bridge: join all-snoopers multicast address

Next to snooping IGMP/MLD queries RFC4541, section 2.1.1.a) recommends
to snoop multicast router advertisements to detect multicast routers.

Multicast router advertisements are sent to an "all-snoopers"
multicast address. To be able to receive them reliably, we need to
join this group.

Otherwise other snooping switches might refrain from forwarding these
advertisements to us.

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Linus Lüssing 2019-01-21 07:26:27 +01:00 committed by David S. Miller
parent a2e2ca3beb
commit 4effd28c12
3 changed files with 78 additions and 5 deletions

View file

@ -292,10 +292,11 @@ struct sockaddr_in {
#define IN_LOOPBACK(a) ((((long int) (a)) & 0xff000000) == 0x7f000000)
/* Defines for Multicast INADDR */
#define INADDR_UNSPEC_GROUP 0xe0000000U /* 224.0.0.0 */
#define INADDR_ALLHOSTS_GROUP 0xe0000001U /* 224.0.0.1 */
#define INADDR_ALLRTRS_GROUP 0xe0000002U /* 224.0.0.2 */
#define INADDR_MAX_LOCAL_GROUP 0xe00000ffU /* 224.0.0.255 */
#define INADDR_UNSPEC_GROUP 0xe0000000U /* 224.0.0.0 */
#define INADDR_ALLHOSTS_GROUP 0xe0000001U /* 224.0.0.1 */
#define INADDR_ALLRTRS_GROUP 0xe0000002U /* 224.0.0.2 */
#define INADDR_ALLSNOOPERS_GROUP 0xe000006aU /* 224.0.0.106 */
#define INADDR_MAX_LOCAL_GROUP 0xe00000ffU /* 224.0.0.255 */
#endif
/* <asm/byteorder.h> contains the htonl type stuff.. */