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/xprt.h> 36 #include <linux/sunrpc/svc_xprt.h> 37 #include <linux/slab.h> 38 #include "nfsd.h" 39 #include "state.h" 40 #include "netns.h" 41 #include "xdr4cb.h" 42 43 #define NFSDDBG_FACILITY NFSDDBG_PROC 44 45 static void nfsd4_mark_cb_fault(struct nfs4_client *, int reason); 46 47 #define NFSPROC4_CB_NULL 0 48 #define NFSPROC4_CB_COMPOUND 1 49 50 /* Index of predefined Linux callback client operations */ 51 52 struct nfs4_cb_compound_hdr { 53 /* args */ 54 u32 ident; /* minorversion 0 only */ 55 u32 nops; 56 __be32 *nops_p; 57 u32 minorversion; 58 /* res */ 59 int status; 60 }; 61 62 /* 63 * Handle decode buffer overflows out-of-line. 64 */ 65 static void print_overflow_msg(const char *func, const struct xdr_stream *xdr) 66 { 67 dprintk("NFS: %s prematurely hit the end of our receive buffer. " 68 "Remaining buffer length is %tu words.\n", 69 func, xdr->end - xdr->p); 70 } 71 72 static __be32 *xdr_encode_empty_array(__be32 *p) 73 { 74 *p++ = xdr_zero; 75 return p; 76 } 77 78 /* 79 * Encode/decode NFSv4 CB basic data types 80 * 81 * Basic NFSv4 callback data types are defined in section 15 of RFC 82 * 3530: "Network File System (NFS) version 4 Protocol" and section 83 * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version 84 * 1 Protocol" 85 */ 86 87 /* 88 * nfs_cb_opnum4 89 * 90 * enum nfs_cb_opnum4 { 91 * OP_CB_GETATTR = 3, 92 * ... 93 * }; 94 */ 95 enum nfs_cb_opnum4 { 96 OP_CB_GETATTR = 3, 97 OP_CB_RECALL = 4, 98 OP_CB_LAYOUTRECALL = 5, 99 OP_CB_NOTIFY = 6, 100 OP_CB_PUSH_DELEG = 7, 101 OP_CB_RECALL_ANY = 8, 102 OP_CB_RECALLABLE_OBJ_AVAIL = 9, 103 OP_CB_RECALL_SLOT = 10, 104 OP_CB_SEQUENCE = 11, 105 OP_CB_WANTS_CANCELLED = 12, 106 OP_CB_NOTIFY_LOCK = 13, 107 OP_CB_NOTIFY_DEVICEID = 14, 108 OP_CB_ILLEGAL = 10044 109 }; 110 111 static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op) 112 { 113 __be32 *p; 114 115 p = xdr_reserve_space(xdr, 4); 116 *p = cpu_to_be32(op); 117 } 118 119 /* 120 * nfs_fh4 121 * 122 * typedef opaque nfs_fh4<NFS4_FHSIZE>; 123 */ 124 static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh) 125 { 126 u32 length = fh->fh_size; 127 __be32 *p; 128 129 BUG_ON(length > NFS4_FHSIZE); 130 p = xdr_reserve_space(xdr, 4 + length); 131 xdr_encode_opaque(p, &fh->fh_base, length); 132 } 133 134 /* 135 * stateid4 136 * 137 * struct stateid4 { 138 * uint32_t seqid; 139 * opaque other[12]; 140 * }; 141 */ 142 static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid) 143 { 144 __be32 *p; 145 146 p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE); 147 *p++ = cpu_to_be32(sid->si_generation); 148 xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE); 149 } 150 151 /* 152 * sessionid4 153 * 154 * typedef opaque sessionid4[NFS4_SESSIONID_SIZE]; 155 */ 156 static void encode_sessionid4(struct xdr_stream *xdr, 157 const struct nfsd4_session *session) 158 { 159 __be32 *p; 160 161 p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN); 162 xdr_encode_opaque_fixed(p, session->se_sessionid.data, 163 NFS4_MAX_SESSIONID_LEN); 164 } 165 166 /* 167 * nfsstat4 168 */ 169 static const struct { 170 int stat; 171 int errno; 172 } nfs_cb_errtbl[] = { 173 { NFS4_OK, 0 }, 174 { NFS4ERR_PERM, -EPERM }, 175 { NFS4ERR_NOENT, -ENOENT }, 176 { NFS4ERR_IO, -EIO }, 177 { NFS4ERR_NXIO, -ENXIO }, 178 { NFS4ERR_ACCESS, -EACCES }, 179 { NFS4ERR_EXIST, -EEXIST }, 180 { NFS4ERR_XDEV, -EXDEV }, 181 { NFS4ERR_NOTDIR, -ENOTDIR }, 182 { NFS4ERR_ISDIR, -EISDIR }, 183 { NFS4ERR_INVAL, -EINVAL }, 184 { NFS4ERR_FBIG, -EFBIG }, 185 { NFS4ERR_NOSPC, -ENOSPC }, 186 { NFS4ERR_ROFS, -EROFS }, 187 { NFS4ERR_MLINK, -EMLINK }, 188 { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG }, 189 { NFS4ERR_NOTEMPTY, -ENOTEMPTY }, 190 { NFS4ERR_DQUOT, -EDQUOT }, 191 { NFS4ERR_STALE, -ESTALE }, 192 { NFS4ERR_BADHANDLE, -EBADHANDLE }, 193 { NFS4ERR_BAD_COOKIE, -EBADCOOKIE }, 194 { NFS4ERR_NOTSUPP, -ENOTSUPP }, 195 { NFS4ERR_TOOSMALL, -ETOOSMALL }, 196 { NFS4ERR_SERVERFAULT, -ESERVERFAULT }, 197 { NFS4ERR_BADTYPE, -EBADTYPE }, 198 { NFS4ERR_LOCKED, -EAGAIN }, 199 { NFS4ERR_RESOURCE, -EREMOTEIO }, 200 { NFS4ERR_SYMLINK, -ELOOP }, 201 { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP }, 202 { NFS4ERR_DEADLOCK, -EDEADLK }, 203 { -1, -EIO } 204 }; 205 206 /* 207 * If we cannot translate the error, the recovery routines should 208 * handle it. 209 * 210 * Note: remaining NFSv4 error codes have values > 10000, so should 211 * not conflict with native Linux error codes. 212 */ 213 static int nfs_cb_stat_to_errno(int status) 214 { 215 int i; 216 217 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) { 218 if (nfs_cb_errtbl[i].stat == status) 219 return nfs_cb_errtbl[i].errno; 220 } 221 222 dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status); 223 return -status; 224 } 225 226 static int decode_cb_op_status(struct xdr_stream *xdr, enum nfs_opnum4 expected, 227 enum nfsstat4 *status) 228 { 229 __be32 *p; 230 u32 op; 231 232 p = xdr_inline_decode(xdr, 4 + 4); 233 if (unlikely(p == NULL)) 234 goto out_overflow; 235 op = be32_to_cpup(p++); 236 if (unlikely(op != expected)) 237 goto out_unexpected; 238 *status = be32_to_cpup(p); 239 return 0; 240 out_overflow: 241 print_overflow_msg(__func__, xdr); 242 return -EIO; 243 out_unexpected: 244 dprintk("NFSD: Callback server returned operation %d but " 245 "we issued a request for %d\n", op, expected); 246 return -EIO; 247 } 248 249 /* 250 * CB_COMPOUND4args 251 * 252 * struct CB_COMPOUND4args { 253 * utf8str_cs tag; 254 * uint32_t minorversion; 255 * uint32_t callback_ident; 256 * nfs_cb_argop4 argarray<>; 257 * }; 258 */ 259 static void encode_cb_compound4args(struct xdr_stream *xdr, 260 struct nfs4_cb_compound_hdr *hdr) 261 { 262 __be32 * p; 263 264 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4); 265 p = xdr_encode_empty_array(p); /* empty tag */ 266 *p++ = cpu_to_be32(hdr->minorversion); 267 *p++ = cpu_to_be32(hdr->ident); 268 269 hdr->nops_p = p; 270 *p = cpu_to_be32(hdr->nops); /* argarray element count */ 271 } 272 273 /* 274 * Update argarray element count 275 */ 276 static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr) 277 { 278 BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS); 279 *hdr->nops_p = cpu_to_be32(hdr->nops); 280 } 281 282 /* 283 * CB_COMPOUND4res 284 * 285 * struct CB_COMPOUND4res { 286 * nfsstat4 status; 287 * utf8str_cs tag; 288 * nfs_cb_resop4 resarray<>; 289 * }; 290 */ 291 static int decode_cb_compound4res(struct xdr_stream *xdr, 292 struct nfs4_cb_compound_hdr *hdr) 293 { 294 u32 length; 295 __be32 *p; 296 297 p = xdr_inline_decode(xdr, 4 + 4); 298 if (unlikely(p == NULL)) 299 goto out_overflow; 300 hdr->status = be32_to_cpup(p++); 301 /* Ignore the tag */ 302 length = be32_to_cpup(p++); 303 p = xdr_inline_decode(xdr, length + 4); 304 if (unlikely(p == NULL)) 305 goto out_overflow; 306 hdr->nops = be32_to_cpup(p); 307 return 0; 308 out_overflow: 309 print_overflow_msg(__func__, xdr); 310 return -EIO; 311 } 312 313 /* 314 * CB_RECALL4args 315 * 316 * struct CB_RECALL4args { 317 * stateid4 stateid; 318 * bool truncate; 319 * nfs_fh4 fh; 320 * }; 321 */ 322 static void encode_cb_recall4args(struct xdr_stream *xdr, 323 const struct nfs4_delegation *dp, 324 struct nfs4_cb_compound_hdr *hdr) 325 { 326 __be32 *p; 327 328 encode_nfs_cb_opnum4(xdr, OP_CB_RECALL); 329 encode_stateid4(xdr, &dp->dl_stid.sc_stateid); 330 331 p = xdr_reserve_space(xdr, 4); 332 *p++ = xdr_zero; /* truncate */ 333 334 encode_nfs_fh4(xdr, &dp->dl_stid.sc_file->fi_fhandle); 335 336 hdr->nops++; 337 } 338 339 /* 340 * CB_SEQUENCE4args 341 * 342 * struct CB_SEQUENCE4args { 343 * sessionid4 csa_sessionid; 344 * sequenceid4 csa_sequenceid; 345 * slotid4 csa_slotid; 346 * slotid4 csa_highest_slotid; 347 * bool csa_cachethis; 348 * referring_call_list4 csa_referring_call_lists<>; 349 * }; 350 */ 351 static void encode_cb_sequence4args(struct xdr_stream *xdr, 352 const struct nfsd4_callback *cb, 353 struct nfs4_cb_compound_hdr *hdr) 354 { 355 struct nfsd4_session *session = cb->cb_clp->cl_cb_session; 356 __be32 *p; 357 358 if (hdr->minorversion == 0) 359 return; 360 361 encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE); 362 encode_sessionid4(xdr, session); 363 364 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4); 365 *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */ 366 *p++ = xdr_zero; /* csa_slotid */ 367 *p++ = xdr_zero; /* csa_highest_slotid */ 368 *p++ = xdr_zero; /* csa_cachethis */ 369 xdr_encode_empty_array(p); /* csa_referring_call_lists */ 370 371 hdr->nops++; 372 } 373 374 /* 375 * CB_SEQUENCE4resok 376 * 377 * struct CB_SEQUENCE4resok { 378 * sessionid4 csr_sessionid; 379 * sequenceid4 csr_sequenceid; 380 * slotid4 csr_slotid; 381 * slotid4 csr_highest_slotid; 382 * slotid4 csr_target_highest_slotid; 383 * }; 384 * 385 * union CB_SEQUENCE4res switch (nfsstat4 csr_status) { 386 * case NFS4_OK: 387 * CB_SEQUENCE4resok csr_resok4; 388 * default: 389 * void; 390 * }; 391 * 392 * Our current back channel implmentation supports a single backchannel 393 * with a single slot. 394 */ 395 static int decode_cb_sequence4resok(struct xdr_stream *xdr, 396 struct nfsd4_callback *cb) 397 { 398 struct nfsd4_session *session = cb->cb_clp->cl_cb_session; 399 struct nfs4_sessionid id; 400 int status; 401 __be32 *p; 402 u32 dummy; 403 404 status = -ESERVERFAULT; 405 406 /* 407 * If the server returns different values for sessionID, slotID or 408 * sequence number, the server is looney tunes. 409 */ 410 p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4); 411 if (unlikely(p == NULL)) 412 goto out_overflow; 413 memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN); 414 if (memcmp(id.data, session->se_sessionid.data, 415 NFS4_MAX_SESSIONID_LEN) != 0) { 416 dprintk("NFS: %s Invalid session id\n", __func__); 417 goto out; 418 } 419 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN); 420 421 dummy = be32_to_cpup(p++); 422 if (dummy != session->se_cb_seq_nr) { 423 dprintk("NFS: %s Invalid sequence number\n", __func__); 424 goto out; 425 } 426 427 dummy = be32_to_cpup(p++); 428 if (dummy != 0) { 429 dprintk("NFS: %s Invalid slotid\n", __func__); 430 goto out; 431 } 432 433 /* 434 * FIXME: process highest slotid and target highest slotid 435 */ 436 status = 0; 437 out: 438 if (status) 439 nfsd4_mark_cb_fault(cb->cb_clp, status); 440 return status; 441 out_overflow: 442 print_overflow_msg(__func__, xdr); 443 return -EIO; 444 } 445 446 static int decode_cb_sequence4res(struct xdr_stream *xdr, 447 struct nfsd4_callback *cb) 448 { 449 enum nfsstat4 nfserr; 450 int status; 451 452 if (cb->cb_minorversion == 0) 453 return 0; 454 455 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &nfserr); 456 if (unlikely(status)) 457 goto out; 458 if (unlikely(nfserr != NFS4_OK)) 459 goto out_default; 460 status = decode_cb_sequence4resok(xdr, cb); 461 out: 462 return status; 463 out_default: 464 return nfs_cb_stat_to_errno(nfserr); 465 } 466 467 /* 468 * NFSv4.0 and NFSv4.1 XDR encode functions 469 * 470 * NFSv4.0 callback argument types are defined in section 15 of RFC 471 * 3530: "Network File System (NFS) version 4 Protocol" and section 20 472 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1 473 * Protocol". 474 */ 475 476 /* 477 * NB: Without this zero space reservation, callbacks over krb5p fail 478 */ 479 static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr, 480 void *__unused) 481 { 482 xdr_reserve_space(xdr, 0); 483 } 484 485 /* 486 * 20.2. Operation 4: CB_RECALL - Recall a Delegation 487 */ 488 static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr, 489 const struct nfsd4_callback *cb) 490 { 491 const struct nfs4_delegation *dp = cb_to_delegation(cb); 492 struct nfs4_cb_compound_hdr hdr = { 493 .ident = cb->cb_clp->cl_cb_ident, 494 .minorversion = cb->cb_minorversion, 495 }; 496 497 encode_cb_compound4args(xdr, &hdr); 498 encode_cb_sequence4args(xdr, cb, &hdr); 499 encode_cb_recall4args(xdr, dp, &hdr); 500 encode_cb_nops(&hdr); 501 } 502 503 504 /* 505 * NFSv4.0 and NFSv4.1 XDR decode functions 506 * 507 * NFSv4.0 callback result types are defined in section 15 of RFC 508 * 3530: "Network File System (NFS) version 4 Protocol" and section 20 509 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1 510 * Protocol". 511 */ 512 513 static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr, 514 void *__unused) 515 { 516 return 0; 517 } 518 519 /* 520 * 20.2. Operation 4: CB_RECALL - Recall a Delegation 521 */ 522 static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, 523 struct xdr_stream *xdr, 524 struct nfsd4_callback *cb) 525 { 526 struct nfs4_cb_compound_hdr hdr; 527 enum nfsstat4 nfserr; 528 int status; 529 530 status = decode_cb_compound4res(xdr, &hdr); 531 if (unlikely(status)) 532 goto out; 533 534 if (cb != NULL) { 535 status = decode_cb_sequence4res(xdr, cb); 536 if (unlikely(status)) 537 goto out; 538 } 539 540 status = decode_cb_op_status(xdr, OP_CB_RECALL, &nfserr); 541 if (unlikely(status)) 542 goto out; 543 if (unlikely(nfserr != NFS4_OK)) 544 status = nfs_cb_stat_to_errno(nfserr); 545 out: 546 return status; 547 } 548 549 /* 550 * RPC procedure tables 551 */ 552 #define PROC(proc, call, argtype, restype) \ 553 [NFSPROC4_CLNT_##proc] = { \ 554 .p_proc = NFSPROC4_CB_##call, \ 555 .p_encode = (kxdreproc_t)nfs4_xdr_enc_##argtype, \ 556 .p_decode = (kxdrdproc_t)nfs4_xdr_dec_##restype, \ 557 .p_arglen = NFS4_enc_##argtype##_sz, \ 558 .p_replen = NFS4_dec_##restype##_sz, \ 559 .p_statidx = NFSPROC4_CB_##call, \ 560 .p_name = #proc, \ 561 } 562 563 static struct rpc_procinfo nfs4_cb_procedures[] = { 564 PROC(CB_NULL, NULL, cb_null, cb_null), 565 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall), 566 }; 567 568 static struct rpc_version nfs_cb_version4 = { 569 /* 570 * Note on the callback rpc program version number: despite language in rfc 571 * 5661 section 18.36.3 requiring servers to use 4 in this field, the 572 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and 573 * in practice that appears to be what implementations use. The section 574 * 18.36.3 language is expected to be fixed in an erratum. 575 */ 576 .number = 1, 577 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures), 578 .procs = nfs4_cb_procedures 579 }; 580 581 static const struct rpc_version *nfs_cb_version[] = { 582 &nfs_cb_version4, 583 }; 584 585 static const struct rpc_program cb_program; 586 587 static struct rpc_stat cb_stats = { 588 .program = &cb_program 589 }; 590 591 #define NFS4_CALLBACK 0x40000000 592 static const struct rpc_program cb_program = { 593 .name = "nfs4_cb", 594 .number = NFS4_CALLBACK, 595 .nrvers = ARRAY_SIZE(nfs_cb_version), 596 .version = nfs_cb_version, 597 .stats = &cb_stats, 598 .pipe_dir_name = "nfsd4_cb", 599 }; 600 601 static int max_cb_time(struct net *net) 602 { 603 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 604 return max(nn->nfsd4_lease/10, (time_t)1) * HZ; 605 } 606 607 static struct rpc_cred *callback_cred; 608 609 int set_callback_cred(void) 610 { 611 if (callback_cred) 612 return 0; 613 callback_cred = rpc_lookup_machine_cred("nfs"); 614 if (!callback_cred) 615 return -ENOMEM; 616 return 0; 617 } 618 619 static struct rpc_cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses) 620 { 621 if (clp->cl_minorversion == 0) { 622 return get_rpccred(callback_cred); 623 } else { 624 struct rpc_auth *auth = client->cl_auth; 625 struct auth_cred acred = {}; 626 627 acred.uid = ses->se_cb_sec.uid; 628 acred.gid = ses->se_cb_sec.gid; 629 return auth->au_ops->lookup_cred(client->cl_auth, &acred, 0); 630 } 631 } 632 633 static struct rpc_clnt *create_backchannel_client(struct rpc_create_args *args) 634 { 635 struct rpc_xprt *xprt; 636 637 if (args->protocol != XPRT_TRANSPORT_BC_TCP) 638 return rpc_create(args); 639 640 xprt = args->bc_xprt->xpt_bc_xprt; 641 if (xprt) { 642 xprt_get(xprt); 643 return rpc_create_xprt(args, xprt); 644 } 645 646 return rpc_create(args); 647 } 648 649 static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses) 650 { 651 int maxtime = max_cb_time(clp->net); 652 struct rpc_timeout timeparms = { 653 .to_initval = maxtime, 654 .to_retries = 0, 655 .to_maxval = maxtime, 656 }; 657 struct rpc_create_args args = { 658 .net = clp->net, 659 .address = (struct sockaddr *) &conn->cb_addr, 660 .addrsize = conn->cb_addrlen, 661 .saddress = (struct sockaddr *) &conn->cb_saddr, 662 .timeout = &timeparms, 663 .program = &cb_program, 664 .version = 0, 665 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET), 666 }; 667 struct rpc_clnt *client; 668 struct rpc_cred *cred; 669 670 if (clp->cl_minorversion == 0) { 671 if (!clp->cl_cred.cr_principal && 672 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5)) 673 return -EINVAL; 674 args.client_name = clp->cl_cred.cr_principal; 675 args.prognumber = conn->cb_prog; 676 args.protocol = XPRT_TRANSPORT_TCP; 677 args.authflavor = clp->cl_cred.cr_flavor; 678 clp->cl_cb_ident = conn->cb_ident; 679 } else { 680 if (!conn->cb_xprt) 681 return -EINVAL; 682 clp->cl_cb_conn.cb_xprt = conn->cb_xprt; 683 clp->cl_cb_session = ses; 684 args.bc_xprt = conn->cb_xprt; 685 args.prognumber = clp->cl_cb_session->se_cb_prog; 686 args.protocol = conn->cb_xprt->xpt_class->xcl_ident | 687 XPRT_TRANSPORT_BC; 688 args.authflavor = ses->se_cb_sec.flavor; 689 } 690 /* Create RPC client */ 691 client = create_backchannel_client(&args); 692 if (IS_ERR(client)) { 693 dprintk("NFSD: couldn't create callback client: %ld\n", 694 PTR_ERR(client)); 695 return PTR_ERR(client); 696 } 697 cred = get_backchannel_cred(clp, client, ses); 698 if (IS_ERR(cred)) { 699 rpc_shutdown_client(client); 700 return PTR_ERR(cred); 701 } 702 clp->cl_cb_client = client; 703 clp->cl_cb_cred = cred; 704 return 0; 705 } 706 707 static void warn_no_callback_path(struct nfs4_client *clp, int reason) 708 { 709 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n", 710 (int)clp->cl_name.len, clp->cl_name.data, reason); 711 } 712 713 static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason) 714 { 715 clp->cl_cb_state = NFSD4_CB_DOWN; 716 warn_no_callback_path(clp, reason); 717 } 718 719 static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason) 720 { 721 clp->cl_cb_state = NFSD4_CB_FAULT; 722 warn_no_callback_path(clp, reason); 723 } 724 725 static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata) 726 { 727 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null); 728 729 if (task->tk_status) 730 nfsd4_mark_cb_down(clp, task->tk_status); 731 else 732 clp->cl_cb_state = NFSD4_CB_UP; 733 } 734 735 static const struct rpc_call_ops nfsd4_cb_probe_ops = { 736 /* XXX: release method to ensure we set the cb channel down if 737 * necessary on early failure? */ 738 .rpc_call_done = nfsd4_cb_probe_done, 739 }; 740 741 static struct workqueue_struct *callback_wq; 742 743 /* 744 * Poke the callback thread to process any updates to the callback 745 * parameters, and send a null probe. 746 */ 747 void nfsd4_probe_callback(struct nfs4_client *clp) 748 { 749 clp->cl_cb_state = NFSD4_CB_UNKNOWN; 750 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags); 751 nfsd4_run_cb(&clp->cl_cb_null); 752 } 753 754 void nfsd4_probe_callback_sync(struct nfs4_client *clp) 755 { 756 nfsd4_probe_callback(clp); 757 flush_workqueue(callback_wq); 758 } 759 760 void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn) 761 { 762 clp->cl_cb_state = NFSD4_CB_UNKNOWN; 763 spin_lock(&clp->cl_lock); 764 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn)); 765 spin_unlock(&clp->cl_lock); 766 } 767 768 /* 769 * There's currently a single callback channel slot. 770 * If the slot is available, then mark it busy. Otherwise, set the 771 * thread for sleeping on the callback RPC wait queue. 772 */ 773 static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task) 774 { 775 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) { 776 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL); 777 dprintk("%s slot is busy\n", __func__); 778 return false; 779 } 780 return true; 781 } 782 783 /* 784 * TODO: cb_sequence should support referring call lists, cachethis, multiple 785 * slots, and mark callback channel down on communication errors. 786 */ 787 static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata) 788 { 789 struct nfsd4_callback *cb = calldata; 790 struct nfs4_client *clp = cb->cb_clp; 791 u32 minorversion = clp->cl_minorversion; 792 793 cb->cb_minorversion = minorversion; 794 if (minorversion) { 795 if (!nfsd41_cb_get_slot(clp, task)) 796 return; 797 } 798 spin_lock(&clp->cl_lock); 799 if (list_empty(&cb->cb_per_client)) { 800 /* This is the first call, not a restart */ 801 cb->cb_done = false; 802 list_add(&cb->cb_per_client, &clp->cl_callbacks); 803 } 804 spin_unlock(&clp->cl_lock); 805 rpc_call_start(task); 806 } 807 808 static void nfsd4_cb_done(struct rpc_task *task, void *calldata) 809 { 810 struct nfsd4_callback *cb = calldata; 811 struct nfs4_client *clp = cb->cb_clp; 812 813 dprintk("%s: minorversion=%d\n", __func__, 814 clp->cl_minorversion); 815 816 if (clp->cl_minorversion) { 817 /* No need for lock, access serialized in nfsd4_cb_prepare */ 818 ++clp->cl_cb_session->se_cb_seq_nr; 819 clear_bit(0, &clp->cl_cb_slot_busy); 820 rpc_wake_up_next(&clp->cl_cb_waitq); 821 dprintk("%s: freed slot, new seqid=%d\n", __func__, 822 clp->cl_cb_session->se_cb_seq_nr); 823 } 824 825 if (clp->cl_cb_client != task->tk_client) { 826 /* We're shutting down or changing cl_cb_client; leave 827 * it to nfsd4_process_cb_update to restart the call if 828 * necessary. */ 829 return; 830 } 831 832 if (cb->cb_done) 833 return; 834 835 switch (cb->cb_ops->done(cb, task)) { 836 case 0: 837 task->tk_status = 0; 838 rpc_restart_call_prepare(task); 839 return; 840 case 1: 841 break; 842 case -1: 843 /* Network partition? */ 844 nfsd4_mark_cb_down(clp, task->tk_status); 845 break; 846 default: 847 BUG(); 848 } 849 cb->cb_done = true; 850 } 851 852 static void nfsd4_cb_release(void *calldata) 853 { 854 struct nfsd4_callback *cb = calldata; 855 struct nfs4_client *clp = cb->cb_clp; 856 857 if (cb->cb_done) { 858 spin_lock(&clp->cl_lock); 859 list_del(&cb->cb_per_client); 860 spin_unlock(&clp->cl_lock); 861 862 cb->cb_ops->release(cb); 863 } 864 } 865 866 static const struct rpc_call_ops nfsd4_cb_ops = { 867 .rpc_call_prepare = nfsd4_cb_prepare, 868 .rpc_call_done = nfsd4_cb_done, 869 .rpc_release = nfsd4_cb_release, 870 }; 871 872 int nfsd4_create_callback_queue(void) 873 { 874 callback_wq = create_singlethread_workqueue("nfsd4_callbacks"); 875 if (!callback_wq) 876 return -ENOMEM; 877 return 0; 878 } 879 880 void nfsd4_destroy_callback_queue(void) 881 { 882 destroy_workqueue(callback_wq); 883 } 884 885 /* must be called under the state lock */ 886 void nfsd4_shutdown_callback(struct nfs4_client *clp) 887 { 888 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags); 889 /* 890 * Note this won't actually result in a null callback; 891 * instead, nfsd4_run_cb_null() will detect the killed 892 * client, destroy the rpc client, and stop: 893 */ 894 nfsd4_run_cb(&clp->cl_cb_null); 895 flush_workqueue(callback_wq); 896 } 897 898 /* requires cl_lock: */ 899 static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp) 900 { 901 struct nfsd4_session *s; 902 struct nfsd4_conn *c; 903 904 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) { 905 list_for_each_entry(c, &s->se_conns, cn_persession) { 906 if (c->cn_flags & NFS4_CDFC4_BACK) 907 return c; 908 } 909 } 910 return NULL; 911 } 912 913 static void nfsd4_process_cb_update(struct nfsd4_callback *cb) 914 { 915 struct nfs4_cb_conn conn; 916 struct nfs4_client *clp = cb->cb_clp; 917 struct nfsd4_session *ses = NULL; 918 struct nfsd4_conn *c; 919 int err; 920 921 /* 922 * This is either an update, or the client dying; in either case, 923 * kill the old client: 924 */ 925 if (clp->cl_cb_client) { 926 rpc_shutdown_client(clp->cl_cb_client); 927 clp->cl_cb_client = NULL; 928 put_rpccred(clp->cl_cb_cred); 929 clp->cl_cb_cred = NULL; 930 } 931 if (clp->cl_cb_conn.cb_xprt) { 932 svc_xprt_put(clp->cl_cb_conn.cb_xprt); 933 clp->cl_cb_conn.cb_xprt = NULL; 934 } 935 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) 936 return; 937 spin_lock(&clp->cl_lock); 938 /* 939 * Only serialized callback code is allowed to clear these 940 * flags; main nfsd code can only set them: 941 */ 942 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)); 943 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags); 944 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn)); 945 c = __nfsd4_find_backchannel(clp); 946 if (c) { 947 svc_xprt_get(c->cn_xprt); 948 conn.cb_xprt = c->cn_xprt; 949 ses = c->cn_session; 950 } 951 spin_unlock(&clp->cl_lock); 952 953 err = setup_callback_client(clp, &conn, ses); 954 if (err) { 955 nfsd4_mark_cb_down(clp, err); 956 return; 957 } 958 /* Yay, the callback channel's back! Restart any callbacks: */ 959 list_for_each_entry(cb, &clp->cl_callbacks, cb_per_client) 960 queue_work(callback_wq, &cb->cb_work); 961 } 962 963 static void 964 nfsd4_run_cb_work(struct work_struct *work) 965 { 966 struct nfsd4_callback *cb = 967 container_of(work, struct nfsd4_callback, cb_work); 968 struct nfs4_client *clp = cb->cb_clp; 969 struct rpc_clnt *clnt; 970 971 if (cb->cb_ops && cb->cb_ops->prepare) 972 cb->cb_ops->prepare(cb); 973 974 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK) 975 nfsd4_process_cb_update(cb); 976 977 clnt = clp->cl_cb_client; 978 if (!clnt) { 979 /* Callback channel broken, or client killed; give up: */ 980 if (cb->cb_ops && cb->cb_ops->release) 981 cb->cb_ops->release(cb); 982 return; 983 } 984 cb->cb_msg.rpc_cred = clp->cl_cb_cred; 985 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN, 986 cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb); 987 } 988 989 void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp, 990 struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op) 991 { 992 cb->cb_clp = clp; 993 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op]; 994 cb->cb_msg.rpc_argp = cb; 995 cb->cb_msg.rpc_resp = cb; 996 cb->cb_ops = ops; 997 INIT_WORK(&cb->cb_work, nfsd4_run_cb_work); 998 INIT_LIST_HEAD(&cb->cb_per_client); 999 cb->cb_done = true; 1000 } 1001 1002 void nfsd4_run_cb(struct nfsd4_callback *cb) 1003 { 1004 queue_work(callback_wq, &cb->cb_work); 1005 } 1006