From c0d59da79534e85eb550d863e35eccc8c3fd8ceb Mon Sep 17 00:00:00 2001 From: wenxu Date: Wed, 20 Nov 2019 10:59:39 +0800 Subject: [PATCH] ip_gre: Make none-tun-dst gre tunnel store tunnel info as metadat_dst in recv Currently collect_md gre tunnel will store the tunnel info(metadata_dst) to skb_dst. And now the non-tun-dst gre tunnel already can add tunnel header through lwtunnel. When received a arp_request on the non-tun-dst gre tunnel. The packet of arp response will send through the non-tun-dst tunnel without tunnel info which will lead the arp response packet to be dropped. If the non-tun-dst gre tunnel also store the tunnel info as metadata_dst, The arp response packet will set the releted tunnel info in the iptunnel_metadata_reply. The following is the test script: ip netns add cl ip l add dev vethc type veth peer name eth0 netns cl ifconfig vethc 172.168.0.7/24 up ip l add dev tun1000 type gretap key 1000 ip link add user1000 type vrf table 1 ip l set user1000 up ip l set dev tun1000 master user1000 ifconfig tun1000 10.0.1.1/24 up ip netns exec cl ifconfig eth0 172.168.0.17/24 up ip netns exec cl ip l add dev tun type gretap local 172.168.0.17 remote 172.168.0.7 key 1000 ip netns exec cl ifconfig tun 10.0.1.7/24 up ip r r 10.0.1.7 encap ip id 1000 dst 172.168.0.17 key dev tun1000 table 1 With this patch ip netns exec cl ping 10.0.1.1 can success Signed-off-by: wenxu Signed-off-by: David S. Miller --- net/ipv4/ip_gre.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index 10636fb6093e..572b6307a2df 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -340,6 +340,8 @@ static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, iph->saddr, iph->daddr, tpi->key); if (tunnel) { + const struct iphdr *tnl_params; + if (__iptunnel_pull_header(skb, hdr_len, tpi->proto, raw_proto, false) < 0) goto drop; @@ -348,7 +350,9 @@ static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, skb_pop_mac_header(skb); else skb_reset_mac_header(skb); - if (tunnel->collect_md) { + + tnl_params = &tunnel->parms.iph; + if (tunnel->collect_md || tnl_params->daddr == 0) { __be16 flags; __be64 tun_id; -- 2.45.2