xref: /netbsd-src/sys/net/if_ppp.c (revision 796c32c94f6e154afc9de0f63da35c91bb739b45)
1 /*	$NetBSD: if_ppp.c,v 1.159 2017/09/17 20:39:04 christos 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 1.159 2017/09/17 20:39:04 christos 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/netisr.h>
141 #include <net/route.h>
142 #ifdef PPP_FILTER
143 #include <net/bpf.h>
144 #endif
145 
146 #include <netinet/in.h>
147 #include <netinet/in_systm.h>
148 #include <netinet/in_var.h>
149 #ifdef INET
150 #include <netinet/ip.h>
151 #endif
152 
153 #include <net/bpf.h>
154 
155 #include <net/slip.h>
156 
157 #ifdef VJC
158 #include <net/slcompress.h>
159 #endif
160 
161 #include <net/ppp_defs.h>
162 #include <net/if_ppp.h>
163 #include <net/if_pppvar.h>
164 #include <sys/cpu.h>
165 
166 #ifdef PPP_COMPRESS
167 #define PACKETPTR	struct mbuf *
168 #include <net/ppp-comp.h>
169 #endif
170 
171 #include "ioconf.h"
172 
173 static int	pppsioctl(struct ifnet *, u_long, void *);
174 static void	ppp_requeue(struct ppp_softc *);
175 static void	ppp_ccp(struct ppp_softc *, struct mbuf *m, int rcvd);
176 static void	ppp_ccp_closed(struct ppp_softc *);
177 static void	ppp_inproc(struct ppp_softc *, struct mbuf *);
178 static void	pppdumpm(struct mbuf *m0);
179 #ifdef ALTQ
180 static void	ppp_ifstart(struct ifnet *ifp);
181 #endif
182 
183 static void	pppintr(void *);
184 
185 extern struct linesw ppp_disc;
186 
187 /*
188  * Some useful mbuf macros not in mbuf.h.
189  */
190 #define M_IS_CLUSTER(m)	((m)->m_flags & M_EXT)
191 
192 #define M_DATASTART(m)							\
193 	(M_IS_CLUSTER(m) ? (m)->m_ext.ext_buf :				\
194 	    (m)->m_flags & M_PKTHDR ? (m)->m_pktdat : (m)->m_dat)
195 
196 #define M_DATASIZE(m)							\
197 	(M_IS_CLUSTER(m) ? (m)->m_ext.ext_size :			\
198 	    (m)->m_flags & M_PKTHDR ? MHLEN: MLEN)
199 
200 /*
201  * We define two link layer specific mbuf flags, to mark high-priority
202  * packets for output, and received packets following lost/corrupted
203  * packets.
204  */
205 #define	M_HIGHPRI	M_LINK0	/* output packet for sc_fastq */
206 #define	M_ERRMARK	M_LINK1	/* rx packet following lost/corrupted pkt */
207 
208 static int ppp_clone_create(struct if_clone *, int);
209 static int ppp_clone_destroy(struct ifnet *);
210 
211 static struct ppp_softc *ppp_create(const char *, int);
212 
213 static LIST_HEAD(, ppp_softc) ppp_softc_list;
214 static kmutex_t ppp_list_lock;
215 
216 struct if_clone ppp_cloner =
217     IF_CLONE_INITIALIZER("ppp", ppp_clone_create, ppp_clone_destroy);
218 
219 #ifdef PPP_COMPRESS
220 static LIST_HEAD(, compressor) ppp_compressors = { NULL };
221 static kmutex_t ppp_compressors_mtx;
222 
223 static int ppp_compressor_init(void);
224 static int ppp_compressor_destroy(void);
225 static struct compressor *ppp_get_compressor(uint8_t);
226 static void ppp_compressor_rele(struct compressor *);
227 #endif /* PPP_COMPRESS */
228 
229 
230 /*
231  * Called from boot code to establish ppp interfaces.
232  */
233 void
234 pppattach(int n __unused)
235 {
236 
237 	/*
238 	 * Nothing to do here, initialization is handled by the
239 	 * module initialization code in pppinit() below).
240 	 */
241 }
242 
243 static void
244 pppinit(void)
245 {
246 	/* Init the compressor sub-sub-system */
247 	ppp_compressor_init();
248 
249 	if (ttyldisc_attach(&ppp_disc) != 0)
250 		panic("%s", __func__);
251 
252 	mutex_init(&ppp_list_lock, MUTEX_DEFAULT, IPL_NONE);
253 	LIST_INIT(&ppp_softc_list);
254 	if_clone_attach(&ppp_cloner);
255 }
256 
257 static int
258 pppdetach(void)
259 {
260 	int error = 0;
261 
262 	if (!LIST_EMPTY(&ppp_softc_list))
263 		error = EBUSY;
264 
265 	if (error == 0)
266 		error = ttyldisc_detach(&ppp_disc);
267 
268 	if (error == 0) {
269 		mutex_destroy(&ppp_list_lock);
270 		if_clone_detach(&ppp_cloner);
271 		ppp_compressor_destroy();
272 	}
273 
274 	return error;
275 }
276 
277 static struct ppp_softc *
278 ppp_create(const char *name, int unit)
279 {
280 	struct ppp_softc *sc, *sci, *scl = NULL;
281 
282 	sc = malloc(sizeof(*sc), M_DEVBUF, M_WAIT|M_ZERO);
283 
284 	mutex_enter(&ppp_list_lock);
285 	if (unit == -1) {
286 		int i = 0;
287 		LIST_FOREACH(sci, &ppp_softc_list, sc_iflist) {
288 			scl = sci;
289 			if (i < sci->sc_unit) {
290 				unit = i;
291 				break;
292 			} else {
293 #ifdef DIAGNOSTIC
294 				KASSERT(i == sci->sc_unit);
295 #endif
296 				i++;
297 			}
298 		}
299 		if (unit == -1)
300 			unit = i;
301 	} else {
302 		LIST_FOREACH(sci, &ppp_softc_list, sc_iflist) {
303 			scl = sci;
304 			if (unit < sci->sc_unit)
305 				break;
306 			else if (unit == sci->sc_unit) {
307 				free(sc, M_DEVBUF);
308 				return NULL;
309 			}
310 		}
311 	}
312 
313 	if (sci != NULL)
314 		LIST_INSERT_BEFORE(sci, sc, sc_iflist);
315 	else if (scl != NULL)
316 		LIST_INSERT_AFTER(scl, sc, sc_iflist);
317 	else
318 		LIST_INSERT_HEAD(&ppp_softc_list, sc, sc_iflist);
319 
320 	mutex_exit(&ppp_list_lock);
321 
322 	if_initname(&sc->sc_if, name, sc->sc_unit = unit);
323 	callout_init(&sc->sc_timo_ch, 0);
324 	sc->sc_if.if_softc = sc;
325 	sc->sc_if.if_mtu = PPP_MTU;
326 	sc->sc_if.if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
327 	sc->sc_if.if_type = IFT_PPP;
328 	sc->sc_if.if_hdrlen = PPP_HDRLEN;
329 	sc->sc_if.if_dlt = DLT_NULL;
330 	sc->sc_if.if_ioctl = pppsioctl;
331 	sc->sc_if.if_output = pppoutput;
332 #ifdef ALTQ
333 	sc->sc_if.if_start = ppp_ifstart;
334 #endif
335 	IFQ_SET_MAXLEN(&sc->sc_if.if_snd, IFQ_MAXLEN);
336 	sc->sc_inq.ifq_maxlen = IFQ_MAXLEN;
337 	sc->sc_fastq.ifq_maxlen = IFQ_MAXLEN;
338 	sc->sc_rawq.ifq_maxlen = IFQ_MAXLEN;
339 	/* Ratio of 1:2 packets between the regular and the fast queue */
340 	sc->sc_maxfastq = 2;
341 	IFQ_SET_READY(&sc->sc_if.if_snd);
342 	if_attach(&sc->sc_if);
343 	if_alloc_sadl(&sc->sc_if);
344 	bpf_attach(&sc->sc_if, DLT_NULL, 0);
345 	return sc;
346 }
347 
348 static int
349 ppp_clone_create(struct if_clone *ifc, int unit)
350 {
351 	return ppp_create(ifc->ifc_name, unit) == NULL ? EEXIST : 0;
352 }
353 
354 static int
355 ppp_clone_destroy(struct ifnet *ifp)
356 {
357 	struct ppp_softc *sc = (struct ppp_softc *)ifp->if_softc;
358 
359 	if (sc->sc_devp != NULL)
360 		return EBUSY; /* Not removing it */
361 
362 	mutex_enter(&ppp_list_lock);
363 	LIST_REMOVE(sc, sc_iflist);
364 	mutex_exit(&ppp_list_lock);
365 
366 	bpf_detach(ifp);
367 	if_detach(ifp);
368 
369 	free(sc, M_DEVBUF);
370 	return 0;
371 }
372 
373 /*
374  * Allocate a ppp interface unit and initialize it.
375  */
376 struct ppp_softc *
377 pppalloc(pid_t pid)
378 {
379 	struct ppp_softc *sc = NULL, *scf;
380 	int i;
381 
382 	mutex_enter(&ppp_list_lock);
383 	LIST_FOREACH(scf, &ppp_softc_list, sc_iflist) {
384 		if (scf->sc_xfer == pid) {
385 			scf->sc_xfer = 0;
386 			mutex_exit(&ppp_list_lock);
387 			return scf;
388 		}
389 		if (scf->sc_devp == NULL && sc == NULL)
390 			sc = scf;
391 	}
392 	mutex_exit(&ppp_list_lock);
393 
394 	if (sc == NULL)
395 		sc = ppp_create(ppp_cloner.ifc_name, -1);
396 
397 	sc->sc_si = softint_establish(SOFTINT_NET, pppintr, sc);
398 	if (sc->sc_si == NULL) {
399 		printf("%s: unable to establish softintr\n",
400 		    sc->sc_if.if_xname);
401 		return (NULL);
402 	}
403 	sc->sc_flags = 0;
404 	sc->sc_mru = PPP_MRU;
405 	sc->sc_relinq = NULL;
406 	(void)memset(&sc->sc_stats, 0, sizeof(sc->sc_stats));
407 #ifdef VJC
408 	sc->sc_comp = malloc(sizeof(struct slcompress), M_DEVBUF, M_NOWAIT);
409 	if (sc->sc_comp)
410 		sl_compress_init(sc->sc_comp);
411 #endif
412 #ifdef PPP_COMPRESS
413 	sc->sc_xc_state = NULL;
414 	sc->sc_rc_state = NULL;
415 #endif /* PPP_COMPRESS */
416 	for (i = 0; i < NUM_NP; ++i)
417 		sc->sc_npmode[i] = NPMODE_ERROR;
418 	sc->sc_npqueue = NULL;
419 	sc->sc_npqtail = &sc->sc_npqueue;
420 	sc->sc_last_sent = sc->sc_last_recv = time_second;
421 
422 	return sc;
423 }
424 
425 /*
426  * Deallocate a ppp unit.  Must be called at splsoftnet or higher.
427  */
428 void
429 pppdealloc(struct ppp_softc *sc)
430 {
431 	struct mbuf *m;
432 
433 	softint_disestablish(sc->sc_si);
434 	if_down(&sc->sc_if);
435 	sc->sc_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
436 	sc->sc_devp = NULL;
437 	sc->sc_xfer = 0;
438 	for (;;) {
439 		IF_DEQUEUE(&sc->sc_rawq, m);
440 		if (m == NULL)
441 			break;
442 		m_freem(m);
443 	}
444 	for (;;) {
445 		IF_DEQUEUE(&sc->sc_inq, m);
446 		if (m == NULL)
447 			break;
448 		m_freem(m);
449 	}
450 	for (;;) {
451 		IF_DEQUEUE(&sc->sc_fastq, m);
452 		if (m == NULL)
453 			break;
454 		m_freem(m);
455 	}
456 	while ((m = sc->sc_npqueue) != NULL) {
457 		sc->sc_npqueue = m->m_nextpkt;
458 		m_freem(m);
459 	}
460 	if (sc->sc_togo != NULL) {
461 		m_freem(sc->sc_togo);
462 		sc->sc_togo = NULL;
463 	}
464 #ifdef PPP_COMPRESS
465 	ppp_ccp_closed(sc);
466 	sc->sc_xc_state = NULL;
467 	sc->sc_rc_state = NULL;
468 #endif /* PPP_COMPRESS */
469 #ifdef PPP_FILTER
470 	if (sc->sc_pass_filt_in.bf_insns != 0) {
471 		free(sc->sc_pass_filt_in.bf_insns, M_DEVBUF);
472 		sc->sc_pass_filt_in.bf_insns = 0;
473 		sc->sc_pass_filt_in.bf_len = 0;
474 	}
475 	if (sc->sc_pass_filt_out.bf_insns != 0) {
476 		free(sc->sc_pass_filt_out.bf_insns, M_DEVBUF);
477 		sc->sc_pass_filt_out.bf_insns = 0;
478 		sc->sc_pass_filt_out.bf_len = 0;
479 	}
480 	if (sc->sc_active_filt_in.bf_insns != 0) {
481 		free(sc->sc_active_filt_in.bf_insns, M_DEVBUF);
482 		sc->sc_active_filt_in.bf_insns = 0;
483 		sc->sc_active_filt_in.bf_len = 0;
484 	}
485 	if (sc->sc_active_filt_out.bf_insns != 0) {
486 		free(sc->sc_active_filt_out.bf_insns, M_DEVBUF);
487 		sc->sc_active_filt_out.bf_insns = 0;
488 		sc->sc_active_filt_out.bf_len = 0;
489 	}
490 #endif /* PPP_FILTER */
491 #ifdef VJC
492 	if (sc->sc_comp != 0) {
493 		free(sc->sc_comp, M_DEVBUF);
494 		sc->sc_comp = 0;
495 	}
496 #endif
497 	(void)ppp_clone_destroy(&sc->sc_if);
498 }
499 
500 /*
501  * Ioctl routine for generic ppp devices.
502  */
503 int
504 pppioctl(struct ppp_softc *sc, u_long cmd, void *data, int flag,
505     struct lwp *l)
506 {
507 	int s, error, flags, mru, npx;
508 	u_int nb;
509 	struct ppp_option_data *odp;
510 	struct compressor *cp;
511 	struct npioctl *npi;
512 	time_t t;
513 #ifdef PPP_FILTER
514 	struct bpf_program *bp, *nbp;
515 	struct bpf_insn *newcode, *oldcode;
516 	int newcodelen;
517 #endif /* PPP_FILTER */
518 #ifdef	PPP_COMPRESS
519 	u_char ccp_option[CCP_MAX_OPTION_LENGTH];
520 #endif
521 
522 	switch (cmd) {
523 	case PPPIOCSFLAGS:
524 	case PPPIOCSMRU:
525 	case PPPIOCSMAXCID:
526 	case PPPIOCSCOMPRESS:
527 	case PPPIOCSNPMODE:
528 		if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE,
529 			KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, &sc->sc_if,
530 			KAUTH_ARG(cmd), NULL) != 0)
531 			return (EPERM);
532 		break;
533 	case PPPIOCXFERUNIT:
534 		/* XXX: Why is this privileged?! */
535 		if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE,
536 			KAUTH_REQ_NETWORK_INTERFACE_GETPRIV, &sc->sc_if,
537 			KAUTH_ARG(cmd), NULL) != 0)
538 			return (EPERM);
539 		break;
540 	default:
541 		break;
542 	}
543 
544 	switch (cmd) {
545 	case FIONREAD:
546 		*(int *)data = sc->sc_inq.ifq_len;
547 		break;
548 
549 	case PPPIOCGUNIT:
550 		*(int *)data = sc->sc_unit;
551 		break;
552 
553 	case PPPIOCGFLAGS:
554 		*(u_int *)data = sc->sc_flags;
555 		break;
556 
557 	case PPPIOCGRAWIN:
558 	{
559 		struct ppp_rawin *rwin = (struct ppp_rawin *)data;
560 		u_char c, q = 0;
561 
562 		for (c = sc->sc_rawin_start; c < sizeof(sc->sc_rawin.buf);)
563 			rwin->buf[q++] = sc->sc_rawin.buf[c++];
564 
565 		for (c = 0; c < sc->sc_rawin_start;)
566 			rwin->buf[q++] = sc->sc_rawin.buf[c++];
567 
568 		rwin->count = sc->sc_rawin.count;
569 	}
570 	break;
571 
572 	case PPPIOCSFLAGS:
573 		flags = *(int *)data & SC_MASK;
574 		s = splsoftnet();
575 #ifdef PPP_COMPRESS
576 		if (sc->sc_flags & SC_CCP_OPEN && !(flags & SC_CCP_OPEN))
577 			ppp_ccp_closed(sc);
578 #endif
579 		splhigh();	/* XXX IMP ME HARDER */
580 		sc->sc_flags = (sc->sc_flags & ~SC_MASK) | flags;
581 		splx(s);
582 		break;
583 
584 	case PPPIOCSMRU:
585 		mru = *(int *)data;
586 		if (mru >= PPP_MINMRU && mru <= PPP_MAXMRU)
587 			sc->sc_mru = mru;
588 		break;
589 
590 	case PPPIOCGMRU:
591 		*(int *)data = sc->sc_mru;
592 		break;
593 
594 #ifdef VJC
595 	case PPPIOCSMAXCID:
596 		if (sc->sc_comp) {
597 			s = splsoftnet();
598 			sl_compress_setup(sc->sc_comp, *(int *)data);
599 			splx(s);
600 		}
601 		break;
602 #endif
603 
604 	case PPPIOCXFERUNIT:
605 		sc->sc_xfer = l->l_proc->p_pid;
606 		break;
607 
608 #ifdef PPP_COMPRESS
609 	case PPPIOCSCOMPRESS:
610 		odp = (struct ppp_option_data *) data;
611 		nb = odp->length;
612 		if (nb > sizeof(ccp_option))
613 			nb = sizeof(ccp_option);
614 		if ((error = copyin(odp->ptr, ccp_option, nb)) != 0)
615 			return (error);
616 		/* preliminary check on the length byte */
617 		if (ccp_option[1] < 2)
618 			return (EINVAL);
619 		cp = ppp_get_compressor(ccp_option[0]);
620 		if (cp == NULL) {
621 			if (sc->sc_flags & SC_DEBUG)
622 				printf("%s: no compressor for [%x %x %x], %x\n",
623 				    sc->sc_if.if_xname, ccp_option[0],
624 				    ccp_option[1], ccp_option[2], nb);
625 			return (EINVAL);	/* no handler found */
626 		}
627 		/*
628 		 * Found a handler for the protocol - try to allocate
629 		 * a compressor or decompressor.
630 		 */
631 		error = 0;
632 		if (odp->transmit) {
633 			s = splsoftnet();
634 			if (sc->sc_xc_state != NULL) {
635 				(*sc->sc_xcomp->comp_free)(sc->sc_xc_state);
636 				ppp_compressor_rele(sc->sc_xcomp);
637 			}
638 			sc->sc_xcomp = cp;
639 			sc->sc_xc_state = cp->comp_alloc(ccp_option, nb);
640 			if (sc->sc_xc_state == NULL) {
641 				if (sc->sc_flags & SC_DEBUG)
642 					printf("%s: comp_alloc failed\n",
643 					    sc->sc_if.if_xname);
644 				error = ENOBUFS;
645 			}
646 			splhigh();	/* XXX IMP ME HARDER */
647 			sc->sc_flags &= ~SC_COMP_RUN;
648 			splx(s);
649 		} else {
650 			s = splsoftnet();
651 			if (sc->sc_rc_state != NULL) {
652 				(*sc->sc_rcomp->decomp_free)(sc->sc_rc_state);
653 				ppp_compressor_rele(sc->sc_rcomp);
654 			}
655 			sc->sc_rcomp = cp;
656 			sc->sc_rc_state = cp->decomp_alloc(ccp_option, nb);
657 			if (sc->sc_rc_state == NULL) {
658 				if (sc->sc_flags & SC_DEBUG)
659 					printf("%s: decomp_alloc failed\n",
660 					    sc->sc_if.if_xname);
661 				error = ENOBUFS;
662 			}
663 			splhigh();	/* XXX IMP ME HARDER */
664 			sc->sc_flags &= ~SC_DECOMP_RUN;
665 			splx(s);
666 		}
667 		return (error);
668 #endif /* PPP_COMPRESS */
669 
670 	case PPPIOCGNPMODE:
671 	case PPPIOCSNPMODE:
672 		npi = (struct npioctl *) data;
673 		switch (npi->protocol) {
674 		case PPP_IP:
675 			npx = NP_IP;
676 			break;
677 		case PPP_IPV6:
678 			npx = NP_IPV6;
679 			break;
680 		default:
681 			return EINVAL;
682 		}
683 		if (cmd == PPPIOCGNPMODE) {
684 			npi->mode = sc->sc_npmode[npx];
685 		} else {
686 			if (npi->mode != sc->sc_npmode[npx]) {
687 				s = splnet();
688 				sc->sc_npmode[npx] = npi->mode;
689 				if (npi->mode != NPMODE_QUEUE) {
690 					ppp_requeue(sc);
691 					ppp_restart(sc);
692 				}
693 				splx(s);
694 			}
695 		}
696 		break;
697 
698 	case PPPIOCGIDLE:
699 		s = splsoftnet();
700 		t = time_second;
701 		((struct ppp_idle *)data)->xmit_idle = t - sc->sc_last_sent;
702 		((struct ppp_idle *)data)->recv_idle = t - sc->sc_last_recv;
703 		splx(s);
704 		break;
705 
706 #ifdef PPP_FILTER
707 	case PPPIOCSPASS:
708 	case PPPIOCSACTIVE:
709 		/* These are no longer supported. */
710 		return EOPNOTSUPP;
711 
712 	case PPPIOCSIPASS:
713 	case PPPIOCSOPASS:
714 	case PPPIOCSIACTIVE:
715 	case PPPIOCSOACTIVE:
716 		nbp = (struct bpf_program *) data;
717 		if ((unsigned) nbp->bf_len > BPF_MAXINSNS)
718 			return EINVAL;
719 		newcodelen = nbp->bf_len * sizeof(struct bpf_insn);
720 		if (newcodelen != 0) {
721 			newcode = malloc(newcodelen, M_DEVBUF, M_WAITOK);
722 			/* WAITOK -- malloc() never fails. */
723 			if ((error = copyin((void *)nbp->bf_insns,
724 				    (void *)newcode, newcodelen)) != 0) {
725 				free(newcode, M_DEVBUF);
726 				return error;
727 			}
728 			if (!bpf_validate(newcode, nbp->bf_len)) {
729 				free(newcode, M_DEVBUF);
730 				return EINVAL;
731 			}
732 		} else
733 			newcode = 0;
734 		switch (cmd) {
735 		case PPPIOCSIPASS:
736 			bp = &sc->sc_pass_filt_in;
737 			break;
738 
739 		case PPPIOCSOPASS:
740 			bp = &sc->sc_pass_filt_out;
741 			break;
742 
743 		case PPPIOCSIACTIVE:
744 			bp = &sc->sc_active_filt_in;
745 			break;
746 
747 		case PPPIOCSOACTIVE:
748 			bp = &sc->sc_active_filt_out;
749 			break;
750 		default:
751 			free(newcode, M_DEVBUF);
752 			return (EPASSTHROUGH);
753 		}
754 		oldcode = bp->bf_insns;
755 		s = splnet();
756 		bp->bf_len = nbp->bf_len;
757 		bp->bf_insns = newcode;
758 		splx(s);
759 		if (oldcode != 0)
760 			free(oldcode, M_DEVBUF);
761 		break;
762 #endif /* PPP_FILTER */
763 
764 	default:
765 		return (EPASSTHROUGH);
766 	}
767 	return (0);
768 }
769 
770 /*
771  * Process an ioctl request to the ppp network interface.
772  */
773 static int
774 pppsioctl(struct ifnet *ifp, u_long cmd, void *data)
775 {
776 	struct ppp_softc *sc = ifp->if_softc;
777 	struct ifaddr *ifa = (struct ifaddr *)data;
778 	struct ifreq *ifr = (struct ifreq *)data;
779 	struct ppp_stats *psp;
780 #ifdef	PPP_COMPRESS
781 	struct ppp_comp_stats *pcp;
782 #endif
783 	int s = splnet(), error = 0;
784 
785 	switch (cmd) {
786 	case SIOCSIFFLAGS:
787 		if ((error = ifioctl_common(ifp, cmd, data)) != 0)
788 			break;
789 		if ((ifp->if_flags & IFF_RUNNING) == 0)
790 			ifp->if_flags &= ~IFF_UP;
791 		break;
792 
793 	case SIOCINITIFADDR:
794 		switch (ifa->ifa_addr->sa_family) {
795 #ifdef INET
796 		case AF_INET:
797 			break;
798 #endif
799 #ifdef INET6
800 		case AF_INET6:
801 			break;
802 #endif
803 		default:
804 			printf("%s: af%d not supported\n", ifp->if_xname,
805 			    ifa->ifa_addr->sa_family);
806 			error = EAFNOSUPPORT;
807 			break;
808 		}
809 		ifa->ifa_rtrequest = p2p_rtrequest;
810 		break;
811 
812 	case SIOCADDMULTI:
813 	case SIOCDELMULTI:
814 		if (ifr == NULL) {
815 			error = EAFNOSUPPORT;
816 			break;
817 		}
818 		switch (ifreq_getaddr(cmd, ifr)->sa_family) {
819 #ifdef INET
820 		case AF_INET:
821 			break;
822 #endif
823 #ifdef INET6
824 		case AF_INET6:
825 			break;
826 #endif
827 		default:
828 			error = EAFNOSUPPORT;
829 			break;
830 		}
831 		break;
832 
833 	case SIOCGPPPSTATS:
834 		psp = &((struct ifpppstatsreq *) data)->stats;
835 		memset(psp, 0, sizeof(*psp));
836 		psp->p = sc->sc_stats;
837 #if defined(VJC) && !defined(SL_NO_STATS)
838 		if (sc->sc_comp) {
839 			psp->vj.vjs_packets = sc->sc_comp->sls_packets;
840 			psp->vj.vjs_compressed = sc->sc_comp->sls_compressed;
841 			psp->vj.vjs_searches = sc->sc_comp->sls_searches;
842 			psp->vj.vjs_misses = sc->sc_comp->sls_misses;
843 			psp->vj.vjs_uncompressedin = sc->sc_comp->sls_uncompressedin;
844 			psp->vj.vjs_compressedin = sc->sc_comp->sls_compressedin;
845 			psp->vj.vjs_errorin = sc->sc_comp->sls_errorin;
846 			psp->vj.vjs_tossed = sc->sc_comp->sls_tossed;
847 		}
848 #endif /* VJC */
849 		break;
850 
851 #ifdef PPP_COMPRESS
852 	case SIOCGPPPCSTATS:
853 		pcp = &((struct ifpppcstatsreq *) data)->stats;
854 		memset(pcp, 0, sizeof(*pcp));
855 		if (sc->sc_xc_state != NULL)
856 			(*sc->sc_xcomp->comp_stat)(sc->sc_xc_state, &pcp->c);
857 		if (sc->sc_rc_state != NULL)
858 			(*sc->sc_rcomp->decomp_stat)(sc->sc_rc_state, &pcp->d);
859 		break;
860 #endif /* PPP_COMPRESS */
861 
862 	default:
863 		if ((error = ifioctl_common(&sc->sc_if, cmd, data)) == ENETRESET)
864 			error = 0;
865 		break;
866 	}
867 	splx(s);
868 	return (error);
869 }
870 
871 /*
872  * Queue a packet.  Start transmission if not active.
873  * Packet is placed in Information field of PPP frame.
874  */
875 int
876 pppoutput(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst,
877     const struct rtentry *rtp)
878 {
879 	struct ppp_softc *sc = ifp->if_softc;
880 	int protocol, address, control;
881 	u_char *cp;
882 	int s, error;
883 #ifdef INET
884 	struct ip *ip;
885 #endif
886 	struct ifqueue *ifq;
887 	enum NPmode mode;
888 	int len;
889 
890 	    if (sc->sc_devp == NULL || (ifp->if_flags & IFF_RUNNING) == 0
891 		|| ((ifp->if_flags & IFF_UP) == 0 && dst->sa_family != AF_UNSPEC)) {
892 		    error = ENETDOWN;	/* sort of */
893 		    goto bad;
894 	    }
895 
896 	IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family);
897 
898 	/*
899 	 * Compute PPP header.
900 	 */
901 	m0->m_flags &= ~M_HIGHPRI;
902 	switch (dst->sa_family) {
903 #ifdef INET
904 	case AF_INET:
905 		address = PPP_ALLSTATIONS;
906 		control = PPP_UI;
907 		protocol = PPP_IP;
908 		mode = sc->sc_npmode[NP_IP];
909 
910 		/*
911 		 * If this packet has the "low delay" bit set in the IP header,
912 		 * put it on the fastq instead.
913 		 */
914 		ip = mtod(m0, struct ip *);
915 		if (ip->ip_tos & IPTOS_LOWDELAY)
916 			m0->m_flags |= M_HIGHPRI;
917 		break;
918 #endif
919 #ifdef INET6
920 	case AF_INET6:
921 		address = PPP_ALLSTATIONS;	/*XXX*/
922 		control = PPP_UI;		/*XXX*/
923 		protocol = PPP_IPV6;
924 		mode = sc->sc_npmode[NP_IPV6];
925 
926 #if 0	/* XXX flowinfo/traffic class, maybe? */
927 	/*
928 	 * If this packet has the "low delay" bit set in the IP header,
929 	 * put it on the fastq instead.
930 	 */
931 		ip = mtod(m0, struct ip *);
932 		if (ip->ip_tos & IPTOS_LOWDELAY)
933 			m0->m_flags |= M_HIGHPRI;
934 #endif
935 		break;
936 #endif
937 	case AF_UNSPEC:
938 		address = PPP_ADDRESS(dst->sa_data);
939 		control = PPP_CONTROL(dst->sa_data);
940 		protocol = PPP_PROTOCOL(dst->sa_data);
941 		mode = NPMODE_PASS;
942 		break;
943 	default:
944 		printf("%s: af%d not supported\n", ifp->if_xname,
945 		    dst->sa_family);
946 		error = EAFNOSUPPORT;
947 		goto bad;
948 	}
949 
950 	/*
951 	 * Drop this packet, or return an error, if necessary.
952 	 */
953 	if (mode == NPMODE_ERROR) {
954 		error = ENETDOWN;
955 		goto bad;
956 	}
957 	if (mode == NPMODE_DROP) {
958 		error = 0;
959 		goto bad;
960 	}
961 
962 	/*
963 	 * Add PPP header.
964 	 */
965 	M_PREPEND(m0, PPP_HDRLEN, M_DONTWAIT);
966 	if (m0 == NULL) {
967 		error = ENOBUFS;
968 		goto bad;
969 	}
970 
971 	cp = mtod(m0, u_char *);
972 	*cp++ = address;
973 	*cp++ = control;
974 	*cp++ = protocol >> 8;
975 	*cp++ = protocol & 0xff;
976 
977 	len = m_length(m0);
978 
979 	if (sc->sc_flags & SC_LOG_OUTPKT) {
980 		printf("%s output: ", ifp->if_xname);
981 		pppdumpm(m0);
982 	}
983 
984 	if ((protocol & 0x8000) == 0) {
985 #ifdef PPP_FILTER
986 		/*
987 		 * Apply the pass and active filters to the packet,
988 		 * but only if it is a data packet.
989 		 */
990 		if (sc->sc_pass_filt_out.bf_insns != 0
991 		    && bpf_filter(sc->sc_pass_filt_out.bf_insns,
992 			(u_char *)m0, len, 0) == 0) {
993 			error = 0;		/* drop this packet */
994 			goto bad;
995 		}
996 
997 		/*
998 		 * Update the time we sent the most recent packet.
999 		 */
1000 		if (sc->sc_active_filt_out.bf_insns == 0
1001 		    || bpf_filter(sc->sc_active_filt_out.bf_insns,
1002 			(u_char *)m0, len, 0))
1003 			sc->sc_last_sent = time_second;
1004 #else
1005 		/*
1006 		 * Update the time we sent the most recent packet.
1007 		 */
1008 		sc->sc_last_sent = time_second;
1009 #endif /* PPP_FILTER */
1010 	}
1011 
1012 	/*
1013 	 * See if bpf wants to look at the packet.
1014 	 */
1015 	bpf_mtap(&sc->sc_if, m0);
1016 
1017 	/*
1018 	 * Put the packet on the appropriate queue.
1019 	 */
1020 	s = splnet();
1021 	if (mode == NPMODE_QUEUE) {
1022 		/* XXX we should limit the number of packets on this queue */
1023 		*sc->sc_npqtail = m0;
1024 		m0->m_nextpkt = NULL;
1025 		sc->sc_npqtail = &m0->m_nextpkt;
1026 	} else {
1027 		ifq = (m0->m_flags & M_HIGHPRI) ? &sc->sc_fastq : NULL;
1028 		if ((error = ifq_enqueue2(&sc->sc_if, ifq, m0)) != 0) {
1029 			splx(s);
1030 			sc->sc_if.if_oerrors++;
1031 			sc->sc_stats.ppp_oerrors++;
1032 			return (error);
1033 		}
1034 		ppp_restart(sc);
1035 	}
1036 	ifp->if_opackets++;
1037 	ifp->if_obytes += len;
1038 
1039 	splx(s);
1040 	return (0);
1041 
1042 bad:
1043 	m_freem(m0);
1044 	return (error);
1045 }
1046 
1047 /*
1048  * After a change in the NPmode for some NP, move packets from the
1049  * npqueue to the send queue or the fast queue as appropriate.
1050  * Should be called at splnet, since we muck with the queues.
1051  */
1052 static void
1053 ppp_requeue(struct ppp_softc *sc)
1054 {
1055 	struct mbuf *m, **mpp;
1056 	struct ifqueue *ifq;
1057 	enum NPmode mode;
1058 	int error;
1059 
1060 	for (mpp = &sc->sc_npqueue; (m = *mpp) != NULL; ) {
1061 		switch (PPP_PROTOCOL(mtod(m, u_char *))) {
1062 		case PPP_IP:
1063 			mode = sc->sc_npmode[NP_IP];
1064 			break;
1065 		case PPP_IPV6:
1066 			mode = sc->sc_npmode[NP_IPV6];
1067 			break;
1068 		default:
1069 			mode = NPMODE_PASS;
1070 		}
1071 
1072 		switch (mode) {
1073 		case NPMODE_PASS:
1074 			/*
1075 			 * This packet can now go on one of the queues to
1076 			 * be sent.
1077 			 */
1078 			*mpp = m->m_nextpkt;
1079 			m->m_nextpkt = NULL;
1080 			ifq = (m->m_flags & M_HIGHPRI) ? &sc->sc_fastq : NULL;
1081 			if ((error = ifq_enqueue2(&sc->sc_if, ifq, m)) != 0) {
1082 				sc->sc_if.if_oerrors++;
1083 				sc->sc_stats.ppp_oerrors++;
1084 			}
1085 			break;
1086 
1087 		case NPMODE_DROP:
1088 		case NPMODE_ERROR:
1089 			*mpp = m->m_nextpkt;
1090 			m_freem(m);
1091 			break;
1092 
1093 		case NPMODE_QUEUE:
1094 			mpp = &m->m_nextpkt;
1095 			break;
1096 		}
1097 	}
1098 	sc->sc_npqtail = mpp;
1099 }
1100 
1101 /*
1102  * Transmitter has finished outputting some stuff;
1103  * remember to call sc->sc_start later at splsoftnet.
1104  */
1105 void
1106 ppp_restart(struct ppp_softc *sc)
1107 {
1108 	int s = splhigh();	/* XXX IMP ME HARDER */
1109 
1110 	sc->sc_flags &= ~SC_TBUSY;
1111 	softint_schedule(sc->sc_si);
1112 	splx(s);
1113 }
1114 
1115 /*
1116  * Get a packet to send.  This procedure is intended to be called at
1117  * splsoftnet, since it may involve time-consuming operations such as
1118  * applying VJ compression, packet compression, address/control and/or
1119  * protocol field compression to the packet.
1120  */
1121 struct mbuf *
1122 ppp_dequeue(struct ppp_softc *sc)
1123 {
1124 	struct mbuf *m, *mp;
1125 	u_char *cp;
1126 	int address, control, protocol;
1127 	int s;
1128 
1129 	/*
1130 	 * Grab a packet to send: first try the fast queue, then the
1131 	 * normal queue.
1132 	 */
1133 	s = splnet();
1134 	if (sc->sc_nfastq < sc->sc_maxfastq) {
1135 		IF_DEQUEUE(&sc->sc_fastq, m);
1136 		if (m != NULL)
1137 			sc->sc_nfastq++;
1138 		else
1139 			IFQ_DEQUEUE(&sc->sc_if.if_snd, m);
1140 	} else {
1141 		sc->sc_nfastq = 0;
1142 		IFQ_DEQUEUE(&sc->sc_if.if_snd, m);
1143 		if (m == NULL) {
1144 			IF_DEQUEUE(&sc->sc_fastq, m);
1145 			if (m != NULL)
1146 				sc->sc_nfastq++;
1147 		}
1148 	}
1149 	splx(s);
1150 
1151 	if (m == NULL)
1152 		return NULL;
1153 
1154 	++sc->sc_stats.ppp_opackets;
1155 
1156 	/*
1157 	 * Extract the ppp header of the new packet.
1158 	 * The ppp header will be in one mbuf.
1159 	 */
1160 	cp = mtod(m, u_char *);
1161 	address = PPP_ADDRESS(cp);
1162 	control = PPP_CONTROL(cp);
1163 	protocol = PPP_PROTOCOL(cp);
1164 
1165 	switch (protocol) {
1166 	case PPP_IP:
1167 #ifdef VJC
1168 		/*
1169 		 * If the packet is a TCP/IP packet, see if we can compress it.
1170 		 */
1171 		if ((sc->sc_flags & SC_COMP_TCP) && sc->sc_comp != NULL) {
1172 			struct ip *ip;
1173 			int type;
1174 
1175 			mp = m;
1176 			ip = (struct ip *) (cp + PPP_HDRLEN);
1177 			if (mp->m_len <= PPP_HDRLEN) {
1178 				mp = mp->m_next;
1179 				if (mp == NULL)
1180 					break;
1181 				ip = mtod(mp, struct ip *);
1182 			}
1183 			/*
1184 			 * This code assumes the IP/TCP header is in one
1185 			 * non-shared mbuf
1186 			 */
1187 			if (ip->ip_p == IPPROTO_TCP) {
1188 				type = sl_compress_tcp(mp, ip, sc->sc_comp,
1189 				    !(sc->sc_flags & SC_NO_TCP_CCID));
1190 				switch (type) {
1191 				case TYPE_UNCOMPRESSED_TCP:
1192 					protocol = PPP_VJC_UNCOMP;
1193 					break;
1194 				case TYPE_COMPRESSED_TCP:
1195 					protocol = PPP_VJC_COMP;
1196 					cp = mtod(m, u_char *);
1197 					cp[0] = address; /* Header has moved */
1198 					cp[1] = control;
1199 					cp[2] = 0;
1200 					break;
1201 				}
1202 				/* Update protocol in PPP header */
1203 				cp[3] = protocol;
1204 			}
1205 		}
1206 #endif	/* VJC */
1207 		break;
1208 
1209 #ifdef PPP_COMPRESS
1210 	case PPP_CCP:
1211 		ppp_ccp(sc, m, 0);
1212 		break;
1213 #endif	/* PPP_COMPRESS */
1214 	}
1215 
1216 #ifdef PPP_COMPRESS
1217 	if (protocol != PPP_LCP && protocol != PPP_CCP
1218 	    && sc->sc_xc_state && (sc->sc_flags & SC_COMP_RUN)) {
1219 		struct mbuf *mcomp = NULL;
1220 		int slen;
1221 
1222 		slen = 0;
1223 		for (mp = m; mp != NULL; mp = mp->m_next)
1224 			slen += mp->m_len;
1225 		(*sc->sc_xcomp->compress)
1226 		    (sc->sc_xc_state, &mcomp, m, slen, sc->sc_if.if_mtu + PPP_HDRLEN);
1227 		if (mcomp != NULL) {
1228 			if (sc->sc_flags & SC_CCP_UP) {
1229 				/*
1230 				 * Send the compressed packet instead of the
1231 				 * original.
1232 				 */
1233 				m_freem(m);
1234 				m = mcomp;
1235 				cp = mtod(m, u_char *);
1236 				protocol = cp[3];
1237 			} else {
1238 				/*
1239 				 * Can't transmit compressed packets until CCP
1240 				 * is up.
1241 				 */
1242 				m_freem(mcomp);
1243 			}
1244 		}
1245 	}
1246 #endif	/* PPP_COMPRESS */
1247 
1248 	/*
1249 	 * Compress the address/control and protocol, if possible.
1250 	 */
1251 	if (sc->sc_flags & SC_COMP_AC && address == PPP_ALLSTATIONS &&
1252 	    control == PPP_UI && protocol != PPP_ALLSTATIONS &&
1253 	    protocol != PPP_LCP) {
1254 		/* can compress address/control */
1255 		m->m_data += 2;
1256 		m->m_len -= 2;
1257 	}
1258 	if (sc->sc_flags & SC_COMP_PROT && protocol < 0xFF) {
1259 		/* can compress protocol */
1260 		if (mtod(m, u_char *) == cp) {
1261 			cp[2] = cp[1];	/* move address/control up */
1262 			cp[1] = cp[0];
1263 		}
1264 		++m->m_data;
1265 		--m->m_len;
1266 	}
1267 
1268 	return m;
1269 }
1270 
1271 /*
1272  * Software interrupt routine, called at splsoftnet.
1273  */
1274 static void
1275 pppintr(void *arg)
1276 {
1277 	struct ppp_softc *sc = arg;
1278 	struct mbuf *m;
1279 	int s;
1280 
1281 	mutex_enter(softnet_lock);
1282 	if (!(sc->sc_flags & SC_TBUSY)
1283 	    && (IFQ_IS_EMPTY(&sc->sc_if.if_snd) == 0 || sc->sc_fastq.ifq_head
1284 		|| sc->sc_outm)) {
1285 		s = splhigh();	/* XXX IMP ME HARDER */
1286 		sc->sc_flags |= SC_TBUSY;
1287 		splx(s);
1288 		(*sc->sc_start)(sc);
1289 	}
1290 	for (;;) {
1291 		s = splnet();
1292 		IF_DEQUEUE(&sc->sc_rawq, m);
1293 		splx(s);
1294 		if (m == NULL)
1295 			break;
1296 		ppp_inproc(sc, m);
1297 	}
1298 	mutex_exit(softnet_lock);
1299 }
1300 
1301 #ifdef PPP_COMPRESS
1302 /*
1303  * Handle a CCP packet.	 `rcvd' is 1 if the packet was received,
1304  * 0 if it is about to be transmitted.
1305  */
1306 static void
1307 ppp_ccp(struct ppp_softc *sc, struct mbuf *m, int rcvd)
1308 {
1309 	u_char *dp, *ep;
1310 	struct mbuf *mp;
1311 	int slen, s;
1312 
1313 	/*
1314 	 * Get a pointer to the data after the PPP header.
1315 	 */
1316 	if (m->m_len <= PPP_HDRLEN) {
1317 		mp = m->m_next;
1318 		if (mp == NULL)
1319 			return;
1320 		dp = mtod(mp, u_char *);
1321 	} else {
1322 		mp = m;
1323 		dp = mtod(mp, u_char *) + PPP_HDRLEN;
1324 	}
1325 
1326 	ep = mtod(mp, u_char *) + mp->m_len;
1327 	if (dp + CCP_HDRLEN > ep)
1328 		return;
1329 	slen = CCP_LENGTH(dp);
1330 	if (dp + slen > ep) {
1331 		if (sc->sc_flags & SC_DEBUG)
1332 			printf("if_ppp/ccp: not enough data in mbuf (%p+%x > %p+%x)\n",
1333 			    dp, slen, mtod(mp, u_char *), mp->m_len);
1334 		return;
1335 	}
1336 
1337 	switch (CCP_CODE(dp)) {
1338 	case CCP_CONFREQ:
1339 	case CCP_TERMREQ:
1340 	case CCP_TERMACK:
1341 		/* CCP must be going down - disable compression */
1342 		if (sc->sc_flags & SC_CCP_UP) {
1343 			s = splhigh();	/* XXX IMP ME HARDER */
1344 			sc->sc_flags &= ~(SC_CCP_UP | SC_COMP_RUN | SC_DECOMP_RUN);
1345 			splx(s);
1346 		}
1347 		break;
1348 
1349 	case CCP_CONFACK:
1350 		if (sc->sc_flags & SC_CCP_OPEN && !(sc->sc_flags & SC_CCP_UP)
1351 		    && slen >= CCP_HDRLEN + CCP_OPT_MINLEN
1352 		    && slen >= CCP_OPT_LENGTH(dp + CCP_HDRLEN) + CCP_HDRLEN) {
1353 			if (!rcvd) {
1354 				/* We're agreeing to send compressed packets. */
1355 				if (sc->sc_xc_state != NULL
1356 				    && (*sc->sc_xcomp->comp_init)
1357 				    (sc->sc_xc_state, dp + CCP_HDRLEN,
1358 					slen - CCP_HDRLEN, sc->sc_unit, 0,
1359 					sc->sc_flags & SC_DEBUG)) {
1360 					s = splhigh();	/* XXX IMP ME HARDER */
1361 					sc->sc_flags |= SC_COMP_RUN;
1362 					splx(s);
1363 				}
1364 			} else {
1365 				/*
1366 				 * Peer is agreeing to send compressed
1367 				 * packets.
1368 				 */
1369 				if (sc->sc_rc_state != NULL
1370 				    && (*sc->sc_rcomp->decomp_init)
1371 				    (sc->sc_rc_state, dp + CCP_HDRLEN, slen - CCP_HDRLEN,
1372 					sc->sc_unit, 0, sc->sc_mru,
1373 					sc->sc_flags & SC_DEBUG)) {
1374 					s = splhigh();	/* XXX IMP ME HARDER */
1375 					sc->sc_flags |= SC_DECOMP_RUN;
1376 					sc->sc_flags &= ~(SC_DC_ERROR | SC_DC_FERROR);
1377 					splx(s);
1378 				}
1379 			}
1380 		}
1381 		break;
1382 
1383 	case CCP_RESETACK:
1384 		if (sc->sc_flags & SC_CCP_UP) {
1385 			if (!rcvd) {
1386 				if (sc->sc_xc_state && (sc->sc_flags & SC_COMP_RUN))
1387 					(*sc->sc_xcomp->comp_reset)(sc->sc_xc_state);
1388 			} else {
1389 				if (sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN)) {
1390 					(*sc->sc_rcomp->decomp_reset)(sc->sc_rc_state);
1391 					s = splhigh();	/* XXX IMP ME HARDER */
1392 					sc->sc_flags &= ~SC_DC_ERROR;
1393 					splx(s);
1394 				}
1395 			}
1396 		}
1397 		break;
1398 	}
1399 }
1400 
1401 /*
1402  * CCP is down; free (de)compressor state if necessary.
1403  */
1404 static void
1405 ppp_ccp_closed(struct ppp_softc *sc)
1406 {
1407 	if (sc->sc_xc_state) {
1408 		(*sc->sc_xcomp->comp_free)(sc->sc_xc_state);
1409 		ppp_compressor_rele(sc->sc_xcomp);
1410 		sc->sc_xc_state = NULL;
1411 	}
1412 	if (sc->sc_rc_state) {
1413 		(*sc->sc_rcomp->decomp_free)(sc->sc_rc_state);
1414 		ppp_compressor_rele(sc->sc_rcomp);
1415 		sc->sc_rc_state = NULL;
1416 	}
1417 }
1418 #endif /* PPP_COMPRESS */
1419 
1420 /*
1421  * PPP packet input routine.
1422  * The caller has checked and removed the FCS and has inserted
1423  * the address/control bytes and the protocol high byte if they
1424  * were omitted.
1425  */
1426 void
1427 ppppktin(struct ppp_softc *sc, struct mbuf *m, int lost)
1428 {
1429 	int s = splhigh();	/* XXX IMP ME HARDER */
1430 
1431 	if (lost)
1432 		m->m_flags |= M_ERRMARK;
1433 	IF_ENQUEUE(&sc->sc_rawq, m);
1434 	softint_schedule(sc->sc_si);
1435 	splx(s);
1436 }
1437 
1438 /*
1439  * Process a received PPP packet, doing decompression as necessary.
1440  * Should be called at splsoftnet.
1441  */
1442 #define COMPTYPE(proto)	((proto) == PPP_VJC_COMP ? TYPE_COMPRESSED_TCP:	      \
1443 	    TYPE_UNCOMPRESSED_TCP)
1444 
1445 static void
1446 ppp_inproc(struct ppp_softc *sc, struct mbuf *m)
1447 {
1448 	struct ifnet *ifp = &sc->sc_if;
1449 	pktqueue_t *pktq = NULL;
1450 	struct ifqueue *inq = NULL;
1451 	int s, ilen, proto, rv;
1452 	u_char *cp, adrs, ctrl;
1453 	struct mbuf *mp, *dmp = NULL;
1454 #ifdef VJC
1455 	int xlen;
1456 	u_char *iphdr;
1457 	u_int hlen;
1458 #endif
1459 
1460 	sc->sc_stats.ppp_ipackets++;
1461 
1462 	if (sc->sc_flags & SC_LOG_INPKT) {
1463 		ilen = 0;
1464 		for (mp = m; mp != NULL; mp = mp->m_next)
1465 			ilen += mp->m_len;
1466 		printf("%s: got %d bytes\n", ifp->if_xname, ilen);
1467 		pppdumpm(m);
1468 	}
1469 
1470 	cp = mtod(m, u_char *);
1471 	adrs = PPP_ADDRESS(cp);
1472 	ctrl = PPP_CONTROL(cp);
1473 	proto = PPP_PROTOCOL(cp);
1474 
1475 	if (m->m_flags & M_ERRMARK) {
1476 		m->m_flags &= ~M_ERRMARK;
1477 		s = splhigh();	/* XXX IMP ME HARDER */
1478 		sc->sc_flags |= SC_VJ_RESET;
1479 		splx(s);
1480 	}
1481 
1482 #ifdef PPP_COMPRESS
1483 	/*
1484 	 * Decompress this packet if necessary, update the receiver's
1485 	 * dictionary, or take appropriate action on a CCP packet.
1486 	 */
1487 	if (proto == PPP_COMP && sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN)
1488 	    && !(sc->sc_flags & SC_DC_ERROR) && !(sc->sc_flags & SC_DC_FERROR)) {
1489 		/* Decompress this packet */
1490 		rv = (*sc->sc_rcomp->decompress)(sc->sc_rc_state, m, &dmp);
1491 		if (rv == DECOMP_OK) {
1492 			m_freem(m);
1493 			if (dmp == NULL) {
1494 				/*
1495 				 * No error, but no decompressed packet
1496 				 * produced
1497 				 */
1498 				return;
1499 			}
1500 			m = dmp;
1501 			cp = mtod(m, u_char *);
1502 			proto = PPP_PROTOCOL(cp);
1503 
1504 		} else {
1505 			/*
1506 			 * An error has occurred in decompression.
1507 			 * Pass the compressed packet up to pppd, which may
1508 			 * take CCP down or issue a Reset-Req.
1509 			 */
1510 			if (sc->sc_flags & SC_DEBUG)
1511 				printf("%s: decompress failed %d\n",
1512 				    ifp->if_xname, rv);
1513 			s = splhigh();	/* XXX IMP ME HARDER */
1514 			sc->sc_flags |= SC_VJ_RESET;
1515 			if (rv == DECOMP_ERROR)
1516 				sc->sc_flags |= SC_DC_ERROR;
1517 			else
1518 				sc->sc_flags |= SC_DC_FERROR;
1519 			splx(s);
1520 		}
1521 
1522 	} else {
1523 		if (sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN))
1524 			(*sc->sc_rcomp->incomp)(sc->sc_rc_state, m);
1525 		if (proto == PPP_CCP)
1526 			ppp_ccp(sc, m, 1);
1527 	}
1528 #endif
1529 
1530 	ilen = 0;
1531 	for (mp = m; mp != NULL; mp = mp->m_next)
1532 		ilen += mp->m_len;
1533 
1534 #ifdef VJC
1535 	if (sc->sc_flags & SC_VJ_RESET) {
1536 		/*
1537 		 * If we've missed a packet, we must toss subsequent compressed
1538 		 * packets which don't have an explicit connection ID.
1539 		 */
1540 		if (sc->sc_comp)
1541 			sl_uncompress_tcp(NULL, 0, TYPE_ERROR, sc->sc_comp);
1542 		s = splhigh();	/* XXX IMP ME HARDER */
1543 		sc->sc_flags &= ~SC_VJ_RESET;
1544 		splx(s);
1545 	}
1546 
1547 	/*
1548 	 * See if we have a VJ-compressed packet to uncompress.
1549 	 */
1550 	if (proto == PPP_VJC_COMP) {
1551 		if ((sc->sc_flags & SC_REJ_COMP_TCP) || sc->sc_comp == 0)
1552 			goto bad;
1553 
1554 		xlen = sl_uncompress_tcp_core(cp + PPP_HDRLEN,
1555 		    m->m_len - PPP_HDRLEN, ilen - PPP_HDRLEN,
1556 		    TYPE_COMPRESSED_TCP, sc->sc_comp, &iphdr, &hlen);
1557 
1558 		if (xlen <= 0) {
1559 			if (sc->sc_flags & SC_DEBUG)
1560 				printf("%s: VJ uncompress failed on type comp\n",
1561 				    ifp->if_xname);
1562 			goto bad;
1563 		}
1564 
1565 		/* Copy the PPP and IP headers into a new mbuf. */
1566 		MGETHDR(mp, M_DONTWAIT, MT_DATA);
1567 		if (mp == NULL)
1568 			goto bad;
1569 		mp->m_len = 0;
1570 		mp->m_next = NULL;
1571 		if (hlen + PPP_HDRLEN > MHLEN) {
1572 			MCLGET(mp, M_DONTWAIT);
1573 			if (M_TRAILINGSPACE(mp) < hlen + PPP_HDRLEN) {
1574 				/* Lose if big headers and no clusters */
1575 				m_freem(mp);
1576 				goto bad;
1577 			}
1578 		}
1579 		cp = mtod(mp, u_char *);
1580 		cp[0] = adrs;
1581 		cp[1] = ctrl;
1582 		cp[2] = 0;
1583 		cp[3] = PPP_IP;
1584 		proto = PPP_IP;
1585 		bcopy(iphdr, cp + PPP_HDRLEN, hlen);
1586 		mp->m_len = hlen + PPP_HDRLEN;
1587 
1588 		/*
1589 		 * Trim the PPP and VJ headers off the old mbuf
1590 		 * and stick the new and old mbufs together.
1591 		 */
1592 		m->m_data += PPP_HDRLEN + xlen;
1593 		m->m_len -= PPP_HDRLEN + xlen;
1594 		if (m->m_len <= M_TRAILINGSPACE(mp)) {
1595 			bcopy(mtod(m, u_char *),
1596 			    mtod(mp, u_char *) + mp->m_len, m->m_len);
1597 			mp->m_len += m->m_len;
1598 			mp->m_next = m_free(m);
1599 		} else
1600 			mp->m_next = m;
1601 		m = mp;
1602 		ilen += hlen - xlen;
1603 
1604 	} else if (proto == PPP_VJC_UNCOMP) {
1605 		if ((sc->sc_flags & SC_REJ_COMP_TCP) || sc->sc_comp == 0)
1606 			goto bad;
1607 
1608 		xlen = sl_uncompress_tcp_core(cp + PPP_HDRLEN,
1609 		    m->m_len - PPP_HDRLEN, ilen - PPP_HDRLEN,
1610 		    TYPE_UNCOMPRESSED_TCP, sc->sc_comp, &iphdr, &hlen);
1611 
1612 		if (xlen < 0) {
1613 			if (sc->sc_flags & SC_DEBUG)
1614 				printf("%s: VJ uncompress failed on type uncomp\n",
1615 				    ifp->if_xname);
1616 			goto bad;
1617 		}
1618 
1619 		proto = PPP_IP;
1620 		cp[3] = PPP_IP;
1621 	}
1622 #endif /* VJC */
1623 
1624 	/*
1625 	 * If the packet will fit in a header mbuf, don't waste a
1626 	 * whole cluster on it.
1627 	 */
1628 	if (ilen <= MHLEN && M_IS_CLUSTER(m)) {
1629 		MGETHDR(mp, M_DONTWAIT, MT_DATA);
1630 		if (mp != NULL) {
1631 			m_copydata(m, 0, ilen, mtod(mp, void *));
1632 			m_freem(m);
1633 			m = mp;
1634 			m->m_len = ilen;
1635 		}
1636 	}
1637 	m->m_pkthdr.len = ilen;
1638 	m_set_rcvif(m, ifp);
1639 
1640 	if ((proto & 0x8000) == 0) {
1641 #ifdef PPP_FILTER
1642 		/*
1643 		 * See whether we want to pass this packet, and
1644 		 * if it counts as link activity.
1645 		 */
1646 		if (sc->sc_pass_filt_in.bf_insns != 0
1647 		    && bpf_filter(sc->sc_pass_filt_in.bf_insns,
1648 			(u_char *)m, ilen, 0) == 0) {
1649 			/* drop this packet */
1650 			m_freem(m);
1651 			return;
1652 		}
1653 		if (sc->sc_active_filt_in.bf_insns == 0
1654 		    || bpf_filter(sc->sc_active_filt_in.bf_insns,
1655 			(u_char *)m, ilen, 0))
1656 			sc->sc_last_recv = time_second;
1657 #else
1658 		/*
1659 		 * Record the time that we received this packet.
1660 		 */
1661 		sc->sc_last_recv = time_second;
1662 #endif /* PPP_FILTER */
1663 	}
1664 
1665 	/* See if bpf wants to look at the packet. */
1666 	bpf_mtap(&sc->sc_if, m);
1667 
1668 	switch (proto) {
1669 #ifdef INET
1670 	case PPP_IP:
1671 		/*
1672 		 * IP packet - take off the ppp header and pass it up to IP.
1673 		 */
1674 		if ((ifp->if_flags & IFF_UP) == 0
1675 		    || sc->sc_npmode[NP_IP] != NPMODE_PASS) {
1676 			/* Interface is down - drop the packet. */
1677 			m_freem(m);
1678 			return;
1679 		}
1680 		m->m_pkthdr.len -= PPP_HDRLEN;
1681 		m->m_data += PPP_HDRLEN;
1682 		m->m_len -= PPP_HDRLEN;
1683 #ifdef GATEWAY
1684 		if (ipflow_fastforward(m))
1685 			return;
1686 #endif
1687 		pktq = ip_pktq;
1688 		break;
1689 #endif
1690 
1691 #ifdef INET6
1692 	case PPP_IPV6:
1693 		/*
1694 		 * IPv6 packet - take off the ppp header and pass it up to
1695 		 * IPv6.
1696 		 */
1697 		if ((ifp->if_flags & IFF_UP) == 0
1698 		    || sc->sc_npmode[NP_IPV6] != NPMODE_PASS) {
1699 			/* interface is down - drop the packet. */
1700 			m_freem(m);
1701 			return;
1702 		}
1703 		m->m_pkthdr.len -= PPP_HDRLEN;
1704 		m->m_data += PPP_HDRLEN;
1705 		m->m_len -= PPP_HDRLEN;
1706 #ifdef GATEWAY
1707 		if (ip6flow_fastforward(&m))
1708 			return;
1709 #endif
1710 		pktq = ip6_pktq;
1711 		break;
1712 #endif
1713 
1714 	default:
1715 		/*
1716 		 * Some other protocol - place on input queue for read().
1717 		 */
1718 		inq = &sc->sc_inq;
1719 		pktq = NULL;
1720 		break;
1721 	}
1722 
1723 	/*
1724 	 * Put the packet on the appropriate input queue.
1725 	 */
1726 	s = splnet();
1727 
1728 	/* pktq: inet or inet6 cases */
1729 	if (__predict_true(pktq)) {
1730 		if (__predict_false(!pktq_enqueue(pktq, m, 0))) {
1731 			ifp->if_iqdrops++;
1732 			goto bad;
1733 		}
1734 		ifp->if_ipackets++;
1735 		ifp->if_ibytes += ilen;
1736 		splx(s);
1737 		return;
1738 	}
1739 
1740 	/* ifq: other protocol cases */
1741 	if (!inq) {
1742 		goto bad;
1743 	}
1744 	if (IF_QFULL(inq)) {
1745 		IF_DROP(inq);
1746 		splx(s);
1747 		if (sc->sc_flags & SC_DEBUG)
1748 			printf("%s: input queue full\n", ifp->if_xname);
1749 		ifp->if_iqdrops++;
1750 		goto bad;
1751 	}
1752 	IF_ENQUEUE(inq, m);
1753 	splx(s);
1754 	ifp->if_ipackets++;
1755 	ifp->if_ibytes += ilen;
1756 
1757 	(*sc->sc_ctlp)(sc);
1758 
1759 	return;
1760 
1761 bad:
1762 	m_freem(m);
1763 	sc->sc_if.if_ierrors++;
1764 	sc->sc_stats.ppp_ierrors++;
1765 }
1766 
1767 #define MAX_DUMP_BYTES	128
1768 
1769 static void
1770 pppdumpm(struct mbuf *m0)
1771 {
1772 	char buf[3*MAX_DUMP_BYTES+4];
1773 	char *bp = buf;
1774 	struct mbuf *m;
1775 
1776 	for (m = m0; m; m = m->m_next) {
1777 		int l = m->m_len;
1778 		u_char *rptr = (u_char *)m->m_data;
1779 
1780 		while (l--) {
1781 			if (bp > buf + sizeof(buf) - 4)
1782 				goto done;
1783 			/* Convert byte to ascii hex */
1784 			*bp++ = hexdigits[*rptr >> 4];
1785 			*bp++ = hexdigits[*rptr++ & 0xf];
1786 		}
1787 
1788 		if (m->m_next) {
1789 			if (bp > buf + sizeof(buf) - 3)
1790 				goto done;
1791 			*bp++ = '|';
1792 		} else
1793 			*bp++ = ' ';
1794 	}
1795 done:
1796 	if (m)
1797 		*bp++ = '>';
1798 	*bp = 0;
1799 	printf("%s\n", buf);
1800 }
1801 
1802 #ifdef ALTQ
1803 /*
1804  * A wrapper to transmit a packet from if_start since ALTQ uses
1805  * if_start to send a packet.
1806  */
1807 static void
1808 ppp_ifstart(struct ifnet *ifp)
1809 {
1810 	struct ppp_softc *sc;
1811 
1812 	sc = ifp->if_softc;
1813 	(*sc->sc_start)(sc);
1814 }
1815 #endif
1816 
1817 static const struct ppp_known_compressor {
1818 	uint8_t code;
1819 	const char *module;
1820 } ppp_known_compressors[] = {
1821 	{ CI_DEFLATE, "ppp_deflate" },
1822 	{ CI_DEFLATE_DRAFT, "ppp_deflate" },
1823 	{ CI_BSD_COMPRESS, "ppp_bsdcomp" },
1824 	{ CI_MPPE, "ppp_mppe" },
1825 	{ 0, NULL }
1826 };
1827 
1828 static int
1829 ppp_compressor_init(void)
1830 {
1831 
1832 	mutex_init(&ppp_compressors_mtx, MUTEX_DEFAULT, IPL_NONE);
1833 	return 0;
1834 }
1835 
1836 static int
1837 ppp_compressor_destroy(void)
1838 {
1839 
1840 	mutex_destroy(&ppp_compressors_mtx);
1841 	return 0;
1842 }
1843 
1844 static void
1845 ppp_compressor_rele(struct compressor *cp)
1846 {
1847 
1848 	mutex_enter(&ppp_compressors_mtx);
1849 	--cp->comp_refcnt;
1850 	mutex_exit(&ppp_compressors_mtx);
1851 }
1852 
1853 static struct compressor *
1854 ppp_get_compressor_noload(uint8_t ci, bool hold)
1855 {
1856 	struct compressor *cp;
1857 
1858 	KASSERT(mutex_owned(&ppp_compressors_mtx));
1859 	LIST_FOREACH(cp, &ppp_compressors, comp_list) {
1860 		if (cp->compress_proto == ci) {
1861 			if (hold)
1862 				++cp->comp_refcnt;
1863 			return cp;
1864 		}
1865 	}
1866 
1867 	return NULL;
1868 }
1869 
1870 static struct compressor *
1871 ppp_get_compressor(uint8_t ci)
1872 {
1873 	struct compressor *cp = NULL;
1874 	const struct ppp_known_compressor *pkc;
1875 
1876 	mutex_enter(&ppp_compressors_mtx);
1877 	cp = ppp_get_compressor_noload(ci, true);
1878 	mutex_exit(&ppp_compressors_mtx);
1879 	if (cp != NULL)
1880 		return cp;
1881 
1882 	kernconfig_lock();
1883 	mutex_enter(&ppp_compressors_mtx);
1884 	cp = ppp_get_compressor_noload(ci, true);
1885 	mutex_exit(&ppp_compressors_mtx);
1886 	if (cp == NULL) {
1887 		/* Not found, so try to autoload a module */
1888 		for (pkc = ppp_known_compressors; pkc->module != NULL; pkc++) {
1889 			if (pkc->code == ci) {
1890 				if (module_autoload(pkc->module,
1891 					MODULE_CLASS_MISC) != 0)
1892 					break;
1893 				mutex_enter(&ppp_compressors_mtx);
1894 				cp = ppp_get_compressor_noload(ci, true);
1895 				mutex_exit(&ppp_compressors_mtx);
1896 				break;
1897 			}
1898 		}
1899 	}
1900 	kernconfig_unlock();
1901 
1902 	return cp;
1903 }
1904 
1905 int
1906 ppp_register_compressor(struct compressor *pc, size_t ncomp)
1907 {
1908 	int error = 0;
1909 	size_t i;
1910 
1911 	mutex_enter(&ppp_compressors_mtx);
1912 	for (i = 0; i < ncomp; i++) {
1913 		if (ppp_get_compressor_noload(pc[i].compress_proto,
1914 			false) != NULL)
1915 			error = EEXIST;
1916 	}
1917 	if (!error) {
1918 		for (i = 0; i < ncomp; i++) {
1919 			pc[i].comp_refcnt = 0;
1920 			LIST_INSERT_HEAD(&ppp_compressors, &pc[i], comp_list);
1921 		}
1922 	}
1923 	mutex_exit(&ppp_compressors_mtx);
1924 
1925 	return error;
1926 }
1927 
1928 int
1929 ppp_unregister_compressor(struct compressor *pc, size_t ncomp)
1930 {
1931 	int error = 0;
1932 	size_t i;
1933 
1934 	mutex_enter(&ppp_compressors_mtx);
1935 	for (i = 0; i < ncomp; i++) {
1936 		if (ppp_get_compressor_noload(pc[i].compress_proto,
1937 			false) != &pc[i])
1938 			error = ENOENT;
1939 		else if (pc[i].comp_refcnt != 0)
1940 			error = EBUSY;
1941 	}
1942 	if (!error) {
1943 		for (i = 0; i < ncomp; i++) {
1944 			LIST_REMOVE(&pc[i], comp_list);
1945 		}
1946 	}
1947 	mutex_exit(&ppp_compressors_mtx);
1948 
1949 	return error;
1950 }
1951 
1952 /*
1953  * Module infrastructure
1954  */
1955 #include "if_module.h"
1956 
1957 #ifdef PPP_FILTER
1958 #define PPP_DEP "bpf_filter,"
1959 #else
1960 #define PPP_DEP
1961 #endif
1962 
1963 IF_MODULE(MODULE_CLASS_DRIVER, ppp, PPP_DEP "slcompress")
1964