tcp: ulp: diag: always print the name if any

Since its introduction in commit 61723b393292 ("tcp: ulp: add functions
to dump ulp-specific information"), the ULP diag info have been exported
only if the requester had CAP_NET_ADMIN.

At least the ULP name can be exported without CAP_NET_ADMIN. This will
already help identifying which layer is being used, e.g. which TCP
connections are in fact MPTCP subflow.

Acked-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250306-net-next-tcp-ulp-diag-net-admin-v1-1-06afdd860fc9@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c
index f428ecf9120f2f596e1d67db2b2a0d0d0e211905..d8bba37dbffd8c6cc7fab2328a88b6ce6ea3e9f4 100644 (file)
--- a/net/ipv4/tcp_diag.c
+++ b/net/ipv4/tcp_diag.c
@@ -83,7 +83,7 @@ static int tcp_diag_put_md5sig(struct sk_buff *skb,
 #endif
 
 static int tcp_diag_put_ulp(struct sk_buff *skb, struct sock *sk,
-                           const struct tcp_ulp_ops *ulp_ops)
+                           const struct tcp_ulp_ops *ulp_ops, bool net_admin)
 {
        struct nlattr *nest;
        int err;
@@ -96,7 +96,7 @@ static int tcp_diag_put_ulp(struct sk_buff *skb, struct sock *sk,
        if (err)
                goto nla_failure;
 
-       if (ulp_ops->get_info)
+       if (net_admin && ulp_ops->get_info)
                err = ulp_ops->get_info(sk, skb);
        if (err)
                goto nla_failure;
@@ -113,6 +113,7 @@ static int tcp_diag_get_aux(struct sock *sk, bool net_admin,
                            struct sk_buff *skb)
 {
        struct inet_connection_sock *icsk = inet_csk(sk);
+       const struct tcp_ulp_ops *ulp_ops;
        int err = 0;
 
 #ifdef CONFIG_TCP_MD5SIG
@@ -129,15 +130,13 @@ static int tcp_diag_get_aux(struct sock *sk, bool net_admin,
        }
 #endif
 
-       if (net_admin) {
-               const struct tcp_ulp_ops *ulp_ops;
-
-               ulp_ops = icsk->icsk_ulp_ops;
-               if (ulp_ops)
-                       err = tcp_diag_put_ulp(skb, sk, ulp_ops);
-               if (err)
+       ulp_ops = icsk->icsk_ulp_ops;
+       if (ulp_ops) {
+               err = tcp_diag_put_ulp(skb, sk, ulp_ops, net_admin);
+               if (err < 0)
                        return err;
        }
+
        return 0;
 }
 
@@ -164,14 +163,14 @@ static size_t tcp_diag_get_aux_size(struct sock *sk, bool net_admin)
        }
 #endif
 
-       if (net_admin && sk_fullsock(sk)) {
+       if (sk_fullsock(sk)) {
                const struct tcp_ulp_ops *ulp_ops;
 
                ulp_ops = icsk->icsk_ulp_ops;
                if (ulp_ops) {
                        size += nla_total_size(0) +
                                nla_total_size(TCP_ULP_NAME_MAX);
-                       if (ulp_ops->get_info_size)
+                       if (net_admin && ulp_ops->get_info_size)
                                size += ulp_ops->get_info_size(sk);
                }
        }