1 /*
2 * (MPSAFE)
3 *
4 * Copyright (c) 1987, 1989, 1992, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * @(#)if_sl.c 8.6 (Berkeley) 2/1/94
32 * $FreeBSD: src/sys/net/if_sl.c,v 1.84.2.2 2002/02/13 00:43:10 dillon Exp $
33 */
34
35 /*
36 * Serial Line interface
37 *
38 * Rick Adams
39 * Center for Seismic Studies
40 * 1300 N 17th Street, Suite 1450
41 * Arlington, Virginia 22209
42 * (703)276-7900
43 * rick@seismo.ARPA
44 * seismo!rick
45 *
46 * Pounded on heavily by Chris Torek (chris@mimsy.umd.edu, umcp-cs!chris).
47 * N.B.: this belongs in netinet, not net, the way it stands now.
48 * Should have a link-layer type designation, but wouldn't be
49 * backwards-compatible.
50 *
51 * Converted to 4.3BSD Beta by Chris Torek.
52 * Other changes made at Berkeley, based in part on code by Kirk Smith.
53 * W. Jolitz added slip abort.
54 *
55 * Hacked almost beyond recognition by Van Jacobson (van@helios.ee.lbl.gov).
56 * Added priority queuing for "interactive" traffic; hooks for TCP
57 * header compression; ICMP filtering (at 2400 baud, some cretin
58 * pinging you can use up all your bandwidth). Made low clist behavior
59 * more robust and slightly less likely to hang serial line.
60 * Sped up a bunch of things.
61 */
62
63 #include "use_sl.h"
64 #include "opt_inet.h"
65
66 #include <sys/param.h>
67 #include <sys/systm.h>
68 #include <sys/proc.h>
69 #include <sys/caps.h>
70 #include <sys/malloc.h>
71 #include <sys/mbuf.h>
72 #include <sys/dkstat.h>
73 #include <sys/socket.h>
74 #include <sys/sockio.h>
75 #include <sys/fcntl.h>
76 #include <sys/signalvar.h>
77 #include <sys/tty.h>
78 #include <sys/kernel.h>
79 #include <sys/sysctl.h>
80 #include <sys/conf.h>
81
82 #include <net/if.h>
83 #include <net/if_types.h>
84 #include <net/ifq_var.h>
85 #include <net/netisr.h>
86
87 #if INET
88 #include <netinet/in.h>
89 #include <netinet/in_systm.h>
90 #include <netinet/in_var.h>
91 #include <netinet/ip.h>
92 #else
93 #error "Huh? Slip without inet?"
94 #endif
95
96 #include <net/slcompress.h>
97 #include "if_slvar.h"
98 #include <net/slip.h>
99
100 #include <net/bpf.h>
101
102 static void slattach (void *);
103 PSEUDO_SET(slattach, if_sl);
104
105 /* Set to 0xC002 for broadcast instead of p-to-p */
106 static int sliffopts = IFF_POINTOPOINT | SC_AUTOCOMP | IFF_MULTICAST;
107 SYSCTL_INT(_net, OID_AUTO, sliffopts, CTLFLAG_RW,
108 &sliffopts, 0, "");
109 TUNABLE_INT("net.sliffopts", &sliffopts);
110
111 /*
112 * SLRMAX is a hard limit on input packet size. To simplify the code
113 * and improve performance, we require that packets fit in an mbuf
114 * cluster, and if we get a compressed packet, there's enough extra
115 * room to expand the header into a max length tcp/ip header (128
116 * bytes). So, SLRMAX can be at most
117 * MCLBYTES - 128
118 *
119 * SLMTU is the default transmit MTU. The transmit MTU should be kept
120 * small enough so that interactive use doesn't suffer, but large
121 * enough to provide good performance. 552 is a good choice for SLMTU
122 * because it is high enough to not fragment TCP packets being routed
123 * through this host. Packet fragmentation is bad with SLIP because
124 * fragment headers aren't compressed. The previous assumptions about
125 * the best MTU value don't really hold when using modern modems with
126 * BTLZ data compression because the modem buffers play a much larger
127 * role in interactive performance than the MTU. The MTU can be changed
128 * at any time to suit the specific environment with ifconfig(8), and
129 * its maximum value is defined as SLTMAX. SLTMAX must not be so large
130 * that it would overflow the stack if BPF is configured (XXX; if_ppp.c
131 * handles this better).
132 *
133 * SLIP_HIWAT is the amount of data that will be queued 'downstream'
134 * of us (i.e., in clists waiting to be picked up by the tty output
135 * interrupt). If we queue a lot of data downstream, it's immune to
136 * our t.o.s. queuing.
137 * E.g., if SLIP_HIWAT is 1024, the interactive traffic in mixed
138 * telnet/ftp will see a 1 sec wait, independent of the mtu (the
139 * wait is dependent on the ftp window size but that's typically
140 * 1k - 4k). So, we want SLIP_HIWAT just big enough to amortize
141 * the cost (in idle time on the wire) of the tty driver running
142 * off the end of its clists & having to call back slstart for a
143 * new packet. For a tty interface with any buffering at all, this
144 * cost will be zero. Even with a totally brain dead interface (like
145 * the one on a typical workstation), the cost will be <= 1 character
146 * time. So, setting SLIP_HIWAT to ~100 guarantees that we'll lose
147 * at most 1% while maintaining good interactive response.
148 */
149 #define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN)
150 #define SLRMAX (MCLBYTES - BUFOFFSET)
151 #define SLBUFSIZE (SLRMAX + BUFOFFSET)
152 #ifndef SLMTU
153 #define SLMTU 552 /* default MTU */
154 #endif
155 #define SLTMAX 1500 /* maximum MTU */
156 #define SLIP_HIWAT 50
157 #define CLISTRESERVE 1024 /* Can't let clists get too low */
158
159 /*
160 * SLIP ABORT ESCAPE MECHANISM:
161 * (inspired by HAYES modem escape arrangement)
162 * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape }
163 * within window time signals a "soft" exit from slip mode by remote end
164 * if the IFF_DEBUG flag is on.
165 */
166 #define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/
167 #define ABT_IDLE 1 /* in seconds - idle before an escape */
168 #define ABT_COUNT 3 /* count of escapes for abort */
169 #define ABT_WINDOW (ABT_COUNT*2+2) /* in seconds - time to count */
170
171 static struct sl_softc sl_softc[NSL];
172
173 #define FRAME_END 0xc0 /* Frame End */
174 #define FRAME_ESCAPE 0xdb /* Frame Esc */
175 #define TRANS_FRAME_END 0xdc /* transposed frame end */
176 #define TRANS_FRAME_ESCAPE 0xdd /* transposed frame esc */
177
178 static int slinit (struct sl_softc *);
179 static struct mbuf *sl_btom (struct sl_softc *, int);
180 static timeout_t sl_keepalive;
181 static timeout_t sl_outfill;
182 static int slclose (struct tty *,int);
183 static int slinput (int, struct tty *);
184 static int slioctl (struct ifnet *, u_long, caddr_t, struct ucred *);
185 static int sltioctl (struct tty *, u_long, caddr_t, int, struct ucred *);
186 static int slopen (cdev_t, struct tty *);
187 static int sloutput (struct ifnet *,
188 struct mbuf *, struct sockaddr *, struct rtentry *);
189 static int slstart (struct tty *);
190
191 static struct linesw slipdisc = {
192 slopen, slclose, l_noread, l_nowrite,
193 sltioctl, slinput, slstart, ttymodem,
194 FRAME_END
195 };
196
197 /*
198 * Called from boot code to establish sl interfaces.
199 */
200 static void
slattach(void * dummy)201 slattach(void *dummy)
202 {
203 struct sl_softc *sc;
204 int i = 0;
205
206 linesw[SLIPDISC] = slipdisc;
207
208 for (sc = sl_softc; i < NSL; sc++) {
209 if_initname(&(sc->sc_if), "sl", i++);
210 sc->sc_if.if_mtu = SLMTU;
211 sc->sc_if.if_flags = sliffopts;
212 sc->sc_if.if_type = IFT_SLIP;
213 sc->sc_if.if_ioctl = slioctl;
214 sc->sc_if.if_output = sloutput;
215 ifq_set_maxlen(&sc->sc_if.if_snd, 50);
216 ifq_set_ready(&sc->sc_if.if_snd);
217 sc->sc_fastq.ifq_maxlen = 32;
218 sc->sc_if.if_linkmib = sc;
219 sc->sc_if.if_linkmiblen = sizeof *sc;
220 callout_init_mp(&sc->sc_oftimeout);
221 callout_init_mp(&sc->sc_katimeout);
222 if_attach(&sc->sc_if, NULL);
223 bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN);
224 }
225 }
226
227 static int
slinit(struct sl_softc * sc)228 slinit(struct sl_softc *sc)
229 {
230 if (sc->sc_ep == NULL)
231 sc->sc_ep = kmalloc(SLBUFSIZE, M_DEVBUF, M_WAITOK);
232 sc->sc_buf = sc->sc_ep + SLBUFSIZE - SLRMAX;
233 sc->sc_mp = sc->sc_buf;
234 sl_compress_init(&sc->sc_comp, -1);
235
236 return (1);
237 }
238
239 /*
240 * Line specific open routine.
241 * Attach the given tty to the first available sl unit.
242 */
243 /* ARGSUSED */
244 static int
slopen(cdev_t dev,struct tty * tp)245 slopen(cdev_t dev, struct tty *tp)
246 {
247 struct sl_softc *sc;
248 int nsl;
249 int error;
250
251 error = caps_priv_check_self(SYSCAP_RESTRICTEDROOT);
252 if (error)
253 return (error);
254
255 lwkt_gettoken(&tty_token);
256 if (tp->t_line == SLIPDISC) {
257 lwkt_reltoken(&tty_token);
258 return (0);
259 }
260
261 for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++) {
262 if (sc->sc_ttyp == NULL && !(sc->sc_flags & SC_STATIC)) {
263 if (slinit(sc) == 0) {
264 lwkt_reltoken(&tty_token);
265 return (ENOBUFS);
266 }
267 tp->t_slsc = (caddr_t)sc;
268 sc->sc_ttyp = tp;
269 sc->sc_if.if_baudrate = tp->t_ospeed;
270 ttyflush(tp, FREAD | FWRITE);
271
272 tp->t_line = SLIPDISC;
273 /*
274 * We don't use t_canq or t_rawq, so reduce their
275 * cblock resources to 0. Reserve enough cblocks
276 * for t_outq to guarantee that we can fit a full
277 * packet if the SLIP_HIWAT check allows slstart()
278 * to loop. Use the same value for the cblock
279 * limit since the reserved blocks should always
280 * be enough. Reserving cblocks probably makes
281 * the CLISTRESERVE check unnecessary and wasteful.
282 */
283 clist_alloc_cblocks(&tp->t_canq, 0);
284 clist_alloc_cblocks(&tp->t_outq,
285 SLIP_HIWAT + 2 * sc->sc_if.if_mtu + 1);
286 clist_alloc_cblocks(&tp->t_rawq, 0);
287
288 if_up(&sc->sc_if);
289 lwkt_reltoken(&tty_token);
290 return (0);
291 }
292 }
293 lwkt_reltoken(&tty_token);
294
295 return (ENXIO);
296 }
297
298 /*
299 * Line specific close routine.
300 * Detach the tty from the sl unit.
301 */
302 static int
slclose(struct tty * tp,int flag)303 slclose(struct tty *tp, int flag)
304 {
305 struct sl_softc *sc;
306
307 lwkt_gettoken(&tty_token);
308 lwkt_gettoken(&tp->t_token);
309 ttyflush(tp, FREAD | FWRITE);
310
311 clist_free_cblocks(&tp->t_outq);
312 tp->t_line = 0;
313 sc = (struct sl_softc *)tp->t_slsc;
314 if (sc != NULL) {
315 if (sc->sc_outfill) {
316 sc->sc_outfill = 0;
317 callout_stop(&sc->sc_oftimeout);
318 }
319 if (sc->sc_keepalive) {
320 sc->sc_keepalive = 0;
321 callout_stop(&sc->sc_katimeout);
322 }
323 if_down(&sc->sc_if);
324 sc->sc_flags &= SC_STATIC;
325 sc->sc_ttyp = NULL;
326 tp->t_slsc = NULL;
327 if (sc->sc_ep) {
328 kfree(sc->sc_ep, M_DEVBUF);
329 sc->sc_ep = NULL;
330 }
331 sc->sc_mp = 0;
332 sc->sc_buf = 0;
333 }
334 lwkt_reltoken(&tp->t_token);
335 lwkt_reltoken(&tty_token);
336
337 return 0;
338 }
339
340 /*
341 * Line specific (tty) ioctl routine.
342 * Provide a way to get the sl unit number.
343 */
344 /* ARGSUSED */
345 static int
sltioctl(struct tty * tp,u_long cmd,caddr_t data,int flag,struct ucred * cred)346 sltioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, struct ucred *cred)
347 {
348 struct sl_softc *sc = (struct sl_softc *)tp->t_slsc, *nc, *tmpnc;
349 int nsl;
350
351 lwkt_gettoken(&tty_token);
352 lwkt_gettoken(&tp->t_token);
353
354 switch (cmd) {
355 case SLIOCGUNIT:
356 *(int *)data = sc->sc_if.if_dunit;
357 break;
358
359 case SLIOCSUNIT:
360 if (sc->sc_if.if_dunit != *(u_int *)data) {
361 for (nsl = NSL, nc = sl_softc; --nsl >= 0; nc++) {
362 if ( nc->sc_if.if_dunit == *(u_int *)data
363 && nc->sc_ttyp == NULL
364 ) {
365 tmpnc = kmalloc(sizeof *tmpnc, M_TEMP,
366 M_WAITOK);
367 *tmpnc = *nc;
368 *nc = *sc;
369 nc->sc_if = tmpnc->sc_if;
370 tmpnc->sc_if = sc->sc_if;
371 *sc = *tmpnc;
372 kfree(tmpnc, M_TEMP);
373 if (sc->sc_if.if_flags & IFF_UP) {
374 if_down(&sc->sc_if);
375 if (!(nc->sc_if.if_flags & IFF_UP))
376 if_up(&nc->sc_if);
377 } else if (nc->sc_if.if_flags & IFF_UP)
378 if_down(&nc->sc_if);
379 sc->sc_flags &= ~SC_STATIC;
380 sc->sc_flags |= (nc->sc_flags & SC_STATIC);
381 tp->t_slsc = sc = nc;
382 clist_alloc_cblocks(&tp->t_outq,
383 SLIP_HIWAT +
384 2 * sc->sc_if.if_mtu + 1);
385 sl_compress_init(&sc->sc_comp, -1);
386 goto slfound;
387 }
388 }
389 lwkt_reltoken(&tp->t_token);
390 lwkt_reltoken(&tty_token);
391 return (ENXIO);
392 }
393 slfound:
394 sc->sc_flags |= SC_STATIC;
395 break;
396
397 case SLIOCSKEEPAL:
398 sc->sc_keepalive = *(u_int *)data * hz;
399 if (sc->sc_keepalive) {
400 sc->sc_flags |= SC_KEEPALIVE;
401 callout_reset(&sc->sc_katimeout, sc->sc_keepalive,
402 sl_keepalive, sc);
403 } else {
404 if ((sc->sc_flags & SC_KEEPALIVE) != 0) {
405 callout_stop(&sc->sc_katimeout);
406 sc->sc_flags &= ~SC_KEEPALIVE;
407 }
408 }
409 break;
410
411 case SLIOCGKEEPAL:
412 *(int *)data = sc->sc_keepalive / hz;
413 break;
414
415 case SLIOCSOUTFILL:
416 sc->sc_outfill = *(u_int *)data * hz;
417 if (sc->sc_outfill) {
418 sc->sc_flags |= SC_OUTWAIT;
419 callout_reset(&sc->sc_oftimeout, sc->sc_outfill,
420 sl_outfill, sc);
421 } else {
422 if ((sc->sc_flags & SC_OUTWAIT) != 0) {
423 callout_stop(&sc->sc_oftimeout);
424 sc->sc_flags &= ~SC_OUTWAIT;
425 }
426 }
427 break;
428
429 case SLIOCGOUTFILL:
430 *(int *)data = sc->sc_outfill / hz;
431 break;
432
433 default:
434 lwkt_reltoken(&tp->t_token);
435 lwkt_reltoken(&tty_token);
436 return (ENOIOCTL);
437 }
438 lwkt_reltoken(&tp->t_token);
439 lwkt_reltoken(&tty_token);
440
441 return (0);
442 }
443
444 /*
445 * Queue a packet. Start transmission if not active.
446 * Compression happens in slstart; if we do it here, IP TOS
447 * will cause us to not compress "background" packets, because
448 * ordering gets trashed. It can be done for all packets in slstart.
449 */
450 static int
sloutput_serialized(struct ifnet * ifp,struct ifaltq_subque * ifsq,struct mbuf * m,struct sockaddr * dst,struct rtentry * rtp)451 sloutput_serialized(struct ifnet *ifp, struct ifaltq_subque *ifsq,
452 struct mbuf *m, struct sockaddr *dst, struct rtentry *rtp)
453 {
454 struct sl_softc *sc = &sl_softc[ifp->if_dunit];
455 struct ip *ip;
456 int error;
457 struct altq_pktattr pktattr;
458
459 ifq_classify(&ifp->if_snd, m, dst->sa_family, &pktattr);
460
461 /*
462 * `Cannot happen' (see slioctl). Someday we will extend
463 * the line protocol to support other address families.
464 */
465 if (dst->sa_family != AF_INET) {
466 kprintf("%s: af%d not supported\n", sc->sc_if.if_xname,
467 dst->sa_family);
468 m_freem(m);
469 IFNET_STAT_INC(&sc->sc_if, noproto, 1);
470 return (EAFNOSUPPORT);
471 }
472
473 if (sc->sc_ttyp == NULL || !(ifp->if_flags & IFF_UP)) {
474 m_freem(m);
475 return (ENETDOWN);
476 }
477 if ((sc->sc_ttyp->t_state & TS_CONNECTED) == 0) {
478 m_freem(m);
479 return (EHOSTUNREACH);
480 }
481 ip = mtod(m, struct ip *);
482 if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) {
483 m_freem(m);
484 return (ENETRESET); /* XXX ? */
485 }
486
487 if ((ip->ip_tos & IPTOS_LOWDELAY) &&
488 !ifq_is_enabled(&sc->sc_if.if_snd)) {
489 if (IF_QFULL(&sc->sc_fastq)) {
490 IF_DROP(&sc->sc_fastq);
491 m_freem(m);
492 error = ENOBUFS;
493 } else {
494 IF_ENQUEUE(&sc->sc_fastq, m);
495 error = 0;
496 }
497 } else {
498 error = ifsq_enqueue(ifsq, m, &pktattr);
499 }
500 if (error) {
501 IFNET_STAT_INC(&sc->sc_if, oqdrops, 1);
502 return (error);
503 }
504 if (sc->sc_ttyp->t_outq.c_cc == 0)
505 slstart(sc->sc_ttyp);
506 return (0);
507 }
508
509 static int
sloutput(struct ifnet * ifp,struct mbuf * m,struct sockaddr * dst,struct rtentry * rtp)510 sloutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
511 struct rtentry *rtp)
512 {
513 struct ifaltq_subque *ifsq = ifq_get_subq_default(&ifp->if_snd);
514 int error;
515
516 ifsq_serialize_hw(ifsq);
517 error = sloutput_serialized(ifp, ifsq, m, dst, rtp);
518 ifsq_deserialize_hw(ifsq);
519
520 return error;
521 }
522
523 /*
524 * Start output on interface. Get another datagram
525 * to send from the interface queue and map it to
526 * the interface before starting output.
527 */
528 static int
slstart(struct tty * tp)529 slstart(struct tty *tp)
530 {
531 struct sl_softc *sc = (struct sl_softc *)tp->t_slsc;
532 struct ifaltq_subque *ifsq = ifq_get_subq_default(&sc->sc_if.if_snd);
533 struct mbuf *m;
534 u_char *cp;
535 struct ip *ip;
536 u_char bpfbuf[SLTMAX + SLIP_HDRLEN];
537 int len = 0;
538
539 lwkt_gettoken(&tp->t_token);
540 for (;;) {
541 /*
542 * Call output process whether or not there is more in the
543 * output queue. We are being called in lieu of ttstart
544 * and must do what it would.
545 */
546 (*tp->t_oproc)(tp);
547
548 if (tp->t_outq.c_cc != 0) {
549 if (sc != NULL)
550 sc->sc_flags &= ~SC_OUTWAIT;
551 if (tp->t_outq.c_cc > SLIP_HIWAT) {
552 lwkt_reltoken(&tp->t_token);
553 return 0;
554 }
555 }
556
557 /*
558 * This happens briefly when the line shuts down.
559 */
560 if (sc == NULL) {
561 lwkt_reltoken(&tp->t_token);
562 return 0;
563 }
564
565 /*
566 * Get a packet and send it to the interface.
567 */
568 IF_DEQUEUE(&sc->sc_fastq, m);
569 if (m)
570 IFNET_STAT_INC(&sc->sc_if, omcasts, 1); /* XXX */
571 else
572 m = ifsq_dequeue(ifsq);
573 if (m == NULL) {
574 lwkt_reltoken(&tp->t_token);
575 return 0;
576 }
577
578 /*
579 * We do the header compression here rather than in sloutput
580 * because the packets will be out of order if we are using TOS
581 * queueing, and the connection id compression will get
582 * munged when this happens.
583 */
584 if (sc->sc_if.if_bpf) {
585 /*
586 * We need to save the TCP/IP header before it's
587 * compressed. To avoid complicated code, we just
588 * copy the entire packet into a stack buffer (since
589 * this is a serial line, packets should be short
590 * and/or the copy should be negligible cost compared
591 * to the packet transmission time).
592 */
593 struct mbuf *m1 = m;
594 u_char *cp = bpfbuf + SLIP_HDRLEN;
595
596 len = 0;
597 do {
598 int mlen = m1->m_len;
599
600 bcopy(mtod(m1, caddr_t), cp, mlen);
601 cp += mlen;
602 len += mlen;
603 } while ((m1 = m1->m_next) != NULL);
604 }
605 ip = mtod(m, struct ip *);
606 if (ip->ip_v == IPVERSION && ip->ip_p == IPPROTO_TCP) {
607 if (sc->sc_if.if_flags & SC_COMPRESS)
608 *mtod(m, u_char *) |= sl_compress_tcp(m, ip,
609 &sc->sc_comp, 1);
610 }
611 if (sc->sc_if.if_bpf) {
612 bpf_gettoken();
613
614 if (sc->sc_if.if_bpf) {
615 /*
616 * Put the SLIP pseudo-"link header" in place.
617 * The compressed header is now at the
618 * beginning of the mbuf.
619 */
620 bpfbuf[SLX_DIR] = SLIPDIR_OUT;
621 bcopy(mtod(m, caddr_t), &bpfbuf[SLX_CHDR],
622 CHDR_LEN);
623 bpf_tap(sc->sc_if.if_bpf, bpfbuf,
624 len + SLIP_HDRLEN);
625 }
626
627 bpf_reltoken();
628 }
629
630 sc->sc_flags &= ~SC_OUTWAIT;
631
632 /*
633 * The extra FRAME_END will start up a new packet, and thus
634 * will flush any accumulated garbage. We do this whenever
635 * the line may have been idle for some time.
636 */
637 if (tp->t_outq.c_cc == 0) {
638 IFNET_STAT_INC(&sc->sc_if, obytes, 1);
639 clist_putc(FRAME_END, &tp->t_outq);
640 }
641
642 while (m) {
643 u_char *ep;
644
645 cp = mtod(m, u_char *); ep = cp + m->m_len;
646 while (cp < ep) {
647 /*
648 * Find out how many bytes in the string we can
649 * handle without doing something special.
650 */
651 u_char *bp = cp;
652
653 while (cp < ep) {
654 switch (*cp++) {
655 case FRAME_ESCAPE:
656 case FRAME_END:
657 --cp;
658 goto out;
659 }
660 }
661 out:
662 if (cp > bp) {
663 /*
664 * Put n characters at once
665 * into the tty output queue.
666 */
667 if (clist_btoq((char *)bp, cp - bp,
668 &tp->t_outq)) {
669 break;
670 }
671 IFNET_STAT_INC(&sc->sc_if, obytes,
672 cp - bp);
673 }
674 /*
675 * If there are characters left in the mbuf,
676 * the first one must be special..
677 * Put it out in a different form.
678 */
679 if (cp < ep) {
680 if (clist_putc(FRAME_ESCAPE, &tp->t_outq))
681 break;
682 if (clist_putc(*cp++ == FRAME_ESCAPE ?
683 TRANS_FRAME_ESCAPE : TRANS_FRAME_END,
684 &tp->t_outq)) {
685 clist_unputc(&tp->t_outq);
686 break;
687 }
688 IFNET_STAT_INC(&sc->sc_if, obytes, 2);
689 }
690 }
691 m = m_free(m);
692 }
693
694 if (clist_putc(FRAME_END, &tp->t_outq)) {
695 /*
696 * Not enough room. Remove a char to make room
697 * and end the packet normally.
698 * If you get many collisions (more than one or two
699 * a day) you probably do not have enough clists
700 * and you should increase "nclist" in param.c.
701 */
702 clist_unputc(&tp->t_outq);
703 clist_putc(FRAME_END, &tp->t_outq);
704 IFNET_STAT_INC(&sc->sc_if, collisions, 1);
705 } else {
706 IFNET_STAT_INC(&sc->sc_if, obytes, 1);
707 IFNET_STAT_INC(&sc->sc_if, opackets, 1);
708 }
709 }
710 lwkt_reltoken(&tp->t_token);
711
712 return 0;
713 }
714
715 /*
716 * Copy data buffer to mbuf chain; add ifnet pointer.
717 */
718 static struct mbuf *
sl_btom(struct sl_softc * sc,int len)719 sl_btom(struct sl_softc *sc, int len)
720 {
721 struct mbuf *m;
722
723 if (len >= MCLBYTES)
724 return (NULL);
725
726 MGETHDR(m, M_NOWAIT, MT_DATA);
727 if (m == NULL)
728 return (NULL);
729
730 /*
731 * If we have more than MHLEN bytes, it's cheaper to
732 * queue the cluster we just filled & allocate a new one
733 * for the input buffer. Otherwise, fill the mbuf we
734 * allocated above. Note that code in the input routine
735 * guarantees that packet will fit in a cluster.
736 */
737 if (len >= MHLEN) {
738 MCLGET(m, M_NOWAIT);
739 if ((m->m_flags & M_EXT) == 0) {
740 /*
741 * we couldn't get a cluster - if memory's this
742 * low, it's time to start dropping packets.
743 */
744 m_free(m);
745 return (NULL);
746 }
747 }
748 bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len);
749 m->m_len = len;
750 m->m_pkthdr.len = len;
751 m->m_pkthdr.rcvif = &sc->sc_if;
752 return (m);
753 }
754
755 /*
756 * tty interface receiver interrupt.
757 */
758 static int
slinput(int c,struct tty * tp)759 slinput(int c, struct tty *tp)
760 {
761 struct sl_softc *sc;
762 struct mbuf *m;
763 int len;
764 u_char chdr[CHDR_LEN];
765
766 #if 0
767 kprintf(" %02x", (unsigned char)c);
768 if ((unsigned char)c == 0xC0)
769 kprintf("\n");
770 #endif
771
772 lwkt_gettoken(&tp->t_token);
773 tk_nin++;
774 sc = (struct sl_softc *)tp->t_slsc;
775 if (sc == NULL) {
776 lwkt_reltoken(&tp->t_token);
777 #if 0
778 kprintf("X");
779 #endif
780 return 0;
781 }
782 if (c & TTY_ERRORMASK || (tp->t_state & TS_CONNECTED) == 0) {
783 sc->sc_flags |= SC_ERROR;
784 lwkt_reltoken(&tp->t_token);
785 #if 0
786 kprintf("Y");
787 #endif
788 return 0;
789 }
790 c &= TTY_CHARMASK;
791
792 IFNET_STAT_INC(&sc->sc_if, ibytes, 1);
793
794 if (sc->sc_if.if_flags & IFF_DEBUG) {
795 if (c == ABT_ESC) {
796 /*
797 * If we have a previous abort, see whether
798 * this one is within the time limit.
799 */
800 if (sc->sc_abortcount &&
801 time_uptime >= sc->sc_starttime + ABT_WINDOW)
802 sc->sc_abortcount = 0;
803 /*
804 * If we see an abort after "idle" time, count it;
805 * record when the first abort escape arrived.
806 */
807 if (time_uptime >= sc->sc_lasttime + ABT_IDLE) {
808 if (++sc->sc_abortcount == 1)
809 sc->sc_starttime = time_uptime;
810 if (sc->sc_abortcount >= ABT_COUNT) {
811 slclose(tp,0);
812 lwkt_reltoken(&tp->t_token);
813 return 0;
814 }
815 }
816 } else
817 sc->sc_abortcount = 0;
818 sc->sc_lasttime = time_uptime;
819 }
820
821 switch (c) {
822
823 case TRANS_FRAME_ESCAPE:
824 if (sc->sc_escape)
825 c = FRAME_ESCAPE;
826 break;
827
828 case TRANS_FRAME_END:
829 if (sc->sc_escape)
830 c = FRAME_END;
831 break;
832
833 case FRAME_ESCAPE:
834 sc->sc_escape = 1;
835 lwkt_reltoken(&tp->t_token);
836 return 0;
837
838 case FRAME_END:
839 sc->sc_flags &= ~SC_KEEPALIVE;
840 if(sc->sc_flags & SC_ERROR) {
841 sc->sc_flags &= ~SC_ERROR;
842 goto newpack;
843 }
844 len = sc->sc_mp - sc->sc_buf;
845 if (len < 3)
846 /* less than min length packet - ignore */
847 goto newpack;
848
849 if (sc->sc_if.if_bpf) {
850 /*
851 * Save the compressed header, so we
852 * can tack it on later. Note that we
853 * will end up copying garbage in some
854 * cases but this is okay. We remember
855 * where the buffer started so we can
856 * compute the new header length.
857 */
858 bcopy(sc->sc_buf, chdr, CHDR_LEN);
859 }
860
861 if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) {
862 if (c & 0x80)
863 c = TYPE_COMPRESSED_TCP;
864 else if (c == TYPE_UNCOMPRESSED_TCP)
865 *sc->sc_buf &= 0x4f; /* XXX */
866 /*
867 * We've got something that's not an IP packet.
868 * If compression is enabled, try to decompress it.
869 * Otherwise, if `auto-enable' compression is on and
870 * it's a reasonable packet, decompress it and then
871 * enable compression. Otherwise, drop it.
872 */
873 if (sc->sc_if.if_flags & SC_COMPRESS) {
874 len = sl_uncompress_tcp(&sc->sc_buf, len,
875 (u_int)c, &sc->sc_comp);
876 if (len <= 0)
877 goto error;
878 } else if ((sc->sc_if.if_flags & SC_AUTOCOMP) &&
879 c == TYPE_UNCOMPRESSED_TCP && len >= 40) {
880 len = sl_uncompress_tcp(&sc->sc_buf, len,
881 (u_int)c, &sc->sc_comp);
882 if (len <= 0)
883 goto error;
884 sc->sc_if.if_flags |= SC_COMPRESS;
885 } else
886 goto error;
887 }
888 if (sc->sc_if.if_bpf) {
889 bpf_gettoken();
890
891 if (sc->sc_if.if_bpf) {
892 /*
893 * Put the SLIP pseudo-"link header" in place.
894 * We couldn't do this any earlier since
895 * decompression probably moved the buffer
896 * pointer. Then, invoke BPF.
897 */
898 u_char *hp = sc->sc_buf - SLIP_HDRLEN;
899
900 hp[SLX_DIR] = SLIPDIR_IN;
901 bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN);
902 bpf_tap(sc->sc_if.if_bpf, hp,
903 len + SLIP_HDRLEN);
904 }
905
906 bpf_reltoken();
907 }
908 m = sl_btom(sc, len);
909 if (m == NULL)
910 goto error;
911
912 IFNET_STAT_INC(&sc->sc_if, ipackets, 1);
913
914 if ((sc->sc_if.if_flags & IFF_UP) == 0) {
915 m_freem(m);
916 goto newpack;
917 }
918
919 if (netisr_queue(NETISR_IP, m)) {
920 IFNET_STAT_INC(&sc->sc_if, ierrors, 1);
921 IFNET_STAT_INC(&sc->sc_if, iqdrops, 1);
922 }
923
924 goto newpack;
925 }
926 if (sc->sc_mp < sc->sc_ep + SLBUFSIZE) {
927 *sc->sc_mp++ = c;
928 sc->sc_escape = 0;
929 lwkt_reltoken(&tp->t_token);
930 return 0;
931 }
932
933 /* can't put lower; would miss an extra frame */
934 sc->sc_flags |= SC_ERROR;
935
936 error:
937 IFNET_STAT_INC(&sc->sc_if, ierrors, 1);
938 newpack:
939 sc->sc_mp = sc->sc_buf = sc->sc_ep + SLBUFSIZE - SLRMAX;
940 sc->sc_escape = 0;
941 lwkt_reltoken(&tp->t_token);
942
943 return 0;
944 }
945
946 /*
947 * Process an ioctl request.
948 */
949 static int
slioctl(struct ifnet * ifp,u_long cmd,caddr_t data,struct ucred * cr)950 slioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
951 {
952 struct ifaddr *ifa = (struct ifaddr *)data;
953 struct ifreq *ifr = (struct ifreq *)data;
954 int error = 0;
955
956 switch (cmd) {
957
958 case SIOCSIFFLAGS:
959 /*
960 * if.c will set the interface up even if we
961 * don't want it to.
962 */
963 if (sl_softc[ifp->if_dunit].sc_ttyp == NULL) {
964 ifp->if_flags &= ~IFF_UP;
965 }
966 break;
967 case SIOCSIFADDR:
968 /*
969 * This is "historical" - set the interface up when
970 * setting the address.
971 */
972 if (ifa->ifa_addr->sa_family == AF_INET) {
973 if (sl_softc[ifp->if_dunit].sc_ttyp != NULL)
974 ifp->if_flags |= IFF_UP;
975 } else {
976 error = EAFNOSUPPORT;
977 }
978 break;
979
980 case SIOCSIFDSTADDR:
981 if (ifa->ifa_addr->sa_family != AF_INET)
982 error = EAFNOSUPPORT;
983 break;
984
985 case SIOCADDMULTI:
986 case SIOCDELMULTI:
987 break;
988
989 case SIOCSIFMTU:
990 /*
991 * Set the interface MTU.
992 */
993 if (ifr->ifr_mtu > SLTMAX)
994 error = EINVAL;
995 else {
996 struct tty *tp;
997
998 ifp->if_mtu = ifr->ifr_mtu;
999 tp = sl_softc[ifp->if_dunit].sc_ttyp;
1000 if (tp != NULL)
1001 clist_alloc_cblocks(&tp->t_outq,
1002 SLIP_HIWAT + 2 * ifp->if_mtu + 1);
1003 }
1004 break;
1005
1006 default:
1007 error = EINVAL;
1008 }
1009 return (error);
1010 }
1011
1012 static void
sl_keepalive(void * chan)1013 sl_keepalive(void *chan)
1014 {
1015 struct sl_softc *sc = chan;
1016 struct tty *tp = sc->sc_ttyp;
1017 struct pgrp *pg;
1018
1019 lwkt_gettoken(&tp->t_token);
1020 if (sc->sc_keepalive) {
1021 if (sc->sc_flags & SC_KEEPALIVE) {
1022 pg = sc->sc_ttyp->t_pgrp;
1023 if (pg) {
1024 pgref(pg);
1025 pgsignal (pg, SIGURG, 1);
1026 pgrel(pg);
1027 }
1028 } else {
1029 sc->sc_flags |= SC_KEEPALIVE;
1030 }
1031 callout_reset(&sc->sc_katimeout, sc->sc_keepalive,
1032 sl_keepalive, sc);
1033 } else {
1034 sc->sc_flags &= ~SC_KEEPALIVE;
1035 }
1036 lwkt_reltoken(&tp->t_token);
1037 }
1038
1039 static void
sl_outfill(void * chan)1040 sl_outfill(void *chan)
1041 {
1042 struct sl_softc *sc = chan;
1043 struct tty *tp = sc->sc_ttyp;
1044
1045 lwkt_gettoken(&tp->t_token);
1046
1047 if (sc->sc_outfill && tp != NULL) {
1048 if (sc->sc_flags & SC_OUTWAIT) {
1049 IFNET_STAT_INC(&sc->sc_if, obytes, 1);
1050 clist_putc(FRAME_END, &tp->t_outq);
1051 (*tp->t_oproc)(tp);
1052 } else
1053 sc->sc_flags |= SC_OUTWAIT;
1054 callout_reset(&sc->sc_oftimeout, sc->sc_outfill,
1055 sl_outfill, sc);
1056 } else {
1057 sc->sc_flags &= ~SC_OUTWAIT;
1058 }
1059 lwkt_reltoken(&tp->t_token);
1060 }
1061
1062 MODULE_VERSION(if_sl, 1);
1063