linux/fs/lockd/xdr.c
Chuck Lever 130e2054d4 SUNRPC: Change return value type of .pc_encode
Returning an undecorated integer is an age-old trope, but it's
not clear (even to previous experts in this code) that the only
valid return values are 1 and 0. These functions do not return
a negative errno, rpc_stat value, or a positive length.

Document there are only two valid return values by having
.pc_encode return only true or false.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-10-13 11:34:49 -04:00

354 lines
7.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/lockd/xdr.c
*
* XDR support for lockd and the lock client.
*
* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/nfs.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/stats.h>
#include <linux/lockd/lockd.h>
#include <uapi/linux/nfs2.h>
#include "svcxdr.h"
static inline loff_t
s32_to_loff_t(__s32 offset)
{
return (loff_t)offset;
}
static inline __s32
loff_t_to_s32(loff_t offset)
{
__s32 res;
if (offset >= NLM_OFFSET_MAX)
res = NLM_OFFSET_MAX;
else if (offset <= -NLM_OFFSET_MAX)
res = -NLM_OFFSET_MAX;
else
res = offset;
return res;
}
/*
* NLM file handles are defined by specification to be a variable-length
* XDR opaque no longer than 1024 bytes. However, this implementation
* constrains their length to exactly the length of an NFSv2 file
* handle.
*/
static bool
svcxdr_decode_fhandle(struct xdr_stream *xdr, struct nfs_fh *fh)
{
__be32 *p;
u32 len;
if (xdr_stream_decode_u32(xdr, &len) < 0)
return false;
if (len != NFS2_FHSIZE)
return false;
p = xdr_inline_decode(xdr, len);
if (!p)
return false;
fh->size = NFS2_FHSIZE;
memcpy(fh->data, p, len);
memset(fh->data + NFS2_FHSIZE, 0, sizeof(fh->data) - NFS2_FHSIZE);
return true;
}
static bool
svcxdr_decode_lock(struct xdr_stream *xdr, struct nlm_lock *lock)
{
struct file_lock *fl = &lock->fl;
s32 start, len, end;
if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
return false;
if (!svcxdr_decode_fhandle(xdr, &lock->fh))
return false;
if (!svcxdr_decode_owner(xdr, &lock->oh))
return false;
if (xdr_stream_decode_u32(xdr, &lock->svid) < 0)
return false;
if (xdr_stream_decode_u32(xdr, &start) < 0)
return false;
if (xdr_stream_decode_u32(xdr, &len) < 0)
return false;
locks_init_lock(fl);
fl->fl_flags = FL_POSIX;
fl->fl_type = F_RDLCK;
end = start + len - 1;
fl->fl_start = s32_to_loff_t(start);
if (len == 0 || end < 0)
fl->fl_end = OFFSET_MAX;
else
fl->fl_end = s32_to_loff_t(end);
return true;
}
static bool
svcxdr_encode_holder(struct xdr_stream *xdr, const struct nlm_lock *lock)
{
const struct file_lock *fl = &lock->fl;
s32 start, len;
/* exclusive */
if (xdr_stream_encode_bool(xdr, fl->fl_type != F_RDLCK) < 0)
return false;
if (xdr_stream_encode_u32(xdr, lock->svid) < 0)
return false;
if (!svcxdr_encode_owner(xdr, &lock->oh))
return false;
start = loff_t_to_s32(fl->fl_start);
if (fl->fl_end == OFFSET_MAX)
len = 0;
else
len = loff_t_to_s32(fl->fl_end - fl->fl_start + 1);
if (xdr_stream_encode_u32(xdr, start) < 0)
return false;
if (xdr_stream_encode_u32(xdr, len) < 0)
return false;
return true;
}
static bool
svcxdr_encode_testrply(struct xdr_stream *xdr, const struct nlm_res *resp)
{
if (!svcxdr_encode_stats(xdr, resp->status))
return false;
switch (resp->status) {
case nlm_lck_denied:
if (!svcxdr_encode_holder(xdr, &resp->lock))
return false;
}
return true;
}
/*
* Decode Call arguments
*/
bool
nlmsvc_decode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
return true;
}
bool
nlmsvc_decode_testargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_args *argp = rqstp->rq_argp;
u32 exclusive;
if (!svcxdr_decode_cookie(xdr, &argp->cookie))
return false;
if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
return false;
if (!svcxdr_decode_lock(xdr, &argp->lock))
return false;
if (exclusive)
argp->lock.fl.fl_type = F_WRLCK;
return true;
}
bool
nlmsvc_decode_lockargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_args *argp = rqstp->rq_argp;
u32 exclusive;
if (!svcxdr_decode_cookie(xdr, &argp->cookie))
return false;
if (xdr_stream_decode_bool(xdr, &argp->block) < 0)
return false;
if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
return false;
if (!svcxdr_decode_lock(xdr, &argp->lock))
return false;
if (exclusive)
argp->lock.fl.fl_type = F_WRLCK;
if (xdr_stream_decode_bool(xdr, &argp->reclaim) < 0)
return false;
if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
return false;
argp->monitor = 1; /* monitor client by default */
return true;
}
bool
nlmsvc_decode_cancargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_args *argp = rqstp->rq_argp;
u32 exclusive;
if (!svcxdr_decode_cookie(xdr, &argp->cookie))
return false;
if (xdr_stream_decode_bool(xdr, &argp->block) < 0)
return false;
if (xdr_stream_decode_bool(xdr, &exclusive) < 0)
return false;
if (!svcxdr_decode_lock(xdr, &argp->lock))
return false;
if (exclusive)
argp->lock.fl.fl_type = F_WRLCK;
return true;
}
bool
nlmsvc_decode_unlockargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_args *argp = rqstp->rq_argp;
if (!svcxdr_decode_cookie(xdr, &argp->cookie))
return false;
if (!svcxdr_decode_lock(xdr, &argp->lock))
return false;
argp->lock.fl.fl_type = F_UNLCK;
return true;
}
bool
nlmsvc_decode_res(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_res *resp = rqstp->rq_argp;
if (!svcxdr_decode_cookie(xdr, &resp->cookie))
return false;
if (!svcxdr_decode_stats(xdr, &resp->status))
return false;
return true;
}
bool
nlmsvc_decode_reboot(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_reboot *argp = rqstp->rq_argp;
__be32 *p;
u32 len;
if (xdr_stream_decode_u32(xdr, &len) < 0)
return false;
if (len > SM_MAXSTRLEN)
return false;
p = xdr_inline_decode(xdr, len);
if (!p)
return false;
argp->len = len;
argp->mon = (char *)p;
if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
return false;
p = xdr_inline_decode(xdr, SM_PRIV_SIZE);
if (!p)
return false;
memcpy(&argp->priv.data, p, sizeof(argp->priv.data));
return true;
}
bool
nlmsvc_decode_shareargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_args *argp = rqstp->rq_argp;
struct nlm_lock *lock = &argp->lock;
memset(lock, 0, sizeof(*lock));
locks_init_lock(&lock->fl);
lock->svid = ~(u32)0;
if (!svcxdr_decode_cookie(xdr, &argp->cookie))
return false;
if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
return false;
if (!svcxdr_decode_fhandle(xdr, &lock->fh))
return false;
if (!svcxdr_decode_owner(xdr, &lock->oh))
return false;
/* XXX: Range checks are missing in the original code */
if (xdr_stream_decode_u32(xdr, &argp->fsm_mode) < 0)
return false;
if (xdr_stream_decode_u32(xdr, &argp->fsm_access) < 0)
return false;
return true;
}
bool
nlmsvc_decode_notify(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_args *argp = rqstp->rq_argp;
struct nlm_lock *lock = &argp->lock;
if (!svcxdr_decode_string(xdr, &lock->caller, &lock->len))
return false;
if (xdr_stream_decode_u32(xdr, &argp->state) < 0)
return false;
return true;
}
/*
* Encode Reply results
*/
bool
nlmsvc_encode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
return true;
}
bool
nlmsvc_encode_testres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_res *resp = rqstp->rq_resp;
return svcxdr_encode_cookie(xdr, &resp->cookie) &&
svcxdr_encode_testrply(xdr, resp);
}
bool
nlmsvc_encode_res(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_res *resp = rqstp->rq_resp;
return svcxdr_encode_cookie(xdr, &resp->cookie) &&
svcxdr_encode_stats(xdr, resp->status);
}
bool
nlmsvc_encode_shareres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
struct nlm_res *resp = rqstp->rq_resp;
if (!svcxdr_encode_cookie(xdr, &resp->cookie))
return false;
if (!svcxdr_encode_stats(xdr, resp->status))
return false;
/* sequence */
if (xdr_stream_encode_u32(xdr, 0) < 0)
return false;
return true;
}