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/sunrpc/xdr.h>
  42 #include <linux/sunrpc/svc.h>
  43 #include <linux/sunrpc/clnt.h>
  44 #include <linux/nfsd/nfsd.h>
  45 #include <linux/nfsd/state.h>
  46 #include <linux/sunrpc/sched.h>
  47 #include <linux/nfs4.h>
  48
  49 #define NFSDDBG_FACILITY                NFSDDBG_PROC
  50
  51 #define NFSPROC4_CB_NULL 0
  52 #define NFSPROC4_CB_COMPOUND 1
  53
  54 /* declarations */
  55 static const struct rpc_call_ops nfs4_cb_null_ops;
  56
  57 /* Index of predefined Linux callback client operations */
  58
  59 enum {
  60         NFSPROC4_CLNT_CB_NULL = 0,
  61         NFSPROC4_CLNT_CB_RECALL,
  62 };
  63
  64 enum nfs_cb_opnum4 {
  65         OP_CB_RECALL            = 4,
  66 };
  67
  68 #define NFS4_MAXTAGLEN          20
  69
  70 #define NFS4_enc_cb_null_sz             0
  71 #define NFS4_dec_cb_null_sz             0
  72 #define cb_compound_enc_hdr_sz          4
  73 #define cb_compound_dec_hdr_sz          (3 + (NFS4_MAXTAGLEN >> 2))
  74 #define op_enc_sz                       1
  75 #define op_dec_sz                       2
  76 #define enc_nfs4_fh_sz                  (1 + (NFS4_FHSIZE >> 2))
  77 #define enc_stateid_sz                  16
  78 #define NFS4_enc_cb_recall_sz           (cb_compound_enc_hdr_sz +       \
  79                                         1 + enc_stateid_sz +            \
  80                                         enc_nfs4_fh_sz)
  81
  82 #define NFS4_dec_cb_recall_sz           (cb_compound_dec_hdr_sz  +      \
  83                                         op_dec_sz)
  84
  85 /*
  86 * Generic encode routines from fs/nfs/nfs4xdr.c
  87 */
  88 static inline __be32 *
  89 xdr_writemem(__be32 *p, const void *ptr, int nbytes)
  90 {
  91         int tmp = XDR_QUADLEN(nbytes);
  92         if (!tmp)
  93                 return p;
  94         p[tmp-1] = 0;
  95         memcpy(p, ptr, nbytes);
  96         return p + tmp;
  97 }
  98
  99 #define WRITE32(n)               *p++ = htonl(n)
 100 #define WRITEMEM(ptr,nbytes)     do {                           \
 101         p = xdr_writemem(p, ptr, nbytes);                       \
 102 } while (0)
 103 #define RESERVE_SPACE(nbytes)   do {                            \
 104         p = xdr_reserve_space(xdr, nbytes);                     \
 105         if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __FUNCTION__); \
 106         BUG_ON(!p);                                             \
 107 } while (0)
 108
 109 /*
 110  * Generic decode routines from fs/nfs/nfs4xdr.c
 111  */
 112 #define DECODE_TAIL                             \
 113         status = 0;                             \
 114 out:                                            \
 115         return status;                          \
 116 xdr_error:                                      \
 117         dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \
 118         status = -EIO;                          \
 119         goto out
 120
 121 #define READ32(x)         (x) = ntohl(*p++)
 122 #define READ64(x)         do {                  \
 123         (x) = (u64)ntohl(*p++) << 32;           \
 124         (x) |= ntohl(*p++);                     \
 125 } while (0)
 126 #define READTIME(x)       do {                  \
 127         p++;                                    \
 128         (x.tv_sec) = ntohl(*p++);               \
 129         (x.tv_nsec) = ntohl(*p++);              \
 130 } while (0)
 131 #define READ_BUF(nbytes)  do { \
 132         p = xdr_inline_decode(xdr, nbytes); \
 133         if (!p) { \
 134                 dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \
 135                         __FUNCTION__, __LINE__); \
 136                 return -EIO; \
 137         } \
 138 } while (0)
 139
 140 struct nfs4_cb_compound_hdr {
 141         int             status;
 142         u32             ident;
 143         u32             nops;
 144         u32             taglen;
 145         char *          tag;
 146 };
 147
 148 static struct {
 149 int stat;
 150 int errno;
 151 } nfs_cb_errtbl[] = {
 152         { NFS4_OK,              0               },
 153         { NFS4ERR_PERM,         EPERM           },
 154         { NFS4ERR_NOENT,        ENOENT          },
 155         { NFS4ERR_IO,           EIO             },
 156         { NFS4ERR_NXIO,         ENXIO           },
 157         { NFS4ERR_ACCESS,       EACCES          },
 158         { NFS4ERR_EXIST,        EEXIST          },
 159         { NFS4ERR_XDEV,         EXDEV           },
 160         { NFS4ERR_NOTDIR,       ENOTDIR         },
 161         { NFS4ERR_ISDIR,        EISDIR          },
 162         { NFS4ERR_INVAL,        EINVAL          },
 163         { NFS4ERR_FBIG,         EFBIG           },
 164         { NFS4ERR_NOSPC,        ENOSPC          },
 165         { NFS4ERR_ROFS,         EROFS           },
 166         { NFS4ERR_MLINK,        EMLINK          },
 167         { NFS4ERR_NAMETOOLONG,  ENAMETOOLONG    },
 168         { NFS4ERR_NOTEMPTY,     ENOTEMPTY       },
 169         { NFS4ERR_DQUOT,        EDQUOT          },
 170         { NFS4ERR_STALE,        ESTALE          },
 171         { NFS4ERR_BADHANDLE,    EBADHANDLE      },
 172         { NFS4ERR_BAD_COOKIE,   EBADCOOKIE      },
 173         { NFS4ERR_NOTSUPP,      ENOTSUPP        },
 174         { NFS4ERR_TOOSMALL,     ETOOSMALL       },
 175         { NFS4ERR_SERVERFAULT,  ESERVERFAULT    },
 176         { NFS4ERR_BADTYPE,      EBADTYPE        },
 177         { NFS4ERR_LOCKED,       EAGAIN          },
 178         { NFS4ERR_RESOURCE,     EREMOTEIO       },
 179         { NFS4ERR_SYMLINK,      ELOOP           },
 180         { NFS4ERR_OP_ILLEGAL,   EOPNOTSUPP      },
 181         { NFS4ERR_DEADLOCK,     EDEADLK         },
 182         { -1,                   EIO             }
 183 };
 184
 185 static int
 186 nfs_cb_stat_to_errno(int stat)
 187 {
 188         int i;
 189         for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
 190                 if (nfs_cb_errtbl[i].stat == stat)
 191                         return nfs_cb_errtbl[i].errno;
 192         }
 193         /* If we cannot translate the error, the recovery routines should
 194         * handle it.
 195         * Note: remaining NFSv4 error codes have values > 10000, so should
 196         * not conflict with native Linux error codes.
 197         */
 198         return stat;
 199 }
 200
 201 /*
 202  * XDR encode
 203  */
 204
 205 static int
 206 encode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr)
 207 {
 208         __be32 * p;
 209
 210         RESERVE_SPACE(16);
 211         WRITE32(0);            /* tag length is always 0 */
 212         WRITE32(NFS4_MINOR_VERSION);
 213         WRITE32(hdr->ident);
 214         WRITE32(hdr->nops);
 215         return 0;
 216 }
 217
 218 static int
 219 encode_cb_recall(struct xdr_stream *xdr, struct nfs4_cb_recall *cb_rec)
 220 {
 221         __be32 *p;
 222         int len = cb_rec->cbr_fhlen;
 223
 224         RESERVE_SPACE(12+sizeof(cb_rec->cbr_stateid) + len);
 225         WRITE32(OP_CB_RECALL);
 226         WRITEMEM(&cb_rec->cbr_stateid, sizeof(stateid_t));
 227         WRITE32(cb_rec->cbr_trunc);
 228         WRITE32(len);
 229         WRITEMEM(cb_rec->cbr_fhval, 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_cb_recall *args)
 245 {
 246         struct xdr_stream xdr;
 247         struct nfs4_cb_compound_hdr hdr = {
 248                 .ident = args->cbr_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 #ifndef MAX
 319 # define MAX(a, b)      (((a) > (b))? (a) : (b))
 320 #endif
 321
 322 #define PROC(proc, call, argtype, restype)                              \
 323 [NFSPROC4_CLNT_##proc] = {                                              \
 324         .p_proc   = NFSPROC4_CB_##call,                                 \
 325         .p_encode = (kxdrproc_t) nfs4_xdr_##argtype,                    \
 326         .p_decode = (kxdrproc_t) nfs4_xdr_##restype,                    \
 327         .p_bufsiz = MAX(NFS4_##argtype##_sz,NFS4_##restype##_sz) << 2,  \
 328         .p_statidx = NFSPROC4_CB_##call,                                \
 329         .p_name   = #proc,                                              \
 330 }
 331
 332 static struct rpc_procinfo     nfs4_cb_procedures[] = {
 333     PROC(CB_NULL,      NULL,     enc_cb_null,     dec_cb_null),
 334     PROC(CB_RECALL,    COMPOUND,   enc_cb_recall,      dec_cb_recall),
 335 };
 336
 337 static struct rpc_version       nfs_cb_version4 = {
 338         .number                 = 1,
 339         .nrprocs                = ARRAY_SIZE(nfs4_cb_procedures),
 340         .procs                  = nfs4_cb_procedures
 341 };
 342
 343 static struct rpc_version *     nfs_cb_version[] = {
 344         NULL,
 345         &nfs_cb_version4,
 346 };
 347
 348 /*
 349  * Use the SETCLIENTID credential
 350  */
 351 static struct rpc_cred *
 352 nfsd4_lookupcred(struct nfs4_client *clp, int taskflags)
 353 {
 354         struct auth_cred acred;
 355         struct rpc_clnt *clnt = clp->cl_callback.cb_client;
 356         struct rpc_cred *ret;
 357
 358         get_group_info(clp->cl_cred.cr_group_info);
 359         acred.uid = clp->cl_cred.cr_uid;
 360         acred.gid = clp->cl_cred.cr_gid;
 361         acred.group_info = clp->cl_cred.cr_group_info;
 362
 363         dprintk("NFSD:     looking up %s cred\n",
 364                 clnt->cl_auth->au_ops->au_name);
 365         ret = rpcauth_lookup_credcache(clnt->cl_auth, &acred, taskflags);
 366         put_group_info(clp->cl_cred.cr_group_info);
 367         return ret;
 368 }
 369
 370 /*
 371  * Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
 372  */
 373 void
 374 nfsd4_probe_callback(struct nfs4_client *clp)
 375 {
 376         struct sockaddr_in      addr;
 377         struct nfs4_callback    *cb = &clp->cl_callback;
 378         struct rpc_timeout      timeparms = {
 379                 .to_initval     = (NFSD_LEASE_TIME/4) * HZ,
 380                 .to_retries     = 5,
 381                 .to_maxval      = (NFSD_LEASE_TIME/2) * HZ,
 382                 .to_exponential = 1,
 383         };
 384         struct rpc_program *    program = &cb->cb_program;
 385         struct rpc_create_args args = {
 386                 .protocol       = IPPROTO_TCP,
 387                 .address        = (struct sockaddr *)&addr,
 388                 .addrsize       = sizeof(addr),
 389                 .timeout        = &timeparms,
 390                 .program        = program,
 391                 .version        = nfs_cb_version[1]->number,
 392                 .authflavor     = RPC_AUTH_UNIX,        /* XXX: need AUTH_GSS... */
 393                 .flags          = (RPC_CLNT_CREATE_NOPING),
 394         };
 395         struct rpc_message msg = {
 396                 .rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
 397                 .rpc_argp       = clp,
 398         };
 399         char clientname[16];
 400         int status;
 401
 402         if (atomic_read(&cb->cb_set))
 403                 return;
 404
 405         /* Initialize address */
 406         memset(&addr, 0, sizeof(addr));
 407         addr.sin_family = AF_INET;
 408         addr.sin_port = htons(cb->cb_port);
 409         addr.sin_addr.s_addr = htonl(cb->cb_addr);
 410
 411         /* Initialize rpc_program */
 412         program->name = "nfs4_cb";
 413         program->number = cb->cb_prog;
 414         program->nrvers = ARRAY_SIZE(nfs_cb_version);
 415         program->version = nfs_cb_version;
 416         program->stats = &cb->cb_stat;
 417
 418         /* Initialize rpc_stat */
 419         memset(program->stats, 0, sizeof(cb->cb_stat));
 420         program->stats->program = program;
 421
 422         /* Just here to make some printk's more useful: */
 423         snprintf(clientname, sizeof(clientname),
 424                 "%u.%u.%u.%u", NIPQUAD(addr.sin_addr));
 425         args.servername = clientname;
 426
 427         /* Create RPC client */
 428         cb->cb_client = rpc_create(&args);
 429         if (IS_ERR(cb->cb_client)) {
 430                 dprintk("NFSD: couldn't create callback client\n");
 431                 goto out_err;
 432         }
 433
 434         /* Kick rpciod, put the call on the wire. */
 435         if (rpciod_up() != 0)
 436                 goto out_clnt;
 437
 438         /* the task holds a reference to the nfs4_client struct */
 439         atomic_inc(&clp->cl_count);
 440
 441         msg.rpc_cred = nfsd4_lookupcred(clp,0);
 442         if (IS_ERR(msg.rpc_cred))
 443                 goto out_rpciod;
 444         status = rpc_call_async(cb->cb_client, &msg, RPC_TASK_ASYNC, &nfs4_cb_null_ops, NULL);
 445         put_rpccred(msg.rpc_cred);
 446
 447         if (status != 0) {
 448                 dprintk("NFSD: asynchronous NFSPROC4_CB_NULL failed!\n");
 449                 goto out_rpciod;
 450         }
 451         return;
 452
 453 out_rpciod:
 454         atomic_dec(&clp->cl_count);
 455         rpciod_down();
 456 out_clnt:
 457         rpc_shutdown_client(cb->cb_client);
 458 out_err:
 459         cb->cb_client = NULL;
 460         dprintk("NFSD: warning: no callback path to client %.*s\n",
 461                 (int)clp->cl_name.len, clp->cl_name.data);
 462 }
 463
 464 static void
 465 nfs4_cb_null(struct rpc_task *task, void *dummy)
 466 {
 467         struct nfs4_client *clp = (struct nfs4_client *)task->tk_msg.rpc_argp;
 468         struct nfs4_callback *cb = &clp->cl_callback;
 469         __be32 addr = htonl(cb->cb_addr);
 470
 471         dprintk("NFSD: nfs4_cb_null task->tk_status %d\n", task->tk_status);
 472
 473         if (task->tk_status < 0) {
 474                 dprintk("NFSD: callback establishment to client %.*s failed\n",
 475                         (int)clp->cl_name.len, clp->cl_name.data);
 476                 goto out;
 477         }
 478         atomic_set(&cb->cb_set, 1);
 479         dprintk("NFSD: callback set to client %u.%u.%u.%u\n", NIPQUAD(addr));
 480 out:
 481         put_nfs4_client(clp);
 482 }
 483
 484 static const struct rpc_call_ops nfs4_cb_null_ops = {
 485         .rpc_call_done = nfs4_cb_null,
 486 };
 487
 488 /*
 489  * called with dp->dl_count inc'ed.
 490  * nfs4_lock_state() may or may not have been called.
 491  */
 492 void
 493 nfsd4_cb_recall(struct nfs4_delegation *dp)
 494 {
 495         struct nfs4_client *clp = dp->dl_client;
 496         struct rpc_clnt *clnt = clp->cl_callback.cb_client;
 497         struct nfs4_cb_recall *cbr = &dp->dl_recall;
 498         struct rpc_message msg = {
 499                 .rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
 500                 .rpc_argp = cbr,
 501         };
 502         int retries = 1;
 503         int status = 0;
 504
 505         if ((!atomic_read(&clp->cl_callback.cb_set)) || !clnt)
 506                 return;
 507
 508         msg.rpc_cred = nfsd4_lookupcred(clp, 0);
 509         if (IS_ERR(msg.rpc_cred))
 510                 goto out;
 511
 512         cbr->cbr_trunc = 0; /* XXX need to implement truncate optimization */
 513         cbr->cbr_dp = dp;
 514
 515         status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
 516         while (retries--) {
 517                 switch (status) {
 518                         case -EIO:
 519                                 /* Network partition? */
 520                         case -EBADHANDLE:
 521                         case -NFS4ERR_BAD_STATEID:
 522                                 /* Race: client probably got cb_recall
 523                                  * before open reply granting delegation */
 524                                 break;
 525                         default:
 526                                 goto out_put_cred;
 527                 }
 528                 ssleep(2);
 529                 status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
 530         }
 531 out_put_cred:
 532         put_rpccred(msg.rpc_cred);
 533 out:
 534         if (status == -EIO)
 535                 atomic_set(&clp->cl_callback.cb_set, 0);
 536         /* Success or failure, now we're either waiting for lease expiration
 537          * or deleg_return. */
 538         dprintk("NFSD: nfs4_cb_recall: dp %p dl_flock %p dl_count %d\n",dp, dp->dl_flock, atomic_read(&dp->dl_count));
 539         nfs4_put_delegation(dp);
 540         return;
 541 }