path: root/fs/nfsd/nfs4callback.c

/*
 *  Copyright (c) 2001 The Regents of the University of Michigan.
 *  All rights reserved.
 *
 *  Kendrick Smith <kmsmith@umich.edu>
 *  Andy Adamson <andros@umich.edu>
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. Neither the name of the University nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <linux/nfs4.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/xprt.h>
#include <linux/sunrpc/svc_xprt.h>
#include <linux/slab.h>
#include "nfsd.h"
#include "state.h"
#include "netns.h"
#include "trace.h"
#include "xdr4cb.h"
#include "xdr4.h"

#define NFSDDBG_FACILITY                NFSDDBG_PROC

static void nfsd4_mark_cb_fault(struct nfs4_client *clp);

#define NFSPROC4_CB_NULL 0
#define NFSPROC4_CB_COMPOUND 1

/* Index of predefined Linux callback client operations */

struct nfs4_cb_compound_hdr {
	/* args */
	u32		ident;	/* minorversion 0 only */
	u32		nops;
	__be32		*nops_p;
	u32		minorversion;
	/* res */
	int		status;
};

static __be32 *xdr_encode_empty_array(__be32 *p)
{
	*p++ = xdr_zero;
	return p;
}

/*
 * Encode/decode NFSv4 CB basic data types
 *
 * Basic NFSv4 callback data types are defined in section 15 of RFC
 * 3530: "Network File System (NFS) version 4 Protocol" and section
 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
 * 1 Protocol"
 */

static void encode_uint32(struct xdr_stream *xdr, u32 n)
{
	WARN_ON_ONCE(xdr_stream_encode_u32(xdr, n) < 0);
}

static void encode_bitmap4(struct xdr_stream *xdr, const __u32 *bitmap,
			   size_t len)
{
	xdr_stream_encode_uint32_array(xdr, bitmap, len);
}

static int decode_cb_fattr4(struct xdr_stream *xdr, uint32_t *bitmap,
				struct nfs4_cb_fattr *fattr)
{
	fattr->ncf_cb_change = 0;
	fattr->ncf_cb_fsize = 0;
	if (bitmap[0] & FATTR4_WORD0_CHANGE)
		if (xdr_stream_decode_u64(xdr, &fattr->ncf_cb_change) < 0)
			return -NFSERR_BAD_XDR;
	if (bitmap[0] & FATTR4_WORD0_SIZE)
		if (xdr_stream_decode_u64(xdr, &fattr->ncf_cb_fsize) < 0)
			return -NFSERR_BAD_XDR;
	return 0;
}

static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
{
	__be32 *p;

	p = xdr_reserve_space(xdr, 4);
	*p = cpu_to_be32(op);
}

/*
 * nfs_fh4
 *
 *	typedef opaque nfs_fh4<NFS4_FHSIZE>;
 */
static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
{
	u32 length = fh->fh_size;
	__be32 *p;

	BUG_ON(length > NFS4_FHSIZE);
	p = xdr_reserve_space(xdr, 4 + length);
	xdr_encode_opaque(p, &fh->fh_raw, length);
}

/*
 * stateid4
 *
 *	struct stateid4 {
 *		uint32_t	seqid;
 *		opaque		other[12];
 *	};
 */
static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
{
	__be32 *p;

	p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
	*p++ = cpu_to_be32(sid->si_generation);
	xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
}

/*
 * sessionid4
 *
 *	typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
 */
static void encode_sessionid4(struct xdr_stream *xdr,
			      const struct nfsd4_session *session)
{
	__be32 *p;

	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
	xdr_encode_opaque_fixed(p, session->se_sessionid.data,
					NFS4_MAX_SESSIONID_LEN);
}

/*
 * nfsstat4
 */
static const struct {
	int stat;
	int errno;
} nfs_cb_errtbl[] = {
	{ NFS4_OK,		0		},
	{ NFS4ERR_PERM,		-EPERM		},
	{ NFS4ERR_NOENT,	-ENOENT		},
	{ NFS4ERR_IO,		-EIO		},
	{ NFS4ERR_NXIO,		-ENXIO		},
	{ NFS4ERR_ACCESS,	-EACCES		},
	{ NFS4ERR_EXIST,	-EEXIST		},
	{ NFS4ERR_XDEV,		-EXDEV		},
	{ NFS4ERR_NOTDIR,	-ENOTDIR	},
	{ NFS4ERR_ISDIR,	-EISDIR		},
	{ NFS4ERR_INVAL,	-EINVAL		},
	{ NFS4ERR_FBIG,		-EFBIG		},
	{ NFS4ERR_NOSPC,	-ENOSPC		},
	{ NFS4ERR_ROFS,		-EROFS		},
	{ NFS4ERR_MLINK,	-EMLINK		},
	{ NFS4ERR_NAMETOOLONG,	-ENAMETOOLONG	},
	{ NFS4ERR_NOTEMPTY,	-ENOTEMPTY	},
	{ NFS4ERR_DQUOT,	-EDQUOT		},
	{ NFS4ERR_STALE,	-ESTALE		},
	{ NFS4ERR_BADHANDLE,	-EBADHANDLE	},
	{ NFS4ERR_BAD_COOKIE,	-EBADCOOKIE	},
	{ NFS4ERR_NOTSUPP,	-ENOTSUPP	},
	{ NFS4ERR_TOOSMALL,	-ETOOSMALL	},
	{ NFS4ERR_SERVERFAULT,	-ESERVERFAULT	},
	{ NFS4ERR_BADTYPE,	-EBADTYPE	},
	{ NFS4ERR_LOCKED,	-EAGAIN		},
	{ NFS4ERR_RESOURCE,	-EREMOTEIO	},
	{ NFS4ERR_SYMLINK,	-ELOOP		},
	{ NFS4ERR_OP_ILLEGAL,	-EOPNOTSUPP	},
	{ NFS4ERR_DEADLOCK,	-EDEADLK	},
	{ -1,			-EIO		}
};

/*
 * If we cannot translate the error, the recovery routines should
 * handle it.
 *
 * Note: remaining NFSv4 error codes have values > 10000, so should
 * not conflict with native Linux error codes.
 */
static int nfs_cb_stat_to_errno(int status)
{
	int i;

	for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
		if (nfs_cb_errtbl[i].stat == status)
			return nfs_cb_errtbl[i].errno;
	}

	dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
	return -status;
}

static int decode_cb_op_status(struct xdr_stream *xdr,
			       enum nfs_cb_opnum4 expected, int *status)
{
	__be32 *p;
	u32 op;

	p = xdr_inline_decode(xdr, 4 + 4);
	if (unlikely(p == NULL))
		goto out_overflow;
	op = be32_to_cpup(p++);
	if (unlikely(op != expected))
		goto out_unexpected;
	*status = nfs_cb_stat_to_errno(be32_to_cpup(p));
	return 0;
out_overflow:
	return -EIO;
out_unexpected:
	dprintk("NFSD: Callback server returned operation %d but "
		"we issued a request for %d\n", op, expected);
	return -EIO;
}

/*
 * CB_COMPOUND4args
 *
 *	struct CB_COMPOUND4args {
 *		utf8str_cs	tag;
 *		uint32_t	minorversion;
 *		uint32_t	callback_ident;
 *		nfs_cb_argop4	argarray<>;
 *	};
*/
static void encode_cb_compound4args(struct xdr_stream *xdr,
				    struct nfs4_cb_compound_hdr *hdr)
{
	__be32 * p;

	p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
	p = xdr_encode_empty_array(p);		/* empty tag */
	*p++ = cpu_to_be32(hdr->minorversion);
	*p++ = cpu_to_be32(hdr->ident);

	hdr->nops_p = p;
	*p = cpu_to_be32(hdr->nops);		/* argarray element count */
}

/*
 * Update argarray element count
 */
static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
{
	BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL