[PATCH nfs-utils v2 2/4] nfsdctl: only resolve netlink family names once

[Jeff Layton <jlayton@kernel.org>]

The current code resolves the string name to an id for every netlink
call. Just resolve the family names once and keep them.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 utils/nfsdctl/nfsdctl.c | 83 ++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 64 insertions(+), 19 deletions(-)

diff --git a/utils/nfsdctl/nfsdctl.c b/utils/nfsdctl/nfsdctl.c
index 6b3c98009488d1687e7e751eaed6c4f1d9613d39..86a4a944d4e131f1114ca358d81779de0a034872 100644
--- a/utils/nfsdctl/nfsdctl.c
+++ b/utils/nfsdctl/nfsdctl.c
@@ -46,9 +46,11 @@
 #include "conffile.h"
 #include "xlog.h"
 
-/* compile note:
- * gcc -I/usr/include/libnl3/ -o <prog-name> <prog-name>.c -lnl-3 -lnl-genl-3
- */
+/* The index of the "lockd" netlink family */
+static int lockd_nl_family;
+
+/* The index of the "nfsd" netlink family */
+static int nfsd_nl_family;
 
 struct nfs_version {
 	uint8_t	major;
@@ -433,24 +435,18 @@ static struct nl_sock *netlink_sock_alloc(void)
 	return sock;
 }
 
-static struct nl_msg *netlink_msg_alloc(struct nl_sock *sock, const char *family)
+static struct nl_msg *netlink_msg_alloc(struct nl_sock *sock, int family)
 {
 	struct nl_msg *msg;
 	int id;
 
-	id = genl_ctrl_resolve(sock, family);
-	if (id < 0) {
-		xlog(L_ERROR, "failed to resolve %s generic netlink family", family);
-		return NULL;
-	}
-
 	msg = nlmsg_alloc();
 	if (!msg) {
 		xlog(L_ERROR, "failed to allocate netlink message");
 		return NULL;
 	}
 
-	if (!genlmsg_put(msg, 0, 0, id, 0, 0, 0, 0)) {
+	if (!genlmsg_put(msg, 0, 0, family, 0, 0, 0, 0)) {
 		xlog(L_ERROR, "failed to add generic netlink headers to netlink message");
 		nlmsg_free(msg);
 		return NULL;
@@ -459,6 +455,31 @@ static struct nl_msg *netlink_msg_alloc(struct nl_sock *sock, const char *family
 	return msg;
 }
 
+static int resolve_family(struct nl_sock *sock, const char *name)
+{
+	int family = genl_ctrl_resolve(sock, name);
+
+	if (family < 0) {
+		xlog(L_ERROR, "failed to resolve %s generic netlink family: %d", name, family);
+		family = 0;
+	}
+	return family;
+}
+
+static int lockd_nl_family_setup(struct nl_sock *sock)
+{
+	if (!lockd_nl_family)
+		lockd_nl_family = resolve_family(sock, LOCKD_FAMILY_NAME);
+	return lockd_nl_family;
+}
+
+static int nfsd_nl_family_setup(struct nl_sock *sock)
+{
+	if (!nfsd_nl_family)
+		nfsd_nl_family = resolve_family(sock, NFSD_FAMILY_NAME);
+	return nfsd_nl_family;
+}
+
 static void status_usage(void)
 {
 	printf("Usage: %s status\n", taskname);
@@ -482,7 +503,10 @@ static int status_func(struct nl_sock *sock, int argc, char ** argv)
 		}
 	}
 
-	msg = netlink_msg_alloc(sock, NFSD_FAMILY_NAME);
+	if (!nfsd_nl_family_setup(sock))
+		return 1;
+
+	msg = netlink_msg_alloc(sock, nfsd_nl_family);
 	if (!msg)
 		return 1;
 
@@ -530,7 +554,10 @@ static int threads_doit(struct nl_sock *sock, int cmd, int grace, int lease,
 	struct nl_cb *cb;
 	int ret;
 
-	msg = netlink_msg_alloc(sock, NFSD_FAMILY_NAME);
+	if (!nfsd_nl_family_setup(sock))
+		return 1;
+
+	msg = netlink_msg_alloc(sock, nfsd_nl_family);
 	if (!msg)
 		return 1;
 
@@ -660,7 +687,10 @@ static int fetch_nfsd_versions(struct nl_sock *sock)
 	struct nl_cb *cb;
 	int ret;
 
-	msg = netlink_msg_alloc(sock, NFSD_FAMILY_NAME);
+	if (!nfsd_nl_family_setup(sock))
+		return 1;
+
+	msg = netlink_msg_alloc(sock, nfsd_nl_family);
 	if (!msg)
 		return 1;
 
@@ -725,7 +755,10 @@ static int set_nfsd_versions(struct nl_sock *sock)
 	struct nl_cb *cb;
 	int i, ret;
 
-	msg = netlink_msg_alloc(sock, NFSD_FAMILY_NAME);
+	if (!nfsd_nl_family_setup(sock))
+		return 1;
+
+	msg = netlink_msg_alloc(sock, nfsd_nl_family);
 	if (!msg)
 		return 1;
 
@@ -906,7 +939,10 @@ static int fetch_current_listeners(struct nl_sock *sock)
 	struct nl_cb *cb;
 	int ret;
 
-	msg = netlink_msg_alloc(sock, NFSD_FAMILY_NAME);
+	if (!nfsd_nl_family_setup(sock))
+		return 1;
+
+	msg = netlink_msg_alloc(sock, nfsd_nl_family);
 	if (!msg)
 		return 1;
 
@@ -1151,7 +1187,10 @@ static int set_listeners(struct nl_sock *sock)
 	struct nl_cb *cb;
 	int i, ret;
 
-	msg = netlink_msg_alloc(sock, NFSD_FAMILY_NAME);
+	if (!nfsd_nl_family_setup(sock))
+		return 1;
+
+	msg = netlink_msg_alloc(sock, nfsd_nl_family);
 	if (!msg)
 		return 1;
 
@@ -1272,7 +1311,10 @@ static int pool_mode_doit(struct nl_sock *sock, int cmd, const char *pool_mode)
 	struct nl_cb *cb;
 	int ret;
 
-	msg = netlink_msg_alloc(sock, NFSD_FAMILY_NAME);
+	if (!nfsd_nl_family_setup(sock))
+		return 1;
+
+	msg = netlink_msg_alloc(sock, nfsd_nl_family);
 	if (!msg)
 		return 1;
 
@@ -1365,7 +1407,10 @@ static int lockd_config_doit(struct nl_sock *sock, int cmd, int grace, int tcppo
 			return 0;
 	}
 
-	msg = netlink_msg_alloc(sock, LOCKD_FAMILY_NAME);
+	if (!lockd_nl_family_setup(sock))
+		return 1;
+
+	msg = netlink_msg_alloc(sock, lockd_nl_family);
 	if (!msg)
 		return 1;
 

-- 
2.52.0