1 /*        $NetBSD: ipcp.c,v 1.6 2025/01/08 19:59:39 christos Exp $    */
2 
3 /*
4  * ipcp.c - PPP IP Control Protocol.
5  *
6  * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in
17  *    the documentation and/or other materials provided with the
18  *    distribution.
19  *
20  * 3. The name "Carnegie Mellon University" must not be used to
21  *    endorse or promote products derived from this software without
22  *    prior written permission. For permission or any legal
23  *    details, please contact
24  *      Office of Technology Transfer
25  *      Carnegie Mellon University
26  *      5000 Forbes Avenue
27  *      Pittsburgh, PA  15213-3890
28  *      (412) 268-4387, fax: (412) 268-7395
29  *      tech-transfer@andrew.cmu.edu
30  *
31  * 4. Redistributions of any form whatsoever must retain the following
32  *    acknowledgment:
33  *    "This product includes software developed by Computing Services
34  *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
35  *
36  * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
37  * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
38  * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
39  * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
40  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
41  * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
42  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
43  */
44 
45 #include <sys/cdefs.h>
46 __RCSID("$NetBSD: ipcp.c,v 1.6 2025/01/08 19:59:39 christos Exp $");
47 
48 #ifdef HAVE_CONFIG_H
49 #include "config.h"
50 #endif
51 
52 #include <stdio.h>
53 #include <string.h>
54 #include <stdlib.h>
55 #include <netdb.h>
56 #include <sys/param.h>
57 #include <sys/types.h>
58 #include <sys/socket.h>
59 #include <netinet/in.h>
60 #include <arpa/inet.h>
61 #include <net/if.h>
62 
63 #include "pppd-private.h"
64 #include "options.h"
65 #include "fsm.h"
66 #include "ipcp.h"
67 #include "pathnames.h"
68 
69 
70 /* global vars */
71 ipcp_options ipcp_wantoptions[NUM_PPP]; /* Options that we want to request */
72 ipcp_options ipcp_gotoptions[NUM_PPP];  /* Options that peer ack'd */
73 ipcp_options ipcp_allowoptions[NUM_PPP]; /* Options we allow peer to request */
74 ipcp_options ipcp_hisoptions[NUM_PPP];  /* Options that we ack'd */
75 
76 char      *ipparam = NULL;    /* Extra parameter for ip up/down scripts */
77 u_int32_t netmask = 0;                  /* IP netmask to set on interface */
78 
79 bool      disable_defaultip = 0;        /* Don't use hostname for default IP adrs */
80 bool      noremoteip = 0;               /* Let him have no IP address */
81 
82 ip_up_hook_fn *ip_up_hook = NULL;
83 ip_down_hook_fn *ip_down_hook = NULL;
84 ip_choose_hook_fn *ip_choose_hook = NULL;
85 
86 
87 /* Notifiers for when IPCP goes up and down */
88 struct notifier *ip_up_notifier = NULL;
89 struct notifier *ip_down_notifier = NULL;
90 
91 /* local vars */
92 static int default_route_set[NUM_PPP];  /* Have set up a default route */
93 static int proxy_arp_set[NUM_PPP];      /* Have created proxy arp entry */
94 static bool usepeerdns;                           /* Ask peer for DNS addrs */
95 static bool usepeerwins;                /* Ask peer for WINS addrs */
96 static bool noresolvconf;               /* Do not create resolv.conf */
97 static int ipcp_is_up;                            /* have called np_up() */
98 static int ipcp_is_open;                /* haven't called np_finished() */
99 static bool ask_for_local;              /* request our address from peer */
100 static char vj_value[8];                /* string form of vj option value */
101 static char netmask_str[20];            /* string form of netmask value */
102 
103 /*
104  * Callbacks for fsm code.  (CI = Configuration Information)
105  */
106 static void ipcp_resetci (fsm *);       /* Reset our CI */
107 static int  ipcp_cilen (fsm *);                 /* Return length of our CI */
108 static void ipcp_addci (fsm *, u_char *, int *); /* Add our CI */
109 static int  ipcp_ackci (fsm *, u_char *, int);    /* Peer ack'd our CI */
110 static int  ipcp_nakci (fsm *, u_char *, int, int);/* Peer nak'd our CI */
111 static int  ipcp_rejci (fsm *, u_char *, int);    /* Peer rej'd our CI */
112 static int  ipcp_reqci (fsm *, u_char *, int *, int); /* Rcv CI */
113 static void ipcp_up (fsm *);            /* We're UP */
114 static void ipcp_down (fsm *);                    /* We're DOWN */
115 static void ipcp_finished (fsm *);      /* Don't need lower layer */
116 
117 fsm ipcp_fsm[NUM_PPP];                  /* IPCP fsm structure */
118 
119 static fsm_callbacks ipcp_callbacks = { /* IPCP callback routines */
120     ipcp_resetci,             /* Reset our Configuration Information */
121     ipcp_cilen,                         /* Length of our Configuration Information */
122     ipcp_addci,                         /* Add our Configuration Information */
123     ipcp_ackci,                         /* ACK our Configuration Information */
124     ipcp_nakci,                         /* NAK our Configuration Information */
125     ipcp_rejci,                         /* Reject our Configuration Information */
126     ipcp_reqci,                         /* Request peer's Configuration Information */
127     ipcp_up,                            /* Called when fsm reaches OPENED state */
128     ipcp_down,                          /* Called when fsm leaves OPENED state */
129     NULL,                     /* Called when we want the lower layer up */
130     ipcp_finished,            /* Called when we want the lower layer down */
131     NULL,                     /* Called when Protocol-Reject received */
132     NULL,                     /* Retransmission is necessary */
133     NULL,                     /* Called to handle protocol-specific codes */
134     "IPCP"                              /* String name of protocol */
135 };
136 
137 /*
138  * Command-line options.
139  */
140 static int setvjslots (char **);
141 static int setdnsaddr (char **);
142 static int setwinsaddr (char **);
143 static int setnetmask (char **);
144 int setipaddr (char *, char **, int);
145 static void printipaddr (struct option *, void (*)(void *, char *,...),void *);
146 
147 static struct option ipcp_option_list[] = {
148     { "noip", o_bool, &ipcp_protent.enabled_flag,
149       "Disable IP and IPCP" },
150     { "-ip", o_bool, &ipcp_protent.enabled_flag,
151       "Disable IP and IPCP", OPT_ALIAS },
152 
153     { "novj", o_bool, &ipcp_wantoptions[0].neg_vj,
154       "Disable VJ compression", OPT_A2CLR, &ipcp_allowoptions[0].neg_vj },
155     { "-vj", o_bool, &ipcp_wantoptions[0].neg_vj,
156       "Disable VJ compression", OPT_ALIAS | OPT_A2CLR,
157       &ipcp_allowoptions[0].neg_vj },
158 
159     { "novjccomp", o_bool, &ipcp_wantoptions[0].cflag,
160       "Disable VJ connection-ID compression", OPT_A2CLR,
161       &ipcp_allowoptions[0].cflag },
162     { "-vjccomp", o_bool, &ipcp_wantoptions[0].cflag,
163       "Disable VJ connection-ID compression", OPT_ALIAS | OPT_A2CLR,
164       &ipcp_allowoptions[0].cflag },
165 
166     { "vj-max-slots", o_special, (void *)setvjslots,
167       "Set maximum VJ header slots",
168       OPT_PRIO | OPT_A2STRVAL | OPT_STATIC, vj_value },
169 
170     { "ipcp-accept-local", o_bool, &ipcp_wantoptions[0].accept_local,
171       "Accept peer's address for us", 1 },
172     { "ipcp-accept-remote", o_bool, &ipcp_wantoptions[0].accept_remote,
173       "Accept peer's address for it", 1 },
174 
175     { "ipparam", o_string, &ipparam,
176       "Set ip script parameter", OPT_PRIO },
177 
178     { "noipdefault", o_bool, &disable_defaultip,
179       "Don't use name for default IP adrs", 1 },
180 
181     { "ms-dns", o_special, (void *)setdnsaddr,
182       "DNS address for the peer's use", OPT_A2LIST },
183     { "ms-wins", o_special, (void *)setwinsaddr,
184       "Nameserver for SMB over TCP/IP for peer", OPT_A2LIST },
185 
186     { "ipcp-restart", o_int, &ipcp_fsm[0].timeouttime,
187       "Set timeout for IPCP", OPT_PRIO },
188     { "ipcp-max-terminate", o_int, &ipcp_fsm[0].maxtermtransmits,
189       "Set max #xmits for term-reqs", OPT_PRIO },
190     { "ipcp-max-configure", o_int, &ipcp_fsm[0].maxconfreqtransmits,
191       "Set max #xmits for conf-reqs", OPT_PRIO },
192     { "ipcp-max-failure", o_int, &ipcp_fsm[0].maxnakloops,
193       "Set max #conf-naks for IPCP", OPT_PRIO },
194 
195     { "defaultroute", o_bool, &ipcp_wantoptions[0].default_route,
196       "Add default route", OPT_ENABLE|1, &ipcp_allowoptions[0].default_route },
197     { "nodefaultroute", o_bool, &ipcp_allowoptions[0].default_route,
198       "disable defaultroute option", OPT_A2CLR,
199       &ipcp_wantoptions[0].default_route },
200     { "-defaultroute", o_bool, &ipcp_allowoptions[0].default_route,
201       "disable defaultroute option", OPT_ALIAS | OPT_A2CLR,
202       &ipcp_wantoptions[0].default_route },
203 
204 #ifdef __linux__
205     { "replacedefaultroute", o_bool,
206                                         &ipcp_wantoptions[0].replace_default_route,
207       "Replace default route", OPT_PRIV | 1
208     },
209     { "noreplacedefaultroute", o_bool,
210                                         &ipcp_wantoptions[0].replace_default_route,
211       "Do not replace default route", 0 },
212 #endif
213     { "proxyarp", o_bool, &ipcp_wantoptions[0].proxy_arp,
214       "Add proxy ARP entry", OPT_ENABLE|1, &ipcp_allowoptions[0].proxy_arp },
215     { "noproxyarp", o_bool, &ipcp_allowoptions[0].proxy_arp,
216       "disable proxyarp option", OPT_A2CLR,
217       &ipcp_wantoptions[0].proxy_arp },
218     { "-proxyarp", o_bool, &ipcp_allowoptions[0].proxy_arp,
219       "disable proxyarp option", OPT_ALIAS | OPT_A2CLR,
220       &ipcp_wantoptions[0].proxy_arp },
221 
222     { "usepeerdns", o_bool, &usepeerdns,
223       "Ask peer for DNS address(es)", 1 },
224 
225     { "usepeerwins", o_bool, &usepeerwins,
226       "Ask peer for WINS address(es)", 1 },
227 
228     { "noresolvconf", o_bool, &noresolvconf,
229       "Do not create resolv.conf", 1 },
230 
231     { "netmask", o_special, (void *)setnetmask,
232       "set netmask", OPT_PRIO | OPT_A2STRVAL | OPT_STATIC, netmask_str },
233 
234     { "ipcp-no-addresses", o_bool, &ipcp_wantoptions[0].old_addrs,
235       "Disable old-style IP-Addresses usage", OPT_A2CLR,
236       &ipcp_allowoptions[0].old_addrs },
237     { "ipcp-no-address", o_bool, &ipcp_wantoptions[0].neg_addr,
238       "Disable IP-Address usage", OPT_A2CLR,
239       &ipcp_allowoptions[0].neg_addr },
240 #ifdef __linux__
241     { "noremoteip", o_bool, &noremoteip,
242       "Allow peer to have no IP address", 1 },
243 #endif
244     { "nosendip", o_bool, &ipcp_wantoptions[0].neg_addr,
245       "Don't send our IP address to peer", OPT_A2CLR,
246       &ipcp_wantoptions[0].old_addrs},
247 
248     { "IP addresses", o_wild, (void *) &setipaddr,
249       "set local and remote IP addresses",
250       OPT_NOARG | OPT_A2PRINTER, (void *) &printipaddr },
251 
252     { NULL }
253 };
254 
255 /*
256  * Protocol entry points from main code.
257  */
258 static void ipcp_init (int);
259 static void ipcp_open (int);
260 static void ipcp_close (int, char *);
261 static void ipcp_lowerup (int);
262 static void ipcp_lowerdown (int);
263 static void ipcp_input (int, u_char *, int);
264 static void ipcp_protrej (int);
265 static int  ipcp_printpkt (u_char *, int,
266                                  void (*) (void *, char *, ...), void *);
267 static void ip_check_options (void);
268 static int  ip_demand_conf (int);
269 static int  ip_active_pkt (u_char *, int);
270 static void create_resolv (u_int32_t, u_int32_t);
271 
272 struct protent ipcp_protent = {
273     PPP_IPCP,
274     ipcp_init,
275     ipcp_input,
276     ipcp_protrej,
277     ipcp_lowerup,
278     ipcp_lowerdown,
279     ipcp_open,
280     ipcp_close,
281     ipcp_printpkt,
282     NULL,
283     1,
284     "IPCP",
285     "IP",
286     ipcp_option_list,
287     ip_check_options,
288     ip_demand_conf,
289     ip_active_pkt
290 };
291 
292 static void ipcp_clear_addrs (int, u_int32_t, u_int32_t, bool);
293 static void ipcp_script (char *, int);  /* Run an up/down script */
294 static void ipcp_script_done (void *);
295 
296 /*
297  * Lengths of configuration options.
298  */
299 #define CILEN_VOID  2
300 #define CILEN_COMPRESS        4         /* min length for compression protocol opt. */
301 #define CILEN_VJ    6         /* length for RFC1332 Van-Jacobson opt. */
302 #define CILEN_ADDR  6         /* new-style single address option */
303 #define CILEN_ADDRS 10        /* old-style dual address option */
304 
305 
306 #define CODENAME(x) ((x) == CONFACK ? "ACK" : \
307                                (x) == CONFNAK ? "NAK" : "REJ")
308 
309 /*
310  * This state variable is used to ensure that we don't
311  * run an ipcp-up/down script while one is already running.
312  */
313 static enum script_state {
314     s_down,
315     s_up,
316 } ipcp_script_state;
317 static pid_t ipcp_script_pid;
318 
319 /*
320  * Make a string representation of a network IP address.
321  */
322 char *
ip_ntoa(u_int32_t ipaddr)323 ip_ntoa(u_int32_t ipaddr)
324 {
325     static char b[64];
326 
327     slprintf(b, sizeof(b), "%I", ipaddr);
328     return b;
329 }
330 
331 /*
332  * Option parsing.
333  */
334 
335 /*
336  * setvjslots - set maximum number of connection slots for VJ compression
337  */
338 static int
setvjslots(char ** argv)339 setvjslots(char **argv)
340 {
341     int value;
342 
343     if (!ppp_int_option(*argv, &value))
344           return 0;
345     if (value < 2 || value > 16) {
346           ppp_option_error("vj-max-slots value must be between 2 and 16");
347           return 0;
348     }
349     ipcp_wantoptions [0].maxslotindex =
350         ipcp_allowoptions[0].maxslotindex = value - 1;
351     slprintf(vj_value, sizeof(vj_value), "%d", value);
352     return 1;
353 }
354 
355 /*
356  * setdnsaddr - set the dns address(es)
357  */
358 static int
setdnsaddr(char ** argv)359 setdnsaddr(char **argv)
360 {
361     u_int32_t dns;
362     struct hostent *hp;
363 
364     dns = inet_addr(*argv);
365     if (dns == (u_int32_t) -1) {
366           if ((hp = gethostbyname(*argv)) == NULL) {
367               ppp_option_error("invalid address parameter '%s' for ms-dns option",
368                                *argv);
369               return 0;
370           }
371           dns = *(u_int32_t *)hp->h_addr;
372     }
373 
374     /* We take the last 2 values given, the 2nd-last as the primary
375        and the last as the secondary.  If only one is given it
376        becomes both primary and secondary. */
377     if (ipcp_allowoptions[0].dnsaddr[1] == 0)
378           ipcp_allowoptions[0].dnsaddr[0] = dns;
379     else
380           ipcp_allowoptions[0].dnsaddr[0] = ipcp_allowoptions[0].dnsaddr[1];
381 
382     /* always set the secondary address value. */
383     ipcp_allowoptions[0].dnsaddr[1] = dns;
384 
385     return (1);
386 }
387 
388 /*
389  * setwinsaddr - set the wins address(es)
390  * This is primrarly used with the Samba package under UNIX or for pointing
391  * the caller to the existing WINS server on a Windows NT platform.
392  */
393 static int
setwinsaddr(char ** argv)394 setwinsaddr(char **argv)
395 {
396     u_int32_t wins;
397     struct hostent *hp;
398 
399     wins = inet_addr(*argv);
400     if (wins == (u_int32_t) -1) {
401           if ((hp = gethostbyname(*argv)) == NULL) {
402               ppp_option_error("invalid address parameter '%s' for ms-wins option",
403                                *argv);
404               return 0;
405           }
406           wins = *(u_int32_t *)hp->h_addr;
407     }
408 
409     /* We take the last 2 values given, the 2nd-last as the primary
410        and the last as the secondary.  If only one is given it
411        becomes both primary and secondary. */
412     if (ipcp_allowoptions[0].winsaddr[1] == 0)
413           ipcp_allowoptions[0].winsaddr[0] = wins;
414     else
415           ipcp_allowoptions[0].winsaddr[0] = ipcp_allowoptions[0].winsaddr[1];
416 
417     /* always set the secondary address value. */
418     ipcp_allowoptions[0].winsaddr[1] = wins;
419 
420     return (1);
421 }
422 
423 /*
424  * setipaddr - Set the IP address
425  * If doit is 0, the call is to check whether this option is
426  * potentially an IP address specification.
427  * Not static so that plugins can call it to set the addresses
428  */
429 int
setipaddr(char * arg,char ** argv,int doit)430 setipaddr(char *arg, char **argv, int doit)
431 {
432     struct hostent *hp;
433     char *colon;
434     u_int32_t local, remote;
435     ipcp_options *wo = &ipcp_wantoptions[0];
436     static int prio_local = 0, prio_remote = 0;
437 
438     /*
439      * IP address pair separated by ":".
440      */
441     if ((colon = strchr(arg, ':')) == NULL)
442           return 0;
443     if (!doit)
444           return 1;
445 
446     /*
447      * If colon first character, then no local addr.
448      */
449     if (colon != arg && option_priority >= prio_local) {
450           *colon = '\0';
451           if ((local = inet_addr(arg)) == (u_int32_t) -1) {
452               if ((hp = gethostbyname(arg)) == NULL) {
453                     ppp_option_error("unknown host: %s", arg);
454                     return 0;
455               }
456               local = *(u_int32_t *)hp->h_addr;
457           }
458           if (ppp_bad_ip_addr(local)) {
459               ppp_option_error("bad local IP address %s", ip_ntoa(local));
460               return 0;
461           }
462           if (local != 0)
463               wo->ouraddr = local;
464           *colon = ':';
465           prio_local = option_priority;
466     }
467 
468     /*
469      * If colon last character, then no remote addr.
470      */
471     if (*++colon != '\0' && option_priority >= prio_remote) {
472           if ((remote = inet_addr(colon)) == (u_int32_t) -1) {
473               if ((hp = gethostbyname(colon)) == NULL) {
474                     ppp_option_error("unknown host: %s", colon);
475                     return 0;
476               }
477               remote = *(u_int32_t *)hp->h_addr;
478               if (remote_name[0] == 0)
479                     strlcpy(remote_name, colon, sizeof(remote_name));
480           }
481           if (ppp_bad_ip_addr(remote)) {
482               ppp_option_error("bad remote IP address %s", ip_ntoa(remote));
483               return 0;
484           }
485           if (remote != 0)
486               wo->hisaddr = remote;
487           prio_remote = option_priority;
488     }
489 
490     return 1;
491 }
492 
493 static void
printipaddr(struct option * opt,void (* printer)(void *,char *,...),void * arg)494 printipaddr(struct option *opt, void (*printer) (void *, char *, ...), void *arg)
495 {
496           ipcp_options *wo = &ipcp_wantoptions[0];
497 
498           if (wo->ouraddr != 0)
499                     printer(arg, "%I", wo->ouraddr);
500           printer(arg, ":");
501           if (wo->hisaddr != 0)
502                     printer(arg, "%I", wo->hisaddr);
503 }
504 
505 /*
506  * setnetmask - set the netmask to be used on the interface.
507  */
508 static int
setnetmask(char ** argv)509 setnetmask(char **argv)
510 {
511     u_int32_t mask;
512     int n;
513     char *p;
514 
515     /*
516      * Unfortunately, if we use inet_addr, we can't tell whether
517      * a result of all 1s is an error or a valid 255.255.255.255.
518      */
519     p = *argv;
520     n = parse_dotted_ip(p, &mask);
521 
522     mask = htonl(mask);
523 
524     if (n == 0 || p[n] != 0 || (netmask & ~mask) != 0) {
525           ppp_option_error("invalid netmask value '%s'", *argv);
526           return 0;
527     }
528 
529     netmask = mask;
530     slprintf(netmask_str, sizeof(netmask_str), "%I", mask);
531 
532     return (1);
533 }
534 
535 int
parse_dotted_ip(char * p,u_int32_t * vp)536 parse_dotted_ip(char *p, u_int32_t *vp)
537 {
538     int n;
539     u_int32_t v, b;
540     char *endp, *p0 = p;
541 
542     v = 0;
543     for (n = 3;; --n) {
544           b = strtoul(p, &endp, 0);
545           if (endp == p)
546               return 0;
547           if (b > 255) {
548               if (n < 3)
549                     return 0;
550               /* accept e.g. 0xffffff00 */
551               *vp = b;
552               return endp - p0;
553           }
554           v |= b << (n * 8);
555           p = endp;
556           if (n == 0)
557               break;
558           if (*p != '.')
559               return 0;
560           ++p;
561     }
562     *vp = v;
563     return p - p0;
564 }
565 
ppp_ipparam()566 const char *ppp_ipparam()
567 {
568     return ipparam;
569 }
570 
571 
572 /*
573  * ipcp_init - Initialize IPCP.
574  */
575 static void
ipcp_init(int unit)576 ipcp_init(int unit)
577 {
578     fsm *f = &ipcp_fsm[unit];
579     ipcp_options *wo = &ipcp_wantoptions[unit];
580     ipcp_options *ao = &ipcp_allowoptions[unit];
581 
582     f->unit = unit;
583     f->protocol = PPP_IPCP;
584     f->callbacks = &ipcp_callbacks;
585     fsm_init(&ipcp_fsm[unit]);
586 
587     /*
588      * Some 3G modems use repeated IPCP NAKs as a way of stalling
589      * until they can contact a server on the network, so we increase
590      * the default number of NAKs we accept before we start treating
591      * them as rejects.
592      */
593     f->maxnakloops = 100;
594 
595     memset(wo, 0, sizeof(*wo));
596     memset(ao, 0, sizeof(*ao));
597 
598     wo->neg_addr = wo->old_addrs = 1;
599     wo->neg_vj = 1;
600     wo->vj_protocol = IPCP_VJ_COMP;
601     wo->maxslotindex = MAX_STATES - 1; /* really max index */
602     wo->cflag = 1;
603 
604 
605     /* max slots and slot-id compression are currently hardwired in */
606     /* ppp_if.c to 16 and 1, this needs to be changed (among other */
607     /* things) gmc */
608 
609     ao->neg_addr = ao->old_addrs = 1;
610     ao->neg_vj = 1;
611     ao->maxslotindex = MAX_STATES - 1;
612     ao->cflag = 1;
613 
614     /*
615      * XXX These control whether the user may use the proxyarp
616      * and defaultroute options.
617      */
618     ao->proxy_arp = 1;
619     ao->default_route = 1;
620 }
621 
622 
623 /*
624  * ipcp_open - IPCP is allowed to come up.
625  */
626 static void
ipcp_open(int unit)627 ipcp_open(int unit)
628 {
629     fsm_open(&ipcp_fsm[unit]);
630     ipcp_is_open = 1;
631 }
632 
633 
634 /*
635  * ipcp_close - Take IPCP down.
636  */
637 static void
ipcp_close(int unit,char * reason)638 ipcp_close(int unit, char *reason)
639 {
640     fsm_close(&ipcp_fsm[unit], reason);
641 }
642 
643 
644 /*
645  * ipcp_lowerup - The lower layer is up.
646  */
647 static void
ipcp_lowerup(int unit)648 ipcp_lowerup(int unit)
649 {
650     fsm_lowerup(&ipcp_fsm[unit]);
651 }
652 
653 
654 /*
655  * ipcp_lowerdown - The lower layer is down.
656  */
657 static void
ipcp_lowerdown(int unit)658 ipcp_lowerdown(int unit)
659 {
660     fsm_lowerdown(&ipcp_fsm[unit]);
661 }
662 
663 
664 /*
665  * ipcp_input - Input IPCP packet.
666  */
667 static void
ipcp_input(int unit,u_char * p,int len)668 ipcp_input(int unit, u_char *p, int len)
669 {
670     fsm_input(&ipcp_fsm[unit], p, len);
671 }
672 
673 
674 /*
675  * ipcp_protrej - A Protocol-Reject was received for IPCP.
676  *
677  * Pretend the lower layer went down, so we shut up.
678  */
679 static void
ipcp_protrej(int unit)680 ipcp_protrej(int unit)
681 {
682     fsm_lowerdown(&ipcp_fsm[unit]);
683 }
684 
685 
686 /*
687  * ipcp_resetci - Reset our CI.
688  * Called by fsm_sconfreq, Send Configure Request.
689  */
690 static void
ipcp_resetci(fsm * f)691 ipcp_resetci(fsm *f)
692 {
693     ipcp_options *wo = &ipcp_wantoptions[f->unit];
694     ipcp_options *go = &ipcp_gotoptions[f->unit];
695     ipcp_options *ao = &ipcp_allowoptions[f->unit];
696 
697     wo->req_addr = ((wo->neg_addr || wo->old_addrs) &&
698           (ao->neg_addr || ao->old_addrs)) ||
699           (wo->hisaddr && !wo->accept_remote);
700     if (wo->ouraddr == 0)
701           wo->accept_local = 1;
702     if (wo->hisaddr == 0)
703           wo->accept_remote = 1;
704     wo->req_dns1 = usepeerdns;          /* Request DNS addresses from the peer */
705     wo->req_dns2 = usepeerdns;
706     wo->req_wins1 = usepeerwins; /* Request WINS addresses from the peer */
707     wo->req_wins2 = usepeerwins;
708     *go = *wo;
709     if (!ask_for_local)
710           go->ouraddr = 0;
711     if (ip_choose_hook) {
712           ip_choose_hook(&wo->hisaddr);
713           if (wo->hisaddr) {
714               wo->accept_remote = 0;
715           }
716     }
717     BZERO(&ipcp_hisoptions[f->unit], sizeof(ipcp_options));
718 }
719 
720 
721 /*
722  * ipcp_cilen - Return length of our CI.
723  * Called by fsm_sconfreq, Send Configure Request.
724  */
725 static int
ipcp_cilen(fsm * f)726 ipcp_cilen(fsm *f)
727 {
728     ipcp_options *go = &ipcp_gotoptions[f->unit];
729     ipcp_options *wo = &ipcp_wantoptions[f->unit];
730     ipcp_options *ho = &ipcp_hisoptions[f->unit];
731 
732 #define LENCIADDRS(neg)                 (neg ? CILEN_ADDRS : 0)
733 #define LENCIVJ(neg, old)     (neg ? (old? CILEN_COMPRESS : CILEN_VJ) : 0)
734 #define LENCIADDR(neg)                  (neg ? CILEN_ADDR : 0)
735 #define LENCIDNS(neg)                   LENCIADDR(neg)
736 #define LENCIWINS(neg)                  LENCIADDR(neg)
737 
738     /*
739      * First see if we want to change our options to the old
740      * forms because we have received old forms from the peer.
741      */
742     if (go->neg_addr && go->old_addrs && !ho->neg_addr && ho->old_addrs)
743           go->neg_addr = 0;
744     if (wo->neg_vj && !go->neg_vj && !go->old_vj) {
745           /* try an older style of VJ negotiation */
746           /* use the old style only if the peer did */
747           if (ho->neg_vj && ho->old_vj) {
748               go->neg_vj = 1;
749               go->old_vj = 1;
750               go->vj_protocol = ho->vj_protocol;
751           }
752     }
753 
754     return (LENCIADDRS(!go->neg_addr && go->old_addrs) +
755               LENCIVJ(go->neg_vj, go->old_vj) +
756               LENCIADDR(go->neg_addr) +
757               LENCIDNS(go->req_dns1) +
758               LENCIDNS(go->req_dns2) +
759               LENCIWINS(go->req_wins1) +
760               LENCIWINS(go->req_wins2)) ;
761 }
762 
763 
764 /*
765  * ipcp_addci - Add our desired CIs to a packet.
766  * Called by fsm_sconfreq, Send Configure Request.
767  */
768 static void
ipcp_addci(fsm * f,u_char * ucp,int * lenp)769 ipcp_addci(fsm *f, u_char *ucp, int *lenp)
770 {
771     ipcp_options *go = &ipcp_gotoptions[f->unit];
772     int len = *lenp;
773 
774 #define ADDCIADDRS(opt, neg, val1, val2) \
775     if (neg) { \
776           if (len >= CILEN_ADDRS) { \
777               u_int32_t l; \
778               PUTCHAR(opt, ucp); \
779               PUTCHAR(CILEN_ADDRS, ucp); \
780               l = ntohl(val1); \
781               PUTLONG(l, ucp); \
782               l = ntohl(val2); \
783               PUTLONG(l, ucp); \
784               len -= CILEN_ADDRS; \
785           } else \
786               go->old_addrs = 0; \
787     }
788 
789 #define ADDCIVJ(opt, neg, val, old, maxslotindex, cflag) \
790     if (neg) { \
791           int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
792           if (len >= vjlen) { \
793               PUTCHAR(opt, ucp); \
794               PUTCHAR(vjlen, ucp); \
795               PUTSHORT(val, ucp); \
796               if (!old) { \
797                     PUTCHAR(maxslotindex, ucp); \
798                     PUTCHAR(cflag, ucp); \
799               } \
800               len -= vjlen; \
801           } else \
802               neg = 0; \
803     }
804 
805 #define ADDCIADDR(opt, neg, val) \
806     if (neg) { \
807           if (len >= CILEN_ADDR) { \
808               u_int32_t l; \
809               PUTCHAR(opt, ucp); \
810               PUTCHAR(CILEN_ADDR, ucp); \
811               l = ntohl(val); \
812               PUTLONG(l, ucp); \
813               len -= CILEN_ADDR; \
814           } else \
815               neg = 0; \
816     }
817 
818 #define ADDCIDNS(opt, neg, addr) \
819     if (neg) { \
820           if (len >= CILEN_ADDR) { \
821               u_int32_t l; \
822               PUTCHAR(opt, ucp); \
823               PUTCHAR(CILEN_ADDR, ucp); \
824               l = ntohl(addr); \
825               PUTLONG(l, ucp); \
826               len -= CILEN_ADDR; \
827           } else \
828               neg = 0; \
829     }
830 
831 #define ADDCIWINS(opt, neg, addr) \
832     if (neg) { \
833           if (len >= CILEN_ADDR) { \
834               u_int32_t l; \
835               PUTCHAR(opt, ucp); \
836               PUTCHAR(CILEN_ADDR, ucp); \
837               l = ntohl(addr); \
838               PUTLONG(l, ucp); \
839               len -= CILEN_ADDR; \
840           } else \
841               neg = 0; \
842     }
843 
844     ADDCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs, go->ouraddr,
845                  go->hisaddr);
846 
847     ADDCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
848               go->maxslotindex, go->cflag);
849 
850     ADDCIADDR(CI_ADDR, go->neg_addr, go->ouraddr);
851 
852     ADDCIDNS(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]);
853 
854     ADDCIDNS(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
855 
856     ADDCIWINS(CI_MS_WINS1, go->req_wins1, go->winsaddr[0]);
857 
858     ADDCIWINS(CI_MS_WINS2, go->req_wins2, go->winsaddr[1]);
859 
860     *lenp -= len;
861 }
862 
863 
864 /*
865  * ipcp_ackci - Ack our CIs.
866  * Called by fsm_rconfack, Receive Configure ACK.
867  *
868  * Returns:
869  *        0 - Ack was bad.
870  *        1 - Ack was good.
871  */
872 static int
ipcp_ackci(fsm * f,u_char * p,int len)873 ipcp_ackci(fsm *f, u_char *p, int len)
874 {
875     ipcp_options *go = &ipcp_gotoptions[f->unit];
876     u_short cilen, citype, cishort;
877     u_int32_t cilong;
878     u_char cimaxslotindex, cicflag;
879 
880     /*
881      * CIs must be in exactly the same order that we sent...
882      * Check packet length and CI length at each step.
883      * If we find any deviations, then this packet is bad.
884      */
885 
886 #define ACKCIADDRS(opt, neg, val1, val2) \
887     if (neg) { \
888           u_int32_t l; \
889           if ((len -= CILEN_ADDRS) < 0) \
890               goto bad; \
891           GETCHAR(citype, p); \
892           GETCHAR(cilen, p); \
893           if (cilen != CILEN_ADDRS || \
894               citype != opt) \
895               goto bad; \
896           GETLONG(l, p); \
897           cilong = htonl(l); \
898           if (val1 != cilong) \
899               goto bad; \
900           GETLONG(l, p); \
901           cilong = htonl(l); \
902           if (val2 != cilong) \
903               goto bad; \
904     }
905 
906 #define ACKCIVJ(opt, neg, val, old, maxslotindex, cflag) \
907     if (neg) { \
908           int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
909           if ((len -= vjlen) < 0) \
910               goto bad; \
911           GETCHAR(citype, p); \
912           GETCHAR(cilen, p); \
913           if (cilen != vjlen || \
914               citype != opt)  \
915               goto bad; \
916           GETSHORT(cishort, p); \
917           if (cishort != val) \
918               goto bad; \
919           if (!old) { \
920               GETCHAR(cimaxslotindex, p); \
921               if (cimaxslotindex != maxslotindex) \
922                     goto bad; \
923               GETCHAR(cicflag, p); \
924               if (cicflag != cflag) \
925                     goto bad; \
926           } \
927     }
928 
929 #define ACKCIADDR(opt, neg, val) \
930     if (neg) { \
931           u_int32_t l; \
932           if ((len -= CILEN_ADDR) < 0) \
933               goto bad; \
934           GETCHAR(citype, p); \
935           GETCHAR(cilen, p); \
936           if (cilen != CILEN_ADDR || \
937               citype != opt) \
938               goto bad; \
939           GETLONG(l, p); \
940           cilong = htonl(l); \
941           if (val != cilong) \
942               goto bad; \
943     }
944 
945 #define ACKCIDNS(opt, neg, addr) \
946     if (neg) { \
947           u_int32_t l; \
948           if ((len -= CILEN_ADDR) < 0) \
949               goto bad; \
950           GETCHAR(citype, p); \
951           GETCHAR(cilen, p); \
952           if (cilen != CILEN_ADDR || citype != opt) \
953               goto bad; \
954           GETLONG(l, p); \
955           cilong = htonl(l); \
956           if (addr != cilong) \
957               goto bad; \
958     }
959 
960 #define ACKCIWINS(opt, neg, addr) \
961     if (neg) { \
962           u_int32_t l; \
963           if ((len -= CILEN_ADDR) < 0) \
964               goto bad; \
965           GETCHAR(citype, p); \
966           GETCHAR(cilen, p); \
967           if (cilen != CILEN_ADDR || citype != opt) \
968               goto bad; \
969           GETLONG(l, p); \
970           cilong = htonl(l); \
971           if (addr != cilong) \
972               goto bad; \
973     }
974 
975     ACKCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs, go->ouraddr,
976                  go->hisaddr);
977 
978     ACKCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
979               go->maxslotindex, go->cflag);
980 
981     ACKCIADDR(CI_ADDR, go->neg_addr, go->ouraddr);
982 
983     ACKCIDNS(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]);
984 
985     ACKCIDNS(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
986 
987     ACKCIWINS(CI_MS_WINS1, go->req_wins1, go->winsaddr[0]);
988 
989     ACKCIWINS(CI_MS_WINS2, go->req_wins2, go->winsaddr[1]);
990 
991     /*
992      * If there are any remaining CIs, then this packet is bad.
993      */
994     if (len != 0)
995           goto bad;
996     return (1);
997 
998 bad:
999     IPCPDEBUG(("ipcp_ackci: received bad Ack!"));
1000     return (0);
1001 }
1002 
1003 /*
1004  * ipcp_nakci - Peer has sent a NAK for some of our CIs.
1005  * This should not modify any state if the Nak is bad
1006  * or if IPCP is in the OPENED state.
1007  * Calback from fsm_rconfnakrej - Receive Configure-Nak or Configure-Reject.
1008  *
1009  * Returns:
1010  *        0 - Nak was bad.
1011  *        1 - Nak was good.
1012  */
1013 static int
ipcp_nakci(fsm * f,u_char * p,int len,int treat_as_reject)1014 ipcp_nakci(fsm *f, u_char *p, int len, int treat_as_reject)
1015 {
1016     ipcp_options *wo = &ipcp_wantoptions[f->unit];
1017     ipcp_options *go = &ipcp_gotoptions[f->unit];
1018     u_char cimaxslotindex, cicflag;
1019     u_char citype, cilen, *next;
1020     u_short cishort;
1021     u_int32_t ciaddr1, ciaddr2, l, cidnsaddr, ciwinsaddr;
1022     ipcp_options no;                    /* options we've seen Naks for */
1023     ipcp_options try;                   /* options to request next time */
1024 
1025     BZERO(&no, sizeof(no));
1026     try = *go;
1027 
1028     /*
1029      * Any Nak'd CIs must be in exactly the same order that we sent.
1030      * Check packet length and CI length at each step.
1031      * If we find any deviations, then this packet is bad.
1032      */
1033 #define NAKCIADDRS(opt, neg, code) \
1034     if ((neg) && \
1035           (cilen = p[1]) == CILEN_ADDRS && \
1036           len >= cilen && \
1037           p[0] == opt) { \
1038           len -= cilen; \
1039           INCPTR(2, p); \
1040           GETLONG(l, p); \
1041           ciaddr1 = htonl(l); \
1042           GETLONG(l, p); \
1043           ciaddr2 = htonl(l); \
1044           no.old_addrs = 1; \
1045           code \
1046     }
1047 
1048 #define NAKCIVJ(opt, neg, code) \
1049     if (go->neg && \
1050           ((cilen = p[1]) == CILEN_COMPRESS || cilen == CILEN_VJ) && \
1051           len >= cilen && \
1052           p[0] == opt) { \
1053           len -= cilen; \
1054           INCPTR(2, p); \
1055           GETSHORT(cishort, p); \
1056           no.neg = 1; \
1057         code \
1058     }
1059 
1060 #define NAKCIADDR(opt, neg, code) \
1061     if (go->neg && \
1062           (cilen = p[1]) == CILEN_ADDR && \
1063           len >= cilen && \
1064           p[0] == opt) { \
1065           len -= cilen; \
1066           INCPTR(2, p); \
1067           GETLONG(l, p); \
1068           ciaddr1 = htonl(l); \
1069           no.neg = 1; \
1070           code \
1071     }
1072 
1073 #define NAKCIDNS(opt, neg, code) \
1074     if (go->neg && \
1075           ((cilen = p[1]) == CILEN_ADDR) && \
1076           len >= cilen && \
1077           p[0] == opt) { \
1078           len -= cilen; \
1079           INCPTR(2, p); \
1080           GETLONG(l, p); \
1081           cidnsaddr = htonl(l); \
1082           no.neg = 1; \
1083           code \
1084     }
1085 
1086 #define NAKCIWINS(opt, neg, code) \
1087     if (go->neg && \
1088           ((cilen = p[1]) == CILEN_ADDR) && \
1089           len >= cilen && \
1090           p[0] == opt) { \
1091           len -= cilen; \
1092           INCPTR(2, p); \
1093           GETLONG(l, p); \
1094           ciwinsaddr = htonl(l); \
1095           no.neg = 1; \
1096           code \
1097     }
1098 
1099     /*
1100      * Accept the peer's idea of {our,his} address, if different
1101      * from our idea, only if the accept_{local,remote} flag is set.
1102      */
1103     NAKCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs,
1104                  if (treat_as_reject) {
1105                        try.old_addrs = 0;
1106                  } else {
1107                        if (go->accept_local && ciaddr1) {
1108                            /* take his idea of our address */
1109                            try.ouraddr = ciaddr1;
1110                        }
1111                        if (go->accept_remote && ciaddr2) {
1112                            /* take his idea of his address */
1113                            try.hisaddr = ciaddr2;
1114                        }
1115                  }
1116           );
1117 
1118     /*
1119      * Accept the peer's value of maxslotindex provided that it
1120      * is less than what we asked for.  Turn off slot-ID compression
1121      * if the peer wants.  Send old-style compress-type option if
1122      * the peer wants.
1123      */
1124     NAKCIVJ(CI_COMPRESSTYPE, neg_vj,
1125               if (treat_as_reject) {
1126                     try.neg_vj = 0;
1127               } else if (cilen == CILEN_VJ) {
1128                     GETCHAR(cimaxslotindex, p);
1129                     GETCHAR(cicflag, p);
1130                     if (cishort == IPCP_VJ_COMP) {
1131                         try.old_vj = 0;
1132                         if (cimaxslotindex < go->maxslotindex)
1133                               try.maxslotindex = cimaxslotindex;
1134                         if (!cicflag)
1135                               try.cflag = 0;
1136                     } else {
1137                         try.neg_vj = 0;
1138                     }
1139               } else {
1140                     if (cishort == IPCP_VJ_COMP || cishort == IPCP_VJ_COMP_OLD) {
1141                         try.old_vj = 1;
1142                         try.vj_protocol = cishort;
1143                     } else {
1144                         try.neg_vj = 0;
1145                     }
1146               }
1147               );
1148 
1149     NAKCIADDR(CI_ADDR, neg_addr,
1150                 if (treat_as_reject) {
1151                       try.neg_addr = 0;
1152                       try.old_addrs = 0;
1153                 } else if (go->accept_local && ciaddr1) {
1154                       /* take his idea of our address */
1155                       try.ouraddr = ciaddr1;
1156                 }
1157                 );
1158 
1159     NAKCIDNS(CI_MS_DNS1, req_dns1,
1160                if (treat_as_reject) {
1161                      try.req_dns1 = 0;
1162                } else {
1163                      try.dnsaddr[0] = cidnsaddr;
1164                }
1165                );
1166 
1167     NAKCIDNS(CI_MS_DNS2, req_dns2,
1168                if (treat_as_reject) {
1169                      try.req_dns2 = 0;
1170                } else {
1171                      try.dnsaddr[1] = cidnsaddr;
1172                }
1173                );
1174 
1175     NAKCIWINS(CI_MS_WINS1, req_wins1,
1176                if (treat_as_reject) {
1177                      try.req_wins1 = 0;
1178                } else {
1179                      try.winsaddr[0] = ciwinsaddr;
1180                }
1181                );
1182 
1183     NAKCIWINS(CI_MS_WINS2, req_wins2,
1184                if (treat_as_reject) {
1185                      try.req_wins2 = 0;
1186                } else {
1187                      try.winsaddr[1] = ciwinsaddr;
1188                }
1189                );
1190 
1191     /*
1192      * There may be remaining CIs, if the peer is requesting negotiation
1193      * on an option that we didn't include in our request packet.
1194      * If they want to negotiate about IP addresses, we comply.
1195      * If they want us to ask for compression, we refuse.
1196      * If they want us to ask for ms-dns, we do that, since some
1197      * peers get huffy if we don't.
1198      */
1199     while (len >= CILEN_VOID) {
1200           GETCHAR(citype, p);
1201           GETCHAR(cilen, p);
1202           if ( cilen < CILEN_VOID || (len -= cilen) < 0 )
1203               goto bad;
1204           next = p + cilen - 2;
1205 
1206           switch (citype) {
1207           case CI_COMPRESSTYPE:
1208               if (go->neg_vj || no.neg_vj ||
1209                     (cilen != CILEN_VJ && cilen != CILEN_COMPRESS))
1210                     goto bad;
1211               no.neg_vj = 1;
1212               break;
1213           case CI_ADDRS:
1214               if ((!go->neg_addr && go->old_addrs) || no.old_addrs
1215                     || cilen != CILEN_ADDRS)
1216                     goto bad;
1217               try.neg_addr = 0;
1218               GETLONG(l, p);
1219               ciaddr1 = htonl(l);
1220               if (ciaddr1 && go->accept_local)
1221                     try.ouraddr = wo->old_addrs ? ciaddr1 : 0;
1222               GETLONG(l, p);
1223               ciaddr2 = htonl(l);
1224               if (ciaddr2 && go->accept_remote)
1225                     try.hisaddr = ciaddr2;
1226               no.old_addrs = 1;
1227               break;
1228           case CI_ADDR:
1229               if (go->neg_addr || no.neg_addr || cilen != CILEN_ADDR)
1230                     goto bad;
1231               try.old_addrs = 0;
1232               GETLONG(l, p);
1233               ciaddr1 = htonl(l);
1234               if (ciaddr1 && go->accept_local)
1235                     try.ouraddr = ciaddr1;
1236               if (try.ouraddr != 0 && wo->neg_addr)
1237                     try.neg_addr = 1;
1238               no.neg_addr = 1;
1239               break;
1240           case CI_MS_DNS1:
1241               if (go->req_dns1 || no.req_dns1 || cilen != CILEN_ADDR)
1242                     goto bad;
1243               GETLONG(l, p);
1244               try.dnsaddr[0] = htonl(l);
1245               try.req_dns1 = 1;
1246               no.req_dns1 = 1;
1247               break;
1248           case CI_MS_DNS2:
1249               if (go->req_dns2 || no.req_dns2 || cilen != CILEN_ADDR)
1250                     goto bad;
1251               GETLONG(l, p);
1252               try.dnsaddr[1] = htonl(l);
1253               try.req_dns2 = 1;
1254               no.req_dns2 = 1;
1255               break;
1256           case CI_MS_WINS1:
1257               if (go->req_wins1 || no.req_wins1 || cilen != CILEN_ADDR)
1258                     goto bad;
1259               GETLONG(l, p);
1260               try.winsaddr[0] = htonl(l);
1261               try.req_wins1 = 1;
1262               no.req_wins1 = 1;
1263               break;
1264           case CI_MS_WINS2:
1265               if (go->req_wins2 || no.req_wins2 || cilen != CILEN_ADDR)
1266                     goto bad;
1267               GETLONG(l, p);
1268               try.winsaddr[1] = htonl(l);
1269               try.req_wins2 = 1;
1270               no.req_wins2 = 1;
1271               break;
1272           }
1273           p = next;
1274     }
1275 
1276     /*
1277      * OK, the Nak is good.  Now we can update state.
1278      * If there are any remaining options, we ignore them.
1279      */
1280     if (f->state != OPENED)
1281           *go = try;
1282 
1283     return 1;
1284 
1285 bad:
1286     IPCPDEBUG(("ipcp_nakci: received bad Nak!"));
1287     return 0;
1288 }
1289 
1290 /*
1291  * ipcp_rejci - Reject some of our CIs.
1292  * Callback from fsm_rconfnakrej.
1293  */
1294 static int
ipcp_rejci(fsm * f,u_char * p,int len)1295 ipcp_rejci(fsm *f, u_char *p, int len)
1296 {
1297     ipcp_options *go = &ipcp_gotoptions[f->unit];
1298     u_char cimaxslotindex, ciflag, cilen;
1299     u_short cishort;
1300     u_int32_t cilong;
1301     ipcp_options try;                   /* options to request next time */
1302 
1303     try = *go;
1304     /*
1305      * Any Rejected CIs must be in exactly the same order that we sent.
1306      * Check packet length and CI length at each step.
1307      * If we find any deviations, then this packet is bad.
1308      */
1309 #define REJCIADDRS(opt, neg, val1, val2) \
1310     if ((neg) && \
1311           (cilen = p[1]) == CILEN_ADDRS && \
1312           len >= cilen && \
1313           p[0] == opt) { \
1314           u_int32_t l; \
1315           len -= cilen; \
1316           INCPTR(2, p); \
1317           GETLONG(l, p); \
1318           cilong = htonl(l); \
1319           /* Check rejected value. */ \
1320           if (cilong != val1) \
1321               goto bad; \
1322           GETLONG(l, p); \
1323           cilong = htonl(l); \
1324           /* Check rejected value. */ \
1325           if (cilong != val2) \
1326               goto bad; \
1327           try.old_addrs = 0; \
1328     }
1329 
1330 #define REJCIVJ(opt, neg, val, old, maxslot, cflag) \
1331     if (go->neg && \
1332           p[1] == (old? CILEN_COMPRESS : CILEN_VJ) && \
1333           len >= p[1] && \
1334           p[0] == opt) { \
1335           len -= p[1]; \
1336           INCPTR(2, p); \
1337           GETSHORT(cishort, p); \
1338           /* Check rejected value. */  \
1339           if (cishort != val) \
1340               goto bad; \
1341           if (!old) { \
1342              GETCHAR(cimaxslotindex, p); \
1343              if (cimaxslotindex != maxslot) \
1344                goto bad; \
1345              GETCHAR(ciflag, p); \
1346              if (ciflag != cflag) \
1347                goto bad; \
1348         } \
1349           try.neg = 0; \
1350      }
1351 
1352 #define REJCIADDR(opt, neg, val) \
1353     if (go->neg && \
1354           (cilen = p[1]) == CILEN_ADDR && \
1355           len >= cilen && \
1356           p[0] == opt) { \
1357           u_int32_t l; \
1358           len -= cilen; \
1359           INCPTR(2, p); \
1360           GETLONG(l, p); \
1361           cilong = htonl(l); \
1362           /* Check rejected value. */ \
1363           if (cilong != val) \
1364               goto bad; \
1365           try.neg = 0; \
1366     }
1367 
1368 #define REJCIDNS(opt, neg, dnsaddr) \
1369     if (go->neg && \
1370           ((cilen = p[1]) == CILEN_ADDR) && \
1371           len >= cilen && \
1372           p[0] == opt) { \
1373           u_int32_t l; \
1374           len -= cilen; \
1375           INCPTR(2, p); \
1376           GETLONG(l, p); \
1377           cilong = htonl(l); \
1378           /* Check rejected value. */ \
1379           if (cilong != dnsaddr) \
1380               goto bad; \
1381           try.neg = 0; \
1382     }
1383 
1384 #define REJCIWINS(opt, neg, addr) \
1385     if (go->neg && \
1386           ((cilen = p[1]) == CILEN_ADDR) && \
1387           len >= cilen && \
1388           p[0] == opt) { \
1389           u_int32_t l; \
1390           len -= cilen; \
1391           INCPTR(2, p); \
1392           GETLONG(l, p); \
1393           cilong = htonl(l); \
1394           /* Check rejected value. */ \
1395           if (cilong != addr) \
1396               goto bad; \
1397           try.neg = 0; \
1398     }
1399 
1400     REJCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs,
1401                  go->ouraddr, go->hisaddr);
1402 
1403     REJCIVJ(CI_COMPRESSTYPE, neg_vj, go->vj_protocol, go->old_vj,
1404               go->maxslotindex, go->cflag);
1405 
1406     REJCIADDR(CI_ADDR, neg_addr, go->ouraddr);
1407 
1408     REJCIDNS(CI_MS_DNS1, req_dns1, go->dnsaddr[0]);
1409 
1410     REJCIDNS(CI_MS_DNS2, req_dns2, go->dnsaddr[1]);
1411 
1412     REJCIWINS(CI_MS_WINS1, req_wins1, go->winsaddr[0]);
1413 
1414     REJCIWINS(CI_MS_WINS2, req_wins2, go->winsaddr[1]);
1415 
1416     /*
1417      * If there are any remaining CIs, then this packet is bad.
1418      */
1419     if (len != 0)
1420           goto bad;
1421     /*
1422      * Now we can update state.
1423      */
1424     if (f->state != OPENED)
1425           *go = try;
1426     return 1;
1427 
1428 bad:
1429     IPCPDEBUG(("ipcp_rejci: received bad Reject!"));
1430     return 0;
1431 }
1432 
1433 
1434 /*
1435  * ipcp_reqci - Check the peer's requested CIs and send appropriate response.
1436  * Callback from fsm_rconfreq, Receive Configure Request
1437  *
1438  * Returns: CONFACK, CONFNAK or CONFREJ and input packet modified
1439  * appropriately.  If reject_if_disagree is non-zero, doesn't return
1440  * CONFNAK; returns CONFREJ if it can't return CONFACK.
1441  */
1442 static int
ipcp_reqci(fsm * f,u_char * inp,int * len,int reject_if_disagree)1443 ipcp_reqci(fsm *f, u_char *inp,         int *len, int reject_if_disagree)
1444 {
1445     ipcp_options *wo = &ipcp_wantoptions[f->unit];
1446     ipcp_options *ho = &ipcp_hisoptions[f->unit];
1447     ipcp_options *ao = &ipcp_allowoptions[f->unit];
1448     u_char *cip, *next;                 /* Pointer to current and next CIs */
1449     u_int32_t cilen, citype;  /* Parsed len, type */
1450     u_short cishort;                    /* Parsed short value */
1451     u_int32_t tl, ciaddr1, ciaddr2;/* Parsed address values */
1452     int rc = CONFACK;                   /* Final packet return code */
1453     int orc;                            /* Individual option return code */
1454     u_char *p;                          /* Pointer to next char to parse */
1455     u_char *ucp = inp;                  /* Pointer to current output char */
1456     u_int32_t l = *len;                 /* Length left */
1457     u_char maxslotindex, cflag;
1458     int d;
1459 
1460     /*
1461      * Reset all his options.
1462      */
1463     BZERO(ho, sizeof(*ho));
1464 
1465     /*
1466      * Process all his options.
1467      */
1468     next = inp;
1469     while (l) {
1470           orc = CONFACK;                          /* Assume success */
1471           cip = p = next;                         /* Remember begining of CI */
1472           if (l < 2 ||                            /* Not enough data for CI header or */
1473               p[1] < 2 ||                         /*  CI length too small or */
1474               p[1] > l) {                         /*  CI length too big? */
1475               IPCPDEBUG(("ipcp_reqci: bad CI length!"));
1476               orc = CONFREJ;            /* Reject bad CI */
1477               cilen = l;                          /* Reject till end of packet */
1478               l = 0;                              /* Don't loop again */
1479               goto endswitch;
1480           }
1481           GETCHAR(citype, p);           /* Parse CI type */
1482           GETCHAR(cilen, p);            /* Parse CI length */
1483           l -= cilen;                             /* Adjust remaining length */
1484           next += cilen;                          /* Step to next CI */
1485 
1486           switch (citype) {             /* Check CI type */
1487           case CI_ADDRS:
1488               if (!ao->old_addrs || ho->neg_addr ||
1489                     cilen != CILEN_ADDRS) {       /* Check CI length */
1490                     orc = CONFREJ;                /* Reject CI */
1491                     break;
1492               }
1493 
1494               /*
1495                * If he has no address, or if we both have his address but
1496                * disagree about it, then NAK it with our idea.
1497                * In particular, if we don't know his address, but he does,
1498                * then accept it.
1499                */
1500               GETLONG(tl, p);           /* Parse source address (his) */
1501               ciaddr1 = htonl(tl);
1502               if (ciaddr1 != wo->hisaddr
1503                     && (ciaddr1 == 0 || !wo->accept_remote)) {
1504                     orc = CONFNAK;
1505                     if (!reject_if_disagree) {
1506                         DECPTR(sizeof(u_int32_t), p);
1507                         tl = ntohl(wo->hisaddr);
1508                         PUTLONG(tl, p);
1509                     }
1510               } else if (ciaddr1 == 0 && wo->hisaddr == 0) {
1511                     /*
1512                      * If neither we nor he knows his address, reject the option.
1513                      */
1514                     orc = CONFREJ;
1515                     wo->req_addr = 0;   /* don't NAK with 0.0.0.0 later */
1516                     break;
1517               }
1518 
1519               /*
1520                * If he doesn't know our address, or if we both have our address
1521                * but disagree about it, then NAK it with our idea.
1522                */
1523               GETLONG(tl, p);           /* Parse desination address (ours) */
1524               ciaddr2 = htonl(tl);
1525               if (ciaddr2 != wo->ouraddr) {
1526                     if (ciaddr2 == 0 || !wo->accept_local) {
1527                         orc = CONFNAK;
1528                         if (!reject_if_disagree && wo->old_addrs) {
1529                               DECPTR(sizeof(u_int32_t), p);
1530                               tl = ntohl(wo->ouraddr);
1531                               PUTLONG(tl, p);
1532                         }
1533                     } else {
1534                         wo->ouraddr = ciaddr2;    /* accept peer's idea */
1535                     }
1536               }
1537 
1538               ho->old_addrs = 1;
1539               ho->hisaddr = ciaddr1;
1540               ho->ouraddr = ciaddr2;
1541               break;
1542 
1543           case CI_ADDR:
1544               if (!ao->neg_addr || ho->old_addrs ||
1545                     cilen != CILEN_ADDR) {        /* Check CI length */
1546                     orc = CONFREJ;                /* Reject CI */
1547                     break;
1548               }
1549 
1550               /*
1551                * If he has no address, or if we both have his address but
1552                * disagree about it, then NAK it with our idea.
1553                * In particular, if we don't know his address, but he does,
1554                * then accept it.
1555                */
1556               GETLONG(tl, p); /* Parse source address (his) */
1557               ciaddr1 = htonl(tl);
1558               if (ciaddr1 != wo->hisaddr
1559                     && (ciaddr1 == 0 || !wo->accept_remote)) {
1560                     orc = CONFNAK;
1561                     if (!reject_if_disagree) {
1562                         DECPTR(sizeof(u_int32_t), p);
1563                         tl = ntohl(wo->hisaddr);
1564                         PUTLONG(tl, p);
1565                     }
1566               } else if (ciaddr1 == 0 && wo->hisaddr == 0) {
1567                     /*
1568                      * Don't ACK an address of 0.0.0.0 - reject it instead.
1569                      */
1570                     orc = CONFREJ;
1571                     wo->req_addr = 0;   /* don't NAK with 0.0.0.0 later */
1572                     break;
1573               }
1574 
1575               ho->neg_addr = 1;
1576               ho->hisaddr = ciaddr1;
1577               break;
1578 
1579           case CI_MS_DNS1:
1580           case CI_MS_DNS2:
1581               /* Microsoft primary or secondary DNS request */
1582               d = citype == CI_MS_DNS2;
1583 
1584               /* If we do not have a DNS address then we cannot send it */
1585               if (ao->dnsaddr[d] == 0 ||
1586                     cilen != CILEN_ADDR) {        /* Check CI length */
1587                     orc = CONFREJ;                /* Reject CI */
1588                     break;
1589               }
1590               GETLONG(tl, p);
1591               if (htonl(tl) != ao->dnsaddr[d]) {
1592                 DECPTR(sizeof(u_int32_t), p);
1593                     tl = ntohl(ao->dnsaddr[d]);
1594                     PUTLONG(tl, p);
1595                     orc = CONFNAK;
1596             }
1597             break;
1598 
1599           case CI_MS_WINS1:
1600           case CI_MS_WINS2:
1601               /* Microsoft primary or secondary WINS request */
1602               d = citype == CI_MS_WINS2;
1603 
1604               /* If we do not have a WINS address then we cannot send it */
1605               if (ao->winsaddr[d] == 0 ||
1606                     cilen != CILEN_ADDR) {        /* Check CI length */
1607                     orc = CONFREJ;                /* Reject CI */
1608                     break;
1609               }
1610               GETLONG(tl, p);
1611               if (htonl(tl) != ao->winsaddr[d]) {
1612                 DECPTR(sizeof(u_int32_t), p);
1613                     tl = ntohl(ao->winsaddr[d]);
1614                     PUTLONG(tl, p);
1615                     orc = CONFNAK;
1616             }
1617             break;
1618 
1619           case CI_COMPRESSTYPE:
1620               if (!ao->neg_vj ||
1621                     (cilen != CILEN_VJ && cilen != CILEN_COMPRESS)) {
1622                     orc = CONFREJ;
1623                     break;
1624               }
1625               GETSHORT(cishort, p);
1626 
1627               if (!(cishort == IPCP_VJ_COMP ||
1628                       (cishort == IPCP_VJ_COMP_OLD && cilen == CILEN_COMPRESS))) {
1629                     orc = CONFREJ;
1630                     break;
1631               }
1632 
1633               ho->neg_vj = 1;
1634               ho->vj_protocol = cishort;
1635               if (cilen == CILEN_VJ) {
1636                     GETCHAR(maxslotindex, p);
1637                     if (maxslotindex > ao->maxslotindex) {
1638                         orc = CONFNAK;
1639                         if (!reject_if_disagree){
1640                               DECPTR(1, p);
1641                               PUTCHAR(ao->maxslotindex, p);
1642                         }
1643                     }
1644                     GETCHAR(cflag, p);
1645                     if (cflag && !ao->cflag) {
1646                         orc = CONFNAK;
1647                         if (!reject_if_disagree){
1648                               DECPTR(1, p);
1649                               PUTCHAR(wo->cflag, p);
1650                         }
1651                     }
1652                     ho->maxslotindex = maxslotindex;
1653                     ho->cflag = cflag;
1654               } else {
1655                     ho->old_vj = 1;
1656                     ho->maxslotindex = MAX_STATES - 1;
1657                     ho->cflag = 1;
1658               }
1659               break;
1660 
1661           default:
1662               orc = CONFREJ;
1663               break;
1664           }
1665 endswitch:
1666           if (orc == CONFACK &&                   /* Good CI */
1667               rc != CONFACK)            /*  but prior CI wasnt? */
1668               continue;                           /* Don't send this one */
1669 
1670           if (orc == CONFNAK) {                   /* Nak this CI? */
1671               if (reject_if_disagree)   /* Getting fed up with sending NAKs? */
1672                     orc = CONFREJ;                /* Get tough if so */
1673               else {
1674                     if (rc == CONFREJ)  /* Rejecting prior CI? */
1675                         continue;                 /* Don't send this one */
1676                     if (rc == CONFACK) {          /* Ack'd all prior CIs? */
1677                         rc = CONFNAK;   /* Not anymore... */
1678                         ucp = inp;                /* Backup */
1679                     }
1680               }
1681           }
1682 
1683           if (orc == CONFREJ &&                   /* Reject this CI */
1684               rc != CONFREJ) {                    /*  but no prior ones? */
1685               rc = CONFREJ;
1686               ucp = inp;                          /* Backup */
1687           }
1688 
1689           /* Need to move CI? */
1690           if (ucp != cip)
1691               BCOPY(cip, ucp, cilen);   /* Move it */
1692 
1693           /* Update output pointer */
1694           INCPTR(cilen, ucp);
1695     }
1696 
1697     /*
1698      * If we aren't rejecting this packet, and we want to negotiate
1699      * their address, and they didn't send their address, then we
1700      * send a NAK with a CI_ADDR option appended.  We assume the
1701      * input buffer is long enough that we can append the extra
1702      * option safely.
1703      */
1704     if (rc != CONFREJ && !ho->neg_addr && !ho->old_addrs &&
1705           wo->req_addr && !reject_if_disagree &&
1706           ((wo->hisaddr && !wo->accept_remote) || !noremoteip)) {
1707           if (rc == CONFACK) {
1708               rc = CONFNAK;
1709               ucp = inp;                          /* reset pointer */
1710               wo->req_addr = 0;                   /* don't ask again */
1711           }
1712           PUTCHAR(CI_ADDR, ucp);
1713           PUTCHAR(CILEN_ADDR, ucp);
1714           tl = ntohl(wo->hisaddr);
1715           PUTLONG(tl, ucp);
1716     }
1717 
1718     *len = ucp - inp;                             /* Compute output length */
1719     IPCPDEBUG(("ipcp: returning Configure-%s", CODENAME(rc)));
1720     return (rc);                        /* Return final code */
1721 }
1722 
1723 
1724 /*
1725  * ip_check_options - check that any IP-related options are OK,
1726  * and assign appropriate defaults.
1727  */
1728 static void
ip_check_options(void)1729 ip_check_options(void)
1730 {
1731     struct hostent *hp;
1732     u_int32_t local;
1733     ipcp_options *wo = &ipcp_wantoptions[0];
1734 
1735     /*
1736      * Default our local IP address based on our hostname.
1737      * If local IP address already given, don't bother.
1738      */
1739     if (wo->ouraddr == 0 && !disable_defaultip) {
1740           /*
1741            * Look up our hostname (possibly with domain name appended)
1742            * and take the first IP address as our local IP address.
1743            * If there isn't an IP address for our hostname, too bad.
1744            */
1745           wo->accept_local = 1;         /* don't insist on this default value */
1746           if ((hp = gethostbyname(hostname)) != NULL) {
1747               local = *(u_int32_t *)hp->h_addr;
1748               if (local != 0 && !ppp_bad_ip_addr(local))
1749                     wo->ouraddr = local;
1750           }
1751     }
1752     ask_for_local = wo->ouraddr != 0 || !disable_defaultip;
1753 }
1754 
1755 
1756 /*
1757  * ip_demand_conf - configure the interface as though
1758  * IPCP were up, for use with dial-on-demand.
1759  */
1760 static int
ip_demand_conf(int u)1761 ip_demand_conf(int u)
1762 {
1763     ipcp_options *wo = &ipcp_wantoptions[u];
1764 
1765     if (wo->hisaddr == 0 && !noremoteip) {
1766           /* make up an arbitrary address for the peer */
1767           wo->hisaddr = htonl(0x0a707070 + ifunit);
1768           wo->accept_remote = 1;
1769     }
1770     if (wo->ouraddr == 0) {
1771           /* make up an arbitrary address for us */
1772           wo->ouraddr = htonl(0x0a404040 + ifunit);
1773           wo->accept_local = 1;
1774           ask_for_local = 0;  /* don't tell the peer this address */
1775     }
1776     if (!sifaddr(u, wo->ouraddr, wo->hisaddr, GetMask(wo->ouraddr)))
1777           return 0;
1778     ipcp_script(path_ippreup, 1);
1779     if (!sifup(u))
1780           return 0;
1781     if (!sifnpmode(u, PPP_IP, NPMODE_QUEUE))
1782           return 0;
1783     if (wo->default_route)
1784           if (sifdefaultroute(u, wo->ouraddr, wo->hisaddr,
1785                                                       wo->replace_default_route))
1786               default_route_set[u] = 1;
1787     if (wo->proxy_arp)
1788           if (sifproxyarp(u, wo->hisaddr))
1789               proxy_arp_set[u] = 1;
1790 
1791     notice("local  IP address %I", wo->ouraddr);
1792     if (wo->hisaddr)
1793           notice("remote IP address %I", wo->hisaddr);
1794 
1795     return 1;
1796 }
1797 
1798 
1799 /*
1800  * ipcp_up - IPCP has come UP.
1801  *
1802  * Configure the IP network interface appropriately and bring it up.
1803  */
1804 static void
ipcp_up(fsm * f)1805 ipcp_up(fsm *f)
1806 {
1807     u_int32_t mask;
1808     ipcp_options *ho = &ipcp_hisoptions[f->unit];
1809     ipcp_options *go = &ipcp_gotoptions[f->unit];
1810     ipcp_options *wo = &ipcp_wantoptions[f->unit];
1811     int ifindex;
1812 
1813     IPCPDEBUG(("ipcp: up"));
1814 
1815     /*
1816      * We must have a non-zero IP address for both ends of the link.
1817      */
1818 
1819     if (wo->hisaddr && !wo->accept_remote && (!(ho->neg_addr || ho->old_addrs) || ho->hisaddr != wo->hisaddr)) {
1820           error("Peer refused to agree to his IP address");
1821           ipcp_close(f->unit, "Refused his IP address");
1822           return;
1823     }
1824     if (!ho->neg_addr && !ho->old_addrs)
1825           ho->hisaddr = wo->hisaddr;
1826 
1827     if (!(go->neg_addr || go->old_addrs) && (wo->neg_addr || wo->old_addrs)
1828           && wo->ouraddr != 0) {
1829           error("Peer refused to agree to our IP address");
1830           ipcp_close(f->unit, "Refused our IP address");
1831           return;
1832     }
1833     if (go->ouraddr == 0) {
1834           error("Could not determine local IP address");
1835           ipcp_close(f->unit, "Could not determine local IP address");
1836           return;
1837     }
1838     if (ho->hisaddr == 0 && !noremoteip) {
1839           ho->hisaddr = htonl(0x0a404040 + ifunit);
1840           warn("Could not determine remote IP address: defaulting to %I",
1841                ho->hisaddr);
1842     }
1843     ppp_script_setenv("IPLOCAL", ip_ntoa(go->ouraddr), 0);
1844     if (ho->hisaddr != 0)
1845           ppp_script_setenv("IPREMOTE", ip_ntoa(ho->hisaddr), 1);
1846 
1847     if (!go->req_dns1)
1848               go->dnsaddr[0] = 0;
1849     if (!go->req_dns2)
1850               go->dnsaddr[1] = 0;
1851     if (go->dnsaddr[0])
1852           ppp_script_setenv("DNS1", ip_ntoa(go->dnsaddr[0]), 0);
1853     if (go->dnsaddr[1])
1854           ppp_script_setenv("DNS2", ip_ntoa(go->dnsaddr[1]), 0);
1855     if (usepeerdns && (go->dnsaddr[0] || go->dnsaddr[1])) {
1856           ppp_script_setenv("USEPEERDNS", "1", 0);
1857           create_resolv(go->dnsaddr[0], go->dnsaddr[1]);
1858     }
1859 
1860     if (go->winsaddr[0])
1861         ppp_script_setenv("WINS1", ip_ntoa(go->winsaddr[0]), 0);
1862     if (go->winsaddr[1])
1863         ppp_script_setenv("WINS2", ip_ntoa(go->winsaddr[1]), 0);
1864     if (usepeerwins && (go->winsaddr[0] || go->winsaddr[1]))
1865         ppp_script_setenv("USEPEERWINS", "1", 0);
1866 
1867     /*
1868      * Check that the peer is allowed to use the IP address it wants.
1869      */
1870     if (ho->hisaddr != 0 && !auth_ip_addr(f->unit, ho->hisaddr)) {
1871           error("Peer is not authorized to use remote address %I", ho->hisaddr);
1872           ipcp_close(f->unit, "Unauthorized remote IP address");
1873           return;
1874     }
1875 
1876     /* set tcp compression */
1877     sifvjcomp(f->unit, ho->neg_vj, ho->cflag, ho->maxslotindex);
1878 
1879     /*
1880      * If we are doing dial-on-demand, the interface is already
1881      * configured, so we put out any saved-up packets, then set the
1882      * interface to pass IP packets.
1883      */
1884     if (demand) {
1885           if (go->ouraddr != wo->ouraddr || ho->hisaddr != wo->hisaddr) {
1886               ipcp_clear_addrs(f->unit, wo->ouraddr, wo->hisaddr,
1887                                               wo->replace_default_route);
1888               if (go->ouraddr != wo->ouraddr) {
1889                     warn("Local IP address changed to %I", go->ouraddr);
1890                     ppp_script_setenv("OLDIPLOCAL", ip_ntoa(wo->ouraddr), 0);
1891                     wo->ouraddr = go->ouraddr;
1892               } else
1893                     ppp_script_unsetenv("OLDIPLOCAL");
1894               if (ho->hisaddr != wo->hisaddr) {
1895                     warn("Remote IP address changed to %I", ho->hisaddr);
1896                     if (wo->hisaddr != 0)
1897                         ppp_script_setenv("OLDIPREMOTE", ip_ntoa(wo->hisaddr), 0);
1898                     wo->hisaddr = ho->hisaddr;
1899               } else
1900                     ppp_script_unsetenv("OLDIPREMOTE");
1901 
1902               /* Set the interface to the new addresses */
1903               mask = GetMask(go->ouraddr);
1904               if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
1905                     if (debug)
1906                         warn("Interface configuration failed");
1907                     ipcp_close(f->unit, "Interface configuration failed");
1908                     return;
1909               }
1910 
1911               /* assign a default route through the interface if required */
1912               if (ipcp_wantoptions[f->unit].default_route)
1913                     if (sifdefaultroute(f->unit, go->ouraddr, ho->hisaddr,
1914                                                        wo->replace_default_route))
1915                         default_route_set[f->unit] = 1;
1916 
1917               /* Make a proxy ARP entry if requested. */
1918               if (ho->hisaddr != 0 && ipcp_wantoptions[f->unit].proxy_arp)
1919                     if (sifproxyarp(f->unit, ho->hisaddr))
1920                         proxy_arp_set[f->unit] = 1;
1921 
1922           }
1923           demand_rexmit(PPP_IP);
1924           sifnpmode(f->unit, PPP_IP, NPMODE_PASS);
1925 
1926     } else {
1927           /*
1928            * Set IP addresses and (if specified) netmask.
1929            */
1930           mask = GetMask(go->ouraddr);
1931 
1932 #if !(defined(SVR4) && (defined(SNI) || defined(__USLC__)))
1933           if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
1934               if (debug)
1935                     warn("Interface configuration failed");
1936               ipcp_close(f->unit, "Interface configuration failed");
1937               return;
1938           }
1939 #endif
1940 
1941           ifindex = if_nametoindex(ifname);
1942 
1943           /* run the pre-up script, if any, and wait for it to finish */
1944           ipcp_script(path_ippreup, 1);
1945 
1946           /* check if preup script renamed the interface */
1947           if (!if_indextoname(ifindex, ifname)) {
1948             error("Interface index %d failed to get renamed by a pre-up script", ifindex);
1949               ipcp_close(f->unit, "Interface configuration failed");
1950               return;
1951           }
1952 
1953           /* bring the interface up for IP */
1954           if (!sifup(f->unit)) {
1955               if (debug)
1956                     warn("Interface failed to come up");
1957               ipcp_close(f->unit, "Interface configuration failed");
1958               return;
1959           }
1960 
1961 #if (defined(SVR4) && (defined(SNI) || defined(__USLC__)))
1962           if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
1963               if (debug)
1964                     warn("Interface configuration failed");
1965               ipcp_close(f->unit, "Interface configuration failed");
1966               return;
1967           }
1968 #endif
1969           sifnpmode(f->unit, PPP_IP, NPMODE_PASS);
1970 
1971           /* assign a default route through the interface if required */
1972           if (ipcp_wantoptions[f->unit].default_route)
1973               if (sifdefaultroute(f->unit, go->ouraddr, ho->hisaddr,
1974                                                    wo->replace_default_route))
1975                     default_route_set[f->unit] = 1;
1976 
1977           /* Make a proxy ARP entry if requested. */
1978           if (ho->hisaddr != 0 && ipcp_wantoptions[f->unit].proxy_arp)
1979               if (sifproxyarp(f->unit, ho->hisaddr))
1980                     proxy_arp_set[f->unit] = 1;
1981 
1982           ipcp_wantoptions[0].ouraddr = go->ouraddr;
1983 
1984           notice("local  IP address %I", go->ouraddr);
1985           if (ho->hisaddr != 0)
1986               notice("remote IP address %I", ho->hisaddr);
1987           if (go->dnsaddr[0])
1988               notice("primary   DNS address %I", go->dnsaddr[0]);
1989           if (go->dnsaddr[1])
1990               notice("secondary DNS address %I", go->dnsaddr[1]);
1991     }
1992 
1993     reset_link_stats(f->unit);
1994 
1995     np_up(f->unit, PPP_IP);
1996     ipcp_is_up = 1;
1997 
1998     notify(ip_up_notifier, 0);
1999     if (ip_up_hook)
2000           ip_up_hook();
2001 
2002     /*
2003      * Execute the ip-up script, like this:
2004      *    /etc/ppp/ip-up interface tty speed local-IP remote-IP
2005      */
2006     if (ipcp_script_state == s_down && ipcp_script_pid == 0) {
2007           ipcp_script_state = s_up;
2008           ipcp_script(path_ipup, 0);
2009     }
2010 }
2011 
2012 
2013 /*
2014  * ipcp_down - IPCP has gone DOWN.
2015  *
2016  * Take the IP network interface down, clear its addresses
2017  * and delete routes through it.
2018  */
2019 static void
ipcp_down(fsm * f)2020 ipcp_down(fsm *f)
2021 {
2022     IPCPDEBUG(("ipcp: down"));
2023     /* XXX a bit IPv4-centric here, we only need to get the stats
2024      * before the interface is marked down. */
2025     /* XXX more correct: we must get the stats before running the notifiers,
2026      * at least for the radius plugin */
2027     ppp_get_link_stats(NULL);
2028     notify(ip_down_notifier, 0);
2029     if (ip_down_hook)
2030           ip_down_hook();
2031     if (ipcp_is_up) {
2032           ipcp_is_up = 0;
2033           np_down(f->unit, PPP_IP);
2034     }
2035     sifvjcomp(f->unit, 0, 0, 0);
2036 
2037     print_link_stats(); /* _after_ running the notifiers and ip_down_hook(),
2038                                * because print_link_stats() sets link_stats_print
2039                                * to 0 (zero) */
2040 
2041     /*
2042      * If we are doing dial-on-demand, set the interface
2043      * to queue up outgoing packets (for now).
2044      */
2045     if (demand) {
2046           sifnpmode(f->unit, PPP_IP, NPMODE_QUEUE);
2047     } else {
2048           sifnpmode(f->unit, PPP_IP, NPMODE_DROP);
2049           sifdown(f->unit);
2050           ipcp_clear_addrs(f->unit, ipcp_gotoptions[f->unit].ouraddr,
2051                                ipcp_hisoptions[f->unit].hisaddr, 0);
2052     }
2053 
2054     /* Execute the ip-down script */
2055     if (ipcp_script_state == s_up && ipcp_script_pid == 0) {
2056           ipcp_script_state = s_down;
2057           ipcp_script(path_ipdown, 0);
2058     }
2059 }
2060 
2061 
2062 /*
2063  * ipcp_clear_addrs() - clear the interface addresses, routes,
2064  * proxy arp entries, etc.
2065  */
2066 static void
ipcp_clear_addrs(int unit,u_int32_t ouraddr,u_int32_t hisaddr,bool replacedefaultroute)2067 ipcp_clear_addrs(int unit, u_int32_t ouraddr, u_int32_t hisaddr, bool replacedefaultroute)
2068 {
2069     if (proxy_arp_set[unit]) {
2070           cifproxyarp(unit, hisaddr);
2071           proxy_arp_set[unit] = 0;
2072     }
2073     /* If replacedefaultroute, sifdefaultroute will be called soon
2074      * with replacedefaultroute set and that will overwrite the current
2075      * default route. This is the case only when doing demand, otherwise
2076      * during demand, this cifdefaultroute would restore the old default
2077      * route which is not what we want in this case. In the non-demand
2078      * case, we'll delete the default route and restore the old if there
2079      * is one saved by an sifdefaultroute with replacedefaultroute.
2080      */
2081     if (!replacedefaultroute && default_route_set[unit]) {
2082           cifdefaultroute(unit, ouraddr, hisaddr);
2083           default_route_set[unit] = 0;
2084     }
2085     cifaddr(unit, ouraddr, hisaddr);
2086 }
2087 
2088 
2089 /*
2090  * ipcp_finished - possibly shut down the lower layers.
2091  */
2092 static void
ipcp_finished(fsm * f)2093 ipcp_finished(fsm *f)
2094 {
2095           if (ipcp_is_open) {
2096                     ipcp_is_open = 0;
2097                     np_finished(f->unit, PPP_IP);
2098           }
2099 }
2100 
2101 
2102 /*
2103  * ipcp_script_done - called when the ip-up or ip-down script
2104  * has finished.
2105  */
2106 static void
ipcp_script_done(void * arg)2107 ipcp_script_done(void *arg)
2108 {
2109     ipcp_script_pid = 0;
2110     switch (ipcp_script_state) {
2111     case s_up:
2112           if (ipcp_fsm[0].state != OPENED) {
2113               ipcp_script_state = s_down;
2114               ipcp_script(path_ipdown, 0);
2115           }
2116           break;
2117     case s_down:
2118           if (ipcp_fsm[0].state == OPENED) {
2119               ipcp_script_state = s_up;
2120               ipcp_script(path_ipup, 0);
2121           }
2122           break;
2123     }
2124 }
2125 
2126 
2127 /*
2128  * ipcp_script - Execute a script with arguments
2129  * interface-name tty-name speed local-IP remote-IP.
2130  */
2131 static void
ipcp_script(char * script,int wait)2132 ipcp_script(char *script, int wait)
2133 {
2134     char strspeed[32], strlocal[32], strremote[32];
2135     char *argv[8];
2136 
2137     slprintf(strspeed, sizeof(strspeed), "%d", baud_rate);
2138     slprintf(strlocal, sizeof(strlocal), "%I", ipcp_gotoptions[0].ouraddr);
2139     slprintf(strremote, sizeof(strremote), "%I", ipcp_hisoptions[0].hisaddr);
2140 
2141     argv[0] = script;
2142     argv[1] = ifname;
2143     argv[2] = devnam;
2144     argv[3] = strspeed;
2145     argv[4] = strlocal;
2146     argv[5] = strremote;
2147     argv[6] = ipparam;
2148     argv[7] = NULL;
2149     if (wait)
2150           run_program(script, argv, 0, NULL, NULL, 1);
2151     else
2152           ipcp_script_pid = run_program(script, argv, 0, ipcp_script_done,
2153                                               NULL, 0);
2154 }
2155 
2156 /*
2157  * create_resolv - create the replacement resolv.conf file
2158  */
2159 static void
create_resolv(u_int32_t peerdns1,u_int32_t peerdns2)2160 create_resolv(u_int32_t peerdns1, u_int32_t peerdns2)
2161 {
2162     FILE *f;
2163 
2164     if (noresolvconf)
2165           return;
2166 
2167     f = fopen(PPP_PATH_RESOLV, "w");
2168     if (f == NULL) {
2169           error("Failed to create %s: %m", PPP_PATH_RESOLV);
2170           return;
2171     }
2172 
2173     if (peerdns1)
2174           fprintf(f, "nameserver %s\n", ip_ntoa(peerdns1));
2175 
2176     if (peerdns2 && peerdns2 != peerdns1)
2177           fprintf(f, "nameserver %s\n", ip_ntoa(peerdns2));
2178 
2179     if (ferror(f))
2180           error("Write failed to %s: %m", PPP_PATH_RESOLV);
2181 
2182     fclose(f);
2183 }
2184 
2185 /*
2186  * ipcp_printpkt - print the contents of an IPCP packet.
2187  */
2188 static char *ipcp_codenames[] = {
2189     "ConfReq", "ConfAck", "ConfNak", "ConfRej",
2190     "TermReq", "TermAck", "CodeRej"
2191 };
2192 
2193 static int
ipcp_printpkt(u_char * p,int plen,void (* printer)(void *,char *,...),void * arg)2194 ipcp_printpkt(u_char *p, int plen,
2195                 void (*printer) (void *, char *, ...), void *arg)
2196 {
2197     int code, id, len, olen;
2198     u_char *pstart, *optend;
2199     u_short cishort;
2200     u_int32_t cilong;
2201 
2202     if (plen < HEADERLEN)
2203           return 0;
2204     pstart = p;
2205     GETCHAR(code, p);
2206     GETCHAR(id, p);
2207     GETSHORT(len, p);
2208     if (len < HEADERLEN || len > plen)
2209           return 0;
2210 
2211     if (code >= 1 && code <= sizeof(ipcp_codenames) / sizeof(char *))
2212           printer(arg, " %s", ipcp_codenames[code-1]);
2213     else
2214           printer(arg, " code=0x%x", code);
2215     printer(arg, " id=0x%x", id);
2216     len -= HEADERLEN;
2217     switch (code) {
2218     case CONFREQ:
2219     case CONFACK:
2220     case CONFNAK:
2221     case CONFREJ:
2222           /* print option list */
2223           while (len >= 2) {
2224               GETCHAR(code, p);
2225               GETCHAR(olen, p);
2226               p -= 2;
2227               if (olen < 2 || olen > len) {
2228                     break;
2229               }
2230               printer(arg, " <");
2231               len -= olen;
2232               optend = p + olen;
2233               switch (code) {
2234               case CI_ADDRS:
2235                     if (olen == CILEN_ADDRS) {
2236                         p += 2;
2237                         GETLONG(cilong, p);
2238                         printer(arg, "addrs %I", htonl(cilong));
2239                         GETLONG(cilong, p);
2240                         printer(arg, " %I", htonl(cilong));
2241                     }
2242                     break;
2243               case CI_COMPRESSTYPE:
2244                     if (olen >= CILEN_COMPRESS) {
2245                         p += 2;
2246                         GETSHORT(cishort, p);
2247                         printer(arg, "compress ");
2248                         switch (cishort) {
2249                         case IPCP_VJ_COMP:
2250                               printer(arg, "VJ");
2251                               break;
2252                         case IPCP_VJ_COMP_OLD:
2253                               printer(arg, "old-VJ");
2254                               break;
2255                         default:
2256                               printer(arg, "0x%x", cishort);
2257                         }
2258                     }
2259                     break;
2260               case CI_ADDR:
2261                     if (olen == CILEN_ADDR) {
2262                         p += 2;
2263                         GETLONG(cilong, p);
2264                         printer(arg, "addr %I", htonl(cilong));
2265                     }
2266                     break;
2267               case CI_MS_DNS1:
2268               case CI_MS_DNS2:
2269                   p += 2;
2270                     GETLONG(cilong, p);
2271                     printer(arg, "ms-dns%d %I", (code == CI_MS_DNS1? 1: 2),
2272                               htonl(cilong));
2273                     break;
2274               case CI_MS_WINS1:
2275               case CI_MS_WINS2:
2276                   p += 2;
2277                     GETLONG(cilong, p);
2278                     printer(arg, "ms-wins %I", htonl(cilong));
2279                     break;
2280               }
2281               while (p < optend) {
2282                     GETCHAR(code, p);
2283                     printer(arg, " %.2x", code);
2284               }
2285               printer(arg, ">");
2286           }
2287           break;
2288 
2289     case TERMACK:
2290     case TERMREQ:
2291           if (len > 0 && *p >= ' ' && *p < 0x7f) {
2292               printer(arg, " ");
2293               print_string((char *)p, len, printer, arg);
2294               p += len;
2295               len = 0;
2296           }
2297           break;
2298     }
2299 
2300     /* print the rest of the bytes in the packet */
2301     for (; len > 0; --len) {
2302           GETCHAR(code, p);
2303           printer(arg, " %.2x", code);
2304     }
2305 
2306     return p - pstart;
2307 }
2308 
2309 /*
2310  * ip_active_pkt - see if this IP packet is worth bringing the link up for.
2311  * We don't bring the link up for IP fragments or for TCP FIN packets
2312  * with no data.
2313  */
2314 #define IP_HDRLEN   20        /* bytes */
2315 #define IP_OFFMASK  0x1fff
2316 #ifndef IPPROTO_TCP
2317 #define IPPROTO_TCP 6
2318 #endif
2319 #define TCP_HDRLEN  20
2320 #define TH_FIN                0x01
2321 
2322 /*
2323  * We use these macros because the IP header may be at an odd address,
2324  * and some compilers might use word loads to get th_off or ip_hl.
2325  */
2326 
2327 #define net_short(x)          (((x)[0] << 8) + (x)[1])
2328 #define get_iphl(x) (((unsigned char *)(x))[0] & 0xF)
2329 #define get_ipoff(x)          net_short((unsigned char *)(x) + 6)
2330 #define get_ipproto(x)        (((unsigned char *)(x))[9])
2331 #define get_tcpoff(x)         (((unsigned char *)(x))[12] >> 4)
2332 #define get_tcpflags(x)       (((unsigned char *)(x))[13])
2333 
2334 static int
ip_active_pkt(u_char * pkt,int len)2335 ip_active_pkt(u_char *pkt, int len)
2336 {
2337     u_char *tcp;
2338     int hlen;
2339 
2340     len -= PPP_HDRLEN;
2341     pkt += PPP_HDRLEN;
2342     if (len < IP_HDRLEN)
2343           return 0;
2344     if ((get_ipoff(pkt) & IP_OFFMASK) != 0)
2345           return 0;
2346     if (get_ipproto(pkt) != IPPROTO_TCP)
2347           return 1;
2348     hlen = get_iphl(pkt) * 4;
2349     if (len < hlen + TCP_HDRLEN)
2350           return 0;
2351     tcp = pkt + hlen;
2352     if ((get_tcpflags(tcp) & TH_FIN) != 0 && len == hlen + get_tcpoff(tcp) * 4)
2353           return 0;
2354     return 1;
2355 }
2356