Repository : ssh://git@diktynna/batman-adv
On branches: main,main
>---------------------------------------------------------------
commit be9b0169c8404f94f4d2e16eb4e7e336135a59f1
Author: Linus Lüssing <linus.luessing(a)c0d3.blue>
Date: Thu Sep 7 03:09:09 2023 +0200
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(a)c0d3.blue>
Signed-off-by: Simon Wunderlich <sw(a)simonwunderlich.de>
Signed-off-by: Sven Eckelmann <sven(a)narfation.org>
>---------------------------------------------------------------
be9b0169c8404f94f4d2e16eb4e7e336135a59f1
net/batman-adv/multicast.c | 79 ++++-
net/batman-adv/multicast.h | 25 +-
net/batman-adv/multicast_forw.c | 732 ++++++++++++++++++++++++++++++++++++++++
net/batman-adv/soft-interface.c | 6 +-
net/batman-adv/types.h | 6 +
5 files changed, 840 insertions(+), 8 deletions(-)
diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c
index f2b1e523..d8ddb20f 100644
--- a/net/batman-adv/multicast.c
+++ b/net/batman-adv/multicast.c
@@ -1177,17 +1177,62 @@ static int batadv_mcast_forw_rtr_count(struct batadv_priv *bat_priv,
}
}
+/**
+ * batadv_mcast_forw_mode_by_count() - get forwarding mode by count
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: the multicast packet to check
+ * @vid: the vlan identifier
+ * @is_routable: stores whether the destination is routable
+ * @count: the number of originators the multicast packet need to be sent to
+ *
+ * For a multicast packet with multiple destination originators, checks which
+ * mode to use. For BATADV_FORW_MCAST it also encapsulates the packet with a
+ * complete batman-adv multicast header.
+ *
+ * Return:
+ * BATADV_FORW_MCAST: If all nodes have multicast packet routing
+ * capabilities and an MTU >= 1280 on all hard interfaces (including us)
+ * and the encapsulated multicast packet with all destination addresses
+ * would still fit into an 1280 bytes batman-adv multicast packet
+ * (excluding the outer ethernet frame) and we could successfully push
+ * the full batman-adv multicast packet header.
+ * BATADV_FORW_UCASTS: If the packet cannot be sent in a batman-adv
+ * multicast packet and the amount of batman-adv unicast packets needed
+ * is smaller or equal to the configured multicast fanout.
+ * BATADV_FORW_BCAST: Otherwise.
+ */
+static enum batadv_forw_mode
+batadv_mcast_forw_mode_by_count(struct batadv_priv *bat_priv,
+ struct sk_buff *skb, unsigned short vid,
+ int is_routable, int count)
+{
+ unsigned int mcast_hdrlen = batadv_mcast_forw_packet_hdrlen(count);
+ u8 own_tvlv_flags = bat_priv->mcast.mla_flags.tvlv_flags;
+
+ if (!atomic_read(&bat_priv->mcast.num_no_mc_ptype_capa) &&
+ own_tvlv_flags & BATADV_MCAST_HAVE_MC_PTYPE_CAPA &&
+ skb->len + mcast_hdrlen <= IPV6_MIN_MTU &&
+ batadv_mcast_forw_push(bat_priv, skb, vid, is_routable, count))
+ return BATADV_FORW_MCAST;
+
+ if (count <= atomic_read(&bat_priv->multicast_fanout))
+ return BATADV_FORW_UCASTS;
+
+ return BATADV_FORW_BCAST;
+}
+
/**
* batadv_mcast_forw_mode() - check on how to forward a multicast packet
* @bat_priv: the bat priv with all the soft interface information
* @skb: the multicast packet to check
+ * @vid: the vlan identifier
* @is_routable: stores whether the destination is routable
*
* Return: The forwarding mode as enum batadv_forw_mode.
*/
enum batadv_forw_mode
batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
- int *is_routable)
+ unsigned short vid, int *is_routable)
{
int ret, tt_count, ip_count, unsnoop_count, total_count;
bool is_unsnoopable = false;
@@ -1217,10 +1262,8 @@ batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
else if (unsnoop_count)
return BATADV_FORW_BCAST;
- if (total_count <= atomic_read(&bat_priv->multicast_fanout))
- return BATADV_FORW_UCASTS;
-
- return BATADV_FORW_BCAST;
+ return batadv_mcast_forw_mode_by_count(bat_priv, skb, vid, *is_routable,
+ total_count);
}
/**
@@ -1780,6 +1823,31 @@ static void batadv_mcast_want_rtr6_update(struct batadv_priv *bat_priv,
}
}
+/**
+ * batadv_mcast_have_mc_ptype_update() - update multicast packet type counter
+ * @bat_priv: the bat priv with all the soft interface information
+ * @orig: the orig_node which multicast state might have changed of
+ * @mcast_flags: flags indicating the new multicast state
+ *
+ * If the BATADV_MCAST_HAVE_MC_PTYPE_CAPA flag of this originator, orig, has
+ * toggled then this method updates the counter accordingly.
+ */
+static void batadv_mcast_have_mc_ptype_update(struct batadv_priv *bat_priv,
+ struct batadv_orig_node *orig,
+ u8 mcast_flags)
+{
+ lockdep_assert_held(&orig->mcast_handler_lock);
+
+ /* switched from flag set to unset */
+ if (!(mcast_flags & BATADV_MCAST_HAVE_MC_PTYPE_CAPA) &&
+ orig->mcast_flags & BATADV_MCAST_HAVE_MC_PTYPE_CAPA)
+ atomic_inc(&bat_priv->mcast.num_no_mc_ptype_capa);
+ /* switched from flag unset to set */
+ else if (mcast_flags & BATADV_MCAST_HAVE_MC_PTYPE_CAPA &&
+ !(orig->mcast_flags & BATADV_MCAST_HAVE_MC_PTYPE_CAPA))
+ atomic_dec(&bat_priv->mcast.num_no_mc_ptype_capa);
+}
+
/**
* batadv_mcast_tvlv_flags_get() - get multicast flags from an OGM TVLV
* @enabled: whether the originator has multicast TVLV support enabled
@@ -1848,6 +1916,7 @@ static void batadv_mcast_tvlv_ogm_handler(struct batadv_priv *bat_priv,
batadv_mcast_want_ipv6_update(bat_priv, orig, mcast_flags);
batadv_mcast_want_rtr4_update(bat_priv, orig, mcast_flags);
batadv_mcast_want_rtr6_update(bat_priv, orig, mcast_flags);
+ batadv_mcast_have_mc_ptype_update(bat_priv, orig, mcast_flags);
orig->mcast_flags = mcast_flags;
spin_unlock_bh(&orig->mcast_handler_lock);
diff --git a/net/batman-adv/multicast.h b/net/batman-adv/multicast.h
index a5c0f384..d97ee51d 100644
--- a/net/batman-adv/multicast.h
+++ b/net/batman-adv/multicast.h
@@ -11,6 +11,7 @@
#include <linux/netlink.h>
#include <linux/skbuff.h>
+#include <linux/types.h>
/**
* enum batadv_forw_mode - the way a packet should be forwarded as
@@ -28,6 +29,12 @@ enum batadv_forw_mode {
*/
BATADV_FORW_UCASTS,
+ /**
+ * @BATADV_FORW_MCAST: forward the packet to some nodes via a
+ * batman-adv multicast packet
+ */
+ BATADV_FORW_MCAST,
+
/** @BATADV_FORW_NONE: don't forward, drop it */
BATADV_FORW_NONE,
};
@@ -36,7 +43,7 @@ enum batadv_forw_mode {
enum batadv_forw_mode
batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
- int *is_routable);
+ unsigned short vid, int *is_routable);
int batadv_mcast_forw_send(struct batadv_priv *bat_priv, struct sk_buff *skb,
unsigned short vid, int is_routable);
@@ -57,11 +64,18 @@ void batadv_mcast_purge_orig(struct batadv_orig_node *orig_node);
int batadv_mcast_forw_tracker_tvlv_handler(struct batadv_priv *bat_priv,
struct sk_buff *skb);
+unsigned int batadv_mcast_forw_packet_hdrlen(unsigned int num_dests);
+
+bool batadv_mcast_forw_push(struct batadv_priv *bat_priv, struct sk_buff *skb,
+ unsigned short vid, int is_routable, int count);
+
+int batadv_mcast_forw_mcsend(struct batadv_priv *bat_priv, struct sk_buff *skb);
+
#else
static inline enum batadv_forw_mode
batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
- int *is_routable)
+ unsigned short vid, int *is_routable)
{
return BATADV_FORW_BCAST;
}
@@ -99,6 +113,13 @@ static inline void batadv_mcast_purge_orig(struct batadv_orig_node *orig_node)
{
}
+static inline int batadv_mcast_forw_mcsend(struct batadv_priv *bat_priv,
+ struct sk_buff *skb)
+{
+ kfree_skb(skb);
+ return NET_XMIT_DROP;
+}
+
#endif /* CONFIG_BATMAN_ADV_MCAST */
#endif /* _NET_BATMAN_ADV_MULTICAST_H_ */
diff --git a/net/batman-adv/multicast_forw.c b/net/batman-adv/multicast_forw.c
index d17341df..a2c5c587 100644
--- a/net/batman-adv/multicast_forw.c
+++ b/net/batman-adv/multicast_forw.c
@@ -7,19 +7,30 @@
#include "multicast.h"
#include "main.h"
+#include <linux/bug.h>
+#include <linux/build_bug.h>
#include <linux/byteorder/generic.h>
+#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/gfp.h>
#include <linux/if_ether.h>
+#include <linux/if_vlan.h>
+#include <linux/ipv6.h>
+#include <linux/limits.h>
#include <linux/netdevice.h>
+#include <linux/rculist.h>
+#include <linux/rcupdate.h>
#include <linux/skbuff.h>
#include <linux/stddef.h>
+#include <linux/string.h>
#include <linux/types.h>
#include <uapi/linux/batadv_packet.h>
+#include "bridge_loop_avoidance.h"
#include "originator.h"
#include "send.h"
+#include "translation-table.h"
#define batadv_mcast_forw_tracker_for_each_dest(dest, num_dests) \
for (; num_dests; num_dests--, (dest) += ETH_ALEN)
@@ -27,6 +38,600 @@
#define batadv_mcast_forw_tracker_for_each_dest2(dest1, dest2, num_dests) \
for (; num_dests; num_dests--, (dest1) += ETH_ALEN, (dest2) += ETH_ALEN)
+/**
+ * batadv_mcast_forw_skb_push() - skb_push and memorize amount of pushed bytes
+ * @skb: the skb to push onto
+ * @size: the amount of bytes to push
+ * @len: stores the total amount of bytes pushed
+ *
+ * Performs an skb_push() onto the given skb and adds the amount of pushed bytes
+ * to the given len pointer.
+ *
+ * Return: the return value of the skb_push() call.
+ */
+static void *batadv_mcast_forw_skb_push(struct sk_buff *skb, size_t size,
+ unsigned short *len)
+{
+ *len += size;
+ return skb_push(skb, size);
+}
+
+/**
+ * batadv_mcast_forw_push_padding() - push 2 padding bytes to skb's front
+ * @skb: the skb to push onto
+ * @tvlv_len: stores the amount of currently pushed TVLV bytes
+ *
+ * Pushes two padding bytes to the front of the given skb.
+ *
+ * Return: On success a pointer to the first byte of the two pushed padding
+ * bytes within the skb. NULL otherwise.
+ */
+static char *
+batadv_mcast_forw_push_padding(struct sk_buff *skb, unsigned short *tvlv_len)
+{
+ const int pad_len = 2;
+ char *padding;
+
+ if (skb_headroom(skb) < pad_len)
+ return NULL;
+
+ padding = batadv_mcast_forw_skb_push(skb, pad_len, tvlv_len);
+ memset(padding, 0, pad_len);
+
+ return padding;
+}
+
+/**
+ * batadv_mcast_forw_push_est_padding() - push padding bytes if necessary
+ * @skb: the skb to potentially push the padding onto
+ * @count: the (estimated) number of originators the multicast packet needs to
+ * be sent to
+ * @tvlv_len: stores the amount of currently pushed TVLV bytes
+ *
+ * If the number of destination entries is even then this adds two
+ * padding bytes to the end of the tracker TVLV.
+ *
+ * Return: true on success or if no padding is needed, false otherwise.
+ */
+static bool
+batadv_mcast_forw_push_est_padding(struct sk_buff *skb, int count,
+ unsigned short *tvlv_len)
+{
+ if (!(count % 2) && !batadv_mcast_forw_push_padding(skb, tvlv_len))
+ return false;
+
+ return true;
+}
+
+/**
+ * batadv_mcast_forw_orig_entry() - get orig_node from an hlist node
+ * @node: the hlist node to get the orig_node from
+ * @entry_offset: the offset of the hlist node within the orig_node struct
+ *
+ * Return: The orig_node containing the hlist node on success, NULL on error.
+ */
+static struct batadv_orig_node *
+batadv_mcast_forw_orig_entry(struct hlist_node *node,
+ size_t entry_offset)
+{
+ /* sanity check */
+ switch (entry_offset) {
+ case offsetof(struct batadv_orig_node, mcast_want_all_ipv4_node):
+ case offsetof(struct batadv_orig_node, mcast_want_all_ipv6_node):
+ case offsetof(struct batadv_orig_node, mcast_want_all_rtr4_node):
+ case offsetof(struct batadv_orig_node, mcast_want_all_rtr6_node):
+ break;
+ default:
+ WARN_ON(1);
+ return NULL;
+ }
+
+ return (struct batadv_orig_node *)((void *)node - entry_offset);
+}
+
+/**
+ * batadv_mcast_forw_push_dest() - push an originator MAC address onto an skb
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: the skb to push the destination address onto
+ * @vid: the vlan identifier
+ * @orig_node: the originator node to get the MAC address from
+ * @num_dests: a pointer to store the number of pushed addresses in
+ * @tvlv_len: stores the amount of currently pushed TVLV bytes
+ *
+ * If the orig_node is a BLA backbone gateway, if there is not enough skb
+ * headroom available or if num_dests is already at its maximum (65535) then
+ * neither the skb nor num_dests is changed. Otherwise the originator's MAC
+ * address is pushed onto the given skb and num_dests incremented by one.
+ *
+ * Return: true if the orig_node is a backbone gateway or if an orig address
+ * was pushed successfully, false otherwise.
+ */
+static bool batadv_mcast_forw_push_dest(struct batadv_priv *bat_priv,
+ struct sk_buff *skb, unsigned short vid,
+ struct batadv_orig_node *orig_node,
+ unsigned short *num_dests,
+ unsigned short *tvlv_len)
+{
+ BUILD_BUG_ON(sizeof_field(struct batadv_tvlv_mcast_tracker, num_dests)
+ != sizeof(__be16));
+
+ /* Avoid sending to other BLA gateways - they already got the frame from
+ * the LAN side we share with them.
+ * TODO: Refactor to take BLA into account earlier in mode check.
+ */
+ if (batadv_bla_is_backbone_gw_orig(bat_priv, orig_node->orig, vid))
+ return true;
+
+ if (skb_headroom(skb) < ETH_ALEN || *num_dests == U16_MAX)
+ return false;
+
+ batadv_mcast_forw_skb_push(skb, ETH_ALEN, tvlv_len);
+ ether_addr_copy(skb->data, orig_node->orig);
+ (*num_dests)++;
+
+ return true;
+}
+
+/**
+ * batadv_mcast_forw_push_dests_list() - push originators from list 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
+ * @head: the list to gather originators from
+ * @entry_offset: offset of an hlist node in an orig_node structure
+ * @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 in the given list onto the given
+ * skb.
+ *
+ * Return: true on success, false otherwise.
+ */
+static int batadv_mcast_forw_push_dests_list(struct batadv_priv *bat_priv,
+ struct sk_buff *skb,
+ unsigned short vid,
+ struct hlist_head *head,
+ size_t entry_offset,
+ unsigned short *num_dests,
+ unsigned short *tvlv_len)
+{
+ struct hlist_node *node;
+ struct batadv_orig_node *orig_node;
+
+ rcu_read_lock();
+ __hlist_for_each_rcu(node, head) {
+ orig_node = batadv_mcast_forw_orig_entry(node, entry_offset);
+ if (!orig_node ||
+ !batadv_mcast_forw_push_dest(bat_priv, skb, vid, orig_node,
+ num_dests, tvlv_len)) {
+ rcu_read_unlock();
+ return false;
+ }
+ }
+ rcu_read_unlock();
+
+ return true;
+}
+
+/**
+ * batadv_mcast_forw_push_tt() - push originators with interest through TT
+ * @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 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;
+}
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 1b0e2c59..89c51b3c 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -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 @@ send:
} 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);
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index 850b184e..00840d57 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -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)
