af_unix: introduce unix_skb_to_scm helper

Instead of open-coding let's consolidate this logic in a separate
helper. This will simplify further changes.

Cc: [email protected]
Cc: [email protected]
Cc: David S. Miller <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Paolo Abeni <[email protected]>
Cc: Simon Horman <[email protected]>
Cc: Leon Romanovsky <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Kuniyuki Iwashima <[email protected]>
Cc: Lennart Poettering <[email protected]>
Cc: Luca Boccassi <[email protected]>
Cc: David Rheinsberg <[email protected]>
Signed-off-by: Alexander Mikhalitsyn <[email protected]>
Link: https://lore.kernel.org/[email protected]
Reviewed-by: Kuniyuki Iwashima <[email protected]>
Reviewed-by: Christian Brauner <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

1 files changed, 8 insertions, 4 deletions

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index fba50ceab42b..df2174d9904d 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1955,6 +1955,12 @@ static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool sen
 	return err;
 }
 
+static void unix_skb_to_scm(struct sk_buff *skb, struct scm_cookie *scm)
+{
+	scm_set_cred(scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
+	unix_set_secdata(scm, skb);
+}
+
 /**
  * unix_maybe_add_creds() - Adds current task uid/gid and struct pid to skb if needed.
  * @skb: skb to attach creds to.
@@ -2565,8 +2571,7 @@ int __unix_dgram_recvmsg(struct sock *sk, struct msghdr *msg, size_t size,
 
 	memset(&scm, 0, sizeof(scm));
 
-	scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
-	unix_set_secdata(&scm, skb);
+	unix_skb_to_scm(skb, &scm);
 
 	if (!(flags & MSG_PEEK)) {
 		if (UNIXCB(skb).fp)
@@ -2951,8 +2956,7 @@ unlock:
 				break;
 		} else if (unix_may_passcred(sk)) {
 			/* Copy credentials */
-			scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
-			unix_set_secdata(&scm, skb);
+			unix_skb_to_scm(skb, &scm);
 			check_creds = true;
 		}