[linux.git] / fs / nfs / callback_xdr.c

/*
 * linux/fs/nfs/callback_xdr.c
 *
 * Copyright (C) 2004 Trond Myklebust
 *
 * NFSv4 callback encode/decode procedures
 */
#include <linux/kernel.h>
#include <linux/sunrpc/svc.h>
#include <linux/nfs4.h>
#include <linux/nfs_fs.h>
#include "nfs4_fs.h"
#include "callback.h"

#define CB_OP_TAGLEN_MAXSZ	(512)
#define CB_OP_HDR_RES_MAXSZ	(2 + CB_OP_TAGLEN_MAXSZ)
#define CB_OP_GETATTR_BITMAP_MAXSZ	(4)
#define CB_OP_GETATTR_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
				CB_OP_GETATTR_BITMAP_MAXSZ + \
				2 + 2 + 3 + 3)
#define CB_OP_RECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)

#define NFSDBG_FACILITY NFSDBG_CALLBACK

typedef __be32 (*callback_process_op_t)(void *, void *);
typedef __be32 (*callback_decode_arg_t)(struct svc_rqst *, struct xdr_stream *, void *);
typedef __be32 (*callback_encode_res_t)(struct svc_rqst *, struct xdr_stream *, void *);


struct callback_op {
	callback_process_op_t process_op;
	callback_decode_arg_t decode_args;
	callback_encode_res_t encode_res;
	long res_maxsize;
};

static struct callback_op callback_ops[];

static __be32 nfs4_callback_null(struct svc_rqst *rqstp, void *argp, void *resp)
{
	return htonl(NFS4_OK);
}

static int nfs4_decode_void(struct svc_rqst *rqstp, uint32_t *p, void *dummy)
{
	return xdr_argsize_check(rqstp, p);
}

static int nfs4_encode_void(struct svc_rqst *rqstp, uint32_t *p, void *dummy)
{
	return xdr_ressize_check(rqstp, p);
}

static uint32_t *read_buf(struct xdr_stream *xdr, int nbytes)
{
	uint32_t *p;

	p = xdr_inline_decode(xdr, nbytes);
	if (unlikely(p == NULL))
		printk(KERN_WARNING "NFSv4 callback reply buffer overflowed!\n");
	return p;
}

static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len, const char **str)
{
	uint32_t *p;

	p = read_buf(xdr, 4);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	*len = ntohl(*p);

	if (*len != 0) {
		p = read_buf(xdr, *len);
		if (unlikely(p == NULL))
			return htonl(NFS4ERR_RESOURCE);
		*str = (const char *)p;
	} else
		*str = NULL;

	return 0;
}

static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
{
	uint32_t *p;

	p = read_buf(xdr, 4);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	fh->size = ntohl(*p);
	if (fh->size > NFS4_FHSIZE)
		return htonl(NFS4ERR_BADHANDLE);
	p = read_buf(xdr, fh->size);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	memcpy(&fh->data[0], p, fh->size);
	memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
	return 0;
}

static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
{
	uint32_t *p;
	unsigned int attrlen;

	p = read_buf(xdr, 4);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	attrlen = ntohl(*p);
	p = read_buf(xdr, attrlen << 2);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	if (likely(attrlen > 0))
		bitmap[0] = ntohl(*p++);
	if (attrlen > 1)
		bitmap[1] = ntohl(*p);
	return 0;
}

static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
{
	uint32_t *p;

	p = read_buf(xdr, 16);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	memcpy(stateid->data, p, 16);
	return 0;
}

static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
{
	uint32_t *p;
	unsigned int minor_version;
	__be32 status;

	status = decode_string(xdr, &hdr->taglen, &hdr->tag);
	if (unlikely(status != 0))
		return status;
	/* We do not like overly long tags! */
	if (hdr->taglen > CB_OP_TAGLEN_MAXSZ-12 || hdr->taglen < 0) {
		printk("NFSv4 CALLBACK %s: client sent tag of length %u\n",
				__FUNCTION__, hdr->taglen);
		return htonl(NFS4ERR_RESOURCE);
	}
	p = read_buf(xdr, 12);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	minor_version = ntohl(*p++);
	/* Check minor version is zero. */
	if (minor_version != 0) {
		printk(KERN_WARNING "%s: NFSv4 server callback with illegal minor version %u!\n",
				__FUNCTION__, minor_version);
		return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
	}
	hdr->callback_ident = ntohl(*p++);
	hdr->nops = ntohl(*p);
	return 0;
}

static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
{
	uint32_t *p;
	p = read_buf(xdr, 4);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	*op = ntohl(*p);
	return 0;
}

static __be32 decode_getattr_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_getattrargs *args)
{
	__be32 status;

	status = decode_fh(xdr, &args->fh);
	if (unlikely(status != 0))
		goto out;
	args->addr = &rqstp->rq_addr;
	status = decode_bitmap(xdr, args->bitmap);
out:
	dprintk("%s: exit with status = %d\n", __FUNCTION__, status);
	return status;
}

static __be32 decode_recall_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_recallargs *args)
{
	uint32_t *p;
	__be32 status;

	args->addr = &rqstp->rq_addr;
	status = decode_stateid(xdr, &args->stateid);
	if (unlikely(status != 0))
		goto out;
	p = read_buf(xdr, 4);
	if (unlikely(p == NULL)) {
		status = htonl(NFS4ERR_RESOURCE);
		goto out;
	}
	args->truncate = ntohl(*p);
	status = decode_fh(xdr, &args->fh);
out:
	dprintk("%s: exit with status = %d\n", __FUNCTION__, status);
	return status;
}

static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
{
	uint32_t *p;

	p = xdr_reserve_space(xdr, 4 + len);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	xdr_encode_opaque(p, str, len);
	return 0;
}

#define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
#define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, uint32_t **savep)
{
	uint32_t bm[2];
	uint32_t *p;

	bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
	bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
	if (bm[1] != 0) {
		p = xdr_reserve_space(xdr, 16);
		if (unlikely(p == NULL))
			return htonl(NFS4ERR_RESOURCE);
		*p++ = htonl(2);
		*p++ = bm[0];
		*p++ = bm[1];
	} else if (bm[0] != 0) {
		p = xdr_reserve_space(xdr, 12);
		if (unlikely(p == NULL))
			return htonl(NFS4ERR_RESOURCE);
		*p++ = htonl(1);
		*p++ = bm[0];
	} else {
		p = xdr_reserve_space(xdr, 8);
		if (unlikely(p == NULL))
			return htonl(NFS4ERR_RESOURCE);
		*p++ = htonl(0);
	}
	*savep = p;
	return 0;
}

static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
{
	uint32_t *p;

	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
		return 0;
	p = xdr_reserve_space(xdr, 8);
	if (unlikely(p == 0))
		return htonl(NFS4ERR_RESOURCE);
	p = xdr_encode_hyper(p, change);
	return 0;
}

static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
{
	uint32_t *p;

	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
		return 0;
	p = xdr_reserve_space(xdr, 8);
	if (unlikely(p == 0))
		return htonl(NFS4ERR_RESOURCE);
	p = xdr_encode_hyper(p, size);
	return 0;
}

static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
{
	uint32_t *p;

	p = xdr_reserve_space(xdr, 12);
	if (unlikely(p == 0))
		return htonl(NFS4ERR_RESOURCE);
	p = xdr_encode_hyper(p, time->tv_sec);
	*p = htonl(time->tv_nsec);
	return 0;
}

static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
{
	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
		return 0;
	return encode_attr_time(xdr,time);
}

static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
{
	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
		return 0;
	return encode_attr_time(xdr,time);
}

static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
{
	__be32 status;

	hdr->status = xdr_reserve_space(xdr, 4);
	if (unlikely(hdr->status == NULL))
		return htonl(NFS4ERR_RESOURCE);
	status = encode_string(xdr, hdr->taglen, hdr->tag);
	if (unlikely(status != 0))
		return status;
	hdr->nops = xdr_reserve_space(xdr, 4);
	if (unlikely(hdr->nops == NULL))
		return htonl(NFS4ERR_RESOURCE);
	return 0;
}

static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
{
	uint32_t *p;
	
	p = xdr_reserve_space(xdr, 8);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	*p++ = htonl(op);
	*p = res;
	return 0;
}

static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct cb_getattrres *res)
{
	uint32_t *savep = NULL;
	__be32 status = res->status;
	
	if (unlikely(status != 0))
		goto out;
	status = encode_attr_bitmap(xdr, res->bitmap, &savep);
	if (unlikely(status != 0))
		goto out;
	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
	if (unlikely(status != 0))
		goto out;
	status = encode_attr_size(xdr, res->bitmap, res->size);
	if (unlikely(status != 0))
		goto out;
	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
	if (unlikely(status != 0))
		goto out;
	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
out:
	dprintk("%s: exit with status = %d\n", __FUNCTION__, status);
	return status;
}

static __be32 process_op(struct svc_rqst *rqstp,
		struct xdr_stream *xdr_in, void *argp,
		struct xdr_stream *xdr_out, void *resp)
{
	struct callback_op *op = &callback_ops[0];
	unsigned int op_nr = OP_CB_ILLEGAL;
	__be32 status = 0;
	long maxlen;
	__be32 res;

	dprintk("%s: start\n", __FUNCTION__);
	status = decode_op_hdr(xdr_in, &op_nr);
	if (likely(status == 0)) {
		switch (op_nr) {
			case OP_CB_GETATTR:
			case OP_CB_RECALL:
				op = &callback_ops[op_nr];
				break;
			default:
				op_nr = OP_CB_ILLEGAL;
				op = &callback_ops[0];
				status = htonl(NFS4ERR_OP_ILLEGAL);
		}
	}

	maxlen = xdr_out->end - xdr_out->p;
	if (maxlen > 0 && maxlen < PAGE_SIZE) {
		if (likely(status == 0 && op->decode_args != NULL))
			status = op->decode_args(rqstp, xdr_in, argp);
		if (likely(status == 0 && op->process_op != NULL))
			status = op->process_op(argp, resp);
	} else
		status = htonl(NFS4ERR_RESOURCE);

	res = encode_op_hdr(xdr_out, op_nr, status);
	if (status == 0)
		status = res;
	if (op->encode_res != NULL && status == 0)
		status = op->encode_res(rqstp, xdr_out, resp);
	dprintk("%s: done, status = %d\n", __FUNCTION__, status);
	return status;
}

/*
 * Decode, process and encode a COMPOUND
 */
static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *resp)
{
	struct cb_compound_hdr_arg hdr_arg;
	struct cb_compound_hdr_res hdr_res;
	struct xdr_stream xdr_in, xdr_out;
	uint32_t *p;
	__be32 status;
	unsigned int nops = 1;

	dprintk("%s: start\n", __FUNCTION__);

	xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);

	p = (uint32_t*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
	xdr_init_encode(&xdr_out, &rqstp->rq_res, p);

	decode_compound_hdr_arg(&xdr_in, &hdr_arg);
	hdr_res.taglen = hdr_arg.taglen;
	hdr_res.tag = hdr_arg.tag;
	hdr_res.nops = NULL;
	encode_compound_hdr_res(&xdr_out, &hdr_res);

	for (;;) {
		status = process_op(rqstp, &xdr_in, argp, &xdr_out, resp);
		if (status != 0)
			break;
		if (nops == hdr_arg.nops)
			break;
		nops++;
	}
	*hdr_res.status = status;
	*hdr_res.nops = htonl(nops);
	dprintk("%s: done, status = %u\n", __FUNCTION__, status);
	return rpc_success;
}

/*
 * Define NFS4 callback COMPOUND ops.
 */
static struct callback_op callback_ops[] = {
	[0] = {
		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
	},
	[OP_CB_GETATTR] = {
		.process_op = (callback_process_op_t)nfs4_callback_getattr,
		.decode_args = (callback_decode_arg_t)decode_getattr_args,
		.encode_res = (callback_encode_res_t)encode_getattr_res,
		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
	},
	[OP_CB_RECALL] = {
		.process_op = (callback_process_op_t)nfs4_callback_recall,
		.decode_args = (callback_decode_arg_t)decode_recall_args,
		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
	}
};

/*
 * Define NFS4 callback procedures
 */
static struct svc_procedure nfs4_callback_procedures1[] = {
	[CB_NULL] = {
		.pc_func = nfs4_callback_null,
		.pc_decode = (kxdrproc_t)nfs4_decode_void,
		.pc_encode = (kxdrproc_t)nfs4_encode_void,
		.pc_xdrressize = 1,
	},
	[CB_COMPOUND] = {
		.pc_func = nfs4_callback_compound,
		.pc_encode = (kxdrproc_t)nfs4_encode_void,
		.pc_argsize = 256,
		.pc_ressize = 256,
		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
	}
};

struct svc_version nfs4_callback_version1 = {
	.vs_vers = 1,
	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
	.vs_proc = nfs4_callback_procedures1,
	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
	.vs_dispatch = NULL,
};
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/nfs/callback_xdr.c
	3	*
	4	* Copyright (C) 2004 Trond Myklebust
	5	*
	6	* NFSv4 callback encode/decode procedures
	7	*/
1da177e4 LT	8	#include <linux/kernel.h>
	9	#include <linux/sunrpc/svc.h>
	10	#include <linux/nfs4.h>
	11	#include <linux/nfs_fs.h>
4ce79717	12	#include "nfs4_fs.h"
1da177e4 LT	13	#include "callback.h"
	14
	15	#define CB_OP_TAGLEN_MAXSZ (512)
	16	#define CB_OP_HDR_RES_MAXSZ (2 + CB_OP_TAGLEN_MAXSZ)
	17	#define CB_OP_GETATTR_BITMAP_MAXSZ (4)
	18	#define CB_OP_GETATTR_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ + \
	19	CB_OP_GETATTR_BITMAP_MAXSZ + \
	20	2 + 2 + 3 + 3)
	21	#define CB_OP_RECALL_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ)
	22
	23	#define NFSDBG_FACILITY NFSDBG_CALLBACK
	24
e6f684f6 AV	25	typedef __be32 (callback_process_op_t)(void , void *);
	26	typedef __be32 (callback_decode_arg_t)(struct svc_rqst , struct xdr_stream , void );
	27	typedef __be32 (callback_encode_res_t)(struct svc_rqst , struct xdr_stream , void );
1da177e4 LT	28
	29
	30	struct callback_op {
	31	callback_process_op_t process_op;
	32	callback_decode_arg_t decode_args;
	33	callback_encode_res_t encode_res;
	34	long res_maxsize;
	35	};
	36
	37	static struct callback_op callback_ops[];
	38
7111c66e	39	static __be32 nfs4_callback_null(struct svc_rqst rqstp, void argp, void *resp)
1da177e4 LT	40	{
	41	return htonl(NFS4_OK);
	42	}
	43
	44	static int nfs4_decode_void(struct svc_rqst rqstp, uint32_t p, void *dummy)
	45	{
	46	return xdr_argsize_check(rqstp, p);
	47	}
	48
	49	static int nfs4_encode_void(struct svc_rqst rqstp, uint32_t p, void *dummy)
	50	{
	51	return xdr_ressize_check(rqstp, p);
	52	}
	53
	54	static uint32_t read_buf(struct xdr_stream xdr, int nbytes)
	55	{
	56	uint32_t *p;
	57
	58	p = xdr_inline_decode(xdr, nbytes);
	59	if (unlikely(p == NULL))
	60	printk(KERN_WARNING "NFSv4 callback reply buffer overflowed!\n");
	61	return p;
	62	}
	63
e6f684f6	64	static __be32 decode_string(struct xdr_stream xdr, unsigned int len, const char **str)
1da177e4 LT	65	{
	66	uint32_t *p;
	67
	68	p = read_buf(xdr, 4);
	69	if (unlikely(p == NULL))
	70	return htonl(NFS4ERR_RESOURCE);
	71	len = ntohl(p);
	72
	73	if (*len != 0) {
	74	p = read_buf(xdr, *len);
	75	if (unlikely(p == NULL))
	76	return htonl(NFS4ERR_RESOURCE);
	77	str = (const char )p;
	78	} else
	79	*str = NULL;
	80
	81	return 0;
	82	}
	83
e6f684f6	84	static __be32 decode_fh(struct xdr_stream xdr, struct nfs_fh fh)
1da177e4 LT	85	{
	86	uint32_t *p;
	87
	88	p = read_buf(xdr, 4);
	89	if (unlikely(p == NULL))
	90	return htonl(NFS4ERR_RESOURCE);
	91	fh->size = ntohl(*p);
	92	if (fh->size > NFS4_FHSIZE)
	93	return htonl(NFS4ERR_BADHANDLE);
	94	p = read_buf(xdr, fh->size);
	95	if (unlikely(p == NULL))
	96	return htonl(NFS4ERR_RESOURCE);
	97	memcpy(&fh->data[0], p, fh->size);
	98	memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
	99	return 0;
	100	}
	101
e6f684f6	102	static __be32 decode_bitmap(struct xdr_stream xdr, uint32_t bitmap)
1da177e4 LT	103	{
	104	uint32_t *p;
	105	unsigned int attrlen;
	106
	107	p = read_buf(xdr, 4);
	108	if (unlikely(p == NULL))
	109	return htonl(NFS4ERR_RESOURCE);
	110	attrlen = ntohl(*p);
	111	p = read_buf(xdr, attrlen << 2);
	112	if (unlikely(p == NULL))
	113	return htonl(NFS4ERR_RESOURCE);
	114	if (likely(attrlen > 0))
	115	bitmap[0] = ntohl(*p++);
	116	if (attrlen > 1)
	117	bitmap[1] = ntohl(*p);
	118	return 0;
	119	}
	120
e6f684f6	121	static __be32 decode_stateid(struct xdr_stream xdr, nfs4_stateid stateid)
1da177e4 LT	122	{
	123	uint32_t *p;
	124
	125	p = read_buf(xdr, 16);
	126	if (unlikely(p == NULL))
	127	return htonl(NFS4ERR_RESOURCE);
	128	memcpy(stateid->data, p, 16);
	129	return 0;
	130	}
	131
e6f684f6	132	static __be32 decode_compound_hdr_arg(struct xdr_stream xdr, struct cb_compound_hdr_arg hdr)
1da177e4 LT	133	{
	134	uint32_t *p;
	135	unsigned int minor_version;
e6f684f6	136	__be32 status;
1da177e4 LT	137
	138	status = decode_string(xdr, &hdr->taglen, &hdr->tag);
	139	if (unlikely(status != 0))
	140	return status;
	141	/* We do not like overly long tags! */
	142	if (hdr->taglen > CB_OP_TAGLEN_MAXSZ-12 \|\| hdr->taglen < 0) {
	143	printk("NFSv4 CALLBACK %s: client sent tag of length %u\n",
	144	__FUNCTION__, hdr->taglen);
	145	return htonl(NFS4ERR_RESOURCE);
	146	}
	147	p = read_buf(xdr, 12);
	148	if (unlikely(p == NULL))
	149	return htonl(NFS4ERR_RESOURCE);
	150	minor_version = ntohl(*p++);
	151	/* Check minor version is zero. */
	152	if (minor_version != 0) {
	153	printk(KERN_WARNING "%s: NFSv4 server callback with illegal minor version %u!\n",
	154	__FUNCTION__, minor_version);
	155	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
	156	}
	157	hdr->callback_ident = ntohl(*p++);
	158	hdr->nops = ntohl(*p);
	159	return 0;
	160	}
	161
e6f684f6	162	static __be32 decode_op_hdr(struct xdr_stream xdr, unsigned int op)
1da177e4 LT	163	{
	164	uint32_t *p;
	165	p = read_buf(xdr, 4);
	166	if (unlikely(p == NULL))
	167	return htonl(NFS4ERR_RESOURCE);
	168	op = ntohl(p);
	169	return 0;
	170	}
	171
e6f684f6	172	static __be32 decode_getattr_args(struct svc_rqst rqstp, struct xdr_stream xdr, struct cb_getattrargs *args)
1da177e4	173	{
e6f684f6	174	__be32 status;
1da177e4 LT	175
	176	status = decode_fh(xdr, &args->fh);
	177	if (unlikely(status != 0))
	178	goto out;
	179	args->addr = &rqstp->rq_addr;
	180	status = decode_bitmap(xdr, args->bitmap);
	181	out:
	182	dprintk("%s: exit with status = %d\n", __FUNCTION__, status);
	183	return status;
	184	}
	185
e6f684f6	186	static __be32 decode_recall_args(struct svc_rqst rqstp, struct xdr_stream xdr, struct cb_recallargs *args)
1da177e4 LT	187	{
1da177e4 LT	188	uint32_t *p;
e6f684f6	189	__be32 status;
1da177e4 LT	190
	191	args->addr = &rqstp->rq_addr;
	192	status = decode_stateid(xdr, &args->stateid);
	193	if (unlikely(status != 0))
	194	goto out;
	195	p = read_buf(xdr, 4);
	196	if (unlikely(p == NULL)) {
	197	status = htonl(NFS4ERR_RESOURCE);
	198	goto out;
	199	}
	200	args->truncate = ntohl(*p);
	201	status = decode_fh(xdr, &args->fh);
	202	out:
	203	dprintk("%s: exit with status = %d\n", __FUNCTION__, status);
3873bc50	204	return status;
1da177e4 LT	205	}
1da177e4 LT	206
e6f684f6	207	static __be32 encode_string(struct xdr_stream xdr, unsigned int len, const char str)
1da177e4 LT	208	{
	209	uint32_t *p;
	210
	211	p = xdr_reserve_space(xdr, 4 + len);
	212	if (unlikely(p == NULL))
	213	return htonl(NFS4ERR_RESOURCE);
	214	xdr_encode_opaque(p, str, len);
	215	return 0;
	216	}
	217
	218	#define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE\|FATTR4_WORD0_SIZE)
	219	#define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA\|FATTR4_WORD1_TIME_MODIFY)
e6f684f6	220	static __be32 encode_attr_bitmap(struct xdr_stream xdr, const uint32_t bitmap, uint32_t **savep)
1da177e4 LT	221	{
	222	uint32_t bm[2];
	223	uint32_t *p;
	224
	225	bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
	226	bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
	227	if (bm[1] != 0) {
	228	p = xdr_reserve_space(xdr, 16);
	229	if (unlikely(p == NULL))
	230	return htonl(NFS4ERR_RESOURCE);
	231	*p++ = htonl(2);
	232	*p++ = bm[0];
	233	*p++ = bm[1];
	234	} else if (bm[0] != 0) {
	235	p = xdr_reserve_space(xdr, 12);
	236	if (unlikely(p == NULL))
	237	return htonl(NFS4ERR_RESOURCE);
	238	*p++ = htonl(1);
	239	*p++ = bm[0];
	240	} else {
	241	p = xdr_reserve_space(xdr, 8);
	242	if (unlikely(p == NULL))
	243	return htonl(NFS4ERR_RESOURCE);
	244	*p++ = htonl(0);
	245	}
	246	*savep = p;
	247	return 0;
	248	}
	249
e6f684f6	250	static __be32 encode_attr_change(struct xdr_stream xdr, const uint32_t bitmap, uint64_t change)
1da177e4 LT	251	{
	252	uint32_t *p;
	253
	254	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
	255	return 0;
	256	p = xdr_reserve_space(xdr, 8);
	257	if (unlikely(p == 0))
	258	return htonl(NFS4ERR_RESOURCE);
	259	p = xdr_encode_hyper(p, change);
	260	return 0;
	261	}
	262
e6f684f6	263	static __be32 encode_attr_size(struct xdr_stream xdr, const uint32_t bitmap, uint64_t size)
1da177e4 LT	264	{
	265	uint32_t *p;
	266
	267	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
	268	return 0;
	269	p = xdr_reserve_space(xdr, 8);
	270	if (unlikely(p == 0))
	271	return htonl(NFS4ERR_RESOURCE);
	272	p = xdr_encode_hyper(p, size);
	273	return 0;
	274	}
	275
e6f684f6	276	static __be32 encode_attr_time(struct xdr_stream xdr, const struct timespec time)
1da177e4 LT	277	{
	278	uint32_t *p;
	279
	280	p = xdr_reserve_space(xdr, 12);
	281	if (unlikely(p == 0))
	282	return htonl(NFS4ERR_RESOURCE);
	283	p = xdr_encode_hyper(p, time->tv_sec);
	284	*p = htonl(time->tv_nsec);
	285	return 0;
	286	}
	287
e6f684f6	288	static __be32 encode_attr_ctime(struct xdr_stream xdr, const uint32_t bitmap, const struct timespec *time)
1da177e4 LT	289	{
	290	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
	291	return 0;
	292	return encode_attr_time(xdr,time);
	293	}
	294
e6f684f6	295	static __be32 encode_attr_mtime(struct xdr_stream xdr, const uint32_t bitmap, const struct timespec *time)
1da177e4 LT	296	{
	297	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
	298	return 0;
	299	return encode_attr_time(xdr,time);
	300	}
	301
e6f684f6	302	static __be32 encode_compound_hdr_res(struct xdr_stream xdr, struct cb_compound_hdr_res hdr)
1da177e4	303	{
e6f684f6	304	__be32 status;
1da177e4 LT	305
	306	hdr->status = xdr_reserve_space(xdr, 4);
	307	if (unlikely(hdr->status == NULL))
	308	return htonl(NFS4ERR_RESOURCE);
	309	status = encode_string(xdr, hdr->taglen, hdr->tag);
	310	if (unlikely(status != 0))
	311	return status;
	312	hdr->nops = xdr_reserve_space(xdr, 4);
	313	if (unlikely(hdr->nops == NULL))
	314	return htonl(NFS4ERR_RESOURCE);
	315	return 0;
	316	}
	317
e6f684f6	318	static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
1da177e4 LT	319	{
	320	uint32_t *p;
	321
	322	p = xdr_reserve_space(xdr, 8);
	323	if (unlikely(p == NULL))
	324	return htonl(NFS4ERR_RESOURCE);
	325	*p++ = htonl(op);
	326	*p = res;
	327	return 0;
	328	}
	329
e6f684f6	330	static __be32 encode_getattr_res(struct svc_rqst rqstp, struct xdr_stream xdr, const struct cb_getattrres *res)
1da177e4	331	{
a162a6b8	332	uint32_t *savep = NULL;
e6f684f6	333	__be32 status = res->status;
1da177e4 LT	334
	335	if (unlikely(status != 0))
	336	goto out;
	337	status = encode_attr_bitmap(xdr, res->bitmap, &savep);
	338	if (unlikely(status != 0))
	339	goto out;
	340	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
	341	if (unlikely(status != 0))
	342	goto out;
	343	status = encode_attr_size(xdr, res->bitmap, res->size);
	344	if (unlikely(status != 0))
	345	goto out;
	346	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
	347	if (unlikely(status != 0))
	348	goto out;
	349	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
	350	savep = htonl((unsigned int)((char )xdr->p - (char *)(savep+1)));
	351	out:
	352	dprintk("%s: exit with status = %d\n", __FUNCTION__, status);
	353	return status;
	354	}
	355
e6f684f6	356	static __be32 process_op(struct svc_rqst *rqstp,
1da177e4 LT	357	struct xdr_stream xdr_in, void argp,
	358	struct xdr_stream xdr_out, void resp)
	359	{
a162a6b8 TM	360	struct callback_op *op = &callback_ops[0];
a162a6b8 TM	361	unsigned int op_nr = OP_CB_ILLEGAL;
e6f684f6	362	__be32 status = 0;
1da177e4	363	long maxlen;
e6f684f6	364	__be32 res;
1da177e4 LT	365
	366	dprintk("%s: start\n", __FUNCTION__);
	367	status = decode_op_hdr(xdr_in, &op_nr);
a162a6b8 TM	368	if (likely(status == 0)) {
	369	switch (op_nr) {
	370	case OP_CB_GETATTR:
	371	case OP_CB_RECALL:
	372	op = &callback_ops[op_nr];
	373	break;
	374	default:
	375	op_nr = OP_CB_ILLEGAL;
	376	op = &callback_ops[0];
	377	status = htonl(NFS4ERR_OP_ILLEGAL);
	378	}
	379	}
1da177e4 LT	380
	381	maxlen = xdr_out->end - xdr_out->p;
	382	if (maxlen > 0 && maxlen < PAGE_SIZE) {
	383	if (likely(status == 0 && op->decode_args != NULL))
	384	status = op->decode_args(rqstp, xdr_in, argp);
	385	if (likely(status == 0 && op->process_op != NULL))
	386	status = op->process_op(argp, resp);
	387	} else
	388	status = htonl(NFS4ERR_RESOURCE);
	389
	390	res = encode_op_hdr(xdr_out, op_nr, status);
	391	if (status == 0)
	392	status = res;
	393	if (op->encode_res != NULL && status == 0)
	394	status = op->encode_res(rqstp, xdr_out, resp);
	395	dprintk("%s: done, status = %d\n", __FUNCTION__, status);
	396	return status;
	397	}
	398
	399	/*
	400	* Decode, process and encode a COMPOUND
	401	*/
7111c66e	402	static __be32 nfs4_callback_compound(struct svc_rqst rqstp, void argp, void *resp)
1da177e4 LT	403	{
	404	struct cb_compound_hdr_arg hdr_arg;
	405	struct cb_compound_hdr_res hdr_res;
	406	struct xdr_stream xdr_in, xdr_out;
	407	uint32_t *p;
e6f684f6	408	__be32 status;
1da177e4 LT	409	unsigned int nops = 1;
	410
	411	dprintk("%s: start\n", __FUNCTION__);
	412
	413	xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
	414
	415	p = (uint32_t)((char )rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
1da177e4 LT	416	xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
	417
	418	decode_compound_hdr_arg(&xdr_in, &hdr_arg);
	419	hdr_res.taglen = hdr_arg.taglen;
	420	hdr_res.tag = hdr_arg.tag;
a162a6b8	421	hdr_res.nops = NULL;
1da177e4 LT	422	encode_compound_hdr_res(&xdr_out, &hdr_res);
	423
	424	for (;;) {
	425	status = process_op(rqstp, &xdr_in, argp, &xdr_out, resp);
	426	if (status != 0)
	427	break;
	428	if (nops == hdr_arg.nops)
	429	break;
	430	nops++;
	431	}
	432	*hdr_res.status = status;
	433	*hdr_res.nops = htonl(nops);
	434	dprintk("%s: done, status = %u\n", __FUNCTION__, status);
	435	return rpc_success;
	436	}
	437
	438	/*
	439	* Define NFS4 callback COMPOUND ops.
	440	*/
	441	static struct callback_op callback_ops[] = {
	442	[0] = {
	443	.res_maxsize = CB_OP_HDR_RES_MAXSZ,
	444	},
	445	[OP_CB_GETATTR] = {
	446	.process_op = (callback_process_op_t)nfs4_callback_getattr,
	447	.decode_args = (callback_decode_arg_t)decode_getattr_args,
	448	.encode_res = (callback_encode_res_t)encode_getattr_res,
	449	.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
	450	},
	451	[OP_CB_RECALL] = {
	452	.process_op = (callback_process_op_t)nfs4_callback_recall,
	453	.decode_args = (callback_decode_arg_t)decode_recall_args,
	454	.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
	455	}
	456	};
	457
	458	/*
	459	* Define NFS4 callback procedures
	460	*/
	461	static struct svc_procedure nfs4_callback_procedures1[] = {
	462	[CB_NULL] = {
	463	.pc_func = nfs4_callback_null,
	464	.pc_decode = (kxdrproc_t)nfs4_decode_void,
	465	.pc_encode = (kxdrproc_t)nfs4_encode_void,
	466	.pc_xdrressize = 1,
	467	},
	468	[CB_COMPOUND] = {
	469	.pc_func = nfs4_callback_compound,
	470	.pc_encode = (kxdrproc_t)nfs4_encode_void,
	471	.pc_argsize = 256,
	472	.pc_ressize = 256,
	473	.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
	474	}
	475	};
	476
	477	struct svc_version nfs4_callback_version1 = {
	478	.vs_vers = 1,
	479	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
	480	.vs_proc = nfs4_callback_procedures1,
	481	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
	482	.vs_dispatch = NULL,
	483	};
	484