From 91b02d3d133bbb101466325cdd9a6007cd9ec5a8 Mon Sep 17 00:00:00 2001
From: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Date: Mon, 31 Oct 2016 13:21:05 +0100
Subject: [PATCH] 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>
---
net/bridge/br_multicast.c | 22 +++++++++++++++++++++-
1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 2136e45f52777..073d54afa0568 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -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);
--
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