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(nfserr); 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 status = nfs_cb_stat_to_errno(nfserr); 568 out: 569 return status; 570 } 571 572 /* 573 * RPC procedure tables 574 */ 575 #define PROC(proc, call, argtype, restype) \ 576 [NFSPROC4_CLNT_##proc] = { \ 577 .p_proc = NFSPROC4_CB_##call, \ 578 .p_encode = (kxdreproc_t)nfs4_xdr_enc_##argtype, \ 579 .p_decode = (kxdrdproc_t)nfs4_xdr_dec_##restype, \ 580 .p_arglen = NFS4_enc_##argtype##_sz, \ 581 .p_replen = NFS4_dec_##restype##_sz, \ 582 .p_statidx = NFSPROC4_CB_##call, \ 583 .p_name = #proc, \ 584 } 585 586 static struct rpc_procinfo nfs4_cb_procedures[] = { 587 PROC(CB_NULL, NULL, cb_null, cb_null), 588 PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall), 589 }; 590 591 static struct rpc_version nfs_cb_version4 = { 592 /* 593 * Note on the callback rpc program version number: despite language in rfc 594 * 5661 section 18.36.3 requiring servers to use 4 in this field, the 595 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and 596 * in practice that appears to be what implementations use. The section 597 * 18.36.3 language is expected to be fixed in an erratum. 598 */ 599 .number = 1, 600 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures), 601 .procs = nfs4_cb_procedures 602 }; 603 604 static struct rpc_version *nfs_cb_version[] = { 605 &nfs_cb_version4, 606 }; 607 608 static struct rpc_program cb_program; 609 610 static struct rpc_stat cb_stats = { 611 .program = &cb_program 612 }; 613 614 #define NFS4_CALLBACK 0x40000000 615 static struct rpc_program cb_program = { 616 .name = "nfs4_cb", 617 .number = NFS4_CALLBACK, 618 .nrvers = ARRAY_SIZE(nfs_cb_version), 619 .version = nfs_cb_version, 620 .stats = &cb_stats, 621 .pipe_dir_name = "/nfsd4_cb", 622 }; 623 624 static int max_cb_time(void) 625 { 626 return max(nfsd4_lease/10, (time_t)1) * HZ; 627 } 628 629 630 static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses) 631 { 632 struct rpc_timeout timeparms = { 633 .to_initval = max_cb_time(), 634 .to_retries = 0, 635 }; 636 struct rpc_create_args args = { 637 .net = &init_net, 638 .address = (struct sockaddr *) &conn->cb_addr, 639 .addrsize = conn->cb_addrlen, 640 .saddress = (struct sockaddr *) &conn->cb_saddr, 641 .timeout = &timeparms, 642 .program = &cb_program, 643 .version = 0, 644 .authflavor = clp->cl_flavor, 645 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET), 646 }; 647 struct rpc_clnt *client; 648 649 if (clp->cl_minorversion == 0) { 650 if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5)) 651 return -EINVAL; 652 args.client_name = clp->cl_principal; 653 args.prognumber = conn->cb_prog, 654 args.protocol = XPRT_TRANSPORT_TCP; 655 clp->cl_cb_ident = conn->cb_ident; 656 } else { 657 if (!conn->cb_xprt) 658 return -EINVAL; 659 clp->cl_cb_conn.cb_xprt = conn->cb_xprt; 660 clp->cl_cb_session = ses; 661 args.bc_xprt = conn->cb_xprt; 662 args.prognumber = clp->cl_cb_session->se_cb_prog; 663 args.protocol = XPRT_TRANSPORT_BC_TCP; 664 } 665 /* Create RPC client */ 666 client = rpc_create(&args); 667 if (IS_ERR(client)) { 668 dprintk("NFSD: couldn't create callback client: %ld\n", 669 PTR_ERR(client)); 670 return PTR_ERR(client); 671 } 672 clp->cl_cb_client = client; 673 return 0; 674 675 } 676 677 static void warn_no_callback_path(struct nfs4_client *clp, int reason) 678 { 679 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n", 680 (int)clp->cl_name.len, clp->cl_name.data, reason); 681 } 682 683 static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason) 684 { 685 clp->cl_cb_state = NFSD4_CB_DOWN; 686 warn_no_callback_path(clp, reason); 687 } 688 689 static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata) 690 { 691 struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null); 692 693 if (task->tk_status) 694 nfsd4_mark_cb_down(clp, task->tk_status); 695 else 696 clp->cl_cb_state = NFSD4_CB_UP; 697 } 698 699 static const struct rpc_call_ops nfsd4_cb_probe_ops = { 700 /* XXX: release method to ensure we set the cb channel down if 701 * necessary on early failure? */ 702 .rpc_call_done = nfsd4_cb_probe_done, 703 }; 704 705 static struct rpc_cred *callback_cred; 706 707 int set_callback_cred(void) 708 { 709 if (callback_cred) 710 return 0; 711 callback_cred = rpc_lookup_machine_cred(); 712 if (!callback_cred) 713 return -ENOMEM; 714 return 0; 715 } 716 717 static struct workqueue_struct *callback_wq; 718 719 static void run_nfsd4_cb(struct nfsd4_callback *cb) 720 { 721 queue_work(callback_wq, &cb->cb_work); 722 } 723 724 static void do_probe_callback(struct nfs4_client *clp) 725 { 726 struct nfsd4_callback *cb = &clp->cl_cb_null; 727 728 cb->cb_op = NULL; 729 cb->cb_clp = clp; 730 731 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL]; 732 cb->cb_msg.rpc_argp = NULL; 733 cb->cb_msg.rpc_resp = NULL; 734 cb->cb_msg.rpc_cred = callback_cred; 735 736 cb->cb_ops = &nfsd4_cb_probe_ops; 737 738 run_nfsd4_cb(cb); 739 } 740 741 /* 742 * Poke the callback thread to process any updates to the callback 743 * parameters, and send a null probe. 744 */ 745 void nfsd4_probe_callback(struct nfs4_client *clp) 746 { 747 /* XXX: atomicity? Also, should we be using cl_cb_flags? */ 748 clp->cl_cb_state = NFSD4_CB_UNKNOWN; 749 set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_cb_flags); 750 do_probe_callback(clp); 751 } 752 753 void nfsd4_probe_callback_sync(struct nfs4_client *clp) 754 { 755 nfsd4_probe_callback(clp); 756 flush_workqueue(callback_wq); 757 } 758 759 void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn) 760 { 761 clp->cl_cb_state = NFSD4_CB_UNKNOWN; 762 spin_lock(&clp->cl_lock); 763 memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn)); 764 spin_unlock(&clp->cl_lock); 765 } 766 767 /* 768 * There's currently a single callback channel slot. 769 * If the slot is available, then mark it busy. Otherwise, set the 770 * thread for sleeping on the callback RPC wait queue. 771 */ 772 static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task) 773 { 774 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) { 775 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL); 776 dprintk("%s slot is busy\n", __func__); 777 return false; 778 } 779 return true; 780 } 781 782 /* 783 * TODO: cb_sequence should support referring call lists, cachethis, multiple 784 * slots, and mark callback channel down on communication errors. 785 */ 786 static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata) 787 { 788 struct nfsd4_callback *cb = calldata; 789 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall); 790 struct nfs4_client *clp = dp->dl_client; 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_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall); 812 struct nfs4_client *clp = dp->dl_client; 813 814 dprintk("%s: minorversion=%d\n", __func__, 815 clp->cl_minorversion); 816 817 if (clp->cl_minorversion) { 818 /* No need for lock, access serialized in nfsd4_cb_prepare */ 819 ++clp->cl_cb_session->se_cb_seq_nr; 820 clear_bit(0, &clp->cl_cb_slot_busy); 821 rpc_wake_up_next(&clp->cl_cb_waitq); 822 dprintk("%s: freed slot, new seqid=%d\n", __func__, 823 clp->cl_cb_session->se_cb_seq_nr); 824 825 /* We're done looking into the sequence information */ 826 task->tk_msg.rpc_resp = NULL; 827 } 828 } 829 830 831 static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata) 832 { 833 struct nfsd4_callback *cb = calldata; 834 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall); 835 struct nfs4_client *clp = dp->dl_client; 836 struct rpc_clnt *current_rpc_client = clp->cl_cb_client; 837 838 nfsd4_cb_done(task, calldata); 839 840 if (current_rpc_client != task->tk_client) { 841 /* We're shutting down or changing cl_cb_client; leave 842 * it to nfsd4_process_cb_update to restart the call if 843 * necessary. */ 844 return; 845 } 846 847 if (cb->cb_done) 848 return; 849 switch (task->tk_status) { 850 case 0: 851 cb->cb_done = true; 852 return; 853 case -EBADHANDLE: 854 case -NFS4ERR_BAD_STATEID: 855 /* Race: client probably got cb_recall 856 * before open reply granting delegation */ 857 break; 858 default: 859 /* Network partition? */ 860 nfsd4_mark_cb_down(clp, task->tk_status); 861 } 862 if (dp->dl_retries--) { 863 rpc_delay(task, 2*HZ); 864 task->tk_status = 0; 865 rpc_restart_call_prepare(task); 866 return; 867 } 868 nfsd4_mark_cb_down(clp, task->tk_status); 869 cb->cb_done = true; 870 } 871 872 static void nfsd4_cb_recall_release(void *calldata) 873 { 874 struct nfsd4_callback *cb = calldata; 875 struct nfs4_client *clp = cb->cb_clp; 876 struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall); 877 878 if (cb->cb_done) { 879 spin_lock(&clp->cl_lock); 880 list_del(&cb->cb_per_client); 881 spin_unlock(&clp->cl_lock); 882 nfs4_put_delegation(dp); 883 } 884 } 885 886 static const struct rpc_call_ops nfsd4_cb_recall_ops = { 887 .rpc_call_prepare = nfsd4_cb_prepare, 888 .rpc_call_done = nfsd4_cb_recall_done, 889 .rpc_release = nfsd4_cb_recall_release, 890 }; 891 892 int nfsd4_create_callback_queue(void) 893 { 894 callback_wq = create_singlethread_workqueue("nfsd4_callbacks"); 895 if (!callback_wq) 896 return -ENOMEM; 897 return 0; 898 } 899 900 void nfsd4_destroy_callback_queue(void) 901 { 902 destroy_workqueue(callback_wq); 903 } 904 905 /* must be called under the state lock */ 906 void nfsd4_shutdown_callback(struct nfs4_client *clp) 907 { 908 set_bit(NFSD4_CLIENT_KILL, &clp->cl_cb_flags); 909 /* 910 * Note this won't actually result in a null callback; 911 * instead, nfsd4_do_callback_rpc() will detect the killed 912 * client, destroy the rpc client, and stop: 913 */ 914 do_probe_callback(clp); 915 flush_workqueue(callback_wq); 916 } 917 918 static void nfsd4_release_cb(struct nfsd4_callback *cb) 919 { 920 if (cb->cb_ops->rpc_release) 921 cb->cb_ops->rpc_release(cb); 922 } 923 924 /* requires cl_lock: */ 925 static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp) 926 { 927 struct nfsd4_session *s; 928 struct nfsd4_conn *c; 929 930 list_for_each_entry(s, &clp->cl_sessions, se_perclnt) { 931 list_for_each_entry(c, &s->se_conns, cn_persession) { 932 if (c->cn_flags & NFS4_CDFC4_BACK) 933 return c; 934 } 935 } 936 return NULL; 937 } 938 939 static void nfsd4_process_cb_update(struct nfsd4_callback *cb) 940 { 941 struct nfs4_cb_conn conn; 942 struct nfs4_client *clp = cb->cb_clp; 943 struct nfsd4_session *ses = NULL; 944 struct nfsd4_conn *c; 945 int err; 946 947 /* 948 * This is either an update, or the client dying; in either case, 949 * kill the old client: 950 */ 951 if (clp->cl_cb_client) { 952 rpc_shutdown_client(clp->cl_cb_client); 953 clp->cl_cb_client = NULL; 954 } 955 if (clp->cl_cb_conn.cb_xprt) { 956 svc_xprt_put(clp->cl_cb_conn.cb_xprt); 957 clp->cl_cb_conn.cb_xprt = NULL; 958 } 959 if (test_bit(NFSD4_CLIENT_KILL, &clp->cl_cb_flags)) 960 return; 961 spin_lock(&clp->cl_lock); 962 /* 963 * Only serialized callback code is allowed to clear these 964 * flags; main nfsd code can only set them: 965 */ 966 BUG_ON(!clp->cl_cb_flags); 967 clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_cb_flags); 968 memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn)); 969 c = __nfsd4_find_backchannel(clp); 970 if (c) { 971 svc_xprt_get(c->cn_xprt); 972 conn.cb_xprt = c->cn_xprt; 973 ses = c->cn_session; 974 } 975 spin_unlock(&clp->cl_lock); 976 977 err = setup_callback_client(clp, &conn, ses); 978 if (err) { 979 warn_no_callback_path(clp, err); 980 return; 981 } 982 /* Yay, the callback channel's back! Restart any callbacks: */ 983 list_for_each_entry(cb, &clp->cl_callbacks, cb_per_client) 984 run_nfsd4_cb(cb); 985 } 986 987 void nfsd4_do_callback_rpc(struct work_struct *w) 988 { 989 struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, cb_work); 990 struct nfs4_client *clp = cb->cb_clp; 991 struct rpc_clnt *clnt; 992 993 if (clp->cl_cb_flags) 994 nfsd4_process_cb_update(cb); 995 996 clnt = clp->cl_cb_client; 997 if (!clnt) { 998 /* Callback channel broken, or client killed; give up: */ 999 nfsd4_release_cb(cb); 1000 return; 1001 } 1002 rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN, 1003 cb->cb_ops, cb); 1004 } 1005 1006 void nfsd4_cb_recall(struct nfs4_delegation *dp) 1007 { 1008 struct nfsd4_callback *cb = &dp->dl_recall; 1009 struct nfs4_client *clp = dp->dl_client; 1010 1011 dp->dl_retries = 1; 1012 cb->cb_op = dp; 1013 cb->cb_clp = clp; 1014 cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL]; 1015 cb->cb_msg.rpc_argp = cb; 1016 cb->cb_msg.rpc_resp = cb; 1017 cb->cb_msg.rpc_cred = callback_cred; 1018 1019 cb->cb_ops = &nfsd4_cb_recall_ops; 1020 dp->dl_retries = 1; 1021 1022 INIT_LIST_HEAD(&cb->cb_per_client); 1023 cb->cb_done = true; 1024 1025 run_nfsd4_cb(&dp->dl_recall); 1026 } 1027