fs/nfs/callback_xdr.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * linux/fs/nfs/callback_xdr.c
   4  *
   5  * Copyright (C) 2004 Trond Myklebust
   6  *
   7  * NFSv4 callback encode/decode procedures
   8  */
   9 #include <linux/kernel.h>
  10 #include <linux/sunrpc/svc.h>
  11 #include <linux/nfs4.h>
  12 #include <linux/nfs_fs.h>
  13 #include <linux/ratelimit.h>
  14 #include <linux/printk.h>
  15 #include <linux/slab.h>
  16 #include <linux/sunrpc/bc_xprt.h>
  17 #include "nfs4_fs.h"
  18 #include "callback.h"
  19 #include "internal.h"
  20 #include "nfs4session.h"
  21 #include "nfs4trace.h"
  22
  23 #define CB_OP_TAGLEN_MAXSZ              (512)
  24 #define CB_OP_HDR_RES_MAXSZ             (2 * 4) // opcode, status
  25 #define CB_OP_GETATTR_BITMAP_MAXSZ      (4 * 4) // bitmap length, 3 bitmaps
  26 #define CB_OP_GETATTR_RES_MAXSZ         (CB_OP_HDR_RES_MAXSZ + \
  27                                          CB_OP_GETATTR_BITMAP_MAXSZ + \
  28                                          /* change, size, atime, ctime,
  29                                           * mtime, deleg_atime, deleg_mtime */\
  30                                          (2 + 2 + 3 + 3 + 3 + 3 + 3) * 4)
  31 #define CB_OP_RECALL_RES_MAXSZ          (CB_OP_HDR_RES_MAXSZ)
  32
  33 #if defined(CONFIG_NFS_V4_1)
  34 #define CB_OP_LAYOUTRECALL_RES_MAXSZ    (CB_OP_HDR_RES_MAXSZ)
  35 #define CB_OP_DEVICENOTIFY_RES_MAXSZ    (CB_OP_HDR_RES_MAXSZ)
  36 #define CB_OP_SEQUENCE_RES_MAXSZ        (CB_OP_HDR_RES_MAXSZ + \
  37                                          NFS4_MAX_SESSIONID_LEN + \
  38                                          (1 + 3) * 4) // seqid, 3 slotids
  39 #define CB_OP_RECALLANY_RES_MAXSZ       (CB_OP_HDR_RES_MAXSZ)
  40 #define CB_OP_RECALLSLOT_RES_MAXSZ      (CB_OP_HDR_RES_MAXSZ)
  41 #define CB_OP_NOTIFY_LOCK_RES_MAXSZ     (CB_OP_HDR_RES_MAXSZ)
  42 #endif /* CONFIG_NFS_V4_1 */
  43 #ifdef CONFIG_NFS_V4_2
  44 #define CB_OP_OFFLOAD_RES_MAXSZ         (CB_OP_HDR_RES_MAXSZ)
  45 #endif /* CONFIG_NFS_V4_2 */
  46
  47 #define NFSDBG_FACILITY NFSDBG_CALLBACK
  48
  49 /* Internal error code */
  50 #define NFS4ERR_RESOURCE_HDR    11050
  51
  52 struct callback_op {
  53         __be32 (*process_op)(void *, void *, struct cb_process_state *);
  54         __be32 (*decode_args)(struct svc_rqst *, struct xdr_stream *, void *);
  55         __be32 (*encode_res)(struct svc_rqst *, struct xdr_stream *,
  56                         const void *);
  57         long res_maxsize;
  58 };
  59
  60 static struct callback_op callback_ops[];
  61
  62 static __be32 nfs4_callback_null(struct svc_rqst *rqstp)
  63 {
  64         return htonl(NFS4_OK);
  65 }
  66
  67 /*
  68  * svc_process_common() looks for an XDR encoder to know when
  69  * not to drop a Reply.
  70  */
  71 static bool nfs4_encode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr)
  72 {
  73         return true;
  74 }
  75
  76 static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len,
  77                 const char **str, size_t maxlen)
  78 {
  79         ssize_t err;
  80
  81         err = xdr_stream_decode_opaque_inline(xdr, (void **)str, maxlen);
  82         if (err < 0)
  83                 return cpu_to_be32(NFS4ERR_RESOURCE);
  84         *len = err;
  85         return 0;
  86 }
  87
  88 static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
  89 {
  90         __be32 *p;
  91
  92         p = xdr_inline_decode(xdr, 4);
  93         if (unlikely(p == NULL))
  94                 return htonl(NFS4ERR_RESOURCE);
  95         fh->size = ntohl(*p);
  96         if (fh->size > NFS4_FHSIZE)
  97                 return htonl(NFS4ERR_BADHANDLE);
  98         p = xdr_inline_decode(xdr, fh->size);
  99         if (unlikely(p == NULL))
 100                 return htonl(NFS4ERR_RESOURCE);
 101         memcpy(&fh->data[0], p, fh->size);
 102         memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
 103         return 0;
 104 }
 105
 106 static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
 107 {
 108         __be32 *p;
 109         unsigned int attrlen;
 110
 111         p = xdr_inline_decode(xdr, 4);
 112         if (unlikely(p == NULL))
 113                 return htonl(NFS4ERR_RESOURCE);
 114         attrlen = ntohl(*p);
 115         p = xdr_inline_decode(xdr, attrlen << 2);
 116         if (unlikely(p == NULL))
 117                 return htonl(NFS4ERR_RESOURCE);
 118         if (likely(attrlen > 0))
 119                 bitmap[0] = ntohl(*p++);
 120         if (attrlen > 1)
 121                 bitmap[1] = ntohl(*p++);
 122         if (attrlen > 2)
 123                 bitmap[2] = ntohl(*p);
 124         return 0;
 125 }
 126
 127 static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 128 {
 129         __be32 *p;
 130
 131         p = xdr_inline_decode(xdr, NFS4_STATEID_SIZE);
 132         if (unlikely(p == NULL))
 133                 return htonl(NFS4ERR_RESOURCE);
 134         memcpy(stateid->data, p, NFS4_STATEID_SIZE);
 135         return 0;
 136 }
 137
 138 static __be32 decode_delegation_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 139 {
 140         stateid->type = NFS4_DELEGATION_STATEID_TYPE;
 141         return decode_stateid(xdr, stateid);
 142 }
 143
 144 static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
 145 {
 146         __be32 *p;
 147         __be32 status;
 148
 149         status = decode_string(xdr, &hdr->taglen, &hdr->tag, CB_OP_TAGLEN_MAXSZ);
 150         if (unlikely(status != 0))
 151                 return status;
 152         p = xdr_inline_decode(xdr, 12);
 153         if (unlikely(p == NULL))
 154                 return htonl(NFS4ERR_RESOURCE);
 155         hdr->minorversion = ntohl(*p++);
 156         /* Check for minor version support */
 157         if (hdr->minorversion <= NFS4_MAX_MINOR_VERSION) {
 158                 hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 and v4.2 */
 159         } else {
 160                 pr_warn_ratelimited("NFS: %s: NFSv4 server callback with "
 161                         "illegal minor version %u!\n",
 162                         __func__, hdr->minorversion);
 163                 return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 164         }
 165         hdr->nops = ntohl(*p);
 166         return 0;
 167 }
 168
 169 static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
 170 {
 171         __be32 *p;
 172         p = xdr_inline_decode(xdr, 4);
 173         if (unlikely(p == NULL))
 174                 return htonl(NFS4ERR_RESOURCE_HDR);
 175         *op = ntohl(*p);
 176         return 0;
 177 }
 178
 179 static __be32 decode_getattr_args(struct svc_rqst *rqstp,
 180                 struct xdr_stream *xdr, void *argp)
 181 {
 182         struct cb_getattrargs *args = argp;
 183         __be32 status;
 184
 185         status = decode_fh(xdr, &args->fh);
 186         if (unlikely(status != 0))
 187                 return status;
 188         return decode_bitmap(xdr, args->bitmap);
 189 }
 190
 191 static __be32 decode_recall_args(struct svc_rqst *rqstp,
 192                 struct xdr_stream *xdr, void *argp)
 193 {
 194         struct cb_recallargs *args = argp;
 195         __be32 *p;
 196         __be32 status;
 197
 198         status = decode_delegation_stateid(xdr, &args->stateid);
 199         if (unlikely(status != 0))
 200                 return status;
 201         p = xdr_inline_decode(xdr, 4);
 202         if (unlikely(p == NULL))
 203                 return htonl(NFS4ERR_RESOURCE);
 204         args->truncate = ntohl(*p);
 205         return decode_fh(xdr, &args->fh);
 206 }
 207
 208 #if defined(CONFIG_NFS_V4_1)
 209 static __be32 decode_layout_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 210 {
 211         stateid->type = NFS4_LAYOUT_STATEID_TYPE;
 212         return decode_stateid(xdr, stateid);
 213 }
 214
 215 static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
 216                                        struct xdr_stream *xdr, void *argp)
 217 {
 218         struct cb_layoutrecallargs *args = argp;
 219         __be32 *p;
 220         __be32 status = 0;
 221         uint32_t iomode;
 222
 223         p = xdr_inline_decode(xdr, 4 * sizeof(uint32_t));
 224         if (unlikely(p == NULL))
 225                 return htonl(NFS4ERR_BADXDR);
 226
 227         args->cbl_layout_type = ntohl(*p++);
 228         /* Depite the spec's xdr, iomode really belongs in the FILE switch,
 229          * as it is unusable and ignored with the other types.
 230          */
 231         iomode = ntohl(*p++);
 232         args->cbl_layoutchanged = ntohl(*p++);
 233         args->cbl_recall_type = ntohl(*p++);
 234
 235         if (args->cbl_recall_type == RETURN_FILE) {
 236                 args->cbl_range.iomode = iomode;
 237                 status = decode_fh(xdr, &args->cbl_fh);
 238                 if (unlikely(status != 0))
 239                         return status;
 240
 241                 p = xdr_inline_decode(xdr, 2 * sizeof(uint64_t));
 242                 if (unlikely(p == NULL))
 243                         return htonl(NFS4ERR_BADXDR);
 244                 p = xdr_decode_hyper(p, &args->cbl_range.offset);
 245                 p = xdr_decode_hyper(p, &args->cbl_range.length);
 246                 return decode_layout_stateid(xdr, &args->cbl_stateid);
 247         } else if (args->cbl_recall_type == RETURN_FSID) {
 248                 p = xdr_inline_decode(xdr, 2 * sizeof(uint64_t));
 249                 if (unlikely(p == NULL))
 250                         return htonl(NFS4ERR_BADXDR);
 251                 p = xdr_decode_hyper(p, &args->cbl_fsid.major);
 252                 p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
 253         } else if (args->cbl_recall_type != RETURN_ALL)
 254                 return htonl(NFS4ERR_BADXDR);
 255         return 0;
 256 }
 257
 258 static
 259 __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
 260                                 struct xdr_stream *xdr,
 261                                 void *argp)
 262 {
 263         struct cb_devicenotifyargs *args = argp;
 264         uint32_t tmp, n, i;
 265         __be32 *p;
 266         __be32 status = 0;
 267
 268         /* Num of device notifications */
 269         p = xdr_inline_decode(xdr, sizeof(uint32_t));
 270         if (unlikely(p == NULL)) {
 271                 status = htonl(NFS4ERR_BADXDR);
 272                 goto out;
 273         }
 274         n = ntohl(*p++);
 275         if (n == 0)
 276                 goto out;
 277
 278         args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
 279         if (!args->devs) {
 280                 status = htonl(NFS4ERR_DELAY);
 281                 goto out;
 282         }
 283
 284         /* Decode each dev notification */
 285         for (i = 0; i < n; i++) {
 286                 struct cb_devicenotifyitem *dev = &args->devs[i];
 287
 288                 p = xdr_inline_decode(xdr, (4 * sizeof(uint32_t)) +
 289                                       NFS4_DEVICEID4_SIZE);
 290                 if (unlikely(p == NULL)) {
 291                         status = htonl(NFS4ERR_BADXDR);
 292                         goto err;
 293                 }
 294
 295                 tmp = ntohl(*p++);      /* bitmap size */
 296                 if (tmp != 1) {
 297                         status = htonl(NFS4ERR_INVAL);
 298                         goto err;
 299                 }
 300                 dev->cbd_notify_type = ntohl(*p++);
 301                 if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
 302                     dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
 303                         status = htonl(NFS4ERR_INVAL);
 304                         goto err;
 305                 }
 306
 307                 tmp = ntohl(*p++);      /* opaque size */
 308                 if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
 309                      (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
 310                     ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
 311                      (tmp != NFS4_DEVICEID4_SIZE + 4))) {
 312                         status = htonl(NFS4ERR_INVAL);
 313                         goto err;
 314                 }
 315                 dev->cbd_layout_type = ntohl(*p++);
 316                 memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
 317                 p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
 318
 319                 if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
 320                         p = xdr_inline_decode(xdr, sizeof(uint32_t));
 321                         if (unlikely(p == NULL)) {
 322                                 status = htonl(NFS4ERR_BADXDR);
 323                                 goto err;
 324                         }
 325                         dev->cbd_immediate = ntohl(*p++);
 326                 } else {
 327                         dev->cbd_immediate = 0;
 328                 }
 329
 330                 dprintk("%s: type %d layout 0x%x immediate %d\n",
 331                         __func__, dev->cbd_notify_type, dev->cbd_layout_type,
 332                         dev->cbd_immediate);
 333         }
 334         args->ndevs = n;
 335         dprintk("%s: ndevs %d\n", __func__, args->ndevs);
 336         return 0;
 337 err:
 338         kfree(args->devs);
 339 out:
 340         args->devs = NULL;
 341         args->ndevs = 0;
 342         dprintk("%s: status %d ndevs %d\n",
 343                 __func__, ntohl(status), args->ndevs);
 344         return status;
 345 }
 346
 347 static __be32 decode_sessionid(struct xdr_stream *xdr,
 348                                  struct nfs4_sessionid *sid)
 349 {
 350         __be32 *p;
 351
 352         p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN);
 353         if (unlikely(p == NULL))
 354                 return htonl(NFS4ERR_RESOURCE);
 355
 356         memcpy(sid->data, p, NFS4_MAX_SESSIONID_LEN);
 357         return 0;
 358 }
 359
 360 static __be32 decode_rc_list(struct xdr_stream *xdr,
 361                                struct referring_call_list *rc_list)
 362 {
 363         __be32 *p;
 364         int i;
 365         __be32 status;
 366
 367         status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
 368         if (status)
 369                 goto out;
 370
 371         status = htonl(NFS4ERR_RESOURCE);
 372         p = xdr_inline_decode(xdr, sizeof(uint32_t));
 373         if (unlikely(p == NULL))
 374                 goto out;
 375
 376         rc_list->rcl_nrefcalls = ntohl(*p++);
 377         if (rc_list->rcl_nrefcalls) {
 378                 p = xdr_inline_decode(xdr,
 379                              rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
 380                 if (unlikely(p == NULL))
 381                         goto out;
 382                 rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
 383                                                 sizeof(*rc_list->rcl_refcalls),
 384                                                 GFP_KERNEL);
 385                 if (unlikely(rc_list->rcl_refcalls == NULL))
 386                         goto out;
 387                 for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
 388                         rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
 389                         rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
 390                 }
 391         }
 392         status = 0;
 393
 394 out:
 395         return status;
 396 }
 397
 398 static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
 399                                         struct xdr_stream *xdr,
 400                                         void *argp)
 401 {
 402         struct cb_sequenceargs *args = argp;
 403         __be32 *p;
 404         int i;
 405         __be32 status;
 406
 407         status = decode_sessionid(xdr, &args->csa_sessionid);
 408         if (status)
 409                 return status;
 410
 411         p = xdr_inline_decode(xdr, 5 * sizeof(uint32_t));
 412         if (unlikely(p == NULL))
 413                 return htonl(NFS4ERR_RESOURCE);
 414
 415         args->csa_addr = svc_addr(rqstp);
 416         args->csa_sequenceid = ntohl(*p++);
 417         args->csa_slotid = ntohl(*p++);
 418         args->csa_highestslotid = ntohl(*p++);
 419         args->csa_cachethis = ntohl(*p++);
 420         args->csa_nrclists = ntohl(*p++);
 421         args->csa_rclists = NULL;
 422         if (args->csa_nrclists) {
 423                 args->csa_rclists = kmalloc_array(args->csa_nrclists,
 424                                                   sizeof(*args->csa_rclists),
 425                                                   GFP_KERNEL);
 426                 if (unlikely(args->csa_rclists == NULL))
 427                         return htonl(NFS4ERR_RESOURCE);
 428
 429                 for (i = 0; i < args->csa_nrclists; i++) {
 430                         status = decode_rc_list(xdr, &args->csa_rclists[i]);
 431                         if (status) {
 432                                 args->csa_nrclists = i;
 433                                 goto out_free;
 434                         }
 435                 }
 436         }
 437         return 0;
 438
 439 out_free:
 440         for (i = 0; i < args->csa_nrclists; i++)
 441                 kfree(args->csa_rclists[i].rcl_refcalls);
 442         kfree(args->csa_rclists);
 443         return status;
 444 }
 445
 446 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
 447                                       struct xdr_stream *xdr,
 448                                       void *argp)
 449 {
 450         struct cb_recallanyargs *args = argp;
 451         uint32_t bitmap[3];
 452         __be32 *p, status;
 453
 454         p = xdr_inline_decode(xdr, 4);
 455         if (unlikely(p == NULL))
 456                 return htonl(NFS4ERR_BADXDR);
 457         args->craa_objs_to_keep = ntohl(*p++);
 458         status = decode_bitmap(xdr, bitmap);
 459         if (unlikely(status))
 460                 return status;
 461         args->craa_type_mask = bitmap[0];
 462
 463         return 0;
 464 }
 465
 466 static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
 467                                         struct xdr_stream *xdr,
 468                                         void *argp)
 469 {
 470         struct cb_recallslotargs *args = argp;
 471         __be32 *p;
 472
 473         p = xdr_inline_decode(xdr, 4);
 474         if (unlikely(p == NULL))
 475                 return htonl(NFS4ERR_BADXDR);
 476         args->crsa_target_highest_slotid = ntohl(*p++);
 477         return 0;
 478 }
 479
 480 static __be32 decode_lockowner(struct xdr_stream *xdr, struct cb_notify_lock_args *args)
 481 {
 482         __be32          *p;
 483         unsigned int    len;
 484
 485         p = xdr_inline_decode(xdr, 12);
 486         if (unlikely(p == NULL))
 487                 return htonl(NFS4ERR_BADXDR);
 488
 489         p = xdr_decode_hyper(p, &args->cbnl_owner.clientid);
 490         len = be32_to_cpu(*p);
 491
 492         p = xdr_inline_decode(xdr, len);
 493         if (unlikely(p == NULL))
 494                 return htonl(NFS4ERR_BADXDR);
 495
 496         /* Only try to decode if the length is right */
 497         if (len == 20) {
 498                 p += 2; /* skip "lock id:" */
 499                 args->cbnl_owner.s_dev = be32_to_cpu(*p++);
 500                 xdr_decode_hyper(p, &args->cbnl_owner.id);
 501                 args->cbnl_valid = true;
 502         } else {
 503                 args->cbnl_owner.s_dev = 0;
 504                 args->cbnl_owner.id = 0;
 505                 args->cbnl_valid = false;
 506         }
 507         return 0;
 508 }
 509
 510 static __be32 decode_notify_lock_args(struct svc_rqst *rqstp,
 511                 struct xdr_stream *xdr, void *argp)
 512 {
 513         struct cb_notify_lock_args *args = argp;
 514         __be32 status;
 515
 516         status = decode_fh(xdr, &args->cbnl_fh);
 517         if (unlikely(status != 0))
 518                 return status;
 519         return decode_lockowner(xdr, args);
 520 }
 521
 522 #endif /* CONFIG_NFS_V4_1 */
 523 #ifdef CONFIG_NFS_V4_2
 524 static __be32 decode_write_response(struct xdr_stream *xdr,
 525                                         struct cb_offloadargs *args)
 526 {
 527         __be32 *p;
 528
 529         /* skip the always zero field */
 530         p = xdr_inline_decode(xdr, 4);
 531         if (unlikely(!p))
 532                 goto out;
 533         p++;
 534
 535         /* decode count, stable_how, verifier */
 536         p = xdr_inline_decode(xdr, 8 + 4);
 537         if (unlikely(!p))
 538                 goto out;
 539         p = xdr_decode_hyper(p, &args->wr_count);
 540         args->wr_writeverf.committed = be32_to_cpup(p);
 541         p = xdr_inline_decode(xdr, NFS4_VERIFIER_SIZE);
 542         if (likely(p)) {
 543                 memcpy(&args->wr_writeverf.verifier.data[0], p,
 544                         NFS4_VERIFIER_SIZE);
 545                 return 0;
 546         }
 547 out:
 548         return htonl(NFS4ERR_RESOURCE);
 549 }
 550
 551 static __be32 decode_offload_args(struct svc_rqst *rqstp,
 552                                         struct xdr_stream *xdr,
 553                                         void *data)
 554 {
 555         struct cb_offloadargs *args = data;
 556         __be32 *p;
 557         __be32 status;
 558
 559         /* decode fh */
 560         status = decode_fh(xdr, &args->coa_fh);
 561         if (unlikely(status != 0))
 562                 return status;
 563
 564         /* decode stateid */
 565         status = decode_stateid(xdr, &args->coa_stateid);
 566         if (unlikely(status != 0))
 567                 return status;
 568
 569         /* decode status */
 570         p = xdr_inline_decode(xdr, 4);
 571         if (unlikely(!p))
 572                 goto out;
 573         args->error = ntohl(*p++);
 574         if (!args->error) {
 575                 status = decode_write_response(xdr, args);
 576                 if (unlikely(status != 0))
 577                         return status;
 578         } else {
 579                 p = xdr_inline_decode(xdr, 8);
 580                 if (unlikely(!p))
 581                         goto out;
 582                 p = xdr_decode_hyper(p, &args->wr_count);
 583         }
 584         return 0;
 585 out:
 586         return htonl(NFS4ERR_RESOURCE);
 587 }
 588 #endif /* CONFIG_NFS_V4_2 */
 589 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
 590 {
 591         if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
 592                 return cpu_to_be32(NFS4ERR_RESOURCE);
 593         return 0;
 594 }
 595
 596 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, size_t sz)
 597 {
 598         if (xdr_stream_encode_uint32_array(xdr, bitmap, sz) < 0)
 599                 return cpu_to_be32(NFS4ERR_RESOURCE);
 600         return 0;
 601 }
 602
 603 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
 604 {
 605         __be32 *p;
 606
 607         if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
 608                 return 0;
 609         p = xdr_reserve_space(xdr, 8);
 610         if (unlikely(!p))
 611                 return htonl(NFS4ERR_RESOURCE);
 612         p = xdr_encode_hyper(p, change);
 613         return 0;
 614 }
 615
 616 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
 617 {
 618         __be32 *p;
 619
 620         if (!(bitmap[0] & FATTR4_WORD0_SIZE))
 621                 return 0;
 622         p = xdr_reserve_space(xdr, 8);
 623         if (unlikely(!p))
 624                 return htonl(NFS4ERR_RESOURCE);
 625         p = xdr_encode_hyper(p, size);
 626         return 0;
 627 }
 628
 629 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec64 *time)
 630 {
 631         __be32 *p;
 632
 633         p = xdr_reserve_space(xdr, 12);
 634         if (unlikely(!p))
 635                 return htonl(NFS4ERR_RESOURCE);
 636         p = xdr_encode_hyper(p, time->tv_sec);
 637         *p = htonl(time->tv_nsec);
 638         return 0;
 639 }
 640
 641 static __be32 encode_attr_atime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
 642 {
 643         if (!(bitmap[1] & FATTR4_WORD1_TIME_ACCESS))
 644                 return 0;
 645         return encode_attr_time(xdr,time);
 646 }
 647
 648 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
 649 {
 650         if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
 651                 return 0;
 652         return encode_attr_time(xdr,time);
 653 }
 654
 655 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
 656 {
 657         if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
 658                 return 0;
 659         return encode_attr_time(xdr,time);
 660 }
 661
 662 static __be32 encode_attr_delegatime(struct xdr_stream *xdr,
 663                                      const uint32_t *bitmap,
 664                                      const struct timespec64 *time)
 665 {
 666         if (!(bitmap[2] & FATTR4_WORD2_TIME_DELEG_ACCESS))
 667                 return 0;
 668         return encode_attr_time(xdr,time);
 669 }
 670
 671 static __be32 encode_attr_delegmtime(struct xdr_stream *xdr,
 672                                      const uint32_t *bitmap,
 673                                      const struct timespec64 *time)
 674 {
 675         if (!(bitmap[2] & FATTR4_WORD2_TIME_DELEG_MODIFY))
 676                 return 0;
 677         return encode_attr_time(xdr,time);
 678 }
 679
 680 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
 681 {
 682         __be32 status;
 683
 684         hdr->status = xdr_reserve_space(xdr, 4);
 685         if (unlikely(hdr->status == NULL))
 686                 return htonl(NFS4ERR_RESOURCE);
 687         status = encode_string(xdr, hdr->taglen, hdr->tag);
 688         if (unlikely(status != 0))
 689                 return status;
 690         hdr->nops = xdr_reserve_space(xdr, 4);
 691         if (unlikely(hdr->nops == NULL))
 692                 return htonl(NFS4ERR_RESOURCE);
 693         return 0;
 694 }
 695
 696 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
 697 {
 698         __be32 *p;
 699
 700         p = xdr_reserve_space(xdr, 8);
 701         if (unlikely(p == NULL))
 702                 return htonl(NFS4ERR_RESOURCE_HDR);
 703         *p++ = htonl(op);
 704         *p = res;
 705         return 0;
 706 }
 707
 708 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 709                 const void *resp)
 710 {
 711         const struct cb_getattrres *res = resp;
 712         __be32 *savep = NULL;
 713         __be32 status = res->status;
 714
 715         if (unlikely(status != 0))
 716                 goto out;
 717         status = encode_attr_bitmap(xdr, res->bitmap, ARRAY_SIZE(res->bitmap));
 718         if (unlikely(status != 0))
 719                 goto out;
 720         status = cpu_to_be32(NFS4ERR_RESOURCE);
 721         savep = xdr_reserve_space(xdr, sizeof(*savep));
 722         if (unlikely(!savep))
 723                 goto out;
 724         status = encode_attr_change(xdr, res->bitmap, res->change_attr);
 725         if (unlikely(status != 0))
 726                 goto out;
 727         status = encode_attr_size(xdr, res->bitmap, res->size);
 728         if (unlikely(status != 0))
 729                 goto out;
 730         status = encode_attr_atime(xdr, res->bitmap, &res->atime);
 731         if (unlikely(status != 0))
 732                 goto out;
 733         status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
 734         if (unlikely(status != 0))
 735                 goto out;
 736         status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
 737         if (unlikely(status != 0))
 738                 goto out;
 739         status = encode_attr_delegatime(xdr, res->bitmap, &res->atime);
 740         if (unlikely(status != 0))
 741                 goto out;
 742         status = encode_attr_delegmtime(xdr, res->bitmap, &res->mtime);
 743         *savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
 744 out:
 745         return status;
 746 }
 747
 748 #if defined(CONFIG_NFS_V4_1)
 749
 750 static __be32 encode_sessionid(struct xdr_stream *xdr,
 751                                  const struct nfs4_sessionid *sid)
 752 {
 753         __be32 *p;
 754
 755         p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
 756         if (unlikely(p == NULL))
 757                 return htonl(NFS4ERR_RESOURCE);
 758
 759         memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
 760         return 0;
 761 }
 762
 763 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
 764                                        struct xdr_stream *xdr,
 765                                        const void *resp)
 766 {
 767         const struct cb_sequenceres *res = resp;
 768         __be32 *p;
 769         __be32 status = res->csr_status;
 770
 771         if (unlikely(status != 0))
 772                 return status;
 773
 774         status = encode_sessionid(xdr, &res->csr_sessionid);
 775         if (status)
 776                 return status;
 777
 778         p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
 779         if (unlikely(p == NULL))
 780                 return htonl(NFS4ERR_RESOURCE);
 781
 782         *p++ = htonl(res->csr_sequenceid);
 783         *p++ = htonl(res->csr_slotid);
 784         *p++ = htonl(res->csr_highestslotid);
 785         *p++ = htonl(res->csr_target_highestslotid);
 786         return 0;
 787 }
 788
 789 static __be32
 790 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 791 {
 792         if (op_nr == OP_CB_SEQUENCE) {
 793                 if (nop != 0)
 794                         return htonl(NFS4ERR_SEQUENCE_POS);
 795         } else {
 796                 if (nop == 0)
 797                         return htonl(NFS4ERR_OP_NOT_IN_SESSION);
 798         }
 799
 800         switch (op_nr) {
 801         case OP_CB_GETATTR:
 802         case OP_CB_RECALL:
 803         case OP_CB_SEQUENCE:
 804         case OP_CB_RECALL_ANY:
 805         case OP_CB_RECALL_SLOT:
 806         case OP_CB_LAYOUTRECALL:
 807         case OP_CB_NOTIFY_DEVICEID:
 808         case OP_CB_NOTIFY_LOCK:
 809                 *op = &callback_ops[op_nr];
 810                 break;
 811
 812         case OP_CB_NOTIFY:
 813         case OP_CB_PUSH_DELEG:
 814         case OP_CB_RECALLABLE_OBJ_AVAIL:
 815         case OP_CB_WANTS_CANCELLED:
 816                 return htonl(NFS4ERR_NOTSUPP);
 817
 818         default:
 819                 return htonl(NFS4ERR_OP_ILLEGAL);
 820         }
 821
 822         return htonl(NFS_OK);
 823 }
 824
 825 static void nfs4_callback_free_slot(struct nfs4_session *session,
 826                 struct nfs4_slot *slot)
 827 {
 828         struct nfs4_slot_table *tbl = &session->bc_slot_table;
 829
 830         spin_lock(&tbl->slot_tbl_lock);
 831         /*
 832          * Let the state manager know callback processing done.
 833          * A single slot, so highest used slotid is either 0 or -1
 834          */
 835         nfs4_free_slot(tbl, slot);
 836         spin_unlock(&tbl->slot_tbl_lock);
 837 }
 838
 839 static void nfs4_cb_free_slot(struct cb_process_state *cps)
 840 {
 841         if (cps->slot) {
 842                 nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);
 843                 cps->slot = NULL;
 844         }
 845 }
 846
 847 #else /* CONFIG_NFS_V4_1 */
 848
 849 static __be32
 850 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 851 {
 852         return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 853 }
 854
 855 static void nfs4_cb_free_slot(struct cb_process_state *cps)
 856 {
 857 }
 858 #endif /* CONFIG_NFS_V4_1 */
 859
 860 #ifdef CONFIG_NFS_V4_2
 861 static __be32
 862 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
 863 {
 864         __be32 status = preprocess_nfs41_op(nop, op_nr, op);
 865         if (status != htonl(NFS4ERR_OP_ILLEGAL))
 866                 return status;
 867
 868         if (op_nr == OP_CB_OFFLOAD) {
 869                 *op = &callback_ops[op_nr];
 870                 return htonl(NFS_OK);
 871         } else
 872                 return htonl(NFS4ERR_NOTSUPP);
 873         return htonl(NFS4ERR_OP_ILLEGAL);
 874 }
 875 #else /* CONFIG_NFS_V4_2 */
 876 static __be32
 877 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
 878 {
 879         return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 880 }
 881 #endif /* CONFIG_NFS_V4_2 */
 882
 883 static __be32
 884 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
 885 {
 886         switch (op_nr) {
 887         case OP_CB_GETATTR:
 888         case OP_CB_RECALL:
 889                 *op = &callback_ops[op_nr];
 890                 break;
 891         default:
 892                 return htonl(NFS4ERR_OP_ILLEGAL);
 893         }
 894
 895         return htonl(NFS_OK);
 896 }
 897
 898 static __be32 process_op(int nop, struct svc_rqst *rqstp,
 899                          struct cb_process_state *cps)
 900 {
 901         struct xdr_stream *xdr_out = &rqstp->rq_res_stream;
 902         struct callback_op *op = &callback_ops[0];
 903         unsigned int op_nr;
 904         __be32 status;
 905         long maxlen;
 906         __be32 res;
 907
 908         status = decode_op_hdr(&rqstp->rq_arg_stream, &op_nr);
 909         if (unlikely(status))
 910                 return status;
 911
 912         switch (cps->minorversion) {
 913         case 0:
 914                 status = preprocess_nfs4_op(op_nr, &op);
 915                 break;
 916         case 1:
 917                 status = preprocess_nfs41_op(nop, op_nr, &op);
 918                 break;
 919         case 2:
 920                 status = preprocess_nfs42_op(nop, op_nr, &op);
 921                 break;
 922         default:
 923                 status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 924         }
 925
 926         if (status == htonl(NFS4ERR_OP_ILLEGAL))
 927                 op_nr = OP_CB_ILLEGAL;
 928         if (status)
 929                 goto encode_hdr;
 930
 931         if (cps->drc_status) {
 932                 status = cps->drc_status;
 933                 goto encode_hdr;
 934         }
 935
 936         maxlen = xdr_out->end - xdr_out->p;
 937         if (maxlen > 0 && maxlen < PAGE_SIZE) {
 938                 status = op->decode_args(rqstp, &rqstp->rq_arg_stream,
 939                                          rqstp->rq_argp);
 940                 if (likely(status == 0))
 941                         status = op->process_op(rqstp->rq_argp, rqstp->rq_resp,
 942                                                 cps);
 943         } else
 944                 status = htonl(NFS4ERR_RESOURCE);
 945
 946 encode_hdr:
 947         res = encode_op_hdr(xdr_out, op_nr, status);
 948         if (unlikely(res))
 949                 return res;
 950         if (op->encode_res != NULL && status == 0)
 951                 status = op->encode_res(rqstp, xdr_out, rqstp->rq_resp);
 952         return status;
 953 }
 954
 955 /*
 956  * Decode, process and encode a COMPOUND
 957  */
 958 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp)
 959 {
 960         struct cb_compound_hdr_arg hdr_arg = { 0 };
 961         struct cb_compound_hdr_res hdr_res = { NULL };
 962         struct cb_process_state cps = {
 963                 .drc_status = 0,
 964                 .clp = NULL,
 965                 .net = SVC_NET(rqstp),
 966         };
 967         unsigned int nops = 0;
 968         __be32 status;
 969
 970         status = decode_compound_hdr_arg(&rqstp->rq_arg_stream, &hdr_arg);
 971         if (status == htonl(NFS4ERR_RESOURCE))
 972                 return rpc_garbage_args;
 973
 974         if (hdr_arg.minorversion == 0) {
 975                 cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
 976                 if (!cps.clp) {
 977                         trace_nfs_cb_no_clp(rqstp->rq_xid, hdr_arg.cb_ident);
 978                         goto out_invalidcred;
 979                 }
 980                 if (!check_gss_callback_principal(cps.clp, rqstp)) {
 981                         trace_nfs_cb_badprinc(rqstp->rq_xid, hdr_arg.cb_ident);
 982                         nfs_put_client(cps.clp);
 983                         goto out_invalidcred;
 984                 }
 985         }
 986
 987         cps.minorversion = hdr_arg.minorversion;
 988         hdr_res.taglen = hdr_arg.taglen;
 989         hdr_res.tag = hdr_arg.tag;
 990         if (encode_compound_hdr_res(&rqstp->rq_res_stream, &hdr_res) != 0) {
 991                 if (cps.clp)
 992                         nfs_put_client(cps.clp);
 993                 return rpc_system_err;
 994         }
 995         while (status == 0 && nops != hdr_arg.nops) {
 996                 status = process_op(nops, rqstp, &cps);
 997                 nops++;
 998         }
 999
1000         /* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
1001         * resource error in cb_compound status without returning op */
1002         if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
1003                 status = htonl(NFS4ERR_RESOURCE);
1004                 nops--;
1005         }
1006
1007         if (svc_is_backchannel(rqstp) && cps.clp) {
1008                 rqstp->bc_to_initval = cps.clp->cl_rpcclient->cl_timeout->to_initval;
1009                 rqstp->bc_to_retries = cps.clp->cl_rpcclient->cl_timeout->to_retries;
1010         }
1011
1012         *hdr_res.status = status;
1013         *hdr_res.nops = htonl(nops);
1014         nfs4_cb_free_slot(&cps);
1015         nfs_put_client(cps.clp);
1016         return rpc_success;
1017
1018 out_invalidcred:
1019         pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
1020         rqstp->rq_auth_stat = rpc_autherr_badcred;
1021         return rpc_success;
1022 }
1023
1024 static int
1025 nfs_callback_dispatch(struct svc_rqst *rqstp)
1026 {
1027         const struct svc_procedure *procp = rqstp->rq_procinfo;
1028
1029         *rqstp->rq_accept_statp = procp->pc_func(rqstp);
1030         return 1;
1031 }
1032
1033 /*
1034  * Define NFS4 callback COMPOUND ops.
1035  */
1036 static struct callback_op callback_ops[] = {
1037         [0] = {
1038                 .res_maxsize = CB_OP_HDR_RES_MAXSZ,
1039         },
1040         [OP_CB_GETATTR] = {
1041                 .process_op = nfs4_callback_getattr,
1042                 .decode_args = decode_getattr_args,
1043                 .encode_res = encode_getattr_res,
1044                 .res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
1045         },
1046         [OP_CB_RECALL] = {
1047                 .process_op = nfs4_callback_recall,
1048                 .decode_args = decode_recall_args,
1049                 .res_maxsize = CB_OP_RECALL_RES_MAXSZ,
1050         },
1051 #if defined(CONFIG_NFS_V4_1)
1052         [OP_CB_LAYOUTRECALL] = {
1053                 .process_op = nfs4_callback_layoutrecall,
1054                 .decode_args = decode_layoutrecall_args,
1055                 .res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
1056         },
1057         [OP_CB_NOTIFY_DEVICEID] = {
1058                 .process_op = nfs4_callback_devicenotify,
1059                 .decode_args = decode_devicenotify_args,
1060                 .res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
1061         },
1062         [OP_CB_SEQUENCE] = {
1063                 .process_op = nfs4_callback_sequence,
1064                 .decode_args = decode_cb_sequence_args,
1065                 .encode_res = encode_cb_sequence_res,
1066                 .res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
1067         },
1068         [OP_CB_RECALL_ANY] = {
1069                 .process_op = nfs4_callback_recallany,
1070                 .decode_args = decode_recallany_args,
1071                 .res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
1072         },
1073         [OP_CB_RECALL_SLOT] = {
1074                 .process_op = nfs4_callback_recallslot,
1075                 .decode_args = decode_recallslot_args,
1076                 .res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
1077         },
1078         [OP_CB_NOTIFY_LOCK] = {
1079                 .process_op = nfs4_callback_notify_lock,
1080                 .decode_args = decode_notify_lock_args,
1081                 .res_maxsize = CB_OP_NOTIFY_LOCK_RES_MAXSZ,
1082         },
1083 #endif /* CONFIG_NFS_V4_1 */
1084 #ifdef CONFIG_NFS_V4_2
1085         [OP_CB_OFFLOAD] = {
1086                 .process_op = nfs4_callback_offload,
1087                 .decode_args = decode_offload_args,
1088                 .res_maxsize = CB_OP_OFFLOAD_RES_MAXSZ,
1089         },
1090 #endif /* CONFIG_NFS_V4_2 */
1091 };
1092
1093 /*
1094  * Define NFS4 callback procedures
1095  */
1096 static const struct svc_procedure nfs4_callback_procedures1[] = {
1097         [CB_NULL] = {
1098                 .pc_func = nfs4_callback_null,
1099                 .pc_encode = nfs4_encode_void,
1100                 .pc_xdrressize = 1,
1101                 .pc_name = "NULL",
1102         },
1103         [CB_COMPOUND] = {
1104                 .pc_func = nfs4_callback_compound,
1105                 .pc_encode = nfs4_encode_void,
1106                 .pc_argsize = 256,
1107                 .pc_argzero = 256,
1108                 .pc_ressize = 256,
1109                 .pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1110                 .pc_name = "COMPOUND",
1111         }
1112 };
1113
1114 static DEFINE_PER_CPU_ALIGNED(unsigned long,
1115                               nfs4_callback_count1[ARRAY_SIZE(nfs4_callback_procedures1)]);
1116 const struct svc_version nfs4_callback_version1 = {
1117         .vs_vers = 1,
1118         .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1119         .vs_proc = nfs4_callback_procedures1,
1120         .vs_count = nfs4_callback_count1,
1121         .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1122         .vs_dispatch = nfs_callback_dispatch,
1123         .vs_hidden = true,
1124         .vs_need_cong_ctrl = true,
1125 };
1126
1127 static DEFINE_PER_CPU_ALIGNED(unsigned long,
1128                               nfs4_callback_count4[ARRAY_SIZE(nfs4_callback_procedures1)]);
1129 const struct svc_version nfs4_callback_version4 = {
1130         .vs_vers = 4,
1131         .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1132         .vs_proc = nfs4_callback_procedures1,
1133         .vs_count = nfs4_callback_count4,
1134         .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1135         .vs_dispatch = nfs_callback_dispatch,
1136         .vs_hidden = true,
1137         .vs_need_cong_ctrl = true,
1138 };