* [PATCH net] tcp: md5: fix IPv4-mapped support
@ 2022-07-26 11:57 Eric Dumazet
2022-07-26 15:06 ` David Ahern
` (3 more replies)
0 siblings, 4 replies; 7+ messages in thread
From: Eric Dumazet @ 2022-07-26 11:57 UTC (permalink / raw)
To: David S . Miller, Jakub Kicinski, Paolo Abeni
Cc: netdev, eric.dumazet, Eric Dumazet, Brian Vazquez,
Dmitry Safonov, David Ahern, Leonard Crestez
After the blamed commit, IPv4 SYN packets handled
by a dual stack IPv6 socket are dropped, even if
perfectly valid.
$ nstat | grep MD5
TcpExtTCPMD5Failure 5 0.0
For a dual stack listener, an incoming IPv4 SYN packet
would call tcp_inbound_md5_hash() with @family == AF_INET,
while tp->af_specific is pointing to tcp_sock_ipv6_specific.
Only later when an IPv4-mapped child is created, tp->af_specific
is changed to tcp_sock_ipv6_mapped_specific.
Fixes: 7bbb765b7349 ("net/tcp: Merge TCP-MD5 inbound callbacks")
Reported-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Dmitry Safonov <dima@arista.com>
Cc: David Ahern <dsahern@kernel.org>
Cc: Leonard Crestez <cdleonard@gmail.com>
---
net/ipv4/tcp.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 002a4a04efbe076ba603d7d42eb85e60d9bf4fb8..766881775abb795c884d048d51c361e805b91989 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -4459,9 +4459,18 @@ tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
return SKB_DROP_REASON_TCP_MD5UNEXPECTED;
}
- /* check the signature */
- genhash = tp->af_specific->calc_md5_hash(newhash, hash_expected,
- NULL, skb);
+ /* Check the signature.
+ * To support dual stack listeners, we need to handle
+ * IPv4-mapped case.
+ */
+ if (family == AF_INET)
+ genhash = tcp_v4_md5_hash_skb(newhash,
+ hash_expected,
+ NULL, skb);
+ else
+ genhash = tp->af_specific->calc_md5_hash(newhash,
+ hash_expected,
+ NULL, skb);
if (genhash || memcmp(hash_location, newhash, 16) != 0) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
--
2.37.1.359.gd136c6c3e2-goog
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH net] tcp: md5: fix IPv4-mapped support
2022-07-26 11:57 [PATCH net] tcp: md5: fix IPv4-mapped support Eric Dumazet
@ 2022-07-26 15:06 ` David Ahern
2022-07-26 17:57 ` Eric Dumazet
2022-07-26 17:13 ` Dmitry Safonov
` (2 subsequent siblings)
3 siblings, 1 reply; 7+ messages in thread
From: David Ahern @ 2022-07-26 15:06 UTC (permalink / raw)
To: Eric Dumazet, David S . Miller, Jakub Kicinski, Paolo Abeni
Cc: netdev, eric.dumazet, Brian Vazquez, Dmitry Safonov, Leonard Crestez
On 7/26/22 5:57 AM, Eric Dumazet wrote:
> After the blamed commit, IPv4 SYN packets handled
> by a dual stack IPv6 socket are dropped, even if
> perfectly valid.
>
> $ nstat | grep MD5
> TcpExtTCPMD5Failure 5 0.0
>
> For a dual stack listener, an incoming IPv4 SYN packet
> would call tcp_inbound_md5_hash() with @family == AF_INET,
> while tp->af_specific is pointing to tcp_sock_ipv6_specific.
>
> Only later when an IPv4-mapped child is created, tp->af_specific
> is changed to tcp_sock_ipv6_mapped_specific.
>
> Fixes: 7bbb765b7349 ("net/tcp: Merge TCP-MD5 inbound callbacks")
> Reported-by: Brian Vazquez <brianvv@google.com>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Dmitry Safonov <dima@arista.com>
> Cc: David Ahern <dsahern@kernel.org>
> Cc: Leonard Crestez <cdleonard@gmail.com>
> ---
> net/ipv4/tcp.c | 15 ++++++++++++---
> 1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
> index 002a4a04efbe076ba603d7d42eb85e60d9bf4fb8..766881775abb795c884d048d51c361e805b91989 100644
> --- a/net/ipv4/tcp.c
> +++ b/net/ipv4/tcp.c
> @@ -4459,9 +4459,18 @@ tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
> return SKB_DROP_REASON_TCP_MD5UNEXPECTED;
> }
>
> - /* check the signature */
> - genhash = tp->af_specific->calc_md5_hash(newhash, hash_expected,
> - NULL, skb);
> + /* Check the signature.
> + * To support dual stack listeners, we need to handle
> + * IPv4-mapped case.
> + */
> + if (family == AF_INET)
> + genhash = tcp_v4_md5_hash_skb(newhash,
> + hash_expected,
> + NULL, skb);
> + else
> + genhash = tp->af_specific->calc_md5_hash(newhash,
> + hash_expected,
> + NULL, skb);
>
> if (genhash || memcmp(hash_location, newhash, 16) != 0) {
> NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
We should get v4-mapped cases added to the fcnal-test.sh permutations.
Reviewed-by: David Ahern <dsahern@kernel.org>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH net] tcp: md5: fix IPv4-mapped support
2022-07-26 11:57 [PATCH net] tcp: md5: fix IPv4-mapped support Eric Dumazet
2022-07-26 15:06 ` David Ahern
@ 2022-07-26 17:13 ` Dmitry Safonov
2022-07-27 8:22 ` Leonard Crestez
2022-07-27 17:30 ` patchwork-bot+netdevbpf
3 siblings, 0 replies; 7+ messages in thread
From: Dmitry Safonov @ 2022-07-26 17:13 UTC (permalink / raw)
To: Eric Dumazet, David S . Miller, Jakub Kicinski, Paolo Abeni
Cc: netdev, eric.dumazet, Brian Vazquez, David Ahern, Leonard Crestez
On 7/26/22 12:57, Eric Dumazet wrote:
> After the blamed commit, IPv4 SYN packets handled
> by a dual stack IPv6 socket are dropped, even if
> perfectly valid.
>
> $ nstat | grep MD5
> TcpExtTCPMD5Failure 5 0.0
>
> For a dual stack listener, an incoming IPv4 SYN packet
> would call tcp_inbound_md5_hash() with @family == AF_INET,
> while tp->af_specific is pointing to tcp_sock_ipv6_specific.
>
> Only later when an IPv4-mapped child is created, tp->af_specific
> is changed to tcp_sock_ipv6_mapped_specific.
Makes sense. Sorry, I didn't spot it at that moment.
>
> Fixes: 7bbb765b7349 ("net/tcp: Merge TCP-MD5 inbound callbacks")
> Reported-by: Brian Vazquez <brianvv@google.com>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Dmitry Safonov <dima@arista.com>
> Cc: David Ahern <dsahern@kernel.org>
> Cc: Leonard Crestez <cdleonard@gmail.com>
Reviewed-by: Dmitry Safonov <dima@arista.com>
Thanks,
Dmitry
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH net] tcp: md5: fix IPv4-mapped support
2022-07-26 15:06 ` David Ahern
@ 2022-07-26 17:57 ` Eric Dumazet
2022-07-26 19:05 ` David Ahern
0 siblings, 1 reply; 7+ messages in thread
From: Eric Dumazet @ 2022-07-26 17:57 UTC (permalink / raw)
To: David Ahern
Cc: David S . Miller, Jakub Kicinski, Paolo Abeni, netdev,
Eric Dumazet, Brian Vazquez, Dmitry Safonov, Leonard Crestez
On Tue, Jul 26, 2022 at 5:06 PM David Ahern <dsahern@kernel.org> wrote:
>
> On 7/26/22 5:57 AM, Eric Dumazet wrote:
> > After the blamed commit, IPv4 SYN packets handled
> > by a dual stack IPv6 socket are dropped, even if
> > perfectly valid.
> >
> > $ nstat | grep MD5
> > TcpExtTCPMD5Failure 5 0.0
> >
> > For a dual stack listener, an incoming IPv4 SYN packet
> > would call tcp_inbound_md5_hash() with @family == AF_INET,
> > while tp->af_specific is pointing to tcp_sock_ipv6_specific.
> >
> > Only later when an IPv4-mapped child is created, tp->af_specific
> > is changed to tcp_sock_ipv6_mapped_specific.
> >
> > Fixes: 7bbb765b7349 ("net/tcp: Merge TCP-MD5 inbound callbacks")
> > Reported-by: Brian Vazquez <brianvv@google.com>
> > Signed-off-by: Eric Dumazet <edumazet@google.com>
> > Cc: Dmitry Safonov <dima@arista.com>
> > Cc: David Ahern <dsahern@kernel.org>
> > Cc: Leonard Crestez <cdleonard@gmail.com>
> > ---
> > net/ipv4/tcp.c | 15 ++++++++++++---
> > 1 file changed, 12 insertions(+), 3 deletions(-)
> >
> > diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
> > index 002a4a04efbe076ba603d7d42eb85e60d9bf4fb8..766881775abb795c884d048d51c361e805b91989 100644
> > --- a/net/ipv4/tcp.c
> > +++ b/net/ipv4/tcp.c
> > @@ -4459,9 +4459,18 @@ tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
> > return SKB_DROP_REASON_TCP_MD5UNEXPECTED;
> > }
> >
> > - /* check the signature */
> > - genhash = tp->af_specific->calc_md5_hash(newhash, hash_expected,
> > - NULL, skb);
> > + /* Check the signature.
> > + * To support dual stack listeners, we need to handle
> > + * IPv4-mapped case.
> > + */
> > + if (family == AF_INET)
> > + genhash = tcp_v4_md5_hash_skb(newhash,
> > + hash_expected,
> > + NULL, skb);
> > + else
> > + genhash = tp->af_specific->calc_md5_hash(newhash,
> > + hash_expected,
> > + NULL, skb);
> >
> > if (genhash || memcmp(hash_location, newhash, 16) != 0) {
> > NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
>
> We should get v4-mapped cases added to the fcnal-test.sh permutations.
>
> Reviewed-by: David Ahern <dsahern@kernel.org>
Although fcnal-test.sh uses ~45 minutes currently :/
Maybe we should make it multi netns and multi threaded to speed up things.
And/or replace various "sleep 1" with more appropriate sync to make
this faster and not flaky in case of system load.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH net] tcp: md5: fix IPv4-mapped support
2022-07-26 17:57 ` Eric Dumazet
@ 2022-07-26 19:05 ` David Ahern
0 siblings, 0 replies; 7+ messages in thread
From: David Ahern @ 2022-07-26 19:05 UTC (permalink / raw)
To: Eric Dumazet
Cc: David S . Miller, Jakub Kicinski, Paolo Abeni, netdev,
Eric Dumazet, Brian Vazquez, Dmitry Safonov, Leonard Crestez
On 7/26/22 11:57 AM, Eric Dumazet wrote:
> Although fcnal-test.sh uses ~45 minutes currently :/
> Maybe we should make it multi netns and multi threaded to speed up things.
>
> And/or replace various "sleep 1" with more appropriate sync to make
> this faster and not flaky in case of system load.
There are currently 700+ permutations (800+ if Mike's vrf patch is only
fcnal-test). That's why the script takes a `-t TEST` argument - to only
run a subset.
nettest now has the capability for 1 command to run both client and
server in different namespaces. I have a branch that did the conversion
of fcnal-test.sh; validating the output to ensure no degradation in test
results (not just pass / fail but tests "fail" (negative tests) for the
right reason) took more time than I had. In the end it did not shorten
the test time by any significant margin so lost the motivation to wade
through the output on the before and after.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH net] tcp: md5: fix IPv4-mapped support
2022-07-26 11:57 [PATCH net] tcp: md5: fix IPv4-mapped support Eric Dumazet
2022-07-26 15:06 ` David Ahern
2022-07-26 17:13 ` Dmitry Safonov
@ 2022-07-27 8:22 ` Leonard Crestez
2022-07-27 17:30 ` patchwork-bot+netdevbpf
3 siblings, 0 replies; 7+ messages in thread
From: Leonard Crestez @ 2022-07-27 8:22 UTC (permalink / raw)
To: Eric Dumazet, David Ahern
Cc: netdev, eric.dumazet, Brian Vazquez, Dmitry Safonov, Paolo Abeni,
Jakub Kicinski, David S . Miller
On 7/26/22 14:57, Eric Dumazet wrote:
> After the blamed commit, IPv4 SYN packets handled
> by a dual stack IPv6 socket are dropped, even if
> perfectly valid.
>
> $ nstat | grep MD5
> TcpExtTCPMD5Failure 5 0.0
>
> For a dual stack listener, an incoming IPv4 SYN packet
> would call tcp_inbound_md5_hash() with @family == AF_INET,
> while tp->af_specific is pointing to tcp_sock_ipv6_specific.
>
> Only later when an IPv4-mapped child is created, tp->af_specific
> is changed to tcp_sock_ipv6_mapped_specific.
>
> Fixes: 7bbb765b7349 ("net/tcp: Merge TCP-MD5 inbound callbacks")
> Reported-by: Brian Vazquez <brianvv@google.com>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Dmitry Safonov <dima@arista.com>
> Cc: David Ahern <dsahern@kernel.org>
> Cc: Leonard Crestez <cdleonard@gmail.com>
I had a test in this area for AO and MD5 but it was incorrect (it did
not actually use an ipv4-mapped-ipv6 address for the ipv6 socket, it
used an ipv6 wildcard address).
After fixing the test I can confirm that this patch does in fact fix
something.
https://github.com/cdleonard/tcp-authopt-test/commit/662a6a7e1a818f4581fc0055e821bc1b4c8d04e8
Tested-by: Leonard Crestez <cdleonard@gmail.com>
> ---
> net/ipv4/tcp.c | 15 ++++++++++++---
> 1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
> index 002a4a04efbe076ba603d7d42eb85e60d9bf4fb8..766881775abb795c884d048d51c361e805b91989 100644
> --- a/net/ipv4/tcp.c
> +++ b/net/ipv4/tcp.c
> @@ -4459,9 +4459,18 @@ tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
> return SKB_DROP_REASON_TCP_MD5UNEXPECTED;
> }
>
> - /* check the signature */
> - genhash = tp->af_specific->calc_md5_hash(newhash, hash_expected,
> - NULL, skb);
> + /* Check the signature.
> + * To support dual stack listeners, we need to handle
> + * IPv4-mapped case.
> + */
> + if (family == AF_INET)
> + genhash = tcp_v4_md5_hash_skb(newhash,
> + hash_expected,
> + NULL, skb);
> + else
> + genhash = tp->af_specific->calc_md5_hash(newhash,
> + hash_expected,
> + NULL, skb);
>
> if (genhash || memcmp(hash_location, newhash, 16) != 0) {
> NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH net] tcp: md5: fix IPv4-mapped support
2022-07-26 11:57 [PATCH net] tcp: md5: fix IPv4-mapped support Eric Dumazet
` (2 preceding siblings ...)
2022-07-27 8:22 ` Leonard Crestez
@ 2022-07-27 17:30 ` patchwork-bot+netdevbpf
3 siblings, 0 replies; 7+ messages in thread
From: patchwork-bot+netdevbpf @ 2022-07-27 17:30 UTC (permalink / raw)
To: Eric Dumazet
Cc: davem, kuba, pabeni, netdev, eric.dumazet, brianvv, dima,
dsahern, cdleonard
Hello:
This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:
On Tue, 26 Jul 2022 11:57:43 +0000 you wrote:
> After the blamed commit, IPv4 SYN packets handled
> by a dual stack IPv6 socket are dropped, even if
> perfectly valid.
>
> $ nstat | grep MD5
> TcpExtTCPMD5Failure 5 0.0
>
> [...]
Here is the summary with links:
- [net] tcp: md5: fix IPv4-mapped support
https://git.kernel.org/netdev/net/c/e62d2e110356
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 7+ messages in thread
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2022-07-26 11:57 [PATCH net] tcp: md5: fix IPv4-mapped support Eric Dumazet
2022-07-26 15:06 ` David Ahern
2022-07-26 17:57 ` Eric Dumazet
2022-07-26 19:05 ` David Ahern
2022-07-26 17:13 ` Dmitry Safonov
2022-07-27 8:22 ` Leonard Crestez
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