xref: /netbsd-src/sys/net/if_ppp.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: if_ppp.c,v 1.161 2018/06/26 06:48:02 msaitoh 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 1.161 2018/06/26 06:48:02 msaitoh 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 
143 #include <netinet/in.h>
144 #include <netinet/in_systm.h>
145 #include <netinet/in_var.h>
146 #ifdef INET
147 #include <netinet/ip.h>
148 #endif
149 
150 #include <net/bpf.h>
151 #include <net/slip.h>
152 
153 #ifdef VJC
154 #include <net/slcompress.h>
155 #endif
156 
157 #include <net/ppp_defs.h>
158 #include <net/if_ppp.h>
159 #include <net/if_pppvar.h>
160 #include <sys/cpu.h>
161 
162 #ifdef PPP_COMPRESS
163 #define PACKETPTR	struct mbuf *
164 #include <net/ppp-comp.h>
165 #endif
166 
167 #include "ioconf.h"
168 
169 static int	pppsioctl(struct ifnet *, u_long, void *);
170 static void	ppp_requeue(struct ppp_softc *);
171 static void	ppp_ccp(struct ppp_softc *, struct mbuf *m, int rcvd);
172 static void	ppp_ccp_closed(struct ppp_softc *);
173 static void	ppp_inproc(struct ppp_softc *, struct mbuf *);
174 static void	pppdumpm(struct mbuf *m0);
175 #ifdef ALTQ
176 static void	ppp_ifstart(struct ifnet *ifp);
177 #endif
178 
179 static void	pppintr(void *);
180 
181 extern struct linesw ppp_disc;
182 
183 /*
184  * Some useful mbuf macros not in mbuf.h.
185  */
186 #define M_IS_CLUSTER(m)	((m)->m_flags & M_EXT)
187 
188 #define M_DATASTART(m)							\
189 	(M_IS_CLUSTER(m) ? (m)->m_ext.ext_buf :				\
190 	    (m)->m_flags & M_PKTHDR ? (m)->m_pktdat : (m)->m_dat)
191 
192 #define M_DATASIZE(m)							\
193 	(M_IS_CLUSTER(m) ? (m)->m_ext.ext_size :			\
194 	    (m)->m_flags & M_PKTHDR ? MHLEN: MLEN)
195 
196 /*
197  * We define two link layer specific mbuf flags, to mark high-priority
198  * packets for output, and received packets following lost/corrupted
199  * packets.
200  */
201 #define	M_HIGHPRI	M_LINK0	/* output packet for sc_fastq */
202 #define	M_ERRMARK	M_LINK1	/* rx packet following lost/corrupted pkt */
203 
204 static int ppp_clone_create(struct if_clone *, int);
205 static int ppp_clone_destroy(struct ifnet *);
206 
207 static struct ppp_softc *ppp_create(const char *, int);
208 
209 static LIST_HEAD(, ppp_softc) ppp_softc_list;
210 static kmutex_t ppp_list_lock;
211 
212 struct if_clone ppp_cloner =
213     IF_CLONE_INITIALIZER("ppp", ppp_clone_create, ppp_clone_destroy);
214 
215 #ifdef PPP_COMPRESS
216 static LIST_HEAD(, compressor) ppp_compressors = { NULL };
217 static kmutex_t ppp_compressors_mtx;
218 
219 static int ppp_compressor_init(void);
220 static int ppp_compressor_destroy(void);
221 static struct compressor *ppp_get_compressor(uint8_t);
222 static void ppp_compressor_rele(struct compressor *);
223 #endif /* PPP_COMPRESS */
224 
225 
226 /*
227  * Called from boot code to establish ppp interfaces.
228  */
229 void
230 pppattach(int n __unused)
231 {
232 
233 	/*
234 	 * Nothing to do here, initialization is handled by the
235 	 * module initialization code in pppinit() below).
236 	 */
237 }
238 
239 static void
240 pppinit(void)
241 {
242 	/* Init the compressor sub-sub-system */
243 	ppp_compressor_init();
244 
245 	if (ttyldisc_attach(&ppp_disc) != 0)
246 		panic("%s", __func__);
247 
248 	mutex_init(&ppp_list_lock, MUTEX_DEFAULT, IPL_NONE);
249 	LIST_INIT(&ppp_softc_list);
250 	if_clone_attach(&ppp_cloner);
251 }
252 
253 static int
254 pppdetach(void)
255 {
256 	int error = 0;
257 
258 	if (!LIST_EMPTY(&ppp_softc_list))
259 		error = EBUSY;
260 
261 	if (error == 0)
262 		error = ttyldisc_detach(&ppp_disc);
263 
264 	if (error == 0) {
265 		mutex_destroy(&ppp_list_lock);
266 		if_clone_detach(&ppp_cloner);
267 		ppp_compressor_destroy();
268 	}
269 
270 	return error;
271 }
272 
273 static struct ppp_softc *
274 ppp_create(const char *name, int unit)
275 {
276 	struct ppp_softc *sc, *sci, *scl = NULL;
277 
278 	sc = malloc(sizeof(*sc), M_DEVBUF, M_WAIT|M_ZERO);
279 
280 	mutex_enter(&ppp_list_lock);
281 	if (unit == -1) {
282 		int i = 0;
283 		LIST_FOREACH(sci, &ppp_softc_list, sc_iflist) {
284 			scl = sci;
285 			if (i < sci->sc_unit) {
286 				unit = i;
287 				break;
288 			} else {
289 #ifdef DIAGNOSTIC
290 				KASSERT(i == sci->sc_unit);
291 #endif
292 				i++;
293 			}
294 		}
295 		if (unit == -1)
296 			unit = i;
297 	} else {
298 		LIST_FOREACH(sci, &ppp_softc_list, sc_iflist) {
299 			scl = sci;
300 			if (unit < sci->sc_unit)
301 				break;
302 			else if (unit == sci->sc_unit) {
303 				free(sc, M_DEVBUF);
304 				return NULL;
305 			}
306 		}
307 	}
308 
309 	if (sci != NULL)
310 		LIST_INSERT_BEFORE(sci, sc, sc_iflist);
311 	else if (scl != NULL)
312 		LIST_INSERT_AFTER(scl, sc, sc_iflist);
313 	else
314 		LIST_INSERT_HEAD(&ppp_softc_list, sc, sc_iflist);
315 
316 	mutex_exit(&ppp_list_lock);
317 
318 	if_initname(&sc->sc_if, name, sc->sc_unit = unit);
319 	callout_init(&sc->sc_timo_ch, 0);
320 	sc->sc_if.if_softc = sc;
321 	sc->sc_if.if_mtu = PPP_MTU;
322 	sc->sc_if.if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
323 	sc->sc_if.if_type = IFT_PPP;
324 	sc->sc_if.if_hdrlen = PPP_HDRLEN;
325 	sc->sc_if.if_dlt = DLT_NULL;
326 	sc->sc_if.if_ioctl = pppsioctl;
327 	sc->sc_if.if_output = pppoutput;
328 #ifdef ALTQ
329 	sc->sc_if.if_start = ppp_ifstart;
330 #endif
331 	IFQ_SET_MAXLEN(&sc->sc_if.if_snd, IFQ_MAXLEN);
332 	sc->sc_inq.ifq_maxlen = IFQ_MAXLEN;
333 	sc->sc_fastq.ifq_maxlen = IFQ_MAXLEN;
334 	sc->sc_rawq.ifq_maxlen = IFQ_MAXLEN;
335 	/* Ratio of 1:2 packets between the regular and the fast queue */
336 	sc->sc_maxfastq = 2;
337 	IFQ_SET_READY(&sc->sc_if.if_snd);
338 	if_attach(&sc->sc_if);
339 	if_alloc_sadl(&sc->sc_if);
340 	bpf_attach(&sc->sc_if, DLT_NULL, 0);
341 	return sc;
342 }
343 
344 static int
345 ppp_clone_create(struct if_clone *ifc, int unit)
346 {
347 	return ppp_create(ifc->ifc_name, unit) == NULL ? EEXIST : 0;
348 }
349 
350 static int
351 ppp_clone_destroy(struct ifnet *ifp)
352 {
353 	struct ppp_softc *sc = (struct ppp_softc *)ifp->if_softc;
354 
355 	if (sc->sc_devp != NULL)
356 		return EBUSY; /* Not removing it */
357 
358 	mutex_enter(&ppp_list_lock);
359 	LIST_REMOVE(sc, sc_iflist);
360 	mutex_exit(&ppp_list_lock);
361 
362 	bpf_detach(ifp);
363 	if_detach(ifp);
364 
365 	free(sc, M_DEVBUF);
366 	return 0;
367 }
368 
369 /*
370  * Allocate a ppp interface unit and initialize it.
371  */
372 struct ppp_softc *
373 pppalloc(pid_t pid)
374 {
375 	struct ppp_softc *sc = NULL, *scf;
376 	int i;
377 
378 	mutex_enter(&ppp_list_lock);
379 	LIST_FOREACH(scf, &ppp_softc_list, sc_iflist) {
380 		if (scf->sc_xfer == pid) {
381 			scf->sc_xfer = 0;
382 			mutex_exit(&ppp_list_lock);
383 			return scf;
384 		}
385 		if (scf->sc_devp == NULL && sc == NULL)
386 			sc = scf;
387 	}
388 	mutex_exit(&ppp_list_lock);
389 
390 	if (sc == NULL)
391 		sc = ppp_create(ppp_cloner.ifc_name, -1);
392 
393 	sc->sc_si = softint_establish(SOFTINT_NET, pppintr, sc);
394 	if (sc->sc_si == NULL) {
395 		printf("%s: unable to establish softintr\n",
396 		    sc->sc_if.if_xname);
397 		return (NULL);
398 	}
399 	sc->sc_flags = 0;
400 	sc->sc_mru = PPP_MRU;
401 	sc->sc_relinq = NULL;
402 	(void)memset(&sc->sc_stats, 0, sizeof(sc->sc_stats));
403 #ifdef VJC
404 	sc->sc_comp = malloc(sizeof(struct slcompress), M_DEVBUF, M_NOWAIT);
405 	if (sc->sc_comp)
406 		sl_compress_init(sc->sc_comp);
407 #endif
408 #ifdef PPP_COMPRESS
409 	sc->sc_xc_state = NULL;
410 	sc->sc_rc_state = NULL;
411 #endif /* PPP_COMPRESS */
412 	for (i = 0; i < NUM_NP; ++i)
413 		sc->sc_npmode[i] = NPMODE_ERROR;
414 	sc->sc_npqueue = NULL;
415 	sc->sc_npqtail = &sc->sc_npqueue;
416 	sc->sc_last_sent = sc->sc_last_recv = time_second;
417 
418 	return sc;
419 }
420 
421 /*
422  * Deallocate a ppp unit.  Must be called at splsoftnet or higher.
423  */
424 void
425 pppdealloc(struct ppp_softc *sc)
426 {
427 	struct mbuf *m;
428 
429 	softint_disestablish(sc->sc_si);
430 	if_down(&sc->sc_if);
431 	sc->sc_if.if_flags &= ~(IFF_UP|IFF_RUNNING);
432 	sc->sc_devp = NULL;
433 	sc->sc_xfer = 0;
434 	for (;;) {
435 		IF_DEQUEUE(&sc->sc_rawq, m);
436 		if (m == NULL)
437 			break;
438 		m_freem(m);
439 	}
440 	for (;;) {
441 		IF_DEQUEUE(&sc->sc_inq, m);
442 		if (m == NULL)
443 			break;
444 		m_freem(m);
445 	}
446 	for (;;) {
447 		IF_DEQUEUE(&sc->sc_fastq, m);
448 		if (m == NULL)
449 			break;
450 		m_freem(m);
451 	}
452 	while ((m = sc->sc_npqueue) != NULL) {
453 		sc->sc_npqueue = m->m_nextpkt;
454 		m_freem(m);
455 	}
456 	if (sc->sc_togo != NULL) {
457 		m_freem(sc->sc_togo);
458 		sc->sc_togo = NULL;
459 	}
460 #ifdef PPP_COMPRESS
461 	ppp_ccp_closed(sc);
462 	sc->sc_xc_state = NULL;
463 	sc->sc_rc_state = NULL;
464 #endif /* PPP_COMPRESS */
465 #ifdef PPP_FILTER
466 	if (sc->sc_pass_filt_in.bf_insns != 0) {
467 		free(sc->sc_pass_filt_in.bf_insns, M_DEVBUF);
468 		sc->sc_pass_filt_in.bf_insns = 0;
469 		sc->sc_pass_filt_in.bf_len = 0;
470 	}
471 	if (sc->sc_pass_filt_out.bf_insns != 0) {
472 		free(sc->sc_pass_filt_out.bf_insns, M_DEVBUF);
473 		sc->sc_pass_filt_out.bf_insns = 0;
474 		sc->sc_pass_filt_out.bf_len = 0;
475 	}
476 	if (sc->sc_active_filt_in.bf_insns != 0) {
477 		free(sc->sc_active_filt_in.bf_insns, M_DEVBUF);
478 		sc->sc_active_filt_in.bf_insns = 0;
479 		sc->sc_active_filt_in.bf_len = 0;
480 	}
481 	if (sc->sc_active_filt_out.bf_insns != 0) {
482 		free(sc->sc_active_filt_out.bf_insns, M_DEVBUF);
483 		sc->sc_active_filt_out.bf_insns = 0;
484 		sc->sc_active_filt_out.bf_len = 0;
485 	}
486 #endif /* PPP_FILTER */
487 #ifdef VJC
488 	if (sc->sc_comp != 0) {
489 		free(sc->sc_comp, M_DEVBUF);
490 		sc->sc_comp = 0;
491 	}
492 #endif
493 	(void)ppp_clone_destroy(&sc->sc_if);
494 }
495 
496 /*
497  * Ioctl routine for generic ppp devices.
498  */
499 int
500 pppioctl(struct ppp_softc *sc, u_long cmd, void *data, int flag,
501     struct lwp *l)
502 {
503 	int s, error, flags, mru, npx;
504 	u_int nb;
505 	struct ppp_option_data *odp;
506 	struct compressor *cp;
507 	struct npioctl *npi;
508 	time_t t;
509 #ifdef PPP_FILTER
510 	struct bpf_program *bp, *nbp;
511 	struct bpf_insn *newcode, *oldcode;
512 	int newcodelen;
513 #endif /* PPP_FILTER */
514 #ifdef	PPP_COMPRESS
515 	u_char ccp_option[CCP_MAX_OPTION_LENGTH];
516 #endif
517 
518 	switch (cmd) {
519 	case PPPIOCSFLAGS:
520 	case PPPIOCSMRU:
521 	case PPPIOCSMAXCID:
522 	case PPPIOCSCOMPRESS:
523 	case PPPIOCSNPMODE:
524 		if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE,
525 			KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, &sc->sc_if,
526 			KAUTH_ARG(cmd), NULL) != 0)
527 			return (EPERM);
528 		break;
529 	case PPPIOCXFERUNIT:
530 		/* XXX: Why is this privileged?! */
531 		if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE,
532 			KAUTH_REQ_NETWORK_INTERFACE_GETPRIV, &sc->sc_if,
533 			KAUTH_ARG(cmd), NULL) != 0)
534 			return (EPERM);
535 		break;
536 	default:
537 		break;
538 	}
539 
540 	switch (cmd) {
541 	case FIONREAD:
542 		*(int *)data = sc->sc_inq.ifq_len;
543 		break;
544 
545 	case PPPIOCGUNIT:
546 		*(int *)data = sc->sc_unit;
547 		break;
548 
549 	case PPPIOCGFLAGS:
550 		*(u_int *)data = sc->sc_flags;
551 		break;
552 
553 	case PPPIOCGRAWIN:
554 	{
555 		struct ppp_rawin *rwin = (struct ppp_rawin *)data;
556 		u_char c, q = 0;
557 
558 		for (c = sc->sc_rawin_start; c < sizeof(sc->sc_rawin.buf);)
559 			rwin->buf[q++] = sc->sc_rawin.buf[c++];
560 
561 		for (c = 0; c < sc->sc_rawin_start;)
562 			rwin->buf[q++] = sc->sc_rawin.buf[c++];
563 
564 		rwin->count = sc->sc_rawin.count;
565 	}
566 	break;
567 
568 	case PPPIOCSFLAGS:
569 		flags = *(int *)data & SC_MASK;
570 		s = splsoftnet();
571 #ifdef PPP_COMPRESS
572 		if (sc->sc_flags & SC_CCP_OPEN && !(flags & SC_CCP_OPEN))
573 			ppp_ccp_closed(sc);
574 #endif
575 		splhigh();	/* XXX IMP ME HARDER */
576 		sc->sc_flags = (sc->sc_flags & ~SC_MASK) | flags;
577 		splx(s);
578 		break;
579 
580 	case PPPIOCSMRU:
581 		mru = *(int *)data;
582 		if (mru >= PPP_MINMRU && mru <= PPP_MAXMRU)
583 			sc->sc_mru = mru;
584 		break;
585 
586 	case PPPIOCGMRU:
587 		*(int *)data = sc->sc_mru;
588 		break;
589 
590 #ifdef VJC
591 	case PPPIOCSMAXCID:
592 		if (sc->sc_comp) {
593 			s = splsoftnet();
594 			sl_compress_setup(sc->sc_comp, *(int *)data);
595 			splx(s);
596 		}
597 		break;
598 #endif
599 
600 	case PPPIOCXFERUNIT:
601 		sc->sc_xfer = l->l_proc->p_pid;
602 		break;
603 
604 #ifdef PPP_COMPRESS
605 	case PPPIOCSCOMPRESS:
606 		odp = (struct ppp_option_data *) data;
607 		nb = odp->length;
608 		if (nb > sizeof(ccp_option))
609 			nb = sizeof(ccp_option);
610 		if ((error = copyin(odp->ptr, ccp_option, nb)) != 0)
611 			return (error);
612 		/* preliminary check on the length byte */
613 		if (ccp_option[1] < 2)
614 			return (EINVAL);
615 		cp = ppp_get_compressor(ccp_option[0]);
616 		if (cp == NULL) {
617 			if (sc->sc_flags & SC_DEBUG)
618 				printf("%s: no compressor for [%x %x %x], %x\n",
619 				    sc->sc_if.if_xname, ccp_option[0],
620 				    ccp_option[1], ccp_option[2], nb);
621 			return (EINVAL);	/* no handler found */
622 		}
623 		/*
624 		 * Found a handler for the protocol - try to allocate
625 		 * a compressor or decompressor.
626 		 */
627 		error = 0;
628 		if (odp->transmit) {
629 			s = splsoftnet();
630 			if (sc->sc_xc_state != NULL) {
631 				(*sc->sc_xcomp->comp_free)(sc->sc_xc_state);
632 				ppp_compressor_rele(sc->sc_xcomp);
633 			}
634 			sc->sc_xcomp = cp;
635 			sc->sc_xc_state = cp->comp_alloc(ccp_option, nb);
636 			if (sc->sc_xc_state == NULL) {
637 				if (sc->sc_flags & SC_DEBUG)
638 					printf("%s: comp_alloc failed\n",
639 					    sc->sc_if.if_xname);
640 				error = ENOBUFS;
641 			}
642 			splhigh();	/* XXX IMP ME HARDER */
643 			sc->sc_flags &= ~SC_COMP_RUN;
644 			splx(s);
645 		} else {
646 			s = splsoftnet();
647 			if (sc->sc_rc_state != NULL) {
648 				(*sc->sc_rcomp->decomp_free)(sc->sc_rc_state);
649 				ppp_compressor_rele(sc->sc_rcomp);
650 			}
651 			sc->sc_rcomp = cp;
652 			sc->sc_rc_state = cp->decomp_alloc(ccp_option, nb);
653 			if (sc->sc_rc_state == NULL) {
654 				if (sc->sc_flags & SC_DEBUG)
655 					printf("%s: decomp_alloc failed\n",
656 					    sc->sc_if.if_xname);
657 				error = ENOBUFS;
658 			}
659 			splhigh();	/* XXX IMP ME HARDER */
660 			sc->sc_flags &= ~SC_DECOMP_RUN;
661 			splx(s);
662 		}
663 		return (error);
664 #endif /* PPP_COMPRESS */
665 
666 	case PPPIOCGNPMODE:
667 	case PPPIOCSNPMODE:
668 		npi = (struct npioctl *) data;
669 		switch (npi->protocol) {
670 		case PPP_IP:
671 			npx = NP_IP;
672 			break;
673 		case PPP_IPV6:
674 			npx = NP_IPV6;
675 			break;
676 		default:
677 			return EINVAL;
678 		}
679 		if (cmd == PPPIOCGNPMODE) {
680 			npi->mode = sc->sc_npmode[npx];
681 		} else {
682 			if (npi->mode != sc->sc_npmode[npx]) {
683 				s = splnet();
684 				sc->sc_npmode[npx] = npi->mode;
685 				if (npi->mode != NPMODE_QUEUE) {
686 					ppp_requeue(sc);
687 					ppp_restart(sc);
688 				}
689 				splx(s);
690 			}
691 		}
692 		break;
693 
694 	case PPPIOCGIDLE:
695 		s = splsoftnet();
696 		t = time_second;
697 		((struct ppp_idle *)data)->xmit_idle = t - sc->sc_last_sent;
698 		((struct ppp_idle *)data)->recv_idle = t - sc->sc_last_recv;
699 		splx(s);
700 		break;
701 
702 #ifdef PPP_FILTER
703 	case PPPIOCSPASS:
704 	case PPPIOCSACTIVE:
705 		/* These are no longer supported. */
706 		return EOPNOTSUPP;
707 
708 	case PPPIOCSIPASS:
709 	case PPPIOCSOPASS:
710 	case PPPIOCSIACTIVE:
711 	case PPPIOCSOACTIVE:
712 		nbp = (struct bpf_program *) data;
713 		if ((unsigned) nbp->bf_len > BPF_MAXINSNS)
714 			return EINVAL;
715 		newcodelen = nbp->bf_len * sizeof(struct bpf_insn);
716 		if (newcodelen != 0) {
717 			newcode = malloc(newcodelen, M_DEVBUF, M_WAITOK);
718 			/* WAITOK -- malloc() never fails. */
719 			if ((error = copyin((void *)nbp->bf_insns,
720 				    (void *)newcode, newcodelen)) != 0) {
721 				free(newcode, M_DEVBUF);
722 				return error;
723 			}
724 			if (!bpf_validate(newcode, nbp->bf_len)) {
725 				free(newcode, M_DEVBUF);
726 				return EINVAL;
727 			}
728 		} else
729 			newcode = 0;
730 		switch (cmd) {
731 		case PPPIOCSIPASS:
732 			bp = &sc->sc_pass_filt_in;
733 			break;
734 
735 		case PPPIOCSOPASS:
736 			bp = &sc->sc_pass_filt_out;
737 			break;
738 
739 		case PPPIOCSIACTIVE:
740 			bp = &sc->sc_active_filt_in;
741 			break;
742 
743 		case PPPIOCSOACTIVE:
744 			bp = &sc->sc_active_filt_out;
745 			break;
746 		default:
747 			free(newcode, M_DEVBUF);
748 			return (EPASSTHROUGH);
749 		}
750 		oldcode = bp->bf_insns;
751 		s = splnet();
752 		bp->bf_len = nbp->bf_len;
753 		bp->bf_insns = newcode;
754 		splx(s);
755 		if (oldcode != 0)
756 			free(oldcode, M_DEVBUF);
757 		break;
758 #endif /* PPP_FILTER */
759 
760 	default:
761 		return (EPASSTHROUGH);
762 	}
763 	return (0);
764 }
765 
766 /*
767  * Process an ioctl request to the ppp network interface.
768  */
769 static int
770 pppsioctl(struct ifnet *ifp, u_long cmd, void *data)
771 {
772 	struct ppp_softc *sc = ifp->if_softc;
773 	struct ifaddr *ifa = (struct ifaddr *)data;
774 	struct ifreq *ifr = (struct ifreq *)data;
775 	struct ppp_stats *psp;
776 #ifdef	PPP_COMPRESS
777 	struct ppp_comp_stats *pcp;
778 #endif
779 	int s = splnet(), error = 0;
780 
781 	switch (cmd) {
782 	case SIOCSIFFLAGS:
783 		if ((error = ifioctl_common(ifp, cmd, data)) != 0)
784 			break;
785 		if ((ifp->if_flags & IFF_RUNNING) == 0)
786 			ifp->if_flags &= ~IFF_UP;
787 		break;
788 
789 	case SIOCINITIFADDR:
790 		switch (ifa->ifa_addr->sa_family) {
791 #ifdef INET
792 		case AF_INET:
793 			break;
794 #endif
795 #ifdef INET6
796 		case AF_INET6:
797 			break;
798 #endif
799 		default:
800 			printf("%s: af%d not supported\n", ifp->if_xname,
801 			    ifa->ifa_addr->sa_family);
802 			error = EAFNOSUPPORT;
803 			break;
804 		}
805 		ifa->ifa_rtrequest = p2p_rtrequest;
806 		break;
807 
808 	case SIOCADDMULTI:
809 	case SIOCDELMULTI:
810 		if (ifr == NULL) {
811 			error = EAFNOSUPPORT;
812 			break;
813 		}
814 		switch (ifreq_getaddr(cmd, ifr)->sa_family) {
815 #ifdef INET
816 		case AF_INET:
817 			break;
818 #endif
819 #ifdef INET6
820 		case AF_INET6:
821 			break;
822 #endif
823 		default:
824 			error = EAFNOSUPPORT;
825 			break;
826 		}
827 		break;
828 
829 	case SIOCGPPPSTATS:
830 		psp = &((struct ifpppstatsreq *) data)->stats;
831 		memset(psp, 0, sizeof(*psp));
832 		psp->p = sc->sc_stats;
833 #if defined(VJC) && !defined(SL_NO_STATS)
834 		if (sc->sc_comp) {
835 			psp->vj.vjs_packets = sc->sc_comp->sls_packets;
836 			psp->vj.vjs_compressed = sc->sc_comp->sls_compressed;
837 			psp->vj.vjs_searches = sc->sc_comp->sls_searches;
838 			psp->vj.vjs_misses = sc->sc_comp->sls_misses;
839 			psp->vj.vjs_uncompressedin = sc->sc_comp->sls_uncompressedin;
840 			psp->vj.vjs_compressedin = sc->sc_comp->sls_compressedin;
841 			psp->vj.vjs_errorin = sc->sc_comp->sls_errorin;
842 			psp->vj.vjs_tossed = sc->sc_comp->sls_tossed;
843 		}
844 #endif /* VJC */
845 		break;
846 
847 #ifdef PPP_COMPRESS
848 	case SIOCGPPPCSTATS:
849 		pcp = &((struct ifpppcstatsreq *) data)->stats;
850 		memset(pcp, 0, sizeof(*pcp));
851 		if (sc->sc_xc_state != NULL)
852 			(*sc->sc_xcomp->comp_stat)(sc->sc_xc_state, &pcp->c);
853 		if (sc->sc_rc_state != NULL)
854 			(*sc->sc_rcomp->decomp_stat)(sc->sc_rc_state, &pcp->d);
855 		break;
856 #endif /* PPP_COMPRESS */
857 
858 	default:
859 		if ((error = ifioctl_common(&sc->sc_if, cmd, data)) == ENETRESET)
860 			error = 0;
861 		break;
862 	}
863 	splx(s);
864 	return (error);
865 }
866 
867 /*
868  * Queue a packet.  Start transmission if not active.
869  * Packet is placed in Information field of PPP frame.
870  */
871 int
872 pppoutput(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst,
873     const struct rtentry *rtp)
874 {
875 	struct ppp_softc *sc = ifp->if_softc;
876 	int protocol, address, control;
877 	u_char *cp;
878 	int s, error;
879 #ifdef INET
880 	struct ip *ip;
881 #endif
882 	struct ifqueue *ifq;
883 	enum NPmode mode;
884 	int len;
885 
886 	    if (sc->sc_devp == NULL || (ifp->if_flags & IFF_RUNNING) == 0
887 		|| ((ifp->if_flags & IFF_UP) == 0 && dst->sa_family != AF_UNSPEC)) {
888 		    error = ENETDOWN;	/* sort of */
889 		    goto bad;
890 	    }
891 
892 	IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family);
893 
894 	/*
895 	 * Compute PPP header.
896 	 */
897 	m0->m_flags &= ~M_HIGHPRI;
898 	switch (dst->sa_family) {
899 #ifdef INET
900 	case AF_INET:
901 		address = PPP_ALLSTATIONS;
902 		control = PPP_UI;
903 		protocol = PPP_IP;
904 		mode = sc->sc_npmode[NP_IP];
905 
906 		/*
907 		 * If this packet has the "low delay" bit set in the IP header,
908 		 * put it on the fastq instead.
909 		 */
910 		ip = mtod(m0, struct ip *);
911 		if (ip->ip_tos & IPTOS_LOWDELAY)
912 			m0->m_flags |= M_HIGHPRI;
913 		break;
914 #endif
915 #ifdef INET6
916 	case AF_INET6:
917 		address = PPP_ALLSTATIONS;	/*XXX*/
918 		control = PPP_UI;		/*XXX*/
919 		protocol = PPP_IPV6;
920 		mode = sc->sc_npmode[NP_IPV6];
921 
922 #if 0	/* XXX flowinfo/traffic class, maybe? */
923 	/*
924 	 * If this packet has the "low delay" bit set in the IP header,
925 	 * put it on the fastq instead.
926 	 */
927 		ip = mtod(m0, struct ip *);
928 		if (ip->ip_tos & IPTOS_LOWDELAY)
929 			m0->m_flags |= M_HIGHPRI;
930 #endif
931 		break;
932 #endif
933 	case AF_UNSPEC:
934 		address = PPP_ADDRESS(dst->sa_data);
935 		control = PPP_CONTROL(dst->sa_data);
936 		protocol = PPP_PROTOCOL(dst->sa_data);
937 		mode = NPMODE_PASS;
938 		break;
939 	default:
940 		printf("%s: af%d not supported\n", ifp->if_xname,
941 		    dst->sa_family);
942 		error = EAFNOSUPPORT;
943 		goto bad;
944 	}
945 
946 	/*
947 	 * Drop this packet, or return an error, if necessary.
948 	 */
949 	if (mode == NPMODE_ERROR) {
950 		error = ENETDOWN;
951 		goto bad;
952 	}
953 	if (mode == NPMODE_DROP) {
954 		error = 0;
955 		goto bad;
956 	}
957 
958 	/*
959 	 * Add PPP header.
960 	 */
961 	M_PREPEND(m0, PPP_HDRLEN, M_DONTWAIT);
962 	if (m0 == NULL) {
963 		error = ENOBUFS;
964 		goto bad;
965 	}
966 
967 	cp = mtod(m0, u_char *);
968 	*cp++ = address;
969 	*cp++ = control;
970 	*cp++ = protocol >> 8;
971 	*cp++ = protocol & 0xff;
972 
973 	len = m_length(m0);
974 
975 	if (sc->sc_flags & SC_LOG_OUTPKT) {
976 		printf("%s output: ", ifp->if_xname);
977 		pppdumpm(m0);
978 	}
979 
980 	if ((protocol & 0x8000) == 0) {
981 #ifdef PPP_FILTER
982 		/*
983 		 * Apply the pass and active filters to the packet,
984 		 * but only if it is a data packet.
985 		 */
986 		if (sc->sc_pass_filt_out.bf_insns != 0
987 		    && bpf_filter(sc->sc_pass_filt_out.bf_insns,
988 			(u_char *)m0, len, 0) == 0) {
989 			error = 0;		/* drop this packet */
990 			goto bad;
991 		}
992 
993 		/*
994 		 * Update the time we sent the most recent packet.
995 		 */
996 		if (sc->sc_active_filt_out.bf_insns == 0
997 		    || bpf_filter(sc->sc_active_filt_out.bf_insns,
998 			(u_char *)m0, len, 0))
999 			sc->sc_last_sent = time_second;
1000 #else
1001 		/*
1002 		 * Update the time we sent the most recent packet.
1003 		 */
1004 		sc->sc_last_sent = time_second;
1005 #endif /* PPP_FILTER */
1006 	}
1007 
1008 	/*
1009 	 * See if bpf wants to look at the packet.
1010 	 */
1011 	bpf_mtap(&sc->sc_if, m0, BPF_D_OUT);
1012 
1013 	/*
1014 	 * Put the packet on the appropriate queue.
1015 	 */
1016 	s = splnet();
1017 	if (mode == NPMODE_QUEUE) {
1018 		/* XXX we should limit the number of packets on this queue */
1019 		*sc->sc_npqtail = m0;
1020 		m0->m_nextpkt = NULL;
1021 		sc->sc_npqtail = &m0->m_nextpkt;
1022 	} else {
1023 		ifq = (m0->m_flags & M_HIGHPRI) ? &sc->sc_fastq : NULL;
1024 		if ((error = ifq_enqueue2(&sc->sc_if, ifq, m0)) != 0) {
1025 			splx(s);
1026 			sc->sc_if.if_oerrors++;
1027 			sc->sc_stats.ppp_oerrors++;
1028 			return (error);
1029 		}
1030 		ppp_restart(sc);
1031 	}
1032 	ifp->if_opackets++;
1033 	ifp->if_obytes += len;
1034 
1035 	splx(s);
1036 	return (0);
1037 
1038 bad:
1039 	m_freem(m0);
1040 	return (error);
1041 }
1042 
1043 /*
1044  * After a change in the NPmode for some NP, move packets from the
1045  * npqueue to the send queue or the fast queue as appropriate.
1046  * Should be called at splnet, since we muck with the queues.
1047  */
1048 static void
1049 ppp_requeue(struct ppp_softc *sc)
1050 {
1051 	struct mbuf *m, **mpp;
1052 	struct ifqueue *ifq;
1053 	enum NPmode mode;
1054 	int error;
1055 
1056 	for (mpp = &sc->sc_npqueue; (m = *mpp) != NULL; ) {
1057 		switch (PPP_PROTOCOL(mtod(m, u_char *))) {
1058 		case PPP_IP:
1059 			mode = sc->sc_npmode[NP_IP];
1060 			break;
1061 		case PPP_IPV6:
1062 			mode = sc->sc_npmode[NP_IPV6];
1063 			break;
1064 		default:
1065 			mode = NPMODE_PASS;
1066 		}
1067 
1068 		switch (mode) {
1069 		case NPMODE_PASS:
1070 			/*
1071 			 * This packet can now go on one of the queues to
1072 			 * be sent.
1073 			 */
1074 			*mpp = m->m_nextpkt;
1075 			m->m_nextpkt = NULL;
1076 			ifq = (m->m_flags & M_HIGHPRI) ? &sc->sc_fastq : NULL;
1077 			if ((error = ifq_enqueue2(&sc->sc_if, ifq, m)) != 0) {
1078 				sc->sc_if.if_oerrors++;
1079 				sc->sc_stats.ppp_oerrors++;
1080 			}
1081 			break;
1082 
1083 		case NPMODE_DROP:
1084 		case NPMODE_ERROR:
1085 			*mpp = m->m_nextpkt;
1086 			m_freem(m);
1087 			break;
1088 
1089 		case NPMODE_QUEUE:
1090 			mpp = &m->m_nextpkt;
1091 			break;
1092 		}
1093 	}
1094 	sc->sc_npqtail = mpp;
1095 }
1096 
1097 /*
1098  * Transmitter has finished outputting some stuff;
1099  * remember to call sc->sc_start later at splsoftnet.
1100  */
1101 void
1102 ppp_restart(struct ppp_softc *sc)
1103 {
1104 	int s = splhigh();	/* XXX IMP ME HARDER */
1105 
1106 	sc->sc_flags &= ~SC_TBUSY;
1107 	softint_schedule(sc->sc_si);
1108 	splx(s);
1109 }
1110 
1111 /*
1112  * Get a packet to send.  This procedure is intended to be called at
1113  * splsoftnet, since it may involve time-consuming operations such as
1114  * applying VJ compression, packet compression, address/control and/or
1115  * protocol field compression to the packet.
1116  */
1117 struct mbuf *
1118 ppp_dequeue(struct ppp_softc *sc)
1119 {
1120 	struct mbuf *m, *mp;
1121 	u_char *cp;
1122 	int address, control, protocol;
1123 	int s;
1124 
1125 	/*
1126 	 * Grab a packet to send: first try the fast queue, then the
1127 	 * normal queue.
1128 	 */
1129 	s = splnet();
1130 	if (sc->sc_nfastq < sc->sc_maxfastq) {
1131 		IF_DEQUEUE(&sc->sc_fastq, m);
1132 		if (m != NULL)
1133 			sc->sc_nfastq++;
1134 		else
1135 			IFQ_DEQUEUE(&sc->sc_if.if_snd, m);
1136 	} else {
1137 		sc->sc_nfastq = 0;
1138 		IFQ_DEQUEUE(&sc->sc_if.if_snd, m);
1139 		if (m == NULL) {
1140 			IF_DEQUEUE(&sc->sc_fastq, m);
1141 			if (m != NULL)
1142 				sc->sc_nfastq++;
1143 		}
1144 	}
1145 	splx(s);
1146 
1147 	if (m == NULL)
1148 		return NULL;
1149 
1150 	++sc->sc_stats.ppp_opackets;
1151 
1152 	/*
1153 	 * Extract the ppp header of the new packet.
1154 	 * The ppp header will be in one mbuf.
1155 	 */
1156 	cp = mtod(m, u_char *);
1157 	address = PPP_ADDRESS(cp);
1158 	control = PPP_CONTROL(cp);
1159 	protocol = PPP_PROTOCOL(cp);
1160 
1161 	switch (protocol) {
1162 	case PPP_IP:
1163 #ifdef VJC
1164 		/*
1165 		 * If the packet is a TCP/IP packet, see if we can compress it.
1166 		 */
1167 		if ((sc->sc_flags & SC_COMP_TCP) && sc->sc_comp != NULL) {
1168 			struct ip *ip;
1169 			int type;
1170 
1171 			mp = m;
1172 			ip = (struct ip *) (cp + PPP_HDRLEN);
1173 			if (mp->m_len <= PPP_HDRLEN) {
1174 				mp = mp->m_next;
1175 				if (mp == NULL)
1176 					break;
1177 				ip = mtod(mp, struct ip *);
1178 			}
1179 			/*
1180 			 * This code assumes the IP/TCP header is in one
1181 			 * non-shared mbuf
1182 			 */
1183 			if (ip->ip_p == IPPROTO_TCP) {
1184 				type = sl_compress_tcp(mp, ip, sc->sc_comp,
1185 				    !(sc->sc_flags & SC_NO_TCP_CCID));
1186 				switch (type) {
1187 				case TYPE_UNCOMPRESSED_TCP:
1188 					protocol = PPP_VJC_UNCOMP;
1189 					break;
1190 				case TYPE_COMPRESSED_TCP:
1191 					protocol = PPP_VJC_COMP;
1192 					cp = mtod(m, u_char *);
1193 					cp[0] = address; /* Header has moved */
1194 					cp[1] = control;
1195 					cp[2] = 0;
1196 					break;
1197 				}
1198 				/* Update protocol in PPP header */
1199 				cp[3] = protocol;
1200 			}
1201 		}
1202 #endif	/* VJC */
1203 		break;
1204 
1205 #ifdef PPP_COMPRESS
1206 	case PPP_CCP:
1207 		ppp_ccp(sc, m, 0);
1208 		break;
1209 #endif	/* PPP_COMPRESS */
1210 	}
1211 
1212 #ifdef PPP_COMPRESS
1213 	if (protocol != PPP_LCP && protocol != PPP_CCP
1214 	    && sc->sc_xc_state && (sc->sc_flags & SC_COMP_RUN)) {
1215 		struct mbuf *mcomp = NULL;
1216 		int slen;
1217 
1218 		slen = 0;
1219 		for (mp = m; mp != NULL; mp = mp->m_next)
1220 			slen += mp->m_len;
1221 		(*sc->sc_xcomp->compress)
1222 		    (sc->sc_xc_state, &mcomp, m, slen, sc->sc_if.if_mtu + PPP_HDRLEN);
1223 		if (mcomp != NULL) {
1224 			if (sc->sc_flags & SC_CCP_UP) {
1225 				/*
1226 				 * Send the compressed packet instead of the
1227 				 * original.
1228 				 */
1229 				m_freem(m);
1230 				m = mcomp;
1231 				cp = mtod(m, u_char *);
1232 				protocol = cp[3];
1233 			} else {
1234 				/*
1235 				 * Can't transmit compressed packets until CCP
1236 				 * is up.
1237 				 */
1238 				m_freem(mcomp);
1239 			}
1240 		}
1241 	}
1242 #endif	/* PPP_COMPRESS */
1243 
1244 	/*
1245 	 * Compress the address/control and protocol, if possible.
1246 	 */
1247 	if (sc->sc_flags & SC_COMP_AC && address == PPP_ALLSTATIONS &&
1248 	    control == PPP_UI && protocol != PPP_ALLSTATIONS &&
1249 	    protocol != PPP_LCP) {
1250 		/* can compress address/control */
1251 		m->m_data += 2;
1252 		m->m_len -= 2;
1253 	}
1254 	if (sc->sc_flags & SC_COMP_PROT && protocol < 0xFF) {
1255 		/* can compress protocol */
1256 		if (mtod(m, u_char *) == cp) {
1257 			cp[2] = cp[1];	/* move address/control up */
1258 			cp[1] = cp[0];
1259 		}
1260 		++m->m_data;
1261 		--m->m_len;
1262 	}
1263 
1264 	return m;
1265 }
1266 
1267 /*
1268  * Software interrupt routine, called at splsoftnet.
1269  */
1270 static void
1271 pppintr(void *arg)
1272 {
1273 	struct ppp_softc *sc = arg;
1274 	struct mbuf *m;
1275 	int s;
1276 
1277 	mutex_enter(softnet_lock);
1278 	if (!(sc->sc_flags & SC_TBUSY)
1279 	    && (IFQ_IS_EMPTY(&sc->sc_if.if_snd) == 0 || sc->sc_fastq.ifq_head
1280 		|| sc->sc_outm)) {
1281 		s = splhigh();	/* XXX IMP ME HARDER */
1282 		sc->sc_flags |= SC_TBUSY;
1283 		splx(s);
1284 		(*sc->sc_start)(sc);
1285 	}
1286 	for (;;) {
1287 		s = splnet();
1288 		IF_DEQUEUE(&sc->sc_rawq, m);
1289 		splx(s);
1290 		if (m == NULL)
1291 			break;
1292 		ppp_inproc(sc, m);
1293 	}
1294 	mutex_exit(softnet_lock);
1295 }
1296 
1297 #ifdef PPP_COMPRESS
1298 /*
1299  * Handle a CCP packet.	 `rcvd' is 1 if the packet was received,
1300  * 0 if it is about to be transmitted.
1301  */
1302 static void
1303 ppp_ccp(struct ppp_softc *sc, struct mbuf *m, int rcvd)
1304 {
1305 	u_char *dp, *ep;
1306 	struct mbuf *mp;
1307 	int slen, s;
1308 
1309 	/*
1310 	 * Get a pointer to the data after the PPP header.
1311 	 */
1312 	if (m->m_len <= PPP_HDRLEN) {
1313 		mp = m->m_next;
1314 		if (mp == NULL)
1315 			return;
1316 		dp = mtod(mp, u_char *);
1317 	} else {
1318 		mp = m;
1319 		dp = mtod(mp, u_char *) + PPP_HDRLEN;
1320 	}
1321 
1322 	ep = mtod(mp, u_char *) + mp->m_len;
1323 	if (dp + CCP_HDRLEN > ep)
1324 		return;
1325 	slen = CCP_LENGTH(dp);
1326 	if (dp + slen > ep) {
1327 		if (sc->sc_flags & SC_DEBUG)
1328 			printf("if_ppp/ccp: not enough data in mbuf (%p+%x > %p+%x)\n",
1329 			    dp, slen, mtod(mp, u_char *), mp->m_len);
1330 		return;
1331 	}
1332 
1333 	switch (CCP_CODE(dp)) {
1334 	case CCP_CONFREQ:
1335 	case CCP_TERMREQ:
1336 	case CCP_TERMACK:
1337 		/* CCP must be going down - disable compression */
1338 		if (sc->sc_flags & SC_CCP_UP) {
1339 			s = splhigh();	/* XXX IMP ME HARDER */
1340 			sc->sc_flags &= ~(SC_CCP_UP | SC_COMP_RUN | SC_DECOMP_RUN);
1341 			splx(s);
1342 		}
1343 		break;
1344 
1345 	case CCP_CONFACK:
1346 		if (sc->sc_flags & SC_CCP_OPEN && !(sc->sc_flags & SC_CCP_UP)
1347 		    && slen >= CCP_HDRLEN + CCP_OPT_MINLEN
1348 		    && slen >= CCP_OPT_LENGTH(dp + CCP_HDRLEN) + CCP_HDRLEN) {
1349 			if (!rcvd) {
1350 				/* We're agreeing to send compressed packets. */
1351 				if (sc->sc_xc_state != NULL
1352 				    && (*sc->sc_xcomp->comp_init)
1353 				    (sc->sc_xc_state, dp + CCP_HDRLEN,
1354 					slen - CCP_HDRLEN, sc->sc_unit, 0,
1355 					sc->sc_flags & SC_DEBUG)) {
1356 					s = splhigh();	/* XXX IMP ME HARDER */
1357 					sc->sc_flags |= SC_COMP_RUN;
1358 					splx(s);
1359 				}
1360 			} else {
1361 				/*
1362 				 * Peer is agreeing to send compressed
1363 				 * packets.
1364 				 */
1365 				if (sc->sc_rc_state != NULL
1366 				    && (*sc->sc_rcomp->decomp_init)
1367 				    (sc->sc_rc_state, dp + CCP_HDRLEN, slen - CCP_HDRLEN,
1368 					sc->sc_unit, 0, sc->sc_mru,
1369 					sc->sc_flags & SC_DEBUG)) {
1370 					s = splhigh();	/* XXX IMP ME HARDER */
1371 					sc->sc_flags |= SC_DECOMP_RUN;
1372 					sc->sc_flags &= ~(SC_DC_ERROR | SC_DC_FERROR);
1373 					splx(s);
1374 				}
1375 			}
1376 		}
1377 		break;
1378 
1379 	case CCP_RESETACK:
1380 		if (sc->sc_flags & SC_CCP_UP) {
1381 			if (!rcvd) {
1382 				if (sc->sc_xc_state && (sc->sc_flags & SC_COMP_RUN))
1383 					(*sc->sc_xcomp->comp_reset)(sc->sc_xc_state);
1384 			} else {
1385 				if (sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN)) {
1386 					(*sc->sc_rcomp->decomp_reset)(sc->sc_rc_state);
1387 					s = splhigh();	/* XXX IMP ME HARDER */
1388 					sc->sc_flags &= ~SC_DC_ERROR;
1389 					splx(s);
1390 				}
1391 			}
1392 		}
1393 		break;
1394 	}
1395 }
1396 
1397 /*
1398  * CCP is down; free (de)compressor state if necessary.
1399  */
1400 static void
1401 ppp_ccp_closed(struct ppp_softc *sc)
1402 {
1403 	if (sc->sc_xc_state) {
1404 		(*sc->sc_xcomp->comp_free)(sc->sc_xc_state);
1405 		ppp_compressor_rele(sc->sc_xcomp);
1406 		sc->sc_xc_state = NULL;
1407 	}
1408 	if (sc->sc_rc_state) {
1409 		(*sc->sc_rcomp->decomp_free)(sc->sc_rc_state);
1410 		ppp_compressor_rele(sc->sc_rcomp);
1411 		sc->sc_rc_state = NULL;
1412 	}
1413 }
1414 #endif /* PPP_COMPRESS */
1415 
1416 /*
1417  * PPP packet input routine.
1418  * The caller has checked and removed the FCS and has inserted
1419  * the address/control bytes and the protocol high byte if they
1420  * were omitted.
1421  */
1422 void
1423 ppppktin(struct ppp_softc *sc, struct mbuf *m, int lost)
1424 {
1425 	int s = splhigh();	/* XXX IMP ME HARDER */
1426 
1427 	if (lost)
1428 		m->m_flags |= M_ERRMARK;
1429 	IF_ENQUEUE(&sc->sc_rawq, m);
1430 	softint_schedule(sc->sc_si);
1431 	splx(s);
1432 }
1433 
1434 /*
1435  * Process a received PPP packet, doing decompression as necessary.
1436  * Should be called at splsoftnet.
1437  */
1438 #define COMPTYPE(proto)	((proto) == PPP_VJC_COMP ? TYPE_COMPRESSED_TCP:	      \
1439 	    TYPE_UNCOMPRESSED_TCP)
1440 
1441 static void
1442 ppp_inproc(struct ppp_softc *sc, struct mbuf *m)
1443 {
1444 	struct ifnet *ifp = &sc->sc_if;
1445 	pktqueue_t *pktq = NULL;
1446 	struct ifqueue *inq = NULL;
1447 	int s, ilen, proto, rv;
1448 	u_char *cp, adrs, ctrl;
1449 	struct mbuf *mp, *dmp = NULL;
1450 #ifdef VJC
1451 	int xlen;
1452 	u_char *iphdr;
1453 	u_int hlen;
1454 #endif
1455 
1456 	sc->sc_stats.ppp_ipackets++;
1457 
1458 	if (sc->sc_flags & SC_LOG_INPKT) {
1459 		ilen = 0;
1460 		for (mp = m; mp != NULL; mp = mp->m_next)
1461 			ilen += mp->m_len;
1462 		printf("%s: got %d bytes\n", ifp->if_xname, ilen);
1463 		pppdumpm(m);
1464 	}
1465 
1466 	cp = mtod(m, u_char *);
1467 	adrs = PPP_ADDRESS(cp);
1468 	ctrl = PPP_CONTROL(cp);
1469 	proto = PPP_PROTOCOL(cp);
1470 
1471 	if (m->m_flags & M_ERRMARK) {
1472 		m->m_flags &= ~M_ERRMARK;
1473 		s = splhigh();	/* XXX IMP ME HARDER */
1474 		sc->sc_flags |= SC_VJ_RESET;
1475 		splx(s);
1476 	}
1477 
1478 #ifdef PPP_COMPRESS
1479 	/*
1480 	 * Decompress this packet if necessary, update the receiver's
1481 	 * dictionary, or take appropriate action on a CCP packet.
1482 	 */
1483 	if (proto == PPP_COMP && sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN)
1484 	    && !(sc->sc_flags & SC_DC_ERROR) && !(sc->sc_flags & SC_DC_FERROR)) {
1485 		/* Decompress this packet */
1486 		rv = (*sc->sc_rcomp->decompress)(sc->sc_rc_state, m, &dmp);
1487 		if (rv == DECOMP_OK) {
1488 			m_freem(m);
1489 			if (dmp == NULL) {
1490 				/*
1491 				 * No error, but no decompressed packet
1492 				 * produced
1493 				 */
1494 				return;
1495 			}
1496 			m = dmp;
1497 			cp = mtod(m, u_char *);
1498 			proto = PPP_PROTOCOL(cp);
1499 
1500 		} else {
1501 			/*
1502 			 * An error has occurred in decompression.
1503 			 * Pass the compressed packet up to pppd, which may
1504 			 * take CCP down or issue a Reset-Req.
1505 			 */
1506 			if (sc->sc_flags & SC_DEBUG)
1507 				printf("%s: decompress failed %d\n",
1508 				    ifp->if_xname, rv);
1509 			s = splhigh();	/* XXX IMP ME HARDER */
1510 			sc->sc_flags |= SC_VJ_RESET;
1511 			if (rv == DECOMP_ERROR)
1512 				sc->sc_flags |= SC_DC_ERROR;
1513 			else
1514 				sc->sc_flags |= SC_DC_FERROR;
1515 			splx(s);
1516 		}
1517 
1518 	} else {
1519 		if (sc->sc_rc_state && (sc->sc_flags & SC_DECOMP_RUN))
1520 			(*sc->sc_rcomp->incomp)(sc->sc_rc_state, m);
1521 		if (proto == PPP_CCP)
1522 			ppp_ccp(sc, m, 1);
1523 	}
1524 #endif
1525 
1526 	ilen = 0;
1527 	for (mp = m; mp != NULL; mp = mp->m_next)
1528 		ilen += mp->m_len;
1529 
1530 #ifdef VJC
1531 	if (sc->sc_flags & SC_VJ_RESET) {
1532 		/*
1533 		 * If we've missed a packet, we must toss subsequent compressed
1534 		 * packets which don't have an explicit connection ID.
1535 		 */
1536 		if (sc->sc_comp)
1537 			sl_uncompress_tcp(NULL, 0, TYPE_ERROR, sc->sc_comp);
1538 		s = splhigh();	/* XXX IMP ME HARDER */
1539 		sc->sc_flags &= ~SC_VJ_RESET;
1540 		splx(s);
1541 	}
1542 
1543 	/*
1544 	 * See if we have a VJ-compressed packet to uncompress.
1545 	 */
1546 	if (proto == PPP_VJC_COMP) {
1547 		if ((sc->sc_flags & SC_REJ_COMP_TCP) || sc->sc_comp == 0)
1548 			goto bad;
1549 
1550 		xlen = sl_uncompress_tcp_core(cp + PPP_HDRLEN,
1551 		    m->m_len - PPP_HDRLEN, ilen - PPP_HDRLEN,
1552 		    TYPE_COMPRESSED_TCP, sc->sc_comp, &iphdr, &hlen);
1553 
1554 		if (xlen <= 0) {
1555 			if (sc->sc_flags & SC_DEBUG)
1556 				printf("%s: VJ uncompress failed on type comp\n",
1557 				    ifp->if_xname);
1558 			goto bad;
1559 		}
1560 
1561 		/* Copy the PPP and IP headers into a new mbuf. */
1562 		MGETHDR(mp, M_DONTWAIT, MT_DATA);
1563 		if (mp == NULL)
1564 			goto bad;
1565 		mp->m_len = 0;
1566 		mp->m_next = NULL;
1567 		if (hlen + PPP_HDRLEN > MHLEN) {
1568 			MCLGET(mp, M_DONTWAIT);
1569 			if (M_TRAILINGSPACE(mp) < hlen + PPP_HDRLEN) {
1570 				/* Lose if big headers and no clusters */
1571 				m_freem(mp);
1572 				goto bad;
1573 			}
1574 		}
1575 		cp = mtod(mp, u_char *);
1576 		cp[0] = adrs;
1577 		cp[1] = ctrl;
1578 		cp[2] = 0;
1579 		cp[3] = PPP_IP;
1580 		proto = PPP_IP;
1581 		bcopy(iphdr, cp + PPP_HDRLEN, hlen);
1582 		mp->m_len = hlen + PPP_HDRLEN;
1583 
1584 		/*
1585 		 * Trim the PPP and VJ headers off the old mbuf
1586 		 * and stick the new and old mbufs together.
1587 		 */
1588 		m->m_data += PPP_HDRLEN + xlen;
1589 		m->m_len -= PPP_HDRLEN + xlen;
1590 		if (m->m_len <= M_TRAILINGSPACE(mp)) {
1591 			bcopy(mtod(m, u_char *),
1592 			    mtod(mp, u_char *) + mp->m_len, m->m_len);
1593 			mp->m_len += m->m_len;
1594 			mp->m_next = m_free(m);
1595 		} else
1596 			mp->m_next = m;
1597 		m = mp;
1598 		ilen += hlen - xlen;
1599 
1600 	} else if (proto == PPP_VJC_UNCOMP) {
1601 		if ((sc->sc_flags & SC_REJ_COMP_TCP) || sc->sc_comp == 0)
1602 			goto bad;
1603 
1604 		xlen = sl_uncompress_tcp_core(cp + PPP_HDRLEN,
1605 		    m->m_len - PPP_HDRLEN, ilen - PPP_HDRLEN,
1606 		    TYPE_UNCOMPRESSED_TCP, sc->sc_comp, &iphdr, &hlen);
1607 
1608 		if (xlen < 0) {
1609 			if (sc->sc_flags & SC_DEBUG)
1610 				printf("%s: VJ uncompress failed on type uncomp\n",
1611 				    ifp->if_xname);
1612 			goto bad;
1613 		}
1614 
1615 		proto = PPP_IP;
1616 		cp[3] = PPP_IP;
1617 	}
1618 #endif /* VJC */
1619 
1620 	/*
1621 	 * If the packet will fit in a header mbuf, don't waste a
1622 	 * whole cluster on it.
1623 	 */
1624 	if (ilen <= MHLEN && M_IS_CLUSTER(m)) {
1625 		MGETHDR(mp, M_DONTWAIT, MT_DATA);
1626 		if (mp != NULL) {
1627 			m_copydata(m, 0, ilen, mtod(mp, void *));
1628 			m_freem(m);
1629 			m = mp;
1630 			m->m_len = ilen;
1631 		}
1632 	}
1633 	m->m_pkthdr.len = ilen;
1634 	m_set_rcvif(m, ifp);
1635 
1636 	if ((proto & 0x8000) == 0) {
1637 #ifdef PPP_FILTER
1638 		/*
1639 		 * See whether we want to pass this packet, and
1640 		 * if it counts as link activity.
1641 		 */
1642 		if (sc->sc_pass_filt_in.bf_insns != 0
1643 		    && bpf_filter(sc->sc_pass_filt_in.bf_insns,
1644 			(u_char *)m, ilen, 0) == 0) {
1645 			/* drop this packet */
1646 			m_freem(m);
1647 			return;
1648 		}
1649 		if (sc->sc_active_filt_in.bf_insns == 0
1650 		    || bpf_filter(sc->sc_active_filt_in.bf_insns,
1651 			(u_char *)m, ilen, 0))
1652 			sc->sc_last_recv = time_second;
1653 #else
1654 		/*
1655 		 * Record the time that we received this packet.
1656 		 */
1657 		sc->sc_last_recv = time_second;
1658 #endif /* PPP_FILTER */
1659 	}
1660 
1661 	/* See if bpf wants to look at the packet. */
1662 	bpf_mtap(&sc->sc_if, m, BPF_D_IN);
1663 
1664 	switch (proto) {
1665 #ifdef INET
1666 	case PPP_IP:
1667 		/*
1668 		 * IP packet - take off the ppp header and pass it up to IP.
1669 		 */
1670 		if ((ifp->if_flags & IFF_UP) == 0
1671 		    || sc->sc_npmode[NP_IP] != NPMODE_PASS) {
1672 			/* Interface is down - drop the packet. */
1673 			m_freem(m);
1674 			return;
1675 		}
1676 		m->m_pkthdr.len -= PPP_HDRLEN;
1677 		m->m_data += PPP_HDRLEN;
1678 		m->m_len -= PPP_HDRLEN;
1679 #ifdef GATEWAY
1680 		if (ipflow_fastforward(m))
1681 			return;
1682 #endif
1683 		pktq = ip_pktq;
1684 		break;
1685 #endif
1686 
1687 #ifdef INET6
1688 	case PPP_IPV6:
1689 		/*
1690 		 * IPv6 packet - take off the ppp header and pass it up to
1691 		 * IPv6.
1692 		 */
1693 		if ((ifp->if_flags & IFF_UP) == 0
1694 		    || sc->sc_npmode[NP_IPV6] != NPMODE_PASS) {
1695 			/* interface is down - drop the packet. */
1696 			m_freem(m);
1697 			return;
1698 		}
1699 		m->m_pkthdr.len -= PPP_HDRLEN;
1700 		m->m_data += PPP_HDRLEN;
1701 		m->m_len -= PPP_HDRLEN;
1702 #ifdef GATEWAY
1703 		if (ip6flow_fastforward(&m))
1704 			return;
1705 #endif
1706 		pktq = ip6_pktq;
1707 		break;
1708 #endif
1709 
1710 	default:
1711 		/*
1712 		 * Some other protocol - place on input queue for read().
1713 		 */
1714 		inq = &sc->sc_inq;
1715 		pktq = NULL;
1716 		break;
1717 	}
1718 
1719 	/*
1720 	 * Put the packet on the appropriate input queue.
1721 	 */
1722 	s = splnet();
1723 
1724 	/* pktq: inet or inet6 cases */
1725 	if (__predict_true(pktq)) {
1726 		if (__predict_false(!pktq_enqueue(pktq, m, 0))) {
1727 			ifp->if_iqdrops++;
1728 			goto bad;
1729 		}
1730 		ifp->if_ipackets++;
1731 		ifp->if_ibytes += ilen;
1732 		splx(s);
1733 		return;
1734 	}
1735 
1736 	/* ifq: other protocol cases */
1737 	if (!inq) {
1738 		goto bad;
1739 	}
1740 	if (IF_QFULL(inq)) {
1741 		IF_DROP(inq);
1742 		splx(s);
1743 		if (sc->sc_flags & SC_DEBUG)
1744 			printf("%s: input queue full\n", ifp->if_xname);
1745 		ifp->if_iqdrops++;
1746 		goto bad;
1747 	}
1748 	IF_ENQUEUE(inq, m);
1749 	splx(s);
1750 	ifp->if_ipackets++;
1751 	ifp->if_ibytes += ilen;
1752 
1753 	(*sc->sc_ctlp)(sc);
1754 
1755 	return;
1756 
1757 bad:
1758 	m_freem(m);
1759 	sc->sc_if.if_ierrors++;
1760 	sc->sc_stats.ppp_ierrors++;
1761 }
1762 
1763 #define MAX_DUMP_BYTES	128
1764 
1765 static void
1766 pppdumpm(struct mbuf *m0)
1767 {
1768 	char buf[3*MAX_DUMP_BYTES+4];
1769 	char *bp = buf;
1770 	struct mbuf *m;
1771 
1772 	for (m = m0; m; m = m->m_next) {
1773 		int l = m->m_len;
1774 		u_char *rptr = (u_char *)m->m_data;
1775 
1776 		while (l--) {
1777 			if (bp > buf + sizeof(buf) - 4)
1778 				goto done;
1779 			/* Convert byte to ascii hex */
1780 			*bp++ = hexdigits[*rptr >> 4];
1781 			*bp++ = hexdigits[*rptr++ & 0xf];
1782 		}
1783 
1784 		if (m->m_next) {
1785 			if (bp > buf + sizeof(buf) - 3)
1786 				goto done;
1787 			*bp++ = '|';
1788 		} else
1789 			*bp++ = ' ';
1790 	}
1791 done:
1792 	if (m)
1793 		*bp++ = '>';
1794 	*bp = 0;
1795 	printf("%s\n", buf);
1796 }
1797 
1798 #ifdef ALTQ
1799 /*
1800  * A wrapper to transmit a packet from if_start since ALTQ uses
1801  * if_start to send a packet.
1802  */
1803 static void
1804 ppp_ifstart(struct ifnet *ifp)
1805 {
1806 	struct ppp_softc *sc;
1807 
1808 	sc = ifp->if_softc;
1809 	(*sc->sc_start)(sc);
1810 }
1811 #endif
1812 
1813 static const struct ppp_known_compressor {
1814 	uint8_t code;
1815 	const char *module;
1816 } ppp_known_compressors[] = {
1817 	{ CI_DEFLATE, "ppp_deflate" },
1818 	{ CI_DEFLATE_DRAFT, "ppp_deflate" },
1819 	{ CI_BSD_COMPRESS, "ppp_bsdcomp" },
1820 	{ CI_MPPE, "ppp_mppe" },
1821 	{ 0, NULL }
1822 };
1823 
1824 static int
1825 ppp_compressor_init(void)
1826 {
1827 
1828 	mutex_init(&ppp_compressors_mtx, MUTEX_DEFAULT, IPL_NONE);
1829 	return 0;
1830 }
1831 
1832 static int
1833 ppp_compressor_destroy(void)
1834 {
1835 
1836 	mutex_destroy(&ppp_compressors_mtx);
1837 	return 0;
1838 }
1839 
1840 static void
1841 ppp_compressor_rele(struct compressor *cp)
1842 {
1843 
1844 	mutex_enter(&ppp_compressors_mtx);
1845 	--cp->comp_refcnt;
1846 	mutex_exit(&ppp_compressors_mtx);
1847 }
1848 
1849 static struct compressor *
1850 ppp_get_compressor_noload(uint8_t ci, bool hold)
1851 {
1852 	struct compressor *cp;
1853 
1854 	KASSERT(mutex_owned(&ppp_compressors_mtx));
1855 	LIST_FOREACH(cp, &ppp_compressors, comp_list) {
1856 		if (cp->compress_proto == ci) {
1857 			if (hold)
1858 				++cp->comp_refcnt;
1859 			return cp;
1860 		}
1861 	}
1862 
1863 	return NULL;
1864 }
1865 
1866 static struct compressor *
1867 ppp_get_compressor(uint8_t ci)
1868 {
1869 	struct compressor *cp = NULL;
1870 	const struct ppp_known_compressor *pkc;
1871 
1872 	mutex_enter(&ppp_compressors_mtx);
1873 	cp = ppp_get_compressor_noload(ci, true);
1874 	mutex_exit(&ppp_compressors_mtx);
1875 	if (cp != NULL)
1876 		return cp;
1877 
1878 	kernconfig_lock();
1879 	mutex_enter(&ppp_compressors_mtx);
1880 	cp = ppp_get_compressor_noload(ci, true);
1881 	mutex_exit(&ppp_compressors_mtx);
1882 	if (cp == NULL) {
1883 		/* Not found, so try to autoload a module */
1884 		for (pkc = ppp_known_compressors; pkc->module != NULL; pkc++) {
1885 			if (pkc->code == ci) {
1886 				if (module_autoload(pkc->module,
1887 					MODULE_CLASS_MISC) != 0)
1888 					break;
1889 				mutex_enter(&ppp_compressors_mtx);
1890 				cp = ppp_get_compressor_noload(ci, true);
1891 				mutex_exit(&ppp_compressors_mtx);
1892 				break;
1893 			}
1894 		}
1895 	}
1896 	kernconfig_unlock();
1897 
1898 	return cp;
1899 }
1900 
1901 int
1902 ppp_register_compressor(struct compressor *pc, size_t ncomp)
1903 {
1904 	int error = 0;
1905 	size_t i;
1906 
1907 	mutex_enter(&ppp_compressors_mtx);
1908 	for (i = 0; i < ncomp; i++) {
1909 		if (ppp_get_compressor_noload(pc[i].compress_proto,
1910 			false) != NULL)
1911 			error = EEXIST;
1912 	}
1913 	if (!error) {
1914 		for (i = 0; i < ncomp; i++) {
1915 			pc[i].comp_refcnt = 0;
1916 			LIST_INSERT_HEAD(&ppp_compressors, &pc[i], comp_list);
1917 		}
1918 	}
1919 	mutex_exit(&ppp_compressors_mtx);
1920 
1921 	return error;
1922 }
1923 
1924 int
1925 ppp_unregister_compressor(struct compressor *pc, size_t ncomp)
1926 {
1927 	int error = 0;
1928 	size_t i;
1929 
1930 	mutex_enter(&ppp_compressors_mtx);
1931 	for (i = 0; i < ncomp; i++) {
1932 		if (ppp_get_compressor_noload(pc[i].compress_proto,
1933 			false) != &pc[i])
1934 			error = ENOENT;
1935 		else if (pc[i].comp_refcnt != 0)
1936 			error = EBUSY;
1937 	}
1938 	if (!error) {
1939 		for (i = 0; i < ncomp; i++) {
1940 			LIST_REMOVE(&pc[i], comp_list);
1941 		}
1942 	}
1943 	mutex_exit(&ppp_compressors_mtx);
1944 
1945 	return error;
1946 }
1947 
1948 /*
1949  * Module infrastructure
1950  */
1951 #include "if_module.h"
1952 
1953 #ifdef PPP_FILTER
1954 #define PPP_DEP "bpf_filter,"
1955 #else
1956 #define PPP_DEP
1957 #endif
1958 
1959 IF_MODULE(MODULE_CLASS_DRIVER, ppp, PPP_DEP "slcompress")
1960