1/*
2 * ipcp.c - PPP IP Control Protocol.
3 *
4 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
5 * Use is subject to license terms.
6 *
7 * Copyright (c) 1989 Carnegie Mellon University.
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms are permitted
11 * provided that the above copyright notice and this paragraph are
12 * duplicated in all such forms and that any documentation,
13 * advertising materials, and other materials related to such
14 * distribution and use acknowledge that the software was developed
15 * by Carnegie Mellon University.  The name of the
16 * University may not be used to endorse or promote products derived
17 * from this software without specific prior written permission.
18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
20 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
21 */
22/*
23 * Copyright (c) 2016 by Delphix. All rights reserved.
24 */
25
26#include <stdio.h>
27#include <string.h>
28#include <netdb.h>
29#include <sys/param.h>
30#include <sys/types.h>
31#include <sys/socket.h>
32#if defined(_linux_) || defined(__linux__)
33#define	__FAVOR_BSD
34#endif
35#include <netinet/in.h>
36#include <netinet/tcp.h>
37#include <arpa/inet.h>
38
39#include "pppd.h"
40#include "fsm.h"
41#include "ipcp.h"
42#include "pathnames.h"
43
44/* global vars */
45ipcp_options ipcp_wantoptions[NUM_PPP];	/* Options that we want to request */
46ipcp_options ipcp_gotoptions[NUM_PPP];	/* Options that peer ack'd */
47ipcp_options ipcp_allowoptions[NUM_PPP]; /* Options we allow peer to request */
48ipcp_options ipcp_hisoptions[NUM_PPP];	/* Options that we ack'd */
49
50bool	ipcp_from_hostname = 0;	/* Local IP address is from hostname lookup */
51
52/* Hook for a plugin to know when IP protocol has come up */
53void (*ip_up_hook) __P((void)) = NULL;
54
55/* Hook for a plugin to know when IP protocol has come down */
56void (*ip_down_hook) __P((void)) = NULL;
57
58/* local vars */
59static bool default_route_set[NUM_PPP];	/* Have set up a default route */
60static bool proxy_arp_set[NUM_PPP];	/* Have created proxy arp entry */
61static bool ipcp_is_up[NUM_PPP];	/* have called np_up() */
62static bool proxy_arp_quiet[NUM_PPP];	/* We should be quiet on error */
63static bool disable_defaultip = 0;	/* Don't use hostname for IP addr */
64
65/*
66 * Callbacks for fsm code.  (CI = Configuration Information)
67 */
68static void ipcp_resetci __P((fsm *));	/* Reset our CI */
69static int  ipcp_cilen __P((fsm *));	        /* Return length of our CI */
70static void ipcp_addci __P((fsm *, u_char *, int *)); /* Add our CI */
71static int  ipcp_ackci __P((fsm *, u_char *, int));	/* Peer ack'd our CI */
72static int  ipcp_nakci __P((fsm *, u_char *, int));	/* Peer nak'd our CI */
73static int  ipcp_rejci __P((fsm *, u_char *, int));	/* Peer rej'd our CI */
74static int  ipcp_reqci __P((fsm *, u_char *, int *, int)); /* Rcv CI */
75static void ipcp_up __P((fsm *));		/* We're UP */
76static void ipcp_down __P((fsm *));		/* We're DOWN */
77static void ipcp_finished __P((fsm *));	/* Don't need lower layer */
78static int  setmsservaddr __P((char *, u_int32_t *));
79
80fsm ipcp_fsm[NUM_PPP];		/* IPCP fsm structure */
81
82static fsm_callbacks ipcp_callbacks = { /* IPCP callback routines */
83    ipcp_resetci,		/* Reset our Configuration Information */
84    ipcp_cilen,			/* Length of our Configuration Information */
85    ipcp_addci,			/* Add our Configuration Information */
86    ipcp_ackci,			/* ACK our Configuration Information */
87    ipcp_nakci,			/* NAK our Configuration Information */
88    ipcp_rejci,			/* Reject our Configuration Information */
89    ipcp_reqci,			/* Request peer's Configuration Information */
90    ipcp_up,			/* Called when fsm reaches OPENED state */
91    ipcp_down,			/* Called when fsm leaves OPENED state */
92    NULL,			/* Called when we want the lower layer up */
93    ipcp_finished,		/* Called when we want the lower layer down */
94    NULL,			/* Retransmission is necessary */
95    NULL,			/* Called to handle protocol-specific codes */
96    "IPCP",			/* String name of protocol */
97    NULL			/* Peer rejected a code number */
98};
99
100/*
101 * Command-line options.
102 */
103static int setvjslots __P((char **));
104static int setdnsaddr __P((char **));
105static int setwinsaddr __P((char **));
106static int autoproxyarp __P((char **));
107
108static option_t ipcp_option_list[] = {
109    { "noip", o_bool, &ipcp_protent.enabled_flag,
110      "Disable IP and IPCP" },
111    { "-ip", o_bool, &ipcp_protent.enabled_flag,
112      "Disable IP and IPCP" },
113    { "novj", o_bool, &ipcp_wantoptions[0].neg_vj,
114      "Disable VJ compression", OPT_A2COPY, &ipcp_allowoptions[0].neg_vj },
115    { "-vj", o_bool, &ipcp_wantoptions[0].neg_vj,
116      "Disable VJ compression", OPT_A2COPY, &ipcp_allowoptions[0].neg_vj },
117    { "novjccomp", o_bool, &ipcp_wantoptions[0].cflag,
118      "Disable VJ connection-ID compression", OPT_A2COPY,
119      &ipcp_allowoptions[0].cflag },
120    { "-vjccomp", o_bool, &ipcp_wantoptions[0].cflag,
121      "Disable VJ connection-ID compression", OPT_A2COPY,
122      &ipcp_allowoptions[0].cflag },
123    { "vj-max-slots", o_special, (void *)setvjslots,
124      "Set maximum VJ header slots" },
125    { "ipcp-accept-local", o_bool, &ipcp_wantoptions[0].accept_local,
126      "Accept peer's address for us", 1 },
127    { "ipcp-accept-remote", o_bool, &ipcp_wantoptions[0].accept_remote,
128      "Accept peer's address for it", 1 },
129    { "ipparam", o_string, &ipparam,
130      "Set ip script parameter" },
131    { "noipdefault", o_bool, &disable_defaultip,
132      "Don't use name for default IP adrs", 1 },
133    { "ms-dns", o_special, (void *)setdnsaddr,
134      "DNS address for the peer's use" },
135    { "ms-wins", o_special, (void *)setwinsaddr,
136      "Nameserver for SMB over TCP/IP for peer" },
137    { "ipcp-restart", o_int, &ipcp_fsm[0].timeouttime,
138      "Set timeout for IPCP" },
139    { "ipcp-max-terminate", o_int, &ipcp_fsm[0].maxtermtransmits,
140      "Set max #xmits for term-reqs" },
141    { "ipcp-max-configure", o_int, &ipcp_fsm[0].maxconfreqtransmits,
142      "Set max #xmits for conf-reqs" },
143    { "ipcp-max-failure", o_int, &ipcp_fsm[0].maxnakloops,
144      "Set max #conf-naks for IPCP" },
145    { "defaultroute", o_bool, &ipcp_wantoptions[0].default_route,
146      "Add default route", OPT_ENABLE|1, &ipcp_allowoptions[0].default_route },
147    { "nodefaultroute", o_bool, &ipcp_allowoptions[0].default_route,
148      "disable defaultroute option", OPT_A2COPY,
149      &ipcp_wantoptions[0].default_route },
150    { "-defaultroute", o_bool, &ipcp_allowoptions[0].default_route,
151      "disable defaultroute option", OPT_A2COPY,
152      &ipcp_wantoptions[0].default_route },
153    { "proxyarp", o_bool, &ipcp_wantoptions[0].proxy_arp,
154      "Add proxy ARP entry", OPT_ENABLE|1, &ipcp_allowoptions[0].proxy_arp },
155    { "autoproxyarp", o_special_noarg, (void *)autoproxyarp,
156      "Add proxy ARP entry if needed", OPT_ENABLE,
157      &ipcp_allowoptions[0].proxy_arp },
158    { "noproxyarp", o_bool, &ipcp_allowoptions[0].proxy_arp,
159      "disable proxyarp option", OPT_A2COPY, &ipcp_wantoptions[0].proxy_arp },
160    { "-proxyarp", o_bool, &ipcp_allowoptions[0].proxy_arp,
161      "disable proxyarp option", OPT_A2COPY, &ipcp_wantoptions[0].proxy_arp },
162    { "usepeerdns", o_bool, &ipcp_wantoptions[0].req_dns1,
163      "Ask peer for DNS address(es)", OPT_A2COPY|1,
164      &ipcp_wantoptions[0].req_dns2 },
165    { NULL }
166};
167
168/*
169 * Protocol entry points from main code.
170 */
171static void ipcp_init __P((int));
172static void ipcp_open __P((int));
173static void ipcp_close __P((int, char *));
174static void ipcp_lowerup __P((int));
175static void ipcp_lowerdown __P((int));
176static void ipcp_input __P((int, u_char *, int));
177static void ipcp_protrej __P((int));
178static int  ipcp_printpkt __P((u_char *, int,
179    void (*) __P((void *, const char *, ...)), void *));
180static void ip_check_options __P((void));
181static int  ip_demand_conf __P((int));
182static int  ip_active_pkt __P((u_char *, int));
183static void ipcp_print_stat __P((int, FILE *));
184
185static void create_resolv __P((u_int32_t, u_int32_t));
186
187struct protent ipcp_protent = {
188    PPP_IPCP,
189    ipcp_init,
190    ipcp_input,
191    ipcp_protrej,
192    ipcp_lowerup,
193    ipcp_lowerdown,
194    ipcp_open,
195    ipcp_close,
196    ipcp_printpkt,
197    NULL,
198    1,
199    "IPCP",
200    "IP",
201    ipcp_option_list,
202    ip_check_options,
203    ip_demand_conf,
204    ip_active_pkt,
205    ipcp_print_stat
206};
207
208static void ipcp_clear_addrs __P((int, u_int32_t, u_int32_t));
209static void ipcp_script __P((char *));		/* Run an up/down script */
210static void ipcp_script_done __P((void *, int));
211
212/*
213 * Lengths of configuration options.
214 */
215#define CILEN_VOID	2
216#define CILEN_COMPRESS	4	/* min length for compression protocol opt. */
217#define CILEN_VJ	6	/* length for RFC1332 Van-Jacobson opt. */
218#define CILEN_ADDR	6	/* new-style single address option */
219#define CILEN_ADDRS	10	/* old-style dual address option */
220
221
222/*
223 * This state variable is used to ensure that we don't
224 * run an ipcp-up/down script while one is already running.
225 */
226static enum script_state {
227    s_down,
228    s_up
229} ipcp_script_state;
230static pid_t ipcp_script_pid;
231
232/*
233 * Make a string representation of a network IP address.
234 */
235char *
236ip_ntoa(ipaddr)
237u_int32_t ipaddr;
238{
239    static char b[64];
240
241    (void) slprintf(b, sizeof(b), "%I", ipaddr);
242    return b;
243}
244
245/*
246 * Option parsing.
247 */
248
249/*
250 * setvjslots - set maximum number of connection slots for VJ compression
251 */
252static int
253setvjslots(argv)
254    char **argv;
255{
256    int value;
257
258    if (!int_option(*argv, &value))
259	return 0;
260    if (value < 2 || value > 16) {
261	option_error("vj-max-slots value must be between 2 and 16");
262	return 0;
263    }
264    ipcp_wantoptions [0].maxslotindex =
265        ipcp_allowoptions[0].maxslotindex = value - 1;
266    return 1;
267}
268
269/*
270 * setmsservaddr - Set the primary and secondary server addresses in the
271 * array.  setdnsaddr() and setwinsaddr() call this function with either
272 * dnsaddr[] or winsaddr[] as the serverarray argument.
273 */
274static int
275setmsservaddr(servname, serverarray)
276    char *servname;
277    u_int32_t *serverarray;
278{
279    u_int32_t addr;
280    struct hostent *hp = NULL;
281
282    addr = inet_addr(servname);
283    if (addr == (u_int32_t) -1) {
284	if ((hp = gethostbyname(servname)) == NULL)
285	    return 0;
286	BCOPY(hp->h_addr, &addr, sizeof (u_int32_t));
287    }
288
289    /*
290     * If there is no primary then this is the first instance of the
291     * option, we must set the primary.  In that case, try to set the
292     * secondary to h_addr_list[1].  If the primary is already set, then
293     * this is the second instance of the option, and we must set
294     * the secondary.
295     */
296    if (serverarray[0] == 0) {
297	serverarray[0] = addr;
298	if (hp != NULL && hp->h_addr_list[1] != NULL)
299	    BCOPY(hp->h_addr_list[1], &serverarray[1], sizeof (u_int32_t));
300	else
301	    serverarray[1] = addr;
302    } else {
303	serverarray[1] = addr;
304    }
305
306    return (1);
307}
308
309/*
310 * setdnsaddr - set the dns address(es)
311 */
312static int
313setdnsaddr(argv)
314    char **argv;
315{
316    if (setmsservaddr(*argv, &(ipcp_allowoptions[0].dnsaddr[0])) == 0) {
317	option_error("invalid address parameter '%s' for ms-dns option", *argv);
318	return (0);
319    }
320
321    return (1);
322}
323
324/*
325 * setwinsaddr - set the wins address(es)
326 * This is primrarly used with the Samba package under UNIX or for pointing
327 * the caller to the existing WINS server on a Windows NT platform.
328 */
329static int
330setwinsaddr(argv)
331    char **argv;
332{
333    if (setmsservaddr(*argv, &(ipcp_allowoptions[0].winsaddr[0])) == 0) {
334	option_error("invalid address parameter '%s' for ms-wins option",
335	    *argv);
336	return (0);
337    }
338
339    return (1);
340}
341
342/*
343 * autoproxyarp -- enable proxy ARP but don't emit error messages if
344 * it's not actually needed.
345 */
346/*ARGSUSED*/
347static int
348autoproxyarp(argv)
349    char **argv;
350{
351    ipcp_wantoptions[0].proxy_arp = 1;
352    proxy_arp_quiet[0] = 1;
353
354    return (1);
355}
356
357
358/*
359 * ipcp_init - Initialize IPCP.
360 */
361static void
362ipcp_init(unit)
363    int unit;
364{
365    fsm *f = &ipcp_fsm[unit];
366    ipcp_options *wo = &ipcp_wantoptions[unit];
367    ipcp_options *ao = &ipcp_allowoptions[unit];
368
369    f->unit = unit;
370    f->protocol = PPP_IPCP;
371    f->callbacks = &ipcp_callbacks;
372    fsm_init(&ipcp_fsm[unit]);
373
374    BZERO(wo, sizeof(*wo));
375    BZERO(ao, sizeof(*ao));
376
377    wo->neg_addr = wo->old_addrs = 1;
378    wo->neg_vj = 1;
379    wo->vj_protocol = IPCP_VJ_COMP;
380    wo->maxslotindex = MAX_STATES - 1; /* really max index */
381    wo->cflag = 1;
382
383    ao->neg_addr = ao->old_addrs = 1;
384    ao->neg_vj = 1;
385    ao->maxslotindex = MAX_STATES - 1;
386    ao->cflag = 1;
387
388    /*
389     * These aren't actually negotiated.  Instead, they control
390     * whether the user may use the proxyarp and defaultroute options.
391     */
392    ao->proxy_arp = 1;
393    ao->default_route = 1;
394    proxy_arp_quiet[unit] = 0;
395}
396
397
398/*
399 * ipcp_open - IPCP is allowed to come up.
400 */
401static void
402ipcp_open(unit)
403    int unit;
404{
405    fsm_open(&ipcp_fsm[unit]);
406}
407
408
409/*
410 * ipcp_close - Take IPCP down.
411 */
412static void
413ipcp_close(unit, reason)
414    int unit;
415    char *reason;
416{
417    fsm_close(&ipcp_fsm[unit], reason);
418}
419
420
421/*
422 * ipcp_lowerup - The lower layer is up.
423 */
424static void
425ipcp_lowerup(unit)
426    int unit;
427{
428    fsm_lowerup(&ipcp_fsm[unit]);
429}
430
431
432/*
433 * ipcp_lowerdown - The lower layer is down.
434 */
435static void
436ipcp_lowerdown(unit)
437    int unit;
438{
439    fsm_lowerdown(&ipcp_fsm[unit]);
440}
441
442
443/*
444 * ipcp_input - Input IPCP packet.
445 */
446static void
447ipcp_input(unit, p, len)
448    int unit;
449    u_char *p;
450    int len;
451{
452    fsm_input(&ipcp_fsm[unit], p, len);
453}
454
455
456/*
457 * ipcp_protrej - A Protocol-Reject was received for IPCP.
458 */
459static void
460ipcp_protrej(unit)
461    int unit;
462{
463    fsm_protreject(&ipcp_fsm[unit]);
464}
465
466
467/*
468 * ipcp_resetci - Reset our CI.
469 * Called by fsm_sconfreq, Send Configure Request.
470 */
471static void
472ipcp_resetci(f)
473    fsm *f;
474{
475    ipcp_options *wo = &ipcp_wantoptions[f->unit];
476    ipcp_options *go = &ipcp_gotoptions[f->unit];
477    ipcp_options *ao = &ipcp_allowoptions[f->unit];
478
479    wo->req_addr = (wo->neg_addr || wo->old_addrs) &&
480	(ao->neg_addr || ao->old_addrs);
481    if (wo->ouraddr == 0 || disable_defaultip)
482	wo->accept_local = 1;
483    if (wo->hisaddr == 0)
484	wo->accept_remote = 1;
485    *go = *wo;
486    if (disable_defaultip)
487	go->ouraddr = 0;
488}
489
490
491/*
492 * ipcp_cilen - Return length of our CI.
493 * Called by fsm_sconfreq, Send Configure Request.
494 */
495static int
496ipcp_cilen(f)
497    fsm *f;
498{
499    ipcp_options *go = &ipcp_gotoptions[f->unit];
500    ipcp_options *wo = &ipcp_wantoptions[f->unit];
501    ipcp_options *ho = &ipcp_hisoptions[f->unit];
502
503#define LENCIADDRS(neg)		(neg ? CILEN_ADDRS : 0)
504#define LENCIVJ(neg, old)	(neg ? (old? CILEN_COMPRESS : CILEN_VJ) : 0)
505#define LENCIADDR(neg)		(neg ? (CILEN_ADDR) : 0)
506
507    /*
508     * First see if we want to change our options to the old
509     * forms because we have received old forms from the peer.
510     */
511    if (go->neg_addr && go->old_addrs && !ho->neg_addr && ho->old_addrs)
512	/* use the old style of address negotiation */
513	go->neg_addr = 0;
514    if (wo->neg_vj && !go->neg_vj && !go->old_vj) {
515	/* try an older style of VJ negotiation */
516	/* use the old style only if the peer did */
517	if (ho->neg_vj && ho->old_vj) {
518	    go->neg_vj = 1;
519	    go->old_vj = 1;
520	    go->vj_protocol = ho->vj_protocol;
521	}
522    }
523
524    return (LENCIADDRS(!go->neg_addr && go->old_addrs) +
525	    LENCIVJ(go->neg_vj, go->old_vj) +
526	    LENCIADDR(go->neg_addr) +
527	    LENCIADDR(go->req_dns1) +
528	    LENCIADDR(go->req_dns2)) ;
529}
530
531
532/*
533 * ipcp_addci - Add our desired CIs to a packet.
534 * Called by fsm_sconfreq, Send Configure Request.
535 */
536static void
537ipcp_addci(f, ucp, lenp)
538    fsm *f;
539    u_char *ucp;
540    int *lenp;
541{
542    ipcp_options *go = &ipcp_gotoptions[f->unit];
543    int len = *lenp;
544
545#define ADDCIADDRS(opt, neg, val1, val2) \
546    if (neg) { \
547	if (len >= CILEN_ADDRS) { \
548	    PUTCHAR(opt, ucp); \
549	    PUTCHAR(CILEN_ADDRS, ucp); \
550	    PUTNLONG(val1, ucp); \
551	    PUTNLONG(val2, ucp); \
552	    len -= CILEN_ADDRS; \
553	} else \
554	    go->old_addrs = 0; \
555    }
556
557#define ADDCIVJ(opt, neg, val, old, maxslotindex, cflag) \
558    if (neg) { \
559	int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
560	if (len >= vjlen) { \
561	    PUTCHAR(opt, ucp); \
562	    PUTCHAR(vjlen, ucp); \
563	    PUTSHORT(val, ucp); \
564	    if (!old) { \
565		PUTCHAR(maxslotindex, ucp); \
566		PUTCHAR(cflag, ucp); \
567	    } \
568	    len -= vjlen; \
569	} else \
570	    neg = 0; \
571    }
572
573#define ADDCIADDR(opt, neg, val) \
574    if (neg) { \
575	if (len >= CILEN_ADDR) { \
576	    PUTCHAR(opt, ucp); \
577	    PUTCHAR(CILEN_ADDR, ucp); \
578	    PUTNLONG(val, ucp); \
579	    len -= CILEN_ADDR; \
580	} else \
581	    neg = 0; \
582    }
583
584    ADDCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs, go->ouraddr,
585	       go->hisaddr);
586
587    ADDCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
588	    go->maxslotindex, go->cflag);
589
590    ADDCIADDR(CI_ADDR, go->neg_addr, go->ouraddr);
591
592    ADDCIADDR(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]);
593
594    ADDCIADDR(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
595
596    *lenp -= len;
597}
598
599
600/*
601 * ipcp_ackci - Ack our CIs.
602 * Called by fsm_rconfack, Receive Configure ACK.
603 *
604 * Returns:
605 *	0 - Ack was bad.
606 *	1 - Ack was good.
607 */
608static int
609ipcp_ackci(f, p, len)
610    fsm *f;
611    u_char *p;
612    int len;
613{
614    ipcp_options *go = &ipcp_gotoptions[f->unit];
615    u_short cilen, citype, cishort;
616    u_int32_t cilong;
617    u_char cimaxslotindex, cicflag;
618
619    /*
620     * CIs must be in exactly the same order that we sent...
621     * Check packet length and CI length at each step.
622     * If we find any deviations, then this packet is bad.
623     */
624
625#define	ACKCHECK(opt, olen) \
626	if ((len -= olen) < 0) \
627	    goto bad; \
628	GETCHAR(citype, p); \
629	GETCHAR(cilen, p); \
630	if (cilen != olen || \
631	    citype != opt) \
632	    goto bad;
633
634#define ACKCIADDRS(opt, neg, val1, val2) \
635    if (neg) { \
636	ACKCHECK(opt, CILEN_ADDRS) \
637	GETNLONG(cilong, p); \
638	if (val1 != cilong) \
639	    goto bad; \
640	GETNLONG(cilong, p); \
641	if (val2 != cilong) \
642	    goto bad; \
643    }
644
645#define ACKCIVJ(opt, neg, val, old, maxslotindex, cflag) \
646    if (neg) { \
647	int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
648	ACKCHECK(opt, vjlen) \
649	GETSHORT(cishort, p); \
650	if (cishort != val) \
651	    goto bad; \
652	if (!old) { \
653	    GETCHAR(cimaxslotindex, p); \
654	    if (cimaxslotindex != maxslotindex) \
655		goto bad; \
656	    GETCHAR(cicflag, p); \
657	    if (cicflag != cflag) \
658		goto bad; \
659	} \
660    }
661
662#define ACKCIADDR(opt, neg, val) \
663    if (neg) { \
664	ACKCHECK(opt, CILEN_ADDR) \
665	GETNLONG(cilong, p); \
666	if (val != cilong) \
667	    goto bad; \
668    }
669
670    ACKCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs, go->ouraddr,
671	       go->hisaddr);
672
673    ACKCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
674	    go->maxslotindex, go->cflag);
675
676    ACKCIADDR(CI_ADDR, go->neg_addr, go->ouraddr);
677
678    ACKCIADDR(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]);
679
680    ACKCIADDR(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
681
682    /*
683     * If there are any remaining CIs, then this packet is bad.
684     */
685    if (len != 0)
686	goto bad;
687    return (1);
688
689bad:
690    IPCPDEBUG(("ipcp_ackci: received bad Ack!"));
691    return (0);
692}
693
694/*
695 * ipcp_nakci - Peer has sent a NAK for some of our CIs.
696 * This should not modify any state if the Nak is bad
697 * or if IPCP is in the OPENED state.
698 * Calback from fsm_rconfnakrej - Receive Configure-Nak or Configure-Reject.
699 *
700 * Returns:
701 *	0 - Nak was bad.
702 *	1 - Nak was good.
703 */
704static int
705ipcp_nakci(f, p, len)
706    fsm *f;
707    u_char *p;
708    int len;
709{
710    ipcp_options *go = &ipcp_gotoptions[f->unit];
711    u_char cimaxslotindex, cicflag;
712    u_char citype, cilen, *next;
713    u_short cishort;
714    u_int32_t ciaddr1, ciaddr2;
715    ipcp_options no;		/* options we've seen Naks for */
716    ipcp_options try;		/* options to request next time */
717
718    BZERO(&no, sizeof(no));
719    try = *go;
720
721    /*
722     * Any Nak'd CIs must be in exactly the same order that we sent.
723     * Check packet length and CI length at each step.
724     * If we find any deviations, then this packet is bad.
725     */
726#define NAKCIADDRS(opt, neg, code) \
727    if ((neg) && \
728	(cilen = p[1]) == CILEN_ADDRS && \
729	len >= cilen && \
730	p[0] == opt) { \
731	len -= cilen; \
732	INCPTR(2, p); \
733	GETNLONG(ciaddr1, p); \
734	GETNLONG(ciaddr2, p); \
735	no.old_addrs = 1; \
736	code \
737    }
738
739#define NAKCIVJ(opt, neg, code) \
740    if (go->neg && \
741	((cilen = p[1]) == CILEN_COMPRESS || cilen == CILEN_VJ) && \
742	len >= cilen && \
743	p[0] == opt) { \
744	len -= cilen; \
745	INCPTR(2, p); \
746	GETSHORT(cishort, p); \
747	no.neg = 1; \
748        code \
749    }
750
751#define NAKCIADDR(opt, neg, code) \
752    if (go->neg && \
753	(cilen = p[1]) == CILEN_ADDR && \
754	len >= cilen && \
755	p[0] == opt) { \
756	len -= cilen; \
757	INCPTR(2, p); \
758	GETNLONG(ciaddr1, p); \
759	no.neg = 1; \
760	code \
761    }
762
763    /*
764     * Accept the peer's idea of {our,its} address, if different
765     * from our idea, only if the accept_{local,remote} flag is set.
766     */
767    NAKCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs,
768	      if (go->accept_local && ciaddr1) { /* Do we know our address? */
769		  try.ouraddr = ciaddr1;
770	      }
771	      if (go->accept_remote && ciaddr2) { /* Does it know its? */
772		  try.hisaddr = ciaddr2;
773	      }
774	      );
775
776    /*
777     * Accept the peer's value of maxslotindex provided that it
778     * is less than what we asked for.  Turn off slot-ID compression
779     * if the peer wants.  Send old-style compress-type option if
780     * the peer wants.
781     */
782    NAKCIVJ(CI_COMPRESSTYPE, neg_vj,
783	    if (cilen == CILEN_VJ) {
784		GETCHAR(cimaxslotindex, p);
785		GETCHAR(cicflag, p);
786		if (cishort == IPCP_VJ_COMP) {
787		    try.old_vj = 0;
788		    if (cimaxslotindex < go->maxslotindex)
789			try.maxslotindex = cimaxslotindex;
790		    if (!cicflag)
791			try.cflag = 0;
792		} else {
793		    try.neg_vj = 0;
794		}
795	    } else {
796		if (cishort == IPCP_VJ_COMP || cishort == IPCP_VJ_COMP_OLD) {
797		    try.old_vj = 1;
798		    try.vj_protocol = cishort;
799		} else {
800		    try.neg_vj = 0;
801		}
802	    }
803	    );
804
805    NAKCIADDR(CI_ADDR, neg_addr,
806	      if (go->accept_local && ciaddr1) { /* Do we know our address? */
807		  try.ouraddr = ciaddr1;
808	      }
809	      );
810
811    NAKCIADDR(CI_MS_DNS1, req_dns1,
812	      try.dnsaddr[0] = ciaddr1;
813	      );
814
815    NAKCIADDR(CI_MS_DNS2, req_dns2,
816	      try.dnsaddr[1] = ciaddr1;
817	      );
818
819    /*
820     * There may be remaining CIs, if the peer is requesting negotiation
821     * on an option that we didn't include in our request packet.
822     * If they want to negotiate about IP addresses, we comply.
823     * If they want us to ask for compression, we refuse.
824     */
825    while (len > CILEN_VOID) {
826	GETCHAR(citype, p);
827	GETCHAR(cilen, p);
828	if( (len -= cilen) < 0 )
829	    goto bad;
830	next = p + cilen - 2;
831
832	switch (citype) {
833	case CI_COMPRESSTYPE:
834	    if (go->neg_vj || no.neg_vj ||
835		(cilen != CILEN_VJ && cilen != CILEN_COMPRESS))
836		goto bad;
837	    no.neg_vj = 1;
838	    break;
839	case CI_ADDRS:
840	    if ((!go->neg_addr && go->old_addrs) || no.old_addrs
841		|| cilen != CILEN_ADDRS)
842		goto bad;
843	    try.neg_addr = 1;
844	    try.old_addrs = 1;
845	    GETNLONG(ciaddr1, p);
846	    if (ciaddr1 && go->accept_local)
847		try.ouraddr = ciaddr1;
848	    GETNLONG(ciaddr2, p);
849	    if (ciaddr2 && go->accept_remote)
850		try.hisaddr = ciaddr2;
851	    no.old_addrs = 1;
852	    break;
853	case CI_ADDR:
854	    if (go->neg_addr || no.neg_addr || cilen != CILEN_ADDR)
855		goto bad;
856	    try.old_addrs = 0;
857	    GETNLONG(ciaddr1, p);
858	    if (ciaddr1 && go->accept_local)
859		try.ouraddr = ciaddr1;
860	    if (try.ouraddr != 0)
861		try.neg_addr = 1;
862	    no.neg_addr = 1;
863	    break;
864	}
865	p = next;
866    }
867
868    /*
869     * OK, the Nak is good.  Now we can update state.
870     * If there are any remaining options, we ignore them.
871     */
872    if (f->state != OPENED)
873	*go = try;
874
875    return 1;
876
877bad:
878    IPCPDEBUG(("ipcp_nakci: received bad Nak!"));
879    return 0;
880}
881
882
883/*
884 * ipcp_rejci - Reject some of our CIs.
885 * Callback from fsm_rconfnakrej.
886 */
887static int
888ipcp_rejci(f, p, len)
889    fsm *f;
890    u_char *p;
891    int len;
892{
893    ipcp_options *go = &ipcp_gotoptions[f->unit];
894    u_char cimaxslotindex, ciflag, cilen;
895    u_short cishort;
896    u_int32_t cilong;
897    ipcp_options try;		/* options to request next time */
898
899    try = *go;
900    /*
901     * Any Rejected CIs must be in exactly the same order that we sent.
902     * Check packet length and CI length at each step.
903     * If we find any deviations, then this packet is bad.
904     */
905#define REJCIADDRS(opt, neg, val1, val2) \
906    if ((neg) && \
907	(cilen = p[1]) == CILEN_ADDRS && \
908	len >= cilen && \
909	p[0] == opt) { \
910	len -= cilen; \
911	INCPTR(2, p); \
912	GETNLONG(cilong, p); \
913	/* Check rejected value. */ \
914	if (cilong != val1) \
915	    goto bad; \
916	GETNLONG(cilong, p); \
917	/* Check rejected value. */ \
918	if (cilong != val2) \
919	    goto bad; \
920	try.old_addrs = 0; \
921    }
922
923#define REJCIVJ(opt, neg, val, old, maxslot, cflag) \
924    if (go->neg && \
925	p[1] == (old? CILEN_COMPRESS : CILEN_VJ) && \
926	len >= p[1] && \
927	p[0] == opt) { \
928	len -= p[1]; \
929	INCPTR(2, p); \
930	GETSHORT(cishort, p); \
931	/* Check rejected value. */  \
932	if (cishort != val) \
933	    goto bad; \
934	if (!old) { \
935	   GETCHAR(cimaxslotindex, p); \
936	   if (cimaxslotindex != maxslot) \
937	     goto bad; \
938	   GETCHAR(ciflag, p); \
939	   if (ciflag != cflag) \
940	     goto bad; \
941        } \
942	try.neg = 0; \
943     }
944
945#define REJCIADDR(opt, neg, addr) \
946    if (go->neg && \
947	((cilen = p[1]) == CILEN_ADDR) && \
948	len >= cilen && \
949	p[0] == opt) { \
950	len -= cilen; \
951	INCPTR(2, p); \
952	GETNLONG(cilong, p); \
953	/* Check rejected value. */ \
954	if (cilong != addr) \
955	    goto bad; \
956	try.neg = 0; \
957    }
958
959    REJCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs,
960	       go->ouraddr, go->hisaddr);
961
962    REJCIVJ(CI_COMPRESSTYPE, neg_vj, go->vj_protocol, go->old_vj,
963	    go->maxslotindex, go->cflag);
964
965    REJCIADDR(CI_ADDR, neg_addr, go->ouraddr);
966
967    REJCIADDR(CI_MS_DNS1, req_dns1, go->dnsaddr[0]);
968
969    REJCIADDR(CI_MS_DNS2, req_dns2, go->dnsaddr[1]);
970
971    /*
972     * If there are any remaining CIs, then this packet is bad.
973     */
974    if (len != 0)
975	goto bad;
976    /*
977     * Now we can update state.
978     */
979    if (f->state != OPENED)
980	*go = try;
981    return 1;
982
983bad:
984    IPCPDEBUG(("ipcp_rejci: received bad Reject!"));
985    return 0;
986}
987
988
989/*
990 * ipcp_reqci - Check the peer's requested CIs and send appropriate response.
991 * Callback from fsm_rconfreq, Receive Configure Request
992 *
993 * Returns: CODE_CONFACK, CODE_CONFNAK or CODE_CONFREJ and input
994 * packet modified appropriately.  If reject_if_disagree is non-zero,
995 * doesn't return CODE_CONFNAK; returns CODE_CONFREJ if it can't
996 * return CODE_CONFACK.
997 */
998static int
999ipcp_reqci(f, p, lenp, dont_nak)
1000    fsm *f;
1001    u_char *p;		/* Requested CIs */
1002    int *lenp;			/* Length of requested CIs */
1003    bool dont_nak;
1004{
1005    ipcp_options *wo = &ipcp_wantoptions[f->unit];
1006    ipcp_options *ho = &ipcp_hisoptions[f->unit];
1007    ipcp_options *ao = &ipcp_allowoptions[f->unit];
1008    ipcp_options *go = &ipcp_gotoptions[f->unit];
1009    int ret, newret;
1010    u_char *p0, *nakp, *rejp, *prev;
1011    u_short cishort;
1012    int len, cilen, type;
1013    u_int32_t tl, ciaddr1, ciaddr2;	/* Parsed address values */
1014    u_char maxslotindex, cflag;
1015    int d;
1016
1017    ret = CODE_CONFACK;
1018    rejp = p0 = p;
1019    nakp = nak_buffer;
1020
1021    /*
1022     * Reset all its options.
1023     */
1024    BZERO(ho, sizeof(*ho));
1025
1026    /*
1027     * Process all its options.
1028     */
1029    for (len = *lenp; len > 0; len -= cilen, p = prev + cilen) {
1030	if ((len < 2) || p[1] > len) {
1031	    /*
1032	     * RFC 1661 page 40 -- if the option extends beyond the
1033	     * packet, then discard the entire packet.
1034	     */
1035	    return (0);
1036	}
1037
1038	newret = CODE_CONFACK;
1039	prev = p;
1040	GETCHAR(type, p);
1041	GETCHAR(cilen, p);
1042
1043	switch (type) {		/* Check CI type */
1044	case CI_ADDRS:
1045	    if (!ao->old_addrs || ho->neg_addr) {
1046		newret = CODE_CONFREJ;
1047		break;
1048	    }
1049
1050	    if (cilen != CILEN_ADDRS) {
1051		/*
1052		 * rfc1661, page 40 -- a recongnized option with an
1053		 * invalid length should be Nak'ed.
1054		 */
1055		newret = CODE_CONFNAK;
1056		ciaddr1 = wo->hisaddr;
1057		ciaddr2 = wo->ouraddr;
1058	    } else {
1059
1060		/*
1061		 * If it has no address, or if we both have its
1062		 * address but disagree about it, then NAK it with our
1063		 * idea. In particular, if we don't know its address,
1064		 * but it does, then accept it.
1065		 */
1066		GETNLONG(ciaddr1, p);
1067		if (ciaddr1 != wo->hisaddr &&
1068		    (ciaddr1 == 0 || !wo->accept_remote)) {
1069		    newret = CODE_CONFNAK;
1070		    ciaddr1 = wo->hisaddr;
1071		} else if (ciaddr1 == 0 && wo->hisaddr == 0) {
1072		    /*
1073		     * If neither we nor he knows his address, reject
1074		     * the option.
1075		     */
1076		    newret = CODE_CONFREJ;
1077		    wo->req_addr = 0;	/* don't NAK with 0.0.0.0 later */
1078		    break;
1079		} else if (ciaddr1 != 0) {
1080		    go->hisaddr = ciaddr1;
1081		}
1082
1083		/*
1084		 * If he doesn't know our address, or if we both have
1085		 * our address * but disagree about it, then NAK it
1086		 * with our idea.
1087		 */
1088		GETNLONG(ciaddr2, p);
1089		if (ciaddr2 != wo->ouraddr) {
1090		    if (ciaddr2 == 0 || !wo->accept_local) {
1091			newret = CODE_CONFNAK;
1092			ciaddr2 = wo->ouraddr;
1093		    } else {
1094			go->ouraddr = ciaddr2;	/* accept peer's idea */
1095		    }
1096		}
1097	    }
1098
1099	    if (newret == CODE_CONFNAK) {
1100		PUTCHAR(type, nakp);
1101		PUTCHAR(CILEN_ADDRS, nakp);
1102		PUTNLONG(ciaddr1, nakp);
1103		PUTNLONG(ciaddr2, nakp);
1104	    }
1105
1106	    ho->old_addrs = 1;
1107	    ho->hisaddr = ciaddr1;
1108	    ho->ouraddr = ciaddr2;
1109	    break;
1110
1111	case CI_ADDR:
1112	    if (!ao->neg_addr || ho->old_addrs) {
1113		newret = CODE_CONFREJ;
1114		break;
1115	    }
1116
1117	    if (cilen != CILEN_ADDR) {
1118		/*
1119		 * rfc1661, page 40 -- a recongnized option with an
1120		 * invalid length should be Nak'ed.
1121		 */
1122		newret = CODE_CONFNAK;
1123		ciaddr1 = wo->hisaddr;
1124	    } else {
1125
1126		/*
1127		 * If he has no address, or if we both have his
1128		 * address but disagree about it, then NAK it with our
1129		 * idea.  In particular, if we don't know his address,
1130		 * but he does, then accept it.
1131		 */
1132		GETNLONG(ciaddr1, p);
1133		if (ciaddr1 != wo->hisaddr &&
1134		    (ciaddr1 == 0 || !wo->accept_remote)) {
1135		    newret = CODE_CONFNAK;
1136		    ciaddr1 = wo->hisaddr;
1137		} else if (ciaddr1 == 0 && wo->hisaddr == 0 &&
1138		    wo->default_route != 0) {
1139		    newret = CODE_CONFNAK;
1140		    /*
1141		     * If this is a dialup line (default_route is
1142		     * set), and neither side knows about its address,
1143		     * suggest an arbitrary rfc1918 address.
1144		     */
1145		    ciaddr1 = htonl(0xc0a80101 + ifunit);
1146		    dbglog("Peer address unknown; suggesting %I", ciaddr1);
1147		} else if (ciaddr1 == 0 && wo->hisaddr == 0) {
1148		    /*
1149		     * If this is not a dialup line, don't ACK an
1150		     * address of 0.0.0.0 - reject it instead.
1151		     */
1152		    newret = CODE_CONFREJ;
1153		    wo->req_addr = 0;	/* don't NAK with 0.0.0.0 later */
1154		    break;
1155		}
1156	    }
1157
1158	    if (newret == CODE_CONFNAK) {
1159		PUTCHAR(type, nakp);
1160		PUTCHAR(CILEN_ADDR, nakp);
1161		PUTNLONG(ciaddr1, nakp);
1162	    }
1163
1164	    ho->neg_addr = 1;
1165	    ho->hisaddr = ciaddr1;
1166	    break;
1167
1168	case CI_MS_DNS1:
1169	case CI_MS_DNS2:
1170	    /* Warning -- these options work backwards. */
1171	    /* Microsoft primary or secondary DNS request */
1172	    d = (type == CI_MS_DNS2 ? 1 : 0);
1173
1174	    if (ao->dnsaddr[d] == 0) {
1175		newret = CODE_CONFREJ;
1176		break;
1177	    }
1178
1179	    if (cilen != CILEN_ADDR) {
1180		newret = CODE_CONFNAK;
1181	    } else {
1182		GETNLONG(tl, p);
1183		if (tl != ao->dnsaddr[d]) {
1184		    newret = CODE_CONFNAK;
1185		}
1186	    }
1187
1188	    if (newret == CODE_CONFNAK) {
1189		PUTCHAR(type, nakp);
1190		PUTCHAR(CILEN_ADDR, nakp);
1191		PUTNLONG(ao->dnsaddr[d], nakp);
1192	    }
1193            break;
1194
1195	case CI_MS_WINS1:
1196	case CI_MS_WINS2:
1197	    /* Warning -- these options work backwards. */
1198	    /* Microsoft primary or secondary WINS request */
1199	    d = (type == CI_MS_WINS2 ? 1 : 0);
1200
1201	    if (ao->winsaddr[d] == 0) {
1202		newret = CODE_CONFREJ;
1203		break;
1204	    }
1205
1206	    if (cilen != CILEN_ADDR) {
1207		newret = CODE_CONFNAK;
1208	    } else {
1209		GETNLONG(tl, p);
1210		if (tl != ao->winsaddr[d]) {
1211		    newret = CODE_CONFNAK;
1212		}
1213	    }
1214
1215	    if (newret == CODE_CONFNAK) {
1216		PUTCHAR(type, nakp);
1217		PUTCHAR(CILEN_ADDR, nakp);
1218		PUTNLONG(ao->winsaddr[d], nakp);
1219	    }
1220            break;
1221
1222	case CI_COMPRESSTYPE:
1223	    if (!ao->neg_vj) {
1224		newret = CODE_CONFREJ;
1225		break;
1226	    }
1227
1228	    maxslotindex = ao->maxslotindex;
1229	    cflag = ao->cflag;
1230	    if (cilen != CILEN_VJ && cilen != CILEN_COMPRESS) {
1231		newret = CODE_CONFNAK;
1232		cishort = IPCP_VJ_COMP;
1233	    } else {
1234		GETSHORT(cishort, p);
1235		if (cishort != IPCP_VJ_COMP &&
1236		    (cishort != IPCP_VJ_COMP_OLD || cilen != CILEN_COMPRESS)) {
1237		    newret = CODE_CONFNAK;
1238		    cishort = IPCP_VJ_COMP;
1239		} else if (cilen == CILEN_VJ) {
1240		    GETCHAR(maxslotindex, p);
1241		    if (maxslotindex > ao->maxslotindex) {
1242			newret = CODE_CONFNAK;
1243			maxslotindex = ao->maxslotindex;
1244		    }
1245		    GETCHAR(cflag, p);
1246		    if (cflag != 0 && ao->cflag == 0) {
1247			newret = CODE_CONFNAK;
1248			cflag = 0;
1249		    }
1250		} else {
1251		    ho->old_vj = 1;
1252		    maxslotindex = MAX_STATES - 1;
1253		    cflag = 1;
1254		}
1255	    }
1256
1257	    if (newret == CODE_CONFNAK) {
1258		PUTCHAR(type, nakp);
1259		if (cishort == IPCP_VJ_COMP) {
1260		    PUTCHAR(CILEN_VJ, nakp);
1261		    PUTSHORT(cishort, nakp);
1262		    PUTCHAR(maxslotindex, nakp);
1263		    PUTCHAR(cflag, nakp);
1264		} else {
1265		    PUTCHAR(CILEN_COMPRESS, nakp);
1266		    PUTSHORT(cishort, nakp);
1267		}
1268	    }
1269	    ho->neg_vj = 1;
1270	    ho->vj_protocol = cishort;
1271	    ho->maxslotindex = maxslotindex;
1272	    ho->cflag = cflag;
1273	    break;
1274
1275	default:
1276	    newret = CODE_CONFREJ;
1277	    break;
1278	}
1279
1280	/* Cope with confused peers. */
1281	if (cilen < 2)
1282	    cilen = 2;
1283
1284	/*
1285	 * If this is an Ack'able CI, but we're sending back a Nak,
1286	 * don't include this CI.
1287	 */
1288	if (newret == CODE_CONFACK && ret != CODE_CONFACK)
1289	    continue;
1290
1291	if (newret == CODE_CONFNAK) {
1292	    if (dont_nak) {
1293		newret = CODE_CONFREJ;
1294	    } else {
1295		/* Ignore subsequent Nak'able things if rejecting. */
1296		if (ret == CODE_CONFREJ)
1297		    continue;
1298		ret = CODE_CONFNAK;
1299	    }
1300	}
1301
1302	if (newret == CODE_CONFREJ) {
1303	    ret = CODE_CONFREJ;
1304	    if (prev != rejp)
1305		BCOPY(prev, rejp, cilen);
1306	    rejp += cilen;
1307	}
1308    }
1309
1310    /*
1311     * If we aren't rejecting this packet, and we want to negotiate
1312     * their address, and they didn't send their address, then we
1313     * send a NAK with a CI_ADDR option appended.  We assume the
1314     * input buffer is long enough that we can append the extra
1315     * option safely.
1316     */
1317    if (ret != CODE_CONFREJ && !ho->neg_addr && !ho->old_addrs &&
1318	wo->req_addr && !dont_nak) {
1319	if (ret == CODE_CONFACK)
1320	    wo->req_addr = 0;		/* don't ask again */
1321	ret = CODE_CONFNAK;
1322	PUTCHAR(CI_ADDR, nakp);
1323	PUTCHAR(CILEN_ADDR, nakp);
1324	PUTNLONG(wo->hisaddr, nakp);
1325    }
1326
1327    switch (ret) {
1328    case CODE_CONFACK:
1329	*lenp = p - p0;
1330	sys_block_proto(PPP_IP);
1331	break;
1332    case CODE_CONFNAK:
1333	*lenp = nakp - nak_buffer;
1334	BCOPY(nak_buffer, p0, *lenp);
1335	break;
1336    case CODE_CONFREJ:
1337	*lenp = rejp - p0;
1338	break;
1339    }
1340
1341    return (ret);			/* Return final code */
1342}
1343
1344
1345/*
1346 * ip_check_options - check that any IP-related options are OK,
1347 * and assign appropriate defaults.
1348 */
1349static void
1350ip_check_options()
1351{
1352    struct hostent *hp;
1353    u_int32_t local;
1354    ipcp_options *wo = &ipcp_wantoptions[0];
1355
1356    /*
1357     * Default our local IP address based on our hostname.
1358     * If local IP address already given, don't bother.
1359     */
1360    if (wo->ouraddr == 0) {
1361	/*
1362	 * Look up our hostname (possibly with domain name appended)
1363	 * and take the first IP address as our local IP address.
1364	 * If there isn't an IP address for our hostname, too bad.
1365	 */
1366	wo->accept_local = 1;	/* don't insist on this default value */
1367	if ((hp = gethostbyname(hostname)) != NULL) {
1368	    BCOPY(hp->h_addr, &local, sizeof (hp->h_addr));
1369	    if (local != 0 && !bad_ip_adrs(local)) {
1370		wo->ouraddr = local;
1371		ipcp_from_hostname = 1;
1372	    }
1373	}
1374    }
1375}
1376
1377
1378/*
1379 * ip_demand_conf - configure the interface as though
1380 * IPCP were up, for use with dial-on-demand.
1381 */
1382static int
1383ip_demand_conf(u)
1384    int u;
1385{
1386    ipcp_options *wo = &ipcp_wantoptions[u];
1387
1388    if (wo->hisaddr == 0) {
1389	/* make up an arbitrary address for the peer */
1390	wo->hisaddr = htonl(0x0a707070 + ifunit);
1391	wo->accept_remote = 1;
1392    }
1393    if (wo->ouraddr == 0) {
1394	/* make up an arbitrary address for us */
1395	wo->ouraddr = htonl(0x0a404040 + ifunit);
1396	wo->accept_local = 1;
1397	disable_defaultip = 1;	/* don't tell the peer this address */
1398    }
1399    if (!sifaddr(u, wo->ouraddr, wo->hisaddr, GetMask(wo->ouraddr)))
1400	return 0;
1401    if (!sifup(u))
1402	return 0;
1403    if (!sifnpmode(u, PPP_IP, NPMODE_QUEUE))
1404	return 0;
1405    if (wo->default_route && sifdefaultroute(u, wo->ouraddr, wo->hisaddr))
1406	default_route_set[u] = 1;
1407    if (wo->proxy_arp && sifproxyarp(u, wo->hisaddr, proxy_arp_quiet[u]))
1408	proxy_arp_set[u] = 1;
1409
1410    notice("local  IP address %I", wo->ouraddr);
1411    notice("remote IP address %I", wo->hisaddr);
1412
1413    return 1;
1414}
1415
1416
1417/*
1418 * ipcp_up - IPCP has come UP.
1419 *
1420 * Configure the IP network interface appropriately and bring it up.
1421 */
1422static void
1423ipcp_up(f)
1424    fsm *f;
1425{
1426    u_int32_t mask;
1427    ipcp_options *ho = &ipcp_hisoptions[f->unit];
1428    ipcp_options *go = &ipcp_gotoptions[f->unit];
1429    ipcp_options *wo = &ipcp_wantoptions[f->unit];
1430
1431    IPCPDEBUG(("ipcp: up"));
1432
1433    /*
1434     * We must have a non-zero IP address for both ends of the link.
1435     */
1436    if (ho->hisaddr == 0)
1437	ho->hisaddr = wo->hisaddr;
1438
1439    if (ho->hisaddr == 0) {
1440	if (wo->accept_remote) {
1441	    /* Pick some rfc1918 address. */
1442	    ho->hisaddr = htonl(0xc0a80101 + ifunit);
1443	    dbglog("Peer refused to provide his address; assuming %I",
1444		ho->hisaddr);
1445	} else {
1446	    error("Could not determine remote IP address");
1447	    ipcp_close(f->unit, "Could not determine remote IP address");
1448	    return;
1449	}
1450    }
1451    if (go->ouraddr == 0) {
1452	error("Could not determine local IP address");
1453	ipcp_close(f->unit, "Could not determine local IP address");
1454	return;
1455    }
1456    script_setenv("IPLOCAL", ip_ntoa(go->ouraddr), 0);
1457    script_setenv("IPREMOTE", ip_ntoa(ho->hisaddr), 1);
1458
1459    /*
1460     * Check that the peer is allowed to use the IP address it wants.
1461     */
1462    if (!auth_ip_addr(f->unit, ho->hisaddr)) {
1463	error("Peer is not authorized to use remote address %I", ho->hisaddr);
1464	ipcp_close(f->unit, "Unauthorized remote IP address");
1465	return;
1466    }
1467
1468    if ((go->req_dns1 && go->dnsaddr[0] != 0) ||
1469	(go->req_dns2 && go->dnsaddr[1] != 0)) {
1470	script_setenv("USEPEERDNS", "1", 0);
1471	if (go->dnsaddr[0] != 0)
1472	    script_setenv("DNS1", ip_ntoa(go->dnsaddr[0]), 0);
1473	if (go->dnsaddr[1] != 0)
1474	    script_setenv("DNS2", ip_ntoa(go->dnsaddr[1]), 0);
1475	create_resolv(go->dnsaddr[0], go->dnsaddr[1]);
1476    }
1477
1478    /* set tcp compression */
1479    if (sifvjcomp(f->unit, ho->neg_vj, ho->cflag, ho->maxslotindex) != 1) {
1480	ipcp_close(f->unit, "Could not enable VJ TCP header compression");
1481	return;
1482    }
1483
1484    /*
1485     * If we are doing dial-on-demand, the interface is already
1486     * configured, so we put out any saved-up packets, then set the
1487     * interface to pass IP packets.
1488     */
1489    if (demand) {
1490	if (go->ouraddr != wo->ouraddr || ho->hisaddr != wo->hisaddr) {
1491	    ipcp_clear_addrs(f->unit, wo->ouraddr, wo->hisaddr);
1492	    if (go->ouraddr != wo->ouraddr) {
1493		warn("Local IP address changed to %I", go->ouraddr);
1494		script_setenv("OLDIPLOCAL", ip_ntoa(wo->ouraddr), 0);
1495		wo->ouraddr = go->ouraddr;
1496	    } else
1497		script_unsetenv("OLDIPLOCAL");
1498	    if (ho->hisaddr != wo->hisaddr) {
1499		warn("Remote IP address changed to %I", ho->hisaddr);
1500		script_setenv("OLDIPREMOTE", ip_ntoa(wo->hisaddr), 0);
1501		wo->hisaddr = ho->hisaddr;
1502	    } else
1503		script_unsetenv("OLDIPREMOTE");
1504
1505	    /* Set the interface to the new addresses */
1506	    mask = GetMask(go->ouraddr);
1507	    if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
1508		warn("Interface configuration failed");
1509		ipcp_close(f->unit, "Interface configuration failed");
1510		return;
1511	    }
1512
1513	    /* assign a default route through the interface if required */
1514	    if (wo->default_route)
1515		if (sifdefaultroute(f->unit, go->ouraddr, ho->hisaddr))
1516		    default_route_set[f->unit] = 1;
1517
1518	    /* Make a proxy ARP entry if requested. */
1519	    if (wo->proxy_arp &&
1520		sifproxyarp(f->unit, ho->hisaddr, proxy_arp_quiet[f->unit]))
1521		proxy_arp_set[f->unit] = 1;
1522
1523	}
1524	demand_rexmit(PPP_IP);
1525	if (sifnpmode(f->unit, PPP_IP, NPMODE_PASS) != 1) {
1526	    ipcp_close(f->unit, "Interface configuration failed.");
1527	    return;
1528	}
1529
1530    } else {
1531	/*
1532	 * Set IP addresses and (if specified) netmask.
1533	 */
1534	mask = GetMask(go->ouraddr);
1535
1536#if SIFUPFIRST
1537	/* bring the interface up for IP */
1538	if (!sifup(f->unit)) {
1539	    warn("Interface failed to come up");
1540	    ipcp_close(f->unit, "Interface configuration failed");
1541	    return;
1542	}
1543#endif
1544
1545	if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
1546	    warn("Interface configuration failed");
1547	    ipcp_close(f->unit, "Interface configuration failed");
1548	    return;
1549	}
1550
1551#if !SIFUPFIRST
1552	/* bring the interface up for IP */
1553	if (!sifup(f->unit)) {
1554	    warn("Interface failed to come up");
1555	    ipcp_close(f->unit, "Interface configuration failed");
1556	    return;
1557	}
1558#endif
1559
1560	if (sifnpmode(f->unit, PPP_IP, NPMODE_PASS) != 1) {
1561	    ipcp_close(f->unit, "Interface configuration failed.");
1562	    return;
1563	}
1564
1565	/* assign a default route through the interface if required */
1566	if (wo->default_route)
1567	    if (sifdefaultroute(f->unit, go->ouraddr, ho->hisaddr))
1568		default_route_set[f->unit] = 1;
1569
1570	/* Make a proxy ARP entry if requested. */
1571	if (wo->proxy_arp &&
1572	    sifproxyarp(f->unit, ho->hisaddr, proxy_arp_quiet[f->unit]))
1573	    proxy_arp_set[f->unit] = 1;
1574
1575	wo->ouraddr = go->ouraddr;
1576
1577	notice("local  IP address %I", go->ouraddr);
1578	notice("remote IP address %I", ho->hisaddr);
1579	if (go->dnsaddr[0] != 0)
1580	    notice("primary   DNS address %I", go->dnsaddr[0]);
1581	if (go->dnsaddr[1] != 0)
1582	    notice("secondary DNS address %I", go->dnsaddr[1]);
1583    }
1584
1585    np_up(f->unit, PPP_IP);
1586    ipcp_is_up[f->unit] = 1;
1587
1588    if (ip_up_hook != NULL)
1589	(*ip_up_hook)();
1590
1591    /*
1592     * Execute the ip-up script, like this:
1593     *	/etc/ppp/ip-up interface tty speed local-IP remote-IP
1594     */
1595    if (ipcp_script_state == s_down && ipcp_script_pid == 0) {
1596	ipcp_script_state = s_up;
1597	ipcp_script(_PATH_IPUP);
1598    }
1599    sys_unblock_proto(PPP_IP);
1600}
1601
1602
1603/*
1604 * ipcp_down - IPCP has gone DOWN.
1605 *
1606 * Take the IP network interface down, clear its addresses
1607 * and delete routes through it.
1608 */
1609static void
1610ipcp_down(f)
1611    fsm *f;
1612{
1613    IPCPDEBUG(("ipcp: down"));
1614    /* XXX a bit IPv4-centric here, we only need to get the stats
1615     * before the interface is marked down. */
1616    update_link_stats(f->unit);
1617    if (ip_down_hook != NULL)
1618	(*ip_down_hook)();
1619    if (ipcp_is_up[f->unit]) {
1620	ipcp_is_up[f->unit] = 0;
1621	np_down(f->unit, PPP_IP);
1622    }
1623    if (sifvjcomp(f->unit, 0, 0, 0) != 1) {
1624	if (debug)
1625	    warn("Failed to disable VJ TCP header compression.");
1626    }
1627
1628    /*
1629     * If we are doing dial-on-demand, set the interface
1630     * to queue up outgoing packets (for now).
1631     */
1632    if (demand) {
1633	if (sifnpmode(f->unit, PPP_IP, NPMODE_QUEUE) != 1) {
1634	    if (debug)
1635		warn("Failed to enable Queueing on outgoing packets.");
1636	}
1637    } else {
1638	if (sifnpmode(f->unit, PPP_IP, NPMODE_ERROR) != 1) {
1639	    if (debug)
1640		warn("Could not set interface to drop packets.");
1641	}
1642	if (sifdown(f->unit) != 1)
1643	    warn("Could not bring interface down.");
1644	ipcp_clear_addrs(f->unit, ipcp_gotoptions[f->unit].ouraddr,
1645			 ipcp_hisoptions[f->unit].hisaddr);
1646    }
1647
1648    /* Execute the ip-down script */
1649    if (ipcp_script_state == s_up && ipcp_script_pid == 0) {
1650	ipcp_script_state = s_down;
1651	ipcp_script(_PATH_IPDOWN);
1652    }
1653}
1654
1655
1656/*
1657 * ipcp_clear_addrs() - clear the interface addresses, routes,
1658 * proxy arp entries, etc.
1659 */
1660static void
1661ipcp_clear_addrs(unit, ouraddr, hisaddr)
1662    int unit;
1663    u_int32_t ouraddr;  /* local address */
1664    u_int32_t hisaddr;  /* remote address */
1665{
1666    if (proxy_arp_set[unit]) {
1667	(void) cifproxyarp(unit, hisaddr);
1668	proxy_arp_set[unit] = 0;
1669    }
1670    if (default_route_set[unit]) {
1671	(void) cifdefaultroute(unit, ouraddr, hisaddr);
1672	default_route_set[unit] = 0;
1673    }
1674    if (cifaddr(unit, ouraddr, hisaddr) != 1)
1675	warn("Could not clear addresses");
1676}
1677
1678
1679/*
1680 * ipcp_finished - possibly shut down the lower layers.
1681 */
1682static void
1683ipcp_finished(f)
1684    fsm *f;
1685{
1686    np_finished(f->unit, PPP_IP);
1687}
1688
1689
1690/*
1691 * ipcp_script_done - called when the ip-up or ip-down script
1692 * has finished.
1693 */
1694/*ARGSUSED*/
1695static void
1696ipcp_script_done(arg, status)
1697    void *arg;
1698    int status;
1699{
1700    ipcp_script_pid = 0;
1701    switch (ipcp_script_state) {
1702    case s_up:
1703	if (ipcp_fsm[0].state != OPENED) {
1704	    ipcp_script_state = s_down;
1705	    ipcp_script(_PATH_IPDOWN);
1706	}
1707	break;
1708    case s_down:
1709	if (ipcp_fsm[0].state == OPENED) {
1710	    ipcp_script_state = s_up;
1711	    ipcp_script(_PATH_IPUP);
1712	}
1713	break;
1714    }
1715}
1716
1717
1718/*
1719 * ipcp_script - Execute a script with arguments
1720 * interface-name tty-name speed local-IP remote-IP.
1721 */
1722static void
1723ipcp_script(script)
1724    char *script;
1725{
1726    char strspeed[32], strlocal[32], strremote[32];
1727    char *argv[8];
1728
1729    (void) slprintf(strspeed, sizeof(strspeed), "%d", baud_rate);
1730    (void) slprintf(strlocal, sizeof(strlocal), "%I",
1731	ipcp_gotoptions[0].ouraddr);
1732    (void) slprintf(strremote, sizeof(strremote), "%I",
1733	ipcp_hisoptions[0].hisaddr);
1734
1735    argv[0] = script;
1736    argv[1] = ifname;
1737    argv[2] = devnam;
1738    argv[3] = strspeed;
1739    argv[4] = strlocal;
1740    argv[5] = strremote;
1741    argv[6] = ipparam;
1742    argv[7] = NULL;
1743    ipcp_script_pid = run_program(script, argv, 0, ipcp_script_done, NULL);
1744}
1745
1746/*
1747 * create_resolv - create the replacement resolv.conf file
1748 */
1749static void
1750create_resolv(peerdns1, peerdns2)
1751    u_int32_t peerdns1, peerdns2;
1752{
1753    FILE *f;
1754
1755    f = fopen(_PATH_RESOLV, "w");
1756    if (f == NULL) {
1757	error("Failed to create %s: %m", _PATH_RESOLV);
1758	return;
1759    }
1760
1761    if (peerdns1)
1762	if (fprintf(f, "nameserver %s\n", ip_ntoa(peerdns1)) <= 0)
1763	    error("Write failed to %s: %m", _PATH_RESOLV);
1764
1765    if (peerdns2)
1766	if (fprintf(f, "nameserver %s\n", ip_ntoa(peerdns2)) <= 0)
1767	    error("Write failed to %s: %m", _PATH_RESOLV);
1768
1769    if (fclose(f) != 0)
1770	error("Failed to close %s: %m", _PATH_RESOLV);
1771}
1772
1773/*
1774 * ipcp_printpkt - print the contents of an IPCP packet.
1775 */
1776static int
1777ipcp_printpkt(p, plen, printer, arg)
1778    u_char *p;
1779    int plen;
1780    void (*printer) __P((void *, const char *, ...));
1781    void *arg;
1782{
1783    int code, id, len, olen;
1784    u_char *pstart, *optend;
1785    u_short cishort;
1786    u_int32_t cilong;
1787
1788    if (plen < HEADERLEN)
1789	return 0;
1790    pstart = p;
1791    GETCHAR(code, p);
1792    GETCHAR(id, p);
1793    GETSHORT(len, p);
1794    if (len < HEADERLEN || len > plen)
1795	return 0;
1796
1797    printer(arg, " %s id=0x%x", code_name(code, 1), id);
1798    len -= HEADERLEN;
1799    switch (code) {
1800    case CODE_CONFREQ:
1801    case CODE_CONFACK:
1802    case CODE_CONFNAK:
1803    case CODE_CONFREJ:
1804	/* print option list */
1805	while (len >= 2) {
1806	    GETCHAR(code, p);
1807	    GETCHAR(olen, p);
1808	    p -= 2;
1809	    if (olen < 2 || olen > len) {
1810		break;
1811	    }
1812	    printer(arg, " <");
1813	    len -= olen;
1814	    optend = p + olen;
1815	    switch (code) {
1816	    case CI_ADDRS:
1817		if (olen == CILEN_ADDRS) {
1818		    p += 2;
1819		    GETNLONG(cilong, p);
1820		    printer(arg, "addrs %I", cilong);
1821		    GETNLONG(cilong, p);
1822		    printer(arg, " %I", cilong);
1823		}
1824		break;
1825	    case CI_COMPRESSTYPE:
1826		if (olen >= CILEN_COMPRESS) {
1827		    p += 2;
1828		    GETSHORT(cishort, p);
1829		    printer(arg, "compress ");
1830		    switch (cishort) {
1831		    case IPCP_VJ_COMP:
1832			printer(arg, "VJ");
1833			break;
1834		    case IPCP_VJ_COMP_OLD:
1835			printer(arg, "old-VJ");
1836			break;
1837		    default:
1838			printer(arg, "0x%x", cishort);
1839		    }
1840		}
1841		break;
1842	    case CI_ADDR:
1843		if (olen == CILEN_ADDR) {
1844		    p += 2;
1845		    GETNLONG(cilong, p);
1846		    printer(arg, "addr %I", cilong);
1847		}
1848		break;
1849	    case CI_MS_DNS1:
1850	    case CI_MS_DNS2:
1851	        p += 2;
1852		GETNLONG(cilong, p);
1853		printer(arg, "ms-dns%d %I", (code == CI_MS_DNS1 ? 1 : 2),
1854		    cilong);
1855		break;
1856	    case CI_MS_WINS1:
1857	    case CI_MS_WINS2:
1858	        p += 2;
1859		GETNLONG(cilong, p);
1860		printer(arg, "ms-wins%d %I", (code == CI_MS_WINS1 ? 1 : 2),
1861		    cilong);
1862		break;
1863	    case CI_SUBNET:
1864		p += 2;
1865		GETNLONG(cilong, p);
1866		printer(arg, "subnet %I", cilong);
1867		break;
1868	    }
1869	    while (p < optend) {
1870		GETCHAR(code, p);
1871		printer(arg, " %.2x", code);
1872	    }
1873	    printer(arg, ">");
1874	}
1875	break;
1876
1877    case CODE_TERMACK:
1878    case CODE_TERMREQ:
1879	if (len > 0 && *p >= ' ' && *p < 0x7f) {
1880	    printer(arg, " ");
1881	    print_string((char *)p, len, printer, arg);
1882	    p += len;
1883	    len = 0;
1884	}
1885	break;
1886    }
1887
1888    /* print the rest of the bytes in the packet */
1889    for (; len > 0; --len) {
1890	GETCHAR(code, p);
1891	printer(arg, " %.2x", code);
1892    }
1893
1894    return p - pstart;
1895}
1896
1897char *
1898tcp_flag_decode(val)
1899    int val;
1900{
1901    static char buf[32];
1902    char *cp = buf;
1903
1904    if (val & TH_URG)
1905	*cp++ = 'U';
1906    if (val & TH_ACK)
1907	*cp++ = 'A';
1908    if (val & TH_PUSH)
1909	*cp++ = 'P';
1910    if (val & TH_RST)
1911	*cp++ = 'R';
1912    if (val & TH_SYN)
1913	*cp++ = 'S';
1914    if (val & TH_FIN)
1915	*cp++ = 'F';
1916    if (cp != buf)
1917	*cp++ = ' ';
1918    *cp = '\0';
1919    return buf;
1920}
1921
1922/*
1923 * ip_active_pkt - see if this IP packet is worth bringing the link up for.
1924 * We don't bring the link up for IP fragments or for TCP FIN packets
1925 * with no data.
1926 */
1927
1928static int
1929ip_active_pkt(pkt, len)
1930    u_char *pkt;
1931    int len;
1932{
1933    u_char *tcp;
1934    struct protoent *pep;
1935    int val;
1936    int hlen;
1937    char buf[32], *cp;
1938    u_int32_t src, dst;
1939
1940    len -= PPP_HDRLEN;
1941    pkt += PPP_HDRLEN;
1942    if (len < IP_HDRLEN) {
1943	dbglog("IP packet of length %d is not activity", len);
1944	return 0;
1945    }
1946    src = get_ipsrc(pkt);
1947    dst = get_ipdst(pkt);
1948    if ((get_ipoff(pkt) & IP_OFFMASK) != 0) {
1949	dbglog("IP fragment from %I->%I is not activity", src, dst);
1950	return 0;
1951    }
1952    val = get_ipproto(pkt);
1953    if (val != IPPROTO_TCP) {
1954	if (debug) {
1955	    if ((pep = getprotobynumber(val)) != NULL) {
1956		cp = pep->p_name;
1957	    } else {
1958		(void) slprintf(buf, sizeof (buf), "IP proto %d", val);
1959		cp = buf;
1960	    }
1961	    info("%s from %I->%I is activity", cp, src, dst);
1962	}
1963	return 1;
1964    }
1965    hlen = get_iphl(pkt) * 4;
1966    if (len < hlen + TCP_HDRLEN) {
1967	dbglog("Bad TCP length %d<%d+%d %I->%I is not activity", len, hlen,
1968	    TCP_HDRLEN, src, dst);
1969	return 0;
1970    }
1971    tcp = pkt + hlen;
1972    val = get_tcpflags(tcp);
1973    hlen += get_tcpoff(tcp) * 4;
1974    if ((val & TH_FIN) != 0 && len == hlen) {
1975	dbglog("Empty TCP FIN %I->%I is not activity", src, dst);
1976	return 0;
1977    }
1978    info("TCP %d data %s%I->%I is activity", len - hlen,
1979	tcp_flag_decode(get_tcpflags(tcp)), src, dst);
1980    return 1;
1981}
1982
1983static void
1984ipcp_print_stat(unit, strptr)
1985    int unit;
1986    FILE *strptr;
1987{
1988    ipcp_options *go = &ipcp_gotoptions[unit];
1989    ipcp_options *ho = &ipcp_hisoptions[unit];
1990    char *proto_name = ipcp_protent.name;
1991
1992    if (!ipcp_protent.enabled_flag) {
1993	(void) flprintf(strptr, "%s disabled\n", proto_name);
1994	return;
1995    }
1996
1997    (void) flprintf(strptr, "%s state: %s", proto_name,
1998	fsm_state(ipcp_fsm[unit].state));
1999    (void) flprintf(strptr, "%s local %I  remote %I", proto_name, go->ouraddr,
2000	ho->ouraddr);
2001}
2002