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