1 /* sys_generic.c 5.7 82/08/11 */ 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 41 uap = (struct a *)u.u_ap; 42 if ((int)uap->count < 0) { 43 u.u_error = EINVAL; 44 return; 45 } 46 GETF(fp, uap->fdes); 47 if ((fp->f_flag&FREAD) == 0) { 48 u.u_error = EBADF; 49 return; 50 } 51 u.u_base = (caddr_t)uap->cbuf; 52 u.u_count = uap->count; 53 u.u_segflg = 0; 54 if ((u.u_procp->p_flag&SNUSIG) && setjmp(u.u_qsav)) { 55 if (u.u_count == uap->count) 56 u.u_eosys = RESTARTSYS; 57 } else if (fp->f_type == DTYPE_SOCKET) 58 u.u_error = soreceive(fp->f_socket, (struct sockaddr *)0); 59 else { 60 ip = fp->f_inode; 61 u.u_offset = fp->f_offset; 62 if ((ip->i_mode&IFMT) == IFREG) { 63 ilock(ip); 64 readi(ip); 65 iunlock(ip); 66 } else 67 readi(ip); 68 fp->f_offset += uap->count - u.u_count; 69 } 70 u.u_r.r_val1 = uap->count - u.u_count; 71 } 72 73 /* 74 * Write system call 75 */ 76 write() 77 { 78 register struct file *fp; 79 register struct inode *ip; 80 register struct a { 81 int fdes; 82 char *cbuf; 83 unsigned count; 84 } *uap; 85 86 uap = (struct a *)u.u_ap; 87 if ((int)uap->count < 0) { 88 u.u_error = EINVAL; 89 return; 90 } 91 GETF(fp, uap->fdes); 92 if ((fp->f_flag&FWRITE) == 0) { 93 u.u_error = EBADF; 94 return; 95 } 96 u.u_base = (caddr_t)uap->cbuf; 97 u.u_count = uap->count; 98 u.u_segflg = 0; 99 if ((u.u_procp->p_flag&SNUSIG) && setjmp(u.u_qsav)) { 100 if (u.u_count == uap->count) 101 u.u_eosys = RESTARTSYS; 102 } else if (fp->f_type == DTYPE_SOCKET) 103 u.u_error = sosend(fp->f_socket, (struct sockaddr *)0); 104 else { 105 ip = fp->f_inode; 106 if (fp->f_flag&FAPPEND) 107 fp->f_offset = ip->i_size; 108 u.u_offset = fp->f_offset; 109 if ((ip->i_mode&IFMT) == IFREG) { 110 ilock(ip); 111 writei(ip); 112 iunlock(ip); 113 } else 114 writei(ip); 115 fp->f_offset += uap->count - u.u_count; 116 } 117 u.u_r.r_val1 = uap->count - u.u_count; 118 } 119 120 readv() 121 { 122 123 } 124 125 writev() 126 { 127 128 } 129 130 /* 131 * Ioctl system call 132 * Check legality, execute common code, 133 * and switch out to individual device routine. 134 */ 135 ioctl() 136 { 137 register struct file *fp; 138 struct a { 139 int fdes; 140 int cmd; 141 caddr_t cmarg; 142 } *uap; 143 register int com, size; 144 char data[IOCPARM_MASK+1]; 145 146 uap = (struct a *)u.u_ap; 147 if ((fp = getf(uap->fdes)) == NULL) 148 return; 149 if ((fp->f_flag & (FREAD|FWRITE)) == 0) { 150 u.u_error = EBADF; 151 return; 152 } 153 com = uap->cmd; 154 155 #ifndef NOCOMPAT 156 /* 157 * Map old style ioctl's into new for the 158 * sake of backwards compatibility (sigh). 159 */ 160 if ((com&~0xffff) == 0) { 161 com = mapioctl(com); 162 if (com == 0) { 163 u.u_error = EINVAL; 164 return; 165 } 166 } 167 #endif 168 if (com == FIOCLEX) { 169 u.u_pofile[uap->fdes] |= EXCLOSE; 170 return; 171 } 172 if (com == FIONCLEX) { 173 u.u_pofile[uap->fdes] &= ~EXCLOSE; 174 return; 175 } 176 177 /* 178 * Interpret high order word to find 179 * amount of data to be copied to/from the 180 * user's address space. 181 * (this'll have to change if we have in+out ioctls) 182 */ 183 size = (com &~ (IOC_INOUT|IOC_VOID)) >> 16; 184 if (size > sizeof (data)) { 185 u.u_error = EFAULT; 186 return; 187 } 188 if (com&IOC_IN && size) { 189 if (copyin(uap->cmarg, (caddr_t)data, size)) { 190 u.u_error = EFAULT; 191 return; 192 } 193 } else 194 *(caddr_t *)data = uap->cmarg; 195 /* 196 * Zero the buffer on the stack so the user 197 * always gets back something deterministic. 198 */ 199 if ((com&IOC_OUT) && size) 200 bzero((caddr_t)data, size); 201 202 if (fp->f_type == DTYPE_SOCKET) 203 soioctl(fp->f_socket, com, data); 204 else { 205 register struct inode *ip = fp->f_inode; 206 int fmt = ip->i_mode & IFMT; 207 dev_t dev; 208 209 if (fmt != IFCHR) { 210 if (com == FIONREAD && (fmt == IFREG || fmt == IFDIR)) { 211 *(off_t *)data = ip->i_size - fp->f_offset; 212 goto returndata; 213 } 214 if (com != FIONBIO && com != FIOASYNC) 215 u.u_error = ENOTTY; 216 return; 217 } 218 dev = ip->i_rdev; 219 u.u_r.r_val1 = 0; 220 if ((u.u_procp->p_flag&SNUSIG) && setjmp(u.u_qsav)) { 221 u.u_eosys = RESTARTSYS; 222 return; 223 } 224 (*cdevsw[major(dev)].d_ioctl)(dev, com, data, 0); 225 } 226 227 returndata: 228 /* 229 * Copy any data to user, size was 230 * already set and checked above. 231 */ 232 if (u.u_error == 0 && com&IOC_OUT) 233 if (size && copyout(data, uap->cmarg, size)) 234 u.u_error = EFAULT; 235 } 236 237 /* 238 * Do nothing specific version of line 239 * discipline specific ioctl command. 240 */ 241 /*ARGSUSED*/ 242 nullioctl(tp, cmd, data, flags) 243 struct tty *tp; 244 char *data; 245 int flags; 246 { 247 248 #ifdef lint 249 tp = tp; data = data; flags = flags; 250 #endif 251 return (cmd); 252 } 253 254 /* 255 * Read the file corresponding to 256 * the inode pointed at by the argument. 257 * The actual read arguments are found 258 * in the variables: 259 * u_base core address for destination 260 * u_offset byte offset in file 261 * u_count number of bytes to read 262 * u_segflg read to kernel/user/user I 263 */ 264 readi(ip) 265 register struct inode *ip; 266 { 267 struct buf *bp; 268 struct fs *fs; 269 dev_t dev; 270 daddr_t lbn, bn; 271 off_t diff; 272 register int on, type; 273 register unsigned n; 274 int size; 275 long bsize; 276 extern int mem_no; 277 278 if (u.u_count == 0) 279 return; 280 dev = (dev_t)ip->i_rdev; 281 if (u.u_offset < 0 && ((ip->i_mode&IFMT) != IFCHR || 282 mem_no != major(dev))) { 283 u.u_error = EINVAL; 284 return; 285 } 286 ip->i_flag |= IACC; 287 type = ip->i_mode&IFMT; 288 if (type == IFCHR) { 289 register c = u.u_count; 290 (*cdevsw[major(dev)].d_read)(dev); 291 CHARGE(sc_tio * (c - u.u_count)); 292 return; 293 } 294 if (type != IFBLK) { 295 dev = ip->i_dev; 296 fs = ip->i_fs; 297 bsize = fs->fs_bsize; 298 } else 299 bsize = BLKDEV_IOSIZE; 300 do { 301 lbn = u.u_offset / bsize; 302 on = u.u_offset % bsize; 303 n = MIN((unsigned)(bsize - on), u.u_count); 304 if (type != IFBLK) { 305 diff = ip->i_size - u.u_offset; 306 if (diff <= 0) 307 return; 308 if (diff < n) 309 n = diff; 310 bn = fsbtodb(fs, bmap(ip, lbn, B_READ)); 311 if (u.u_error) 312 return; 313 size = blksize(fs, ip, lbn); 314 } else { 315 size = bsize; 316 bn = lbn * (BLKDEV_IOSIZE/DEV_BSIZE); 317 rablock = bn + (BLKDEV_IOSIZE/DEV_BSIZE); 318 rasize = bsize; 319 } 320 if ((long)bn<0) { 321 bp = geteblk(size); 322 clrbuf(bp); 323 } else if (ip->i_lastr + 1 == lbn) 324 bp = breada(dev, bn, size, rablock, rasize); 325 else 326 bp = bread(dev, bn, size); 327 ip->i_lastr = lbn; 328 n = MIN(n, size - bp->b_resid); 329 if (n != 0) { 330 if (u.u_segflg != 1) { 331 if (copyout(bp->b_un.b_addr+on, u.u_base, n)) { 332 u.u_error = EFAULT; 333 goto bad; 334 } 335 } else 336 bcopy(bp->b_un.b_addr + on, u.u_base, n); 337 u.u_base += n; 338 u.u_offset += n; 339 u.u_count -= n; 340 bad: 341 ; 342 } 343 if (n + on == bsize || u.u_offset == ip->i_size) 344 bp->b_flags |= B_AGE; 345 brelse(bp); 346 } while (u.u_error == 0 && u.u_count != 0 && n != 0); 347 } 348 349 /* 350 * Write the file corresponding to 351 * the inode pointed at by the argument. 352 * The actual write arguments are found 353 * in the variables: 354 * u_base core address for source 355 * u_offset byte offset in file 356 * u_count number of bytes to write 357 * u_segflg write to kernel/user/user I 358 */ 359 writei(ip) 360 register struct inode *ip; 361 { 362 struct buf *bp; 363 register struct fs *fs; 364 dev_t dev; 365 daddr_t lbn, bn; 366 register int on, type; 367 register unsigned n; 368 long bsize; 369 int size, i, count; 370 extern int mem_no; 371 372 dev = (dev_t)ip->i_rdev; 373 if (u.u_offset < 0 && ((ip->i_mode&IFMT) != IFCHR || 374 mem_no != major(dev)) ) { 375 u.u_error = EINVAL; 376 return; 377 } 378 type = ip->i_mode & IFMT; 379 if (type == IFCHR) { 380 ip->i_flag |= IUPD|ICHG; 381 CHARGE(sc_tio * u.u_count); 382 (*cdevsw[major(dev)].d_write)(dev); 383 return; 384 } 385 if (u.u_count == 0) 386 return; 387 if ((ip->i_mode & IFMT) == IFREG && 388 u.u_offset + u.u_count > u.u_limit[LIM_FSIZE]) { 389 psignal(u.u_procp, SIGXFSZ); 390 u.u_error = EMFILE; 391 return; 392 } 393 if (type!=IFBLK) { 394 dev = ip->i_dev; 395 fs = ip->i_fs; 396 bsize = fs->fs_bsize; 397 } else 398 bsize = BLKDEV_IOSIZE; 399 do { 400 lbn = u.u_offset / bsize; 401 on = u.u_offset % bsize; 402 n = MIN((unsigned)(bsize - on), u.u_count); 403 if (type != IFBLK) { 404 bn = fsbtodb(fs, bmap(ip, lbn, B_WRITE, (int)(on + n))); 405 if (u.u_error || (long)bn<0) 406 return; 407 if(u.u_offset + n > ip->i_size && 408 (type == IFDIR || type == IFREG || type == IFLNK)) 409 ip->i_size = u.u_offset + n; 410 size = blksize(fs, ip, lbn); 411 } else { 412 size = bsize; 413 bn = lbn * (BLKDEV_IOSIZE/DEV_BSIZE); 414 } 415 count = howmany(size, DEV_BSIZE); 416 for (i = 0; i < count; i += CLSIZE) 417 if (mfind(dev, bn + i)) 418 munhash(dev, bn + i); 419 if (n == bsize) 420 bp = getblk(dev, bn, size); 421 else 422 bp = bread(dev, bn, size); 423 if (u.u_segflg != 1) { 424 if (copyin(u.u_base, bp->b_un.b_addr + on, n)) { 425 u.u_error = EFAULT; 426 goto bad; 427 } 428 } else 429 bcopy(u.u_base, bp->b_un.b_addr + on, n); 430 u.u_base += n; 431 u.u_offset += n; 432 u.u_count -= n; 433 bad: 434 ; 435 if (u.u_error != 0) 436 brelse(bp); 437 else { 438 if ((ip->i_mode&IFMT) == IFDIR) 439 /* 440 * Writing to clear a directory entry. 441 * Must insure the write occurs before 442 * the inode is freed, or may end up 443 * pointing at a new (different) file 444 * if inode is quickly allocated again 445 * and system crashes. 446 */ 447 bwrite(bp); 448 else if (n + on == bsize) { 449 bp->b_flags |= B_AGE; 450 bawrite(bp); 451 } else 452 bdwrite(bp); 453 } 454 ip->i_flag |= IUPD|ICHG; 455 if (u.u_ruid != 0) 456 ip->i_mode &= ~(ISUID|ISGID); 457 } while (u.u_error == 0 && u.u_count != 0); 458 } 459 460 /* 461 * Move n bytes at byte location 462 * &bp->b_un.b_addr[o] to/from (flag) the 463 * user/kernel (u.segflg) area starting at u.base. 464 * Update all the arguments by the number 465 * of bytes moved. 466 */ 467 iomove(cp, n, flag) 468 register caddr_t cp; 469 register unsigned n; 470 { 471 register int t; 472 473 if (n==0) 474 return; 475 if (u.u_segflg != 1) { 476 if (flag==B_WRITE) 477 t = copyin(u.u_base, (caddr_t)cp, n); 478 else 479 t = copyout((caddr_t)cp, u.u_base, n); 480 if (t) { 481 u.u_error = EFAULT; 482 return; 483 } 484 } else 485 if (flag == B_WRITE) 486 bcopy(u.u_base, (caddr_t)cp, n); 487 else 488 bcopy((caddr_t)cp, u.u_base, n); 489 u.u_base += n; 490 u.u_offset += n; 491 u.u_count -= n; 492 } 493 494 readip(ip, uio) 495 register struct inode *ip; 496 register struct uio *uio; 497 { 498 register struct iovec *iov = uio->uio_iov; 499 struct buf *bp; 500 struct fs *fs; 501 dev_t dev; 502 daddr_t lbn, bn; 503 off_t diff; 504 register int on, type; 505 register unsigned n; 506 int size; 507 long bsize; 508 extern int mem_no; 509 int error = 0; 510 511 uio->uio_resid = 0; 512 if (uio->uio_iovcnt == 0) 513 return (0); 514 dev = (dev_t)ip->i_rdev; 515 if (uio->uio_offset < 0 && 516 ((ip->i_mode&IFMT) != IFCHR || mem_no != major(dev))) { 517 error = EINVAL; 518 goto bad; 519 } 520 ip->i_flag |= IACC; 521 type = ip->i_mode&IFMT; 522 if (type == IFCHR) { 523 register c = u.u_count; 524 error = (*cdevsw[major(dev)].d_read)(dev, uio); 525 CHARGE(sc_tio * (c - u.u_count)); 526 return (error); 527 } 528 if (type != IFBLK) { 529 dev = ip->i_dev; 530 fs = ip->i_fs; 531 bsize = fs->fs_bsize; 532 } else 533 bsize = BLKDEV_IOSIZE; 534 nextiov: 535 if (uio->uio_iovcnt == 0) 536 goto getresid; 537 if (iov->iov_len > 0) 538 do { 539 lbn = uio->uio_offset / bsize; 540 on = uio->uio_offset % bsize; 541 n = MIN((unsigned)(bsize - on), iov->iov_len); 542 if (type != IFBLK) { 543 diff = ip->i_size - uio->uio_offset; 544 if (diff <= 0) 545 return; 546 if (diff < n) 547 n = diff; 548 bn = fsbtodb(fs, bmap(ip, lbn, B_READ)); 549 if (u.u_error) 550 goto getresid; 551 size = blksize(fs, ip, lbn); 552 } else { 553 size = bsize; 554 bn = lbn * (BLKDEV_IOSIZE/DEV_BSIZE); 555 rablock = bn + (BLKDEV_IOSIZE/DEV_BSIZE); 556 rasize = bsize; 557 } 558 if ((long)bn<0) { 559 bp = geteblk(size); 560 clrbuf(bp); 561 } else if (ip->i_lastr + 1 == lbn) 562 bp = breada(dev, bn, size, rablock, rasize); 563 else 564 bp = bread(dev, bn, size); 565 ip->i_lastr = lbn; 566 n = MIN(n, size - bp->b_resid); 567 if (n != 0) { 568 if (uio->uio_segflg != 1) { 569 if (copyout(bp->b_un.b_addr+on, iov->iov_base, n)) { 570 error = EFAULT; 571 goto getresid; 572 } 573 } else 574 bcopy(bp->b_un.b_addr + on, iov->iov_base, n); 575 iov->iov_base += n; 576 uio->uio_offset += n; 577 iov->iov_len -= n; 578 bad: 579 ; 580 } 581 if (n + on == bsize || uio->uio_offset == ip->i_size) 582 bp->b_flags |= B_AGE; 583 brelse(bp); 584 } while (u.u_error == 0 && iov->iov_len != 0 && n != 0); 585 if (u.u_error == 0 && n > 0) { 586 iov++; 587 uio->uio_iovcnt--; 588 goto nextiov; 589 } 590 getresid: 591 while (uio->uio_iovcnt > 0) { 592 uio->uio_resid += iov->iov_len; 593 iov++; 594 uio->uio_iovcnt--; 595 } 596 return (error); 597 } 598