1 /* 2 * Copyright (c) 2001 The Regents of the University of Michigan. 3 * All rights reserved. 4 * 5 * Kendrick Smith <kmsmith@umich.edu> 6 * Andy Adamson <andros@umich.edu> 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED 22 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 23 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 24 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 28 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 29 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 31 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #include <linux/sunrpc/clnt.h> 35 #include <linux/sunrpc/svc_xprt.h> 36 #include <linux/slab.h> 37 #include "nfsd.h" 38 #include "state.h" 39 40 #define NFSDDBG_FACILITY NFSDDBG_PROC 41 42 static void nfsd4_mark_cb_fault(struct nfs4_client *, int reason); 43 44 #define NFSPROC4_CB_NULL 0 45 #define NFSPROC4_CB_COMPOUND 1 46 47 /* Index of predefined Linux callback client operations */ 48 49 enum { 50 NFSPROC4_CLNT_CB_NULL = 0, 51 NFSPROC4_CLNT_CB_RECALL, 52 NFSPROC4_CLNT_CB_SEQUENCE, 53 }; 54 55 #define NFS4_MAXTAGLEN 20 56 57 #define NFS4_enc_cb_null_sz 0 58 #define NFS4_dec_cb_null_sz 0 59 #define cb_compound_enc_hdr_sz 4 60 #define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2)) 61 #define sessionid_sz (NFS4_MAX_SESSIONID_LEN >> 2) 62 #define cb_sequence_enc_sz (sessionid_sz + 4 + \ 63 1 /* no referring calls list yet */) 64 #define cb_sequence_dec_sz (op_dec_sz + sessionid_sz + 4) 65 66 #define op_enc_sz 1 67 #define op_dec_sz 2 68 #define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2)) 69 #define enc_stateid_sz (NFS4_STATEID_SIZE >> 2) 70 #define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \ 71 cb_sequence_enc_sz + \ 72 1 + enc_stateid_sz + \ 73 enc_nfs4_fh_sz) 74 75 #define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \ 76 cb_sequence_dec_sz + \ 77 op_dec_sz) 78 79 struct nfs4_cb_compound_hdr { 80 /* args */ 81 u32 ident; /* minorversion 0 only */ 82 u32 nops; 83 __be32 *nops_p; 84 u32 minorversion; 85 /* res */ 86 int status; 87 }; 88 89 /* 90 * Handle decode buffer overflows out-of-line. 91 */ 92 static void print_overflow_msg(const char *func, const struct xdr_stream *xdr) 93 { 94 dprintk("NFS: %s prematurely hit the end of our receive buffer. " 95 "Remaining buffer length is %tu words.\n", 96 func, xdr->end - xdr->p); 97 } 98 99 static __be32 *xdr_encode_empty_array(__be32 *p) 100 { 101 *p++ = xdr_zero; 102 return p; 103 } 104 105 /* 106 * Encode/decode NFSv4 CB basic data types 107 * 108 * Basic NFSv4 callback data types are defined in section 15 of RFC 109 * 3530: "Network File System (NFS) version 4 Protocol" and section 110 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version 111 * 1 Protocol" 112 */ 113 114 /* 115 * nfs_cb_opnum4 116 * 117 * enum nfs_cb_opnum4 { 118 * OP_CB_GETATTR = 3, 119 * ... 120 * }; 121 */ 122 enum nfs_cb_opnum4 { 123 OP_CB_GETATTR = 3, 124 OP_CB_RECALL = 4, 125 OP_CB_LAYOUTRECALL = 5, 126 OP_CB_NOTIFY = 6, 127 OP_CB_PUSH_DELEG = 7, 128 OP_CB_RECALL_ANY = 8, 129 OP_CB_RECALLABLE_OBJ_AVAIL = 9, 130 OP_CB_RECALL_SLOT = 10, 131 OP_CB_SEQUENCE = 11, 132 OP_CB_WANTS_CANCELLED = 12, 133 OP_CB_NOTIFY_LOCK = 13, 134 OP_CB_NOTIFY_DEVICEID = 14, 135 OP_CB_ILLEGAL = 10044 136 }; 137 138 static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op) 139 { 140 __be32 *p; 141 142 p = xdr_reserve_space(xdr, 4); 143 *p = cpu_to_be32(op); 144 } 145 146 /* 147 * nfs_fh4 148 * 149 * typedef opaque nfs_fh4<NFS4_FHSIZE>; 150 */ 151 static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh) 152 { 153 u32 length = fh->fh_size; 154 __be32 *p; 155 156 BUG_ON(length > NFS4_FHSIZE); 157 p = xdr_reserve_space(xdr, 4 + length); 158 xdr_encode_opaque(p, &fh->fh_base, length); 159 } 160 161 /* 162 * stateid4 163 * 164 * struct stateid4 { 165 * uint32_t seqid; 166 * opaque other[12]; 167 * }; 168 */ 169 static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid) 170 { 171 __be32 *p; 172 173 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE); 174 *p++ = cpu_to_be32(sid->si_generation); 175 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE); 176 } 177 178 /* 179 * sessionid4 180 * 181 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE]; 182 */ 183 static void encode_sessionid4(struct xdr_stream *xdr, 184 const struct nfsd4_session *session) 185 { 186 __be32 *p; 187 188 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN); 189 xdr_encode_opaque_fixed(p, session->se_sessionid.data, 190 NFS4_MAX_SESSIONID_LEN); 191 } 192 193 /* 194 * nfsstat4 195 */ 196 static const struct { 197 int stat; 198 int errno; 199 } nfs_cb_errtbl[] = { 200 { NFS4_OK, 0 }, 201 { NFS4ERR_PERM, -EPERM }, 202 { NFS4ERR_NOENT, -ENOENT }, 203 { NFS4ERR_IO, -EIO }, 204 { NFS4ERR_NXIO, -ENXIO }, 205 { NFS4ERR_ACCESS, -EACCES }, 206 { NFS4ERR_EXIST, -EEXIST }, 207 { NFS4ERR_XDEV, -EXDEV }, 208 { NFS4ERR_NOTDIR, -ENOTDIR }, 209 { NFS4ERR_ISDIR, -EISDIR }, 210 { NFS4ERR_INVAL, -EINVAL }, 211 { NFS4ERR_FBIG, -EFBIG }, 212 { NFS4ERR_NOSPC, -ENOSPC }, 213 { NFS4ERR_ROFS, -EROFS }, 214 { NFS4ERR_MLINK, -EMLINK }, 215 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG }, 216 { NFS4ERR_NOTEMPTY, -ENOTEMPTY }, 217 { NFS4ERR_DQUOT, -EDQUOT }, 218 { NFS4ERR_STALE, -ESTALE }, 219 { NFS4ERR_BADHANDLE, -EBADHANDLE }, 220 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE }, 221 { NFS4ERR_NOTSUPP, -ENOTSUPP }, 222 { NFS4ERR_TOOSMALL, -ETOOSMALL }, 223 { NFS4ERR_SERVERFAULT, -ESERVERFAULT }, 224 { NFS4ERR_BADTYPE, -EBADTYPE }, 225 { NFS4ERR_LOCKED, -EAGAIN }, 226 { NFS4ERR_RESOURCE, -EREMOTEIO }, 227 { NFS4ERR_SYMLINK, -ELOOP }, 228 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP }, 229 { NFS4ERR_DEADLOCK, -EDEADLK }, 230 { -1, -EIO } 231 }; 232 233 /* 234 * If we cannot translate the error, the recovery routines should 235 * handle it. 236 * 237 * Note: remaining NFSv4 error codes have values > 10000, so should 238 * not conflict with native Linux error codes. 239 */ 240 static int nfs_cb_stat_to_errno(int status) 241 { 242 int i; 243 244 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) { 245 if (nfs_cb_errtbl[i].stat == status) 246 return nfs_cb_errtbl[i].errno; 247 } 248 249 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status); 250 return -status; 251 } 252 253 static int decode_cb_op_status(struct xdr_stream *xdr, enum nfs_opnum4 expected, 254 enum nfsstat4 *status) 255 { 256 __be32 *p; 257 u32 op; 258 259 p = xdr_inline_decode(xdr, 4 + 4); 260 if (unlikely(p == NULL)) 261 goto out_overflow; 262 op = be32_to_cpup(p++); 263 if (unlikely(op != expected)) 264 goto out_unexpected; 265 *status = be32_to_cpup(p); 266 return 0; 267 out_overflow: 268 print_overflow_msg(__func__, xdr); 269 return -EIO; 270 out_unexpected: 271 dprintk("NFSD: Callback server returned operation %d but " 272 "we issued a request for %d\n", op, expected); 273 return -EIO; 274 } 275 276 /* 277 * CB_COMPOUND4args 278 * 279 * struct CB_COMPOUND4args { 280 * utf8str_cs tag; 281 * uint32_t minorversion; 282 * uint32_t callback_ident; 283 * nfs_cb_argop4 argarray<>; 284 * }; 285 */ 286 static void encode_cb_compound4args(struct xdr_stream *xdr, 287 struct nfs4_cb_compound_hdr *hdr) 288 { 289 __be32 * p; 290 291 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4); 292 p = xdr_encode_empty_array(p); /* empty tag */ 293 *p++ = cpu_to_be32(hdr->minorversion); 294 *p++ = cpu_to_be32(hdr->ident); 295 296 hdr->nops_p = p; 297 *p = cpu_to_be32(hdr->nops); /* argarray element count */ 298 } 299 300 /* 301 * Update argarray element count 302 */ 303 static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr) 304 { 305 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS); 306 *hdr->nops_p = cpu_to_be32(hdr->nops); 307 } 308 309 /* 310 * CB_COMPOUND4res 311 * 312 * struct CB_COMPOUND4res { 313 * nfsstat4 status; 314 * utf8str_cs tag; 315 * nfs_cb_resop4 resarray<>; 316 * }; 317 */ 318 static int decode_cb_compound4res(struct xdr_stream *xdr, 319 struct nfs4_cb_compound_hdr *hdr) 320 { 321 u32 length; 322 __be32 *p; 323 324 p = xdr_inline_decode(xdr, 4 + 4); 325 if (unlikely(p == NULL)) 326 goto out_overflow; 327 hdr->status = be32_to_cpup(p++); 328 /* Ignore the tag */ 329 length = be32_to_cpup(p++); 330 p = xdr_inline_decode(xdr, length + 4); 331 if (unlikely(p == NULL)) 332 goto out_overflow; 333 hdr->nops = be32_to_cpup(p); 334 return 0; 335 out_overflow: 336 print_overflow_msg(__func__, xdr); 337 return -EIO; 338 } 339 340 /* 341 * CB_RECALL4args 342 * 343 * struct CB_RECALL4args { 344 * stateid4 stateid; 345 * bool truncate; 346 * nfs_fh4 fh; 347 * }; 348 */ 349 static void encode_cb_recall4args(struct xdr_stream *xdr, 350 const struct nfs4_delegation *dp, 351 struct nfs4_cb_compound_hdr *hdr) 352 { 353 __be32 *p; 354 355 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL); 356 encode_stateid4(xdr, &dp->dl_stid.sc_stateid); 357 358 p = xdr_reserve_space(xdr, 4); 359 *p++ = xdr_zero; /* truncate */ 360 361 encode_nfs_fh4(xdr, &dp->dl_fh); 362 363 hdr->nops++; 364 } 365 366 /* 367 * CB_SEQUENCE4args 368 * 369 * struct CB_SEQUENCE4args { 370 * sessionid4 csa_sessionid; 371 * sequenceid4 csa_sequenceid; 372 * slotid4 csa_slotid; 373 * slotid4 csa_highest_slotid; 374 * bool csa_cachethis; 375 * referring_call_list4 csa_referring_call_lists<>; 376 * }; 377 */ 378 static void encode_cb_sequence4args(struct xdr_stream *xdr, 379 const struct nfsd4_callback *cb, 380 struct nfs4_cb_compound_hdr *hdr) 381 { 382 struct nfsd4_session *session = cb->cb_clp->cl_cb_session; 383 __be32 *p; 384 385 if (hdr->minorversion == 0) 386 return; 387 388 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE); 389 encode_sessionid4(xdr, session); 390 391 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4); 392 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */ 393 *p++ = xdr_zero; /* csa_slotid */ 394 *p++ = xdr_zero; /* csa_highest_slotid */ 395 *p++ = xdr_zero; /* csa_cachethis */ 396 xdr_encode_empty_array(p); /* csa_referring_call_lists */ 397 398 hdr->nops++; 399 } 400 401 /* 402 * CB_SEQUENCE4resok 403 * 404 * struct CB_SEQUENCE4resok { 405 * sessionid4 csr_sessionid; 406 * sequenceid4 csr_sequenceid; 407 * slotid4 csr_slotid; 408 * slotid4 csr_highest_slotid; 409 * slotid4 csr_target_highest_slotid; 410 * }; 411 * 412 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) { 413 * case NFS4_OK: 414 * CB_SEQUENCE4resok csr_resok4; 415 * default: 416 * void; 417 * }; 418 * 419 * Our current back channel implmentation supports a single backchannel 420 * with a single slot. 421 */ 422 static int decode_cb_sequence4resok(struct xdr_stream *xdr, 423 struct nfsd4_callback *cb) 424 { 425 struct nfsd4_session *session = cb->cb_clp->cl_cb_session; 426 struct nfs4_sessionid id; 427 int status; 428 __be32 *p; 429 u32 dummy; 430 431 status = -ESERVERFAULT; 432 433 /* 434 * If the server returns different values for sessionID, slotID or 435 * sequence number, the server is looney tunes. 436 */ 437 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4); 438 if (unlikely(p == NULL)) 439 goto out_overflow; 440 memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN); 441 if (memcmp(id.data, session->se_sessionid.data, 442 NFS4_MAX_SESSIONID_LEN) != 0) { 443 dprintk("NFS: %s Invalid session id\n", __func__); 444 goto out; 445 } 446 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN); 447 448 dummy = be32_to_cpup(p++); 449 if (dummy != session->se_cb_seq_nr) { 450 dprintk("NFS: %s Invalid sequence number\n", __func__); 451 goto out; 452 } 453 454 dummy = be32_to_cpup(p++); 455 if (dummy != 0) { 456 dprintk("NFS: %s Invalid slotid\n", __func__); 457 goto out; 458 } 459 460 /* 461 * FIXME: process highest slotid and target highest slotid 462 */ 463 status = 0; 464 out: 465 if (status) 466 nfsd4_mark_cb_fault(cb->cb_clp, status); 467 return status; 468 out_overflow: 469 print_overflow_msg(__func__, xdr); 470 return -EIO; 471 } 472 473 static int decode_cb_sequence4res(struct xdr_stream *xdr, 474 struct nfsd4_callback *cb) 475 { 476 enum nfsstat4 nfserr; 477 int status; 478 479 if (cb->cb_minorversion == 0) 480 return 0; 481 482 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &nfserr); 483 if (unlikely(status)) 484 goto out; 485 if (unlikely(nfserr != NFS4_OK)) 486 goto out_default; 487 status = decode_cb_sequence4resok(xdr, cb); 488 out: 489 return status; 490 out_default: 491 return nfs_cb_stat_to_errno(nfserr); 492 } 493 494 /* 495 * NFSv4.0 and NFSv4.1 XDR encode functions 496 * 497 * NFSv4.0 callback argument types are defined in section 15 of RFC 498 * 3530: "Network File System (NFS) version 4 Protocol" and section 20 499 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1 500 * Protocol". 501 */ 502 503 /* 504 * NB: Without this zero space reservation, callbacks over krb5p fail 505 */ 506 static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr, 507 void *__unused) 508 { 509 xdr_reserve_space(xdr, 0); 510 } 511 512 /* 513 * 20.2. Operation 4: CB_RECALL - Recall a Delegation 514 */ 515 static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr, 516 const struct nfsd4_callback *cb) 517 { 518 const struct nfs4_delegation *args = cb->cb_op; 519 struct nfs4_cb_compound_hdr hdr = { 520 .ident = cb->cb_clp->cl_cb_ident, 521 .minorversion = cb->cb_minorversion, 522 }; 523 524 encode_cb_compound4args(xdr, &hdr); 525 encode_cb_sequence4args(xdr, cb, &hdr); 526 encode_cb_recall4args(xdr, args, &hdr); 527 encode_cb_nops(&hdr); 528 } 529 530 531 /* 532 * NFSv4.0 and NFSv4.1 XDR decode functions 533 * 534 * NFSv4.0 callback result types are defined in section 15 of RFC 535 * 3530: "Network File System (NFS) version 4 Protocol" and section 20 536 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1 537 * Protocol". 538 */ 539 540 static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr, 541 void *__unused) 542 { 543 return 0; 544 } 545 546 /* 547 * 20.2. Operation 4: CB_RECALL - Recall a Delegation 548 */ 549 static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, 550 struct xdr_stream *xdr, 551 struct nfsd4_callback *cb) 552 { 553 struct nfs4_cb_compound_hdr hdr; 554 enum nfsstat4 nfserr; 555 int status; 556 557 status = decode_cb_compound4res(xdr, &hdr); 558 if (unlikely(status)) 559 goto out; 560 561 if (cb != NULL) { 562 status = decode_cb_sequence4res(xdr, cb); 563 if (unlikely(status)) 564 goto out; 565 } 566 567 status = decode_cb_op_status(xdr, OP_CB_RECALL, &nfserr); 568 if (unlikely(status)) 569 goto out; 570 if (unlikely(nfserr != NFS4_OK)) 571 status = nfs_cb_stat_to_errno(nfserr); 572 out: 573 return status; 574 } 575 576 /* 577 * RPC procedure tables 578 */ 579 #define PROC(proc, call, argtype, restype) \ 580 [NFSPROC4_CLNT_##proc] = { \ 581 .p_proc = NFSPROC4_CB_##call, \ 582 .p_encode = (kxdreproc_t)nfs4_xdr_enc_##argtype, \ 583 .p_decode = (kxdrdproc_t)nfs4_xdr_dec_##restype, \ 584 .p_arglen = NFS4_enc_##argtype##_sz, \ 585 .p_replen = NFS4_dec_##restype##_sz, \ 586 .p_statidx = NFSPROC4_CB_##call, \ 587 .p_name = #proc, \ 588 } 589 590 static struct rpc_procinfo nfs4_cb_procedures[] = { 591 PROC(CB_NULL, NULL, cb_null, cb_null), 592 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall), 593 }; 594 595 static struct rpc_version nfs_cb_version4 = { 596 /* 597 * Note on the callback rpc program version number: despite language in rfc 598 * 5661 section 18.36.3 requiring servers to use 4 in this field, the 599 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and 600 * in practice that appears to be what implementations use. The section 601 * 18.36.3 language is expected to be fixed in an erratum. 602 */ 603 .number = 1, 604 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures), 605 .procs = nfs4_cb_procedures 606 }; 607 608 static struct rpc_version *nfs_cb_version[] = { 609 &nfs_cb_version4, 610 }; 611 612 static struct rpc_program cb_program; 613 614 static struct rpc_stat cb_stats = { 615 .program = &cb_program 616 }; 617 618 #define NFS4_CALLBACK 0x40000000 619 static struct rpc_program cb_program = { 620 .name = "nfs4_cb", 621 .number = NFS4_CALLBACK, 622 .nrvers = ARRAY_SIZE(nfs_cb_version), 623 .version = nfs_cb_version, 624 .stats = &cb_stats, 625 .pipe_dir_name = "/nfsd4_cb", 626 }; 627 628 static int max_cb_time(void) 629 { 630 return max(nfsd4_lease/10, (time_t)1) * HZ; 631 } 632 633 634 static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses) 635 { 636 struct rpc_timeout timeparms = { 637 .to_initval = max_cb_time(), 638 .to_retries = 0, 639 }; 640 struct rpc_create_args args = { 641 .net = &init_net, 642 .address = (struct sockaddr *) &conn->cb_addr, 643 .addrsize = conn->cb_addrlen, 644 .saddress = (struct sockaddr *) &conn->cb_saddr, 645 .timeout = &timeparms, 646 .program = &cb_program, 647 .version = 0, 648 .authflavor = clp->cl_flavor, 649 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET), 650 }; 651 struct rpc_clnt *client; 652 653 if (clp->cl_minorversion == 0) { 654 if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5)) 655 return -EINVAL; 656 args.client_name = clp->cl_principal; 657 args.prognumber = conn->cb_prog, 658 args.protocol = XPRT_TRANSPORT_TCP; 659 clp->cl_cb_ident = conn->cb_ident; 660 } else { 661 if (!conn->cb_xprt) 662 return -EINVAL; 663 clp->cl_cb_conn.cb_xprt = conn->cb_xprt; 664 clp->cl_cb_session = ses; 665 args.bc_xprt = conn->cb_xprt; 666 args.prognumber = clp->cl_cb_session->se_cb_prog; 667 args.protocol = XPRT_TRANSPORT_BC_TCP; 668 } 669 /* Create RPC client */ 670 client = rpc_create(&args); 671 if (IS_ERR(client)) { 672 dprintk("NFSD: couldn't create callback client: %ld\n", 673 PTR_ERR(client)); 674 return PTR_ERR(client); 675 } 676 clp->cl_cb_client = client; 677 return 0; 678 679 } 680 681 static void warn_no_callback_path(struct nfs4_client *clp, int reason) 682 { 683 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n", 684 (int)clp->cl_name.len, clp->cl_name.data, reason); 685 } 686 687 static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason) 688 { 689 clp->cl_cb_state = NFSD4_CB_DOWN; 690 warn_no_callback_path(clp, reason); 691 } 692 693 static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason) 694 { 695 clp->cl_cb_state = NFSD4_CB_FAULT; 696 warn_no_callback_path(clp, reason); 697 } 698 699 static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata) 700 { 701 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null); 702 703 if (task->tk_status) 704 nfsd4_mark_cb_down(clp, task->tk_status); 705 else 706 clp->cl_cb_state = NFSD4_CB_UP; 707 } 708 709 static const struct rpc_call_ops nfsd4_cb_probe_ops = { 710 /* XXX: release method to ensure we set the cb channel down if 711 * necessary on early failure? */ 712 .rpc_call_done = nfsd4_cb_probe_done, 713 }; 714 715 static struct rpc_cred *callback_cred; 716 717 int set_callback_cred(void) 718 { 719 if (callback_cred) 720 return 0; 721 callback_cred = rpc_lookup_machine_cred("nfs"); 722 if (!callback_cred) 723 return -ENOMEM; 724 return 0; 725 } 726 727 static struct workqueue_struct *callback_wq; 728 729 static void run_nfsd4_cb(struct nfsd4_callback *cb) 730 { 731 queue_work(callback_wq, &cb->cb_work); 732 } 733 734 static void do_probe_callback(struct nfs4_client *clp) 735 { 736 struct nfsd4_callback *cb = &clp->cl_cb_null; 737 738 cb->cb_op = NULL; 739 cb->cb_clp = clp; 740 741 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL]; 742 cb->cb_msg.rpc_argp = NULL; 743 cb->cb_msg.rpc_resp = NULL; 744 cb->cb_msg.rpc_cred = callback_cred; 745 746 cb->cb_ops = &nfsd4_cb_probe_ops; 747 748 run_nfsd4_cb(cb); 749 } 750 751 /* 752 * Poke the callback thread to process any updates to the callback 753 * parameters, and send a null probe. 754 */ 755 void nfsd4_probe_callback(struct nfs4_client *clp) 756 { 757 /* XXX: atomicity? Also, should we be using cl_cb_flags? */ 758 clp->cl_cb_state = NFSD4_CB_UNKNOWN; 759 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_cb_flags); 760 do_probe_callback(clp); 761 } 762 763 void nfsd4_probe_callback_sync(struct nfs4_client *clp) 764 { 765 nfsd4_probe_callback(clp); 766 flush_workqueue(callback_wq); 767 } 768 769 void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn) 770 { 771 clp->cl_cb_state = NFSD4_CB_UNKNOWN; 772 spin_lock(&clp->cl_lock); 773 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn)); 774 spin_unlock(&clp->cl_lock); 775 } 776 777 /* 778 * There's currently a single callback channel slot. 779 * If the slot is available, then mark it busy. Otherwise, set the 780 * thread for sleeping on the callback RPC wait queue. 781 */ 782 static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task) 783 { 784 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) { 785 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL); 786 dprintk("%s slot is busy\n", __func__); 787 return false; 788 } 789 return true; 790 } 791 792 /* 793 * TODO: cb_sequence should support referring call lists, cachethis, multiple 794 * slots, and mark callback channel down on communication errors. 795 */ 796 static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata) 797 { 798 struct nfsd4_callback *cb = calldata; 799 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall); 800 struct nfs4_client *clp = dp->dl_stid.sc_client; 801 u32 minorversion = clp->cl_minorversion; 802 803 cb->cb_minorversion = minorversion; 804 if (minorversion) { 805 if (!nfsd41_cb_get_slot(clp, task)) 806 return; 807 } 808 spin_lock(&clp->cl_lock); 809 if (list_empty(&cb->cb_per_client)) { 810 /* This is the first call, not a restart */ 811 cb->cb_done = false; 812 list_add(&cb->cb_per_client, &clp->cl_callbacks); 813 } 814 spin_unlock(&clp->cl_lock); 815 rpc_call_start(task); 816 } 817 818 static void nfsd4_cb_done(struct rpc_task *task, void *calldata) 819 { 820 struct nfsd4_callback *cb = calldata; 821 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall); 822 struct nfs4_client *clp = dp->dl_stid.sc_client; 823 824 dprintk("%s: minorversion=%d\n", __func__, 825 clp->cl_minorversion); 826 827 if (clp->cl_minorversion) { 828 /* No need for lock, access serialized in nfsd4_cb_prepare */ 829 ++clp->cl_cb_session->se_cb_seq_nr; 830 clear_bit(0, &clp->cl_cb_slot_busy); 831 rpc_wake_up_next(&clp->cl_cb_waitq); 832 dprintk("%s: freed slot, new seqid=%d\n", __func__, 833 clp->cl_cb_session->se_cb_seq_nr); 834 835 /* We're done looking into the sequence information */ 836 task->tk_msg.rpc_resp = NULL; 837 } 838 } 839 840 841 static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata) 842 { 843 struct nfsd4_callback *cb = calldata; 844 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall); 845 struct nfs4_client *clp = dp->dl_stid.sc_client; 846 struct rpc_clnt *current_rpc_client = clp->cl_cb_client; 847 848 nfsd4_cb_done(task, calldata); 849 850 if (current_rpc_client != task->tk_client) { 851 /* We're shutting down or changing cl_cb_client; leave 852 * it to nfsd4_process_cb_update to restart the call if 853 * necessary. */ 854 return; 855 } 856 857 if (cb->cb_done) 858 return; 859 switch (task->tk_status) { 860 case 0: 861 cb->cb_done = true; 862 return; 863 case -EBADHANDLE: 864 case -NFS4ERR_BAD_STATEID: 865 /* Race: client probably got cb_recall 866 * before open reply granting delegation */ 867 break; 868 default: 869 /* Network partition? */ 870 nfsd4_mark_cb_down(clp, task->tk_status); 871 } 872 if (dp->dl_retries--) { 873 rpc_delay(task, 2*HZ); 874 task->tk_status = 0; 875 rpc_restart_call_prepare(task); 876 return; 877 } 878 nfsd4_mark_cb_down(clp, task->tk_status); 879 cb->cb_done = true; 880 } 881 882 static void nfsd4_cb_recall_release(void *calldata) 883 { 884 struct nfsd4_callback *cb = calldata; 885 struct nfs4_client *clp = cb->cb_clp; 886 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall); 887 888 if (cb->cb_done) { 889 spin_lock(&clp->cl_lock); 890 list_del(&cb->cb_per_client); 891 spin_unlock(&clp->cl_lock); 892 nfs4_put_delegation(dp); 893 } 894 } 895 896 static const struct rpc_call_ops nfsd4_cb_recall_ops = { 897 .rpc_call_prepare = nfsd4_cb_prepare, 898 .rpc_call_done = nfsd4_cb_recall_done, 899 .rpc_release = nfsd4_cb_recall_release, 900 }; 901 902 int nfsd4_create_callback_queue(void) 903 { 904 callback_wq = create_singlethread_workqueue("nfsd4_callbacks"); 905 if (!callback_wq) 906 return -ENOMEM; 907 return 0; 908 } 909 910 void nfsd4_destroy_callback_queue(void) 911 { 912 destroy_workqueue(callback_wq); 913 } 914 915 /* must be called under the state lock */ 916 void nfsd4_shutdown_callback(struct nfs4_client *clp) 917 { 918 set_bit(NFSD4_CLIENT_KILL, &clp->cl_cb_flags); 919 /* 920 * Note this won't actually result in a null callback; 921 * instead, nfsd4_do_callback_rpc() will detect the killed 922 * client, destroy the rpc client, and stop: 923 */ 924 do_probe_callback(clp); 925 flush_workqueue(callback_wq); 926 } 927 928 static void nfsd4_release_cb(struct nfsd4_callback *cb) 929 { 930 if (cb->cb_ops->rpc_release) 931 cb->cb_ops->rpc_release(cb); 932 } 933 934 /* requires cl_lock: */ 935 static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp) 936 { 937 struct nfsd4_session *s; 938 struct nfsd4_conn *c; 939 940 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) { 941 list_for_each_entry(c, &s->se_conns, cn_persession) { 942 if (c->cn_flags & NFS4_CDFC4_BACK) 943 return c; 944 } 945 } 946 return NULL; 947 } 948 949 static void nfsd4_process_cb_update(struct nfsd4_callback *cb) 950 { 951 struct nfs4_cb_conn conn; 952 struct nfs4_client *clp = cb->cb_clp; 953 struct nfsd4_session *ses = NULL; 954 struct nfsd4_conn *c; 955 int err; 956 957 /* 958 * This is either an update, or the client dying; in either case, 959 * kill the old client: 960 */ 961 if (clp->cl_cb_client) { 962 rpc_shutdown_client(clp->cl_cb_client); 963 clp->cl_cb_client = NULL; 964 } 965 if (clp->cl_cb_conn.cb_xprt) { 966 svc_xprt_put(clp->cl_cb_conn.cb_xprt); 967 clp->cl_cb_conn.cb_xprt = NULL; 968 } 969 if (test_bit(NFSD4_CLIENT_KILL, &clp->cl_cb_flags)) 970 return; 971 spin_lock(&clp->cl_lock); 972 /* 973 * Only serialized callback code is allowed to clear these 974 * flags; main nfsd code can only set them: 975 */ 976 BUG_ON(!clp->cl_cb_flags); 977 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_cb_flags); 978 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn)); 979 c = __nfsd4_find_backchannel(clp); 980 if (c) { 981 svc_xprt_get(c->cn_xprt); 982 conn.cb_xprt = c->cn_xprt; 983 ses = c->cn_session; 984 } 985 spin_unlock(&clp->cl_lock); 986 987 err = setup_callback_client(clp, &conn, ses); 988 if (err) { 989 warn_no_callback_path(clp, err); 990 return; 991 } 992 /* Yay, the callback channel's back! Restart any callbacks: */ 993 list_for_each_entry(cb, &clp->cl_callbacks, cb_per_client) 994 run_nfsd4_cb(cb); 995 } 996 997 void nfsd4_do_callback_rpc(struct work_struct *w) 998 { 999 struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, cb_work); 1000 struct nfs4_client *clp = cb->cb_clp; 1001 struct rpc_clnt *clnt; 1002 1003 if (clp->cl_cb_flags) 1004 nfsd4_process_cb_update(cb); 1005 1006 clnt = clp->cl_cb_client; 1007 if (!clnt) { 1008 /* Callback channel broken, or client killed; give up: */ 1009 nfsd4_release_cb(cb); 1010 return; 1011 } 1012 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN, 1013 cb->cb_ops, cb); 1014 } 1015 1016 void nfsd4_cb_recall(struct nfs4_delegation *dp) 1017 { 1018 struct nfsd4_callback *cb = &dp->dl_recall; 1019 struct nfs4_client *clp = dp->dl_stid.sc_client; 1020 1021 dp->dl_retries = 1; 1022 cb->cb_op = dp; 1023 cb->cb_clp = clp; 1024 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL]; 1025 cb->cb_msg.rpc_argp = cb; 1026 cb->cb_msg.rpc_resp = cb; 1027 cb->cb_msg.rpc_cred = callback_cred; 1028 1029 cb->cb_ops = &nfsd4_cb_recall_ops; 1030 dp->dl_retries = 1; 1031 1032 INIT_LIST_HEAD(&cb->cb_per_client); 1033 cb->cb_done = true; 1034 1035 run_nfsd4_cb(&dp->dl_recall); 1036 } 1037