ptyfs_vnops.c revision 1.16
1 /* $NetBSD: ptyfs_vnops.c,v 1.16 2006/07/23 22:06:10 ad Exp $ */ 2 3 /* 4 * Copyright (c) 1993, 1995 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed 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 * @(#)procfs_vnops.c 8.18 (Berkeley) 5/21/95 35 */ 36 37 /* 38 * Copyright (c) 1993 Jan-Simon Pendry 39 * 40 * This code is derived from software contributed to Berkeley by 41 * Jan-Simon Pendry. 42 * 43 * Redistribution and use in source and binary forms, with or without 44 * modification, are permitted provided that the following conditions 45 * are met: 46 * 1. Redistributions of source code must retain the above copyright 47 * notice, this list of conditions and the following disclaimer. 48 * 2. Redistributions in binary form must reproduce the above copyright 49 * notice, this list of conditions and the following disclaimer in the 50 * documentation and/or other materials provided with the distribution. 51 * 3. All advertising materials mentioning features or use of this software 52 * must display the following acknowledgement: 53 * This product includes software developed by the University of 54 * California, Berkeley and its contributors. 55 * 4. Neither the name of the University nor the names of its contributors 56 * may be used to endorse or promote products derived from this software 57 * without specific prior written permission. 58 * 59 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 60 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 61 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 62 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 63 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 64 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 65 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 66 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 67 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 68 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 69 * SUCH DAMAGE. 70 * 71 * @(#)procfs_vnops.c 8.18 (Berkeley) 5/21/95 72 */ 73 74 /* 75 * ptyfs vnode interface 76 */ 77 78 #include <sys/cdefs.h> 79 __KERNEL_RCSID(0, "$NetBSD: ptyfs_vnops.c,v 1.16 2006/07/23 22:06:10 ad Exp $"); 80 81 #include <sys/param.h> 82 #include <sys/systm.h> 83 #include <sys/time.h> 84 #include <sys/kernel.h> 85 #include <sys/file.h> 86 #include <sys/filedesc.h> 87 #include <sys/proc.h> 88 #include <sys/vnode.h> 89 #include <sys/namei.h> 90 #include <sys/malloc.h> 91 #include <sys/mount.h> 92 #include <sys/select.h> 93 #include <sys/dirent.h> 94 #include <sys/resourcevar.h> 95 #include <sys/stat.h> 96 #include <sys/conf.h> 97 #include <sys/tty.h> 98 #include <sys/pty.h> 99 #include <sys/kauth.h> 100 101 #include <uvm/uvm_extern.h> /* for PAGE_SIZE */ 102 103 #include <machine/reg.h> 104 105 #include <fs/ptyfs/ptyfs.h> 106 #include <miscfs/genfs/genfs.h> 107 #include <miscfs/specfs/specdev.h> 108 109 /* 110 * Vnode Operations. 111 * 112 */ 113 114 int ptyfs_lookup (void *); 115 #define ptyfs_create genfs_eopnotsupp 116 #define ptyfs_mknod genfs_eopnotsupp 117 int ptyfs_open (void *); 118 int ptyfs_close (void *); 119 int ptyfs_access (void *); 120 int ptyfs_getattr (void *); 121 int ptyfs_setattr (void *); 122 int ptyfs_read (void *); 123 int ptyfs_write (void *); 124 #define ptyfs_fcntl genfs_fcntl 125 int ptyfs_ioctl (void *); 126 int ptyfs_poll (void *); 127 int ptyfs_kqfilter (void *); 128 #define ptyfs_revoke genfs_revoke 129 #define ptyfs_mmap genfs_eopnotsupp 130 #define ptyfs_fsync genfs_nullop 131 #define ptyfs_seek genfs_nullop 132 #define ptyfs_remove genfs_eopnotsupp 133 #define ptyfs_link genfs_abortop 134 #define ptyfs_rename genfs_eopnotsupp 135 #define ptyfs_mkdir genfs_eopnotsupp 136 #define ptyfs_rmdir genfs_eopnotsupp 137 #define ptyfs_symlink genfs_abortop 138 int ptyfs_readdir (void *); 139 #define ptyfs_readlink genfs_eopnotsupp 140 #define ptyfs_abortop genfs_abortop 141 int ptyfs_reclaim (void *); 142 #define ptyfs_lock genfs_lock 143 #define ptyfs_unlock genfs_unlock 144 #define ptyfs_bmap genfs_badop 145 #define ptyfs_strategy genfs_badop 146 int ptyfs_print (void *); 147 int ptyfs_pathconf (void *); 148 #define ptyfs_islocked genfs_islocked 149 #define ptyfs_advlock genfs_einval 150 #define ptyfs_bwrite genfs_eopnotsupp 151 #define ptyfs_putpages genfs_null_putpages 152 153 static int ptyfs_update(struct vnode *, const struct timespec *, 154 const struct timespec *, int); 155 static int ptyfs_chown(struct vnode *, uid_t, gid_t, kauth_cred_t, 156 struct lwp *); 157 static int ptyfs_chmod(struct vnode *, mode_t, kauth_cred_t, struct lwp *); 158 static int atoi(const char *, size_t); 159 160 extern const struct cdevsw pts_cdevsw, ptc_cdevsw; 161 162 /* 163 * ptyfs vnode operations. 164 */ 165 int (**ptyfs_vnodeop_p)(void *); 166 const struct vnodeopv_entry_desc ptyfs_vnodeop_entries[] = { 167 { &vop_default_desc, vn_default_error }, 168 { &vop_lookup_desc, ptyfs_lookup }, /* lookup */ 169 { &vop_create_desc, ptyfs_create }, /* create */ 170 { &vop_mknod_desc, ptyfs_mknod }, /* mknod */ 171 { &vop_open_desc, ptyfs_open }, /* open */ 172 { &vop_close_desc, ptyfs_close }, /* close */ 173 { &vop_access_desc, ptyfs_access }, /* access */ 174 { &vop_getattr_desc, ptyfs_getattr }, /* getattr */ 175 { &vop_setattr_desc, ptyfs_setattr }, /* setattr */ 176 { &vop_read_desc, ptyfs_read }, /* read */ 177 { &vop_write_desc, ptyfs_write }, /* write */ 178 { &vop_ioctl_desc, ptyfs_ioctl }, /* ioctl */ 179 { &vop_fcntl_desc, ptyfs_fcntl }, /* fcntl */ 180 { &vop_poll_desc, ptyfs_poll }, /* poll */ 181 { &vop_kqfilter_desc, ptyfs_kqfilter }, /* kqfilter */ 182 { &vop_revoke_desc, ptyfs_revoke }, /* revoke */ 183 { &vop_mmap_desc, ptyfs_mmap }, /* mmap */ 184 { &vop_fsync_desc, ptyfs_fsync }, /* fsync */ 185 { &vop_seek_desc, ptyfs_seek }, /* seek */ 186 { &vop_remove_desc, ptyfs_remove }, /* remove */ 187 { &vop_link_desc, ptyfs_link }, /* link */ 188 { &vop_rename_desc, ptyfs_rename }, /* rename */ 189 { &vop_mkdir_desc, ptyfs_mkdir }, /* mkdir */ 190 { &vop_rmdir_desc, ptyfs_rmdir }, /* rmdir */ 191 { &vop_symlink_desc, ptyfs_symlink }, /* symlink */ 192 { &vop_readdir_desc, ptyfs_readdir }, /* readdir */ 193 { &vop_readlink_desc, ptyfs_readlink }, /* readlink */ 194 { &vop_abortop_desc, ptyfs_abortop }, /* abortop */ 195 { &vop_inactive_desc, spec_inactive }, /* inactive */ 196 { &vop_reclaim_desc, ptyfs_reclaim }, /* reclaim */ 197 { &vop_lock_desc, ptyfs_lock }, /* lock */ 198 { &vop_unlock_desc, ptyfs_unlock }, /* unlock */ 199 { &vop_bmap_desc, ptyfs_bmap }, /* bmap */ 200 { &vop_strategy_desc, ptyfs_strategy }, /* strategy */ 201 { &vop_print_desc, ptyfs_print }, /* print */ 202 { &vop_islocked_desc, ptyfs_islocked }, /* islocked */ 203 { &vop_pathconf_desc, ptyfs_pathconf }, /* pathconf */ 204 { &vop_advlock_desc, ptyfs_advlock }, /* advlock */ 205 { &vop_bwrite_desc, ptyfs_bwrite }, /* bwrite */ 206 { &vop_putpages_desc, ptyfs_putpages }, /* putpages */ 207 { NULL, NULL } 208 }; 209 const struct vnodeopv_desc ptyfs_vnodeop_opv_desc = 210 { &ptyfs_vnodeop_p, ptyfs_vnodeop_entries }; 211 212 /* 213 * _reclaim is called when getnewvnode() 214 * wants to make use of an entry on the vnode 215 * free list. at this time the filesystem needs 216 * to free any private data and remove the node 217 * from any private lists. 218 */ 219 int 220 ptyfs_reclaim(void *v) 221 { 222 struct vop_reclaim_args /* { 223 struct vnode *a_vp; 224 } */ *ap = v; 225 return ptyfs_freevp(ap->a_vp); 226 } 227 228 /* 229 * Return POSIX pathconf information applicable to special devices. 230 */ 231 int 232 ptyfs_pathconf(void *v) 233 { 234 struct vop_pathconf_args /* { 235 struct vnode *a_vp; 236 int a_name; 237 register_t *a_retval; 238 } */ *ap = v; 239 240 switch (ap->a_name) { 241 case _PC_LINK_MAX: 242 *ap->a_retval = LINK_MAX; 243 return 0; 244 case _PC_MAX_CANON: 245 *ap->a_retval = MAX_CANON; 246 return 0; 247 case _PC_MAX_INPUT: 248 *ap->a_retval = MAX_INPUT; 249 return 0; 250 case _PC_PIPE_BUF: 251 *ap->a_retval = PIPE_BUF; 252 return 0; 253 case _PC_CHOWN_RESTRICTED: 254 *ap->a_retval = 1; 255 return 0; 256 case _PC_VDISABLE: 257 *ap->a_retval = _POSIX_VDISABLE; 258 return 0; 259 case _PC_SYNC_IO: 260 *ap->a_retval = 1; 261 return 0; 262 default: 263 return EINVAL; 264 } 265 } 266 267 /* 268 * _print is used for debugging. 269 * just print a readable description 270 * of (vp). 271 */ 272 int 273 ptyfs_print(void *v) 274 { 275 struct vop_print_args /* { 276 struct vnode *a_vp; 277 } */ *ap = v; 278 struct ptyfsnode *ptyfs = VTOPTYFS(ap->a_vp); 279 280 printf("tag VT_PTYFS, type %d, pty %d\n", 281 ptyfs->ptyfs_type, ptyfs->ptyfs_pty); 282 return 0; 283 } 284 285 /* 286 * Invent attributes for ptyfsnode (vp) and store 287 * them in (vap). 288 * Directories lengths are returned as zero since 289 * any real length would require the genuine size 290 * to be computed, and nothing cares anyway. 291 * 292 * this is relatively minimal for ptyfs. 293 */ 294 int 295 ptyfs_getattr(void *v) 296 { 297 struct vop_getattr_args /* { 298 struct vnode *a_vp; 299 struct vattr *a_vap; 300 kauth_cred_t a_cred; 301 struct lwp *a_l; 302 } */ *ap = v; 303 struct ptyfsnode *ptyfs = VTOPTYFS(ap->a_vp); 304 struct vattr *vap = ap->a_vap; 305 306 PTYFS_ITIMES(ptyfs, NULL, NULL, NULL); 307 308 /* start by zeroing out the attributes */ 309 VATTR_NULL(vap); 310 311 /* next do all the common fields */ 312 vap->va_type = ap->a_vp->v_type; 313 vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsidx.__fsid_val[0]; 314 vap->va_fileid = ptyfs->ptyfs_fileno; 315 vap->va_gen = 0; 316 vap->va_flags = 0; 317 vap->va_nlink = 1; 318 vap->va_blocksize = PAGE_SIZE; 319 320 vap->va_atime = ptyfs->ptyfs_atime; 321 vap->va_mtime = ptyfs->ptyfs_mtime; 322 vap->va_ctime = ptyfs->ptyfs_ctime; 323 vap->va_birthtime = ptyfs->ptyfs_birthtime; 324 vap->va_mode = ptyfs->ptyfs_mode; 325 vap->va_flags = ptyfs->ptyfs_flags; 326 vap->va_uid = ptyfs->ptyfs_uid; 327 vap->va_gid = ptyfs->ptyfs_gid; 328 329 switch (ptyfs->ptyfs_type) { 330 case PTYFSpts: 331 case PTYFSptc: 332 if (pty_isfree(ptyfs->ptyfs_pty, 1)) 333 return ENOENT; 334 vap->va_bytes = vap->va_size = 0; 335 vap->va_rdev = ap->a_vp->v_rdev; 336 break; 337 case PTYFSroot: 338 vap->va_rdev = 0; 339 vap->va_bytes = vap->va_size = DEV_BSIZE; 340 break; 341 342 default: 343 return EOPNOTSUPP; 344 } 345 346 return 0; 347 } 348 349 /*ARGSUSED*/ 350 int 351 ptyfs_setattr(void *v) 352 { 353 struct vop_setattr_args /* { 354 struct vnodeop_desc *a_desc; 355 struct vnode *a_vp; 356 struct vattr *a_vap; 357 kauth_cred_t a_cred; 358 struct lwp *a_l; 359 } */ *ap = v; 360 struct vnode *vp = ap->a_vp; 361 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 362 struct vattr *vap = ap->a_vap; 363 kauth_cred_t cred = ap->a_cred; 364 struct lwp *l = ap->a_l; 365 int error; 366 367 if (vap->va_size != VNOVAL) { 368 switch (ptyfs->ptyfs_type) { 369 case PTYFSroot: 370 return EISDIR; 371 case PTYFSpts: 372 case PTYFSptc: 373 break; 374 default: 375 return EINVAL; 376 } 377 } 378 379 if (vap->va_flags != VNOVAL) { 380 if (vp->v_mount->mnt_flag & MNT_RDONLY) 381 return EROFS; 382 if (kauth_cred_geteuid(cred) != ptyfs->ptyfs_uid && 383 (error = kauth_authorize_generic(cred, KAUTH_GENERIC_ISSUSER, 384 &l->l_acflag)) != 0) 385 return error; 386 if (kauth_authorize_generic(cred, KAUTH_GENERIC_ISSUSER, NULL) == 0) { 387 if ((ptyfs->ptyfs_flags & (SF_IMMUTABLE | SF_APPEND)) && 388 securelevel > 0) 389 return EPERM; 390 /* Snapshot flag cannot be set or cleared */ 391 if ((vap->va_flags & SF_SNAPSHOT) != 392 (ptyfs->ptyfs_flags & SF_SNAPSHOT)) 393 return EPERM; 394 ptyfs->ptyfs_flags = vap->va_flags; 395 } else { 396 if ((ptyfs->ptyfs_flags & (SF_IMMUTABLE | SF_APPEND)) || 397 (vap->va_flags & UF_SETTABLE) != vap->va_flags) 398 return EPERM; 399 if ((ptyfs->ptyfs_flags & SF_SETTABLE) != 400 (vap->va_flags & SF_SETTABLE)) 401 return EPERM; 402 ptyfs->ptyfs_flags &= SF_SETTABLE; 403 ptyfs->ptyfs_flags |= (vap->va_flags & UF_SETTABLE); 404 } 405 ptyfs->ptyfs_flag |= PTYFS_CHANGE; 406 if (vap->va_flags & (IMMUTABLE | APPEND)) 407 return 0; 408 } 409 if (ptyfs->ptyfs_flags & (IMMUTABLE | APPEND)) 410 return EPERM; 411 /* 412 * Go through the fields and update iff not VNOVAL. 413 */ 414 if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) { 415 if (vp->v_mount->mnt_flag & MNT_RDONLY) 416 return EROFS; 417 if (ptyfs->ptyfs_type == PTYFSroot) 418 return EPERM; 419 error = ptyfs_chown(vp, vap->va_uid, vap->va_gid, cred, l); 420 if (error) 421 return error; 422 } 423 424 if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL || 425 vap->va_birthtime.tv_sec != VNOVAL) { 426 if (vp->v_mount->mnt_flag & MNT_RDONLY) 427 return EROFS; 428 if ((ptyfs->ptyfs_flags & SF_SNAPSHOT) != 0) 429 return EPERM; 430 if (kauth_cred_geteuid(cred) != ptyfs->ptyfs_uid && 431 (error = kauth_authorize_generic(cred, KAUTH_GENERIC_ISSUSER, 432 &l->l_acflag)) && 433 ((vap->va_vaflags & VA_UTIMES_NULL) == 0 || 434 (error = VOP_ACCESS(vp, VWRITE, cred, l)) != 0)) 435 return (error); 436 if (vap->va_atime.tv_sec != VNOVAL) 437 if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) 438 ptyfs->ptyfs_flag |= PTYFS_ACCESS; 439 if (vap->va_mtime.tv_sec != VNOVAL) 440 ptyfs->ptyfs_flag |= PTYFS_CHANGE | PTYFS_MODIFY; 441 if (vap->va_birthtime.tv_sec != VNOVAL) 442 ptyfs->ptyfs_birthtime = vap->va_birthtime; 443 ptyfs->ptyfs_flag |= PTYFS_CHANGE; 444 error = ptyfs_update(vp, &vap->va_atime, &vap->va_mtime, 0); 445 if (error) 446 return error; 447 } 448 if (vap->va_mode != (mode_t)VNOVAL) { 449 if (vp->v_mount->mnt_flag & MNT_RDONLY) 450 return EROFS; 451 if (ptyfs->ptyfs_type == PTYFSroot) 452 return EPERM; 453 if ((ptyfs->ptyfs_flags & SF_SNAPSHOT) != 0 && 454 (vap->va_mode & 455 (S_IXUSR|S_IWUSR|S_IXGRP|S_IWGRP|S_IXOTH|S_IWOTH))) 456 return EPERM; 457 error = ptyfs_chmod(vp, vap->va_mode, cred, l); 458 if (error) 459 return error; 460 } 461 VN_KNOTE(vp, NOTE_ATTRIB); 462 return 0; 463 } 464 465 /* 466 * Change the mode on a file. 467 * Inode must be locked before calling. 468 */ 469 static int 470 ptyfs_chmod(struct vnode *vp, mode_t mode, kauth_cred_t cred, struct lwp *l) 471 { 472 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 473 int error; 474 475 if (kauth_cred_geteuid(cred) != ptyfs->ptyfs_uid && 476 (error = kauth_authorize_generic(cred, KAUTH_GENERIC_ISSUSER, 477 &l->l_acflag)) != 0) 478 return error; 479 ptyfs->ptyfs_mode &= ~ALLPERMS; 480 ptyfs->ptyfs_mode |= (mode & ALLPERMS); 481 return 0; 482 } 483 484 /* 485 * Perform chown operation on inode ip; 486 * inode must be locked prior to call. 487 */ 488 static int 489 ptyfs_chown(struct vnode *vp, uid_t uid, gid_t gid, kauth_cred_t cred, 490 struct lwp *l) 491 { 492 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 493 int error, ismember = 0; 494 495 if (uid == (uid_t)VNOVAL) 496 uid = ptyfs->ptyfs_uid; 497 if (gid == (gid_t)VNOVAL) 498 gid = ptyfs->ptyfs_gid; 499 /* 500 * If we don't own the file, are trying to change the owner 501 * of the file, or are not a member of the target group, 502 * the caller's credentials must imply super-user privilege 503 * or the call fails. 504 */ 505 if ((kauth_cred_geteuid(cred) != ptyfs->ptyfs_uid || uid != ptyfs->ptyfs_uid || 506 (gid != ptyfs->ptyfs_gid && 507 !(kauth_cred_getegid(cred) == gid || 508 (kauth_cred_ismember_gid(cred, gid, &ismember) == 0 && ismember)))) && 509 ((error = kauth_authorize_generic(cred, KAUTH_GENERIC_ISSUSER, 510 &l->l_acflag)) != 0)) 511 return error; 512 513 ptyfs->ptyfs_gid = gid; 514 ptyfs->ptyfs_uid = uid; 515 return 0; 516 } 517 518 /* 519 * implement access checking. 520 * 521 * actually, the check for super-user is slightly 522 * broken since it will allow read access to write-only 523 * objects. this doesn't cause any particular trouble 524 * but does mean that the i/o entry points need to check 525 * that the operation really does make sense. 526 */ 527 int 528 ptyfs_access(void *v) 529 { 530 struct vop_access_args /* { 531 struct vnode *a_vp; 532 int a_mode; 533 kauth_cred_t a_cred; 534 struct lwp *a_l; 535 } */ *ap = v; 536 struct vattr va; 537 int error; 538 539 if ((error = VOP_GETATTR(ap->a_vp, &va, ap->a_cred, ap->a_l)) != 0) 540 return error; 541 542 return vaccess(va.va_type, va.va_mode, 543 va.va_uid, va.va_gid, ap->a_mode, ap->a_cred); 544 } 545 546 /* 547 * lookup. this is incredibly complicated in the 548 * general case, however for most pseudo-filesystems 549 * very little needs to be done. 550 * 551 * Locking isn't hard here, just poorly documented. 552 * 553 * If we're looking up ".", just vref the parent & return it. 554 * 555 * If we're looking up "..", unlock the parent, and lock "..". If everything 556 * went ok, and we're on the last component and the caller requested the 557 * parent locked, try to re-lock the parent. We do this to prevent lock 558 * races. 559 * 560 * For anything else, get the needed node. Then unlock the parent if not 561 * the last component or not LOCKPARENT (i.e. if we wouldn't re-lock the 562 * parent in the .. case). 563 * 564 * We try to exit with the parent locked in error cases. 565 */ 566 int 567 ptyfs_lookup(void *v) 568 { 569 struct vop_lookup_args /* { 570 struct vnode * a_dvp; 571 struct vnode ** a_vpp; 572 struct componentname * a_cnp; 573 } */ *ap = v; 574 struct componentname *cnp = ap->a_cnp; 575 struct vnode **vpp = ap->a_vpp; 576 struct vnode *dvp = ap->a_dvp; 577 const char *pname = cnp->cn_nameptr; 578 struct ptyfsnode *ptyfs; 579 int pty, error, wantpunlock; 580 581 *vpp = NULL; 582 cnp->cn_flags &= ~PDIRUNLOCK; 583 584 if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME) 585 return EROFS; 586 587 if (cnp->cn_namelen == 1 && *pname == '.') { 588 *vpp = dvp; 589 VREF(dvp); 590 return 0; 591 } 592 593 wantpunlock = ~cnp->cn_flags & (LOCKPARENT | ISLASTCN); 594 ptyfs = VTOPTYFS(dvp); 595 switch (ptyfs->ptyfs_type) { 596 case PTYFSroot: 597 /* 598 * Shouldn't get here with .. in the root node. 599 */ 600 if (cnp->cn_flags & ISDOTDOT) 601 return EIO; 602 603 pty = atoi(pname, cnp->cn_namelen); 604 605 if (pty < 0 || pty >= npty || pty_isfree(pty, 1)) 606 break; 607 608 error = ptyfs_allocvp(dvp->v_mount, vpp, PTYFSpts, pty, 609 curlwp); 610 if (error == 0 && wantpunlock) { 611 VOP_UNLOCK(dvp, 0); 612 cnp->cn_flags |= PDIRUNLOCK; 613 } 614 return error; 615 616 default: 617 return ENOTDIR; 618 } 619 620 return cnp->cn_nameiop == LOOKUP ? ENOENT : EROFS; 621 } 622 623 /* 624 * readdir returns directory entries from ptyfsnode (vp). 625 * 626 * the strategy here with ptyfs is to generate a single 627 * directory entry at a time (struct dirent) and then 628 * copy that out to userland using uiomove. a more efficent 629 * though more complex implementation, would try to minimize 630 * the number of calls to uiomove(). for ptyfs, this is 631 * hardly worth the added code complexity. 632 * 633 * this should just be done through read() 634 */ 635 int 636 ptyfs_readdir(void *v) 637 { 638 struct vop_readdir_args /* { 639 struct vnode *a_vp; 640 struct uio *a_uio; 641 kauth_cred_t a_cred; 642 int *a_eofflag; 643 off_t **a_cookies; 644 int *a_ncookies; 645 } */ *ap = v; 646 struct uio *uio = ap->a_uio; 647 struct dirent d; 648 struct ptyfsnode *ptyfs; 649 off_t i; 650 int error; 651 off_t *cookies = NULL; 652 int ncookies; 653 struct vnode *vp; 654 int nc = 0; 655 656 vp = ap->a_vp; 657 ptyfs = VTOPTYFS(vp); 658 659 if (uio->uio_resid < UIO_MX) 660 return EINVAL; 661 if (uio->uio_offset < 0) 662 return EINVAL; 663 664 error = 0; 665 i = uio->uio_offset; 666 (void)memset(&d, 0, sizeof(d)); 667 d.d_reclen = UIO_MX; 668 ncookies = uio->uio_resid / UIO_MX; 669 670 switch (ptyfs->ptyfs_type) { 671 case PTYFSroot: /* root */ 672 673 if (i >= npty) 674 return 0; 675 676 if (ap->a_ncookies) { 677 ncookies = min(ncookies, (npty + 2 - i)); 678 cookies = malloc(ncookies * sizeof (off_t), 679 M_TEMP, M_WAITOK); 680 *ap->a_cookies = cookies; 681 } 682 683 for (; i < 2; i++) { 684 switch (i) { 685 case 0: /* `.' */ 686 case 1: /* `..' */ 687 d.d_fileno = PTYFS_FILENO(0, PTYFSroot); 688 d.d_namlen = i + 1; 689 (void)memcpy(d.d_name, "..", d.d_namlen); 690 d.d_name[i + 1] = '\0'; 691 d.d_type = DT_DIR; 692 break; 693 } 694 if ((error = uiomove(&d, UIO_MX, uio)) != 0) 695 break; 696 if (cookies) 697 *cookies++ = i + 1; 698 nc++; 699 } 700 if (error) { 701 ncookies = nc; 702 break; 703 } 704 for (; uio->uio_resid >= UIO_MX && i < npty; i++) { 705 /* check for used ptys */ 706 if (pty_isfree(i - 2, 1)) 707 continue; 708 709 d.d_fileno = PTYFS_FILENO(i - 2, PTYFSpts); 710 d.d_namlen = snprintf(d.d_name, sizeof(d.d_name), 711 "%lld", (long long)(i - 2)); 712 d.d_type = DT_CHR; 713 if ((error = uiomove(&d, UIO_MX, uio)) != 0) 714 break; 715 if (cookies) 716 *cookies++ = i + 1; 717 nc++; 718 } 719 ncookies = nc; 720 break; 721 722 default: 723 error = ENOTDIR; 724 break; 725 } 726 727 if (ap->a_ncookies) { 728 if (error) { 729 if (cookies) 730 free(*ap->a_cookies, M_TEMP); 731 *ap->a_ncookies = 0; 732 *ap->a_cookies = NULL; 733 } else 734 *ap->a_ncookies = ncookies; 735 } 736 uio->uio_offset = i; 737 return error; 738 } 739 740 int 741 ptyfs_open(void *v) 742 { 743 struct vop_open_args /* { 744 struct vnode *a_vp; 745 int a_mode; 746 kauth_cred_t a_cred; 747 struct lwp *a_l; 748 } */ *ap = v; 749 struct vnode *vp = ap->a_vp; 750 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 751 752 ptyfs->ptyfs_flag |= PTYFS_CHANGE|PTYFS_ACCESS; 753 switch (ptyfs->ptyfs_type) { 754 case PTYFSpts: 755 case PTYFSptc: 756 return spec_open(v); 757 case PTYFSroot: 758 return 0; 759 default: 760 return EINVAL; 761 } 762 } 763 764 int 765 ptyfs_close(void *v) 766 { 767 struct vop_close_args /* { 768 struct vnode *a_vp; 769 int a_fflag; 770 kauth_cred_t a_cred; 771 struct lwp *a_l; 772 } */ *ap = v; 773 struct vnode *vp = ap->a_vp; 774 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 775 776 simple_lock(&vp->v_interlock); 777 if (vp->v_usecount > 1) 778 PTYFS_ITIMES(ptyfs, NULL, NULL, NULL); 779 simple_unlock(&vp->v_interlock); 780 781 switch (ptyfs->ptyfs_type) { 782 case PTYFSpts: 783 case PTYFSptc: 784 return spec_close(v); 785 case PTYFSroot: 786 return 0; 787 default: 788 return EINVAL; 789 } 790 } 791 792 int 793 ptyfs_read(void *v) 794 { 795 struct vop_read_args /* { 796 struct vnode *a_vp; 797 struct uio *a_uio; 798 int a_ioflag; 799 kauth_cred_t a_cred; 800 } */ *ap = v; 801 struct timespec ts; 802 struct vnode *vp = ap->a_vp; 803 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 804 int error; 805 806 ptyfs->ptyfs_flag |= PTYFS_ACCESS; 807 /* hardclock() resolution is good enough for ptyfs */ 808 getnanotime(&ts); 809 (void)ptyfs_update(vp, &ts, &ts, 0); 810 811 switch (ptyfs->ptyfs_type) { 812 case PTYFSpts: 813 VOP_UNLOCK(vp, 0); 814 error = (*pts_cdevsw.d_read)(vp->v_rdev, ap->a_uio, 815 ap->a_ioflag); 816 vn_lock(vp, LK_RETRY|LK_EXCLUSIVE); 817 return error; 818 case PTYFSptc: 819 VOP_UNLOCK(vp, 0); 820 error = (*ptc_cdevsw.d_read)(vp->v_rdev, ap->a_uio, 821 ap->a_ioflag); 822 vn_lock(vp, LK_RETRY|LK_EXCLUSIVE); 823 return error; 824 default: 825 return EOPNOTSUPP; 826 } 827 } 828 829 int 830 ptyfs_write(void *v) 831 { 832 struct vop_write_args /* { 833 struct vnode *a_vp; 834 struct uio *a_uio; 835 int a_ioflag; 836 kauth_cred_t a_cred; 837 } */ *ap = v; 838 struct timespec ts; 839 struct vnode *vp = ap->a_vp; 840 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 841 int error; 842 843 ptyfs->ptyfs_flag |= PTYFS_MODIFY; 844 getnanotime(&ts); 845 (void)ptyfs_update(vp, &ts, &ts, 0); 846 847 switch (ptyfs->ptyfs_type) { 848 case PTYFSpts: 849 VOP_UNLOCK(vp, 0); 850 error = (*pts_cdevsw.d_write)(vp->v_rdev, ap->a_uio, 851 ap->a_ioflag); 852 vn_lock(vp, LK_RETRY|LK_EXCLUSIVE); 853 return error; 854 case PTYFSptc: 855 VOP_UNLOCK(vp, 0); 856 error = (*ptc_cdevsw.d_write)(vp->v_rdev, ap->a_uio, 857 ap->a_ioflag); 858 vn_lock(vp, LK_RETRY|LK_EXCLUSIVE); 859 return error; 860 default: 861 return EOPNOTSUPP; 862 } 863 } 864 865 int 866 ptyfs_ioctl(void *v) 867 { 868 struct vop_ioctl_args /* { 869 struct vnode *a_vp; 870 u_long a_command; 871 void *a_data; 872 int a_fflag; 873 kauth_cred_t a_cred; 874 struct lwp *a_l; 875 } */ *ap = v; 876 struct vnode *vp = ap->a_vp; 877 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 878 879 switch (ptyfs->ptyfs_type) { 880 case PTYFSpts: 881 return (*pts_cdevsw.d_ioctl)(vp->v_rdev, ap->a_command, 882 ap->a_data, ap->a_fflag, ap->a_l); 883 case PTYFSptc: 884 return (*ptc_cdevsw.d_ioctl)(vp->v_rdev, ap->a_command, 885 ap->a_data, ap->a_fflag, ap->a_l); 886 default: 887 return EOPNOTSUPP; 888 } 889 } 890 891 int 892 ptyfs_poll(void *v) 893 { 894 struct vop_poll_args /* { 895 struct vnode *a_vp; 896 int a_events; 897 struct lwp *a_l; 898 } */ *ap = v; 899 struct vnode *vp = ap->a_vp; 900 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 901 902 switch (ptyfs->ptyfs_type) { 903 case PTYFSpts: 904 return (*pts_cdevsw.d_poll)(vp->v_rdev, ap->a_events, ap->a_l); 905 case PTYFSptc: 906 return (*ptc_cdevsw.d_poll)(vp->v_rdev, ap->a_events, ap->a_l); 907 default: 908 return genfs_poll(v); 909 } 910 } 911 912 int 913 ptyfs_kqfilter(void *v) 914 { 915 struct vop_kqfilter_args /* { 916 struct vnode *a_vp; 917 struct knote *a_kn; 918 } */ *ap = v; 919 struct vnode *vp = ap->a_vp; 920 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 921 922 switch (ptyfs->ptyfs_type) { 923 case PTYFSpts: 924 return (*pts_cdevsw.d_kqfilter)(vp->v_rdev, ap->a_kn); 925 case PTYFSptc: 926 return (*ptc_cdevsw.d_kqfilter)(vp->v_rdev, ap->a_kn); 927 default: 928 return genfs_kqfilter(v); 929 } 930 } 931 932 static int 933 ptyfs_update(struct vnode *vp, const struct timespec *acc, 934 const struct timespec *mod, int flags) 935 { 936 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 937 938 if (vp->v_mount->mnt_flag & MNT_RDONLY) 939 return 0; 940 941 PTYFS_ITIMES(ptyfs, acc, mod, NULL); 942 return 0; 943 } 944 945 void 946 ptyfs_itimes(struct ptyfsnode *ptyfs, const struct timespec *acc, 947 const struct timespec *mod, const struct timespec *cre) 948 { 949 struct timespec now; 950 951 KASSERT(ptyfs->ptyfs_flag & (PTYFS_ACCESS|PTYFS_CHANGE|PTYFS_MODIFY)); 952 953 getnanotime(&now); 954 if (ptyfs->ptyfs_flag & (PTYFS_ACCESS|PTYFS_MODIFY)) { 955 if (acc == NULL) 956 acc = &now; 957 ptyfs->ptyfs_atime = *acc; 958 } 959 if (ptyfs->ptyfs_flag & PTYFS_MODIFY) { 960 if (mod == NULL) 961 mod = &now; 962 ptyfs->ptyfs_mtime = *mod; 963 } 964 if (ptyfs->ptyfs_flag & PTYFS_CHANGE) { 965 if (cre == NULL) 966 cre = &now; 967 ptyfs->ptyfs_ctime = *cre; 968 } 969 ptyfs->ptyfs_flag &= ~(PTYFS_ACCESS|PTYFS_CHANGE|PTYFS_MODIFY); 970 } 971 972 /* 973 * convert decimal ascii to int 974 */ 975 static int 976 atoi(const char *b, size_t len) 977 { 978 int p = 0; 979 980 while (len--) { 981 char c = *b++; 982 if (c < '0' || c > '9') 983 return -1; 984 p = 10 * p + (c - '0'); 985 } 986 987 return p; 988 } 989
Indexes created Fri Sep 26 08:10:20 GMT 2025