/*

   * XDR support for nfsd
   *
   * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   */

  #include "xdr.h"

  #include "auth.h"

  
  #define NFSDDBG_FACILITY		NFSDDBG_XDR

  /*
   * Mapping of S_IF* types to NFS file types
   */
  static u32	nfs_ftypes[] = {
  	NFNON,  NFCHR,  NFCHR, NFBAD,
  	NFDIR,  NFBAD,  NFBLK, NFBAD,
  	NFREG,  NFBAD,  NFLNK, NFBAD,
  	NFSOCK, NFBAD,  NFLNK, NFBAD,
  };
  
  
  /*
   * XDR functions for basic NFS types
   */

  static __be32 *
  decode_fh(__be32 *p, struct svc_fh *fhp)

  {
  	fh_init(fhp, NFS_FHSIZE);
  	memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE);
  	fhp->fh_handle.fh_size = NFS_FHSIZE;
  
  	/* FIXME: Look up export pointer here and verify
  	 * Sun Secure RPC if requested */
  	return p + (NFS_FHSIZE >> 2);
  }

  /* Helper function for NFSv2 ACL code */

  __be32 *nfs2svc_decode_fh(__be32 *p, struct svc_fh *fhp)

  {
  	return decode_fh(p, fhp);
  }

  static __be32 *

  encode_fh(__be32 *p, struct svc_fh *fhp)

  {
  	memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE);
  	return p + (NFS_FHSIZE>> 2);
  }
  
  /*
   * Decode a file name and make sure that the path contains
   * no slashes or null bytes.
   */

  static __be32 *

  decode_filename(__be32 *p, char **namp, unsigned int *lenp)

  {
  	char		*name;

  	unsigned int	i;

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

  static __be32 *

  decode_pathname(__be32 *p, char **namp, unsigned int *lenp)

  {
  	char		*name;

  	unsigned int	i;

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

  static __be32 *

  decode_sattr(__be32 *p, struct iattr *iap)

  {
  	u32	tmp, tmp1;
  
  	iap->ia_valid = 0;
  
  	/* Sun client bug compatibility check: some sun clients seem to
  	 * put 0xffff in the mode field when they mean 0xffffffff.
  	 * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah.
  	 */
  	if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) {
  		iap->ia_valid |= ATTR_MODE;
  		iap->ia_mode = tmp;
  	}
  	if ((tmp = ntohl(*p++)) != (u32)-1) {
  		iap->ia_valid |= ATTR_UID;
  		iap->ia_uid = tmp;
  	}
  	if ((tmp = ntohl(*p++)) != (u32)-1) {
  		iap->ia_valid |= ATTR_GID;
  		iap->ia_gid = tmp;
  	}
  	if ((tmp = ntohl(*p++)) != (u32)-1) {
  		iap->ia_valid |= ATTR_SIZE;
  		iap->ia_size = tmp;
  	}
  	tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
  	if (tmp != (u32)-1 && tmp1 != (u32)-1) {
  		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
  		iap->ia_atime.tv_sec = tmp;
  		iap->ia_atime.tv_nsec = tmp1 * 1000; 
  	}
  	tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
  	if (tmp != (u32)-1 && tmp1 != (u32)-1) {
  		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
  		iap->ia_mtime.tv_sec = tmp;
  		iap->ia_mtime.tv_nsec = tmp1 * 1000; 
  		/*
  		 * Passing the invalid value useconds=1000000 for mtime
  		 * is a Sun convention for "set both mtime and atime to
  		 * current server time".  It's needed to make permissions
  		 * checks for the "touch" program across v2 mounts to
  		 * Solaris and Irix boxes work correctly. See description of
  		 * sattr in section 6.1 of "NFS Illustrated" by
  		 * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
  		 */
  		if (tmp1 == 1000000)
  			iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
  	}
  	return p;
  }

  static __be32 *
  encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,

  	     struct kstat *stat)

  {

  	struct dentry	*dentry = fhp->fh_dentry;

  	int type;
  	struct timespec time;

  	u32 f;

  	type = (stat->mode & S_IFMT);

  
  	*p++ = htonl(nfs_ftypes[type >> 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(type) && stat->size > NFS_MAXPATHLEN) {

  		*p++ = htonl(NFS_MAXPATHLEN);
  	} else {

  		*p++ = htonl((u32) stat->size);

  	}

  	*p++ = htonl((u32) stat->blksize);

  	if (S_ISCHR(type) || S_ISBLK(type))

  		*p++ = htonl(new_encode_dev(stat->rdev));

  	else
  		*p++ = htonl(0xffffffff);

  	*p++ = htonl((u32) stat->blocks);

  	switch (fsid_source(fhp)) {
  	default:
  	case FSIDSOURCE_DEV:

  		*p++ = htonl(new_encode_dev(stat->dev));

  		break;
  	case FSIDSOURCE_FSID:
  		*p++ = htonl((u32) fhp->fh_export->ex_fsid);
  		break;
  	case FSIDSOURCE_UUID:
  		f = ((u32*)fhp->fh_export->ex_uuid)[0];
  		f ^= ((u32*)fhp->fh_export->ex_uuid)[1];
  		f ^= ((u32*)fhp->fh_export->ex_uuid)[2];
  		f ^= ((u32*)fhp->fh_export->ex_uuid)[3];
  		*p++ = htonl(f);
  		break;
  	}

  	*p++ = htonl((u32) stat->ino);
  	*p++ = htonl((u32) stat->atime.tv_sec);
  	*p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0);

  	lease_get_mtime(dentry->d_inode, &time); 
  	*p++ = htonl((u32) time.tv_sec);
  	*p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0); 

  	*p++ = htonl((u32) stat->ctime.tv_sec);
  	*p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0);

  
  	return p;
  }

  /* Helper function for NFSv2 ACL code */

  __be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)

  {

  	struct kstat stat;

  	vfs_getattr(fhp->fh_export->ex_path.mnt, fhp->fh_dentry, &stat);

  	return encode_fattr(rqstp, p, fhp, &stat);

  }

  
  /*
   * XDR decode functions
   */
  int

  nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)

  {
  	return xdr_argsize_check(rqstp, p);
  }
  
  int

  nfssvc_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

  nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,

  					struct nfsd_sattrargs *args)
  {

  	p = decode_fh(p, &args->fh);
  	if (!p)

  		return 0;

  	p = decode_sattr(p, &args->attrs);

  
  	return xdr_argsize_check(rqstp, p);
  }
  
  int

  nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,

  					struct nfsd_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

  nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,

  					struct nfsd_readargs *args)
  {
  	unsigned int len;
  	int v,pn;
  	if (!(p = decode_fh(p, &args->fh)))
  		return 0;
  
  	args->offset    = ntohl(*p++);
  	len = args->count     = ntohl(*p++);
  	p++; /* totalcount - unused */

  	if (len > NFSSVC_MAXBLKSIZE_V2)
  		len = NFSSVC_MAXBLKSIZE_V2;

  
  	/* set up somewhere to store response.
  	 * We take pages, put them on reslist and include in iovec
  	 */
  	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

  nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,

  					struct nfsd_writeargs *args)
  {

  	unsigned int len, hdr, dlen;

  	int v;

  	if (!(p = decode_fh(p, &args->fh)))
  		return 0;
  
  	p++;				/* beginoffset */
  	args->offset = ntohl(*p++);	/* offset */
  	p++;				/* totalcount */
  	len = args->len = ntohl(*p++);

  	/*
  	 * The protocol specifies a maximum of 8192 bytes.
  	 */

  	if (len > NFSSVC_MAXBLKSIZE_V2)

  		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;
  
  	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

  nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,

  					struct nfsd_createargs *args)
  {

  	if (   !(p = decode_fh(p, &args->fh))
  	    || !(p = decode_filename(p, &args->name, &args->len)))

  		return 0;

  	p = decode_sattr(p, &args->attrs);

  
  	return xdr_argsize_check(rqstp, p);
  }
  
  int

  nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,

  					struct nfsd_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

  nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd_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

  nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,

  					struct nfsd_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

  nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,

  					struct nfsd_symlinkargs *args)
  {

  	if (   !(p = decode_fh(p, &args->ffh))
  	    || !(p = decode_filename(p, &args->fname, &args->flen))
  	    || !(p = decode_pathname(p, &args->tname, &args->tlen)))

  		return 0;

  	p = decode_sattr(p, &args->attrs);

  
  	return xdr_argsize_check(rqstp, p);
  }
  
  int

  nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,

  					struct nfsd_readdirargs *args)
  {
  	if (!(p = decode_fh(p, &args->fh)))
  		return 0;
  	args->cookie = ntohl(*p++);
  	args->count  = ntohl(*p++);
  	if (args->count > PAGE_SIZE)
  		args->count = PAGE_SIZE;

  	args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused++]);

  
  	return xdr_argsize_check(rqstp, p);
  }
  
  /*
   * XDR encode functions
   */
  int

  nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)

  {
  	return xdr_ressize_check(rqstp, p);
  }
  
  int

  nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,

  					struct nfsd_attrstat *resp)
  {

  	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);

  	return xdr_ressize_check(rqstp, p);
  }
  
  int

  nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,

  					struct nfsd_diropres *resp)
  {
  	p = encode_fh(p, &resp->fh);

  	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);

  	return xdr_ressize_check(rqstp, p);
  }
  
  int

  nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,

  					struct nfsd_readlinkres *resp)
  {
  	*p++ = htonl(resp->len);
  	xdr_ressize_check(rqstp, p);
  	rqstp->rq_res.page_len = resp->len;
  	if (resp->len & 3) {
  		/* need to pad the tail */

  		rqstp->rq_res.tail[0].iov_base = p;
  		*p = 0;
  		rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
  	}
  	return 1;
  }
  
  int

  nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p,

  					struct nfsd_readres *resp)
  {

  	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);

  	*p++ = htonl(resp->count);
  	xdr_ressize_check(rqstp, p);

  	/* now update rqstp->rq_res to reflect data as well */

  	rqstp->rq_res.page_len = resp->count;
  	if (resp->count & 3) {
  		/* need to pad the tail */

  		rqstp->rq_res.tail[0].iov_base = p;
  		*p = 0;
  		rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
  	}
  	return 1;
  }
  
  int

  nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,

  					struct nfsd_readdirres *resp)
  {
  	xdr_ressize_check(rqstp, p);
  	p = resp->buffer;
  	*p++ = 0;			/* no more entries */
  	*p++ = htonl((resp->common.err == nfserr_eof));
  	rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
  
  	return 1;
  }
  
  int

  nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p,

  					struct nfsd_statfsres *resp)
  {
  	struct kstatfs	*stat = &resp->stats;

  	*p++ = htonl(NFSSVC_MAXBLKSIZE_V2);	/* max transfer size */

  	*p++ = htonl(stat->f_bsize);
  	*p++ = htonl(stat->f_blocks);
  	*p++ = htonl(stat->f_bfree);
  	*p++ = htonl(stat->f_bavail);
  	return xdr_ressize_check(rqstp, p);
  }
  
  int

  nfssvc_encode_entry(void *ccdv, const char *name,
  		    int namlen, loff_t offset, u64 ino, unsigned int d_type)

  {

  	struct readdir_cd *ccd = ccdv;

  	struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);

  	__be32	*p = cd->buffer;

  	int	buflen, slen;
  
  	/*
  	dprintk("nfsd: entry(%.*s off %ld ino %ld)
  ",
  			namlen, name, offset, ino);
  	 */
  
  	if (offset > ~((u32) 0)) {
  		cd->common.err = nfserr_fbig;
  		return -EINVAL;
  	}
  	if (cd->offset)
  		*cd->offset = htonl(offset);
  	if (namlen > NFS2_MAXNAMLEN)
  		namlen = NFS2_MAXNAMLEN;/* truncate filename */
  
  	slen = XDR_QUADLEN(namlen);
  	if ((buflen = cd->buflen - slen - 4) < 0) {
  		cd->common.err = nfserr_toosmall;
  		return -EINVAL;
  	}

  	if (ino > ~((u32) 0)) {
  		cd->common.err = nfserr_fbig;
  		return -EINVAL;
  	}

  	*p++ = xdr_one;				/* mark entry present */
  	*p++ = htonl((u32) ino);		/* file id */
  	p    = xdr_encode_array(p, name, namlen);/* name length & name */
  	cd->offset = p;			/* remember pointer */

  	*p++ = htonl(~0U);		/* offset of next entry */

  
  	cd->buflen = buflen;
  	cd->buffer = p;
  	cd->common.err = nfs_ok;
  	return 0;
  }
  
  /*
   * XDR release functions
   */
  int

  nfssvc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,

  					struct nfsd_fhandle *resp)
  {
  	fh_put(&resp->fh);
  	return 1;
  }