From: "Maciej Żenczykowski" <zenczykowski@gmail.com>
To: "Maciej Żenczykowski" <maze@google.com>,
"David S . Miller" <davem@davemloft.net>
Cc: Linux Network Development Mailing List <netdev@vger.kernel.org>
Subject: [PATCH 2/2] net/ipv6: ensure ip6_dst_mtu_forward() returns at least IPV6_MIN_MTU
Date: Wed, 7 Oct 2020 20:31:02 -0700 [thread overview]
Message-ID: <20201008033102.623894-2-zenczykowski@gmail.com> (raw)
In-Reply-To: <20201008033102.623894-1-zenczykowski@gmail.com>
From: Maciej Żenczykowski <maze@google.com>
This is basically just a refactor.
But it does affect (a presumably buggy) call site in:
net/netfilter/nf_flow_table_core.c
flow_offload_fill_route()
Signed-off-by: Maciej Żenczykowski <maze@google.com>
---
include/net/ip6_route.h | 4 ++--
net/ipv6/ip6_output.c | 2 --
2 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 598415743f46..25c113dd88ea 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -313,14 +313,14 @@ static inline unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst)
struct inet6_dev *idev;
unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
if (mtu)
- return mtu;
+ return max(mtu, (unsigned)IPV6_MIN_MTU);
rcu_read_lock();
idev = __in6_dev_get(dst->dev);
mtu = idev ? idev->cnf.mtu6 : IPV6_MIN_MTU;
rcu_read_unlock();
- return mtu;
+ return max(mtu, (unsigned)IPV6_MIN_MTU);
}
u32 ip6_mtu_from_fib6(const struct fib6_result *res,
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index c78e67d7747f..bc85f92adaf9 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -540,8 +540,6 @@ int ip6_forward(struct sk_buff *skb)
}
mtu = ip6_dst_mtu_forward(dst);
- if (mtu < IPV6_MIN_MTU)
- mtu = IPV6_MIN_MTU;
if (ip6_pkt_too_big(skb, mtu)) {
/* Again, force OUTPUT device used as source address */
--
2.28.0.806.g8561365e88-goog
next prev parent reply other threads:[~2020-10-08 3:31 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-08 3:31 [PATCH 1/2] net/ipv6: always honour route mtu during forwarding Maciej Żenczykowski
2020-10-08 3:31 ` Maciej Żenczykowski [this message]
2020-10-08 6:04 ` Lorenzo Colitti
2020-10-08 6:22 ` Maciej Żenczykowski
2020-10-08 16:31 ` David Ahern
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