[PATCH net-next v4 1/3] sock: Introduce sk_set_prio_allowed helper function

[Anna Emese Nyiri <annaemesenyiri@gmail.com>]

Simplify priority setting permissions with the 'sk_set_prio_allowed'
function, centralizing the validation logic. This change is made in
anticipation of a second caller in a following patch.
No functional changes.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>

Suggested-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Anna Emese Nyiri <annaemesenyiri@gmail.com>
---
 net/core/sock.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/net/core/sock.c b/net/core/sock.c
index 74729d20cd00..9016f984d44e 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -454,6 +454,13 @@ static int sock_set_timeout(long *timeo_p, sockptr_t optval, int optlen,
 	return 0;
 }
 
+static bool sk_set_prio_allowed(const struct sock *sk, int val)
+{
+	return ((val >= TC_PRIO_BESTEFFORT && val <= TC_PRIO_INTERACTIVE) ||
+		sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) ||
+		sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN));
+}
+
 static bool sock_needs_netstamp(const struct sock *sk)
 {
 	switch (sk->sk_family) {
@@ -1193,9 +1200,7 @@ int sk_setsockopt(struct sock *sk, int level, int optname,
 	/* handle options which do not require locking the socket. */
 	switch (optname) {
 	case SO_PRIORITY:
-		if ((val >= 0 && val <= 6) ||
-		    sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) ||
-		    sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
+		if (sk_set_prio_allowed(sk, val)) {
 			sock_set_priority(sk, val);
 			return 0;
 		}
-- 
2.43.0