* [PATCH net v2] ipv4: reset rt_iif for recirculated mcast/bcast out pkts
@ 2019-06-26 6:21 Stephen Suryaputra
2019-06-26 17:28 ` David Ahern
2019-06-26 19:40 ` David Miller
0 siblings, 2 replies; 3+ messages in thread
From: Stephen Suryaputra @ 2019-06-26 6:21 UTC (permalink / raw)
To: netdev; +Cc: dsahern, Stephen Suryaputra
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>
---
include/net/route.h | 1 +
net/ipv4/ip_output.c | 12 ++++++++++++
net/ipv4/route.c | 33 +++++++++++++++++++++++++++++++++
3 files changed, 46 insertions(+)
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,
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH net v2] ipv4: reset rt_iif for recirculated mcast/bcast out pkts
2019-06-26 6:21 [PATCH net v2] ipv4: reset rt_iif for recirculated mcast/bcast out pkts Stephen Suryaputra
@ 2019-06-26 17:28 ` David Ahern
2019-06-26 19:40 ` David Miller
1 sibling, 0 replies; 3+ messages in thread
From: David Ahern @ 2019-06-26 17:28 UTC (permalink / raw)
To: Stephen Suryaputra, netdev
On 6/26/19 12:21 AM, Stephen Suryaputra wrote:
> 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>
> ---
> include/net/route.h | 1 +
> net/ipv4/ip_output.c | 12 ++++++++++++
> net/ipv4/route.c | 33 +++++++++++++++++++++++++++++++++
> 3 files changed, 46 insertions(+)
Reviewed-by: David Ahern <dsahern@gmail.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH net v2] ipv4: reset rt_iif for recirculated mcast/bcast out pkts
2019-06-26 6:21 [PATCH net v2] ipv4: reset rt_iif for recirculated mcast/bcast out pkts Stephen Suryaputra
2019-06-26 17:28 ` David Ahern
@ 2019-06-26 19:40 ` David Miller
1 sibling, 0 replies; 3+ messages in thread
From: David Miller @ 2019-06-26 19:40 UTC (permalink / raw)
To: ssuryaextr; +Cc: netdev, dsahern
From: Stephen Suryaputra <ssuryaextr@gmail.com>
Date: Wed, 26 Jun 2019 02:21:16 -0400
> 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>
Applied and queued up for -stable, thanks.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-06-26 19:40 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-06-26 6:21 [PATCH net v2] ipv4: reset rt_iif for recirculated mcast/bcast out pkts Stephen Suryaputra
2019-06-26 17:28 ` David Ahern
2019-06-26 19:40 ` David Miller
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).