Add support for root on nfs using v3. Code adapted from NetBSD.

Tested on sparc by miod, octeon by aalm and armv7 by me.
miod ok.

3 files changed, 88 insertions, 52 deletions

diff --git a/sys/nfs/nfs_boot.c b/sys/nfs/nfs_boot.c
index 8f89fad49ec..3b1d26d9600 100644
--- a/sys/nfs/nfs_boot.c
+++ b/sys/nfs/nfs_boot.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nfs_boot.c,v 1.28 2013/09/12 13:12:33 deraadt Exp $ */
+/*	$OpenBSD: nfs_boot.c,v 1.29 2013/09/20 23:51:44 fgsch Exp $ */
 /*	$NetBSD: nfs_boot.c,v 1.26 1996/05/07 02:51:25 thorpej Exp $	*/
 
 /*
@@ -104,7 +104,7 @@ static int bp_getfile(struct sockaddr_in *bpsin, char *key,
 
 /* mountd RPC */
 static int md_mount(struct sockaddr_in *mdsin, char *path,
-	u_char *fh);
+	struct nfs_args *argp);
 
 char	*nfsbootdevname;
 
@@ -268,11 +268,36 @@ int
 nfs_boot_getfh(struct sockaddr_in *bpsin, char *key,
     struct nfs_dlmount *ndmntp, int retries)
 {
+	struct nfs_args *args;
 	char pathname[MAXPATHLEN];
 	char *sp, *dp, *endp;
 	struct sockaddr_in *sin;
 	int error;
 
+	args = &ndmntp->ndm_args;
+
+	/* Initialize mount args. */
+	bzero((caddr_t) args, sizeof(*args));
+	args->addr     = (struct sockaddr *)&ndmntp->ndm_saddr;
+	args->addrlen  = args->addr->sa_len;
+	args->sotype   = SOCK_DGRAM;
+	args->fh       = ndmntp->ndm_fh;
+	args->hostname = ndmntp->ndm_host;
+	args->flags    = NFSMNT_NFSV3;
+#ifdef	NFS_BOOT_OPTIONS
+	args->flags    |= NFS_BOOT_OPTIONS;
+#endif
+#ifdef	NFS_BOOT_RWSIZE
+	/*
+	 * Reduce rsize,wsize for interfaces that consistently
+	 * drop fragments of long UDP messages.	 (i.e. wd8003).
+	 * You can always change these later via remount.
+	 */
+	args->flags   |= NFSMNT_WSIZE | NFSMNT_RSIZE;
+	args->wsize    = NFS_BOOT_RWSIZE;
+	args->rsize    = NFS_BOOT_RWSIZE;
+#endif
+
 	sin = &ndmntp->ndm_saddr;
 
 	/*
@@ -290,7 +315,7 @@ nfs_boot_getfh(struct sockaddr_in *bpsin, char *key,
 	 * Get file handle for "key" (root or swap)
 	 * using RPC to mountd/mount
 	 */
-	error = md_mount(sin, pathname, ndmntp->ndm_fh);
+	error = md_mount(sin, pathname, args);
 	if (error) {
 		printf("nfs_boot: mountd %s, error=%d\n", key, error);
 		return (error);
@@ -298,9 +323,11 @@ nfs_boot_getfh(struct sockaddr_in *bpsin, char *key,
 
 	/* Set port number for NFS use. */
 	/* XXX: NFS port is always 2049, right? */
-	error = krpc_portmap(sin, NFS_PROG, NFS_VER2, &sin->sin_port);
+	error = krpc_portmap(sin, NFS_PROG,
+	    (args->flags & NFSMNT_NFSV3) ? NFS_VER3 : NFS_VER2,
+	    &sin->sin_port);
 	if (error) {
-		printf("nfs_boot: portmap NFS/v2, error=%d\n", error);
+		printf("nfs_boot: portmap NFS, error=%d\n", error);
 		return (error);
 	}
 
@@ -515,31 +542,49 @@ out:
  * mdsin:	mountd server address
  */
 static int
-md_mount(struct sockaddr_in *mdsin, char *path, u_char *fhp)
+md_mount(struct sockaddr_in *mdsin, char *path, struct nfs_args *argp)
 {
 	/* The RPC structures */
 	struct rdata {
 		u_int32_t errno;
-		u_int8_t  fh[NFSX_V2FH];
+		union {
+			u_int8_t v2fh[NFSX_V2FH];
+			struct {
+				u_int32_t fhlen;
+				u_int8_t fh[1];
+			} v3fh;
+		} fh;
 	} *rdata;
 	struct mbuf *m;
-	int error;
+	u_int8_t *fh;
+	int minlen, error;
+	int mntver;
+
+	mntver = (argp->flags & NFSMNT_NFSV3) ? 3 : 2;
+	do {
+		error = krpc_portmap(mdsin, RPCPROG_MNT, mntver,
+		    &mdsin->sin_port);
+		if (error)
+			continue;
 
-	/* Get port number for MOUNTD. */
-	error = krpc_portmap(mdsin, RPCPROG_MNT, RPCMNT_VER1,
-						 &mdsin->sin_port);
-	if (error) return error;
+		m = xdr_string_encode(path, strlen(path));
+		if (m == NULL)
+			return ENOMEM;
 
-	m = xdr_string_encode(path, strlen(path));
-	if (m == NULL)
-		return ENOMEM;
+		/* Do RPC to mountd. */
+		error = krpc_call(mdsin, RPCPROG_MNT, mntver,
+		    RPCMNT_MOUNT, &m, NULL, -1);
 
-	/* Do RPC to mountd. */
-	error = krpc_call(mdsin, RPCPROG_MNT, RPCMNT_VER1,
-			RPCMNT_MOUNT, &m, NULL, -1);
+		if (error != EPROGMISMATCH)
+			break;
+		/* Try lower version of mountd. */
+	} while (--mntver >= 1);
 	if (error)
 		return error;	/* message already freed */
 
+	if (mntver != 3)
+		argp->flags &= ~NFSMNT_NFSV3;
+
 	/* The reply might have only the errno. */
 	if (m->m_len < 4)
 		goto bad;
@@ -550,13 +595,26 @@ md_mount(struct sockaddr_in *mdsin, char *path, u_char *fhp)
 		goto out;
 
 	 /* Have errno==0, so the fh must be there. */
-	if (m->m_len < sizeof(*rdata)) {
-		m = m_pullup(m, sizeof(*rdata));
-		if (m == NULL)
+	if (mntver == 3) {
+		argp->fhsize = fxdr_unsigned(u_int32_t, rdata->fh.v3fh.fhlen);
+		if (argp->fhsize > NFSX_V3FHMAX)
 			goto bad;
+		minlen = 2 * sizeof(u_int32_t) + argp->fhsize;
+	} else {
+		argp->fhsize = NFSX_V2FH;
+		minlen = sizeof(u_int32_t) + argp->fhsize;
+	}
+
+	if (m->m_len < minlen) {
+		m = m_pullup(m, minlen);
+		if (m == NULL)
+			return (EBADRPC);
 		rdata = mtod(m, struct rdata *);
 	}
-	bcopy(rdata->fh, fhp, NFSX_V2FH);
+
+	fh = (mntver == 3) ? rdata->fh.v3fh.fh : rdata->fh.v2fh;
+	bcopy(fh, argp->fh, argp->fhsize);
+
 	goto out;
 
 bad:
diff --git a/sys/nfs/nfs_vfsops.c b/sys/nfs/nfs_vfsops.c
index d6a7cbb830b..fcf86b1569e 100644
--- a/sys/nfs/nfs_vfsops.c
+++ b/sys/nfs/nfs_vfsops.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nfs_vfsops.c,v 1.97 2013/04/17 16:22:24 florian Exp $	*/
+/*	$OpenBSD: nfs_vfsops.c,v 1.98 2013/09/20 23:51:44 fgsch Exp $	*/
 /*	$NetBSD: nfs_vfsops.c,v 1.46.4.1 1996/05/25 22:40:35 fvdl Exp $	*/
 
 /*
@@ -365,7 +365,6 @@ nfs_mountroot(void)
 struct mount *
 nfs_mount_diskless(struct nfs_dlmount *ndmntp, char *mntname, int mntflag)
 {
-	struct nfs_args args;
 	struct mount *mp;
 	struct mbuf *m;
 	int error;
@@ -374,35 +373,13 @@ nfs_mount_diskless(struct nfs_dlmount *ndmntp, char *mntname, int mntflag)
 		panic("nfs_mount_diskless: vfs_rootmountalloc failed");
 	mp->mnt_flag |= mntflag;
 
-	/* Initialize mount args. */
-	bzero((caddr_t) &args, sizeof(args));
-	args.addr     = (struct sockaddr *)&ndmntp->ndm_saddr;
-	args.addrlen  = args.addr->sa_len;
-	args.sotype   = SOCK_DGRAM;
-	args.fh	      = ndmntp->ndm_fh;
-	args.fhsize   = NFSX_V2FH;
-	args.hostname = ndmntp->ndm_host;
-
-#ifdef	NFS_BOOT_OPTIONS
-	args.flags    |= NFS_BOOT_OPTIONS;
-#endif
-#ifdef	NFS_BOOT_RWSIZE
-	/*
-	 * Reduce rsize,wsize for interfaces that consistently
-	 * drop fragments of long UDP messages.	 (i.e. wd8003).
-	 * You can always change these later via remount.
-	 */
-	args.flags   |= NFSMNT_WSIZE | NFSMNT_RSIZE;
-	args.wsize    = NFS_BOOT_RWSIZE;
-	args.rsize    = NFS_BOOT_RWSIZE;
-#endif
-
 	/* Get mbuf for server sockaddr. */
 	m = m_get(M_WAIT, MT_SONAME);
-	bcopy((caddr_t)args.addr, mtod(m, caddr_t),
-	    (m->m_len = args.addr->sa_len));
+	bcopy((caddr_t)ndmntp->ndm_args.addr, mtod(m, caddr_t),
+	    (m->m_len = ndmntp->ndm_args.addr->sa_len));
 
-	error = mountnfs(&args, mp, m, mntname, args.hostname);
+	error = mountnfs(&ndmntp->ndm_args, mp, m, mntname,
+	    ndmntp->ndm_args.hostname);
 	if (error)
 		panic("nfs_mountroot: mount %s failed: %d", mntname, error);
 
diff --git a/sys/nfs/nfsdiskless.h b/sys/nfs/nfsdiskless.h
index 762ec2c6717..f379f26aa6e 100644
--- a/sys/nfs/nfsdiskless.h
+++ b/sys/nfs/nfsdiskless.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nfsdiskless.h,v 1.9 2013/04/17 16:22:24 florian Exp $	*/
+/*	$OpenBSD: nfsdiskless.h,v 1.10 2013/09/20 23:51:44 fgsch Exp $	*/
 /*	$NetBSD: nfsdiskless.h,v 1.9 1996/02/18 11:54:00 fvdl Exp $	*/
 
 /*
@@ -50,9 +50,10 @@
  * client/server byte ordering differences.
  */
 struct nfs_dlmount {
+	struct nfs_args ndm_args;
 	struct sockaddr_in ndm_saddr;  		/* Address of file server */
 	char		ndm_host[MNAMELEN]; 	/* Host name for mount pt */
-	u_char		ndm_fh[NFSX_V2FH]; 	/* The file's file handle */
+	u_char		ndm_fh[NFSX_V3FHMAX]; 	/* The file's file handle */
 };
 struct nfs_diskless {
 	struct sockaddr_in nd_boot;	/* Address of boot server */