0);
|
||||
atomic_set(&bat_priv->mcast.num_no_mc_ptype_capa, 0);
|
||||
#endif
|
||||
atomic_set(&bat_priv->gw.mode, BATADV_GW_MODE_OFF);
|
||||
atomic_set(&bat_priv->gw.bandwidth_down, 100);
|
||||
|
||||
@ -1342,6 +1342,12 @@ struct batadv_priv_mcast {
|
||||
/** @num_want_all_rtr6: counter for items in want_all_rtr6_list */
|
||||
atomic_t num_want_all_rtr6;
|
||||
|
||||
/**
|
||||
* @num_no_mc_ptype_capa: counter for number of nodes without the
|
||||
* BATADV_MCAST_HAVE_MC_PTYPE_CAPA flag
|
||||
*/
|
||||
atomic_t num_no_mc_ptype_capa;
|
||||
|
||||
/**
|
||||
* @want_lists_lock: lock for protecting modifications to mcasts
|
||||
* want_all_{unsnoopables,ipv4,ipv6}_list (traversals are rcu-locked)
|
||||
|
||||
Loading…
Reference in New Issue
Block a user