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 #include "netns.h" 40 #include "xdr4cb.h" 41 42 #define NFSDDBG_FACILITY NFSDDBG_PROC 43 44 static void nfsd4_mark_cb_fault(struct nfs4_client *, int reason); 45 46 #define NFSPROC4_CB_NULL 0 47 #define NFSPROC4_CB_COMPOUND 1 48 49 /* Index of predefined Linux callback client operations */ 50 51 enum { 52 NFSPROC4_CLNT_CB_NULL = 0, 53 NFSPROC4_CLNT_CB_RECALL, 54 NFSPROC4_CLNT_CB_SEQUENCE, 55 }; 56 57 struct nfs4_cb_compound_hdr { 58 /* args */ 59 u32 ident; /* minorversion 0 only */ 60 u32 nops; 61 __be32 *nops_p; 62 u32 minorversion; 63 /* res */ 64 int status; 65 }; 66 67 /* 68 * Handle decode buffer overflows out-of-line. 69 */ 70 static void print_overflow_msg(const char *func, const struct xdr_stream *xdr) 71 { 72 dprintk("NFS: %s prematurely hit the end of our receive buffer. " 73 "Remaining buffer length is %tu words.\n", 74 func, xdr->end - xdr->p); 75 } 76 77 static __be32 *xdr_encode_empty_array(__be32 *p) 78 { 79 *p++ = xdr_zero; 80 return p; 81 } 82 83 /* 84 * Encode/decode NFSv4 CB basic data types 85 * 86 * Basic NFSv4 callback data types are defined in section 15 of RFC 87 * 3530: "Network File System (NFS) version 4 Protocol" and section 88 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version 89 * 1 Protocol" 90 */ 91 92 /* 93 * nfs_cb_opnum4 94 * 95 * enum nfs_cb_opnum4 { 96 * OP_CB_GETATTR = 3, 97 * ... 98 * }; 99 */ 100 enum nfs_cb_opnum4 { 101 OP_CB_GETATTR = 3, 102 OP_CB_RECALL = 4, 103 OP_CB_LAYOUTRECALL = 5, 104 OP_CB_NOTIFY = 6, 105 OP_CB_PUSH_DELEG = 7, 106 OP_CB_RECALL_ANY = 8, 107 OP_CB_RECALLABLE_OBJ_AVAIL = 9, 108 OP_CB_RECALL_SLOT = 10, 109 OP_CB_SEQUENCE = 11, 110 OP_CB_WANTS_CANCELLED = 12, 111 OP_CB_NOTIFY_LOCK = 13, 112 OP_CB_NOTIFY_DEVICEID = 14, 113 OP_CB_ILLEGAL = 10044 114 }; 115 116 static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op) 117 { 118 __be32 *p; 119 120 p = xdr_reserve_space(xdr, 4); 121 *p = cpu_to_be32(op); 122 } 123 124 /* 125 * nfs_fh4 126 * 127 * typedef opaque nfs_fh4<NFS4_FHSIZE>; 128 */ 129 static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh) 130 { 131 u32 length = fh->fh_size; 132 __be32 *p; 133 134 BUG_ON(length > NFS4_FHSIZE); 135 p = xdr_reserve_space(xdr, 4 + length); 136 xdr_encode_opaque(p, &fh->fh_base, length); 137 } 138 139 /* 140 * stateid4 141 * 142 * struct stateid4 { 143 * uint32_t seqid; 144 * opaque other[12]; 145 * }; 146 */ 147 static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid) 148 { 149 __be32 *p; 150 151 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE); 152 *p++ = cpu_to_be32(sid->si_generation); 153 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE); 154 } 155 156 /* 157 * sessionid4 158 * 159 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE]; 160 */ 161 static void encode_sessionid4(struct xdr_stream *xdr, 162 const struct nfsd4_session *session) 163 { 164 __be32 *p; 165 166 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN); 167 xdr_encode_opaque_fixed(p, session->se_sessionid.data, 168 NFS4_MAX_SESSIONID_LEN); 169 } 170 171 /* 172 * nfsstat4 173 */ 174 static const struct { 175 int stat; 176 int errno; 177 } nfs_cb_errtbl[] = { 178 { NFS4_OK, 0 }, 179 { NFS4ERR_PERM, -EPERM }, 180 { NFS4ERR_NOENT, -ENOENT }, 181 { NFS4ERR_IO, -EIO }, 182 { NFS4ERR_NXIO, -ENXIO }, 183 { NFS4ERR_ACCESS, -EACCES }, 184 { NFS4ERR_EXIST, -EEXIST }, 185 { NFS4ERR_XDEV, -EXDEV }, 186 { NFS4ERR_NOTDIR, -ENOTDIR }, 187 { NFS4ERR_ISDIR, -EISDIR }, 188 { NFS4ERR_INVAL, -EINVAL }, 189 { NFS4ERR_FBIG, -EFBIG }, 190 { NFS4ERR_NOSPC, -ENOSPC }, 191 { NFS4ERR_ROFS, -EROFS }, 192 { NFS4ERR_MLINK, -EMLINK }, 193 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG }, 194 { NFS4ERR_NOTEMPTY, -ENOTEMPTY }, 195 { NFS4ERR_DQUOT, -EDQUOT }, 196 { NFS4ERR_STALE, -ESTALE }, 197 { NFS4ERR_BADHANDLE, -EBADHANDLE }, 198 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE }, 199 { NFS4ERR_NOTSUPP, -ENOTSUPP }, 200 { NFS4ERR_TOOSMALL, -ETOOSMALL }, 201 { NFS4ERR_SERVERFAULT, -ESERVERFAULT }, 202 { NFS4ERR_BADTYPE, -EBADTYPE }, 203 { NFS4ERR_LOCKED, -EAGAIN }, 204 { NFS4ERR_RESOURCE, -EREMOTEIO }, 205 { NFS4ERR_SYMLINK, -ELOOP }, 206 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP }, 207 { NFS4ERR_DEADLOCK, -EDEADLK }, 208 { -1, -EIO } 209 }; 210 211 /* 212 * If we cannot translate the error, the recovery routines should 213 * handle it. 214 * 215 * Note: remaining NFSv4 error codes have values > 10000, so should 216 * not conflict with native Linux error codes. 217 */ 218 static int nfs_cb_stat_to_errno(int status) 219 { 220 int i; 221 222 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) { 223 if (nfs_cb_errtbl[i].stat == status) 224 return nfs_cb_errtbl[i].errno; 225 } 226 227 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status); 228 return -status; 229 } 230 231 static int decode_cb_op_status(struct xdr_stream *xdr, enum nfs_opnum4 expected, 232 enum nfsstat4 *status) 233 { 234 __be32 *p; 235 u32 op; 236 237 p = xdr_inline_decode(xdr, 4 + 4); 238 if (unlikely(p == NULL)) 239 goto out_overflow; 240 op = be32_to_cpup(p++); 241 if (unlikely(op != expected)) 242 goto out_unexpected; 243 *status = be32_to_cpup(p); 244 return 0; 245 out_overflow: 246 print_overflow_msg(__func__, xdr); 247 return -EIO; 248 out_unexpected: 249 dprintk("NFSD: Callback server returned operation %d but " 250 "we issued a request for %d\n", op, expected); 251 return -EIO; 252 } 253 254 /* 255 * CB_COMPOUND4args 256 * 257 * struct CB_COMPOUND4args { 258 * utf8str_cs tag; 259 * uint32_t minorversion; 260 * uint32_t callback_ident; 261 * nfs_cb_argop4 argarray<>; 262 * }; 263 */ 264 static void encode_cb_compound4args(struct xdr_stream *xdr, 265 struct nfs4_cb_compound_hdr *hdr) 266 { 267 __be32 * p; 268 269 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4); 270 p = xdr_encode_empty_array(p); /* empty tag */ 271 *p++ = cpu_to_be32(hdr->minorversion); 272 *p++ = cpu_to_be32(hdr->ident); 273 274 hdr->nops_p = p; 275 *p = cpu_to_be32(hdr->nops); /* argarray element count */ 276 } 277 278 /* 279 * Update argarray element count 280 */ 281 static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr) 282 { 283 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS); 284 *hdr->nops_p = cpu_to_be32(hdr->nops); 285 } 286 287 /* 288 * CB_COMPOUND4res 289 * 290 * struct CB_COMPOUND4res { 291 * nfsstat4 status; 292 * utf8str_cs tag; 293 * nfs_cb_resop4 resarray<>; 294 * }; 295 */ 296 static int decode_cb_compound4res(struct xdr_stream *xdr, 297 struct nfs4_cb_compound_hdr *hdr) 298 { 299 u32 length; 300 __be32 *p; 301 302 p = xdr_inline_decode(xdr, 4 + 4); 303 if (unlikely(p == NULL)) 304 goto out_overflow; 305 hdr->status = be32_to_cpup(p++); 306 /* Ignore the tag */ 307 length = be32_to_cpup(p++); 308 p = xdr_inline_decode(xdr, length + 4); 309 if (unlikely(p == NULL)) 310 goto out_overflow; 311 hdr->nops = be32_to_cpup(p); 312 return 0; 313 out_overflow: 314 print_overflow_msg(__func__, xdr); 315 return -EIO; 316 } 317 318 /* 319 * CB_RECALL4args 320 * 321 * struct CB_RECALL4args { 322 * stateid4 stateid; 323 * bool truncate; 324 * nfs_fh4 fh; 325 * }; 326 */ 327 static void encode_cb_recall4args(struct xdr_stream *xdr, 328 const struct nfs4_delegation *dp, 329 struct nfs4_cb_compound_hdr *hdr) 330 { 331 __be32 *p; 332 333 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL); 334 encode_stateid4(xdr, &dp->dl_stid.sc_stateid); 335 336 p = xdr_reserve_space(xdr, 4); 337 *p++ = xdr_zero; /* truncate */ 338 339 encode_nfs_fh4(xdr, &dp->dl_fh); 340 341 hdr->nops++; 342 } 343 344 /* 345 * CB_SEQUENCE4args 346 * 347 * struct CB_SEQUENCE4args { 348 * sessionid4 csa_sessionid; 349 * sequenceid4 csa_sequenceid; 350 * slotid4 csa_slotid; 351 * slotid4 csa_highest_slotid; 352 * bool csa_cachethis; 353 * referring_call_list4 csa_referring_call_lists<>; 354 * }; 355 */ 356 static void encode_cb_sequence4args(struct xdr_stream *xdr, 357 const struct nfsd4_callback *cb, 358 struct nfs4_cb_compound_hdr *hdr) 359 { 360 struct nfsd4_session *session = cb->cb_clp->cl_cb_session; 361 __be32 *p; 362 363 if (hdr->minorversion == 0) 364 return; 365 366 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE); 367 encode_sessionid4(xdr, session); 368 369 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4); 370 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */ 371 *p++ = xdr_zero; /* csa_slotid */ 372 *p++ = xdr_zero; /* csa_highest_slotid */ 373 *p++ = xdr_zero; /* csa_cachethis */ 374 xdr_encode_empty_array(p); /* csa_referring_call_lists */ 375 376 hdr->nops++; 377 } 378 379 /* 380 * CB_SEQUENCE4resok 381 * 382 * struct CB_SEQUENCE4resok { 383 * sessionid4 csr_sessionid; 384 * sequenceid4 csr_sequenceid; 385 * slotid4 csr_slotid; 386 * slotid4 csr_highest_slotid; 387 * slotid4 csr_target_highest_slotid; 388 * }; 389 * 390 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) { 391 * case NFS4_OK: 392 * CB_SEQUENCE4resok csr_resok4; 393 * default: 394 * void; 395 * }; 396 * 397 * Our current back channel implmentation supports a single backchannel 398 * with a single slot. 399 */ 400 static int decode_cb_sequence4resok(struct xdr_stream *xdr, 401 struct nfsd4_callback *cb) 402 { 403 struct nfsd4_session *session = cb->cb_clp->cl_cb_session; 404 struct nfs4_sessionid id; 405 int status; 406 __be32 *p; 407 u32 dummy; 408 409 status = -ESERVERFAULT; 410 411 /* 412 * If the server returns different values for sessionID, slotID or 413 * sequence number, the server is looney tunes. 414 */ 415 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4); 416 if (unlikely(p == NULL)) 417 goto out_overflow; 418 memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN); 419 if (memcmp(id.data, session->se_sessionid.data, 420 NFS4_MAX_SESSIONID_LEN) != 0) { 421 dprintk("NFS: %s Invalid session id\n", __func__); 422 goto out; 423 } 424 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN); 425 426 dummy = be32_to_cpup(p++); 427 if (dummy != session->se_cb_seq_nr) { 428 dprintk("NFS: %s Invalid sequence number\n", __func__); 429 goto out; 430 } 431 432 dummy = be32_to_cpup(p++); 433 if (dummy != 0) { 434 dprintk("NFS: %s Invalid slotid\n", __func__); 435 goto out; 436 } 437 438 /* 439 * FIXME: process highest slotid and target highest slotid 440 */ 441 status = 0; 442 out: 443 if (status) 444 nfsd4_mark_cb_fault(cb->cb_clp, status); 445 return status; 446 out_overflow: 447 print_overflow_msg(__func__, xdr); 448 return -EIO; 449 } 450 451 static int decode_cb_sequence4res(struct xdr_stream *xdr, 452 struct nfsd4_callback *cb) 453 { 454 enum nfsstat4 nfserr; 455 int status; 456 457 if (cb->cb_minorversion == 0) 458 return 0; 459 460 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &nfserr); 461 if (unlikely(status)) 462 goto out; 463 if (unlikely(nfserr != NFS4_OK)) 464 goto out_default; 465 status = decode_cb_sequence4resok(xdr, cb); 466 out: 467 return status; 468 out_default: 469 return nfs_cb_stat_to_errno(nfserr); 470 } 471 472 /* 473 * NFSv4.0 and NFSv4.1 XDR encode functions 474 * 475 * NFSv4.0 callback argument types are defined in section 15 of RFC 476 * 3530: "Network File System (NFS) version 4 Protocol" and section 20 477 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1 478 * Protocol". 479 */ 480 481 /* 482 * NB: Without this zero space reservation, callbacks over krb5p fail 483 */ 484 static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr, 485 void *__unused) 486 { 487 xdr_reserve_space(xdr, 0); 488 } 489 490 /* 491 * 20.2. Operation 4: CB_RECALL - Recall a Delegation 492 */ 493 static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr, 494 const struct nfsd4_callback *cb) 495 { 496 const struct nfs4_delegation *args = cb->cb_op; 497 struct nfs4_cb_compound_hdr hdr = { 498 .ident = cb->cb_clp->cl_cb_ident, 499 .minorversion = cb->cb_minorversion, 500 }; 501 502 encode_cb_compound4args(xdr, &hdr); 503 encode_cb_sequence4args(xdr, cb, &hdr); 504 encode_cb_recall4args(xdr, args, &hdr); 505 encode_cb_nops(&hdr); 506 } 507 508 509 /* 510 * NFSv4.0 and NFSv4.1 XDR decode functions 511 * 512 * NFSv4.0 callback result types are defined in section 15 of RFC 513 * 3530: "Network File System (NFS) version 4 Protocol" and section 20 514 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1 515 * Protocol". 516 */ 517 518 static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr, 519 void *__unused) 520 { 521 return 0; 522 } 523 524 /* 525 * 20.2. Operation 4: CB_RECALL - Recall a Delegation 526 */ 527 static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, 528 struct xdr_stream *xdr, 529 struct nfsd4_callback *cb) 530 { 531 struct nfs4_cb_compound_hdr hdr; 532 enum nfsstat4 nfserr; 533 int status; 534 535 status = decode_cb_compound4res(xdr, &hdr); 536 if (unlikely(status)) 537 goto out; 538 539 if (cb != NULL) { 540 status = decode_cb_sequence4res(xdr, cb); 541 if (unlikely(status)) 542 goto out; 543 } 544 545 status = decode_cb_op_status(xdr, OP_CB_RECALL, &nfserr); 546 if (unlikely(status)) 547 goto out; 548 if (unlikely(nfserr != NFS4_OK)) 549 status = nfs_cb_stat_to_errno(nfserr); 550 out: 551 return status; 552 } 553 554 /* 555 * RPC procedure tables 556 */ 557 #define PROC(proc, call, argtype, restype) \ 558 [NFSPROC4_CLNT_##proc] = { \ 559 .p_proc = NFSPROC4_CB_##call, \ 560 .p_encode = (kxdreproc_t)nfs4_xdr_enc_##argtype, \ 561 .p_decode = (kxdrdproc_t)nfs4_xdr_dec_##restype, \ 562 .p_arglen = NFS4_enc_##argtype##_sz, \ 563 .p_replen = NFS4_dec_##restype##_sz, \ 564 .p_statidx = NFSPROC4_CB_##call, \ 565 .p_name = #proc, \ 566 } 567 568 static struct rpc_procinfo nfs4_cb_procedures[] = { 569 PROC(CB_NULL, NULL, cb_null, cb_null), 570 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall), 571 }; 572 573 static struct rpc_version nfs_cb_version4 = { 574 /* 575 * Note on the callback rpc program version number: despite language in rfc 576 * 5661 section 18.36.3 requiring servers to use 4 in this field, the 577 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and 578 * in practice that appears to be what implementations use. The section 579 * 18.36.3 language is expected to be fixed in an erratum. 580 */ 581 .number = 1, 582 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures), 583 .procs = nfs4_cb_procedures 584 }; 585 586 static const struct rpc_version *nfs_cb_version[] = { 587 &nfs_cb_version4, 588 }; 589 590 static const struct rpc_program cb_program; 591 592 static struct rpc_stat cb_stats = { 593 .program = &cb_program 594 }; 595 596 #define NFS4_CALLBACK 0x40000000 597 static const struct rpc_program cb_program = { 598 .name = "nfs4_cb", 599 .number = NFS4_CALLBACK, 600 .nrvers = ARRAY_SIZE(nfs_cb_version), 601 .version = nfs_cb_version, 602 .stats = &cb_stats, 603 .pipe_dir_name = "nfsd4_cb", 604 }; 605 606 static int max_cb_time(struct net *net) 607 { 608 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 609 return max(nn->nfsd4_lease/10, (time_t)1) * HZ; 610 } 611 612 static struct rpc_cred *callback_cred; 613 614 int set_callback_cred(void) 615 { 616 if (callback_cred) 617 return 0; 618 callback_cred = rpc_lookup_machine_cred("nfs"); 619 if (!callback_cred) 620 return -ENOMEM; 621 return 0; 622 } 623 624 static struct rpc_cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses) 625 { 626 if (clp->cl_minorversion == 0) { 627 return get_rpccred(callback_cred); 628 } else { 629 struct rpc_auth *auth = client->cl_auth; 630 struct auth_cred acred = {}; 631 632 acred.uid = ses->se_cb_sec.uid; 633 acred.gid = ses->se_cb_sec.gid; 634 return auth->au_ops->lookup_cred(client->cl_auth, &acred, 0); 635 } 636 } 637 638 static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses) 639 { 640 struct rpc_timeout timeparms = { 641 .to_initval = max_cb_time(clp->net), 642 .to_retries = 0, 643 }; 644 struct rpc_create_args args = { 645 .net = clp->net, 646 .address = (struct sockaddr *) &conn->cb_addr, 647 .addrsize = conn->cb_addrlen, 648 .saddress = (struct sockaddr *) &conn->cb_saddr, 649 .timeout = &timeparms, 650 .program = &cb_program, 651 .version = 0, 652 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET), 653 }; 654 struct rpc_clnt *client; 655 struct rpc_cred *cred; 656 657 if (clp->cl_minorversion == 0) { 658 if (!clp->cl_cred.cr_principal && 659 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5)) 660 return -EINVAL; 661 args.client_name = clp->cl_cred.cr_principal; 662 args.prognumber = conn->cb_prog, 663 args.protocol = XPRT_TRANSPORT_TCP; 664 args.authflavor = clp->cl_cred.cr_flavor; 665 clp->cl_cb_ident = conn->cb_ident; 666 } else { 667 if (!conn->cb_xprt) 668 return -EINVAL; 669 clp->cl_cb_conn.cb_xprt = conn->cb_xprt; 670 clp->cl_cb_session = ses; 671 args.bc_xprt = conn->cb_xprt; 672 args.prognumber = clp->cl_cb_session->se_cb_prog; 673 args.protocol = XPRT_TRANSPORT_BC_TCP; 674 args.authflavor = ses->se_cb_sec.flavor; 675 } 676 /* Create RPC client */ 677 client = rpc_create(&args); 678 if (IS_ERR(client)) { 679 dprintk("NFSD: couldn't create callback client: %ld\n", 680 PTR_ERR(client)); 681 return PTR_ERR(client); 682 } 683 cred = get_backchannel_cred(clp, client, ses); 684 if (IS_ERR(cred)) { 685 rpc_shutdown_client(client); 686 return PTR_ERR(cred); 687 } 688 clp->cl_cb_client = client; 689 clp->cl_cb_cred = cred; 690 return 0; 691 } 692 693 static void warn_no_callback_path(struct nfs4_client *clp, int reason) 694 { 695 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n", 696 (int)clp->cl_name.len, clp->cl_name.data, reason); 697 } 698 699 static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason) 700 { 701 clp->cl_cb_state = NFSD4_CB_DOWN; 702 warn_no_callback_path(clp, reason); 703 } 704 705 static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason) 706 { 707 clp->cl_cb_state = NFSD4_CB_FAULT; 708 warn_no_callback_path(clp, reason); 709 } 710 711 static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata) 712 { 713 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null); 714 715 if (task->tk_status) 716 nfsd4_mark_cb_down(clp, task->tk_status); 717 else 718 clp->cl_cb_state = NFSD4_CB_UP; 719 } 720 721 static const struct rpc_call_ops nfsd4_cb_probe_ops = { 722 /* XXX: release method to ensure we set the cb channel down if 723 * necessary on early failure? */ 724 .rpc_call_done = nfsd4_cb_probe_done, 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; 744 745 cb->cb_ops = &nfsd4_cb_probe_ops; 746 747 run_nfsd4_cb(cb); 748 } 749 750 /* 751 * Poke the callback thread to process any updates to the callback 752 * parameters, and send a null probe. 753 */ 754 void nfsd4_probe_callback(struct nfs4_client *clp) 755 { 756 clp->cl_cb_state = NFSD4_CB_UNKNOWN; 757 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags); 758 do_probe_callback(clp); 759 } 760 761 void nfsd4_probe_callback_sync(struct nfs4_client *clp) 762 { 763 nfsd4_probe_callback(clp); 764 flush_workqueue(callback_wq); 765 } 766 767 void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn) 768 { 769 clp->cl_cb_state = NFSD4_CB_UNKNOWN; 770 spin_lock(&clp->cl_lock); 771 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn)); 772 spin_unlock(&clp->cl_lock); 773 } 774 775 /* 776 * There's currently a single callback channel slot. 777 * If the slot is available, then mark it busy. Otherwise, set the 778 * thread for sleeping on the callback RPC wait queue. 779 */ 780 static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task) 781 { 782 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) { 783 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL); 784 dprintk("%s slot is busy\n", __func__); 785 return false; 786 } 787 return true; 788 } 789 790 /* 791 * TODO: cb_sequence should support referring call lists, cachethis, multiple 792 * slots, and mark callback channel down on communication errors. 793 */ 794 static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata) 795 { 796 struct nfsd4_callback *cb = calldata; 797 struct nfs4_client *clp = cb->cb_clp; 798 u32 minorversion = clp->cl_minorversion; 799 800 cb->cb_minorversion = minorversion; 801 if (minorversion) { 802 if (!nfsd41_cb_get_slot(clp, task)) 803 return; 804 } 805 spin_lock(&clp->cl_lock); 806 if (list_empty(&cb->cb_per_client)) { 807 /* This is the first call, not a restart */ 808 cb->cb_done = false; 809 list_add(&cb->cb_per_client, &clp->cl_callbacks); 810 } 811 spin_unlock(&clp->cl_lock); 812 rpc_call_start(task); 813 } 814 815 static void nfsd4_cb_done(struct rpc_task *task, void *calldata) 816 { 817 struct nfsd4_callback *cb = calldata; 818 struct nfs4_client *clp = cb->cb_clp; 819 820 dprintk("%s: minorversion=%d\n", __func__, 821 clp->cl_minorversion); 822 823 if (clp->cl_minorversion) { 824 /* No need for lock, access serialized in nfsd4_cb_prepare */ 825 ++clp->cl_cb_session->se_cb_seq_nr; 826 clear_bit(0, &clp->cl_cb_slot_busy); 827 rpc_wake_up_next(&clp->cl_cb_waitq); 828 dprintk("%s: freed slot, new seqid=%d\n", __func__, 829 clp->cl_cb_session->se_cb_seq_nr); 830 831 /* We're done looking into the sequence information */ 832 task->tk_msg.rpc_resp = NULL; 833 } 834 } 835 836 837 static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata) 838 { 839 struct nfsd4_callback *cb = calldata; 840 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall); 841 struct nfs4_client *clp = cb->cb_clp; 842 struct rpc_clnt *current_rpc_client = clp->cl_cb_client; 843 844 nfsd4_cb_done(task, calldata); 845 846 if (current_rpc_client != task->tk_client) { 847 /* We're shutting down or changing cl_cb_client; leave 848 * it to nfsd4_process_cb_update to restart the call if 849 * necessary. */ 850 return; 851 } 852 853 if (cb->cb_done) 854 return; 855 switch (task->tk_status) { 856 case 0: 857 cb->cb_done = true; 858 return; 859 case -EBADHANDLE: 860 case -NFS4ERR_BAD_STATEID: 861 /* Race: client probably got cb_recall 862 * before open reply granting delegation */ 863 break; 864 default: 865 /* Network partition? */ 866 nfsd4_mark_cb_down(clp, task->tk_status); 867 } 868 if (dp->dl_retries--) { 869 rpc_delay(task, 2*HZ); 870 task->tk_status = 0; 871 rpc_restart_call_prepare(task); 872 return; 873 } 874 nfsd4_mark_cb_down(clp, task->tk_status); 875 cb->cb_done = true; 876 } 877 878 static void nfsd4_cb_recall_release(void *calldata) 879 { 880 struct nfsd4_callback *cb = calldata; 881 struct nfs4_client *clp = cb->cb_clp; 882 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall); 883 884 if (cb->cb_done) { 885 spin_lock(&clp->cl_lock); 886 list_del(&cb->cb_per_client); 887 spin_unlock(&clp->cl_lock); 888 nfs4_put_delegation(dp); 889 } 890 } 891 892 static const struct rpc_call_ops nfsd4_cb_recall_ops = { 893 .rpc_call_prepare = nfsd4_cb_prepare, 894 .rpc_call_done = nfsd4_cb_recall_done, 895 .rpc_release = nfsd4_cb_recall_release, 896 }; 897 898 int nfsd4_create_callback_queue(void) 899 { 900 callback_wq = create_singlethread_workqueue("nfsd4_callbacks"); 901 if (!callback_wq) 902 return -ENOMEM; 903 return 0; 904 } 905 906 void nfsd4_destroy_callback_queue(void) 907 { 908 destroy_workqueue(callback_wq); 909 } 910 911 /* must be called under the state lock */ 912 void nfsd4_shutdown_callback(struct nfs4_client *clp) 913 { 914 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags); 915 /* 916 * Note this won't actually result in a null callback; 917 * instead, nfsd4_do_callback_rpc() will detect the killed 918 * client, destroy the rpc client, and stop: 919 */ 920 do_probe_callback(clp); 921 flush_workqueue(callback_wq); 922 } 923 924 static void nfsd4_release_cb(struct nfsd4_callback *cb) 925 { 926 if (cb->cb_ops->rpc_release) 927 cb->cb_ops->rpc_release(cb); 928 } 929 930 /* requires cl_lock: */ 931 static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp) 932 { 933 struct nfsd4_session *s; 934 struct nfsd4_conn *c; 935 936 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) { 937 list_for_each_entry(c, &s->se_conns, cn_persession) { 938 if (c->cn_flags & NFS4_CDFC4_BACK) 939 return c; 940 } 941 } 942 return NULL; 943 } 944 945 static void nfsd4_process_cb_update(struct nfsd4_callback *cb) 946 { 947 struct nfs4_cb_conn conn; 948 struct nfs4_client *clp = cb->cb_clp; 949 struct nfsd4_session *ses = NULL; 950 struct nfsd4_conn *c; 951 int err; 952 953 /* 954 * This is either an update, or the client dying; in either case, 955 * kill the old client: 956 */ 957 if (clp->cl_cb_client) { 958 rpc_shutdown_client(clp->cl_cb_client); 959 clp->cl_cb_client = NULL; 960 put_rpccred(clp->cl_cb_cred); 961 clp->cl_cb_cred = NULL; 962 } 963 if (clp->cl_cb_conn.cb_xprt) { 964 svc_xprt_put(clp->cl_cb_conn.cb_xprt); 965 clp->cl_cb_conn.cb_xprt = NULL; 966 } 967 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) 968 return; 969 spin_lock(&clp->cl_lock); 970 /* 971 * Only serialized callback code is allowed to clear these 972 * flags; main nfsd code can only set them: 973 */ 974 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)); 975 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags); 976 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn)); 977 c = __nfsd4_find_backchannel(clp); 978 if (c) { 979 svc_xprt_get(c->cn_xprt); 980 conn.cb_xprt = c->cn_xprt; 981 ses = c->cn_session; 982 } 983 spin_unlock(&clp->cl_lock); 984 985 err = setup_callback_client(clp, &conn, ses); 986 if (err) { 987 nfsd4_mark_cb_down(clp, err); 988 return; 989 } 990 /* Yay, the callback channel's back! Restart any callbacks: */ 991 list_for_each_entry(cb, &clp->cl_callbacks, cb_per_client) 992 run_nfsd4_cb(cb); 993 } 994 995 static void nfsd4_do_callback_rpc(struct work_struct *w) 996 { 997 struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, cb_work); 998 struct nfs4_client *clp = cb->cb_clp; 999 struct rpc_clnt *clnt; 1000 1001 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK) 1002 nfsd4_process_cb_update(cb); 1003 1004 clnt = clp->cl_cb_client; 1005 if (!clnt) { 1006 /* Callback channel broken, or client killed; give up: */ 1007 nfsd4_release_cb(cb); 1008 return; 1009 } 1010 cb->cb_msg.rpc_cred = clp->cl_cb_cred; 1011 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN, 1012 cb->cb_ops, cb); 1013 } 1014 1015 void nfsd4_init_callback(struct nfsd4_callback *cb) 1016 { 1017 INIT_WORK(&cb->cb_work, nfsd4_do_callback_rpc); 1018 } 1019 1020 void nfsd4_cb_recall(struct nfs4_delegation *dp) 1021 { 1022 struct nfsd4_callback *cb = &dp->dl_recall; 1023 struct nfs4_client *clp = dp->dl_stid.sc_client; 1024 1025 dp->dl_retries = 1; 1026 cb->cb_op = dp; 1027 cb->cb_clp = clp; 1028 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL]; 1029 cb->cb_msg.rpc_argp = cb; 1030 cb->cb_msg.rpc_resp = cb; 1031 1032 cb->cb_ops = &nfsd4_cb_recall_ops; 1033 1034 INIT_LIST_HEAD(&cb->cb_per_client); 1035 cb->cb_done = true; 1036 1037 run_nfsd4_cb(&dp->dl_recall); 1038 } 1039