1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 2007-2009 Google Inc. and Amit Singh 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions are 9 * met: 10 * 11 * * Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * * Redistributions in binary form must reproduce the above 14 * copyright notice, this list of conditions and the following disclaimer 15 * in the documentation and/or other materials provided with the 16 * distribution. 17 * * Neither the name of Google Inc. nor the names of its 18 * contributors may be used to endorse or promote products derived from 19 * this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 24 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 25 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 27 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 31 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 * 33 * Copyright (C) 2005 Csaba Henk. 34 * All rights reserved. 35 * 36 * Copyright (c) 2019 The FreeBSD Foundation 37 * 38 * Portions of this software were developed by BFF Storage Systems, LLC under 39 * sponsorship from the FreeBSD Foundation. 40 * 41 * Redistribution and use in source and binary forms, with or without 42 * modification, are permitted provided that the following conditions 43 * are met: 44 * 1. Redistributions of source code must retain the above copyright 45 * notice, this list of conditions and the following disclaimer. 46 * 2. Redistributions in binary form must reproduce the above copyright 47 * notice, this list of conditions and the following disclaimer in the 48 * documentation and/or other materials provided with the distribution. 49 * 50 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND 51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 53 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE 54 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 55 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 56 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 57 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 58 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 59 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 60 * SUCH DAMAGE. 61 */ 62 63 #include <sys/cdefs.h> 64 #include <sys/param.h> 65 #include <sys/systm.h> 66 #include <sys/counter.h> 67 #include <sys/module.h> 68 #include <sys/errno.h> 69 #include <sys/kernel.h> 70 #include <sys/conf.h> 71 #include <sys/uio.h> 72 #include <sys/malloc.h> 73 #include <sys/queue.h> 74 #include <sys/lock.h> 75 #include <sys/sx.h> 76 #include <sys/mutex.h> 77 #include <sys/proc.h> 78 #include <sys/mount.h> 79 #include <sys/vnode.h> 80 #include <sys/sdt.h> 81 #include <sys/sysctl.h> 82 83 #include "fuse.h" 84 #include "fuse_file.h" 85 #include "fuse_internal.h" 86 #include "fuse_io.h" 87 #include "fuse_ipc.h" 88 #include "fuse_node.h" 89 90 MALLOC_DEFINE(M_FUSE_FILEHANDLE, "fuse_filefilehandle", "FUSE file handle"); 91 92 SDT_PROVIDER_DECLARE(fusefs); 93 /* 94 * Fuse trace probe: 95 * arg0: verbosity. Higher numbers give more verbose messages 96 * arg1: Textual message 97 */ 98 SDT_PROBE_DEFINE2(fusefs, , file, trace, "int", "char*"); 99 100 static counter_u64_t fuse_fh_count; 101 102 SYSCTL_COUNTER_U64(_vfs_fusefs_stats, OID_AUTO, filehandle_count, CTLFLAG_RD, 103 &fuse_fh_count, "number of open FUSE filehandles"); 104 105 /* Get the FUFH type for a particular access mode */ 106 static inline fufh_type_t 107 fflags_2_fufh_type(int fflags) 108 { 109 if ((fflags & FREAD) && (fflags & FWRITE)) 110 return FUFH_RDWR; 111 else if (fflags & (FWRITE)) 112 return FUFH_WRONLY; 113 else if (fflags & (FREAD)) 114 return FUFH_RDONLY; 115 else if (fflags & (FEXEC)) 116 return FUFH_EXEC; 117 else 118 panic("FUSE: What kind of a flag is this (%x)?", fflags); 119 } 120 121 int 122 fuse_filehandle_open(struct vnode *vp, int a_mode, 123 struct fuse_filehandle **fufhp, struct thread *td, struct ucred *cred) 124 { 125 struct mount *mp = vnode_mount(vp); 126 struct fuse_data *data = fuse_get_mpdata(mp); 127 struct fuse_dispatcher fdi; 128 const struct fuse_open_out default_foo = { 129 .fh = 0, 130 .open_flags = FOPEN_KEEP_CACHE, 131 .padding = 0 132 }; 133 struct fuse_open_in *foi = NULL; 134 const struct fuse_open_out *foo; 135 fufh_type_t fufh_type; 136 int dataflags = data->dataflags; 137 int err = 0; 138 int oflags = 0; 139 int op = FUSE_OPEN; 140 int relop = FUSE_RELEASE; 141 int fsess_no_op_support = FSESS_NO_OPEN_SUPPORT; 142 143 fufh_type = fflags_2_fufh_type(a_mode); 144 oflags = fufh_type_2_fflags(fufh_type); 145 146 if (vnode_isdir(vp)) { 147 op = FUSE_OPENDIR; 148 relop = FUSE_RELEASEDIR; 149 fsess_no_op_support = FSESS_NO_OPENDIR_SUPPORT; 150 /* vn_open_vnode already rejects FWRITE on directories */ 151 MPASS(fufh_type == FUFH_RDONLY || fufh_type == FUFH_EXEC); 152 } 153 fdisp_init(&fdi, sizeof(*foi)); 154 if (fsess_not_impl(mp, op) && dataflags & fsess_no_op_support) { 155 /* The operation implicitly succeeds */ 156 foo = &default_foo; 157 } else { 158 fdisp_make_vp(&fdi, op, vp, td, cred); 159 160 foi = fdi.indata; 161 foi->flags = oflags; 162 163 err = fdisp_wait_answ(&fdi); 164 if (err == ENOSYS && dataflags & fsess_no_op_support) { 165 /* The operation implicitly succeeds */ 166 foo = &default_foo; 167 fsess_set_notimpl(mp, op); 168 fsess_set_notimpl(mp, relop); 169 err = 0; 170 } else if (err) { 171 SDT_PROBE2(fusefs, , file, trace, 1, 172 "OUCH ... daemon didn't give fh"); 173 if (err == ENOENT) 174 fuse_internal_vnode_disappear(vp); 175 goto out; 176 } else { 177 foo = fdi.answ; 178 } 179 } 180 181 fuse_filehandle_init(vp, fufh_type, fufhp, td, cred, foo); 182 fuse_vnode_open(vp, foo->open_flags, td); 183 184 out: 185 if (foi) 186 fdisp_destroy(&fdi); 187 return err; 188 } 189 190 int 191 fuse_filehandle_close(struct vnode *vp, struct fuse_filehandle *fufh, 192 struct thread *td, struct ucred *cred) 193 { 194 struct mount *mp = vnode_mount(vp); 195 struct fuse_dispatcher fdi; 196 struct fuse_release_in *fri; 197 198 int err = 0; 199 int op = FUSE_RELEASE; 200 201 if (fuse_isdeadfs(vp)) { 202 goto out; 203 } 204 if (vnode_isdir(vp)) 205 op = FUSE_RELEASEDIR; 206 207 if (fsess_not_impl(mp, op)) 208 goto out; 209 210 fdisp_init(&fdi, sizeof(*fri)); 211 fdisp_make_vp(&fdi, op, vp, td, cred); 212 fri = fdi.indata; 213 fri->fh = fufh->fh_id; 214 fri->flags = fufh_type_2_fflags(fufh->fufh_type); 215 /* 216 * If the file has a POSIX lock then we're supposed to set lock_owner. 217 * If not, then lock_owner is undefined. So we may as well always set 218 * it. 219 */ 220 fri->lock_owner = td->td_proc->p_pid; 221 222 err = fdisp_wait_answ(&fdi); 223 fdisp_destroy(&fdi); 224 225 out: 226 counter_u64_add(fuse_fh_count, -1); 227 LIST_REMOVE(fufh, next); 228 free(fufh, M_FUSE_FILEHANDLE); 229 230 return err; 231 } 232 233 /* 234 * Check for a valid file handle, first the type requested, but if that 235 * isn't valid, try for FUFH_RDWR. 236 * Return true if there is any file handle with the correct credentials and 237 * a fufh type that includes the provided one. 238 * A pid of 0 means "don't care" 239 */ 240 bool 241 fuse_filehandle_validrw(struct vnode *vp, int mode, 242 struct ucred *cred, pid_t pid) 243 { 244 struct fuse_vnode_data *fvdat = VTOFUD(vp); 245 struct fuse_filehandle *fufh; 246 fufh_type_t fufh_type = fflags_2_fufh_type(mode); 247 248 /* 249 * Unlike fuse_filehandle_get, we want to search for a filehandle with 250 * the exact cred, and no fallback 251 */ 252 LIST_FOREACH(fufh, &fvdat->handles, next) { 253 if (fufh->fufh_type == fufh_type && 254 fufh->uid == cred->cr_uid && 255 fufh->gid == cred->cr_rgid && 256 (pid == 0 || fufh->pid == pid)) 257 return true; 258 } 259 260 if (fufh_type == FUFH_EXEC) 261 return false; 262 263 /* Fallback: find a RDWR list entry with the right cred */ 264 LIST_FOREACH(fufh, &fvdat->handles, next) { 265 if (fufh->fufh_type == FUFH_RDWR && 266 fufh->uid == cred->cr_uid && 267 fufh->gid == cred->cr_rgid && 268 (pid == 0 || fufh->pid == pid)) 269 return true; 270 } 271 272 return false; 273 } 274 275 int 276 fuse_filehandle_get(struct vnode *vp, int fflag, 277 struct fuse_filehandle **fufhp, struct ucred *cred, pid_t pid) 278 { 279 struct fuse_vnode_data *fvdat = VTOFUD(vp); 280 struct fuse_filehandle *fufh; 281 fufh_type_t fufh_type; 282 283 fufh_type = fflags_2_fufh_type(fflag); 284 /* cred can be NULL for in-kernel clients */ 285 if (cred == NULL) 286 goto fallback; 287 288 LIST_FOREACH(fufh, &fvdat->handles, next) { 289 if (fufh->fufh_type == fufh_type && 290 fufh->uid == cred->cr_uid && 291 fufh->gid == cred->cr_rgid && 292 (pid == 0 || fufh->pid == pid)) 293 goto found; 294 } 295 296 fallback: 297 /* Fallback: find a list entry with the right flags */ 298 LIST_FOREACH(fufh, &fvdat->handles, next) { 299 if (fufh->fufh_type == fufh_type) 300 break; 301 } 302 303 if (fufh == NULL) 304 return EBADF; 305 306 found: 307 if (fufhp != NULL) 308 *fufhp = fufh; 309 return 0; 310 } 311 312 /* Get a file handle with any kind of flags */ 313 int 314 fuse_filehandle_get_anyflags(struct vnode *vp, 315 struct fuse_filehandle **fufhp, struct ucred *cred, pid_t pid) 316 { 317 struct fuse_vnode_data *fvdat = VTOFUD(vp); 318 struct fuse_filehandle *fufh; 319 320 if (cred == NULL) 321 goto fallback; 322 323 LIST_FOREACH(fufh, &fvdat->handles, next) { 324 if (fufh->uid == cred->cr_uid && 325 fufh->gid == cred->cr_rgid && 326 (pid == 0 || fufh->pid == pid)) 327 goto found; 328 } 329 330 fallback: 331 /* Fallback: find any list entry */ 332 fufh = LIST_FIRST(&fvdat->handles); 333 334 if (fufh == NULL) 335 return EBADF; 336 337 found: 338 if (fufhp != NULL) 339 *fufhp = fufh; 340 return 0; 341 } 342 343 int 344 fuse_filehandle_getrw(struct vnode *vp, int fflag, 345 struct fuse_filehandle **fufhp, struct ucred *cred, pid_t pid) 346 { 347 int err; 348 349 err = fuse_filehandle_get(vp, fflag, fufhp, cred, pid); 350 if (err) 351 err = fuse_filehandle_get(vp, FREAD | FWRITE, fufhp, cred, pid); 352 return err; 353 } 354 355 void 356 fuse_filehandle_init(struct vnode *vp, fufh_type_t fufh_type, 357 struct fuse_filehandle **fufhp, struct thread *td, const struct ucred *cred, 358 const struct fuse_open_out *foo) 359 { 360 struct fuse_vnode_data *fvdat = VTOFUD(vp); 361 struct fuse_filehandle *fufh; 362 363 fufh = malloc(sizeof(struct fuse_filehandle), M_FUSE_FILEHANDLE, 364 M_WAITOK); 365 MPASS(fufh != NULL); 366 fufh->fh_id = foo->fh; 367 fufh->fufh_type = fufh_type; 368 fufh->gid = cred->cr_rgid; 369 fufh->uid = cred->cr_uid; 370 fufh->pid = td->td_proc->p_pid; 371 fufh->fuse_open_flags = foo->open_flags; 372 if (!FUFH_IS_VALID(fufh)) { 373 panic("FUSE: init: invalid filehandle id (type=%d)", fufh_type); 374 } 375 LIST_INSERT_HEAD(&fvdat->handles, fufh, next); 376 if (fufhp != NULL) 377 *fufhp = fufh; 378 379 counter_u64_add(fuse_fh_count, 1); 380 381 if (foo->open_flags & FOPEN_DIRECT_IO) { 382 ASSERT_VOP_ELOCKED(vp, __func__); 383 VTOFUD(vp)->flag |= FN_DIRECTIO; 384 fuse_io_invalbuf(vp, td); 385 } else { 386 if ((foo->open_flags & FOPEN_KEEP_CACHE) == 0) 387 fuse_io_invalbuf(vp, td); 388 VTOFUD(vp)->flag &= ~FN_DIRECTIO; 389 } 390 391 } 392 393 void 394 fuse_file_init(void) 395 { 396 fuse_fh_count = counter_u64_alloc(M_WAITOK); 397 } 398 399 void 400 fuse_file_destroy(void) 401 { 402 counter_u64_free(fuse_fh_count); 403 } 404