linux/fs/lockd/xdr.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * linux/fs/lockd/xdr.c
   4 *
   5 * XDR support for lockd and the lock client.
   6 *
   7 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   8 */
   9
  10#include <linux/types.h>
  11#include <linux/sched.h>
  12#include <linux/nfs.h>
  13
  14#include <linux/sunrpc/xdr.h>
  15#include <linux/sunrpc/clnt.h>
  16#include <linux/sunrpc/svc.h>
  17#include <linux/sunrpc/stats.h>
  18#include <linux/lockd/lockd.h>
  19
  20#include <uapi/linux/nfs2.h>
  21
  22#define NLMDBG_FACILITY         NLMDBG_XDR
  23
  24
  25static inline loff_t
  26s32_to_loff_t(__s32 offset)
  27{
  28        return (loff_t)offset;
  29}
  30
  31static inline __s32
  32loff_t_to_s32(loff_t offset)
  33{
  34        __s32 res;
  35        if (offset >= NLM_OFFSET_MAX)
  36                res = NLM_OFFSET_MAX;
  37        else if (offset <= -NLM_OFFSET_MAX)
  38                res = -NLM_OFFSET_MAX;
  39        else
  40                res = offset;
  41        return res;
  42}
  43
  44/*
  45 * XDR functions for basic NLM types
  46 */
  47static __be32 *nlm_decode_cookie(__be32 *p, struct nlm_cookie *c)
  48{
  49        unsigned int    len;
  50
  51        len = ntohl(*p++);
  52        
  53        if(len==0)
  54        {
  55                c->len=4;
  56                memset(c->data, 0, 4);  /* hockeypux brain damage */
  57        }
  58        else if(len<=NLM_MAXCOOKIELEN)
  59        {
  60                c->len=len;
  61                memcpy(c->data, p, len);
  62                p+=XDR_QUADLEN(len);
  63        }
  64        else 
  65        {
  66                dprintk("lockd: bad cookie size %d (only cookies under "
  67                        "%d bytes are supported.)\n",
  68                                len, NLM_MAXCOOKIELEN);
  69                return NULL;
  70        }
  71        return p;
  72}
  73
  74static inline __be32 *
  75nlm_encode_cookie(__be32 *p, struct nlm_cookie *c)
  76{
  77        *p++ = htonl(c->len);
  78        memcpy(p, c->data, c->len);
  79        p+=XDR_QUADLEN(c->len);
  80        return p;
  81}
  82
  83static __be32 *
  84nlm_decode_fh(__be32 *p, struct nfs_fh *f)
  85{
  86        unsigned int    len;
  87
  88        if ((len = ntohl(*p++)) != NFS2_FHSIZE) {
  89                dprintk("lockd: bad fhandle size %d (should be %d)\n",
  90                        len, NFS2_FHSIZE);
  91                return NULL;
  92        }
  93        f->size = NFS2_FHSIZE;
  94        memset(f->data, 0, sizeof(f->data));
  95        memcpy(f->data, p, NFS2_FHSIZE);
  96        return p + XDR_QUADLEN(NFS2_FHSIZE);
  97}
  98
  99/*
 100 * Encode and decode owner handle
 101 */
 102static inline __be32 *
 103nlm_decode_oh(__be32 *p, struct xdr_netobj *oh)
 104{
 105        return xdr_decode_netobj(p, oh);
 106}
 107
 108static inline __be32 *
 109nlm_encode_oh(__be32 *p, struct xdr_netobj *oh)
 110{
 111        return xdr_encode_netobj(p, oh);
 112}
 113
 114static __be32 *
 115nlm_decode_lock(__be32 *p, struct nlm_lock *lock)
 116{
 117        struct file_lock        *fl = &lock->fl;
 118        s32                     start, len, end;
 119
 120        if (!(p = xdr_decode_string_inplace(p, &lock->caller,
 121                                            &lock->len,
 122                                            NLM_MAXSTRLEN))
 123         || !(p = nlm_decode_fh(p, &lock->fh))
 124         || !(p = nlm_decode_oh(p, &lock->oh)))
 125                return NULL;
 126        lock->svid  = ntohl(*p++);
 127
 128        locks_init_lock(fl);
 129        fl->fl_owner = current->files;
 130        fl->fl_pid   = (pid_t)lock->svid;
 131        fl->fl_flags = FL_POSIX;
 132        fl->fl_type  = F_RDLCK;         /* as good as anything else */
 133        start = ntohl(*p++);
 134        len = ntohl(*p++);
 135        end = start + len - 1;
 136
 137        fl->fl_start = s32_to_loff_t(start);
 138
 139        if (len == 0 || end < 0)
 140                fl->fl_end = OFFSET_MAX;
 141        else
 142                fl->fl_end = s32_to_loff_t(end);
 143        return p;
 144}
 145
 146/*
 147 * Encode result of a TEST/TEST_MSG call
 148 */
 149static __be32 *
 150nlm_encode_testres(__be32 *p, struct nlm_res *resp)
 151{
 152        s32             start, len;
 153
 154        if (!(p = nlm_encode_cookie(p, &resp->cookie)))
 155                return NULL;
 156        *p++ = resp->status;
 157
 158        if (resp->status == nlm_lck_denied) {
 159                struct file_lock        *fl = &resp->lock.fl;
 160
 161                *p++ = (fl->fl_type == F_RDLCK)? xdr_zero : xdr_one;
 162                *p++ = htonl(resp->lock.svid);
 163
 164                /* Encode owner handle. */
 165                if (!(p = xdr_encode_netobj(p, &resp->lock.oh)))
 166                        return NULL;
 167
 168                start = loff_t_to_s32(fl->fl_start);
 169                if (fl->fl_end == OFFSET_MAX)
 170                        len = 0;
 171                else
 172                        len = loff_t_to_s32(fl->fl_end - fl->fl_start + 1);
 173
 174                *p++ = htonl(start);
 175                *p++ = htonl(len);
 176        }
 177
 178        return p;
 179}
 180
 181
 182/*
 183 * First, the server side XDR functions
 184 */
 185int
 186nlmsvc_decode_testargs(struct svc_rqst *rqstp, __be32 *p)
 187{
 188        struct nlm_args *argp = rqstp->rq_argp;
 189        u32     exclusive;
 190
 191        if (!(p = nlm_decode_cookie(p, &argp->cookie)))
 192                return 0;
 193
 194        exclusive = ntohl(*p++);
 195        if (!(p = nlm_decode_lock(p, &argp->lock)))
 196                return 0;
 197        if (exclusive)
 198                argp->lock.fl.fl_type = F_WRLCK;
 199
 200        return xdr_argsize_check(rqstp, p);
 201}
 202
 203int
 204nlmsvc_encode_testres(struct svc_rqst *rqstp, __be32 *p)
 205{
 206        struct nlm_res *resp = rqstp->rq_resp;
 207
 208        if (!(p = nlm_encode_testres(p, resp)))
 209                return 0;
 210        return xdr_ressize_check(rqstp, p);
 211}
 212
 213int
 214nlmsvc_decode_lockargs(struct svc_rqst *rqstp, __be32 *p)
 215{
 216        struct nlm_args *argp = rqstp->rq_argp;
 217        u32     exclusive;
 218
 219        if (!(p = nlm_decode_cookie(p, &argp->cookie)))
 220                return 0;
 221        argp->block  = ntohl(*p++);
 222        exclusive    = ntohl(*p++);
 223        if (!(p = nlm_decode_lock(p, &argp->lock)))
 224                return 0;
 225        if (exclusive)
 226                argp->lock.fl.fl_type = F_WRLCK;
 227        argp->reclaim = ntohl(*p++);
 228        argp->state   = ntohl(*p++);
 229        argp->monitor = 1;              /* monitor client by default */
 230
 231        return xdr_argsize_check(rqstp, p);
 232}
 233
 234int
 235nlmsvc_decode_cancargs(struct svc_rqst *rqstp, __be32 *p)
 236{
 237        struct nlm_args *argp = rqstp->rq_argp;
 238        u32     exclusive;
 239
 240        if (!(p = nlm_decode_cookie(p, &argp->cookie)))
 241                return 0;
 242        argp->block = ntohl(*p++);
 243        exclusive = ntohl(*p++);
 244        if (!(p = nlm_decode_lock(p, &argp->lock)))
 245                return 0;
 246        if (exclusive)
 247                argp->lock.fl.fl_type = F_WRLCK;
 248        return xdr_argsize_check(rqstp, p);
 249}
 250
 251int
 252nlmsvc_decode_unlockargs(struct svc_rqst *rqstp, __be32 *p)
 253{
 254        struct nlm_args *argp = rqstp->rq_argp;
 255
 256        if (!(p = nlm_decode_cookie(p, &argp->cookie))
 257         || !(p = nlm_decode_lock(p, &argp->lock)))
 258                return 0;
 259        argp->lock.fl.fl_type = F_UNLCK;
 260        return xdr_argsize_check(rqstp, p);
 261}
 262
 263int
 264nlmsvc_decode_shareargs(struct svc_rqst *rqstp, __be32 *p)
 265{
 266        struct nlm_args *argp = rqstp->rq_argp;
 267        struct nlm_lock *lock = &argp->lock;
 268
 269        memset(lock, 0, sizeof(*lock));
 270        locks_init_lock(&lock->fl);
 271        lock->svid = ~(u32) 0;
 272        lock->fl.fl_pid = (pid_t)lock->svid;
 273
 274        if (!(p = nlm_decode_cookie(p, &argp->cookie))
 275         || !(p = xdr_decode_string_inplace(p, &lock->caller,
 276                                            &lock->len, NLM_MAXSTRLEN))
 277         || !(p = nlm_decode_fh(p, &lock->fh))
 278         || !(p = nlm_decode_oh(p, &lock->oh)))
 279                return 0;
 280        argp->fsm_mode = ntohl(*p++);
 281        argp->fsm_access = ntohl(*p++);
 282        return xdr_argsize_check(rqstp, p);
 283}
 284
 285int
 286nlmsvc_encode_shareres(struct svc_rqst *rqstp, __be32 *p)
 287{
 288        struct nlm_res *resp = rqstp->rq_resp;
 289
 290        if (!(p = nlm_encode_cookie(p, &resp->cookie)))
 291                return 0;
 292        *p++ = resp->status;
 293        *p++ = xdr_zero;                /* sequence argument */
 294        return xdr_ressize_check(rqstp, p);
 295}
 296
 297int
 298nlmsvc_encode_res(struct svc_rqst *rqstp, __be32 *p)
 299{
 300        struct nlm_res *resp = rqstp->rq_resp;
 301
 302        if (!(p = nlm_encode_cookie(p, &resp->cookie)))
 303                return 0;
 304        *p++ = resp->status;
 305        return xdr_ressize_check(rqstp, p);
 306}
 307
 308int
 309nlmsvc_decode_notify(struct svc_rqst *rqstp, __be32 *p)
 310{
 311        struct nlm_args *argp = rqstp->rq_argp;
 312        struct nlm_lock *lock = &argp->lock;
 313
 314        if (!(p = xdr_decode_string_inplace(p, &lock->caller,
 315                                            &lock->len, NLM_MAXSTRLEN)))
 316                return 0;
 317        argp->state = ntohl(*p++);
 318        return xdr_argsize_check(rqstp, p);
 319}
 320
 321int
 322nlmsvc_decode_reboot(struct svc_rqst *rqstp, __be32 *p)
 323{
 324        struct nlm_reboot *argp = rqstp->rq_argp;
 325
 326        if (!(p = xdr_decode_string_inplace(p, &argp->mon, &argp->len, SM_MAXSTRLEN)))
 327                return 0;
 328        argp->state = ntohl(*p++);
 329        memcpy(&argp->priv.data, p, sizeof(argp->priv.data));
 330        p += XDR_QUADLEN(SM_PRIV_SIZE);
 331        return xdr_argsize_check(rqstp, p);
 332}
 333
 334int
 335nlmsvc_decode_res(struct svc_rqst *rqstp, __be32 *p)
 336{
 337        struct nlm_res *resp = rqstp->rq_argp;
 338
 339        if (!(p = nlm_decode_cookie(p, &resp->cookie)))
 340                return 0;
 341        resp->status = *p++;
 342        return xdr_argsize_check(rqstp, p);
 343}
 344
 345int
 346nlmsvc_decode_void(struct svc_rqst *rqstp, __be32 *p)
 347{
 348        return xdr_argsize_check(rqstp, p);
 349}
 350
 351int
 352nlmsvc_encode_void(struct svc_rqst *rqstp, __be32 *p)
 353{
 354        return xdr_ressize_check(rqstp, p);
 355}
 356