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 int *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 = nfs_cb_stat_to_errno(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 cb->cb_seq_status = status; 439 return status; 440 out_overflow: 441 print_overflow_msg(__func__, xdr); 442 status = -EIO; 443 goto out; 444 } 445 446 static int decode_cb_sequence4res(struct xdr_stream *xdr, 447 struct nfsd4_callback *cb) 448 { 449 int status; 450 451 if (cb->cb_minorversion == 0) 452 return 0; 453 454 status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &cb->cb_seq_status); 455 if (unlikely(status || cb->cb_seq_status)) 456 return status; 457 458 return decode_cb_sequence4resok(xdr, cb); 459 } 460 461 /* 462 * NFSv4.0 and NFSv4.1 XDR encode functions 463 * 464 * NFSv4.0 callback argument types are defined in section 15 of RFC 465 * 3530: "Network File System (NFS) version 4 Protocol" and section 20 466 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1 467 * Protocol". 468 */ 469 470 /* 471 * NB: Without this zero space reservation, callbacks over krb5p fail 472 */ 473 static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr, 474 void *__unused) 475 { 476 xdr_reserve_space(xdr, 0); 477 } 478 479 /* 480 * 20.2. Operation 4: CB_RECALL - Recall a Delegation 481 */ 482 static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr, 483 const struct nfsd4_callback *cb) 484 { 485 const struct nfs4_delegation *dp = cb_to_delegation(cb); 486 struct nfs4_cb_compound_hdr hdr = { 487 .ident = cb->cb_clp->cl_cb_ident, 488 .minorversion = cb->cb_minorversion, 489 }; 490 491 encode_cb_compound4args(xdr, &hdr); 492 encode_cb_sequence4args(xdr, cb, &hdr); 493 encode_cb_recall4args(xdr, dp, &hdr); 494 encode_cb_nops(&hdr); 495 } 496 497 498 /* 499 * NFSv4.0 and NFSv4.1 XDR decode functions 500 * 501 * NFSv4.0 callback result types are defined in section 15 of RFC 502 * 3530: "Network File System (NFS) version 4 Protocol" and section 20 503 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1 504 * Protocol". 505 */ 506 507 static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr, 508 void *__unused) 509 { 510 return 0; 511 } 512 513 /* 514 * 20.2. Operation 4: CB_RECALL - Recall a Delegation 515 */ 516 static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, 517 struct xdr_stream *xdr, 518 struct nfsd4_callback *cb) 519 { 520 struct nfs4_cb_compound_hdr hdr; 521 int status; 522 523 status = decode_cb_compound4res(xdr, &hdr); 524 if (unlikely(status)) 525 return status; 526 527 if (cb != NULL) { 528 status = decode_cb_sequence4res(xdr, cb); 529 if (unlikely(status || cb->cb_seq_status)) 530 return status; 531 } 532 533 return decode_cb_op_status(xdr, OP_CB_RECALL, &cb->cb_status); 534 } 535 536 #ifdef CONFIG_NFSD_PNFS 537 /* 538 * CB_LAYOUTRECALL4args 539 * 540 * struct layoutrecall_file4 { 541 * nfs_fh4 lor_fh; 542 * offset4 lor_offset; 543 * length4 lor_length; 544 * stateid4 lor_stateid; 545 * }; 546 * 547 * union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) { 548 * case LAYOUTRECALL4_FILE: 549 * layoutrecall_file4 lor_layout; 550 * case LAYOUTRECALL4_FSID: 551 * fsid4 lor_fsid; 552 * case LAYOUTRECALL4_ALL: 553 * void; 554 * }; 555 * 556 * struct CB_LAYOUTRECALL4args { 557 * layouttype4 clora_type; 558 * layoutiomode4 clora_iomode; 559 * bool clora_changed; 560 * layoutrecall4 clora_recall; 561 * }; 562 */ 563 static void encode_cb_layout4args(struct xdr_stream *xdr, 564 const struct nfs4_layout_stateid *ls, 565 struct nfs4_cb_compound_hdr *hdr) 566 { 567 __be32 *p; 568 569 BUG_ON(hdr->minorversion == 0); 570 571 p = xdr_reserve_space(xdr, 5 * 4); 572 *p++ = cpu_to_be32(OP_CB_LAYOUTRECALL); 573 *p++ = cpu_to_be32(ls->ls_layout_type); 574 *p++ = cpu_to_be32(IOMODE_ANY); 575 *p++ = cpu_to_be32(1); 576 *p = cpu_to_be32(RETURN_FILE); 577 578 encode_nfs_fh4(xdr, &ls->ls_stid.sc_file->fi_fhandle); 579 580 p = xdr_reserve_space(xdr, 2 * 8); 581 p = xdr_encode_hyper(p, 0); 582 xdr_encode_hyper(p, NFS4_MAX_UINT64); 583 584 encode_stateid4(xdr, &ls->ls_recall_sid); 585 586 hdr->nops++; 587 } 588 589 static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req, 590 struct xdr_stream *xdr, 591 const struct nfsd4_callback *cb) 592 { 593 const struct nfs4_layout_stateid *ls = 594 container_of(cb, struct nfs4_layout_stateid, ls_recall); 595 struct nfs4_cb_compound_hdr hdr = { 596 .ident = 0, 597 .minorversion = cb->cb_minorversion, 598 }; 599 600 encode_cb_compound4args(xdr, &hdr); 601 encode_cb_sequence4args(xdr, cb, &hdr); 602 encode_cb_layout4args(xdr, ls, &hdr); 603 encode_cb_nops(&hdr); 604 } 605 606 static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp, 607 struct xdr_stream *xdr, 608 struct nfsd4_callback *cb) 609 { 610 struct nfs4_cb_compound_hdr hdr; 611 int status; 612 613 status = decode_cb_compound4res(xdr, &hdr); 614 if (unlikely(status)) 615 return status; 616 617 if (cb) { 618 status = decode_cb_sequence4res(xdr, cb); 619 if (unlikely(status || cb->cb_seq_status)) 620 return status; 621 } 622 return decode_cb_op_status(xdr, OP_CB_LAYOUTRECALL, &cb->cb_status); 623 } 624 #endif /* CONFIG_NFSD_PNFS */ 625 626 /* 627 * RPC procedure tables 628 */ 629 #define PROC(proc, call, argtype, restype) \ 630 [NFSPROC4_CLNT_##proc] = { \ 631 .p_proc = NFSPROC4_CB_##call, \ 632 .p_encode = (kxdreproc_t)nfs4_xdr_enc_##argtype, \ 633 .p_decode = (kxdrdproc_t)nfs4_xdr_dec_##restype, \ 634 .p_arglen = NFS4_enc_##argtype##_sz, \ 635 .p_replen = NFS4_dec_##restype##_sz, \ 636 .p_statidx = NFSPROC4_CB_##call, \ 637 .p_name = #proc, \ 638 } 639 640 static struct rpc_procinfo nfs4_cb_procedures[] = { 641 PROC(CB_NULL, NULL, cb_null, cb_null), 642 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall), 643 #ifdef CONFIG_NFSD_PNFS 644 PROC(CB_LAYOUT, COMPOUND, cb_layout, cb_layout), 645 #endif 646 }; 647 648 static struct rpc_version nfs_cb_version4 = { 649 /* 650 * Note on the callback rpc program version number: despite language in rfc 651 * 5661 section 18.36.3 requiring servers to use 4 in this field, the 652 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and 653 * in practice that appears to be what implementations use. The section 654 * 18.36.3 language is expected to be fixed in an erratum. 655 */ 656 .number = 1, 657 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures), 658 .procs = nfs4_cb_procedures 659 }; 660 661 static const struct rpc_version *nfs_cb_version[] = { 662 &nfs_cb_version4, 663 }; 664 665 static const struct rpc_program cb_program; 666 667 static struct rpc_stat cb_stats = { 668 .program = &cb_program 669 }; 670 671 #define NFS4_CALLBACK 0x40000000 672 static const struct rpc_program cb_program = { 673 .name = "nfs4_cb", 674 .number = NFS4_CALLBACK, 675 .nrvers = ARRAY_SIZE(nfs_cb_version), 676 .version = nfs_cb_version, 677 .stats = &cb_stats, 678 .pipe_dir_name = "nfsd4_cb", 679 }; 680 681 static int max_cb_time(struct net *net) 682 { 683 struct nfsd_net *nn = net_generic(net, nfsd_net_id); 684 return max(nn->nfsd4_lease/10, (time_t)1) * HZ; 685 } 686 687 static struct rpc_cred *callback_cred; 688 689 int set_callback_cred(void) 690 { 691 if (callback_cred) 692 return 0; 693 callback_cred = rpc_lookup_machine_cred("nfs"); 694 if (!callback_cred) 695 return -ENOMEM; 696 return 0; 697 } 698 699 static struct rpc_cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses) 700 { 701 if (clp->cl_minorversion == 0) { 702 return get_rpccred(callback_cred); 703 } else { 704 struct rpc_auth *auth = client->cl_auth; 705 struct auth_cred acred = {}; 706 707 acred.uid = ses->se_cb_sec.uid; 708 acred.gid = ses->se_cb_sec.gid; 709 return auth->au_ops->lookup_cred(client->cl_auth, &acred, 0); 710 } 711 } 712 713 static struct rpc_clnt *create_backchannel_client(struct rpc_create_args *args) 714 { 715 struct rpc_xprt *xprt; 716 717 if (args->protocol != XPRT_TRANSPORT_BC_TCP) 718 return rpc_create(args); 719 720 xprt = args->bc_xprt->xpt_bc_xprt; 721 if (xprt) { 722 xprt_get(xprt); 723 return rpc_create_xprt(args, xprt); 724 } 725 726 return rpc_create(args); 727 } 728 729 static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses) 730 { 731 int maxtime = max_cb_time(clp->net); 732 struct rpc_timeout timeparms = { 733 .to_initval = maxtime, 734 .to_retries = 0, 735 .to_maxval = maxtime, 736 }; 737 struct rpc_create_args args = { 738 .net = clp->net, 739 .address = (struct sockaddr *) &conn->cb_addr, 740 .addrsize = conn->cb_addrlen, 741 .saddress = (struct sockaddr *) &conn->cb_saddr, 742 .timeout = &timeparms, 743 .program = &cb_program, 744 .version = 0, 745 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET), 746 }; 747 struct rpc_clnt *client; 748 struct rpc_cred *cred; 749 750 if (clp->cl_minorversion == 0) { 751 if (!clp->cl_cred.cr_principal && 752 (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5)) 753 return -EINVAL; 754 args.client_name = clp->cl_cred.cr_principal; 755 args.prognumber = conn->cb_prog; 756 args.protocol = XPRT_TRANSPORT_TCP; 757 args.authflavor = clp->cl_cred.cr_flavor; 758 clp->cl_cb_ident = conn->cb_ident; 759 } else { 760 if (!conn->cb_xprt) 761 return -EINVAL; 762 clp->cl_cb_conn.cb_xprt = conn->cb_xprt; 763 clp->cl_cb_session = ses; 764 args.bc_xprt = conn->cb_xprt; 765 args.prognumber = clp->cl_cb_session->se_cb_prog; 766 args.protocol = conn->cb_xprt->xpt_class->xcl_ident | 767 XPRT_TRANSPORT_BC; 768 args.authflavor = ses->se_cb_sec.flavor; 769 } 770 /* Create RPC client */ 771 client = create_backchannel_client(&args); 772 if (IS_ERR(client)) { 773 dprintk("NFSD: couldn't create callback client: %ld\n", 774 PTR_ERR(client)); 775 return PTR_ERR(client); 776 } 777 cred = get_backchannel_cred(clp, client, ses); 778 if (IS_ERR(cred)) { 779 rpc_shutdown_client(client); 780 return PTR_ERR(cred); 781 } 782 clp->cl_cb_client = client; 783 clp->cl_cb_cred = cred; 784 return 0; 785 } 786 787 static void warn_no_callback_path(struct nfs4_client *clp, int reason) 788 { 789 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n", 790 (int)clp->cl_name.len, clp->cl_name.data, reason); 791 } 792 793 static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason) 794 { 795 clp->cl_cb_state = NFSD4_CB_DOWN; 796 warn_no_callback_path(clp, reason); 797 } 798 799 static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason) 800 { 801 clp->cl_cb_state = NFSD4_CB_FAULT; 802 warn_no_callback_path(clp, reason); 803 } 804 805 static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata) 806 { 807 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null); 808 809 if (task->tk_status) 810 nfsd4_mark_cb_down(clp, task->tk_status); 811 else 812 clp->cl_cb_state = NFSD4_CB_UP; 813 } 814 815 static const struct rpc_call_ops nfsd4_cb_probe_ops = { 816 /* XXX: release method to ensure we set the cb channel down if 817 * necessary on early failure? */ 818 .rpc_call_done = nfsd4_cb_probe_done, 819 }; 820 821 static struct workqueue_struct *callback_wq; 822 823 /* 824 * Poke the callback thread to process any updates to the callback 825 * parameters, and send a null probe. 826 */ 827 void nfsd4_probe_callback(struct nfs4_client *clp) 828 { 829 clp->cl_cb_state = NFSD4_CB_UNKNOWN; 830 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags); 831 nfsd4_run_cb(&clp->cl_cb_null); 832 } 833 834 void nfsd4_probe_callback_sync(struct nfs4_client *clp) 835 { 836 nfsd4_probe_callback(clp); 837 flush_workqueue(callback_wq); 838 } 839 840 void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn) 841 { 842 clp->cl_cb_state = NFSD4_CB_UNKNOWN; 843 spin_lock(&clp->cl_lock); 844 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn)); 845 spin_unlock(&clp->cl_lock); 846 } 847 848 /* 849 * There's currently a single callback channel slot. 850 * If the slot is available, then mark it busy. Otherwise, set the 851 * thread for sleeping on the callback RPC wait queue. 852 */ 853 static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task) 854 { 855 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) { 856 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL); 857 /* Race breaker */ 858 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) { 859 dprintk("%s slot is busy\n", __func__); 860 return false; 861 } 862 rpc_wake_up_queued_task(&clp->cl_cb_waitq, task); 863 } 864 return true; 865 } 866 867 /* 868 * TODO: cb_sequence should support referring call lists, cachethis, multiple 869 * slots, and mark callback channel down on communication errors. 870 */ 871 static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata) 872 { 873 struct nfsd4_callback *cb = calldata; 874 struct nfs4_client *clp = cb->cb_clp; 875 u32 minorversion = clp->cl_minorversion; 876 877 cb->cb_minorversion = minorversion; 878 /* 879 * cb_seq_status is only set in decode_cb_sequence4res, 880 * and so will remain 1 if an rpc level failure occurs. 881 */ 882 cb->cb_seq_status = 1; 883 cb->cb_status = 0; 884 if (minorversion) { 885 if (!nfsd41_cb_get_slot(clp, task)) 886 return; 887 } 888 rpc_call_start(task); 889 } 890 891 static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb) 892 { 893 struct nfs4_client *clp = cb->cb_clp; 894 struct nfsd4_session *session = clp->cl_cb_session; 895 bool ret = true; 896 897 if (!clp->cl_minorversion) { 898 /* 899 * If the backchannel connection was shut down while this 900 * task was queued, we need to resubmit it after setting up 901 * a new backchannel connection. 902 * 903 * Note that if we lost our callback connection permanently 904 * the submission code will error out, so we don't need to 905 * handle that case here. 906 */ 907 if (task->tk_flags & RPC_TASK_KILLED) 908 goto need_restart; 909 910 return true; 911 } 912 913 switch (cb->cb_seq_status) { 914 case 0: 915 /* 916 * No need for lock, access serialized in nfsd4_cb_prepare 917 * 918 * RFC5661 20.9.3 919 * If CB_SEQUENCE returns an error, then the state of the slot 920 * (sequence ID, cached reply) MUST NOT change. 921 */ 922 ++session->se_cb_seq_nr; 923 break; 924 case -ESERVERFAULT: 925 ++session->se_cb_seq_nr; 926 case 1: 927 case -NFS4ERR_BADSESSION: 928 nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status); 929 ret = false; 930 break; 931 case -NFS4ERR_DELAY: 932 if (!rpc_restart_call(task)) 933 goto out; 934 935 rpc_delay(task, 2 * HZ); 936 return false; 937 case -NFS4ERR_BADSLOT: 938 goto retry_nowait; 939 case -NFS4ERR_SEQ_MISORDERED: 940 if (session->se_cb_seq_nr != 1) { 941 session->se_cb_seq_nr = 1; 942 goto retry_nowait; 943 } 944 break; 945 default: 946 dprintk("%s: unprocessed error %d\n", __func__, 947 cb->cb_seq_status); 948 } 949 950 clear_bit(0, &clp->cl_cb_slot_busy); 951 rpc_wake_up_next(&clp->cl_cb_waitq); 952 dprintk("%s: freed slot, new seqid=%d\n", __func__, 953 clp->cl_cb_session->se_cb_seq_nr); 954 955 if (task->tk_flags & RPC_TASK_KILLED) 956 goto need_restart; 957 out: 958 return ret; 959 retry_nowait: 960 if (rpc_restart_call_prepare(task)) 961 ret = false; 962 goto out; 963 need_restart: 964 task->tk_status = 0; 965 cb->cb_need_restart = true; 966 return false; 967 } 968 969 static void nfsd4_cb_done(struct rpc_task *task, void *calldata) 970 { 971 struct nfsd4_callback *cb = calldata; 972 struct nfs4_client *clp = cb->cb_clp; 973 974 dprintk("%s: minorversion=%d\n", __func__, 975 clp->cl_minorversion); 976 977 if (!nfsd4_cb_sequence_done(task, cb)) 978 return; 979 980 if (cb->cb_status) { 981 WARN_ON_ONCE(task->tk_status); 982 task->tk_status = cb->cb_status; 983 } 984 985 switch (cb->cb_ops->done(cb, task)) { 986 case 0: 987 task->tk_status = 0; 988 rpc_restart_call_prepare(task); 989 return; 990 case 1: 991 break; 992 case -1: 993 /* Network partition? */ 994 nfsd4_mark_cb_down(clp, task->tk_status); 995 break; 996 default: 997 BUG(); 998 } 999 } 1000 1001 static void nfsd4_cb_release(void *calldata) 1002 { 1003 struct nfsd4_callback *cb = calldata; 1004 1005 if (cb->cb_need_restart) 1006 nfsd4_run_cb(cb); 1007 else 1008 cb->cb_ops->release(cb); 1009 1010 } 1011 1012 static const struct rpc_call_ops nfsd4_cb_ops = { 1013 .rpc_call_prepare = nfsd4_cb_prepare, 1014 .rpc_call_done = nfsd4_cb_done, 1015 .rpc_release = nfsd4_cb_release, 1016 }; 1017 1018 int nfsd4_create_callback_queue(void) 1019 { 1020 callback_wq = create_singlethread_workqueue("nfsd4_callbacks"); 1021 if (!callback_wq) 1022 return -ENOMEM; 1023 return 0; 1024 } 1025 1026 void nfsd4_destroy_callback_queue(void) 1027 { 1028 destroy_workqueue(callback_wq); 1029 } 1030 1031 /* must be called under the state lock */ 1032 void nfsd4_shutdown_callback(struct nfs4_client *clp) 1033 { 1034 set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags); 1035 /* 1036 * Note this won't actually result in a null callback; 1037 * instead, nfsd4_run_cb_null() will detect the killed 1038 * client, destroy the rpc client, and stop: 1039 */ 1040 nfsd4_run_cb(&clp->cl_cb_null); 1041 flush_workqueue(callback_wq); 1042 } 1043 1044 /* requires cl_lock: */ 1045 static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp) 1046 { 1047 struct nfsd4_session *s; 1048 struct nfsd4_conn *c; 1049 1050 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) { 1051 list_for_each_entry(c, &s->se_conns, cn_persession) { 1052 if (c->cn_flags & NFS4_CDFC4_BACK) 1053 return c; 1054 } 1055 } 1056 return NULL; 1057 } 1058 1059 static void nfsd4_process_cb_update(struct nfsd4_callback *cb) 1060 { 1061 struct nfs4_cb_conn conn; 1062 struct nfs4_client *clp = cb->cb_clp; 1063 struct nfsd4_session *ses = NULL; 1064 struct nfsd4_conn *c; 1065 int err; 1066 1067 /* 1068 * This is either an update, or the client dying; in either case, 1069 * kill the old client: 1070 */ 1071 if (clp->cl_cb_client) { 1072 rpc_shutdown_client(clp->cl_cb_client); 1073 clp->cl_cb_client = NULL; 1074 put_rpccred(clp->cl_cb_cred); 1075 clp->cl_cb_cred = NULL; 1076 } 1077 if (clp->cl_cb_conn.cb_xprt) { 1078 svc_xprt_put(clp->cl_cb_conn.cb_xprt); 1079 clp->cl_cb_conn.cb_xprt = NULL; 1080 } 1081 if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) 1082 return; 1083 spin_lock(&clp->cl_lock); 1084 /* 1085 * Only serialized callback code is allowed to clear these 1086 * flags; main nfsd code can only set them: 1087 */ 1088 BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)); 1089 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags); 1090 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn)); 1091 c = __nfsd4_find_backchannel(clp); 1092 if (c) { 1093 svc_xprt_get(c->cn_xprt); 1094 conn.cb_xprt = c->cn_xprt; 1095 ses = c->cn_session; 1096 } 1097 spin_unlock(&clp->cl_lock); 1098 1099 err = setup_callback_client(clp, &conn, ses); 1100 if (err) { 1101 nfsd4_mark_cb_down(clp, err); 1102 return; 1103 } 1104 } 1105 1106 static void 1107 nfsd4_run_cb_work(struct work_struct *work) 1108 { 1109 struct nfsd4_callback *cb = 1110 container_of(work, struct nfsd4_callback, cb_work); 1111 struct nfs4_client *clp = cb->cb_clp; 1112 struct rpc_clnt *clnt; 1113 1114 if (cb->cb_need_restart) { 1115 cb->cb_need_restart = false; 1116 } else { 1117 if (cb->cb_ops && cb->cb_ops->prepare) 1118 cb->cb_ops->prepare(cb); 1119 } 1120 1121 if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK) 1122 nfsd4_process_cb_update(cb); 1123 1124 clnt = clp->cl_cb_client; 1125 if (!clnt) { 1126 /* Callback channel broken, or client killed; give up: */ 1127 if (cb->cb_ops && cb->cb_ops->release) 1128 cb->cb_ops->release(cb); 1129 return; 1130 } 1131 1132 /* 1133 * Don't send probe messages for 4.1 or later. 1134 */ 1135 if (!cb->cb_ops && clp->cl_minorversion) { 1136 clp->cl_cb_state = NFSD4_CB_UP; 1137 return; 1138 } 1139 1140 cb->cb_msg.rpc_cred = clp->cl_cb_cred; 1141 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN, 1142 cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb); 1143 } 1144 1145 void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp, 1146 struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op) 1147 { 1148 cb->cb_clp = clp; 1149 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op]; 1150 cb->cb_msg.rpc_argp = cb; 1151 cb->cb_msg.rpc_resp = cb; 1152 cb->cb_ops = ops; 1153 INIT_WORK(&cb->cb_work, nfsd4_run_cb_work); 1154 cb->cb_seq_status = 1; 1155 cb->cb_status = 0; 1156 cb->cb_need_restart = false; 1157 } 1158 1159 void nfsd4_run_cb(struct nfsd4_callback *cb) 1160 { 1161 queue_work(callback_wq, &cb->cb_work); 1162 } 1163