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Message-Id: <20190627103938.7488-11-sw@simonwunderlich.de>
Date: Thu, 27 Jun 2019 12:39:38 +0200
From: Simon Wunderlich <sw@...onwunderlich.de>
To: davem@...emloft.net
Cc: netdev@...r.kernel.org, b.a.t.m.a.n@...ts.open-mesh.org,
Linus Lüssing <linus.luessing@...3.blue>,
Sven Eckelmann <sven@...fation.org>,
Simon Wunderlich <sw@...onwunderlich.de>
Subject: [PATCH 10/10] batman-adv: mcast: apply optimizations for routable packets, too
From: Linus Lüssing <linus.luessing@...3.blue>
Now that we not only track the presence of multicast listeners but also
multicast routers we can safely apply group-aware multicast-to-unicast
forwarding to packets with a destination address of scope greater than
link-local as well.
Signed-off-by: Linus Lüssing <linus.luessing@...3.blue>
Signed-off-by: Sven Eckelmann <sven@...fation.org>
Signed-off-by: Simon Wunderlich <sw@...onwunderlich.de>
---
net/batman-adv/multicast.c | 259 +++++++++++++++++++++++++++++++++++++++++----
1 file changed, 241 insertions(+), 18 deletions(-)
diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c
index 284861761780..40ceab958ca9 100644
--- a/net/batman-adv/multicast.c
+++ b/net/batman-adv/multicast.c
@@ -974,6 +974,7 @@ static bool batadv_mcast_is_report_ipv4(struct sk_buff *skb)
* @bat_priv: the bat priv with all the soft interface information
* @skb: the IPv4 packet to check
* @is_unsnoopable: stores whether the destination is snoopable
+ * @is_routable: stores whether the destination is routable
*
* Checks whether the given IPv4 packet has the potential to be forwarded with a
* mode more optimal than classic flooding.
@@ -983,7 +984,8 @@ static bool batadv_mcast_is_report_ipv4(struct sk_buff *skb)
*/
static int batadv_mcast_forw_mode_check_ipv4(struct batadv_priv *bat_priv,
struct sk_buff *skb,
- bool *is_unsnoopable)
+ bool *is_unsnoopable,
+ int *is_routable)
{
struct iphdr *iphdr;
@@ -996,16 +998,13 @@ static int batadv_mcast_forw_mode_check_ipv4(struct batadv_priv *bat_priv,
iphdr = ip_hdr(skb);
- /* TODO: Implement Multicast Router Discovery (RFC4286),
- * then allow scope > link local, too
- */
- if (!ipv4_is_local_multicast(iphdr->daddr))
- return -EINVAL;
-
/* link-local multicast listeners behind a bridge are
* not snoopable (see RFC4541, section 2.1.2.2)
*/
- *is_unsnoopable = true;
+ if (ipv4_is_local_multicast(iphdr->daddr))
+ *is_unsnoopable = true;
+ else
+ *is_routable = ETH_P_IP;
return 0;
}
@@ -1040,6 +1039,7 @@ static bool batadv_mcast_is_report_ipv6(struct sk_buff *skb)
* @bat_priv: the bat priv with all the soft interface information
* @skb: the IPv6 packet to check
* @is_unsnoopable: stores whether the destination is snoopable
+ * @is_routable: stores whether the destination is routable
*
* Checks whether the given IPv6 packet has the potential to be forwarded with a
* mode more optimal than classic flooding.
@@ -1048,7 +1048,8 @@ static bool batadv_mcast_is_report_ipv6(struct sk_buff *skb)
*/
static int batadv_mcast_forw_mode_check_ipv6(struct batadv_priv *bat_priv,
struct sk_buff *skb,
- bool *is_unsnoopable)
+ bool *is_unsnoopable,
+ int *is_routable)
{
struct ipv6hdr *ip6hdr;
@@ -1061,10 +1062,7 @@ static int batadv_mcast_forw_mode_check_ipv6(struct batadv_priv *bat_priv,
ip6hdr = ipv6_hdr(skb);
- /* TODO: Implement Multicast Router Discovery (RFC4286),
- * then allow scope > link local, too
- */
- if (IPV6_ADDR_MC_SCOPE(&ip6hdr->daddr) != IPV6_ADDR_SCOPE_LINKLOCAL)
+ if (IPV6_ADDR_MC_SCOPE(&ip6hdr->daddr) < IPV6_ADDR_SCOPE_LINKLOCAL)
return -EINVAL;
/* link-local-all-nodes multicast listeners behind a bridge are
@@ -1072,6 +1070,8 @@ static int batadv_mcast_forw_mode_check_ipv6(struct batadv_priv *bat_priv,
*/
if (ipv6_addr_is_ll_all_nodes(&ip6hdr->daddr))
*is_unsnoopable = true;
+ else if (IPV6_ADDR_MC_SCOPE(&ip6hdr->daddr) > IPV6_ADDR_SCOPE_LINKLOCAL)
+ *is_routable = ETH_P_IPV6;
return 0;
}
@@ -1081,6 +1081,7 @@ static int batadv_mcast_forw_mode_check_ipv6(struct batadv_priv *bat_priv,
* @bat_priv: the bat priv with all the soft interface information
* @skb: the multicast frame to check
* @is_unsnoopable: stores whether the destination is snoopable
+ * @is_routable: stores whether the destination is routable
*
* Checks whether the given multicast ethernet frame has the potential to be
* forwarded with a mode more optimal than classic flooding.
@@ -1089,7 +1090,8 @@ static int batadv_mcast_forw_mode_check_ipv6(struct batadv_priv *bat_priv,
*/
static int batadv_mcast_forw_mode_check(struct batadv_priv *bat_priv,
struct sk_buff *skb,
- bool *is_unsnoopable)
+ bool *is_unsnoopable,
+ int *is_routable)
{
struct ethhdr *ethhdr = eth_hdr(skb);
@@ -1099,13 +1101,15 @@ static int batadv_mcast_forw_mode_check(struct batadv_priv *bat_priv,
switch (ntohs(ethhdr->h_proto)) {
case ETH_P_IP:
return batadv_mcast_forw_mode_check_ipv4(bat_priv, skb,
- is_unsnoopable);
+ is_unsnoopable,
+ is_routable);
case ETH_P_IPV6:
if (!IS_ENABLED(CONFIG_IPV6))
return -EINVAL;
return batadv_mcast_forw_mode_check_ipv6(bat_priv, skb,
- is_unsnoopable);
+ is_unsnoopable,
+ is_routable);
default:
return -EINVAL;
}
@@ -1136,6 +1140,29 @@ static int batadv_mcast_forw_want_all_ip_count(struct batadv_priv *bat_priv,
}
/**
+ * batadv_mcast_forw_rtr_count() - count nodes with a multicast router
+ * @bat_priv: the bat priv with all the soft interface information
+ * @protocol: the ethernet protocol type to count multicast routers for
+ *
+ * Return: the number of nodes which want all routable IPv4 multicast traffic
+ * if the protocol is ETH_P_IP or the number of nodes which want all routable
+ * IPv6 traffic if the protocol is ETH_P_IPV6. Otherwise returns 0.
+ */
+
+static int batadv_mcast_forw_rtr_count(struct batadv_priv *bat_priv,
+ int protocol)
+{
+ switch (protocol) {
+ case ETH_P_IP:
+ return atomic_read(&bat_priv->mcast.num_want_all_rtr4);
+ case ETH_P_IPV6:
+ return atomic_read(&bat_priv->mcast.num_want_all_rtr6);
+ default:
+ return 0;
+ }
+}
+
+/**
* batadv_mcast_forw_tt_node_get() - get a multicast tt node
* @bat_priv: the bat priv with all the soft interface information
* @ethhdr: the ether header containing the multicast destination
@@ -1257,6 +1284,84 @@ batadv_mcast_forw_unsnoop_node_get(struct batadv_priv *bat_priv)
}
/**
+ * batadv_mcast_forw_rtr4_node_get() - get a node with an ipv4 mcast router flag
+ * @bat_priv: the bat priv with all the soft interface information
+ *
+ * Return: an orig_node which has the BATADV_MCAST_WANT_NO_RTR4 flag unset and
+ * increases its refcount.
+ */
+static struct batadv_orig_node *
+batadv_mcast_forw_rtr4_node_get(struct batadv_priv *bat_priv)
+{
+ struct batadv_orig_node *tmp_orig_node, *orig_node = NULL;
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(tmp_orig_node,
+ &bat_priv->mcast.want_all_rtr4_list,
+ mcast_want_all_rtr4_node) {
+ if (!kref_get_unless_zero(&tmp_orig_node->refcount))
+ continue;
+
+ orig_node = tmp_orig_node;
+ break;
+ }
+ rcu_read_unlock();
+
+ return orig_node;
+}
+
+/**
+ * batadv_mcast_forw_rtr6_node_get() - get a node with an ipv6 mcast router flag
+ * @bat_priv: the bat priv with all the soft interface information
+ *
+ * Return: an orig_node which has the BATADV_MCAST_WANT_NO_RTR6 flag unset
+ * and increases its refcount.
+ */
+static struct batadv_orig_node *
+batadv_mcast_forw_rtr6_node_get(struct batadv_priv *bat_priv)
+{
+ struct batadv_orig_node *tmp_orig_node, *orig_node = NULL;
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(tmp_orig_node,
+ &bat_priv->mcast.want_all_rtr6_list,
+ mcast_want_all_rtr6_node) {
+ if (!kref_get_unless_zero(&tmp_orig_node->refcount))
+ continue;
+
+ orig_node = tmp_orig_node;
+ break;
+ }
+ rcu_read_unlock();
+
+ return orig_node;
+}
+
+/**
+ * batadv_mcast_forw_rtr_node_get() - get a node with an ipv4/ipv6 router flag
+ * @bat_priv: the bat priv with all the soft interface information
+ * @ethhdr: an ethernet header to determine the protocol family from
+ *
+ * Return: an orig_node which has no BATADV_MCAST_WANT_NO_RTR4 or
+ * BATADV_MCAST_WANT_NO_RTR6 flag, depending on the provided ethhdr, set and
+ * increases its refcount.
+ */
+static struct batadv_orig_node *
+batadv_mcast_forw_rtr_node_get(struct batadv_priv *bat_priv,
+ struct ethhdr *ethhdr)
+{
+ switch (ntohs(ethhdr->h_proto)) {
+ case ETH_P_IP:
+ return batadv_mcast_forw_rtr4_node_get(bat_priv);
+ case ETH_P_IPV6:
+ return batadv_mcast_forw_rtr6_node_get(bat_priv);
+ default:
+ /* we shouldn't be here... */
+ return NULL;
+ }
+}
+
+/**
* 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
@@ -1274,8 +1379,11 @@ batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
bool is_unsnoopable = false;
unsigned int mcast_fanout;
struct ethhdr *ethhdr;
+ int is_routable = 0;
+ int rtr_count = 0;
- ret = batadv_mcast_forw_mode_check(bat_priv, skb, &is_unsnoopable);
+ ret = batadv_mcast_forw_mode_check(bat_priv, skb, &is_unsnoopable,
+ &is_routable);
if (ret == -ENOMEM)
return BATADV_FORW_NONE;
else if (ret < 0)
@@ -1288,8 +1396,9 @@ batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
ip_count = batadv_mcast_forw_want_all_ip_count(bat_priv, ethhdr);
unsnoop_count = !is_unsnoopable ? 0 :
atomic_read(&bat_priv->mcast.num_want_all_unsnoopables);
+ rtr_count = batadv_mcast_forw_rtr_count(bat_priv, is_routable);
- total_count = tt_count + ip_count + unsnoop_count;
+ total_count = tt_count + ip_count + unsnoop_count + rtr_count;
switch (total_count) {
case 1:
@@ -1299,6 +1408,9 @@ batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
*orig = batadv_mcast_forw_ip_node_get(bat_priv, ethhdr);
else if (unsnoop_count)
*orig = batadv_mcast_forw_unsnoop_node_get(bat_priv);
+ else if (rtr_count)
+ *orig = batadv_mcast_forw_rtr_node_get(bat_priv,
+ ethhdr);
if (*orig)
return BATADV_FORW_SINGLE;
@@ -1470,6 +1582,111 @@ batadv_mcast_forw_want_all(struct batadv_priv *bat_priv,
}
/**
+ * batadv_mcast_forw_want_all_rtr4() - forward to nodes with want-all-rtr4
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: the multicast packet to transmit
+ * @vid: the vlan identifier
+ *
+ * Sends copies of a frame with multicast destination to any node with a
+ * BATADV_MCAST_WANT_NO_RTR4 flag unset. A transmission is performed via a
+ * batman-adv unicast packet for each such destination node.
+ *
+ * Return: NET_XMIT_DROP on memory allocation failure, NET_XMIT_SUCCESS
+ * otherwise.
+ */
+static int
+batadv_mcast_forw_want_all_rtr4(struct batadv_priv *bat_priv,
+ struct sk_buff *skb, unsigned short vid)
+{
+ struct batadv_orig_node *orig_node;
+ int ret = NET_XMIT_SUCCESS;
+ struct sk_buff *newskb;
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(orig_node,
+ &bat_priv->mcast.want_all_rtr4_list,
+ mcast_want_all_rtr4_node) {
+ newskb = skb_copy(skb, GFP_ATOMIC);
+ if (!newskb) {
+ ret = NET_XMIT_DROP;
+ break;
+ }
+
+ batadv_send_skb_unicast(bat_priv, newskb, BATADV_UNICAST, 0,
+ orig_node, vid);
+ }
+ rcu_read_unlock();
+ return ret;
+}
+
+/**
+ * batadv_mcast_forw_want_all_rtr6() - forward to nodes with want-all-rtr6
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: The multicast packet to transmit
+ * @vid: the vlan identifier
+ *
+ * Sends copies of a frame with multicast destination to any node with a
+ * BATADV_MCAST_WANT_NO_RTR6 flag unset. A transmission is performed via a
+ * batman-adv unicast packet for each such destination node.
+ *
+ * Return: NET_XMIT_DROP on memory allocation failure, NET_XMIT_SUCCESS
+ * otherwise.
+ */
+static int
+batadv_mcast_forw_want_all_rtr6(struct batadv_priv *bat_priv,
+ struct sk_buff *skb, unsigned short vid)
+{
+ struct batadv_orig_node *orig_node;
+ int ret = NET_XMIT_SUCCESS;
+ struct sk_buff *newskb;
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(orig_node,
+ &bat_priv->mcast.want_all_rtr6_list,
+ mcast_want_all_rtr6_node) {
+ newskb = skb_copy(skb, GFP_ATOMIC);
+ if (!newskb) {
+ ret = NET_XMIT_DROP;
+ break;
+ }
+
+ batadv_send_skb_unicast(bat_priv, newskb, BATADV_UNICAST, 0,
+ orig_node, vid);
+ }
+ rcu_read_unlock();
+ return ret;
+}
+
+/**
+ * batadv_mcast_forw_want_rtr() - forward packet to nodes in a want-all-rtr list
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: the multicast packet to transmit
+ * @vid: the vlan identifier
+ *
+ * Sends copies of a frame with multicast destination to any node with a
+ * BATADV_MCAST_WANT_NO_RTR4 or BATADV_MCAST_WANT_NO_RTR6 flag unset. A
+ * transmission is performed via a batman-adv unicast packet for each such
+ * destination node.
+ *
+ * Return: NET_XMIT_DROP on memory allocation failure or if the protocol family
+ * is neither IPv4 nor IPv6. NET_XMIT_SUCCESS otherwise.
+ */
+static int
+batadv_mcast_forw_want_rtr(struct batadv_priv *bat_priv,
+ struct sk_buff *skb, unsigned short vid)
+{
+ switch (ntohs(eth_hdr(skb)->h_proto)) {
+ case ETH_P_IP:
+ return batadv_mcast_forw_want_all_rtr4(bat_priv, skb, vid);
+ case ETH_P_IPV6:
+ return batadv_mcast_forw_want_all_rtr6(bat_priv, skb, vid);
+ default:
+ /* we shouldn't be here... */
+ return NET_XMIT_DROP;
+ }
+}
+
+/**
* batadv_mcast_forw_send() - send packet to any detected multicast recpient
* @bat_priv: the bat priv with all the soft interface information
* @skb: the multicast packet to transmit
@@ -1502,6 +1719,12 @@ int batadv_mcast_forw_send(struct batadv_priv *bat_priv, struct sk_buff *skb,
return ret;
}
+ ret = batadv_mcast_forw_want_rtr(bat_priv, skb, vid);
+ if (ret != NET_XMIT_SUCCESS) {
+ kfree_skb(skb);
+ return ret;
+ }
+
consume_skb(skb);
return ret;
}
--
2.11.0
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