1 /* 2 * Copyright (c) 1995 Ugen J.S.Antsilevich 3 * 4 * Redistribution and use in source forms, with and without modification, 5 * are permitted provided that this entire comment appears intact. 6 * 7 * Redistribution in binary form may occur without any restrictions. 8 * Obviously, it would be nice if you gave credit where credit is due 9 * but requiring it would be too onerous. 10 * 11 * This software is provided ``AS IS'' without any warranties of any kind. 12 * 13 * Snoop stuff. 14 * 15 * $FreeBSD$ 16 */ 17 18 #include <sys/param.h> 19 #include <sys/systm.h> 20 #include <sys/filio.h> 21 #if defined(COMPAT_43) || defined(COMPAT_SUNOS) 22 #include <sys/ioctl_compat.h> 23 #endif 24 #include <sys/malloc.h> 25 #include <sys/tty.h> 26 #include <sys/conf.h> 27 #include <sys/poll.h> 28 #include <sys/kernel.h> 29 #include <sys/snoop.h> 30 #include <sys/vnode.h> 31 #include <sys/conf.h> 32 33 static d_open_t snpopen; 34 static d_close_t snpclose; 35 static d_read_t snpread; 36 static d_write_t snpwrite; 37 static d_ioctl_t snpioctl; 38 static d_poll_t snppoll; 39 40 #define CDEV_MAJOR 53 41 static struct cdevsw snp_cdevsw = { 42 /* open */ snpopen, 43 /* close */ snpclose, 44 /* read */ snpread, 45 /* write */ snpwrite, 46 /* ioctl */ snpioctl, 47 /* poll */ snppoll, 48 /* mmap */ nommap, 49 /* strategy */ nostrategy, 50 /* name */ "snp", 51 /* maj */ CDEV_MAJOR, 52 /* dump */ nodump, 53 /* psize */ nopsize, 54 /* flags */ 0, 55 }; 56 57 58 #ifndef MIN 59 #define MIN(a,b) (((a)<(b))?(a):(b)) 60 #endif 61 62 static MALLOC_DEFINE(M_SNP, "snp", "Snoop device data"); 63 64 #define ttytosnp(t) (struct snoop *)(t)->t_sc 65 static struct tty *snpdevtotty __P((dev_t dev)); 66 static int snp_detach __P((struct snoop *snp)); 67 68 /* 69 * The number of the "snoop" line discipline. This gets determined at 70 * module load time. 71 */ 72 static int mylinedisc; 73 74 static int 75 dsnwrite(struct tty *tp, struct uio *uio, int flag) 76 { 77 struct snoop *snp = ttytosnp(tp); 78 int error = 0; 79 char ibuf[1024]; 80 int ilen; 81 struct iovec iov; 82 struct uio uio2; 83 84 while (uio->uio_resid) { 85 ilen = MIN(sizeof(ibuf), uio->uio_resid); 86 error = uiomove(ibuf, ilen, uio); 87 if (error) 88 break; 89 snpin(snp, ibuf, ilen); 90 /* Hackish, but I think it's the least of all evils. */ 91 iov.iov_base = ibuf; 92 iov.iov_len = ilen; 93 uio2.uio_iov = &iov; 94 uio2.uio_iovcnt = 1; 95 uio2.uio_offset = 0; 96 uio2.uio_resid = ilen; 97 uio2.uio_segflg = UIO_SYSSPACE; 98 uio2.uio_rw = UIO_WRITE; 99 uio2.uio_procp = uio->uio_procp; 100 error = ttwrite(tp, &uio2, flag); 101 if (error) 102 break; 103 } 104 return (error); 105 } 106 107 /* 108 * XXX should there be a global version of this? 109 */ 110 static int 111 l_nullioctl(struct tty *tp, u_long cmd, char *data, int flags, struct proc *p) 112 { 113 114 return (ENOIOCTL); 115 } 116 117 static struct linesw snpdisc = { 118 ttyopen, ttylclose, ttread, dsnwrite, 119 l_nullioctl, ttyinput, ttstart, ttymodem }; 120 121 static struct tty * 122 snpdevtotty (dev) 123 dev_t dev; 124 { 125 struct cdevsw *cdp; 126 127 cdp = devsw(dev); 128 if (cdp && cdp->d_flags & D_TTY) 129 return (dev->si_tty); 130 return (NULL); 131 } 132 133 #define SNP_INPUT_BUF 5 /* This is even too much, the maximal 134 * interactive mode write is 3 bytes 135 * length for function keys... 136 */ 137 138 static int 139 snpwrite(dev, uio, flag) 140 dev_t dev; 141 struct uio *uio; 142 int flag; 143 { 144 int len, i, error; 145 struct snoop *snp = dev->si_drv1; 146 struct tty *tp; 147 char c[SNP_INPUT_BUF]; 148 149 if (snp->snp_tty == NULL) 150 return (EIO); 151 152 tp = snp->snp_tty; 153 154 if ((tp->t_sc == snp) && (tp->t_state & TS_SNOOP) && 155 tp->t_line == mylinedisc) 156 goto tty_input; 157 158 printf("Snoop: attempt to write to bad tty.\n"); 159 return (EIO); 160 161 tty_input: 162 if (!(tp->t_state & TS_ISOPEN)) 163 return (EIO); 164 165 while (uio->uio_resid > 0) { 166 len = MIN(uio->uio_resid, SNP_INPUT_BUF); 167 if ((error = uiomove(c, len, uio)) != 0) 168 return (error); 169 for (i=0; i < len; i++) { 170 if (ttyinput(c[i], tp)) 171 return (EIO); 172 } 173 } 174 return 0; 175 176 } 177 178 179 static int 180 snpread(dev, uio, flag) 181 dev_t dev; 182 struct uio *uio; 183 int flag; 184 { 185 struct snoop *snp = dev->si_drv1; 186 int len, n, nblen, s, error = 0; 187 caddr_t from; 188 char *nbuf; 189 190 KASSERT(snp->snp_len + snp->snp_base <= snp->snp_blen, 191 ("snoop buffer error")); 192 193 if (snp->snp_tty == NULL) 194 return (EIO); 195 196 snp->snp_flags &= ~SNOOP_RWAIT; 197 198 do { 199 if (snp->snp_len == 0) { 200 if (flag & IO_NDELAY) 201 return (EWOULDBLOCK); 202 snp->snp_flags |= SNOOP_RWAIT; 203 tsleep((caddr_t)snp, (PZERO + 1) | PCATCH, "snprd", 0); 204 } 205 } while (snp->snp_len == 0); 206 207 n = snp->snp_len; 208 209 while (snp->snp_len > 0 && uio->uio_resid > 0 && error == 0) { 210 len = MIN(uio->uio_resid, snp->snp_len); 211 from = (caddr_t)(snp->snp_buf + snp->snp_base); 212 if (len == 0) 213 break; 214 215 error = uiomove(from, len, uio); 216 snp->snp_base += len; 217 snp->snp_len -= len; 218 } 219 if ((snp->snp_flags & SNOOP_OFLOW) && (n < snp->snp_len)) { 220 snp->snp_flags &= ~SNOOP_OFLOW; 221 } 222 s = spltty(); 223 nblen = snp->snp_blen; 224 if (((nblen / 2) >= SNOOP_MINLEN) && (nblen / 2) >= snp->snp_len) { 225 while (((nblen / 2) >= snp->snp_len) && ((nblen / 2) >= SNOOP_MINLEN)) 226 nblen = nblen / 2; 227 if ((nbuf = malloc(nblen, M_SNP, M_NOWAIT)) != NULL) { 228 bcopy(snp->snp_buf + snp->snp_base, nbuf, snp->snp_len); 229 free(snp->snp_buf, M_SNP); 230 snp->snp_buf = nbuf; 231 snp->snp_blen = nblen; 232 snp->snp_base = 0; 233 } 234 } 235 splx(s); 236 237 return error; 238 } 239 240 int 241 snpinc(struct snoop *snp, char c) 242 { 243 char buf; 244 245 buf = c; 246 return (snpin(snp, &buf, 1)); 247 } 248 249 250 int 251 snpin(snp, buf, n) 252 struct snoop *snp; 253 char *buf; 254 int n; 255 { 256 int s_free, s_tail; 257 int s, len, nblen; 258 caddr_t from, to; 259 char *nbuf; 260 261 KASSERT(n >= 0, ("negative snoop char count")); 262 263 if (n == 0) 264 return 0; 265 266 if (snp->snp_flags & SNOOP_DOWN) { 267 printf("Snoop: more data to down interface.\n"); 268 return 0; 269 } 270 271 if (snp->snp_flags & SNOOP_OFLOW) { 272 printf("Snoop: buffer overflow.\n"); 273 /* 274 * On overflow we just repeat the standart close 275 * procedure...yes , this is waste of space but.. Then next 276 * read from device will fail if one would recall he is 277 * snooping and retry... 278 */ 279 280 return (snpdown(snp)); 281 } 282 s_tail = snp->snp_blen - (snp->snp_len + snp->snp_base); 283 s_free = snp->snp_blen - snp->snp_len; 284 285 286 if (n > s_free) { 287 s = spltty(); 288 nblen = snp->snp_blen; 289 while ((n > s_free) && ((nblen * 2) <= SNOOP_MAXLEN)) { 290 nblen = snp->snp_blen * 2; 291 s_free = nblen - (snp->snp_len + snp->snp_base); 292 } 293 if ((n <= s_free) && (nbuf = malloc(nblen, M_SNP, M_NOWAIT))) { 294 bcopy(snp->snp_buf + snp->snp_base, nbuf, snp->snp_len); 295 free(snp->snp_buf, M_SNP); 296 snp->snp_buf = nbuf; 297 snp->snp_blen = nblen; 298 snp->snp_base = 0; 299 } else { 300 snp->snp_flags |= SNOOP_OFLOW; 301 if (snp->snp_flags & SNOOP_RWAIT) { 302 snp->snp_flags &= ~SNOOP_RWAIT; 303 wakeup((caddr_t)snp); 304 } 305 splx(s); 306 return 0; 307 } 308 splx(s); 309 } 310 if (n > s_tail) { 311 from = (caddr_t)(snp->snp_buf + snp->snp_base); 312 to = (caddr_t)(snp->snp_buf); 313 len = snp->snp_len; 314 bcopy(from, to, len); 315 snp->snp_base = 0; 316 } 317 to = (caddr_t)(snp->snp_buf + snp->snp_base + snp->snp_len); 318 bcopy(buf, to, n); 319 snp->snp_len += n; 320 321 if (snp->snp_flags & SNOOP_RWAIT) { 322 snp->snp_flags &= ~SNOOP_RWAIT; 323 wakeup((caddr_t)snp); 324 } 325 selwakeup(&snp->snp_sel); 326 snp->snp_sel.si_pid = 0; 327 328 return n; 329 } 330 331 static int 332 snpopen(dev, flag, mode, p) 333 dev_t dev; 334 int flag, mode; 335 struct proc *p; 336 { 337 struct snoop *snp; 338 int error; 339 340 if ((error = suser(p)) != 0) 341 return (error); 342 343 if (dev->si_drv1 == NULL) { 344 if (!(dev->si_flags & SI_NAMED)) 345 make_dev(&snp_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 346 0600, "snp%d", dev2unit(dev)); 347 dev->si_drv1 = snp = malloc(sizeof(*snp), M_SNP, M_WAITOK|M_ZERO); 348 } else 349 return (EBUSY); 350 351 /* 352 * We intentionally do not OR flags with SNOOP_OPEN, but set them so 353 * all previous settings (especially SNOOP_OFLOW) will be cleared. 354 */ 355 snp->snp_flags = SNOOP_OPEN; 356 357 snp->snp_buf = malloc(SNOOP_MINLEN, M_SNP, M_WAITOK); 358 snp->snp_blen = SNOOP_MINLEN; 359 snp->snp_base = 0; 360 snp->snp_len = 0; 361 362 /* 363 * snp_tty == NULL is for inactive snoop devices. 364 */ 365 snp->snp_tty = NULL; 366 snp->snp_target = NODEV; 367 return (0); 368 } 369 370 371 static int 372 snp_detach(snp) 373 struct snoop *snp; 374 { 375 struct tty *tp; 376 377 snp->snp_base = 0; 378 snp->snp_len = 0; 379 380 /* 381 * If line disc. changed we do not touch this pointer, SLIP/PPP will 382 * change it anyway. 383 */ 384 385 if (snp->snp_tty == NULL) 386 goto detach_notty; 387 388 tp = snp->snp_tty; 389 390 if (tp && (tp->t_sc == snp) && (tp->t_state & TS_SNOOP) && 391 tp->t_line == mylinedisc) { 392 tp->t_sc = NULL; 393 tp->t_state &= ~TS_SNOOP; 394 tp->t_line = snp->snp_olddisc; 395 } else 396 printf("Snoop: bad attached tty data.\n"); 397 398 snp->snp_tty = NULL; 399 snp->snp_target = NODEV; 400 401 detach_notty: 402 selwakeup(&snp->snp_sel); 403 snp->snp_sel.si_pid = 0; 404 if ((snp->snp_flags & SNOOP_OPEN) == 0) 405 free(snp, M_SNP); 406 407 return (0); 408 } 409 410 static int 411 snpclose(dev, flags, fmt, p) 412 dev_t dev; 413 int flags; 414 int fmt; 415 struct proc *p; 416 { 417 struct snoop *snp = dev->si_drv1; 418 419 snp->snp_blen = 0; 420 free(snp->snp_buf, M_SNP); 421 snp->snp_flags &= ~SNOOP_OPEN; 422 dev->si_drv1 = NULL; 423 destroy_dev(dev); 424 425 return (snp_detach(snp)); 426 } 427 428 int 429 snpdown(snp) 430 struct snoop *snp; 431 { 432 433 if (snp->snp_blen != SNOOP_MINLEN) { 434 free(snp->snp_buf, M_SNP); 435 snp->snp_buf = malloc(SNOOP_MINLEN, M_SNP, M_WAITOK); 436 snp->snp_blen = SNOOP_MINLEN; 437 } 438 snp->snp_flags |= SNOOP_DOWN; 439 440 return (snp_detach(snp)); 441 } 442 443 444 static int 445 snpioctl(dev, cmd, data, flags, p) 446 dev_t dev; 447 u_long cmd; 448 caddr_t data; 449 int flags; 450 struct proc *p; 451 { 452 dev_t tdev; 453 struct snoop *snp = dev->si_drv1; 454 struct tty *tp, *tpo; 455 int s; 456 457 switch (cmd) { 458 case SNPSTTY: 459 tdev = udev2dev(*((udev_t *)data), 0); 460 if (tdev == NODEV) 461 return (snpdown(snp)); 462 463 tp = snpdevtotty(tdev); 464 if (!tp) 465 return (EINVAL); 466 467 s = spltty(); 468 469 if (snp->snp_target == NODEV) { 470 tpo = snp->snp_tty; 471 if (tpo) 472 tpo->t_state &= ~TS_SNOOP; 473 } 474 475 tp->t_sc = (caddr_t)snp; 476 tp->t_state |= TS_SNOOP; 477 snp->snp_olddisc = tp->t_line; 478 tp->t_line = mylinedisc; 479 snp->snp_tty = tp; 480 snp->snp_target = tdev; 481 482 /* 483 * Clean overflow and down flags - 484 * we'll have a chance to get them in the future :))) 485 */ 486 snp->snp_flags &= ~SNOOP_OFLOW; 487 snp->snp_flags &= ~SNOOP_DOWN; 488 splx(s); 489 break; 490 491 case SNPGTTY: 492 /* 493 * We keep snp_target field specially to make 494 * SNPGTTY happy, else we can't know what is device 495 * major/minor for tty. 496 */ 497 *((dev_t *)data) = snp->snp_target; 498 break; 499 500 case FIONBIO: 501 break; 502 503 case FIOASYNC: 504 if (*(int *)data) 505 snp->snp_flags |= SNOOP_ASYNC; 506 else 507 snp->snp_flags &= ~SNOOP_ASYNC; 508 break; 509 510 case FIONREAD: 511 s = spltty(); 512 if (snp->snp_tty != NULL) 513 *(int *)data = snp->snp_len; 514 else 515 if (snp->snp_flags & SNOOP_DOWN) { 516 if (snp->snp_flags & SNOOP_OFLOW) 517 *(int *)data = SNP_OFLOW; 518 else 519 *(int *)data = SNP_TTYCLOSE; 520 } else { 521 *(int *)data = SNP_DETACH; 522 } 523 splx(s); 524 break; 525 526 default: 527 return (ENOTTY); 528 } 529 return (0); 530 } 531 532 533 static int 534 snppoll(dev, events, p) 535 dev_t dev; 536 int events; 537 struct proc *p; 538 { 539 struct snoop *snp = dev->si_drv1; 540 int revents = 0; 541 542 543 /* 544 * If snoop is down, we don't want to poll() forever so we return 1. 545 * Caller should see if we down via FIONREAD ioctl(). The last should 546 * return -1 to indicate down state. 547 */ 548 if (events & (POLLIN | POLLRDNORM)) { 549 if (snp->snp_flags & SNOOP_DOWN || snp->snp_len > 0) 550 revents |= events & (POLLIN | POLLRDNORM); 551 else 552 selrecord(p, &snp->snp_sel); 553 } 554 return (revents); 555 } 556 557 static void 558 snp_clone(void *arg, char *name, int namelen, dev_t *dev) 559 { 560 int u; 561 562 if (*dev != NODEV) 563 return; 564 if (dev_stdclone(name, NULL, "snp", &u) != 1) 565 return; 566 *dev = make_dev(&snp_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600, 567 "snp%d", u); 568 return; 569 } 570 571 static int 572 snp_modevent(module_t mod, int type, void *data) 573 { 574 static eventhandler_tag eh_tag = NULL; 575 576 switch (type) { 577 case MOD_LOAD: 578 eh_tag = EVENTHANDLER_REGISTER(dev_clone, snp_clone, 0, 1000); 579 mylinedisc = ldisc_register(LDISC_LOAD, &snpdisc); 580 cdevsw_add(&snp_cdevsw); 581 break; 582 case MOD_UNLOAD: 583 EVENTHANDLER_DEREGISTER(dev_clone, eh_tag); 584 ldisc_deregister(mylinedisc); 585 cdevsw_remove(&snp_cdevsw); 586 break; 587 default: 588 break; 589 } 590 return 0; 591 } 592 593 static moduledata_t snp_mod = { 594 "snp", 595 snp_modevent, 596 NULL 597 }; 598 DECLARE_MODULE(snp, snp_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE+CDEV_MAJOR); 599