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 #define PFS_MAXBUFSIZ 1024 * 1024 72 73 /* 74 * Returns the fileno, adjusted for target pid 75 */ 76 static uint32_t 77 pn_fileno(struct pfs_node *pn, pid_t pid) 78 { 79 80 KASSERT(pn->pn_fileno > 0, 81 ("%s(): no fileno allocated", __func__)); 82 if (pid != NO_PID) 83 return (pn->pn_fileno * NO_PID + pid); 84 return (pn->pn_fileno); 85 } 86 87 /* 88 * Returns non-zero if given file is visible to given thread. 89 */ 90 static int 91 pfs_visible_proc(struct thread *td, struct pfs_node *pn, struct proc *proc) 92 { 93 int visible; 94 95 if (proc == NULL) 96 return (0); 97 98 PROC_LOCK_ASSERT(proc, MA_OWNED); 99 100 visible = ((proc->p_flag & P_WEXIT) == 0); 101 if (visible) 102 visible = (p_cansee(td, proc) == 0); 103 if (visible && pn->pn_vis != NULL) 104 visible = pn_vis(td, proc, pn); 105 if (!visible) 106 return (0); 107 return (1); 108 } 109 110 static int 111 pfs_visible(struct thread *td, struct pfs_node *pn, pid_t pid, 112 struct proc **p) 113 { 114 struct proc *proc; 115 116 PFS_TRACE(("%s (pid: %d, req: %d)", 117 pn->pn_name, pid, td->td_proc->p_pid)); 118 119 if (p) 120 *p = NULL; 121 if (pid == NO_PID) 122 PFS_RETURN (1); 123 proc = pfind(pid); 124 if (proc == NULL) 125 PFS_RETURN (0); 126 if (pfs_visible_proc(td, pn, proc)) { 127 if (p) 128 *p = proc; 129 else 130 PROC_UNLOCK(proc); 131 PFS_RETURN (1); 132 } 133 PROC_UNLOCK(proc); 134 PFS_RETURN (0); 135 } 136 137 static int 138 pfs_lookup_proc(pid_t pid, struct proc **p) 139 { 140 struct proc *proc; 141 142 proc = pfind(pid); 143 if (proc == NULL) 144 return (0); 145 if ((proc->p_flag & P_WEXIT) != 0) { 146 PROC_UNLOCK(proc); 147 return (0); 148 } 149 _PHOLD(proc); 150 PROC_UNLOCK(proc); 151 *p = proc; 152 return (1); 153 } 154 155 /* 156 * Verify permissions 157 */ 158 static int 159 pfs_access(struct vop_access_args *va) 160 { 161 struct vnode *vn = va->a_vp; 162 struct pfs_vdata *pvd = vn->v_data; 163 struct vattr vattr; 164 int error; 165 166 PFS_TRACE(("%s", pvd->pvd_pn->pn_name)); 167 (void)pvd; 168 169 error = VOP_GETATTR(vn, &vattr, va->a_cred); 170 if (error) 171 PFS_RETURN (error); 172 error = vaccess(vn->v_type, vattr.va_mode, vattr.va_uid, vattr.va_gid, 173 va->a_accmode, va->a_cred); 174 PFS_RETURN (error); 175 } 176 177 /* 178 * Close a file or directory 179 */ 180 static int 181 pfs_close(struct vop_close_args *va) 182 { 183 struct vnode *vn = va->a_vp; 184 struct pfs_vdata *pvd = vn->v_data; 185 struct pfs_node *pn = pvd->pvd_pn; 186 struct proc *proc; 187 int error; 188 189 PFS_TRACE(("%s", pn->pn_name)); 190 pfs_assert_not_owned(pn); 191 192 /* 193 * Do nothing unless this is the last close and the node has a 194 * last-close handler. 195 */ 196 if (vrefcnt(vn) > 1 || pn->pn_close == NULL) 197 PFS_RETURN (0); 198 199 if (pvd->pvd_pid != NO_PID) { 200 proc = pfind(pvd->pvd_pid); 201 } else { 202 proc = NULL; 203 } 204 205 error = pn_close(va->a_td, proc, pn); 206 207 if (proc != NULL) 208 PROC_UNLOCK(proc); 209 210 PFS_RETURN (error); 211 } 212 213 /* 214 * Get file attributes 215 */ 216 static int 217 pfs_getattr(struct vop_getattr_args *va) 218 { 219 struct vnode *vn = va->a_vp; 220 struct pfs_vdata *pvd = vn->v_data; 221 struct pfs_node *pn = pvd->pvd_pn; 222 struct vattr *vap = va->a_vap; 223 struct proc *proc; 224 int error = 0; 225 226 PFS_TRACE(("%s", pn->pn_name)); 227 pfs_assert_not_owned(pn); 228 229 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc)) 230 PFS_RETURN (ENOENT); 231 232 vap->va_type = vn->v_type; 233 vap->va_fileid = pn_fileno(pn, pvd->pvd_pid); 234 vap->va_flags = 0; 235 vap->va_blocksize = PAGE_SIZE; 236 vap->va_bytes = vap->va_size = 0; 237 vap->va_filerev = 0; 238 vap->va_fsid = vn->v_mount->mnt_stat.f_fsid.val[0]; 239 vap->va_nlink = 1; 240 nanotime(&vap->va_ctime); 241 vap->va_atime = vap->va_mtime = vap->va_ctime; 242 243 switch (pn->pn_type) { 244 case pfstype_procdir: 245 case pfstype_root: 246 case pfstype_dir: 247 #if 0 248 pfs_lock(pn); 249 /* compute link count */ 250 pfs_unlock(pn); 251 #endif 252 vap->va_mode = 0555; 253 break; 254 case pfstype_file: 255 case pfstype_symlink: 256 vap->va_mode = 0444; 257 break; 258 default: 259 printf("shouldn't be here!\n"); 260 vap->va_mode = 0; 261 break; 262 } 263 264 if (proc != NULL) { 265 vap->va_uid = proc->p_ucred->cr_ruid; 266 vap->va_gid = proc->p_ucred->cr_rgid; 267 } else { 268 vap->va_uid = 0; 269 vap->va_gid = 0; 270 } 271 272 if (pn->pn_attr != NULL) 273 error = pn_attr(curthread, proc, pn, vap); 274 275 if(proc != NULL) 276 PROC_UNLOCK(proc); 277 278 PFS_RETURN (error); 279 } 280 281 /* 282 * Perform an ioctl 283 */ 284 static int 285 pfs_ioctl(struct vop_ioctl_args *va) 286 { 287 struct vnode *vn; 288 struct pfs_vdata *pvd; 289 struct pfs_node *pn; 290 struct proc *proc; 291 int error; 292 293 vn = va->a_vp; 294 vn_lock(vn, LK_SHARED | LK_RETRY); 295 if (VN_IS_DOOMED(vn)) { 296 VOP_UNLOCK(vn); 297 return (EBADF); 298 } 299 pvd = vn->v_data; 300 pn = pvd->pvd_pn; 301 302 PFS_TRACE(("%s: %lx", pn->pn_name, va->a_command)); 303 pfs_assert_not_owned(pn); 304 305 if (vn->v_type != VREG) { 306 VOP_UNLOCK(vn); 307 PFS_RETURN (EINVAL); 308 } 309 KASSERT_PN_IS_FILE(pn); 310 311 if (pn->pn_ioctl == NULL) { 312 VOP_UNLOCK(vn); 313 PFS_RETURN (ENOTTY); 314 } 315 316 /* 317 * This is necessary because process' privileges may 318 * have changed since the open() call. 319 */ 320 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc)) { 321 VOP_UNLOCK(vn); 322 PFS_RETURN (EIO); 323 } 324 325 error = pn_ioctl(curthread, proc, pn, va->a_command, va->a_data); 326 327 if (proc != NULL) 328 PROC_UNLOCK(proc); 329 330 VOP_UNLOCK(vn); 331 PFS_RETURN (error); 332 } 333 334 /* 335 * Perform getextattr 336 */ 337 static int 338 pfs_getextattr(struct vop_getextattr_args *va) 339 { 340 struct vnode *vn = va->a_vp; 341 struct pfs_vdata *pvd = vn->v_data; 342 struct pfs_node *pn = pvd->pvd_pn; 343 struct proc *proc; 344 int error; 345 346 PFS_TRACE(("%s", pn->pn_name)); 347 pfs_assert_not_owned(pn); 348 349 /* 350 * This is necessary because either process' privileges may 351 * have changed since the open() call. 352 */ 353 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc)) 354 PFS_RETURN (EIO); 355 356 if (pn->pn_getextattr == NULL) 357 error = EOPNOTSUPP; 358 else 359 error = pn_getextattr(curthread, proc, pn, 360 va->a_attrnamespace, va->a_name, va->a_uio, 361 va->a_size, va->a_cred); 362 363 if (proc != NULL) 364 PROC_UNLOCK(proc); 365 366 PFS_RETURN (error); 367 } 368 369 /* 370 * Convert a vnode to its component name 371 */ 372 static int 373 pfs_vptocnp(struct vop_vptocnp_args *ap) 374 { 375 struct vnode *vp = ap->a_vp; 376 struct vnode **dvp = ap->a_vpp; 377 struct pfs_vdata *pvd = vp->v_data; 378 struct pfs_node *pd = pvd->pvd_pn; 379 struct pfs_node *pn; 380 struct mount *mp; 381 char *buf = ap->a_buf; 382 size_t *buflen = ap->a_buflen; 383 char pidbuf[PFS_NAMELEN]; 384 pid_t pid = pvd->pvd_pid; 385 int len, i, error, locked; 386 387 i = *buflen; 388 error = 0; 389 390 pfs_lock(pd); 391 392 if (vp->v_type == VDIR && pd->pn_type == pfstype_root) { 393 *dvp = vp; 394 vhold(*dvp); 395 pfs_unlock(pd); 396 PFS_RETURN (0); 397 } else if (vp->v_type == VDIR && pd->pn_type == pfstype_procdir) { 398 len = snprintf(pidbuf, sizeof(pidbuf), "%d", pid); 399 i -= len; 400 if (i < 0) { 401 error = ENOMEM; 402 goto failed; 403 } 404 bcopy(pidbuf, buf + i, len); 405 } else { 406 len = strlen(pd->pn_name); 407 i -= len; 408 if (i < 0) { 409 error = ENOMEM; 410 goto failed; 411 } 412 bcopy(pd->pn_name, buf + i, len); 413 } 414 415 pn = pd->pn_parent; 416 pfs_unlock(pd); 417 418 mp = vp->v_mount; 419 error = vfs_busy(mp, 0); 420 if (error) 421 return (error); 422 423 /* 424 * vp is held by caller. 425 */ 426 locked = VOP_ISLOCKED(vp); 427 VOP_UNLOCK(vp); 428 429 error = pfs_vncache_alloc(mp, dvp, pn, pid); 430 if (error) { 431 vn_lock(vp, locked | LK_RETRY); 432 vfs_unbusy(mp); 433 PFS_RETURN(error); 434 } 435 436 *buflen = i; 437 VOP_UNLOCK(*dvp); 438 vn_lock(vp, locked | LK_RETRY); 439 vfs_unbusy(mp); 440 441 PFS_RETURN (0); 442 failed: 443 pfs_unlock(pd); 444 PFS_RETURN(error); 445 } 446 447 /* 448 * Look up a file or directory 449 */ 450 static int 451 pfs_lookup(struct vop_cachedlookup_args *va) 452 { 453 struct vnode *vn = va->a_dvp; 454 struct vnode **vpp = va->a_vpp; 455 struct componentname *cnp = va->a_cnp; 456 struct pfs_vdata *pvd = vn->v_data; 457 struct pfs_node *pd = pvd->pvd_pn; 458 struct pfs_node *pn, *pdn = NULL; 459 struct mount *mp; 460 pid_t pid = pvd->pvd_pid; 461 char *pname; 462 int error, i, namelen, visible; 463 464 PFS_TRACE(("%.*s", (int)cnp->cn_namelen, cnp->cn_nameptr)); 465 pfs_assert_not_owned(pd); 466 467 if (vn->v_type != VDIR) 468 PFS_RETURN (ENOTDIR); 469 KASSERT_PN_IS_DIR(pd); 470 471 /* 472 * Don't support DELETE or RENAME. CREATE is supported so 473 * that O_CREAT will work, but the lookup will still fail if 474 * the file does not exist. 475 */ 476 if ((cnp->cn_flags & ISLASTCN) && 477 (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) 478 PFS_RETURN (EOPNOTSUPP); 479 480 /* shortcut: check if the name is too long */ 481 if (cnp->cn_namelen >= PFS_NAMELEN) 482 PFS_RETURN (ENOENT); 483 484 /* check that parent directory is visible... */ 485 if (!pfs_visible(curthread, pd, pvd->pvd_pid, NULL)) 486 PFS_RETURN (ENOENT); 487 488 /* self */ 489 namelen = cnp->cn_namelen; 490 pname = cnp->cn_nameptr; 491 if (namelen == 1 && pname[0] == '.') { 492 pn = pd; 493 *vpp = vn; 494 VREF(vn); 495 PFS_RETURN (0); 496 } 497 498 mp = vn->v_mount; 499 500 /* parent */ 501 if (cnp->cn_flags & ISDOTDOT) { 502 if (pd->pn_type == pfstype_root) 503 PFS_RETURN (EIO); 504 error = vfs_busy(mp, MBF_NOWAIT); 505 if (error != 0) { 506 vfs_ref(mp); 507 VOP_UNLOCK(vn); 508 error = vfs_busy(mp, 0); 509 vn_lock(vn, LK_EXCLUSIVE | LK_RETRY); 510 vfs_rel(mp); 511 if (error != 0) 512 PFS_RETURN(ENOENT); 513 if (VN_IS_DOOMED(vn)) { 514 vfs_unbusy(mp); 515 PFS_RETURN(ENOENT); 516 } 517 } 518 VOP_UNLOCK(vn); 519 KASSERT(pd->pn_parent != NULL, 520 ("%s(): non-root directory has no parent", __func__)); 521 /* 522 * This one is tricky. Descendents of procdir nodes 523 * inherit their parent's process affinity, but 524 * there's no easy reverse mapping. For simplicity, 525 * we assume that if this node is a procdir, its 526 * parent isn't (which is correct as long as 527 * descendents of procdir nodes are never procdir 528 * nodes themselves) 529 */ 530 if (pd->pn_type == pfstype_procdir) 531 pid = NO_PID; 532 pfs_lock(pd); 533 pn = pd->pn_parent; 534 pfs_unlock(pd); 535 goto got_pnode; 536 } 537 538 pfs_lock(pd); 539 540 /* named node */ 541 for (pn = pd->pn_nodes; pn != NULL; pn = pn->pn_next) 542 if (pn->pn_type == pfstype_procdir) 543 pdn = pn; 544 else if (pn->pn_name[namelen] == '\0' && 545 bcmp(pname, pn->pn_name, namelen) == 0) { 546 pfs_unlock(pd); 547 goto got_pnode; 548 } 549 550 /* process dependent node */ 551 if ((pn = pdn) != NULL) { 552 pid = 0; 553 for (pid = 0, i = 0; i < namelen && isdigit(pname[i]); ++i) 554 if ((pid = pid * 10 + pname[i] - '0') > PID_MAX) 555 break; 556 if (i == cnp->cn_namelen) { 557 pfs_unlock(pd); 558 goto got_pnode; 559 } 560 } 561 562 pfs_unlock(pd); 563 564 PFS_RETURN (ENOENT); 565 566 got_pnode: 567 pfs_assert_not_owned(pd); 568 pfs_assert_not_owned(pn); 569 visible = pfs_visible(curthread, pn, pid, NULL); 570 if (!visible) { 571 error = ENOENT; 572 goto failed; 573 } 574 575 error = pfs_vncache_alloc(mp, vpp, pn, pid); 576 if (error) 577 goto failed; 578 579 if (cnp->cn_flags & ISDOTDOT) { 580 vfs_unbusy(mp); 581 vn_lock(vn, LK_EXCLUSIVE | LK_RETRY); 582 if (VN_IS_DOOMED(vn)) { 583 vput(*vpp); 584 *vpp = NULL; 585 PFS_RETURN(ENOENT); 586 } 587 } 588 if (cnp->cn_flags & MAKEENTRY && !VN_IS_DOOMED(vn)) 589 cache_enter(vn, *vpp, cnp); 590 PFS_RETURN (0); 591 failed: 592 if (cnp->cn_flags & ISDOTDOT) { 593 vfs_unbusy(mp); 594 vn_lock(vn, LK_EXCLUSIVE | LK_RETRY); 595 *vpp = NULL; 596 } 597 PFS_RETURN(error); 598 } 599 600 /* 601 * Open a file or directory. 602 */ 603 static int 604 pfs_open(struct vop_open_args *va) 605 { 606 struct vnode *vn = va->a_vp; 607 struct pfs_vdata *pvd = vn->v_data; 608 struct pfs_node *pn = pvd->pvd_pn; 609 int mode = va->a_mode; 610 611 PFS_TRACE(("%s (mode 0x%x)", pn->pn_name, mode)); 612 pfs_assert_not_owned(pn); 613 614 /* check if the requested mode is permitted */ 615 if (((mode & FREAD) && !(mode & PFS_RD)) || 616 ((mode & FWRITE) && !(mode & PFS_WR))) 617 PFS_RETURN (EPERM); 618 619 /* we don't support locking */ 620 if ((mode & O_SHLOCK) || (mode & O_EXLOCK)) 621 PFS_RETURN (EOPNOTSUPP); 622 623 PFS_RETURN (0); 624 } 625 626 struct sbuf_seek_helper { 627 off_t skip_bytes; 628 struct uio *uio; 629 }; 630 631 static int 632 pfs_sbuf_uio_drain(void *arg, const char *data, int len) 633 { 634 struct sbuf_seek_helper *ssh; 635 struct uio *uio; 636 int error, skipped; 637 638 ssh = arg; 639 uio = ssh->uio; 640 skipped = 0; 641 642 /* Need to discard first uio_offset bytes. */ 643 if (ssh->skip_bytes > 0) { 644 if (ssh->skip_bytes >= len) { 645 ssh->skip_bytes -= len; 646 return (len); 647 } 648 649 data += ssh->skip_bytes; 650 len -= ssh->skip_bytes; 651 skipped = ssh->skip_bytes; 652 ssh->skip_bytes = 0; 653 } 654 655 error = uiomove(__DECONST(void *, data), len, uio); 656 if (error != 0) 657 return (-error); 658 659 /* 660 * The fill function has more to emit, but the reader is finished. 661 * This is similar to the truncated read case for non-draining PFS 662 * sbufs, and should be handled appropriately in fill-routines. 663 */ 664 if (uio->uio_resid == 0) 665 return (-ENOBUFS); 666 667 return (skipped + len); 668 } 669 670 /* 671 * Read from a file 672 */ 673 static int 674 pfs_read(struct vop_read_args *va) 675 { 676 struct vnode *vn = va->a_vp; 677 struct pfs_vdata *pvd = vn->v_data; 678 struct pfs_node *pn = pvd->pvd_pn; 679 struct uio *uio = va->a_uio; 680 struct proc *proc; 681 struct sbuf *sb = NULL; 682 int error, locked; 683 off_t buflen, buflim; 684 struct sbuf_seek_helper ssh; 685 686 PFS_TRACE(("%s", pn->pn_name)); 687 pfs_assert_not_owned(pn); 688 689 if (vn->v_type != VREG) 690 PFS_RETURN (EINVAL); 691 KASSERT_PN_IS_FILE(pn); 692 693 if (!(pn->pn_flags & PFS_RD)) 694 PFS_RETURN (EBADF); 695 696 if (pn->pn_fill == NULL) 697 PFS_RETURN (EIO); 698 699 /* 700 * This is necessary because either process' privileges may 701 * have changed since the open() call. 702 */ 703 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc)) 704 PFS_RETURN (EIO); 705 if (proc != NULL) { 706 _PHOLD(proc); 707 PROC_UNLOCK(proc); 708 } 709 710 vhold(vn); 711 locked = VOP_ISLOCKED(vn); 712 VOP_UNLOCK(vn); 713 714 if (pn->pn_flags & PFS_RAWRD) { 715 PFS_TRACE(("%zd resid", uio->uio_resid)); 716 error = pn_fill(curthread, proc, pn, NULL, uio); 717 PFS_TRACE(("%zd resid", uio->uio_resid)); 718 goto ret; 719 } 720 721 if (uio->uio_resid < 0 || uio->uio_offset < 0 || 722 uio->uio_resid > OFF_MAX - uio->uio_offset) { 723 error = EINVAL; 724 goto ret; 725 } 726 buflen = uio->uio_offset + uio->uio_resid + 1; 727 if (pn->pn_flags & PFS_AUTODRAIN) 728 /* 729 * We can use a smaller buffer if we can stream output to the 730 * consumer. 731 */ 732 buflim = PAGE_SIZE; 733 else 734 buflim = PFS_MAXBUFSIZ; 735 if (buflen > buflim) 736 buflen = buflim; 737 738 sb = sbuf_new(sb, NULL, buflen, 0); 739 if (sb == NULL) { 740 error = EIO; 741 goto ret; 742 } 743 744 if (pn->pn_flags & PFS_AUTODRAIN) { 745 ssh.skip_bytes = uio->uio_offset; 746 ssh.uio = uio; 747 sbuf_set_drain(sb, pfs_sbuf_uio_drain, &ssh); 748 } 749 750 error = pn_fill(curthread, proc, pn, sb, uio); 751 752 if (error) { 753 sbuf_delete(sb); 754 goto ret; 755 } 756 757 /* 758 * XXX: If the buffer overflowed, sbuf_len() will not return 759 * the data length. Then just use the full length because an 760 * overflowed sbuf must be full. 761 */ 762 error = sbuf_finish(sb); 763 if ((pn->pn_flags & PFS_AUTODRAIN)) { 764 /* 765 * ENOBUFS just indicates early termination of the fill 766 * function as the caller's buffer was already filled. Squash 767 * to zero. 768 */ 769 if (uio->uio_resid == 0 && error == ENOBUFS) 770 error = 0; 771 } else { 772 if (error == 0) 773 buflen = sbuf_len(sb); 774 else 775 /* The trailing byte is not valid. */ 776 buflen--; 777 error = uiomove_frombuf(sbuf_data(sb), buflen, uio); 778 } 779 sbuf_delete(sb); 780 ret: 781 vn_lock(vn, locked | LK_RETRY); 782 vdrop(vn); 783 if (proc != NULL) 784 PRELE(proc); 785 PFS_RETURN (error); 786 } 787 788 /* 789 * Iterate through directory entries 790 */ 791 static int 792 pfs_iterate(struct thread *td, struct proc *proc, struct pfs_node *pd, 793 struct pfs_node **pn, struct proc **p) 794 { 795 int visible; 796 797 sx_assert(&allproc_lock, SX_SLOCKED); 798 pfs_assert_owned(pd); 799 again: 800 if (*pn == NULL) { 801 /* first node */ 802 *pn = pd->pn_nodes; 803 } else if ((*pn)->pn_type != pfstype_procdir) { 804 /* next node */ 805 *pn = (*pn)->pn_next; 806 } 807 if (*pn != NULL && (*pn)->pn_type == pfstype_procdir) { 808 /* next process */ 809 if (*p == NULL) 810 *p = LIST_FIRST(&allproc); 811 else 812 *p = LIST_NEXT(*p, p_list); 813 /* out of processes: next node */ 814 if (*p == NULL) 815 *pn = (*pn)->pn_next; 816 else 817 PROC_LOCK(*p); 818 } 819 820 if ((*pn) == NULL) 821 return (-1); 822 823 if (*p != NULL) { 824 visible = pfs_visible_proc(td, *pn, *p); 825 PROC_UNLOCK(*p); 826 } else if (proc != NULL) { 827 visible = pfs_visible_proc(td, *pn, proc); 828 } else { 829 visible = 1; 830 } 831 if (!visible) 832 goto again; 833 834 return (0); 835 } 836 837 /* Directory entry list */ 838 struct pfsentry { 839 STAILQ_ENTRY(pfsentry) link; 840 struct dirent entry; 841 }; 842 STAILQ_HEAD(pfsdirentlist, pfsentry); 843 844 /* 845 * Return directory entries. 846 */ 847 static int 848 pfs_readdir(struct vop_readdir_args *va) 849 { 850 struct vnode *vn = va->a_vp; 851 struct pfs_vdata *pvd = vn->v_data; 852 struct pfs_node *pd = pvd->pvd_pn; 853 pid_t pid = pvd->pvd_pid; 854 struct proc *p, *proc; 855 struct pfs_node *pn; 856 struct uio *uio; 857 struct pfsentry *pfsent, *pfsent2; 858 struct pfsdirentlist lst; 859 off_t offset; 860 int error, i, resid; 861 862 STAILQ_INIT(&lst); 863 error = 0; 864 KASSERT(pd->pn_info == vn->v_mount->mnt_data, 865 ("%s(): pn_info does not match mountpoint", __func__)); 866 PFS_TRACE(("%s pid %lu", pd->pn_name, (unsigned long)pid)); 867 pfs_assert_not_owned(pd); 868 869 if (vn->v_type != VDIR) 870 PFS_RETURN (ENOTDIR); 871 KASSERT_PN_IS_DIR(pd); 872 uio = va->a_uio; 873 874 /* only allow reading entire entries */ 875 offset = uio->uio_offset; 876 resid = uio->uio_resid; 877 if (offset < 0 || offset % PFS_DELEN != 0 || 878 (resid && resid < PFS_DELEN)) 879 PFS_RETURN (EINVAL); 880 if (resid == 0) 881 PFS_RETURN (0); 882 883 proc = NULL; 884 if (pid != NO_PID && !pfs_lookup_proc(pid, &proc)) 885 PFS_RETURN (ENOENT); 886 887 sx_slock(&allproc_lock); 888 pfs_lock(pd); 889 890 KASSERT(pid == NO_PID || proc != NULL, 891 ("%s(): no process for pid %lu", __func__, (unsigned long)pid)); 892 893 if (pid != NO_PID) { 894 PROC_LOCK(proc); 895 896 /* check if the directory is visible to the caller */ 897 if (!pfs_visible_proc(curthread, pd, proc)) { 898 _PRELE(proc); 899 PROC_UNLOCK(proc); 900 pfs_unlock(pd); 901 sx_sunlock(&allproc_lock); 902 PFS_RETURN (ENOENT); 903 } 904 } 905 906 /* skip unwanted entries */ 907 for (pn = NULL, p = NULL; offset > 0; offset -= PFS_DELEN) { 908 if (pfs_iterate(curthread, proc, pd, &pn, &p) == -1) { 909 /* nothing left... */ 910 if (proc != NULL) { 911 _PRELE(proc); 912 PROC_UNLOCK(proc); 913 } 914 pfs_unlock(pd); 915 sx_sunlock(&allproc_lock); 916 PFS_RETURN (0); 917 } 918 } 919 920 /* fill in entries */ 921 while (pfs_iterate(curthread, proc, pd, &pn, &p) != -1 && 922 resid >= PFS_DELEN) { 923 if ((pfsent = malloc(sizeof(struct pfsentry), M_IOV, 924 M_NOWAIT | M_ZERO)) == NULL) { 925 error = ENOMEM; 926 break; 927 } 928 pfsent->entry.d_reclen = PFS_DELEN; 929 pfsent->entry.d_fileno = pn_fileno(pn, pid); 930 /* PFS_DELEN was picked to fit PFS_NAMLEN */ 931 for (i = 0; i < PFS_NAMELEN - 1 && pn->pn_name[i] != '\0'; ++i) 932 pfsent->entry.d_name[i] = pn->pn_name[i]; 933 pfsent->entry.d_namlen = i; 934 /* NOTE: d_off is the offset of the *next* entry. */ 935 pfsent->entry.d_off = offset + PFS_DELEN; 936 switch (pn->pn_type) { 937 case pfstype_procdir: 938 KASSERT(p != NULL, 939 ("reached procdir node with p == NULL")); 940 pfsent->entry.d_namlen = snprintf(pfsent->entry.d_name, 941 PFS_NAMELEN, "%d", p->p_pid); 942 /* fall through */ 943 case pfstype_root: 944 case pfstype_dir: 945 case pfstype_this: 946 case pfstype_parent: 947 pfsent->entry.d_type = DT_DIR; 948 break; 949 case pfstype_file: 950 pfsent->entry.d_type = DT_REG; 951 break; 952 case pfstype_symlink: 953 pfsent->entry.d_type = DT_LNK; 954 break; 955 default: 956 panic("%s has unexpected node type: %d", pn->pn_name, pn->pn_type); 957 } 958 PFS_TRACE(("%s", pfsent->entry.d_name)); 959 dirent_terminate(&pfsent->entry); 960 STAILQ_INSERT_TAIL(&lst, pfsent, link); 961 offset += PFS_DELEN; 962 resid -= PFS_DELEN; 963 } 964 if (proc != NULL) { 965 _PRELE(proc); 966 PROC_UNLOCK(proc); 967 } 968 pfs_unlock(pd); 969 sx_sunlock(&allproc_lock); 970 i = 0; 971 STAILQ_FOREACH_SAFE(pfsent, &lst, link, pfsent2) { 972 if (error == 0) 973 error = uiomove(&pfsent->entry, PFS_DELEN, uio); 974 free(pfsent, M_IOV); 975 i++; 976 } 977 PFS_TRACE(("%ju bytes", (uintmax_t)(i * PFS_DELEN))); 978 PFS_RETURN (error); 979 } 980 981 /* 982 * Read a symbolic link 983 */ 984 static int 985 pfs_readlink(struct vop_readlink_args *va) 986 { 987 struct vnode *vn = va->a_vp; 988 struct pfs_vdata *pvd = vn->v_data; 989 struct pfs_node *pn = pvd->pvd_pn; 990 struct uio *uio = va->a_uio; 991 struct proc *proc = NULL; 992 char buf[PATH_MAX]; 993 struct sbuf sb; 994 int error, locked; 995 996 PFS_TRACE(("%s", pn->pn_name)); 997 pfs_assert_not_owned(pn); 998 999 if (vn->v_type != VLNK) 1000 PFS_RETURN (EINVAL); 1001 KASSERT_PN_IS_LINK(pn); 1002 1003 if (pn->pn_fill == NULL) 1004 PFS_RETURN (EIO); 1005 1006 if (pvd->pvd_pid != NO_PID) { 1007 if ((proc = pfind(pvd->pvd_pid)) == NULL) 1008 PFS_RETURN (EIO); 1009 if (proc->p_flag & P_WEXIT) { 1010 PROC_UNLOCK(proc); 1011 PFS_RETURN (EIO); 1012 } 1013 _PHOLD(proc); 1014 PROC_UNLOCK(proc); 1015 } 1016 vhold(vn); 1017 locked = VOP_ISLOCKED(vn); 1018 VOP_UNLOCK(vn); 1019 1020 /* sbuf_new() can't fail with a static buffer */ 1021 sbuf_new(&sb, buf, sizeof buf, 0); 1022 1023 error = pn_fill(curthread, proc, pn, &sb, NULL); 1024 1025 if (proc != NULL) 1026 PRELE(proc); 1027 vn_lock(vn, locked | LK_RETRY); 1028 vdrop(vn); 1029 1030 if (error) { 1031 sbuf_delete(&sb); 1032 PFS_RETURN (error); 1033 } 1034 1035 if (sbuf_finish(&sb) != 0) { 1036 sbuf_delete(&sb); 1037 PFS_RETURN (ENAMETOOLONG); 1038 } 1039 1040 error = uiomove_frombuf(sbuf_data(&sb), sbuf_len(&sb), uio); 1041 sbuf_delete(&sb); 1042 PFS_RETURN (error); 1043 } 1044 1045 /* 1046 * Reclaim a vnode 1047 */ 1048 static int 1049 pfs_reclaim(struct vop_reclaim_args *va) 1050 { 1051 struct vnode *vn = va->a_vp; 1052 struct pfs_vdata *pvd = vn->v_data; 1053 struct pfs_node *pn = pvd->pvd_pn; 1054 1055 PFS_TRACE(("%s", pn->pn_name)); 1056 pfs_assert_not_owned(pn); 1057 1058 return (pfs_vncache_free(va->a_vp)); 1059 } 1060 1061 /* 1062 * Set attributes 1063 */ 1064 static int 1065 pfs_setattr(struct vop_setattr_args *va) 1066 { 1067 struct vnode *vn = va->a_vp; 1068 struct pfs_vdata *pvd = vn->v_data; 1069 struct pfs_node *pn = pvd->pvd_pn; 1070 1071 PFS_TRACE(("%s", pn->pn_name)); 1072 pfs_assert_not_owned(pn); 1073 1074 /* Silently ignore unchangeable attributes. */ 1075 PFS_RETURN (0); 1076 } 1077 1078 /* 1079 * Write to a file 1080 */ 1081 static int 1082 pfs_write(struct vop_write_args *va) 1083 { 1084 struct vnode *vn = va->a_vp; 1085 struct pfs_vdata *pvd = vn->v_data; 1086 struct pfs_node *pn = pvd->pvd_pn; 1087 struct uio *uio = va->a_uio; 1088 struct proc *proc; 1089 struct sbuf sb; 1090 int error; 1091 1092 PFS_TRACE(("%s", pn->pn_name)); 1093 pfs_assert_not_owned(pn); 1094 1095 if (vn->v_type != VREG) 1096 PFS_RETURN (EINVAL); 1097 KASSERT_PN_IS_FILE(pn); 1098 1099 if (!(pn->pn_flags & PFS_WR)) 1100 PFS_RETURN (EBADF); 1101 1102 if (pn->pn_fill == NULL) 1103 PFS_RETURN (EIO); 1104 1105 if (uio->uio_resid > PFS_MAXBUFSIZ) 1106 PFS_RETURN (EIO); 1107 1108 /* 1109 * This is necessary because either process' privileges may 1110 * have changed since the open() call. 1111 */ 1112 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc)) 1113 PFS_RETURN (EIO); 1114 if (proc != NULL) { 1115 _PHOLD(proc); 1116 PROC_UNLOCK(proc); 1117 } 1118 1119 if (pn->pn_flags & PFS_RAWWR) { 1120 error = pn_fill(curthread, proc, pn, NULL, uio); 1121 if (proc != NULL) 1122 PRELE(proc); 1123 PFS_RETURN (error); 1124 } 1125 1126 sbuf_uionew(&sb, uio, &error); 1127 if (error) { 1128 if (proc != NULL) 1129 PRELE(proc); 1130 PFS_RETURN (error); 1131 } 1132 1133 error = pn_fill(curthread, proc, pn, &sb, uio); 1134 1135 sbuf_delete(&sb); 1136 if (proc != NULL) 1137 PRELE(proc); 1138 PFS_RETURN (error); 1139 } 1140 1141 /* 1142 * Vnode operations 1143 */ 1144 struct vop_vector pfs_vnodeops = { 1145 .vop_default = &default_vnodeops, 1146 1147 .vop_access = pfs_access, 1148 .vop_cachedlookup = pfs_lookup, 1149 .vop_close = pfs_close, 1150 .vop_create = VOP_EOPNOTSUPP, 1151 .vop_getattr = pfs_getattr, 1152 .vop_getextattr = pfs_getextattr, 1153 .vop_ioctl = pfs_ioctl, 1154 .vop_link = VOP_EOPNOTSUPP, 1155 .vop_lookup = vfs_cache_lookup, 1156 .vop_mkdir = VOP_EOPNOTSUPP, 1157 .vop_mknod = VOP_EOPNOTSUPP, 1158 .vop_open = pfs_open, 1159 .vop_read = pfs_read, 1160 .vop_readdir = pfs_readdir, 1161 .vop_readlink = pfs_readlink, 1162 .vop_reclaim = pfs_reclaim, 1163 .vop_remove = VOP_EOPNOTSUPP, 1164 .vop_rename = VOP_EOPNOTSUPP, 1165 .vop_rmdir = VOP_EOPNOTSUPP, 1166 .vop_setattr = pfs_setattr, 1167 .vop_symlink = VOP_EOPNOTSUPP, 1168 .vop_vptocnp = pfs_vptocnp, 1169 .vop_write = pfs_write, 1170 .vop_add_writecount = vop_stdadd_writecount_nomsync, 1171 /* XXX I've probably forgotten a few that need VOP_EOPNOTSUPP */ 1172 }; 1173 VFS_VOP_VECTOR_REGISTER(pfs_vnodeops); 1174