fs/nfs/callback_xdr.c

   1 /*
   2  * linux/fs/nfs/callback_xdr.c
   3  *
   4  * Copyright (C) 2004 Trond Myklebust
   5  *
   6  * NFSv4 callback encode/decode procedures
   7  */
   8 #include <linux/kernel.h>
   9 #include <linux/sunrpc/svc.h>
  10 #include <linux/nfs4.h>
  11 #include <linux/nfs_fs.h>
  12 #include <linux/slab.h>
  13 #include <linux/sunrpc/bc_xprt.h>
  14 #include "nfs4_fs.h"
  15 #include "callback.h"
  16 #include "internal.h"
  17
  18 #define CB_OP_TAGLEN_MAXSZ      (512)
  19 #define CB_OP_HDR_RES_MAXSZ     (2 + CB_OP_TAGLEN_MAXSZ)
  20 #define CB_OP_GETATTR_BITMAP_MAXSZ      (4)
  21 #define CB_OP_GETATTR_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ + \
  22                                 CB_OP_GETATTR_BITMAP_MAXSZ + \
  23                                 2 + 2 + 3 + 3)
  24 #define CB_OP_RECALL_RES_MAXSZ  (CB_OP_HDR_RES_MAXSZ)
  25
  26 #if defined(CONFIG_NFS_V4_1)
  27 #define CB_OP_LAYOUTRECALL_RES_MAXSZ    (CB_OP_HDR_RES_MAXSZ)
  28 #define CB_OP_SEQUENCE_RES_MAXSZ        (CB_OP_HDR_RES_MAXSZ + \
  29                                         4 + 1 + 3)
  30 #define CB_OP_RECALLANY_RES_MAXSZ       (CB_OP_HDR_RES_MAXSZ)
  31 #define CB_OP_RECALLSLOT_RES_MAXSZ      (CB_OP_HDR_RES_MAXSZ)
  32 #endif /* CONFIG_NFS_V4_1 */
  33
  34 #define NFSDBG_FACILITY NFSDBG_CALLBACK
  35
  36 /* Internal error code */
  37 #define NFS4ERR_RESOURCE_HDR    11050
  38
  39 typedef __be32 (*callback_process_op_t)(void *, void *,
  40                                         struct cb_process_state *);
  41 typedef __be32 (*callback_decode_arg_t)(struct svc_rqst *, struct xdr_stream *, void *);
  42 typedef __be32 (*callback_encode_res_t)(struct svc_rqst *, struct xdr_stream *, void *);
  43
  44
  45 struct callback_op {
  46         callback_process_op_t process_op;
  47         callback_decode_arg_t decode_args;
  48         callback_encode_res_t encode_res;
  49         long res_maxsize;
  50 };
  51
  52 static struct callback_op callback_ops[];
  53
  54 static __be32 nfs4_callback_null(struct svc_rqst *rqstp, void *argp, void *resp)
  55 {
  56         return htonl(NFS4_OK);
  57 }
  58
  59 static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
  60 {
  61         return xdr_argsize_check(rqstp, p);
  62 }
  63
  64 static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
  65 {
  66         return xdr_ressize_check(rqstp, p);
  67 }
  68
  69 static __be32 *read_buf(struct xdr_stream *xdr, int nbytes)
  70 {
  71         __be32 *p;
  72
  73         p = xdr_inline_decode(xdr, nbytes);
  74         if (unlikely(p == NULL))
  75                 printk(KERN_WARNING "NFSv4 callback reply buffer overflowed!\n");
  76         return p;
  77 }
  78
  79 static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len, const char **str)
  80 {
  81         __be32 *p;
  82
  83         p = read_buf(xdr, 4);
  84         if (unlikely(p == NULL))
  85                 return htonl(NFS4ERR_RESOURCE);
  86         *len = ntohl(*p);
  87
  88         if (*len != 0) {
  89                 p = read_buf(xdr, *len);
  90                 if (unlikely(p == NULL))
  91                         return htonl(NFS4ERR_RESOURCE);
  92                 *str = (const char *)p;
  93         } else
  94                 *str = NULL;
  95
  96         return 0;
  97 }
  98
  99 static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
 100 {
 101         __be32 *p;
 102
 103         p = read_buf(xdr, 4);
 104         if (unlikely(p == NULL))
 105                 return htonl(NFS4ERR_RESOURCE);
 106         fh->size = ntohl(*p);
 107         if (fh->size > NFS4_FHSIZE)
 108                 return htonl(NFS4ERR_BADHANDLE);
 109         p = read_buf(xdr, fh->size);
 110         if (unlikely(p == NULL))
 111                 return htonl(NFS4ERR_RESOURCE);
 112         memcpy(&fh->data[0], p, fh->size);
 113         memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
 114         return 0;
 115 }
 116
 117 static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
 118 {
 119         __be32 *p;
 120         unsigned int attrlen;
 121
 122         p = read_buf(xdr, 4);
 123         if (unlikely(p == NULL))
 124                 return htonl(NFS4ERR_RESOURCE);
 125         attrlen = ntohl(*p);
 126         p = read_buf(xdr, attrlen << 2);
 127         if (unlikely(p == NULL))
 128                 return htonl(NFS4ERR_RESOURCE);
 129         if (likely(attrlen > 0))
 130                 bitmap[0] = ntohl(*p++);
 131         if (attrlen > 1)
 132                 bitmap[1] = ntohl(*p);
 133         return 0;
 134 }
 135
 136 static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 137 {
 138         __be32 *p;
 139
 140         p = read_buf(xdr, 16);
 141         if (unlikely(p == NULL))
 142                 return htonl(NFS4ERR_RESOURCE);
 143         memcpy(stateid->data, p, 16);
 144         return 0;
 145 }
 146
 147 static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
 148 {
 149         __be32 *p;
 150         __be32 status;
 151
 152         status = decode_string(xdr, &hdr->taglen, &hdr->tag);
 153         if (unlikely(status != 0))
 154                 return status;
 155         /* We do not like overly long tags! */
 156         if (hdr->taglen > CB_OP_TAGLEN_MAXSZ - 12) {
 157                 printk("NFSv4 CALLBACK %s: client sent tag of length %u\n",
 158                                 __func__, hdr->taglen);
 159                 return htonl(NFS4ERR_RESOURCE);
 160         }
 161         p = read_buf(xdr, 12);
 162         if (unlikely(p == NULL))
 163                 return htonl(NFS4ERR_RESOURCE);
 164         hdr->minorversion = ntohl(*p++);
 165         /* Check minor version is zero or one. */
 166         if (hdr->minorversion <= 1) {
 167                 hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 */
 168         } else {
 169                 printk(KERN_WARNING "%s: NFSv4 server callback with "
 170                         "illegal minor version %u!\n",
 171                         __func__, hdr->minorversion);
 172                 return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 173         }
 174         hdr->nops = ntohl(*p);
 175         dprintk("%s: minorversion %d nops %d\n", __func__,
 176                 hdr->minorversion, hdr->nops);
 177         return 0;
 178 }
 179
 180 static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
 181 {
 182         __be32 *p;
 183         p = read_buf(xdr, 4);
 184         if (unlikely(p == NULL))
 185                 return htonl(NFS4ERR_RESOURCE_HDR);
 186         *op = ntohl(*p);
 187         return 0;
 188 }
 189
 190 static __be32 decode_getattr_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_getattrargs *args)
 191 {
 192         __be32 status;
 193
 194         status = decode_fh(xdr, &args->fh);
 195         if (unlikely(status != 0))
 196                 goto out;
 197         args->addr = svc_addr(rqstp);
 198         status = decode_bitmap(xdr, args->bitmap);
 199 out:
 200         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 201         return status;
 202 }
 203
 204 static __be32 decode_recall_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_recallargs *args)
 205 {
 206         __be32 *p;
 207         __be32 status;
 208
 209         args->addr = svc_addr(rqstp);
 210         status = decode_stateid(xdr, &args->stateid);
 211         if (unlikely(status != 0))
 212                 goto out;
 213         p = read_buf(xdr, 4);
 214         if (unlikely(p == NULL)) {
 215                 status = htonl(NFS4ERR_RESOURCE);
 216                 goto out;
 217         }
 218         args->truncate = ntohl(*p);
 219         status = decode_fh(xdr, &args->fh);
 220 out:
 221         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 222         return status;
 223 }
 224
 225 #if defined(CONFIG_NFS_V4_1)
 226
 227 static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
 228                                        struct xdr_stream *xdr,
 229                                        struct cb_layoutrecallargs *args)
 230 {
 231         __be32 *p;
 232         __be32 status = 0;
 233         uint32_t iomode;
 234
 235         args->cbl_addr = svc_addr(rqstp);
 236         p = read_buf(xdr, 4 * sizeof(uint32_t));
 237         if (unlikely(p == NULL)) {
 238                 status = htonl(NFS4ERR_BADXDR);
 239                 goto out;
 240         }
 241
 242         args->cbl_layout_type = ntohl(*p++);
 243         /* Depite the spec's xdr, iomode really belongs in the FILE switch,
 244          * as it is unusable and ignored with the other types.
 245          */
 246         iomode = ntohl(*p++);
 247         args->cbl_layoutchanged = ntohl(*p++);
 248         args->cbl_recall_type = ntohl(*p++);
 249
 250         if (args->cbl_recall_type == RETURN_FILE) {
 251                 args->cbl_range.iomode = iomode;
 252                 status = decode_fh(xdr, &args->cbl_fh);
 253                 if (unlikely(status != 0))
 254                         goto out;
 255
 256                 p = read_buf(xdr, 2 * sizeof(uint64_t));
 257                 if (unlikely(p == NULL)) {
 258                         status = htonl(NFS4ERR_BADXDR);
 259                         goto out;
 260                 }
 261                 p = xdr_decode_hyper(p, &args->cbl_range.offset);
 262                 p = xdr_decode_hyper(p, &args->cbl_range.length);
 263                 status = decode_stateid(xdr, &args->cbl_stateid);
 264                 if (unlikely(status != 0))
 265                         goto out;
 266         } else if (args->cbl_recall_type == RETURN_FSID) {
 267                 p = read_buf(xdr, 2 * sizeof(uint64_t));
 268                 if (unlikely(p == NULL)) {
 269                         status = htonl(NFS4ERR_BADXDR);
 270                         goto out;
 271                 }
 272                 p = xdr_decode_hyper(p, &args->cbl_fsid.major);
 273                 p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
 274         } else if (args->cbl_recall_type != RETURN_ALL) {
 275                 status = htonl(NFS4ERR_BADXDR);
 276                 goto out;
 277         }
 278         dprintk("%s: ltype 0x%x iomode %d changed %d recall_type %d\n",
 279                 __func__,
 280                 args->cbl_layout_type, iomode,
 281                 args->cbl_layoutchanged, args->cbl_recall_type);
 282 out:
 283         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 284         return status;
 285 }
 286
 287 static __be32 decode_sessionid(struct xdr_stream *xdr,
 288                                  struct nfs4_sessionid *sid)
 289 {
 290         __be32 *p;
 291         int len = NFS4_MAX_SESSIONID_LEN;
 292
 293         p = read_buf(xdr, len);
 294         if (unlikely(p == NULL))
 295                 return htonl(NFS4ERR_RESOURCE);
 296
 297         memcpy(sid->data, p, len);
 298         return 0;
 299 }
 300
 301 static __be32 decode_rc_list(struct xdr_stream *xdr,
 302                                struct referring_call_list *rc_list)
 303 {
 304         __be32 *p;
 305         int i;
 306         __be32 status;
 307
 308         status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
 309         if (status)
 310                 goto out;
 311
 312         status = htonl(NFS4ERR_RESOURCE);
 313         p = read_buf(xdr, sizeof(uint32_t));
 314         if (unlikely(p == NULL))
 315                 goto out;
 316
 317         rc_list->rcl_nrefcalls = ntohl(*p++);
 318         if (rc_list->rcl_nrefcalls) {
 319                 p = read_buf(xdr,
 320                              rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
 321                 if (unlikely(p == NULL))
 322                         goto out;
 323                 rc_list->rcl_refcalls = kmalloc(rc_list->rcl_nrefcalls *
 324                                                 sizeof(*rc_list->rcl_refcalls),
 325                                                 GFP_KERNEL);
 326                 if (unlikely(rc_list->rcl_refcalls == NULL))
 327                         goto out;
 328                 for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
 329                         rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
 330                         rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
 331                 }
 332         }
 333         status = 0;
 334
 335 out:
 336         return status;
 337 }
 338
 339 static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
 340                                         struct xdr_stream *xdr,
 341                                         struct cb_sequenceargs *args)
 342 {
 343         __be32 *p;
 344         int i;
 345         __be32 status;
 346
 347         status = decode_sessionid(xdr, &args->csa_sessionid);
 348         if (status)
 349                 goto out;
 350
 351         status = htonl(NFS4ERR_RESOURCE);
 352         p = read_buf(xdr, 5 * sizeof(uint32_t));
 353         if (unlikely(p == NULL))
 354                 goto out;
 355
 356         args->csa_addr = svc_addr(rqstp);
 357         args->csa_sequenceid = ntohl(*p++);
 358         args->csa_slotid = ntohl(*p++);
 359         args->csa_highestslotid = ntohl(*p++);
 360         args->csa_cachethis = ntohl(*p++);
 361         args->csa_nrclists = ntohl(*p++);
 362         args->csa_rclists = NULL;
 363         if (args->csa_nrclists) {
 364                 args->csa_rclists = kmalloc(args->csa_nrclists *
 365                                             sizeof(*args->csa_rclists),
 366                                             GFP_KERNEL);
 367                 if (unlikely(args->csa_rclists == NULL))
 368                         goto out;
 369
 370                 for (i = 0; i < args->csa_nrclists; i++) {
 371                         status = decode_rc_list(xdr, &args->csa_rclists[i]);
 372                         if (status)
 373                                 goto out_free;
 374                 }
 375         }
 376         status = 0;
 377
 378         dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u slotid %u "
 379                 "highestslotid %u cachethis %d nrclists %u\n",
 380                 __func__,
 381                 ((u32 *)&args->csa_sessionid)[0],
 382                 ((u32 *)&args->csa_sessionid)[1],
 383                 ((u32 *)&args->csa_sessionid)[2],
 384                 ((u32 *)&args->csa_sessionid)[3],
 385                 args->csa_sequenceid, args->csa_slotid,
 386                 args->csa_highestslotid, args->csa_cachethis,
 387                 args->csa_nrclists);
 388 out:
 389         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 390         return status;
 391
 392 out_free:
 393         for (i = 0; i < args->csa_nrclists; i++)
 394                 kfree(args->csa_rclists[i].rcl_refcalls);
 395         kfree(args->csa_rclists);
 396         goto out;
 397 }
 398
 399 static __be32 decode_recallany_args(struct svc_rqst *rqstp,
 400                                       struct xdr_stream *xdr,
 401                                       struct cb_recallanyargs *args)
 402 {
 403         __be32 *p;
 404
 405         args->craa_addr = svc_addr(rqstp);
 406         p = read_buf(xdr, 4);
 407         if (unlikely(p == NULL))
 408                 return htonl(NFS4ERR_BADXDR);
 409         args->craa_objs_to_keep = ntohl(*p++);
 410         p = read_buf(xdr, 4);
 411         if (unlikely(p == NULL))
 412                 return htonl(NFS4ERR_BADXDR);
 413         args->craa_type_mask = ntohl(*p);
 414
 415         return 0;
 416 }
 417
 418 static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
 419                                         struct xdr_stream *xdr,
 420                                         struct cb_recallslotargs *args)
 421 {
 422         __be32 *p;
 423
 424         args->crsa_addr = svc_addr(rqstp);
 425         p = read_buf(xdr, 4);
 426         if (unlikely(p == NULL))
 427                 return htonl(NFS4ERR_BADXDR);
 428         args->crsa_target_max_slots = ntohl(*p++);
 429         return 0;
 430 }
 431
 432 #endif /* CONFIG_NFS_V4_1 */
 433
 434 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
 435 {
 436         __be32 *p;
 437
 438         p = xdr_reserve_space(xdr, 4 + len);
 439         if (unlikely(p == NULL))
 440                 return htonl(NFS4ERR_RESOURCE);
 441         xdr_encode_opaque(p, str, len);
 442         return 0;
 443 }
 444
 445 #define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
 446 #define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
 447 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, __be32 **savep)
 448 {
 449         __be32 bm[2];
 450         __be32 *p;
 451
 452         bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
 453         bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
 454         if (bm[1] != 0) {
 455                 p = xdr_reserve_space(xdr, 16);
 456                 if (unlikely(p == NULL))
 457                         return htonl(NFS4ERR_RESOURCE);
 458                 *p++ = htonl(2);
 459                 *p++ = bm[0];
 460                 *p++ = bm[1];
 461         } else if (bm[0] != 0) {
 462                 p = xdr_reserve_space(xdr, 12);
 463                 if (unlikely(p == NULL))
 464                         return htonl(NFS4ERR_RESOURCE);
 465                 *p++ = htonl(1);
 466                 *p++ = bm[0];
 467         } else {
 468                 p = xdr_reserve_space(xdr, 8);
 469                 if (unlikely(p == NULL))
 470                         return htonl(NFS4ERR_RESOURCE);
 471                 *p++ = htonl(0);
 472         }
 473         *savep = p;
 474         return 0;
 475 }
 476
 477 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
 478 {
 479         __be32 *p;
 480
 481         if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
 482                 return 0;
 483         p = xdr_reserve_space(xdr, 8);
 484         if (unlikely(!p))
 485                 return htonl(NFS4ERR_RESOURCE);
 486         p = xdr_encode_hyper(p, change);
 487         return 0;
 488 }
 489
 490 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
 491 {
 492         __be32 *p;
 493
 494         if (!(bitmap[0] & FATTR4_WORD0_SIZE))
 495                 return 0;
 496         p = xdr_reserve_space(xdr, 8);
 497         if (unlikely(!p))
 498                 return htonl(NFS4ERR_RESOURCE);
 499         p = xdr_encode_hyper(p, size);
 500         return 0;
 501 }
 502
 503 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
 504 {
 505         __be32 *p;
 506
 507         p = xdr_reserve_space(xdr, 12);
 508         if (unlikely(!p))
 509                 return htonl(NFS4ERR_RESOURCE);
 510         p = xdr_encode_hyper(p, time->tv_sec);
 511         *p = htonl(time->tv_nsec);
 512         return 0;
 513 }
 514
 515 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
 516 {
 517         if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
 518                 return 0;
 519         return encode_attr_time(xdr,time);
 520 }
 521
 522 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
 523 {
 524         if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
 525                 return 0;
 526         return encode_attr_time(xdr,time);
 527 }
 528
 529 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
 530 {
 531         __be32 status;
 532
 533         hdr->status = xdr_reserve_space(xdr, 4);
 534         if (unlikely(hdr->status == NULL))
 535                 return htonl(NFS4ERR_RESOURCE);
 536         status = encode_string(xdr, hdr->taglen, hdr->tag);
 537         if (unlikely(status != 0))
 538                 return status;
 539         hdr->nops = xdr_reserve_space(xdr, 4);
 540         if (unlikely(hdr->nops == NULL))
 541                 return htonl(NFS4ERR_RESOURCE);
 542         return 0;
 543 }
 544
 545 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
 546 {
 547         __be32 *p;
 548
 549         p = xdr_reserve_space(xdr, 8);
 550         if (unlikely(p == NULL))
 551                 return htonl(NFS4ERR_RESOURCE_HDR);
 552         *p++ = htonl(op);
 553         *p = res;
 554         return 0;
 555 }
 556
 557 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct cb_getattrres *res)
 558 {
 559         __be32 *savep = NULL;
 560         __be32 status = res->status;
 561
 562         if (unlikely(status != 0))
 563                 goto out;
 564         status = encode_attr_bitmap(xdr, res->bitmap, &savep);
 565         if (unlikely(status != 0))
 566                 goto out;
 567         status = encode_attr_change(xdr, res->bitmap, res->change_attr);
 568         if (unlikely(status != 0))
 569                 goto out;
 570         status = encode_attr_size(xdr, res->bitmap, res->size);
 571         if (unlikely(status != 0))
 572                 goto out;
 573         status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
 574         if (unlikely(status != 0))
 575                 goto out;
 576         status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
 577         *savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
 578 out:
 579         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 580         return status;
 581 }
 582
 583 #if defined(CONFIG_NFS_V4_1)
 584
 585 static __be32 encode_sessionid(struct xdr_stream *xdr,
 586                                  const struct nfs4_sessionid *sid)
 587 {
 588         __be32 *p;
 589         int len = NFS4_MAX_SESSIONID_LEN;
 590
 591         p = xdr_reserve_space(xdr, len);
 592         if (unlikely(p == NULL))
 593                 return htonl(NFS4ERR_RESOURCE);
 594
 595         memcpy(p, sid, len);
 596         return 0;
 597 }
 598
 599 static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
 600                                        struct xdr_stream *xdr,
 601                                        const struct cb_sequenceres *res)
 602 {
 603         __be32 *p;
 604         unsigned status = res->csr_status;
 605
 606         if (unlikely(status != 0))
 607                 goto out;
 608
 609         encode_sessionid(xdr, &res->csr_sessionid);
 610
 611         p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
 612         if (unlikely(p == NULL))
 613                 return htonl(NFS4ERR_RESOURCE);
 614
 615         *p++ = htonl(res->csr_sequenceid);
 616         *p++ = htonl(res->csr_slotid);
 617         *p++ = htonl(res->csr_highestslotid);
 618         *p++ = htonl(res->csr_target_highestslotid);
 619 out:
 620         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 621         return status;
 622 }
 623
 624 static __be32
 625 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 626 {
 627         if (op_nr == OP_CB_SEQUENCE) {
 628                 if (nop != 0)
 629                         return htonl(NFS4ERR_SEQUENCE_POS);
 630         } else {
 631                 if (nop == 0)
 632                         return htonl(NFS4ERR_OP_NOT_IN_SESSION);
 633         }
 634
 635         switch (op_nr) {
 636         case OP_CB_GETATTR:
 637         case OP_CB_RECALL:
 638         case OP_CB_SEQUENCE:
 639         case OP_CB_RECALL_ANY:
 640         case OP_CB_RECALL_SLOT:
 641         case OP_CB_LAYOUTRECALL:
 642                 *op = &callback_ops[op_nr];
 643                 break;
 644
 645         case OP_CB_NOTIFY_DEVICEID:
 646         case OP_CB_NOTIFY:
 647         case OP_CB_PUSH_DELEG:
 648         case OP_CB_RECALLABLE_OBJ_AVAIL:
 649         case OP_CB_WANTS_CANCELLED:
 650         case OP_CB_NOTIFY_LOCK:
 651                 return htonl(NFS4ERR_NOTSUPP);
 652
 653         default:
 654                 return htonl(NFS4ERR_OP_ILLEGAL);
 655         }
 656
 657         return htonl(NFS_OK);
 658 }
 659
 660 static void nfs4_callback_free_slot(struct nfs4_session *session)
 661 {
 662         struct nfs4_slot_table *tbl = &session->bc_slot_table;
 663
 664         spin_lock(&tbl->slot_tbl_lock);
 665         /*
 666          * Let the state manager know callback processing done.
 667          * A single slot, so highest used slotid is either 0 or -1
 668          */
 669         tbl->highest_used_slotid--;
 670         nfs4_check_drain_bc_complete(session);
 671         spin_unlock(&tbl->slot_tbl_lock);
 672 }
 673
 674 static void nfs4_cb_free_slot(struct nfs_client *clp)
 675 {
 676         if (clp && clp->cl_session)
 677                 nfs4_callback_free_slot(clp->cl_session);
 678 }
 679
 680 /* A single slot, so highest used slotid is either 0 or -1 */
 681 void nfs4_cb_take_slot(struct nfs_client *clp)
 682 {
 683         struct nfs4_slot_table *tbl = &clp->cl_session->bc_slot_table;
 684
 685         spin_lock(&tbl->slot_tbl_lock);
 686         tbl->highest_used_slotid++;
 687         BUG_ON(tbl->highest_used_slotid != 0);
 688         spin_unlock(&tbl->slot_tbl_lock);
 689 }
 690
 691 #else /* CONFIG_NFS_V4_1 */
 692
 693 static __be32
 694 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 695 {
 696         return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 697 }
 698
 699 static void nfs4_cb_free_slot(struct nfs_client *clp)
 700 {
 701 }
 702 #endif /* CONFIG_NFS_V4_1 */
 703
 704 static __be32
 705 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
 706 {
 707         switch (op_nr) {
 708         case OP_CB_GETATTR:
 709         case OP_CB_RECALL:
 710                 *op = &callback_ops[op_nr];
 711                 break;
 712         default:
 713                 return htonl(NFS4ERR_OP_ILLEGAL);
 714         }
 715
 716         return htonl(NFS_OK);
 717 }
 718
 719 static __be32 process_op(uint32_t minorversion, int nop,
 720                 struct svc_rqst *rqstp,
 721                 struct xdr_stream *xdr_in, void *argp,
 722                 struct xdr_stream *xdr_out, void *resp,
 723                 struct cb_process_state *cps)
 724 {
 725         struct callback_op *op = &callback_ops[0];
 726         unsigned int op_nr;
 727         __be32 status;
 728         long maxlen;
 729         __be32 res;
 730
 731         dprintk("%s: start\n", __func__);
 732         status = decode_op_hdr(xdr_in, &op_nr);
 733         if (unlikely(status))
 734                 return status;
 735
 736         dprintk("%s: minorversion=%d nop=%d op_nr=%u\n",
 737                 __func__, minorversion, nop, op_nr);
 738
 739         status = minorversion ? preprocess_nfs41_op(nop, op_nr, &op) :
 740                                 preprocess_nfs4_op(op_nr, &op);
 741         if (status == htonl(NFS4ERR_OP_ILLEGAL))
 742                 op_nr = OP_CB_ILLEGAL;
 743         if (status)
 744                 goto encode_hdr;
 745
 746         if (cps->drc_status) {
 747                 status = cps->drc_status;
 748                 goto encode_hdr;
 749         }
 750
 751         maxlen = xdr_out->end - xdr_out->p;
 752         if (maxlen > 0 && maxlen < PAGE_SIZE) {
 753                 status = op->decode_args(rqstp, xdr_in, argp);
 754                 if (likely(status == 0))
 755                         status = op->process_op(argp, resp, cps);
 756         } else
 757                 status = htonl(NFS4ERR_RESOURCE);
 758
 759 encode_hdr:
 760         res = encode_op_hdr(xdr_out, op_nr, status);
 761         if (unlikely(res))
 762                 return res;
 763         if (op->encode_res != NULL && status == 0)
 764                 status = op->encode_res(rqstp, xdr_out, resp);
 765         dprintk("%s: done, status = %d\n", __func__, ntohl(status));
 766         return status;
 767 }
 768
 769 /*
 770  * Decode, process and encode a COMPOUND
 771  */
 772 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *resp)
 773 {
 774         struct cb_compound_hdr_arg hdr_arg = { 0 };
 775         struct cb_compound_hdr_res hdr_res = { NULL };
 776         struct xdr_stream xdr_in, xdr_out;
 777         __be32 *p, status;
 778         struct cb_process_state cps = {
 779                 .drc_status = 0,
 780                 .clp = NULL,
 781         };
 782         unsigned int nops = 0;
 783
 784         dprintk("%s: start\n", __func__);
 785
 786         xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
 787
 788         p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
 789         xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
 790
 791         status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
 792         if (status == __constant_htonl(NFS4ERR_RESOURCE))
 793                 return rpc_garbage_args;
 794
 795         if (hdr_arg.minorversion == 0) {
 796                 cps.clp = nfs4_find_client_ident(hdr_arg.cb_ident);
 797                 if (!cps.clp || !check_gss_callback_principal(cps.clp, rqstp))
 798                         return rpc_drop_reply;
 799         }
 800
 801         hdr_res.taglen = hdr_arg.taglen;
 802         hdr_res.tag = hdr_arg.tag;
 803         if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0)
 804                 return rpc_system_err;
 805
 806         while (status == 0 && nops != hdr_arg.nops) {
 807                 status = process_op(hdr_arg.minorversion, nops, rqstp,
 808                                     &xdr_in, argp, &xdr_out, resp, &cps);
 809                 nops++;
 810         }
 811
 812         /* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
 813         * resource error in cb_compound status without returning op */
 814         if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
 815                 status = htonl(NFS4ERR_RESOURCE);
 816                 nops--;
 817         }
 818
 819         *hdr_res.status = status;
 820         *hdr_res.nops = htonl(nops);
 821         nfs4_cb_free_slot(cps.clp);
 822         nfs_put_client(cps.clp);
 823         dprintk("%s: done, status = %u\n", __func__, ntohl(status));
 824         return rpc_success;
 825 }
 826
 827 /*
 828  * Define NFS4 callback COMPOUND ops.
 829  */
 830 static struct callback_op callback_ops[] = {
 831         [0] = {
 832                 .res_maxsize = CB_OP_HDR_RES_MAXSZ,
 833         },
 834         [OP_CB_GETATTR] = {
 835                 .process_op = (callback_process_op_t)nfs4_callback_getattr,
 836                 .decode_args = (callback_decode_arg_t)decode_getattr_args,
 837                 .encode_res = (callback_encode_res_t)encode_getattr_res,
 838                 .res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
 839         },
 840         [OP_CB_RECALL] = {
 841                 .process_op = (callback_process_op_t)nfs4_callback_recall,
 842                 .decode_args = (callback_decode_arg_t)decode_recall_args,
 843                 .res_maxsize = CB_OP_RECALL_RES_MAXSZ,
 844         },
 845 #if defined(CONFIG_NFS_V4_1)
 846         [OP_CB_LAYOUTRECALL] = {
 847                 .process_op = (callback_process_op_t)nfs4_callback_layoutrecall,
 848                 .decode_args =
 849                         (callback_decode_arg_t)decode_layoutrecall_args,
 850                 .res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
 851         },
 852         [OP_CB_SEQUENCE] = {
 853                 .process_op = (callback_process_op_t)nfs4_callback_sequence,
 854                 .decode_args = (callback_decode_arg_t)decode_cb_sequence_args,
 855                 .encode_res = (callback_encode_res_t)encode_cb_sequence_res,
 856                 .res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
 857         },
 858         [OP_CB_RECALL_ANY] = {
 859                 .process_op = (callback_process_op_t)nfs4_callback_recallany,
 860                 .decode_args = (callback_decode_arg_t)decode_recallany_args,
 861                 .res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
 862         },
 863         [OP_CB_RECALL_SLOT] = {
 864                 .process_op = (callback_process_op_t)nfs4_callback_recallslot,
 865                 .decode_args = (callback_decode_arg_t)decode_recallslot_args,
 866                 .res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
 867         },
 868 #endif /* CONFIG_NFS_V4_1 */
 869 };
 870
 871 /*
 872  * Define NFS4 callback procedures
 873  */
 874 static struct svc_procedure nfs4_callback_procedures1[] = {
 875         [CB_NULL] = {
 876                 .pc_func = nfs4_callback_null,
 877                 .pc_decode = (kxdrproc_t)nfs4_decode_void,
 878                 .pc_encode = (kxdrproc_t)nfs4_encode_void,
 879                 .pc_xdrressize = 1,
 880         },
 881         [CB_COMPOUND] = {
 882                 .pc_func = nfs4_callback_compound,
 883                 .pc_encode = (kxdrproc_t)nfs4_encode_void,
 884                 .pc_argsize = 256,
 885                 .pc_ressize = 256,
 886                 .pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
 887         }
 888 };
 889
 890 struct svc_version nfs4_callback_version1 = {
 891         .vs_vers = 1,
 892         .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
 893         .vs_proc = nfs4_callback_procedures1,
 894         .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
 895         .vs_dispatch = NULL,
 896         .vs_hidden = 1,
 897 };
 898
 899 struct svc_version nfs4_callback_version4 = {
 900         .vs_vers = 4,
 901         .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
 902         .vs_proc = nfs4_callback_procedures1,
 903         .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
 904         .vs_dispatch = NULL,
 905 };