nfs3xdr.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 1,104 行 · 第 1/2 页

/*
 * 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

#ifdef NFSD_OPTIMIZE_SPACE
# define inline
#endif


/*
 * 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 inline u32 *
encode_time3(u32 *p, struct timespec *time)
{
	*p++ = htonl((u32) time->tv_sec); *p++ = htonl(time->tv_nsec);
	return p;
}

static inline u32 *
decode_time3(u32 *p, struct timespec *time)
{
	time->tv_sec = ntohl(*p++);
	time->tv_nsec = ntohl(*p++);
	return p;
}

static inline u32 *
decode_fh(u32 *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);
}

static inline u32 *
encode_fh(u32 *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 inline u32 *
decode_filename(u32 *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 inline u32 *
decode_pathname(u32 *p, char **namp, int *lenp)
{
	char		*name;
	int		i;

	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS3_MAXPATHLEN)) != NULL) {
		for (i = 0, name = *namp; i < *lenp; i++, name++) {
			if (*name == '\0')
				return NULL;
		}
	}

	return p;
}

static inline u32 *
decode_sattr3(u32 *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 inline u32 *
encode_fattr3(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
{
	struct vfsmount *mnt = fhp->fh_export->ex_mnt;
	struct dentry	*dentry = fhp->fh_dentry;
	struct kstat stat;
	struct timespec time;

	vfs_getattr(mnt, dentry, &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));
	if (is_fsid(fhp, rqstp->rq_reffh))
		p = xdr_encode_hyper(p, (u64) fhp->fh_export->ex_fsid);
	else
		p = xdr_encode_hyper(p, (u64) huge_encode_dev(stat.dev));
	p = xdr_encode_hyper(p, (u64) stat.ino);
	p = encode_time3(p, &stat.atime);
	lease_get_mtime(dentry->d_inode, &time); 
	p = encode_time3(p, &time);
	p = encode_time3(p, &stat.ctime);

	return p;
}

static inline u32 *
encode_saved_post_attr(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
{
	struct inode	*inode = fhp->fh_dentry->d_inode;

	/* Attributes to follow */
	*p++ = xdr_one;

	*p++ = htonl(nfs3_ftypes[(fhp->fh_post_mode & S_IFMT) >> 12]);
	*p++ = htonl((u32) fhp->fh_post_mode);
	*p++ = htonl((u32) fhp->fh_post_nlink);
	*p++ = htonl((u32) nfsd_ruid(rqstp, fhp->fh_post_uid));
	*p++ = htonl((u32) nfsd_rgid(rqstp, fhp->fh_post_gid));
	if (S_ISLNK(fhp->fh_post_mode) && fhp->fh_post_size > NFS3_MAXPATHLEN) {
		p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
	} else {
		p = xdr_encode_hyper(p, (u64) fhp->fh_post_size);
	}
	p = xdr_encode_hyper(p, ((u64)fhp->fh_post_blocks) << 9);
	*p++ = fhp->fh_post_rdev[0];
	*p++ = fhp->fh_post_rdev[1];
	if (is_fsid(fhp, rqstp->rq_reffh))
		p = xdr_encode_hyper(p, (u64) fhp->fh_export->ex_fsid);
	else
		p = xdr_encode_hyper(p, (u64)huge_encode_dev(inode->i_sb->s_dev));
	p = xdr_encode_hyper(p, (u64) inode->i_ino);
	p = encode_time3(p, &fhp->fh_post_atime);
	p = encode_time3(p, &fhp->fh_post_mtime);
	p = encode_time3(p, &fhp->fh_post_ctime);

	return p;
}

/*
 * 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 u32 *
encode_post_op_attr(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
{
	struct dentry *dentry = fhp->fh_dentry;
	if (dentry && dentry->d_inode != NULL) {
		*p++ = xdr_one;		/* attributes follow */
		return encode_fattr3(rqstp, p, fhp);
	}
	*p++ = xdr_zero;
	return p;
}

/*
 * Enocde weak cache consistency data
 */
static u32 *
encode_wcc_data(struct svc_rqst *rqstp, u32 *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);
}


/*
 * XDR decode functions
 */
int
nfs3svc_decode_fhandle(struct svc_rqst *rqstp, u32 *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, u32 *p,
					struct nfsd3_sattrargs *args)
{
	if (!(p = decode_fh(p, &args->fh))
	 || !(p = decode_sattr3(p, &args->attrs)))
		return 0;

	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, u32 *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, u32 *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, u32 *p,
					struct nfsd3_readargs *args)
{
	unsigned int len;
	int v,pn;

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

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

	if (len > NFSSVC_MAXBLKSIZE)
		len = NFSSVC_MAXBLKSIZE;

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

int
nfs3svc_decode_writeargs(struct svc_rqst *rqstp, u32 *p,
					struct nfsd3_writeargs *args)
{
	unsigned int len, v, hdr;

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

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

	hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
	if (rqstp->rq_arg.len < len + hdr)
		return 0;

	args->vec[0].iov_base = (void*)p;
	args->vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;

	if (len > NFSSVC_MAXBLKSIZE)
		len = NFSSVC_MAXBLKSIZE;
	v=  0;
	while (len > args->vec[v].iov_len) {
		len -= args->vec[v].iov_len;
		v++;
		args->vec[v].iov_base = page_address(rqstp->rq_argpages[v]);
		args->vec[v].iov_len = PAGE_SIZE;
	}
	args->vec[v].iov_len = len;
	args->vlen = v+1;

	return args->count == args->len && args->vec[0].iov_len > 0;
}

int
nfs3svc_decode_createargs(struct svc_rqst *rqstp, u32 *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:
		if (!(p = decode_sattr3(p, &args->attrs)))
			return 0;
		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, u32 *p,
					struct nfsd3_createargs *args)
{
	if (!(p = decode_fh(p, &args->fh))
	 || !(p = decode_filename(p, &args->name, &args->len))
	 || !(p = decode_sattr3(p, &args->attrs)))
		return 0;

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, u32 *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))
	 || !(p = decode_sattr3(p, &args->attrs))
		)
		return 0;
	/* 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
	 */
	svc_take_page(rqstp);
	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-1]);
	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, u32 *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) {
		if (!(p = decode_sattr3(p, &args->attrs)))
			return 0;
	}

	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, u32 *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, u32 *p,
					struct nfsd3_readlinkargs *args)
{
	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	svc_take_page(rqstp);
	args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused-1]);

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_linkargs(struct svc_rqst *rqstp, u32 *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, u32 *p,
					struct nfsd3_readdirargs *args)
{
	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	p = xdr_decode_hyper(p, &args->cookie);
	args->verf   = p; p += 2;
	args->dircount = ~0;
	args->count  = ntohl(*p++);