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From:   =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= <marcandre.lureau@redhat.com>
To:     netdev@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org, sgarzare@redhat.com,
        davem@davemloft.net, kuba@kernel.org,
        =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= <marcandre.lureau@redhat.com>
Subject: [PATCH 02/10] sock: move sock_copy_peercred() from af_unix
Date:   Thu, 21 Oct 2021 16:37:06 +0400
Message-Id: <20211021123714.1125384-3-marcandre.lureau@redhat.com>
In-Reply-To: <20211021123714.1125384-1-marcandre.lureau@redhat.com>
References: <20211021123714.1125384-1-marcandre.lureau@redhat.com>
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SO_PEERCRED can be made to work with other kind of sockets.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 include/net/sock.h |  3 +++
 net/core/sock.c    | 25 +++++++++++++++++++++++++
 net/unix/af_unix.c | 26 +-------------------------
 3 files changed, 29 insertions(+), 25 deletions(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index 8b12953752e6..d6877df26200 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1819,6 +1819,9 @@ void sock_init_data(struct socket *sock, struct sock *sk);
 /* Set socket peer PID and credentials with current process. */
 void sock_init_peercred(struct sock *sk);
 
+/* Copy peer credentials from peersk */
+void sock_copy_peercred(struct sock *sk, struct sock *peersk);
+
 /*
  * Socket reference counting postulates.
  *
diff --git a/net/core/sock.c b/net/core/sock.c
index 997e8d256e2f..f6b2662824df 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -3214,6 +3214,31 @@ void sock_init_peercred(struct sock *sk)
 }
 EXPORT_SYMBOL(sock_init_peercred);
 
+void sock_copy_peercred(struct sock *sk, struct sock *peersk)
+{
+	const struct cred *old_cred;
+	struct pid *old_pid;
+
+	if (sk < peersk) {
+		spin_lock(&sk->sk_peer_lock);
+		spin_lock_nested(&peersk->sk_peer_lock, SINGLE_DEPTH_NESTING);
+	} else {
+		spin_lock(&peersk->sk_peer_lock);
+		spin_lock_nested(&sk->sk_peer_lock, SINGLE_DEPTH_NESTING);
+	}
+	old_pid = sk->sk_peer_pid;
+	old_cred = sk->sk_peer_cred;
+	sk->sk_peer_pid  = get_pid(peersk->sk_peer_pid);
+	sk->sk_peer_cred = get_cred(peersk->sk_peer_cred);
+
+	spin_unlock(&sk->sk_peer_lock);
+	spin_unlock(&peersk->sk_peer_lock);
+
+	put_pid(old_pid);
+	put_cred(old_cred);
+}
+EXPORT_SYMBOL(sock_copy_peercred);
+
 void lock_sock_nested(struct sock *sk, int subclass)
 {
 	/* The sk_lock has mutex_lock() semantics here. */
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index e56f320dff20..9109df1efdb6 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -606,30 +606,6 @@ static void unix_release_sock(struct sock *sk, int embrion)
 		unix_gc();		/* Garbage collect fds */
 }
 
-static void copy_peercred(struct sock *sk, struct sock *peersk)
-{
-	const struct cred *old_cred;
-	struct pid *old_pid;
-
-	if (sk < peersk) {
-		spin_lock(&sk->sk_peer_lock);
-		spin_lock_nested(&peersk->sk_peer_lock, SINGLE_DEPTH_NESTING);
-	} else {
-		spin_lock(&peersk->sk_peer_lock);
-		spin_lock_nested(&sk->sk_peer_lock, SINGLE_DEPTH_NESTING);
-	}
-	old_pid = sk->sk_peer_pid;
-	old_cred = sk->sk_peer_cred;
-	sk->sk_peer_pid  = get_pid(peersk->sk_peer_pid);
-	sk->sk_peer_cred = get_cred(peersk->sk_peer_cred);
-
-	spin_unlock(&sk->sk_peer_lock);
-	spin_unlock(&peersk->sk_peer_lock);
-
-	put_pid(old_pid);
-	put_cred(old_cred);
-}
-
 static int unix_listen(struct socket *sock, int backlog)
 {
 	int err;
@@ -1460,7 +1436,7 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 	smp_store_release(&newu->addr, otheru->addr);
 
 	/* Set credentials */
-	copy_peercred(sk, other);
+	sock_copy_peercred(sk, other);
 
 	sock->state	= SS_CONNECTED;
 	sk->sk_state	= TCP_ESTABLISHED;
-- 
2.33.0.721.g106298f7f9