batman-adv: Avoid redundant multicast TT entries
Commit Message
If a node signals that it wants all traffic for a specific protocol
family then there is no need to announce individual multicast addresses
via TT.
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
---
net/batman-adv/multicast.c | 56 ++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 52 insertions(+), 4 deletions(-)
Comments
On Sonntag, 4. März 2018 12:58:37 CET Linus Lüssing wrote:
> If a node signals that it wants all traffic for a specific protocol
> family then there is no need to announce individual multicast addresses
> via TT.
>
> Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
> ---
> net/batman-adv/multicast.c | 56 ++++++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 52 insertions(+), 4 deletions(-)
I cannot say much about the TT details but just some remarks about some coding
style details.
> +static bool batadv_mcast_addr_is_ipv4(unsigned char *addr)
We usually would use "const u8 *addr" here maybe I missed something
but I would expect that this is also used here.
> +{
> + const unsigned char prefix[] = { 0x01, 0x00, 0x5E };
All other single line array initializations in the code used "{" without
extra space after it and "}" without extra space before it.
> + return !memcmp(prefix, addr, sizeof(prefix));
> +}
Could you please use "== 0" here instead of "!". Every time I read !memcmp, I
am assuming for a short period of time that the memcpy must "fail" here.
> +static bool batadv_mcast_addr_is_ipv6(unsigned char *addr)
We usually would use "const u8 *addr" here maybe I missed something
but I would expect that this is also used here.
> +{
> + const unsigned char prefix[] = { 0x33, 0x33 };
All other single line array initializations in the code used "{" without
extra space after it and "}" without extra space before it.
> +
> + return !memcmp(prefix, addr, sizeof(prefix));
Could you please use "== 0" here instead of "!". Every time I read !memcmp, I
am assuming for a short period of time that the memcpy must "fail" here.
Kind regards,
Sven
@@ -102,7 +102,36 @@ static struct net_device *batadv_mcast_get_bridge(struct net_device *soft_iface)
}
/**
+ * batadv_mcast_addr_is_ipv4() - check if multicast MAC is IPv4
+ * @addr: the MAC address to check
+ *
+ * Return: True, if MAC address is one reserved for IPv4 multicast, false
+ * otherwise.
+ */
+static bool batadv_mcast_addr_is_ipv4(unsigned char *addr)
+{
+ const unsigned char prefix[] = { 0x01, 0x00, 0x5E };
+
+ return !memcmp(prefix, addr, sizeof(prefix));
+}
+
+/**
+ * batadv_mcast_addr_is_ipv6() - check if multicast MAC is IPv6
+ * @addr: the MAC address to check
+ *
+ * Return: True, if MAC address is one reserved for IPv6 multicast, false
+ * otherwise.
+ */
+static bool batadv_mcast_addr_is_ipv6(unsigned char *addr)
+{
+ const unsigned char prefix[] = { 0x33, 0x33 };
+
+ return !memcmp(prefix, addr, sizeof(prefix));
+}
+
+/**
* batadv_mcast_mla_softif_get() - get softif multicast listeners
+ * @bat_priv: the bat priv with all the soft interface information
* @dev: the device to collect multicast addresses from
* @mcast_list: a list to put found addresses into
*
@@ -119,9 +148,12 @@ static struct net_device *batadv_mcast_get_bridge(struct net_device *soft_iface)
* Return: -ENOMEM on memory allocation error or the number of
* items added to the mcast_list otherwise.
*/
-static int batadv_mcast_mla_softif_get(struct net_device *dev,
+static int batadv_mcast_mla_softif_get(struct batadv_priv *bat_priv,
+ struct net_device *dev,
struct hlist_head *mcast_list)
{
+ bool all_ipv4 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV4;
+ bool all_ipv6 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV6;
struct net_device *bridge = batadv_mcast_get_bridge(dev);
struct netdev_hw_addr *mc_list_entry;
struct batadv_hw_addr *new;
@@ -129,6 +161,12 @@ static int batadv_mcast_mla_softif_get(struct net_device *dev,
netif_addr_lock_bh(bridge ? bridge : dev);
netdev_for_each_mc_addr(mc_list_entry, bridge ? bridge : dev) {
+ if (all_ipv4 && batadv_mcast_addr_is_ipv4(mc_list_entry->addr))
+ continue;
+
+ if (all_ipv6 && batadv_mcast_addr_is_ipv6(mc_list_entry->addr))
+ continue;
+
new = kmalloc(sizeof(*new), GFP_ATOMIC);
if (!new) {
ret = -ENOMEM;
@@ -193,6 +231,7 @@ static void batadv_mcast_mla_br_addr_cpy(char *dst, const struct br_ip *src)
/**
* batadv_mcast_mla_bridge_get() - get bridged-in multicast listeners
+ * @bat_priv: the bat priv with all the soft interface information
* @dev: a bridge slave whose bridge to collect multicast addresses from
* @mcast_list: a list to put found addresses into
*
@@ -204,10 +243,13 @@ static void batadv_mcast_mla_br_addr_cpy(char *dst, const struct br_ip *src)
* Return: -ENOMEM on memory allocation error or the number of
* items added to the mcast_list otherwise.
*/
-static int batadv_mcast_mla_bridge_get(struct net_device *dev,
+static int batadv_mcast_mla_bridge_get(struct batadv_priv *bat_priv,
+ struct net_device *dev,
struct hlist_head *mcast_list)
{
struct list_head bridge_mcast_list = LIST_HEAD_INIT(bridge_mcast_list);
+ bool all_ipv4 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV4;
+ bool all_ipv6 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV6;
struct br_ip_list *br_ip_entry, *tmp;
struct batadv_hw_addr *new;
u8 mcast_addr[ETH_ALEN];
@@ -221,6 +263,12 @@ static int batadv_mcast_mla_bridge_get(struct net_device *dev,
goto out;
list_for_each_entry(br_ip_entry, &bridge_mcast_list, list) {
+ if (all_ipv4 && br_ip_entry->addr.proto == htons(ETH_P_IP))
+ continue;
+
+ if (all_ipv6 && br_ip_entry->addr.proto == htons(ETH_P_IPV6))
+ continue;
+
batadv_mcast_mla_br_addr_cpy(mcast_addr, &br_ip_entry->addr);
if (batadv_mcast_mla_is_duplicate(mcast_addr, mcast_list))
continue;
@@ -568,11 +616,11 @@ static void __batadv_mcast_mla_update(struct batadv_priv *bat_priv)
if (!batadv_mcast_mla_tvlv_update(bat_priv))
goto update;
- ret = batadv_mcast_mla_softif_get(soft_iface, &mcast_list);
+ ret = batadv_mcast_mla_softif_get(bat_priv, soft_iface, &mcast_list);
if (ret < 0)
goto out;
- ret = batadv_mcast_mla_bridge_get(soft_iface, &mcast_list);
+ ret = batadv_mcast_mla_bridge_get(bat_priv, soft_iface, &mcast_list);
if (ret < 0)
goto out;