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   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/sunrpc/xdr.h>
  43 #include <linux/sunrpc/svc.h>
  44 #include <linux/sunrpc/clnt.h>
  45 #include <linux/nfsd/nfsd.h>
  46 #include <linux/nfsd/state.h>
  47 #include <linux/sunrpc/sched.h>
  48 #include <linux/nfs4.h>
  49
  50 #define NFSDDBG_FACILITY                NFSDDBG_PROC
  51
  52 #define NFSPROC4_CB_NULL 0
  53 #define NFSPROC4_CB_COMPOUND 1
  54
  55 /* declarations */
  56 static const struct rpc_call_ops nfs4_cb_null_ops;
  57
  58 /* Index of predefined Linux callback client operations */
  59
  60 enum {
  61         NFSPROC4_CLNT_CB_NULL = 0,
  62         NFSPROC4_CLNT_CB_RECALL,
  63 };
  64
  65 enum nfs_cb_opnum4 {
  66         OP_CB_RECALL            = 4,
  67 };
  68
  69 #define NFS4_MAXTAGLEN          20
  70
  71 #define NFS4_enc_cb_null_sz             0
  72 #define NFS4_dec_cb_null_sz             0
  73 #define cb_compound_enc_hdr_sz          4
  74 #define cb_compound_dec_hdr_sz          (3 + (NFS4_MAXTAGLEN >> 2))
  75 #define op_enc_sz                       1
  76 #define op_dec_sz                       2
  77 #define enc_nfs4_fh_sz                  (1 + (NFS4_FHSIZE >> 2))
  78 #define enc_stateid_sz                  16
  79 #define NFS4_enc_cb_recall_sz           (cb_compound_enc_hdr_sz +       \
  80                                         1 + enc_stateid_sz +            \
  81                                         enc_nfs4_fh_sz)
  82
  83 #define NFS4_dec_cb_recall_sz           (cb_compound_dec_hdr_sz  +      \
  84                                         op_dec_sz)
  85
  86 /*
  87 * Generic encode routines from fs/nfs/nfs4xdr.c
  88 */
  89 static inline __be32 *
  90 xdr_writemem(__be32 *p, const void *ptr, int nbytes)
  91 {
  92         int tmp = XDR_QUADLEN(nbytes);
  93         if (!tmp)
  94                 return p;
  95         p[tmp-1] = 0;
  96         memcpy(p, ptr, nbytes);
  97         return p + tmp;
  98 }
  99
 100 #define WRITE32(n)               *p++ = htonl(n)
 101 #define WRITEMEM(ptr,nbytes)     do {                           \
 102         p = xdr_writemem(p, ptr, nbytes);                       \
 103 } while (0)
 104 #define RESERVE_SPACE(nbytes)   do {                            \
 105         p = xdr_reserve_space(xdr, nbytes);                     \
 106         if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __FUNCTION__); \
 107         BUG_ON(!p);                                             \
 108 } while (0)
 109
 110 /*
 111  * Generic decode routines from fs/nfs/nfs4xdr.c
 112  */
 113 #define DECODE_TAIL                             \
 114         status = 0;                             \
 115 out:                                            \
 116         return status;                          \
 117 xdr_error:                                      \
 118         dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \
 119         status = -EIO;                          \
 120         goto out
 121
 122 #define READ32(x)         (x) = ntohl(*p++)
 123 #define READ64(x)         do {                  \
 124         (x) = (u64)ntohl(*p++) << 32;           \
 125         (x) |= ntohl(*p++);                     \
 126 } while (0)
 127 #define READTIME(x)       do {                  \
 128         p++;                                    \
 129         (x.tv_sec) = ntohl(*p++);               \
 130         (x.tv_nsec) = ntohl(*p++);              \
 131 } while (0)
 132 #define READ_BUF(nbytes)  do { \
 133         p = xdr_inline_decode(xdr, nbytes); \
 134         if (!p) { \
 135                 dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \
 136                         __FUNCTION__, __LINE__); \
 137                 return -EIO; \
 138         } \
 139 } while (0)
 140
 141 struct nfs4_cb_compound_hdr {
 142         int             status;
 143         u32             ident;
 144         u32             nops;
 145         u32             taglen;
 146         char *          tag;
 147 };
 148
 149 static struct {
 150 int stat;
 151 int errno;
 152 } nfs_cb_errtbl[] = {
 153         { NFS4_OK,              0               },
 154         { NFS4ERR_PERM,         EPERM           },
 155         { NFS4ERR_NOENT,        ENOENT          },
 156         { NFS4ERR_IO,           EIO             },
 157         { NFS4ERR_NXIO,         ENXIO           },
 158         { NFS4ERR_ACCESS,       EACCES          },
 159         { NFS4ERR_EXIST,        EEXIST          },
 160         { NFS4ERR_XDEV,         EXDEV           },
 161         { NFS4ERR_NOTDIR,       ENOTDIR         },
 162         { NFS4ERR_ISDIR,        EISDIR          },
 163         { NFS4ERR_INVAL,        EINVAL          },
 164         { NFS4ERR_FBIG,         EFBIG           },
 165         { NFS4ERR_NOSPC,        ENOSPC          },
 166         { NFS4ERR_ROFS,         EROFS           },
 167         { NFS4ERR_MLINK,        EMLINK          },
 168         { NFS4ERR_NAMETOOLONG,  ENAMETOOLONG    },
 169         { NFS4ERR_NOTEMPTY,     ENOTEMPTY       },
 170         { NFS4ERR_DQUOT,        EDQUOT          },
 171         { NFS4ERR_STALE,        ESTALE          },
 172         { NFS4ERR_BADHANDLE,    EBADHANDLE      },
 173         { NFS4ERR_BAD_COOKIE,   EBADCOOKIE      },
 174         { NFS4ERR_NOTSUPP,      ENOTSUPP        },
 175         { NFS4ERR_TOOSMALL,     ETOOSMALL       },
 176         { NFS4ERR_SERVERFAULT,  ESERVERFAULT    },
 177         { NFS4ERR_BADTYPE,      EBADTYPE        },
 178         { NFS4ERR_LOCKED,       EAGAIN          },
 179         { NFS4ERR_RESOURCE,     EREMOTEIO       },
 180         { NFS4ERR_SYMLINK,      ELOOP           },
 181         { NFS4ERR_OP_ILLEGAL,   EOPNOTSUPP      },
 182         { NFS4ERR_DEADLOCK,     EDEADLK         },
 183         { -1,                   EIO             }
 184 };
 185
 186 static int
 187 nfs_cb_stat_to_errno(int stat)
 188 {
 189         int i;
 190         for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
 191                 if (nfs_cb_errtbl[i].stat == stat)
 192                         return nfs_cb_errtbl[i].errno;
 193         }
 194         /* If we cannot translate the error, the recovery routines should
 195         * handle it.
 196         * Note: remaining NFSv4 error codes have values > 10000, so should
 197         * not conflict with native Linux error codes.
 198         */
 199         return stat;
 200 }
 201
 202 /*
 203  * XDR encode
 204  */
 205
 206 static int
 207 encode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr)
 208 {
 209         __be32 * p;
 210
 211         RESERVE_SPACE(16);
 212         WRITE32(0);            /* tag length is always 0 */
 213         WRITE32(NFS4_MINOR_VERSION);
 214         WRITE32(hdr->ident);
 215         WRITE32(hdr->nops);
 216         return 0;
 217 }
 218
 219 static int
 220 encode_cb_recall(struct xdr_stream *xdr, struct nfs4_cb_recall *cb_rec)
 221 {
 222         __be32 *p;
 223         int len = cb_rec->cbr_fhlen;
 224
 225         RESERVE_SPACE(12+sizeof(cb_rec->cbr_stateid) + len);
 226         WRITE32(OP_CB_RECALL);
 227         WRITEMEM(&cb_rec->cbr_stateid, sizeof(stateid_t));
 228         WRITE32(cb_rec->cbr_trunc);
 229         WRITE32(len);
 230         WRITEMEM(cb_rec->cbr_fhval, len);
 231         return 0;
 232 }
 233
 234 static int
 235 nfs4_xdr_enc_cb_null(struct rpc_rqst *req, __be32 *p)
 236 {
 237         struct xdr_stream xdrs, *xdr = &xdrs;
 238
 239         xdr_init_encode(&xdrs, &req->rq_snd_buf, p);
 240         RESERVE_SPACE(0);
 241         return 0;
 242 }
 243
 244 static int
 245 nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p, struct nfs4_cb_recall *args)
 246 {
 247         struct xdr_stream xdr;
 248         struct nfs4_cb_compound_hdr hdr = {
 249                 .ident = args->cbr_ident,
 250                 .nops   = 1,
 251         };
 252
 253         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
 254         encode_cb_compound_hdr(&xdr, &hdr);
 255         return (encode_cb_recall(&xdr, args));
 256 }
 257
 258
 259 static int
 260 decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){
 261         __be32 *p;
 262
 263         READ_BUF(8);
 264         READ32(hdr->status);
 265         READ32(hdr->taglen);
 266         READ_BUF(hdr->taglen + 4);
 267         hdr->tag = (char *)p;
 268         p += XDR_QUADLEN(hdr->taglen);
 269         READ32(hdr->nops);
 270         return 0;
 271 }
 272
 273 static int
 274 decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
 275 {
 276         __be32 *p;
 277         u32 op;
 278         int32_t nfserr;
 279
 280         READ_BUF(8);
 281         READ32(op);
 282         if (op != expected) {
 283                 dprintk("NFSD: decode_cb_op_hdr: Callback server returned "
 284                          " operation %d but we issued a request for %d\n",
 285                          op, expected);
 286                 return -EIO;
 287         }
 288         READ32(nfserr);
 289         if (nfserr != NFS_OK)
 290                 return -nfs_cb_stat_to_errno(nfserr);
 291         return 0;
 292 }
 293
 294 static int
 295 nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p)
 296 {
 297         return 0;
 298 }
 299
 300 static int
 301 nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p)
 302 {
 303         struct xdr_stream xdr;
 304         struct nfs4_cb_compound_hdr hdr;
 305         int status;
 306
 307         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
 308         status = decode_cb_compound_hdr(&xdr, &hdr);
 309         if (status)
 310                 goto out;
 311         status = decode_cb_op_hdr(&xdr, OP_CB_RECALL);
 312 out:
 313         return status;
 314 }
 315
 316 /*
 317  * RPC procedure tables
 318  */
 319 #define PROC(proc, call, argtype, restype)                              \
 320 [NFSPROC4_CLNT_##proc] = {                                              \
 321         .p_proc   = NFSPROC4_CB_##call,                                 \
 322         .p_encode = (kxdrproc_t) nfs4_xdr_##argtype,                    \
 323         .p_decode = (kxdrproc_t) nfs4_xdr_##restype,                    \
 324         .p_arglen = NFS4_##argtype##_sz,                                \
 325         .p_replen = NFS4_##restype##_sz,                                \
 326         .p_statidx = NFSPROC4_CB_##call,                                \
 327         .p_name   = #proc,                                              \
 328 }
 329
 330 static struct rpc_procinfo     nfs4_cb_procedures[] = {
 331     PROC(CB_NULL,      NULL,     enc_cb_null,     dec_cb_null),
 332     PROC(CB_RECALL,    COMPOUND,   enc_cb_recall,      dec_cb_recall),
 333 };
 334
 335 static struct rpc_version       nfs_cb_version4 = {
 336         .number                 = 1,
 337         .nrprocs                = ARRAY_SIZE(nfs4_cb_procedures),
 338         .procs                  = nfs4_cb_procedures
 339 };
 340
 341 static struct rpc_version *     nfs_cb_version[] = {
 342         NULL,
 343         &nfs_cb_version4,
 344 };
 345
 346 /*
 347  * Use the SETCLIENTID credential
 348  */
 349 static struct rpc_cred *
 350 nfsd4_lookupcred(struct nfs4_client *clp, int taskflags)
 351 {
 352         struct auth_cred acred;
 353         struct rpc_clnt *clnt = clp->cl_callback.cb_client;
 354         struct rpc_cred *ret;
 355
 356         get_group_info(clp->cl_cred.cr_group_info);
 357         acred.uid = clp->cl_cred.cr_uid;
 358         acred.gid = clp->cl_cred.cr_gid;
 359         acred.group_info = clp->cl_cred.cr_group_info;
 360
 361         dprintk("NFSD:     looking up %s cred\n",
 362                 clnt->cl_auth->au_ops->au_name);
 363         ret = rpcauth_lookup_credcache(clnt->cl_auth, &acred, taskflags);
 364         put_group_info(clp->cl_cred.cr_group_info);
 365         return ret;
 366 }
 367
 368 /*
 369  * Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
 370  */
 371 void
 372 nfsd4_probe_callback(struct nfs4_client *clp)
 373 {
 374         struct sockaddr_in      addr;
 375         struct nfs4_callback    *cb = &clp->cl_callback;
 376         struct rpc_timeout      timeparms = {
 377                 .to_initval     = (NFSD_LEASE_TIME/4) * HZ,
 378                 .to_retries     = 5,
 379                 .to_maxval      = (NFSD_LEASE_TIME/2) * HZ,
 380                 .to_exponential = 1,
 381         };
 382         struct rpc_program *    program = &cb->cb_program;
 383         struct rpc_create_args args = {
 384                 .protocol       = IPPROTO_TCP,
 385                 .address        = (struct sockaddr *)&addr,
 386                 .addrsize       = sizeof(addr),
 387                 .timeout        = &timeparms,
 388                 .program        = program,
 389                 .version        = nfs_cb_version[1]->number,
 390                 .authflavor     = RPC_AUTH_UNIX,        /* XXX: need AUTH_GSS... */
 391                 .flags          = (RPC_CLNT_CREATE_NOPING),
 392         };
 393         struct rpc_message msg = {
 394                 .rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
 395                 .rpc_argp       = clp,
 396         };
 397         char clientname[16];
 398         int status;
 399
 400         if (atomic_read(&cb->cb_set))
 401                 return;
 402
 403         /* Initialize address */
 404         memset(&addr, 0, sizeof(addr));
 405         addr.sin_family = AF_INET;
 406         addr.sin_port = htons(cb->cb_port);
 407         addr.sin_addr.s_addr = htonl(cb->cb_addr);
 408
 409         /* Initialize rpc_program */
 410         program->name = "nfs4_cb";
 411         program->number = cb->cb_prog;
 412         program->nrvers = ARRAY_SIZE(nfs_cb_version);
 413         program->version = nfs_cb_version;
 414         program->stats = &cb->cb_stat;
 415
 416         /* Initialize rpc_stat */
 417         memset(program->stats, 0, sizeof(cb->cb_stat));
 418         program->stats->program = program;
 419
 420         /* Just here to make some printk's more useful: */
 421         snprintf(clientname, sizeof(clientname),
 422                 "%u.%u.%u.%u", NIPQUAD(addr.sin_addr));
 423         args.servername = clientname;
 424
 425         /* Create RPC client */
 426         cb->cb_client = rpc_create(&args);
 427         if (IS_ERR(cb->cb_client)) {
 428                 dprintk("NFSD: couldn't create callback client\n");
 429                 goto out_err;
 430         }
 431
 432         /* the task holds a reference to the nfs4_client struct */
 433         atomic_inc(&clp->cl_count);
 434
 435         msg.rpc_cred = nfsd4_lookupcred(clp,0);
 436         if (IS_ERR(msg.rpc_cred))
 437                 goto out_release_clp;
 438         status = rpc_call_async(cb->cb_client, &msg, RPC_TASK_ASYNC, &nfs4_cb_null_ops, NULL);
 439         put_rpccred(msg.rpc_cred);
 440
 441         if (status != 0) {
 442                 dprintk("NFSD: asynchronous NFSPROC4_CB_NULL failed!\n");
 443                 goto out_release_clp;
 444         }
 445         return;
 446
 447 out_release_clp:
 448         atomic_dec(&clp->cl_count);
 449         rpc_shutdown_client(cb->cb_client);
 450 out_err:
 451         cb->cb_client = NULL;
 452         dprintk("NFSD: warning: no callback path to client %.*s\n",
 453                 (int)clp->cl_name.len, clp->cl_name.data);
 454 }
 455
 456 static void
 457 nfs4_cb_null(struct rpc_task *task, void *dummy)
 458 {
 459         struct nfs4_client *clp = (struct nfs4_client *)task->tk_msg.rpc_argp;
 460         struct nfs4_callback *cb = &clp->cl_callback;
 461         __be32 addr = htonl(cb->cb_addr);
 462
 463         dprintk("NFSD: nfs4_cb_null task->tk_status %d\n", task->tk_status);
 464
 465         if (task->tk_status < 0) {
 466                 dprintk("NFSD: callback establishment to client %.*s failed\n",
 467                         (int)clp->cl_name.len, clp->cl_name.data);
 468                 goto out;
 469         }
 470         atomic_set(&cb->cb_set, 1);
 471         dprintk("NFSD: callback set to client %u.%u.%u.%u\n", NIPQUAD(addr));
 472 out:
 473         put_nfs4_client(clp);
 474 }
 475
 476 static const struct rpc_call_ops nfs4_cb_null_ops = {
 477         .rpc_call_done = nfs4_cb_null,
 478 };
 479
 480 /*
 481  * called with dp->dl_count inc'ed.
 482  * nfs4_lock_state() may or may not have been called.
 483  */
 484 void
 485 nfsd4_cb_recall(struct nfs4_delegation *dp)
 486 {
 487         struct nfs4_client *clp = dp->dl_client;
 488         struct rpc_clnt *clnt = clp->cl_callback.cb_client;
 489         struct nfs4_cb_recall *cbr = &dp->dl_recall;
 490         struct rpc_message msg = {
 491                 .rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
 492                 .rpc_argp = cbr,
 493         };
 494         int retries = 1;
 495         int status = 0;
 496
 497         if ((!atomic_read(&clp->cl_callback.cb_set)) || !clnt)
 498                 return;
 499
 500         msg.rpc_cred = nfsd4_lookupcred(clp, 0);
 501         if (IS_ERR(msg.rpc_cred))
 502                 goto out;
 503
 504         cbr->cbr_trunc = 0; /* XXX need to implement truncate optimization */
 505         cbr->cbr_dp = dp;
 506
 507         status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
 508         while (retries--) {
 509                 switch (status) {
 510                         case -EIO:
 511                                 /* Network partition? */
 512                         case -EBADHANDLE:
 513                         case -NFS4ERR_BAD_STATEID:
 514                                 /* Race: client probably got cb_recall
 515                                  * before open reply granting delegation */
 516                                 break;
 517                         default:
 518                                 goto out_put_cred;
 519                 }
 520                 ssleep(2);
 521                 status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
 522         }
 523 out_put_cred:
 524         put_rpccred(msg.rpc_cred);
 525 out:
 526         if (status == -EIO)
 527                 atomic_set(&clp->cl_callback.cb_set, 0);
 528         /* Success or failure, now we're either waiting for lease expiration
 529          * or deleg_return. */
 530         dprintk("NFSD: nfs4_cb_recall: dp %p dl_flock %p dl_count %d\n",dp, dp->dl_flock, atomic_read(&dp->dl_count));
 531         nfs4_put_delegation(dp);
 532         return;
 533 }