1 /* 2 * linux/fs/nfsd/nfs4callback.c 3 * 4 * Copyright (c) 2001 The Regents of the University of Michigan. 5 * All rights reserved. 6 * 7 * Kendrick Smith <kmsmith@umich.edu> 8 * Andy Adamson <andros@umich.edu> 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its 20 * contributors may be used to endorse or promote products derived 21 * from this software without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED 24 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 25 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 26 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 30 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 #include <linux/module.h> 37 #include <linux/list.h> 38 #include <linux/inet.h> 39 #include <linux/errno.h> 40 #include <linux/delay.h> 41 #include <linux/sched.h> 42 #include <linux/kthread.h> 43 #include <linux/sunrpc/xdr.h> 44 #include <linux/sunrpc/svc.h> 45 #include <linux/sunrpc/clnt.h> 46 #include <linux/nfsd/nfsd.h> 47 #include <linux/nfsd/state.h> 48 #include <linux/sunrpc/sched.h> 49 #include <linux/nfs4.h> 50 51 #define NFSDDBG_FACILITY NFSDDBG_PROC 52 53 #define NFSPROC4_CB_NULL 0 54 #define NFSPROC4_CB_COMPOUND 1 55 56 /* Index of predefined Linux callback client operations */ 57 58 enum { 59 NFSPROC4_CLNT_CB_NULL = 0, 60 NFSPROC4_CLNT_CB_RECALL, 61 }; 62 63 enum nfs_cb_opnum4 { 64 OP_CB_RECALL = 4, 65 }; 66 67 #define NFS4_MAXTAGLEN 20 68 69 #define NFS4_enc_cb_null_sz 0 70 #define NFS4_dec_cb_null_sz 0 71 #define cb_compound_enc_hdr_sz 4 72 #define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2)) 73 #define op_enc_sz 1 74 #define op_dec_sz 2 75 #define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2)) 76 #define enc_stateid_sz (NFS4_STATEID_SIZE >> 2) 77 #define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \ 78 1 + enc_stateid_sz + \ 79 enc_nfs4_fh_sz) 80 81 #define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \ 82 op_dec_sz) 83 84 /* 85 * Generic encode routines from fs/nfs/nfs4xdr.c 86 */ 87 static inline __be32 * 88 xdr_writemem(__be32 *p, const void *ptr, int nbytes) 89 { 90 int tmp = XDR_QUADLEN(nbytes); 91 if (!tmp) 92 return p; 93 p[tmp-1] = 0; 94 memcpy(p, ptr, nbytes); 95 return p + tmp; 96 } 97 98 #define WRITE32(n) *p++ = htonl(n) 99 #define WRITEMEM(ptr,nbytes) do { \ 100 p = xdr_writemem(p, ptr, nbytes); \ 101 } while (0) 102 #define RESERVE_SPACE(nbytes) do { \ 103 p = xdr_reserve_space(xdr, nbytes); \ 104 if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __func__); \ 105 BUG_ON(!p); \ 106 } while (0) 107 108 /* 109 * Generic decode routines from fs/nfs/nfs4xdr.c 110 */ 111 #define DECODE_TAIL \ 112 status = 0; \ 113 out: \ 114 return status; \ 115 xdr_error: \ 116 dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \ 117 status = -EIO; \ 118 goto out 119 120 #define READ32(x) (x) = ntohl(*p++) 121 #define READ64(x) do { \ 122 (x) = (u64)ntohl(*p++) << 32; \ 123 (x) |= ntohl(*p++); \ 124 } while (0) 125 #define READTIME(x) do { \ 126 p++; \ 127 (x.tv_sec) = ntohl(*p++); \ 128 (x.tv_nsec) = ntohl(*p++); \ 129 } while (0) 130 #define READ_BUF(nbytes) do { \ 131 p = xdr_inline_decode(xdr, nbytes); \ 132 if (!p) { \ 133 dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \ 134 __func__, __LINE__); \ 135 return -EIO; \ 136 } \ 137 } while (0) 138 139 struct nfs4_cb_compound_hdr { 140 int status; 141 u32 ident; 142 u32 nops; 143 u32 taglen; 144 char * tag; 145 }; 146 147 static struct { 148 int stat; 149 int errno; 150 } nfs_cb_errtbl[] = { 151 { NFS4_OK, 0 }, 152 { NFS4ERR_PERM, EPERM }, 153 { NFS4ERR_NOENT, ENOENT }, 154 { NFS4ERR_IO, EIO }, 155 { NFS4ERR_NXIO, ENXIO }, 156 { NFS4ERR_ACCESS, EACCES }, 157 { NFS4ERR_EXIST, EEXIST }, 158 { NFS4ERR_XDEV, EXDEV }, 159 { NFS4ERR_NOTDIR, ENOTDIR }, 160 { NFS4ERR_ISDIR, EISDIR }, 161 { NFS4ERR_INVAL, EINVAL }, 162 { NFS4ERR_FBIG, EFBIG }, 163 { NFS4ERR_NOSPC, ENOSPC }, 164 { NFS4ERR_ROFS, EROFS }, 165 { NFS4ERR_MLINK, EMLINK }, 166 { NFS4ERR_NAMETOOLONG, ENAMETOOLONG }, 167 { NFS4ERR_NOTEMPTY, ENOTEMPTY }, 168 { NFS4ERR_DQUOT, EDQUOT }, 169 { NFS4ERR_STALE, ESTALE }, 170 { NFS4ERR_BADHANDLE, EBADHANDLE }, 171 { NFS4ERR_BAD_COOKIE, EBADCOOKIE }, 172 { NFS4ERR_NOTSUPP, ENOTSUPP }, 173 { NFS4ERR_TOOSMALL, ETOOSMALL }, 174 { NFS4ERR_SERVERFAULT, ESERVERFAULT }, 175 { NFS4ERR_BADTYPE, EBADTYPE }, 176 { NFS4ERR_LOCKED, EAGAIN }, 177 { NFS4ERR_RESOURCE, EREMOTEIO }, 178 { NFS4ERR_SYMLINK, ELOOP }, 179 { NFS4ERR_OP_ILLEGAL, EOPNOTSUPP }, 180 { NFS4ERR_DEADLOCK, EDEADLK }, 181 { -1, EIO } 182 }; 183 184 static int 185 nfs_cb_stat_to_errno(int stat) 186 { 187 int i; 188 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) { 189 if (nfs_cb_errtbl[i].stat == stat) 190 return nfs_cb_errtbl[i].errno; 191 } 192 /* If we cannot translate the error, the recovery routines should 193 * handle it. 194 * Note: remaining NFSv4 error codes have values > 10000, so should 195 * not conflict with native Linux error codes. 196 */ 197 return stat; 198 } 199 200 /* 201 * XDR encode 202 */ 203 204 static int 205 encode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr) 206 { 207 __be32 * p; 208 209 RESERVE_SPACE(16); 210 WRITE32(0); /* tag length is always 0 */ 211 WRITE32(NFS4_MINOR_VERSION); 212 WRITE32(hdr->ident); 213 WRITE32(hdr->nops); 214 return 0; 215 } 216 217 static int 218 encode_cb_recall(struct xdr_stream *xdr, struct nfs4_cb_recall *cb_rec) 219 { 220 __be32 *p; 221 int len = cb_rec->cbr_fhlen; 222 223 RESERVE_SPACE(12+sizeof(cb_rec->cbr_stateid) + len); 224 WRITE32(OP_CB_RECALL); 225 WRITE32(cb_rec->cbr_stateid.si_generation); 226 WRITEMEM(&cb_rec->cbr_stateid.si_opaque, sizeof(stateid_opaque_t)); 227 WRITE32(cb_rec->cbr_trunc); 228 WRITE32(len); 229 WRITEMEM(cb_rec->cbr_fhval, len); 230 return 0; 231 } 232 233 static int 234 nfs4_xdr_enc_cb_null(struct rpc_rqst *req, __be32 *p) 235 { 236 struct xdr_stream xdrs, *xdr = &xdrs; 237 238 xdr_init_encode(&xdrs, &req->rq_snd_buf, p); 239 RESERVE_SPACE(0); 240 return 0; 241 } 242 243 static int 244 nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p, struct nfs4_cb_recall *args) 245 { 246 struct xdr_stream xdr; 247 struct nfs4_cb_compound_hdr hdr = { 248 .ident = args->cbr_ident, 249 .nops = 1, 250 }; 251 252 xdr_init_encode(&xdr, &req->rq_snd_buf, p); 253 encode_cb_compound_hdr(&xdr, &hdr); 254 return (encode_cb_recall(&xdr, args)); 255 } 256 257 258 static int 259 decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){ 260 __be32 *p; 261 262 READ_BUF(8); 263 READ32(hdr->status); 264 READ32(hdr->taglen); 265 READ_BUF(hdr->taglen + 4); 266 hdr->tag = (char *)p; 267 p += XDR_QUADLEN(hdr->taglen); 268 READ32(hdr->nops); 269 return 0; 270 } 271 272 static int 273 decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected) 274 { 275 __be32 *p; 276 u32 op; 277 int32_t nfserr; 278 279 READ_BUF(8); 280 READ32(op); 281 if (op != expected) { 282 dprintk("NFSD: decode_cb_op_hdr: Callback server returned " 283 " operation %d but we issued a request for %d\n", 284 op, expected); 285 return -EIO; 286 } 287 READ32(nfserr); 288 if (nfserr != NFS_OK) 289 return -nfs_cb_stat_to_errno(nfserr); 290 return 0; 291 } 292 293 static int 294 nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p) 295 { 296 return 0; 297 } 298 299 static int 300 nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p) 301 { 302 struct xdr_stream xdr; 303 struct nfs4_cb_compound_hdr hdr; 304 int status; 305 306 xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p); 307 status = decode_cb_compound_hdr(&xdr, &hdr); 308 if (status) 309 goto out; 310 status = decode_cb_op_hdr(&xdr, OP_CB_RECALL); 311 out: 312 return status; 313 } 314 315 /* 316 * RPC procedure tables 317 */ 318 #define PROC(proc, call, argtype, restype) \ 319 [NFSPROC4_CLNT_##proc] = { \ 320 .p_proc = NFSPROC4_CB_##call, \ 321 .p_encode = (kxdrproc_t) nfs4_xdr_##argtype, \ 322 .p_decode = (kxdrproc_t) nfs4_xdr_##restype, \ 323 .p_arglen = NFS4_##argtype##_sz, \ 324 .p_replen = NFS4_##restype##_sz, \ 325 .p_statidx = NFSPROC4_CB_##call, \ 326 .p_name = #proc, \ 327 } 328 329 static struct rpc_procinfo nfs4_cb_procedures[] = { 330 PROC(CB_NULL, NULL, enc_cb_null, dec_cb_null), 331 PROC(CB_RECALL, COMPOUND, enc_cb_recall, dec_cb_recall), 332 }; 333 334 static struct rpc_version nfs_cb_version4 = { 335 .number = 1, 336 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures), 337 .procs = nfs4_cb_procedures 338 }; 339 340 static struct rpc_version * nfs_cb_version[] = { 341 NULL, 342 &nfs_cb_version4, 343 }; 344 345 static struct rpc_program cb_program; 346 347 static struct rpc_stat cb_stats = { 348 .program = &cb_program 349 }; 350 351 #define NFS4_CALLBACK 0x40000000 352 static struct rpc_program cb_program = { 353 .name = "nfs4_cb", 354 .number = NFS4_CALLBACK, 355 .nrvers = ARRAY_SIZE(nfs_cb_version), 356 .version = nfs_cb_version, 357 .stats = &cb_stats, 358 .pipe_dir_name = "/nfsd4_cb", 359 }; 360 361 /* Reference counting, callback cleanup, etc., all look racy as heck. 362 * And why is cb_set an atomic? */ 363 364 static int do_probe_callback(void *data) 365 { 366 struct nfs4_client *clp = data; 367 struct sockaddr_in addr; 368 struct nfs4_callback *cb = &clp->cl_callback; 369 struct rpc_timeout timeparms = { 370 .to_initval = (NFSD_LEASE_TIME/4) * HZ, 371 .to_retries = 5, 372 .to_maxval = (NFSD_LEASE_TIME/2) * HZ, 373 .to_exponential = 1, 374 }; 375 struct rpc_create_args args = { 376 .protocol = IPPROTO_TCP, 377 .address = (struct sockaddr *)&addr, 378 .addrsize = sizeof(addr), 379 .timeout = &timeparms, 380 .program = &cb_program, 381 .prognumber = cb->cb_prog, 382 .version = nfs_cb_version[1]->number, 383 .authflavor = clp->cl_flavor, 384 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET), 385 .client_name = clp->cl_principal, 386 }; 387 struct rpc_message msg = { 388 .rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL], 389 .rpc_argp = clp, 390 }; 391 struct rpc_clnt *client; 392 int status; 393 394 if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5)) { 395 status = nfserr_cb_path_down; 396 goto out_err; 397 } 398 399 /* Initialize address */ 400 memset(&addr, 0, sizeof(addr)); 401 addr.sin_family = AF_INET; 402 addr.sin_port = htons(cb->cb_port); 403 addr.sin_addr.s_addr = htonl(cb->cb_addr); 404 405 /* Create RPC client */ 406 client = rpc_create(&args); 407 if (IS_ERR(client)) { 408 dprintk("NFSD: couldn't create callback client\n"); 409 status = PTR_ERR(client); 410 goto out_err; 411 } 412 413 status = rpc_call_sync(client, &msg, RPC_TASK_SOFT); 414 415 if (status) 416 goto out_release_client; 417 418 cb->cb_client = client; 419 atomic_set(&cb->cb_set, 1); 420 put_nfs4_client(clp); 421 return 0; 422 out_release_client: 423 rpc_shutdown_client(client); 424 out_err: 425 dprintk("NFSD: warning: no callback path to client %.*s\n", 426 (int)clp->cl_name.len, clp->cl_name.data); 427 put_nfs4_client(clp); 428 return status; 429 } 430 431 /* 432 * Set up the callback client and put a NFSPROC4_CB_NULL on the wire... 433 */ 434 void 435 nfsd4_probe_callback(struct nfs4_client *clp) 436 { 437 struct task_struct *t; 438 439 BUG_ON(atomic_read(&clp->cl_callback.cb_set)); 440 441 /* the task holds a reference to the nfs4_client struct */ 442 atomic_inc(&clp->cl_count); 443 444 t = kthread_run(do_probe_callback, clp, "nfs4_cb_probe"); 445 446 if (IS_ERR(t)) 447 atomic_dec(&clp->cl_count); 448 449 return; 450 } 451 452 /* 453 * called with dp->dl_count inc'ed. 454 * nfs4_lock_state() may or may not have been called. 455 */ 456 void 457 nfsd4_cb_recall(struct nfs4_delegation *dp) 458 { 459 struct nfs4_client *clp = dp->dl_client; 460 struct rpc_clnt *clnt = clp->cl_callback.cb_client; 461 struct nfs4_cb_recall *cbr = &dp->dl_recall; 462 struct rpc_message msg = { 463 .rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL], 464 .rpc_argp = cbr, 465 }; 466 int retries = 1; 467 int status = 0; 468 469 cbr->cbr_trunc = 0; /* XXX need to implement truncate optimization */ 470 cbr->cbr_dp = dp; 471 472 status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT); 473 while (retries--) { 474 switch (status) { 475 case -EIO: 476 /* Network partition? */ 477 atomic_set(&clp->cl_callback.cb_set, 0); 478 case -EBADHANDLE: 479 case -NFS4ERR_BAD_STATEID: 480 /* Race: client probably got cb_recall 481 * before open reply granting delegation */ 482 break; 483 default: 484 goto out_put_cred; 485 } 486 ssleep(2); 487 status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT); 488 } 489 out_put_cred: 490 /* 491 * Success or failure, now we're either waiting for lease expiration 492 * or deleg_return. 493 */ 494 put_nfs4_client(clp); 495 nfs4_put_delegation(dp); 496 return; 497 } 498