[patch netdev] net: PIM register decapsulation and Forwarding.

From: Saranya Panjarathina
Date: Sat May 14 2022 - 10:36:29 EST


From: Saranya_PL <plsaranya@xxxxxxxxx>

PIM register packet is decapsulated but not forwarded in RP

__pim_rcv decapsulates the PIM register packet and reinjects for forwarding
after replacing the skb->dev to reg_dev (vif with VIFF_Register)

Ideally the incoming device should be same as skb->dev where the
original PIM register packet is received. mcache would not have
reg_vif as IIF. Decapsulated packet forwarding is failing
because of IIF mismatch. In RP for this S,G RPF interface would be
skb->dev vif only, so that would be IIF for the cache entry.

Signed-off-by: Saranya Panjarathina <plsaranya@xxxxxxxxx>
---
net/ipv4/ipmr.c | 2 +-
net/ipv6/ip6mr.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 13e6329784fb..7b9586335fb7 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -598,7 +598,7 @@ static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
skb->protocol = htons(ETH_P_IP);
skb->ip_summed = CHECKSUM_NONE;

- skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
+ skb_tunnel_rx(skb, skb->dev, dev_net(skb->dev));

netif_rx(skb);

diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 4e74bc61a3db..147e29a818ca 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -566,7 +566,7 @@ static int pim6_rcv(struct sk_buff *skb)
skb->protocol = htons(ETH_P_IPV6);
skb->ip_summed = CHECKSUM_NONE;

- skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
+ skb_tunnel_rx(skb, skb->dev, net);

netif_rx(skb);

--
2.20.1