if_tun.c revision 1.41
1 /* $NetBSD: if_tun.c,v 1.41 2000/12/18 19:50:45 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 1988, Julian Onions <jpo (at) cs.nott.ac.uk> 5 * Nottingham University 1987. 6 * 7 * This source may be freely distributed, however I would be interested 8 * in any changes that are made. 9 * 10 * This driver takes packets off the IP i/f and hands them up to a 11 * user process to have its wicked way with. This driver has its 12 * roots in a similar driver written by Phil Cockcroft (formerly) at 13 * UCL. This driver is based much more on read/write/poll mode of 14 * operation though. 15 */ 16 17 #include "tun.h" 18 #if NTUN > 0 19 20 #include "opt_inet.h" 21 #include "opt_ns.h" 22 23 #include <sys/param.h> 24 #include <sys/proc.h> 25 #include <sys/systm.h> 26 #include <sys/mbuf.h> 27 #include <sys/buf.h> 28 #include <sys/protosw.h> 29 #include <sys/socket.h> 30 #include <sys/ioctl.h> 31 #include <sys/errno.h> 32 #include <sys/syslog.h> 33 #include <sys/select.h> 34 #include <sys/poll.h> 35 #include <sys/file.h> 36 #include <sys/signalvar.h> 37 #include <sys/conf.h> 38 39 #include <machine/cpu.h> 40 41 #include <net/if.h> 42 #include <net/if_ether.h> 43 #include <net/netisr.h> 44 #include <net/route.h> 45 46 47 #ifdef INET 48 #include <netinet/in.h> 49 #include <netinet/in_systm.h> 50 #include <netinet/in_var.h> 51 #include <netinet/ip.h> 52 #include <netinet/if_inarp.h> 53 #endif 54 55 #ifdef NS 56 #include <netns/ns.h> 57 #include <netns/ns_if.h> 58 #endif 59 60 #include "bpfilter.h" 61 #if NBPFILTER > 0 62 #include <sys/time.h> 63 #include <net/bpf.h> 64 #endif 65 66 #include <net/if_tun.h> 67 68 #define TUNDEBUG if (tundebug) printf 69 int tundebug = 0; 70 71 struct tun_softc tunctl[NTUN]; 72 extern int ifqmaxlen; 73 void tunattach __P((int)); 74 75 int tun_ioctl __P((struct ifnet *, u_long, caddr_t)); 76 int tun_output __P((struct ifnet *, struct mbuf *, struct sockaddr *, 77 struct rtentry *rt)); 78 79 static void tuninit __P((struct tun_softc *)); 80 81 void 82 tunattach(unused) 83 int unused; 84 { 85 int i; 86 struct ifnet *ifp; 87 88 for (i = 0; i < NTUN; i++) { 89 tunctl[i].tun_flags = TUN_INITED; 90 91 ifp = &tunctl[i].tun_if; 92 sprintf(ifp->if_xname, "tun%d", i); 93 ifp->if_softc = &tunctl[i]; 94 ifp->if_mtu = TUNMTU; 95 ifp->if_ioctl = tun_ioctl; 96 ifp->if_output = tun_output; 97 ifp->if_flags = IFF_POINTOPOINT; 98 ifp->if_snd.ifq_maxlen = ifqmaxlen; 99 ifp->if_collisions = 0; 100 ifp->if_ierrors = 0; 101 ifp->if_oerrors = 0; 102 ifp->if_ipackets = 0; 103 ifp->if_opackets = 0; 104 ifp->if_dlt = DLT_NULL; 105 if_attach(ifp); 106 #if NBPFILTER > 0 107 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 108 #endif 109 } 110 } 111 112 /* 113 * tunnel open - must be superuser & the device must be 114 * configured in 115 */ 116 int 117 tunopen(dev, flag, mode, p) 118 dev_t dev; 119 int flag, mode; 120 struct proc *p; 121 { 122 struct ifnet *ifp; 123 struct tun_softc *tp; 124 int unit, error; 125 126 if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) 127 return (error); 128 129 if ((unit = minor(dev)) >= NTUN) 130 return (ENXIO); 131 tp = &tunctl[unit]; 132 if (tp->tun_flags & TUN_OPEN) 133 return ENXIO; 134 ifp = &tp->tun_if; 135 tp->tun_flags |= TUN_OPEN; 136 TUNDEBUG("%s: open\n", ifp->if_xname); 137 return (0); 138 } 139 140 /* 141 * tunclose - close the device - mark i/f down & delete 142 * routing info 143 */ 144 int 145 tunclose(dev, flag, mode, p) 146 dev_t dev; 147 int flag; 148 int mode; 149 struct proc *p; 150 { 151 int unit = minor(dev), s; 152 struct tun_softc *tp = &tunctl[unit]; 153 struct ifnet *ifp = &tp->tun_if; 154 struct mbuf *m; 155 156 tp->tun_flags &= ~TUN_OPEN; 157 158 /* 159 * junk all pending output 160 */ 161 do { 162 s = splimp(); 163 IF_DEQUEUE(&ifp->if_snd, m); 164 splx(s); 165 if (m) 166 m_freem(m); 167 } while (m); 168 169 if (ifp->if_flags & IFF_UP) { 170 s = splimp(); 171 if_down(ifp); 172 if (ifp->if_flags & IFF_RUNNING) { 173 /* find internet addresses and delete routes */ 174 struct ifaddr *ifa; 175 for (ifa = ifp->if_addrlist.tqh_first; ifa != 0; 176 ifa = ifa->ifa_list.tqe_next) { 177 #ifdef INET 178 if (ifa->ifa_addr->sa_family == AF_INET) { 179 rtinit(ifa, (int)RTM_DELETE, 180 tp->tun_flags & TUN_DSTADDR 181 ? RTF_HOST 182 : 0); 183 } 184 #endif 185 } 186 } 187 splx(s); 188 } 189 tp->tun_pgrp = 0; 190 selwakeup(&tp->tun_rsel); 191 192 TUNDEBUG ("%s: closed\n", ifp->if_xname); 193 return (0); 194 } 195 196 static void 197 tuninit(tp) 198 struct tun_softc *tp; 199 { 200 struct ifnet *ifp = &tp->tun_if; 201 struct ifaddr *ifa; 202 203 TUNDEBUG("%s: tuninit\n", ifp->if_xname); 204 205 ifp->if_flags |= IFF_UP | IFF_RUNNING; 206 207 tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); 208 for (ifa = ifp->if_addrlist.tqh_first; ifa != 0; 209 ifa = ifa->ifa_list.tqe_next) { 210 #ifdef INET 211 if (ifa->ifa_addr->sa_family == AF_INET) { 212 struct sockaddr_in *sin; 213 214 sin = satosin(ifa->ifa_addr); 215 if (sin && sin->sin_addr.s_addr) 216 tp->tun_flags |= TUN_IASET; 217 218 if (ifp->if_flags & IFF_POINTOPOINT) { 219 sin = satosin(ifa->ifa_dstaddr); 220 if (sin && sin->sin_addr.s_addr) 221 tp->tun_flags |= TUN_DSTADDR; 222 } 223 } 224 #endif 225 } 226 227 return; 228 } 229 230 /* 231 * Process an ioctl request. 232 */ 233 int 234 tun_ioctl(ifp, cmd, data) 235 struct ifnet *ifp; 236 u_long cmd; 237 caddr_t data; 238 { 239 int error = 0, s; 240 241 s = splimp(); 242 switch(cmd) { 243 case SIOCSIFADDR: 244 tuninit((struct tun_softc *)(ifp->if_softc)); 245 TUNDEBUG("%s: address set\n", ifp->if_xname); 246 break; 247 case SIOCSIFDSTADDR: 248 tuninit((struct tun_softc *)(ifp->if_softc)); 249 TUNDEBUG("%s: destination address set\n", ifp->if_xname); 250 break; 251 case SIOCSIFBRDADDR: 252 TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); 253 break; 254 case SIOCSIFMTU: { 255 struct ifreq *ifr = (struct ifreq *) data; 256 if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { 257 error = EINVAL; 258 break; 259 } 260 TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); 261 ifp->if_mtu = ifr->ifr_mtu; 262 break; 263 } 264 case SIOCADDMULTI: 265 case SIOCDELMULTI: { 266 struct ifreq *ifr = (struct ifreq *) data; 267 if (ifr == 0) { 268 error = EAFNOSUPPORT; /* XXX */ 269 break; 270 } 271 switch (ifr->ifr_addr.sa_family) { 272 273 #ifdef INET 274 case AF_INET: 275 break; 276 #endif 277 278 default: 279 error = EAFNOSUPPORT; 280 break; 281 } 282 break; 283 } 284 case SIOCSIFFLAGS: 285 break; 286 default: 287 error = EINVAL; 288 } 289 splx(s); 290 return (error); 291 } 292 293 /* 294 * tun_output - queue packets from higher level ready to put out. 295 */ 296 int 297 tun_output(ifp, m0, dst, rt) 298 struct ifnet *ifp; 299 struct mbuf *m0; 300 struct sockaddr *dst; 301 struct rtentry *rt; 302 { 303 struct tun_softc *tp = ifp->if_softc; 304 struct proc *p; 305 #ifdef INET 306 int s; 307 #endif 308 309 TUNDEBUG ("%s: tun_output\n", ifp->if_xname); 310 311 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 312 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 313 tp->tun_flags); 314 m_freem (m0); 315 return (EHOSTDOWN); 316 } 317 318 #if NBPFILTER > 0 319 if (ifp->if_bpf) { 320 /* 321 * We need to prepend the address family as 322 * a four byte field. Cons up a dummy header 323 * to pacify bpf. This is safe because bpf 324 * will only read from the mbuf (i.e., it won't 325 * try to free it or keep a pointer to it). 326 */ 327 struct mbuf m; 328 u_int32_t af = dst->sa_family; 329 330 m.m_next = m0; 331 m.m_len = sizeof(af); 332 m.m_data = (char *)⁡ 333 334 bpf_mtap(ifp->if_bpf, &m); 335 } 336 #endif 337 338 switch(dst->sa_family) { 339 #ifdef INET 340 case AF_INET: 341 if (tp->tun_flags & TUN_PREPADDR) { 342 /* Simple link-layer header */ 343 M_PREPEND(m0, dst->sa_len, M_DONTWAIT); 344 if (m0 == NULL) { 345 IF_DROP(&ifp->if_snd); 346 return (ENOBUFS); 347 } 348 bcopy(dst, mtod(m0, char *), dst->sa_len); 349 } 350 /* FALLTHROUGH */ 351 case AF_UNSPEC: 352 s = splimp(); 353 if (IF_QFULL(&ifp->if_snd)) { 354 IF_DROP(&ifp->if_snd); 355 m_freem(m0); 356 splx(s); 357 ifp->if_collisions++; 358 return (ENOBUFS); 359 } 360 IF_ENQUEUE(&ifp->if_snd, m0); 361 splx(s); 362 ifp->if_opackets++; 363 break; 364 #endif 365 default: 366 m_freem(m0); 367 return (EAFNOSUPPORT); 368 } 369 370 if (tp->tun_flags & TUN_RWAIT) { 371 tp->tun_flags &= ~TUN_RWAIT; 372 wakeup((caddr_t)tp); 373 } 374 if (tp->tun_flags & TUN_ASYNC && tp->tun_pgrp) { 375 if (tp->tun_pgrp > 0) 376 gsignal(tp->tun_pgrp, SIGIO); 377 else if ((p = pfind(-tp->tun_pgrp)) != NULL) 378 psignal(p, SIGIO); 379 } 380 selwakeup(&tp->tun_rsel); 381 return (0); 382 } 383 384 /* 385 * the cdevsw interface is now pretty minimal. 386 */ 387 int 388 tunioctl(dev, cmd, data, flag, p) 389 dev_t dev; 390 u_long cmd; 391 caddr_t data; 392 int flag; 393 struct proc *p; 394 { 395 int unit = minor(dev), s; 396 struct tun_softc *tp = &tunctl[unit]; 397 398 switch (cmd) { 399 case TUNSDEBUG: 400 tundebug = *(int *)data; 401 break; 402 403 case TUNGDEBUG: 404 *(int *)data = tundebug; 405 break; 406 407 case TUNSIFMODE: 408 switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { 409 case IFF_POINTOPOINT: 410 case IFF_BROADCAST: 411 s = splimp(); 412 if (tp->tun_if.if_flags & IFF_UP) { 413 splx(s); 414 return (EBUSY); 415 } 416 tp->tun_if.if_flags &= 417 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); 418 tp->tun_if.if_flags |= *(int *)data; 419 splx(s); 420 break; 421 default: 422 return (EINVAL); 423 break; 424 } 425 break; 426 427 case TUNSLMODE: 428 if (*(int *)data) 429 tp->tun_flags |= TUN_PREPADDR; 430 else 431 tp->tun_flags &= ~TUN_PREPADDR; 432 break; 433 434 case FIONBIO: 435 if (*(int *)data) 436 tp->tun_flags |= TUN_NBIO; 437 else 438 tp->tun_flags &= ~TUN_NBIO; 439 break; 440 441 case FIOASYNC: 442 if (*(int *)data) 443 tp->tun_flags |= TUN_ASYNC; 444 else 445 tp->tun_flags &= ~TUN_ASYNC; 446 break; 447 448 case FIONREAD: 449 s = splimp(); 450 if (tp->tun_if.if_snd.ifq_head) 451 *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; 452 else 453 *(int *)data = 0; 454 splx(s); 455 break; 456 457 case TIOCSPGRP: 458 tp->tun_pgrp = *(int *)data; 459 break; 460 461 case TIOCGPGRP: 462 *(int *)data = tp->tun_pgrp; 463 break; 464 465 default: 466 return (ENOTTY); 467 } 468 return (0); 469 } 470 471 /* 472 * The cdevsw read interface - reads a packet at a time, or at 473 * least as much of a packet as can be read. 474 */ 475 int 476 tunread(dev, uio, ioflag) 477 dev_t dev; 478 struct uio *uio; 479 int ioflag; 480 { 481 int unit = minor(dev); 482 struct tun_softc *tp = &tunctl[unit]; 483 struct ifnet *ifp = &tp->tun_if; 484 struct mbuf *m, *m0; 485 int error=0, len, s; 486 487 TUNDEBUG ("%s: read\n", ifp->if_xname); 488 if ((tp->tun_flags & TUN_READY) != TUN_READY) { 489 TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); 490 return EHOSTDOWN; 491 } 492 493 tp->tun_flags &= ~TUN_RWAIT; 494 495 s = splimp(); 496 do { 497 IF_DEQUEUE(&ifp->if_snd, m0); 498 if (m0 == 0) { 499 if (tp->tun_flags & TUN_NBIO) { 500 splx(s); 501 return (EWOULDBLOCK); 502 } 503 tp->tun_flags |= TUN_RWAIT; 504 if (tsleep((caddr_t)tp, PZERO|PCATCH, "tunread", 0)) { 505 splx(s); 506 return (EINTR); 507 } 508 } 509 } while (m0 == 0); 510 splx(s); 511 512 while (m0 && uio->uio_resid > 0 && error == 0) { 513 len = min(uio->uio_resid, m0->m_len); 514 if (len == 0) 515 break; 516 error = uiomove(mtod(m0, caddr_t), len, uio); 517 MFREE(m0, m); 518 m0 = m; 519 } 520 521 if (m0) { 522 TUNDEBUG("Dropping mbuf\n"); 523 m_freem(m0); 524 } 525 if (error) 526 ifp->if_ierrors++; 527 return (error); 528 } 529 530 /* 531 * the cdevsw write interface - an atomic write is a packet - or else! 532 */ 533 int 534 tunwrite(dev, uio, ioflag) 535 dev_t dev; 536 struct uio *uio; 537 int ioflag; 538 { 539 int unit = minor (dev); 540 struct tun_softc *tp = &tunctl[unit]; 541 struct ifnet *ifp = &tp->tun_if; 542 struct mbuf *top, **mp, *m; 543 struct ifqueue *ifq; 544 struct sockaddr dst; 545 int isr, error=0, s, tlen, mlen; 546 547 TUNDEBUG("%s: tunwrite\n", ifp->if_xname); 548 549 if (tp->tun_flags & TUN_PREPADDR) { 550 if (uio->uio_resid < sizeof(dst)) 551 return (EIO); 552 error = uiomove((caddr_t)&dst, sizeof(dst), uio); 553 if (dst.sa_len > sizeof(dst)) { 554 /* Duh.. */ 555 char discard; 556 int n = dst.sa_len - sizeof(dst); 557 while (n--) 558 if ((error = uiomove(&discard, 1, uio)) != 0) 559 return (error); 560 } 561 } else { 562 #ifdef INET 563 dst.sa_family = AF_INET; 564 #endif 565 } 566 567 if (uio->uio_resid < 0 || uio->uio_resid > TUNMTU) { 568 TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, 569 (unsigned long)uio->uio_resid); 570 return (EIO); 571 } 572 573 switch (dst.sa_family) { 574 #ifdef INET 575 case AF_INET: 576 ifq = &ipintrq; 577 isr = NETISR_IP; 578 break; 579 #endif 580 default: 581 return (EAFNOSUPPORT); 582 } 583 584 tlen = uio->uio_resid; 585 586 /* get a header mbuf */ 587 MGETHDR(m, M_DONTWAIT, MT_DATA); 588 if (m == NULL) 589 return (ENOBUFS); 590 mlen = MHLEN; 591 592 top = 0; 593 mp = ⊤ 594 while (error == 0 && uio->uio_resid > 0) { 595 m->m_len = min(mlen, uio->uio_resid); 596 error = uiomove(mtod (m, caddr_t), m->m_len, uio); 597 *mp = m; 598 mp = &m->m_next; 599 if (uio->uio_resid > 0) { 600 MGET (m, M_DONTWAIT, MT_DATA); 601 if (m == 0) { 602 error = ENOBUFS; 603 break; 604 } 605 mlen = MLEN; 606 } 607 } 608 if (error) { 609 if (top) 610 m_freem (top); 611 ifp->if_ierrors++; 612 return (error); 613 } 614 615 top->m_pkthdr.len = tlen; 616 top->m_pkthdr.rcvif = ifp; 617 618 #if NBPFILTER > 0 619 if (ifp->if_bpf) { 620 /* 621 * We need to prepend the address family as 622 * a four byte field. Cons up a dummy header 623 * to pacify bpf. This is safe because bpf 624 * will only read from the mbuf (i.e., it won't 625 * try to free it or keep a pointer to it). 626 */ 627 struct mbuf m; 628 u_int32_t af = AF_INET; 629 630 m.m_next = top; 631 m.m_len = sizeof(af); 632 m.m_data = (char *)⁡ 633 634 bpf_mtap(ifp->if_bpf, &m); 635 } 636 #endif 637 638 s = splimp(); 639 if (IF_QFULL(ifq)) { 640 IF_DROP(ifq); 641 splx(s); 642 ifp->if_collisions++; 643 m_freem(top); 644 return (ENOBUFS); 645 } 646 IF_ENQUEUE(ifq, top); 647 splx(s); 648 ifp->if_ipackets++; 649 schednetisr(isr); 650 return (error); 651 } 652 653 /* 654 * tunpoll - the poll interface, this is only useful on reads 655 * really. The write detect always returns true, write never blocks 656 * anyway, it either accepts the packet or drops it. 657 */ 658 int 659 tunpoll(dev, events, p) 660 dev_t dev; 661 int events; 662 struct proc *p; 663 { 664 int unit = minor(dev), s; 665 struct tun_softc *tp = &tunctl[unit]; 666 struct ifnet *ifp = &tp->tun_if; 667 int revents = 0; 668 669 s = splimp(); 670 TUNDEBUG("%s: tunpoll\n", ifp->if_xname); 671 672 if (events & (POLLIN | POLLRDNORM)) { 673 if (ifp->if_snd.ifq_len > 0) { 674 TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, 675 ifp->if_snd.ifq_len); 676 revents |= events & (POLLIN | POLLRDNORM); 677 } else { 678 TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); 679 selrecord(p, &tp->tun_rsel); 680 } 681 } 682 683 if (events & (POLLOUT | POLLWRNORM)) 684 revents |= events & (POLLOUT | POLLWRNORM); 685 686 splx(s); 687 return (revents); 688 } 689 690 #endif /* NTUN */ 691
Indexes created Tue Sep 23 14:10:03 GMT 2025