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                 if (unlikely(rc_list->rcl_nrefcalls > xdr->buf->len))
 379                         goto out;
 380                 p = xdr_inline_decode(xdr,
 381                              rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
 382                 if (unlikely(p == NULL))
 383                         goto out;
 384                 rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
 385                                                 sizeof(*rc_list->rcl_refcalls),
 386                                                 GFP_KERNEL);
 387                 if (unlikely(rc_list->rcl_refcalls == NULL))
 388                         goto out;
 389                 for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
 390                         rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
 391                         rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
 392                 }
 393         }
 394         status = 0;
 395
 396 out:
 397         return status;
 398 }
 399
 400 static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
 401                                         struct xdr_stream *xdr,
 402                                         void *argp)
 403 {
 404         struct cb_sequenceargs *args = argp;
 405         __be32 *p;
 406         int i;
 407         __be32 status;
 408
 409         status = decode_sessionid(xdr, &args->csa_sessionid);
 410         if (status)
 411                 return status;
 412
 413         p = xdr_inline_decode(xdr, 5 * sizeof(uint32_t));
 414         if (unlikely(p == NULL))
 415                 return htonl(NFS4ERR_RESOURCE);
 416
 417         args->csa_addr = svc_addr(rqstp);
 418         args->csa_sequenceid = ntohl(*p++);
 419         args->csa_slotid = ntohl(*p++);
 420         args->csa_highestslotid = ntohl(*p++);
 421         args->csa_cachethis = ntohl(*p++);
 422         args->csa_nrclists = ntohl(*p++);
 423         args->csa_rclists = NULL;
 424         if (args->csa_nrclists) {
 425                 args->csa_rclists = kmalloc_array(args->csa_nrclists,
 426                                                   sizeof(*args->csa_rclists),
 427                                                   GFP_KERNEL);
 428                 if (unlikely(args->csa_rclists == NULL))
 429                         return htonl(NFS4ERR_RESOURCE);
 430
 431                 for (i = 0; i < args->csa_nrclists; i++) {
 432                         status = decode_rc_list(xdr, &args->csa_rclists[i]);
 433                         if (status) {
 434                                 args->csa_nrclists = i;
 435                                 goto out_free;
 436                         }
 437                 }
 438         }
 439         return 0;
 440
 441 out_free:
 442         for (i = 0; i < args->csa_nrclists; i++)
 443                 kfree(args->csa_rclists[i].rcl_refcalls);
 444         kfree(args->csa_rclists);
 445         return status;
 446 }
 447
 448 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
 449                                       struct xdr_stream *xdr,
 450                                       void *argp)
 451 {
 452         struct cb_recallanyargs *args = argp;
 453         uint32_t bitmap[3];
 454         __be32 *p, status;
 455
 456         p = xdr_inline_decode(xdr, 4);
 457         if (unlikely(p == NULL))
 458                 return htonl(NFS4ERR_BADXDR);
 459         args->craa_objs_to_keep = ntohl(*p++);
 460         status = decode_bitmap(xdr, bitmap);
 461         if (unlikely(status))
 462                 return status;
 463         args->craa_type_mask = bitmap[0];
 464
 465         return 0;
 466 }
 467
 468 static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
 469                                         struct xdr_stream *xdr,
 470                                         void *argp)
 471 {
 472         struct cb_recallslotargs *args = argp;
 473         __be32 *p;
 474
 475         p = xdr_inline_decode(xdr, 4);
 476         if (unlikely(p == NULL))
 477                 return htonl(NFS4ERR_BADXDR);
 478         args->crsa_target_highest_slotid = ntohl(*p++);
 479         return 0;
 480 }
 481
 482 static __be32 decode_lockowner(struct xdr_stream *xdr, struct cb_notify_lock_args *args)
 483 {
 484         __be32          *p;
 485         unsigned int    len;
 486
 487         p = xdr_inline_decode(xdr, 12);
 488         if (unlikely(p == NULL))
 489                 return htonl(NFS4ERR_BADXDR);
 490
 491         p = xdr_decode_hyper(p, &args->cbnl_owner.clientid);
 492         len = be32_to_cpu(*p);
 493
 494         p = xdr_inline_decode(xdr, len);
 495         if (unlikely(p == NULL))
 496                 return htonl(NFS4ERR_BADXDR);
 497
 498         /* Only try to decode if the length is right */
 499         if (len == 20) {
 500                 p += 2; /* skip "lock id:" */
 501                 args->cbnl_owner.s_dev = be32_to_cpu(*p++);
 502                 xdr_decode_hyper(p, &args->cbnl_owner.id);
 503                 args->cbnl_valid = true;
 504         } else {
 505                 args->cbnl_owner.s_dev = 0;
 506                 args->cbnl_owner.id = 0;
 507                 args->cbnl_valid = false;
 508         }
 509         return 0;
 510 }
 511
 512 static __be32 decode_notify_lock_args(struct svc_rqst *rqstp,
 513                 struct xdr_stream *xdr, void *argp)
 514 {
 515         struct cb_notify_lock_args *args = argp;
 516         __be32 status;
 517
 518         status = decode_fh(xdr, &args->cbnl_fh);
 519         if (unlikely(status != 0))
 520                 return status;
 521         return decode_lockowner(xdr, args);
 522 }
 523
 524 #endif /* CONFIG_NFS_V4_1 */
 525 #ifdef CONFIG_NFS_V4_2
 526 static __be32 decode_write_response(struct xdr_stream *xdr,
 527                                         struct cb_offloadargs *args)
 528 {
 529         __be32 *p;
 530
 531         /* skip the always zero field */
 532         p = xdr_inline_decode(xdr, 4);
 533         if (unlikely(!p))
 534                 goto out;
 535         p++;
 536
 537         /* decode count, stable_how, verifier */
 538         p = xdr_inline_decode(xdr, 8 + 4);
 539         if (unlikely(!p))
 540                 goto out;
 541         p = xdr_decode_hyper(p, &args->wr_count);
 542         args->wr_writeverf.committed = be32_to_cpup(p);
 543         p = xdr_inline_decode(xdr, NFS4_VERIFIER_SIZE);
 544         if (likely(p)) {
 545                 memcpy(&args->wr_writeverf.verifier.data[0], p,
 546                         NFS4_VERIFIER_SIZE);
 547                 return 0;
 548         }
 549 out:
 550         return htonl(NFS4ERR_RESOURCE);
 551 }
 552
 553 static __be32 decode_offload_args(struct svc_rqst *rqstp,
 554                                         struct xdr_stream *xdr,
 555                                         void *data)
 556 {
 557         struct cb_offloadargs *args = data;
 558         __be32 *p;
 559         __be32 status;
 560
 561         /* decode fh */
 562         status = decode_fh(xdr, &args->coa_fh);
 563         if (unlikely(status != 0))
 564                 return status;
 565
 566         /* decode stateid */
 567         status = decode_stateid(xdr, &args->coa_stateid);
 568         if (unlikely(status != 0))
 569                 return status;
 570
 571         /* decode status */
 572         p = xdr_inline_decode(xdr, 4);
 573         if (unlikely(!p))
 574                 goto out;
 575         args->error = ntohl(*p++);
 576         if (!args->error) {
 577                 status = decode_write_response(xdr, args);
 578                 if (unlikely(status != 0))
 579                         return status;
 580         } else {
 581                 p = xdr_inline_decode(xdr, 8);
 582                 if (unlikely(!p))
 583                         goto out;
 584                 p = xdr_decode_hyper(p, &args->wr_count);
 585         }
 586         return 0;
 587 out:
 588         return htonl(NFS4ERR_RESOURCE);
 589 }
 590 #endif /* CONFIG_NFS_V4_2 */
 591 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
 592 {
 593         if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
 594                 return cpu_to_be32(NFS4ERR_RESOURCE);
 595         return 0;
 596 }
 597
 598 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, size_t sz)
 599 {
 600         if (xdr_stream_encode_uint32_array(xdr, bitmap, sz) < 0)
 601                 return cpu_to_be32(NFS4ERR_RESOURCE);
 602         return 0;
 603 }
 604
 605 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
 606 {
 607         __be32 *p;
 608
 609         if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
 610                 return 0;
 611         p = xdr_reserve_space(xdr, 8);
 612         if (unlikely(!p))
 613                 return htonl(NFS4ERR_RESOURCE);
 614         p = xdr_encode_hyper(p, change);
 615         return 0;
 616 }
 617
 618 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
 619 {
 620         __be32 *p;
 621
 622         if (!(bitmap[0] & FATTR4_WORD0_SIZE))
 623                 return 0;
 624         p = xdr_reserve_space(xdr, 8);
 625         if (unlikely(!p))
 626                 return htonl(NFS4ERR_RESOURCE);
 627         p = xdr_encode_hyper(p, size);
 628         return 0;
 629 }
 630
 631 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec64 *time)
 632 {
 633         __be32 *p;
 634
 635         p = xdr_reserve_space(xdr, 12);
 636         if (unlikely(!p))
 637                 return htonl(NFS4ERR_RESOURCE);
 638         p = xdr_encode_hyper(p, time->tv_sec);
 639         *p = htonl(time->tv_nsec);
 640         return 0;
 641 }
 642
 643 static __be32 encode_attr_atime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
 644 {
 645         if (!(bitmap[1] & FATTR4_WORD1_TIME_ACCESS))
 646                 return 0;
 647         return encode_attr_time(xdr,time);
 648 }
 649
 650 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
 651 {
 652         if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
 653                 return 0;
 654         return encode_attr_time(xdr,time);
 655 }
 656
 657 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
 658 {
 659         if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
 660                 return 0;
 661         return encode_attr_time(xdr,time);
 662 }
 663
 664 static __be32 encode_attr_delegatime(struct xdr_stream *xdr,
 665                                      const uint32_t *bitmap,
 666                                      const struct timespec64 *time)
 667 {
 668         if (!(bitmap[2] & FATTR4_WORD2_TIME_DELEG_ACCESS))
 669                 return 0;
 670         return encode_attr_time(xdr,time);
 671 }
 672
 673 static __be32 encode_attr_delegmtime(struct xdr_stream *xdr,
 674                                      const uint32_t *bitmap,
 675                                      const struct timespec64 *time)
 676 {
 677         if (!(bitmap[2] & FATTR4_WORD2_TIME_DELEG_MODIFY))
 678                 return 0;
 679         return encode_attr_time(xdr,time);
 680 }
 681
 682 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
 683 {
 684         __be32 status;
 685
 686         hdr->status = xdr_reserve_space(xdr, 4);
 687         if (unlikely(hdr->status == NULL))
 688                 return htonl(NFS4ERR_RESOURCE);
 689         status = encode_string(xdr, hdr->taglen, hdr->tag);
 690         if (unlikely(status != 0))
 691                 return status;
 692         hdr->nops = xdr_reserve_space(xdr, 4);
 693         if (unlikely(hdr->nops == NULL))
 694                 return htonl(NFS4ERR_RESOURCE);
 695         return 0;
 696 }
 697
 698 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
 699 {
 700         __be32 *p;
 701
 702         p = xdr_reserve_space(xdr, 8);
 703         if (unlikely(p == NULL))
 704                 return htonl(NFS4ERR_RESOURCE_HDR);
 705         *p++ = htonl(op);
 706         *p = res;
 707         return 0;
 708 }
 709
 710 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 711                 const void *resp)
 712 {
 713         const struct cb_getattrres *res = resp;
 714         __be32 *savep = NULL;
 715         __be32 status = res->status;
 716
 717         if (unlikely(status != 0))
 718                 goto out;
 719         status = encode_attr_bitmap(xdr, res->bitmap, ARRAY_SIZE(res->bitmap));
 720         if (unlikely(status != 0))
 721                 goto out;
 722         status = cpu_to_be32(NFS4ERR_RESOURCE);
 723         savep = xdr_reserve_space(xdr, sizeof(*savep));
 724         if (unlikely(!savep))
 725                 goto out;
 726         status = encode_attr_change(xdr, res->bitmap, res->change_attr);
 727         if (unlikely(status != 0))
 728                 goto out;
 729         status = encode_attr_size(xdr, res->bitmap, res->size);
 730         if (unlikely(status != 0))
 731                 goto out;
 732         status = encode_attr_atime(xdr, res->bitmap, &res->atime);
 733         if (unlikely(status != 0))
 734                 goto out;
 735         status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
 736         if (unlikely(status != 0))
 737                 goto out;
 738         status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
 739         if (unlikely(status != 0))
 740                 goto out;
 741         status = encode_attr_delegatime(xdr, res->bitmap, &res->atime);
 742         if (unlikely(status != 0))
 743                 goto out;
 744         status = encode_attr_delegmtime(xdr, res->bitmap, &res->mtime);
 745         *savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
 746 out:
 747         return status;
 748 }
 749
 750 #if defined(CONFIG_NFS_V4_1)
 751
 752 static __be32 encode_sessionid(struct xdr_stream *xdr,
 753                                  const struct nfs4_sessionid *sid)
 754 {
 755         __be32 *p;
 756
 757         p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
 758         if (unlikely(p == NULL))
 759                 return htonl(NFS4ERR_RESOURCE);
 760
 761         memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
 762         return 0;
 763 }
 764
 765 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
 766                                        struct xdr_stream *xdr,
 767                                        const void *resp)
 768 {
 769         const struct cb_sequenceres *res = resp;
 770         __be32 *p;
 771         __be32 status = res->csr_status;
 772
 773         if (unlikely(status != 0))
 774                 return status;
 775
 776         status = encode_sessionid(xdr, &res->csr_sessionid);
 777         if (status)
 778                 return status;
 779
 780         p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
 781         if (unlikely(p == NULL))
 782                 return htonl(NFS4ERR_RESOURCE);
 783
 784         *p++ = htonl(res->csr_sequenceid);
 785         *p++ = htonl(res->csr_slotid);
 786         *p++ = htonl(res->csr_highestslotid);
 787         *p++ = htonl(res->csr_target_highestslotid);
 788         return 0;
 789 }
 790
 791 static __be32
 792 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 793 {
 794         if (op_nr == OP_CB_SEQUENCE) {
 795                 if (nop != 0)
 796                         return htonl(NFS4ERR_SEQUENCE_POS);
 797         } else {
 798                 if (nop == 0)
 799                         return htonl(NFS4ERR_OP_NOT_IN_SESSION);
 800         }
 801
 802         switch (op_nr) {
 803         case OP_CB_GETATTR:
 804         case OP_CB_RECALL:
 805         case OP_CB_SEQUENCE:
 806         case OP_CB_RECALL_ANY:
 807         case OP_CB_RECALL_SLOT:
 808         case OP_CB_LAYOUTRECALL:
 809         case OP_CB_NOTIFY_DEVICEID:
 810         case OP_CB_NOTIFY_LOCK:
 811                 *op = &callback_ops[op_nr];
 812                 break;
 813
 814         case OP_CB_NOTIFY:
 815         case OP_CB_PUSH_DELEG:
 816         case OP_CB_RECALLABLE_OBJ_AVAIL:
 817         case OP_CB_WANTS_CANCELLED:
 818                 return htonl(NFS4ERR_NOTSUPP);
 819
 820         default:
 821                 return htonl(NFS4ERR_OP_ILLEGAL);
 822         }
 823
 824         return htonl(NFS_OK);
 825 }
 826
 827 static void nfs4_callback_free_slot(struct nfs4_session *session,
 828                 struct nfs4_slot *slot)
 829 {
 830         struct nfs4_slot_table *tbl = &session->bc_slot_table;
 831
 832         spin_lock(&tbl->slot_tbl_lock);
 833         /*
 834          * Let the state manager know callback processing done.
 835          * A single slot, so highest used slotid is either 0 or -1
 836          */
 837         nfs4_free_slot(tbl, slot);
 838         spin_unlock(&tbl->slot_tbl_lock);
 839 }
 840
 841 static void nfs4_cb_free_slot(struct cb_process_state *cps)
 842 {
 843         if (cps->slot) {
 844                 nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);
 845                 cps->slot = NULL;
 846         }
 847 }
 848
 849 #else /* CONFIG_NFS_V4_1 */
 850
 851 static __be32
 852 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 853 {
 854         return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 855 }
 856
 857 static void nfs4_cb_free_slot(struct cb_process_state *cps)
 858 {
 859 }
 860 #endif /* CONFIG_NFS_V4_1 */
 861
 862 #ifdef CONFIG_NFS_V4_2
 863 static __be32
 864 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
 865 {
 866         __be32 status = preprocess_nfs41_op(nop, op_nr, op);
 867         if (status != htonl(NFS4ERR_OP_ILLEGAL))
 868                 return status;
 869
 870         if (op_nr == OP_CB_OFFLOAD) {
 871                 *op = &callback_ops[op_nr];
 872                 return htonl(NFS_OK);
 873         } else
 874                 return htonl(NFS4ERR_NOTSUPP);
 875         return htonl(NFS4ERR_OP_ILLEGAL);
 876 }
 877 #else /* CONFIG_NFS_V4_2 */
 878 static __be32
 879 preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
 880 {
 881         return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 882 }
 883 #endif /* CONFIG_NFS_V4_2 */
 884
 885 static __be32
 886 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
 887 {
 888         switch (op_nr) {
 889         case OP_CB_GETATTR:
 890         case OP_CB_RECALL:
 891                 *op = &callback_ops[op_nr];
 892                 break;
 893         default:
 894                 return htonl(NFS4ERR_OP_ILLEGAL);
 895         }
 896
 897         return htonl(NFS_OK);
 898 }
 899
 900 static __be32 process_op(int nop, struct svc_rqst *rqstp,
 901                          struct cb_process_state *cps)
 902 {
 903         struct xdr_stream *xdr_out = &rqstp->rq_res_stream;
 904         struct callback_op *op = &callback_ops[0];
 905         unsigned int op_nr;
 906         __be32 status;
 907         long maxlen;
 908         __be32 res;
 909
 910         status = decode_op_hdr(&rqstp->rq_arg_stream, &op_nr);
 911         if (unlikely(status))
 912                 return status;
 913
 914         switch (cps->minorversion) {
 915         case 0:
 916                 status = preprocess_nfs4_op(op_nr, &op);
 917                 break;
 918         case 1:
 919                 status = preprocess_nfs41_op(nop, op_nr, &op);
 920                 break;
 921         case 2:
 922                 status = preprocess_nfs42_op(nop, op_nr, &op);
 923                 break;
 924         default:
 925                 status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 926         }
 927
 928         if (status == htonl(NFS4ERR_OP_ILLEGAL))
 929                 op_nr = OP_CB_ILLEGAL;
 930         if (status)
 931                 goto encode_hdr;
 932
 933         if (cps->drc_status) {
 934                 status = cps->drc_status;
 935                 goto encode_hdr;
 936         }
 937
 938         maxlen = xdr_out->end - xdr_out->p;
 939         if (maxlen > 0 && maxlen < PAGE_SIZE) {
 940                 status = op->decode_args(rqstp, &rqstp->rq_arg_stream,
 941                                          rqstp->rq_argp);
 942                 if (likely(status == 0))
 943                         status = op->process_op(rqstp->rq_argp, rqstp->rq_resp,
 944                                                 cps);
 945         } else
 946                 status = htonl(NFS4ERR_RESOURCE);
 947
 948 encode_hdr:
 949         res = encode_op_hdr(xdr_out, op_nr, status);
 950         if (unlikely(res))
 951                 return res;
 952         if (op->encode_res != NULL && status == 0)
 953                 status = op->encode_res(rqstp, xdr_out, rqstp->rq_resp);
 954         return status;
 955 }
 956
 957 /*
 958  * Decode, process and encode a COMPOUND
 959  */
 960 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp)
 961 {
 962         struct cb_compound_hdr_arg hdr_arg = { 0 };
 963         struct cb_compound_hdr_res hdr_res = { NULL };
 964         struct cb_process_state cps = {
 965                 .drc_status = 0,
 966                 .clp = NULL,
 967                 .net = SVC_NET(rqstp),
 968         };
 969         unsigned int nops = 0;
 970         __be32 status;
 971
 972         status = decode_compound_hdr_arg(&rqstp->rq_arg_stream, &hdr_arg);
 973         if (status == htonl(NFS4ERR_RESOURCE))
 974                 return rpc_garbage_args;
 975
 976         if (hdr_arg.minorversion == 0) {
 977                 cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
 978                 if (!cps.clp) {
 979                         trace_nfs_cb_no_clp(rqstp->rq_xid, hdr_arg.cb_ident);
 980                         goto out_invalidcred;
 981                 }
 982                 if (!check_gss_callback_principal(cps.clp, rqstp)) {
 983                         trace_nfs_cb_badprinc(rqstp->rq_xid, hdr_arg.cb_ident);
 984                         nfs_put_client(cps.clp);
 985                         goto out_invalidcred;
 986                 }
 987         }
 988
 989         cps.minorversion = hdr_arg.minorversion;
 990         hdr_res.taglen = hdr_arg.taglen;
 991         hdr_res.tag = hdr_arg.tag;
 992         if (encode_compound_hdr_res(&rqstp->rq_res_stream, &hdr_res) != 0) {
 993                 if (cps.clp)
 994                         nfs_put_client(cps.clp);
 995                 return rpc_system_err;
 996         }
 997         while (status == 0 && nops != hdr_arg.nops) {
 998                 status = process_op(nops, rqstp, &cps);
 999                 nops++;
1000         }
1001
1002         /* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
1003         * resource error in cb_compound status without returning op */
1004         if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
1005                 status = htonl(NFS4ERR_RESOURCE);
1006                 nops--;
1007         }
1008
1009         if (svc_is_backchannel(rqstp) && cps.clp) {
1010                 rqstp->bc_to_initval = cps.clp->cl_rpcclient->cl_timeout->to_initval;
1011                 rqstp->bc_to_retries = cps.clp->cl_rpcclient->cl_timeout->to_retries;
1012         }
1013
1014         *hdr_res.status = status;
1015         *hdr_res.nops = htonl(nops);
1016         nfs4_cb_free_slot(&cps);
1017         nfs_put_client(cps.clp);
1018         return rpc_success;
1019
1020 out_invalidcred:
1021         pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
1022         rqstp->rq_auth_stat = rpc_autherr_badcred;
1023         return rpc_success;
1024 }
1025
1026 static int
1027 nfs_callback_dispatch(struct svc_rqst *rqstp)
1028 {
1029         const struct svc_procedure *procp = rqstp->rq_procinfo;
1030
1031         *rqstp->rq_accept_statp = procp->pc_func(rqstp);
1032         return 1;
1033 }
1034
1035 /*
1036  * Define NFS4 callback COMPOUND ops.
1037  */
1038 static struct callback_op callback_ops[] = {
1039         [0] = {
1040                 .res_maxsize = CB_OP_HDR_RES_MAXSZ,
1041         },
1042         [OP_CB_GETATTR] = {
1043                 .process_op = nfs4_callback_getattr,
1044                 .decode_args = decode_getattr_args,
1045                 .encode_res = encode_getattr_res,
1046                 .res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
1047         },
1048         [OP_CB_RECALL] = {
1049                 .process_op = nfs4_callback_recall,
1050                 .decode_args = decode_recall_args,
1051                 .res_maxsize = CB_OP_RECALL_RES_MAXSZ,
1052         },
1053 #if defined(CONFIG_NFS_V4_1)
1054         [OP_CB_LAYOUTRECALL] = {
1055                 .process_op = nfs4_callback_layoutrecall,
1056                 .decode_args = decode_layoutrecall_args,
1057                 .res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
1058         },
1059         [OP_CB_NOTIFY_DEVICEID] = {
1060                 .process_op = nfs4_callback_devicenotify,
1061                 .decode_args = decode_devicenotify_args,
1062                 .res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
1063         },
1064         [OP_CB_SEQUENCE] = {
1065                 .process_op = nfs4_callback_sequence,
1066                 .decode_args = decode_cb_sequence_args,
1067                 .encode_res = encode_cb_sequence_res,
1068                 .res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
1069         },
1070         [OP_CB_RECALL_ANY] = {
1071                 .process_op = nfs4_callback_recallany,
1072                 .decode_args = decode_recallany_args,
1073                 .res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
1074         },
1075         [OP_CB_RECALL_SLOT] = {
1076                 .process_op = nfs4_callback_recallslot,
1077                 .decode_args = decode_recallslot_args,
1078                 .res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
1079         },
1080         [OP_CB_NOTIFY_LOCK] = {
1081                 .process_op = nfs4_callback_notify_lock,
1082                 .decode_args = decode_notify_lock_args,
1083                 .res_maxsize = CB_OP_NOTIFY_LOCK_RES_MAXSZ,
1084         },
1085 #endif /* CONFIG_NFS_V4_1 */
1086 #ifdef CONFIG_NFS_V4_2
1087         [OP_CB_OFFLOAD] = {
1088                 .process_op = nfs4_callback_offload,
1089                 .decode_args = decode_offload_args,
1090                 .res_maxsize = CB_OP_OFFLOAD_RES_MAXSZ,
1091         },
1092 #endif /* CONFIG_NFS_V4_2 */
1093 };
1094
1095 /*
1096  * Define NFS4 callback procedures
1097  */
1098 static const struct svc_procedure nfs4_callback_procedures1[] = {
1099         [CB_NULL] = {
1100                 .pc_func = nfs4_callback_null,
1101                 .pc_encode = nfs4_encode_void,
1102                 .pc_xdrressize = 1,
1103                 .pc_name = "NULL",
1104         },
1105         [CB_COMPOUND] = {
1106                 .pc_func = nfs4_callback_compound,
1107                 .pc_encode = nfs4_encode_void,
1108                 .pc_argsize = 256,
1109                 .pc_argzero = 256,
1110                 .pc_ressize = 256,
1111                 .pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
1112                 .pc_name = "COMPOUND",
1113         }
1114 };
1115
1116 static DEFINE_PER_CPU_ALIGNED(unsigned long,
1117                               nfs4_callback_count1[ARRAY_SIZE(nfs4_callback_procedures1)]);
1118 const struct svc_version nfs4_callback_version1 = {
1119         .vs_vers = 1,
1120         .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1121         .vs_proc = nfs4_callback_procedures1,
1122         .vs_count = nfs4_callback_count1,
1123         .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1124         .vs_dispatch = nfs_callback_dispatch,
1125         .vs_hidden = true,
1126         .vs_need_cong_ctrl = true,
1127 };
1128
1129 static DEFINE_PER_CPU_ALIGNED(unsigned long,
1130                               nfs4_callback_count4[ARRAY_SIZE(nfs4_callback_procedures1)]);
1131 const struct svc_version nfs4_callback_version4 = {
1132         .vs_vers = 4,
1133         .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
1134         .vs_proc = nfs4_callback_procedures1,
1135         .vs_count = nfs4_callback_count4,
1136         .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
1137         .vs_dispatch = nfs_callback_dispatch,
1138         .vs_hidden = true,
1139         .vs_need_cong_ctrl = true,
1140 };