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| author | Stephen Suryaputra <ssuryaextr@gmail.com> | 2019-06-26 09:21:16 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-06-26 22:40:10 +0300 |
| commit | 5b18f1289808fee5d04a7e6ecf200189f41a4db6 (patch) | |
| tree | c4f8ffda52e1fa30489d1eae8c7f4066c0fc2df6 | |
| parent | ee4297420d56a0033a8593e80b33fcc93fda8509 (diff) | |
| download | linux-5b18f1289808fee5d04a7e6ecf200189f41a4db6.tar.xz | |
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>
| -rw-r--r-- | include/net/route.h | 1 | ||||
| -rw-r--r-- | net/ipv4/ip_output.c | 12 | ||||
| -rw-r--r-- | net/ipv4/route.c | 33 |
3 files changed, 46 insertions, 0 deletions
diff --git a/include/net/route.h b/include/net/route.h index 065b47754f05..55ff71ffb796 100644 --- a/include/net/route.h +++ b/include/net/route.h @@ -221,6 +221,7 @@ void ip_rt_get_source(u8 *src, struct sk_buff *skb, struct rtable *rt); struct rtable *rt_dst_alloc(struct net_device *dev, unsigned int flags, u16 type, bool nopolicy, bool noxfrm, bool will_cache); +struct rtable *rt_dst_clone(struct net_device *dev, struct rtable *rt); struct in_ifaddr; void fib_add_ifaddr(struct in_ifaddr *); 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, |