1 /* $NetBSD: kernfs_vnops.c,v 1.161 2019/08/29 06:43:13 hannken Exp $ */ 2 3 /* 4 * Copyright (c) 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software donated to Berkeley by 8 * Jan-Simon Pendry. 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 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kernfs_vnops.c 8.15 (Berkeley) 5/21/95 35 */ 36 37 /* 38 * Kernel parameter filesystem (/kern) 39 */ 40 41 #include <sys/cdefs.h> 42 __KERNEL_RCSID(0, "$NetBSD: kernfs_vnops.c,v 1.161 2019/08/29 06:43:13 hannken Exp $"); 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kernel.h> 47 #include <sys/vmmeter.h> 48 #include <sys/time.h> 49 #include <sys/proc.h> 50 #include <sys/vnode.h> 51 #include <sys/malloc.h> 52 #include <sys/file.h> 53 #include <sys/stat.h> 54 #include <sys/mount.h> 55 #include <sys/namei.h> 56 #include <sys/buf.h> 57 #include <sys/dirent.h> 58 #include <sys/msgbuf.h> 59 60 #include <miscfs/genfs/genfs.h> 61 #include <miscfs/kernfs/kernfs.h> 62 #include <miscfs/specfs/specdev.h> 63 64 #include <uvm/uvm_extern.h> 65 66 #define KSTRING 256 /* Largest I/O available via this filesystem */ 67 #define UIO_MX 32 68 69 #define READ_MODE (S_IRUSR|S_IRGRP|S_IROTH) 70 #define WRITE_MODE (S_IWUSR|S_IRUSR|S_IRGRP|S_IROTH) 71 #define UREAD_MODE (S_IRUSR) 72 #define DIR_MODE (S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH) 73 #define UDIR_MODE (S_IRUSR|S_IXUSR) 74 75 #define N(s) sizeof(s)-1, s 76 const struct kern_target kern_targets[] = { 77 /* NOTE: The name must be less than UIO_MX-16 chars in length */ 78 /* name data tag type ro/rw */ 79 { DT_DIR, N("."), 0, KFSkern, VDIR, DIR_MODE }, 80 { DT_DIR, N(".."), 0, KFSroot, VDIR, DIR_MODE }, 81 { DT_REG, N("boottime"), &boottime.tv_sec, KFSint, VREG, READ_MODE }, 82 /* XXXUNCONST */ 83 { DT_REG, N("copyright"), __UNCONST(copyright), 84 KFSstring, VREG, READ_MODE }, 85 { DT_REG, N("hostname"), 0, KFShostname, VREG, WRITE_MODE }, 86 { DT_REG, N("hz"), &hz, KFSint, VREG, READ_MODE }, 87 { DT_REG, N("loadavg"), 0, KFSavenrun, VREG, READ_MODE }, 88 { DT_REG, N("msgbuf"), 0, KFSmsgbuf, VREG, READ_MODE }, 89 { DT_REG, N("pagesize"), &uvmexp.pagesize, KFSint, VREG, READ_MODE }, 90 { DT_REG, N("physmem"), &physmem, KFSint, VREG, READ_MODE }, 91 #if 0 92 { DT_DIR, N("root"), 0, KFSnull, VDIR, DIR_MODE }, 93 #endif 94 { DT_BLK, N("rootdev"), &rootdev, KFSdevice, VBLK, READ_MODE }, 95 { DT_CHR, N("rrootdev"), &rrootdev, KFSdevice, VCHR, READ_MODE }, 96 { DT_REG, N("time"), 0, KFStime, VREG, READ_MODE }, 97 /* XXXUNCONST */ 98 { DT_REG, N("version"), __UNCONST(version), 99 KFSstring, VREG, READ_MODE }, 100 }; 101 const struct kern_target subdir_targets[] = { 102 /* NOTE: The name must be less than UIO_MX-16 chars in length */ 103 /* name data tag type ro/rw */ 104 { DT_DIR, N("."), 0, KFSsubdir, VDIR, DIR_MODE }, 105 { DT_DIR, N(".."), 0, KFSkern, VDIR, DIR_MODE }, 106 }; 107 #undef N 108 SIMPLEQ_HEAD(,dyn_kern_target) dyn_kern_targets = 109 SIMPLEQ_HEAD_INITIALIZER(dyn_kern_targets); 110 int nkern_targets = sizeof(kern_targets) / sizeof(kern_targets[0]); 111 const int static_nkern_targets = sizeof(kern_targets) / sizeof(kern_targets[0]); 112 int nkern_dirs = 2; 113 114 int kernfs_try_fileop(kfstype, kfsfileop, void *, int); 115 int kernfs_try_xread(kfstype, const struct kernfs_node *, char **, 116 size_t, int); 117 int kernfs_try_xwrite(kfstype, const struct kernfs_node *, char *, 118 size_t, int); 119 120 static int kernfs_default_xread(void *v); 121 static int kernfs_default_xwrite(void *v); 122 static int kernfs_default_fileop_getattr(void *); 123 124 /* must include all fileop's */ 125 const struct kernfs_fileop kernfs_default_fileops[] = { 126 { .kf_fileop = KERNFS_XREAD }, 127 { .kf_fileop = KERNFS_XWRITE }, 128 { .kf_fileop = KERNFS_FILEOP_OPEN }, 129 { .kf_fileop = KERNFS_FILEOP_GETATTR, 130 .kf_vop = kernfs_default_fileop_getattr }, 131 { .kf_fileop = KERNFS_FILEOP_IOCTL }, 132 { .kf_fileop = KERNFS_FILEOP_CLOSE }, 133 { .kf_fileop = KERNFS_FILEOP_READ, 134 .kf_vop = kernfs_default_xread }, 135 { .kf_fileop = KERNFS_FILEOP_WRITE, 136 .kf_vop = kernfs_default_xwrite }, 137 }; 138 139 int kernfs_lookup(void *); 140 #define kernfs_create genfs_eopnotsupp 141 #define kernfs_mknod genfs_eopnotsupp 142 int kernfs_open(void *); 143 int kernfs_close(void *); 144 int kernfs_access(void *); 145 int kernfs_getattr(void *); 146 int kernfs_setattr(void *); 147 int kernfs_read(void *); 148 int kernfs_write(void *); 149 #define kernfs_fcntl genfs_fcntl 150 int kernfs_ioctl(void *); 151 #define kernfs_poll genfs_poll 152 #define kernfs_revoke genfs_revoke 153 #define kernfs_fsync genfs_nullop 154 #define kernfs_seek genfs_nullop 155 #define kernfs_remove genfs_eopnotsupp 156 int kernfs_link(void *); 157 #define kernfs_rename genfs_eopnotsupp 158 #define kernfs_mkdir genfs_eopnotsupp 159 #define kernfs_rmdir genfs_eopnotsupp 160 int kernfs_symlink(void *); 161 int kernfs_readdir(void *); 162 #define kernfs_readlink genfs_eopnotsupp 163 #define kernfs_abortop genfs_abortop 164 int kernfs_inactive(void *); 165 int kernfs_reclaim(void *); 166 #define kernfs_lock genfs_lock 167 #define kernfs_unlock genfs_unlock 168 #define kernfs_bmap genfs_badop 169 #define kernfs_strategy genfs_badop 170 int kernfs_print(void *); 171 #define kernfs_islocked genfs_islocked 172 int kernfs_pathconf(void *); 173 #define kernfs_advlock genfs_einval 174 #define kernfs_bwrite genfs_eopnotsupp 175 int kernfs_getpages(void *); 176 #define kernfs_putpages genfs_putpages 177 178 static int kernfs_xread(struct kernfs_node *, int, char **, 179 size_t, size_t *); 180 static int kernfs_xwrite(const struct kernfs_node *, char *, size_t); 181 182 int (**kernfs_vnodeop_p)(void *); 183 const struct vnodeopv_entry_desc kernfs_vnodeop_entries[] = { 184 { &vop_default_desc, vn_default_error }, 185 { &vop_lookup_desc, kernfs_lookup }, /* lookup */ 186 { &vop_create_desc, kernfs_create }, /* create */ 187 { &vop_mknod_desc, kernfs_mknod }, /* mknod */ 188 { &vop_open_desc, kernfs_open }, /* open */ 189 { &vop_close_desc, kernfs_close }, /* close */ 190 { &vop_access_desc, kernfs_access }, /* access */ 191 { &vop_getattr_desc, kernfs_getattr }, /* getattr */ 192 { &vop_setattr_desc, kernfs_setattr }, /* setattr */ 193 { &vop_read_desc, kernfs_read }, /* read */ 194 { &vop_write_desc, kernfs_write }, /* write */ 195 { &vop_fallocate_desc, genfs_eopnotsupp }, /* fallocate */ 196 { &vop_fdiscard_desc, genfs_eopnotsupp }, /* fdiscard */ 197 { &vop_fcntl_desc, kernfs_fcntl }, /* fcntl */ 198 { &vop_ioctl_desc, kernfs_ioctl }, /* ioctl */ 199 { &vop_poll_desc, kernfs_poll }, /* poll */ 200 { &vop_revoke_desc, kernfs_revoke }, /* revoke */ 201 { &vop_fsync_desc, kernfs_fsync }, /* fsync */ 202 { &vop_seek_desc, kernfs_seek }, /* seek */ 203 { &vop_remove_desc, kernfs_remove }, /* remove */ 204 { &vop_link_desc, kernfs_link }, /* link */ 205 { &vop_rename_desc, kernfs_rename }, /* rename */ 206 { &vop_mkdir_desc, kernfs_mkdir }, /* mkdir */ 207 { &vop_rmdir_desc, kernfs_rmdir }, /* rmdir */ 208 { &vop_symlink_desc, kernfs_symlink }, /* symlink */ 209 { &vop_readdir_desc, kernfs_readdir }, /* readdir */ 210 { &vop_readlink_desc, kernfs_readlink }, /* readlink */ 211 { &vop_abortop_desc, kernfs_abortop }, /* abortop */ 212 { &vop_inactive_desc, kernfs_inactive }, /* inactive */ 213 { &vop_reclaim_desc, kernfs_reclaim }, /* reclaim */ 214 { &vop_lock_desc, kernfs_lock }, /* lock */ 215 { &vop_unlock_desc, kernfs_unlock }, /* unlock */ 216 { &vop_bmap_desc, kernfs_bmap }, /* bmap */ 217 { &vop_strategy_desc, kernfs_strategy }, /* strategy */ 218 { &vop_print_desc, kernfs_print }, /* print */ 219 { &vop_islocked_desc, kernfs_islocked }, /* islocked */ 220 { &vop_pathconf_desc, kernfs_pathconf }, /* pathconf */ 221 { &vop_advlock_desc, kernfs_advlock }, /* advlock */ 222 { &vop_bwrite_desc, kernfs_bwrite }, /* bwrite */ 223 { &vop_getpages_desc, kernfs_getpages }, /* getpages */ 224 { &vop_putpages_desc, kernfs_putpages }, /* putpages */ 225 { NULL, NULL } 226 }; 227 const struct vnodeopv_desc kernfs_vnodeop_opv_desc = 228 { &kernfs_vnodeop_p, kernfs_vnodeop_entries }; 229 230 static inline int 231 kernfs_fileop_compare(struct kernfs_fileop *a, struct kernfs_fileop *b) 232 { 233 if (a->kf_type < b->kf_type) 234 return -1; 235 if (a->kf_type > b->kf_type) 236 return 1; 237 if (a->kf_fileop < b->kf_fileop) 238 return -1; 239 if (a->kf_fileop > b->kf_fileop) 240 return 1; 241 return (0); 242 } 243 244 SPLAY_HEAD(kfsfileoptree, kernfs_fileop) kfsfileoptree = 245 SPLAY_INITIALIZER(kfsfileoptree); 246 SPLAY_PROTOTYPE(kfsfileoptree, kernfs_fileop, kf_node, kernfs_fileop_compare); 247 SPLAY_GENERATE(kfsfileoptree, kernfs_fileop, kf_node, kernfs_fileop_compare); 248 249 kfstype 250 kernfs_alloctype(int nkf, const struct kernfs_fileop *kf) 251 { 252 static u_char nextfreetype = KFSlasttype; 253 struct kernfs_fileop *dkf, *fkf, skf; 254 int i; 255 256 /* XXX need to keep track of dkf's memory if we support 257 deallocating types */ 258 dkf = malloc(sizeof(kernfs_default_fileops), M_TEMP, M_WAITOK); 259 memcpy(dkf, kernfs_default_fileops, sizeof(kernfs_default_fileops)); 260 261 for (i = 0; i < sizeof(kernfs_default_fileops) / 262 sizeof(kernfs_default_fileops[0]); i++) { 263 dkf[i].kf_type = nextfreetype; 264 SPLAY_INSERT(kfsfileoptree, &kfsfileoptree, &dkf[i]); 265 } 266 267 for (i = 0; i < nkf; i++) { 268 skf.kf_type = nextfreetype; 269 skf.kf_fileop = kf[i].kf_fileop; 270 if ((fkf = SPLAY_FIND(kfsfileoptree, &kfsfileoptree, &skf))) 271 fkf->kf_vop = kf[i].kf_vop; 272 } 273 274 return nextfreetype++; 275 } 276 277 int 278 kernfs_try_fileop(kfstype type, kfsfileop fileop, void *v, int error) 279 { 280 struct kernfs_fileop *kf, skf; 281 282 skf.kf_type = type; 283 skf.kf_fileop = fileop; 284 if ((kf = SPLAY_FIND(kfsfileoptree, &kfsfileoptree, &skf))) 285 if (kf->kf_vop) 286 return kf->kf_vop(v); 287 return error; 288 } 289 290 int 291 kernfs_try_xread(kfstype type, const struct kernfs_node *kfs, char **bfp, 292 size_t len, int error) 293 { 294 struct kernfs_fileop *kf, skf; 295 296 skf.kf_type = type; 297 skf.kf_fileop = KERNFS_XREAD; 298 if ((kf = SPLAY_FIND(kfsfileoptree, &kfsfileoptree, &skf))) 299 if (kf->kf_xread) 300 return kf->kf_xread(kfs, bfp, len); 301 return error; 302 } 303 304 int 305 kernfs_try_xwrite(kfstype type, const struct kernfs_node *kfs, char *bf, 306 size_t len, int error) 307 { 308 struct kernfs_fileop *kf, skf; 309 310 skf.kf_type = type; 311 skf.kf_fileop = KERNFS_XWRITE; 312 if ((kf = SPLAY_FIND(kfsfileoptree, &kfsfileoptree, &skf))) 313 if (kf->kf_xwrite) 314 return kf->kf_xwrite(kfs, bf, len); 315 return error; 316 } 317 318 int 319 kernfs_addentry(kernfs_parentdir_t *pkt, kernfs_entry_t *dkt) 320 { 321 struct kernfs_subdir *ks, *parent; 322 323 if (pkt == NULL) { 324 SIMPLEQ_INSERT_TAIL(&dyn_kern_targets, dkt, dkt_queue); 325 nkern_targets++; 326 if (dkt->dkt_kt.kt_vtype == VDIR) 327 nkern_dirs++; 328 } else { 329 parent = (struct kernfs_subdir *)pkt->kt_data; 330 SIMPLEQ_INSERT_TAIL(&parent->ks_entries, dkt, dkt_queue); 331 parent->ks_nentries++; 332 if (dkt->dkt_kt.kt_vtype == VDIR) 333 parent->ks_dirs++; 334 } 335 if (dkt->dkt_kt.kt_vtype == VDIR && dkt->dkt_kt.kt_data == NULL) { 336 ks = malloc(sizeof(struct kernfs_subdir), 337 M_TEMP, M_WAITOK); 338 SIMPLEQ_INIT(&ks->ks_entries); 339 ks->ks_nentries = 2; /* . and .. */ 340 ks->ks_dirs = 2; 341 ks->ks_parent = pkt ? pkt : &kern_targets[0]; 342 dkt->dkt_kt.kt_data = ks; 343 } 344 return 0; 345 } 346 347 static int 348 kernfs_xread(struct kernfs_node *kfs, int off, char **bufp, size_t len, size_t *wrlen) 349 { 350 const struct kern_target *kt; 351 int err; 352 353 kt = kfs->kfs_kt; 354 355 switch (kfs->kfs_type) { 356 case KFStime: { 357 struct timeval tv; 358 359 microtime(&tv); 360 snprintf(*bufp, len, "%lld %ld\n", (long long)tv.tv_sec, 361 (long)tv.tv_usec); 362 break; 363 } 364 365 case KFSint: { 366 int *ip = kt->kt_data; 367 368 snprintf(*bufp, len, "%d\n", *ip); 369 break; 370 } 371 372 case KFSstring: { 373 char *cp = kt->kt_data; 374 375 *bufp = cp; 376 break; 377 } 378 379 case KFSmsgbuf: { 380 long n; 381 382 /* 383 * deal with cases where the message buffer has 384 * become corrupted. 385 */ 386 if (!logenabled(msgbufp)) { 387 msgbufenabled = 0; 388 return (ENXIO); 389 } 390 391 /* 392 * Note that reads of /kern/msgbuf won't necessarily yield 393 * consistent results, if the message buffer is modified 394 * while the read is in progress. The worst that can happen 395 * is that incorrect data will be read. There's no way 396 * that this can crash the system unless the values in the 397 * message buffer header are corrupted, but that'll cause 398 * the system to die anyway. 399 */ 400 if (off >= msgbufp->msg_bufs) { 401 *wrlen = 0; 402 return (0); 403 } 404 n = msgbufp->msg_bufx + off; 405 if (n >= msgbufp->msg_bufs) 406 n -= msgbufp->msg_bufs; 407 len = uimin(msgbufp->msg_bufs - n, msgbufp->msg_bufs - off); 408 *bufp = msgbufp->msg_bufc + n; 409 *wrlen = len; 410 return (0); 411 } 412 413 case KFShostname: { 414 char *cp = hostname; 415 size_t xlen = hostnamelen; 416 417 if (xlen >= (len - 2)) 418 return (EINVAL); 419 420 memcpy(*bufp, cp, xlen); 421 (*bufp)[xlen] = '\n'; 422 (*bufp)[xlen+1] = '\0'; 423 break; 424 } 425 426 case KFSavenrun: 427 averunnable.fscale = FSCALE; 428 snprintf(*bufp, len, "%d %d %d %ld\n", 429 averunnable.ldavg[0], averunnable.ldavg[1], 430 averunnable.ldavg[2], averunnable.fscale); 431 break; 432 433 default: 434 err = kernfs_try_xread(kfs->kfs_type, kfs, bufp, len, 435 EOPNOTSUPP); 436 if (err) 437 return err; 438 } 439 440 len = strlen(*bufp); 441 if (len <= off) 442 *wrlen = 0; 443 else { 444 *bufp += off; 445 *wrlen = len - off; 446 } 447 return (0); 448 } 449 450 static int 451 kernfs_xwrite(const struct kernfs_node *kfs, char *bf, size_t len) 452 { 453 454 switch (kfs->kfs_type) { 455 case KFShostname: 456 if (bf[len-1] == '\n') 457 --len; 458 memcpy(hostname, bf, len); 459 hostname[len] = '\0'; 460 hostnamelen = (size_t) len; 461 return (0); 462 463 default: 464 return kernfs_try_xwrite(kfs->kfs_type, kfs, bf, len, EIO); 465 } 466 } 467 468 469 /* 470 * vp is the current namei directory 471 * ndp is the name to locate in that directory... 472 */ 473 int 474 kernfs_lookup(void *v) 475 { 476 struct vop_lookup_v2_args /* { 477 struct vnode * a_dvp; 478 struct vnode ** a_vpp; 479 struct componentname * a_cnp; 480 } */ *ap = v; 481 struct componentname *cnp = ap->a_cnp; 482 struct vnode **vpp = ap->a_vpp; 483 struct vnode *dvp = ap->a_dvp; 484 const char *pname = cnp->cn_nameptr; 485 const struct kernfs_node *kfs; 486 const struct kern_target *kt; 487 const struct dyn_kern_target *dkt; 488 const struct kernfs_subdir *ks; 489 int error, i; 490 491 *vpp = NULLVP; 492 493 if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME) 494 return (EROFS); 495 496 if (cnp->cn_namelen == 1 && *pname == '.') { 497 *vpp = dvp; 498 vref(dvp); 499 return (0); 500 } 501 502 kfs = VTOKERN(dvp); 503 switch (kfs->kfs_type) { 504 case KFSkern: 505 /* 506 * Shouldn't get here with .. in the root node. 507 */ 508 if (cnp->cn_flags & ISDOTDOT) 509 return (EIO); 510 511 for (i = 0; i < static_nkern_targets; i++) { 512 kt = &kern_targets[i]; 513 if (cnp->cn_namelen == kt->kt_namlen && 514 memcmp(kt->kt_name, pname, cnp->cn_namelen) == 0) 515 goto found; 516 } 517 SIMPLEQ_FOREACH(dkt, &dyn_kern_targets, dkt_queue) { 518 if (cnp->cn_namelen == dkt->dkt_kt.kt_namlen && 519 memcmp(dkt->dkt_kt.kt_name, pname, cnp->cn_namelen) == 0) { 520 kt = &dkt->dkt_kt; 521 goto found; 522 } 523 } 524 break; 525 526 found: 527 error = vcache_get(dvp->v_mount, &kt, sizeof(kt), vpp); 528 return error; 529 530 case KFSsubdir: 531 ks = (struct kernfs_subdir *)kfs->kfs_kt->kt_data; 532 if (cnp->cn_flags & ISDOTDOT) { 533 kt = ks->ks_parent; 534 goto found; 535 } 536 537 SIMPLEQ_FOREACH(dkt, &ks->ks_entries, dkt_queue) { 538 if (cnp->cn_namelen == dkt->dkt_kt.kt_namlen && 539 memcmp(dkt->dkt_kt.kt_name, pname, cnp->cn_namelen) == 0) { 540 kt = &dkt->dkt_kt; 541 goto found; 542 } 543 } 544 break; 545 546 default: 547 return (ENOTDIR); 548 } 549 550 return (cnp->cn_nameiop == LOOKUP ? ENOENT : EROFS); 551 } 552 553 int 554 kernfs_open(void *v) 555 { 556 struct vop_open_args /* { 557 struct vnode *a_vp; 558 int a_mode; 559 kauth_cred_t a_cred; 560 } */ *ap = v; 561 struct kernfs_node *kfs = VTOKERN(ap->a_vp); 562 563 return kernfs_try_fileop(kfs->kfs_type, KERNFS_FILEOP_OPEN, v, 0); 564 } 565 566 int 567 kernfs_close(void *v) 568 { 569 struct vop_close_args /* { 570 struct vnode *a_vp; 571 int a_fflag; 572 kauth_cred_t a_cred; 573 } */ *ap = v; 574 struct kernfs_node *kfs = VTOKERN(ap->a_vp); 575 576 return kernfs_try_fileop(kfs->kfs_type, KERNFS_FILEOP_CLOSE, v, 0); 577 } 578 579 int 580 kernfs_access(void *v) 581 { 582 struct vop_access_args /* { 583 struct vnode *a_vp; 584 int a_mode; 585 kauth_cred_t a_cred; 586 } */ *ap = v; 587 struct vattr va; 588 int error; 589 590 if ((error = VOP_GETATTR(ap->a_vp, &va, ap->a_cred)) != 0) 591 return (error); 592 593 return kauth_authorize_vnode(ap->a_cred, 594 KAUTH_ACCESS_ACTION(ap->a_mode, ap->a_vp->v_type, va.va_mode), 595 ap->a_vp, NULL, genfs_can_access(va.va_type, va.va_mode, 596 va.va_uid, va.va_gid, ap->a_mode, ap->a_cred)); 597 } 598 599 static int 600 kernfs_default_fileop_getattr(void *v) 601 { 602 struct vop_getattr_args /* { 603 struct vnode *a_vp; 604 struct vattr *a_vap; 605 kauth_cred_t a_cred; 606 } */ *ap = v; 607 struct vattr *vap = ap->a_vap; 608 609 vap->va_nlink = 1; 610 vap->va_bytes = vap->va_size = 0; 611 612 return 0; 613 } 614 615 int 616 kernfs_getattr(void *v) 617 { 618 struct vop_getattr_args /* { 619 struct vnode *a_vp; 620 struct vattr *a_vap; 621 kauth_cred_t a_cred; 622 } */ *ap = v; 623 struct kernfs_node *kfs = VTOKERN(ap->a_vp); 624 struct kernfs_subdir *ks; 625 struct vattr *vap = ap->a_vap; 626 int error = 0; 627 char strbuf[KSTRING], *bf; 628 size_t nread, total; 629 630 vattr_null(vap); 631 vap->va_type = ap->a_vp->v_type; 632 vap->va_uid = 0; 633 vap->va_gid = 0; 634 vap->va_mode = kfs->kfs_mode; 635 vap->va_fileid = kfs->kfs_fileno; 636 vap->va_flags = 0; 637 vap->va_size = 0; 638 vap->va_blocksize = DEV_BSIZE; 639 /* Make all times be current TOD, except for the "boottime" node. */ 640 if (kfs->kfs_kt->kt_namlen == 8 && 641 !memcmp(kfs->kfs_kt->kt_name, "boottime", 8)) { 642 vap->va_ctime = boottime; 643 } else { 644 getnanotime(&vap->va_ctime); 645 } 646 vap->va_atime = vap->va_mtime = vap->va_ctime; 647 vap->va_gen = 0; 648 vap->va_flags = 0; 649 vap->va_rdev = 0; 650 vap->va_bytes = 0; 651 652 switch (kfs->kfs_type) { 653 case KFSkern: 654 vap->va_nlink = nkern_dirs; 655 vap->va_bytes = vap->va_size = DEV_BSIZE; 656 break; 657 658 case KFSdevice: 659 vap->va_nlink = 1; 660 vap->va_rdev = ap->a_vp->v_rdev; 661 break; 662 663 case KFSroot: 664 vap->va_nlink = 1; 665 vap->va_bytes = vap->va_size = DEV_BSIZE; 666 break; 667 668 case KFSsubdir: 669 ks = (struct kernfs_subdir *)kfs->kfs_kt->kt_data; 670 vap->va_nlink = ks->ks_dirs; 671 vap->va_bytes = vap->va_size = DEV_BSIZE; 672 break; 673 674 case KFSnull: 675 case KFStime: 676 case KFSint: 677 case KFSstring: 678 case KFShostname: 679 case KFSavenrun: 680 case KFSmsgbuf: 681 vap->va_nlink = 1; 682 total = 0; 683 do { 684 bf = strbuf; 685 error = kernfs_xread(kfs, total, &bf, 686 sizeof(strbuf), &nread); 687 total += nread; 688 } while (error == 0 && nread != 0); 689 vap->va_bytes = vap->va_size = total; 690 break; 691 692 default: 693 error = kernfs_try_fileop(kfs->kfs_type, 694 KERNFS_FILEOP_GETATTR, v, EINVAL); 695 break; 696 } 697 698 return (error); 699 } 700 701 /*ARGSUSED*/ 702 int 703 kernfs_setattr(void *v) 704 { 705 706 /* 707 * Silently ignore attribute changes. 708 * This allows for open with truncate to have no 709 * effect until some data is written. I want to 710 * do it this way because all writes are atomic. 711 */ 712 return (0); 713 } 714 715 int 716 kernfs_default_xread(void *v) 717 { 718 struct vop_read_args /* { 719 struct vnode *a_vp; 720 struct uio *a_uio; 721 int a_ioflag; 722 kauth_cred_t a_cred; 723 } */ *ap = v; 724 struct uio *uio = ap->a_uio; 725 struct kernfs_node *kfs = VTOKERN(ap->a_vp); 726 char strbuf[KSTRING], *bf; 727 int off; 728 size_t len; 729 int error; 730 731 if (ap->a_vp->v_type == VDIR) 732 return EISDIR; 733 734 off = (int)uio->uio_offset; 735 /* Don't allow negative offsets */ 736 if (off < 0) 737 return EINVAL; 738 739 bf = strbuf; 740 if ((error = kernfs_xread(kfs, off, &bf, sizeof(strbuf), &len)) == 0) 741 error = uiomove(bf, len, uio); 742 return (error); 743 } 744 745 int 746 kernfs_read(void *v) 747 { 748 struct vop_read_args /* { 749 struct vnode *a_vp; 750 struct uio *a_uio; 751 int a_ioflag; 752 struct ucred *a_cred; 753 } */ *ap = v; 754 struct kernfs_node *kfs = VTOKERN(ap->a_vp); 755 756 if (kfs->kfs_type < KFSlasttype) { 757 /* use default function */ 758 return kernfs_default_xread(v); 759 } 760 return kernfs_try_fileop(kfs->kfs_type, KERNFS_FILEOP_READ, v, 761 EOPNOTSUPP); 762 } 763 764 static int 765 kernfs_default_xwrite(void *v) 766 { 767 struct vop_write_args /* { 768 struct vnode *a_vp; 769 struct uio *a_uio; 770 int a_ioflag; 771 kauth_cred_t a_cred; 772 } */ *ap = v; 773 struct kernfs_node *kfs = VTOKERN(ap->a_vp); 774 struct uio *uio = ap->a_uio; 775 int error; 776 size_t xlen; 777 char strbuf[KSTRING]; 778 779 if (uio->uio_offset != 0) 780 return (EINVAL); 781 782 xlen = uimin(uio->uio_resid, KSTRING-1); 783 if ((error = uiomove(strbuf, xlen, uio)) != 0) 784 return (error); 785 786 if (uio->uio_resid != 0) 787 return (EIO); 788 789 strbuf[xlen] = '\0'; 790 xlen = strlen(strbuf); 791 return (kernfs_xwrite(kfs, strbuf, xlen)); 792 } 793 794 int 795 kernfs_write(void *v) 796 { 797 struct vop_write_args /* { 798 struct vnode *a_vp; 799 struct uio *a_uio; 800 int a_ioflag; 801 kauth_cred_t a_cred; 802 } */ *ap = v; 803 struct kernfs_node *kfs = VTOKERN(ap->a_vp); 804 805 if (kfs->kfs_type < KFSlasttype) { 806 /* use default function */ 807 return kernfs_default_xwrite(v); 808 } 809 return kernfs_try_fileop(kfs->kfs_type, KERNFS_FILEOP_WRITE, v, 810 EOPNOTSUPP); 811 } 812 813 int 814 kernfs_ioctl(void *v) 815 { 816 struct vop_ioctl_args /* { 817 const struct vnodeop_desc *a_desc; 818 struct vnode *a_vp; 819 u_long a_command; 820 void *a_data; 821 int a_fflag; 822 kauth_cred_t a_cred; 823 } */ *ap = v; 824 struct kernfs_node *kfs = VTOKERN(ap->a_vp); 825 826 return kernfs_try_fileop(kfs->kfs_type, KERNFS_FILEOP_IOCTL, v, 827 EPASSTHROUGH); 828 } 829 830 static int 831 kernfs_setdirentfileno_kt(struct dirent *d, const struct kern_target *kt, 832 struct vop_readdir_args *ap) 833 { 834 struct kernfs_node *kfs; 835 struct vnode *vp; 836 int error; 837 838 if ((error = vcache_get(ap->a_vp->v_mount, &kt, sizeof(kt), &vp)) != 0) 839 return error; 840 kfs = VTOKERN(vp); 841 d->d_fileno = kfs->kfs_fileno; 842 vrele(vp); 843 return 0; 844 } 845 846 static int 847 kernfs_setdirentfileno(struct dirent *d, off_t entry, 848 struct kernfs_node *thisdir_kfs, const struct kern_target *parent_kt, 849 const struct kern_target *kt, struct vop_readdir_args *ap) 850 { 851 const struct kern_target *ikt; 852 int error; 853 854 switch (entry) { 855 case 0: 856 d->d_fileno = thisdir_kfs->kfs_fileno; 857 return 0; 858 case 1: 859 ikt = parent_kt; 860 break; 861 default: 862 ikt = kt; 863 break; 864 } 865 if (ikt != thisdir_kfs->kfs_kt) { 866 if ((error = kernfs_setdirentfileno_kt(d, ikt, ap)) != 0) 867 return error; 868 } else 869 d->d_fileno = thisdir_kfs->kfs_fileno; 870 return 0; 871 } 872 873 int 874 kernfs_readdir(void *v) 875 { 876 struct vop_readdir_args /* { 877 struct vnode *a_vp; 878 struct uio *a_uio; 879 kauth_cred_t a_cred; 880 int *a_eofflag; 881 off_t **a_cookies; 882 int a_*ncookies; 883 } */ *ap = v; 884 struct uio *uio = ap->a_uio; 885 struct dirent d; 886 struct kernfs_node *kfs = VTOKERN(ap->a_vp); 887 const struct kern_target *kt; 888 const struct dyn_kern_target *dkt = NULL; 889 const struct kernfs_subdir *ks; 890 off_t i, j; 891 int error; 892 off_t *cookies = NULL; 893 int ncookies = 0, n; 894 895 if (uio->uio_resid < UIO_MX) 896 return (EINVAL); 897 if (uio->uio_offset < 0) 898 return (EINVAL); 899 900 error = 0; 901 i = uio->uio_offset; 902 memset(&d, 0, sizeof(d)); 903 d.d_reclen = UIO_MX; 904 ncookies = uio->uio_resid / UIO_MX; 905 906 switch (kfs->kfs_type) { 907 case KFSkern: 908 if (i >= nkern_targets) 909 return (0); 910 911 if (ap->a_ncookies) { 912 ncookies = uimin(ncookies, (nkern_targets - i)); 913 cookies = malloc(ncookies * sizeof(off_t), M_TEMP, 914 M_WAITOK); 915 *ap->a_cookies = cookies; 916 } 917 918 n = 0; 919 for (; i < nkern_targets && uio->uio_resid >= UIO_MX; i++) { 920 if (i < static_nkern_targets) 921 kt = &kern_targets[i]; 922 else { 923 if (dkt == NULL) { 924 dkt = SIMPLEQ_FIRST(&dyn_kern_targets); 925 for (j = static_nkern_targets; j < i && 926 dkt != NULL; j++) 927 dkt = SIMPLEQ_NEXT(dkt, dkt_queue); 928 if (j != i) 929 break; 930 } else { 931 dkt = SIMPLEQ_NEXT(dkt, dkt_queue); 932 } 933 if (dkt == NULL) 934 break; 935 kt = &dkt->dkt_kt; 936 } 937 if (kt->kt_tag == KFSdevice) { 938 dev_t *dp = kt->kt_data; 939 struct vnode *fvp; 940 941 if (*dp == NODEV || 942 !vfinddev(*dp, kt->kt_vtype, &fvp)) 943 continue; 944 vrele(fvp); 945 } 946 if (kt->kt_tag == KFSmsgbuf) { 947 if (!logenabled(msgbufp)) { 948 continue; 949 } 950 } 951 d.d_namlen = kt->kt_namlen; 952 if ((error = kernfs_setdirentfileno(&d, i, kfs, 953 &kern_targets[0], kt, ap)) != 0) 954 break; 955 memcpy(d.d_name, kt->kt_name, kt->kt_namlen + 1); 956 d.d_type = kt->kt_type; 957 if ((error = uiomove(&d, UIO_MX, uio)) != 0) 958 break; 959 if (cookies) 960 *cookies++ = i + 1; 961 n++; 962 } 963 ncookies = n; 964 break; 965 966 case KFSroot: 967 if (i >= 2) 968 return 0; 969 970 if (ap->a_ncookies) { 971 ncookies = uimin(ncookies, (2 - i)); 972 cookies = malloc(ncookies * sizeof(off_t), M_TEMP, 973 M_WAITOK); 974 *ap->a_cookies = cookies; 975 } 976 977 n = 0; 978 for (; i < 2 && uio->uio_resid >= UIO_MX; i++) { 979 kt = &kern_targets[i]; 980 d.d_namlen = kt->kt_namlen; 981 d.d_fileno = KERNFS_FILENO(kt, kt->kt_tag, 0); 982 memcpy(d.d_name, kt->kt_name, kt->kt_namlen + 1); 983 d.d_type = kt->kt_type; 984 if ((error = uiomove(&d, UIO_MX, uio)) != 0) 985 break; 986 if (cookies) 987 *cookies++ = i + 1; 988 n++; 989 } 990 ncookies = n; 991 break; 992 993 case KFSsubdir: 994 ks = (struct kernfs_subdir *)kfs->kfs_kt->kt_data; 995 if (i >= ks->ks_nentries) 996 return (0); 997 998 if (ap->a_ncookies) { 999 ncookies = uimin(ncookies, (ks->ks_nentries - i)); 1000 cookies = malloc(ncookies * sizeof(off_t), M_TEMP, 1001 M_WAITOK); 1002 *ap->a_cookies = cookies; 1003 } 1004 1005 dkt = SIMPLEQ_FIRST(&ks->ks_entries); 1006 for (j = 0; j < i && dkt != NULL; j++) 1007 dkt = SIMPLEQ_NEXT(dkt, dkt_queue); 1008 n = 0; 1009 for (; i < ks->ks_nentries && uio->uio_resid >= UIO_MX; i++) { 1010 if (i < 2) 1011 kt = &subdir_targets[i]; 1012 else { 1013 /* check if ks_nentries lied to us */ 1014 if (dkt == NULL) 1015 break; 1016 kt = &dkt->dkt_kt; 1017 dkt = SIMPLEQ_NEXT(dkt, dkt_queue); 1018 } 1019 if (kt->kt_tag == KFSdevice) { 1020 dev_t *dp = kt->kt_data; 1021 struct vnode *fvp; 1022 1023 if (*dp == NODEV || 1024 !vfinddev(*dp, kt->kt_vtype, &fvp)) 1025 continue; 1026 vrele(fvp); 1027 } 1028 d.d_namlen = kt->kt_namlen; 1029 if ((error = kernfs_setdirentfileno(&d, i, kfs, 1030 ks->ks_parent, kt, ap)) != 0) 1031 break; 1032 memcpy(d.d_name, kt->kt_name, kt->kt_namlen + 1); 1033 d.d_type = kt->kt_type; 1034 if ((error = uiomove(&d, UIO_MX, uio)) != 0) 1035 break; 1036 if (cookies) 1037 *cookies++ = i + 1; 1038 n++; 1039 } 1040 ncookies = n; 1041 break; 1042 1043 default: 1044 error = ENOTDIR; 1045 break; 1046 } 1047 1048 if (ap->a_ncookies) { 1049 if (error) { 1050 if (cookies) 1051 free(*ap->a_cookies, M_TEMP); 1052 *ap->a_ncookies = 0; 1053 *ap->a_cookies = NULL; 1054 } else 1055 *ap->a_ncookies = ncookies; 1056 } 1057 1058 uio->uio_offset = i; 1059 return (error); 1060 } 1061 1062 int 1063 kernfs_inactive(void *v) 1064 { 1065 struct vop_inactive_v2_args /* { 1066 struct vnode *a_vp; 1067 bool *a_recycle; 1068 } */ *ap = v; 1069 1070 *ap->a_recycle = false; 1071 1072 return (0); 1073 } 1074 1075 int 1076 kernfs_reclaim(void *v) 1077 { 1078 struct vop_reclaim_v2_args /* { 1079 struct vnode *a_vp; 1080 } */ *ap = v; 1081 struct vnode *vp = ap->a_vp; 1082 struct kernfs_node *kfs = VTOKERN(vp); 1083 1084 VOP_UNLOCK(vp); 1085 1086 vp->v_data = NULL; 1087 mutex_enter(&kfs_lock); 1088 TAILQ_REMOVE(&VFSTOKERNFS(vp->v_mount)->nodelist, kfs, kfs_list); 1089 mutex_exit(&kfs_lock); 1090 kmem_free(kfs, sizeof(struct kernfs_node)); 1091 1092 return 0; 1093 } 1094 1095 /* 1096 * Return POSIX pathconf information applicable to special devices. 1097 */ 1098 int 1099 kernfs_pathconf(void *v) 1100 { 1101 struct vop_pathconf_args /* { 1102 struct vnode *a_vp; 1103 int a_name; 1104 register_t *a_retval; 1105 } */ *ap = v; 1106 1107 switch (ap->a_name) { 1108 case _PC_LINK_MAX: 1109 *ap->a_retval = LINK_MAX; 1110 return (0); 1111 case _PC_MAX_CANON: 1112 *ap->a_retval = MAX_CANON; 1113 return (0); 1114 case _PC_MAX_INPUT: 1115 *ap->a_retval = MAX_INPUT; 1116 return (0); 1117 case _PC_PIPE_BUF: 1118 *ap->a_retval = PIPE_BUF; 1119 return (0); 1120 case _PC_CHOWN_RESTRICTED: 1121 *ap->a_retval = 1; 1122 return (0); 1123 case _PC_VDISABLE: 1124 *ap->a_retval = _POSIX_VDISABLE; 1125 return (0); 1126 case _PC_SYNC_IO: 1127 *ap->a_retval = 1; 1128 return (0); 1129 default: 1130 return (EINVAL); 1131 } 1132 /* NOTREACHED */ 1133 } 1134 1135 /* 1136 * Print out the contents of a /dev/fd vnode. 1137 */ 1138 /* ARGSUSED */ 1139 int 1140 kernfs_print(void *v) 1141 { 1142 1143 printf("tag VT_KERNFS, kernfs vnode\n"); 1144 return (0); 1145 } 1146 1147 int 1148 kernfs_link(void *v) 1149 { 1150 struct vop_link_v2_args /* { 1151 struct vnode *a_dvp; 1152 struct vnode *a_vp; 1153 struct componentname *a_cnp; 1154 } */ *ap = v; 1155 1156 VOP_ABORTOP(ap->a_dvp, ap->a_cnp); 1157 return (EROFS); 1158 } 1159 1160 int 1161 kernfs_symlink(void *v) 1162 { 1163 struct vop_symlink_v3_args /* { 1164 struct vnode *a_dvp; 1165 struct vnode **a_vpp; 1166 struct componentname *a_cnp; 1167 struct vattr *a_vap; 1168 char *a_target; 1169 } */ *ap = v; 1170 1171 VOP_ABORTOP(ap->a_dvp, ap->a_cnp); 1172 return (EROFS); 1173 } 1174 1175 int 1176 kernfs_getpages(void *v) 1177 { 1178 struct vop_getpages_args /* { 1179 struct vnode *a_vp; 1180 voff_t a_offset; 1181 struct vm_page **a_m; 1182 int *a_count; 1183 int a_centeridx; 1184 vm_prot_t a_access_type; 1185 int a_advice; 1186 int a_flags; 1187 } */ *ap = v; 1188 1189 if ((ap->a_flags & PGO_LOCKED) == 0) 1190 mutex_exit(ap->a_vp->v_interlock); 1191 1192 return (EFAULT); 1193 } 1194