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authorStephen Suryaputra <ssuryaextr@gmail.com>2019-06-26 02:21:16 -0400
committerDavid S. Miller <davem@davemloft.net>2019-06-26 12:40:10 -0700
commit5b18f1289808fee5d04a7e6ecf200189f41a4db6 (patch)
treec4f8ffda52e1fa30489d1eae8c7f4066c0fc2df6 /net
parentee4297420d56a0033a8593e80b33fcc93fda8509 (diff)
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ipv4: reset rt_iif for recirculated mcast/bcast out pkts
Multicast or broadcast egress packets have rt_iif set to the oif. These packets might be recirculated back as input and lookup to the raw sockets may fail because they are bound to the incoming interface (skb_iif). If rt_iif is not zero, during the lookup, inet_iif() function returns rt_iif instead of skb_iif. Hence, the lookup fails. v2: Make it non vrf specific (David Ahern). Reword the changelog to reflect it. Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/ip_output.c12
-rw-r--r--net/ipv4/route.c33
2 files changed, 45 insertions, 0 deletions
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 16f9159234a2..8c2ec35b6512 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -318,6 +318,7 @@ static int ip_finish_output(struct net *net, struct sock *sk, struct sk_buff *sk
static int ip_mc_finish_output(struct net *net, struct sock *sk,
struct sk_buff *skb)
{
+ struct rtable *new_rt;
int ret;
ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb);
@@ -326,6 +327,17 @@ static int ip_mc_finish_output(struct net *net, struct sock *sk,
return ret;
}
+ /* Reset rt_iif so that inet_iif() will return skb->skb_iif. Setting
+ * this to non-zero causes ipi_ifindex in in_pktinfo to be overwritten,
+ * see ipv4_pktinfo_prepare().
+ */
+ new_rt = rt_dst_clone(net->loopback_dev, skb_rtable(skb));
+ if (new_rt) {
+ new_rt->rt_iif = 0;
+ skb_dst_drop(skb);
+ skb_dst_set(skb, &new_rt->dst);
+ }
+
return dev_loopback_xmit(net, sk, skb);
}
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 6cb7cff22db9..8ea0735a6754 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1647,6 +1647,39 @@ struct rtable *rt_dst_alloc(struct net_device *dev,
}
EXPORT_SYMBOL(rt_dst_alloc);
+struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt)
+{
+ struct rtable *new_rt;
+
+ new_rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
+ rt->dst.flags);
+
+ if (new_rt) {
+ new_rt->rt_genid = rt_genid_ipv4(dev_net(dev));
+ new_rt->rt_flags = rt->rt_flags;
+ new_rt->rt_type = rt->rt_type;
+ new_rt->rt_is_input = rt->rt_is_input;
+ new_rt->rt_iif = rt->rt_iif;
+ new_rt->rt_pmtu = rt->rt_pmtu;
+ new_rt->rt_mtu_locked = rt->rt_mtu_locked;
+ new_rt->rt_gw_family = rt->rt_gw_family;
+ if (rt->rt_gw_family == AF_INET)
+ new_rt->rt_gw4 = rt->rt_gw4;
+ else if (rt->rt_gw_family == AF_INET6)
+ new_rt->rt_gw6 = rt->rt_gw6;
+ INIT_LIST_HEAD(&new_rt->rt_uncached);
+
+ new_rt->dst.flags |= DST_HOST;
+ new_rt->dst.input = rt->dst.input;
+ new_rt->dst.output = rt->dst.output;
+ new_rt->dst.error = rt->dst.error;
+ new_rt->dst.lastuse = jiffies;
+ new_rt->dst.lwtstate = lwtstate_get(rt->dst.lwtstate);
+ }
+ return new_rt;
+}
+EXPORT_SYMBOL(rt_dst_clone);
+
/* called in rcu_read_lock() section */
int ip_mc_validate_source(struct sk_buff *skb, __be32 daddr, __be32 saddr,
u8 tos, struct net_device *dev,