xref: /netbsd-src/sys/net/if_ppp.c (revision d909946ca08dceb44d7d0f22ec9488679695d976)
1 /*	$NetBSD: if_ppp.c,v 1.157 2016/08/07 17:38:34 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 1.157 2016/08/07 17:38:34 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 			error = EAFNOSUPPORT;
805 			break;
806 		}
807 		ifa->ifa_rtrequest = p2p_rtrequest;
808 		break;
809 
810 	case SIOCADDMULTI:
811 	case SIOCDELMULTI:
812 		if (ifr == NULL) {
813 			error = EAFNOSUPPORT;
814 			break;
815 		}
816 		switch (ifreq_getaddr(cmd, ifr)->sa_family) {
817 #ifdef INET
818 		case AF_INET:
819 			break;
820 #endif
821 #ifdef INET6
822 		case AF_INET6:
823 			break;
824 #endif
825 		default:
826 			error = EAFNOSUPPORT;
827 			break;
828 		}
829 		break;
830 
831 	case SIOCGPPPSTATS:
832 		psp = &((struct ifpppstatsreq *) data)->stats;
833 		memset(psp, 0, sizeof(*psp));
834 		psp->p = sc->sc_stats;
835 #if defined(VJC) && !defined(SL_NO_STATS)
836 		if (sc->sc_comp) {
837 			psp->vj.vjs_packets = sc->sc_comp->sls_packets;
838 			psp->vj.vjs_compressed = sc->sc_comp->sls_compressed;
839 			psp->vj.vjs_searches = sc->sc_comp->sls_searches;
840 			psp->vj.vjs_misses = sc->sc_comp->sls_misses;
841 			psp->vj.vjs_uncompressedin = sc->sc_comp->sls_uncompressedin;
842 			psp->vj.vjs_compressedin = sc->sc_comp->sls_compressedin;
843 			psp->vj.vjs_errorin = sc->sc_comp->sls_errorin;
844 			psp->vj.vjs_tossed = sc->sc_comp->sls_tossed;
845 		}
846 #endif /* VJC */
847 		break;
848 
849 #ifdef PPP_COMPRESS
850 	case SIOCGPPPCSTATS:
851 		pcp = &((struct ifpppcstatsreq *) data)->stats;
852 		memset(pcp, 0, sizeof(*pcp));
853 		if (sc->sc_xc_state != NULL)
854 			(*sc->sc_xcomp->comp_stat)(sc->sc_xc_state, &pcp->c);
855 		if (sc->sc_rc_state != NULL)
856 			(*sc->sc_rcomp->decomp_stat)(sc->sc_rc_state, &pcp->d);
857 		break;
858 #endif /* PPP_COMPRESS */
859 
860 	default:
861 		if ((error = ifioctl_common(&sc->sc_if, cmd, data)) == ENETRESET)
862 			error = 0;
863 		break;
864 	}
865 	splx(s);
866 	return (error);
867 }
868 
869 /*
870  * Queue a packet.  Start transmission if not active.
871  * Packet is placed in Information field of PPP frame.
872  */
873 int
874 pppoutput(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst,
875     const struct rtentry *rtp)
876 {
877 	struct ppp_softc *sc = ifp->if_softc;
878 	int protocol, address, control;
879 	u_char *cp;
880 	int s, error;
881 #ifdef INET
882 	struct ip *ip;
883 #endif
884 	struct ifqueue *ifq;
885 	enum NPmode mode;
886 	int len;
887 
888 	    if (sc->sc_devp == NULL || (ifp->if_flags & IFF_RUNNING) == 0
889 		|| ((ifp->if_flags & IFF_UP) == 0 && dst->sa_family != AF_UNSPEC)) {
890 		    error = ENETDOWN;	/* sort of */
891 		    goto bad;
892 	    }
893 
894 	IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family);
895 
896 	/*
897 	 * Compute PPP header.
898 	 */
899 	m0->m_flags &= ~M_HIGHPRI;
900 	switch (dst->sa_family) {
901 #ifdef INET
902 	case AF_INET:
903 		address = PPP_ALLSTATIONS;
904 		control = PPP_UI;
905 		protocol = PPP_IP;
906 		mode = sc->sc_npmode[NP_IP];
907 
908 		/*
909 		 * If this packet has the "low delay" bit set in the IP header,
910 		 * put it on the fastq instead.
911 		 */
912 		ip = mtod(m0, struct ip *);
913 		if (ip->ip_tos & IPTOS_LOWDELAY)
914 			m0->m_flags |= M_HIGHPRI;
915 		break;
916 #endif
917 #ifdef INET6
918 	case AF_INET6:
919 		address = PPP_ALLSTATIONS;	/*XXX*/
920 		control = PPP_UI;		/*XXX*/
921 		protocol = PPP_IPV6;
922 		mode = sc->sc_npmode[NP_IPV6];
923 
924 #if 0	/* XXX flowinfo/traffic class, maybe? */
925 	/*
926 	 * If this packet has the "low delay" bit set in the IP header,
927 	 * put it on the fastq instead.
928 	 */
929 		ip = mtod(m0, struct ip *);
930 		if (ip->ip_tos & IPTOS_LOWDELAY)
931 			m0->m_flags |= M_HIGHPRI;
932 #endif
933 		break;
934 #endif
935 	case AF_UNSPEC:
936 		address = PPP_ADDRESS(dst->sa_data);
937 		control = PPP_CONTROL(dst->sa_data);
938 		protocol = PPP_PROTOCOL(dst->sa_data);
939 		mode = NPMODE_PASS;
940 		break;
941 	default:
942 		printf("%s: af%d not supported\n", ifp->if_xname,
943 		    dst->sa_family);
944 		error = EAFNOSUPPORT;
945 		goto bad;
946 	}
947 
948 	/*
949 	 * Drop this packet, or return an error, if necessary.
950 	 */
951 	if (mode == NPMODE_ERROR) {
952 		error = ENETDOWN;
953 		goto bad;
954 	}
955 	if (mode == NPMODE_DROP) {
956 		error = 0;
957 		goto bad;
958 	}
959 
960 	/*
961 	 * Add PPP header.
962 	 */
963 	M_PREPEND(m0, PPP_HDRLEN, M_DONTWAIT);
964 	if (m0 == NULL) {
965 		error = ENOBUFS;
966 		goto bad;
967 	}
968 
969 	cp = mtod(m0, u_char *);
970 	*cp++ = address;
971 	*cp++ = control;
972 	*cp++ = protocol >> 8;
973 	*cp++ = protocol & 0xff;
974 
975 	len = m_length(m0);
976 
977 	if (sc->sc_flags & SC_LOG_OUTPKT) {
978 		printf("%s output: ", ifp->if_xname);
979 		pppdumpm(m0);
980 	}
981 
982 	if ((protocol & 0x8000) == 0) {
983 #ifdef PPP_FILTER
984 		/*
985 		 * Apply the pass and active filters to the packet,
986 		 * but only if it is a data packet.
987 		 */
988 		if (sc->sc_pass_filt_out.bf_insns != 0
989 		    && bpf_filter(sc->sc_pass_filt_out.bf_insns,
990 			(u_char *)m0, len, 0) == 0) {
991 			error = 0;		/* drop this packet */
992 			goto bad;
993 		}
994 
995 		/*
996 		 * Update the time we sent the most recent packet.
997 		 */
998 		if (sc->sc_active_filt_out.bf_insns == 0
999 		    || bpf_filter(sc->sc_active_filt_out.bf_insns,
1000 			(u_char *)m0, len, 0))
1001 			sc->sc_last_sent = time_second;
1002 #else
1003 		/*
1004 		 * Update the time we sent the most recent packet.
1005 		 */
1006 		sc->sc_last_sent = time_second;
1007 #endif /* PPP_FILTER */
1008 	}
1009 
1010 	/*
1011 	 * See if bpf wants to look at the packet.
1012 	 */
1013 	bpf_mtap(&sc->sc_if, m0);
1014 
1015 	/*
1016 	 * Put the packet on the appropriate queue.
1017 	 */
1018 	s = splnet();
1019 	if (mode == NPMODE_QUEUE) {
1020 		/* XXX we should limit the number of packets on this queue */
1021 		*sc->sc_npqtail = m0;
1022 		m0->m_nextpkt = NULL;
1023 		sc->sc_npqtail = &m0->m_nextpkt;
1024 	} else {
1025 		ifq = (m0->m_flags & M_HIGHPRI) ? &sc->sc_fastq : NULL;
1026 		if ((error = ifq_enqueue2(&sc->sc_if, ifq, m0)) != 0) {
1027 			splx(s);
1028 			sc->sc_if.if_oerrors++;
1029 			sc->sc_stats.ppp_oerrors++;
1030 			return (error);
1031 		}
1032 		ppp_restart(sc);
1033 	}
1034 	ifp->if_opackets++;
1035 	ifp->if_obytes += len;
1036 
1037 	splx(s);
1038 	return (0);
1039 
1040 bad:
1041 	m_freem(m0);
1042 	return (error);
1043 }
1044 
1045 /*
1046  * After a change in the NPmode for some NP, move packets from the
1047  * npqueue to the send queue or the fast queue as appropriate.
1048  * Should be called at splnet, since we muck with the queues.
1049  */
1050 static void
1051 ppp_requeue(struct ppp_softc *sc)
1052 {
1053 	struct mbuf *m, **mpp;
1054 	struct ifqueue *ifq;
1055 	enum NPmode mode;
1056 	int error;
1057 
1058 	for (mpp = &sc->sc_npqueue; (m = *mpp) != NULL; ) {
1059 		switch (PPP_PROTOCOL(mtod(m, u_char *))) {
1060 		case PPP_IP:
1061 			mode = sc->sc_npmode[NP_IP];
1062 			break;
1063 		case PPP_IPV6:
1064 			mode = sc->sc_npmode[NP_IPV6];
1065 			break;
1066 		default:
1067 			mode = NPMODE_PASS;
1068 		}
1069 
1070 		switch (mode) {
1071 		case NPMODE_PASS:
1072 			/*
1073 			 * This packet can now go on one of the queues to
1074 			 * be sent.
1075 			 */
1076 			*mpp = m->m_nextpkt;
1077 			m->m_nextpkt = NULL;
1078 			ifq = (m->m_flags & M_HIGHPRI) ? &sc->sc_fastq : NULL;
1079 			if ((error = ifq_enqueue2(&sc->sc_if, ifq, m)) != 0) {
1080 				sc->sc_if.if_oerrors++;
1081 				sc->sc_stats.ppp_oerrors++;
1082 			}
1083 			break;
1084 
1085 		case NPMODE_DROP:
1086 		case NPMODE_ERROR:
1087 			*mpp = m->m_nextpkt;
1088 			m_freem(m);
1089 			break;
1090 
1091 		case NPMODE_QUEUE:
1092 			mpp = &m->m_nextpkt;
1093 			break;
1094 		}
1095 	}
1096 	sc->sc_npqtail = mpp;
1097 }
1098 
1099 /*
1100  * Transmitter has finished outputting some stuff;
1101  * remember to call sc->sc_start later at splsoftnet.
1102  */
1103 void
1104 ppp_restart(struct ppp_softc *sc)
1105 {
1106 	int s = splhigh();	/* XXX IMP ME HARDER */
1107 
1108 	sc->sc_flags &= ~SC_TBUSY;
1109 	softint_schedule(sc->sc_si);
1110 	splx(s);
1111 }
1112 
1113 /*
1114  * Get a packet to send.  This procedure is intended to be called at
1115  * splsoftnet, since it may involve time-consuming operations such as
1116  * applying VJ compression, packet compression, address/control and/or
1117  * protocol field compression to the packet.
1118  */
1119 struct mbuf *
1120 ppp_dequeue(struct ppp_softc *sc)
1121 {
1122 	struct mbuf *m, *mp;
1123 	u_char *cp;
1124 	int address, control, protocol;
1125 	int s;
1126 
1127 	/*
1128 	 * Grab a packet to send: first try the fast queue, then the
1129 	 * normal queue.
1130 	 */
1131 	s = splnet();
1132 	if (sc->sc_nfastq < sc->sc_maxfastq) {
1133 		IF_DEQUEUE(&sc->sc_fastq, m);
1134 		if (m != NULL)
1135 			sc->sc_nfastq++;
1136 		else
1137 			IFQ_DEQUEUE(&sc->sc_if.if_snd, m);
1138 	} else {
1139 		sc->sc_nfastq = 0;
1140 		IFQ_DEQUEUE(&sc->sc_if.if_snd, m);
1141 		if (m == NULL) {
1142 			IF_DEQUEUE(&sc->sc_fastq, m);
1143 			if (m != NULL)
1144 				sc->sc_nfastq++;
1145 		}
1146 	}
1147 	splx(s);
1148 
1149 	if (m == NULL)
1150 		return NULL;
1151 
1152 	++sc->sc_stats.ppp_opackets;
1153 
1154 	/*
1155 	 * Extract the ppp header of the new packet.
1156 	 * The ppp header will be in one mbuf.
1157 	 */
1158 	cp = mtod(m, u_char *);
1159 	address = PPP_ADDRESS(cp);
1160 	control = PPP_CONTROL(cp);
1161 	protocol = PPP_PROTOCOL(cp);
1162 
1163 	switch (protocol) {
1164 	case PPP_IP:
1165 #ifdef VJC
1166 		/*
1167 		 * If the packet is a TCP/IP packet, see if we can compress it.
1168 		 */
1169 		if ((sc->sc_flags & SC_COMP_TCP) && sc->sc_comp != NULL) {
1170 			struct ip *ip;
1171 			int type;
1172 
1173 			mp = m;
1174 			ip = (struct ip *) (cp + PPP_HDRLEN);
1175 			if (mp->m_len <= PPP_HDRLEN) {
1176 				mp = mp->m_next;
1177 				if (mp == NULL)
1178 					break;
1179 				ip = mtod(mp, struct ip *);
1180 			}
1181 			/*
1182 			 * This code assumes the IP/TCP header is in one
1183 			 * non-shared mbuf
1184 			 */
1185 			if (ip->ip_p == IPPROTO_TCP) {
1186 				type = sl_compress_tcp(mp, ip, sc->sc_comp,
1187 				    !(sc->sc_flags & SC_NO_TCP_CCID));
1188 				switch (type) {
1189 				case TYPE_UNCOMPRESSED_TCP:
1190 					protocol = PPP_VJC_UNCOMP;
1191 					break;
1192 				case TYPE_COMPRESSED_TCP:
1193 					protocol = PPP_VJC_COMP;
1194 					cp = mtod(m, u_char *);
1195 					cp[0] = address; /* Header has moved */
1196 					cp[1] = control;
1197 					cp[2] = 0;
1198 					break;
1199 				}
1200 				/* Update protocol in PPP header */
1201 				cp[3] = protocol;
1202 			}
1203 		}
1204 #endif	/* VJC */
1205 		break;
1206 
1207 #ifdef PPP_COMPRESS
1208 	case PPP_CCP:
1209 		ppp_ccp(sc, m, 0);
1210 		break;
1211 #endif	/* PPP_COMPRESS */
1212 	}
1213 
1214 #ifdef PPP_COMPRESS
1215 	if (protocol != PPP_LCP && protocol != PPP_CCP
1216 	    && sc->sc_xc_state && (sc->sc_flags & SC_COMP_RUN)) {
1217 		struct mbuf *mcomp = NULL;
1218 		int slen;
1219 
1220 		slen = 0;
1221 		for (mp = m; mp != NULL; mp = mp->m_next)
1222 			slen += mp->m_len;
1223 		(*sc->sc_xcomp->compress)
1224 		    (sc->sc_xc_state, &mcomp, m, slen, sc->sc_if.if_mtu + PPP_HDRLEN);
1225 		if (mcomp != NULL) {
1226 			if (sc->sc_flags & SC_CCP_UP) {
1227 				/*
1228 				 * Send the compressed packet instead of the
1229 				 * original.
1230 				 */
1231 				m_freem(m);
1232 				m = mcomp;
1233 				cp = mtod(m, u_char *);
1234 				protocol = cp[3];
1235 			} else {
1236 				/*
1237 				 * Can't transmit compressed packets until CCP
1238 				 * is up.
1239 				 */
1240 				m_freem(mcomp);
1241 			}
1242 		}
1243 	}
1244 #endif	/* PPP_COMPRESS */
1245 
1246 	/*
1247 	 * Compress the address/control and protocol, if possible.
1248 	 */
1249 	if (sc->sc_flags & SC_COMP_AC && address == PPP_ALLSTATIONS &&
1250 	    control == PPP_UI && protocol != PPP_ALLSTATIONS &&
1251 	    protocol != PPP_LCP) {
1252 		/* can compress address/control */
1253 		m->m_data += 2;
1254 		m->m_len -= 2;
1255 	}
1256 	if (sc->sc_flags & SC_COMP_PROT && protocol < 0xFF) {
1257 		/* can compress protocol */
1258 		if (mtod(m, u_char *) == cp) {
1259 			cp[2] = cp[1];	/* move address/control up */
1260 			cp[1] = cp[0];
1261 		}
1262 		++m->m_data;
1263 		--m->m_len;
1264 	}
1265 
1266 	return m;
1267 }
1268 
1269 /*
1270  * Software interrupt routine, called at splsoftnet.
1271  */
1272 static void
1273 pppintr(void *arg)
1274 {
1275 	struct ppp_softc *sc = arg;
1276 	struct mbuf *m;
1277 	int s;
1278 
1279 	mutex_enter(softnet_lock);
1280 	if (!(sc->sc_flags & SC_TBUSY)
1281 	    && (IFQ_IS_EMPTY(&sc->sc_if.if_snd) == 0 || sc->sc_fastq.ifq_head
1282 		|| sc->sc_outm)) {
1283 		s = splhigh();	/* XXX IMP ME HARDER */
1284 		sc->sc_flags |= SC_TBUSY;
1285 		splx(s);
1286 		(*sc->sc_start)(sc);
1287 	}
1288 	for (;;) {
1289 		s = splnet();
1290 		IF_DEQUEUE(&sc->sc_rawq, m);
1291 		splx(s);
1292 		if (m == NULL)
1293 			break;
1294 		ppp_inproc(sc, m);
1295 	}
1296 	mutex_exit(softnet_lock);
1297 }
1298 
1299 #ifdef PPP_COMPRESS
1300 /*
1301  * Handle a CCP packet.	 `rcvd' is 1 if the packet was received,
1302  * 0 if it is about to be transmitted.
1303  */
1304 static void
1305 ppp_ccp(struct ppp_softc *sc, struct mbuf *m, int rcvd)
1306 {
1307 	u_char *dp, *ep;
1308 	struct mbuf *mp;
1309 	int slen, s;
1310 
1311 	/*
1312 	 * Get a pointer to the data after the PPP header.
1313 	 */
1314 	if (m->m_len <= PPP_HDRLEN) {
1315 		mp = m->m_next;
1316 		if (mp == NULL)
1317 			return;
1318 		dp = mtod(mp, u_char *);
1319 	} else {
1320 		mp = m;
1321 		dp = mtod(mp, u_char *) + PPP_HDRLEN;
1322 	}
1323 
1324 	ep = mtod(mp, u_char *) + mp->m_len;
1325 	if (dp + CCP_HDRLEN > ep)
1326 		return;
1327 	slen = CCP_LENGTH(dp);
1328 	if (dp + slen > ep) {
1329 		if (sc->sc_flags & SC_DEBUG)
1330 			printf("if_ppp/ccp: not enough data in mbuf (%p+%x > %p+%x)\n",
1331 			    dp, slen, mtod(mp, u_char *), mp->m_len);
1332 		return;
1333 	}
1334 
1335 	switch (CCP_CODE(dp)) {
1336 	case CCP_CONFREQ:
1337 	case CCP_TERMREQ:
1338 	case CCP_TERMACK:
1339 		/* CCP must be going down - disable compression */
1340 		if (sc->sc_flags & SC_CCP_UP) {
1341 			s = splhigh();	/* XXX IMP ME HARDER */
1342 			sc->sc_flags &= ~(SC_CCP_UP | SC_COMP_RUN | SC_DECOMP_RUN);
1343 			splx(s);
1344 		}
1345 		break;
1346 
1347 	case CCP_CONFACK:
1348 		if (sc->sc_flags & SC_CCP_OPEN && !(sc->sc_flags & SC_CCP_UP)
1349 		    && slen >= CCP_HDRLEN + CCP_OPT_MINLEN
1350 		    && slen >= CCP_OPT_LENGTH(dp + CCP_HDRLEN) + CCP_HDRLEN) {
1351 			if (!rcvd) {
1352 				/* We're agreeing to send compressed packets. */
1353 				if (sc->sc_xc_state != NULL
1354 				    && (*sc->sc_xcomp->comp_init)
1355 				    (sc->sc_xc_state, dp + CCP_HDRLEN,
1356 					slen - CCP_HDRLEN, sc->sc_unit, 0,
1357 					sc->sc_flags & SC_DEBUG)) {
1358 					s = splhigh();	/* XXX IMP ME HARDER */
1359 					sc->sc_flags |= SC_COMP_RUN;
1360 					splx(s);
1361 				}
1362 			} else {
1363 				/*
1364 				 * Peer is agreeing to send compressed
1365 				 * packets.
1366 				 */
1367 				if (sc->sc_rc_state != NULL
1368 				    && (*sc->sc_rcomp->decomp_init)
1369 				    (sc->sc_rc_state, dp + CCP_HDRLEN, slen - CCP_HDRLEN,
1370 					sc->sc_unit, 0, sc->sc_mru,
1371 					sc->sc_flags & SC_DEBUG)) {
1372 					s = splhigh();	/* XXX IMP ME HARDER */
1373 					sc->sc_flags |= SC_DECOMP_RUN;
1374 					sc->sc_flags &= ~(SC_DC_ERROR | SC_DC_FERROR);
1375 					splx(s);
1376 				}
1377 			}
1378 		}
1379 		break;
1380 
1381 	case CCP_RESETACK:
1382 		if (sc->sc_flags & SC_CCP_UP) {
1383 			if (!rcvd) {
1384 				if (sc->sc_xc_state && (sc->sc_flags & SC_COMP_RUN))
1385 					(*sc->sc_xcomp->comp_reset)(sc->sc_xc_state);
1386 			} else {
1387 				if (sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN)) {
1388 					(*sc->sc_rcomp->decomp_reset)(sc->sc_rc_state);
1389 					s = splhigh();	/* XXX IMP ME HARDER */
1390 					sc->sc_flags &= ~SC_DC_ERROR;
1391 					splx(s);
1392 				}
1393 			}
1394 		}
1395 		break;
1396 	}
1397 }
1398 
1399 /*
1400  * CCP is down; free (de)compressor state if necessary.
1401  */
1402 static void
1403 ppp_ccp_closed(struct ppp_softc *sc)
1404 {
1405 	if (sc->sc_xc_state) {
1406 		(*sc->sc_xcomp->comp_free)(sc->sc_xc_state);
1407 		ppp_compressor_rele(sc->sc_xcomp);
1408 		sc->sc_xc_state = NULL;
1409 	}
1410 	if (sc->sc_rc_state) {
1411 		(*sc->sc_rcomp->decomp_free)(sc->sc_rc_state);
1412 		ppp_compressor_rele(sc->sc_rcomp);
1413 		sc->sc_rc_state = NULL;
1414 	}
1415 }
1416 #endif /* PPP_COMPRESS */
1417 
1418 /*
1419  * PPP packet input routine.
1420  * The caller has checked and removed the FCS and has inserted
1421  * the address/control bytes and the protocol high byte if they
1422  * were omitted.
1423  */
1424 void
1425 ppppktin(struct ppp_softc *sc, struct mbuf *m, int lost)
1426 {
1427 	int s = splhigh();	/* XXX IMP ME HARDER */
1428 
1429 	if (lost)
1430 		m->m_flags |= M_ERRMARK;
1431 	IF_ENQUEUE(&sc->sc_rawq, m);
1432 	softint_schedule(sc->sc_si);
1433 	splx(s);
1434 }
1435 
1436 /*
1437  * Process a received PPP packet, doing decompression as necessary.
1438  * Should be called at splsoftnet.
1439  */
1440 #define COMPTYPE(proto)	((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 && sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN)
1486 	    && !(sc->sc_flags & SC_DC_ERROR) && !(sc->sc_flags & SC_DC_FERROR)) {
1487 		/* Decompress this packet */
1488 		rv = (*sc->sc_rcomp->decompress)(sc->sc_rc_state, m, &dmp);
1489 		if (rv == DECOMP_OK) {
1490 			m_freem(m);
1491 			if (dmp == NULL) {
1492 				/*
1493 				 * No error, but no decompressed packet
1494 				 * produced
1495 				 */
1496 				return;
1497 			}
1498 			m = dmp;
1499 			cp = mtod(m, u_char *);
1500 			proto = PPP_PROTOCOL(cp);
1501 
1502 		} else {
1503 			/*
1504 			 * An error has occurred in decompression.
1505 			 * Pass the compressed packet up to pppd, which may
1506 			 * take CCP down or issue a Reset-Req.
1507 			 */
1508 			if (sc->sc_flags & SC_DEBUG)
1509 				printf("%s: decompress failed %d\n",
1510 				    ifp->if_xname, rv);
1511 			s = splhigh();	/* XXX IMP ME HARDER */
1512 			sc->sc_flags |= SC_VJ_RESET;
1513 			if (rv == DECOMP_ERROR)
1514 				sc->sc_flags |= SC_DC_ERROR;
1515 			else
1516 				sc->sc_flags |= SC_DC_FERROR;
1517 			splx(s);
1518 		}
1519 
1520 	} else {
1521 		if (sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN))
1522 			(*sc->sc_rcomp->incomp)(sc->sc_rc_state, m);
1523 		if (proto == PPP_CCP)
1524 			ppp_ccp(sc, m, 1);
1525 	}
1526 #endif
1527 
1528 	ilen = 0;
1529 	for (mp = m; mp != NULL; mp = mp->m_next)
1530 		ilen += mp->m_len;
1531 
1532 #ifdef VJC
1533 	if (sc->sc_flags & SC_VJ_RESET) {
1534 		/*
1535 		 * If we've missed a packet, we must toss subsequent compressed
1536 		 * packets which don't have an explicit connection ID.
1537 		 */
1538 		if (sc->sc_comp)
1539 			sl_uncompress_tcp(NULL, 0, TYPE_ERROR, sc->sc_comp);
1540 		s = splhigh();	/* XXX IMP ME HARDER */
1541 		sc->sc_flags &= ~SC_VJ_RESET;
1542 		splx(s);
1543 	}
1544 
1545 	/*
1546 	 * See if we have a VJ-compressed packet to uncompress.
1547 	 */
1548 	if (proto == PPP_VJC_COMP) {
1549 		if ((sc->sc_flags & SC_REJ_COMP_TCP) || sc->sc_comp == 0)
1550 			goto bad;
1551 
1552 		xlen = sl_uncompress_tcp_core(cp + PPP_HDRLEN,
1553 		    m->m_len - PPP_HDRLEN, ilen - PPP_HDRLEN,
1554 		    TYPE_COMPRESSED_TCP, sc->sc_comp, &iphdr, &hlen);
1555 
1556 		if (xlen <= 0) {
1557 			if (sc->sc_flags & SC_DEBUG)
1558 				printf("%s: VJ uncompress failed on type comp\n",
1559 				    ifp->if_xname);
1560 			goto bad;
1561 		}
1562 
1563 		/* Copy the PPP and IP headers into a new mbuf. */
1564 		MGETHDR(mp, M_DONTWAIT, MT_DATA);
1565 		if (mp == NULL)
1566 			goto bad;
1567 		mp->m_len = 0;
1568 		mp->m_next = NULL;
1569 		if (hlen + PPP_HDRLEN > MHLEN) {
1570 			MCLGET(mp, M_DONTWAIT);
1571 			if (M_TRAILINGSPACE(mp) < hlen + PPP_HDRLEN) {
1572 				/* Lose if big headers and no clusters */
1573 				m_freem(mp);
1574 				goto bad;
1575 			}
1576 		}
1577 		cp = mtod(mp, u_char *);
1578 		cp[0] = adrs;
1579 		cp[1] = ctrl;
1580 		cp[2] = 0;
1581 		cp[3] = PPP_IP;
1582 		proto = PPP_IP;
1583 		bcopy(iphdr, cp + PPP_HDRLEN, hlen);
1584 		mp->m_len = hlen + PPP_HDRLEN;
1585 
1586 		/*
1587 		 * Trim the PPP and VJ headers off the old mbuf
1588 		 * and stick the new and old mbufs together.
1589 		 */
1590 		m->m_data += PPP_HDRLEN + xlen;
1591 		m->m_len -= PPP_HDRLEN + xlen;
1592 		if (m->m_len <= M_TRAILINGSPACE(mp)) {
1593 			bcopy(mtod(m, u_char *),
1594 			    mtod(mp, u_char *) + mp->m_len, m->m_len);
1595 			mp->m_len += m->m_len;
1596 			MFREE(m, mp->m_next);
1597 		} else
1598 			mp->m_next = m;
1599 		m = mp;
1600 		ilen += hlen - xlen;
1601 
1602 	} else if (proto == PPP_VJC_UNCOMP) {
1603 		if ((sc->sc_flags & SC_REJ_COMP_TCP) || sc->sc_comp == 0)
1604 			goto bad;
1605 
1606 		xlen = sl_uncompress_tcp_core(cp + PPP_HDRLEN,
1607 		    m->m_len - PPP_HDRLEN, ilen - PPP_HDRLEN,
1608 		    TYPE_UNCOMPRESSED_TCP, sc->sc_comp, &iphdr, &hlen);
1609 
1610 		if (xlen < 0) {
1611 			if (sc->sc_flags & SC_DEBUG)
1612 				printf("%s: VJ uncompress failed on type uncomp\n",
1613 				    ifp->if_xname);
1614 			goto bad;
1615 		}
1616 
1617 		proto = PPP_IP;
1618 		cp[3] = PPP_IP;
1619 	}
1620 #endif /* VJC */
1621 
1622 	/*
1623 	 * If the packet will fit in a header mbuf, don't waste a
1624 	 * whole cluster on it.
1625 	 */
1626 	if (ilen <= MHLEN && M_IS_CLUSTER(m)) {
1627 		MGETHDR(mp, M_DONTWAIT, MT_DATA);
1628 		if (mp != NULL) {
1629 			m_copydata(m, 0, ilen, mtod(mp, void *));
1630 			m_freem(m);
1631 			m = mp;
1632 			m->m_len = ilen;
1633 		}
1634 	}
1635 	m->m_pkthdr.len = ilen;
1636 	m_set_rcvif(m, ifp);
1637 
1638 	if ((proto & 0x8000) == 0) {
1639 #ifdef PPP_FILTER
1640 		/*
1641 		 * See whether we want to pass this packet, and
1642 		 * if it counts as link activity.
1643 		 */
1644 		if (sc->sc_pass_filt_in.bf_insns != 0
1645 		    && bpf_filter(sc->sc_pass_filt_in.bf_insns,
1646 			(u_char *)m, ilen, 0) == 0) {
1647 			/* drop this packet */
1648 			m_freem(m);
1649 			return;
1650 		}
1651 		if (sc->sc_active_filt_in.bf_insns == 0
1652 		    || bpf_filter(sc->sc_active_filt_in.bf_insns,
1653 			(u_char *)m, ilen, 0))
1654 			sc->sc_last_recv = time_second;
1655 #else
1656 		/*
1657 		 * Record the time that we received this packet.
1658 		 */
1659 		sc->sc_last_recv = time_second;
1660 #endif /* PPP_FILTER */
1661 	}
1662 
1663 	/* See if bpf wants to look at the packet. */
1664 	bpf_mtap(&sc->sc_if, m);
1665 
1666 	switch (proto) {
1667 #ifdef INET
1668 	case PPP_IP:
1669 		/*
1670 		 * IP packet - take off the ppp header and pass it up to IP.
1671 		 */
1672 		if ((ifp->if_flags & IFF_UP) == 0
1673 		    || sc->sc_npmode[NP_IP] != NPMODE_PASS) {
1674 			/* Interface is down - drop the packet. */
1675 			m_freem(m);
1676 			return;
1677 		}
1678 		m->m_pkthdr.len -= PPP_HDRLEN;
1679 		m->m_data += PPP_HDRLEN;
1680 		m->m_len -= PPP_HDRLEN;
1681 #ifdef GATEWAY
1682 		if (ipflow_fastforward(m))
1683 			return;
1684 #endif
1685 		pktq = ip_pktq;
1686 		break;
1687 #endif
1688 
1689 #ifdef INET6
1690 	case PPP_IPV6:
1691 		/*
1692 		 * IPv6 packet - take off the ppp header and pass it up to
1693 		 * IPv6.
1694 		 */
1695 		if ((ifp->if_flags & IFF_UP) == 0
1696 		    || sc->sc_npmode[NP_IPV6] != NPMODE_PASS) {
1697 			/* interface is down - drop the packet. */
1698 			m_freem(m);
1699 			return;
1700 		}
1701 		m->m_pkthdr.len -= PPP_HDRLEN;
1702 		m->m_data += PPP_HDRLEN;
1703 		m->m_len -= PPP_HDRLEN;
1704 #ifdef GATEWAY
1705 		if (ip6flow_fastforward(&m))
1706 			return;
1707 #endif
1708 		pktq = ip6_pktq;
1709 		break;
1710 #endif
1711 
1712 	default:
1713 		/*
1714 		 * Some other protocol - place on input queue for read().
1715 		 */
1716 		inq = &sc->sc_inq;
1717 		pktq = NULL;
1718 		break;
1719 	}
1720 
1721 	/*
1722 	 * Put the packet on the appropriate input queue.
1723 	 */
1724 	s = splnet();
1725 
1726 	/* pktq: inet or inet6 cases */
1727 	if (__predict_true(pktq)) {
1728 		if (__predict_false(!pktq_enqueue(pktq, m, 0))) {
1729 			ifp->if_iqdrops++;
1730 			goto bad;
1731 		}
1732 		ifp->if_ipackets++;
1733 		ifp->if_ibytes += ilen;
1734 		splx(s);
1735 		return;
1736 	}
1737 
1738 	/* ifq: other protocol cases */
1739 	if (!inq) {
1740 		goto bad;
1741 	}
1742 	if (IF_QFULL(inq)) {
1743 		IF_DROP(inq);
1744 		splx(s);
1745 		if (sc->sc_flags & SC_DEBUG)
1746 			printf("%s: input queue full\n", ifp->if_xname);
1747 		ifp->if_iqdrops++;
1748 		goto bad;
1749 	}
1750 	IF_ENQUEUE(inq, m);
1751 	splx(s);
1752 	ifp->if_ipackets++;
1753 	ifp->if_ibytes += ilen;
1754 
1755 	(*sc->sc_ctlp)(sc);
1756 
1757 	return;
1758 
1759 bad:
1760 	m_freem(m);
1761 	sc->sc_if.if_ierrors++;
1762 	sc->sc_stats.ppp_ierrors++;
1763 }
1764 
1765 #define MAX_DUMP_BYTES	128
1766 
1767 static void
1768 pppdumpm(struct mbuf *m0)
1769 {
1770 	char buf[3*MAX_DUMP_BYTES+4];
1771 	char *bp = buf;
1772 	struct mbuf *m;
1773 
1774 	for (m = m0; m; m = m->m_next) {
1775 		int l = m->m_len;
1776 		u_char *rptr = (u_char *)m->m_data;
1777 
1778 		while (l--) {
1779 			if (bp > buf + sizeof(buf) - 4)
1780 				goto done;
1781 			/* Convert byte to ascii hex */
1782 			*bp++ = hexdigits[*rptr >> 4];
1783 			*bp++ = hexdigits[*rptr++ & 0xf];
1784 		}
1785 
1786 		if (m->m_next) {
1787 			if (bp > buf + sizeof(buf) - 3)
1788 				goto done;
1789 			*bp++ = '|';
1790 		} else
1791 			*bp++ = ' ';
1792 	}
1793 done:
1794 	if (m)
1795 		*bp++ = '>';
1796 	*bp = 0;
1797 	printf("%s\n", buf);
1798 }
1799 
1800 #ifdef ALTQ
1801 /*
1802  * A wrapper to transmit a packet from if_start since ALTQ uses
1803  * if_start to send a packet.
1804  */
1805 static void
1806 ppp_ifstart(struct ifnet *ifp)
1807 {
1808 	struct ppp_softc *sc;
1809 
1810 	sc = ifp->if_softc;
1811 	(*sc->sc_start)(sc);
1812 }
1813 #endif
1814 
1815 static const struct ppp_known_compressor {
1816 	uint8_t code;
1817 	const char *module;
1818 } ppp_known_compressors[] = {
1819 	{ CI_DEFLATE, "ppp_deflate" },
1820 	{ CI_DEFLATE_DRAFT, "ppp_deflate" },
1821 	{ CI_BSD_COMPRESS, "ppp_bsdcomp" },
1822 	{ CI_MPPE, "ppp_mppe" },
1823 	{ 0, NULL }
1824 };
1825 
1826 static int
1827 ppp_compressor_init(void)
1828 {
1829 
1830 	mutex_init(&ppp_compressors_mtx, MUTEX_DEFAULT, IPL_NONE);
1831 	return 0;
1832 }
1833 
1834 static int
1835 ppp_compressor_destroy(void)
1836 {
1837 
1838 	mutex_destroy(&ppp_compressors_mtx);
1839 	return 0;
1840 }
1841 
1842 static void
1843 ppp_compressor_rele(struct compressor *cp)
1844 {
1845 
1846 	mutex_enter(&ppp_compressors_mtx);
1847 	--cp->comp_refcnt;
1848 	mutex_exit(&ppp_compressors_mtx);
1849 }
1850 
1851 static struct compressor *
1852 ppp_get_compressor_noload(uint8_t ci, bool hold)
1853 {
1854 	struct compressor *cp;
1855 
1856 	KASSERT(mutex_owned(&ppp_compressors_mtx));
1857 	LIST_FOREACH(cp, &ppp_compressors, comp_list) {
1858 		if (cp->compress_proto == ci) {
1859 			if (hold)
1860 				++cp->comp_refcnt;
1861 			return cp;
1862 		}
1863 	}
1864 
1865 	return NULL;
1866 }
1867 
1868 static struct compressor *
1869 ppp_get_compressor(uint8_t ci)
1870 {
1871 	struct compressor *cp = NULL;
1872 	const struct ppp_known_compressor *pkc;
1873 
1874 	mutex_enter(&ppp_compressors_mtx);
1875 	cp = ppp_get_compressor_noload(ci, true);
1876 	mutex_exit(&ppp_compressors_mtx);
1877 	if (cp != NULL)
1878 		return cp;
1879 
1880 	kernconfig_lock();
1881 	mutex_enter(&ppp_compressors_mtx);
1882 	cp = ppp_get_compressor_noload(ci, true);
1883 	mutex_exit(&ppp_compressors_mtx);
1884 	if (cp == NULL) {
1885 		/* Not found, so try to autoload a module */
1886 		for (pkc = ppp_known_compressors; pkc->module != NULL; pkc++) {
1887 			if (pkc->code == ci) {
1888 				if (module_autoload(pkc->module,
1889 					MODULE_CLASS_MISC) != 0)
1890 					break;
1891 				mutex_enter(&ppp_compressors_mtx);
1892 				cp = ppp_get_compressor_noload(ci, true);
1893 				mutex_exit(&ppp_compressors_mtx);
1894 				break;
1895 			}
1896 		}
1897 	}
1898 	kernconfig_unlock();
1899 
1900 	return cp;
1901 }
1902 
1903 int
1904 ppp_register_compressor(struct compressor *pc, size_t ncomp)
1905 {
1906 	int error = 0;
1907 	size_t i;
1908 
1909 	mutex_enter(&ppp_compressors_mtx);
1910 	for (i = 0; i < ncomp; i++) {
1911 		if (ppp_get_compressor_noload(pc[i].compress_proto,
1912 			false) != NULL)
1913 			error = EEXIST;
1914 	}
1915 	if (!error) {
1916 		for (i = 0; i < ncomp; i++) {
1917 			pc[i].comp_refcnt = 0;
1918 			LIST_INSERT_HEAD(&ppp_compressors, &pc[i], comp_list);
1919 		}
1920 	}
1921 	mutex_exit(&ppp_compressors_mtx);
1922 
1923 	return error;
1924 }
1925 
1926 int
1927 ppp_unregister_compressor(struct compressor *pc, size_t ncomp)
1928 {
1929 	int error = 0;
1930 	size_t i;
1931 
1932 	mutex_enter(&ppp_compressors_mtx);
1933 	for (i = 0; i < ncomp; i++) {
1934 		if (ppp_get_compressor_noload(pc[i].compress_proto,
1935 			false) != &pc[i])
1936 			error = ENOENT;
1937 		else if (pc[i].comp_refcnt != 0)
1938 			error = EBUSY;
1939 	}
1940 	if (!error) {
1941 		for (i = 0; i < ncomp; i++) {
1942 			LIST_REMOVE(&pc[i], comp_list);
1943 		}
1944 	}
1945 	mutex_exit(&ppp_compressors_mtx);
1946 
1947 	return error;
1948 }
1949 
1950 /*
1951  * Module infrastructure
1952  */
1953 #include "if_module.h"
1954 
1955 #ifdef PPP_FILTER
1956 #define PPP_DEP "bpf_filter,"
1957 #else
1958 #define PPP_DEP
1959 #endif
1960 
1961 IF_MODULE(MODULE_CLASS_DRIVER, ppp, PPP_DEP "slcompress")
1962