nfs3xdr.c

linux 内核源代码

__be32 *
nfs3_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus)
{
	struct nfs_entry old = *entry;

	if (!*p++) {
		if (!*p)
			return ERR_PTR(-EAGAIN);
		entry->eof = 1;
		return ERR_PTR(-EBADCOOKIE);
	}

	p = xdr_decode_hyper(p, &entry->ino);
	entry->len  = ntohl(*p++);
	entry->name = (const char *) p;
	p += XDR_QUADLEN(entry->len);
	entry->prev_cookie = entry->cookie;
	p = xdr_decode_hyper(p, &entry->cookie);

	if (plus) {
		entry->fattr->valid = 0;
		p = xdr_decode_post_op_attr(p, entry->fattr);
		/* In fact, a post_op_fh3: */
		if (*p++) {
			p = xdr_decode_fhandle(p, entry->fh);
			/* Ugh -- server reply was truncated */
			if (p == NULL) {
				dprintk("NFS: FH truncated\n");
				*entry = old;
				return ERR_PTR(-EAGAIN);
			}
		} else
			memset((u8*)(entry->fh), 0, sizeof(*entry->fh));
	}

	entry->eof = !p[0] && p[1];
	return p;
}

/*
 * Encode COMMIT arguments
 */
static int
nfs3_xdr_commitargs(struct rpc_rqst *req, __be32 *p, struct nfs_writeargs *args)
{
	p = xdr_encode_fhandle(p, args->fh);
	p = xdr_encode_hyper(p, args->offset);
	*p++ = htonl(args->count);
	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
	return 0;
}

#ifdef CONFIG_NFS_V3_ACL
/*
 * Encode GETACL arguments
 */
static int
nfs3_xdr_getaclargs(struct rpc_rqst *req, __be32 *p,
		    struct nfs3_getaclargs *args)
{
	struct rpc_auth	*auth = req->rq_task->tk_msg.rpc_cred->cr_auth;
	unsigned int replen;

	p = xdr_encode_fhandle(p, args->fh);
	*p++ = htonl(args->mask);
	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);

	if (args->mask & (NFS_ACL | NFS_DFACL)) {
		/* Inline the page array */
		replen = (RPC_REPHDRSIZE + auth->au_rslack +
			  ACL3_getaclres_sz) << 2;
		xdr_inline_pages(&req->rq_rcv_buf, replen, args->pages, 0,
				 NFSACL_MAXPAGES << PAGE_SHIFT);
	}
	return 0;
}

/*
 * Encode SETACL arguments
 */
static int
nfs3_xdr_setaclargs(struct rpc_rqst *req, __be32 *p,
                   struct nfs3_setaclargs *args)
{
	struct xdr_buf *buf = &req->rq_snd_buf;
	unsigned int base, len_in_head, len = nfsacl_size(
		(args->mask & NFS_ACL)   ? args->acl_access  : NULL,
		(args->mask & NFS_DFACL) ? args->acl_default : NULL);
	int count, err;

	p = xdr_encode_fhandle(p, NFS_FH(args->inode));
	*p++ = htonl(args->mask);
	base = (char *)p - (char *)buf->head->iov_base;
	/* put as much of the acls into head as possible. */
	len_in_head = min_t(unsigned int, buf->head->iov_len - base, len);
	len -= len_in_head;
	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p + (len_in_head >> 2));

	for (count = 0; (count << PAGE_SHIFT) < len; count++) {
		args->pages[count] = alloc_page(GFP_KERNEL);
		if (!args->pages[count]) {
			while (count)
				__free_page(args->pages[--count]);
			return -ENOMEM;
		}
	}
	xdr_encode_pages(buf, args->pages, 0, len);

	err = nfsacl_encode(buf, base, args->inode,
			    (args->mask & NFS_ACL) ?
			    args->acl_access : NULL, 1, 0);
	if (err > 0)
		err = nfsacl_encode(buf, base + err, args->inode,
				    (args->mask & NFS_DFACL) ?
				    args->acl_default : NULL, 1,
				    NFS_ACL_DEFAULT);
	return (err > 0) ? 0 : err;
}
#endif  /* CONFIG_NFS_V3_ACL */

/*
 * NFS XDR decode functions
 */

/*
 * Decode attrstat reply.
 */
static int
nfs3_xdr_attrstat(struct rpc_rqst *req, __be32 *p, struct nfs_fattr *fattr)
{
	int	status;

	if ((status = ntohl(*p++)))
		return -nfs_stat_to_errno(status);
	xdr_decode_fattr(p, fattr);
	return 0;
}

/*
 * Decode status+wcc_data reply
 * SATTR, REMOVE, RMDIR
 */
static int
nfs3_xdr_wccstat(struct rpc_rqst *req, __be32 *p, struct nfs_fattr *fattr)
{
	int	status;

	if ((status = ntohl(*p++)))
		status = -nfs_stat_to_errno(status);
	xdr_decode_wcc_data(p, fattr);
	return status;
}

static int
nfs3_xdr_removeres(struct rpc_rqst *req, __be32 *p, struct nfs_removeres *res)
{
	return nfs3_xdr_wccstat(req, p, &res->dir_attr);
}

/*
 * Decode LOOKUP reply
 */
static int
nfs3_xdr_lookupres(struct rpc_rqst *req, __be32 *p, struct nfs3_diropres *res)
{
	int	status;

	if ((status = ntohl(*p++))) {
		status = -nfs_stat_to_errno(status);
	} else {
		if (!(p = xdr_decode_fhandle(p, res->fh)))
			return -errno_NFSERR_IO;
		p = xdr_decode_post_op_attr(p, res->fattr);
	}
	xdr_decode_post_op_attr(p, res->dir_attr);
	return status;
}

/*
 * Decode ACCESS reply
 */
static int
nfs3_xdr_accessres(struct rpc_rqst *req, __be32 *p, struct nfs3_accessres *res)
{
	int	status = ntohl(*p++);

	p = xdr_decode_post_op_attr(p, res->fattr);
	if (status)
		return -nfs_stat_to_errno(status);
	res->access = ntohl(*p++);
	return 0;
}

static int
nfs3_xdr_readlinkargs(struct rpc_rqst *req, __be32 *p, struct nfs3_readlinkargs *args)
{
	struct rpc_auth	*auth = req->rq_task->tk_msg.rpc_cred->cr_auth;
	unsigned int replen;

	p = xdr_encode_fhandle(p, args->fh);
	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);

	/* Inline the page array */
	replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS3_readlinkres_sz) << 2;
	xdr_inline_pages(&req->rq_rcv_buf, replen, args->pages, args->pgbase, args->pglen);
	return 0;
}

/*
 * Decode READLINK reply
 */
static int
nfs3_xdr_readlinkres(struct rpc_rqst *req, __be32 *p, struct nfs_fattr *fattr)
{
	struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
	struct kvec *iov = rcvbuf->head;
	int hdrlen, len, recvd;
	char	*kaddr;
	int	status;

	status = ntohl(*p++);
	p = xdr_decode_post_op_attr(p, fattr);

	if (status != 0)
		return -nfs_stat_to_errno(status);

	/* Convert length of symlink */
	len = ntohl(*p++);
	if (len >= rcvbuf->page_len || len <= 0) {
		dprintk("nfs: server returned giant symlink!\n");
		return -ENAMETOOLONG;
	}

	hdrlen = (u8 *) p - (u8 *) iov->iov_base;
	if (iov->iov_len < hdrlen) {
		dprintk("NFS: READLINK reply header overflowed:"
				"length %d > %Zu\n", hdrlen, iov->iov_len);
		return -errno_NFSERR_IO;
	} else if (iov->iov_len != hdrlen) {
		dprintk("NFS: READLINK header is short. "
			"iovec will be shifted.\n");
		xdr_shift_buf(rcvbuf, iov->iov_len - hdrlen);
	}
	recvd = req->rq_rcv_buf.len - hdrlen;
	if (recvd < len) {
		dprintk("NFS: server cheating in readlink reply: "
				"count %u > recvd %u\n", len, recvd);
		return -EIO;
	}

	/* NULL terminate the string we got */
	kaddr = (char*)kmap_atomic(rcvbuf->pages[0], KM_USER0);
	kaddr[len+rcvbuf->page_base] = '\0';
	kunmap_atomic(kaddr, KM_USER0);
	return 0;
}

/*
 * Decode READ reply
 */
static int
nfs3_xdr_readres(struct rpc_rqst *req, __be32 *p, struct nfs_readres *res)
{
	struct kvec *iov = req->rq_rcv_buf.head;
	int	status, count, ocount, recvd, hdrlen;

	status = ntohl(*p++);
	p = xdr_decode_post_op_attr(p, res->fattr);

	if (status != 0)
		return -nfs_stat_to_errno(status);

	/* Decode reply could and EOF flag. NFSv3 is somewhat redundant
	 * in that it puts the count both in the res struct and in the
	 * opaque data count. */
	count    = ntohl(*p++);
	res->eof = ntohl(*p++);
	ocount   = ntohl(*p++);

	if (ocount != count) {
		dprintk("NFS: READ count doesn't match RPC opaque count.\n");
		return -errno_NFSERR_IO;
	}

	hdrlen = (u8 *) p - (u8 *) iov->iov_base;
	if (iov->iov_len < hdrlen) {
		dprintk("NFS: READ reply header overflowed:"
				"length %d > %Zu\n", hdrlen, iov->iov_len);
       		return -errno_NFSERR_IO;
	} else if (iov->iov_len != hdrlen) {
		dprintk("NFS: READ header is short. iovec will be shifted.\n");
		xdr_shift_buf(&req->rq_rcv_buf, iov->iov_len - hdrlen);
	}

	recvd = req->rq_rcv_buf.len - hdrlen;
	if (count > recvd) {
		dprintk("NFS: server cheating in read reply: "
			"count %d > recvd %d\n", count, recvd);
		count = recvd;
		res->eof = 0;
	}

	if (count < res->count)
		res->count = count;

	return count;
}

/*
 * Decode WRITE response
 */
static int
nfs3_xdr_writeres(struct rpc_rqst *req, __be32 *p, struct nfs_writeres *res)
{
	int	status;

	status = ntohl(*p++);
	p = xdr_decode_wcc_data(p, res->fattr);

	if (status != 0)
		return -nfs_stat_to_errno(status);

	res->count = ntohl(*p++);
	res->verf->committed = (enum nfs3_stable_how)ntohl(*p++);
	res->verf->verifier[0] = *p++;
	res->verf->verifier[1] = *p++;

	return res->count;
}

/*
 * Decode a CREATE response
 */
static int
nfs3_xdr_createres(struct rpc_rqst *req, __be32 *p, struct nfs3_diropres *res)
{
	int	status;

	status = ntohl(*p++);
	if (status == 0) {
		if (*p++) {
			if (!(p = xdr_decode_fhandle(p, res->fh)))
				return -errno_NFSERR_IO;
			p = xdr_decode_post_op_attr(p, res->fattr);
		} else {
			memset(res->fh, 0, sizeof(*res->fh));
			/* Do decode post_op_attr but set it to NULL */
			p = xdr_decode_post_op_attr(p, res->fattr);
			res->fattr->valid = 0;
		}
	} else {
		status = -nfs_stat_to_errno(status);
	}
	p = xdr_decode_wcc_data(p, res->dir_attr);
	return status;
}

/*
 * Decode RENAME reply
 */
static int
nfs3_xdr_renameres(struct rpc_rqst *req, __be32 *p, struct nfs3_renameres *res)
{
	int	status;

	if ((status = ntohl(*p++)) != 0)
		status = -nfs_stat_to_errno(status);
	p = xdr_decode_wcc_data(p, res->fromattr);
	p = xdr_decode_wcc_data(p, res->toattr);
	return status;
}

/*
 * Decode LINK reply
 */
static int
nfs3_xdr_linkres(struct rpc_rqst *req, __be32 *p, struct nfs3_linkres *res)
{
	int	status;

	if ((status = ntohl(*p++)) != 0)
		status = -nfs_stat_to_errno(status);
	p = xdr_decode_post_op_attr(p, res->fattr);
	p = xdr_decode_wcc_data(p, res->dir_attr);
	return status;
}

/*
 * Decode FSSTAT reply
 */
static int
nfs3_xdr_fsstatres(struct rpc_rqst *req, __be32 *p, struct nfs_fsstat *res)
{
	int		status;

	status = ntohl(*p++);

	p = xdr_decode_post_op_attr(p, res->fattr);
	if (status != 0)
		return -nfs_stat_to_errno(status);

	p = xdr_decode_hyper(p, &res->tbytes);
	p = xdr_decode_hyper(p, &res->fbytes);
	p = xdr_decode_hyper(p, &res->abytes);
	p = xdr_decode_hyper(p, &res->tfiles);
	p = xdr_decode_hyper(p, &res->ffiles);
	p = xdr_decode_hyper(p, &res->afiles);

	/* ignore invarsec */
	return 0;
}

/*
 * Decode FSINFO reply
 */
static int
nfs3_xdr_fsinfores(struct rpc_rqst *req, __be32 *p, struct nfs_fsinfo *res)
{
	int		status;

	status = ntohl(*p++);

	p = xdr_decode_post_op_attr(p, res->fattr);
	if (status != 0)
		return -nfs_stat_to_errno(status);

	res->rtmax  = ntohl(*p++);
	res->rtpref = ntohl(*p++);
	res->rtmult = ntohl(*p++);
	res->wtmax  = ntohl(*p++);
	res->wtpref = ntohl(*p++);
	res->wtmult = ntohl(*p++);
	res->dtpref = ntohl(*p++);
	p = xdr_decode_hyper(p, &res->maxfilesize);

	/* ignore time_delta and properties */
	res->lease_time = 0;
	return 0;
}

/*
 * Decode PATHCONF reply
 */
static int
nfs3_xdr_pathconfres(struct rpc_rqst *req, __be32 *p, struct nfs_pathconf *res)
{
	int		status;

	status = ntohl(*p++);

	p = xdr_decode_post_op_attr(p, res->fattr);
	if (status != 0)
		return -nfs_stat_to_errno(status);
	res->max_link = ntohl(*p++);
	res->max_namelen = ntohl(*p++);

	/* ignore remaining fields */
	return 0;
}

/*
 * Decode COMMIT reply
 */
static int
nfs3_xdr_commitres(struct rpc_rqst *req, __be32 *p, struct nfs_writeres *res)
{
	int		status;

	status = ntohl(*p++);
	p = xdr_decode_wcc_data(p, res->fattr);
	if (status != 0)
		return -nfs_stat_to_errno(status);

	res->verf->verifier[0] = *p++;
	res->verf->verifier[1] = *p++;
	return 0;
}

#ifdef CONFIG_NFS_V3_ACL
/*
 * Decode GETACL reply
 */
static int
nfs3_xdr_getaclres(struct rpc_rqst *req, __be32 *p,
		   struct nfs3_getaclres *res)
{
	struct xdr_buf *buf = &req->rq_rcv_buf;
	int status = ntohl(*p++);
	struct posix_acl **acl;
	unsigned int *aclcnt;
	int err, base;

	if (status != 0)
		return -nfs_stat_to_errno(status);
	p = xdr_decode_post_op_attr(p, res->fattr);
	res->mask = ntohl(*p++);
	if (res->mask & ~(NFS_ACL|NFS_ACLCNT|NFS_DFACL|NFS_DFACLCNT))
		return -EINVAL;
	base = (char *)p - (char *)req->rq_rcv_buf.head->iov_base;

	acl = (res->mask & NFS_ACL) ? &res->acl_access : NULL;
	aclcnt = (res->mask & NFS_ACLCNT) ? &res->acl_access_count : NULL;
	err = nfsacl_decode(buf, base, aclcnt, acl);

	acl = (res->mask & NFS_DFACL) ? &res->acl_default : NULL;
	aclcnt = (res->mask & NFS_DFACLCNT) ? &res->acl_default_count : NULL;
	if (err > 0)
		err = nfsacl_decode(buf, base + err, aclcnt, acl);
	return (err > 0) ? 0 : err;
}

/*
 * Decode setacl reply.
 */
static int
nfs3_xdr_setaclres(struct rpc_rqst *req, __be32 *p, struct nfs_fattr *fattr)
{
	int status = ntohl(*p++);

	if (status)
		return -nfs_stat_to_errno(status);
	xdr_decode_post_op_attr(p, fattr);
	return 0;
}
#endif  /* CONFIG_NFS_V3_ACL */

#define PROC(proc, argtype, restype, timer)				\
[NFS3PROC_##proc] = {							\
	.p_proc      = NFS3PROC_##proc,					\
	.p_encode    = (kxdrproc_t) nfs3_xdr_##argtype,			\
	.p_decode    = (kxdrproc_t) nfs3_xdr_##restype,			\
	.p_arglen    = NFS3_##argtype##_sz,				\
	.p_replen    = NFS3_##restype##_sz,				\
	.p_timer     = timer,						\
	.p_statidx   = NFS3PROC_##proc,					\
	.p_name      = #proc,						\
	}

struct rpc_procinfo	nfs3_procedures[] = {
  PROC(GETATTR,		fhandle,	attrstat, 1),
  PROC(SETATTR, 	sattrargs,	wccstat, 0),
  PROC(LOOKUP,		diropargs,	lookupres, 2),
  PROC(ACCESS,		accessargs,	accessres, 1),
  PROC(READLINK,	readlinkargs,	readlinkres, 3),
  PROC(READ,		readargs,	readres, 3),
  PROC(WRITE,		writeargs,	writeres, 4),
  PROC(CREATE,		createargs,	createres, 0),
  PROC(MKDIR,		mkdirargs,	createres, 0),
  PROC(SYMLINK,		symlinkargs,	createres, 0),
  PROC(MKNOD,		mknodargs,	createres, 0),
  PROC(REMOVE,		removeargs,	removeres, 0),
  PROC(RMDIR,		diropargs,	wccstat, 0),
  PROC(RENAME,		renameargs,	renameres, 0),
  PROC(LINK,		linkargs,	linkres, 0),
  PROC(READDIR,		readdirargs,	readdirres, 3),
  PROC(READDIRPLUS,	readdirargs,	readdirres, 3),
  PROC(FSSTAT,		fhandle,	fsstatres, 0),
  PROC(FSINFO,  	fhandle,	fsinfores, 0),
  PROC(PATHCONF,	fhandle,	pathconfres, 0),
  PROC(COMMIT,		commitargs,	commitres, 5),
};

struct rpc_version		nfs_version3 = {
	.number			= 3,
	.nrprocs		= ARRAY_SIZE(nfs3_procedures),
	.procs			= nfs3_procedures
};

#ifdef CONFIG_NFS_V3_ACL
static struct rpc_procinfo	nfs3_acl_procedures[] = {
	[ACLPROC3_GETACL] = {
		.p_proc = ACLPROC3_GETACL,
		.p_encode = (kxdrproc_t) nfs3_xdr_getaclargs,
		.p_decode = (kxdrproc_t) nfs3_xdr_getaclres,
		.p_arglen = ACL3_getaclargs_sz,
		.p_replen = ACL3_getaclres_sz,
		.p_timer = 1,
		.p_name = "GETACL",
	},
	[ACLPROC3_SETACL] = {
		.p_proc = ACLPROC3_SETACL,
		.p_encode = (kxdrproc_t) nfs3_xdr_setaclargs,
		.p_decode = (kxdrproc_t) nfs3_xdr_setaclres,
		.p_arglen = ACL3_setaclargs_sz,
		.p_replen = ACL3_setaclres_sz,
		.p_timer = 0,
		.p_name = "SETACL",
	},
};

struct rpc_version		nfsacl_version3 = {
	.number			= 3,
	.nrprocs		= sizeof(nfs3_acl_procedures)/
				  sizeof(nfs3_acl_procedures[0]),
	.procs			= nfs3_acl_procedures,
};
#endif  /* CONFIG_NFS_V3_ACL */