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