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

/*
 * linux/fs/nfs/nfs3xdr.c
 *
 * XDR functions to encode/decode NFSv3 RPC arguments and results.
 *
 * Copyright (C) 1996, 1997 Olaf Kirch
 */

#include <linux/param.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/utsname.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/in.h>
#include <linux/pagemap.h>
#include <linux/proc_fs.h>
#include <linux/kdev_t.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfs.h>
#include <linux/nfs3.h>
#include <linux/nfs_fs.h>

/* Uncomment this to support servers requiring longword lengths */
#define NFS_PAD_WRITES		1

#define NFSDBG_FACILITY		NFSDBG_XDR

/* Mapping from NFS error code to "errno" error code. */
#define errno_NFSERR_IO		EIO

extern int			nfs_stat_to_errno(int);

/*
 * Declare the space requirements for NFS arguments and replies as
 * number of 32bit-words
 */
#define NFS3_fhandle_sz		1+16
#define NFS3_fh_sz		NFS3_fhandle_sz	/* shorthand */
#define NFS3_sattr_sz		15
#define NFS3_filename_sz	1+(NFS3_MAXNAMLEN>>2)
#define NFS3_path_sz		1+(NFS3_MAXPATHLEN>>2)
#define NFS3_fattr_sz		21
#define NFS3_wcc_attr_sz		6
#define NFS3_pre_op_attr_sz	1+NFS3_wcc_attr_sz
#define NFS3_post_op_attr_sz	1+NFS3_fattr_sz
#define NFS3_wcc_data_sz		NFS3_pre_op_attr_sz+NFS3_post_op_attr_sz
#define NFS3_fsstat_sz		
#define NFS3_fsinfo_sz		
#define NFS3_pathconf_sz		
#define NFS3_entry_sz		NFS3_filename_sz+3

#define NFS3_enc_void_sz	0
#define NFS3_sattrargs_sz	NFS3_fh_sz+NFS3_sattr_sz+3
#define NFS3_diropargs_sz	NFS3_fh_sz+NFS3_filename_sz
#define NFS3_accessargs_sz	NFS3_fh_sz+1
#define NFS3_readlinkargs_sz	NFS3_fh_sz
#define NFS3_readargs_sz	NFS3_fh_sz+3
#define NFS3_writeargs_sz	NFS3_fh_sz+5
#define NFS3_createargs_sz	NFS3_diropargs_sz+NFS3_sattr_sz
#define NFS3_mkdirargs_sz	NFS3_diropargs_sz+NFS3_sattr_sz
#define NFS3_symlinkargs_sz	NFS3_diropargs_sz+NFS3_path_sz+NFS3_sattr_sz
#define NFS3_mknodargs_sz	NFS3_diropargs_sz+2+NFS3_sattr_sz
#define NFS3_renameargs_sz	NFS3_diropargs_sz+NFS3_diropargs_sz
#define NFS3_linkargs_sz		NFS3_fh_sz+NFS3_diropargs_sz
#define NFS3_readdirargs_sz	NFS3_fh_sz+2
#define NFS3_commitargs_sz	NFS3_fh_sz+3

#define NFS3_dec_void_sz	0
#define NFS3_attrstat_sz	1+NFS3_fattr_sz
#define NFS3_wccstat_sz		1+NFS3_wcc_data_sz
#define NFS3_lookupres_sz	1+NFS3_fh_sz+(2 * NFS3_post_op_attr_sz)
#define NFS3_accessres_sz	1+NFS3_post_op_attr_sz+1
#define NFS3_readlinkres_sz	1+NFS3_post_op_attr_sz
#define NFS3_readres_sz		1+NFS3_post_op_attr_sz+3
#define NFS3_writeres_sz	1+NFS3_wcc_data_sz+4
#define NFS3_createres_sz	1+NFS3_fh_sz+NFS3_post_op_attr_sz+NFS3_wcc_data_sz
#define NFS3_renameres_sz	1+(2 * NFS3_wcc_data_sz)
#define NFS3_linkres_sz		1+NFS3_post_op_attr_sz+NFS3_wcc_data_sz
#define NFS3_readdirres_sz	1+NFS3_post_op_attr_sz+2
#define NFS3_fsstatres_sz	1+NFS3_post_op_attr_sz+13
#define NFS3_fsinfores_sz	1+NFS3_post_op_attr_sz+12
#define NFS3_pathconfres_sz	1+NFS3_post_op_attr_sz+6
#define NFS3_commitres_sz	1+NFS3_wcc_data_sz+2

/*
 * Map file type to S_IFMT bits
 */
static struct {
	unsigned int	mode;
	unsigned int	nfs2type;
} nfs_type2fmt[] = {
      { 0,		NFNON	},
      { S_IFREG,	NFREG	},
      { S_IFDIR,	NFDIR	},
      { S_IFBLK,	NFBLK	},
      { S_IFCHR,	NFCHR	},
      { S_IFLNK,	NFLNK	},
      { S_IFSOCK,	NFSOCK	},
      { S_IFIFO,	NFFIFO	},
      { 0,		NFBAD	}
};

/*
 * Common NFS XDR functions as inlines
 */
static inline u32 *
xdr_encode_fhandle(u32 *p, struct nfs_fh *fh)
{
	*p++ = htonl(fh->size);
	memcpy(p, fh->data, fh->size);
	return p + XDR_QUADLEN(fh->size);
}

static inline u32 *
xdr_decode_fhandle(u32 *p, struct nfs_fh *fh)
{
	/*
	 * Zero all nonused bytes
	 */
	memset((u8 *)fh, 0, sizeof(*fh));
	if ((fh->size = ntohl(*p++)) <= NFS3_FHSIZE) {
		memcpy(fh->data, p, fh->size);
		return p + XDR_QUADLEN(fh->size);
	}
	return NULL;
}

/*
 * Encode/decode time.
 * Since the VFS doesn't care for fractional times, we ignore the
 * nanosecond field.
 */
static inline u32 *
xdr_encode_time(u32 *p, time_t time)
{
	*p++ = htonl(time);
	*p++ = 0;
	return p;
}

static inline u32 *
xdr_decode_time3(u32 *p, u64 *timep)
{
	u64 tmp = (u64)ntohl(*p++) << 32;
	*timep = tmp + (u64)ntohl(*p++);
	return p;
}

static inline u32 *
xdr_encode_time3(u32 *p, u64 time)
{
	*p++ = htonl(time >> 32);
	*p++ = htonl(time & 0xFFFFFFFF);
	return p;
}

static inline u32 *
xdr_decode_string2(u32 *p, char **string, unsigned int *len,
			unsigned int maxlen)
{
	*len = ntohl(*p++);
	if (*len > maxlen)
		return NULL;
	*string = (char *) p;
	return p + XDR_QUADLEN(*len);
}

static inline u32 *
xdr_decode_fattr(u32 *p, struct nfs_fattr *fattr)
{
	unsigned int	type;
	int		fmode;

	type = ntohl(*p++);
	if (type >= NF3BAD)
		type = NF3BAD;
	fmode = nfs_type2fmt[type].mode;
	fattr->type = nfs_type2fmt[type].nfs2type;
	fattr->mode = (ntohl(*p++) & ~S_IFMT) | fmode;
	fattr->nlink = ntohl(*p++);
	fattr->uid = ntohl(*p++);
	fattr->gid = ntohl(*p++);
	p = xdr_decode_hyper(p, &fattr->size);
	p = xdr_decode_hyper(p, &fattr->du.nfs3.used);
	/* Turn remote device info into Linux-specific dev_t */
	fattr->rdev = ntohl(*p++) << MINORBITS;
	fattr->rdev |= ntohl(*p++) & MINORMASK;
	p = xdr_decode_hyper(p, &fattr->fsid);
	p = xdr_decode_hyper(p, &fattr->fileid);
	p = xdr_decode_time3(p, &fattr->atime);
	p = xdr_decode_time3(p, &fattr->mtime);
	p = xdr_decode_time3(p, &fattr->ctime);

	/* Update the mode bits */
	fattr->valid |= (NFS_ATTR_FATTR | NFS_ATTR_FATTR_V3);
	return p;
}

static inline u32 *
xdr_encode_sattr(u32 *p, struct iattr *attr)
{
	if (attr->ia_valid & ATTR_MODE) {
		*p++ = xdr_one;
		*p++ = htonl(attr->ia_mode);
	} else {
		*p++ = xdr_zero;
	}
	if (attr->ia_valid & ATTR_UID) {
		*p++ = xdr_one;
		*p++ = htonl(attr->ia_uid);
	} else {
		*p++ = xdr_zero;
	}
	if (attr->ia_valid & ATTR_GID) {
		*p++ = xdr_one;
		*p++ = htonl(attr->ia_gid);
	} else {
		*p++ = xdr_zero;
	}
	if (attr->ia_valid & ATTR_SIZE) {
		*p++ = xdr_one;
		p = xdr_encode_hyper(p, (__u64) attr->ia_size);
	} else {
		*p++ = xdr_zero;
	}
	if (attr->ia_valid & ATTR_ATIME_SET) {
		*p++ = xdr_two;
		p = xdr_encode_time(p, attr->ia_atime);
	} else if (attr->ia_valid & ATTR_ATIME) {
		*p++ = xdr_one;
	} else {
		*p++ = xdr_zero;
	}
	if (attr->ia_valid & ATTR_MTIME_SET) {
		*p++ = xdr_two;
		p = xdr_encode_time(p, attr->ia_mtime);
	} else if (attr->ia_valid & ATTR_MTIME) {
		*p++ = xdr_one;
	} else {
		*p++ = xdr_zero;
	}
	return p;
}

static inline u32 *
xdr_decode_wcc_attr(u32 *p, struct nfs_fattr *fattr)
{
	p = xdr_decode_hyper(p, &fattr->pre_size);
	p = xdr_decode_time3(p, &fattr->pre_mtime);
	p = xdr_decode_time3(p, &fattr->pre_ctime);
	fattr->valid |= NFS_ATTR_WCC;
	return p;
}

static inline u32 *
xdr_decode_post_op_attr(u32 *p, struct nfs_fattr *fattr)
{
	if (*p++)
		p = xdr_decode_fattr(p, fattr);
	return p;
}

static inline u32 *
xdr_decode_pre_op_attr(u32 *p, struct nfs_fattr *fattr)
{
	if (*p++)
		return xdr_decode_wcc_attr(p, fattr);
	return p;
}


static inline u32 *
xdr_decode_wcc_data(u32 *p, struct nfs_fattr *fattr)
{
	p = xdr_decode_pre_op_attr(p, fattr);
	return xdr_decode_post_op_attr(p, fattr);
}

/*
 * NFS encode functions
 */
/*
 * Encode void argument
 */
static int
nfs3_xdr_enc_void(struct rpc_rqst *req, u32 *p, void *dummy)
{
	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
	return 0;
}

/*
 * Encode file handle argument
 */
static int
nfs3_xdr_fhandle(struct rpc_rqst *req, u32 *p, struct nfs_fh *fh)
{
	p = xdr_encode_fhandle(p, fh);
	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
	return 0;
}

/*
 * Encode SETATTR arguments
 */
static int
nfs3_xdr_sattrargs(struct rpc_rqst *req, u32 *p, struct nfs3_sattrargs *args)
{
	p = xdr_encode_fhandle(p, args->fh);
	p = xdr_encode_sattr(p, args->sattr);
	*p++ = htonl(args->guard);
	if (args->guard)
		p = xdr_encode_time3(p, args->guardtime);
	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
	return 0;
}

/*
 * Encode directory ops argument
 */
static int
nfs3_xdr_diropargs(struct rpc_rqst *req, u32 *p, struct nfs3_diropargs *args)
{
	p = xdr_encode_fhandle(p, args->fh);
	p = xdr_encode_array(p, args->name, args->len);
	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
	return 0;
}

/*
 * Encode access() argument
 */
static int
nfs3_xdr_accessargs(struct rpc_rqst *req, u32 *p, struct nfs3_accessargs *args)
{
	p = xdr_encode_fhandle(p, args->fh);
	*p++ = htonl(args->access);
	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
	return 0;
}

/*
 * Arguments to a READ call. Since we read data directly into the page
 * cache, we also set up the reply iovec here so that iov[1] points
 * exactly to the page we want to fetch.
 */
static int
nfs3_xdr_readargs(struct rpc_rqst *req, u32 *p, struct nfs_readargs *args)
{
	struct rpc_auth	*auth = req->rq_task->tk_auth;
	int		buflen, replen;
	unsigned int	nr;

	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);

	/* Get the number of buffers in the receive iovec */
	nr = args->nriov;

	if (nr+2 > MAX_IOVEC) {
		printk(KERN_ERR "NFS: Bad number of iov's in xdr_readargs\n");
		return -EINVAL;
	}

	/* set up reply iovec */
	replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS3_readres_sz) << 2;
	buflen = req->rq_rvec[0].iov_len;
	req->rq_rvec[0].iov_len  = replen;

	/* Copy the iovec */
	memcpy(req->rq_rvec + 1, args->iov, nr * sizeof(struct iovec));

	req->rq_rvec[nr+1].iov_base = (u8 *) req->rq_rvec[0].iov_base + replen;
	req->rq_rvec[nr+1].iov_len  = buflen - replen;
	req->rq_rlen = args->count + buflen;
	req->rq_rnr += nr+1;

	return 0;
}

/*
 * Write arguments. Splice the buffer to be written into the iovec.
 */
static int
nfs3_xdr_writeargs(struct rpc_rqst *req, u32 *p, struct nfs_writeargs *args)
{
	unsigned int	nr;
	u32 count = args->count;

	p = xdr_encode_fhandle(p, args->fh);
	p = xdr_encode_hyper(p, args->offset);
	*p++ = htonl(count);
	*p++ = htonl(args->stable);
	*p++ = htonl(count);
	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);

	/* Get the number of buffers in the send iovec */
	nr = args->nriov;

	if (nr+2 > MAX_IOVEC) {
		printk(KERN_ERR "NFS: Bad number of iov's in xdr_writeargs\n");
		return -EINVAL;
	}

	/* Copy the iovec */
	memcpy(req->rq_svec + 1, args->iov, nr * sizeof(struct iovec));

#ifdef NFS_PAD_WRITES
	/*
	 * Some old servers require that the message length
	 * be a multiple of 4, so we pad it here if needed.
	 */
	if (count & 3) {
		struct iovec	*iov = req->rq_svec + nr + 1;
		int		pad = 4 - (count & 3);

		iov->iov_base = (void *) "\0\0\0";
		iov->iov_len  = pad;
		count += pad;
		nr++;
	}
#endif
	req->rq_slen += count;
	req->rq_snr  += nr;

	return 0;
}

/*
 * Encode CREATE arguments
 */
static int
nfs3_xdr_createargs(struct rpc_rqst *req, u32 *p, struct nfs3_createargs *args)
{
	p = xdr_encode_fhandle(p, args->fh);
	p = xdr_encode_array(p, args->name, args->len);

	*p++ = htonl(args->createmode);
	if (args->createmode == NFS3_CREATE_EXCLUSIVE) {
		*p++ = args->verifier[0];
		*p++ = args->verifier[1];
	} else
		p = xdr_encode_sattr(p, args->sattr);

	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
	return 0;
}

/*
 * Encode MKDIR arguments
 */
static int
nfs3_xdr_mkdirargs(struct rpc_rqst *req, u32 *p, struct nfs3_mkdirargs *args)
{
	p = xdr_encode_fhandle(p, args->fh);
	p = xdr_encode_array(p, args->name, args->len);
	p = xdr_encode_sattr(p, args->sattr);
	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
	return 0;
}

/*
 * Encode SYMLINK arguments
 */
static int
nfs3_xdr_symlinkargs(struct rpc_rqst *req, u32 *p, struct nfs3_symlinkargs *args)
{
	p = xdr_encode_fhandle(p, args->fromfh);
	p = xdr_encode_array(p, args->fromname, args->fromlen);
	p = xdr_encode_sattr(p, args->sattr);
	p = xdr_encode_array(p, args->topath, args->tolen);
	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
	return 0;
}

/*
 * Encode MKNOD arguments
 */
static int
nfs3_xdr_mknodargs(struct rpc_rqst *req, u32 *p, struct nfs3_mknodargs *args)
{
	p = xdr_encode_fhandle(p, args->fh);
	p = xdr_encode_array(p, args->name, args->len);
	*p++ = htonl(args->type);
	p = xdr_encode_sattr(p, args->sattr);
	if (args->type == NF3CHR || args->type == NF3BLK) {
		*p++ = htonl(args->rdev >> MINORBITS);
		*p++ = htonl(args->rdev & MINORMASK);
	}

	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
	return 0;
}

/*
 * Encode RENAME arguments
 */
static int
nfs3_xdr_renameargs(struct rpc_rqst *req, u32 *p, struct nfs3_renameargs *args)
{
	p = xdr_encode_fhandle(p, args->fromfh);
	p = xdr_encode_array(p, args->fromname, args->fromlen);
	p = xdr_encode_fhandle(p, args->tofh);
	p = xdr_encode_array(p, args->toname, args->tolen);
	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
	return 0;
}

/*
 * Encode LINK arguments
 */
static int
nfs3_xdr_linkargs(struct rpc_rqst *req, u32 *p, struct nfs3_linkargs *args)
{
	p = xdr_encode_fhandle(p, args->fromfh);
	p = xdr_encode_fhandle(p, args->tofh);
	p = xdr_encode_array(p, args->toname, args->tolen);
	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
	return 0;
}

/*
 * Encode arguments to readdir call
 */
static int
nfs3_xdr_readdirargs(struct rpc_rqst *req, u32 *p, struct nfs3_readdirargs *args)
{
	struct rpc_auth	*auth = req->rq_task->tk_auth;
	int		buflen, replen;

	p = xdr_encode_fhandle(p, args->fh);
	p = xdr_encode_hyper(p, args->cookie);
	*p++ = args->verf[0];
	*p++ = args->verf[1];
	if (args->plus) {
		/* readdirplus: need dircount + buffer size.
		 * We just make sure we make dircount big enough */
		*p++ = htonl(args->bufsiz >> 3);
	}
	*p++ = htonl(args->bufsiz);
	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);

	/* set up reply iovec */