1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 2001 Dag-Erling Coïdan Smørgrav 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 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer 12 * in this position and unchanged. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. The name of the author may not be used to endorse or promote products 17 * derived from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 #include "opt_pseudofs.h" 35 36 #include <sys/param.h> 37 #include <sys/kernel.h> 38 #include <sys/systm.h> 39 #include <sys/ctype.h> 40 #include <sys/dirent.h> 41 #include <sys/fcntl.h> 42 #include <sys/limits.h> 43 #include <sys/lock.h> 44 #include <sys/malloc.h> 45 #include <sys/mount.h> 46 #include <sys/mutex.h> 47 #include <sys/namei.h> 48 #include <sys/proc.h> 49 #include <sys/sbuf.h> 50 #include <sys/sx.h> 51 #include <sys/sysctl.h> 52 #include <sys/vnode.h> 53 54 #include <fs/pseudofs/pseudofs.h> 55 #include <fs/pseudofs/pseudofs_internal.h> 56 57 #define KASSERT_PN_IS_DIR(pn) \ 58 KASSERT((pn)->pn_type == pfstype_root || \ 59 (pn)->pn_type == pfstype_dir || \ 60 (pn)->pn_type == pfstype_procdir, \ 61 ("%s(): VDIR vnode refers to non-directory pfs_node", __func__)) 62 63 #define KASSERT_PN_IS_FILE(pn) \ 64 KASSERT((pn)->pn_type == pfstype_file, \ 65 ("%s(): VREG vnode refers to non-file pfs_node", __func__)) 66 67 #define KASSERT_PN_IS_LINK(pn) \ 68 KASSERT((pn)->pn_type == pfstype_symlink, \ 69 ("%s(): VLNK vnode refers to non-link pfs_node", __func__)) 70 71 /* 72 * Returns the fileno, adjusted for target pid 73 */ 74 static uint32_t 75 pn_fileno(struct pfs_node *pn, pid_t pid) 76 { 77 78 KASSERT(pn->pn_fileno > 0, 79 ("%s(): no fileno allocated", __func__)); 80 if (pid != NO_PID) 81 return (pn->pn_fileno * NO_PID + pid); 82 return (pn->pn_fileno); 83 } 84 85 /* 86 * Returns non-zero if given file is visible to given thread. 87 */ 88 static int 89 pfs_visible_proc(struct thread *td, struct pfs_node *pn, struct proc *proc) 90 { 91 int visible; 92 93 if (proc == NULL) 94 return (0); 95 96 PROC_LOCK_ASSERT(proc, MA_OWNED); 97 98 visible = ((proc->p_flag & P_WEXIT) == 0); 99 if (visible) 100 visible = (p_cansee(td, proc) == 0); 101 if (visible && pn->pn_vis != NULL) 102 visible = pn_vis(td, proc, pn); 103 if (!visible) 104 return (0); 105 return (1); 106 } 107 108 static int 109 pfs_visible(struct thread *td, struct pfs_node *pn, pid_t pid, 110 struct proc **p) 111 { 112 struct proc *proc; 113 114 PFS_TRACE(("%s (pid: %d, req: %d)", 115 pn->pn_name, pid, td->td_proc->p_pid)); 116 117 if (p) 118 *p = NULL; 119 if (pid == NO_PID) 120 PFS_RETURN (1); 121 proc = pfind(pid); 122 if (proc == NULL) 123 PFS_RETURN (0); 124 if (pfs_visible_proc(td, pn, proc)) { 125 if (p) 126 *p = proc; 127 else 128 PROC_UNLOCK(proc); 129 PFS_RETURN (1); 130 } 131 PROC_UNLOCK(proc); 132 PFS_RETURN (0); 133 } 134 135 static int 136 pfs_lookup_proc(pid_t pid, struct proc **p) 137 { 138 struct proc *proc; 139 140 proc = pfind(pid); 141 if (proc == NULL) 142 return (0); 143 if ((proc->p_flag & P_WEXIT) != 0) { 144 PROC_UNLOCK(proc); 145 return (0); 146 } 147 _PHOLD(proc); 148 PROC_UNLOCK(proc); 149 *p = proc; 150 return (1); 151 } 152 153 /* 154 * Verify permissions 155 */ 156 static int 157 pfs_access(struct vop_access_args *va) 158 { 159 struct vnode *vn = va->a_vp; 160 struct pfs_vdata *pvd = vn->v_data; 161 struct vattr vattr; 162 int error; 163 164 PFS_TRACE(("%s", pvd->pvd_pn->pn_name)); 165 (void)pvd; 166 167 error = VOP_GETATTR(vn, &vattr, va->a_cred); 168 if (error) 169 PFS_RETURN (error); 170 error = vaccess(vn->v_type, vattr.va_mode, vattr.va_uid, 171 vattr.va_gid, va->a_accmode, va->a_cred, NULL); 172 PFS_RETURN (error); 173 } 174 175 /* 176 * Close a file or directory 177 */ 178 static int 179 pfs_close(struct vop_close_args *va) 180 { 181 struct vnode *vn = va->a_vp; 182 struct pfs_vdata *pvd = vn->v_data; 183 struct pfs_node *pn = pvd->pvd_pn; 184 struct proc *proc; 185 int error; 186 187 PFS_TRACE(("%s", pn->pn_name)); 188 pfs_assert_not_owned(pn); 189 190 /* 191 * Do nothing unless this is the last close and the node has a 192 * last-close handler. 193 */ 194 if (vrefcnt(vn) > 1 || pn->pn_close == NULL) 195 PFS_RETURN (0); 196 197 if (pvd->pvd_pid != NO_PID) { 198 proc = pfind(pvd->pvd_pid); 199 } else { 200 proc = NULL; 201 } 202 203 error = pn_close(va->a_td, proc, pn); 204 205 if (proc != NULL) 206 PROC_UNLOCK(proc); 207 208 PFS_RETURN (error); 209 } 210 211 /* 212 * Get file attributes 213 */ 214 static int 215 pfs_getattr(struct vop_getattr_args *va) 216 { 217 struct vnode *vn = va->a_vp; 218 struct pfs_vdata *pvd = vn->v_data; 219 struct pfs_node *pn = pvd->pvd_pn; 220 struct vattr *vap = va->a_vap; 221 struct proc *proc; 222 int error = 0; 223 224 PFS_TRACE(("%s", pn->pn_name)); 225 pfs_assert_not_owned(pn); 226 227 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc)) 228 PFS_RETURN (ENOENT); 229 230 vap->va_type = vn->v_type; 231 vap->va_fileid = pn_fileno(pn, pvd->pvd_pid); 232 vap->va_flags = 0; 233 vap->va_blocksize = PAGE_SIZE; 234 vap->va_bytes = vap->va_size = 0; 235 vap->va_filerev = 0; 236 vap->va_fsid = vn->v_mount->mnt_stat.f_fsid.val[0]; 237 vap->va_nlink = 1; 238 nanotime(&vap->va_ctime); 239 vap->va_atime = vap->va_mtime = vap->va_ctime; 240 241 switch (pn->pn_type) { 242 case pfstype_procdir: 243 case pfstype_root: 244 case pfstype_dir: 245 #if 0 246 pfs_lock(pn); 247 /* compute link count */ 248 pfs_unlock(pn); 249 #endif 250 vap->va_mode = 0555; 251 break; 252 case pfstype_file: 253 case pfstype_symlink: 254 vap->va_mode = 0444; 255 break; 256 default: 257 printf("shouldn't be here!\n"); 258 vap->va_mode = 0; 259 break; 260 } 261 262 if (proc != NULL) { 263 vap->va_uid = proc->p_ucred->cr_ruid; 264 vap->va_gid = proc->p_ucred->cr_rgid; 265 } else { 266 vap->va_uid = 0; 267 vap->va_gid = 0; 268 } 269 270 if (pn->pn_attr != NULL) 271 error = pn_attr(curthread, proc, pn, vap); 272 273 if(proc != NULL) 274 PROC_UNLOCK(proc); 275 276 PFS_RETURN (error); 277 } 278 279 /* 280 * Perform an ioctl 281 */ 282 static int 283 pfs_ioctl(struct vop_ioctl_args *va) 284 { 285 struct vnode *vn; 286 struct pfs_vdata *pvd; 287 struct pfs_node *pn; 288 struct proc *proc; 289 int error; 290 291 vn = va->a_vp; 292 vn_lock(vn, LK_SHARED | LK_RETRY); 293 if (VN_IS_DOOMED(vn)) { 294 VOP_UNLOCK(vn); 295 return (EBADF); 296 } 297 pvd = vn->v_data; 298 pn = pvd->pvd_pn; 299 300 PFS_TRACE(("%s: %lx", pn->pn_name, va->a_command)); 301 pfs_assert_not_owned(pn); 302 303 if (vn->v_type != VREG) { 304 VOP_UNLOCK(vn); 305 PFS_RETURN (EINVAL); 306 } 307 KASSERT_PN_IS_FILE(pn); 308 309 if (pn->pn_ioctl == NULL) { 310 VOP_UNLOCK(vn); 311 PFS_RETURN (ENOTTY); 312 } 313 314 /* 315 * This is necessary because process' privileges may 316 * have changed since the open() call. 317 */ 318 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc)) { 319 VOP_UNLOCK(vn); 320 PFS_RETURN (EIO); 321 } 322 323 error = pn_ioctl(curthread, proc, pn, va->a_command, va->a_data); 324 325 if (proc != NULL) 326 PROC_UNLOCK(proc); 327 328 VOP_UNLOCK(vn); 329 PFS_RETURN (error); 330 } 331 332 /* 333 * Perform getextattr 334 */ 335 static int 336 pfs_getextattr(struct vop_getextattr_args *va) 337 { 338 struct vnode *vn = va->a_vp; 339 struct pfs_vdata *pvd = vn->v_data; 340 struct pfs_node *pn = pvd->pvd_pn; 341 struct proc *proc; 342 int error; 343 344 PFS_TRACE(("%s", pn->pn_name)); 345 pfs_assert_not_owned(pn); 346 347 /* 348 * This is necessary because either process' privileges may 349 * have changed since the open() call. 350 */ 351 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc)) 352 PFS_RETURN (EIO); 353 354 if (pn->pn_getextattr == NULL) 355 error = EOPNOTSUPP; 356 else 357 error = pn_getextattr(curthread, proc, pn, 358 va->a_attrnamespace, va->a_name, va->a_uio, 359 va->a_size, va->a_cred); 360 361 if (proc != NULL) 362 PROC_UNLOCK(proc); 363 364 PFS_RETURN (error); 365 } 366 367 /* 368 * Convert a vnode to its component name 369 */ 370 static int 371 pfs_vptocnp(struct vop_vptocnp_args *ap) 372 { 373 struct vnode *vp = ap->a_vp; 374 struct vnode **dvp = ap->a_vpp; 375 struct pfs_vdata *pvd = vp->v_data; 376 struct pfs_node *pd = pvd->pvd_pn; 377 struct pfs_node *pn; 378 struct mount *mp; 379 char *buf = ap->a_buf; 380 size_t *buflen = ap->a_buflen; 381 char pidbuf[PFS_NAMELEN]; 382 pid_t pid = pvd->pvd_pid; 383 int len, i, error, locked; 384 385 i = *buflen; 386 error = 0; 387 388 pfs_lock(pd); 389 390 if (vp->v_type == VDIR && pd->pn_type == pfstype_root) { 391 *dvp = vp; 392 vhold(*dvp); 393 pfs_unlock(pd); 394 PFS_RETURN (0); 395 } else if (vp->v_type == VDIR && pd->pn_type == pfstype_procdir) { 396 len = snprintf(pidbuf, sizeof(pidbuf), "%d", pid); 397 i -= len; 398 if (i < 0) { 399 error = ENOMEM; 400 goto failed; 401 } 402 bcopy(pidbuf, buf + i, len); 403 } else { 404 len = strlen(pd->pn_name); 405 i -= len; 406 if (i < 0) { 407 error = ENOMEM; 408 goto failed; 409 } 410 bcopy(pd->pn_name, buf + i, len); 411 } 412 413 pn = pd->pn_parent; 414 pfs_unlock(pd); 415 416 mp = vp->v_mount; 417 error = vfs_busy(mp, 0); 418 if (error) 419 return (error); 420 421 /* 422 * vp is held by caller. 423 */ 424 locked = VOP_ISLOCKED(vp); 425 VOP_UNLOCK(vp); 426 427 error = pfs_vncache_alloc(mp, dvp, pn, pid); 428 if (error) { 429 vn_lock(vp, locked | LK_RETRY); 430 vfs_unbusy(mp); 431 PFS_RETURN(error); 432 } 433 434 *buflen = i; 435 VOP_UNLOCK(*dvp); 436 vn_lock(vp, locked | LK_RETRY); 437 vfs_unbusy(mp); 438 439 PFS_RETURN (0); 440 failed: 441 pfs_unlock(pd); 442 PFS_RETURN(error); 443 } 444 445 /* 446 * Look up a file or directory 447 */ 448 static int 449 pfs_lookup(struct vop_cachedlookup_args *va) 450 { 451 struct vnode *vn = va->a_dvp; 452 struct vnode **vpp = va->a_vpp; 453 struct componentname *cnp = va->a_cnp; 454 struct pfs_vdata *pvd = vn->v_data; 455 struct pfs_node *pd = pvd->pvd_pn; 456 struct pfs_node *pn, *pdn = NULL; 457 struct mount *mp; 458 pid_t pid = pvd->pvd_pid; 459 char *pname; 460 int error, i, namelen, visible; 461 462 PFS_TRACE(("%.*s", (int)cnp->cn_namelen, cnp->cn_nameptr)); 463 pfs_assert_not_owned(pd); 464 465 if (vn->v_type != VDIR) 466 PFS_RETURN (ENOTDIR); 467 KASSERT_PN_IS_DIR(pd); 468 469 /* 470 * Don't support DELETE or RENAME. CREATE is supported so 471 * that O_CREAT will work, but the lookup will still fail if 472 * the file does not exist. 473 */ 474 if ((cnp->cn_flags & ISLASTCN) && 475 (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) 476 PFS_RETURN (EOPNOTSUPP); 477 478 /* shortcut: check if the name is too long */ 479 if (cnp->cn_namelen >= PFS_NAMELEN) 480 PFS_RETURN (ENOENT); 481 482 /* check that parent directory is visible... */ 483 if (!pfs_visible(curthread, pd, pvd->pvd_pid, NULL)) 484 PFS_RETURN (ENOENT); 485 486 /* self */ 487 namelen = cnp->cn_namelen; 488 pname = cnp->cn_nameptr; 489 if (namelen == 1 && pname[0] == '.') { 490 pn = pd; 491 *vpp = vn; 492 VREF(vn); 493 PFS_RETURN (0); 494 } 495 496 mp = vn->v_mount; 497 498 /* parent */ 499 if (cnp->cn_flags & ISDOTDOT) { 500 if (pd->pn_type == pfstype_root) 501 PFS_RETURN (EIO); 502 error = vfs_busy(mp, MBF_NOWAIT); 503 if (error != 0) { 504 vfs_ref(mp); 505 VOP_UNLOCK(vn); 506 error = vfs_busy(mp, 0); 507 vn_lock(vn, LK_EXCLUSIVE | LK_RETRY); 508 vfs_rel(mp); 509 if (error != 0) 510 PFS_RETURN(ENOENT); 511 if (VN_IS_DOOMED(vn)) { 512 vfs_unbusy(mp); 513 PFS_RETURN(ENOENT); 514 } 515 } 516 VOP_UNLOCK(vn); 517 KASSERT(pd->pn_parent != NULL, 518 ("%s(): non-root directory has no parent", __func__)); 519 /* 520 * This one is tricky. Descendents of procdir nodes 521 * inherit their parent's process affinity, but 522 * there's no easy reverse mapping. For simplicity, 523 * we assume that if this node is a procdir, its 524 * parent isn't (which is correct as long as 525 * descendents of procdir nodes are never procdir 526 * nodes themselves) 527 */ 528 if (pd->pn_type == pfstype_procdir) 529 pid = NO_PID; 530 pfs_lock(pd); 531 pn = pd->pn_parent; 532 pfs_unlock(pd); 533 goto got_pnode; 534 } 535 536 pfs_lock(pd); 537 538 /* named node */ 539 for (pn = pd->pn_nodes; pn != NULL; pn = pn->pn_next) 540 if (pn->pn_type == pfstype_procdir) 541 pdn = pn; 542 else if (pn->pn_name[namelen] == '\0' && 543 bcmp(pname, pn->pn_name, namelen) == 0) { 544 pfs_unlock(pd); 545 goto got_pnode; 546 } 547 548 /* process dependent node */ 549 if ((pn = pdn) != NULL) { 550 pid = 0; 551 for (pid = 0, i = 0; i < namelen && isdigit(pname[i]); ++i) 552 if ((pid = pid * 10 + pname[i] - '0') > PID_MAX) 553 break; 554 if (i == cnp->cn_namelen) { 555 pfs_unlock(pd); 556 goto got_pnode; 557 } 558 } 559 560 pfs_unlock(pd); 561 562 PFS_RETURN (ENOENT); 563 564 got_pnode: 565 pfs_assert_not_owned(pd); 566 pfs_assert_not_owned(pn); 567 visible = pfs_visible(curthread, pn, pid, NULL); 568 if (!visible) { 569 error = ENOENT; 570 goto failed; 571 } 572 573 error = pfs_vncache_alloc(mp, vpp, pn, pid); 574 if (error) 575 goto failed; 576 577 if (cnp->cn_flags & ISDOTDOT) { 578 vfs_unbusy(mp); 579 vn_lock(vn, LK_EXCLUSIVE | LK_RETRY); 580 if (VN_IS_DOOMED(vn)) { 581 vput(*vpp); 582 *vpp = NULL; 583 PFS_RETURN(ENOENT); 584 } 585 } 586 if (cnp->cn_flags & MAKEENTRY && !VN_IS_DOOMED(vn)) 587 cache_enter(vn, *vpp, cnp); 588 PFS_RETURN (0); 589 failed: 590 if (cnp->cn_flags & ISDOTDOT) { 591 vfs_unbusy(mp); 592 vn_lock(vn, LK_EXCLUSIVE | LK_RETRY); 593 *vpp = NULL; 594 } 595 PFS_RETURN(error); 596 } 597 598 /* 599 * Open a file or directory. 600 */ 601 static int 602 pfs_open(struct vop_open_args *va) 603 { 604 struct vnode *vn = va->a_vp; 605 struct pfs_vdata *pvd = vn->v_data; 606 struct pfs_node *pn = pvd->pvd_pn; 607 int mode = va->a_mode; 608 609 PFS_TRACE(("%s (mode 0x%x)", pn->pn_name, mode)); 610 pfs_assert_not_owned(pn); 611 612 /* check if the requested mode is permitted */ 613 if (((mode & FREAD) && !(mode & PFS_RD)) || 614 ((mode & FWRITE) && !(mode & PFS_WR))) 615 PFS_RETURN (EPERM); 616 617 /* we don't support locking */ 618 if ((mode & O_SHLOCK) || (mode & O_EXLOCK)) 619 PFS_RETURN (EOPNOTSUPP); 620 621 PFS_RETURN (0); 622 } 623 624 /* 625 * Read from a file 626 */ 627 static int 628 pfs_read(struct vop_read_args *va) 629 { 630 struct vnode *vn = va->a_vp; 631 struct pfs_vdata *pvd = vn->v_data; 632 struct pfs_node *pn = pvd->pvd_pn; 633 struct uio *uio = va->a_uio; 634 struct proc *proc; 635 struct sbuf *sb = NULL; 636 int error, locked; 637 off_t buflen; 638 639 PFS_TRACE(("%s", pn->pn_name)); 640 pfs_assert_not_owned(pn); 641 642 if (vn->v_type != VREG) 643 PFS_RETURN (EINVAL); 644 KASSERT_PN_IS_FILE(pn); 645 646 if (!(pn->pn_flags & PFS_RD)) 647 PFS_RETURN (EBADF); 648 649 if (pn->pn_fill == NULL) 650 PFS_RETURN (EIO); 651 652 /* 653 * This is necessary because either process' privileges may 654 * have changed since the open() call. 655 */ 656 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc)) 657 PFS_RETURN (EIO); 658 if (proc != NULL) { 659 _PHOLD(proc); 660 PROC_UNLOCK(proc); 661 } 662 663 vhold(vn); 664 locked = VOP_ISLOCKED(vn); 665 VOP_UNLOCK(vn); 666 667 if (pn->pn_flags & PFS_RAWRD) { 668 PFS_TRACE(("%zd resid", uio->uio_resid)); 669 error = pn_fill(curthread, proc, pn, NULL, uio); 670 PFS_TRACE(("%zd resid", uio->uio_resid)); 671 goto ret; 672 } 673 674 if (uio->uio_resid < 0 || uio->uio_offset < 0 || 675 uio->uio_resid > OFF_MAX - uio->uio_offset) { 676 error = EINVAL; 677 goto ret; 678 } 679 buflen = uio->uio_offset + uio->uio_resid; 680 if (buflen > MAXPHYS) 681 buflen = MAXPHYS; 682 683 sb = sbuf_new(sb, NULL, buflen + 1, 0); 684 if (sb == NULL) { 685 error = EIO; 686 goto ret; 687 } 688 689 error = pn_fill(curthread, proc, pn, sb, uio); 690 691 if (error) { 692 sbuf_delete(sb); 693 goto ret; 694 } 695 696 /* 697 * XXX: If the buffer overflowed, sbuf_len() will not return 698 * the data length. Then just use the full length because an 699 * overflowed sbuf must be full. 700 */ 701 if (sbuf_finish(sb) == 0) 702 buflen = sbuf_len(sb); 703 error = uiomove_frombuf(sbuf_data(sb), buflen, uio); 704 sbuf_delete(sb); 705 ret: 706 vn_lock(vn, locked | LK_RETRY); 707 vdrop(vn); 708 if (proc != NULL) 709 PRELE(proc); 710 PFS_RETURN (error); 711 } 712 713 /* 714 * Iterate through directory entries 715 */ 716 static int 717 pfs_iterate(struct thread *td, struct proc *proc, struct pfs_node *pd, 718 struct pfs_node **pn, struct proc **p) 719 { 720 int visible; 721 722 sx_assert(&allproc_lock, SX_SLOCKED); 723 pfs_assert_owned(pd); 724 again: 725 if (*pn == NULL) { 726 /* first node */ 727 *pn = pd->pn_nodes; 728 } else if ((*pn)->pn_type != pfstype_procdir) { 729 /* next node */ 730 *pn = (*pn)->pn_next; 731 } 732 if (*pn != NULL && (*pn)->pn_type == pfstype_procdir) { 733 /* next process */ 734 if (*p == NULL) 735 *p = LIST_FIRST(&allproc); 736 else 737 *p = LIST_NEXT(*p, p_list); 738 /* out of processes: next node */ 739 if (*p == NULL) 740 *pn = (*pn)->pn_next; 741 else 742 PROC_LOCK(*p); 743 } 744 745 if ((*pn) == NULL) 746 return (-1); 747 748 if (*p != NULL) { 749 visible = pfs_visible_proc(td, *pn, *p); 750 PROC_UNLOCK(*p); 751 } else if (proc != NULL) { 752 visible = pfs_visible_proc(td, *pn, proc); 753 } else { 754 visible = 1; 755 } 756 if (!visible) 757 goto again; 758 759 return (0); 760 } 761 762 /* Directory entry list */ 763 struct pfsentry { 764 STAILQ_ENTRY(pfsentry) link; 765 struct dirent entry; 766 }; 767 STAILQ_HEAD(pfsdirentlist, pfsentry); 768 769 /* 770 * Return directory entries. 771 */ 772 static int 773 pfs_readdir(struct vop_readdir_args *va) 774 { 775 struct vnode *vn = va->a_vp; 776 struct pfs_vdata *pvd = vn->v_data; 777 struct pfs_node *pd = pvd->pvd_pn; 778 pid_t pid = pvd->pvd_pid; 779 struct proc *p, *proc; 780 struct pfs_node *pn; 781 struct uio *uio; 782 struct pfsentry *pfsent, *pfsent2; 783 struct pfsdirentlist lst; 784 off_t offset; 785 int error, i, resid; 786 787 STAILQ_INIT(&lst); 788 error = 0; 789 KASSERT(pd->pn_info == vn->v_mount->mnt_data, 790 ("%s(): pn_info does not match mountpoint", __func__)); 791 PFS_TRACE(("%s pid %lu", pd->pn_name, (unsigned long)pid)); 792 pfs_assert_not_owned(pd); 793 794 if (vn->v_type != VDIR) 795 PFS_RETURN (ENOTDIR); 796 KASSERT_PN_IS_DIR(pd); 797 uio = va->a_uio; 798 799 /* only allow reading entire entries */ 800 offset = uio->uio_offset; 801 resid = uio->uio_resid; 802 if (offset < 0 || offset % PFS_DELEN != 0 || 803 (resid && resid < PFS_DELEN)) 804 PFS_RETURN (EINVAL); 805 if (resid == 0) 806 PFS_RETURN (0); 807 808 proc = NULL; 809 if (pid != NO_PID && !pfs_lookup_proc(pid, &proc)) 810 PFS_RETURN (ENOENT); 811 812 sx_slock(&allproc_lock); 813 pfs_lock(pd); 814 815 KASSERT(pid == NO_PID || proc != NULL, 816 ("%s(): no process for pid %lu", __func__, (unsigned long)pid)); 817 818 if (pid != NO_PID) { 819 PROC_LOCK(proc); 820 821 /* check if the directory is visible to the caller */ 822 if (!pfs_visible_proc(curthread, pd, proc)) { 823 _PRELE(proc); 824 PROC_UNLOCK(proc); 825 sx_sunlock(&allproc_lock); 826 pfs_unlock(pd); 827 PFS_RETURN (ENOENT); 828 } 829 } 830 831 /* skip unwanted entries */ 832 for (pn = NULL, p = NULL; offset > 0; offset -= PFS_DELEN) { 833 if (pfs_iterate(curthread, proc, pd, &pn, &p) == -1) { 834 /* nothing left... */ 835 if (proc != NULL) { 836 _PRELE(proc); 837 PROC_UNLOCK(proc); 838 } 839 pfs_unlock(pd); 840 sx_sunlock(&allproc_lock); 841 PFS_RETURN (0); 842 } 843 } 844 845 /* fill in entries */ 846 while (pfs_iterate(curthread, proc, pd, &pn, &p) != -1 && 847 resid >= PFS_DELEN) { 848 if ((pfsent = malloc(sizeof(struct pfsentry), M_IOV, 849 M_NOWAIT | M_ZERO)) == NULL) { 850 error = ENOMEM; 851 break; 852 } 853 pfsent->entry.d_reclen = PFS_DELEN; 854 pfsent->entry.d_fileno = pn_fileno(pn, pid); 855 /* PFS_DELEN was picked to fit PFS_NAMLEN */ 856 for (i = 0; i < PFS_NAMELEN - 1 && pn->pn_name[i] != '\0'; ++i) 857 pfsent->entry.d_name[i] = pn->pn_name[i]; 858 pfsent->entry.d_namlen = i; 859 /* NOTE: d_off is the offset of the *next* entry. */ 860 pfsent->entry.d_off = offset + PFS_DELEN; 861 switch (pn->pn_type) { 862 case pfstype_procdir: 863 KASSERT(p != NULL, 864 ("reached procdir node with p == NULL")); 865 pfsent->entry.d_namlen = snprintf(pfsent->entry.d_name, 866 PFS_NAMELEN, "%d", p->p_pid); 867 /* fall through */ 868 case pfstype_root: 869 case pfstype_dir: 870 case pfstype_this: 871 case pfstype_parent: 872 pfsent->entry.d_type = DT_DIR; 873 break; 874 case pfstype_file: 875 pfsent->entry.d_type = DT_REG; 876 break; 877 case pfstype_symlink: 878 pfsent->entry.d_type = DT_LNK; 879 break; 880 default: 881 panic("%s has unexpected node type: %d", pn->pn_name, pn->pn_type); 882 } 883 PFS_TRACE(("%s", pfsent->entry.d_name)); 884 dirent_terminate(&pfsent->entry); 885 STAILQ_INSERT_TAIL(&lst, pfsent, link); 886 offset += PFS_DELEN; 887 resid -= PFS_DELEN; 888 } 889 if (proc != NULL) { 890 _PRELE(proc); 891 PROC_UNLOCK(proc); 892 } 893 pfs_unlock(pd); 894 sx_sunlock(&allproc_lock); 895 i = 0; 896 STAILQ_FOREACH_SAFE(pfsent, &lst, link, pfsent2) { 897 if (error == 0) 898 error = uiomove(&pfsent->entry, PFS_DELEN, uio); 899 free(pfsent, M_IOV); 900 i++; 901 } 902 PFS_TRACE(("%ju bytes", (uintmax_t)(i * PFS_DELEN))); 903 PFS_RETURN (error); 904 } 905 906 /* 907 * Read a symbolic link 908 */ 909 static int 910 pfs_readlink(struct vop_readlink_args *va) 911 { 912 struct vnode *vn = va->a_vp; 913 struct pfs_vdata *pvd = vn->v_data; 914 struct pfs_node *pn = pvd->pvd_pn; 915 struct uio *uio = va->a_uio; 916 struct proc *proc = NULL; 917 char buf[PATH_MAX]; 918 struct sbuf sb; 919 int error, locked; 920 921 PFS_TRACE(("%s", pn->pn_name)); 922 pfs_assert_not_owned(pn); 923 924 if (vn->v_type != VLNK) 925 PFS_RETURN (EINVAL); 926 KASSERT_PN_IS_LINK(pn); 927 928 if (pn->pn_fill == NULL) 929 PFS_RETURN (EIO); 930 931 if (pvd->pvd_pid != NO_PID) { 932 if ((proc = pfind(pvd->pvd_pid)) == NULL) 933 PFS_RETURN (EIO); 934 if (proc->p_flag & P_WEXIT) { 935 PROC_UNLOCK(proc); 936 PFS_RETURN (EIO); 937 } 938 _PHOLD(proc); 939 PROC_UNLOCK(proc); 940 } 941 vhold(vn); 942 locked = VOP_ISLOCKED(vn); 943 VOP_UNLOCK(vn); 944 945 /* sbuf_new() can't fail with a static buffer */ 946 sbuf_new(&sb, buf, sizeof buf, 0); 947 948 error = pn_fill(curthread, proc, pn, &sb, NULL); 949 950 if (proc != NULL) 951 PRELE(proc); 952 vn_lock(vn, locked | LK_RETRY); 953 vdrop(vn); 954 955 if (error) { 956 sbuf_delete(&sb); 957 PFS_RETURN (error); 958 } 959 960 if (sbuf_finish(&sb) != 0) { 961 sbuf_delete(&sb); 962 PFS_RETURN (ENAMETOOLONG); 963 } 964 965 error = uiomove_frombuf(sbuf_data(&sb), sbuf_len(&sb), uio); 966 sbuf_delete(&sb); 967 PFS_RETURN (error); 968 } 969 970 /* 971 * Reclaim a vnode 972 */ 973 static int 974 pfs_reclaim(struct vop_reclaim_args *va) 975 { 976 struct vnode *vn = va->a_vp; 977 struct pfs_vdata *pvd = vn->v_data; 978 struct pfs_node *pn = pvd->pvd_pn; 979 980 PFS_TRACE(("%s", pn->pn_name)); 981 pfs_assert_not_owned(pn); 982 983 return (pfs_vncache_free(va->a_vp)); 984 } 985 986 /* 987 * Set attributes 988 */ 989 static int 990 pfs_setattr(struct vop_setattr_args *va) 991 { 992 struct vnode *vn = va->a_vp; 993 struct pfs_vdata *pvd = vn->v_data; 994 struct pfs_node *pn = pvd->pvd_pn; 995 996 PFS_TRACE(("%s", pn->pn_name)); 997 pfs_assert_not_owned(pn); 998 999 /* Silently ignore unchangeable attributes. */ 1000 PFS_RETURN (0); 1001 } 1002 1003 /* 1004 * Write to a file 1005 */ 1006 static int 1007 pfs_write(struct vop_write_args *va) 1008 { 1009 struct vnode *vn = va->a_vp; 1010 struct pfs_vdata *pvd = vn->v_data; 1011 struct pfs_node *pn = pvd->pvd_pn; 1012 struct uio *uio = va->a_uio; 1013 struct proc *proc; 1014 struct sbuf sb; 1015 int error; 1016 1017 PFS_TRACE(("%s", pn->pn_name)); 1018 pfs_assert_not_owned(pn); 1019 1020 if (vn->v_type != VREG) 1021 PFS_RETURN (EINVAL); 1022 KASSERT_PN_IS_FILE(pn); 1023 1024 if (!(pn->pn_flags & PFS_WR)) 1025 PFS_RETURN (EBADF); 1026 1027 if (pn->pn_fill == NULL) 1028 PFS_RETURN (EIO); 1029 1030 /* 1031 * This is necessary because either process' privileges may 1032 * have changed since the open() call. 1033 */ 1034 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc)) 1035 PFS_RETURN (EIO); 1036 if (proc != NULL) { 1037 _PHOLD(proc); 1038 PROC_UNLOCK(proc); 1039 } 1040 1041 if (pn->pn_flags & PFS_RAWWR) { 1042 error = pn_fill(curthread, proc, pn, NULL, uio); 1043 if (proc != NULL) 1044 PRELE(proc); 1045 PFS_RETURN (error); 1046 } 1047 1048 sbuf_uionew(&sb, uio, &error); 1049 if (error) { 1050 if (proc != NULL) 1051 PRELE(proc); 1052 PFS_RETURN (error); 1053 } 1054 1055 error = pn_fill(curthread, proc, pn, &sb, uio); 1056 1057 sbuf_delete(&sb); 1058 if (proc != NULL) 1059 PRELE(proc); 1060 PFS_RETURN (error); 1061 } 1062 1063 /* 1064 * Vnode operations 1065 */ 1066 struct vop_vector pfs_vnodeops = { 1067 .vop_default = &default_vnodeops, 1068 1069 .vop_access = pfs_access, 1070 .vop_cachedlookup = pfs_lookup, 1071 .vop_close = pfs_close, 1072 .vop_create = VOP_EOPNOTSUPP, 1073 .vop_getattr = pfs_getattr, 1074 .vop_getextattr = pfs_getextattr, 1075 .vop_ioctl = pfs_ioctl, 1076 .vop_link = VOP_EOPNOTSUPP, 1077 .vop_lookup = vfs_cache_lookup, 1078 .vop_mkdir = VOP_EOPNOTSUPP, 1079 .vop_mknod = VOP_EOPNOTSUPP, 1080 .vop_open = pfs_open, 1081 .vop_read = pfs_read, 1082 .vop_readdir = pfs_readdir, 1083 .vop_readlink = pfs_readlink, 1084 .vop_reclaim = pfs_reclaim, 1085 .vop_remove = VOP_EOPNOTSUPP, 1086 .vop_rename = VOP_EOPNOTSUPP, 1087 .vop_rmdir = VOP_EOPNOTSUPP, 1088 .vop_setattr = pfs_setattr, 1089 .vop_symlink = VOP_EOPNOTSUPP, 1090 .vop_vptocnp = pfs_vptocnp, 1091 .vop_write = pfs_write, 1092 /* XXX I've probably forgotten a few that need VOP_EOPNOTSUPP */ 1093 }; 1094 VFS_VOP_VECTOR_REGISTER(pfs_vnodeops); 1095