Multicast optimizations for bridges

index 3dbf9d2..31546f5 100644
@@ -109,3 +109,42 @@ void batadv_free_rcu_tvlv_handler(struct rcu_head *rcu)
 }
 
 #endif /* < KERNEL_VERSION(3, 0, 0) */
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 16, 0)
+
+int br_multicast_list_adjacent(struct net_device *dev,
+			       struct list_head *br_ip_list)
+{
+	return 0;
+}
+
+bool br_multicast_has_querier_adjacent(struct net_device *dev, int proto)
+{
+	return false;
+}
+
+#endif /* < KERNEL_VERSION(3, 16, 0) */
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 17, 0)
+
+bool br_multicast_has_querier_anywhere(struct net_device *dev, int proto)
+{
+	pr_warn_once("Old kernel detected (< 3.17) - multicast optimizations disabled\n");
+
+	return false;
+}
+
+#if !(IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_BRIDGE_IGMP_SNOOPING))
+int br_multicast_list_adjacent(struct net_device *dev,
+			       struct list_head *br_ip_list)
+{
+	return 0;
+}
+
+bool br_multicast_has_querier_adjacent(struct net_device *dev, int proto)
+{
+	return false;
+}
+#endif
+
+#endif /* < KERNEL_VERSION(3, 17, 0) */

index ed5b815..14de948 100644
@@ -240,6 +240,12 @@ static inline void skb_reset_mac_len(struct sk_buff *skb)
 
 #endif /* < KERNEL_VERSION(3, 0, 0) */
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 1, 0)
+
+#define IS_ENABLED(x) defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+
+#endif /* < KERNEL_VERSION(3, 1, 0) */
+
 #if LINUX_VERSION_CODE < KERNEL_VERSION(3, 3, 0)
 
 #define batadv_interface_add_vid(x, y, z) \

@@ -444,6 +450,32 @@ static int __batadv_interface_kill_vid(struct net_device *dev, __be16 proto,\
 
 #define pskb_copy_for_clone pskb_copy
 
+int br_multicast_list_adjacent(struct net_device *dev,
+			       struct list_head *br_ip_list);
+bool br_multicast_has_querier_adjacent(struct net_device *dev, int proto);
+
+struct br_ip {
+	union {
+		__be32  ip4;
+#if IS_ENABLED(CONFIG_IPV6)
+		struct in6_addr ip6;
+#endif
+	} u;
+	__be16          proto;
+	__u16           vid;
+};
+
+struct br_ip_list {
+	struct list_head list;
+	struct br_ip addr;
+};
+
 #endif /* < KERNEL_VERSION(3, 16, 0) */
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 17, 0)
+
+bool br_multicast_has_querier_anywhere(struct net_device *dev, int proto);
+
+#endif /* < KERNEL_VERSION(3, 17, 0) */
+
 #endif /* _NET_BATMAN_ADV_COMPAT_H_ */

index 4bb500b..1e1e000 100644
@@ -169,6 +169,7 @@ enum batadv_uev_type {
 #include <linux/netdevice.h>	/* netdevice */
 #include <linux/etherdevice.h>  /* ethernet address classification */
 #include <linux/if_ether.h>	/* ethernet header */
+#include <linux/if_bridge.h>	/* bridge / multicast-snooping communication */
 #include <linux/poll.h>		/* poll_table */
 #include <linux/kthread.h>	/* kernel threads */
 #include <linux/pkt_sched.h>	/* schedule types */

@@ -177,6 +178,7 @@ enum batadv_uev_type {
 #include <linux/slab.h>
 #include <net/sock.h>		/* struct sock */
 #include <net/addrconf.h>	/* ipv6 address stuff */
+#include <net/ip.h>
 #include <linux/ip.h>
 #include <net/rtnetlink.h>
 #include <linux/jiffies.h>

@@ -223,6 +225,7 @@ __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr);
  * @BATADV_DBG_BLA: bridge loop avoidance messages
  * @BATADV_DBG_DAT: ARP snooping and DAT related messages
  * @BATADV_DBG_NC: network coding related messages
+ * @BATADV_DBG_MCAST: multicast related messages
  * @BATADV_DBG_ALL: the union of all the above log levels
  */
 enum batadv_dbg_level {

@@ -232,7 +235,8 @@ enum batadv_dbg_level {
 	BATADV_DBG_BLA    = BIT(3),
 	BATADV_DBG_DAT    = BIT(4),
 	BATADV_DBG_NC	  = BIT(5),
-	BATADV_DBG_ALL    = 63,
+	BATADV_DBG_MCAST  = BIT(6),
+	BATADV_DBG_ALL    = 127,
 };
 
 #ifdef CONFIG_BATMAN_ADV_DEBUG

230 lines not on this page · raw message

index c05f64a..2a80997 100644
@@ -292,6 +292,123 @@ static bool batadv_mcast_has_bridge(struct batadv_priv *bat_priv)
 }
 
 /**
+ * batadv_mcast_querier_log - debug output regarding the querier status on link
+ * @bat_priv: the bat priv with all the soft interface information
+ * @str_proto: a string for the querier protocol (e.g. "IGMP" or "MLD")
+ * @old_querier: the previous querier state on our link
+ * @new_querier: the new querier state on our link
+ *
+ * Outputs debug messages to the logging facility with log level 'mcast'
+ * regarding changes to the querier status on the link which are relevant
+ * to our multicast optimizations.
+ *
+ * Usually this is about whether a querier appeared or vanished in
+ * our mesh or whether the querier is in the suboptimal position of being
+ * behind our local bridge segment.
+ *
+ * This is only interesting for nodes with a bridge on top of their
+ * soft interface.
+ */
+static void
+batadv_mcast_querier_log(struct batadv_priv *bat_priv, char *str_proto,
+			 struct batadv_mcast_querier_state *old_querier,
+			 struct batadv_mcast_querier_state *new_querier)
+{
+	if (!old_querier->exists && new_querier->exists)
+		batadv_dbg(BATADV_DBG_MCAST, bat_priv,
+			   "%s Querier appeared (good!)\n", str_proto);
+	else if (old_querier->exists && !new_querier->exists)
+		batadv_dbg(BATADV_DBG_MCAST, bat_priv,
+			   "%s Querier disappeared (bad)\n", str_proto);
+	else if (!bat_priv->mcast.bridged && !new_querier->exists)
+		batadv_dbg(BATADV_DBG_MCAST, bat_priv,
+			   "Note: No %s Querier present\n", str_proto);
+
+	if (!new_querier->exists)
+		return;
+
+	if (!old_querier->shadowing && new_querier->shadowing)
+		batadv_dbg(BATADV_DBG_MCAST, bat_priv,
+			   "%s Querier is behind our bridged segment: Might shadow listeners (bad)\n",
+			   str_proto);
+	else if (old_querier->shadowing && !new_querier->shadowing)
+		batadv_dbg(BATADV_DBG_MCAST, bat_priv,
+			   "%s Querier is not behind our bridged segment (good!)\n",
+			   str_proto);
+}
+
+/**
+ * batadv_mcast_bridge_log - debug output for topology changes in bridged setups
+ * @bat_priv: the bat priv with all the soft interface information
+ * @bridged: a flag about whether the soft interface is currently bridged or not
+ * @querier_ipv4: (maybe) new status of a potential, selected IGMP querier
+ * @querier_ipv6: (maybe) new status of a potential, selected MLD querier
+ *
+ * If no bridges are ever used on this node, then this function does nothing.
+ *
+ * Otherwise this function outputs debug information to the 'mcast' log level
+ * which might be relevant to our multicast optimizations.
+ *
+ * More precisely, it outputs information when a bridge interface is added or
+ * removed from a soft interface. And when a bridge is present, it further
+ * outputs information about the querier state which is relevant for the
+ * multicast flags this node is going to set.
+ */
+static void
+batadv_mcast_bridge_log(struct batadv_priv *bat_priv, bool bridged,
+			struct batadv_mcast_querier_state *querier_ipv4,
+			struct batadv_mcast_querier_state *querier_ipv6)
+{
+	if (!bat_priv->mcast.bridged && bridged)
+		batadv_dbg(BATADV_DBG_MCAST, bat_priv,
+			   "Bridge added: Setting U-flag\n");
+	else if (bat_priv->mcast.bridged && !bridged)
+		batadv_dbg(BATADV_DBG_MCAST, bat_priv,
+			   "Bridge removed: Unsetting U-flag\n");
+	if (!bridged)
+		return;
+
+	batadv_mcast_querier_log(bat_priv, "IGMP",
+				 &bat_priv->mcast.querier_ipv4, querier_ipv4);
+	batadv_mcast_querier_log(bat_priv, "MLD",
+				 &bat_priv->mcast.querier_ipv6, querier_ipv6);
+}
+
+/**
+ * batadv_mcast_flags_logs - output debug information about mcast flag changes
+ * @bat_priv: the bat priv with all the soft interface information
+ * @mcast_flags: flags indicating the new multicast state
+ *
+ * Whenever the multicast flags this nodes announces changes (@mcast_flags vs.
+ * bat_priv->mcast.flags), this notifies userspace via the 'mcast' log level.
+ */
+static void batadv_mcast_flags_log(struct batadv_priv *bat_priv, uint8_t flags)
+{
+	char str_undefined[] = "<undefined>";
+	char str_flags[] = "[...]";
+	char *str_flags_old = str_undefined;
+	uint8_t old_flags = bat_priv->mcast.flags;
+
+	if (!bat_priv->mcast.enabled)
+		goto print;
+
+	str_flags_old = str_flags;
+
+	sprintf(str_flags_old, "[%c%c%c]",
+		old_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES ? 'U' : '.',
+		old_flags & BATADV_MCAST_WANT_ALL_IPV4 ? '4' : '.',
+		old_flags & BATADV_MCAST_WANT_ALL_IPV6 ? '6' : '.');
+
+print:
+	batadv_dbg(BATADV_DBG_MCAST, bat_priv,
+		   "Changing multicast flags from '%s' to '[%c%c%c]'\n",
+		   str_flags_old,
+		   flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES ? 'U' : '.',
+		   flags & BATADV_MCAST_WANT_ALL_IPV4 ? '4' : '.',
+		   flags & BATADV_MCAST_WANT_ALL_IPV6 ? '6' : '.');
+}
+
+/**
  * batadv_mcast_mla_tvlv_update - update multicast tvlv
  * @bat_priv: the bat priv with all the soft interface information
  *

@@ -304,18 +421,33 @@ static bool batadv_mcast_has_bridge(struct batadv_priv *bat_priv)
 static bool batadv_mcast_mla_tvlv_update(struct batadv_priv *bat_priv)
 {
 	struct batadv_tvlv_mcast_data mcast_data;
+	struct batadv_mcast_querier_state querier_ipv4, querier_ipv6;
 	struct net_device *dev = bat_priv->soft_iface;
+	bool bridged;
 
 	mcast_data.flags = BATADV_NO_FLAGS;
 	memset(mcast_data.reserved, 0, sizeof(mcast_data.reserved));
+	memset(&querier_ipv4, 0, sizeof(querier_ipv4));
+	memset(&querier_ipv6, 0, sizeof(querier_ipv6));
 
-	if (!batadv_mcast_has_bridge(bat_priv))
+	bridged = batadv_mcast_has_bridge(bat_priv);
+	if (!bridged)
 		goto update;
 
 #if !IS_ENABLED(CONFIG_BRIDGE_IGMP_SNOOPING)
 	pr_warn_once("No bridge IGMP snooping compiled - multicast optimizations disabled\n");
 #endif
 
+	querier_ipv4 = (struct batadv_mcast_querier_state){
+		.exists = br_multicast_has_querier_anywhere(dev, ETH_P_IP),
+		.shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IP),
+	};
+
+	querier_ipv6 = (struct batadv_mcast_querier_state){
+		.exists = br_multicast_has_querier_anywhere(dev, ETH_P_IPV6),
+		.shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IPV6),
+	};
+
 	mcast_data.flags |= BATADV_MCAST_WANT_ALL_UNSNOOPABLES;
 
 	/* 1) If no querier exists at all, then multicast listeners on

@@ -327,21 +459,31 @@ static bool batadv_mcast_mla_tvlv_update(struct batadv_priv *bat_priv)
 	 * In both cases, we will signalize other batman nodes that
 	 * we need all multicast traffic of the according protocol.
 	 */
-	if (!br_multicast_has_querier_anywhere(dev, ETH_P_IP) ||
-	    br_multicast_has_querier_adjacent(dev, ETH_P_IP))
+	if (!querier_ipv4.exists || querier_ipv4.shadowing)
 		mcast_data.flags |= BATADV_MCAST_WANT_ALL_IPV4;
 
-	if (!br_multicast_has_querier_anywhere(dev, ETH_P_IPV6) ||
-	    br_multicast_has_querier_adjacent(dev, ETH_P_IPV6))
+	if (!querier_ipv6.exists || querier_ipv6.shadowing)
 		mcast_data.flags |= BATADV_MCAST_WANT_ALL_IPV6;
 
 update:
+	batadv_mcast_bridge_log(bat_priv, bridged, &querier_ipv4,
+				&querier_ipv6);
+
+	if (memcmp(&bat_priv->mcast.querier_ipv4, &querier_ipv4,
+		   sizeof(querier_ipv4)))
+		bat_priv->mcast.querier_ipv4 = querier_ipv4;
+	if (memcmp(&bat_priv->mcast.querier_ipv6, &querier_ipv6,
+		   sizeof(querier_ipv6)))
+		bat_priv->mcast.querier_ipv6 = querier_ipv6;
+
 	if (!bat_priv->mcast.enabled ||
 	    mcast_data.flags != bat_priv->mcast.flags) {
+		batadv_mcast_flags_log(bat_priv, mcast_data.flags);
 		batadv_tvlv_container_register(bat_priv, BATADV_TVLV_MCAST, 1,
 					       &mcast_data, sizeof(mcast_data));
 		bat_priv->mcast.flags = mcast_data.flags;
 		bat_priv->mcast.enabled = true;
+		bat_priv->mcast.bridged = bridged;
 	}
 
 	return !(mcast_data.flags &

index 9bf382d..0265a58 100644
@@ -745,7 +745,12 @@ static int batadv_softif_init_late(struct net_device *dev)
 	atomic_set(&bat_priv->distributed_arp_table, 1);
 #endif
 #ifdef CONFIG_BATMAN_ADV_MCAST
+	bat_priv->mcast.querier_ipv4 = (struct batadv_mcast_querier_state){
+		.exists = false, .shadowing = false };
+	bat_priv->mcast.querier_ipv6 = (struct batadv_mcast_querier_state){
+		.exists = false, .shadowing = false };
 	bat_priv->mcast.flags = BATADV_NO_FLAGS;
+	bat_priv->mcast.bridged = false;
 	atomic_set(&bat_priv->multicast_mode, 1);
 	atomic_set(&bat_priv->mcast.num_disabled, 0);
 	atomic_set(&bat_priv->mcast.num_want_all_unsnoopables, 0);

index 8854c05..b27c79d 100644
@@ -625,14 +625,28 @@ struct batadv_priv_dat {
 
 #ifdef CONFIG_BATMAN_ADV_MCAST
 /**
+ * struct batadv_mcast_querier_state - IGMP/MLD querier state when bridged
+ * @exists: whether a querier exists in the mesh
+ * @shadowing: if a querier exists, whether it is potentially shadowing
+ *  multicast listeners (i.e. querier is behind our own bridge segment)
+ */
+struct batadv_mcast_querier_state {
+	bool exists;
+	bool shadowing;
+};
+
+/**
  * struct batadv_priv_mcast - per mesh interface mcast data
  * @mla_list: list of multicast addresses we are currently announcing via TT
  * @want_all_unsnoopables_list: a list of orig_nodes wanting all unsnoopable
  *  multicast traffic
  * @want_all_ipv4_list: a list of orig_nodes wanting all IPv4 multicast traffic
  * @want_all_ipv6_list: a list of orig_nodes wanting all IPv6 multicast traffic
+ * @querier_ipv4: the current state of an IGMP querier in the mesh (if bridged)
+ * @querier_ipv6: the current state of an MLD querier in the mesh (if bridged)
  * @flags: the flags we have last sent in our mcast tvlv
  * @enabled: whether the multicast tvlv is currently enabled
+ * @bridged: whether the soft interface currently has a bridge on top
  * @num_disabled: number of nodes that have no mcast tvlv
  * @num_want_all_unsnoopables: number of nodes wanting unsnoopable IP traffic
  * @num_want_all_ipv4: counter for items in want_all_ipv4_list

@@ -645,8 +659,11 @@ struct batadv_priv_mcast {
 	struct hlist_head want_all_unsnoopables_list;
 	struct hlist_head want_all_ipv4_list;
 	struct hlist_head want_all_ipv6_list;
+	struct batadv_mcast_querier_state querier_ipv4;
+	struct batadv_mcast_querier_state querier_ipv6;
 	uint8_t flags;
 	bool enabled;
+	bool bridged;
 	atomic_t num_disabled;
 	atomic_t num_want_all_unsnoopables;
 	atomic_t num_want_all_ipv4;

index a12e25e..cd7c282 100644
@@ -30,6 +30,7 @@
 #include "bridge_loop_avoidance.h"
 #include "distributed-arp-table.h"
 #include "network-coding.h"
+#include "multicast.h"
 
 static struct dentry *batadv_debugfs;
 

@@ -332,6 +333,20 @@ static int batadv_nc_nodes_open(struct inode *inode, struct file *file)
 }
 #endif
 
+#ifdef CONFIG_BATMAN_ADV_MCAST
+/**
+ * batadv_mcast_flags_open - prepare file handler for reads from mcast_flags
+ * @inode: inode which was opened
+ * @file: file handle to be initialized
+ */
+static int batadv_mcast_flags_open(struct inode *inode, struct file *file)
+{
+	struct net_device *net_dev = (struct net_device *)inode->i_private;
+
+	return single_open(file, batadv_mcast_flags_seq_print_text, net_dev);
+}
+#endif
+
 #define BATADV_DEBUGINFO(_name, _mode, _open)		\
 struct batadv_debuginfo batadv_debuginfo_##_name = {	\
 	.attr = { .name = __stringify(_name),		\

@@ -372,6 +387,9 @@ static BATADV_DEBUGINFO(transtable_local, S_IRUGO,
 #ifdef CONFIG_BATMAN_ADV_NC
 static BATADV_DEBUGINFO(nc_nodes, S_IRUGO, batadv_nc_nodes_open);
 #endif
+#ifdef CONFIG_BATMAN_ADV_MCAST
+static BATADV_DEBUGINFO(mcast_flags, S_IRUGO, batadv_mcast_flags_open);
+#endif
 
 static struct batadv_debuginfo *batadv_mesh_debuginfos[] = {
 	&batadv_debuginfo_originators,

@@ -388,6 +406,9 @@ static struct batadv_debuginfo *batadv_mesh_debuginfos[] = {
 #ifdef CONFIG_BATMAN_ADV_NC
 	&batadv_debuginfo_nc_nodes,
 #endif
+#ifdef CONFIG_BATMAN_ADV_MCAST
+	&batadv_debuginfo_mcast_flags,
+#endif
 	NULL,
 };
 

116 lines not on this page · raw message

index 73b5d45..5344160 100644
@@ -42,6 +42,8 @@ batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
 
 void batadv_mcast_init(struct batadv_priv *bat_priv);
 
+int batadv_mcast_flags_seq_print_text(struct seq_file *seq, void *offset);
+
 void batadv_mcast_free(struct batadv_priv *bat_priv);
 
 void batadv_mcast_purge_orig(struct batadv_orig_node *orig_node);