linux/fs/nfs/callback_xdr.c

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/*
* linux/fs/nfs/callback_xdr.c
*
* Copyright (C) 2004 Trond Myklebust
*
* NFSv4 callback encode/decode procedures
*/
#include <linux/kernel.h>
#include <linux/sunrpc/svc.h>
#include <linux/nfs4.h>
#include <linux/nfs_fs.h>
#include "nfs4_fs.h"
#include "callback.h"
#define CB_OP_TAGLEN_MAXSZ (512)
#define CB_OP_HDR_RES_MAXSZ (2 + CB_OP_TAGLEN_MAXSZ)
#define CB_OP_GETATTR_BITMAP_MAXSZ (4)
#define CB_OP_GETATTR_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ + \
CB_OP_GETATTR_BITMAP_MAXSZ + \
2 + 2 + 3 + 3)
#define CB_OP_RECALL_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ)
#define NFSDBG_FACILITY NFSDBG_CALLBACK
typedef __be32 (*callback_process_op_t)(void *, void *);
typedef __be32 (*callback_decode_arg_t)(struct svc_rqst *, struct xdr_stream *, void *);
typedef __be32 (*callback_encode_res_t)(struct svc_rqst *, struct xdr_stream *, void *);
struct callback_op {
callback_process_op_t process_op;
callback_decode_arg_t decode_args;
callback_encode_res_t encode_res;
long res_maxsize;
};
static struct callback_op callback_ops[];
static __be32 nfs4_callback_null(struct svc_rqst *rqstp, void *argp, void *resp)
{
return htonl(NFS4_OK);
}
static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
{
return xdr_argsize_check(rqstp, p);
}
static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
{
return xdr_ressize_check(rqstp, p);
}
static __be32 *read_buf(struct xdr_stream *xdr, int nbytes)
{
__be32 *p;
p = xdr_inline_decode(xdr, nbytes);
if (unlikely(p == NULL))
printk(KERN_WARNING "NFSv4 callback reply buffer overflowed!\n");
return p;
}
static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len, const char **str)
{
__be32 *p;
p = read_buf(xdr, 4);
if (unlikely(p == NULL))
return htonl(NFS4ERR_RESOURCE);
*len = ntohl(*p);
if (*len != 0) {
p = read_buf(xdr, *len);
if (unlikely(p == NULL))
return htonl(NFS4ERR_RESOURCE);
*str = (const char *)p;
} else
*str = NULL;
return 0;
}
static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
{
__be32 *p;
p = read_buf(xdr, 4);
if (unlikely(p == NULL))
return htonl(NFS4ERR_RESOURCE);
fh->size = ntohl(*p);
if (fh->size > NFS4_FHSIZE)
return htonl(NFS4ERR_BADHANDLE);
p = read_buf(xdr, fh->size);
if (unlikely(p == NULL))
return htonl(NFS4ERR_RESOURCE);
memcpy(&fh->data[0], p, fh->size);
memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
return 0;
}
static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
{
__be32 *p;
unsigned int attrlen;
p = read_buf(xdr, 4);
if (unlikely(p == NULL))
return htonl(NFS4ERR_RESOURCE);
attrlen = ntohl(*p);
p = read_buf(xdr, attrlen << 2);
if (unlikely(p == NULL))
return htonl(NFS4ERR_RESOURCE);
if (likely(attrlen > 0))
bitmap[0] = ntohl(*p++);
if (attrlen > 1)
bitmap[1] = ntohl(*p);
return 0;
}
static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
{
__be32 *p;
p = read_buf(xdr, 16);
if (unlikely(p == NULL))
return htonl(NFS4ERR_RESOURCE);
memcpy(stateid->data, p, 16);
return 0;
}
static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
{
__be32 *p;
__be32 status;
status = decode_string(xdr, &hdr->taglen, &hdr->tag);
if (unlikely(status != 0))
return status;
/* We do not like overly long tags! */
if (hdr->taglen > CB_OP_TAGLEN_MAXSZ - 12) {
printk("NFSv4 CALLBACK %s: client sent tag of length %u\n",
__func__, hdr->taglen);
return htonl(NFS4ERR_RESOURCE);
}
p = read_buf(xdr, 12);
if (unlikely(p == NULL))
return htonl(NFS4ERR_RESOURCE);
hdr->minorversion = ntohl(*p++);
/* Check minor version is zero or one. */
if (hdr->minorversion <= 1) {
p++; /* skip callback_ident */
} else {
printk(KERN_WARNING "%s: NFSv4 server callback with "
"illegal minor version %u!\n",
__func__, hdr->minorversion);
return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
}
hdr->nops = ntohl(*p);
dprintk("%s: minorversion %d nops %d\n", __func__,
hdr->minorversion, hdr->nops);
return 0;
}
static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
{
__be32 *p;
p = read_buf(xdr, 4);
if (unlikely(p == NULL))
return htonl(NFS4ERR_RESOURCE);
*op = ntohl(*p);
return 0;
}
static __be32 decode_getattr_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_getattrargs *args)
{
__be32 status;
status = decode_fh(xdr, &args->fh);
if (unlikely(status != 0))
goto out;
args->addr = svc_addr(rqstp);
status = decode_bitmap(xdr, args->bitmap);
out:
dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
return status;
}
static __be32 decode_recall_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_recallargs *args)
{
__be32 *p;
__be32 status;
args->addr = svc_addr(rqstp);
status = decode_stateid(xdr, &args->stateid);
if (unlikely(status != 0))
goto out;
p = read_buf(xdr, 4);
if (unlikely(p == NULL)) {
status = htonl(NFS4ERR_RESOURCE);
goto out;
}
args->truncate = ntohl(*p);
status = decode_fh(xdr, &args->fh);
out:
dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
return status;
}
static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
{
__be32 *p;
p = xdr_reserve_space(xdr, 4 + len);
if (unlikely(p == NULL))
return htonl(NFS4ERR_RESOURCE);
xdr_encode_opaque(p, str, len);
return 0;
}
#define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
#define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, __be32 **savep)
{
__be32 bm[2];
__be32 *p;
bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
if (bm[1] != 0) {
p = xdr_reserve_space(xdr, 16);
if (unlikely(p == NULL))
return htonl(NFS4ERR_RESOURCE);
*p++ = htonl(2);
*p++ = bm[0];
*p++ = bm[1];
} else if (bm[0] != 0) {
p = xdr_reserve_space(xdr, 12);
if (unlikely(p == NULL))
return htonl(NFS4ERR_RESOURCE);
*p++ = htonl(1);
*p++ = bm[0];
} else {
p = xdr_reserve_space(xdr, 8);
if (unlikely(p == NULL))
return htonl(NFS4ERR_RESOURCE);
*p++ = htonl(0);
}
*savep = p;
return 0;
}
static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
{
__be32 *p;
if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
return 0;
p = xdr_reserve_space(xdr, 8);
if (unlikely(!p))
return htonl(NFS4ERR_RESOURCE);
p = xdr_encode_hyper(p, change);
return 0;
}
static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
{
__be32 *p;
if (!(bitmap[0] & FATTR4_WORD0_SIZE))
return 0;
p = xdr_reserve_space(xdr, 8);
if (unlikely(!p))
return htonl(NFS4ERR_RESOURCE);
p = xdr_encode_hyper(p, size);
return 0;
}
static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
{
__be32 *p;
p = xdr_reserve_space(xdr, 12);
if (unlikely(!p))
return htonl(NFS4ERR_RESOURCE);
p = xdr_encode_hyper(p, time->tv_sec);
*p = htonl(time->tv_nsec);
return 0;
}
static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
{
if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
return 0;
return encode_attr_time(xdr,time);
}
static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
{
if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
return 0;
return encode_attr_time(xdr,time);
}
static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
{
__be32 status;
hdr->status = xdr_reserve_space(xdr, 4);
if (unlikely(hdr->status == NULL))
return htonl(NFS4ERR_RESOURCE);
status = encode_string(xdr, hdr->taglen, hdr->tag);
if (unlikely(status != 0))
return status;
hdr->nops = xdr_reserve_space(xdr, 4);
if (unlikely(hdr->nops == NULL))
return htonl(NFS4ERR_RESOURCE);
return 0;
}
static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
{
__be32 *p;
p = xdr_reserve_space(xdr, 8);
if (unlikely(p == NULL))
return htonl(NFS4ERR_RESOURCE);
*p++ = htonl(op);
*p = res;
return 0;
}
static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct cb_getattrres *res)
{
__be32 *savep = NULL;
__be32 status = res->status;
if (unlikely(status != 0))
goto out;
status = encode_attr_bitmap(xdr, res->bitmap, &savep);
if (unlikely(status != 0))
goto out;
status = encode_attr_change(xdr, res->bitmap, res->change_attr);
if (unlikely(status != 0))
goto out;
status = encode_attr_size(xdr, res->bitmap, res->size);
if (unlikely(status != 0))
goto out;
status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
if (unlikely(status != 0))
goto out;
status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
out:
dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
return status;
}
static __be32 process_op(struct svc_rqst *rqstp,
struct xdr_stream *xdr_in, void *argp,
struct xdr_stream *xdr_out, void *resp)
{
struct callback_op *op = &callback_ops[0];
unsigned int op_nr = OP_CB_ILLEGAL;
__be32 status = 0;
long maxlen;
__be32 res;
dprintk("%s: start\n", __func__);
status = decode_op_hdr(xdr_in, &op_nr);
if (likely(status == 0)) {
switch (op_nr) {
case OP_CB_GETATTR:
case OP_CB_RECALL:
op = &callback_ops[op_nr];
break;
default:
op_nr = OP_CB_ILLEGAL;
op = &callback_ops[0];
status = htonl(NFS4ERR_OP_ILLEGAL);
}
}
maxlen = xdr_out->end - xdr_out->p;
if (maxlen > 0 && maxlen < PAGE_SIZE) {
if (likely(status == 0 && op->decode_args != NULL))
status = op->decode_args(rqstp, xdr_in, argp);
if (likely(status == 0 && op->process_op != NULL))
status = op->process_op(argp, resp);
} else
status = htonl(NFS4ERR_RESOURCE);
res = encode_op_hdr(xdr_out, op_nr, status);
if (status == 0)
status = res;
if (op->encode_res != NULL && status == 0)
status = op->encode_res(rqstp, xdr_out, resp);
dprintk("%s: done, status = %d\n", __func__, ntohl(status));
return status;
}
/*
* Decode, process and encode a COMPOUND
*/
static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *resp)
{
struct cb_compound_hdr_arg hdr_arg = { 0 };
struct cb_compound_hdr_res hdr_res = { NULL };
struct xdr_stream xdr_in, xdr_out;
__be32 *p;
__be32 status;
unsigned int nops = 0;
dprintk("%s: start\n", __func__);
xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
if (status == __constant_htonl(NFS4ERR_RESOURCE))
return rpc_garbage_args;
hdr_res.taglen = hdr_arg.taglen;
hdr_res.tag = hdr_arg.tag;
if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0)
return rpc_system_err;
while (status == 0 && nops != hdr_arg.nops) {
status = process_op(rqstp, &xdr_in, argp, &xdr_out, resp);
nops++;
}
*hdr_res.status = status;
*hdr_res.nops = htonl(nops);
dprintk("%s: done, status = %u\n", __func__, ntohl(status));
return rpc_success;
}
/*
* Define NFS4 callback COMPOUND ops.
*/
static struct callback_op callback_ops[] = {
[0] = {
.res_maxsize = CB_OP_HDR_RES_MAXSZ,
},
[OP_CB_GETATTR] = {
.process_op = (callback_process_op_t)nfs4_callback_getattr,
.decode_args = (callback_decode_arg_t)decode_getattr_args,
.encode_res = (callback_encode_res_t)encode_getattr_res,
.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
},
[OP_CB_RECALL] = {
.process_op = (callback_process_op_t)nfs4_callback_recall,
.decode_args = (callback_decode_arg_t)decode_recall_args,
.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
}
};
/*
* Define NFS4 callback procedures
*/
static struct svc_procedure nfs4_callback_procedures1[] = {
[CB_NULL] = {
.pc_func = nfs4_callback_null,
.pc_decode = (kxdrproc_t)nfs4_decode_void,
.pc_encode = (kxdrproc_t)nfs4_encode_void,
.pc_xdrressize = 1,
},
[CB_COMPOUND] = {
.pc_func = nfs4_callback_compound,
.pc_encode = (kxdrproc_t)nfs4_encode_void,
.pc_argsize = 256,
.pc_ressize = 256,
.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
}
};
struct svc_version nfs4_callback_version1 = {
.vs_vers = 1,
.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
.vs_proc = nfs4_callback_procedures1,
.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
.vs_dispatch = NULL,
};