[PATCH RESEND v2 0/3] Introduce getsockname io_uring_cmd

[PATCH RESEND v2 0/3] Introduce getsockname io_uring_cmd

[Gabriel Krisman Bertazi]

[Resending v2 because silly git-format-patch doesn't To from
the branch description, only Cc, so it was missing Jen]s.

Since V1:
  - minor style fixes
  - Resend with (more) maintainers cc'ed
  - rebased to axboe/for-next.
--

This feature has been requested a few times in the liburing repository
and Discord channels, such as in [1,2].  If anything, it also helps
solve a long standing issue in the bind-listen test that results in
occasional test failures.

The patchset is divided in three parts: Patch 1 merges the getpeername
and getsockname implementation in the network layer, making further
patches easier; Patch 2 splits out a helper used by io_uring, like done
for other network commands; Finally, patch 3 plumbs the new command in
io_uring.

The syscall path was tested by booting a Linux distro, which does all
sorts of getsockname/getpeername syscalls.  The io_uring side was tested
with a couple of new liburing subtests available at:

   https://github.com/krisman/liburing.git -b socket

Based on top of Jens' for-next.

[1] https://github.com/axboe/liburing/issues/1356
[2] https://discord.com/channels/1241076672589991966/1241076672589991970/1429975797912830074

---

CC: netdev@vger.kernel.org
CC: io-uring@vger.kernel.org
CC: Jakub Kicinski <kuba@kernel.org>
CC: David S. Miller <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Kuniyuki Iwashima <kuniyu@google.com>
CC: Paolo Abeni <pabeni@redhat.com>
CC: Willem de Bruijn <willemb@google.com>
CC: Simon Horman <horms@kernel.org>

Gabriel Krisman Bertazi (3):
  socket: Unify getsockname and getpeername implementation
  socket: Split out a getsockname helper for io_uring
  io_uring: Introduce getsockname io_uring cmd

 include/linux/socket.h        |  6 +--
 include/uapi/linux/io_uring.h |  1 +
 io_uring/cmd_net.c            | 23 ++++++++++++
 net/compat.c                  |  4 +-
 net/socket.c                  | 69 +++++++++++------------------------
 5 files changed, 51 insertions(+), 52 deletions(-)

-- 
2.51.0

[PATCH v2 1/3] socket: Unify getsockname and getpeername implementation

[Gabriel Krisman Bertazi]

They are already implemented by the same get_name hook in the protocol
level.  Bring the unification one level up to reduce code duplication
in preparation to supporting these as io_uring operations.

Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
---
 include/linux/socket.h |  4 +--
 net/compat.c           |  4 +--
 net/socket.c           | 55 ++++++++++--------------------------------
 3 files changed, 16 insertions(+), 47 deletions(-)

diff --git a/include/linux/socket.h b/include/linux/socket.h
index 3b262487ec06..937fe331ff1e 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -454,9 +454,7 @@ extern int __sys_connect(int fd, struct sockaddr __user *uservaddr,
 extern int __sys_listen(int fd, int backlog);
 extern int __sys_listen_socket(struct socket *sock, int backlog);
 extern int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
-			     int __user *usockaddr_len);
-extern int __sys_getpeername(int fd, struct sockaddr __user *usockaddr,
-			     int __user *usockaddr_len);
+			     int __user *usockaddr_len, int peer);
 extern int __sys_socketpair(int family, int type, int protocol,
 			    int __user *usockvec);
 extern int __sys_shutdown_sock(struct socket *sock, int how);
diff --git a/net/compat.c b/net/compat.c
index 485db8ee9b28..2c9bd0edac99 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -460,10 +460,10 @@ COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)
 		ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), 0);
 		break;
 	case SYS_GETSOCKNAME:
-		ret = __sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2]));
+		ret = __sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2]), 0);
 		break;
 	case SYS_GETPEERNAME:
-		ret = __sys_getpeername(a0, compat_ptr(a1), compat_ptr(a[2]));
+		ret = __sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2]), 1);
 		break;
 	case SYS_SOCKETPAIR:
 		ret = __sys_socketpair(a0, a1, a[2], compat_ptr(a[3]));
diff --git a/net/socket.c b/net/socket.c
index e8892b218708..ee438b9425da 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2128,12 +2128,11 @@ SYSCALL_DEFINE3(connect, int, fd, struct sockaddr __user *, uservaddr,
 }
 
 /*
- *	Get the local address ('name') of a socket object. Move the obtained
- *	name to user space.
+ *	Get the address (remote or local ('name')) of a socket object. Move the
+ *	obtained name to user space.
  */
-
 int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
-		      int __user *usockaddr_len)
+		      int __user *usockaddr_len, int peer)
 {
 	struct socket *sock;
 	struct sockaddr_storage address;
@@ -2146,11 +2145,14 @@ int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
 	if (unlikely(!sock))
 		return -ENOTSOCK;
 
-	err = security_socket_getsockname(sock);
+	if (peer)
+		err = security_socket_getpeername(sock);
+	else
+		err = security_socket_getsockname(sock);
 	if (err)
 		return err;
 
-	err = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 0);
+	err = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, peer);
 	if (err < 0)
 		return err;
 
@@ -2161,44 +2163,13 @@ int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
 SYSCALL_DEFINE3(getsockname, int, fd, struct sockaddr __user *, usockaddr,
 		int __user *, usockaddr_len)
 {
-	return __sys_getsockname(fd, usockaddr, usockaddr_len);
-}
-
-/*
- *	Get the remote address ('name') of a socket object. Move the obtained
- *	name to user space.
- */
-
-int __sys_getpeername(int fd, struct sockaddr __user *usockaddr,
-		      int __user *usockaddr_len)
-{
-	struct socket *sock;
-	struct sockaddr_storage address;
-	CLASS(fd, f)(fd);
-	int err;
-
-	if (fd_empty(f))
-		return -EBADF;
-	sock = sock_from_file(fd_file(f));
-	if (unlikely(!sock))
-		return -ENOTSOCK;
-
-	err = security_socket_getpeername(sock);
-	if (err)
-		return err;
-
-	err = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 1);
-	if (err < 0)
-		return err;
-
-	/* "err" is actually length in this case */
-	return move_addr_to_user(&address, err, usockaddr, usockaddr_len);
+	return __sys_getsockname(fd, usockaddr, usockaddr_len, 0);
 }
 
 SYSCALL_DEFINE3(getpeername, int, fd, struct sockaddr __user *, usockaddr,
 		int __user *, usockaddr_len)
 {
-	return __sys_getpeername(fd, usockaddr, usockaddr_len);
+	return __sys_getsockname(fd, usockaddr, usockaddr_len, 1);
 }
 
 /*
@@ -3162,12 +3133,12 @@ SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args)
 	case SYS_GETSOCKNAME:
 		err =
 		    __sys_getsockname(a0, (struct sockaddr __user *)a1,
-				      (int __user *)a[2]);
+				      (int __user *)a[2], 0);
 		break;
 	case SYS_GETPEERNAME:
 		err =
-		    __sys_getpeername(a0, (struct sockaddr __user *)a1,
-				      (int __user *)a[2]);
+		    __sys_getsockname(a0, (struct sockaddr __user *)a1,
+				      (int __user *)a[2], 1);
 		break;
 	case SYS_SOCKETPAIR:
 		err = __sys_socketpair(a0, a1, a[2], (int __user *)a[3]);
-- 
2.51.0

Re: [PATCH v2 1/3] socket: Unify getsockname and getpeername implementation

[Jakub Kicinski]

On Fri, 21 Nov 2025 11:09:46 -0500 Gabriel Krisman Bertazi wrote:
>  include/linux/socket.h |  4 +--
>  net/compat.c           |  4 +--
>  net/socket.c           | 55 ++++++++++--------------------------------

socket layer maintainers, please review

Re: [PATCH v2 1/3] socket: Unify getsockname and getpeername implementation

[Kuniyuki Iwashima]

On Fri, Nov 21, 2025 at 8:10 AM Gabriel Krisman Bertazi <krisman@suse.de> wrote:
>
> They are already implemented by the same get_name hook in the protocol
> level.  Bring the unification one level up to reduce code duplication
> in preparation to supporting these as io_uring operations.
>
> Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
> ---
>  include/linux/socket.h |  4 +--
>  net/compat.c           |  4 +--
>  net/socket.c           | 55 ++++++++++--------------------------------
>  3 files changed, 16 insertions(+), 47 deletions(-)
>
> diff --git a/include/linux/socket.h b/include/linux/socket.h
> index 3b262487ec06..937fe331ff1e 100644
> --- a/include/linux/socket.h
> +++ b/include/linux/socket.h
> @@ -454,9 +454,7 @@ extern int __sys_connect(int fd, struct sockaddr __user *uservaddr,
>  extern int __sys_listen(int fd, int backlog);
>  extern int __sys_listen_socket(struct socket *sock, int backlog);
>  extern int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
> -                            int __user *usockaddr_len);
> -extern int __sys_getpeername(int fd, struct sockaddr __user *usockaddr,
> -                            int __user *usockaddr_len);
> +                            int __user *usockaddr_len, int peer);
>  extern int __sys_socketpair(int family, int type, int protocol,
>                             int __user *usockvec);
>  extern int __sys_shutdown_sock(struct socket *sock, int how);
> diff --git a/net/compat.c b/net/compat.c
> index 485db8ee9b28..2c9bd0edac99 100644
> --- a/net/compat.c
> +++ b/net/compat.c
> @@ -460,10 +460,10 @@ COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)
>                 ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), 0);
>                 break;
>         case SYS_GETSOCKNAME:
> -               ret = __sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2]));
> +               ret = __sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2]), 0);
>                 break;
>         case SYS_GETPEERNAME:
> -               ret = __sys_getpeername(a0, compat_ptr(a1), compat_ptr(a[2]));
> +               ret = __sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2]), 1);
>                 break;
>         case SYS_SOCKETPAIR:
>                 ret = __sys_socketpair(a0, a1, a[2], compat_ptr(a[3]));
> diff --git a/net/socket.c b/net/socket.c
> index e8892b218708..ee438b9425da 100644
> --- a/net/socket.c
> +++ b/net/socket.c
> @@ -2128,12 +2128,11 @@ SYSCALL_DEFINE3(connect, int, fd, struct sockaddr __user *, uservaddr,
>  }
>
>  /*
> - *     Get the local address ('name') of a socket object. Move the obtained
> - *     name to user space.
> + *     Get the address (remote or local ('name')) of a socket object. Move the

nit: Get the remote or local address ('name')

Otherwise, looks good.

Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>


> + *     obtained name to user space.
>   */
> -
>  int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
> -                     int __user *usockaddr_len)
> +                     int __user *usockaddr_len, int peer)
>  {
>         struct socket *sock;
>         struct sockaddr_storage address;
> @@ -2146,11 +2145,14 @@ int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
>         if (unlikely(!sock))
>                 return -ENOTSOCK;
>
> -       err = security_socket_getsockname(sock);
> +       if (peer)
> +               err = security_socket_getpeername(sock);
> +       else
> +               err = security_socket_getsockname(sock);
>         if (err)
>                 return err;
>
> -       err = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 0);
> +       err = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, peer);
>         if (err < 0)
>                 return err;
>
> @@ -2161,44 +2163,13 @@ int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
>  SYSCALL_DEFINE3(getsockname, int, fd, struct sockaddr __user *, usockaddr,
>                 int __user *, usockaddr_len)
>  {
> -       return __sys_getsockname(fd, usockaddr, usockaddr_len);
> -}
> -
> -/*
> - *     Get the remote address ('name') of a socket object. Move the obtained
> - *     name to user space.
> - */
> -
> -int __sys_getpeername(int fd, struct sockaddr __user *usockaddr,
> -                     int __user *usockaddr_len)
> -{
> -       struct socket *sock;
> -       struct sockaddr_storage address;
> -       CLASS(fd, f)(fd);
> -       int err;
> -
> -       if (fd_empty(f))
> -               return -EBADF;
> -       sock = sock_from_file(fd_file(f));
> -       if (unlikely(!sock))
> -               return -ENOTSOCK;
> -
> -       err = security_socket_getpeername(sock);
> -       if (err)
> -               return err;
> -
> -       err = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 1);
> -       if (err < 0)
> -               return err;
> -
> -       /* "err" is actually length in this case */
> -       return move_addr_to_user(&address, err, usockaddr, usockaddr_len);
> +       return __sys_getsockname(fd, usockaddr, usockaddr_len, 0);
>  }
>
>  SYSCALL_DEFINE3(getpeername, int, fd, struct sockaddr __user *, usockaddr,
>                 int __user *, usockaddr_len)
>  {
> -       return __sys_getpeername(fd, usockaddr, usockaddr_len);
> +       return __sys_getsockname(fd, usockaddr, usockaddr_len, 1);
>  }
>
>  /*
> @@ -3162,12 +3133,12 @@ SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args)
>         case SYS_GETSOCKNAME:
>                 err =
>                     __sys_getsockname(a0, (struct sockaddr __user *)a1,
> -                                     (int __user *)a[2]);
> +                                     (int __user *)a[2], 0);
>                 break;
>         case SYS_GETPEERNAME:
>                 err =
> -                   __sys_getpeername(a0, (struct sockaddr __user *)a1,
> -                                     (int __user *)a[2]);
> +                   __sys_getsockname(a0, (struct sockaddr __user *)a1,
> +                                     (int __user *)a[2], 1);
>                 break;
>         case SYS_SOCKETPAIR:
>                 err = __sys_socketpair(a0, a1, a[2], (int __user *)a[3]);
> --
> 2.51.0
>

[PATCH v2 2/3] socket: Split out a getsockname helper for io_uring

[Gabriel Krisman Bertazi]

Similar to getsockopt, split out a helper to check security and issue
the operation from the main handler that can be used by io_uring.

Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
---
 include/linux/socket.h |  2 ++
 net/socket.c           | 34 +++++++++++++++++++---------------
 2 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/include/linux/socket.h b/include/linux/socket.h
index 937fe331ff1e..5afb5ef2990c 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -453,6 +453,8 @@ extern int __sys_connect(int fd, struct sockaddr __user *uservaddr,
 			 int addrlen);
 extern int __sys_listen(int fd, int backlog);
 extern int __sys_listen_socket(struct socket *sock, int backlog);
+extern int do_getsockname(struct socket *sock, struct sockaddr_storage *address,
+			  int peer, struct sockaddr __user *usockaddr, int __user *usockaddr_len);
 extern int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
 			     int __user *usockaddr_len, int peer);
 extern int __sys_socketpair(int family, int type, int protocol,
diff --git a/net/socket.c b/net/socket.c
index ee438b9425da..9c110b529cdd 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2127,6 +2127,24 @@ SYSCALL_DEFINE3(connect, int, fd, struct sockaddr __user *, uservaddr,
 	return __sys_connect(fd, uservaddr, addrlen);
 }
 
+int do_getsockname(struct socket *sock, struct sockaddr_storage *address, int peer,
+		   struct sockaddr __user *usockaddr, int __user *usockaddr_len)
+{
+	int err;
+
+	if (peer)
+		err = security_socket_getpeername(sock);
+	else
+		err = security_socket_getsockname(sock);
+	if (err)
+		return err;
+	err = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)address, peer);
+	if (err < 0)
+		return err;
+	/* "err" is actually length in this case */
+	return move_addr_to_user(address, err, usockaddr, usockaddr_len);
+}
+
 /*
  *	Get the address (remote or local ('name')) of a socket object. Move the
  *	obtained name to user space.
@@ -2137,27 +2155,13 @@ int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
 	struct socket *sock;
 	struct sockaddr_storage address;
 	CLASS(fd, f)(fd);
-	int err;
 
 	if (fd_empty(f))
 		return -EBADF;
 	sock = sock_from_file(fd_file(f));
 	if (unlikely(!sock))
 		return -ENOTSOCK;
-
-	if (peer)
-		err = security_socket_getpeername(sock);
-	else
-		err = security_socket_getsockname(sock);
-	if (err)
-		return err;
-
-	err = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, peer);
-	if (err < 0)
-		return err;
-
-	/* "err" is actually length in this case */
-	return move_addr_to_user(&address, err, usockaddr, usockaddr_len);
+	return do_getsockname(sock, &address, peer, usockaddr, usockaddr_len);
 }
 
 SYSCALL_DEFINE3(getsockname, int, fd, struct sockaddr __user *, usockaddr,
-- 
2.51.0

Re: [PATCH v2 2/3] socket: Split out a getsockname helper for io_uring

[Kuniyuki Iwashima]

On Fri, Nov 21, 2025 at 8:10 AM Gabriel Krisman Bertazi <krisman@suse.de> wrote:
>
> Similar to getsockopt, split out a helper to check security and issue
> the operation from the main handler that can be used by io_uring.
>
> Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
> ---
>  include/linux/socket.h |  2 ++
>  net/socket.c           | 34 +++++++++++++++++++---------------
>  2 files changed, 21 insertions(+), 15 deletions(-)
>
> diff --git a/include/linux/socket.h b/include/linux/socket.h
> index 937fe331ff1e..5afb5ef2990c 100644
> --- a/include/linux/socket.h
> +++ b/include/linux/socket.h
> @@ -453,6 +453,8 @@ extern int __sys_connect(int fd, struct sockaddr __user *uservaddr,
>                          int addrlen);
>  extern int __sys_listen(int fd, int backlog);
>  extern int __sys_listen_socket(struct socket *sock, int backlog);
> +extern int do_getsockname(struct socket *sock, struct sockaddr_storage *address,
> +                         int peer, struct sockaddr __user *usockaddr, int __user *usockaddr_len);
>  extern int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
>                              int __user *usockaddr_len, int peer);
>  extern int __sys_socketpair(int family, int type, int protocol,
> diff --git a/net/socket.c b/net/socket.c
> index ee438b9425da..9c110b529cdd 100644
> --- a/net/socket.c
> +++ b/net/socket.c
> @@ -2127,6 +2127,24 @@ SYSCALL_DEFINE3(connect, int, fd, struct sockaddr __user *, uservaddr,
>         return __sys_connect(fd, uservaddr, addrlen);
>  }
>
> +int do_getsockname(struct socket *sock, struct sockaddr_storage *address, int peer,
> +                  struct sockaddr __user *usockaddr, int __user *usockaddr_len)
> +{
> +       int err;
> +
> +       if (peer)
> +               err = security_socket_getpeername(sock);
> +       else
> +               err = security_socket_getsockname(sock);
> +       if (err)
> +               return err;
> +       err = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)address, peer);
> +       if (err < 0)
> +               return err;
> +       /* "err" is actually length in this case */
> +       return move_addr_to_user(address, err, usockaddr, usockaddr_len);
> +}
> +
>  /*
>   *     Get the address (remote or local ('name')) of a socket object. Move the
>   *     obtained name to user space.
> @@ -2137,27 +2155,13 @@ int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
>         struct socket *sock;
>         struct sockaddr_storage address;

Could you move this to do_getsockname() ?

The patch 3 also does not need to define it.


>         CLASS(fd, f)(fd);
> -       int err;
>
>         if (fd_empty(f))
>                 return -EBADF;
>         sock = sock_from_file(fd_file(f));
>         if (unlikely(!sock))
>                 return -ENOTSOCK;
> -
> -       if (peer)
> -               err = security_socket_getpeername(sock);
> -       else
> -               err = security_socket_getsockname(sock);
> -       if (err)
> -               return err;
> -
> -       err = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, peer);
> -       if (err < 0)
> -               return err;
> -
> -       /* "err" is actually length in this case */
> -       return move_addr_to_user(&address, err, usockaddr, usockaddr_len);
> +       return do_getsockname(sock, &address, peer, usockaddr, usockaddr_len);
>  }
>
>  SYSCALL_DEFINE3(getsockname, int, fd, struct sockaddr __user *, usockaddr,
> --
> 2.51.0
>

[PATCH v2 3/3] io_uring: Introduce getsockname io_uring cmd

[Gabriel Krisman Bertazi]

Introduce a socket-specific io_uring_cmd to support
getsockname/getpeername via io_uring.  I made this an io_uring_cmd
instead of a new operation to avoid polluting the command namespace with
what is exclusively a socket operation.  In addition, since we don't
need to conform to existing interfaces, this merges the
getsockname/getpeername in a single operation, since the implementation
is pretty much the same.

This has been frequently requested, for instance at [1] and more
recently in the project Discord channel. The main use-case is to support
fixed socket file descriptors.

[1] https://github.com/axboe/liburing/issues/1356

Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
---
 include/uapi/linux/io_uring.h |  1 +
 io_uring/cmd_net.c            | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 3d921cbb84f8..6a97c5376019 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -1010,6 +1010,7 @@ enum io_uring_socket_op {
 	SOCKET_URING_OP_GETSOCKOPT,
 	SOCKET_URING_OP_SETSOCKOPT,
 	SOCKET_URING_OP_TX_TIMESTAMP,
+	SOCKET_URING_OP_GETSOCKNAME,
 };
 
 /*
diff --git a/io_uring/cmd_net.c b/io_uring/cmd_net.c
index 27a09aa4c9d0..90f58f883f62 100644
--- a/io_uring/cmd_net.c
+++ b/io_uring/cmd_net.c
@@ -132,6 +132,27 @@ static int io_uring_cmd_timestamp(struct socket *sock,
 	return -EAGAIN;
 }
 
+static int io_uring_cmd_getsockname(struct socket *sock,
+				    struct io_uring_cmd *cmd,
+				    unsigned int issue_flags)
+{
+	const struct io_uring_sqe *sqe = cmd->sqe;
+	struct sockaddr_storage address;
+	struct sockaddr __user *uaddr;
+	unsigned int peer;
+	int __user *ulen;
+
+	if (sqe->ioprio || sqe->__pad1 || sqe->len || sqe->rw_flags)
+		return -EINVAL;
+
+	uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr));
+	ulen = u64_to_user_ptr(sqe->addr3);
+	peer = READ_ONCE(sqe->optlen);
+	if (peer > 1)
+		return -EINVAL;
+	return do_getsockname(sock, &address, 0, uaddr, ulen);
+}
+
 int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)
 {
 	struct socket *sock = cmd->file->private_data;
@@ -159,6 +180,8 @@ int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)
 		return io_uring_cmd_setsockopt(sock, cmd, issue_flags);
 	case SOCKET_URING_OP_TX_TIMESTAMP:
 		return io_uring_cmd_timestamp(sock, cmd, issue_flags);
+	case SOCKET_URING_OP_GETSOCKNAME:
+		return io_uring_cmd_getsockname(sock, cmd, issue_flags);
 	default:
 		return -EOPNOTSUPP;
 	}
-- 
2.51.0

[PATCH v2 0/3] Introduce getsockname io_uring_cmd

[Gabriel Krisman Bertazi]

Since V1:
  - minor style fixes
  - Resend with (more) maintainers cc'ed
  - rebased to axboe/for-next.
--

This feature has been requested a few times in the liburing repository
and Discord channels, such as in [1,2].  If anything, it also helps
solve a long standing issue in the bind-listen test that results in
occasional test failures.

The patchset is divided in three parts: Patch 1 merges the getpeername
and getsockname implementation in the network layer, making further
patches easier; Patch 2 splits out a helper used by io_uring, like done
for other network commands; Finally, patch 3 plumbs the new command in
io_uring.

The syscall path was tested by booting a Linux distro, which does all
sorts of getsockname/getpeername syscalls.  The io_uring side was tested
with a couple of new liburing subtests available at:

   https://github.com/krisman/liburing.git -b socket

Based on top of Jens' for-next.

[1] https://github.com/axboe/liburing/issues/1356
[2] https://discord.com/channels/1241076672589991966/1241076672589991970/1429975797912830074

---
To: Jens Axboe <axboe@kernel.dk>
CC: netdev@vger.kernel.org
CC: io-uring@vger.kernel.org
CC: Jakub Kicinski <kuba@kernel.org>
CC: David S. Miller <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Kuniyuki Iwashima <kuniyu@google.com>
CC: Paolo Abeni <pabeni@redhat.com>
CC: Willem de Bruijn <willemb@google.com>
CC: Simon Horman <horms@kernel.org>
Base: axboe/for-next

Gabriel Krisman Bertazi (3):
  socket: Unify getsockname and getpeername implementation
  socket: Split out a getsockname helper for io_uring
  io_uring: Introduce getsockname io_uring cmd

 include/linux/socket.h        |  6 +--
 include/uapi/linux/io_uring.h |  1 +
 io_uring/cmd_net.c            | 23 ++++++++++++
 net/compat.c                  |  4 +-
 net/socket.c                  | 69 +++++++++++------------------------
 5 files changed, 51 insertions(+), 52 deletions(-)

-- 
2.51.0

[PATCH v2 3/3] io_uring: Introduce getsockname io_uring cmd

[Gabriel Krisman Bertazi]

Introduce a socket-specific io_uring_cmd to support
getsockname/getpeername via io_uring.  I made this an io_uring_cmd
instead of a new operation to avoid polluting the command namespace with
what is exclusively a socket operation.  In addition, since we don't
need to conform to existing interfaces, this merges the
getsockname/getpeername in a single operation, since the implementation
is pretty much the same.

This has been frequently requested, for instance at [1] and more
recently in the project Discord channel. The main use-case is to support
fixed socket file descriptors.

[1] https://github.com/axboe/liburing/issues/1356

Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
---
 include/uapi/linux/io_uring.h |  1 +
 io_uring/cmd_net.c            | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 3d921cbb84f8..6a97c5376019 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -1010,6 +1010,7 @@ enum io_uring_socket_op {
 	SOCKET_URING_OP_GETSOCKOPT,
 	SOCKET_URING_OP_SETSOCKOPT,
 	SOCKET_URING_OP_TX_TIMESTAMP,
+	SOCKET_URING_OP_GETSOCKNAME,
 };
 
 /*
diff --git a/io_uring/cmd_net.c b/io_uring/cmd_net.c
index 27a09aa4c9d0..90f58f883f62 100644
--- a/io_uring/cmd_net.c
+++ b/io_uring/cmd_net.c
@@ -132,6 +132,27 @@ static int io_uring_cmd_timestamp(struct socket *sock,
 	return -EAGAIN;
 }
 
+static int io_uring_cmd_getsockname(struct socket *sock,
+				    struct io_uring_cmd *cmd,
+				    unsigned int issue_flags)
+{
+	const struct io_uring_sqe *sqe = cmd->sqe;
+	struct sockaddr_storage address;
+	struct sockaddr __user *uaddr;
+	unsigned int peer;
+	int __user *ulen;
+
+	if (sqe->ioprio || sqe->__pad1 || sqe->len || sqe->rw_flags)
+		return -EINVAL;
+
+	uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr));
+	ulen = u64_to_user_ptr(sqe->addr3);
+	peer = READ_ONCE(sqe->optlen);
+	if (peer > 1)
+		return -EINVAL;
+	return do_getsockname(sock, &address, 0, uaddr, ulen);
+}
+
 int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)
 {
 	struct socket *sock = cmd->file->private_data;
@@ -159,6 +180,8 @@ int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)
 		return io_uring_cmd_setsockopt(sock, cmd, issue_flags);
 	case SOCKET_URING_OP_TX_TIMESTAMP:
 		return io_uring_cmd_timestamp(sock, cmd, issue_flags);
+	case SOCKET_URING_OP_GETSOCKNAME:
+		return io_uring_cmd_getsockname(sock, cmd, issue_flags);
 	default:
 		return -EOPNOTSUPP;
 	}
-- 
2.51.0