ptyfs_vnops.c revision 1.12.10.3
1 /* $NetBSD: ptyfs_vnops.c,v 1.12.10.3 2006/03/11 04:55:28 elad 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 1.12.10.3 2006/03/11 04:55:28 elad 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> 99 100 #include <uvm/uvm_extern.h> /* for PAGE_SIZE */ 101 102 #include <machine/reg.h> 103 104 #include <fs/ptyfs/ptyfs.h> 105 #include <miscfs/genfs/genfs.h> 106 #include <miscfs/specfs/specdev.h> 107 108 /* 109 * Vnode Operations. 110 * 111 */ 112 113 int ptyfs_lookup (void *); 114 #define ptyfs_create genfs_eopnotsupp 115 #define ptyfs_mknod genfs_eopnotsupp 116 int ptyfs_open (void *); 117 int ptyfs_close (void *); 118 int ptyfs_access (void *); 119 int ptyfs_getattr (void *); 120 int ptyfs_setattr (void *); 121 int ptyfs_read (void *); 122 int ptyfs_write (void *); 123 #define ptyfs_fcntl genfs_fcntl 124 int ptyfs_ioctl (void *); 125 int ptyfs_poll (void *); 126 int ptyfs_kqfilter (void *); 127 #define ptyfs_revoke genfs_revoke 128 #define ptyfs_mmap genfs_eopnotsupp 129 #define ptyfs_fsync genfs_nullop 130 #define ptyfs_seek genfs_nullop 131 #define ptyfs_remove genfs_eopnotsupp 132 #define ptyfs_link genfs_abortop 133 #define ptyfs_rename genfs_eopnotsupp 134 #define ptyfs_mkdir genfs_eopnotsupp 135 #define ptyfs_rmdir genfs_eopnotsupp 136 #define ptyfs_symlink genfs_abortop 137 int ptyfs_readdir (void *); 138 #define ptyfs_readlink genfs_eopnotsupp 139 #define ptyfs_abortop genfs_abortop 140 int ptyfs_reclaim (void *); 141 #define ptyfs_lock genfs_lock 142 #define ptyfs_unlock genfs_unlock 143 #define ptyfs_bmap genfs_badop 144 #define ptyfs_strategy genfs_badop 145 int ptyfs_print (void *); 146 int ptyfs_pathconf (void *); 147 #define ptyfs_islocked genfs_islocked 148 #define ptyfs_advlock genfs_einval 149 #define ptyfs_bwrite genfs_eopnotsupp 150 #define ptyfs_putpages genfs_null_putpages 151 152 static int ptyfs_update(struct vnode *, const struct timespec *, 153 const struct timespec *, int); 154 static int ptyfs_chown(struct vnode *, uid_t, gid_t, kauth_cred_t, 155 struct proc *); 156 static int ptyfs_chmod(struct vnode *, mode_t, kauth_cred_t, struct proc *); 157 static int atoi(const char *, size_t); 158 159 extern const struct cdevsw pts_cdevsw, ptc_cdevsw; 160 161 /* 162 * ptyfs vnode operations. 163 */ 164 int (**ptyfs_vnodeop_p)(void *); 165 const struct vnodeopv_entry_desc ptyfs_vnodeop_entries[] = { 166 { &vop_default_desc, vn_default_error }, 167 { &vop_lookup_desc, ptyfs_lookup }, /* lookup */ 168 { &vop_create_desc, ptyfs_create }, /* create */ 169 { &vop_mknod_desc, ptyfs_mknod }, /* mknod */ 170 { &vop_open_desc, ptyfs_open }, /* open */ 171 { &vop_close_desc, ptyfs_close }, /* close */ 172 { &vop_access_desc, ptyfs_access }, /* access */ 173 { &vop_getattr_desc, ptyfs_getattr }, /* getattr */ 174 { &vop_setattr_desc, ptyfs_setattr }, /* setattr */ 175 { &vop_read_desc, ptyfs_read }, /* read */ 176 { &vop_write_desc, ptyfs_write }, /* write */ 177 { &vop_ioctl_desc, ptyfs_ioctl }, /* ioctl */ 178 { &vop_fcntl_desc, ptyfs_fcntl }, /* fcntl */ 179 { &vop_poll_desc, ptyfs_poll }, /* poll */ 180 { &vop_kqfilter_desc, ptyfs_kqfilter }, /* kqfilter */ 181 { &vop_revoke_desc, ptyfs_revoke }, /* revoke */ 182 { &vop_mmap_desc, ptyfs_mmap }, /* mmap */ 183 { &vop_fsync_desc, ptyfs_fsync }, /* fsync */ 184 { &vop_seek_desc, ptyfs_seek }, /* seek */ 185 { &vop_remove_desc, ptyfs_remove }, /* remove */ 186 { &vop_link_desc, ptyfs_link }, /* link */ 187 { &vop_rename_desc, ptyfs_rename }, /* rename */ 188 { &vop_mkdir_desc, ptyfs_mkdir }, /* mkdir */ 189 { &vop_rmdir_desc, ptyfs_rmdir }, /* rmdir */ 190 { &vop_symlink_desc, ptyfs_symlink }, /* symlink */ 191 { &vop_readdir_desc, ptyfs_readdir }, /* readdir */ 192 { &vop_readlink_desc, ptyfs_readlink }, /* readlink */ 193 { &vop_abortop_desc, ptyfs_abortop }, /* abortop */ 194 { &vop_inactive_desc, spec_inactive }, /* inactive */ 195 { &vop_reclaim_desc, ptyfs_reclaim }, /* reclaim */ 196 { &vop_lock_desc, ptyfs_lock }, /* lock */ 197 { &vop_unlock_desc, ptyfs_unlock }, /* unlock */ 198 { &vop_bmap_desc, ptyfs_bmap }, /* bmap */ 199 { &vop_strategy_desc, ptyfs_strategy }, /* strategy */ 200 { &vop_print_desc, ptyfs_print }, /* print */ 201 { &vop_islocked_desc, ptyfs_islocked }, /* islocked */ 202 { &vop_pathconf_desc, ptyfs_pathconf }, /* pathconf */ 203 { &vop_advlock_desc, ptyfs_advlock }, /* advlock */ 204 { &vop_bwrite_desc, ptyfs_bwrite }, /* bwrite */ 205 { &vop_putpages_desc, ptyfs_putpages }, /* putpages */ 206 { NULL, NULL } 207 }; 208 const struct vnodeopv_desc ptyfs_vnodeop_opv_desc = 209 { &ptyfs_vnodeop_p, ptyfs_vnodeop_entries }; 210 211 /* 212 * _reclaim is called when getnewvnode() 213 * wants to make use of an entry on the vnode 214 * free list. at this time the filesystem needs 215 * to free any private data and remove the node 216 * from any private lists. 217 */ 218 int 219 ptyfs_reclaim(void *v) 220 { 221 struct vop_reclaim_args /* { 222 struct vnode *a_vp; 223 } */ *ap = v; 224 return ptyfs_freevp(ap->a_vp); 225 } 226 227 /* 228 * Return POSIX pathconf information applicable to special devices. 229 */ 230 int 231 ptyfs_pathconf(void *v) 232 { 233 struct vop_pathconf_args /* { 234 struct vnode *a_vp; 235 int a_name; 236 register_t *a_retval; 237 } */ *ap = v; 238 239 switch (ap->a_name) { 240 case _PC_LINK_MAX: 241 *ap->a_retval = LINK_MAX; 242 return 0; 243 case _PC_MAX_CANON: 244 *ap->a_retval = MAX_CANON; 245 return 0; 246 case _PC_MAX_INPUT: 247 *ap->a_retval = MAX_INPUT; 248 return 0; 249 case _PC_PIPE_BUF: 250 *ap->a_retval = PIPE_BUF; 251 return 0; 252 case _PC_CHOWN_RESTRICTED: 253 *ap->a_retval = 1; 254 return 0; 255 case _PC_VDISABLE: 256 *ap->a_retval = _POSIX_VDISABLE; 257 return 0; 258 case _PC_SYNC_IO: 259 *ap->a_retval = 1; 260 return 0; 261 default: 262 return EINVAL; 263 } 264 } 265 266 /* 267 * _print is used for debugging. 268 * just print a readable description 269 * of (vp). 270 */ 271 int 272 ptyfs_print(void *v) 273 { 274 struct vop_print_args /* { 275 struct vnode *a_vp; 276 } */ *ap = v; 277 struct ptyfsnode *ptyfs = VTOPTYFS(ap->a_vp); 278 279 printf("tag VT_PTYFS, type %d, pty %d\n", 280 ptyfs->ptyfs_type, ptyfs->ptyfs_pty); 281 return 0; 282 } 283 284 /* 285 * Invent attributes for ptyfsnode (vp) and store 286 * them in (vap). 287 * Directories lengths are returned as zero since 288 * any real length would require the genuine size 289 * to be computed, and nothing cares anyway. 290 * 291 * this is relatively minimal for ptyfs. 292 */ 293 int 294 ptyfs_getattr(void *v) 295 { 296 struct vop_getattr_args /* { 297 struct vnode *a_vp; 298 struct vattr *a_vap; 299 kauth_cred_t a_cred; 300 struct lwp *a_l; 301 } */ *ap = v; 302 struct ptyfsnode *ptyfs = VTOPTYFS(ap->a_vp); 303 struct vattr *vap = ap->a_vap; 304 305 PTYFS_ITIMES(ptyfs, NULL, NULL, NULL); 306 307 /* start by zeroing out the attributes */ 308 VATTR_NULL(vap); 309 310 /* next do all the common fields */ 311 vap->va_type = ap->a_vp->v_type; 312 vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsidx.__fsid_val[0]; 313 vap->va_fileid = ptyfs->ptyfs_fileno; 314 vap->va_gen = 0; 315 vap->va_flags = 0; 316 vap->va_nlink = 1; 317 vap->va_blocksize = PAGE_SIZE; 318 319 vap->va_atime = ptyfs->ptyfs_atime; 320 vap->va_mtime = ptyfs->ptyfs_mtime; 321 vap->va_ctime = ptyfs->ptyfs_ctime; 322 vap->va_birthtime = ptyfs->ptyfs_birthtime; 323 vap->va_mode = ptyfs->ptyfs_mode; 324 vap->va_flags = ptyfs->ptyfs_flags; 325 vap->va_uid = ptyfs->ptyfs_uid; 326 vap->va_gid = ptyfs->ptyfs_gid; 327 328 switch (ptyfs->ptyfs_type) { 329 case PTYFSpts: 330 case PTYFSptc: 331 if (pty_isfree(ptyfs->ptyfs_pty, 1)) 332 return ENOENT; 333 vap->va_bytes = vap->va_size = 0; 334 vap->va_rdev = ap->a_vp->v_rdev; 335 break; 336 case PTYFSroot: 337 vap->va_rdev = 0; 338 vap->va_bytes = vap->va_size = DEV_BSIZE; 339 break; 340 341 default: 342 return EOPNOTSUPP; 343 } 344 345 return 0; 346 } 347 348 /*ARGSUSED*/ 349 int 350 ptyfs_setattr(void *v) 351 { 352 struct vop_setattr_args /* { 353 struct vnodeop_desc *a_desc; 354 struct vnode *a_vp; 355 struct vattr *a_vap; 356 kauth_cred_t a_cred; 357 struct lwp *a_l; 358 } */ *ap = v; 359 struct vnode *vp = ap->a_vp; 360 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 361 struct vattr *vap = ap->a_vap; 362 kauth_cred_t cred = ap->a_cred; 363 struct lwp *l = ap->a_l; 364 struct proc *p = l->l_proc; 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 &p->p_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, p); 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 &p->p_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, p); 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 proc *p) 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 &p->p_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 proc *p) 491 { 492 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 493 int error, ismember; 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 error = kauth_cred_ismember_gid(cred, gid, &ismember); 506 if (error) 507 return (error); 508 if ((kauth_cred_geteuid(cred) != ptyfs->ptyfs_uid || uid != ptyfs->ptyfs_uid || 509 (gid != ptyfs->ptyfs_gid && 510 !(kauth_cred_getegid(cred) == gid || ismember))) && 511 ((error = kauth_authorize_generic(cred, KAUTH_GENERIC_ISSUSER, 512 &p->p_acflag)) != 0)) 513 return error; 514 515 ptyfs->ptyfs_gid = gid; 516 ptyfs->ptyfs_uid = uid; 517 return 0; 518 } 519 520 /* 521 * implement access checking. 522 * 523 * actually, the check for super-user is slightly 524 * broken since it will allow read access to write-only 525 * objects. this doesn't cause any particular trouble 526 * but does mean that the i/o entry points need to check 527 * that the operation really does make sense. 528 */ 529 int 530 ptyfs_access(void *v) 531 { 532 struct vop_access_args /* { 533 struct vnode *a_vp; 534 int a_mode; 535 kauth_cred_t a_cred; 536 struct lwp *a_l; 537 } */ *ap = v; 538 struct vattr va; 539 int error; 540 541 if ((error = VOP_GETATTR(ap->a_vp, &va, ap->a_cred, ap->a_l)) != 0) 542 return error; 543 544 return vaccess(va.va_type, va.va_mode, 545 va.va_uid, va.va_gid, ap->a_mode, ap->a_cred); 546 } 547 548 /* 549 * lookup. this is incredibly complicated in the 550 * general case, however for most pseudo-filesystems 551 * very little needs to be done. 552 * 553 * Locking isn't hard here, just poorly documented. 554 * 555 * If we're looking up ".", just vref the parent & return it. 556 * 557 * If we're looking up "..", unlock the parent, and lock "..". If everything 558 * went ok, and we're on the last component and the caller requested the 559 * parent locked, try to re-lock the parent. We do this to prevent lock 560 * races. 561 * 562 * For anything else, get the needed node. Then unlock the parent if not 563 * the last component or not LOCKPARENT (i.e. if we wouldn't re-lock the 564 * parent in the .. case). 565 * 566 * We try to exit with the parent locked in error cases. 567 */ 568 int 569 ptyfs_lookup(void *v) 570 { 571 struct vop_lookup_args /* { 572 struct vnode * a_dvp; 573 struct vnode ** a_vpp; 574 struct componentname * a_cnp; 575 } */ *ap = v; 576 struct componentname *cnp = ap->a_cnp; 577 struct vnode **vpp = ap->a_vpp; 578 struct vnode *dvp = ap->a_dvp; 579 const char *pname = cnp->cn_nameptr; 580 struct ptyfsnode *ptyfs; 581 int pty, error, wantpunlock; 582 583 *vpp = NULL; 584 cnp->cn_flags &= ~PDIRUNLOCK; 585 586 if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME) 587 return EROFS; 588 589 if (cnp->cn_namelen == 1 && *pname == '.') { 590 *vpp = dvp; 591 VREF(dvp); 592 return 0; 593 } 594 595 wantpunlock = ~cnp->cn_flags & (LOCKPARENT | ISLASTCN); 596 ptyfs = VTOPTYFS(dvp); 597 switch (ptyfs->ptyfs_type) { 598 case PTYFSroot: 599 /* 600 * Shouldn't get here with .. in the root node. 601 */ 602 if (cnp->cn_flags & ISDOTDOT) 603 return EIO; 604 605 pty = atoi(pname, cnp->cn_namelen); 606 607 if (pty < 0 || pty >= npty || pty_isfree(pty, 1)) 608 break; 609 610 error = ptyfs_allocvp(dvp->v_mount, vpp, PTYFSpts, pty, 611 curlwp); 612 if (error == 0 && wantpunlock) { 613 VOP_UNLOCK(dvp, 0); 614 cnp->cn_flags |= PDIRUNLOCK; 615 } 616 return error; 617 618 default: 619 return ENOTDIR; 620 } 621 622 return cnp->cn_nameiop == LOOKUP ? ENOENT : EROFS; 623 } 624 625 /* 626 * readdir returns directory entries from ptyfsnode (vp). 627 * 628 * the strategy here with ptyfs is to generate a single 629 * directory entry at a time (struct dirent) and then 630 * copy that out to userland using uiomove. a more efficent 631 * though more complex implementation, would try to minimize 632 * the number of calls to uiomove(). for ptyfs, this is 633 * hardly worth the added code complexity. 634 * 635 * this should just be done through read() 636 */ 637 int 638 ptyfs_readdir(void *v) 639 { 640 struct vop_readdir_args /* { 641 struct vnode *a_vp; 642 struct uio *a_uio; 643 kauth_cred_t a_cred; 644 int *a_eofflag; 645 off_t **a_cookies; 646 int *a_ncookies; 647 } */ *ap = v; 648 struct uio *uio = ap->a_uio; 649 struct dirent d; 650 struct ptyfsnode *ptyfs; 651 off_t i; 652 int error; 653 off_t *cookies = NULL; 654 int ncookies; 655 struct vnode *vp; 656 int nc = 0; 657 658 vp = ap->a_vp; 659 ptyfs = VTOPTYFS(vp); 660 661 if (uio->uio_resid < UIO_MX) 662 return EINVAL; 663 if (uio->uio_offset < 0) 664 return EINVAL; 665 666 error = 0; 667 i = uio->uio_offset; 668 (void)memset(&d, 0, sizeof(d)); 669 d.d_reclen = UIO_MX; 670 ncookies = uio->uio_resid / UIO_MX; 671 672 switch (ptyfs->ptyfs_type) { 673 case PTYFSroot: /* root */ 674 675 if (i >= npty) 676 return 0; 677 678 if (ap->a_ncookies) { 679 ncookies = min(ncookies, (npty + 2 - i)); 680 cookies = malloc(ncookies * sizeof (off_t), 681 M_TEMP, M_WAITOK); 682 *ap->a_cookies = cookies; 683 } 684 685 for (; i < 2; i++) { 686 switch (i) { 687 case 0: /* `.' */ 688 case 1: /* `..' */ 689 d.d_fileno = PTYFS_FILENO(0, PTYFSroot); 690 d.d_namlen = i + 1; 691 (void)memcpy(d.d_name, "..", d.d_namlen); 692 d.d_name[i + 1] = '\0'; 693 d.d_type = DT_DIR; 694 break; 695 } 696 if ((error = uiomove(&d, UIO_MX, uio)) != 0) 697 break; 698 if (cookies) 699 *cookies++ = i + 1; 700 nc++; 701 } 702 if (error) { 703 ncookies = nc; 704 break; 705 } 706 for (; uio->uio_resid >= UIO_MX && i < npty; i++) { 707 /* check for used ptys */ 708 if (pty_isfree(i - 2, 1)) 709 continue; 710 711 d.d_fileno = PTYFS_FILENO(i - 2, PTYFSpts); 712 d.d_namlen = snprintf(d.d_name, sizeof(d.d_name), 713 "%lld", (long long)(i - 2)); 714 d.d_type = DT_CHR; 715 if ((error = uiomove(&d, UIO_MX, uio)) != 0) 716 break; 717 if (cookies) 718 *cookies++ = i + 1; 719 nc++; 720 } 721 ncookies = nc; 722 break; 723 724 default: 725 error = ENOTDIR; 726 break; 727 } 728 729 if (ap->a_ncookies) { 730 if (error) { 731 if (cookies) 732 free(*ap->a_cookies, M_TEMP); 733 *ap->a_ncookies = 0; 734 *ap->a_cookies = NULL; 735 } else 736 *ap->a_ncookies = ncookies; 737 } 738 uio->uio_offset = i; 739 return error; 740 } 741 742 int 743 ptyfs_open(void *v) 744 { 745 struct vop_open_args /* { 746 struct vnode *a_vp; 747 int a_mode; 748 kauth_cred_t a_cred; 749 struct lwp *a_l; 750 } */ *ap = v; 751 struct vnode *vp = ap->a_vp; 752 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 753 754 ptyfs->ptyfs_flag |= PTYFS_CHANGE|PTYFS_ACCESS; 755 switch (ptyfs->ptyfs_type) { 756 case PTYFSpts: 757 case PTYFSptc: 758 return spec_open(v); 759 case PTYFSroot: 760 return 0; 761 default: 762 return EINVAL; 763 } 764 } 765 766 int 767 ptyfs_close(void *v) 768 { 769 struct vop_close_args /* { 770 struct vnode *a_vp; 771 int a_fflag; 772 kauth_cred_t a_cred; 773 struct lwp *a_l; 774 } */ *ap = v; 775 struct vnode *vp = ap->a_vp; 776 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 777 778 simple_lock(&vp->v_interlock); 779 if (vp->v_usecount > 1) 780 PTYFS_ITIMES(ptyfs, NULL, NULL, NULL); 781 simple_unlock(&vp->v_interlock); 782 783 switch (ptyfs->ptyfs_type) { 784 case PTYFSpts: 785 case PTYFSptc: 786 return spec_close(v); 787 case PTYFSroot: 788 return 0; 789 default: 790 return EINVAL; 791 } 792 } 793 794 int 795 ptyfs_read(void *v) 796 { 797 struct vop_read_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 timespec ts; 804 struct vnode *vp = ap->a_vp; 805 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 806 int error; 807 808 ptyfs->ptyfs_flag |= PTYFS_ACCESS; 809 /* hardclock() resolution is good enough for ptyfs */ 810 TIMEVAL_TO_TIMESPEC(&time, &ts); 811 (void)ptyfs_update(vp, &ts, &ts, 0); 812 813 switch (ptyfs->ptyfs_type) { 814 case PTYFSpts: 815 VOP_UNLOCK(vp, 0); 816 error = (*pts_cdevsw.d_read)(vp->v_rdev, ap->a_uio, 817 ap->a_ioflag); 818 vn_lock(vp, LK_RETRY|LK_EXCLUSIVE); 819 return error; 820 case PTYFSptc: 821 VOP_UNLOCK(vp, 0); 822 error = (*ptc_cdevsw.d_read)(vp->v_rdev, ap->a_uio, 823 ap->a_ioflag); 824 vn_lock(vp, LK_RETRY|LK_EXCLUSIVE); 825 return error; 826 default: 827 return EOPNOTSUPP; 828 } 829 } 830 831 int 832 ptyfs_write(void *v) 833 { 834 struct vop_write_args /* { 835 struct vnode *a_vp; 836 struct uio *a_uio; 837 int a_ioflag; 838 kauth_cred_t a_cred; 839 } */ *ap = v; 840 struct timespec ts; 841 struct vnode *vp = ap->a_vp; 842 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 843 int error; 844 845 ptyfs->ptyfs_flag |= PTYFS_MODIFY; 846 /* hardclock() resolution is good enough for ptyfs */ 847 TIMEVAL_TO_TIMESPEC(&time, &ts); 848 (void)ptyfs_update(vp, &ts, &ts, 0); 849 850 switch (ptyfs->ptyfs_type) { 851 case PTYFSpts: 852 VOP_UNLOCK(vp, 0); 853 error = (*pts_cdevsw.d_write)(vp->v_rdev, ap->a_uio, 854 ap->a_ioflag); 855 vn_lock(vp, LK_RETRY|LK_EXCLUSIVE); 856 return error; 857 case PTYFSptc: 858 VOP_UNLOCK(vp, 0); 859 error = (*ptc_cdevsw.d_write)(vp->v_rdev, ap->a_uio, 860 ap->a_ioflag); 861 vn_lock(vp, LK_RETRY|LK_EXCLUSIVE); 862 return error; 863 default: 864 return EOPNOTSUPP; 865 } 866 } 867 868 int 869 ptyfs_ioctl(void *v) 870 { 871 struct vop_ioctl_args /* { 872 struct vnode *a_vp; 873 u_long a_command; 874 void *a_data; 875 int a_fflag; 876 kauth_cred_t a_cred; 877 struct lwp *a_l; 878 } */ *ap = v; 879 struct vnode *vp = ap->a_vp; 880 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 881 882 switch (ptyfs->ptyfs_type) { 883 case PTYFSpts: 884 return (*pts_cdevsw.d_ioctl)(vp->v_rdev, ap->a_command, 885 ap->a_data, ap->a_fflag, ap->a_l); 886 case PTYFSptc: 887 return (*ptc_cdevsw.d_ioctl)(vp->v_rdev, ap->a_command, 888 ap->a_data, ap->a_fflag, ap->a_l); 889 default: 890 return EOPNOTSUPP; 891 } 892 } 893 894 int 895 ptyfs_poll(void *v) 896 { 897 struct vop_poll_args /* { 898 struct vnode *a_vp; 899 int a_events; 900 struct lwp *a_l; 901 } */ *ap = v; 902 struct vnode *vp = ap->a_vp; 903 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 904 905 switch (ptyfs->ptyfs_type) { 906 case PTYFSpts: 907 return (*pts_cdevsw.d_poll)(vp->v_rdev, ap->a_events, ap->a_l); 908 case PTYFSptc: 909 return (*ptc_cdevsw.d_poll)(vp->v_rdev, ap->a_events, ap->a_l); 910 default: 911 return genfs_poll(v); 912 } 913 } 914 915 int 916 ptyfs_kqfilter(void *v) 917 { 918 struct vop_kqfilter_args /* { 919 struct vnode *a_vp; 920 struct knote *a_kn; 921 } */ *ap = v; 922 struct vnode *vp = ap->a_vp; 923 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 924 925 switch (ptyfs->ptyfs_type) { 926 case PTYFSpts: 927 return (*pts_cdevsw.d_kqfilter)(vp->v_rdev, ap->a_kn); 928 case PTYFSptc: 929 return (*ptc_cdevsw.d_kqfilter)(vp->v_rdev, ap->a_kn); 930 default: 931 return genfs_kqfilter(v); 932 } 933 } 934 935 static int 936 ptyfs_update(struct vnode *vp, const struct timespec *acc, 937 const struct timespec *mod, int flags) 938 { 939 struct ptyfsnode *ptyfs = VTOPTYFS(vp); 940 941 if (vp->v_mount->mnt_flag & MNT_RDONLY) 942 return 0; 943 944 PTYFS_ITIMES(ptyfs, acc, mod, NULL); 945 return 0; 946 } 947 948 void 949 ptyfs_itimes(struct ptyfsnode *ptyfs, const struct timespec *acc, 950 const struct timespec *mod, const struct timespec *cre) 951 { 952 struct timespec *ts = NULL, tsb; 953 954 KASSERT(ptyfs->ptyfs_flag & (PTYFS_ACCESS|PTYFS_CHANGE|PTYFS_MODIFY)); 955 if (ptyfs->ptyfs_flag & (PTYFS_ACCESS|PTYFS_MODIFY)) { 956 if (acc == NULL) 957 acc = ts == NULL ? (ts = nanotime(&tsb)) : ts; 958 ptyfs->ptyfs_atime = *acc; 959 } 960 if (ptyfs->ptyfs_flag & PTYFS_MODIFY) { 961 if (mod == NULL) 962 mod = ts == NULL ? (ts = nanotime(&tsb)) : ts; 963 ptyfs->ptyfs_mtime = *mod; 964 } 965 if (ptyfs->ptyfs_flag & PTYFS_CHANGE) { 966 if (cre == NULL) 967 cre = ts == NULL ? (ts = nanotime(&tsb)) : ts; 968 ptyfs->ptyfs_ctime = *cre; 969 } 970 ptyfs->ptyfs_flag &= ~(PTYFS_ACCESS|PTYFS_CHANGE|PTYFS_MODIFY); 971 } 972 973 /* 974 * convert decimal ascii to int 975 */ 976 static int 977 atoi(const char *b, size_t len) 978 { 979 int p = 0; 980 981 while (len--) { 982 char c = *b++; 983 if (c < '0' || c > '9') 984 return -1; 985 p = 10 * p + (c - '0'); 986 } 987 988 return p; 989 } 990
Indexes created Thu Oct 23 22:10:10 GMT 2025