fs/lockd/xdr.c

   1 /*
   2  * linux/fs/lockd/xdr.c
   3  *
   4  * XDR support for lockd and the lock client.
   5  *
   6  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   7  */
   8
   9 #include <linux/types.h>
  10 #include <linux/sched.h>
  11 #include <linux/utsname.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 #include <linux/lockd/sm_inter.h>
  20
  21 #define NLMDBG_FACILITY         NLMDBG_XDR
  22
  23
  24 static inline loff_t
  25 s32_to_loff_t(__s32 offset)
  26 {
  27         return (loff_t)offset;
  28 }
  29
  30 static inline __s32
  31 loff_t_to_s32(loff_t offset)
  32 {
  33         __s32 res;
  34         if (offset >= NLM_OFFSET_MAX)
  35                 res = NLM_OFFSET_MAX;
  36         else if (offset <= -NLM_OFFSET_MAX)
  37                 res = -NLM_OFFSET_MAX;
  38         else
  39                 res = offset;
  40         return res;
  41 }
  42
  43 /*
  44  * XDR functions for basic NLM types
  45  */
  46 static __be32 *nlm_decode_cookie(__be32 *p, struct nlm_cookie *c)
  47 {
  48         unsigned int    len;
  49
  50         len = ntohl(*p++);
  51
  52         if(len==0)
  53         {
  54                 c->len=4;
  55                 memset(c->data, 0, 4);  /* hockeypux brain damage */
  56         }
  57         else if(len<=NLM_MAXCOOKIELEN)
  58         {
  59                 c->len=len;
  60                 memcpy(c->data, p, len);
  61                 p+=XDR_QUADLEN(len);
  62         }
  63         else
  64         {
  65                 printk(KERN_NOTICE
  66                         "lockd: bad cookie size %d (only cookies under %d bytes are supported.)\n", len, NLM_MAXCOOKIELEN);
  67                 return NULL;
  68         }
  69         return p;
  70 }
  71
  72 static inline __be32 *
  73 nlm_encode_cookie(__be32 *p, struct nlm_cookie *c)
  74 {
  75         *p++ = htonl(c->len);
  76         memcpy(p, c->data, c->len);
  77         p+=XDR_QUADLEN(c->len);
  78         return p;
  79 }
  80
  81 static __be32 *
  82 nlm_decode_fh(__be32 *p, struct nfs_fh *f)
  83 {
  84         unsigned int    len;
  85
  86         if ((len = ntohl(*p++)) != NFS2_FHSIZE) {
  87                 printk(KERN_NOTICE
  88                         "lockd: bad fhandle size %d (should be %d)\n",
  89                         len, NFS2_FHSIZE);
  90                 return NULL;
  91         }
  92         f->size = NFS2_FHSIZE;
  93         memset(f->data, 0, sizeof(f->data));
  94         memcpy(f->data, p, NFS2_FHSIZE);
  95         return p + XDR_QUADLEN(NFS2_FHSIZE);
  96 }
  97
  98 static inline __be32 *
  99 nlm_encode_fh(__be32 *p, struct nfs_fh *f)
 100 {
 101         *p++ = htonl(NFS2_FHSIZE);
 102         memcpy(p, f->data, NFS2_FHSIZE);
 103         return p + XDR_QUADLEN(NFS2_FHSIZE);
 104 }
 105
 106 /*
 107  * Encode and decode owner handle
 108  */
 109 static inline __be32 *
 110 nlm_decode_oh(__be32 *p, struct xdr_netobj *oh)
 111 {
 112         return xdr_decode_netobj(p, oh);
 113 }
 114
 115 static inline __be32 *
 116 nlm_encode_oh(__be32 *p, struct xdr_netobj *oh)
 117 {
 118         return xdr_encode_netobj(p, oh);
 119 }
 120
 121 static __be32 *
 122 nlm_decode_lock(__be32 *p, struct nlm_lock *lock)
 123 {
 124         struct file_lock        *fl = &lock->fl;
 125         s32                     start, len, end;
 126
 127         if (!(p = xdr_decode_string_inplace(p, &lock->caller,
 128                                             &lock->len,
 129                                             NLM_MAXSTRLEN))
 130          || !(p = nlm_decode_fh(p, &lock->fh))
 131          || !(p = nlm_decode_oh(p, &lock->oh)))
 132                 return NULL;
 133         lock->svid  = ntohl(*p++);
 134
 135         locks_init_lock(fl);
 136         fl->fl_owner = current->files;
 137         fl->fl_pid   = (pid_t)lock->svid;
 138         fl->fl_flags = FL_POSIX;
 139         fl->fl_type  = F_RDLCK;         /* as good as anything else */
 140         start = ntohl(*p++);
 141         len = ntohl(*p++);
 142         end = start + len - 1;
 143
 144         fl->fl_start = s32_to_loff_t(start);
 145
 146         if (len == 0 || end < 0)
 147                 fl->fl_end = OFFSET_MAX;
 148         else
 149                 fl->fl_end = s32_to_loff_t(end);
 150         return p;
 151 }
 152
 153 /*
 154  * Encode a lock as part of an NLM call
 155  */
 156 static __be32 *
 157 nlm_encode_lock(__be32 *p, struct nlm_lock *lock)
 158 {
 159         struct file_lock        *fl = &lock->fl;
 160         __s32                   start, len;
 161
 162         if (!(p = xdr_encode_string(p, lock->caller))
 163          || !(p = nlm_encode_fh(p, &lock->fh))
 164          || !(p = nlm_encode_oh(p, &lock->oh)))
 165                 return NULL;
 166
 167         if (fl->fl_start > NLM_OFFSET_MAX
 168          || (fl->fl_end > NLM_OFFSET_MAX && fl->fl_end != OFFSET_MAX))
 169                 return NULL;
 170
 171         start = loff_t_to_s32(fl->fl_start);
 172         if (fl->fl_end == OFFSET_MAX)
 173                 len = 0;
 174         else
 175                 len = loff_t_to_s32(fl->fl_end - fl->fl_start + 1);
 176
 177         *p++ = htonl(lock->svid);
 178         *p++ = htonl(start);
 179         *p++ = htonl(len);
 180
 181         return p;
 182 }
 183
 184 /*
 185  * Encode result of a TEST/TEST_MSG call
 186  */
 187 static __be32 *
 188 nlm_encode_testres(__be32 *p, struct nlm_res *resp)
 189 {
 190         s32             start, len;
 191
 192         if (!(p = nlm_encode_cookie(p, &resp->cookie)))
 193                 return NULL;
 194         *p++ = resp->status;
 195
 196         if (resp->status == nlm_lck_denied) {
 197                 struct file_lock        *fl = &resp->lock.fl;
 198
 199                 *p++ = (fl->fl_type == F_RDLCK)? xdr_zero : xdr_one;
 200                 *p++ = htonl(resp->lock.svid);
 201
 202                 /* Encode owner handle. */
 203                 if (!(p = xdr_encode_netobj(p, &resp->lock.oh)))
 204                         return NULL;
 205
 206                 start = loff_t_to_s32(fl->fl_start);
 207                 if (fl->fl_end == OFFSET_MAX)
 208                         len = 0;
 209                 else
 210                         len = loff_t_to_s32(fl->fl_end - fl->fl_start + 1);
 211
 212                 *p++ = htonl(start);
 213                 *p++ = htonl(len);
 214         }
 215
 216         return p;
 217 }
 218
 219
 220 /*
 221  * First, the server side XDR functions
 222  */
 223 int
 224 nlmsvc_decode_testargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
 225 {
 226         u32     exclusive;
 227
 228         if (!(p = nlm_decode_cookie(p, &argp->cookie)))
 229                 return 0;
 230
 231         exclusive = ntohl(*p++);
 232         if (!(p = nlm_decode_lock(p, &argp->lock)))
 233                 return 0;
 234         if (exclusive)
 235                 argp->lock.fl.fl_type = F_WRLCK;
 236
 237         return xdr_argsize_check(rqstp, p);
 238 }
 239
 240 int
 241 nlmsvc_encode_testres(struct svc_rqst *rqstp, __be32 *p, struct nlm_res *resp)
 242 {
 243         if (!(p = nlm_encode_testres(p, resp)))
 244                 return 0;
 245         return xdr_ressize_check(rqstp, p);
 246 }
 247
 248 int
 249 nlmsvc_decode_lockargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
 250 {
 251         u32     exclusive;
 252
 253         if (!(p = nlm_decode_cookie(p, &argp->cookie)))
 254                 return 0;
 255         argp->block  = ntohl(*p++);
 256         exclusive    = ntohl(*p++);
 257         if (!(p = nlm_decode_lock(p, &argp->lock)))
 258                 return 0;
 259         if (exclusive)
 260                 argp->lock.fl.fl_type = F_WRLCK;
 261         argp->reclaim = ntohl(*p++);
 262         argp->state   = ntohl(*p++);
 263         argp->monitor = 1;              /* monitor client by default */
 264
 265         return xdr_argsize_check(rqstp, p);
 266 }
 267
 268 int
 269 nlmsvc_decode_cancargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
 270 {
 271         u32     exclusive;
 272
 273         if (!(p = nlm_decode_cookie(p, &argp->cookie)))
 274                 return 0;
 275         argp->block = ntohl(*p++);
 276         exclusive = ntohl(*p++);
 277         if (!(p = nlm_decode_lock(p, &argp->lock)))
 278                 return 0;
 279         if (exclusive)
 280                 argp->lock.fl.fl_type = F_WRLCK;
 281         return xdr_argsize_check(rqstp, p);
 282 }
 283
 284 int
 285 nlmsvc_decode_unlockargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
 286 {
 287         if (!(p = nlm_decode_cookie(p, &argp->cookie))
 288          || !(p = nlm_decode_lock(p, &argp->lock)))
 289                 return 0;
 290         argp->lock.fl.fl_type = F_UNLCK;
 291         return xdr_argsize_check(rqstp, p);
 292 }
 293
 294 int
 295 nlmsvc_decode_shareargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
 296 {
 297         struct nlm_lock *lock = &argp->lock;
 298
 299         memset(lock, 0, sizeof(*lock));
 300         locks_init_lock(&lock->fl);
 301         lock->svid = ~(u32) 0;
 302         lock->fl.fl_pid = (pid_t)lock->svid;
 303
 304         if (!(p = nlm_decode_cookie(p, &argp->cookie))
 305          || !(p = xdr_decode_string_inplace(p, &lock->caller,
 306                                             &lock->len, NLM_MAXSTRLEN))
 307          || !(p = nlm_decode_fh(p, &lock->fh))
 308          || !(p = nlm_decode_oh(p, &lock->oh)))
 309                 return 0;
 310         argp->fsm_mode = ntohl(*p++);
 311         argp->fsm_access = ntohl(*p++);
 312         return xdr_argsize_check(rqstp, p);
 313 }
 314
 315 int
 316 nlmsvc_encode_shareres(struct svc_rqst *rqstp, __be32 *p, struct nlm_res *resp)
 317 {
 318         if (!(p = nlm_encode_cookie(p, &resp->cookie)))
 319                 return 0;
 320         *p++ = resp->status;
 321         *p++ = xdr_zero;                /* sequence argument */
 322         return xdr_ressize_check(rqstp, p);
 323 }
 324
 325 int
 326 nlmsvc_encode_res(struct svc_rqst *rqstp, __be32 *p, struct nlm_res *resp)
 327 {
 328         if (!(p = nlm_encode_cookie(p, &resp->cookie)))
 329                 return 0;
 330         *p++ = resp->status;
 331         return xdr_ressize_check(rqstp, p);
 332 }
 333
 334 int
 335 nlmsvc_decode_notify(struct svc_rqst *rqstp, __be32 *p, struct nlm_args *argp)
 336 {
 337         struct nlm_lock *lock = &argp->lock;
 338
 339         if (!(p = xdr_decode_string_inplace(p, &lock->caller,
 340                                             &lock->len, NLM_MAXSTRLEN)))
 341                 return 0;
 342         argp->state = ntohl(*p++);
 343         return xdr_argsize_check(rqstp, p);
 344 }
 345
 346 int
 347 nlmsvc_decode_reboot(struct svc_rqst *rqstp, __be32 *p, struct nlm_reboot *argp)
 348 {
 349         if (!(p = xdr_decode_string_inplace(p, &argp->mon, &argp->len, SM_MAXSTRLEN)))
 350                 return 0;
 351         argp->state = ntohl(*p++);
 352         /* Preserve the address in network byte order */
 353         argp->addr = *p++;
 354         argp->vers = *p++;
 355         argp->proto = *p++;
 356         return xdr_argsize_check(rqstp, p);
 357 }
 358
 359 int
 360 nlmsvc_decode_res(struct svc_rqst *rqstp, __be32 *p, struct nlm_res *resp)
 361 {
 362         if (!(p = nlm_decode_cookie(p, &resp->cookie)))
 363                 return 0;
 364         resp->status = *p++;
 365         return xdr_argsize_check(rqstp, p);
 366 }
 367
 368 int
 369 nlmsvc_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
 370 {
 371         return xdr_argsize_check(rqstp, p);
 372 }
 373
 374 int
 375 nlmsvc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
 376 {
 377         return xdr_ressize_check(rqstp, p);
 378 }
 379
 380 /*
 381  * Now, the client side XDR functions
 382  */
 383 #ifdef NLMCLNT_SUPPORT_SHARES
 384 static int
 385 nlmclt_decode_void(struct rpc_rqst *req, u32 *p, void *ptr)
 386 {
 387         return 0;
 388 }
 389 #endif
 390
 391 static int
 392 nlmclt_encode_testargs(struct rpc_rqst *req, __be32 *p, nlm_args *argp)
 393 {
 394         struct nlm_lock *lock = &argp->lock;
 395
 396         if (!(p = nlm_encode_cookie(p, &argp->cookie)))
 397                 return -EIO;
 398         *p++ = (lock->fl.fl_type == F_WRLCK)? xdr_one : xdr_zero;
 399         if (!(p = nlm_encode_lock(p, lock)))
 400                 return -EIO;
 401         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 402         return 0;
 403 }
 404
 405 static int
 406 nlmclt_decode_testres(struct rpc_rqst *req, __be32 *p, struct nlm_res *resp)
 407 {
 408         if (!(p = nlm_decode_cookie(p, &resp->cookie)))
 409                 return -EIO;
 410         resp->status = *p++;
 411         if (resp->status == nlm_lck_denied) {
 412                 struct file_lock        *fl = &resp->lock.fl;
 413                 u32                     excl;
 414                 s32                     start, len, end;
 415
 416                 memset(&resp->lock, 0, sizeof(resp->lock));
 417                 locks_init_lock(fl);
 418                 excl = ntohl(*p++);
 419                 resp->lock.svid = ntohl(*p++);
 420                 fl->fl_pid = (pid_t)resp->lock.svid;
 421                 if (!(p = nlm_decode_oh(p, &resp->lock.oh)))
 422                         return -EIO;
 423
 424                 fl->fl_flags = FL_POSIX;
 425                 fl->fl_type  = excl? F_WRLCK : F_RDLCK;
 426                 start = ntohl(*p++);
 427                 len = ntohl(*p++);
 428                 end = start + len - 1;
 429
 430                 fl->fl_start = s32_to_loff_t(start);
 431                 if (len == 0 || end < 0)
 432                         fl->fl_end = OFFSET_MAX;
 433                 else
 434                         fl->fl_end = s32_to_loff_t(end);
 435         }
 436         return 0;
 437 }
 438
 439
 440 static int
 441 nlmclt_encode_lockargs(struct rpc_rqst *req, __be32 *p, nlm_args *argp)
 442 {
 443         struct nlm_lock *lock = &argp->lock;
 444
 445         if (!(p = nlm_encode_cookie(p, &argp->cookie)))
 446                 return -EIO;
 447         *p++ = argp->block? xdr_one : xdr_zero;
 448         *p++ = (lock->fl.fl_type == F_WRLCK)? xdr_one : xdr_zero;
 449         if (!(p = nlm_encode_lock(p, lock)))
 450                 return -EIO;
 451         *p++ = argp->reclaim? xdr_one : xdr_zero;
 452         *p++ = htonl(argp->state);
 453         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 454         return 0;
 455 }
 456
 457 static int
 458 nlmclt_encode_cancargs(struct rpc_rqst *req, __be32 *p, nlm_args *argp)
 459 {
 460         struct nlm_lock *lock = &argp->lock;
 461
 462         if (!(p = nlm_encode_cookie(p, &argp->cookie)))
 463                 return -EIO;
 464         *p++ = argp->block? xdr_one : xdr_zero;
 465         *p++ = (lock->fl.fl_type == F_WRLCK)? xdr_one : xdr_zero;
 466         if (!(p = nlm_encode_lock(p, lock)))
 467                 return -EIO;
 468         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 469         return 0;
 470 }
 471
 472 static int
 473 nlmclt_encode_unlockargs(struct rpc_rqst *req, __be32 *p, nlm_args *argp)
 474 {
 475         struct nlm_lock *lock = &argp->lock;
 476
 477         if (!(p = nlm_encode_cookie(p, &argp->cookie)))
 478                 return -EIO;
 479         if (!(p = nlm_encode_lock(p, lock)))
 480                 return -EIO;
 481         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 482         return 0;
 483 }
 484
 485 static int
 486 nlmclt_encode_res(struct rpc_rqst *req, __be32 *p, struct nlm_res *resp)
 487 {
 488         if (!(p = nlm_encode_cookie(p, &resp->cookie)))
 489                 return -EIO;
 490         *p++ = resp->status;
 491         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 492         return 0;
 493 }
 494
 495 static int
 496 nlmclt_encode_testres(struct rpc_rqst *req, __be32 *p, struct nlm_res *resp)
 497 {
 498         if (!(p = nlm_encode_testres(p, resp)))
 499                 return -EIO;
 500         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 501         return 0;
 502 }
 503
 504 static int
 505 nlmclt_decode_res(struct rpc_rqst *req, __be32 *p, struct nlm_res *resp)
 506 {
 507         if (!(p = nlm_decode_cookie(p, &resp->cookie)))
 508                 return -EIO;
 509         resp->status = *p++;
 510         return 0;
 511 }
 512
 513 /*
 514  * Buffer requirements for NLM
 515  */
 516 #define NLM_void_sz             0
 517 #define NLM_cookie_sz           1+XDR_QUADLEN(NLM_MAXCOOKIELEN)
 518 #define NLM_caller_sz           1+XDR_QUADLEN(sizeof(utsname()->nodename))
 519 #define NLM_netobj_sz           1+XDR_QUADLEN(XDR_MAX_NETOBJ)
 520 /* #define NLM_owner_sz         1+XDR_QUADLEN(NLM_MAXOWNER) */
 521 #define NLM_fhandle_sz          1+XDR_QUADLEN(NFS2_FHSIZE)
 522 #define NLM_lock_sz             3+NLM_caller_sz+NLM_netobj_sz+NLM_fhandle_sz
 523 #define NLM_holder_sz           4+NLM_netobj_sz
 524
 525 #define NLM_testargs_sz         NLM_cookie_sz+1+NLM_lock_sz
 526 #define NLM_lockargs_sz         NLM_cookie_sz+4+NLM_lock_sz
 527 #define NLM_cancargs_sz         NLM_cookie_sz+2+NLM_lock_sz
 528 #define NLM_unlockargs_sz       NLM_cookie_sz+NLM_lock_sz
 529
 530 #define NLM_testres_sz          NLM_cookie_sz+1+NLM_holder_sz
 531 #define NLM_res_sz              NLM_cookie_sz+1
 532 #define NLM_norep_sz            0
 533
 534 #ifndef MAX
 535 # define MAX(a, b)              (((a) > (b))? (a) : (b))
 536 #endif
 537
 538 /*
 539  * For NLM, a void procedure really returns nothing
 540  */
 541 #define nlmclt_decode_norep     NULL
 542
 543 #define PROC(proc, argtype, restype)    \
 544 [NLMPROC_##proc] = {                                                    \
 545         .p_proc      = NLMPROC_##proc,                                  \
 546         .p_encode    = (kxdrproc_t) nlmclt_encode_##argtype,            \
 547         .p_decode    = (kxdrproc_t) nlmclt_decode_##restype,            \
 548         .p_bufsiz    = MAX(NLM_##argtype##_sz, NLM_##restype##_sz) << 2,        \
 549         .p_statidx   = NLMPROC_##proc,                                  \
 550         .p_name      = #proc,                                           \
 551         }
 552
 553 static struct rpc_procinfo      nlm_procedures[] = {
 554     PROC(TEST,          testargs,       testres),
 555     PROC(LOCK,          lockargs,       res),
 556     PROC(CANCEL,        cancargs,       res),
 557     PROC(UNLOCK,        unlockargs,     res),
 558     PROC(GRANTED,       testargs,       res),
 559     PROC(TEST_MSG,      testargs,       norep),
 560     PROC(LOCK_MSG,      lockargs,       norep),
 561     PROC(CANCEL_MSG,    cancargs,       norep),
 562     PROC(UNLOCK_MSG,    unlockargs,     norep),
 563     PROC(GRANTED_MSG,   testargs,       norep),
 564     PROC(TEST_RES,      testres,        norep),
 565     PROC(LOCK_RES,      res,            norep),
 566     PROC(CANCEL_RES,    res,            norep),
 567     PROC(UNLOCK_RES,    res,            norep),
 568     PROC(GRANTED_RES,   res,            norep),
 569 #ifdef NLMCLNT_SUPPORT_SHARES
 570     PROC(SHARE,         shareargs,      shareres),
 571     PROC(UNSHARE,       shareargs,      shareres),
 572     PROC(NM_LOCK,       lockargs,       res),
 573     PROC(FREE_ALL,      notify,         void),
 574 #endif
 575 };
 576
 577 static struct rpc_version       nlm_version1 = {
 578                 .number         = 1,
 579                 .nrprocs        = 16,
 580                 .procs          = nlm_procedures,
 581 };
 582
 583 static struct rpc_version       nlm_version3 = {
 584                 .number         = 3,
 585                 .nrprocs        = 24,
 586                 .procs          = nlm_procedures,
 587 };
 588
 589 #ifdef  CONFIG_LOCKD_V4
 590 extern struct rpc_version nlm_version4;
 591 #endif
 592
 593 static struct rpc_version *     nlm_versions[] = {
 594         [1] = &nlm_version1,
 595         [3] = &nlm_version3,
 596 #ifdef  CONFIG_LOCKD_V4
 597         [4] = &nlm_version4,
 598 #endif
 599 };
 600
 601 static struct rpc_stat          nlm_stats;
 602
 603 struct rpc_program              nlm_program = {
 604                 .name           = "lockd",
 605                 .number         = NLM_PROGRAM,
 606                 .nrvers         = ARRAY_SIZE(nlm_versions),
 607                 .version        = nlm_versions,
 608                 .stats          = &nlm_stats,
 609 };
 610
 611 #ifdef RPC_DEBUG
 612 const char *nlmdbg_cookie2a(const struct nlm_cookie *cookie)
 613 {
 614         /*
 615          * We can get away with a static buffer because we're only
 616          * called with BKL held.
 617          */
 618         static char buf[2*NLM_MAXCOOKIELEN+1];
 619         int i;
 620         int len = sizeof(buf);
 621         char *p = buf;
 622
 623         len--;  /* allow for trailing \0 */
 624         if (len < 3)
 625                 return "???";
 626         for (i = 0 ; i < cookie->len ; i++) {
 627                 if (len < 2) {
 628                         strcpy(p-3, "...");
 629                         break;
 630                 }
 631                 sprintf(p, "%02x", cookie->data[i]);
 632                 p += 2;
 633                 len -= 2;
 634         }
 635         *p = '\0';
 636
 637         return buf;
 638 }
 639 #endif