1 /* 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software donated to Berkeley by 6 * Jan-Simon Pendry. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 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. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)fdesc_vnops.c 8.9 (Berkeley) 1/21/94 37 * 38 * $FreeBSD$ 39 */ 40 41 /* 42 * /dev/fd Filesystem 43 */ 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/proc.h> 48 #include <sys/kernel.h> /* boottime */ 49 #include <sys/filedesc.h> 50 #include <sys/vnode.h> 51 #include <sys/malloc.h> 52 #include <sys/file.h> 53 #include <sys/stat.h> 54 #include <sys/mount.h> 55 #include <sys/namei.h> 56 #include <sys/dirent.h> 57 #include <sys/conf.h> 58 #include <miscfs/fdesc/fdesc.h> 59 60 #define FDL_WANT 0x01 61 #define FDL_LOCKED 0x02 62 static int fdcache_lock; 63 64 static vop_t **fdesc_vnodeop_p; 65 66 #define NFDCACHE 4 67 #define FD_NHASH(ix) \ 68 (&fdhashtbl[(ix) & fdhash]) 69 static LIST_HEAD(fdhashhead, fdescnode) *fdhashtbl; 70 static u_long fdhash; 71 72 static int fdesc_badop __P((void)); 73 static int fdesc_getattr __P((struct vop_getattr_args *ap)); 74 static int fdesc_inactive __P((struct vop_inactive_args *ap)); 75 static int fdesc_lookup __P((struct vop_lookup_args *ap)); 76 static int fdesc_open __P((struct vop_open_args *ap)); 77 static int fdesc_print __P((struct vop_print_args *ap)); 78 static int fdesc_readdir __P((struct vop_readdir_args *ap)); 79 static int fdesc_reclaim __P((struct vop_reclaim_args *ap)); 80 static int fdesc_poll __P((struct vop_poll_args *ap)); 81 static int fdesc_setattr __P((struct vop_setattr_args *ap)); 82 83 /* 84 * Initialise cache headers 85 */ 86 int 87 fdesc_init(vfsp) 88 struct vfsconf *vfsp; 89 { 90 91 fdhashtbl = hashinit(NFDCACHE, M_CACHE, &fdhash); 92 return (0); 93 } 94 95 int 96 fdesc_allocvp(ftype, ix, mp, vpp, p) 97 fdntype ftype; 98 int ix; 99 struct mount *mp; 100 struct vnode **vpp; 101 struct proc *p; 102 { 103 struct fdhashhead *fc; 104 struct fdescnode *fd; 105 int error = 0; 106 107 fc = FD_NHASH(ix); 108 loop: 109 for (fd = fc->lh_first; fd != 0; fd = fd->fd_hash.le_next) { 110 if (fd->fd_ix == ix && fd->fd_vnode->v_mount == mp) { 111 if (vget(fd->fd_vnode, 0, p)) 112 goto loop; 113 *vpp = fd->fd_vnode; 114 return (error); 115 } 116 } 117 118 /* 119 * otherwise lock the array while we call getnewvnode 120 * since that can block. 121 */ 122 if (fdcache_lock & FDL_LOCKED) { 123 fdcache_lock |= FDL_WANT; 124 (void) tsleep((caddr_t) &fdcache_lock, PINOD, "fdalvp", 0); 125 goto loop; 126 } 127 fdcache_lock |= FDL_LOCKED; 128 129 /* 130 * Do the MALLOC before the getnewvnode since doing so afterward 131 * might cause a bogus v_data pointer to get dereferenced 132 * elsewhere if MALLOC should block. 133 */ 134 MALLOC(fd, struct fdescnode *, sizeof(struct fdescnode), M_TEMP, M_WAITOK); 135 136 error = getnewvnode(VT_FDESC, mp, fdesc_vnodeop_p, vpp); 137 if (error) { 138 FREE(fd, M_TEMP); 139 goto out; 140 } 141 (*vpp)->v_data = fd; 142 fd->fd_vnode = *vpp; 143 fd->fd_type = ftype; 144 fd->fd_fd = -1; 145 fd->fd_ix = ix; 146 LIST_INSERT_HEAD(fc, fd, fd_hash); 147 148 out: 149 fdcache_lock &= ~FDL_LOCKED; 150 151 if (fdcache_lock & FDL_WANT) { 152 fdcache_lock &= ~FDL_WANT; 153 wakeup((caddr_t) &fdcache_lock); 154 } 155 156 return (error); 157 } 158 159 /* 160 * vp is the current namei directory 161 * ndp is the name to locate in that directory... 162 */ 163 static int 164 fdesc_lookup(ap) 165 struct vop_lookup_args /* { 166 struct vnode * a_dvp; 167 struct vnode ** a_vpp; 168 struct componentname * a_cnp; 169 } */ *ap; 170 { 171 struct vnode **vpp = ap->a_vpp; 172 struct vnode *dvp = ap->a_dvp; 173 struct componentname *cnp = ap->a_cnp; 174 char *pname = cnp->cn_nameptr; 175 struct proc *p = cnp->cn_proc; 176 int nlen = cnp->cn_namelen; 177 int nfiles = p->p_fd->fd_nfiles; 178 u_int fd; 179 int error; 180 struct vnode *fvp; 181 182 if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME) { 183 error = EROFS; 184 goto bad; 185 } 186 187 VOP_UNLOCK(dvp, 0, p); 188 if (cnp->cn_namelen == 1 && *pname == '.') { 189 *vpp = dvp; 190 VREF(dvp); 191 vn_lock(dvp, LK_SHARED | LK_RETRY, p); 192 return (0); 193 } 194 195 if (VTOFDESC(dvp)->fd_type != Froot) { 196 error = ENOTDIR; 197 goto bad; 198 } 199 200 fd = 0; 201 /* the only time a leading 0 is acceptable is if it's "0" */ 202 if (*pname == '0' && nlen != 1) { 203 error = ENOENT; 204 goto bad; 205 } 206 while (nlen--) { 207 if (*pname < '0' || *pname > '9') { 208 error = ENOENT; 209 goto bad; 210 } 211 fd = 10 * fd + *pname++ - '0'; 212 } 213 214 if (fd >= nfiles || p->p_fd->fd_ofiles[fd] == NULL) { 215 error = EBADF; 216 goto bad; 217 } 218 219 error = fdesc_allocvp(Fdesc, FD_DESC+fd, dvp->v_mount, &fvp, p); 220 if (error) 221 goto bad; 222 VTOFDESC(fvp)->fd_fd = fd; 223 vn_lock(fvp, LK_SHARED | LK_RETRY, p); 224 *vpp = fvp; 225 return (0); 226 227 bad: 228 vn_lock(dvp, LK_SHARED | LK_RETRY, p); 229 *vpp = NULL; 230 return (error); 231 } 232 233 static int 234 fdesc_open(ap) 235 struct vop_open_args /* { 236 struct vnode *a_vp; 237 int a_mode; 238 struct ucred *a_cred; 239 struct proc *a_p; 240 } */ *ap; 241 { 242 struct vnode *vp = ap->a_vp; 243 244 if (VTOFDESC(vp)->fd_type == Froot) 245 return (0); 246 247 /* 248 * XXX Kludge: set p->p_dupfd to contain the value of the the file 249 * descriptor being sought for duplication. The error return ensures 250 * that the vnode for this device will be released by vn_open. Open 251 * will detect this special error and take the actions in dupfdopen. 252 * Other callers of vn_open or VOP_OPEN will simply report the 253 * error. 254 */ 255 ap->a_p->p_dupfd = VTOFDESC(vp)->fd_fd; /* XXX */ 256 return (ENODEV); 257 } 258 259 static int 260 fdesc_getattr(ap) 261 struct vop_getattr_args /* { 262 struct vnode *a_vp; 263 struct vattr *a_vap; 264 struct ucred *a_cred; 265 struct proc *a_p; 266 } */ *ap; 267 { 268 struct vnode *vp = ap->a_vp; 269 struct vattr *vap = ap->a_vap; 270 struct filedesc *fdp = ap->a_p->p_fd; 271 struct file *fp; 272 struct stat stb; 273 u_int fd; 274 int error = 0; 275 276 switch (VTOFDESC(vp)->fd_type) { 277 case Froot: 278 VATTR_NULL(vap); 279 280 vap->va_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 281 vap->va_type = VDIR; 282 vap->va_nlink = 2; 283 vap->va_size = DEV_BSIZE; 284 vap->va_fileid = VTOFDESC(vp)->fd_ix; 285 vap->va_uid = 0; 286 vap->va_gid = 0; 287 vap->va_blocksize = DEV_BSIZE; 288 vap->va_atime.tv_sec = boottime.tv_sec; 289 vap->va_atime.tv_nsec = 0; 290 vap->va_mtime = vap->va_atime; 291 vap->va_ctime = vap->va_mtime; 292 vap->va_gen = 0; 293 vap->va_flags = 0; 294 vap->va_rdev = 0; 295 vap->va_bytes = 0; 296 break; 297 298 case Fdesc: 299 fd = VTOFDESC(vp)->fd_fd; 300 301 if (fd >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[fd]) == NULL) 302 return (EBADF); 303 304 bzero(&stb, sizeof(stb)); 305 error = fo_stat(fp, &stb, ap->a_p); 306 if (error == 0) { 307 VATTR_NULL(vap); 308 vap->va_type = IFTOVT(stb.st_mode); 309 vap->va_mode = stb.st_mode; 310 #define FDRX (VREAD|VEXEC) 311 if (vap->va_type == VDIR) 312 vap->va_mode &= ~((FDRX)|(FDRX>>3)|(FDRX>>6)); 313 #undef FDRX 314 vap->va_nlink = 1; 315 vap->va_flags = 0; 316 vap->va_bytes = stb.st_blocks * stb.st_blksize; 317 vap->va_fileid = VTOFDESC(vp)->fd_ix; 318 vap->va_size = stb.st_size; 319 vap->va_blocksize = stb.st_blksize; 320 vap->va_rdev = stb.st_rdev; 321 322 /* 323 * If no time data is provided, use the current time. 324 */ 325 if (stb.st_atimespec.tv_sec == 0 && 326 stb.st_atimespec.tv_nsec == 0) 327 nanotime(&stb.st_atimespec); 328 329 if (stb.st_ctimespec.tv_sec == 0 && 330 stb.st_ctimespec.tv_nsec == 0) 331 nanotime(&stb.st_ctimespec); 332 333 if (stb.st_mtimespec.tv_sec == 0 && 334 stb.st_mtimespec.tv_nsec == 0) 335 nanotime(&stb.st_mtimespec); 336 337 vap->va_atime = stb.st_atimespec; 338 vap->va_mtime = stb.st_mtimespec; 339 vap->va_ctime = stb.st_ctimespec; 340 vap->va_uid = stb.st_uid; 341 vap->va_gid = stb.st_gid; 342 } 343 break; 344 345 default: 346 panic("fdesc_getattr"); 347 break; 348 } 349 350 if (error == 0) 351 vp->v_type = vap->va_type; 352 return (error); 353 } 354 355 static int 356 fdesc_setattr(ap) 357 struct vop_setattr_args /* { 358 struct vnode *a_vp; 359 struct vattr *a_vap; 360 struct ucred *a_cred; 361 struct proc *a_p; 362 } */ *ap; 363 { 364 struct vattr *vap = ap->a_vap; 365 struct vnode *vp; 366 struct mount *mp; 367 struct file *fp; 368 unsigned fd; 369 int error; 370 371 /* 372 * Can't mess with the root vnode 373 */ 374 if (VTOFDESC(ap->a_vp)->fd_type == Froot) 375 return (EACCES); 376 377 fd = VTOFDESC(ap->a_vp)->fd_fd; 378 379 /* 380 * Allow setattr where there is an underlying vnode. 381 */ 382 error = getvnode(ap->a_p->p_fd, fd, &fp); 383 if (error) { 384 /* 385 * getvnode() returns EINVAL if the file descriptor is not 386 * backed by a vnode. Silently drop all changes except 387 * chflags(2) in this case. 388 */ 389 if (error == EINVAL) { 390 if (vap->va_flags != VNOVAL) 391 error = EOPNOTSUPP; 392 else 393 error = 0; 394 } 395 return (error); 396 } 397 vp = (struct vnode *)fp->f_data; 398 if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) 399 return (error); 400 error = VOP_SETATTR(vp, ap->a_vap, ap->a_cred, ap->a_p); 401 vn_finished_write(mp); 402 return (error); 403 } 404 405 #define UIO_MX 16 406 407 static int 408 fdesc_readdir(ap) 409 struct vop_readdir_args /* { 410 struct vnode *a_vp; 411 struct uio *a_uio; 412 struct ucred *a_cred; 413 int *a_eofflag; 414 u_long *a_cookies; 415 int a_ncookies; 416 } */ *ap; 417 { 418 struct uio *uio = ap->a_uio; 419 struct filedesc *fdp; 420 struct dirent d; 421 struct dirent *dp = &d; 422 int error, i, off, fcnt; 423 424 /* 425 * We don't allow exporting fdesc mounts, and currently local 426 * requests do not need cookies. 427 */ 428 if (ap->a_ncookies) 429 panic("fdesc_readdir: not hungry"); 430 431 if (VTOFDESC(ap->a_vp)->fd_type != Froot) 432 panic("fdesc_readdir: not dir"); 433 434 off = (int)uio->uio_offset; 435 if (off != uio->uio_offset || off < 0 || (u_int)off % UIO_MX != 0 || 436 uio->uio_resid < UIO_MX) 437 return (EINVAL); 438 i = (u_int)off / UIO_MX; 439 fdp = uio->uio_procp->p_fd; 440 error = 0; 441 442 fcnt = i - 2; /* The first two nodes are `.' and `..' */ 443 444 while (i < fdp->fd_nfiles + 2 && uio->uio_resid >= UIO_MX) { 445 switch (i) { 446 case 0: /* `.' */ 447 case 1: /* `..' */ 448 bzero((caddr_t)dp, UIO_MX); 449 450 dp->d_fileno = i + FD_ROOT; 451 dp->d_namlen = i + 1; 452 dp->d_reclen = UIO_MX; 453 bcopy("..", dp->d_name, dp->d_namlen); 454 dp->d_name[i + 1] = '\0'; 455 dp->d_type = DT_DIR; 456 break; 457 default: 458 if (fdp->fd_ofiles[fcnt] == NULL) 459 goto done; 460 461 bzero((caddr_t) dp, UIO_MX); 462 dp->d_namlen = sprintf(dp->d_name, "%d", fcnt); 463 dp->d_reclen = UIO_MX; 464 dp->d_type = DT_UNKNOWN; 465 dp->d_fileno = i + FD_DESC; 466 break; 467 } 468 /* 469 * And ship to userland 470 */ 471 error = uiomove((caddr_t) dp, UIO_MX, uio); 472 if (error) 473 break; 474 i++; 475 fcnt++; 476 } 477 478 done: 479 uio->uio_offset = i * UIO_MX; 480 return (error); 481 } 482 483 static int 484 fdesc_poll(ap) 485 struct vop_poll_args /* { 486 struct vnode *a_vp; 487 int a_events; 488 struct ucred *a_cred; 489 struct proc *a_p; 490 } */ *ap; 491 { 492 return seltrue(0, ap->a_events, ap->a_p); 493 } 494 495 static int 496 fdesc_inactive(ap) 497 struct vop_inactive_args /* { 498 struct vnode *a_vp; 499 struct proc *a_p; 500 } */ *ap; 501 { 502 struct vnode *vp = ap->a_vp; 503 504 /* 505 * Clear out the v_type field to avoid 506 * nasty things happening in vgone(). 507 */ 508 VOP_UNLOCK(vp, 0, ap->a_p); 509 vp->v_type = VNON; 510 return (0); 511 } 512 513 static int 514 fdesc_reclaim(ap) 515 struct vop_reclaim_args /* { 516 struct vnode *a_vp; 517 } */ *ap; 518 { 519 struct vnode *vp = ap->a_vp; 520 struct fdescnode *fd = VTOFDESC(vp); 521 522 LIST_REMOVE(fd, fd_hash); 523 FREE(vp->v_data, M_TEMP); 524 vp->v_data = 0; 525 526 return (0); 527 } 528 529 /* 530 * Print out the contents of a /dev/fd vnode. 531 */ 532 /* ARGSUSED */ 533 static int 534 fdesc_print(ap) 535 struct vop_print_args /* { 536 struct vnode *a_vp; 537 } */ *ap; 538 { 539 540 printf("tag VT_NON, fdesc vnode\n"); 541 return (0); 542 } 543 544 /* 545 * /dev/fd "should never get here" operation 546 */ 547 static int 548 fdesc_badop() 549 { 550 551 panic("fdesc: bad op"); 552 /* NOTREACHED */ 553 } 554 555 static struct vnodeopv_entry_desc fdesc_vnodeop_entries[] = { 556 { &vop_default_desc, (vop_t *) vop_defaultop }, 557 { &vop_access_desc, (vop_t *) vop_null }, 558 { &vop_bmap_desc, (vop_t *) fdesc_badop }, 559 { &vop_getattr_desc, (vop_t *) fdesc_getattr }, 560 { &vop_inactive_desc, (vop_t *) fdesc_inactive }, 561 { &vop_lookup_desc, (vop_t *) fdesc_lookup }, 562 { &vop_open_desc, (vop_t *) fdesc_open }, 563 { &vop_pathconf_desc, (vop_t *) vop_stdpathconf }, 564 { &vop_poll_desc, (vop_t *) fdesc_poll }, 565 { &vop_print_desc, (vop_t *) fdesc_print }, 566 { &vop_readdir_desc, (vop_t *) fdesc_readdir }, 567 { &vop_reclaim_desc, (vop_t *) fdesc_reclaim }, 568 { &vop_setattr_desc, (vop_t *) fdesc_setattr }, 569 { NULL, NULL } 570 }; 571 static struct vnodeopv_desc fdesc_vnodeop_opv_desc = 572 { &fdesc_vnodeop_p, fdesc_vnodeop_entries }; 573 574 VNODEOP_SET(fdesc_vnodeop_opv_desc); 575