1 /*- 2 * Copyright (c) 2001 Dag-Erling Co�dan Sm�rgrav 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer 10 * in this position and unchanged. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. The name of the author may not be used to endorse or promote products 15 * derived from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 #include <sys/param.h> 32 #include <sys/kernel.h> 33 #include <sys/systm.h> 34 #include <sys/ctype.h> 35 #include <sys/dirent.h> 36 #include <sys/fcntl.h> 37 #include <sys/lock.h> 38 #include <sys/mount.h> 39 #include <sys/mutex.h> 40 #include <sys/namei.h> 41 #include <sys/proc.h> 42 #include <sys/sbuf.h> 43 #include <sys/sx.h> 44 #include <sys/sysctl.h> 45 #include <sys/vnode.h> 46 47 #include <fs/pseudofs/pseudofs.h> 48 #include <fs/pseudofs/pseudofs_internal.h> 49 50 #if 0 51 #define PFS_TRACE(foo) \ 52 do { \ 53 printf("pseudofs: %s(): line %d: ", __func__, __LINE__); \ 54 printf foo ; \ 55 printf("\n"); \ 56 } while (0) 57 #define PFS_RETURN(err) \ 58 do { \ 59 printf("pseudofs: %s(): line %d: returning %d\n", \ 60 __func__, __LINE__, err); \ 61 return (err); \ 62 } while (0) 63 #else 64 #define PFS_TRACE(foo) \ 65 do { /* nothing */ } while (0) 66 #define PFS_RETURN(err) \ 67 return (err) 68 #endif 69 70 /* 71 * Returns non-zero if given file is visible to given process 72 */ 73 static int 74 pfs_visible(struct thread *td, struct pfs_node *pn, pid_t pid) 75 { 76 struct proc *proc; 77 int r; 78 79 PFS_TRACE(("%s (pid: %d, req: %d)", 80 pn->pn_name, pid, td->td_proc->p_pid)); 81 82 if (pn->pn_flags & PFS_DISABLED) 83 PFS_RETURN (0); 84 85 r = 1; 86 if (pid != NO_PID) { 87 if ((proc = pfind(pid)) == NULL) 88 PFS_RETURN (0); 89 if (p_cansee(td, proc) != 0 || 90 (pn->pn_vis != NULL && !(pn->pn_vis)(td, proc, pn))) 91 r = 0; 92 PROC_UNLOCK(proc); 93 } 94 PFS_RETURN (r); 95 } 96 97 /* 98 * Verify permissions 99 */ 100 static int 101 pfs_access(struct vop_access_args *va) 102 { 103 struct vnode *vn = va->a_vp; 104 struct vattr vattr; 105 int error; 106 107 PFS_TRACE((((struct pfs_vdata *)vn->v_data)->pvd_pn->pn_name)); 108 109 error = VOP_GETATTR(vn, &vattr, va->a_cred, va->a_td); 110 if (error) 111 PFS_RETURN (error); 112 error = vaccess(vn->v_type, vattr.va_mode, vattr.va_uid, 113 vattr.va_gid, va->a_mode, va->a_cred, NULL); 114 PFS_RETURN (error); 115 } 116 117 /* 118 * Close a file or directory 119 */ 120 static int 121 pfs_close(struct vop_close_args *va) 122 { 123 struct vnode *vn = va->a_vp; 124 struct pfs_vdata *pvd = (struct pfs_vdata *)vn->v_data; 125 struct pfs_node *pn = pvd->pvd_pn; 126 struct proc *proc; 127 int error; 128 129 PFS_TRACE((pn->pn_name)); 130 131 /* 132 * Do nothing unless this is the last close and the node has a 133 * last-close handler. 134 */ 135 if (vrefcnt(vn) > 1 || pn->pn_close == NULL) 136 PFS_RETURN (0); 137 138 if (pvd->pvd_pid != NO_PID) 139 proc = pfind(pvd->pvd_pid); 140 else 141 proc = NULL; 142 143 error = (pn->pn_close)(va->a_td, proc, pn); 144 145 if (proc != NULL) 146 PROC_UNLOCK(proc); 147 148 PFS_RETURN (error); 149 } 150 151 /* 152 * Get file attributes 153 */ 154 static int 155 pfs_getattr(struct vop_getattr_args *va) 156 { 157 struct vnode *vn = va->a_vp; 158 struct pfs_vdata *pvd = (struct pfs_vdata *)vn->v_data; 159 struct pfs_node *pn = pvd->pvd_pn; 160 struct vattr *vap = va->a_vap; 161 struct proc *proc; 162 int error = 0; 163 164 PFS_TRACE((pn->pn_name)); 165 166 if (!pfs_visible(curthread, pn, pvd->pvd_pid)) 167 PFS_RETURN (ENOENT); 168 169 VATTR_NULL(vap); 170 vap->va_type = vn->v_type; 171 vap->va_fileid = pn->pn_fileno; 172 vap->va_flags = 0; 173 vap->va_blocksize = PAGE_SIZE; 174 vap->va_bytes = vap->va_size = 0; 175 vap->va_fsid = vn->v_mount->mnt_stat.f_fsid.val[0]; 176 vap->va_nlink = 1; 177 nanotime(&vap->va_ctime); 178 vap->va_atime = vap->va_mtime = vap->va_ctime; 179 180 switch (pn->pn_type) { 181 case pfstype_procdir: 182 case pfstype_root: 183 case pfstype_dir: 184 vap->va_mode = 0555; 185 break; 186 case pfstype_file: 187 case pfstype_symlink: 188 vap->va_mode = 0444; 189 break; 190 default: 191 printf("shouldn't be here!\n"); 192 vap->va_mode = 0; 193 break; 194 } 195 196 if (pvd->pvd_pid != NO_PID) { 197 if ((proc = pfind(pvd->pvd_pid)) == NULL) 198 PFS_RETURN (ENOENT); 199 vap->va_uid = proc->p_ucred->cr_ruid; 200 vap->va_gid = proc->p_ucred->cr_rgid; 201 if (pn->pn_attr != NULL) 202 error = (pn->pn_attr)(va->a_td, proc, pn, vap); 203 PROC_UNLOCK(proc); 204 } else { 205 vap->va_uid = 0; 206 vap->va_gid = 0; 207 } 208 209 PFS_RETURN (error); 210 } 211 212 /* 213 * Perform an ioctl 214 */ 215 static int 216 pfs_ioctl(struct vop_ioctl_args *va) 217 { 218 struct vnode *vn = va->a_vp; 219 struct pfs_vdata *pvd = (struct pfs_vdata *)vn->v_data; 220 struct pfs_node *pn = pvd->pvd_pn; 221 struct proc *proc = NULL; 222 int error; 223 224 PFS_TRACE(("%s: %lx", pn->pn_name, va->a_command)); 225 226 if (vn->v_type != VREG) 227 PFS_RETURN (EINVAL); 228 229 if (pn->pn_ioctl == NULL) 230 PFS_RETURN (ENOTTY); 231 232 /* 233 * This is necessary because process' privileges may 234 * have changed since the open() call. 235 */ 236 if (!pfs_visible(curthread, pn, pvd->pvd_pid)) 237 PFS_RETURN (EIO); 238 239 /* XXX duplicates bits of pfs_visible() */ 240 if (pvd->pvd_pid != NO_PID) { 241 if ((proc = pfind(pvd->pvd_pid)) == NULL) 242 PFS_RETURN (EIO); 243 _PHOLD(proc); 244 PROC_UNLOCK(proc); 245 } 246 247 error = (pn->pn_ioctl)(curthread, proc, pn, va->a_command, va->a_data); 248 249 if (proc != NULL) 250 PRELE(proc); 251 252 PFS_RETURN (error); 253 } 254 255 /* 256 * Perform getextattr 257 */ 258 static int 259 pfs_getextattr(struct vop_getextattr_args *va) 260 { 261 struct vnode *vn = va->a_vp; 262 struct pfs_vdata *pvd = (struct pfs_vdata *)vn->v_data; 263 struct pfs_node *pn = pvd->pvd_pn; 264 struct proc *proc = NULL; 265 int error; 266 267 PFS_TRACE((pd->pn_name)); 268 269 if (!pfs_visible(curthread, pn, pvd->pvd_pid)) 270 PFS_RETURN (ENOENT); 271 272 if (pn->pn_getextattr == NULL) 273 PFS_RETURN (EOPNOTSUPP); 274 275 /* 276 * This is necessary because either process' privileges may 277 * have changed since the open() call. 278 */ 279 if (!pfs_visible(curthread, pn, pvd->pvd_pid)) 280 PFS_RETURN (EIO); 281 282 /* XXX duplicates bits of pfs_visible() */ 283 if (pvd->pvd_pid != NO_PID) { 284 if ((proc = pfind(pvd->pvd_pid)) == NULL) 285 PFS_RETURN (EIO); 286 _PHOLD(proc); 287 PROC_UNLOCK(proc); 288 } 289 290 error = (pn->pn_getextattr)(curthread, proc, pn, va->a_attrnamespace, 291 va->a_name, va->a_uio, va->a_size, va->a_cred); 292 293 if (proc != NULL) 294 PRELE(proc); 295 296 PFS_RETURN (error); 297 } 298 299 /* 300 * Look up a file or directory 301 * 302 * XXX NOTE! pfs_lookup() has been hooked into vop_lookup_desc! This 303 * will result in a lookup operation for a vnode which may already be 304 * cached, therefore we have to be careful to purge the VFS cache when 305 * reusing a vnode. 306 * 307 * This code will work, but is not really correct. Normally we would hook 308 * vfs_cache_lookup() into vop_lookup_desc and hook pfs_lookup() into 309 * vop_cachedlookup_desc. 310 */ 311 static int 312 pfs_lookup(struct vop_lookup_args *va) 313 { 314 struct vnode *vn = va->a_dvp; 315 struct vnode **vpp = va->a_vpp; 316 struct componentname *cnp = va->a_cnp; 317 struct pfs_vdata *pvd = (struct pfs_vdata *)vn->v_data; 318 struct pfs_node *pd = pvd->pvd_pn; 319 struct pfs_node *pn, *pdn = NULL; 320 pid_t pid = pvd->pvd_pid; 321 int lockparent; 322 int wantparent; 323 char *pname; 324 int error, i, namelen; 325 326 PFS_TRACE(("%.*s", (int)cnp->cn_namelen, cnp->cn_nameptr)); 327 328 cnp->cn_flags &= ~PDIRUNLOCK; 329 330 if (vn->v_type != VDIR) 331 PFS_RETURN (ENOTDIR); 332 333 /* 334 * Don't support DELETE or RENAME. CREATE is supported so 335 * that O_CREAT will work, but the lookup will still fail if 336 * the file does not exist. 337 */ 338 if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME) 339 PFS_RETURN (EOPNOTSUPP); 340 341 /* shortcut: check if the name is too long */ 342 if (cnp->cn_namelen >= PFS_NAMELEN) 343 PFS_RETURN (ENOENT); 344 345 /* check that parent directory is visisble... */ 346 if (!pfs_visible(curthread, pd, pvd->pvd_pid)) 347 PFS_RETURN (ENOENT); 348 349 lockparent = cnp->cn_flags & LOCKPARENT; 350 wantparent = cnp->cn_flags & (LOCKPARENT | WANTPARENT); 351 352 353 /* self */ 354 namelen = cnp->cn_namelen; 355 pname = cnp->cn_nameptr; 356 if (namelen == 1 && *pname == '.') { 357 pn = pd; 358 *vpp = vn; 359 VREF(vn); 360 PFS_RETURN (0); 361 } 362 363 /* parent */ 364 if (cnp->cn_flags & ISDOTDOT) { 365 if (pd->pn_type == pfstype_root) 366 PFS_RETURN (EIO); 367 VOP_UNLOCK(vn, 0, cnp->cn_thread); 368 cnp->cn_flags |= PDIRUNLOCK; 369 370 KASSERT(pd->pn_parent, ("non-root directory has no parent")); 371 /* 372 * This one is tricky. Descendents of procdir nodes 373 * inherit their parent's process affinity, but 374 * there's no easy reverse mapping. For simplicity, 375 * we assume that if this node is a procdir, its 376 * parent isn't (which is correct as long as 377 * descendents of procdir nodes are never procdir 378 * nodes themselves) 379 */ 380 if (pd->pn_type == pfstype_procdir) 381 pid = NO_PID; 382 pn = pd->pn_parent; 383 goto got_pnode; 384 } 385 386 /* named node */ 387 for (pn = pd->pn_nodes; pn != NULL; pn = pn->pn_next) 388 if (pn->pn_type == pfstype_procdir) 389 pdn = pn; 390 else if (pn->pn_name[namelen] == '\0' 391 && bcmp(pname, pn->pn_name, namelen) == 0) 392 goto got_pnode; 393 394 /* process dependent node */ 395 if ((pn = pdn) != NULL) { 396 pid = 0; 397 for (pid = 0, i = 0; i < namelen && isdigit(pname[i]); ++i) 398 if ((pid = pid * 10 + pname[i] - '0') > PID_MAX) 399 break; 400 if (i == cnp->cn_namelen) 401 goto got_pnode; 402 } 403 404 PFS_RETURN (ENOENT); 405 got_pnode: 406 if (pn != pd->pn_parent && !pn->pn_parent) 407 pn->pn_parent = pd; 408 if (!pfs_visible(curthread, pn, pvd->pvd_pid)) 409 PFS_RETURN (ENOENT); 410 411 error = pfs_vncache_alloc(vn->v_mount, vpp, pn, pid); 412 if (error) 413 PFS_RETURN (error); 414 415 if ((cnp->cn_flags & ISDOTDOT) && (cnp->cn_flags & ISLASTCN) 416 && lockparent) { 417 vn_lock(vn, LK_EXCLUSIVE|LK_RETRY, cnp->cn_thread); 418 cnp->cn_flags &= ~PDIRUNLOCK; 419 } 420 if (!((lockparent && (cnp->cn_flags & ISLASTCN)) || 421 (cnp->cn_flags & ISDOTDOT))) 422 VOP_UNLOCK(vn, 0, cnp->cn_thread); 423 424 /* 425 * XXX See comment at top of the routine. 426 */ 427 if (cnp->cn_flags & MAKEENTRY) 428 cache_enter(vn, *vpp, cnp); 429 PFS_RETURN (0); 430 } 431 432 /* 433 * Open a file or directory. 434 */ 435 static int 436 pfs_open(struct vop_open_args *va) 437 { 438 struct vnode *vn = va->a_vp; 439 struct pfs_vdata *pvd = (struct pfs_vdata *)vn->v_data; 440 struct pfs_node *pn = pvd->pvd_pn; 441 int mode = va->a_mode; 442 443 PFS_TRACE(("%s (mode 0x%x)", pn->pn_name, mode)); 444 445 /* 446 * check if the file is visible to the caller 447 * 448 * XXX Not sure if this is necessary, as the VFS system calls 449 * XXX pfs_lookup() and pfs_access() first, and pfs_lookup() 450 * XXX calls pfs_visible(). There's a race condition here, but 451 * XXX calling pfs_visible() from here doesn't really close it, 452 * XXX and the only consequence of that race is an EIO further 453 * XXX down the line. 454 */ 455 if (!pfs_visible(va->a_td, pn, pvd->pvd_pid)) 456 PFS_RETURN (ENOENT); 457 458 /* check if the requested mode is permitted */ 459 if (((mode & FREAD) && !(mode & PFS_RD)) || 460 ((mode & FWRITE) && !(mode & PFS_WR))) 461 PFS_RETURN (EPERM); 462 463 /* we don't support locking */ 464 if ((mode & O_SHLOCK) || (mode & O_EXLOCK)) 465 PFS_RETURN (EOPNOTSUPP); 466 467 PFS_RETURN (0); 468 } 469 470 /* 471 * Read from a file 472 */ 473 static int 474 pfs_read(struct vop_read_args *va) 475 { 476 struct vnode *vn = va->a_vp; 477 struct pfs_vdata *pvd = (struct pfs_vdata *)vn->v_data; 478 struct pfs_node *pn = pvd->pvd_pn; 479 struct uio *uio = va->a_uio; 480 struct proc *proc = NULL; 481 struct sbuf *sb = NULL; 482 char *ps; 483 int error, xlen; 484 485 PFS_TRACE((pn->pn_name)); 486 487 if (vn->v_type != VREG) 488 PFS_RETURN (EINVAL); 489 490 if (!(pn->pn_flags & PFS_RD)) 491 PFS_RETURN (EBADF); 492 493 if (pn->pn_func == NULL) 494 PFS_RETURN (EIO); 495 496 /* 497 * This is necessary because either process' privileges may 498 * have changed since the open() call. 499 */ 500 if (!pfs_visible(curthread, pn, pvd->pvd_pid)) 501 PFS_RETURN (EIO); 502 503 /* XXX duplicates bits of pfs_visible() */ 504 if (pvd->pvd_pid != NO_PID) { 505 if ((proc = pfind(pvd->pvd_pid)) == NULL) 506 PFS_RETURN (EIO); 507 _PHOLD(proc); 508 PROC_UNLOCK(proc); 509 } 510 511 if (pn->pn_flags & PFS_RAWRD) { 512 error = (pn->pn_func)(curthread, proc, pn, NULL, uio); 513 if (proc != NULL) 514 PRELE(proc); 515 PFS_RETURN (error); 516 } 517 518 sb = sbuf_new(sb, NULL, uio->uio_offset + uio->uio_resid, 0); 519 if (sb == NULL) { 520 if (proc != NULL) 521 PRELE(proc); 522 PFS_RETURN (EIO); 523 } 524 525 error = (pn->pn_func)(curthread, proc, pn, sb, uio); 526 527 if (proc != NULL) 528 PRELE(proc); 529 530 if (error) { 531 sbuf_delete(sb); 532 PFS_RETURN (error); 533 } 534 535 /* XXX we should possibly detect and handle overflows */ 536 sbuf_finish(sb); 537 ps = sbuf_data(sb) + uio->uio_offset; 538 xlen = sbuf_len(sb) - uio->uio_offset; 539 xlen = imin(xlen, uio->uio_resid); 540 error = (xlen <= 0 ? 0 : uiomove(ps, xlen, uio)); 541 sbuf_delete(sb); 542 PFS_RETURN (error); 543 } 544 545 /* 546 * Iterate through directory entries 547 */ 548 static int 549 pfs_iterate(struct thread *td, pid_t pid, struct pfs_node *pd, 550 struct pfs_node **pn, struct proc **p) 551 { 552 sx_assert(&allproc_lock, SX_LOCKED); 553 again: 554 if (*pn == NULL) { 555 /* first node */ 556 *pn = pd->pn_nodes; 557 } else if ((*pn)->pn_type != pfstype_procdir) { 558 /* next node */ 559 *pn = (*pn)->pn_next; 560 } 561 if (*pn != NULL && (*pn)->pn_type == pfstype_procdir) { 562 /* next process */ 563 if (*p == NULL) 564 *p = LIST_FIRST(&allproc); 565 else 566 *p = LIST_NEXT(*p, p_list); 567 /* out of processes: next node */ 568 if (*p == NULL) 569 *pn = (*pn)->pn_next; 570 } 571 572 if ((*pn) == NULL) 573 return (-1); 574 575 if (!pfs_visible(td, *pn, *p ? (*p)->p_pid : pid)) 576 goto again; 577 578 return (0); 579 } 580 581 /* 582 * Return directory entries. 583 */ 584 static int 585 pfs_readdir(struct vop_readdir_args *va) 586 { 587 struct vnode *vn = va->a_vp; 588 struct pfs_info *pi = (struct pfs_info *)vn->v_mount->mnt_data; 589 struct pfs_vdata *pvd = (struct pfs_vdata *)vn->v_data; 590 struct pfs_node *pd = pvd->pvd_pn; 591 pid_t pid = pvd->pvd_pid; 592 struct pfs_node *pn; 593 struct dirent entry; 594 struct uio *uio; 595 struct proc *p; 596 off_t offset; 597 int error, i, resid; 598 599 PFS_TRACE((pd->pn_name)); 600 601 if (vn->v_type != VDIR) 602 PFS_RETURN (ENOTDIR); 603 uio = va->a_uio; 604 605 /* check if the directory is visible to the caller */ 606 if (!pfs_visible(curthread, pd, pid)) 607 PFS_RETURN (ENOENT); 608 609 /* only allow reading entire entries */ 610 offset = uio->uio_offset; 611 resid = uio->uio_resid; 612 if (offset < 0 || offset % PFS_DELEN != 0 || resid < PFS_DELEN) 613 PFS_RETURN (EINVAL); 614 615 /* skip unwanted entries */ 616 sx_slock(&allproc_lock); 617 for (pn = NULL, p = NULL; offset > 0; offset -= PFS_DELEN) 618 if (pfs_iterate(curthread, pid, pd, &pn, &p) == -1) { 619 /* nothing left... */ 620 sx_sunlock(&allproc_lock); 621 PFS_RETURN (0); 622 } 623 624 /* fill in entries */ 625 entry.d_reclen = PFS_DELEN; 626 while (pfs_iterate(curthread, pid, pd, &pn, &p) != -1 && resid > 0) { 627 if (!pn->pn_parent) 628 pn->pn_parent = pd; 629 if (!pn->pn_fileno) 630 pfs_fileno_alloc(pi, pn); 631 if (pid != NO_PID) 632 entry.d_fileno = pn->pn_fileno * NO_PID + pid; 633 else 634 entry.d_fileno = pn->pn_fileno; 635 /* PFS_DELEN was picked to fit PFS_NAMLEN */ 636 for (i = 0; i < PFS_NAMELEN - 1 && pn->pn_name[i] != '\0'; ++i) 637 entry.d_name[i] = pn->pn_name[i]; 638 entry.d_name[i] = 0; 639 entry.d_namlen = i; 640 switch (pn->pn_type) { 641 case pfstype_procdir: 642 KASSERT(p != NULL, 643 ("reached procdir node with p == NULL")); 644 entry.d_fileno = pn->pn_fileno * NO_PID + p->p_pid; 645 entry.d_namlen = snprintf(entry.d_name, 646 PFS_NAMELEN, "%d", p->p_pid); 647 /* fall through */ 648 case pfstype_root: 649 case pfstype_dir: 650 case pfstype_this: 651 case pfstype_parent: 652 entry.d_type = DT_DIR; 653 break; 654 case pfstype_file: 655 entry.d_type = DT_REG; 656 break; 657 case pfstype_symlink: 658 entry.d_type = DT_LNK; 659 break; 660 default: 661 sx_sunlock(&allproc_lock); 662 panic("%s has unexpected node type: %d", pn->pn_name, pn->pn_type); 663 } 664 PFS_TRACE((entry.d_name)); 665 if ((error = uiomove(&entry, PFS_DELEN, uio))) { 666 sx_sunlock(&allproc_lock); 667 PFS_RETURN (error); 668 } 669 offset += PFS_DELEN; 670 resid -= PFS_DELEN; 671 } 672 673 sx_sunlock(&allproc_lock); 674 uio->uio_offset += offset; 675 PFS_RETURN (0); 676 } 677 678 /* 679 * Read a symbolic link 680 */ 681 static int 682 pfs_readlink(struct vop_readlink_args *va) 683 { 684 struct vnode *vn = va->a_vp; 685 struct pfs_vdata *pvd = (struct pfs_vdata *)vn->v_data; 686 struct pfs_node *pn = pvd->pvd_pn; 687 struct uio *uio = va->a_uio; 688 struct proc *proc = NULL; 689 char buf[MAXPATHLEN], *ps; 690 struct sbuf sb; 691 int error, xlen; 692 693 PFS_TRACE((pn->pn_name)); 694 695 if (vn->v_type != VLNK) 696 PFS_RETURN (EINVAL); 697 698 if (pn->pn_func == NULL) 699 PFS_RETURN (EIO); 700 701 if (pvd->pvd_pid != NO_PID) { 702 if ((proc = pfind(pvd->pvd_pid)) == NULL) 703 PFS_RETURN (EIO); 704 _PHOLD(proc); 705 PROC_UNLOCK(proc); 706 } 707 708 /* sbuf_new() can't fail with a static buffer */ 709 sbuf_new(&sb, buf, sizeof buf, 0); 710 711 error = (pn->pn_func)(curthread, proc, pn, &sb, NULL); 712 713 if (proc != NULL) 714 PRELE(proc); 715 716 if (error) { 717 sbuf_delete(&sb); 718 PFS_RETURN (error); 719 } 720 721 /* XXX we should detect and handle overflows */ 722 sbuf_finish(&sb); 723 ps = sbuf_data(&sb) + uio->uio_offset; 724 xlen = sbuf_len(&sb) - uio->uio_offset; 725 xlen = imin(xlen, uio->uio_resid); 726 error = (xlen <= 0 ? 0 : uiomove(ps, xlen, uio)); 727 sbuf_delete(&sb); 728 PFS_RETURN (error); 729 } 730 731 /* 732 * Reclaim a vnode 733 */ 734 static int 735 pfs_reclaim(struct vop_reclaim_args *va) 736 { 737 PFS_TRACE((((struct pfs_vdata *)va->a_vp->v_data)->pvd_pn->pn_name)); 738 739 return (pfs_vncache_free(va->a_vp)); 740 } 741 742 /* 743 * Set attributes 744 */ 745 static int 746 pfs_setattr(struct vop_setattr_args *va) 747 { 748 PFS_TRACE((((struct pfs_vdata *)va->a_vp->v_data)->pvd_pn->pn_name)); 749 750 PFS_RETURN (EOPNOTSUPP); 751 } 752 753 /* 754 * Read from a file 755 */ 756 static int 757 pfs_write(struct vop_read_args *va) 758 { 759 struct vnode *vn = va->a_vp; 760 struct pfs_vdata *pvd = (struct pfs_vdata *)vn->v_data; 761 struct pfs_node *pn = pvd->pvd_pn; 762 struct uio *uio = va->a_uio; 763 struct proc *proc = NULL; 764 struct sbuf sb; 765 int error; 766 767 PFS_TRACE((pn->pn_name)); 768 769 if (vn->v_type != VREG) 770 PFS_RETURN (EINVAL); 771 772 if (!(pn->pn_flags & PFS_WR)) 773 PFS_RETURN (EBADF); 774 775 if (pn->pn_func == NULL) 776 PFS_RETURN (EIO); 777 778 /* 779 * This is necessary because either process' privileges may 780 * have changed since the open() call. 781 */ 782 if (!pfs_visible(curthread, pn, pvd->pvd_pid)) 783 PFS_RETURN (EIO); 784 785 /* XXX duplicates bits of pfs_visible() */ 786 if (pvd->pvd_pid != NO_PID) { 787 if ((proc = pfind(pvd->pvd_pid)) == NULL) 788 PFS_RETURN (EIO); 789 _PHOLD(proc); 790 PROC_UNLOCK(proc); 791 } 792 793 if (pn->pn_flags & PFS_RAWWR) { 794 error = (pn->pn_func)(curthread, proc, pn, NULL, uio); 795 if (proc != NULL) 796 PRELE(proc); 797 PFS_RETURN (error); 798 } 799 800 sbuf_uionew(&sb, uio, &error); 801 if (error) 802 PFS_RETURN (error); 803 804 error = (pn->pn_func)(curthread, proc, pn, &sb, uio); 805 806 if (proc != NULL) 807 PRELE(proc); 808 809 sbuf_delete(&sb); 810 PFS_RETURN (error); 811 } 812 813 /* 814 * Vnode operations 815 */ 816 vop_t **pfs_vnodeop_p; 817 static struct vnodeopv_entry_desc pfs_vnodeop_entries[] = { 818 { &vop_default_desc, (vop_t *)vop_defaultop }, 819 { &vop_access_desc, (vop_t *)pfs_access }, 820 { &vop_close_desc, (vop_t *)pfs_close }, 821 { &vop_create_desc, (vop_t *)vop_eopnotsupp }, 822 { &vop_getattr_desc, (vop_t *)pfs_getattr }, 823 { &vop_getextattr_desc, (vop_t *)pfs_getextattr }, 824 { &vop_ioctl_desc, (vop_t *)pfs_ioctl }, 825 { &vop_link_desc, (vop_t *)vop_eopnotsupp }, 826 { &vop_lookup_desc, (vop_t *)pfs_lookup }, 827 { &vop_mkdir_desc, (vop_t *)vop_eopnotsupp }, 828 { &vop_mknod_desc, (vop_t *)vop_eopnotsupp }, 829 { &vop_open_desc, (vop_t *)pfs_open }, 830 { &vop_read_desc, (vop_t *)pfs_read }, 831 { &vop_readdir_desc, (vop_t *)pfs_readdir }, 832 { &vop_readlink_desc, (vop_t *)pfs_readlink }, 833 { &vop_reclaim_desc, (vop_t *)pfs_reclaim }, 834 { &vop_remove_desc, (vop_t *)vop_eopnotsupp }, 835 { &vop_rename_desc, (vop_t *)vop_eopnotsupp }, 836 { &vop_rmdir_desc, (vop_t *)vop_eopnotsupp }, 837 { &vop_setattr_desc, (vop_t *)pfs_setattr }, 838 { &vop_symlink_desc, (vop_t *)vop_eopnotsupp }, 839 { &vop_write_desc, (vop_t *)pfs_write }, 840 /* XXX I've probably forgotten a few that need vop_eopnotsupp */ 841 { NULL, (vop_t *)NULL } 842 }; 843 844 static struct vnodeopv_desc pfs_vnodeop_opv_desc = 845 { &pfs_vnodeop_p, pfs_vnodeop_entries }; 846 847 VNODEOP_SET(pfs_vnodeop_opv_desc); 848