| 1 | /* sys_generic.c 5.10 82/08/14 */ |
| 2 | |
| 3 | #include "../h/param.h" |
| 4 | #include "../h/systm.h" |
| 5 | #include "../h/dir.h" |
| 6 | #include "../h/user.h" |
| 7 | #include "../h/tty.h" |
| 8 | #include "../h/file.h" |
| 9 | #include "../h/inode.h" |
| 10 | #include "../h/buf.h" |
| 11 | #include "../h/proc.h" |
| 12 | #include "../h/inline.h" |
| 13 | #include "../h/conf.h" |
| 14 | #include "../h/socket.h" |
| 15 | #include "../h/socketvar.h" |
| 16 | #include "../h/cmap.h" |
| 17 | #include "../h/vlimit.h" |
| 18 | #include "../h/fs.h" |
| 19 | #ifdef MUSH |
| 20 | #include "../h/quota.h" |
| 21 | #include "../h/share.h" |
| 22 | #else |
| 23 | #define CHARGE(nothing) |
| 24 | #endif |
| 25 | #include "../h/descrip.h" |
| 26 | #include "../h/uio.h" |
| 27 | |
| 28 | /* |
| 29 | * Read system call. |
| 30 | */ |
| 31 | read() |
| 32 | { |
| 33 | register struct file *fp; |
| 34 | register struct inode *ip; |
| 35 | register struct a { |
| 36 | int fdes; |
| 37 | char *cbuf; |
| 38 | unsigned count; |
| 39 | } *uap; |
| 40 | struct uio auio; |
| 41 | struct iovec aiov; |
| 42 | |
| 43 | uap = (struct a *)u.u_ap; |
| 44 | if ((int)uap->count < 0) { |
| 45 | u.u_error = EINVAL; |
| 46 | return; |
| 47 | } |
| 48 | GETF(fp, uap->fdes); |
| 49 | if ((fp->f_flag&FREAD) == 0) { |
| 50 | u.u_error = EBADF; |
| 51 | return; |
| 52 | } |
| 53 | aiov.iov_base = (caddr_t)uap->cbuf; |
| 54 | aiov.iov_len = uap->count; |
| 55 | auio.uio_iov = &aiov; |
| 56 | auio.uio_iovcnt = 1; |
| 57 | auio.uio_segflg = 0; |
| 58 | auio.uio_resid = uap->count; |
| 59 | u.u_base = (caddr_t)0xc0000000; |
| 60 | u.u_count = 0x40000000; |
| 61 | if ((u.u_procp->p_flag&SNUSIG) && setjmp(u.u_qsav)) { |
| 62 | if (auio.uio_resid == uap->count) |
| 63 | u.u_eosys = RESTARTSYS; |
| 64 | } else if (fp->f_type == DTYPE_SOCKET) |
| 65 | u.u_error = soreceive(fp->f_socket, (struct sockaddr *)0, &auio); |
| 66 | else { |
| 67 | ip = fp->f_inode; |
| 68 | auio.uio_offset = fp->f_offset; |
| 69 | if ((ip->i_mode&IFMT) == IFREG) { |
| 70 | ilock(ip); |
| 71 | u.u_error = readip(ip, &auio); |
| 72 | iunlock(ip); |
| 73 | } else |
| 74 | u.u_error = readip(ip, &auio); |
| 75 | fp->f_offset += uap->count - auio.uio_resid; |
| 76 | } |
| 77 | u.u_r.r_val1 = uap->count - auio.uio_resid; |
| 78 | } |
| 79 | |
| 80 | /* |
| 81 | * Write system call |
| 82 | */ |
| 83 | write() |
| 84 | { |
| 85 | register struct file *fp; |
| 86 | register struct inode *ip; |
| 87 | register struct a { |
| 88 | int fdes; |
| 89 | char *cbuf; |
| 90 | unsigned count; |
| 91 | } *uap; |
| 92 | |
| 93 | uap = (struct a *)u.u_ap; |
| 94 | if ((int)uap->count < 0) { |
| 95 | u.u_error = EINVAL; |
| 96 | return; |
| 97 | } |
| 98 | GETF(fp, uap->fdes); |
| 99 | if ((fp->f_flag&FWRITE) == 0) { |
| 100 | u.u_error = EBADF; |
| 101 | return; |
| 102 | } |
| 103 | u.u_base = (caddr_t)uap->cbuf; |
| 104 | u.u_count = uap->count; |
| 105 | u.u_segflg = 0; |
| 106 | if ((u.u_procp->p_flag&SNUSIG) && setjmp(u.u_qsav)) { |
| 107 | if (u.u_count == uap->count) |
| 108 | u.u_eosys = RESTARTSYS; |
| 109 | } else if (fp->f_type == DTYPE_SOCKET) |
| 110 | u.u_error = sosend(fp->f_socket, (struct sockaddr *)0); |
| 111 | else { |
| 112 | ip = fp->f_inode; |
| 113 | if (fp->f_flag&FAPPEND) |
| 114 | fp->f_offset = ip->i_size; |
| 115 | u.u_offset = fp->f_offset; |
| 116 | if ((ip->i_mode&IFMT) == IFREG) { |
| 117 | ilock(ip); |
| 118 | writei(ip); |
| 119 | iunlock(ip); |
| 120 | } else |
| 121 | writei(ip); |
| 122 | fp->f_offset += uap->count - u.u_count; |
| 123 | } |
| 124 | u.u_r.r_val1 = uap->count - u.u_count; |
| 125 | } |
| 126 | |
| 127 | readv() |
| 128 | { |
| 129 | |
| 130 | } |
| 131 | |
| 132 | writev() |
| 133 | { |
| 134 | |
| 135 | } |
| 136 | |
| 137 | /* |
| 138 | * Ioctl system call |
| 139 | * Check legality, execute common code, |
| 140 | * and switch out to individual device routine. |
| 141 | */ |
| 142 | ioctl() |
| 143 | { |
| 144 | register struct file *fp; |
| 145 | struct a { |
| 146 | int fdes; |
| 147 | int cmd; |
| 148 | caddr_t cmarg; |
| 149 | } *uap; |
| 150 | register int com, size; |
| 151 | char data[IOCPARM_MASK+1]; |
| 152 | |
| 153 | uap = (struct a *)u.u_ap; |
| 154 | if ((fp = getf(uap->fdes)) == NULL) |
| 155 | return; |
| 156 | if ((fp->f_flag & (FREAD|FWRITE)) == 0) { |
| 157 | u.u_error = EBADF; |
| 158 | return; |
| 159 | } |
| 160 | com = uap->cmd; |
| 161 | |
| 162 | #ifndef NOCOMPAT |
| 163 | /* |
| 164 | * Map old style ioctl's into new for the |
| 165 | * sake of backwards compatibility (sigh). |
| 166 | */ |
| 167 | if ((com&~0xffff) == 0) { |
| 168 | com = mapioctl(com); |
| 169 | if (com == 0) { |
| 170 | u.u_error = EINVAL; |
| 171 | return; |
| 172 | } |
| 173 | } |
| 174 | #endif |
| 175 | if (com == FIOCLEX) { |
| 176 | u.u_pofile[uap->fdes] |= EXCLOSE; |
| 177 | return; |
| 178 | } |
| 179 | if (com == FIONCLEX) { |
| 180 | u.u_pofile[uap->fdes] &= ~EXCLOSE; |
| 181 | return; |
| 182 | } |
| 183 | |
| 184 | /* |
| 185 | * Interpret high order word to find |
| 186 | * amount of data to be copied to/from the |
| 187 | * user's address space. |
| 188 | * (this'll have to change if we have in+out ioctls) |
| 189 | */ |
| 190 | size = (com &~ (IOC_INOUT|IOC_VOID)) >> 16; |
| 191 | if (size > sizeof (data)) { |
| 192 | u.u_error = EFAULT; |
| 193 | return; |
| 194 | } |
| 195 | if (com&IOC_IN && size) { |
| 196 | if (copyin(uap->cmarg, (caddr_t)data, size)) { |
| 197 | u.u_error = EFAULT; |
| 198 | return; |
| 199 | } |
| 200 | } else |
| 201 | *(caddr_t *)data = uap->cmarg; |
| 202 | /* |
| 203 | * Zero the buffer on the stack so the user |
| 204 | * always gets back something deterministic. |
| 205 | */ |
| 206 | if ((com&IOC_OUT) && size) |
| 207 | bzero((caddr_t)data, size); |
| 208 | |
| 209 | if (fp->f_type == DTYPE_SOCKET) |
| 210 | soioctl(fp->f_socket, com, data); |
| 211 | else { |
| 212 | register struct inode *ip = fp->f_inode; |
| 213 | int fmt = ip->i_mode & IFMT; |
| 214 | dev_t dev; |
| 215 | |
| 216 | if (fmt != IFCHR) { |
| 217 | if (com == FIONREAD && (fmt == IFREG || fmt == IFDIR)) { |
| 218 | *(off_t *)data = ip->i_size - fp->f_offset; |
| 219 | goto returndata; |
| 220 | } |
| 221 | if (com != FIONBIO && com != FIOASYNC) |
| 222 | u.u_error = ENOTTY; |
| 223 | return; |
| 224 | } |
| 225 | dev = ip->i_rdev; |
| 226 | u.u_r.r_val1 = 0; |
| 227 | if ((u.u_procp->p_flag&SNUSIG) && setjmp(u.u_qsav)) { |
| 228 | u.u_eosys = RESTARTSYS; |
| 229 | return; |
| 230 | } |
| 231 | (*cdevsw[major(dev)].d_ioctl)(dev, com, data, 0); |
| 232 | } |
| 233 | |
| 234 | returndata: |
| 235 | /* |
| 236 | * Copy any data to user, size was |
| 237 | * already set and checked above. |
| 238 | */ |
| 239 | if (u.u_error == 0 && com&IOC_OUT) |
| 240 | if (size && copyout(data, uap->cmarg, size)) |
| 241 | u.u_error = EFAULT; |
| 242 | } |
| 243 | |
| 244 | /* |
| 245 | * Do nothing specific version of line |
| 246 | * discipline specific ioctl command. |
| 247 | */ |
| 248 | /*ARGSUSED*/ |
| 249 | nullioctl(tp, cmd, data, flags) |
| 250 | struct tty *tp; |
| 251 | char *data; |
| 252 | int flags; |
| 253 | { |
| 254 | |
| 255 | #ifdef lint |
| 256 | tp = tp; data = data; flags = flags; |
| 257 | #endif |
| 258 | return (cmd); |
| 259 | } |
| 260 | |
| 261 | /* |
| 262 | * Write the file corresponding to |
| 263 | * the inode pointed at by the argument. |
| 264 | * The actual write arguments are found |
| 265 | * in the variables: |
| 266 | * u_base core address for source |
| 267 | * u_offset byte offset in file |
| 268 | * u_count number of bytes to write |
| 269 | * u_segflg write to kernel/user/user I |
| 270 | */ |
| 271 | writei(ip) |
| 272 | register struct inode *ip; |
| 273 | { |
| 274 | struct buf *bp; |
| 275 | register struct fs *fs; |
| 276 | dev_t dev; |
| 277 | daddr_t lbn, bn; |
| 278 | register int on, type; |
| 279 | register unsigned n; |
| 280 | long bsize; |
| 281 | int size, i, count; |
| 282 | extern int mem_no; |
| 283 | |
| 284 | dev = (dev_t)ip->i_rdev; |
| 285 | if (u.u_offset < 0 && ((ip->i_mode&IFMT) != IFCHR || |
| 286 | mem_no != major(dev)) ) { |
| 287 | u.u_error = EINVAL; |
| 288 | return; |
| 289 | } |
| 290 | type = ip->i_mode & IFMT; |
| 291 | if (type == IFCHR) { |
| 292 | ip->i_flag |= IUPD|ICHG; |
| 293 | CHARGE(sc_tio * u.u_count); |
| 294 | (*cdevsw[major(dev)].d_write)(dev); |
| 295 | return; |
| 296 | } |
| 297 | if (u.u_count == 0) |
| 298 | return; |
| 299 | if ((ip->i_mode & IFMT) == IFREG && |
| 300 | u.u_offset + u.u_count > u.u_limit[LIM_FSIZE]) { |
| 301 | psignal(u.u_procp, SIGXFSZ); |
| 302 | u.u_error = EMFILE; |
| 303 | return; |
| 304 | } |
| 305 | if (type!=IFBLK) { |
| 306 | dev = ip->i_dev; |
| 307 | fs = ip->i_fs; |
| 308 | bsize = fs->fs_bsize; |
| 309 | } else |
| 310 | bsize = BLKDEV_IOSIZE; |
| 311 | do { |
| 312 | lbn = u.u_offset / bsize; |
| 313 | on = u.u_offset % bsize; |
| 314 | n = MIN((unsigned)(bsize - on), u.u_count); |
| 315 | if (type != IFBLK) { |
| 316 | bn = fsbtodb(fs, bmap(ip, lbn, B_WRITE, (int)(on + n))); |
| 317 | if (u.u_error || (long)bn<0) |
| 318 | return; |
| 319 | if(u.u_offset + n > ip->i_size && |
| 320 | (type == IFDIR || type == IFREG || type == IFLNK)) |
| 321 | ip->i_size = u.u_offset + n; |
| 322 | size = blksize(fs, ip, lbn); |
| 323 | } else { |
| 324 | size = bsize; |
| 325 | bn = lbn * (BLKDEV_IOSIZE/DEV_BSIZE); |
| 326 | } |
| 327 | count = howmany(size, DEV_BSIZE); |
| 328 | for (i = 0; i < count; i += CLSIZE) |
| 329 | if (mfind(dev, bn + i)) |
| 330 | munhash(dev, bn + i); |
| 331 | if (n == bsize) |
| 332 | bp = getblk(dev, bn, size); |
| 333 | else |
| 334 | bp = bread(dev, bn, size); |
| 335 | if (u.u_segflg != 1) { |
| 336 | if (copyin(u.u_base, bp->b_un.b_addr + on, n)) { |
| 337 | u.u_error = EFAULT; |
| 338 | goto bad; |
| 339 | } |
| 340 | } else |
| 341 | bcopy(u.u_base, bp->b_un.b_addr + on, n); |
| 342 | u.u_base += n; |
| 343 | u.u_offset += n; |
| 344 | u.u_count -= n; |
| 345 | bad: |
| 346 | ; |
| 347 | if (u.u_error != 0) |
| 348 | brelse(bp); |
| 349 | else { |
| 350 | if ((ip->i_mode&IFMT) == IFDIR) |
| 351 | /* |
| 352 | * Writing to clear a directory entry. |
| 353 | * Must insure the write occurs before |
| 354 | * the inode is freed, or may end up |
| 355 | * pointing at a new (different) file |
| 356 | * if inode is quickly allocated again |
| 357 | * and system crashes. |
| 358 | */ |
| 359 | bwrite(bp); |
| 360 | else if (n + on == bsize) { |
| 361 | bp->b_flags |= B_AGE; |
| 362 | bawrite(bp); |
| 363 | } else |
| 364 | bdwrite(bp); |
| 365 | } |
| 366 | ip->i_flag |= IUPD|ICHG; |
| 367 | if (u.u_ruid != 0) |
| 368 | ip->i_mode &= ~(ISUID|ISGID); |
| 369 | } while (u.u_error == 0 && u.u_count != 0); |
| 370 | } |
| 371 | |
| 372 | /* |
| 373 | * Move n bytes at byte location |
| 374 | * &bp->b_un.b_addr[o] to/from (flag) the |
| 375 | * user/kernel (u.segflg) area starting at u.base. |
| 376 | * Update all the arguments by the number |
| 377 | * of bytes moved. |
| 378 | */ |
| 379 | iomove(cp, n, flag) |
| 380 | register caddr_t cp; |
| 381 | register unsigned n; |
| 382 | { |
| 383 | register int t; |
| 384 | |
| 385 | if (n==0) |
| 386 | return; |
| 387 | if (u.u_segflg != 1) { |
| 388 | if (flag==B_WRITE) |
| 389 | t = copyin(u.u_base, (caddr_t)cp, n); |
| 390 | else |
| 391 | t = copyout((caddr_t)cp, u.u_base, n); |
| 392 | if (t) { |
| 393 | u.u_error = EFAULT; |
| 394 | return; |
| 395 | } |
| 396 | } else |
| 397 | if (flag == B_WRITE) |
| 398 | bcopy(u.u_base, (caddr_t)cp, n); |
| 399 | else |
| 400 | bcopy((caddr_t)cp, u.u_base, n); |
| 401 | u.u_base += n; |
| 402 | u.u_offset += n; |
| 403 | u.u_count -= n; |
| 404 | } |
| 405 | |
| 406 | readip1(ip, base, len, offset, segflg, aresid) |
| 407 | struct inode *ip; |
| 408 | caddr_t base; |
| 409 | int len, offset, segflg; |
| 410 | int *aresid; |
| 411 | { |
| 412 | struct uio auio; |
| 413 | struct iovec aiov; |
| 414 | int error; |
| 415 | |
| 416 | auio.uio_iov = &aiov; |
| 417 | auio.uio_iovcnt = 1; |
| 418 | aiov.iov_base = base; |
| 419 | aiov.iov_len = len; |
| 420 | auio.uio_resid = len; |
| 421 | auio.uio_offset = offset; |
| 422 | auio.uio_segflg = segflg; |
| 423 | error = readip(ip, &auio); |
| 424 | if (aresid) |
| 425 | *aresid = auio.uio_resid; |
| 426 | else |
| 427 | if (auio.uio_resid) |
| 428 | error = EIO; |
| 429 | return (error); |
| 430 | } |
| 431 | |
| 432 | readip(ip, uio) |
| 433 | register struct inode *ip; |
| 434 | register struct uio *uio; |
| 435 | { |
| 436 | register struct iovec *iov; |
| 437 | struct buf *bp; |
| 438 | struct fs *fs; |
| 439 | dev_t dev; |
| 440 | daddr_t lbn, bn; |
| 441 | off_t diff; |
| 442 | register int on, type; |
| 443 | register unsigned n; |
| 444 | int size; |
| 445 | long bsize; |
| 446 | extern int mem_no; |
| 447 | int error = 0; |
| 448 | |
| 449 | dev = (dev_t)ip->i_rdev; |
| 450 | if (uio->uio_offset < 0 && |
| 451 | ((ip->i_mode&IFMT) != IFCHR || mem_no != major(dev))) |
| 452 | return (EINVAL); |
| 453 | ip->i_flag |= IACC; |
| 454 | type = ip->i_mode&IFMT; |
| 455 | if (type == IFCHR) { |
| 456 | register c = u.u_count; |
| 457 | (*cdevsw[major(dev)].d_read)(dev, uio); |
| 458 | CHARGE(sc_tio * (c - uio->uio_resid)); |
| 459 | return (u.u_error); |
| 460 | } |
| 461 | if (type != IFBLK) { |
| 462 | dev = ip->i_dev; |
| 463 | fs = ip->i_fs; |
| 464 | bsize = fs->fs_bsize; |
| 465 | } else |
| 466 | bsize = BLKDEV_IOSIZE; |
| 467 | nextiov: |
| 468 | if (uio->uio_iovcnt == 0) |
| 469 | return (0); |
| 470 | iov = uio->uio_iov; |
| 471 | if (iov->iov_len > 0) |
| 472 | do { |
| 473 | lbn = uio->uio_offset / bsize; |
| 474 | on = uio->uio_offset % bsize; |
| 475 | n = MIN((unsigned)(bsize - on), iov->iov_len); |
| 476 | if (type != IFBLK) { |
| 477 | diff = ip->i_size - uio->uio_offset; |
| 478 | if (diff <= 0) |
| 479 | return; |
| 480 | if (diff < n) |
| 481 | n = diff; |
| 482 | bn = fsbtodb(fs, bmap(ip, lbn, B_READ)); |
| 483 | if (u.u_error) |
| 484 | return (u.u_error); |
| 485 | size = blksize(fs, ip, lbn); |
| 486 | } else { |
| 487 | size = bsize; |
| 488 | bn = lbn * (BLKDEV_IOSIZE/DEV_BSIZE); |
| 489 | rablock = bn + (BLKDEV_IOSIZE/DEV_BSIZE); |
| 490 | rasize = bsize; |
| 491 | } |
| 492 | if ((long)bn<0) { |
| 493 | bp = geteblk(size); |
| 494 | clrbuf(bp); |
| 495 | } else if (ip->i_lastr + 1 == lbn) |
| 496 | bp = breada(dev, bn, size, rablock, rasize); |
| 497 | else |
| 498 | bp = bread(dev, bn, size); |
| 499 | ip->i_lastr = lbn; |
| 500 | n = MIN(n, size - bp->b_resid); |
| 501 | if (n != 0) { |
| 502 | if (uio->uio_segflg != 1) { |
| 503 | if (copyout(bp->b_un.b_addr+on, iov->iov_base, n)) { |
| 504 | brelse(bp); |
| 505 | return (EFAULT); |
| 506 | } |
| 507 | } else |
| 508 | bcopy(bp->b_un.b_addr + on, iov->iov_base, n); |
| 509 | iov->iov_base += n; |
| 510 | uio->uio_offset += n; |
| 511 | iov->iov_len -= n; |
| 512 | uio->uio_resid -= n; |
| 513 | } |
| 514 | if (n + on == bsize || uio->uio_offset == ip->i_size) |
| 515 | bp->b_flags |= B_AGE; |
| 516 | brelse(bp); |
| 517 | } while (u.u_error == 0 && iov->iov_len != 0 && n != 0); |
| 518 | if (u.u_error == 0 && iov->iov_len == 0) { |
| 519 | uio->uio_iov++; |
| 520 | uio->uio_iovcnt--; |
| 521 | goto nextiov; |
| 522 | } |
| 523 | return (error); |
| 524 | } |
| 525 | |
| 526 | uiomove(cp, n, dir, uio) |
| 527 | register caddr_t cp; |
| 528 | register unsigned n; |
| 529 | enum uio_direction dir; |
| 530 | struct uio *uio; |
| 531 | { |
| 532 | register struct iovec *iov; |
| 533 | int bad, cnt; |
| 534 | |
| 535 | if (n == 0) |
| 536 | return (0); |
| 537 | if (uio->uio_segflg != 1) { |
| 538 | if (dir == UIO_READFROM) |
| 539 | #ifdef notdef |
| 540 | bad = copyuin(uio, (caddr_t)cp, n); |
| 541 | #else |
| 542 | panic("uiomove"); |
| 543 | #endif |
| 544 | else |
| 545 | bad = copyuout((caddr_t)cp, n, uio); |
| 546 | if (bad) |
| 547 | return (EFAULT); |
| 548 | } else { |
| 549 | while (n > 0 && uio->uio_iovcnt) { |
| 550 | iov = uio->uio_iov; |
| 551 | cnt = iov->iov_len; |
| 552 | if (cnt > n) |
| 553 | cnt = n; |
| 554 | if (dir == UIO_READFROM) |
| 555 | bcopy(iov->iov_base, (caddr_t)cp, cnt); |
| 556 | else |
| 557 | bcopy((caddr_t)cp, iov->iov_base, cnt); |
| 558 | iov->iov_base += cnt; |
| 559 | iov->iov_len -= cnt; |
| 560 | uio->uio_resid -= cnt; |
| 561 | n -= cnt; |
| 562 | } |
| 563 | } |
| 564 | return (0); |
| 565 | } |