fs/nfsd/nfs4callback.c

   1 /*
   2  *  linux/fs/nfsd/nfs4callback.c
   3  *
   4  *  Copyright (c) 2001 The Regents of the University of Michigan.
   5  *  All rights reserved.
   6  *
   7  *  Kendrick Smith <kmsmith@umich.edu>
   8  *  Andy Adamson <andros@umich.edu>
   9  *
  10  *  Redistribution and use in source and binary forms, with or without
  11  *  modification, are permitted provided that the following conditions
  12  *  are met:
  13  *
  14  *  1. Redistributions of source code must retain the above copyright
  15  *     notice, this list of conditions and the following disclaimer.
  16  *  2. Redistributions in binary form must reproduce the above copyright
  17  *     notice, this list of conditions and the following disclaimer in the
  18  *     documentation and/or other materials provided with the distribution.
  19  *  3. Neither the name of the University nor the names of its
  20  *     contributors may be used to endorse or promote products derived
  21  *     from this software without specific prior written permission.
  22  *
  23  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  24  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  25  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  26  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  28  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  29  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  30  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  31  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  32  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  33  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  34  */
  35
  36 #include <linux/module.h>
  37 #include <linux/list.h>
  38 #include <linux/inet.h>
  39 #include <linux/errno.h>
  40 #include <linux/delay.h>
  41 #include <linux/sched.h>
  42 #include <linux/kthread.h>
  43 #include <linux/sunrpc/xdr.h>
  44 #include <linux/sunrpc/svc.h>
  45 #include <linux/sunrpc/clnt.h>
  46 #include <linux/nfsd/nfsd.h>
  47 #include <linux/nfsd/state.h>
  48 #include <linux/sunrpc/sched.h>
  49 #include <linux/nfs4.h>
  50
  51 #define NFSDDBG_FACILITY                NFSDDBG_PROC
  52
  53 #define NFSPROC4_CB_NULL 0
  54 #define NFSPROC4_CB_COMPOUND 1
  55
  56 /* Index of predefined Linux callback client operations */
  57
  58 enum {
  59         NFSPROC4_CLNT_CB_NULL = 0,
  60         NFSPROC4_CLNT_CB_RECALL,
  61 };
  62
  63 enum nfs_cb_opnum4 {
  64         OP_CB_RECALL            = 4,
  65 };
  66
  67 #define NFS4_MAXTAGLEN          20
  68
  69 #define NFS4_enc_cb_null_sz             0
  70 #define NFS4_dec_cb_null_sz             0
  71 #define cb_compound_enc_hdr_sz          4
  72 #define cb_compound_dec_hdr_sz          (3 + (NFS4_MAXTAGLEN >> 2))
  73 #define op_enc_sz                       1
  74 #define op_dec_sz                       2
  75 #define enc_nfs4_fh_sz                  (1 + (NFS4_FHSIZE >> 2))
  76 #define enc_stateid_sz                  (NFS4_STATEID_SIZE >> 2)
  77 #define NFS4_enc_cb_recall_sz           (cb_compound_enc_hdr_sz +       \
  78                                         1 + enc_stateid_sz +            \
  79                                         enc_nfs4_fh_sz)
  80
  81 #define NFS4_dec_cb_recall_sz           (cb_compound_dec_hdr_sz  +      \
  82                                         op_dec_sz)
  83
  84 /*
  85 * Generic encode routines from fs/nfs/nfs4xdr.c
  86 */
  87 static inline __be32 *
  88 xdr_writemem(__be32 *p, const void *ptr, int nbytes)
  89 {
  90         int tmp = XDR_QUADLEN(nbytes);
  91         if (!tmp)
  92                 return p;
  93         p[tmp-1] = 0;
  94         memcpy(p, ptr, nbytes);
  95         return p + tmp;
  96 }
  97
  98 #define WRITE32(n)               *p++ = htonl(n)
  99 #define WRITEMEM(ptr,nbytes)     do {                           \
 100         p = xdr_writemem(p, ptr, nbytes);                       \
 101 } while (0)
 102 #define RESERVE_SPACE(nbytes)   do {                            \
 103         p = xdr_reserve_space(xdr, nbytes);                     \
 104         if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __func__); \
 105         BUG_ON(!p);                                             \
 106 } while (0)
 107
 108 /*
 109  * Generic decode routines from fs/nfs/nfs4xdr.c
 110  */
 111 #define DECODE_TAIL                             \
 112         status = 0;                             \
 113 out:                                            \
 114         return status;                          \
 115 xdr_error:                                      \
 116         dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \
 117         status = -EIO;                          \
 118         goto out
 119
 120 #define READ32(x)         (x) = ntohl(*p++)
 121 #define READ64(x)         do {                  \
 122         (x) = (u64)ntohl(*p++) << 32;           \
 123         (x) |= ntohl(*p++);                     \
 124 } while (0)
 125 #define READTIME(x)       do {                  \
 126         p++;                                    \
 127         (x.tv_sec) = ntohl(*p++);               \
 128         (x.tv_nsec) = ntohl(*p++);              \
 129 } while (0)
 130 #define READ_BUF(nbytes)  do { \
 131         p = xdr_inline_decode(xdr, nbytes); \
 132         if (!p) { \
 133                 dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \
 134                         __func__, __LINE__); \
 135                 return -EIO; \
 136         } \
 137 } while (0)
 138
 139 struct nfs4_cb_compound_hdr {
 140         int             status;
 141         u32             ident;
 142         u32             nops;
 143         u32             taglen;
 144         char *          tag;
 145 };
 146
 147 static struct {
 148 int stat;
 149 int errno;
 150 } nfs_cb_errtbl[] = {
 151         { NFS4_OK,              0               },
 152         { NFS4ERR_PERM,         EPERM           },
 153         { NFS4ERR_NOENT,        ENOENT          },
 154         { NFS4ERR_IO,           EIO             },
 155         { NFS4ERR_NXIO,         ENXIO           },
 156         { NFS4ERR_ACCESS,       EACCES          },
 157         { NFS4ERR_EXIST,        EEXIST          },
 158         { NFS4ERR_XDEV,         EXDEV           },
 159         { NFS4ERR_NOTDIR,       ENOTDIR         },
 160         { NFS4ERR_ISDIR,        EISDIR          },
 161         { NFS4ERR_INVAL,        EINVAL          },
 162         { NFS4ERR_FBIG,         EFBIG           },
 163         { NFS4ERR_NOSPC,        ENOSPC          },
 164         { NFS4ERR_ROFS,         EROFS           },
 165         { NFS4ERR_MLINK,        EMLINK          },
 166         { NFS4ERR_NAMETOOLONG,  ENAMETOOLONG    },
 167         { NFS4ERR_NOTEMPTY,     ENOTEMPTY       },
 168         { NFS4ERR_DQUOT,        EDQUOT          },
 169         { NFS4ERR_STALE,        ESTALE          },
 170         { NFS4ERR_BADHANDLE,    EBADHANDLE      },
 171         { NFS4ERR_BAD_COOKIE,   EBADCOOKIE      },
 172         { NFS4ERR_NOTSUPP,      ENOTSUPP        },
 173         { NFS4ERR_TOOSMALL,     ETOOSMALL       },
 174         { NFS4ERR_SERVERFAULT,  ESERVERFAULT    },
 175         { NFS4ERR_BADTYPE,      EBADTYPE        },
 176         { NFS4ERR_LOCKED,       EAGAIN          },
 177         { NFS4ERR_RESOURCE,     EREMOTEIO       },
 178         { NFS4ERR_SYMLINK,      ELOOP           },
 179         { NFS4ERR_OP_ILLEGAL,   EOPNOTSUPP      },
 180         { NFS4ERR_DEADLOCK,     EDEADLK         },
 181         { -1,                   EIO             }
 182 };
 183
 184 static int
 185 nfs_cb_stat_to_errno(int stat)
 186 {
 187         int i;
 188         for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
 189                 if (nfs_cb_errtbl[i].stat == stat)
 190                         return nfs_cb_errtbl[i].errno;
 191         }
 192         /* If we cannot translate the error, the recovery routines should
 193         * handle it.
 194         * Note: remaining NFSv4 error codes have values > 10000, so should
 195         * not conflict with native Linux error codes.
 196         */
 197         return stat;
 198 }
 199
 200 /*
 201  * XDR encode
 202  */
 203
 204 static int
 205 encode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr)
 206 {
 207         __be32 * p;
 208
 209         RESERVE_SPACE(16);
 210         WRITE32(0);            /* tag length is always 0 */
 211         WRITE32(NFS4_MINOR_VERSION);
 212         WRITE32(hdr->ident);
 213         WRITE32(hdr->nops);
 214         return 0;
 215 }
 216
 217 static int
 218 encode_cb_recall(struct xdr_stream *xdr, struct nfs4_delegation *dp)
 219 {
 220         __be32 *p;
 221         int len = dp->dl_fh.fh_size;
 222
 223         RESERVE_SPACE(12+sizeof(dp->dl_stateid) + len);
 224         WRITE32(OP_CB_RECALL);
 225         WRITE32(dp->dl_stateid.si_generation);
 226         WRITEMEM(&dp->dl_stateid.si_opaque, sizeof(stateid_opaque_t));
 227         WRITE32(0); /* truncate optimization not implemented */
 228         WRITE32(len);
 229         WRITEMEM(&dp->dl_fh.fh_base, len);
 230         return 0;
 231 }
 232
 233 static int
 234 nfs4_xdr_enc_cb_null(struct rpc_rqst *req, __be32 *p)
 235 {
 236         struct xdr_stream xdrs, *xdr = &xdrs;
 237
 238         xdr_init_encode(&xdrs, &req->rq_snd_buf, p);
 239         RESERVE_SPACE(0);
 240         return 0;
 241 }
 242
 243 static int
 244 nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p, struct nfs4_delegation *args)
 245 {
 246         struct xdr_stream xdr;
 247         struct nfs4_cb_compound_hdr hdr = {
 248                 .ident = args->dl_ident,
 249                 .nops   = 1,
 250         };
 251
 252         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
 253         encode_cb_compound_hdr(&xdr, &hdr);
 254         return (encode_cb_recall(&xdr, args));
 255 }
 256
 257
 258 static int
 259 decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){
 260         __be32 *p;
 261
 262         READ_BUF(8);
 263         READ32(hdr->status);
 264         READ32(hdr->taglen);
 265         READ_BUF(hdr->taglen + 4);
 266         hdr->tag = (char *)p;
 267         p += XDR_QUADLEN(hdr->taglen);
 268         READ32(hdr->nops);
 269         return 0;
 270 }
 271
 272 static int
 273 decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
 274 {
 275         __be32 *p;
 276         u32 op;
 277         int32_t nfserr;
 278
 279         READ_BUF(8);
 280         READ32(op);
 281         if (op != expected) {
 282                 dprintk("NFSD: decode_cb_op_hdr: Callback server returned "
 283                          " operation %d but we issued a request for %d\n",
 284                          op, expected);
 285                 return -EIO;
 286         }
 287         READ32(nfserr);
 288         if (nfserr != NFS_OK)
 289                 return -nfs_cb_stat_to_errno(nfserr);
 290         return 0;
 291 }
 292
 293 static int
 294 nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p)
 295 {
 296         return 0;
 297 }
 298
 299 static int
 300 nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p)
 301 {
 302         struct xdr_stream xdr;
 303         struct nfs4_cb_compound_hdr hdr;
 304         int status;
 305
 306         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
 307         status = decode_cb_compound_hdr(&xdr, &hdr);
 308         if (status)
 309                 goto out;
 310         status = decode_cb_op_hdr(&xdr, OP_CB_RECALL);
 311 out:
 312         return status;
 313 }
 314
 315 /*
 316  * RPC procedure tables
 317  */
 318 #define PROC(proc, call, argtype, restype)                              \
 319 [NFSPROC4_CLNT_##proc] = {                                              \
 320         .p_proc   = NFSPROC4_CB_##call,                                 \
 321         .p_encode = (kxdrproc_t) nfs4_xdr_##argtype,                    \
 322         .p_decode = (kxdrproc_t) nfs4_xdr_##restype,                    \
 323         .p_arglen = NFS4_##argtype##_sz,                                \
 324         .p_replen = NFS4_##restype##_sz,                                \
 325         .p_statidx = NFSPROC4_CB_##call,                                \
 326         .p_name   = #proc,                                              \
 327 }
 328
 329 static struct rpc_procinfo     nfs4_cb_procedures[] = {
 330     PROC(CB_NULL,      NULL,     enc_cb_null,     dec_cb_null),
 331     PROC(CB_RECALL,    COMPOUND,   enc_cb_recall,      dec_cb_recall),
 332 };
 333
 334 static struct rpc_version       nfs_cb_version4 = {
 335         .number                 = 1,
 336         .nrprocs                = ARRAY_SIZE(nfs4_cb_procedures),
 337         .procs                  = nfs4_cb_procedures
 338 };
 339
 340 static struct rpc_version *     nfs_cb_version[] = {
 341         NULL,
 342         &nfs_cb_version4,
 343 };
 344
 345 static struct rpc_program cb_program;
 346
 347 static struct rpc_stat cb_stats = {
 348                 .program        = &cb_program
 349 };
 350
 351 #define NFS4_CALLBACK 0x40000000
 352 static struct rpc_program cb_program = {
 353                 .name           = "nfs4_cb",
 354                 .number         = NFS4_CALLBACK,
 355                 .nrvers         = ARRAY_SIZE(nfs_cb_version),
 356                 .version        = nfs_cb_version,
 357                 .stats          = &cb_stats,
 358                 .pipe_dir_name  = "/nfsd4_cb",
 359 };
 360
 361 static int max_cb_time(void)
 362 {
 363         return max(NFSD_LEASE_TIME/10, (time_t)1) * HZ;
 364 }
 365
 366 /* Reference counting, callback cleanup, etc., all look racy as heck.
 367  * And why is cb_set an atomic? */
 368
 369 int setup_callback_client(struct nfs4_client *clp)
 370 {
 371         struct sockaddr_in      addr;
 372         struct nfs4_cb_conn *cb = &clp->cl_cb_conn;
 373         struct rpc_timeout      timeparms = {
 374                 .to_initval     = max_cb_time(),
 375                 .to_retries     = 0,
 376         };
 377         struct rpc_create_args args = {
 378                 .protocol       = IPPROTO_TCP,
 379                 .address        = (struct sockaddr *)&addr,
 380                 .addrsize       = sizeof(addr),
 381                 .timeout        = &timeparms,
 382                 .program        = &cb_program,
 383                 .prognumber     = cb->cb_prog,
 384                 .version        = nfs_cb_version[1]->number,
 385                 .authflavor     = clp->cl_flavor,
 386                 .flags          = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
 387                 .client_name    = clp->cl_principal,
 388         };
 389         struct rpc_clnt *client;
 390
 391         if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5))
 392                 return -EINVAL;
 393
 394         /* Initialize address */
 395         memset(&addr, 0, sizeof(addr));
 396         addr.sin_family = AF_INET;
 397         addr.sin_port = htons(cb->cb_port);
 398         addr.sin_addr.s_addr = htonl(cb->cb_addr);
 399
 400         /* Create RPC client */
 401         client = rpc_create(&args);
 402         if (IS_ERR(client)) {
 403                 dprintk("NFSD: couldn't create callback client: %ld\n",
 404                         PTR_ERR(client));
 405                 return PTR_ERR(client);
 406         }
 407         cb->cb_client = client;
 408         return 0;
 409
 410 }
 411
 412 static void warn_no_callback_path(struct nfs4_client *clp, int reason)
 413 {
 414         dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
 415                 (int)clp->cl_name.len, clp->cl_name.data, reason);
 416 }
 417
 418 static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
 419 {
 420         struct nfs4_client *clp = calldata;
 421
 422         if (task->tk_status)
 423                 warn_no_callback_path(clp, task->tk_status);
 424         else
 425                 atomic_set(&clp->cl_cb_conn.cb_set, 1);
 426         put_nfs4_client(clp);
 427 }
 428
 429 static const struct rpc_call_ops nfsd4_cb_probe_ops = {
 430         .rpc_call_done = nfsd4_cb_probe_done,
 431 };
 432
 433 static struct rpc_cred *lookup_cb_cred(struct nfs4_cb_conn *cb)
 434 {
 435         struct auth_cred acred = {
 436                 .machine_cred = 1
 437         };
 438
 439         /*
 440          * Note in the gss case this doesn't actually have to wait for a
 441          * gss upcall (or any calls to the client); this just creates a
 442          * non-uptodate cred which the rpc state machine will fill in with
 443          * a refresh_upcall later.
 444          */
 445         return rpcauth_lookup_credcache(cb->cb_client->cl_auth, &acred,
 446                                                         RPCAUTH_LOOKUP_NEW);
 447 }
 448
 449 void do_probe_callback(struct nfs4_client *clp)
 450 {
 451         struct nfs4_cb_conn *cb = &clp->cl_cb_conn;
 452         struct rpc_message msg = {
 453                 .rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
 454                 .rpc_argp       = clp,
 455         };
 456         struct rpc_cred *cred;
 457         int status;
 458
 459         cred = lookup_cb_cred(cb);
 460         if (IS_ERR(cred)) {
 461                 status = PTR_ERR(cred);
 462                 goto out;
 463         }
 464         cb->cb_cred = cred;
 465         msg.rpc_cred = cb->cb_cred;
 466         status = rpc_call_async(cb->cb_client, &msg, RPC_TASK_SOFT,
 467                                 &nfsd4_cb_probe_ops, (void *)clp);
 468 out:
 469         if (status) {
 470                 warn_no_callback_path(clp, status);
 471                 put_nfs4_client(clp);
 472         }
 473 }
 474
 475 /*
 476  * Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
 477  */
 478 void
 479 nfsd4_probe_callback(struct nfs4_client *clp)
 480 {
 481         int status;
 482
 483         BUG_ON(atomic_read(&clp->cl_cb_conn.cb_set));
 484
 485         status = setup_callback_client(clp);
 486         if (status) {
 487                 warn_no_callback_path(clp, status);
 488                 return;
 489         }
 490
 491         /* the task holds a reference to the nfs4_client struct */
 492         atomic_inc(&clp->cl_count);
 493
 494         do_probe_callback(clp);
 495 }
 496
 497 static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
 498 {
 499         struct nfs4_delegation *dp = calldata;
 500         struct nfs4_client *clp = dp->dl_client;
 501
 502         switch (task->tk_status) {
 503         case -EIO:
 504                 /* Network partition? */
 505                 atomic_set(&clp->cl_cb_conn.cb_set, 0);
 506                 warn_no_callback_path(clp, task->tk_status);
 507         case -EBADHANDLE:
 508         case -NFS4ERR_BAD_STATEID:
 509                 /* Race: client probably got cb_recall
 510                  * before open reply granting delegation */
 511                 break;
 512         default:
 513                 /* success, or error we can't handle */
 514                 return;
 515         }
 516         if (dp->dl_retries--) {
 517                 rpc_delay(task, 2*HZ);
 518                 task->tk_status = 0;
 519                 rpc_restart_call(task);
 520         } else {
 521                 atomic_set(&clp->cl_cb_conn.cb_set, 0);
 522                 warn_no_callback_path(clp, task->tk_status);
 523         }
 524 }
 525
 526 static void nfsd4_cb_recall_release(void *calldata)
 527 {
 528         struct nfs4_delegation *dp = calldata;
 529         struct nfs4_client *clp = dp->dl_client;
 530
 531         nfs4_put_delegation(dp);
 532         put_nfs4_client(clp);
 533 }
 534
 535 static const struct rpc_call_ops nfsd4_cb_recall_ops = {
 536         .rpc_call_done = nfsd4_cb_recall_done,
 537         .rpc_release = nfsd4_cb_recall_release,
 538 };
 539
 540 /*
 541  * called with dp->dl_count inc'ed.
 542  */
 543 void
 544 nfsd4_cb_recall(struct nfs4_delegation *dp)
 545 {
 546         struct nfs4_client *clp = dp->dl_client;
 547         struct rpc_clnt *clnt = clp->cl_cb_conn.cb_client;
 548         struct rpc_message msg = {
 549                 .rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
 550                 .rpc_argp = dp,
 551                 .rpc_cred = clp->cl_cb_conn.cb_cred
 552         };
 553         int status;
 554
 555         dp->dl_retries = 1;
 556         status = rpc_call_async(clnt, &msg, RPC_TASK_SOFT,
 557                                 &nfsd4_cb_recall_ops, dp);
 558         if (status) {
 559                 put_nfs4_client(clp);
 560                 nfs4_put_delegation(dp);
 561         }
 562 }