nfs3xdr.c

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/*
 * linux/fs/nfsd/nfs3xdr.c
 *
 * XDR support for nfsd/protocol version 3.
 *
 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <[e-mail]>
 */

#include <linux/types.h>
#include <linux/sched.h>
#include <linux/nfs3.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, time_t secs)
{
	*p++ = htonl((u32) secs); *p++ = 0;
	return p;
}

static inline u32 *
decode_time3(u32 *p, time_t *secp)
{
	*secp = ntohl(*p++);
	return p + 1;
}

static inline u32 *
decode_fh(u32 *p, struct svc_fh *fhp)
{
	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)
{
	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(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 = ntohl(*p++), 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 = ntohl(*p++), p++;
	}
	return p;
}

static inline u32 *
encode_fattr3(struct svc_rqst *rqstp, u32 *p, struct dentry *dentry)
{
	struct inode	*inode = dentry->d_inode;

	*p++ = htonl(nfs3_ftypes[(inode->i_mode & S_IFMT) >> 12]);
	*p++ = htonl((u32) inode->i_mode);
	*p++ = htonl((u32) inode->i_nlink);
	*p++ = htonl((u32) nfsd_ruid(rqstp, inode->i_uid));
	*p++ = htonl((u32) nfsd_rgid(rqstp, inode->i_gid));
	if (S_ISLNK(inode->i_mode) && inode->i_size > NFS3_MAXPATHLEN) {
		p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
	} else {
		p = xdr_encode_hyper(p, (u64) inode->i_size);
	}
	if (inode->i_blksize == 0 && inode->i_blocks == 0)
		/* Minix file system(?) i_size is (hopefully) close enough */
		p = xdr_encode_hyper(p, (u64)(inode->i_size +511)& ~511);
	else
		p = xdr_encode_hyper(p, ((u64)inode->i_blocks) << 9);
	*p++ = htonl((u32) MAJOR(inode->i_rdev));
	*p++ = htonl((u32) MINOR(inode->i_rdev));
	p = xdr_encode_hyper(p, (u64) inode->i_dev);
	p = xdr_encode_hyper(p, (u64) inode->i_ino);
	p = encode_time3(p, inode->i_atime);
	p = encode_time3(p, lease_get_mtime(inode));
	p = encode_time3(p, inode->i_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++ = htonl((u32) MAJOR(fhp->fh_post_rdev));
	*p++ = htonl((u32) MINOR(fhp->fh_post_rdev));
	p = xdr_encode_hyper(p, (u64) inode->i_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 dentry *dentry)
{
	if (dentry && dentry->d_inode != NULL) {
		*p++ = xdr_one;		/* attributes follow */
		return encode_fattr3(rqstp, p, dentry);
	}
	*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, dentry);
}

/*
 * Check buffer bounds after decoding arguments
 */
static inline int
xdr_argsize_check(struct svc_rqst *rqstp, u32 *p)
{
	struct svc_buf	*buf = &rqstp->rq_argbuf;

	return p - buf->base <= buf->buflen;
}

static inline int
xdr_ressize_check(struct svc_rqst *rqstp, u32 *p)
{
	struct svc_buf	*buf = &rqstp->rq_resbuf;

	buf->len = p - buf->base;
	dprintk("nfsd: ressize_check p %p base %p len %d\n",
			p, buf->base, buf->buflen);
	return (buf->len <= buf->buflen);
}

/*
 * XDR decode functions
 */
int
nfs3svc_decode_fhandle(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
{
	if (!(p = decode_fh(p, fhp)))
		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)
		p = decode_time3(p, &args->guardtime);

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

	args->count = ntohl(*p++);
	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_writeargs(struct svc_rqst *rqstp, u32 *p,
					struct nfsd3_writeargs *args)
{
	if (!(p = decode_fh(p, &args->fh))
	 || !(p = xdr_decode_hyper(p, &args->offset)))
		return 0;

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

	return xdr_argsize_check(rqstp, p);
}

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

	return xdr_argsize_check(rqstp, p);
}

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++);