Add support for suppressing different NFS versions.

e.g.  -N 2
means that NFSv2 won't be supported, just v3 and v4 (if the kernel
supports them).

3 files changed, 40 insertions, 2 deletions

diff --git a/support/include/nfs/nfs.h b/support/include/nfs/nfs.h
index c7fc42c..2cf6857 100644
--- a/support/include/nfs/nfs.h
+++ b/support/include/nfs/nfs.h
@@ -10,6 +10,9 @@
 #define	NFS3_FHSIZE	64
 #define	NFS_FHSIZE	32
 
+#define NFSD_MINVERS 2
+#define NFSD_MAXVERS 4
+
 struct nfs_fh_len {
 	int		fh_size;
 	u_int8_t	fh_handle[NFS3_FHSIZE];
@@ -40,7 +43,11 @@ struct nfs_fh_old {
 #define NFSCTL_LOCKD		0x10000
 #define LOCKDCTL_SVC		NFSCTL_LOCKD
 
+#define NFSCTL_VERUNSET(_cltbits, _v) ((_cltbits) &= ~(1 << ((_v) - 1))) 
+
+#define NFSCTL_VERISSET(_cltbits, _v) ((_cltbits) & (1 << ((_v) - 1))) 
 
+#define NFSCTL_ALLBITS (~0)
 
 /* SVC */
 struct nfsctl_svc {
diff --git a/support/include/nfslib.h b/support/include/nfslib.h
index 8c83262..50892e2 100644
--- a/support/include/nfslib.h
+++ b/support/include/nfslib.h
@@ -120,7 +120,7 @@ int			wildmat(char *text, char *pattern);
  * nfsd library functions.
  */
 int			nfsctl(int, struct nfsctl_arg *, union nfsctl_res *);
-int			nfssvc(int port, int nrservs);
+int			nfssvc(int port, int nrservs, unsigned int versbits);
 int			nfsaddclient(struct nfsctl_client *clp);
 int			nfsdelclient(struct nfsctl_client *clp);
 int			nfsexport(struct nfsctl_export *exp);
diff --git a/support/nfs/nfssvc.c b/support/nfs/nfssvc.c
index 38240a0..c51ace1 100644
--- a/support/nfs/nfssvc.c
+++ b/support/nfs/nfssvc.c
@@ -12,15 +12,46 @@
 
 #include <unistd.h>
 #include <fcntl.h>
+#include <errno.h>
+#include <syslog.h>
 
 #include "nfslib.h"
 
+static void
+nfssvc_versbits(unsigned int ctlbits)
+{
+	int fd, n, off;
+	char buf[BUFSIZ], *ptr;
+
+	ptr = buf;
+	off = 0;
+	fd = open("/proc/fs/nfsd/versions", O_WRONLY);
+	if (fd < 0)
+		return;
+
+	for (n = NFSD_MINVERS; n <= NFSD_MAXVERS; n++) {
+		if (NFSCTL_VERISSET(ctlbits, n))
+		    off += snprintf(ptr+off, BUFSIZ - off, "+%d ", n);
+		else
+		    off += snprintf(ptr+off, BUFSIZ - off, "-%d ", n);
+	}
+	snprintf(ptr+off, BUFSIZ - off, "\n");
+	if (write(fd, buf, strlen(buf)) != strlen(buf)) {
+		syslog(LOG_ERR, "nfssvc: Setting version failed: errno %d (%s)", 
+			errno, strerror(errno));
+	}
+	close(fd);
+
+	return;
+}
 int
-nfssvc(int port, int nrservs)
+nfssvc(int port, int nrservs, unsigned int versbits)
 {
 	struct nfsctl_arg	arg;
 	int fd;
 
+	nfssvc_versbits(versbits);
+
 	fd = open("/proc/fs/nfsd/threads", O_WRONLY);
 	if (fd < 0)
 		fd = open("/proc/fs/nfs/threads", O_WRONLY);