From bb18ef8e7e180d8590df2808ec4014af114756cb Mon Sep 17 00:00:00 2001
From: Nikolay Aleksandrov <nikolay@nvidia.com>
Date: Fri, 13 Aug 2021 17:59:57 +0300
Subject: net: bridge: mcast: record querier port device ifindex instead of
 pointer

Currently when a querier port is detected its net_bridge_port pointer is
recorded, but it's used only for comparisons so it's fine to have stale
pointer, in order to dereference and use the port pointer a proper
accounting of its usage must be implemented adding unnecessary
complexity. To solve the problem we can just store the netdevice ifindex
instead of the port pointer and retrieve the bridge port. It is a best
effort and the device needs to be validated that is still part of that
bridge before use, but that is small price to pay for avoiding querier
reference counting for each port/vlan.

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/bridge/br_multicast.c | 19 ++++++++++++-------
 net/bridge/br_private.h   |  2 +-
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index df6bf6a237aa..853b947edf87 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -2850,7 +2850,8 @@ update:
 	brmctx->ip4_querier.addr.src.ip4 = saddr;
 
 	/* update protected by general multicast_lock by caller */
-	rcu_assign_pointer(brmctx->ip4_querier.port, port);
+	if (port)
+		brmctx->ip4_querier.port_ifidx = port->dev->ifindex;
 
 	return true;
 }
@@ -2875,7 +2876,8 @@ update:
 	brmctx->ip6_querier.addr.src.ip6 = *saddr;
 
 	/* update protected by general multicast_lock by caller */
-	rcu_assign_pointer(brmctx->ip6_querier.port, port);
+	if (port)
+		brmctx->ip6_querier.port_ifidx = port->dev->ifindex;
 
 	return true;
 }
@@ -3675,7 +3677,7 @@ static void br_multicast_query_expired(struct net_bridge_mcast *brmctx,
 	if (query->startup_sent < brmctx->multicast_startup_query_count)
 		query->startup_sent++;
 
-	RCU_INIT_POINTER(querier->port, NULL);
+	querier->port_ifidx = 0;
 	br_multicast_send_query(brmctx, NULL, query);
 out:
 	spin_unlock(&brmctx->br->multicast_lock);
@@ -3732,12 +3734,12 @@ void br_multicast_ctx_init(struct net_bridge *br,
 	brmctx->multicast_membership_interval = 260 * HZ;
 
 	brmctx->ip4_other_query.delay_time = 0;
-	brmctx->ip4_querier.port = NULL;
+	brmctx->ip4_querier.port_ifidx = 0;
 	brmctx->multicast_igmp_version = 2;
 #if IS_ENABLED(CONFIG_IPV6)
 	brmctx->multicast_mld_version = 1;
 	brmctx->ip6_other_query.delay_time = 0;
-	brmctx->ip6_querier.port = NULL;
+	brmctx->ip6_querier.port_ifidx = 0;
 #endif
 
 	timer_setup(&brmctx->ip4_mc_router_timer,
@@ -4479,6 +4481,7 @@ bool br_multicast_has_querier_adjacent(struct net_device *dev, int proto)
 	struct net_bridge *br;
 	struct net_bridge_port *port;
 	bool ret = false;
+	int port_ifidx;
 
 	rcu_read_lock();
 	if (!netif_is_bridge_port(dev))
@@ -4493,14 +4496,16 @@ bool br_multicast_has_querier_adjacent(struct net_device *dev, int proto)
 
 	switch (proto) {
 	case ETH_P_IP:
+		port_ifidx = brmctx->ip4_querier.port_ifidx;
 		if (!timer_pending(&brmctx->ip4_other_query.timer) ||
-		    rcu_dereference(brmctx->ip4_querier.port) == port)
+		    port_ifidx == port->dev->ifindex)
 			goto unlock;
 		break;
 #if IS_ENABLED(CONFIG_IPV6)
 	case ETH_P_IPV6:
+		port_ifidx = brmctx->ip6_querier.port_ifidx;
 		if (!timer_pending(&brmctx->ip6_other_query.timer) ||
-		    rcu_dereference(brmctx->ip6_querier.port) == port)
+		    port_ifidx == port->dev->ifindex)
 			goto unlock;
 		break;
 #endif
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index c4a8fee990c9..30ca978676f3 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -81,7 +81,7 @@ struct bridge_mcast_other_query {
 /* selected querier */
 struct bridge_mcast_querier {
 	struct br_ip addr;
-	struct net_bridge_port __rcu	*port;
+	int port_ifidx;
 };
 
 /* IGMP/MLD statistics */
-- 
cgit v1.2.3


From 67b746f94ff39d8b998c4ea9493c6ab2d6c225d4 Mon Sep 17 00:00:00 2001
From: Nikolay Aleksandrov <nikolay@nvidia.com>
Date: Fri, 13 Aug 2021 17:59:58 +0300
Subject: net: bridge: mcast: make sure querier port/address updates are
 consistent

Use a sequence counter to make sure port/address updates can be read
consistently without requiring the bridge multicast_lock. We need to
zero out the port and address when the other querier has expired and
we're about to select ourselves as querier. br_multicast_read_querier
will be used later when dumping querier state. Updates are done only
with the multicast spinlock and softirqs disabled, while reads are done
from process context and from softirqs (due to notifications).

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/bridge/br_multicast.c | 74 +++++++++++++++++++++++++++++++++--------------
 net/bridge/br_private.h   |  1 +
 2 files changed, 54 insertions(+), 21 deletions(-)

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 853b947edf87..701cf46b89de 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -1659,11 +1659,38 @@ again_under_lmqt:
 	}
 }
 
+static void br_multicast_read_querier(const struct bridge_mcast_querier *querier,
+				      struct bridge_mcast_querier *dest)
+{
+	unsigned int seq;
+
+	memset(dest, 0, sizeof(*dest));
+	do {
+		seq = read_seqcount_begin(&querier->seq);
+		dest->port_ifidx = querier->port_ifidx;
+		memcpy(&dest->addr, &querier->addr, sizeof(struct br_ip));
+	} while (read_seqcount_retry(&querier->seq, seq));
+}
+
+static void br_multicast_update_querier(struct net_bridge_mcast *brmctx,
+					struct bridge_mcast_querier *querier,
+					int ifindex,
+					struct br_ip *saddr)
+{
+	lockdep_assert_held_once(&brmctx->br->multicast_lock);
+
+	write_seqcount_begin(&querier->seq);
+	querier->port_ifidx = ifindex;
+	memcpy(&querier->addr, saddr, sizeof(*saddr));
+	write_seqcount_end(&querier->seq);
+}
+
 static void br_multicast_send_query(struct net_bridge_mcast *brmctx,
 				    struct net_bridge_mcast_port *pmctx,
 				    struct bridge_mcast_own_query *own_query)
 {
 	struct bridge_mcast_other_query *other_query = NULL;
+	struct bridge_mcast_querier *querier;
 	struct br_ip br_group;
 	unsigned long time;
 
@@ -1676,10 +1703,12 @@ static void br_multicast_send_query(struct net_bridge_mcast *brmctx,
 
 	if (pmctx ? (own_query == &pmctx->ip4_own_query) :
 		    (own_query == &brmctx->ip4_own_query)) {
+		querier = &brmctx->ip4_querier;
 		other_query = &brmctx->ip4_other_query;
 		br_group.proto = htons(ETH_P_IP);
 #if IS_ENABLED(CONFIG_IPV6)
 	} else {
+		querier = &brmctx->ip6_querier;
 		other_query = &brmctx->ip6_other_query;
 		br_group.proto = htons(ETH_P_IPV6);
 #endif
@@ -1688,6 +1717,13 @@ static void br_multicast_send_query(struct net_bridge_mcast *brmctx,
 	if (!other_query || timer_pending(&other_query->timer))
 		return;
 
+	/* we're about to select ourselves as querier */
+	if (!pmctx && querier->port_ifidx) {
+		struct br_ip zeroip = {};
+
+		br_multicast_update_querier(brmctx, querier, 0, &zeroip);
+	}
+
 	__br_multicast_send_query(brmctx, pmctx, NULL, NULL, &br_group, false,
 				  0, NULL);
 
@@ -2830,9 +2866,9 @@ unlock_continue:
 
 static bool br_ip4_multicast_select_querier(struct net_bridge_mcast *brmctx,
 					    struct net_bridge_mcast_port *pmctx,
-					    __be32 saddr)
+					    struct br_ip *saddr)
 {
-	struct net_bridge_port *port = pmctx ? pmctx->port : NULL;
+	int port_ifidx = pmctx ? pmctx->port->dev->ifindex : 0;
 
 	if (!timer_pending(&brmctx->ip4_own_query.timer) &&
 	    !timer_pending(&brmctx->ip4_other_query.timer))
@@ -2841,17 +2877,14 @@ static bool br_ip4_multicast_select_querier(struct net_bridge_mcast *brmctx,
 	if (!brmctx->ip4_querier.addr.src.ip4)
 		goto update;
 
-	if (ntohl(saddr) <= ntohl(brmctx->ip4_querier.addr.src.ip4))
+	if (ntohl(saddr->src.ip4) <= ntohl(brmctx->ip4_querier.addr.src.ip4))
 		goto update;
 
 	return false;
 
 update:
-	brmctx->ip4_querier.addr.src.ip4 = saddr;
-
-	/* update protected by general multicast_lock by caller */
-	if (port)
-		brmctx->ip4_querier.port_ifidx = port->dev->ifindex;
+	br_multicast_update_querier(brmctx, &brmctx->ip4_querier, port_ifidx,
+				    saddr);
 
 	return true;
 }
@@ -2859,25 +2892,23 @@ update:
 #if IS_ENABLED(CONFIG_IPV6)
 static bool br_ip6_multicast_select_querier(struct net_bridge_mcast *brmctx,
 					    struct net_bridge_mcast_port *pmctx,
-					    struct in6_addr *saddr)
+					    struct br_ip *saddr)
 {
-	struct net_bridge_port *port = pmctx ? pmctx->port : NULL;
+	int port_ifidx = pmctx ? pmctx->port->dev->ifindex : 0;
 
 	if (!timer_pending(&brmctx->ip6_own_query.timer) &&
 	    !timer_pending(&brmctx->ip6_other_query.timer))
 		goto update;
 
-	if (ipv6_addr_cmp(saddr, &brmctx->ip6_querier.addr.src.ip6) <= 0)
+	if (ipv6_addr_cmp(&saddr->src.ip6,
+			  &brmctx->ip6_querier.addr.src.ip6) <= 0)
 		goto update;
 
 	return false;
 
 update:
-	brmctx->ip6_querier.addr.src.ip6 = *saddr;
-
-	/* update protected by general multicast_lock by caller */
-	if (port)
-		brmctx->ip6_querier.port_ifidx = port->dev->ifindex;
+	br_multicast_update_querier(brmctx, &brmctx->ip6_querier, port_ifidx,
+				    saddr);
 
 	return true;
 }
@@ -3084,7 +3115,7 @@ br_ip4_multicast_query_received(struct net_bridge_mcast *brmctx,
 				struct br_ip *saddr,
 				unsigned long max_delay)
 {
-	if (!br_ip4_multicast_select_querier(brmctx, pmctx, saddr->src.ip4))
+	if (!br_ip4_multicast_select_querier(brmctx, pmctx, saddr))
 		return;
 
 	br_multicast_update_query_timer(brmctx, query, max_delay);
@@ -3099,7 +3130,7 @@ br_ip6_multicast_query_received(struct net_bridge_mcast *brmctx,
 				struct br_ip *saddr,
 				unsigned long max_delay)
 {
-	if (!br_ip6_multicast_select_querier(brmctx, pmctx, &saddr->src.ip6))
+	if (!br_ip6_multicast_select_querier(brmctx, pmctx, saddr))
 		return;
 
 	br_multicast_update_query_timer(brmctx, query, max_delay);
@@ -3119,7 +3150,7 @@ static void br_ip4_multicast_query(struct net_bridge_mcast *brmctx,
 	struct igmpv3_query *ih3;
 	struct net_bridge_port_group *p;
 	struct net_bridge_port_group __rcu **pp;
-	struct br_ip saddr;
+	struct br_ip saddr = {};
 	unsigned long max_delay;
 	unsigned long now = jiffies;
 	__be32 group;
@@ -3199,7 +3230,7 @@ static int br_ip6_multicast_query(struct net_bridge_mcast *brmctx,
 	struct mld2_query *mld2q;
 	struct net_bridge_port_group *p;
 	struct net_bridge_port_group __rcu **pp;
-	struct br_ip saddr;
+	struct br_ip saddr = {};
 	unsigned long max_delay;
 	unsigned long now = jiffies;
 	unsigned int offset = skb_transport_offset(skb);
@@ -3677,7 +3708,6 @@ static void br_multicast_query_expired(struct net_bridge_mcast *brmctx,
 	if (query->startup_sent < brmctx->multicast_startup_query_count)
 		query->startup_sent++;
 
-	querier->port_ifidx = 0;
 	br_multicast_send_query(brmctx, NULL, query);
 out:
 	spin_unlock(&brmctx->br->multicast_lock);
@@ -3735,11 +3765,13 @@ void br_multicast_ctx_init(struct net_bridge *br,
 
 	brmctx->ip4_other_query.delay_time = 0;
 	brmctx->ip4_querier.port_ifidx = 0;
+	seqcount_init(&brmctx->ip4_querier.seq);
 	brmctx->multicast_igmp_version = 2;
 #if IS_ENABLED(CONFIG_IPV6)
 	brmctx->multicast_mld_version = 1;
 	brmctx->ip6_other_query.delay_time = 0;
 	brmctx->ip6_querier.port_ifidx = 0;
+	seqcount_init(&brmctx->ip6_querier.seq);
 #endif
 
 	timer_setup(&brmctx->ip4_mc_router_timer,
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 30ca978676f3..70e2d9a7f105 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -82,6 +82,7 @@ struct bridge_mcast_other_query {
 struct bridge_mcast_querier {
 	struct br_ip addr;
 	int port_ifidx;
+	seqcount_t seq;
 };
 
 /* IGMP/MLD statistics */
-- 
cgit v1.2.3


From c3fb3698f935381161101d2479d66dd48c106183 Mon Sep 17 00:00:00 2001
From: Nikolay Aleksandrov <nikolay@nvidia.com>
Date: Fri, 13 Aug 2021 17:59:59 +0300
Subject: net: bridge: mcast: consolidate querier selection for ipv4 and ipv6

We can consolidate both functions as they share almost the same logic.
This is easier to maintain and we have a single querier update function.

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/bridge/br_multicast.c | 67 ++++++++++++++++++++---------------------------
 1 file changed, 29 insertions(+), 38 deletions(-)

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 701cf46b89de..3705b7ace62d 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -2864,55 +2864,46 @@ unlock_continue:
 }
 #endif
 
-static bool br_ip4_multicast_select_querier(struct net_bridge_mcast *brmctx,
-					    struct net_bridge_mcast_port *pmctx,
-					    struct br_ip *saddr)
+static bool br_multicast_select_querier(struct net_bridge_mcast *brmctx,
+					struct net_bridge_mcast_port *pmctx,
+					struct br_ip *saddr)
 {
 	int port_ifidx = pmctx ? pmctx->port->dev->ifindex : 0;
+	struct timer_list *own_timer, *other_timer;
+	struct bridge_mcast_querier *querier;
 
-	if (!timer_pending(&brmctx->ip4_own_query.timer) &&
-	    !timer_pending(&brmctx->ip4_other_query.timer))
-		goto update;
-
-	if (!brmctx->ip4_querier.addr.src.ip4)
-		goto update;
-
-	if (ntohl(saddr->src.ip4) <= ntohl(brmctx->ip4_querier.addr.src.ip4))
-		goto update;
-
-	return false;
-
-update:
-	br_multicast_update_querier(brmctx, &brmctx->ip4_querier, port_ifidx,
-				    saddr);
-
-	return true;
-}
-
+	switch (saddr->proto) {
+	case htons(ETH_P_IP):
+		querier = &brmctx->ip4_querier;
+		own_timer = &brmctx->ip4_own_query.timer;
+		other_timer = &brmctx->ip4_other_query.timer;
+		if (!querier->addr.src.ip4 ||
+		    ntohl(saddr->src.ip4) <= ntohl(querier->addr.src.ip4))
+			goto update;
+		break;
 #if IS_ENABLED(CONFIG_IPV6)
-static bool br_ip6_multicast_select_querier(struct net_bridge_mcast *brmctx,
-					    struct net_bridge_mcast_port *pmctx,
-					    struct br_ip *saddr)
-{
-	int port_ifidx = pmctx ? pmctx->port->dev->ifindex : 0;
-
-	if (!timer_pending(&brmctx->ip6_own_query.timer) &&
-	    !timer_pending(&brmctx->ip6_other_query.timer))
-		goto update;
+	case htons(ETH_P_IPV6):
+		querier = &brmctx->ip6_querier;
+		own_timer = &brmctx->ip6_own_query.timer;
+		other_timer = &brmctx->ip6_other_query.timer;
+		if (ipv6_addr_cmp(&saddr->src.ip6, &querier->addr.src.ip6) <= 0)
+			goto update;
+		break;
+#endif
+	default:
+		return false;
+	}
 
-	if (ipv6_addr_cmp(&saddr->src.ip6,
-			  &brmctx->ip6_querier.addr.src.ip6) <= 0)
+	if (!timer_pending(own_timer) && !timer_pending(other_timer))
 		goto update;
 
 	return false;
 
 update:
-	br_multicast_update_querier(brmctx, &brmctx->ip6_querier, port_ifidx,
-				    saddr);
+	br_multicast_update_querier(brmctx, querier, port_ifidx, saddr);
 
 	return true;
 }
-#endif
 
 static void
 br_multicast_update_query_timer(struct net_bridge_mcast *brmctx,
@@ -3115,7 +3106,7 @@ br_ip4_multicast_query_received(struct net_bridge_mcast *brmctx,
 				struct br_ip *saddr,
 				unsigned long max_delay)
 {
-	if (!br_ip4_multicast_select_querier(brmctx, pmctx, saddr))
+	if (!br_multicast_select_querier(brmctx, pmctx, saddr))
 		return;
 
 	br_multicast_update_query_timer(brmctx, query, max_delay);
@@ -3130,7 +3121,7 @@ br_ip6_multicast_query_received(struct net_bridge_mcast *brmctx,
 				struct br_ip *saddr,
 				unsigned long max_delay)
 {
-	if (!br_ip6_multicast_select_querier(brmctx, pmctx, saddr))
+	if (!br_multicast_select_querier(brmctx, pmctx, saddr))
 		return;
 
 	br_multicast_update_query_timer(brmctx, query, max_delay);
-- 
cgit v1.2.3


From c7fa1d9b1fb179375e889ff076a1566ecc997bfc Mon Sep 17 00:00:00 2001
From: Nikolay Aleksandrov <nikolay@nvidia.com>
Date: Fri, 13 Aug 2021 18:00:00 +0300
Subject: net: bridge: mcast: dump ipv4 querier state

Add support for dumping global IPv4 querier state, we dump the state
only if our own querier is enabled or there has been another external
querier which has won the election. For the bridge global state we use
a new attribute IFLA_BR_MCAST_QUERIER_STATE and embed the state inside.
The structure is:
 [IFLA_BR_MCAST_QUERIER_STATE]
  `[BRIDGE_QUERIER_IP_ADDRESS] - ip address of the querier
  `[BRIDGE_QUERIER_IP_PORT]    - bridge port ifindex where the querier was
                                 seen (set only if external querier)
  `[BRIDGE_QUERIER_IP_OTHER_TIMER]   -  other querier timeout

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/uapi/linux/if_bridge.h | 10 ++++++
 include/uapi/linux/if_link.h   |  1 +
 net/bridge/br_multicast.c      | 73 ++++++++++++++++++++++++++++++++++++++++++
 net/bridge/br_netlink.c        |  5 ++-
 net/bridge/br_private.h        |  4 +++
 5 files changed, 92 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h
index 620d86e825b8..e0fff67fcd88 100644
--- a/include/uapi/linux/if_bridge.h
+++ b/include/uapi/linux/if_bridge.h
@@ -770,4 +770,14 @@ struct br_boolopt_multi {
 	__u32 optval;
 	__u32 optmask;
 };
+
+enum {
+	BRIDGE_QUERIER_UNSPEC,
+	BRIDGE_QUERIER_IP_ADDRESS,
+	BRIDGE_QUERIER_IP_PORT,
+	BRIDGE_QUERIER_IP_OTHER_TIMER,
+	BRIDGE_QUERIER_PAD,
+	__BRIDGE_QUERIER_MAX
+};
+#define BRIDGE_QUERIER_MAX (__BRIDGE_QUERIER_MAX - 1)
 #endif /* _UAPI_LINUX_IF_BRIDGE_H */
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 5310003523ce..8aad65b69054 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -479,6 +479,7 @@ enum {
 	IFLA_BR_MCAST_MLD_VERSION,
 	IFLA_BR_VLAN_STATS_PER_PORT,
 	IFLA_BR_MULTI_BOOLOPT,
+	IFLA_BR_MCAST_QUERIER_STATE,
 	__IFLA_BR_MAX,
 };
 
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 3705b7ace62d..4513bc13b6d3 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -2905,6 +2905,79 @@ update:
 	return true;
 }
 
+static struct net_bridge_port *
+__br_multicast_get_querier_port(struct net_bridge *br,
+				const struct bridge_mcast_querier *querier)
+{
+	int port_ifidx = READ_ONCE(querier->port_ifidx);
+	struct net_bridge_port *p;
+	struct net_device *dev;
+
+	if (port_ifidx == 0)
+		return NULL;
+
+	dev = dev_get_by_index_rcu(dev_net(br->dev), port_ifidx);
+	if (!dev)
+		return NULL;
+	p = br_port_get_rtnl_rcu(dev);
+	if (!p || p->br != br)
+		return NULL;
+
+	return p;
+}
+
+size_t br_multicast_querier_state_size(void)
+{
+	return nla_total_size(sizeof(0)) +      /* nest attribute */
+	       nla_total_size(sizeof(__be32)) + /* BRIDGE_QUERIER_IP_ADDRESS */
+	       nla_total_size(sizeof(int)) +    /* BRIDGE_QUERIER_IP_PORT */
+	       nla_total_size_64bit(sizeof(u64)); /* BRIDGE_QUERIER_IP_OTHER_TIMER */
+}
+
+/* protected by rtnl or rcu */
+int br_multicast_dump_querier_state(struct sk_buff *skb,
+				    const struct net_bridge_mcast *brmctx,
+				    int nest_attr)
+{
+	struct bridge_mcast_querier querier = {};
+	struct net_bridge_port *p;
+	struct nlattr *nest;
+
+	if (!brmctx->multicast_querier &&
+	    !timer_pending(&brmctx->ip4_other_query.timer))
+		return 0;
+
+	nest = nla_nest_start(skb, nest_attr);
+	if (!nest)
+		return -EMSGSIZE;
+
+	rcu_read_lock();
+	br_multicast_read_querier(&brmctx->ip4_querier, &querier);
+	if (nla_put_in_addr(skb, BRIDGE_QUERIER_IP_ADDRESS,
+			    querier.addr.src.ip4)) {
+		rcu_read_unlock();
+		goto out_err;
+	}
+
+	p = __br_multicast_get_querier_port(brmctx->br, &querier);
+	if (timer_pending(&brmctx->ip4_other_query.timer) &&
+	    (nla_put_u64_64bit(skb, BRIDGE_QUERIER_IP_OTHER_TIMER,
+			       br_timer_value(&brmctx->ip4_other_query.timer),
+			       BRIDGE_QUERIER_PAD) ||
+	     (p && nla_put_u32(skb, BRIDGE_QUERIER_IP_PORT, p->dev->ifindex)))) {
+		rcu_read_unlock();
+		goto out_err;
+	}
+	rcu_read_unlock();
+	nla_nest_end(skb, nest);
+
+	return 0;
+
+out_err:
+	nla_nest_cancel(skb, nest);
+	return -EMSGSIZE;
+}
+
 static void
 br_multicast_update_query_timer(struct net_bridge_mcast *brmctx,
 				struct bridge_mcast_other_query *query,
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 8ae026fa2ad7..2f184ad8ae29 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1501,6 +1501,7 @@ static size_t br_get_size(const struct net_device *brdev)
 	       nla_total_size_64bit(sizeof(u64)) + /* IFLA_BR_MCAST_STARTUP_QUERY_INTVL */
 	       nla_total_size(sizeof(u8)) +	/* IFLA_BR_MCAST_IGMP_VERSION */
 	       nla_total_size(sizeof(u8)) +	/* IFLA_BR_MCAST_MLD_VERSION */
+	       br_multicast_querier_state_size() + /* IFLA_BR_MCAST_QUERIER_STATE */
 #endif
 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 	       nla_total_size(sizeof(u8)) +     /* IFLA_BR_NF_CALL_IPTABLES */
@@ -1587,7 +1588,9 @@ static int br_fill_info(struct sk_buff *skb, const struct net_device *brdev)
 	    nla_put_u32(skb, IFLA_BR_MCAST_STARTUP_QUERY_CNT,
 			br->multicast_ctx.multicast_startup_query_count) ||
 	    nla_put_u8(skb, IFLA_BR_MCAST_IGMP_VERSION,
-		       br->multicast_ctx.multicast_igmp_version))
+		       br->multicast_ctx.multicast_igmp_version) ||
+	    br_multicast_dump_querier_state(skb, &br->multicast_ctx,
+					    IFLA_BR_MCAST_QUERIER_STATE))
 		return -EMSGSIZE;
 #if IS_ENABLED(CONFIG_IPV6)
 	if (nla_put_u8(skb, IFLA_BR_MCAST_MLD_VERSION,
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 70e2d9a7f105..9b1bf98a2c5a 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -948,6 +948,10 @@ int br_mdb_replay(struct net_device *br_dev, struct net_device *dev,
 		  struct netlink_ext_ack *extack);
 int br_rports_fill_info(struct sk_buff *skb,
 			const struct net_bridge_mcast *brmctx);
+int br_multicast_dump_querier_state(struct sk_buff *skb,
+				    const struct net_bridge_mcast *brmctx,
+				    int nest_attr);
+size_t br_multicast_querier_state_size(void);
 
 static inline bool br_group_is_l2(const struct br_ip *group)
 {
-- 
cgit v1.2.3


From 85b4108211742c5dd4f9f56c1d0704b4e0d4c98e Mon Sep 17 00:00:00 2001
From: Nikolay Aleksandrov <nikolay@nvidia.com>
Date: Fri, 13 Aug 2021 18:00:01 +0300
Subject: net: bridge: mcast: dump ipv6 querier state

Add support for dumping global IPv6 querier state, we dump the state
only if our own querier is enabled or there has been another external
querier which has won the election. For the bridge global state we use
a new attribute IFLA_BR_MCAST_QUERIER_STATE and embed the state inside.
The structure is:
  [IFLA_BR_MCAST_QUERIER_STATE]
   `[BRIDGE_QUERIER_IPV6_ADDRESS] - ip address of the querier
   `[BRIDGE_QUERIER_IPV6_PORT]    - bridge port ifindex where the querier
                                    was seen (set only if external querier)
   `[BRIDGE_QUERIER_IPV6_OTHER_TIMER]   -  other querier timeout

IPv4 and IPv6 attributes are embedded at the same level of
IFLA_BR_MCAST_QUERIER_STATE. If we didn't dump anything we cancel the nest
and return.

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/uapi/linux/if_bridge.h |  3 +++
 net/bridge/br_multicast.c      | 36 ++++++++++++++++++++++++++++++++----
 2 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h
index e0fff67fcd88..eceaad200bf6 100644
--- a/include/uapi/linux/if_bridge.h
+++ b/include/uapi/linux/if_bridge.h
@@ -777,6 +777,9 @@ enum {
 	BRIDGE_QUERIER_IP_PORT,
 	BRIDGE_QUERIER_IP_OTHER_TIMER,
 	BRIDGE_QUERIER_PAD,
+	BRIDGE_QUERIER_IPV6_ADDRESS,
+	BRIDGE_QUERIER_IPV6_PORT,
+	BRIDGE_QUERIER_IPV6_OTHER_TIMER,
 	__BRIDGE_QUERIER_MAX
 };
 #define BRIDGE_QUERIER_MAX (__BRIDGE_QUERIER_MAX - 1)
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 4513bc13b6d3..0e5d6ba03457 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -2943,15 +2943,15 @@ int br_multicast_dump_querier_state(struct sk_buff *skb,
 	struct net_bridge_port *p;
 	struct nlattr *nest;
 
-	if (!brmctx->multicast_querier &&
-	    !timer_pending(&brmctx->ip4_other_query.timer))
-		return 0;
-
 	nest = nla_nest_start(skb, nest_attr);
 	if (!nest)
 		return -EMSGSIZE;
 
 	rcu_read_lock();
+	if (!brmctx->multicast_querier &&
+	    !timer_pending(&brmctx->ip4_other_query.timer))
+		goto out_v6;
+
 	br_multicast_read_querier(&brmctx->ip4_querier, &querier);
 	if (nla_put_in_addr(skb, BRIDGE_QUERIER_IP_ADDRESS,
 			    querier.addr.src.ip4)) {
@@ -2968,8 +2968,36 @@ int br_multicast_dump_querier_state(struct sk_buff *skb,
 		rcu_read_unlock();
 		goto out_err;
 	}
+
+out_v6:
+#if IS_ENABLED(CONFIG_IPV6)
+	if (!brmctx->multicast_querier &&
+	    !timer_pending(&brmctx->ip6_other_query.timer))
+		goto out;
+
+	br_multicast_read_querier(&brmctx->ip6_querier, &querier);
+	if (nla_put_in6_addr(skb, BRIDGE_QUERIER_IPV6_ADDRESS,
+			     &querier.addr.src.ip6)) {
+		rcu_read_unlock();
+		goto out_err;
+	}
+
+	p = __br_multicast_get_querier_port(brmctx->br, &querier);
+	if (timer_pending(&brmctx->ip6_other_query.timer) &&
+	    (nla_put_u64_64bit(skb, BRIDGE_QUERIER_IPV6_OTHER_TIMER,
+			       br_timer_value(&brmctx->ip6_other_query.timer),
+			       BRIDGE_QUERIER_PAD) ||
+	     (p && nla_put_u32(skb, BRIDGE_QUERIER_IPV6_PORT,
+			       p->dev->ifindex)))) {
+		rcu_read_unlock();
+		goto out_err;
+	}
+out:
+#endif
 	rcu_read_unlock();
 	nla_nest_end(skb, nest);
+	if (!nla_len(nest))
+		nla_nest_cancel(skb, nest);
 
 	return 0;
 
-- 
cgit v1.2.3


From ddc649d158c560c6685be1701900a6e456ecceac Mon Sep 17 00:00:00 2001
From: Nikolay Aleksandrov <nikolay@nvidia.com>
Date: Fri, 13 Aug 2021 18:00:02 +0300
Subject: net: bridge: vlan: dump mcast ctx querier state

Use the new mcast querier state dump infrastructure and export vlans'
mcast context querier state embedded in attribute
BRIDGE_VLANDB_GOPTS_MCAST_QUERIER_STATE.

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/uapi/linux/if_bridge.h | 1 +
 net/bridge/br_vlan_options.c   | 5 ++++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h
index eceaad200bf6..f71a81fdbbc6 100644
--- a/include/uapi/linux/if_bridge.h
+++ b/include/uapi/linux/if_bridge.h
@@ -563,6 +563,7 @@ enum {
 	BRIDGE_VLANDB_GOPTS_MCAST_QUERIER,
 	BRIDGE_VLANDB_GOPTS_MCAST_ROUTER,
 	BRIDGE_VLANDB_GOPTS_MCAST_ROUTER_PORTS,
+	BRIDGE_VLANDB_GOPTS_MCAST_QUERIER_STATE,
 	__BRIDGE_VLANDB_GOPTS_MAX
 };
 #define BRIDGE_VLANDB_GOPTS_MAX (__BRIDGE_VLANDB_GOPTS_MAX - 1)
diff --git a/net/bridge/br_vlan_options.c b/net/bridge/br_vlan_options.c
index b4fd5fa441b7..49dec53a4a74 100644
--- a/net/bridge/br_vlan_options.c
+++ b/net/bridge/br_vlan_options.c
@@ -299,7 +299,9 @@ bool br_vlan_global_opts_fill(struct sk_buff *skb, u16 vid, u16 vid_range,
 	    nla_put_u8(skb, BRIDGE_VLANDB_GOPTS_MCAST_QUERIER,
 		       v_opts->br_mcast_ctx.multicast_querier) ||
 	    nla_put_u8(skb, BRIDGE_VLANDB_GOPTS_MCAST_ROUTER,
-		       v_opts->br_mcast_ctx.multicast_router))
+		       v_opts->br_mcast_ctx.multicast_router) ||
+	    br_multicast_dump_querier_state(skb, &v_opts->br_mcast_ctx,
+					    BRIDGE_VLANDB_GOPTS_MCAST_QUERIER_STATE))
 		goto out_err;
 
 	clockval = jiffies_to_clock_t(v_opts->br_mcast_ctx.multicast_last_member_interval);
@@ -379,6 +381,7 @@ static size_t rtnl_vlan_global_opts_nlmsg_size(void)
 		+ nla_total_size(sizeof(u64)) /* BRIDGE_VLANDB_GOPTS_MCAST_STARTUP_QUERY_INTVL */
 		+ nla_total_size(sizeof(u8)) /* BRIDGE_VLANDB_GOPTS_MCAST_QUERIER */
 		+ nla_total_size(sizeof(u8)) /* BRIDGE_VLANDB_GOPTS_MCAST_ROUTER */
+		+ br_multicast_querier_state_size() /* BRIDGE_VLANDB_GOPTS_MCAST_QUERIER_STATE */
 #endif
 		+ nla_total_size(sizeof(u16)); /* BRIDGE_VLANDB_GOPTS_RANGE */
 }
-- 
cgit v1.2.3