nfs3xdr.c

《嵌入式系统设计与实例开发实验教材二源码》Linux内核移植与编译实验

	replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS3_readdirres_sz) << 2;
	buflen = req->rq_rvec[0].iov_len;
	req->rq_rvec[0].iov_len  = replen;
	req->rq_rvec[1].iov_base = args->buffer;
	req->rq_rvec[1].iov_len  = args->bufsiz;
	req->rq_rvec[2].iov_base = (u8 *) req->rq_rvec[0].iov_base + replen;
	req->rq_rvec[2].iov_len  = buflen - replen;
	req->rq_rlen = buflen + args->bufsiz;
	req->rq_rnr += 2;

	return 0;
}

/*
 * Decode the result of a readdir call.
 * We just check for syntactical correctness.
 */
static int
nfs3_xdr_readdirres(struct rpc_rqst *req, u32 *p, struct nfs3_readdirres *res)
{
	struct iovec	*iov = req->rq_rvec;
	int		hdrlen;
	int		status, nr;
	unsigned int	len;
	u32		*entry, *end;

	status = ntohl(*p++);
	/* Decode post_op_attrs */
	p = xdr_decode_post_op_attr(p, res->dir_attr);
	if (status)
		return -nfs_stat_to_errno(status);
	/* Decode verifier cookie */
	if (res->verf) {
		res->verf[0] = *p++;
		res->verf[1] = *p++;
	} else {
		p += 2;
	}

	hdrlen = (u8 *) p - (u8 *) iov->iov_base;
	if (iov->iov_len > hdrlen) {
		dprintk("NFS: READDIR header is short. iovec will be shifted.\n");
		xdr_shift_iovec(iov, req->rq_rnr, iov->iov_len - hdrlen);
	}

	p   = (u32 *) iov[1].iov_base;
	end = (u32 *) ((u8 *) p + iov[1].iov_len);
	for (nr = 0; *p++; nr++) {
		entry = p - 1;
		if (p + 3 > end)
			goto short_pkt;
		p += 2;				/* inode # */
		len = ntohl(*p++);		/* string length */
		p += XDR_QUADLEN(len) + 2;	/* name + cookie */
		if (len > NFS3_MAXNAMLEN) {
			printk(KERN_WARNING "NFS: giant filename in readdir (len %x)!\n",
						len);
			return -errno_NFSERR_IO;
		}

		if (res->plus) {
			/* post_op_attr */
			if (p > end)
				goto short_pkt;
			if (*p++) {
				p += 21;
				if (p > end)
					goto short_pkt;
			}
			/* post_op_fh3 */
			if (*p++) {
				if (p > end)
					goto short_pkt;
				len = ntohl(*p++);
				if (len > NFS3_FHSIZE) {
					printk(KERN_WARNING "NFS: giant filehandle in "
						"readdir (len %x)!\n", len);
					return -errno_NFSERR_IO;
				}
				p += XDR_QUADLEN(len);
			}
		}

		if (p + 2 > end)
			goto short_pkt;
	}

	return nr;
 short_pkt:
	printk(KERN_NOTICE "NFS: short packet in readdir reply!\n");
	/* truncate listing */
	entry[0] = entry[1] = 0;
	return nr;
}

u32 *
nfs3_decode_dirent(u32 *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) {
		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 {
			/* If we don't get a file handle, the attrs
			 * aren't worth a lot. */
			entry->fattr.valid = 0;
		}
	}

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

/*
 * Encode COMMIT arguments
 */
static int
nfs3_xdr_commitargs(struct rpc_rqst *req, u32 *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;
}

/*
 * NFS XDR decode functions
 */
/*
 * Decode void reply
 */
static int
nfs3_xdr_dec_void(struct rpc_rqst *req, u32 *p, void *dummy)
{
	return 0;
}

/*
 * Decode attrstat reply.
 */
static int
nfs3_xdr_attrstat(struct rpc_rqst *req, u32 *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, u32 *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;
}

/*
 * Decode LOOKUP reply
 */
static int
nfs3_xdr_lookupres(struct rpc_rqst *req, u32 *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, u32 *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, u32 *p, struct nfs3_readlinkargs *args)
{
	struct rpc_task *task = req->rq_task;
	struct rpc_auth *auth = task->tk_auth;
	int		buflen, replen;

	p = xdr_encode_fhandle(p, args->fh);
	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
	replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS3_readlinkres_sz) << 2;
	buflen = req->rq_rvec[0].iov_len;
	req->rq_rvec[0].iov_len  = replen;
	req->rq_rvec[1].iov_base = args->buffer;
	req->rq_rvec[1].iov_len  = args->bufsiz;
	req->rq_rvec[2].iov_base = (u8 *) req->rq_rvec[0].iov_base + replen;
	req->rq_rvec[2].iov_len  = buflen - replen;
	req->rq_rlen = buflen + args->bufsiz;
	req->rq_rnr += 2;
	return 0;
}

/*
 * Decode READLINK reply
 */
static int
nfs3_xdr_readlinkres(struct rpc_rqst *req, u32 *p, struct nfs3_readlinkres *res)
{
	struct iovec	*iov = req->rq_rvec;
	int		hdrlen;
	u32	*strlen;
	char	*string;
	int	status;
	unsigned int len;

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

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

	hdrlen = (u8 *) p - (u8 *) iov->iov_base;
	if (iov->iov_len > hdrlen) {
		dprintk("NFS: READLINK header is short. iovec will be shifted.\n");
		xdr_shift_iovec(iov, req->rq_rnr, iov->iov_len - hdrlen);
	}

	strlen = (u32*)res->buffer;
	/* Convert length of symlink */
	len = ntohl(*strlen);
	if (len > res->bufsiz - 5)
		len = res->bufsiz - 5;
	*strlen = len;
	/* NULL terminate the string we got */
	string = (char *)(strlen + 1);
	string[len] = 0;
	return 0;
}

/*
 * Decode READ reply
 */
static int
nfs3_xdr_readres(struct rpc_rqst *req, u32 *p, struct nfs_readres *res)
{
	struct iovec *iov = req->rq_rvec;
	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) {
		printk(KERN_WARNING "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 header is short. iovec will be shifted.\n");
		xdr_shift_iovec(iov, req->rq_rnr, iov->iov_len - hdrlen);
	}

	recvd = req->rq_rlen - hdrlen;
	if (count > recvd) {
		printk(KERN_WARNING "NFS: server cheating in read reply: "
			"count %d > recvd %d\n", count, recvd);
		count = recvd;
	}

	if (count < res->count) {
		xdr_zero_iovec(iov+1, req->rq_rnr-2, res->count - count);
		res->count = count;
	}

	return count;
}

/*
 * Decode WRITE response
 */
static int
nfs3_xdr_writeres(struct rpc_rqst *req, u32 *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, u32 *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, u32 *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, u32 *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, u32 *p, struct nfs_fsinfo *res)
{
	struct nfs_fattr dummy;
	int		status;

	status = ntohl(*p++);

	p = xdr_decode_post_op_attr(p, &dummy);
	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, u32 *p, struct nfs_fsinfo *res)
{
	struct nfs_fattr dummy;
	int		status;

	status = ntohl(*p++);

	p = xdr_decode_post_op_attr(p, &dummy);
	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 */
	return 0;
}

/*
 * Decode PATHCONF reply
 */
static int
nfs3_xdr_pathconfres(struct rpc_rqst *req, u32 *p, struct nfs_fsinfo *res)
{
	struct nfs_fattr dummy;
	int		status;

	status = ntohl(*p++);

	p = xdr_decode_post_op_attr(p, &dummy);
	if (status != 0)
		return -nfs_stat_to_errno(status);
	res->linkmax = ntohl(*p++);
	res->namelen = ntohl(*p++);

	/* ignore remaining fields */
	return 0;
}

/*
 * Decode COMMIT reply
 */
static int
nfs3_xdr_commitres(struct rpc_rqst *req, u32 *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;
}

#ifndef MAX
# define MAX(a, b)	(((a) > (b))? (a) : (b))
#endif

#define PROC(proc, argtype, restype)				\
    { "nfs3_" #proc,						\
      (kxdrproc_t) nfs3_xdr_##argtype,				\
      (kxdrproc_t) nfs3_xdr_##restype,				\
      MAX(NFS3_##argtype##_sz,NFS3_##restype##_sz) << 2,	\
      0							\
    }

static struct rpc_procinfo	nfs3_procedures[22] = {
  PROC(null,		enc_void,	dec_void),
  PROC(getattr,		fhandle,	attrstat),
  PROC(setattr, 	sattrargs,	wccstat),
  PROC(lookup,		diropargs,	lookupres),
  PROC(access,		accessargs,	accessres),
  PROC(readlink,	readlinkargs,	readlinkres),
  PROC(read,		readargs,	readres),
  PROC(write,		writeargs,	writeres),
  PROC(create,		createargs,	createres),
  PROC(mkdir,		mkdirargs,	createres),
  PROC(symlink,		symlinkargs,	createres),
  PROC(mknod,		mknodargs,	createres),
  PROC(remove,		diropargs,	wccstat),
  PROC(rmdir,		diropargs,	wccstat),
  PROC(rename,		renameargs,	renameres),
  PROC(link,		linkargs,	linkres),
  PROC(readdir,		readdirargs,	readdirres),
  PROC(readdirplus,	readdirargs,	readdirres),
  PROC(fsstat,		fhandle,	fsstatres),
  PROC(fsinfo,  	fhandle,	fsinfores),
  PROC(pathconf,	fhandle,	pathconfres),
  PROC(commit,		commitargs,	commitres),
};

struct rpc_version		nfs_version3 = {
	3,
	sizeof(nfs3_procedures)/sizeof(nfs3_procedures[0]),
	nfs3_procedures
};