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).

5 files changed, 89 insertions, 12 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);
diff --git a/utils/nfsd/nfsd.c b/utils/nfsd/nfsd.c
index 05506ee..fa6ee71 100644
--- a/utils/nfsd/nfsd.c
+++ b/utils/nfsd/nfsd.c
@@ -24,10 +24,18 @@
 
 static void	usage(const char *);
 
+static struct option longopts[] =
+{
+	{ "help", 0, 0, 'h' },
+	{ "no-nfs-version", 1, 0, 'N' },
+	{ NULL, 0, 0, 0 }
+};
+unsigned int versbits = NFSCTL_ALLBITS;
+
 int
 main(int argc, char **argv)
 {
-	int	count = 1, c, error, port, fd;
+	int	count = 1, c, error, port, fd, found_one;
 	struct servent *ent;
 
 	ent = getservbyname ("nfs", "udp");
@@ -36,7 +44,7 @@ main(int argc, char **argv)
 	else
 		port = 2049;
 
-	while ((c = getopt(argc, argv, "hp:P:")) != EOF) {
+	while ((c = getopt_long(argc, argv, "hN:p:P:", longopts, NULL)) != EOF) {
 		switch(c) {
 		case 'P':	/* XXX for nfs-server compatibility */
 		case 'p':
@@ -47,12 +55,36 @@ main(int argc, char **argv)
 				usage(argv [0]);
 			}
 			break;
+		case 'N':
+			switch((c = atoi(optarg))) {
+			case 2:
+			case 3:
+			case 4:
+				NFSCTL_VERUNSET(versbits, c);
+				break;
+			default:
+				fprintf(stderr, "%c: Unsupported version\n", c);
+				exit(1);
+			}
 			break;
-		case 'h':
 		default:
+			fprintf(stderr, "Invalid argument: '%c'\n", c);
+		case 'h':
 			usage(argv[0]);
 		}
 	}
+	/*
+	 * Do some sanity checking, if the ctlbits are set
+	 */
+	found_one = 0;
+	for (c = NFSD_MINVERS; c <= NFSD_MAXVERS; c++) {
+		if (NFSCTL_VERISSET(versbits, c))
+			found_one = 1;
+	}
+	if (!found_one) {
+		fprintf(stderr, "no version specified\n");
+		exit(1);
+	}			
 
 	if (chdir(NFS_STATEDIR)) {
 		fprintf(stderr, "%s: chdir(%s) failed: %s\n",
@@ -69,7 +101,6 @@ main(int argc, char **argv)
 			count = 1;
 		}
 	}
-
 	/* KLUDGE ALERT:
 	   Some kernels let nfsd kernel threads inherit open files
 	   from the program that spawns them (i.e. us).  So close
@@ -84,9 +115,9 @@ main(int argc, char **argv)
 	}
 	closeall(3);
 
-	if ((error = nfssvc(port, count)) < 0) {
+	openlog("nfsd", LOG_PID, LOG_DAEMON);
+	if ((error = nfssvc(port, count, versbits)) < 0) {
 		int e = errno;
-		openlog("nfsd", LOG_PID, LOG_DAEMON);
 		syslog(LOG_ERR, "nfssvc: %s", strerror(e));
 		closelog();
 	}
@@ -97,7 +128,8 @@ main(int argc, char **argv)
 static void
 usage(const char *prog)
 {
-	fprintf(stderr, "usage:\n"
-			"%s nrservs\n", prog);
+	fprintf(stderr, "Usage:\n"
+		"%s [-p|-P|--port port] [-N|--no-nfs-version version ] nrservs\n", 
+		prog);
 	exit(2);
 }
diff --git a/utils/nfsd/nfsd.man b/utils/nfsd/nfsd.man
index a890ea6..d175d11 100644
--- a/utils/nfsd/nfsd.man
+++ b/utils/nfsd/nfsd.man
@@ -6,7 +6,7 @@
 .SH NAME
 rpc.nfsd \- NFS server process
 .SH SYNOPSIS
-.BI "/usr/sbin/rpc.nfsd [-p " port "] " nproc
+.BI "/usr/sbin/rpc.nfsd [" options "]" " "nproc
 .SH DESCRIPTION
 The
 .B rpc.nfsd
@@ -22,11 +22,18 @@ server provides an ancillary service needed to satisfy mount requests
 by NFS clients.
 .SH OPTIONS
 .TP
-.BI \-p " port"
+.B \-p " or " \-\-port  port
 specify a diferent port to listen on for NFS requests. By default,
 .B rpc.nfsd
 will listen on port 2049.
 .TP
+.B \-N " or " \-\-no-nfs-version vers
+This option can be used to request that 
+.B rpc.nfsd
+does not offer certain versions of NFS. The current version of
+.B rpc.nfsd
+can support both NFS version 2,3 and the newer version 4.
+.TP
 .I nproc
 specify the number of NFS server threads. By default, just one
 thread is started. However, for optimum performance several threads