- 根目录:
- fs
- lockd
- clntxdr.c
/*
* linux/fs/lockd/clntxdr.c
*
* XDR functions to encode/decode NLM version 3 RPC arguments and results.
* NLM version 3 is backwards compatible with NLM versions 1 and 2.
*
* NLM client-side only.
*
* Copyright (C) 2010, Oracle. All rights reserved.
*/
#include <linux/types.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/stats.h>
#include <linux/lockd/lockd.h>
#include <uapi/linux/nfs2.h>
#define NLMDBG_FACILITY NLMDBG_XDR
#if (NLMCLNT_OHSIZE > XDR_MAX_NETOBJ)
# error "NLM host name cannot be larger than XDR_MAX_NETOBJ!"
#endif
/*
* Declare the space requirements for NLM arguments and replies as
* number of 32bit-words
*/
#define NLM_cookie_sz (1+(NLM_MAXCOOKIELEN>>2))
#define NLM_caller_sz (1+(NLMCLNT_OHSIZE>>2))
#define NLM_owner_sz (1+(NLMCLNT_OHSIZE>>2))
#define NLM_fhandle_sz (1+(NFS2_FHSIZE>>2))
#define NLM_lock_sz (3+NLM_caller_sz+NLM_owner_sz+NLM_fhandle_sz)
#define NLM_holder_sz (4+NLM_owner_sz)
#define NLM_testargs_sz (NLM_cookie_sz+1+NLM_lock_sz)
#define NLM_lockargs_sz (NLM_cookie_sz+4+NLM_lock_sz)
#define NLM_cancargs_sz (NLM_cookie_sz+2+NLM_lock_sz)
#define NLM_unlockargs_sz (NLM_cookie_sz+NLM_lock_sz)
#define NLM_testres_sz (NLM_cookie_sz+1+NLM_holder_sz)
#define NLM_res_sz (NLM_cookie_sz+1)
#define NLM_norep_sz (0)
static 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;
}
static void nlm_compute_offsets(const struct nlm_lock *lock,
u32 *l_offset, u32 *l_len)
{
const struct file_lock *fl = &lock->fl;
*l_offset = loff_t_to_s32(fl->fl_start);
if (fl->fl_end == OFFSET_MAX)
*l_len = 0;
else
*l_len = loff_t_to_s32(fl->fl_end - fl->fl_start + 1);
}
/*
* Handle decode buffer overflows out-of-line.
*/
static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
{
dprintk("lockd: %s prematurely hit the end of our receive buffer. "
"Remaining buffer length is %tu words.\n",
func, xdr->end - xdr->p);
}
/*
* Encode/decode NLMv3 basic data types
*
* Basic NLMv3 data types are not defined in an IETF standards
* document. X/Open has a description of these data types that
* is useful. See Chapter 10 of "Protocols for Interworking:
* XNFS, Version 3W".
*
* Not all basic data types have their own encoding and decoding
* functions. For run-time efficiency, some data types are encoded
* or decoded inline.
*/
static void encode_bool(struct xdr_stream *xdr, const int value)
{
__be32 *p;
p = xdr_reserve_space(xdr, 4);
*p = value ? xdr_one : xdr_zero;
}
static void encode_int32(struct xdr_stream *xdr, const s32 value)
{
__be32 *p;
p = xdr_reserve_space(xdr, 4);
*p = cpu_to_be32(value);
}
/*
* typedef opaque netobj<MAXNETOBJ_SZ>
*/
static void encode_netobj(struct xdr_stream *xdr,
const u8 *data, const unsigned int length)
{
__be32 *p;
p = xdr_reserve_space(xdr, 4 + length);
xdr_encode_opaque(p, data, length);
}
static int decode_netobj(struct xdr_stream *xdr,
struct xdr_netobj *obj)
{
u32 length;
__be32 *p;
p = xdr_inline_decode(xdr, 4);
if (unlikely(p == NULL))
goto out_overflow;
length = be32_to_cpup(p++);
if (unlikely(length > XDR_MAX_NETOBJ))
goto out_size;
obj->len = length;
obj->data = (u8 *)p;
return 0;
out_size:
dprintk("NFS: returned netobj was too long: %u\n", length);
return -EIO;
out_overflow:
print_overflow_msg(__func__, xdr);
return -EIO;
}
/*
* netobj cookie;
*/
static void encode_cookie(struct xdr_stream *xdr,
const struct nlm_cookie *cookie)
{
encode_netobj(xdr, (u8 *)&cookie->data, cookie->len);
}
static int decode_cookie(struct xdr_stream *xdr,
struct nlm_cookie *cookie)
{
u32 length;
__be32 *p;
p = xdr_inline_decode(xdr, 4);
if (unlikely(p == NULL))
goto out_overflow;
length = be32_to_cpup(p++);
/* apparently HPUX can return empty cookies */
if (length == 0)
goto out_hpux;
if (length > NLM_MAXCOOKIELEN)
goto out_size;
p = xdr_inline_decode(xdr, length);
if (unlikely(p == NULL))
goto out_overflow;
cookie->len = length;
memcpy(cookie->data, p, length);
return 0;
out_hpux:
cookie->len = 4;
memset(cookie->data, 0, 4);
return 0;
out_size:
dprintk("NFS: returned cookie was too long: %u\n", length);
return -EIO;
out_overflow:
print_overflow_msg(__func__, xdr);
return -EIO;
}
/*
* netobj fh;
*/
static void encode_fh(struct xdr_stream *xdr, const struct nfs_fh *fh)
{
encode_netobj(xdr, (u8 *)&fh->data, NFS2_FHSIZE);
}
/*
* enum nlm_stats {
* LCK_GRANTED = 0,
* LCK_DENIED = 1,
* LCK_DENIED_NOLOCKS = 2,
* LCK_BLOCKED = 3,
* LCK_DENIED_GRACE_PERIOD = 4
* };
*
*
* struct nlm_stat {
* nlm_stats stat;
* };
*
* NB: we don't swap bytes for the NLM status values. The upper
* layers deal directly with the status value in network byte
* order.
*/
static void encode_nlm_stat(struct xdr_stream *xdr,
const __be32 stat)
{
__be32 *p;
WARN_ON_ONCE(be32_to_cpu(stat) > NLM_LCK_DENIED_GRACE_PERIOD);
p = xdr_reserve_space(xdr, 4);
*p = stat;
}
static int decode_nlm_stat(struct xdr_stream *xdr,
__be32 *stat)
{
__be32 *p;
p = xdr_inline_decode(xdr, 4);
if (unlikely(p == NULL))
goto out_overflow;
if (unlikely(ntohl(*p) > ntohl(nlm_lck_denied_grace_period)))
goto out_enum;
*stat = *p;
return 0;
out_enum:
dprintk("%s: server returned invalid nlm_stats value: %u\n",
__func__, be32_to_cpup(p));
return -EIO;
out_overflow:
print_overflow_msg(__func__, xdr);
return -EIO;
}
/*
* struct nlm_holder {
* bool exclusive;
* int uppid;
* netobj oh;
* unsigned l_offset;
* unsigned l_len;
* };
*/
static void encode_nlm_holder(struct xdr_stream *xdr,
const struct nlm_res *result)
{
const struct nlm_lock *lock = &result->lock;
u32 l_offset, l_len;
__be32 *p;
encode_bool(xdr, lock->fl.fl_type == F_RDLCK);
encode_int32(xdr, lock->svid);
encode_netobj(xdr, lock->oh.data, lock->oh.len);
p = xdr_reserve_space(xdr, 4 + 4);
nlm_compute_offsets(lock, &l_offset, &l_len);
*p++ = cpu_to_be32(l_offset);
*p = cpu_to_be32(l_len);
}
static int decode_nlm_holder(struct xdr_stream *xdr, struct nlm_res *result)
{
struct nlm_lock *lock = &result->lock;
struct file_lock *fl = &lock->fl;
u32 exclusive, l_offset, l_len;
int error;
__be32 *p;
s32 end;
memset(lock, 0, sizeof(*lock));
locks_init_lock(fl);
p = xdr_inline_decode(xdr, 4 + 4);
if (unlikely(p == NULL))
goto out_overflow;
exclusive = be32_to_cpup(p++);
lock->svid = be32_to_cpup(p);
fl->fl_pid = (pid_t)lock->svid;
error = decode_netobj(xdr, &lock->oh);
if (unlikely(error))
goto out;
p = xdr_inline_decode(xdr, 4 + 4);
if (unlikely(p == NULL))
goto out_overflow;
fl->fl_flags = FL_POSIX;
fl->fl_type = exclusive != 0 ? F_WRLCK : F_RDLCK;
l_offset = be32_to_cpup(p++);
l_len = be32_to_cpup(p);
end = l_offset + l_len - 1;
fl->fl_start = (loff_t)l_offset;
if (l_len == 0 || end < 0)
fl->fl_end = OFFSET_MAX;
else
fl->fl_end = (loff_t)end;
error = 0;
out:
return error;
out_overflow:
print_overflow_msg(__func__, xdr);
return -EIO;
}
/*
* string caller_name<LM_MAXSTRLEN>;
*/
static void encode_caller_name(struct xdr_stream *xdr, const char *name)
{
/* NB: client-side does not set lock->len */
u32 length = strlen(name);
__be32 *p;
p = xdr_reserve_space(xdr, 4 + length);
xdr_encode_opaque(p, name, length);
}
/*
* struct nlm_lock {
* string caller_name<LM_MAXSTRLEN>;
* netobj fh;
* netobj oh;
* int uppid;
* unsigned l_offset;
* unsigned l_len;
* };
*/
static void encode_nlm_lock(struct xdr_stream *xdr,
const struct nlm_lock *lock)
{
u32 l_offset, l_len;
__be32 *p;
encode_caller_name(xdr, lock->caller);
encode_fh(xdr, &lock->fh);
encode_netobj(xdr, lock->oh.data, lock->oh.len);
p = xdr_reserve_space(xdr, 4 + 4 + 4);
*p++ = cpu_to_be32(lock->svid);
nlm_compute_offsets(lock, &l_offset, &l_len);
*p++ = cpu_to_be32(l_offset);
*p = cpu_to_be32(l_len);
}
/*
* NLMv3 XDR encode functions
*
* NLMv3 argument types are defined in Chapter 10 of The Open Group's
* "Protocols for Interworking: XNFS, Version 3W".
*/
/*
* struct nlm_testargs {
* netobj cookie;
* bool exclusive;
* struct nlm_lock alock;
* };
*/
static void nlm_xdr_enc_testargs(struct rpc_rqst *req,
struct xdr_stream *xdr,
const struct nlm_args *args)
{
const struct nlm_lock *lock = &args->lock;
encode_cookie(xdr, &args->cookie);
encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
encode_nlm_lock(xdr, lock);
}
/*
* struct nlm_lockargs {
* netobj cookie;
* bool block;
* bool exclusive;
* struct nlm_lock alock;
* bool reclaim;
* int state;
* };
*/
static void nlm_xdr_enc_lockargs(struct rpc_rqst *req,
struct xdr_stream *xdr,
const struct nlm_args *args)
{
const struct nlm_lock *lock = &args->lock;
encode_cookie(xdr, &args->cookie);
encode_bool(xdr, args->block);
encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
encode_nlm_lock(xdr, lock);
encode_bool(xdr, args->reclaim);
encode_int32(xdr, args->state);
}
/*
* struct nlm_cancargs {
* netobj cookie;
* bool block;
* bool exclusive;
* struct nlm_lock alock;
* };
*/
static void nlm_xdr_enc_cancargs(struct rpc_rqst *req,
struct xdr_stream *xdr,
const struct nlm_args *args)
{
const struct nlm_lock *lock = &args->lock;
encode_cookie(xdr, &args->cookie);
encode_bool(xdr, args->block);
encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
encode_nlm_lock(xdr, lock);
}
/*
* struct nlm_unlockargs {
* netobj cookie;
* struct nlm_lock alock;
* };
*/
static void nlm_xdr_enc_unlockargs(struct rpc_rqst *req,
struct xdr_stream *xdr,
const struct nlm_args *args)
{
const struct nlm_lock *lock = &args->lock;
encode_cookie(xdr, &args->cookie);
encode_nlm_lock(xdr, lock);
}
/*
* struct nlm_res {
* netobj cookie;
* nlm_stat stat;
* };
*/
static void nlm_xdr_enc_res(struct rpc_rqst *req,
struct xdr_stream *xdr,
const struct nlm_res *result)
{
encode_cookie(xdr, &result->cookie);
encode_nlm_stat(xdr, result->status);
}
/*
* union nlm_testrply switch (nlm_stats stat) {
* case LCK_DENIED:
* struct nlm_holder holder;
* default:
* void;
* };
*
* struct nlm_testres {
* netobj cookie;
* nlm_testrply test_stat;
* };
*/
static void encode_nlm_testrply(struct xdr_stream *xdr,
const struct nlm_res *result)
{
if (result->status == nlm_lck_denied)
encode_nlm_holder(xdr, result);
}
static void nlm_xdr_enc_testres(struct rpc_rqst *req,
struct xdr_stream *xdr,
const struct nlm_res *result)
{
encode_cookie(xdr, &result->cookie);
encode_nlm_stat(xdr, result->status);
encode_nlm_testrply(xdr, result);
}
/*
* NLMv3 XDR decode functions
*
* NLMv3 result types are defined in Chapter 10 of The Open Group's
* "Protocols for Interworking: XNFS, Version 3W".
*/
/*
* union nlm_testrply switch (nlm_stats stat) {
* case LCK_DENIED:
* struct nlm_holder holder;
* default:
* void;
* };
*
* struct nlm_testres {
* netobj cookie;
* nlm_testrply test_stat;
* };
*/
static int decode_nlm_testrply(struct xdr_stream *xdr,
struct nlm_res *result)
{
int error;
error = decode_nlm_stat(xdr, &result->status);
if (unlikely(error))
goto out;
if (result->status == nlm_lck_denied)
error = decode_nlm_holder(xdr, result);
out:
return error;
}
static int nlm_xdr_dec_testres(struct rpc_rqst *req,
struct xdr_stream *xdr,
struct nlm_res *result)
{
int error;
error = decode_cookie(xdr, &result->cookie);
if (unlikely(error))
goto out;
error = decode_nlm_testrply(xdr, result);
out:
return error;
}
/*
* struct nlm_res {
* netobj cookie;
* nlm_stat stat;
* };
*/
static int nlm_xdr_dec_res(struct rpc_rqst *req,
struct xdr_stream *xdr,
struct nlm_res *result)
{
int error;
error = decode_cookie(xdr, &result->cookie);
if (unlikely(error))
goto out;
error = decode_nlm_stat(xdr, &result->status);
out:
return error;
}
/*
* For NLM, a void procedure really returns nothing
*/
#define nlm_xdr_dec_norep NULL
#define PROC(proc, argtype, restype) \
[NLMPROC_##proc] = { \
.p_proc = NLMPROC_##proc, \
.p_encode = (kxdreproc_t)nlm_xdr_enc_##argtype, \
.p_decode = (kxdrdproc_t)nlm_xdr_dec_##restype, \
.p_arglen = NLM_##argtype##_sz, \
.p_replen = NLM_##restype##_sz, \
.p_statidx = NLMPROC_##proc, \
.p_name = #proc, \
}
static struct rpc_procinfo nlm_procedures[] = {
PROC(TEST, testargs, testres),
PROC(LOCK, lockargs, res),
PROC(CANCEL, cancargs, res),
PROC(UNLOCK, unlockargs, res),
PROC(GRANTED, testargs, res),
PROC(TEST_MSG, testargs, norep),
PROC(LOCK_MSG, lockargs, norep),
PROC(CANCEL_MSG, cancargs, norep),
PROC(UNLOCK_MSG, unlockargs, norep),
PROC(GRANTED_MSG, testargs, norep),
PROC(TEST_RES, testres, norep),
PROC(LOCK_RES, res, norep),
PROC(CANCEL_RES, res, norep),
PROC(UNLOCK_RES, res, norep),
PROC(GRANTED_RES, res, norep),
};
static const struct rpc_version nlm_version1 = {
.number = 1,
.nrprocs = ARRAY_SIZE(nlm_procedures),
.procs = nlm_procedures,
};
static const struct rpc_version nlm_version3 = {
.number = 3,
.nrprocs = ARRAY_SIZE(nlm_procedures),
.procs = nlm_procedures,
};
static const struct rpc_version *nlm_versions[] = {
[1] = &nlm_version1,
[3] = &nlm_version3,
#ifdef CONFIG_LOCKD_V4
[4] = &nlm_version4,
#endif
};
static struct rpc_stat nlm_rpc_stats;
const struct rpc_program nlm_program = {
.name = "lockd",
.number = NLM_PROGRAM,
.nrvers = ARRAY_SIZE(nlm_versions),
.version = nlm_versions,
.stats = &nlm_rpc_stats,
};