This is the first step to track in dedicated, per protocol family variables if we can actively and safely use multicast snooping. To later use these in the fast/data path instead of performing all these checks for every packet and to later notify DSA/switchdev about this state.
This toggles these new variables to true after a Maximum Response Delay (default: 10 seconds) if a new IGMP or MLD querier has appeared. This can be triggered either through receiving an IGMP/MLD query from another host or by a user enabling our own IGMP/MLD querier. This is the first of several requirements, similar to what br_multicast_querier_exists() already checks so far, to be able to reliably receive IGMP/MLD reports, which in turn are needed to build a complete multicast database. No functional change for the fast/data path yet. Signed-off-by: Linus Lüssing <[email protected]> --- net/bridge/br_multicast.c | 91 +++++++++++++++++++++++++++++++++++++-- net/bridge/br_private.h | 2 + 2 files changed, 90 insertions(+), 3 deletions(-) diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index 22d12e545966..5cc713adcf9b 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1069,6 +1069,65 @@ static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge_mcast *brm return skb; } +static bool br_ip4_multicast_querier_exists(struct net_bridge_mcast *brmctx) +{ + return __br_multicast_querier_exists(brmctx, &brmctx->ip4_other_query, false); +} + +#if IS_ENABLED(CONFIG_IPV6) +static bool br_ip6_multicast_querier_exists(struct net_bridge_mcast *brmctx) +{ + return __br_multicast_querier_exists(brmctx, &brmctx->ip6_other_query, true); +} +#endif + +static void br_ip4_multicast_update_active(struct net_bridge_mcast *brmctx, + bool force_inactive) +{ + if (force_inactive) + brmctx->ip4_active = false; + else + brmctx->ip4_active = br_ip4_multicast_querier_exists(brmctx); +} + +static void br_ip6_multicast_update_active(struct net_bridge_mcast *brmctx, + bool force_inactive) +{ +#if IS_ENABLED(CONFIG_IPV6) + if (force_inactive) + brmctx->ip6_active = false; + else + brmctx->ip6_active = br_ip6_multicast_querier_exists(brmctx); +#endif +} + +/** + * br_multicast_update_active() - update mcast active state + * @brmctx: the bridge multicast context to check + * + * This (potentially) updates the IPv4/IPv6 multicast active state. And by + * that enables or disables snooping of multicast payload traffic in fast + * path. + * + * The multicast active state is set, per protocol family, if: + * + * - an IGMP/MLD querier is present + * + * And is unset otherwise. + * + * This function should be called by anything that changes one of the + * above prerequisites. + */ +static void br_multicast_update_active(struct net_bridge_mcast *brmctx) +{ + bool force_inactive = false; + + lockdep_assert_held_once(&brmctx->br->multicast_lock); + + br_ip4_multicast_update_active(brmctx, force_inactive); + br_ip6_multicast_update_active(brmctx, force_inactive); +} + #if IS_ENABLED(CONFIG_IPV6) static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge_mcast *brmctx, struct net_bridge_mcast_port *pmctx, @@ -1762,10 +1821,34 @@ static void br_ip6_multicast_querier_expired(struct timer_list *t) } #endif -static void br_multicast_query_delay_expired(struct timer_list *t) +static void br_ip4_multicast_query_delay_expired(struct timer_list *t) { + struct net_bridge_mcast *brmctx = timer_container_of(brmctx, t, + ip4_other_query.delay_timer); + + spin_lock(&brmctx->br->multicast_lock); + /* an own or other IGMP querier appeared some seconds ago and all + * reports should have arrived by now, maybe set multicast state to active + */ + br_multicast_update_active(brmctx); + spin_unlock(&brmctx->br->multicast_lock); } +#if IS_ENABLED(CONFIG_IPV6) +static void br_ip6_multicast_query_delay_expired(struct timer_list *t) +{ + struct net_bridge_mcast *brmctx = timer_container_of(brmctx, t, + ip6_other_query.delay_timer); + + spin_lock(&brmctx->br->multicast_lock); + /* an own or other MLD querier appeared some seconds ago and all + * reports should have arrived, maybe set multicast state to active + */ + br_multicast_update_active(brmctx); + spin_unlock(&brmctx->br->multicast_lock); +} +#endif + static void br_multicast_select_own_querier(struct net_bridge_mcast *brmctx, struct br_ip *ip, struct sk_buff *skb) @@ -4112,11 +4195,13 @@ void br_multicast_ctx_init(struct net_bridge *br, brmctx->multicast_membership_interval = 260 * HZ; brmctx->ip4_querier.port_ifidx = 0; + brmctx->ip4_active = 0; seqcount_spinlock_init(&brmctx->ip4_querier.seq, &br->multicast_lock); brmctx->multicast_igmp_version = 2; #if IS_ENABLED(CONFIG_IPV6) brmctx->multicast_mld_version = 1; brmctx->ip6_querier.port_ifidx = 0; + brmctx->ip6_active = 0; seqcount_spinlock_init(&brmctx->ip6_querier.seq, &br->multicast_lock); #endif @@ -4125,7 +4210,7 @@ void br_multicast_ctx_init(struct net_bridge *br, timer_setup(&brmctx->ip4_other_query.timer, br_ip4_multicast_querier_expired, 0); timer_setup(&brmctx->ip4_other_query.delay_timer, - br_multicast_query_delay_expired, 0); + br_ip4_multicast_query_delay_expired, 0); timer_setup(&brmctx->ip4_own_query.timer, br_ip4_multicast_query_expired, 0); #if IS_ENABLED(CONFIG_IPV6) @@ -4134,7 +4219,7 @@ void br_multicast_ctx_init(struct net_bridge *br, timer_setup(&brmctx->ip6_other_query.timer, br_ip6_multicast_querier_expired, 0); timer_setup(&brmctx->ip6_other_query.delay_timer, - br_multicast_query_delay_expired, 0); + br_ip6_multicast_query_delay_expired, 0); timer_setup(&brmctx->ip6_own_query.timer, br_ip6_multicast_query_expired, 0); #endif diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index 8de0904b9627..f83c24def595 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -160,12 +160,14 @@ struct net_bridge_mcast { struct bridge_mcast_other_query ip4_other_query; struct bridge_mcast_own_query ip4_own_query; struct bridge_mcast_querier ip4_querier; + bool ip4_active; #if IS_ENABLED(CONFIG_IPV6) struct hlist_head ip6_mc_router_list; struct timer_list ip6_mc_router_timer; struct bridge_mcast_other_query ip6_other_query; struct bridge_mcast_own_query ip6_own_query; struct bridge_mcast_querier ip6_querier; + bool ip6_active; #endif /* IS_ENABLED(CONFIG_IPV6) */ #endif /* CONFIG_BRIDGE_IGMP_SNOOPING */ }; -- 2.50.1
