[PATCH v1 net 0/5] tcp: Fix bind() regression for v4-mapped-v6 address

[PATCH v1 net 0/5] tcp: Fix bind() regression for v4-mapped-v6 address

[Kuniyuki Iwashima]

Since bhash2 was introduced, bind() is broken in two cases related
to v4-mapped-v6 address.

This series fixes the regression and adds test to cover the cases.


Kuniyuki Iwashima (5):
  tcp: Fix bind() regression for v4-mapped-v6 wildcard address.
  tcp: Fix bind() regression for v4-mapped-v6 non-wildcard address.
  selftest: tcp: Fix address length in bind_wildcard.c.
  selftest: tcp: Move expected_errno into each test case in
    bind_wildcard.c.
  selftest: tcp: Add v4-mapped-v6 cases in bind_wildcard.c.

 include/net/ipv6.h                          |  5 ++
 net/ipv4/inet_hashtables.c                  | 12 +++-
 tools/testing/selftests/net/bind_wildcard.c | 68 +++++++++++++++++----
 3 files changed, 72 insertions(+), 13 deletions(-)

-- 
2.30.2

[PATCH v1 net 1/5] tcp: Fix bind() regression for v4-mapped-v6 wildcard address.

[Kuniyuki Iwashima]

Andrei Vagin reported bind() regression with strace logs.

If we bind() a TCPv6 socket to ::FFFF:0.0.0.0 and then bind() a TCPv4
socket to 127.0.0.1, the 2nd bind() should fail but now succeeds.

  from socket import *

  s1 = socket(AF_INET6, SOCK_STREAM)
  s1.bind(('::ffff:0.0.0.0', 0))

  s2 = socket(AF_INET, SOCK_STREAM)
  s2.bind(('127.0.0.1', s1.getsockname()[1]))

During the 2nd bind(), if tb->family is AF_INET6 and sk->sk_family is
AF_INET in inet_bind2_bucket_match_addr_any(), we still need to check
if tb has the v4-mapped-v6 wildcard address.

The example above does not work after commit 5456262d2baa ("net: Fix
incorrect address comparison when searching for a bind2 bucket"), but
the blamed change is not the commit.

Before the commit, the leading zeros of ::FFFF:0.0.0.0 were treated
as 0.0.0.0, and the sequence above worked by chance.  Technically, this
case has been broken since bhash2 was introduced.

Note that if we bind() two sockets to 127.0.0.1 and then ::FFFF:0.0.0.0,
the 2nd bind() fails properly because we fall back to using bhash to
detect conflicts for the v4-mapped-v6 address.

Fixes: 28044fc1d495 ("net: Add a bhash2 table hashed by port and address")
Reported-by: Andrei Vagin <avagin@google.com>
Closes: https://lore.kernel.org/netdev/ZPuYBOFC8zsK6r9T@google.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
 include/net/ipv6.h         | 5 +++++
 net/ipv4/inet_hashtables.c | 3 ++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 0675be0f3fa0..56d8217ea6cf 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -784,6 +784,11 @@ static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
 					cpu_to_be32(0x0000ffff))) == 0UL;
 }
 
+static inline bool ipv6_addr_v4mapped_any(const struct in6_addr *a)
+{
+	return ipv6_addr_v4mapped(a) && ipv4_is_zeronet(a->s6_addr32[3]);
+}
+
 static inline bool ipv6_addr_v4mapped_loopback(const struct in6_addr *a)
 {
 	return ipv6_addr_v4mapped(a) && ipv4_is_loopback(a->s6_addr32[3]);
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 7876b7d703cb..0a9b20eb81c4 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -837,7 +837,8 @@ bool inet_bind2_bucket_match_addr_any(const struct inet_bind2_bucket *tb, const
 		if (sk->sk_family == AF_INET)
 			return net_eq(ib2_net(tb), net) && tb->port == port &&
 				tb->l3mdev == l3mdev &&
-				ipv6_addr_any(&tb->v6_rcv_saddr);
+				(ipv6_addr_any(&tb->v6_rcv_saddr) ||
+				 ipv6_addr_v4mapped_any(&tb->v6_rcv_saddr));
 
 		return false;
 	}
-- 
2.30.2

Re: [PATCH v1 net 1/5] tcp: Fix bind() regression for v4-mapped-v6 wildcard address.

[Andrei Vagin]

On Mon, Sep 11, 2023 at 9:52 AM Kuniyuki Iwashima <kuniyu@amazon.com> wrote:
>
> Andrei Vagin reported bind() regression with strace logs.
>
> If we bind() a TCPv6 socket to ::FFFF:0.0.0.0 and then bind() a TCPv4
> socket to 127.0.0.1, the 2nd bind() should fail but now succeeds.
>
>   from socket import *
>
>   s1 = socket(AF_INET6, SOCK_STREAM)
>   s1.bind(('::ffff:0.0.0.0', 0))
>
>   s2 = socket(AF_INET, SOCK_STREAM)
>   s2.bind(('127.0.0.1', s1.getsockname()[1]))
>
> During the 2nd bind(), if tb->family is AF_INET6 and sk->sk_family is
> AF_INET in inet_bind2_bucket_match_addr_any(), we still need to check
> if tb has the v4-mapped-v6 wildcard address.
>
> The example above does not work after commit 5456262d2baa ("net: Fix
> incorrect address comparison when searching for a bind2 bucket"), but
> the blamed change is not the commit.
>
> Before the commit, the leading zeros of ::FFFF:0.0.0.0 were treated
> as 0.0.0.0, and the sequence above worked by chance.  Technically, this
> case has been broken since bhash2 was introduced.
>
> Note that if we bind() two sockets to 127.0.0.1 and then ::FFFF:0.0.0.0,
> the 2nd bind() fails properly because we fall back to using bhash to
> detect conflicts for the v4-mapped-v6 address.

I think we have one more issue here:

socket(AF_INET6, SOCK_STREAM|SOCK_CLOEXEC, IPPROTO_IP) = 3
socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC, IPPROTO_IP) = 4
bind(3, {sa_family=AF_INET6, sin6_port=htons(9999),
sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::ffff:127.0.0.1",
&sin6_addr), sin6_scope_id=0}, 28) = 0
bind(4, {sa_family=AF_INET, sin_port=htons(9999),
sin_addr=inet_addr("127.0.0.1")}, 16) = 0

I think the second bind has to return EADDRINUSE, doesn't it?

I don't deep dive to this code, but after a quick look, I think we can
do something like this:

diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 7876b7d703cb..f7a700d392d0 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -110,8 +110,13 @@ static void inet_bind2_bucket_init(struct
inet_bind2_bucket *tb,
        tb->l3mdev    = l3mdev;
        tb->port      = port;
 #if IS_ENABLED(CONFIG_IPV6)
-       tb->family    = sk->sk_family;
-       if (sk->sk_family == AF_INET6)
+
+       if (sk->sk_family == AF_INET6 &&
+           ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
+               tb->family = AF_INET;
+       else
+               tb->family = sk->sk_family;
+       if (tb->family == AF_INET6)
                tb->v6_rcv_saddr = sk->sk_v6_rcv_saddr;
        else
 #endif
@@ -149,10 +154,15 @@ static bool inet_bind2_bucket_addr_match(const
struct inet_bind2_bucket *tb2,
                                         const struct sock *sk)
 {
 #if IS_ENABLED(CONFIG_IPV6)
-       if (sk->sk_family != tb2->family)
+       unsigned short family = sk->sk_family;
+
+       if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
+               family = AF_INET;
+
+       if (family != tb2->family)
                return false;

-       if (sk->sk_family == AF_INET6)
+       if (family == AF_INET6)
                return ipv6_addr_equal(&tb2->v6_rcv_saddr,
                                       &sk->sk_v6_rcv_saddr);
 #endif
@@ -816,10 +826,15 @@ static bool inet_bind2_bucket_match(const struct
inet_bind2_bucket *tb,
                                    int l3mdev, const struct sock *sk)
 {
 #if IS_ENABLED(CONFIG_IPV6)
-       if (sk->sk_family != tb->family)
+       unsigned short family = sk->sk_family;
+
+       if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
+               family = AF_INET;
+
+       if (family != tb->family)
                return false;

-       if (sk->sk_family == AF_INET6)
+       if (family == AF_INET6)
                return net_eq(ib2_net(tb), net) && tb->port == port &&
                        tb->l3mdev == l3mdev &&
                        ipv6_addr_equal(&tb->v6_rcv_saddr,
&sk->sk_v6_rcv_saddr);



>
> Fixes: 28044fc1d495 ("net: Add a bhash2 table hashed by port and address")
> Reported-by: Andrei Vagin <avagin@google.com>
> Closes: https://lore.kernel.org/netdev/ZPuYBOFC8zsK6r9T@google.com/
> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
> ---
>  include/net/ipv6.h         | 5 +++++
>  net/ipv4/inet_hashtables.c | 3 ++-
>  2 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/include/net/ipv6.h b/include/net/ipv6.h
> index 0675be0f3fa0..56d8217ea6cf 100644
> --- a/include/net/ipv6.h
> +++ b/include/net/ipv6.h
> @@ -784,6 +784,11 @@ static inline bool ipv6_addr_v4mapped(const struct in6_addr *a)
>                                         cpu_to_be32(0x0000ffff))) == 0UL;
>  }
>
> +static inline bool ipv6_addr_v4mapped_any(const struct in6_addr *a)
> +{
> +       return ipv6_addr_v4mapped(a) && ipv4_is_zeronet(a->s6_addr32[3]);
> +}
> +
>  static inline bool ipv6_addr_v4mapped_loopback(const struct in6_addr *a)
>  {
>         return ipv6_addr_v4mapped(a) && ipv4_is_loopback(a->s6_addr32[3]);
> diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
> index 7876b7d703cb..0a9b20eb81c4 100644
> --- a/net/ipv4/inet_hashtables.c
> +++ b/net/ipv4/inet_hashtables.c
> @@ -837,7 +837,8 @@ bool inet_bind2_bucket_match_addr_any(const struct inet_bind2_bucket *tb, const
>                 if (sk->sk_family == AF_INET)
>                         return net_eq(ib2_net(tb), net) && tb->port == port &&
>                                 tb->l3mdev == l3mdev &&
> -                               ipv6_addr_any(&tb->v6_rcv_saddr);
> +                               (ipv6_addr_any(&tb->v6_rcv_saddr) ||
> +                                ipv6_addr_v4mapped_any(&tb->v6_rcv_saddr));
>
>                 return false;
>         }
> --
> 2.30.2
>

Re: [PATCH v1 net 1/5] tcp: Fix bind() regression for v4-mapped-v6 wildcard address.

[Kuniyuki Iwashima]

From: Andrei Vagin <avagin@google.com>
Date: Mon, 11 Sep 2023 13:00:19 -0700
> On Mon, Sep 11, 2023 at 9:52 AM Kuniyuki Iwashima <kuniyu@amazon.com> wrote:
> >
> > Andrei Vagin reported bind() regression with strace logs.
> >
> > If we bind() a TCPv6 socket to ::FFFF:0.0.0.0 and then bind() a TCPv4
> > socket to 127.0.0.1, the 2nd bind() should fail but now succeeds.
> >
> >   from socket import *
> >
> >   s1 = socket(AF_INET6, SOCK_STREAM)
> >   s1.bind(('::ffff:0.0.0.0', 0))
> >
> >   s2 = socket(AF_INET, SOCK_STREAM)
> >   s2.bind(('127.0.0.1', s1.getsockname()[1]))
> >
> > During the 2nd bind(), if tb->family is AF_INET6 and sk->sk_family is
> > AF_INET in inet_bind2_bucket_match_addr_any(), we still need to check
> > if tb has the v4-mapped-v6 wildcard address.
> >
> > The example above does not work after commit 5456262d2baa ("net: Fix
> > incorrect address comparison when searching for a bind2 bucket"), but
> > the blamed change is not the commit.
> >
> > Before the commit, the leading zeros of ::FFFF:0.0.0.0 were treated
> > as 0.0.0.0, and the sequence above worked by chance.  Technically, this
> > case has been broken since bhash2 was introduced.
> >
> > Note that if we bind() two sockets to 127.0.0.1 and then ::FFFF:0.0.0.0,
> > the 2nd bind() fails properly because we fall back to using bhash to
> > detect conflicts for the v4-mapped-v6 address.
> 
> I think we have one more issue here:
> 
> socket(AF_INET6, SOCK_STREAM|SOCK_CLOEXEC, IPPROTO_IP) = 3
> socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC, IPPROTO_IP) = 4
> bind(3, {sa_family=AF_INET6, sin6_port=htons(9999),
> sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::ffff:127.0.0.1",
> &sin6_addr), sin6_scope_id=0}, 28) = 0
> bind(4, {sa_family=AF_INET, sin_port=htons(9999),
> sin_addr=inet_addr("127.0.0.1")}, 16) = 0
> 
> I think the second bind has to return EADDRINUSE, doesn't it?

Correct, and the following patch fixes it separately.
Sorry, I forgot to add you in CC of the entire series.
https://lore.kernel.org/netdev/20230911183700.60878-4-kuniyu@amazon.com/

[PATCH v1 net 2/5] tcp: Fix bind() regression for v4-mapped-v6 non-wildcard address.

[Kuniyuki Iwashima]

Since bhash2 was introduced, the example below does now work as expected.
These two bind() should conflict, but the 2nd bind() now succeeds.

  from socket import *

  s1 = socket(AF_INET6, SOCK_STREAM)
  s1.bind(('::ffff:127.0.0.1', 0))

  s2 = socket(AF_INET, SOCK_STREAM)
  s2.bind(('127.0.0.1', s1.getsockname()[1]))

During the 2nd bind() in inet_csk_get_port(), inet_bind2_bucket_find()
fails to find the 1st socket's tb2, so inet_bind2_bucket_create() allocates
a new tb2 for the 2nd socket.  Then, we call inet_csk_bind_conflict() that
checks conflicts in the new tb2 by inet_bhash2_conflict().  However, the
new tb2 does not include the 1st socket, thus the bind() finally succeeds.

In this case, inet_bind2_bucket_match() must check if AF_INET6 tb2 has
the conflicting v4-mapped-v6 address so that inet_bind2_bucket_find()
returns the 1st socket's tb2.

Note that if we bind two sockets to 127.0.0.1 and then ::FFFF:127.0.0.1,
the 2nd bind() fails properly for the same reason mentinoed in the previous
commit.

Fixes: 28044fc1d495 ("net: Add a bhash2 table hashed by port and address")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
 net/ipv4/inet_hashtables.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 0a9b20eb81c4..54505100c914 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -816,8 +816,15 @@ static bool inet_bind2_bucket_match(const struct inet_bind2_bucket *tb,
 				    int l3mdev, const struct sock *sk)
 {
 #if IS_ENABLED(CONFIG_IPV6)
-	if (sk->sk_family != tb->family)
+	if (sk->sk_family != tb->family) {
+		if (sk->sk_family == AF_INET)
+			return net_eq(ib2_net(tb), net) && tb->port == port &&
+				tb->l3mdev == l3mdev &&
+				ipv6_addr_v4mapped(&tb->v6_rcv_saddr) &&
+				tb->v6_rcv_saddr.s6_addr32[3] == sk->sk_rcv_saddr;
+
 		return false;
+	}
 
 	if (sk->sk_family == AF_INET6)
 		return net_eq(ib2_net(tb), net) && tb->port == port &&
-- 
2.30.2

Re: [PATCH v1 net 2/5] tcp: Fix bind() regression for v4-mapped-v6 non-wildcard address.

[Eric Dumazet]

On Mon, Sep 11, 2023 at 6:52 PM Kuniyuki Iwashima <kuniyu@amazon.com> wrote:
>
> Since bhash2 was introduced, the example below does now work as expected.
> These two bind() should conflict, but the 2nd bind() now succeeds.
>
>   from socket import *
>
>   s1 = socket(AF_INET6, SOCK_STREAM)
>   s1.bind(('::ffff:127.0.0.1', 0))
>
>   s2 = socket(AF_INET, SOCK_STREAM)
>   s2.bind(('127.0.0.1', s1.getsockname()[1]))
>
> During the 2nd bind() in inet_csk_get_port(), inet_bind2_bucket_find()
> fails to find the 1st socket's tb2, so inet_bind2_bucket_create() allocates
> a new tb2 for the 2nd socket.  Then, we call inet_csk_bind_conflict() that
> checks conflicts in the new tb2 by inet_bhash2_conflict().  However, the
> new tb2 does not include the 1st socket, thus the bind() finally succeeds.
>
> In this case, inet_bind2_bucket_match() must check if AF_INET6 tb2 has
> the conflicting v4-mapped-v6 address so that inet_bind2_bucket_find()
> returns the 1st socket's tb2.
>
> Note that if we bind two sockets to 127.0.0.1 and then ::FFFF:127.0.0.1,
> the 2nd bind() fails properly for the same reason mentinoed in the previous
> commit.
>
> Fixes: 28044fc1d495 ("net: Add a bhash2 table hashed by port and address")
> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
> ---
>  net/ipv4/inet_hashtables.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
> index 0a9b20eb81c4..54505100c914 100644
> --- a/net/ipv4/inet_hashtables.c
> +++ b/net/ipv4/inet_hashtables.c
> @@ -816,8 +816,15 @@ static bool inet_bind2_bucket_match(const struct inet_bind2_bucket *tb,
>                                     int l3mdev, const struct sock *sk)
>  {
>  #if IS_ENABLED(CONFIG_IPV6)
> -       if (sk->sk_family != tb->family)
> +       if (sk->sk_family != tb->family) {
> +               if (sk->sk_family == AF_INET)
> +                       return net_eq(ib2_net(tb), net) && tb->port == port &&
> +                               tb->l3mdev == l3mdev &&
> +                               ipv6_addr_v4mapped(&tb->v6_rcv_saddr) &&
> +                               tb->v6_rcv_saddr.s6_addr32[3] == sk->sk_rcv_saddr;
> +
>                 return false;
> +       }
>
>         if (sk->sk_family == AF_INET6)
>                 return net_eq(ib2_net(tb), net) && tb->port == port &&
> --

Could we first factorize all these "net_eq(ib2_net(tb), net) &&
tb->port == port" checks ?

diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 7876b7d703cb5647086c45ca547c4caadc00c091..6240c802ed772272028e6e65bf90f345dd2d1619
100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -832,24 +832,24 @@ static bool inet_bind2_bucket_match(const struct
inet_bind2_bucket *tb,
 bool inet_bind2_bucket_match_addr_any(const struct inet_bind2_bucket
*tb, const struct net *net,
                                      unsigned short port, int l3mdev,
const struct sock *sk)
 {
+       if (!net_eq(ib2_net(tb), net) || tb->port != port)
+               return false;
+
 #if IS_ENABLED(CONFIG_IPV6)
        if (sk->sk_family != tb->family) {
                if (sk->sk_family == AF_INET)
-                       return net_eq(ib2_net(tb), net) && tb->port == port &&
-                               tb->l3mdev == l3mdev &&
+                       return  tb->l3mdev == l3mdev &&
                                ipv6_addr_any(&tb->v6_rcv_saddr);

                return false;
        }

        if (sk->sk_family == AF_INET6)
-               return net_eq(ib2_net(tb), net) && tb->port == port &&
-                       tb->l3mdev == l3mdev &&
+               return  tb->l3mdev == l3mdev &&
                        ipv6_addr_any(&tb->v6_rcv_saddr);
        else
 #endif
-               return net_eq(ib2_net(tb), net) && tb->port == port &&
-                       tb->l3mdev == l3mdev && tb->rcv_saddr == 0;
+               return tb->l3mdev == l3mdev && tb->rcv_saddr == 0;
 }

 /* The socket's bhash2 hashbucket spinlock must be held when this is called */

Re: [PATCH v1 net 2/5] tcp: Fix bind() regression for v4-mapped-v6 non-wildcard address.

[Kuniyuki Iwashima]

From: Eric Dumazet <edumazet@google.com>
Date: Mon, 11 Sep 2023 19:51:44 +0200
> On Mon, Sep 11, 2023 at 6:52 PM Kuniyuki Iwashima <kuniyu@amazon.com> wrote:
> >
> > Since bhash2 was introduced, the example below does now work as expected.
> > These two bind() should conflict, but the 2nd bind() now succeeds.
> >
> >   from socket import *
> >
> >   s1 = socket(AF_INET6, SOCK_STREAM)
> >   s1.bind(('::ffff:127.0.0.1', 0))
> >
> >   s2 = socket(AF_INET, SOCK_STREAM)
> >   s2.bind(('127.0.0.1', s1.getsockname()[1]))
> >
> > During the 2nd bind() in inet_csk_get_port(), inet_bind2_bucket_find()
> > fails to find the 1st socket's tb2, so inet_bind2_bucket_create() allocates
> > a new tb2 for the 2nd socket.  Then, we call inet_csk_bind_conflict() that
> > checks conflicts in the new tb2 by inet_bhash2_conflict().  However, the
> > new tb2 does not include the 1st socket, thus the bind() finally succeeds.
> >
> > In this case, inet_bind2_bucket_match() must check if AF_INET6 tb2 has
> > the conflicting v4-mapped-v6 address so that inet_bind2_bucket_find()
> > returns the 1st socket's tb2.
> >
> > Note that if we bind two sockets to 127.0.0.1 and then ::FFFF:127.0.0.1,
> > the 2nd bind() fails properly for the same reason mentinoed in the previous
> > commit.
> >
> > Fixes: 28044fc1d495 ("net: Add a bhash2 table hashed by port and address")
> > Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
> > ---
> >  net/ipv4/inet_hashtables.c | 9 ++++++++-
> >  1 file changed, 8 insertions(+), 1 deletion(-)
> >
> > diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
> > index 0a9b20eb81c4..54505100c914 100644
> > --- a/net/ipv4/inet_hashtables.c
> > +++ b/net/ipv4/inet_hashtables.c
> > @@ -816,8 +816,15 @@ static bool inet_bind2_bucket_match(const struct inet_bind2_bucket *tb,
> >                                     int l3mdev, const struct sock *sk)
> >  {
> >  #if IS_ENABLED(CONFIG_IPV6)
> > -       if (sk->sk_family != tb->family)
> > +       if (sk->sk_family != tb->family) {
> > +               if (sk->sk_family == AF_INET)
> > +                       return net_eq(ib2_net(tb), net) && tb->port == port &&
> > +                               tb->l3mdev == l3mdev &&
> > +                               ipv6_addr_v4mapped(&tb->v6_rcv_saddr) &&
> > +                               tb->v6_rcv_saddr.s6_addr32[3] == sk->sk_rcv_saddr;
> > +
> >                 return false;
> > +       }
> >
> >         if (sk->sk_family == AF_INET6)
> >                 return net_eq(ib2_net(tb), net) && tb->port == port &&
> > --
> 
> Could we first factorize all these "net_eq(ib2_net(tb), net) &&
> tb->port == port" checks ?

That's much cleaner :)
I'll add a prep patch first in v2.

Thanks!

> 
> diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
> index 7876b7d703cb5647086c45ca547c4caadc00c091..6240c802ed772272028e6e65bf90f345dd2d1619
> 100644
> --- a/net/ipv4/inet_hashtables.c
> +++ b/net/ipv4/inet_hashtables.c
> @@ -832,24 +832,24 @@ static bool inet_bind2_bucket_match(const struct
> inet_bind2_bucket *tb,
>  bool inet_bind2_bucket_match_addr_any(const struct inet_bind2_bucket
> *tb, const struct net *net,
>                                       unsigned short port, int l3mdev,
> const struct sock *sk)
>  {
> +       if (!net_eq(ib2_net(tb), net) || tb->port != port)
> +               return false;
> +
>  #if IS_ENABLED(CONFIG_IPV6)
>         if (sk->sk_family != tb->family) {
>                 if (sk->sk_family == AF_INET)
> -                       return net_eq(ib2_net(tb), net) && tb->port == port &&
> -                               tb->l3mdev == l3mdev &&
> +                       return  tb->l3mdev == l3mdev &&
>                                 ipv6_addr_any(&tb->v6_rcv_saddr);
> 
>                 return false;
>         }
> 
>         if (sk->sk_family == AF_INET6)
> -               return net_eq(ib2_net(tb), net) && tb->port == port &&
> -                       tb->l3mdev == l3mdev &&
> +               return  tb->l3mdev == l3mdev &&
>                         ipv6_addr_any(&tb->v6_rcv_saddr);
>         else
>  #endif
> -               return net_eq(ib2_net(tb), net) && tb->port == port &&
> -                       tb->l3mdev == l3mdev && tb->rcv_saddr == 0;
> +               return tb->l3mdev == l3mdev && tb->rcv_saddr == 0;
>  }
> 
>  /* The socket's bhash2 hashbucket spinlock must be held when this is called */

[PATCH v1 net 3/5] selftest: tcp: Fix address length in bind_wildcard.c.

[Kuniyuki Iwashima]

The selftest passes the IPv6 address length for an IPv4 address.
We should pass the correct length.

Note inet_bind_sk() does not check if the size is larger than
sizeof(struct sockaddr_in), so there is no real bug in this
selftest.

Fixes: 13715acf8ab5 ("selftest: Add test for bind() conflicts.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
 tools/testing/selftests/net/bind_wildcard.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/bind_wildcard.c b/tools/testing/selftests/net/bind_wildcard.c
index 58edfc15d28b..e7ebe72e879d 100644
--- a/tools/testing/selftests/net/bind_wildcard.c
+++ b/tools/testing/selftests/net/bind_wildcard.c
@@ -100,7 +100,7 @@ void bind_sockets(struct __test_metadata *_metadata,
 TEST_F(bind_wildcard, v4_v6)
 {
 	bind_sockets(_metadata, self,
-		     (struct sockaddr *)&self->addr4, sizeof(self->addr6),
+		     (struct sockaddr *)&self->addr4, sizeof(self->addr4),
 		     (struct sockaddr *)&self->addr6, sizeof(self->addr6));
 }
 
-- 
2.30.2

[PATCH v1 net 4/5] selftest: tcp: Move expected_errno into each test case in bind_wildcard.c.

[Kuniyuki Iwashima]

This is a preparation patch for the following patch.

Let's define expected_errno in each test case so that we can add other test
cases easily.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
 tools/testing/selftests/net/bind_wildcard.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/net/bind_wildcard.c b/tools/testing/selftests/net/bind_wildcard.c
index e7ebe72e879d..81f694536099 100644
--- a/tools/testing/selftests/net/bind_wildcard.c
+++ b/tools/testing/selftests/net/bind_wildcard.c
@@ -10,37 +10,41 @@ FIXTURE(bind_wildcard)
 {
 	struct sockaddr_in addr4;
 	struct sockaddr_in6 addr6;
-	int expected_errno;
 };
 
 FIXTURE_VARIANT(bind_wildcard)
 {
 	const __u32 addr4_const;
 	const struct in6_addr *addr6_const;
+	int expected_errno;
 };
 
 FIXTURE_VARIANT_ADD(bind_wildcard, v4_any_v6_any)
 {
 	.addr4_const = INADDR_ANY,
 	.addr6_const = &in6addr_any,
+	.expected_errno = EADDRINUSE,
 };
 
 FIXTURE_VARIANT_ADD(bind_wildcard, v4_any_v6_local)
 {
 	.addr4_const = INADDR_ANY,
 	.addr6_const = &in6addr_loopback,
+	.expected_errno = 0,
 };
 
 FIXTURE_VARIANT_ADD(bind_wildcard, v4_local_v6_any)
 {
 	.addr4_const = INADDR_LOOPBACK,
 	.addr6_const = &in6addr_any,
+	.expected_errno = EADDRINUSE,
 };
 
 FIXTURE_VARIANT_ADD(bind_wildcard, v4_local_v6_local)
 {
 	.addr4_const = INADDR_LOOPBACK,
 	.addr6_const = &in6addr_loopback,
+	.expected_errno = 0,
 };
 
 FIXTURE_SETUP(bind_wildcard)
@@ -52,11 +56,6 @@ FIXTURE_SETUP(bind_wildcard)
 	self->addr6.sin6_family = AF_INET6;
 	self->addr6.sin6_port = htons(0);
 	self->addr6.sin6_addr = *variant->addr6_const;
-
-	if (variant->addr6_const == &in6addr_any)
-		self->expected_errno = EADDRINUSE;
-	else
-		self->expected_errno = 0;
 }
 
 FIXTURE_TEARDOWN(bind_wildcard)
@@ -65,6 +64,7 @@ FIXTURE_TEARDOWN(bind_wildcard)
 
 void bind_sockets(struct __test_metadata *_metadata,
 		  FIXTURE_DATA(bind_wildcard) *self,
+		  int expected_errno,
 		  struct sockaddr *addr1, socklen_t addrlen1,
 		  struct sockaddr *addr2, socklen_t addrlen2)
 {
@@ -86,9 +86,9 @@ void bind_sockets(struct __test_metadata *_metadata,
 	ASSERT_GT(fd[1], 0);
 
 	ret = bind(fd[1], addr2, addrlen2);
-	if (self->expected_errno) {
+	if (expected_errno) {
 		ASSERT_EQ(ret, -1);
-		ASSERT_EQ(errno, self->expected_errno);
+		ASSERT_EQ(errno, expected_errno);
 	} else {
 		ASSERT_EQ(ret, 0);
 	}
@@ -99,14 +99,14 @@ void bind_sockets(struct __test_metadata *_metadata,
 
 TEST_F(bind_wildcard, v4_v6)
 {
-	bind_sockets(_metadata, self,
+	bind_sockets(_metadata, self, variant->expected_errno,
 		     (struct sockaddr *)&self->addr4, sizeof(self->addr4),
 		     (struct sockaddr *)&self->addr6, sizeof(self->addr6));
 }
 
 TEST_F(bind_wildcard, v6_v4)
 {
-	bind_sockets(_metadata, self,
+	bind_sockets(_metadata, self, variant->expected_errno,
 		     (struct sockaddr *)&self->addr6, sizeof(self->addr6),
 		     (struct sockaddr *)&self->addr4, sizeof(self->addr4));
 }
-- 
2.30.2

[PATCH v1 net 5/5] selftest: tcp: Add v4-mapped-v6 cases in bind_wildcard.c.

[Kuniyuki Iwashima]

We add these 8 test cases in bind_wildcard.c to check bind() conflicts.

  1st bind()          2nd bind()
  ---------           ---------
  0.0.0.0             ::FFFF:0.0.0.0
  ::FFFF:0.0.0.0      0.0.0.0
  0.0.0.0             ::FFFF:127.0.0.1
  ::FFFF:127.0.0.1    0.0.0.0
  127.0.0.1           ::FFFF:0.0.0.0
  ::FFFF:0.0.0.0      127.0.0.1
  127.0.0.1           ::FFFF:127.0.0.1
  ::FFFF:127.0.0.1    127.0.0.1

All test passed without bhash2 and with bhash2 and this series.

 Before bhash2:
  $ uname -r
  6.0.0-rc1-00393-g0bf73255d3a3
  $ ./bind_wildcard
  ...
  # PASSED: 16 / 16 tests passed.

 Just after bhash2:
  $ uname -r
  6.0.0-rc1-00394-g28044fc1d495
  $ ./bind_wildcard
  ...
  ok 15 bind_wildcard.v4_local_v6_v4mapped_local.v4_v6
  not ok 16 bind_wildcard.v4_local_v6_v4mapped_local.v6_v4
  # FAILED: 15 / 16 tests passed.

 On net.git:
  $ ./bind_wildcard
  ...
  not ok 14 bind_wildcard.v4_local_v6_v4mapped_any.v6_v4
  not ok 16 bind_wildcard.v4_local_v6_v4mapped_local.v6_v4
  # FAILED: 13 / 16 tests passed.

 With this series:
  $ ./bind_wildcard
  ...
  # PASSED: 16 / 16 tests passed.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
 tools/testing/selftests/net/bind_wildcard.c | 46 +++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/tools/testing/selftests/net/bind_wildcard.c b/tools/testing/selftests/net/bind_wildcard.c
index 81f694536099..a2662348cdb1 100644
--- a/tools/testing/selftests/net/bind_wildcard.c
+++ b/tools/testing/selftests/net/bind_wildcard.c
@@ -6,6 +6,24 @@
 
 #include "../kselftest_harness.h"
 
+struct in6_addr in6addr_v4mapped_any = {
+	.s6_addr = {
+		0, 0, 0, 0,
+		0, 0, 0, 0,
+		0, 0, 255, 255,
+		0, 0, 0, 0
+	}
+};
+
+struct in6_addr in6addr_v4mapped_loopback = {
+	.s6_addr = {
+		0, 0, 0, 0,
+		0, 0, 0, 0,
+		0, 0, 255, 255,
+		127, 0, 0, 1
+	}
+};
+
 FIXTURE(bind_wildcard)
 {
 	struct sockaddr_in addr4;
@@ -33,6 +51,20 @@ FIXTURE_VARIANT_ADD(bind_wildcard, v4_any_v6_local)
 	.expected_errno = 0,
 };
 
+FIXTURE_VARIANT_ADD(bind_wildcard, v4_any_v6_v4mapped_any)
+{
+	.addr4_const = INADDR_ANY,
+	.addr6_const = &in6addr_v4mapped_any,
+	.expected_errno = EADDRINUSE,
+};
+
+FIXTURE_VARIANT_ADD(bind_wildcard, v4_any_v6_v4mapped_local)
+{
+	.addr4_const = INADDR_ANY,
+	.addr6_const = &in6addr_v4mapped_loopback,
+	.expected_errno = EADDRINUSE,
+};
+
 FIXTURE_VARIANT_ADD(bind_wildcard, v4_local_v6_any)
 {
 	.addr4_const = INADDR_LOOPBACK,
@@ -47,6 +79,20 @@ FIXTURE_VARIANT_ADD(bind_wildcard, v4_local_v6_local)
 	.expected_errno = 0,
 };
 
+FIXTURE_VARIANT_ADD(bind_wildcard, v4_local_v6_v4mapped_any)
+{
+	.addr4_const = INADDR_LOOPBACK,
+	.addr6_const = &in6addr_v4mapped_any,
+	.expected_errno = EADDRINUSE,
+};
+
+FIXTURE_VARIANT_ADD(bind_wildcard, v4_local_v6_v4mapped_local)
+{
+	.addr4_const = INADDR_LOOPBACK,
+	.addr6_const = &in6addr_v4mapped_loopback,
+	.expected_errno = EADDRINUSE,
+};
+
 FIXTURE_SETUP(bind_wildcard)
 {
 	self->addr4.sin_family = AF_INET;
-- 
2.30.2