NFSD: add a userspace-rpcbind flag to listener_set

Describe the interface that lets a caller take over rpcbind registration.

The request gains a userspace-rpcbind flag. The reply echoes the flag,
lists the programs and versions that the caller should register, and
names the listeners that came up.

NLM is absent. lockd owns its own svc_serv and still registers itself.

Assisted-by: LLM
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260915-nfsd-norpcb-v3-2-3c60d49ade02@kernel.org
Signed-off-by: Chuck Lever <cel@kernel.org>

1 files changed, 20 insertions, 0 deletions

diff --git a/include/uapi/linux/nfsd_netlink.h b/include/uapi/linux/nfsd_netlink.h
index 87da1d0bb21e..c125af0cc6a5 100644
--- a/include/uapi/linux/nfsd_netlink.h
+++ b/include/uapi/linux/nfsd_netlink.h
@@ -50,6 +50,15 @@ enum nfsd_xprtsec_mode {
 	NFSD_XPRTSEC_MODE_MTLS = 4,
 };
 
+/*
+ * Constraints that apply to an rpcbind registration. no-udp means the kernel
+ * would not have registered this program and version over UDP, so the caller
+ * must skip the udp and udp6 netids for it.
+ */
+enum nfsd_rpcbind_flags {
+	NFSD_RPCBIND_FLAGS_NO_UDP = 1,
+};
+
 enum {
 	NFSD_A_CACHE_NOTIFY_CACHE_TYPE = 1,
 
@@ -114,7 +123,18 @@ enum {
 };
 
 enum {
+	NFSD_A_RPCBIND_PROGRAM = 1,
+	NFSD_A_RPCBIND_VERSION,
+	NFSD_A_RPCBIND_FLAGS,
+
+	__NFSD_A_RPCBIND_MAX,
+	NFSD_A_RPCBIND_MAX = (__NFSD_A_RPCBIND_MAX - 1)
+};
+
+enum {
 	NFSD_A_SERVER_SOCK_ADDR = 1,
+	NFSD_A_SERVER_SOCK_USERSPACE_RPCBIND,
+	NFSD_A_SERVER_SOCK_RPCBIND,
 
 	__NFSD_A_SERVER_SOCK_MAX,
 	NFSD_A_SERVER_SOCK_MAX = (__NFSD_A_SERVER_SOCK_MAX - 1)