[nfs] Add support for NFS protocol

Tested-by: Robin Smidsrød <robin@smidsrod.no>
Signed-off-by: Marin Hannache <git@mareo.fr>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/net/oncrpc/mount.c

@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2013 Marin Hannache <ipxe@mareo.fr>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <libgen.h>
+#include <byteswap.h>
+#include <ipxe/time.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/open.h>
+#include <ipxe/features.h>
+#include <ipxe/oncrpc.h>
+#include <ipxe/oncrpc_iob.h>
+#include <ipxe/nfs.h>
+#include <ipxe/mount.h>
+
+/** @file
+ *
+ * NFS MOUNT protocol
+ *
+ */
+
+/** MNT procedure number */
+#define MOUNT_MNT       1
+/** UMNT procedure number */
+#define MOUNT_UMNT      3
+
+/**
+ * Send a MNT request
+ *
+ * @v intf              Interface to send the request on
+ * @v session           ONC RPC session
+ * @v mountpoinrt       The path of the directory to mount.
+ * @ret rc              Return status code
+ */
+int mount_mnt ( struct interface *intf, struct oncrpc_session *session,
+                const char *mountpoint ) {
+	struct oncrpc_field fields[] = {
+		ONCRPC_FIELD ( str, mountpoint ),
+		ONCRPC_FIELD_END,
+	};
+
+	return oncrpc_call ( intf, session, MOUNT_MNT, fields );
+}
+
+/**
+ * Send a UMNT request
+ *
+ * @v intf              Interface to send the request on
+ * @v session           ONC RPC session
+ * @v mountpoinrt       The path of the directory to unmount.
+ * @ret rc              Return status code
+ */
+int mount_umnt ( struct interface *intf, struct oncrpc_session *session,
+                 const char *mountpoint ) {
+	struct oncrpc_field fields[] = {
+		ONCRPC_FIELD ( str, mountpoint ),
+		ONCRPC_FIELD_END,
+	};
+
+	return oncrpc_call ( intf, session, MOUNT_UMNT, fields );
+}
+
+/**
+ * Parse an MNT reply
+ *
+ * @v mnt_reply         A structure where the data will be saved
+ * @v reply             The ONC RPC reply to get data from
+ * @ret rc              Return status code
+ */
+int mount_get_mnt_reply ( struct mount_mnt_reply *mnt_reply,
+                          struct oncrpc_reply *reply ) {
+	if (  ! mnt_reply || ! reply )
+		return -EINVAL;
+
+	mnt_reply->status = oncrpc_iob_get_int ( reply->data );
+
+	switch ( mnt_reply->status )
+	{
+	case MNT3_OK:
+		break;
+	case MNT3ERR_NOENT:
+		return -ENOENT;
+	case MNT3ERR_IO:
+		return -EIO;
+	case MNT3ERR_ACCES:
+		return -EACCES;
+	case MNT3ERR_NOTDIR:
+		return -ENOTDIR;
+	case MNT3ERR_NAMETOOLONG:
+		return -ENAMETOOLONG;
+	default:
+		return -EPROTO;
+	}
+
+	nfs_iob_get_fh ( reply->data, &mnt_reply->fh );
+
+	return 0;
+}

src/net/oncrpc/nfs.c

@@ -0,0 +1,288 @@
+/*
+ * Copyright (C) 2013 Marin Hannache <ipxe@mareo.fr>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <libgen.h>
+#include <byteswap.h>
+#include <ipxe/time.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/open.h>
+#include <ipxe/features.h>
+#include <ipxe/nfs.h>
+#include <ipxe/oncrpc.h>
+#include <ipxe/oncrpc_iob.h>
+#include <ipxe/portmap.h>
+#include <ipxe/mount.h>
+#include <ipxe/settings.h>
+
+/** @file
+ *
+ * Network File System protocol
+ *
+ */
+
+/** NFS LOOKUP procedure */
+#define NFS_LOOKUP      3
+/** NFS READLINK procedure */
+#define NFS_READLINK    5
+/** NFS READ procedure */
+#define NFS_READ        6
+
+/**
+ * Extract a file handle from the beginning of an I/O buffer
+ *
+ * @v io_buf            I/O buffer
+ * @v fh                File handle
+ * @ret size            Size of the data read
+ */
+size_t nfs_iob_get_fh ( struct io_buffer *io_buf, struct nfs_fh *fh ) {
+	fh->size = oncrpc_iob_get_int ( io_buf );
+
+	if ( fh->size > 64 )
+		return sizeof ( uint32_t );
+
+	memcpy (fh->fh, io_buf->data, fh->size );
+	iob_pull ( io_buf, fh->size );
+
+	return fh->size + sizeof ( uint32_t );
+}
+
+/**
+ * Add a file handle to the end of an I/O buffer
+ *
+ * @v io_buf            I/O buffer
+ * @v fh                File handle
+ * @ret size            Size of the data written
+ */
+size_t nfs_iob_add_fh ( struct io_buffer *io_buf, const struct nfs_fh *fh ) {
+	size_t s;
+
+	s = oncrpc_iob_add_int ( io_buf, fh->size );
+	memcpy ( iob_put ( io_buf, fh->size ), &fh->fh, fh->size );
+
+	return s + fh->size;
+}
+
+/**
+ * Send a LOOKUP request
+ *
+ * @v intf              Interface to send the request on
+ * @v session           ONC RPC session
+ * @v fh                The file handle of the the directory
+ * @v filename          The file name
+ * @ret rc              Return status code
+ */
+int nfs_lookup ( struct interface *intf, struct oncrpc_session *session,
+                 const struct nfs_fh *fh, const char *filename ) {
+	struct oncrpc_field fields[] = {
+		ONCRPC_SUBFIELD ( array, fh->size, &fh->fh ),
+		ONCRPC_FIELD ( str, filename ),
+		ONCRPC_FIELD_END,
+	};
+
+	return oncrpc_call ( intf, session, NFS_LOOKUP, fields );
+}
+
+/**
+ * Send a READLINK request
+ *
+ * @v intf              Interface to send the request on
+ * @v session           ONC RPC session
+ * @v fh                The symlink file handle
+ * @ret rc              Return status code
+ */
+int nfs_readlink ( struct interface *intf, struct oncrpc_session *session,
+                   const struct nfs_fh *fh ) {
+	struct oncrpc_field fields[] = {
+		ONCRPC_SUBFIELD ( array, fh->size, &fh->fh ),
+		ONCRPC_FIELD_END,
+	};
+
+	return oncrpc_call ( intf, session, NFS_READLINK, fields );
+}
+
+/**
+ * Send a READ request
+ *
+ * @v intf              Interface to send the request on
+ * @v session           ONC RPC session
+ * @v fh                The file handle
+ * @v offset            Offset
+ * @v count             Byte count
+ * @ret rc              Return status code
+ */
+int nfs_read ( struct interface *intf, struct oncrpc_session *session,
+               const struct nfs_fh *fh, uint64_t offset, uint32_t count ) {
+	struct oncrpc_field fields[] = {
+		ONCRPC_SUBFIELD ( array, fh->size, &fh->fh ),
+		ONCRPC_FIELD ( int64, offset ),
+		ONCRPC_FIELD ( int32, count ),
+		ONCRPC_FIELD_END,
+	};
+
+	return oncrpc_call ( intf, session, NFS_READ, fields );
+}
+
+/**
+ * Parse a LOOKUP reply
+ *
+ * @v lookup_reply      A structure where the data will be saved
+ * @v reply             The ONC RPC reply to get data from
+ * @ret rc              Return status code
+ */
+int nfs_get_lookup_reply ( struct nfs_lookup_reply *lookup_reply,
+                           struct oncrpc_reply *reply ) {
+	if ( ! lookup_reply || ! reply )
+		return -EINVAL;
+
+	lookup_reply->status = oncrpc_iob_get_int ( reply->data );
+	switch ( lookup_reply->status )
+	{
+	case NFS3_OK:
+		break;
+	case NFS3ERR_PERM:
+		return -EPERM;
+	case NFS3ERR_NOENT:
+		return -ENOENT;
+	case NFS3ERR_IO:
+		return -EIO;
+	case NFS3ERR_ACCES:
+		return -EACCES;
+	case NFS3ERR_NOTDIR:
+		return -ENOTDIR;
+	case NFS3ERR_NAMETOOLONG:
+		return -ENAMETOOLONG;
+	case NFS3ERR_STALE:
+		return -ESTALE;
+	case NFS3ERR_BADHANDLE:
+	case NFS3ERR_SERVERFAULT:
+	default:
+		return -EPROTO;
+	}
+
+	nfs_iob_get_fh ( reply->data, &lookup_reply->fh );
+
+	if ( oncrpc_iob_get_int ( reply->data ) == 1 )
+		lookup_reply->ent_type = oncrpc_iob_get_int ( reply->data );
+
+	return 0;
+}
+/**
+ * Parse a READLINK reply
+ *
+ * @v readlink_reply    A structure where the data will be saved
+ * @v reply             The ONC RPC reply to get data from
+ * @ret rc              Return status code
+ */
+int nfs_get_readlink_reply ( struct nfs_readlink_reply *readlink_reply,
+                             struct oncrpc_reply *reply ) {
+	if ( ! readlink_reply || ! reply )
+		return -EINVAL;
+
+	readlink_reply->status = oncrpc_iob_get_int ( reply->data );
+	switch ( readlink_reply->status )
+	{
+	case NFS3_OK:
+		 break;
+	case NFS3ERR_IO:
+		return -EIO;
+	case NFS3ERR_ACCES:
+		return -EACCES;
+	case NFS3ERR_INVAL:
+		return -EINVAL;
+	case NFS3ERR_NOTSUPP:
+		return -ENOTSUP;
+	case NFS3ERR_STALE:
+		return -ESTALE;
+	case NFS3ERR_BADHANDLE:
+	case NFS3ERR_SERVERFAULT:
+	default:
+		return -EPROTO;
+	}
+
+	if ( oncrpc_iob_get_int ( reply->data ) == 1 )
+		iob_pull ( reply->data, 5 * sizeof ( uint32_t ) +
+		                        8 * sizeof ( uint64_t ) );
+
+	readlink_reply->path_len = oncrpc_iob_get_int ( reply->data );
+	readlink_reply->path     = reply->data->data;
+
+	return 0;
+}
+
+/**
+ * Parse a READ reply
+ *
+ * @v read_reply        A structure where the data will be saved
+ * @v reply             The ONC RPC reply to get data from
+ * @ret rc              Return status code
+ */
+int nfs_get_read_reply ( struct nfs_read_reply *read_reply,
+                         struct oncrpc_reply *reply ) {
+	if ( ! read_reply || ! reply )
+		return -EINVAL;
+
+	read_reply->status = oncrpc_iob_get_int ( reply->data );
+	switch ( read_reply->status )
+	{
+	case NFS3_OK:
+		 break;
+	case NFS3ERR_PERM:
+		return -EPERM;
+	case NFS3ERR_NOENT:
+		return -ENOENT;
+	case NFS3ERR_IO:
+		return -EIO;
+	case NFS3ERR_NXIO:
+		return -ENXIO;
+	case NFS3ERR_ACCES:
+		return -EACCES;
+	case NFS3ERR_INVAL:
+		return -EINVAL;
+	case NFS3ERR_STALE:
+		return -ESTALE;
+	case NFS3ERR_BADHANDLE:
+	case NFS3ERR_SERVERFAULT:
+	default:
+		return -EPROTO;
+	}
+
+	if ( oncrpc_iob_get_int ( reply->data ) == 1 )
+	{
+		iob_pull ( reply->data, 5 * sizeof ( uint32_t ) );
+		read_reply->filesize = oncrpc_iob_get_int64 ( reply->data );
+		iob_pull ( reply->data, 7 * sizeof ( uint64_t ) );
+	}
+
+	read_reply->count    = oncrpc_iob_get_int ( reply->data );
+	read_reply->eof      = oncrpc_iob_get_int ( reply->data );
+	read_reply->data_len = oncrpc_iob_get_int ( reply->data );
+	read_reply->data     = reply->data->data;
+
+	if ( read_reply->count != read_reply->data_len )
+		return -EPROTO;
+
+	return 0;
+}
+

src/net/oncrpc/nfs_open.c

@@ -0,0 +1,711 @@
+/*
+ * Copyright (C) 2013 Marin Hannache <ipxe@mareo.fr>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <libgen.h>
+#include <byteswap.h>
+#include <ipxe/time.h>
+#include <ipxe/socket.h>
+#include <ipxe/tcpip.h>
+#include <ipxe/in.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/xfer.h>
+#include <ipxe/open.h>
+#include <ipxe/uri.h>
+#include <ipxe/features.h>
+#include <ipxe/nfs.h>
+#include <ipxe/nfs_open.h>
+#include <ipxe/oncrpc.h>
+#include <ipxe/oncrpc_iob.h>
+#include <ipxe/portmap.h>
+#include <ipxe/mount.h>
+
+/** @file
+ *
+ * Network File System protocol
+ *
+ */
+
+FEATURE ( FEATURE_PROTOCOL, "NFS", DHCP_EB_FEATURE_NFS, 1 );
+
+#define NFS_RSIZE 100000
+
+enum nfs_pm_state {
+	NFS_PORTMAP_NONE = 0,
+	NFS_PORTMAP_MOUNTPORT,
+	NFS_PORTMAP_NFSPORT,
+	MFS_PORTMAP_CLOSED,
+};
+
+enum nfs_mount_state {
+	NFS_MOUNT_NONE = 0,
+	NFS_MOUNT_MNT,
+	NFS_MOUNT_UMNT,
+	NFS_MOUNT_CLOSED,
+};
+
+enum nfs_state {
+	NFS_NONE = 0,
+	NFS_LOOKUP,
+	NFS_LOOKUP_SENT,
+	NFS_READLINK,
+	NFS_READLINK_SENT,
+	NFS_READ,
+	NFS_READ_SENT,
+	NFS_CLOSED,
+};
+
+/**
+ * A NFS request
+ *
+ */
+struct nfs_request {
+	/** Reference counter */
+	struct refcnt           refcnt;
+	/** Data transfer interface */
+	struct interface        xfer;
+
+	struct interface        pm_intf;
+	struct interface        mount_intf;
+	struct interface        nfs_intf;
+
+	enum nfs_pm_state       pm_state;
+	enum nfs_mount_state    mount_state;
+	enum nfs_state          nfs_state;
+
+	struct oncrpc_session   pm_session;
+	struct oncrpc_session   mount_session;
+	struct oncrpc_session   nfs_session;
+
+	struct oncrpc_cred_sys  auth_sys;
+
+	char *                  hostname;
+	char *                  path;
+	char *                  mountpoint;
+	char *                  filename;
+	size_t                  filename_offset;
+
+	struct nfs_fh           readlink_fh;
+	struct nfs_fh           current_fh;
+	uint64_t                file_offset;
+
+	size_t                  remaining;
+	int                     eof;
+};
+
+static void nfs_step ( struct nfs_request *nfs );
+
+/**
+ * Free NFS request
+ *
+ * @v refcnt		Reference counter
+ */
+static void nfs_free ( struct refcnt *refcnt ) {
+	struct nfs_request      *nfs;
+
+	nfs = container_of ( refcnt, struct nfs_request, refcnt );
+	DBGC ( nfs, "NFS_OPEN %p freed\n", nfs );
+
+	free ( nfs->hostname );
+	free ( nfs->path );
+	free ( nfs->auth_sys.hostname );
+	free ( nfs );
+}
+
+/**
+ * Mark NFS operation as complete
+ *
+ * @v nfs		NFS request
+ * @v rc		Return status code
+ */
+static void nfs_done ( struct nfs_request *nfs, int rc ) {
+	if ( rc == 0 && nfs->nfs_state != NFS_CLOSED )
+		rc = -ECONNRESET;
+
+	DBGC ( nfs, "NFS_OPEN %p completed (%s)\n", nfs, strerror ( rc ) );
+
+	intf_shutdown ( &nfs->xfer, rc );
+	intf_shutdown ( &nfs->pm_intf, rc );
+	intf_shutdown ( &nfs->mount_intf, rc );
+	intf_shutdown ( &nfs->nfs_intf, rc );
+}
+
+static int nfs_connect ( struct interface *intf, uint16_t port,
+                         const char *hostname ) {
+	struct sockaddr_tcpip   peer;
+	struct sockaddr_tcpip   local;
+
+	if ( ! intf || ! hostname || ! port )
+		return -EINVAL;
+
+	memset ( &peer, 0, sizeof ( peer ) );
+	memset ( &peer, 0, sizeof ( local ) );
+	peer.st_port = htons ( port );
+
+	/* Use a local port < 1024 to avoid using the 'insecure' option in
+	 * /etc/exports file. */
+	local.st_port = htons ( 1 + ( rand() % 1023 ) );
+
+	return xfer_open_named_socket ( intf, SOCK_STREAM,
+	                                ( struct sockaddr * ) &peer, hostname,
+                                        ( struct sockaddr * ) &local );
+}
+
+static void nfs_pm_step ( struct nfs_request *nfs ) {
+	int     rc;
+
+	if ( ! xfer_window ( &nfs->pm_intf ) )
+		return;
+
+	if ( nfs->pm_state == NFS_PORTMAP_NONE ) {
+		DBGC ( nfs, "NFS_OPEN %p GETPORT call (mount)\n", nfs );
+
+		rc = portmap_getport ( &nfs->pm_intf, &nfs->pm_session,
+		                       ONCRPC_MOUNT, MOUNT_VERS,
+		                       PORTMAP_PROTO_TCP );
+		if ( rc != 0 )
+			goto err;
+
+		nfs->pm_state++;
+		return;
+	}
+
+	if ( nfs->pm_state == NFS_PORTMAP_NFSPORT ) {
+		DBGC ( nfs, "NFS_OPEN %p GETPORT call (nfs)\n", nfs );
+
+		rc = portmap_getport ( &nfs->pm_intf, &nfs->pm_session,
+		                       ONCRPC_NFS, NFS_VERS,
+		                       PORTMAP_PROTO_TCP );
+		if ( rc != 0 )
+			goto err;
+
+		return;
+	}
+
+	return;
+err:
+	nfs_done ( nfs, rc );
+}
+
+static int nfs_pm_deliver ( struct nfs_request *nfs,
+                            struct io_buffer *io_buf,
+                            struct xfer_metadata *meta __unused ) {
+	int                             rc;
+	struct oncrpc_reply             reply;
+	struct portmap_getport_reply    getport_reply;
+
+	oncrpc_get_reply ( &nfs->pm_session, &reply, io_buf );
+	if ( reply.accept_state != 0 )
+	{
+		rc = -EPROTO;
+		goto err;
+	}
+
+	if ( nfs->pm_state == NFS_PORTMAP_MOUNTPORT ) {
+		DBGC ( nfs, "NFS_OPEN %p got GETPORT reply (mount)\n", nfs );
+
+		rc = portmap_get_getport_reply ( &getport_reply, &reply );
+		if ( rc != 0 )
+			goto err;
+
+		rc = nfs_connect ( &nfs->mount_intf, getport_reply.port,
+	                           nfs->hostname );
+		if ( rc != 0 )
+			goto err;
+
+		nfs->pm_state++;
+		nfs_pm_step ( nfs );
+
+		goto done;
+	}
+
+	if ( nfs->pm_state == NFS_PORTMAP_NFSPORT ) {
+		DBGC ( nfs, "NFS_OPEN %p got GETPORT reply (nfs)\n", nfs );
+
+		rc = portmap_get_getport_reply ( &getport_reply, &reply );
+		if ( rc != 0 )
+			goto err;
+
+		rc = nfs_connect ( &nfs->nfs_intf, getport_reply.port,
+	                           nfs->hostname );
+		if ( rc != 0 )
+			goto err;
+
+		intf_shutdown ( &nfs->pm_intf, 0 );
+		nfs->pm_state++;
+
+		goto done;
+	}
+
+	rc = -EPROTO;
+err:
+	nfs_done ( nfs, rc );
+done:
+	free_iob ( io_buf );
+	return 0;
+}
+
+static void nfs_mount_step ( struct nfs_request *nfs ) {
+	int     rc;
+
+	if ( ! xfer_window ( &nfs->mount_intf ) )
+		return;
+
+	if ( nfs->mount_state == NFS_MOUNT_NONE ) {
+		DBGC ( nfs, "NFS_OPEN %p MNT call (%s)\n", nfs,
+		       nfs->mountpoint );
+
+		rc = mount_mnt ( &nfs->mount_intf, &nfs->mount_session,
+		                 nfs->mountpoint );
+		if ( rc != 0 )
+			goto err;
+
+		nfs->mount_state++;
+		return;
+	}
+
+	if ( nfs->mount_state == NFS_MOUNT_UMNT ) {
+		DBGC ( nfs, "NFS_OPEN %p UMNT call\n", nfs );
+
+		rc = mount_umnt ( &nfs->mount_intf, &nfs->mount_session,
+		                  nfs->mountpoint );
+		if ( rc != 0 )
+			goto err;
+	}
+
+	return;
+err:
+	nfs_done ( nfs, rc );
+}
+
+static int nfs_mount_deliver ( struct nfs_request *nfs,
+                               struct io_buffer *io_buf,
+                               struct xfer_metadata *meta __unused ) {
+	int                     rc;
+	char                    *sep;
+	struct oncrpc_reply     reply;
+	struct mount_mnt_reply  mnt_reply;
+
+	oncrpc_get_reply ( &nfs->mount_session, &reply, io_buf );
+	if ( reply.accept_state != 0 )
+	{
+		rc = -EPROTO;
+		goto err;
+	}
+
+	if ( nfs->mount_state == NFS_MOUNT_MNT ) {
+		DBGC ( nfs, "NFS_OPEN %p got MNT reply\n", nfs );
+		rc = mount_get_mnt_reply ( &mnt_reply, &reply );
+		if ( rc != 0 ) {
+			if ( mnt_reply.status != MNT3ERR_NOTDIR )
+				goto err;
+
+			if ( strcmp ( nfs->mountpoint, "/" ) == 0 )
+				goto err;
+
+			sep = strrchr ( nfs->mountpoint, '/' );
+			nfs->filename[-1] = '/';
+			nfs->filename     = sep + 1;
+			*sep = '\0';
+
+			DBGC ( nfs, "NFS_OPEN %p ENOTDIR received retrying" \
+			       "with %s\n", nfs, nfs->mountpoint );
+			goto done;
+		}
+
+		nfs->current_fh = mnt_reply.fh;
+		nfs->nfs_state = NFS_LOOKUP;
+		nfs_step ( nfs );
+
+		goto done;
+	}
+
+	if ( nfs->mount_state == NFS_MOUNT_UMNT ) {
+		DBGC ( nfs, "NFS_OPEN %p got UMNT reply\n", nfs );
+		nfs_done ( nfs, 0 );
+
+		goto done;
+	}
+
+	rc = -EPROTO;
+err:
+	nfs_done ( nfs, rc );
+done:
+	free_iob ( io_buf );
+	return 0;
+}
+
+static void nfs_step ( struct nfs_request *nfs ) {
+	int     rc;
+	char    *path_component = NULL;
+
+	if ( ! xfer_window ( &nfs->nfs_intf ) )
+		return;
+
+	if ( nfs->nfs_state == NFS_LOOKUP ) {
+		while ( path_component == NULL || path_component[0] == '\0') {
+			path_component = nfs->filename;
+			while ( *nfs->filename != '\0' ) {
+				nfs->filename_offset++;
+				if ( *nfs->filename++ == '/' ) {
+					*(nfs->filename - 1) = '\0';
+					break;
+				}
+			}
+		}
+
+		DBGC ( nfs, "NFS_OPEN %p LOOKUP call (%s)\n", nfs,
+                       path_component );
+
+		rc = nfs_lookup ( &nfs->nfs_intf, &nfs->nfs_session,
+		                  &nfs->current_fh, path_component );
+		if ( rc != 0 )
+			goto err;
+
+		nfs->nfs_state++;
+		return;
+	}
+
+
+	if ( nfs->nfs_state == NFS_READLINK ) {
+		DBGC ( nfs, "NFS_OPEN %p READLINK call\n", nfs );
+
+		rc = nfs_readlink ( &nfs->nfs_intf, &nfs->nfs_session,
+		                    &nfs->readlink_fh );
+		if ( rc != 0 )
+			goto err;
+
+		nfs->nfs_state++;
+		return;
+	}
+
+	if ( nfs->nfs_state == NFS_READ ) {
+		DBGC ( nfs, "NFS_OPEN %p READ call\n", nfs );
+
+		rc = nfs_read ( &nfs->nfs_intf, &nfs->nfs_session,
+		                &nfs->current_fh, nfs->file_offset,
+		                NFS_RSIZE );
+		if ( rc != 0 )
+			goto err;
+
+		nfs->nfs_state++;
+		return;
+	}
+
+	return;
+err:
+	nfs_done ( nfs, rc );
+}
+
+static int nfs_deliver ( struct nfs_request *nfs,
+                         struct io_buffer *io_buf,
+                         struct xfer_metadata *meta __unused ) {
+	int                     rc;
+	struct oncrpc_reply     reply;
+
+	if ( nfs->remaining == 0 ) {
+		oncrpc_get_reply ( &nfs->nfs_session, &reply, io_buf );
+		if ( reply.accept_state != 0 ) {
+			rc = -EPROTO;
+			goto err;
+		}
+	}
+
+	if ( nfs->nfs_state == NFS_LOOKUP_SENT ) {
+		struct nfs_lookup_reply lookup_reply;
+
+		DBGC ( nfs, "NFS_OPEN %p got LOOKUP reply\n", nfs );
+
+		rc = nfs_get_lookup_reply ( &lookup_reply, &reply );
+		if ( rc != 0 )
+			goto err;
+
+		if ( lookup_reply.ent_type == NFS_ATTR_SYMLINK ) {
+			nfs->readlink_fh = lookup_reply.fh;
+			nfs->nfs_state = NFS_READLINK;
+		} else {
+			nfs->current_fh = lookup_reply.fh;
+
+			if ( nfs->filename[0] == '\0' )
+				nfs->nfs_state = NFS_READ;
+			else
+				nfs->nfs_state--;
+		}
+
+		nfs_step ( nfs );
+		goto done;
+	}
+
+	if ( nfs->nfs_state == NFS_READLINK_SENT ) {
+		char                      *new_filename;
+		struct nfs_readlink_reply readlink_reply;
+
+		DBGC ( nfs, "NFS_OPEN %p got READLINK reply\n", nfs );
+
+		rc = nfs_get_readlink_reply ( &readlink_reply, &reply );
+		if ( rc != 0 )
+			goto err;
+
+		if ( readlink_reply.path_len == 0 )
+			return -EINVAL;
+
+		if ( readlink_reply.path[0] == '/' ) {
+			if ( strncmp ( readlink_reply.path, nfs->mountpoint,
+			               strlen ( nfs->mountpoint ) ) != 0 )
+				return -EINVAL;
+
+			/* The mountpoint part of the path is ended by a '/' */
+			if ( strlen ( nfs->mountpoint ) !=
+			     readlink_reply.path_len ) {
+				readlink_reply.path     += 1;
+				readlink_reply.path_len -= 1;
+			}
+
+			/* We are considering the last part of the absolute
+			 * path as a relative path from the mountpoint.
+			 */
+			readlink_reply.path     += strlen ( nfs->mountpoint );
+			readlink_reply.path_len -= strlen ( nfs->mountpoint );
+		}
+
+		new_filename = malloc ( readlink_reply.path_len +
+		                        strlen ( nfs->filename ) + 2 );
+		if ( ! new_filename ) {
+			rc = -ENOMEM;
+			goto err;
+		}
+
+		memcpy ( new_filename, readlink_reply.path,
+		         readlink_reply.path_len );
+		strcpy ( new_filename + readlink_reply.path_len + 1,
+		         nfs->filename );
+		new_filename[readlink_reply.path_len] = '/';
+
+		free ( nfs->filename - nfs->filename_offset );
+		nfs->filename = new_filename;
+		nfs->filename_offset = 0;
+
+		DBGC ( nfs, "NFS_OPEN %p new filename: %s\n", nfs,
+		       nfs->filename );
+
+		nfs->nfs_state = NFS_LOOKUP;
+		nfs_step ( nfs );
+		goto done;
+	}
+
+	if ( nfs->nfs_state == NFS_READ_SENT ) {
+		if ( nfs->remaining == 0 ) {
+			DBGC ( nfs, "NFS_OPEN %p got READ reply\n", nfs );
+
+			struct nfs_read_reply read_reply;
+
+			rc = nfs_get_read_reply ( &read_reply, &reply );
+			if ( rc != 0 )
+				goto err;
+
+			if ( nfs->file_offset == 0 ) {
+				DBGC2 ( nfs, "NFS_OPEN %p size: %llu bytes\n",
+				        nfs, read_reply.filesize );
+
+				xfer_seek ( &nfs->xfer, read_reply.filesize );
+				xfer_seek ( &nfs->xfer, 0 );
+			}
+
+			nfs->file_offset += read_reply.count;
+			nfs->remaining    = read_reply.count;
+			nfs->eof          = read_reply.eof;
+		}
+
+		size_t len = iob_len ( io_buf );
+		if ( len > nfs->remaining )
+			iob_unput ( io_buf, len - nfs->remaining );
+
+		nfs->remaining -= iob_len ( io_buf );
+
+		DBGC ( nfs, "NFS_OPEN %p got %zd bytes\n", nfs,
+		       iob_len ( io_buf ) );
+
+		rc = xfer_deliver_iob ( &nfs->xfer, iob_disown ( io_buf ) );
+		if ( rc != 0 )
+			goto err;
+
+		if ( nfs->remaining == 0 ) {
+			if ( ! nfs->eof ) {
+				nfs->nfs_state--;
+				nfs_step ( nfs );
+			} else {
+				intf_shutdown ( &nfs->nfs_intf, 0 );
+				nfs->nfs_state++;
+				nfs->mount_state++;
+				nfs_mount_step ( nfs );
+			}
+		}
+
+		return 0;
+	}
+
+	rc = -EPROTO;
+err:
+	nfs_done ( nfs, rc );
+done:
+	free_iob ( io_buf );
+	return 0;
+}
+
+/*****************************************************************************
+ * Interfaces
+ *
+ */
+
+static struct interface_operation nfs_xfer_operations[] = {
+	INTF_OP ( intf_close, struct nfs_request *, nfs_done ),
+};
+
+/** NFS data transfer interface descriptor */
+static struct interface_descriptor nfs_xfer_desc =
+	INTF_DESC ( struct nfs_request, xfer, nfs_xfer_operations );
+
+static struct interface_operation nfs_pm_operations[] = {
+	INTF_OP ( intf_close, struct nfs_request *, nfs_done ),
+	INTF_OP ( xfer_deliver, struct nfs_request *, nfs_pm_deliver ),
+	INTF_OP ( xfer_window_changed, struct nfs_request *, nfs_pm_step ),
+};
+
+static struct interface_descriptor nfs_pm_desc =
+	INTF_DESC ( struct nfs_request, pm_intf, nfs_pm_operations );
+
+static struct interface_operation nfs_mount_operations[] = {
+	INTF_OP ( intf_close, struct nfs_request *, nfs_done ),
+	INTF_OP ( xfer_deliver, struct nfs_request *, nfs_mount_deliver ),
+	INTF_OP ( xfer_window_changed, struct nfs_request *, nfs_mount_step ),
+};
+
+static struct interface_descriptor nfs_mount_desc =
+	INTF_DESC ( struct nfs_request, mount_intf, nfs_mount_operations );
+
+static struct interface_operation nfs_operations[] = {
+	INTF_OP ( intf_close, struct nfs_request *, nfs_done ),
+	INTF_OP ( xfer_deliver, struct nfs_request *, nfs_deliver ),
+	INTF_OP ( xfer_window_changed, struct nfs_request *, nfs_step ),
+};
+
+static struct interface_descriptor nfs_desc =
+	INTF_DESC_PASSTHRU ( struct nfs_request, nfs_intf, nfs_operations,
+	                     xfer );
+
+/*****************************************************************************
+ *
+ * URI opener
+ *
+ */
+
+static int nfs_parse_uri ( struct nfs_request *nfs, const struct uri *uri ) {
+	int     rc;
+
+	if ( ! uri || ! uri->host || ! uri->path )
+		return -EINVAL;
+
+	if ( ! ( nfs->path = strdup ( uri->path ) ) )
+		return -ENOMEM;
+
+	if ( ! ( nfs->hostname = strdup ( uri->host ) ) ) {
+		rc = -ENOMEM;
+		goto err_hostname;
+	}
+
+	nfs->filename   = basename ( nfs->path );
+	nfs->mountpoint = dirname ( nfs->path );
+
+	if ( nfs->filename[0] == '\0' )
+		goto err_filename;
+
+	DBGC ( nfs, "NFS_OPEN %p URI parsed: (mountpoint=%s, filename=%s)\n",
+	       nfs, nfs->mountpoint, nfs->filename );
+
+	return 0;
+
+err_filename:
+	rc = -EINVAL;
+	free ( nfs->hostname );
+err_hostname:
+	free ( nfs->path );
+	return rc;
+}
+
+/**
+ * Initiate a NFS connection
+ *
+ * @v xfer		Data transfer interface
+ * @v uri		Uniform Resource Identifier
+ * @ret rc		Return status code
+ */
+static int nfs_open ( struct interface *xfer, struct uri *uri ) {
+	int                     rc;
+	struct nfs_request      *nfs;
+
+	nfs = zalloc ( sizeof ( *nfs ) );
+	if ( ! nfs )
+		return -ENOMEM;
+
+	rc = nfs_parse_uri( nfs, uri );
+	if ( rc != 0 )
+		goto err_uri;
+
+	rc = oncrpc_init_cred_sys ( &nfs->auth_sys );
+	if ( rc != 0 )
+		goto err_cred;
+
+	ref_init ( &nfs->refcnt, nfs_free );
+	intf_init ( &nfs->xfer, &nfs_xfer_desc, &nfs->refcnt );
+	intf_init ( &nfs->pm_intf, &nfs_pm_desc, &nfs->refcnt );
+	intf_init ( &nfs->mount_intf, &nfs_mount_desc, &nfs->refcnt );
+	intf_init ( &nfs->nfs_intf, &nfs_desc, &nfs->refcnt );
+
+	portmap_init_session ( &nfs->pm_session, &nfs->auth_sys.credential );
+	mount_init_session ( &nfs->mount_session, &nfs->auth_sys.credential );
+	nfs_init_session ( &nfs->nfs_session, &nfs->auth_sys.credential );
+
+	rc = nfs_connect ( &nfs->pm_intf, PORTMAP_PORT, nfs->hostname );
+	if ( rc != 0 )
+		goto err_connect;
+
+	/* Attach to parent interface, mortalise self, and return */
+	intf_plug_plug ( &nfs->xfer, xfer );
+	ref_put ( &nfs->refcnt );
+
+	return 0;
+
+err_connect:
+	free ( nfs->auth_sys.hostname );
+err_cred:
+err_uri:
+	free ( nfs );
+	return rc;
+}
+
+/** NFS URI opener */
+struct uri_opener nfs_uri_opener __uri_opener = {
+	.scheme	= "nfs",
+	.open	= nfs_open,
+};

src/net/oncrpc/oncrpc_iob.c

@@ -0,0 +1,200 @@
+/*
+ * Copyright (C) 2013 Marin Hannache <ipxe@mareo.fr>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <byteswap.h>
+#include <ipxe/socket.h>
+#include <ipxe/tcpip.h>
+#include <ipxe/in.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/xfer.h>
+#include <ipxe/open.h>
+#include <ipxe/uri.h>
+#include <ipxe/features.h>
+#include <ipxe/oncrpc.h>
+#include <ipxe/oncrpc_iob.h>
+
+/** @file
+ *
+ * SUN ONC RPC protocol
+ *
+ */
+
+size_t oncrpc_iob_add_fields ( struct io_buffer *io_buf,
+                               const struct oncrpc_field fields[] ) {
+	size_t i;
+	size_t s = 0;
+
+	struct oncrpc_field f;
+
+	if ( ! io_buf )
+		return 0;
+
+	for ( i = 0; fields[i].type != oncrpc_none; i++ ) {
+		f = fields[i];
+		switch ( f.type ) {
+		case oncrpc_int32:
+			s += oncrpc_iob_add_int ( io_buf, f.value.int32 );
+			break;
+
+		case oncrpc_int64:
+			s += oncrpc_iob_add_int64 ( io_buf, f.value.int64 );
+			break;
+
+		case oncrpc_str:
+			s += oncrpc_iob_add_string ( io_buf, f.value.str );
+			break;
+
+		case oncrpc_array:
+			s += oncrpc_iob_add_array ( io_buf,
+			                            f.value.array.length,
+			                            f.value.array.ptr );
+			break;
+
+		case oncrpc_intarray:
+			s += oncrpc_iob_add_intarray ( io_buf,
+			                               f.value.intarray.length,
+			                               f.value.intarray.ptr );
+			break;
+
+		case oncrpc_cred:
+			s += oncrpc_iob_add_cred ( io_buf, f.value.cred);
+			break;
+
+		default:
+			return s;
+		}
+	}
+
+	return s;
+}
+
+/**
+ * Add an array of bytes to the end of an I/O buffer
+ *
+ * @v io_buf            I/O buffer
+ * @v val               String
+ * @ret size            Size of the data written
+ *
+ * In the ONC RPC protocol, every data is four byte paded, we add padding when
+ * necessary by using oncrpc_align()
+ */
+size_t oncrpc_iob_add_array ( struct io_buffer *io_buf, size_t length,
+                              const void *data ) {
+	size_t padding = oncrpc_align ( length ) - length;
+
+	oncrpc_iob_add_int ( io_buf, length );
+	memcpy ( iob_put ( io_buf, length ), data, length );
+	memset ( iob_put ( io_buf, padding ), 0, padding );
+
+	return length + padding + sizeof ( uint32_t );
+}
+
+/**
+ * Add an int array to the end of an I/O buffer
+ *
+ * @v io_buf            I/O buffer
+ * @v length            Length od the array
+ * @v val               Int array
+ * @ret size            Size of the data written
+ */
+size_t oncrpc_iob_add_intarray ( struct io_buffer *io_buf, size_t length,
+                                 const uint32_t *array ) {
+	size_t                  i;
+
+	oncrpc_iob_add_int ( io_buf, length );
+
+	for ( i = 0; i < length; ++i )
+		oncrpc_iob_add_int ( io_buf, array[i] );
+
+	return ( ( length + 1 ) * sizeof ( uint32_t ) );
+}
+
+/**
+ * Add credential information to the end of an I/O buffer
+ *
+ * @v io_buf            I/O buffer
+ * @v cred              Credential information
+ * @ret size            Size of the data written
+ */
+size_t oncrpc_iob_add_cred ( struct io_buffer *io_buf,
+                             const struct oncrpc_cred *cred ) {
+	struct oncrpc_cred_sys  *syscred;
+	size_t                  s;
+
+	struct oncrpc_field credfields[] = {
+		ONCRPC_FIELD ( int32, cred->flavor ),
+		ONCRPC_FIELD ( int32, cred->length ),
+		ONCRPC_FIELD_END,
+	};
+
+	if ( ! io_buf || ! cred )
+		return 0;
+
+	s  = oncrpc_iob_add_fields ( io_buf, credfields);
+
+	switch ( cred->flavor ) {
+	case ONCRPC_AUTH_NONE:
+		break;
+
+	case ONCRPC_AUTH_SYS:
+		syscred = container_of ( cred, struct oncrpc_cred_sys,
+		                         credential );
+
+		struct oncrpc_field syscredfields[] = {
+			ONCRPC_FIELD ( int32, syscred->stamp ),
+			ONCRPC_FIELD ( str, syscred->hostname ),
+			ONCRPC_FIELD ( int32, syscred->uid ),
+			ONCRPC_FIELD ( int32, syscred->gid ),
+			ONCRPC_SUBFIELD ( intarray, syscred->aux_gid_len,
+			                  syscred->aux_gid ),
+			ONCRPC_FIELD_END,
+		};
+
+		s += oncrpc_iob_add_fields ( io_buf, syscredfields );
+		break;
+	}
+
+	return s;
+}
+
+/**
+ * Get credential information from the beginning of an I/O buffer
+ *
+ * @v io_buf            I/O buffer
+ * @v cred              Struct where the information will be saved
+ * @ret size            Size of the data read
+ */
+size_t oncrpc_iob_get_cred ( struct io_buffer *io_buf,
+                             struct oncrpc_cred *cred ) {
+	if ( cred == NULL )
+		return * ( uint32_t * ) io_buf->data;
+
+	cred->flavor = oncrpc_iob_get_int ( io_buf );
+	cred->length = oncrpc_iob_get_int ( io_buf );
+
+	iob_pull ( io_buf, cred->length );
+
+	return ( 2 * sizeof ( uint32_t ) + cred->length );
+}

src/net/oncrpc/portmap.c

@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2013 Marin Hannache <ipxe@mareo.fr>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <byteswap.h>
+#include <ipxe/socket.h>
+#include <ipxe/tcpip.h>
+#include <ipxe/in.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/xfer.h>
+#include <ipxe/open.h>
+#include <ipxe/uri.h>
+#include <ipxe/features.h>
+#include <ipxe/timer.h>
+#include <ipxe/oncrpc.h>
+#include <ipxe/oncrpc_iob.h>
+#include <ipxe/portmap.h>
+
+/** @file
+ *
+ * PORTMAPPER protocol.
+ *
+ */
+
+/** PORTMAP GETPORT procedure. */
+#define PORTMAP_GETPORT 3
+
+/**
+ * Send a GETPORT request
+ *
+ * @v intf              Interface to send the request on
+ * @v session           ONC RPC session
+ * @v prog              ONC RPC program number
+ * @v vers              ONC RPC rogram version number
+ * @v proto             Protocol (TCP or UDP)
+ * @ret rc              Return status code
+ */
+int portmap_getport ( struct interface *intf, struct oncrpc_session *session,
+                      uint32_t prog, uint32_t vers, uint32_t proto ) {
+	struct oncrpc_field fields[] = {
+		ONCRPC_FIELD ( int32, prog ),
+		ONCRPC_FIELD ( int32, vers ),
+		ONCRPC_FIELD ( int32, proto ),
+		ONCRPC_FIELD ( int32, 0 ), /* The port field is only meaningful
+		                              in GETPORT reply */
+		ONCRPC_FIELD_END,
+	};
+
+	return oncrpc_call ( intf, session, PORTMAP_GETPORT, fields );
+}
+
+/**
+ * Parse a GETPORT reply
+ *
+ * @v getport_reply     A structure where the data will be saved
+ * @v reply             The ONC RPC reply to get data from
+ * @ret rc              Return status code
+ */
+int portmap_get_getport_reply ( struct portmap_getport_reply *getport_reply,
+                                struct oncrpc_reply *reply ) {
+	if ( ! getport_reply || ! reply )
+		return -EINVAL;
+
+	getport_reply->port = oncrpc_iob_get_int ( reply->data );
+	if ( getport_reply == 0 || getport_reply->port >= 65536 )
+		return -EINVAL;
+
+	return 0;
+}

src/net/tcp/oncrpc.c

@@ -0,0 +1,250 @@
+/*
+ * Copyright (C) 2013 Marin Hannache <ipxe@mareo.fr>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <byteswap.h>
+#include <ipxe/socket.h>
+#include <ipxe/tcpip.h>
+#include <ipxe/in.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/dhcp.h>
+#include <ipxe/xfer.h>
+#include <ipxe/open.h>
+#include <ipxe/uri.h>
+#include <ipxe/features.h>
+#include <ipxe/oncrpc.h>
+#include <ipxe/oncrpc_iob.h>
+#include <ipxe/init.h>
+#include <ipxe/settings.h>
+#include <config/general.h>
+
+/** @file
+ *
+ * SUN ONC RPC protocol
+ *
+ */
+
+/** Set most significant bit to 1. */
+#define SET_LAST_FRAME( x ) ( (x) | 1 << 31 )
+#define GET_FRAME_SIZE( x ) ( (x) & ~( 1 << 31 ) )
+
+#define ONCRPC_CALL     0
+#define ONCRPC_REPLY    1
+
+/** AUTH NONE authentication flavor */
+struct oncrpc_cred oncrpc_auth_none = {
+	.flavor = ONCRPC_AUTH_NONE,
+	.length = 0
+};
+
+struct setting uid_setting __setting ( SETTING_AUTH ) = {
+	.name        = "uid",
+	.description = "User ID",
+	.tag         = DHCP_EB_UID,
+	.type        = &setting_type_uint32
+};
+
+struct setting gid_setting __setting ( SETTING_AUTH ) = {
+	.name        = "gid",
+	.description = "Group ID",
+	.tag         = DHCP_EB_GID,
+	.type        = &setting_type_uint32
+};
+
+/**
+ * Initialize an ONC RPC AUTH SYS credential structure
+ *
+ * @v auth_sys          The structure to initialize
+ *
+ * The hostname field is filled with the value of the hostname setting, if the
+ * hostname setting is empty, PRODUCT_SHORT_NAME (usually "iPXE") is used
+ * instead.
+ */
+int oncrpc_init_cred_sys ( struct oncrpc_cred_sys *auth_sys ) {
+	if ( ! auth_sys )
+		return -EINVAL;
+
+	fetch_string_setting_copy ( NULL, &hostname_setting,
+	                            &auth_sys->hostname );
+	if ( ! auth_sys->hostname )
+		if ( ! ( auth_sys->hostname = strdup ( PRODUCT_SHORT_NAME ) ) )
+			return -ENOMEM;
+
+	auth_sys->uid         = fetch_uintz_setting ( NULL, &uid_setting );
+	auth_sys->gid         = fetch_uintz_setting ( NULL, &uid_setting );
+	auth_sys->aux_gid_len = 0;
+	auth_sys->stamp       = 0;
+
+	auth_sys->credential.flavor = ONCRPC_AUTH_SYS;
+	auth_sys->credential.length = 16 +
+	                              oncrpc_strlen ( auth_sys->hostname );
+
+	return 0;
+}
+
+/**
+ * Prepare an ONC RPC session structure to be used by the ONC RPC layer
+ *
+ * @v session           ONC RPC session
+ * @v credential        Credential structure pointer
+ * @v verifier          Verifier structure pointer
+ * @v prog_name         ONC RPC program number
+ * @v prog_vers         ONC RPC program version number
+ */
+void oncrpc_init_session ( struct oncrpc_session *session,
+                           struct oncrpc_cred *credential,
+                           struct oncrpc_cred *verifier, uint32_t prog_name,
+                           uint32_t prog_vers ) {
+	if ( ! session )
+		return;
+
+	session->rpc_id     = rand();
+	session->credential = credential;
+	session->verifier   = verifier;
+	session->prog_name  = prog_name;
+	session->prog_vers  = prog_vers;
+}
+
+int oncrpc_call ( struct interface *intf, struct oncrpc_session *session,
+                  uint32_t proc_name, const struct oncrpc_field fields[] ) {
+	int              rc;
+	size_t           frame_size;
+	struct io_buffer *io_buf;
+
+	if ( ! session )
+		return -EINVAL;
+
+	struct oncrpc_field header[] = {
+		ONCRPC_FIELD ( int32, 0 ),
+		ONCRPC_FIELD ( int32, ++session->rpc_id ),
+		ONCRPC_FIELD ( int32, ONCRPC_CALL ),
+		ONCRPC_FIELD ( int32, ONCRPC_VERS ),
+		ONCRPC_FIELD ( int32, session->prog_name ),
+		ONCRPC_FIELD ( int32, session->prog_vers ),
+		ONCRPC_FIELD ( int32, proc_name ),
+		ONCRPC_FIELD ( cred, session->credential ),
+		ONCRPC_FIELD ( cred, session->verifier ),
+		ONCRPC_FIELD_END,
+	};
+
+	frame_size  = oncrpc_compute_size ( header );
+	frame_size += oncrpc_compute_size ( fields );
+
+	io_buf = alloc_iob ( frame_size );
+	if ( ! io_buf )
+		return -ENOBUFS;
+
+	header[0].value.int32 = SET_LAST_FRAME ( frame_size -
+	                                         sizeof ( uint32_t ) );
+
+	oncrpc_iob_add_fields ( io_buf, header );
+	oncrpc_iob_add_fields ( io_buf, fields );
+
+	rc = xfer_deliver_iob ( intf, io_buf );
+	if ( rc != 0 )
+		free_iob ( io_buf );
+
+	return rc;
+}
+
+size_t oncrpc_compute_size ( const struct oncrpc_field fields[] ) {
+
+	size_t i;
+	size_t size = 0;
+
+	for ( i = 0; fields[i].type != oncrpc_none; i++ ) {
+		switch ( fields[i].type ) {
+		case oncrpc_int32:
+			size += sizeof ( uint32_t );
+			break;
+
+		case oncrpc_int64:
+			size += sizeof ( uint64_t );
+			break;
+
+		case oncrpc_str:
+			size += oncrpc_strlen ( fields[i].value.str );
+			break;
+
+		case oncrpc_array:
+			size += oncrpc_align ( fields[i].value.array.length );
+			size += sizeof ( uint32_t );
+			break;
+
+		case oncrpc_intarray:
+			size += sizeof ( uint32_t ) *
+				fields[i].value.intarray.length;
+			size += sizeof ( uint32_t );
+			break;
+
+		case oncrpc_cred:
+			size += fields[i].value.cred->length;
+			size += 2 * sizeof ( uint32_t );
+			break;
+
+		default:
+			return size;
+		}
+	}
+
+	return size;
+}
+
+/**
+ * Parse an I/O buffer to extract a ONC RPC REPLY
+ * @v session	        ONC RPC session
+ * @v reply             Reply structure where data will be saved
+ * @v io_buf            I/O buffer
+ */
+int oncrpc_get_reply ( struct oncrpc_session *session __unused,
+                       struct oncrpc_reply *reply, struct io_buffer *io_buf ) {
+	if ( ! reply || ! io_buf )
+		return -EINVAL;
+
+	reply->frame_size = GET_FRAME_SIZE ( oncrpc_iob_get_int ( io_buf ) );
+	reply->rpc_id     = oncrpc_iob_get_int ( io_buf );
+
+	/* iPXE has no support for handling ONC RPC call */
+	if ( oncrpc_iob_get_int ( io_buf ) != ONCRPC_REPLY )
+		return -ENOSYS;
+
+	reply->reply_state = oncrpc_iob_get_int ( io_buf );
+
+	if ( reply->reply_state == 0 )
+	{
+		/* verifier.flavor */
+		oncrpc_iob_get_int ( io_buf );
+		/* verifier.length */
+		iob_pull ( io_buf, oncrpc_iob_get_int ( io_buf ));
+
+		/* We don't use the verifier in iPXE, let it be an empty
+		   verifier. */
+		reply->verifier = &oncrpc_auth_none;
+	}
+
+	reply->accept_state = oncrpc_iob_get_int ( io_buf );
+	reply->data         = io_buf;
+
+	return 0;
+}