nfs3xdr.c

linux 内核源代码

/*
 * linux/fs/nfsd/nfs3xdr.c
 *
 * XDR support for nfsd/protocol version 3.
 *
 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <[e-mail]>
 *
 * 2003-08-09 Jamie Lokier: Use htonl() for nanoseconds, not htons()!
 */

#include <linux/types.h>
#include <linux/time.h>
#include <linux/nfs3.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/dcache.h>
#include <linux/namei.h>
#include <linux/mm.h>
#include <linux/vfs.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>
#include <linux/nfsd/xdr3.h>

#define NFSDDBG_FACILITY		NFSDDBG_XDR


/*
 * Mapping of S_IF* types to NFS file types
 */
static u32	nfs3_ftypes[] = {
	NF3NON,  NF3FIFO, NF3CHR, NF3BAD,
	NF3DIR,  NF3BAD,  NF3BLK, NF3BAD,
	NF3REG,  NF3BAD,  NF3LNK, NF3BAD,
	NF3SOCK, NF3BAD,  NF3LNK, NF3BAD,
};

/*
 * XDR functions for basic NFS types
 */
static __be32 *
encode_time3(__be32 *p, struct timespec *time)
{
	*p++ = htonl((u32) time->tv_sec); *p++ = htonl(time->tv_nsec);
	return p;
}

static __be32 *
decode_time3(__be32 *p, struct timespec *time)
{
	time->tv_sec = ntohl(*p++);
	time->tv_nsec = ntohl(*p++);
	return p;
}

static __be32 *
decode_fh(__be32 *p, struct svc_fh *fhp)
{
	unsigned int size;
	fh_init(fhp, NFS3_FHSIZE);
	size = ntohl(*p++);
	if (size > NFS3_FHSIZE)
		return NULL;

	memcpy(&fhp->fh_handle.fh_base, p, size);
	fhp->fh_handle.fh_size = size;
	return p + XDR_QUADLEN(size);
}

/* Helper function for NFSv3 ACL code */
__be32 *nfs3svc_decode_fh(__be32 *p, struct svc_fh *fhp)
{
	return decode_fh(p, fhp);
}

static __be32 *
encode_fh(__be32 *p, struct svc_fh *fhp)
{
	unsigned int size = fhp->fh_handle.fh_size;
	*p++ = htonl(size);
	if (size) p[XDR_QUADLEN(size)-1]=0;
	memcpy(p, &fhp->fh_handle.fh_base, size);
	return p + XDR_QUADLEN(size);
}

/*
 * Decode a file name and make sure that the path contains
 * no slashes or null bytes.
 */
static __be32 *
decode_filename(__be32 *p, char **namp, int *lenp)
{
	char		*name;
	int		i;

	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS3_MAXNAMLEN)) != NULL) {
		for (i = 0, name = *namp; i < *lenp; i++, name++) {
			if (*name == '\0' || *name == '/')
				return NULL;
		}
	}

	return p;
}

static __be32 *
decode_sattr3(__be32 *p, struct iattr *iap)
{
	u32	tmp;

	iap->ia_valid = 0;

	if (*p++) {
		iap->ia_valid |= ATTR_MODE;
		iap->ia_mode = ntohl(*p++);
	}
	if (*p++) {
		iap->ia_valid |= ATTR_UID;
		iap->ia_uid = ntohl(*p++);
	}
	if (*p++) {
		iap->ia_valid |= ATTR_GID;
		iap->ia_gid = ntohl(*p++);
	}
	if (*p++) {
		u64	newsize;

		iap->ia_valid |= ATTR_SIZE;
		p = xdr_decode_hyper(p, &newsize);
		if (newsize <= NFS_OFFSET_MAX)
			iap->ia_size = newsize;
		else
			iap->ia_size = NFS_OFFSET_MAX;
	}
	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
		iap->ia_valid |= ATTR_ATIME;
	} else if (tmp == 2) {		/* set to client time */
		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
		iap->ia_atime.tv_sec = ntohl(*p++);
		iap->ia_atime.tv_nsec = ntohl(*p++);
	}
	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
		iap->ia_valid |= ATTR_MTIME;
	} else if (tmp == 2) {		/* set to client time */
		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
		iap->ia_mtime.tv_sec = ntohl(*p++);
		iap->ia_mtime.tv_nsec = ntohl(*p++);
	}
	return p;
}

static __be32 *encode_fsid(__be32 *p, struct svc_fh *fhp)
{
	u64 f;
	switch(fsid_source(fhp)) {
	default:
	case FSIDSOURCE_DEV:
		p = xdr_encode_hyper(p, (u64)huge_encode_dev
				     (fhp->fh_dentry->d_inode->i_sb->s_dev));
		break;
	case FSIDSOURCE_FSID:
		p = xdr_encode_hyper(p, (u64) fhp->fh_export->ex_fsid);
		break;
	case FSIDSOURCE_UUID:
		f = ((u64*)fhp->fh_export->ex_uuid)[0];
		f ^= ((u64*)fhp->fh_export->ex_uuid)[1];
		p = xdr_encode_hyper(p, f);
		break;
	}
	return p;
}

static __be32 *
encode_fattr3(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
	      struct kstat *stat)
{
	*p++ = htonl(nfs3_ftypes[(stat->mode & S_IFMT) >> 12]);
	*p++ = htonl((u32) stat->mode);
	*p++ = htonl((u32) stat->nlink);
	*p++ = htonl((u32) nfsd_ruid(rqstp, stat->uid));
	*p++ = htonl((u32) nfsd_rgid(rqstp, stat->gid));
	if (S_ISLNK(stat->mode) && stat->size > NFS3_MAXPATHLEN) {
		p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
	} else {
		p = xdr_encode_hyper(p, (u64) stat->size);
	}
	p = xdr_encode_hyper(p, ((u64)stat->blocks) << 9);
	*p++ = htonl((u32) MAJOR(stat->rdev));
	*p++ = htonl((u32) MINOR(stat->rdev));
	p = encode_fsid(p, fhp);
	p = xdr_encode_hyper(p, stat->ino);
	p = encode_time3(p, &stat->atime);
	p = encode_time3(p, &stat->mtime);
	p = encode_time3(p, &stat->ctime);

	return p;
}

static __be32 *
encode_saved_post_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
{
	/* Attributes to follow */
	*p++ = xdr_one;
	return encode_fattr3(rqstp, p, fhp, &fhp->fh_post_attr);
}

/*
 * Encode post-operation attributes.
 * The inode may be NULL if the call failed because of a stale file
 * handle. In this case, no attributes are returned.
 */
static __be32 *
encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
{
	struct dentry *dentry = fhp->fh_dentry;
	if (dentry && dentry->d_inode) {
	        int err;
		struct kstat stat;

		err = vfs_getattr(fhp->fh_export->ex_mnt, dentry, &stat);
		if (!err) {
			*p++ = xdr_one;		/* attributes follow */
			lease_get_mtime(dentry->d_inode, &stat.mtime);
			return encode_fattr3(rqstp, p, fhp, &stat);
		}
	}
	*p++ = xdr_zero;
	return p;
}

/* Helper for NFSv3 ACLs */
__be32 *
nfs3svc_encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
{
	return encode_post_op_attr(rqstp, p, fhp);
}

/*
 * Enocde weak cache consistency data
 */
static __be32 *
encode_wcc_data(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
{
	struct dentry	*dentry = fhp->fh_dentry;

	if (dentry && dentry->d_inode && fhp->fh_post_saved) {
		if (fhp->fh_pre_saved) {
			*p++ = xdr_one;
			p = xdr_encode_hyper(p, (u64) fhp->fh_pre_size);
			p = encode_time3(p, &fhp->fh_pre_mtime);
			p = encode_time3(p, &fhp->fh_pre_ctime);
		} else {
			*p++ = xdr_zero;
		}
		return encode_saved_post_attr(rqstp, p, fhp);
	}
	/* no pre- or post-attrs */
	*p++ = xdr_zero;
	return encode_post_op_attr(rqstp, p, fhp);
}

/*
 * Fill in the post_op attr for the wcc data
 */
void fill_post_wcc(struct svc_fh *fhp)
{
	int err;

	if (fhp->fh_post_saved)
		printk("nfsd: inode locked twice during operation.\n");

	err = vfs_getattr(fhp->fh_export->ex_mnt, fhp->fh_dentry,
			&fhp->fh_post_attr);
	if (err)
		fhp->fh_post_saved = 0;
	else
		fhp->fh_post_saved = 1;
}

/*
 * XDR decode functions
 */
int
nfs3svc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
{
	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_sattrargs *args)
{
	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	p = decode_sattr3(p, &args->attrs);

	if ((args->check_guard = ntohl(*p++)) != 0) { 
		struct timespec time; 
		p = decode_time3(p, &time);
		args->guardtime = time.tv_sec;
	}

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_diropargs *args)
{
	if (!(p = decode_fh(p, &args->fh))
	 || !(p = decode_filename(p, &args->name, &args->len)))
		return 0;

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_accessargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_accessargs *args)
{
	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	args->access = ntohl(*p++);

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_readargs *args)
{
	unsigned int len;
	int v,pn;
	u32 max_blocksize = svc_max_payload(rqstp);

	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	p = xdr_decode_hyper(p, &args->offset);

	len = args->count = ntohl(*p++);

	if (len > max_blocksize)
		len = max_blocksize;

	/* set up the kvec */
	v=0;
	while (len > 0) {
		pn = rqstp->rq_resused++;
		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_respages[pn]);
		rqstp->rq_vec[v].iov_len = len < PAGE_SIZE? len : PAGE_SIZE;
		len -= rqstp->rq_vec[v].iov_len;
		v++;
	}
	args->vlen = v;
	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_writeargs *args)
{
	unsigned int len, v, hdr, dlen;
	u32 max_blocksize = svc_max_payload(rqstp);

	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	p = xdr_decode_hyper(p, &args->offset);

	args->count = ntohl(*p++);
	args->stable = ntohl(*p++);
	len = args->len = ntohl(*p++);
	/*
	 * The count must equal the amount of data passed.
	 */
	if (args->count != args->len)
		return 0;

	/*
	 * Check to make sure that we got the right number of
	 * bytes.
	 */
	hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
	dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
		- hdr;
	/*
	 * Round the length of the data which was specified up to
	 * the next multiple of XDR units and then compare that
	 * against the length which was actually received.
	 * Note that when RPCSEC/GSS (for example) is used, the
	 * data buffer can be padded so dlen might be larger
	 * than required.  It must never be smaller.
	 */
	if (dlen < XDR_QUADLEN(len)*4)
		return 0;

	if (args->count > max_blocksize) {
		args->count = max_blocksize;
		len = args->len = max_blocksize;
	}
	rqstp->rq_vec[0].iov_base = (void*)p;
	rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
	v = 0;
	while (len > rqstp->rq_vec[v].iov_len) {
		len -= rqstp->rq_vec[v].iov_len;
		v++;
		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
		rqstp->rq_vec[v].iov_len = PAGE_SIZE;
	}
	rqstp->rq_vec[v].iov_len = len;
	args->vlen = v + 1;
	return 1;
}

int
nfs3svc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_createargs *args)
{
	if (!(p = decode_fh(p, &args->fh))
	 || !(p = decode_filename(p, &args->name, &args->len)))
		return 0;

	switch (args->createmode = ntohl(*p++)) {
	case NFS3_CREATE_UNCHECKED:
	case NFS3_CREATE_GUARDED:
		p = decode_sattr3(p, &args->attrs);
		break;
	case NFS3_CREATE_EXCLUSIVE:
		args->verf = p;
		p += 2;
		break;
	default:
		return 0;
	}

	return xdr_argsize_check(rqstp, p);
}
int
nfs3svc_decode_mkdirargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_createargs *args)
{
	if (!(p = decode_fh(p, &args->fh)) ||
	    !(p = decode_filename(p, &args->name, &args->len)))
		return 0;
	p = decode_sattr3(p, &args->attrs);

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_symlinkargs *args)
{
	unsigned int len;
	int avail;
	char *old, *new;
	struct kvec *vec;

	if (!(p = decode_fh(p, &args->ffh)) ||
	    !(p = decode_filename(p, &args->fname, &args->flen))
		)
		return 0;
	p = decode_sattr3(p, &args->attrs);

	/* now decode the pathname, which might be larger than the first page.
	 * As we have to check for nul's anyway, we copy it into a new page
	 * This page appears in the rq_res.pages list, but as pages_len is always
	 * 0, it won't get in the way
	 */
	len = ntohl(*p++);
	if (len == 0 || len > NFS3_MAXPATHLEN || len >= PAGE_SIZE)
		return 0;
	args->tname = new =
		page_address(rqstp->rq_respages[rqstp->rq_resused++]);
	args->tlen = len;
	/* first copy and check from the first page */
	old = (char*)p;
	vec = &rqstp->rq_arg.head[0];
	avail = vec->iov_len - (old - (char*)vec->iov_base);
	while (len && avail && *old) {
		*new++ = *old++;
		len--;
		avail--;
	}
	/* now copy next page if there is one */
	if (len && !avail && rqstp->rq_arg.page_len) {
		avail = rqstp->rq_arg.page_len;
		if (avail > PAGE_SIZE) avail = PAGE_SIZE;
		old = page_address(rqstp->rq_arg.pages[0]);
	}
	while (len && avail && *old) {
		*new++ = *old++;
		len--;
		avail--;
	}
	*new = '\0';
	if (len)
		return 0;

	return 1;
}

int
nfs3svc_decode_mknodargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_mknodargs *args)
{
	if (!(p = decode_fh(p, &args->fh))
	 || !(p = decode_filename(p, &args->name, &args->len)))
		return 0;

	args->ftype = ntohl(*p++);

	if (args->ftype == NF3BLK  || args->ftype == NF3CHR
	 || args->ftype == NF3SOCK || args->ftype == NF3FIFO)
		p = decode_sattr3(p, &args->attrs);

	if (args->ftype == NF3BLK || args->ftype == NF3CHR) {
		args->major = ntohl(*p++);
		args->minor = ntohl(*p++);
	}

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_renameargs *args)
{
	if (!(p = decode_fh(p, &args->ffh))
	 || !(p = decode_filename(p, &args->fname, &args->flen))
	 || !(p = decode_fh(p, &args->tfh))
	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
		return 0;

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_readlinkargs *args)
{
	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	args->buffer =
		page_address(rqstp->rq_respages[rqstp->rq_resused++]);

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_linkargs *args)
{
	if (!(p = decode_fh(p, &args->ffh))
	 || !(p = decode_fh(p, &args->tfh))
	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
		return 0;

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_readdirargs *args)
{