2020-10-29 10:02:17

by Vladimir Oltean

Subject: [PATCH net-next] net: bridge: explicitly convert between mdb entry state and port group flags

When creating a new multicast port group, there is implicit conversion
between the __u8 state member of struct br_mdb_entry and the unsigned
char flags member of struct net_bridge_port_group. This implicit
conversion relies on the fact that MDB_PERMANENT is equal to
MDB_PG_FLAGS_PERMANENT.

Let's be more explicit and convert the state to flags manually.

Signed-off-by: Vladimir Oltean <[email protected]>
---
net/bridge/br_mdb.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c
index 3c8863418d0b..8846c5bcd075 100644
--- a/net/bridge/br_mdb.c
+++ b/net/bridge/br_mdb.c
@@ -846,6 +846,7 @@ static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
struct net_bridge_port_group __rcu **pp;
struct br_ip group, star_group;
unsigned long now = jiffies;
+ unsigned char flags = 0;
u8 filter_mode;
int err;

@@ -904,7 +905,10 @@ static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
filter_mode = br_multicast_is_star_g(&group) ? MCAST_EXCLUDE :
MCAST_INCLUDE;

- p = br_multicast_new_port_group(port, &group, *pp, entry->state, NULL,
+ if (entry->state == MDB_PERMANENT)
+ flags |= MDB_PG_FLAGS_PERMANENT;
+
+ p = br_multicast_new_port_group(port, &group, *pp, flags, NULL,
filter_mode, RTPROT_STATIC);
if (unlikely(!p)) {
NL_SET_ERR_MSG_MOD(extack, "Couldn't allocate new port group");
--
2.25.1

2020-10-31 01:01:46

by Jakub Kicinski

Subject: Re: [PATCH net-next] net: bridge: explicitly convert between mdb entry state and port group flags

On Thu, 29 Oct 2020 01:48:15 +0200 Vladimir Oltean wrote:
> When creating a new multicast port group, there is implicit conversion
> between the __u8 state member of struct br_mdb_entry and the unsigned
> char flags member of struct net_bridge_port_group. This implicit
> conversion relies on the fact that MDB_PERMANENT is equal to
> MDB_PG_FLAGS_PERMANENT.
>
> Let's be more explicit and convert the state to flags manually.
>
> Signed-off-by: Vladimir Oltean <[email protected]>

Applied, thanks!