[net-next v2 05/11] net: bridge: mcast: prepare is-router function for mcast router split

Linus Lüssing
2021-05-09T19:45:49Z

In preparation for the upcoming split of multicast router state into
their IPv4 and IPv6 variants make br_multicast_is_router() protocol
family aware.

Note that for now br_ip6_multicast_is_router() uses the currently still
common ip4_mc_router_timer for now. It will be renamed to
ip6_mc_router_timer later when the split is performed.

While at it also renames the "1" and "2" constants in
br_multicast_is_router() to the MDB_RTR_TYPE_TEMP_QUERY and
MDB_RTR_TYPE_PERM enums.

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
---
net/bridge/br_input.c | 2 +-
net/bridge/br_multicast.c | 5 +++--
net/bridge/br_private.h | 36 ++++++++++++++++++++++++++++++++----
3 files changed, 36 insertions(+), 7 deletions(-)

diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 8875e95..1f50630 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -132,7 +132,7 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
br_multicast_querier_exists(br, eth_hdr(skb), mdst)) {
if ((mdst && mdst->host_joined) ||
- br_multicast_is_router(br)) {
+ br_multicast_is_router(br, skb)) {
local_rcv = true;
br->dev->stats.multicast++;
}
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 7edbbc9..048b5b9 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -1391,7 +1391,8 @@ static void br_multicast_local_router_expired(struct timer_list *t)
spin_lock(&br->multicast_lock);
if (br->multicast_router == MDB_RTR_TYPE_DISABLED ||
br->multicast_router == MDB_RTR_TYPE_PERM ||
- timer_pending(&br->ip4_mc_router_timer))
+ br_ip4_multicast_is_router(br) ||
+ br_ip6_multicast_is_router(br))
goto out;

br_mc_router_state_change(br, false);
@@ -3622,7 +3623,7 @@ bool br_multicast_router(const struct net_device *dev)
bool is_router;

spin_lock_bh(&br->multicast_lock);
- is_router = br_multicast_is_router(br);
+ is_router = br_multicast_is_router(br, NULL);
spin_unlock_bh(&br->multicast_lock);
return is_router;
}
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 26e91d2..ac5ca5b 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -864,11 +864,39 @@ static inline bool br_group_is_l2(const struct br_ip *group)
#define mlock_dereference(X, br) \
rcu_dereference_protected(X, lockdep_is_held(&br->multicast_lock))

-static inline bool br_multicast_is_router(struct net_bridge *br)
+static inline bool br_ip4_multicast_is_router(struct net_bridge *br)
{
- return br->multicast_router == 2 ||
- (br->multicast_router == 1 &&
- timer_pending(&br->ip4_mc_router_timer));
+ return timer_pending(&br->ip4_mc_router_timer);
+}
+
+static inline bool br_ip6_multicast_is_router(struct net_bridge *br)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+ return timer_pending(&br->ip4_mc_router_timer);
+#else
+ return false;
+#endif
+}
+
+static inline bool
+br_multicast_is_router(struct net_bridge *br, struct sk_buff *skb)
+{
+ if (br->multicast_router == MDB_RTR_TYPE_PERM)
+ return true;
+
+ if (br->multicast_router == MDB_RTR_TYPE_TEMP_QUERY) {
+ if (skb) {
+ if (skb->protocol == htons(ETH_P_IP))
+ return br_ip4_multicast_is_router(br);
+ else if (skb->protocol == htons(ETH_P_IPV6))
+ return br_ip6_multicast_is_router(br);
+ } else {
+ return br_ip4_multicast_is_router(br) ||
+ br_ip6_multicast_is_router(br);
+ }
+ }
+
+ return false;
}

static inline bool
--
2.31.0