xref: /netbsd-src/sys/net/if_ppp.c (revision 7d62b00eb9ad855ffcd7da46b41e23feb5476fac)
1 /*	$NetBSD: if_ppp.c,v 1.172 2022/09/03 02:47:59 thorpej Exp $	*/
2 /*	Id: if_ppp.c,v 1.6 1997/03/04 03:33:00 paulus Exp 	*/
3 
4 /*
5  * if_ppp.c - Point-to-Point Protocol (PPP) Asynchronous driver.
6  *
7  * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  *
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in
18  *    the documentation and/or other materials provided with the
19  *    distribution.
20  *
21  * 3. The name "Carnegie Mellon University" must not be used to
22  *    endorse or promote products derived from this software without
23  *    prior written permission. For permission or any legal
24  *    details, please contact
25  *      Office of Technology Transfer
26  *      Carnegie Mellon University
27  *      5000 Forbes Avenue
28  *      Pittsburgh, PA  15213-3890
29  *      (412) 268-4387, fax: (412) 268-7395
30  *      tech-transfer@andrew.cmu.edu
31  *
32  * 4. Redistributions of any form whatsoever must retain the following
33  *    acknowledgment:
34  *    "This product includes software developed by Computing Services
35  *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
36  *
37  * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
38  * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
39  * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
40  * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
41  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
42  * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
43  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
44  *
45  * Based on:
46  *	@(#)if_sl.c	7.6.1.2 (Berkeley) 2/15/89
47  *
48  * Copyright (c) 1987 Regents of the University of California.
49  * All rights reserved.
50  *
51  * Redistribution and use in source and binary forms are permitted
52  * provided that the above copyright notice and this paragraph are
53  * duplicated in all such forms and that any documentation,
54  * advertising materials, and other materials related to such
55  * distribution and use acknowledge that the software was developed
56  * by the University of California, Berkeley.  The name of the
57  * University may not be used to endorse or promote products derived
58  * from this software without specific prior written permission.
59  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
60  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
61  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
62  *
63  * Serial Line interface
64  *
65  * Rick Adams
66  * Center for Seismic Studies
67  * 1300 N 17th Street, Suite 1450
68  * Arlington, Virginia 22209
69  * (703)276-7900
70  * rick@seismo.ARPA
71  * seismo!rick
72  *
73  * Pounded on heavily by Chris Torek (chris@mimsy.umd.edu, umcp-cs!chris).
74  * Converted to 4.3BSD Beta by Chris Torek.
75  * Other changes made at Berkeley, based in part on code by Kirk Smith.
76  *
77  * Converted to 4.3BSD+ 386BSD by Brad Parker (brad@cayman.com)
78  * Added VJ tcp header compression; more unified ioctls
79  *
80  * Extensively modified by Paul Mackerras (paulus@cs.anu.edu.au).
81  * Cleaned up a lot of the mbuf-related code to fix bugs that
82  * caused system crashes and packet corruption.  Changed pppstart
83  * so that it doesn't just give up with a collision if the whole
84  * packet doesn't fit in the output ring buffer.
85  *
86  * Added priority queueing for interactive IP packets, following
87  * the model of if_sl.c, plus hooks for bpf.
88  * Paul Mackerras (paulus@cs.anu.edu.au).
89  */
90 
91 /* from if_sl.c,v 1.11 84/10/04 12:54:47 rick Exp */
92 /* from NetBSD: if_ppp.c,v 1.15.2.2 1994/07/28 05:17:58 cgd Exp */
93 
94 /*
95  * XXX IMP ME HARDER
96  *
97  * This is an explanation of that comment.  This code used to use
98  * splimp() to block both network and tty interrupts.  However,
99  * that call is deprecated.  So, we have replaced the uses of
100  * splimp() with splhigh() in order to applomplish what it needs
101  * to accomplish, and added that happy little comment.
102  */
103 
104 #include <sys/cdefs.h>
105 __KERNEL_RCSID(0, "$NetBSD: if_ppp.c,v 1.172 2022/09/03 02:47:59 thorpej Exp $");
106 
107 #ifdef _KERNEL_OPT
108 #include "ppp.h"
109 #include "opt_inet.h"
110 #include "opt_gateway.h"
111 #include "opt_ppp.h"
112 #endif
113 
114 #ifdef INET
115 #define VJC
116 #endif
117 #define PPP_COMPRESS
118 
119 #include <sys/param.h>
120 #include <sys/proc.h>
121 #include <sys/mbuf.h>
122 #include <sys/socket.h>
123 #include <sys/ioctl.h>
124 #include <sys/kernel.h>
125 #include <sys/systm.h>
126 #include <sys/time.h>
127 #include <sys/malloc.h>
128 #include <sys/module.h>
129 #include <sys/mutex.h>
130 #include <sys/once.h>
131 #include <sys/conf.h>
132 #include <sys/kauth.h>
133 #include <sys/intr.h>
134 #include <sys/socketvar.h>
135 #include <sys/device.h>
136 #include <sys/module.h>
137 
138 #include <net/if.h>
139 #include <net/if_types.h>
140 #include <net/route.h>
141 
142 #include <netinet/in.h>
143 #include <netinet/in_systm.h>
144 #include <netinet/in_var.h>
145 #ifdef INET
146 #include <netinet/ip.h>
147 #endif
148 
149 #include <net/bpf.h>
150 #include <net/slip.h>
151 
152 #ifdef VJC
153 #include <net/slcompress.h>
154 #endif
155 
156 #include <net/ppp_defs.h>
157 #include <net/if_ppp.h>
158 #include <net/if_pppvar.h>
159 #include <sys/cpu.h>
160 
161 #ifdef PPP_COMPRESS
162 #define PACKETPTR	struct mbuf *
163 #include <net/ppp-comp.h>
164 #endif
165 
166 #include "ioconf.h"
167 
168 static int	pppsioctl(struct ifnet *, u_long, void *);
169 static void	ppp_requeue(struct ppp_softc *);
170 static void	ppp_ccp(struct ppp_softc *, struct mbuf *m, int rcvd);
171 static void	ppp_ccp_closed(struct ppp_softc *);
172 static void	ppp_inproc(struct ppp_softc *, struct mbuf *);
173 static void	pppdumpm(struct mbuf *m0);
174 #ifdef ALTQ
175 static void	ppp_ifstart(struct ifnet *ifp);
176 #endif
177 
178 static void	pppintr(void *);
179 
180 extern struct linesw ppp_disc;
181 
182 /*
183  * We define two link layer specific mbuf flags, to mark high-priority
184  * packets for output, and received packets following lost/corrupted
185  * packets.
186  */
187 #define	M_HIGHPRI	M_LINK0	/* output packet for sc_fastq */
188 #define	M_ERRMARK	M_LINK1	/* rx packet following lost/corrupted pkt */
189 
190 static int ppp_clone_create(struct if_clone *, int);
191 static int ppp_clone_destroy(struct ifnet *);
192 
193 static struct ppp_softc *ppp_create(const char *, int);
194 
195 static struct {
196 	LIST_HEAD(ppp_sclist, ppp_softc) list;
197 	kmutex_t lock;
198 } ppp_softcs __cacheline_aligned;
199 
200 struct if_clone ppp_cloner =
201     IF_CLONE_INITIALIZER("ppp", ppp_clone_create, ppp_clone_destroy);
202 
203 #ifdef PPP_COMPRESS
204 static LIST_HEAD(, compressor) ppp_compressors = { NULL };
205 static kmutex_t ppp_compressors_mtx;
206 
207 static int ppp_compressor_init(void);
208 static int ppp_compressor_destroy(void);
209 static struct compressor *ppp_get_compressor(uint8_t);
210 static void ppp_compressor_rele(struct compressor *);
211 #endif /* PPP_COMPRESS */
212 
213 
214 /*
215  * Called from boot code to establish ppp interfaces.
216  */
217 void
218 pppattach(int n __unused)
219 {
220 
221 	/*
222 	 * Nothing to do here, initialization is handled by the
223 	 * module initialization code in pppinit() below).
224 	 */
225 }
226 
227 static void
228 pppinit(void)
229 {
230 	/* Init the compressor sub-sub-system */
231 	ppp_compressor_init();
232 
233 	if (ttyldisc_attach(&ppp_disc) != 0)
234 		panic("%s", __func__);
235 
236 	mutex_init(&ppp_softcs.lock, MUTEX_DEFAULT, IPL_NONE);
237 	LIST_INIT(&ppp_softcs.list);
238 	if_clone_attach(&ppp_cloner);
239 }
240 
241 static int
242 pppdetach(void)
243 {
244 	int error = 0;
245 
246 	if (!LIST_EMPTY(&ppp_softcs.list))
247 		error = EBUSY;
248 
249 	if (error == 0)
250 		error = ttyldisc_detach(&ppp_disc);
251 
252 	if (error == 0) {
253 		mutex_destroy(&ppp_softcs.lock);
254 		if_clone_detach(&ppp_cloner);
255 		ppp_compressor_destroy();
256 	}
257 
258 	return error;
259 }
260 
261 static struct ppp_softc *
262 ppp_create(const char *name, int unit)
263 {
264 	struct ppp_softc *sc, *sci, *scl = NULL;
265 
266 	sc = malloc(sizeof(*sc), M_DEVBUF, M_WAIT|M_ZERO);
267 
268 	mutex_enter(&ppp_softcs.lock);
269 	if (unit == -1) {
270 		int i = 0;
271 		LIST_FOREACH(sci, &ppp_softcs.list, sc_iflist) {
272 			scl = sci;
273 			if (i < sci->sc_unit) {
274 				unit = i;
275 				break;
276 			} else {
277 #ifdef DIAGNOSTIC
278 				KASSERT(i == sci->sc_unit);
279 #endif
280 				i++;
281 			}
282 		}
283 		if (unit == -1)
284 			unit = i;
285 	} else {
286 		LIST_FOREACH(sci, &ppp_softcs.list, sc_iflist) {
287 			scl = sci;
288 			if (unit < sci->sc_unit)
289 				break;
290 			else if (unit == sci->sc_unit) {
291 				free(sc, M_DEVBUF);
292 				mutex_exit(&ppp_softcs.lock);
293 				return NULL;
294 			}
295 		}
296 	}
297 
298 	if (sci != NULL)
299 		LIST_INSERT_BEFORE(sci, sc, sc_iflist);
300 	else if (scl != NULL)
301 		LIST_INSERT_AFTER(scl, sc, sc_iflist);
302 	else
303 		LIST_INSERT_HEAD(&ppp_softcs.list, sc, sc_iflist);
304 
305 	mutex_exit(&ppp_softcs.lock);
306 
307 	if_initname(&sc->sc_if, name, sc->sc_unit = unit);
308 	callout_init(&sc->sc_timo_ch, 0);
309 	sc->sc_if.if_softc = sc;
310 	sc->sc_if.if_mtu = PPP_MTU;
311 	sc->sc_if.if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
312 	sc->sc_if.if_type = IFT_PPP;
313 	sc->sc_if.if_hdrlen = PPP_HDRLEN;
314 	sc->sc_if.if_dlt = DLT_NULL;
315 	sc->sc_if.if_ioctl = pppsioctl;
316 	sc->sc_if.if_output = pppoutput;
317 #ifdef ALTQ
318 	sc->sc_if.if_start = ppp_ifstart;
319 #endif
320 	IFQ_SET_MAXLEN(&sc->sc_if.if_snd, IFQ_MAXLEN);
321 	IFQ_SET_MAXLEN(&sc->sc_inq, IFQ_MAXLEN);
322 	IFQ_SET_MAXLEN(&sc->sc_fastq, IFQ_MAXLEN);
323 	IFQ_SET_MAXLEN(&sc->sc_rawq, IFQ_MAXLEN);
324 
325 	IFQ_LOCK_INIT(&sc->sc_fastq);
326 
327 	/* Ratio of 1:2 packets between the regular and the fast queue */
328 	sc->sc_maxfastq = 2;
329 	IFQ_SET_READY(&sc->sc_if.if_snd);
330 	if_attach(&sc->sc_if);
331 	if_alloc_sadl(&sc->sc_if);
332 	bpf_attach(&sc->sc_if, DLT_NULL, 0);
333 	return sc;
334 }
335 
336 static int
337 ppp_clone_create(struct if_clone *ifc, int unit)
338 {
339 	return ppp_create(ifc->ifc_name, unit) == NULL ? EEXIST : 0;
340 }
341 
342 static int
343 ppp_clone_destroy(struct ifnet *ifp)
344 {
345 	struct ppp_softc *sc = (struct ppp_softc *)ifp->if_softc;
346 
347 	if (sc->sc_devp != NULL)
348 		return EBUSY; /* Not removing it */
349 
350 	mutex_enter(&ppp_softcs.lock);
351 	LIST_REMOVE(sc, sc_iflist);
352 	mutex_exit(&ppp_softcs.lock);
353 
354 	bpf_detach(ifp);
355 	if_detach(ifp);
356 
357 	IFQ_LOCK_DESTROY(&sc->sc_fastq);
358 
359 	free(sc, M_DEVBUF);
360 	return 0;
361 }
362 
363 /*
364  * Allocate a ppp interface unit and initialize it.
365  */
366 struct ppp_softc *
367 pppalloc(pid_t pid)
368 {
369 	struct ppp_softc *sc = NULL, *scf;
370 	int i;
371 
372 	mutex_enter(&ppp_softcs.lock);
373 	LIST_FOREACH(scf, &ppp_softcs.list, sc_iflist) {
374 		if (scf->sc_xfer == pid) {
375 			scf->sc_xfer = 0;
376 			mutex_exit(&ppp_softcs.lock);
377 			return scf;
378 		}
379 		if (scf->sc_devp == NULL && sc == NULL)
380 			sc = scf;
381 	}
382 	mutex_exit(&ppp_softcs.lock);
383 
384 	if (sc == NULL)
385 		sc = ppp_create(ppp_cloner.ifc_name, -1);
386 
387 	sc->sc_si = softint_establish(SOFTINT_NET, pppintr, sc);
388 	if (sc->sc_si == NULL) {
389 		printf("%s: unable to establish softintr\n",
390 		    sc->sc_if.if_xname);
391 		return NULL;
392 	}
393 	sc->sc_flags = 0;
394 	sc->sc_mru = PPP_MRU;
395 	sc->sc_relinq = NULL;
396 	(void)memset(&sc->sc_stats, 0, sizeof(sc->sc_stats));
397 #ifdef VJC
398 	sc->sc_comp = malloc(sizeof(struct slcompress), M_DEVBUF, M_NOWAIT);
399 	if (sc->sc_comp)
400 		sl_compress_init(sc->sc_comp);
401 #endif
402 #ifdef PPP_COMPRESS
403 	sc->sc_xc_state = NULL;
404 	sc->sc_rc_state = NULL;
405 #endif /* PPP_COMPRESS */
406 	for (i = 0; i < NUM_NP; ++i)
407 		sc->sc_npmode[i] = NPMODE_ERROR;
408 	sc->sc_npqueue = NULL;
409 	sc->sc_npqtail = &sc->sc_npqueue;
410 	sc->sc_last_sent = sc->sc_last_recv = time_second;
411 
412 	return sc;
413 }
414 
415 /*
416  * Deallocate a ppp unit.  Must be called at splsoftnet or higher.
417  */
418 void
419 pppdealloc(struct ppp_softc *sc)
420 {
421 	struct mbuf *m;
422 
423 	softint_disestablish(sc->sc_si);
424 	if_down(&sc->sc_if);
425 	sc->sc_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
426 	sc->sc_devp = NULL;
427 	sc->sc_xfer = 0;
428 	for (;;) {
429 		IF_DEQUEUE(&sc->sc_rawq, m);
430 		if (m == NULL)
431 			break;
432 		m_freem(m);
433 	}
434 	for (;;) {
435 		IF_DEQUEUE(&sc->sc_inq, m);
436 		if (m == NULL)
437 			break;
438 		m_freem(m);
439 	}
440 	for (;;) {
441 		IF_DEQUEUE(&sc->sc_fastq, m);
442 		if (m == NULL)
443 			break;
444 		m_freem(m);
445 	}
446 	while ((m = sc->sc_npqueue) != NULL) {
447 		sc->sc_npqueue = m->m_nextpkt;
448 		m_freem(m);
449 	}
450 	if (sc->sc_togo != NULL) {
451 		m_freem(sc->sc_togo);
452 		sc->sc_togo = NULL;
453 	}
454 #ifdef PPP_COMPRESS
455 	ppp_ccp_closed(sc);
456 	sc->sc_xc_state = NULL;
457 	sc->sc_rc_state = NULL;
458 #endif /* PPP_COMPRESS */
459 #ifdef PPP_FILTER
460 	if (sc->sc_pass_filt_in.bf_insns != 0) {
461 		free(sc->sc_pass_filt_in.bf_insns, M_DEVBUF);
462 		sc->sc_pass_filt_in.bf_insns = 0;
463 		sc->sc_pass_filt_in.bf_len = 0;
464 	}
465 	if (sc->sc_pass_filt_out.bf_insns != 0) {
466 		free(sc->sc_pass_filt_out.bf_insns, M_DEVBUF);
467 		sc->sc_pass_filt_out.bf_insns = 0;
468 		sc->sc_pass_filt_out.bf_len = 0;
469 	}
470 	if (sc->sc_active_filt_in.bf_insns != 0) {
471 		free(sc->sc_active_filt_in.bf_insns, M_DEVBUF);
472 		sc->sc_active_filt_in.bf_insns = 0;
473 		sc->sc_active_filt_in.bf_len = 0;
474 	}
475 	if (sc->sc_active_filt_out.bf_insns != 0) {
476 		free(sc->sc_active_filt_out.bf_insns, M_DEVBUF);
477 		sc->sc_active_filt_out.bf_insns = 0;
478 		sc->sc_active_filt_out.bf_len = 0;
479 	}
480 #endif /* PPP_FILTER */
481 #ifdef VJC
482 	if (sc->sc_comp != 0) {
483 		free(sc->sc_comp, M_DEVBUF);
484 		sc->sc_comp = 0;
485 	}
486 #endif
487 	(void)ppp_clone_destroy(&sc->sc_if);
488 }
489 
490 /*
491  * Ioctl routine for generic ppp devices.
492  */
493 int
494 pppioctl(struct ppp_softc *sc, u_long cmd, void *data, int flag,
495     struct lwp *l)
496 {
497 	int s, error, flags, mru, npx;
498 	u_int nb;
499 	struct ppp_option_data *odp;
500 	struct compressor *cp;
501 	struct npioctl *npi;
502 	time_t t;
503 #ifdef PPP_FILTER
504 	struct bpf_program *bp, *nbp;
505 	struct bpf_insn *newcode, *oldcode;
506 	int newcodelen;
507 #endif /* PPP_FILTER */
508 #ifdef	PPP_COMPRESS
509 	u_char ccp_option[CCP_MAX_OPTION_LENGTH];
510 #endif
511 
512 	switch (cmd) {
513 	case PPPIOCSFLAGS:
514 	case PPPIOCSMRU:
515 	case PPPIOCSMAXCID:
516 	case PPPIOCSCOMPRESS:
517 	case PPPIOCSNPMODE:
518 		if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE,
519 			KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, &sc->sc_if,
520 			KAUTH_ARG(cmd), NULL) != 0)
521 			return EPERM;
522 		break;
523 	case PPPIOCXFERUNIT:
524 		/* XXX: Why is this privileged?! */
525 		if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE,
526 			KAUTH_REQ_NETWORK_INTERFACE_GETPRIV, &sc->sc_if,
527 			KAUTH_ARG(cmd), NULL) != 0)
528 			return EPERM;
529 		break;
530 	default:
531 		break;
532 	}
533 
534 	switch (cmd) {
535 	case FIONREAD:
536 		*(int *)data = sc->sc_inq.ifq_len;
537 		break;
538 
539 	case PPPIOCGUNIT:
540 		*(int *)data = sc->sc_unit;
541 		break;
542 
543 	case PPPIOCGFLAGS:
544 		*(u_int *)data = sc->sc_flags;
545 		break;
546 
547 	case PPPIOCGRAWIN:
548 	{
549 		struct ppp_rawin *rwin = (struct ppp_rawin *)data;
550 		u_char c, q = 0;
551 
552 		for (c = sc->sc_rawin_start; c < sizeof(sc->sc_rawin.buf);)
553 			rwin->buf[q++] = sc->sc_rawin.buf[c++];
554 
555 		for (c = 0; c < sc->sc_rawin_start;)
556 			rwin->buf[q++] = sc->sc_rawin.buf[c++];
557 
558 		rwin->count = sc->sc_rawin.count;
559 	}
560 	break;
561 
562 	case PPPIOCSFLAGS:
563 		flags = *(int *)data & SC_MASK;
564 		s = splsoftnet();
565 #ifdef PPP_COMPRESS
566 		if (sc->sc_flags & SC_CCP_OPEN && !(flags & SC_CCP_OPEN))
567 			ppp_ccp_closed(sc);
568 #endif
569 		splhigh();	/* XXX IMP ME HARDER */
570 		sc->sc_flags = (sc->sc_flags & ~SC_MASK) | flags;
571 		splx(s);
572 		break;
573 
574 	case PPPIOCSMRU:
575 		mru = *(int *)data;
576 		if (mru >= PPP_MINMRU && mru <= PPP_MAXMRU)
577 			sc->sc_mru = mru;
578 		break;
579 
580 	case PPPIOCGMRU:
581 		*(int *)data = sc->sc_mru;
582 		break;
583 
584 #ifdef VJC
585 	case PPPIOCSMAXCID:
586 		if (sc->sc_comp) {
587 			s = splsoftnet();
588 			sl_compress_setup(sc->sc_comp, *(int *)data);
589 			splx(s);
590 		}
591 		break;
592 #endif
593 
594 	case PPPIOCXFERUNIT:
595 		sc->sc_xfer = l->l_proc->p_pid;
596 		break;
597 
598 #ifdef PPP_COMPRESS
599 	case PPPIOCSCOMPRESS:
600 		odp = (struct ppp_option_data *)data;
601 		nb = odp->length;
602 		if (nb > sizeof(ccp_option))
603 			nb = sizeof(ccp_option);
604 		if (nb < 3)
605 			return EINVAL;
606 		if ((error = copyin(odp->ptr, ccp_option, nb)) != 0)
607 			return error;
608 		/* preliminary check on the length byte */
609 		if (ccp_option[1] < 2)
610 			return EINVAL;
611 		cp = ppp_get_compressor(ccp_option[0]);
612 		if (cp == NULL) {
613 			if (sc->sc_flags & SC_DEBUG)
614 				printf("%s: no compressor for [%x %x %x], %x\n",
615 				    sc->sc_if.if_xname, ccp_option[0],
616 				    ccp_option[1], ccp_option[2], nb);
617 			return EINVAL;	/* no handler found */
618 		}
619 		/*
620 		 * Found a handler for the protocol - try to allocate
621 		 * a compressor or decompressor.
622 		 */
623 		error = 0;
624 		if (odp->transmit) {
625 			s = splsoftnet();
626 			if (sc->sc_xc_state != NULL) {
627 				(*sc->sc_xcomp->comp_free)(sc->sc_xc_state);
628 				ppp_compressor_rele(sc->sc_xcomp);
629 			}
630 			sc->sc_xcomp = cp;
631 			sc->sc_xc_state = cp->comp_alloc(ccp_option, nb);
632 			if (sc->sc_xc_state == NULL) {
633 				if (sc->sc_flags & SC_DEBUG)
634 					printf("%s: comp_alloc failed\n",
635 					    sc->sc_if.if_xname);
636 				error = ENOBUFS;
637 			}
638 			splhigh();	/* XXX IMP ME HARDER */
639 			sc->sc_flags &= ~SC_COMP_RUN;
640 			splx(s);
641 		} else {
642 			s = splsoftnet();
643 			if (sc->sc_rc_state != NULL) {
644 				(*sc->sc_rcomp->decomp_free)(sc->sc_rc_state);
645 				ppp_compressor_rele(sc->sc_rcomp);
646 			}
647 			sc->sc_rcomp = cp;
648 			sc->sc_rc_state = cp->decomp_alloc(ccp_option, nb);
649 			if (sc->sc_rc_state == NULL) {
650 				if (sc->sc_flags & SC_DEBUG)
651 					printf("%s: decomp_alloc failed\n",
652 					    sc->sc_if.if_xname);
653 				error = ENOBUFS;
654 			}
655 			splhigh();	/* XXX IMP ME HARDER */
656 			sc->sc_flags &= ~SC_DECOMP_RUN;
657 			splx(s);
658 		}
659 		return error;
660 #endif /* PPP_COMPRESS */
661 
662 	case PPPIOCGNPMODE:
663 	case PPPIOCSNPMODE:
664 		npi = (struct npioctl *)data;
665 		switch (npi->protocol) {
666 		case PPP_IP:
667 			npx = NP_IP;
668 			break;
669 		case PPP_IPV6:
670 			npx = NP_IPV6;
671 			break;
672 		default:
673 			return EINVAL;
674 		}
675 		if (cmd == PPPIOCGNPMODE) {
676 			npi->mode = sc->sc_npmode[npx];
677 		} else {
678 			if (npi->mode != sc->sc_npmode[npx]) {
679 				s = splnet();
680 				sc->sc_npmode[npx] = npi->mode;
681 				if (npi->mode != NPMODE_QUEUE) {
682 					ppp_requeue(sc);
683 					ppp_restart(sc);
684 				}
685 				splx(s);
686 			}
687 		}
688 		break;
689 
690 	case PPPIOCGIDLE:
691 		s = splsoftnet();
692 		t = time_second;
693 		((struct ppp_idle *)data)->xmit_idle = t - sc->sc_last_sent;
694 		((struct ppp_idle *)data)->recv_idle = t - sc->sc_last_recv;
695 		splx(s);
696 		break;
697 
698 #ifdef PPP_FILTER
699 	case PPPIOCSPASS:
700 	case PPPIOCSACTIVE:
701 		/* These are no longer supported. */
702 		return EOPNOTSUPP;
703 
704 	case PPPIOCSIPASS:
705 	case PPPIOCSOPASS:
706 	case PPPIOCSIACTIVE:
707 	case PPPIOCSOACTIVE:
708 		nbp = (struct bpf_program *)data;
709 		if ((unsigned) nbp->bf_len > BPF_MAXINSNS)
710 			return EINVAL;
711 		newcodelen = nbp->bf_len * sizeof(struct bpf_insn);
712 		if (newcodelen != 0) {
713 			newcode = malloc(newcodelen, M_DEVBUF, M_WAITOK);
714 			/* WAITOK -- malloc() never fails. */
715 			if ((error = copyin((void *)nbp->bf_insns,
716 				    (void *)newcode, newcodelen)) != 0) {
717 				free(newcode, M_DEVBUF);
718 				return error;
719 			}
720 			if (!bpf_validate(newcode, nbp->bf_len)) {
721 				free(newcode, M_DEVBUF);
722 				return EINVAL;
723 			}
724 		} else
725 			newcode = 0;
726 		switch (cmd) {
727 		case PPPIOCSIPASS:
728 			bp = &sc->sc_pass_filt_in;
729 			break;
730 
731 		case PPPIOCSOPASS:
732 			bp = &sc->sc_pass_filt_out;
733 			break;
734 
735 		case PPPIOCSIACTIVE:
736 			bp = &sc->sc_active_filt_in;
737 			break;
738 
739 		case PPPIOCSOACTIVE:
740 			bp = &sc->sc_active_filt_out;
741 			break;
742 		default:
743 			free(newcode, M_DEVBUF);
744 			return EPASSTHROUGH;
745 		}
746 		oldcode = bp->bf_insns;
747 		s = splnet();
748 		bp->bf_len = nbp->bf_len;
749 		bp->bf_insns = newcode;
750 		splx(s);
751 		if (oldcode != 0)
752 			free(oldcode, M_DEVBUF);
753 		break;
754 #endif /* PPP_FILTER */
755 
756 	default:
757 		return EPASSTHROUGH;
758 	}
759 	return 0;
760 }
761 
762 /*
763  * Process an ioctl request to the ppp network interface.
764  */
765 static int
766 pppsioctl(struct ifnet *ifp, u_long cmd, void *data)
767 {
768 	struct ppp_softc *sc = ifp->if_softc;
769 	struct ifaddr *ifa = (struct ifaddr *)data;
770 	struct ifreq *ifr = (struct ifreq *)data;
771 	struct ppp_stats *psp;
772 #ifdef	PPP_COMPRESS
773 	struct ppp_comp_stats *pcp;
774 #endif
775 	int s = splnet(), error = 0;
776 
777 	switch (cmd) {
778 	case SIOCSIFFLAGS:
779 		if ((error = ifioctl_common(ifp, cmd, data)) != 0)
780 			break;
781 		if ((ifp->if_flags & IFF_RUNNING) == 0)
782 			ifp->if_flags &= ~IFF_UP;
783 		break;
784 
785 	case SIOCINITIFADDR:
786 		switch (ifa->ifa_addr->sa_family) {
787 #ifdef INET
788 		case AF_INET:
789 			break;
790 #endif
791 #ifdef INET6
792 		case AF_INET6:
793 			break;
794 #endif
795 		default:
796 			printf("%s: af%d not supported\n", ifp->if_xname,
797 			    ifa->ifa_addr->sa_family);
798 			error = EAFNOSUPPORT;
799 			break;
800 		}
801 		ifa->ifa_rtrequest = p2p_rtrequest;
802 		break;
803 
804 	case SIOCADDMULTI:
805 	case SIOCDELMULTI:
806 		if (ifr == NULL) {
807 			error = EAFNOSUPPORT;
808 			break;
809 		}
810 		switch (ifreq_getaddr(cmd, ifr)->sa_family) {
811 #ifdef INET
812 		case AF_INET:
813 			break;
814 #endif
815 #ifdef INET6
816 		case AF_INET6:
817 			break;
818 #endif
819 		default:
820 			error = EAFNOSUPPORT;
821 			break;
822 		}
823 		break;
824 
825 	case SIOCGPPPSTATS:
826 		psp = &((struct ifpppstatsreq *)data)->stats;
827 		memset(psp, 0, sizeof(*psp));
828 		psp->p = sc->sc_stats;
829 #if defined(VJC) && !defined(SL_NO_STATS)
830 		if (sc->sc_comp) {
831 			psp->vj.vjs_packets = sc->sc_comp->sls_packets;
832 			psp->vj.vjs_compressed = sc->sc_comp->sls_compressed;
833 			psp->vj.vjs_searches = sc->sc_comp->sls_searches;
834 			psp->vj.vjs_misses = sc->sc_comp->sls_misses;
835 			psp->vj.vjs_uncompressedin = sc->sc_comp->sls_uncompressedin;
836 			psp->vj.vjs_compressedin = sc->sc_comp->sls_compressedin;
837 			psp->vj.vjs_errorin = sc->sc_comp->sls_errorin;
838 			psp->vj.vjs_tossed = sc->sc_comp->sls_tossed;
839 		}
840 #endif /* VJC */
841 		break;
842 
843 #ifdef PPP_COMPRESS
844 	case SIOCGPPPCSTATS:
845 		pcp = &((struct ifpppcstatsreq *)data)->stats;
846 		memset(pcp, 0, sizeof(*pcp));
847 		if (sc->sc_xc_state != NULL)
848 			(*sc->sc_xcomp->comp_stat)(sc->sc_xc_state, &pcp->c);
849 		if (sc->sc_rc_state != NULL)
850 			(*sc->sc_rcomp->decomp_stat)(sc->sc_rc_state, &pcp->d);
851 		break;
852 #endif /* PPP_COMPRESS */
853 
854 	default:
855 		if ((error = ifioctl_common(&sc->sc_if, cmd, data)) == ENETRESET)
856 			error = 0;
857 		break;
858 	}
859 	splx(s);
860 	return error;
861 }
862 
863 /*
864  * Queue a packet.  Start transmission if not active.
865  * Packet is placed in Information field of PPP frame.
866  */
867 int
868 pppoutput(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst,
869     const struct rtentry *rtp)
870 {
871 	struct ppp_softc *sc = ifp->if_softc;
872 	int protocol, address, control;
873 	u_char *cp;
874 	int s, error;
875 #ifdef INET
876 	struct ip *ip;
877 #endif
878 	struct ifqueue *ifq;
879 	enum NPmode mode;
880 	int len;
881 
882 	    if (sc->sc_devp == NULL ||
883 		(ifp->if_flags & IFF_RUNNING) == 0 ||
884 		((ifp->if_flags & IFF_UP) == 0 &&
885 		    dst->sa_family != AF_UNSPEC)) {
886 		    error = ENETDOWN;	/* sort of */
887 		    goto bad;
888 	    }
889 
890 	IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family);
891 
892 	/*
893 	 * Compute PPP header.
894 	 */
895 	m0->m_flags &= ~M_HIGHPRI;
896 	switch (dst->sa_family) {
897 #ifdef INET
898 	case AF_INET:
899 		address = PPP_ALLSTATIONS;
900 		control = PPP_UI;
901 		protocol = PPP_IP;
902 		mode = sc->sc_npmode[NP_IP];
903 
904 		/*
905 		 * If this packet has the "low delay" bit set in the IP header,
906 		 * put it on the fastq instead.
907 		 */
908 		ip = mtod(m0, struct ip *);
909 		if (ip->ip_tos & IPTOS_LOWDELAY)
910 			m0->m_flags |= M_HIGHPRI;
911 		break;
912 #endif
913 #ifdef INET6
914 	case AF_INET6:
915 		address = PPP_ALLSTATIONS;	/*XXX*/
916 		control = PPP_UI;		/*XXX*/
917 		protocol = PPP_IPV6;
918 		mode = sc->sc_npmode[NP_IPV6];
919 
920 #if 0	/* XXX flowinfo/traffic class, maybe? */
921 	/*
922 	 * If this packet has the "low delay" bit set in the IP header,
923 	 * put it on the fastq instead.
924 	 */
925 		ip = mtod(m0, struct ip *);
926 		if (ip->ip_tos & IPTOS_LOWDELAY)
927 			m0->m_flags |= M_HIGHPRI;
928 #endif
929 		break;
930 #endif
931 	case AF_UNSPEC:
932 		address = PPP_ADDRESS(dst->sa_data);
933 		control = PPP_CONTROL(dst->sa_data);
934 		protocol = PPP_PROTOCOL(dst->sa_data);
935 		mode = NPMODE_PASS;
936 		break;
937 	default:
938 		printf("%s: af%d not supported\n", ifp->if_xname,
939 		    dst->sa_family);
940 		error = EAFNOSUPPORT;
941 		goto bad;
942 	}
943 
944 	/*
945 	 * Drop this packet, or return an error, if necessary.
946 	 */
947 	if (mode == NPMODE_ERROR) {
948 		error = ENETDOWN;
949 		goto bad;
950 	}
951 	if (mode == NPMODE_DROP) {
952 		error = 0;
953 		goto bad;
954 	}
955 
956 	/*
957 	 * Add PPP header.
958 	 */
959 	M_PREPEND(m0, PPP_HDRLEN, M_DONTWAIT);
960 	if (m0 == NULL) {
961 		error = ENOBUFS;
962 		goto bad;
963 	}
964 
965 	cp = mtod(m0, u_char *);
966 	*cp++ = address;
967 	*cp++ = control;
968 	*cp++ = protocol >> 8;
969 	*cp++ = protocol & 0xff;
970 
971 	len = m_length(m0);
972 
973 	if (sc->sc_flags & SC_LOG_OUTPKT) {
974 		printf("%s output: ", ifp->if_xname);
975 		pppdumpm(m0);
976 	}
977 
978 	if ((protocol & 0x8000) == 0) {
979 #ifdef PPP_FILTER
980 		/*
981 		 * Apply the pass and active filters to the packet,
982 		 * but only if it is a data packet.
983 		 */
984 		if (sc->sc_pass_filt_out.bf_insns != 0 &&
985 		    bpf_filter(sc->sc_pass_filt_out.bf_insns,
986 			(u_char *)m0, len, 0) == 0) {
987 			error = 0;		/* drop this packet */
988 			goto bad;
989 		}
990 
991 		/*
992 		 * Update the time we sent the most recent packet.
993 		 */
994 		if (sc->sc_active_filt_out.bf_insns == 0 ||
995 		    bpf_filter(sc->sc_active_filt_out.bf_insns,
996 			(u_char *)m0, len, 0))
997 			sc->sc_last_sent = time_second;
998 #else
999 		/*
1000 		 * Update the time we sent the most recent packet.
1001 		 */
1002 		sc->sc_last_sent = time_second;
1003 #endif /* PPP_FILTER */
1004 	}
1005 
1006 	/*
1007 	 * See if bpf wants to look at the packet.
1008 	 */
1009 	bpf_mtap(&sc->sc_if, m0, BPF_D_OUT);
1010 
1011 	/*
1012 	 * Put the packet on the appropriate queue.
1013 	 */
1014 	s = splnet();
1015 	if (mode == NPMODE_QUEUE) {
1016 		/* XXX we should limit the number of packets on this queue */
1017 		*sc->sc_npqtail = m0;
1018 		m0->m_nextpkt = NULL;
1019 		sc->sc_npqtail = &m0->m_nextpkt;
1020 	} else {
1021 		ifq = (m0->m_flags & M_HIGHPRI) ? &sc->sc_fastq : NULL;
1022 		if ((error = ifq_enqueue2(&sc->sc_if, ifq, m0)) != 0) {
1023 			splx(s);
1024 			if_statinc(&sc->sc_if, if_oerrors);
1025 			sc->sc_stats.ppp_oerrors++;
1026 			return error;
1027 		}
1028 		ppp_restart(sc);
1029 	}
1030 	if_statadd2(ifp, if_opackets, 1, if_obytes, len);
1031 
1032 	splx(s);
1033 	return 0;
1034 
1035 bad:
1036 	m_freem(m0);
1037 	return error;
1038 }
1039 
1040 /*
1041  * After a change in the NPmode for some NP, move packets from the
1042  * npqueue to the send queue or the fast queue as appropriate.
1043  * Should be called at splnet, since we muck with the queues.
1044  */
1045 static void
1046 ppp_requeue(struct ppp_softc *sc)
1047 {
1048 	struct mbuf *m, **mpp;
1049 	struct ifqueue *ifq;
1050 	enum NPmode mode;
1051 	int error;
1052 
1053 	for (mpp = &sc->sc_npqueue; (m = *mpp) != NULL; ) {
1054 		switch (PPP_PROTOCOL(mtod(m, u_char *))) {
1055 		case PPP_IP:
1056 			mode = sc->sc_npmode[NP_IP];
1057 			break;
1058 		case PPP_IPV6:
1059 			mode = sc->sc_npmode[NP_IPV6];
1060 			break;
1061 		default:
1062 			mode = NPMODE_PASS;
1063 		}
1064 
1065 		switch (mode) {
1066 		case NPMODE_PASS:
1067 			/*
1068 			 * This packet can now go on one of the queues to
1069 			 * be sent.
1070 			 */
1071 			*mpp = m->m_nextpkt;
1072 			m->m_nextpkt = NULL;
1073 			ifq = (m->m_flags & M_HIGHPRI) ? &sc->sc_fastq : NULL;
1074 			if ((error = ifq_enqueue2(&sc->sc_if, ifq, m)) != 0) {
1075 				if_statinc(&sc->sc_if, if_oerrors);
1076 				sc->sc_stats.ppp_oerrors++;
1077 			}
1078 			break;
1079 
1080 		case NPMODE_DROP:
1081 		case NPMODE_ERROR:
1082 			*mpp = m->m_nextpkt;
1083 			m_freem(m);
1084 			break;
1085 
1086 		case NPMODE_QUEUE:
1087 			mpp = &m->m_nextpkt;
1088 			break;
1089 		}
1090 	}
1091 	sc->sc_npqtail = mpp;
1092 }
1093 
1094 /*
1095  * Transmitter has finished outputting some stuff;
1096  * remember to call sc->sc_start later at splsoftnet.
1097  */
1098 void
1099 ppp_restart(struct ppp_softc *sc)
1100 {
1101 	int s = splhigh();	/* XXX IMP ME HARDER */
1102 
1103 	sc->sc_flags &= ~SC_TBUSY;
1104 	softint_schedule(sc->sc_si);
1105 	splx(s);
1106 }
1107 
1108 /*
1109  * Get a packet to send.  This procedure is intended to be called at
1110  * splsoftnet, since it may involve time-consuming operations such as
1111  * applying VJ compression, packet compression, address/control and/or
1112  * protocol field compression to the packet.
1113  */
1114 struct mbuf *
1115 ppp_dequeue(struct ppp_softc *sc)
1116 {
1117 	struct mbuf *m, *mp;
1118 	u_char *cp;
1119 	int address, control, protocol;
1120 	int s;
1121 
1122 	/*
1123 	 * Grab a packet to send: first try the fast queue, then the
1124 	 * normal queue.
1125 	 */
1126 	s = splnet();
1127 	if (sc->sc_nfastq < sc->sc_maxfastq) {
1128 		IF_DEQUEUE(&sc->sc_fastq, m);
1129 		if (m != NULL)
1130 			sc->sc_nfastq++;
1131 		else
1132 			IFQ_DEQUEUE(&sc->sc_if.if_snd, m);
1133 	} else {
1134 		sc->sc_nfastq = 0;
1135 		IFQ_DEQUEUE(&sc->sc_if.if_snd, m);
1136 		if (m == NULL) {
1137 			IF_DEQUEUE(&sc->sc_fastq, m);
1138 			if (m != NULL)
1139 				sc->sc_nfastq++;
1140 		}
1141 	}
1142 	splx(s);
1143 
1144 	if (m == NULL)
1145 		return NULL;
1146 
1147 	++sc->sc_stats.ppp_opackets;
1148 
1149 	/*
1150 	 * Extract the ppp header of the new packet.
1151 	 * The ppp header will be in one mbuf.
1152 	 */
1153 	cp = mtod(m, u_char *);
1154 	address = PPP_ADDRESS(cp);
1155 	control = PPP_CONTROL(cp);
1156 	protocol = PPP_PROTOCOL(cp);
1157 
1158 	switch (protocol) {
1159 	case PPP_IP:
1160 #ifdef VJC
1161 		/*
1162 		 * If the packet is a TCP/IP packet, see if we can compress it.
1163 		 */
1164 		if ((sc->sc_flags & SC_COMP_TCP) && sc->sc_comp != NULL) {
1165 			struct ip *ip;
1166 			int type;
1167 
1168 			mp = m;
1169 			ip = (struct ip *)(cp + PPP_HDRLEN);
1170 			if (mp->m_len <= PPP_HDRLEN) {
1171 				mp = mp->m_next;
1172 				if (mp == NULL)
1173 					break;
1174 				ip = mtod(mp, struct ip *);
1175 			}
1176 			/*
1177 			 * This code assumes the IP/TCP header is in one
1178 			 * non-shared mbuf
1179 			 */
1180 			if (ip->ip_p == IPPROTO_TCP) {
1181 				type = sl_compress_tcp(mp, ip, sc->sc_comp,
1182 				    !(sc->sc_flags & SC_NO_TCP_CCID));
1183 				switch (type) {
1184 				case TYPE_UNCOMPRESSED_TCP:
1185 					protocol = PPP_VJC_UNCOMP;
1186 					break;
1187 				case TYPE_COMPRESSED_TCP:
1188 					protocol = PPP_VJC_COMP;
1189 					cp = mtod(m, u_char *);
1190 					cp[0] = address; /* Header has moved */
1191 					cp[1] = control;
1192 					cp[2] = 0;
1193 					break;
1194 				}
1195 				/* Update protocol in PPP header */
1196 				cp[3] = protocol;
1197 			}
1198 		}
1199 #endif	/* VJC */
1200 		break;
1201 
1202 #ifdef PPP_COMPRESS
1203 	case PPP_CCP:
1204 		ppp_ccp(sc, m, 0);
1205 		break;
1206 #endif	/* PPP_COMPRESS */
1207 	}
1208 
1209 #ifdef PPP_COMPRESS
1210 	if (protocol != PPP_LCP && protocol != PPP_CCP &&
1211 	    sc->sc_xc_state && (sc->sc_flags & SC_COMP_RUN)) {
1212 		struct mbuf *mcomp = NULL;
1213 		int slen;
1214 
1215 		slen = 0;
1216 		for (mp = m; mp != NULL; mp = mp->m_next)
1217 			slen += mp->m_len;
1218 		(*sc->sc_xcomp->compress)
1219 		    (sc->sc_xc_state, &mcomp, m, slen, sc->sc_if.if_mtu + PPP_HDRLEN);
1220 		if (mcomp != NULL) {
1221 			if (sc->sc_flags & SC_CCP_UP) {
1222 				/*
1223 				 * Send the compressed packet instead of the
1224 				 * original.
1225 				 */
1226 				m_freem(m);
1227 				m = mcomp;
1228 				cp = mtod(m, u_char *);
1229 				protocol = cp[3];
1230 			} else {
1231 				/*
1232 				 * Can't transmit compressed packets until CCP
1233 				 * is up.
1234 				 */
1235 				m_freem(mcomp);
1236 			}
1237 		}
1238 	}
1239 #endif	/* PPP_COMPRESS */
1240 
1241 	/*
1242 	 * Compress the address/control and protocol, if possible.
1243 	 */
1244 	if (sc->sc_flags & SC_COMP_AC && address == PPP_ALLSTATIONS &&
1245 	    control == PPP_UI && protocol != PPP_ALLSTATIONS &&
1246 	    protocol != PPP_LCP) {
1247 		/* can compress address/control */
1248 		m->m_data += 2;
1249 		m->m_len -= 2;
1250 	}
1251 	if (sc->sc_flags & SC_COMP_PROT && protocol < 0xFF) {
1252 		/* can compress protocol */
1253 		if (mtod(m, u_char *) == cp) {
1254 			cp[2] = cp[1];	/* move address/control up */
1255 			cp[1] = cp[0];
1256 		}
1257 		++m->m_data;
1258 		--m->m_len;
1259 	}
1260 
1261 	return m;
1262 }
1263 
1264 /*
1265  * Software interrupt routine, called at splsoftnet.
1266  */
1267 static void
1268 pppintr(void *arg)
1269 {
1270 	struct ppp_softc *sc = arg;
1271 	struct mbuf *m;
1272 	int s;
1273 
1274 	mutex_enter(softnet_lock);
1275 	if (!(sc->sc_flags & SC_TBUSY) &&
1276 	    (IFQ_IS_EMPTY(&sc->sc_if.if_snd) == 0 ||
1277 		sc->sc_fastq.ifq_head ||
1278 		sc->sc_outm)) {
1279 		s = splhigh();	/* XXX IMP ME HARDER */
1280 		sc->sc_flags |= SC_TBUSY;
1281 		splx(s);
1282 		(*sc->sc_start)(sc);
1283 	}
1284 	for (;;) {
1285 		s = splnet();
1286 		IF_DEQUEUE(&sc->sc_rawq, m);
1287 		splx(s);
1288 		if (m == NULL)
1289 			break;
1290 		ppp_inproc(sc, m);
1291 	}
1292 	mutex_exit(softnet_lock);
1293 }
1294 
1295 #ifdef PPP_COMPRESS
1296 /*
1297  * Handle a CCP packet.	 `rcvd' is 1 if the packet was received,
1298  * 0 if it is about to be transmitted.
1299  */
1300 static void
1301 ppp_ccp(struct ppp_softc *sc, struct mbuf *m, int rcvd)
1302 {
1303 	u_char *dp, *ep;
1304 	struct mbuf *mp;
1305 	int slen, s;
1306 
1307 	/*
1308 	 * Get a pointer to the data after the PPP header.
1309 	 */
1310 	if (m->m_len <= PPP_HDRLEN) {
1311 		mp = m->m_next;
1312 		if (mp == NULL)
1313 			return;
1314 		dp = mtod(mp, u_char *);
1315 	} else {
1316 		mp = m;
1317 		dp = mtod(mp, u_char *) + PPP_HDRLEN;
1318 	}
1319 
1320 	ep = mtod(mp, u_char *) + mp->m_len;
1321 	if (dp + CCP_HDRLEN > ep)
1322 		return;
1323 	slen = CCP_LENGTH(dp);
1324 	if (dp + slen > ep) {
1325 		if (sc->sc_flags & SC_DEBUG)
1326 			printf("if_ppp/ccp: not enough data in mbuf (%p+%x > %p+%x)\n",
1327 			    dp, slen, mtod(mp, u_char *), mp->m_len);
1328 		return;
1329 	}
1330 
1331 	switch (CCP_CODE(dp)) {
1332 	case CCP_CONFREQ:
1333 	case CCP_TERMREQ:
1334 	case CCP_TERMACK:
1335 		/* CCP must be going down - disable compression */
1336 		if (sc->sc_flags & SC_CCP_UP) {
1337 			s = splhigh();	/* XXX IMP ME HARDER */
1338 			sc->sc_flags &= ~(SC_CCP_UP | SC_COMP_RUN | SC_DECOMP_RUN);
1339 			splx(s);
1340 		}
1341 		break;
1342 
1343 	case CCP_CONFACK:
1344 		if (sc->sc_flags & SC_CCP_OPEN &&
1345 		    !(sc->sc_flags & SC_CCP_UP) &&
1346 		    slen >= CCP_HDRLEN + CCP_OPT_MINLEN &&
1347 		    slen >= CCP_OPT_LENGTH(dp + CCP_HDRLEN) + CCP_HDRLEN) {
1348 			if (!rcvd) {
1349 				/* We're agreeing to send compressed packets. */
1350 				if (sc->sc_xc_state != NULL &&
1351 				    (*sc->sc_xcomp->comp_init)(sc->sc_xc_state,
1352 					dp + CCP_HDRLEN, slen - CCP_HDRLEN,
1353 					sc->sc_unit, 0,
1354 					sc->sc_flags & SC_DEBUG)) {
1355 					s = splhigh();	/* XXX IMP ME HARDER */
1356 					sc->sc_flags |= SC_COMP_RUN;
1357 					splx(s);
1358 				}
1359 			} else {
1360 				/*
1361 				 * Peer is agreeing to send compressed
1362 				 * packets.
1363 				 */
1364 				if (sc->sc_rc_state != NULL &&
1365 				    (*sc->sc_rcomp->decomp_init)(
1366 					sc->sc_rc_state,
1367 					dp + CCP_HDRLEN, slen - CCP_HDRLEN,
1368 					sc->sc_unit, 0, sc->sc_mru,
1369 					sc->sc_flags & SC_DEBUG)) {
1370 					s = splhigh();	/* XXX IMP ME HARDER */
1371 					sc->sc_flags |= SC_DECOMP_RUN;
1372 					sc->sc_flags &=
1373 					    ~(SC_DC_ERROR | SC_DC_FERROR);
1374 					splx(s);
1375 				}
1376 			}
1377 		}
1378 		break;
1379 
1380 	case CCP_RESETACK:
1381 		if (sc->sc_flags & SC_CCP_UP) {
1382 			if (!rcvd) {
1383 				if (sc->sc_xc_state && (sc->sc_flags & SC_COMP_RUN))
1384 					(*sc->sc_xcomp->comp_reset)(sc->sc_xc_state);
1385 			} else {
1386 				if (sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN)) {
1387 					(*sc->sc_rcomp->decomp_reset)(sc->sc_rc_state);
1388 					s = splhigh();	/* XXX IMP ME HARDER */
1389 					sc->sc_flags &= ~SC_DC_ERROR;
1390 					splx(s);
1391 				}
1392 			}
1393 		}
1394 		break;
1395 	}
1396 }
1397 
1398 /*
1399  * CCP is down; free (de)compressor state if necessary.
1400  */
1401 static void
1402 ppp_ccp_closed(struct ppp_softc *sc)
1403 {
1404 	if (sc->sc_xc_state) {
1405 		(*sc->sc_xcomp->comp_free)(sc->sc_xc_state);
1406 		ppp_compressor_rele(sc->sc_xcomp);
1407 		sc->sc_xc_state = NULL;
1408 	}
1409 	if (sc->sc_rc_state) {
1410 		(*sc->sc_rcomp->decomp_free)(sc->sc_rc_state);
1411 		ppp_compressor_rele(sc->sc_rcomp);
1412 		sc->sc_rc_state = NULL;
1413 	}
1414 }
1415 #endif /* PPP_COMPRESS */
1416 
1417 /*
1418  * PPP packet input routine.
1419  * The caller has checked and removed the FCS and has inserted
1420  * the address/control bytes and the protocol high byte if they
1421  * were omitted.
1422  */
1423 void
1424 ppppktin(struct ppp_softc *sc, struct mbuf *m, int lost)
1425 {
1426 	int s = splhigh();	/* XXX IMP ME HARDER */
1427 
1428 	if (lost)
1429 		m->m_flags |= M_ERRMARK;
1430 	IF_ENQUEUE(&sc->sc_rawq, m);
1431 	softint_schedule(sc->sc_si);
1432 	splx(s);
1433 }
1434 
1435 /*
1436  * Process a received PPP packet, doing decompression as necessary.
1437  * Should be called at splsoftnet.
1438  */
1439 #define COMPTYPE(proto)							      \
1440 	((proto) == PPP_VJC_COMP ? TYPE_COMPRESSED_TCP			      \
1441 	    : TYPE_UNCOMPRESSED_TCP)
1442 
1443 static void
1444 ppp_inproc(struct ppp_softc *sc, struct mbuf *m)
1445 {
1446 	struct ifnet *ifp = &sc->sc_if;
1447 	pktqueue_t *pktq = NULL;
1448 	struct ifqueue *inq = NULL;
1449 	int s, ilen, proto, rv;
1450 	u_char *cp, adrs, ctrl;
1451 	struct mbuf *mp, *dmp = NULL;
1452 #ifdef VJC
1453 	int xlen;
1454 	u_char *iphdr;
1455 	u_int hlen;
1456 #endif
1457 
1458 	sc->sc_stats.ppp_ipackets++;
1459 
1460 	if (sc->sc_flags & SC_LOG_INPKT) {
1461 		ilen = 0;
1462 		for (mp = m; mp != NULL; mp = mp->m_next)
1463 			ilen += mp->m_len;
1464 		printf("%s: got %d bytes\n", ifp->if_xname, ilen);
1465 		pppdumpm(m);
1466 	}
1467 
1468 	cp = mtod(m, u_char *);
1469 	adrs = PPP_ADDRESS(cp);
1470 	ctrl = PPP_CONTROL(cp);
1471 	proto = PPP_PROTOCOL(cp);
1472 
1473 	if (m->m_flags & M_ERRMARK) {
1474 		m->m_flags &= ~M_ERRMARK;
1475 		s = splhigh();	/* XXX IMP ME HARDER */
1476 		sc->sc_flags |= SC_VJ_RESET;
1477 		splx(s);
1478 	}
1479 
1480 #ifdef PPP_COMPRESS
1481 	/*
1482 	 * Decompress this packet if necessary, update the receiver's
1483 	 * dictionary, or take appropriate action on a CCP packet.
1484 	 */
1485 	if (proto == PPP_COMP &&
1486 	    sc->sc_rc_state &&
1487 	    (sc->sc_flags & SC_DECOMP_RUN) &&
1488 	    !(sc->sc_flags & SC_DC_ERROR) &&
1489 	    !(sc->sc_flags & SC_DC_FERROR)) {
1490 		/* Decompress this packet */
1491 		rv = (*sc->sc_rcomp->decompress)(sc->sc_rc_state, m, &dmp);
1492 		if (rv == DECOMP_OK) {
1493 			m_freem(m);
1494 			if (dmp == NULL) {
1495 				/*
1496 				 * No error, but no decompressed packet
1497 				 * produced
1498 				 */
1499 				return;
1500 			}
1501 			m = dmp;
1502 			cp = mtod(m, u_char *);
1503 			proto = PPP_PROTOCOL(cp);
1504 
1505 		} else {
1506 			/*
1507 			 * An error has occurred in decompression.
1508 			 * Pass the compressed packet up to pppd, which may
1509 			 * take CCP down or issue a Reset-Req.
1510 			 */
1511 			if (sc->sc_flags & SC_DEBUG)
1512 				printf("%s: decompress failed %d\n",
1513 				    ifp->if_xname, rv);
1514 			s = splhigh();	/* XXX IMP ME HARDER */
1515 			sc->sc_flags |= SC_VJ_RESET;
1516 			if (rv == DECOMP_ERROR)
1517 				sc->sc_flags |= SC_DC_ERROR;
1518 			else
1519 				sc->sc_flags |= SC_DC_FERROR;
1520 			splx(s);
1521 		}
1522 
1523 	} else {
1524 		if (sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN))
1525 			(*sc->sc_rcomp->incomp)(sc->sc_rc_state, m);
1526 		if (proto == PPP_CCP)
1527 			ppp_ccp(sc, m, 1);
1528 	}
1529 #endif
1530 
1531 	ilen = 0;
1532 	for (mp = m; mp != NULL; mp = mp->m_next)
1533 		ilen += mp->m_len;
1534 
1535 #ifdef VJC
1536 	if (sc->sc_flags & SC_VJ_RESET) {
1537 		/*
1538 		 * If we've missed a packet, we must toss subsequent compressed
1539 		 * packets which don't have an explicit connection ID.
1540 		 */
1541 		if (sc->sc_comp)
1542 			sl_uncompress_tcp(NULL, 0, TYPE_ERROR, sc->sc_comp);
1543 		s = splhigh();	/* XXX IMP ME HARDER */
1544 		sc->sc_flags &= ~SC_VJ_RESET;
1545 		splx(s);
1546 	}
1547 
1548 	/*
1549 	 * See if we have a VJ-compressed packet to uncompress.
1550 	 */
1551 	if (proto == PPP_VJC_COMP) {
1552 		if ((sc->sc_flags & SC_REJ_COMP_TCP) || sc->sc_comp == 0)
1553 			goto bad;
1554 
1555 		xlen = sl_uncompress_tcp_core(cp + PPP_HDRLEN,
1556 		    m->m_len - PPP_HDRLEN, ilen - PPP_HDRLEN,
1557 		    TYPE_COMPRESSED_TCP, sc->sc_comp, &iphdr, &hlen);
1558 		if (xlen <= 0) {
1559 			if (sc->sc_flags & SC_DEBUG) {
1560 				printf("%s: VJ uncompress failed"
1561 				    " on type comp\n",
1562 				    ifp->if_xname);
1563 			}
1564 			goto bad;
1565 		}
1566 
1567 		/* Copy the PPP and IP headers into a new mbuf. */
1568 		MGETHDR(mp, M_DONTWAIT, MT_DATA);
1569 		if (mp == NULL)
1570 			goto bad;
1571 		mp->m_len = 0;
1572 		mp->m_next = NULL;
1573 		if (hlen + PPP_HDRLEN > MHLEN) {
1574 			MCLGET(mp, M_DONTWAIT);
1575 			if (M_TRAILINGSPACE(mp) < hlen + PPP_HDRLEN) {
1576 				/* Lose if big headers and no clusters */
1577 				m_freem(mp);
1578 				goto bad;
1579 			}
1580 		}
1581 		cp = mtod(mp, u_char *);
1582 		cp[0] = adrs;
1583 		cp[1] = ctrl;
1584 		cp[2] = 0;
1585 		cp[3] = PPP_IP;
1586 		proto = PPP_IP;
1587 		bcopy(iphdr, cp + PPP_HDRLEN, hlen);
1588 		mp->m_len = hlen + PPP_HDRLEN;
1589 
1590 		/*
1591 		 * Trim the PPP and VJ headers off the old mbuf
1592 		 * and stick the new and old mbufs together.
1593 		 */
1594 		m->m_data += PPP_HDRLEN + xlen;
1595 		m->m_len -= PPP_HDRLEN + xlen;
1596 		if (m->m_len <= M_TRAILINGSPACE(mp)) {
1597 			bcopy(mtod(m, u_char *),
1598 			    mtod(mp, u_char *) + mp->m_len, m->m_len);
1599 			mp->m_len += m->m_len;
1600 			mp->m_next = m_free(m);
1601 		} else
1602 			mp->m_next = m;
1603 		m = mp;
1604 		ilen += hlen - xlen;
1605 
1606 	} else if (proto == PPP_VJC_UNCOMP) {
1607 		if ((sc->sc_flags & SC_REJ_COMP_TCP) || sc->sc_comp == 0)
1608 			goto bad;
1609 
1610 		xlen = sl_uncompress_tcp_core(cp + PPP_HDRLEN,
1611 		    m->m_len - PPP_HDRLEN, ilen - PPP_HDRLEN,
1612 		    TYPE_UNCOMPRESSED_TCP, sc->sc_comp, &iphdr, &hlen);
1613 		if (xlen < 0) {
1614 			if (sc->sc_flags & SC_DEBUG) {
1615 				printf("%s: VJ uncompress failed"
1616 				    " on type uncomp\n",
1617 				    ifp->if_xname);
1618 			}
1619 			goto bad;
1620 		}
1621 
1622 		proto = PPP_IP;
1623 		cp[3] = PPP_IP;
1624 	}
1625 #endif /* VJC */
1626 
1627 	/*
1628 	 * If the packet will fit in a header mbuf, don't waste a
1629 	 * whole cluster on it.
1630 	 */
1631 	if (ilen <= MHLEN && (m->m_flags & M_EXT)) {
1632 		MGETHDR(mp, M_DONTWAIT, MT_DATA);
1633 		if (mp != NULL) {
1634 			m_copydata(m, 0, ilen, mtod(mp, void *));
1635 			m_freem(m);
1636 			m = mp;
1637 			m->m_len = ilen;
1638 		}
1639 	}
1640 	m->m_pkthdr.len = ilen;
1641 	m_set_rcvif(m, ifp);
1642 
1643 	if ((proto & 0x8000) == 0) {
1644 #ifdef PPP_FILTER
1645 		/*
1646 		 * See whether we want to pass this packet, and
1647 		 * if it counts as link activity.
1648 		 */
1649 		if (sc->sc_pass_filt_in.bf_insns != 0 &&
1650 		    bpf_filter(sc->sc_pass_filt_in.bf_insns,
1651 			(u_char *)m, ilen, 0) == 0) {
1652 			/* drop this packet */
1653 			m_freem(m);
1654 			return;
1655 		}
1656 		if (sc->sc_active_filt_in.bf_insns == 0 ||
1657 		    bpf_filter(sc->sc_active_filt_in.bf_insns,
1658 			(u_char *)m, ilen, 0))
1659 			sc->sc_last_recv = time_second;
1660 #else
1661 		/*
1662 		 * Record the time that we received this packet.
1663 		 */
1664 		sc->sc_last_recv = time_second;
1665 #endif /* PPP_FILTER */
1666 	}
1667 
1668 	/* See if bpf wants to look at the packet. */
1669 	bpf_mtap(&sc->sc_if, m, BPF_D_IN);
1670 
1671 	switch (proto) {
1672 #ifdef INET
1673 	case PPP_IP:
1674 		/*
1675 		 * IP packet - take off the ppp header and pass it up to IP.
1676 		 */
1677 		if ((ifp->if_flags & IFF_UP) == 0 ||
1678 		    sc->sc_npmode[NP_IP] != NPMODE_PASS) {
1679 			/* Interface is down - drop the packet. */
1680 			m_freem(m);
1681 			return;
1682 		}
1683 		m->m_pkthdr.len -= PPP_HDRLEN;
1684 		m->m_data += PPP_HDRLEN;
1685 		m->m_len -= PPP_HDRLEN;
1686 #ifdef GATEWAY
1687 		if (ipflow_fastforward(m))
1688 			return;
1689 #endif
1690 		pktq = ip_pktq;
1691 		break;
1692 #endif
1693 
1694 #ifdef INET6
1695 	case PPP_IPV6:
1696 		/*
1697 		 * IPv6 packet - take off the ppp header and pass it up to
1698 		 * IPv6.
1699 		 */
1700 		if ((ifp->if_flags & IFF_UP) == 0 ||
1701 		    sc->sc_npmode[NP_IPV6] != NPMODE_PASS) {
1702 			/* interface is down - drop the packet. */
1703 			m_freem(m);
1704 			return;
1705 		}
1706 		m->m_pkthdr.len -= PPP_HDRLEN;
1707 		m->m_data += PPP_HDRLEN;
1708 		m->m_len -= PPP_HDRLEN;
1709 #ifdef GATEWAY
1710 		if (ip6flow_fastforward(&m))
1711 			return;
1712 #endif
1713 		pktq = ip6_pktq;
1714 		break;
1715 #endif
1716 
1717 	default:
1718 		/*
1719 		 * Some other protocol - place on input queue for read().
1720 		 */
1721 		inq = &sc->sc_inq;
1722 		pktq = NULL;
1723 		break;
1724 	}
1725 
1726 	/*
1727 	 * Put the packet on the appropriate input queue.
1728 	 */
1729 	s = splnet();
1730 
1731 	/* pktq: inet or inet6 cases */
1732 	if (__predict_true(pktq)) {
1733 		if (__predict_false(!pktq_enqueue(pktq, m, 0))) {
1734 			splx(s);
1735 			if_statinc(ifp, if_iqdrops);
1736 			goto bad;
1737 		}
1738 		if_statadd2(ifp, if_ipackets, 1, if_ibytes, ilen);
1739 		splx(s);
1740 		return;
1741 	}
1742 
1743 	/* ifq: other protocol cases */
1744 	if (!inq) {
1745 		splx(s);
1746 		goto bad;
1747 	}
1748 	if (IF_QFULL(inq)) {
1749 		IF_DROP(inq);
1750 		splx(s);
1751 		if (sc->sc_flags & SC_DEBUG)
1752 			printf("%s: input queue full\n", ifp->if_xname);
1753 		if_statinc(ifp, if_iqdrops);
1754 		goto bad;
1755 	}
1756 	IF_ENQUEUE(inq, m);
1757 	splx(s);
1758 	if_statadd2(ifp, if_ipackets, 1, if_ibytes, ilen);
1759 
1760 	(*sc->sc_ctlp)(sc);
1761 
1762 	return;
1763 
1764 bad:
1765 	m_freem(m);
1766 	if_statinc(&sc->sc_if, if_ierrors);
1767 	sc->sc_stats.ppp_ierrors++;
1768 }
1769 
1770 #define MAX_DUMP_BYTES	128
1771 
1772 static void
1773 pppdumpm(struct mbuf *m0)
1774 {
1775 	char buf[3*MAX_DUMP_BYTES+4];
1776 	char *bp = buf;
1777 	struct mbuf *m;
1778 
1779 	for (m = m0; m; m = m->m_next) {
1780 		int l = m->m_len;
1781 		u_char *rptr = (u_char *)m->m_data;
1782 
1783 		while (l--) {
1784 			if (bp > buf + sizeof(buf) - 4)
1785 				goto done;
1786 			/* Convert byte to ascii hex */
1787 			*bp++ = hexdigits[*rptr >> 4];
1788 			*bp++ = hexdigits[*rptr++ & 0xf];
1789 		}
1790 
1791 		if (m->m_next) {
1792 			if (bp > buf + sizeof(buf) - 3)
1793 				goto done;
1794 			*bp++ = '|';
1795 		} else
1796 			*bp++ = ' ';
1797 	}
1798 done:
1799 	if (m)
1800 		*bp++ = '>';
1801 	*bp = 0;
1802 	printf("%s\n", buf);
1803 }
1804 
1805 #ifdef ALTQ
1806 /*
1807  * A wrapper to transmit a packet from if_start since ALTQ uses
1808  * if_start to send a packet.
1809  */
1810 static void
1811 ppp_ifstart(struct ifnet *ifp)
1812 {
1813 	struct ppp_softc *sc;
1814 
1815 	sc = ifp->if_softc;
1816 	(*sc->sc_start)(sc);
1817 }
1818 #endif
1819 
1820 static const struct ppp_known_compressor {
1821 	uint8_t code;
1822 	const char *module;
1823 } ppp_known_compressors[] = {
1824 	{ CI_DEFLATE, "ppp_deflate" },
1825 	{ CI_DEFLATE_DRAFT, "ppp_deflate" },
1826 	{ CI_BSD_COMPRESS, "ppp_bsdcomp" },
1827 	{ CI_MPPE, "ppp_mppe" },
1828 	{ 0, NULL }
1829 };
1830 
1831 static int
1832 ppp_compressor_init(void)
1833 {
1834 
1835 	mutex_init(&ppp_compressors_mtx, MUTEX_DEFAULT, IPL_NONE);
1836 	return 0;
1837 }
1838 
1839 static int
1840 ppp_compressor_destroy(void)
1841 {
1842 
1843 	mutex_destroy(&ppp_compressors_mtx);
1844 	return 0;
1845 }
1846 
1847 static void
1848 ppp_compressor_rele(struct compressor *cp)
1849 {
1850 
1851 	mutex_enter(&ppp_compressors_mtx);
1852 	--cp->comp_refcnt;
1853 	mutex_exit(&ppp_compressors_mtx);
1854 }
1855 
1856 static struct compressor *
1857 ppp_get_compressor_noload(uint8_t ci, bool hold)
1858 {
1859 	struct compressor *cp;
1860 
1861 	KASSERT(mutex_owned(&ppp_compressors_mtx));
1862 	LIST_FOREACH(cp, &ppp_compressors, comp_list) {
1863 		if (cp->compress_proto == ci) {
1864 			if (hold)
1865 				++cp->comp_refcnt;
1866 			return cp;
1867 		}
1868 	}
1869 
1870 	return NULL;
1871 }
1872 
1873 static struct compressor *
1874 ppp_get_compressor(uint8_t ci)
1875 {
1876 	struct compressor *cp = NULL;
1877 	const struct ppp_known_compressor *pkc;
1878 
1879 	mutex_enter(&ppp_compressors_mtx);
1880 	cp = ppp_get_compressor_noload(ci, true);
1881 	mutex_exit(&ppp_compressors_mtx);
1882 	if (cp != NULL)
1883 		return cp;
1884 
1885 	kernconfig_lock();
1886 	mutex_enter(&ppp_compressors_mtx);
1887 	cp = ppp_get_compressor_noload(ci, true);
1888 	mutex_exit(&ppp_compressors_mtx);
1889 	if (cp == NULL) {
1890 		/* Not found, so try to autoload a module */
1891 		for (pkc = ppp_known_compressors; pkc->module != NULL; pkc++) {
1892 			if (pkc->code == ci) {
1893 				if (module_autoload(pkc->module,
1894 					MODULE_CLASS_MISC) != 0)
1895 					break;
1896 				mutex_enter(&ppp_compressors_mtx);
1897 				cp = ppp_get_compressor_noload(ci, true);
1898 				mutex_exit(&ppp_compressors_mtx);
1899 				break;
1900 			}
1901 		}
1902 	}
1903 	kernconfig_unlock();
1904 
1905 	return cp;
1906 }
1907 
1908 int
1909 ppp_register_compressor(struct compressor *pc, size_t ncomp)
1910 {
1911 	int error = 0;
1912 	size_t i;
1913 
1914 	mutex_enter(&ppp_compressors_mtx);
1915 	for (i = 0; i < ncomp; i++) {
1916 		if (ppp_get_compressor_noload(pc[i].compress_proto,
1917 			false) != NULL)
1918 			error = EEXIST;
1919 	}
1920 	if (!error) {
1921 		for (i = 0; i < ncomp; i++) {
1922 			pc[i].comp_refcnt = 0;
1923 			LIST_INSERT_HEAD(&ppp_compressors, &pc[i], comp_list);
1924 		}
1925 	}
1926 	mutex_exit(&ppp_compressors_mtx);
1927 
1928 	return error;
1929 }
1930 
1931 int
1932 ppp_unregister_compressor(struct compressor *pc, size_t ncomp)
1933 {
1934 	int error = 0;
1935 	size_t i;
1936 
1937 	mutex_enter(&ppp_compressors_mtx);
1938 	for (i = 0; i < ncomp; i++) {
1939 		if (ppp_get_compressor_noload(pc[i].compress_proto,
1940 			false) != &pc[i])
1941 			error = ENOENT;
1942 		else if (pc[i].comp_refcnt != 0)
1943 			error = EBUSY;
1944 	}
1945 	if (!error) {
1946 		for (i = 0; i < ncomp; i++) {
1947 			LIST_REMOVE(&pc[i], comp_list);
1948 		}
1949 	}
1950 	mutex_exit(&ppp_compressors_mtx);
1951 
1952 	return error;
1953 }
1954 
1955 /*
1956  * Module infrastructure
1957  */
1958 #include "if_module.h"
1959 
1960 #ifdef PPP_FILTER
1961 #define PPP_DEP "bpf_filter,"
1962 #else
1963 #define PPP_DEP
1964 #endif
1965 
1966 IF_MODULE(MODULE_CLASS_DRIVER, ppp, PPP_DEP "slcompress")
1967