bridge: mcast: add router port on PIM hello message

When we receive a PIM Hello message on a port we can consider that it
has a multicast router attached, thus it is correct to add it to the
router list. The only catch is it shouldn't be considered for a querier.

Using Daniel's description:
leaf-11  leaf-12  leaf-13
       \   |    /
        bridge-1
         /    \
    host-11  host-12

 - all ports in bridge-1 are in a single vlan aware bridge
 - leaf-11 is the IGMP querier
 - leaf-13 is the PIM DR
 - host-11 TXes packets to 226.10.10.10
 - bridge-1 only forwards the 226.10.10.10 traffic out the port to
   leaf-11, it should also forward this traffic out the port to leaf-13

Suggested-by: Daniel Walton <dwalton@cumulusnetworks.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Nikolay Aleksandrov 2016-10-31 13:21:05 +01:00 committed by David S. Miller
parent 56245cae19
commit 91b02d3d13

View File

@ -25,6 +25,7 @@
#include <linux/slab.h>
#include <linux/timer.h>
#include <linux/inetdevice.h>
#include <linux/mroute.h>
#include <net/ip.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6.h>
@ -1638,6 +1639,21 @@ static void br_multicast_err_count(const struct net_bridge *br,
u64_stats_update_end(&pstats->syncp);
}
static void br_multicast_pim(struct net_bridge *br,
struct net_bridge_port *port,
const struct sk_buff *skb)
{
unsigned int offset = skb_transport_offset(skb);
struct pimhdr *pimhdr, _pimhdr;
pimhdr = skb_header_pointer(skb, offset, sizeof(_pimhdr), &_pimhdr);
if (!pimhdr || pim_hdr_version(pimhdr) != PIM_VERSION ||
pim_hdr_type(pimhdr) != PIM_TYPE_HELLO)
return;
br_multicast_mark_router(br, port);
}
static int br_multicast_ipv4_rcv(struct net_bridge *br,
struct net_bridge_port *port,
struct sk_buff *skb,
@ -1650,8 +1666,12 @@ static int br_multicast_ipv4_rcv(struct net_bridge *br,
err = ip_mc_check_igmp(skb, &skb_trimmed);
if (err == -ENOMSG) {
if (!ipv4_is_local_multicast(ip_hdr(skb)->daddr))
if (!ipv4_is_local_multicast(ip_hdr(skb)->daddr)) {
BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
} else if (pim_ipv4_all_pim_routers(ip_hdr(skb)->daddr)) {
if (ip_hdr(skb)->protocol == IPPROTO_PIM)
br_multicast_pim(br, port, skb);
}
return 0;
} else if (err < 0) {
br_multicast_err_count(br, port, skb->protocol);