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      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 #define RCSID	"$Id: ipcp.c,v 1.54 2000/04/15 01:27:11 masputra Exp $"
     24 
     25 /*
     26  * TODO:
     27  */
     28 
     29 #include <stdio.h>
     30 #include <string.h>
     31 #include <netdb.h>
     32 #include <sys/param.h>
     33 #include <sys/types.h>
     34 #include <sys/socket.h>
     35 #if defined(_linux_) || defined(__linux__)
     36 #define	__FAVOR_BSD
     37 #endif
     38 #include <netinet/in.h>
     39 #include <netinet/tcp.h>
     40 #include <arpa/inet.h>
     41 
     42 #include "pppd.h"
     43 #include "fsm.h"
     44 #include "ipcp.h"
     45 #include "pathnames.h"
     46 
     47 #if !defined(lint) && !defined(_lint)
     48 static const char rcsid[] = RCSID;
     49 #endif
     50 
     51 /* global vars */
     52 ipcp_options ipcp_wantoptions[NUM_PPP];	/* Options that we want to request */
     53 ipcp_options ipcp_gotoptions[NUM_PPP];	/* Options that peer ack'd */
     54 ipcp_options ipcp_allowoptions[NUM_PPP]; /* Options we allow peer to request */
     55 ipcp_options ipcp_hisoptions[NUM_PPP];	/* Options that we ack'd */
     56 
     57 bool	ipcp_from_hostname = 0;	/* Local IP address is from hostname lookup */
     58 
     59 /* Hook for a plugin to know when IP protocol has come up */
     60 void (*ip_up_hook) __P((void)) = NULL;
     61 
     62 /* Hook for a plugin to know when IP protocol has come down */
     63 void (*ip_down_hook) __P((void)) = NULL;
     64 
     65 /* local vars */
     66 static bool default_route_set[NUM_PPP];	/* Have set up a default route */
     67 static bool proxy_arp_set[NUM_PPP];	/* Have created proxy arp entry */
     68 static bool ipcp_is_up[NUM_PPP];	/* have called np_up() */
     69 static bool proxy_arp_quiet[NUM_PPP];	/* We should be quiet on error */
     70 static bool disable_defaultip = 0;	/* Don't use hostname for IP addr */
     71 
     72 /*
     73  * Callbacks for fsm code.  (CI = Configuration Information)
     74  */
     75 static void ipcp_resetci __P((fsm *));	/* Reset our CI */
     76 static int  ipcp_cilen __P((fsm *));	        /* Return length of our CI */
     77 static void ipcp_addci __P((fsm *, u_char *, int *)); /* Add our CI */
     78 static int  ipcp_ackci __P((fsm *, u_char *, int));	/* Peer ack'd our CI */
     79 static int  ipcp_nakci __P((fsm *, u_char *, int));	/* Peer nak'd our CI */
     80 static int  ipcp_rejci __P((fsm *, u_char *, int));	/* Peer rej'd our CI */
     81 static int  ipcp_reqci __P((fsm *, u_char *, int *, int)); /* Rcv CI */
     82 static void ipcp_up __P((fsm *));		/* We're UP */
     83 static void ipcp_down __P((fsm *));		/* We're DOWN */
     84 static void ipcp_finished __P((fsm *));	/* Don't need lower layer */
     85 static int  setmsservaddr __P((char *, u_int32_t *));
     86 
     87 fsm ipcp_fsm[NUM_PPP];		/* IPCP fsm structure */
     88 
     89 static fsm_callbacks ipcp_callbacks = { /* IPCP callback routines */
     90     ipcp_resetci,		/* Reset our Configuration Information */
     91     ipcp_cilen,			/* Length of our Configuration Information */
     92     ipcp_addci,			/* Add our Configuration Information */
     93     ipcp_ackci,			/* ACK our Configuration Information */
     94     ipcp_nakci,			/* NAK our Configuration Information */
     95     ipcp_rejci,			/* Reject our Configuration Information */
     96     ipcp_reqci,			/* Request peer's Configuration Information */
     97     ipcp_up,			/* Called when fsm reaches OPENED state */
     98     ipcp_down,			/* Called when fsm leaves OPENED state */
     99     NULL,			/* Called when we want the lower layer up */
    100     ipcp_finished,		/* Called when we want the lower layer down */
    101     NULL,			/* Retransmission is necessary */
    102     NULL,			/* Called to handle protocol-specific codes */
    103     "IPCP",			/* String name of protocol */
    104     NULL			/* Peer rejected a code number */
    105 };
    106 
    107 /*
    108  * Command-line options.
    109  */
    110 static int setvjslots __P((char **));
    111 static int setdnsaddr __P((char **));
    112 static int setwinsaddr __P((char **));
    113 static int autoproxyarp __P((char **));
    114 
    115 static option_t ipcp_option_list[] = {
    116     { "noip", o_bool, &ipcp_protent.enabled_flag,
    117       "Disable IP and IPCP" },
    118     { "-ip", o_bool, &ipcp_protent.enabled_flag,
    119       "Disable IP and IPCP" },
    120     { "novj", o_bool, &ipcp_wantoptions[0].neg_vj,
    121       "Disable VJ compression", OPT_A2COPY, &ipcp_allowoptions[0].neg_vj },
    122     { "-vj", o_bool, &ipcp_wantoptions[0].neg_vj,
    123       "Disable VJ compression", OPT_A2COPY, &ipcp_allowoptions[0].neg_vj },
    124     { "novjccomp", o_bool, &ipcp_wantoptions[0].cflag,
    125       "Disable VJ connection-ID compression", OPT_A2COPY,
    126       &ipcp_allowoptions[0].cflag },
    127     { "-vjccomp", o_bool, &ipcp_wantoptions[0].cflag,
    128       "Disable VJ connection-ID compression", OPT_A2COPY,
    129       &ipcp_allowoptions[0].cflag },
    130     { "vj-max-slots", o_special, (void *)setvjslots,
    131       "Set maximum VJ header slots" },
    132     { "ipcp-accept-local", o_bool, &ipcp_wantoptions[0].accept_local,
    133       "Accept peer's address for us", 1 },
    134     { "ipcp-accept-remote", o_bool, &ipcp_wantoptions[0].accept_remote,
    135       "Accept peer's address for it", 1 },
    136     { "ipparam", o_string, &ipparam,
    137       "Set ip script parameter" },
    138     { "noipdefault", o_bool, &disable_defaultip,
    139       "Don't use name for default IP adrs", 1 },
    140     { "ms-dns", o_special, (void *)setdnsaddr,
    141       "DNS address for the peer's use" },
    142     { "ms-wins", o_special, (void *)setwinsaddr,
    143       "Nameserver for SMB over TCP/IP for peer" },
    144     { "ipcp-restart", o_int, &ipcp_fsm[0].timeouttime,
    145       "Set timeout for IPCP" },
    146     { "ipcp-max-terminate", o_int, &ipcp_fsm[0].maxtermtransmits,
    147       "Set max #xmits for term-reqs" },
    148     { "ipcp-max-configure", o_int, &ipcp_fsm[0].maxconfreqtransmits,
    149       "Set max #xmits for conf-reqs" },
    150     { "ipcp-max-failure", o_int, &ipcp_fsm[0].maxnakloops,
    151       "Set max #conf-naks for IPCP" },
    152     { "defaultroute", o_bool, &ipcp_wantoptions[0].default_route,
    153       "Add default route", OPT_ENABLE|1, &ipcp_allowoptions[0].default_route },
    154     { "nodefaultroute", o_bool, &ipcp_allowoptions[0].default_route,
    155       "disable defaultroute option", OPT_A2COPY,
    156       &ipcp_wantoptions[0].default_route },
    157     { "-defaultroute", o_bool, &ipcp_allowoptions[0].default_route,
    158       "disable defaultroute option", OPT_A2COPY,
    159       &ipcp_wantoptions[0].default_route },
    160     { "proxyarp", o_bool, &ipcp_wantoptions[0].proxy_arp,
    161       "Add proxy ARP entry", OPT_ENABLE|1, &ipcp_allowoptions[0].proxy_arp },
    162     { "autoproxyarp", o_special_noarg, (void *)autoproxyarp,
    163       "Add proxy ARP entry if needed", OPT_ENABLE,
    164       &ipcp_allowoptions[0].proxy_arp },
    165     { "noproxyarp", o_bool, &ipcp_allowoptions[0].proxy_arp,
    166       "disable proxyarp option", OPT_A2COPY, &ipcp_wantoptions[0].proxy_arp },
    167     { "-proxyarp", o_bool, &ipcp_allowoptions[0].proxy_arp,
    168       "disable proxyarp option", OPT_A2COPY, &ipcp_wantoptions[0].proxy_arp },
    169     { "usepeerdns", o_bool, &ipcp_wantoptions[0].req_dns1,
    170       "Ask peer for DNS address(es)", OPT_A2COPY|1,
    171       &ipcp_wantoptions[0].req_dns2 },
    172     { NULL }
    173 };
    174 
    175 /*
    176  * Protocol entry points from main code.
    177  */
    178 static void ipcp_init __P((int));
    179 static void ipcp_open __P((int));
    180 static void ipcp_close __P((int, char *));
    181 static void ipcp_lowerup __P((int));
    182 static void ipcp_lowerdown __P((int));
    183 static void ipcp_input __P((int, u_char *, int));
    184 static void ipcp_protrej __P((int));
    185 static int  ipcp_printpkt __P((u_char *, int,
    186     void (*) __P((void *, const char *, ...)), void *));
    187 static void ip_check_options __P((void));
    188 static int  ip_demand_conf __P((int));
    189 static int  ip_active_pkt __P((u_char *, int));
    190 static void ipcp_print_stat __P((int, FILE *));
    191 
    192 static void create_resolv __P((u_int32_t, u_int32_t));
    193 
    194 struct protent ipcp_protent = {
    195     PPP_IPCP,
    196     ipcp_init,
    197     ipcp_input,
    198     ipcp_protrej,
    199     ipcp_lowerup,
    200     ipcp_lowerdown,
    201     ipcp_open,
    202     ipcp_close,
    203     ipcp_printpkt,
    204     NULL,
    205     1,
    206     "IPCP",
    207     "IP",
    208     ipcp_option_list,
    209     ip_check_options,
    210     ip_demand_conf,
    211     ip_active_pkt,
    212     ipcp_print_stat
    213 };
    214 
    215 static void ipcp_clear_addrs __P((int, u_int32_t, u_int32_t));
    216 static void ipcp_script __P((char *));		/* Run an up/down script */
    217 static void ipcp_script_done __P((void *, int));
    218 
    219 /*
    220  * Lengths of configuration options.
    221  */
    222 #define CILEN_VOID	2
    223 #define CILEN_COMPRESS	4	/* min length for compression protocol opt. */
    224 #define CILEN_VJ	6	/* length for RFC1332 Van-Jacobson opt. */
    225 #define CILEN_ADDR	6	/* new-style single address option */
    226 #define CILEN_ADDRS	10	/* old-style dual address option */
    227 
    228 
    229 /*
    230  * This state variable is used to ensure that we don't
    231  * run an ipcp-up/down script while one is already running.
    232  */
    233 static enum script_state {
    234     s_down,
    235     s_up
    236 } ipcp_script_state;
    237 static pid_t ipcp_script_pid;
    238 
    239 /*
    240  * Make a string representation of a network IP address.
    241  */
    242 char *
    243 ip_ntoa(ipaddr)
    244 u_int32_t ipaddr;
    245 {
    246     static char b[64];
    247 
    248     (void) slprintf(b, sizeof(b), "%I", ipaddr);
    249     return b;
    250 }
    251 
    252 /*
    253  * Option parsing.
    254  */
    255 
    256 /*
    257  * setvjslots - set maximum number of connection slots for VJ compression
    258  */
    259 static int
    260 setvjslots(argv)
    261     char **argv;
    262 {
    263     int value;
    264 
    265     if (!int_option(*argv, &value))
    266 	return 0;
    267     if (value < 2 || value > 16) {
    268 	option_error("vj-max-slots value must be between 2 and 16");
    269 	return 0;
    270     }
    271     ipcp_wantoptions [0].maxslotindex =
    272         ipcp_allowoptions[0].maxslotindex = value - 1;
    273     return 1;
    274 }
    275 
    276 /*
    277  * setmsservaddr - Set the primary and secondary server addresses in the
    278  * array.  setdnsaddr() and setwinsaddr() call this function with either
    279  * dnsaddr[] or winsaddr[] as the serverarray argument.
    280  */
    281 static int
    282 setmsservaddr(servname, serverarray)
    283     char *servname;
    284     u_int32_t *serverarray;
    285 {
    286     u_int32_t addr;
    287     struct hostent *hp = NULL;
    288 
    289     addr = inet_addr(servname);
    290     if (addr == (u_int32_t) -1) {
    291 	if ((hp = gethostbyname(servname)) == NULL)
    292 	    return 0;
    293 	BCOPY(hp->h_addr, &addr, sizeof (u_int32_t));
    294     }
    295 
    296     /*
    297      * If there is no primary then this is the first instance of the
    298      * option, we must set the primary.  In that case, try to set the
    299      * secondary to h_addr_list[1].  If the primary is already set, then
    300      * this is the second instance of the option, and we must set
    301      * the secondary.
    302      */
    303     if (serverarray[0] == 0) {
    304 	serverarray[0] = addr;
    305 	if (hp != NULL && hp->h_addr_list[1] != NULL)
    306 	    BCOPY(hp->h_addr_list[1], &serverarray[1], sizeof (u_int32_t));
    307 	else
    308 	    serverarray[1] = addr;
    309     } else {
    310 	serverarray[1] = addr;
    311     }
    312 
    313     return (1);
    314 }
    315 
    316 /*
    317  * setdnsaddr - set the dns address(es)
    318  */
    319 static int
    320 setdnsaddr(argv)
    321     char **argv;
    322 {
    323     if (setmsservaddr(*argv, &(ipcp_allowoptions[0].dnsaddr[0])) == 0) {
    324 	option_error("invalid address parameter '%s' for ms-dns option", *argv);
    325 	return (0);
    326     }
    327 
    328     return (1);
    329 }
    330 
    331 /*
    332  * setwinsaddr - set the wins address(es)
    333  * This is primrarly used with the Samba package under UNIX or for pointing
    334  * the caller to the existing WINS server on a Windows NT platform.
    335  */
    336 static int
    337 setwinsaddr(argv)
    338     char **argv;
    339 {
    340     if (setmsservaddr(*argv, &(ipcp_allowoptions[0].winsaddr[0])) == 0) {
    341 	option_error("invalid address parameter '%s' for ms-wins option",
    342 	    *argv);
    343 	return (0);
    344     }
    345 
    346     return (1);
    347 }
    348 
    349 /*
    350  * autoproxyarp -- enable proxy ARP but don't emit error messages if
    351  * it's not actually needed.
    352  */
    353 /*ARGSUSED*/
    354 static int
    355 autoproxyarp(argv)
    356     char **argv;
    357 {
    358     ipcp_wantoptions[0].proxy_arp = 1;
    359     proxy_arp_quiet[0] = 1;
    360 
    361     return (1);
    362 }
    363 
    364 
    365 /*
    366  * ipcp_init - Initialize IPCP.
    367  */
    368 static void
    369 ipcp_init(unit)
    370     int unit;
    371 {
    372     fsm *f = &ipcp_fsm[unit];
    373     ipcp_options *wo = &ipcp_wantoptions[unit];
    374     ipcp_options *ao = &ipcp_allowoptions[unit];
    375 
    376     f->unit = unit;
    377     f->protocol = PPP_IPCP;
    378     f->callbacks = &ipcp_callbacks;
    379     fsm_init(&ipcp_fsm[unit]);
    380 
    381     BZERO(wo, sizeof(*wo));
    382     BZERO(ao, sizeof(*ao));
    383 
    384     wo->neg_addr = wo->old_addrs = 1;
    385     wo->neg_vj = 1;
    386     wo->vj_protocol = IPCP_VJ_COMP;
    387     wo->maxslotindex = MAX_STATES - 1; /* really max index */
    388     wo->cflag = 1;
    389 
    390     ao->neg_addr = ao->old_addrs = 1;
    391     ao->neg_vj = 1;
    392     ao->maxslotindex = MAX_STATES - 1;
    393     ao->cflag = 1;
    394 
    395     /*
    396      * These aren't actually negotiated.  Instead, they control
    397      * whether the user may use the proxyarp and defaultroute options.
    398      */
    399     ao->proxy_arp = 1;
    400     ao->default_route = 1;
    401     proxy_arp_quiet[unit] = 0;
    402 }
    403 
    404 
    405 /*
    406  * ipcp_open - IPCP is allowed to come up.
    407  */
    408 static void
    409 ipcp_open(unit)
    410     int unit;
    411 {
    412     fsm_open(&ipcp_fsm[unit]);
    413 }
    414 
    415 
    416 /*
    417  * ipcp_close - Take IPCP down.
    418  */
    419 static void
    420 ipcp_close(unit, reason)
    421     int unit;
    422     char *reason;
    423 {
    424     fsm_close(&ipcp_fsm[unit], reason);
    425 }
    426 
    427 
    428 /*
    429  * ipcp_lowerup - The lower layer is up.
    430  */
    431 static void
    432 ipcp_lowerup(unit)
    433     int unit;
    434 {
    435     fsm_lowerup(&ipcp_fsm[unit]);
    436 }
    437 
    438 
    439 /*
    440  * ipcp_lowerdown - The lower layer is down.
    441  */
    442 static void
    443 ipcp_lowerdown(unit)
    444     int unit;
    445 {
    446     fsm_lowerdown(&ipcp_fsm[unit]);
    447 }
    448 
    449 
    450 /*
    451  * ipcp_input - Input IPCP packet.
    452  */
    453 static void
    454 ipcp_input(unit, p, len)
    455     int unit;
    456     u_char *p;
    457     int len;
    458 {
    459     fsm_input(&ipcp_fsm[unit], p, len);
    460 }
    461 
    462 
    463 /*
    464  * ipcp_protrej - A Protocol-Reject was received for IPCP.
    465  */
    466 static void
    467 ipcp_protrej(unit)
    468     int unit;
    469 {
    470     fsm_protreject(&ipcp_fsm[unit]);
    471 }
    472 
    473 
    474 /*
    475  * ipcp_resetci - Reset our CI.
    476  * Called by fsm_sconfreq, Send Configure Request.
    477  */
    478 static void
    479 ipcp_resetci(f)
    480     fsm *f;
    481 {
    482     ipcp_options *wo = &ipcp_wantoptions[f->unit];
    483     ipcp_options *go = &ipcp_gotoptions[f->unit];
    484     ipcp_options *ao = &ipcp_allowoptions[f->unit];
    485 
    486     wo->req_addr = (wo->neg_addr || wo->old_addrs) &&
    487 	(ao->neg_addr || ao->old_addrs);
    488     if (wo->ouraddr == 0 || disable_defaultip)
    489 	wo->accept_local = 1;
    490     if (wo->hisaddr == 0)
    491 	wo->accept_remote = 1;
    492     *go = *wo;
    493     if (disable_defaultip)
    494 	go->ouraddr = 0;
    495 }
    496 
    497 
    498 /*
    499  * ipcp_cilen - Return length of our CI.
    500  * Called by fsm_sconfreq, Send Configure Request.
    501  */
    502 static int
    503 ipcp_cilen(f)
    504     fsm *f;
    505 {
    506     ipcp_options *go = &ipcp_gotoptions[f->unit];
    507     ipcp_options *wo = &ipcp_wantoptions[f->unit];
    508     ipcp_options *ho = &ipcp_hisoptions[f->unit];
    509 
    510 #define LENCIADDRS(neg)		(neg ? CILEN_ADDRS : 0)
    511 #define LENCIVJ(neg, old)	(neg ? (old? CILEN_COMPRESS : CILEN_VJ) : 0)
    512 #define LENCIADDR(neg)		(neg ? (CILEN_ADDR) : 0)
    513 
    514     /*
    515      * First see if we want to change our options to the old
    516      * forms because we have received old forms from the peer.
    517      */
    518     if (go->neg_addr && go->old_addrs && !ho->neg_addr && ho->old_addrs)
    519 	/* use the old style of address negotiation */
    520 	go->neg_addr = 0;
    521     if (wo->neg_vj && !go->neg_vj && !go->old_vj) {
    522 	/* try an older style of VJ negotiation */
    523 	/* use the old style only if the peer did */
    524 	if (ho->neg_vj && ho->old_vj) {
    525 	    go->neg_vj = 1;
    526 	    go->old_vj = 1;
    527 	    go->vj_protocol = ho->vj_protocol;
    528 	}
    529     }
    530 
    531     return (LENCIADDRS(!go->neg_addr && go->old_addrs) +
    532 	    LENCIVJ(go->neg_vj, go->old_vj) +
    533 	    LENCIADDR(go->neg_addr) +
    534 	    LENCIADDR(go->req_dns1) +
    535 	    LENCIADDR(go->req_dns2)) ;
    536 }
    537 
    538 
    539 /*
    540  * ipcp_addci - Add our desired CIs to a packet.
    541  * Called by fsm_sconfreq, Send Configure Request.
    542  */
    543 static void
    544 ipcp_addci(f, ucp, lenp)
    545     fsm *f;
    546     u_char *ucp;
    547     int *lenp;
    548 {
    549     ipcp_options *go = &ipcp_gotoptions[f->unit];
    550     int len = *lenp;
    551 
    552 #define ADDCIADDRS(opt, neg, val1, val2) \
    553     if (neg) { \
    554 	if (len >= CILEN_ADDRS) { \
    555 	    PUTCHAR(opt, ucp); \
    556 	    PUTCHAR(CILEN_ADDRS, ucp); \
    557 	    PUTNLONG(val1, ucp); \
    558 	    PUTNLONG(val2, ucp); \
    559 	    len -= CILEN_ADDRS; \
    560 	} else \
    561 	    go->old_addrs = 0; \
    562     }
    563 
    564 #define ADDCIVJ(opt, neg, val, old, maxslotindex, cflag) \
    565     if (neg) { \
    566 	int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
    567 	if (len >= vjlen) { \
    568 	    PUTCHAR(opt, ucp); \
    569 	    PUTCHAR(vjlen, ucp); \
    570 	    PUTSHORT(val, ucp); \
    571 	    if (!old) { \
    572 		PUTCHAR(maxslotindex, ucp); \
    573 		PUTCHAR(cflag, ucp); \
    574 	    } \
    575 	    len -= vjlen; \
    576 	} else \
    577 	    neg = 0; \
    578     }
    579 
    580 #define ADDCIADDR(opt, neg, val) \
    581     if (neg) { \
    582 	if (len >= CILEN_ADDR) { \
    583 	    PUTCHAR(opt, ucp); \
    584 	    PUTCHAR(CILEN_ADDR, ucp); \
    585 	    PUTNLONG(val, ucp); \
    586 	    len -= CILEN_ADDR; \
    587 	} else \
    588 	    neg = 0; \
    589     }
    590 
    591     ADDCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs, go->ouraddr,
    592 	       go->hisaddr);
    593 
    594     ADDCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
    595 	    go->maxslotindex, go->cflag);
    596 
    597     ADDCIADDR(CI_ADDR, go->neg_addr, go->ouraddr);
    598 
    599     ADDCIADDR(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]);
    600 
    601     ADDCIADDR(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
    602 
    603     *lenp -= len;
    604 }
    605 
    606 
    607 /*
    608  * ipcp_ackci - Ack our CIs.
    609  * Called by fsm_rconfack, Receive Configure ACK.
    610  *
    611  * Returns:
    612  *	0 - Ack was bad.
    613  *	1 - Ack was good.
    614  */
    615 static int
    616 ipcp_ackci(f, p, len)
    617     fsm *f;
    618     u_char *p;
    619     int len;
    620 {
    621     ipcp_options *go = &ipcp_gotoptions[f->unit];
    622     u_short cilen, citype, cishort;
    623     u_int32_t cilong;
    624     u_char cimaxslotindex, cicflag;
    625 
    626     /*
    627      * CIs must be in exactly the same order that we sent...
    628      * Check packet length and CI length at each step.
    629      * If we find any deviations, then this packet is bad.
    630      */
    631 
    632 #define	ACKCHECK(opt, olen) \
    633 	if ((len -= olen) < 0) \
    634 	    goto bad; \
    635 	GETCHAR(citype, p); \
    636 	GETCHAR(cilen, p); \
    637 	if (cilen != olen || \
    638 	    citype != opt) \
    639 	    goto bad;
    640 
    641 #define ACKCIADDRS(opt, neg, val1, val2) \
    642     if (neg) { \
    643 	ACKCHECK(opt, CILEN_ADDRS) \
    644 	GETNLONG(cilong, p); \
    645 	if (val1 != cilong) \
    646 	    goto bad; \
    647 	GETNLONG(cilong, p); \
    648 	if (val2 != cilong) \
    649 	    goto bad; \
    650     }
    651 
    652 #define ACKCIVJ(opt, neg, val, old, maxslotindex, cflag) \
    653     if (neg) { \
    654 	int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
    655 	ACKCHECK(opt, vjlen) \
    656 	GETSHORT(cishort, p); \
    657 	if (cishort != val) \
    658 	    goto bad; \
    659 	if (!old) { \
    660 	    GETCHAR(cimaxslotindex, p); \
    661 	    if (cimaxslotindex != maxslotindex) \
    662 		goto bad; \
    663 	    GETCHAR(cicflag, p); \
    664 	    if (cicflag != cflag) \
    665 		goto bad; \
    666 	} \
    667     }
    668 
    669 #define ACKCIADDR(opt, neg, val) \
    670     if (neg) { \
    671 	ACKCHECK(opt, CILEN_ADDR) \
    672 	GETNLONG(cilong, p); \
    673 	if (val != cilong) \
    674 	    goto bad; \
    675     }
    676 
    677     ACKCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs, go->ouraddr,
    678 	       go->hisaddr);
    679 
    680     ACKCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
    681 	    go->maxslotindex, go->cflag);
    682 
    683     ACKCIADDR(CI_ADDR, go->neg_addr, go->ouraddr);
    684 
    685     ACKCIADDR(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]);
    686 
    687     ACKCIADDR(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
    688 
    689     /*
    690      * If there are any remaining CIs, then this packet is bad.
    691      */
    692     if (len != 0)
    693 	goto bad;
    694     return (1);
    695 
    696 bad:
    697     IPCPDEBUG(("ipcp_ackci: received bad Ack!"));
    698     return (0);
    699 }
    700 
    701 /*
    702  * ipcp_nakci - Peer has sent a NAK for some of our CIs.
    703  * This should not modify any state if the Nak is bad
    704  * or if IPCP is in the OPENED state.
    705  * Calback from fsm_rconfnakrej - Receive Configure-Nak or Configure-Reject.
    706  *
    707  * Returns:
    708  *	0 - Nak was bad.
    709  *	1 - Nak was good.
    710  */
    711 static int
    712 ipcp_nakci(f, p, len)
    713     fsm *f;
    714     u_char *p;
    715     int len;
    716 {
    717     ipcp_options *go = &ipcp_gotoptions[f->unit];
    718     u_char cimaxslotindex, cicflag;
    719     u_char citype, cilen, *next;
    720     u_short cishort;
    721     u_int32_t ciaddr1, ciaddr2;
    722     ipcp_options no;		/* options we've seen Naks for */
    723     ipcp_options try;		/* options to request next time */
    724 
    725     BZERO(&no, sizeof(no));
    726     try = *go;
    727 
    728     /*
    729      * Any Nak'd CIs must be in exactly the same order that we sent.
    730      * Check packet length and CI length at each step.
    731      * If we find any deviations, then this packet is bad.
    732      */
    733 #define NAKCIADDRS(opt, neg, code) \
    734     if ((neg) && \
    735 	(cilen = p[1]) == CILEN_ADDRS && \
    736 	len >= cilen && \
    737 	p[0] == opt) { \
    738 	len -= cilen; \
    739 	INCPTR(2, p); \
    740 	GETNLONG(ciaddr1, p); \
    741 	GETNLONG(ciaddr2, p); \
    742 	no.old_addrs = 1; \
    743 	code \
    744     }
    745 
    746 #define NAKCIVJ(opt, neg, code) \
    747     if (go->neg && \
    748 	((cilen = p[1]) == CILEN_COMPRESS || cilen == CILEN_VJ) && \
    749 	len >= cilen && \
    750 	p[0] == opt) { \
    751 	len -= cilen; \
    752 	INCPTR(2, p); \
    753 	GETSHORT(cishort, p); \
    754 	no.neg = 1; \
    755         code \
    756     }
    757 
    758 #define NAKCIADDR(opt, neg, code) \
    759     if (go->neg && \
    760 	(cilen = p[1]) == CILEN_ADDR && \
    761 	len >= cilen && \
    762 	p[0] == opt) { \
    763 	len -= cilen; \
    764 	INCPTR(2, p); \
    765 	GETNLONG(ciaddr1, p); \
    766 	no.neg = 1; \
    767 	code \
    768     }
    769 
    770     /*
    771      * Accept the peer's idea of {our,his} address, if different
    772      * from our idea, only if the accept_{local,remote} flag is set.
    773      */
    774     NAKCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs,
    775 	      if (go->accept_local && ciaddr1) { /* Do we know our address? */
    776 		  try.ouraddr = ciaddr1;
    777 	      }
    778 	      if (go->accept_remote && ciaddr2) { /* Does he know his? */
    779 		  try.hisaddr = ciaddr2;
    780 	      }
    781 	      );
    782 
    783     /*
    784      * Accept the peer's value of maxslotindex provided that it
    785      * is less than what we asked for.  Turn off slot-ID compression
    786      * if the peer wants.  Send old-style compress-type option if
    787      * the peer wants.
    788      */
    789     NAKCIVJ(CI_COMPRESSTYPE, neg_vj,
    790 	    if (cilen == CILEN_VJ) {
    791 		GETCHAR(cimaxslotindex, p);
    792 		GETCHAR(cicflag, p);
    793 		if (cishort == IPCP_VJ_COMP) {
    794 		    try.old_vj = 0;
    795 		    if (cimaxslotindex < go->maxslotindex)
    796 			try.maxslotindex = cimaxslotindex;
    797 		    if (!cicflag)
    798 			try.cflag = 0;
    799 		} else {
    800 		    try.neg_vj = 0;
    801 		}
    802 	    } else {
    803 		if (cishort == IPCP_VJ_COMP || cishort == IPCP_VJ_COMP_OLD) {
    804 		    try.old_vj = 1;
    805 		    try.vj_protocol = cishort;
    806 		} else {
    807 		    try.neg_vj = 0;
    808 		}
    809 	    }
    810 	    );
    811 
    812     NAKCIADDR(CI_ADDR, neg_addr,
    813 	      if (go->accept_local && ciaddr1) { /* Do we know our address? */
    814 		  try.ouraddr = ciaddr1;
    815 	      }
    816 	      );
    817 
    818     NAKCIADDR(CI_MS_DNS1, req_dns1,
    819 	      try.dnsaddr[0] = ciaddr1;
    820 	      );
    821 
    822     NAKCIADDR(CI_MS_DNS2, req_dns2,
    823 	      try.dnsaddr[1] = ciaddr1;
    824 	      );
    825 
    826     /*
    827      * There may be remaining CIs, if the peer is requesting negotiation
    828      * on an option that we didn't include in our request packet.
    829      * If they want to negotiate about IP addresses, we comply.
    830      * If they want us to ask for compression, we refuse.
    831      */
    832     while (len > CILEN_VOID) {
    833 	GETCHAR(citype, p);
    834 	GETCHAR(cilen, p);
    835 	if( (len -= cilen) < 0 )
    836 	    goto bad;
    837 	next = p + cilen - 2;
    838 
    839 	switch (citype) {
    840 	case CI_COMPRESSTYPE:
    841 	    if (go->neg_vj || no.neg_vj ||
    842 		(cilen != CILEN_VJ && cilen != CILEN_COMPRESS))
    843 		goto bad;
    844 	    no.neg_vj = 1;
    845 	    break;
    846 	case CI_ADDRS:
    847 	    if ((!go->neg_addr && go->old_addrs) || no.old_addrs
    848 		|| cilen != CILEN_ADDRS)
    849 		goto bad;
    850 	    try.neg_addr = 1;
    851 	    try.old_addrs = 1;
    852 	    GETNLONG(ciaddr1, p);
    853 	    if (ciaddr1 && go->accept_local)
    854 		try.ouraddr = ciaddr1;
    855 	    GETNLONG(ciaddr2, p);
    856 	    if (ciaddr2 && go->accept_remote)
    857 		try.hisaddr = ciaddr2;
    858 	    no.old_addrs = 1;
    859 	    break;
    860 	case CI_ADDR:
    861 	    if (go->neg_addr || no.neg_addr || cilen != CILEN_ADDR)
    862 		goto bad;
    863 	    try.old_addrs = 0;
    864 	    GETNLONG(ciaddr1, p);
    865 	    if (ciaddr1 && go->accept_local)
    866 		try.ouraddr = ciaddr1;
    867 	    if (try.ouraddr != 0)
    868 		try.neg_addr = 1;
    869 	    no.neg_addr = 1;
    870 	    break;
    871 	}
    872 	p = next;
    873     }
    874 
    875     /*
    876      * OK, the Nak is good.  Now we can update state.
    877      * If there are any remaining options, we ignore them.
    878      */
    879     if (f->state != OPENED)
    880 	*go = try;
    881 
    882     return 1;
    883 
    884 bad:
    885     IPCPDEBUG(("ipcp_nakci: received bad Nak!"));
    886     return 0;
    887 }
    888 
    889 
    890 /*
    891  * ipcp_rejci - Reject some of our CIs.
    892  * Callback from fsm_rconfnakrej.
    893  */
    894 static int
    895 ipcp_rejci(f, p, len)
    896     fsm *f;
    897     u_char *p;
    898     int len;
    899 {
    900     ipcp_options *go = &ipcp_gotoptions[f->unit];
    901     u_char cimaxslotindex, ciflag, cilen;
    902     u_short cishort;
    903     u_int32_t cilong;
    904     ipcp_options try;		/* options to request next time */
    905 
    906     try = *go;
    907     /*
    908      * Any Rejected CIs must be in exactly the same order that we sent.
    909      * Check packet length and CI length at each step.
    910      * If we find any deviations, then this packet is bad.
    911      */
    912 #define REJCIADDRS(opt, neg, val1, val2) \
    913     if ((neg) && \
    914 	(cilen = p[1]) == CILEN_ADDRS && \
    915 	len >= cilen && \
    916 	p[0] == opt) { \
    917 	len -= cilen; \
    918 	INCPTR(2, p); \
    919 	GETNLONG(cilong, p); \
    920 	/* Check rejected value. */ \
    921 	if (cilong != val1) \
    922 	    goto bad; \
    923 	GETNLONG(cilong, p); \
    924 	/* Check rejected value. */ \
    925 	if (cilong != val2) \
    926 	    goto bad; \
    927 	try.old_addrs = 0; \
    928     }
    929 
    930 #define REJCIVJ(opt, neg, val, old, maxslot, cflag) \
    931     if (go->neg && \
    932 	p[1] == (old? CILEN_COMPRESS : CILEN_VJ) && \
    933 	len >= p[1] && \
    934 	p[0] == opt) { \
    935 	len -= p[1]; \
    936 	INCPTR(2, p); \
    937 	GETSHORT(cishort, p); \
    938 	/* Check rejected value. */  \
    939 	if (cishort != val) \
    940 	    goto bad; \
    941 	if (!old) { \
    942 	   GETCHAR(cimaxslotindex, p); \
    943 	   if (cimaxslotindex != maxslot) \
    944 	     goto bad; \
    945 	   GETCHAR(ciflag, p); \
    946 	   if (ciflag != cflag) \
    947 	     goto bad; \
    948         } \
    949 	try.neg = 0; \
    950      }
    951 
    952 #define REJCIADDR(opt, neg, addr) \
    953     if (go->neg && \
    954 	((cilen = p[1]) == CILEN_ADDR) && \
    955 	len >= cilen && \
    956 	p[0] == opt) { \
    957 	len -= cilen; \
    958 	INCPTR(2, p); \
    959 	GETNLONG(cilong, p); \
    960 	/* Check rejected value. */ \
    961 	if (cilong != addr) \
    962 	    goto bad; \
    963 	try.neg = 0; \
    964     }
    965 
    966     REJCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs,
    967 	       go->ouraddr, go->hisaddr);
    968 
    969     REJCIVJ(CI_COMPRESSTYPE, neg_vj, go->vj_protocol, go->old_vj,
    970 	    go->maxslotindex, go->cflag);
    971 
    972     REJCIADDR(CI_ADDR, neg_addr, go->ouraddr);
    973 
    974     REJCIADDR(CI_MS_DNS1, req_dns1, go->dnsaddr[0]);
    975 
    976     REJCIADDR(CI_MS_DNS2, req_dns2, go->dnsaddr[1]);
    977 
    978     /*
    979      * If there are any remaining CIs, then this packet is bad.
    980      */
    981     if (len != 0)
    982 	goto bad;
    983     /*
    984      * Now we can update state.
    985      */
    986     if (f->state != OPENED)
    987 	*go = try;
    988     return 1;
    989 
    990 bad:
    991     IPCPDEBUG(("ipcp_rejci: received bad Reject!"));
    992     return 0;
    993 }
    994 
    995 
    996 /*
    997  * ipcp_reqci - Check the peer's requested CIs and send appropriate response.
    998  * Callback from fsm_rconfreq, Receive Configure Request
    999  *
   1000  * Returns: CODE_CONFACK, CODE_CONFNAK or CODE_CONFREJ and input
   1001  * packet modified appropriately.  If reject_if_disagree is non-zero,
   1002  * doesn't return CODE_CONFNAK; returns CODE_CONFREJ if it can't
   1003  * return CODE_CONFACK.
   1004  */
   1005 static int
   1006 ipcp_reqci(f, p, lenp, dont_nak)
   1007     fsm *f;
   1008     u_char *p;		/* Requested CIs */
   1009     int *lenp;			/* Length of requested CIs */
   1010     bool dont_nak;
   1011 {
   1012     ipcp_options *wo = &ipcp_wantoptions[f->unit];
   1013     ipcp_options *ho = &ipcp_hisoptions[f->unit];
   1014     ipcp_options *ao = &ipcp_allowoptions[f->unit];
   1015     ipcp_options *go = &ipcp_gotoptions[f->unit];
   1016     int ret, newret;
   1017     u_char *p0, *nakp, *rejp, *prev;
   1018     u_short cishort;
   1019     int len, cilen, type;
   1020     u_int32_t tl, ciaddr1, ciaddr2;	/* Parsed address values */
   1021     u_char maxslotindex, cflag;
   1022     int d;
   1023 
   1024     ret = CODE_CONFACK;
   1025     rejp = p0 = p;
   1026     nakp = nak_buffer;
   1027 
   1028     /*
   1029      * Reset all his options.
   1030      */
   1031     BZERO(ho, sizeof(*ho));
   1032 
   1033     /*
   1034      * Process all his options.
   1035      */
   1036     for (len = *lenp; len > 0; len -= cilen, p = prev + cilen) {
   1037 	if ((len < 2) || p[1] > len) {
   1038 	    /*
   1039 	     * RFC 1661 page 40 -- if the option extends beyond the
   1040 	     * packet, then discard the entire packet.
   1041 	     */
   1042 	    return (0);
   1043 	}
   1044 
   1045 	newret = CODE_CONFACK;
   1046 	prev = p;
   1047 	GETCHAR(type, p);
   1048 	GETCHAR(cilen, p);
   1049 
   1050 	switch (type) {		/* Check CI type */
   1051 	case CI_ADDRS:
   1052 	    if (!ao->old_addrs || ho->neg_addr) {
   1053 		newret = CODE_CONFREJ;
   1054 		break;
   1055 	    }
   1056 
   1057 	    if (cilen != CILEN_ADDRS) {
   1058 		/*
   1059 		 * rfc1661, page 40 -- a recongnized option with an
   1060 		 * invalid length should be Nak'ed.
   1061 		 */
   1062 		newret = CODE_CONFNAK;
   1063 		ciaddr1 = wo->hisaddr;
   1064 		ciaddr2 = wo->ouraddr;
   1065 	    } else {
   1066 
   1067 		/*
   1068 		 * If he has no address, or if we both have his
   1069 		 * address but disagree about it, then NAK it with our
   1070 		 * idea.  In particular, if we don't know his address,
   1071 		 * but he does, then accept it.
   1072 		 */
   1073 		GETNLONG(ciaddr1, p);
   1074 		if (ciaddr1 != wo->hisaddr &&
   1075 		    (ciaddr1 == 0 || !wo->accept_remote)) {
   1076 		    newret = CODE_CONFNAK;
   1077 		    ciaddr1 = wo->hisaddr;
   1078 		} else if (ciaddr1 == 0 && wo->hisaddr == 0) {
   1079 		    /*
   1080 		     * If neither we nor he knows his address, reject
   1081 		     * the option.
   1082 		     */
   1083 		    newret = CODE_CONFREJ;
   1084 		    wo->req_addr = 0;	/* don't NAK with 0.0.0.0 later */
   1085 		    break;
   1086 		} else if (ciaddr1 != 0) {
   1087 		    go->hisaddr = ciaddr1;
   1088 		}
   1089 
   1090 		/*
   1091 		 * If he doesn't know our address, or if we both have
   1092 		 * our address * but disagree about it, then NAK it
   1093 		 * with our idea.
   1094 		 */
   1095 		GETNLONG(ciaddr2, p);
   1096 		if (ciaddr2 != wo->ouraddr) {
   1097 		    if (ciaddr2 == 0 || !wo->accept_local) {
   1098 			newret = CODE_CONFNAK;
   1099 			ciaddr2 = wo->ouraddr;
   1100 		    } else {
   1101 			go->ouraddr = ciaddr2;	/* accept peer's idea */
   1102 		    }
   1103 		}
   1104 	    }
   1105 
   1106 	    if (newret == CODE_CONFNAK) {
   1107 		PUTCHAR(type, nakp);
   1108 		PUTCHAR(CILEN_ADDRS, nakp);
   1109 		PUTNLONG(ciaddr1, nakp);
   1110 		PUTNLONG(ciaddr2, nakp);
   1111 	    }
   1112 
   1113 	    ho->old_addrs = 1;
   1114 	    ho->hisaddr = ciaddr1;
   1115 	    ho->ouraddr = ciaddr2;
   1116 	    break;
   1117 
   1118 	case CI_ADDR:
   1119 	    if (!ao->neg_addr || ho->old_addrs) {
   1120 		newret = CODE_CONFREJ;
   1121 		break;
   1122 	    }
   1123 
   1124 	    if (cilen != CILEN_ADDR) {
   1125 		/*
   1126 		 * rfc1661, page 40 -- a recongnized option with an
   1127 		 * invalid length should be Nak'ed.
   1128 		 */
   1129 		newret = CODE_CONFNAK;
   1130 		ciaddr1 = wo->hisaddr;
   1131 	    } else {
   1132 
   1133 		/*
   1134 		 * If he has no address, or if we both have his
   1135 		 * address but disagree about it, then NAK it with our
   1136 		 * idea.  In particular, if we don't know his address,
   1137 		 * but he does, then accept it.
   1138 		 */
   1139 		GETNLONG(ciaddr1, p);
   1140 		if (ciaddr1 != wo->hisaddr &&
   1141 		    (ciaddr1 == 0 || !wo->accept_remote)) {
   1142 		    newret = CODE_CONFNAK;
   1143 		    ciaddr1 = wo->hisaddr;
   1144 		} else if (ciaddr1 == 0 && wo->hisaddr == 0 &&
   1145 		    wo->default_route != 0) {
   1146 		    newret = CODE_CONFNAK;
   1147 		    /*
   1148 		     * If this is a dialup line (default_route is
   1149 		     * set), and neither side knows about his address,
   1150 		     * suggest an arbitrary rfc1918 address.
   1151 		     */
   1152 		    ciaddr1 = htonl(0xc0a80101 + ifunit);
   1153 		    dbglog("Peer address unknown; suggesting %I", ciaddr1);
   1154 		} else if (ciaddr1 == 0 && wo->hisaddr == 0) {
   1155 		    /*
   1156 		     * If this is not a dialup line, don't ACK an
   1157 		     * address of 0.0.0.0 - reject it instead.
   1158 		     */
   1159 		    newret = CODE_CONFREJ;
   1160 		    wo->req_addr = 0;	/* don't NAK with 0.0.0.0 later */
   1161 		    break;
   1162 		}
   1163 	    }
   1164 
   1165 	    if (newret == CODE_CONFNAK) {
   1166 		PUTCHAR(type, nakp);
   1167 		PUTCHAR(CILEN_ADDR, nakp);
   1168 		PUTNLONG(ciaddr1, nakp);
   1169 	    }
   1170 
   1171 	    ho->neg_addr = 1;
   1172 	    ho->hisaddr = ciaddr1;
   1173 	    break;
   1174 
   1175 	case CI_MS_DNS1:
   1176 	case CI_MS_DNS2:
   1177 	    /* Warning -- these options work backwards. */
   1178 	    /* Microsoft primary or secondary DNS request */
   1179 	    d = (type == CI_MS_DNS2 ? 1 : 0);
   1180 
   1181 	    if (ao->dnsaddr[d] == 0) {
   1182 		newret = CODE_CONFREJ;
   1183 		break;
   1184 	    }
   1185 
   1186 	    if (cilen != CILEN_ADDR) {
   1187 		newret = CODE_CONFNAK;
   1188 	    } else {
   1189 		GETNLONG(tl, p);
   1190 		if (tl != ao->dnsaddr[d]) {
   1191 		    newret = CODE_CONFNAK;
   1192 		}
   1193 	    }
   1194 
   1195 	    if (newret == CODE_CONFNAK) {
   1196 		PUTCHAR(type, nakp);
   1197 		PUTCHAR(CILEN_ADDR, nakp);
   1198 		PUTNLONG(ao->dnsaddr[d], nakp);
   1199 	    }
   1200             break;
   1201 
   1202 	case CI_MS_WINS1:
   1203 	case CI_MS_WINS2:
   1204 	    /* Warning -- these options work backwards. */
   1205 	    /* Microsoft primary or secondary WINS request */
   1206 	    d = (type == CI_MS_WINS2 ? 1 : 0);
   1207 
   1208 	    if (ao->winsaddr[d] == 0) {
   1209 		newret = CODE_CONFREJ;
   1210 		break;
   1211 	    }
   1212 
   1213 	    if (cilen != CILEN_ADDR) {
   1214 		newret = CODE_CONFNAK;
   1215 	    } else {
   1216 		GETNLONG(tl, p);
   1217 		if (tl != ao->winsaddr[d]) {
   1218 		    newret = CODE_CONFNAK;
   1219 		}
   1220 	    }
   1221 
   1222 	    if (newret == CODE_CONFNAK) {
   1223 		PUTCHAR(type, nakp);
   1224 		PUTCHAR(CILEN_ADDR, nakp);
   1225 		PUTNLONG(ao->winsaddr[d], nakp);
   1226 	    }
   1227             break;
   1228 
   1229 	case CI_COMPRESSTYPE:
   1230 	    if (!ao->neg_vj) {
   1231 		newret = CODE_CONFREJ;
   1232 		break;
   1233 	    }
   1234 
   1235 	    maxslotindex = ao->maxslotindex;
   1236 	    cflag = ao->cflag;
   1237 	    if (cilen != CILEN_VJ && cilen != CILEN_COMPRESS) {
   1238 		newret = CODE_CONFNAK;
   1239 		cishort = IPCP_VJ_COMP;
   1240 	    } else {
   1241 		GETSHORT(cishort, p);
   1242 		if (cishort != IPCP_VJ_COMP &&
   1243 		    (cishort != IPCP_VJ_COMP_OLD || cilen != CILEN_COMPRESS)) {
   1244 		    newret = CODE_CONFNAK;
   1245 		    cishort = IPCP_VJ_COMP;
   1246 		} else if (cilen == CILEN_VJ) {
   1247 		    GETCHAR(maxslotindex, p);
   1248 		    if (maxslotindex > ao->maxslotindex) {
   1249 			newret = CODE_CONFNAK;
   1250 			maxslotindex = ao->maxslotindex;
   1251 		    }
   1252 		    GETCHAR(cflag, p);
   1253 		    if (cflag != 0 && ao->cflag == 0) {
   1254 			newret = CODE_CONFNAK;
   1255 			cflag = 0;
   1256 		    }
   1257 		} else {
   1258 		    ho->old_vj = 1;
   1259 		    maxslotindex = MAX_STATES - 1;
   1260 		    cflag = 1;
   1261 		}
   1262 	    }
   1263 
   1264 	    if (newret == CODE_CONFNAK) {
   1265 		PUTCHAR(type, nakp);
   1266 		if (cishort == IPCP_VJ_COMP) {
   1267 		    PUTCHAR(CILEN_VJ, nakp);
   1268 		    PUTSHORT(cishort, nakp);
   1269 		    PUTCHAR(maxslotindex, nakp);
   1270 		    PUTCHAR(cflag, nakp);
   1271 		} else {
   1272 		    PUTCHAR(CILEN_COMPRESS, nakp);
   1273 		    PUTSHORT(cishort, nakp);
   1274 		}
   1275 	    }
   1276 	    ho->neg_vj = 1;
   1277 	    ho->vj_protocol = cishort;
   1278 	    ho->maxslotindex = maxslotindex;
   1279 	    ho->cflag = cflag;
   1280 	    break;
   1281 
   1282 	default:
   1283 	    newret = CODE_CONFREJ;
   1284 	    break;
   1285 	}
   1286 
   1287 	/* Cope with confused peers. */
   1288 	if (cilen < 2)
   1289 	    cilen = 2;
   1290 
   1291 	/*
   1292 	 * If this is an Ack'able CI, but we're sending back a Nak,
   1293 	 * don't include this CI.
   1294 	 */
   1295 	if (newret == CODE_CONFACK && ret != CODE_CONFACK)
   1296 	    continue;
   1297 
   1298 	if (newret == CODE_CONFNAK) {
   1299 	    if (dont_nak) {
   1300 		newret = CODE_CONFREJ;
   1301 	    } else {
   1302 		/* Ignore subsequent Nak'able things if rejecting. */
   1303 		if (ret == CODE_CONFREJ)
   1304 		    continue;
   1305 		ret = CODE_CONFNAK;
   1306 	    }
   1307 	}
   1308 
   1309 	if (newret == CODE_CONFREJ) {
   1310 	    ret = CODE_CONFREJ;
   1311 	    if (prev != rejp)
   1312 		BCOPY(prev, rejp, cilen);
   1313 	    rejp += cilen;
   1314 	}
   1315     }
   1316 
   1317     /*
   1318      * If we aren't rejecting this packet, and we want to negotiate
   1319      * their address, and they didn't send their address, then we
   1320      * send a NAK with a CI_ADDR option appended.  We assume the
   1321      * input buffer is long enough that we can append the extra
   1322      * option safely.
   1323      */
   1324     if (ret != CODE_CONFREJ && !ho->neg_addr && !ho->old_addrs &&
   1325 	wo->req_addr && !dont_nak) {
   1326 	if (ret == CODE_CONFACK)
   1327 	    wo->req_addr = 0;		/* don't ask again */
   1328 	ret = CODE_CONFNAK;
   1329 	PUTCHAR(CI_ADDR, nakp);
   1330 	PUTCHAR(CILEN_ADDR, nakp);
   1331 	PUTNLONG(wo->hisaddr, nakp);
   1332     }
   1333 
   1334     switch (ret) {
   1335     case CODE_CONFACK:
   1336 	*lenp = p - p0;
   1337 	sys_block_proto(PPP_IP);
   1338 	break;
   1339     case CODE_CONFNAK:
   1340 	*lenp = nakp - nak_buffer;
   1341 	BCOPY(nak_buffer, p0, *lenp);
   1342 	break;
   1343     case CODE_CONFREJ:
   1344 	*lenp = rejp - p0;
   1345 	break;
   1346     }
   1347 
   1348     return (ret);			/* Return final code */
   1349 }
   1350 
   1351 
   1352 /*
   1353  * ip_check_options - check that any IP-related options are OK,
   1354  * and assign appropriate defaults.
   1355  */
   1356 static void
   1357 ip_check_options()
   1358 {
   1359     struct hostent *hp;
   1360     u_int32_t local;
   1361     ipcp_options *wo = &ipcp_wantoptions[0];
   1362 
   1363     /*
   1364      * Default our local IP address based on our hostname.
   1365      * If local IP address already given, don't bother.
   1366      */
   1367     if (wo->ouraddr == 0) {
   1368 	/*
   1369 	 * Look up our hostname (possibly with domain name appended)
   1370 	 * and take the first IP address as our local IP address.
   1371 	 * If there isn't an IP address for our hostname, too bad.
   1372 	 */
   1373 	wo->accept_local = 1;	/* don't insist on this default value */
   1374 	if ((hp = gethostbyname(hostname)) != NULL) {
   1375 	    BCOPY(hp->h_addr, &local, sizeof (hp->h_addr));
   1376 	    if (local != 0 && !bad_ip_adrs(local)) {
   1377 		wo->ouraddr = local;
   1378 		ipcp_from_hostname = 1;
   1379 	    }
   1380 	}
   1381     }
   1382 }
   1383 
   1384 
   1385 /*
   1386  * ip_demand_conf - configure the interface as though
   1387  * IPCP were up, for use with dial-on-demand.
   1388  */
   1389 static int
   1390 ip_demand_conf(u)
   1391     int u;
   1392 {
   1393     ipcp_options *wo = &ipcp_wantoptions[u];
   1394 
   1395     if (wo->hisaddr == 0) {
   1396 	/* make up an arbitrary address for the peer */
   1397 	wo->hisaddr = htonl(0x0a707070 + ifunit);
   1398 	wo->accept_remote = 1;
   1399     }
   1400     if (wo->ouraddr == 0) {
   1401 	/* make up an arbitrary address for us */
   1402 	wo->ouraddr = htonl(0x0a404040 + ifunit);
   1403 	wo->accept_local = 1;
   1404 	disable_defaultip = 1;	/* don't tell the peer this address */
   1405     }
   1406     if (!sifaddr(u, wo->ouraddr, wo->hisaddr, GetMask(wo->ouraddr)))
   1407 	return 0;
   1408     if (!sifup(u))
   1409 	return 0;
   1410     if (!sifnpmode(u, PPP_IP, NPMODE_QUEUE))
   1411 	return 0;
   1412     if (wo->default_route && sifdefaultroute(u, wo->ouraddr, wo->hisaddr))
   1413 	default_route_set[u] = 1;
   1414     if (wo->proxy_arp && sifproxyarp(u, wo->hisaddr, proxy_arp_quiet[u]))
   1415 	proxy_arp_set[u] = 1;
   1416 
   1417     notice("local  IP address %I", wo->ouraddr);
   1418     notice("remote IP address %I", wo->hisaddr);
   1419 
   1420     return 1;
   1421 }
   1422 
   1423 
   1424 /*
   1425  * ipcp_up - IPCP has come UP.
   1426  *
   1427  * Configure the IP network interface appropriately and bring it up.
   1428  */
   1429 static void
   1430 ipcp_up(f)
   1431     fsm *f;
   1432 {
   1433     u_int32_t mask;
   1434     ipcp_options *ho = &ipcp_hisoptions[f->unit];
   1435     ipcp_options *go = &ipcp_gotoptions[f->unit];
   1436     ipcp_options *wo = &ipcp_wantoptions[f->unit];
   1437 
   1438     IPCPDEBUG(("ipcp: up"));
   1439 
   1440     /*
   1441      * We must have a non-zero IP address for both ends of the link.
   1442      */
   1443     if (ho->hisaddr == 0)
   1444 	ho->hisaddr = wo->hisaddr;
   1445 
   1446     if (ho->hisaddr == 0) {
   1447 	if (wo->accept_remote) {
   1448 	    /* Pick some rfc1918 address. */
   1449 	    ho->hisaddr = htonl(0xc0a80101 + ifunit);
   1450 	    dbglog("Peer refused to provide his address; assuming %I",
   1451 		ho->hisaddr);
   1452 	} else {
   1453 	    error("Could not determine remote IP address");
   1454 	    ipcp_close(f->unit, "Could not determine remote IP address");
   1455 	    return;
   1456 	}
   1457     }
   1458     if (go->ouraddr == 0) {
   1459 	error("Could not determine local IP address");
   1460 	ipcp_close(f->unit, "Could not determine local IP address");
   1461 	return;
   1462     }
   1463     script_setenv("IPLOCAL", ip_ntoa(go->ouraddr), 0);
   1464     script_setenv("IPREMOTE", ip_ntoa(ho->hisaddr), 1);
   1465 
   1466     /*
   1467      * Check that the peer is allowed to use the IP address it wants.
   1468      */
   1469     if (!auth_ip_addr(f->unit, ho->hisaddr)) {
   1470 	error("Peer is not authorized to use remote address %I", ho->hisaddr);
   1471 	ipcp_close(f->unit, "Unauthorized remote IP address");
   1472 	return;
   1473     }
   1474 
   1475     if ((go->req_dns1 && go->dnsaddr[0] != 0) ||
   1476 	(go->req_dns2 && go->dnsaddr[1] != 0)) {
   1477 	script_setenv("USEPEERDNS", "1", 0);
   1478 	if (go->dnsaddr[0] != 0)
   1479 	    script_setenv("DNS1", ip_ntoa(go->dnsaddr[0]), 0);
   1480 	if (go->dnsaddr[1] != 0)
   1481 	    script_setenv("DNS2", ip_ntoa(go->dnsaddr[1]), 0);
   1482 	create_resolv(go->dnsaddr[0], go->dnsaddr[1]);
   1483     }
   1484 
   1485     /* set tcp compression */
   1486     if (sifvjcomp(f->unit, ho->neg_vj, ho->cflag, ho->maxslotindex) != 1) {
   1487 	ipcp_close(f->unit, "Could not enable VJ TCP header compression");
   1488 	return;
   1489     }
   1490 
   1491     /*
   1492      * If we are doing dial-on-demand, the interface is already
   1493      * configured, so we put out any saved-up packets, then set the
   1494      * interface to pass IP packets.
   1495      */
   1496     if (demand) {
   1497 	if (go->ouraddr != wo->ouraddr || ho->hisaddr != wo->hisaddr) {
   1498 	    ipcp_clear_addrs(f->unit, wo->ouraddr, wo->hisaddr);
   1499 	    if (go->ouraddr != wo->ouraddr) {
   1500 		warn("Local IP address changed to %I", go->ouraddr);
   1501 		script_setenv("OLDIPLOCAL", ip_ntoa(wo->ouraddr), 0);
   1502 		wo->ouraddr = go->ouraddr;
   1503 	    } else
   1504 		script_unsetenv("OLDIPLOCAL");
   1505 	    if (ho->hisaddr != wo->hisaddr) {
   1506 		warn("Remote IP address changed to %I", ho->hisaddr);
   1507 		script_setenv("OLDIPREMOTE", ip_ntoa(wo->hisaddr), 0);
   1508 		wo->hisaddr = ho->hisaddr;
   1509 	    } else
   1510 		script_unsetenv("OLDIPREMOTE");
   1511 
   1512 	    /* Set the interface to the new addresses */
   1513 	    mask = GetMask(go->ouraddr);
   1514 	    if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
   1515 		warn("Interface configuration failed");
   1516 		ipcp_close(f->unit, "Interface configuration failed");
   1517 		return;
   1518 	    }
   1519 
   1520 	    /* assign a default route through the interface if required */
   1521 	    if (wo->default_route)
   1522 		if (sifdefaultroute(f->unit, go->ouraddr, ho->hisaddr))
   1523 		    default_route_set[f->unit] = 1;
   1524 
   1525 	    /* Make a proxy ARP entry if requested. */
   1526 	    if (wo->proxy_arp &&
   1527 		sifproxyarp(f->unit, ho->hisaddr, proxy_arp_quiet[f->unit]))
   1528 		proxy_arp_set[f->unit] = 1;
   1529 
   1530 	}
   1531 	demand_rexmit(PPP_IP);
   1532 	if (sifnpmode(f->unit, PPP_IP, NPMODE_PASS) != 1) {
   1533 	    ipcp_close(f->unit, "Interface configuration failed.");
   1534 	    return;
   1535 	}
   1536 
   1537     } else {
   1538 	/*
   1539 	 * Set IP addresses and (if specified) netmask.
   1540 	 */
   1541 	mask = GetMask(go->ouraddr);
   1542 
   1543 #if SIFUPFIRST
   1544 	/* bring the interface up for IP */
   1545 	if (!sifup(f->unit)) {
   1546 	    warn("Interface failed to come up");
   1547 	    ipcp_close(f->unit, "Interface configuration failed");
   1548 	    return;
   1549 	}
   1550 #endif
   1551 
   1552 	if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
   1553 	    warn("Interface configuration failed");
   1554 	    ipcp_close(f->unit, "Interface configuration failed");
   1555 	    return;
   1556 	}
   1557 
   1558 #if !SIFUPFIRST
   1559 	/* bring the interface up for IP */
   1560 	if (!sifup(f->unit)) {
   1561 	    warn("Interface failed to come up");
   1562 	    ipcp_close(f->unit, "Interface configuration failed");
   1563 	    return;
   1564 	}
   1565 #endif
   1566 
   1567 	if (sifnpmode(f->unit, PPP_IP, NPMODE_PASS) != 1) {
   1568 	    ipcp_close(f->unit, "Interface configuration failed.");
   1569 	    return;
   1570 	}
   1571 
   1572 	/* assign a default route through the interface if required */
   1573 	if (wo->default_route)
   1574 	    if (sifdefaultroute(f->unit, go->ouraddr, ho->hisaddr))
   1575 		default_route_set[f->unit] = 1;
   1576 
   1577 	/* Make a proxy ARP entry if requested. */
   1578 	if (wo->proxy_arp &&
   1579 	    sifproxyarp(f->unit, ho->hisaddr, proxy_arp_quiet[f->unit]))
   1580 	    proxy_arp_set[f->unit] = 1;
   1581 
   1582 	wo->ouraddr = go->ouraddr;
   1583 
   1584 	notice("local  IP address %I", go->ouraddr);
   1585 	notice("remote IP address %I", ho->hisaddr);
   1586 	if (go->dnsaddr[0] != 0)
   1587 	    notice("primary   DNS address %I", go->dnsaddr[0]);
   1588 	if (go->dnsaddr[1] != 0)
   1589 	    notice("secondary DNS address %I", go->dnsaddr[1]);
   1590     }
   1591 
   1592     np_up(f->unit, PPP_IP);
   1593     ipcp_is_up[f->unit] = 1;
   1594 
   1595     if (ip_up_hook != NULL)
   1596 	(*ip_up_hook)();
   1597 
   1598     /*
   1599      * Execute the ip-up script, like this:
   1600      *	/etc/ppp/ip-up interface tty speed local-IP remote-IP
   1601      */
   1602     if (ipcp_script_state == s_down && ipcp_script_pid == 0) {
   1603 	ipcp_script_state = s_up;
   1604 	ipcp_script(_PATH_IPUP);
   1605     }
   1606     sys_unblock_proto(PPP_IP);
   1607 }
   1608 
   1609 
   1610 /*
   1611  * ipcp_down - IPCP has gone DOWN.
   1612  *
   1613  * Take the IP network interface down, clear its addresses
   1614  * and delete routes through it.
   1615  */
   1616 static void
   1617 ipcp_down(f)
   1618     fsm *f;
   1619 {
   1620     IPCPDEBUG(("ipcp: down"));
   1621     /* XXX a bit IPv4-centric here, we only need to get the stats
   1622      * before the interface is marked down. */
   1623     update_link_stats(f->unit);
   1624     if (ip_down_hook != NULL)
   1625 	(*ip_down_hook)();
   1626     if (ipcp_is_up[f->unit]) {
   1627 	ipcp_is_up[f->unit] = 0;
   1628 	np_down(f->unit, PPP_IP);
   1629     }
   1630     if (sifvjcomp(f->unit, 0, 0, 0) != 1) {
   1631 	if (debug)
   1632 	    warn("Failed to disable VJ TCP header compression.");
   1633     }
   1634 
   1635     /*
   1636      * If we are doing dial-on-demand, set the interface
   1637      * to queue up outgoing packets (for now).
   1638      */
   1639     if (demand) {
   1640 	if (sifnpmode(f->unit, PPP_IP, NPMODE_QUEUE) != 1) {
   1641 	    if (debug)
   1642 		warn("Failed to enable Queueing on outgoing packets.");
   1643 	}
   1644     } else {
   1645 	if (sifnpmode(f->unit, PPP_IP, NPMODE_ERROR) != 1) {
   1646 	    if (debug)
   1647 		warn("Could not set interface to drop packets.");
   1648 	}
   1649 	if (sifdown(f->unit) != 1)
   1650 	    warn("Could not bring interface down.");
   1651 	ipcp_clear_addrs(f->unit, ipcp_gotoptions[f->unit].ouraddr,
   1652 			 ipcp_hisoptions[f->unit].hisaddr);
   1653     }
   1654 
   1655     /* Execute the ip-down script */
   1656     if (ipcp_script_state == s_up && ipcp_script_pid == 0) {
   1657 	ipcp_script_state = s_down;
   1658 	ipcp_script(_PATH_IPDOWN);
   1659     }
   1660 }
   1661 
   1662 
   1663 /*
   1664  * ipcp_clear_addrs() - clear the interface addresses, routes,
   1665  * proxy arp entries, etc.
   1666  */
   1667 static void
   1668 ipcp_clear_addrs(unit, ouraddr, hisaddr)
   1669     int unit;
   1670     u_int32_t ouraddr;  /* local address */
   1671     u_int32_t hisaddr;  /* remote address */
   1672 {
   1673     if (proxy_arp_set[unit]) {
   1674 	(void) cifproxyarp(unit, hisaddr);
   1675 	proxy_arp_set[unit] = 0;
   1676     }
   1677     if (default_route_set[unit]) {
   1678 	(void) cifdefaultroute(unit, ouraddr, hisaddr);
   1679 	default_route_set[unit] = 0;
   1680     }
   1681     if (cifaddr(unit, ouraddr, hisaddr) != 1)
   1682 	warn("Could not clear addresses");
   1683 }
   1684 
   1685 
   1686 /*
   1687  * ipcp_finished - possibly shut down the lower layers.
   1688  */
   1689 static void
   1690 ipcp_finished(f)
   1691     fsm *f;
   1692 {
   1693     np_finished(f->unit, PPP_IP);
   1694 }
   1695 
   1696 
   1697 /*
   1698  * ipcp_script_done - called when the ip-up or ip-down script
   1699  * has finished.
   1700  */
   1701 /*ARGSUSED*/
   1702 static void
   1703 ipcp_script_done(arg, status)
   1704     void *arg;
   1705     int status;
   1706 {
   1707     ipcp_script_pid = 0;
   1708     switch (ipcp_script_state) {
   1709     case s_up:
   1710 	if (ipcp_fsm[0].state != OPENED) {
   1711 	    ipcp_script_state = s_down;
   1712 	    ipcp_script(_PATH_IPDOWN);
   1713 	}
   1714 	break;
   1715     case s_down:
   1716 	if (ipcp_fsm[0].state == OPENED) {
   1717 	    ipcp_script_state = s_up;
   1718 	    ipcp_script(_PATH_IPUP);
   1719 	}
   1720 	break;
   1721     }
   1722 }
   1723 
   1724 
   1725 /*
   1726  * ipcp_script - Execute a script with arguments
   1727  * interface-name tty-name speed local-IP remote-IP.
   1728  */
   1729 static void
   1730 ipcp_script(script)
   1731     char *script;
   1732 {
   1733     char strspeed[32], strlocal[32], strremote[32];
   1734     char *argv[8];
   1735 
   1736     (void) slprintf(strspeed, sizeof(strspeed), "%d", baud_rate);
   1737     (void) slprintf(strlocal, sizeof(strlocal), "%I",
   1738 	ipcp_gotoptions[0].ouraddr);
   1739     (void) slprintf(strremote, sizeof(strremote), "%I",
   1740 	ipcp_hisoptions[0].hisaddr);
   1741 
   1742     argv[0] = script;
   1743     argv[1] = ifname;
   1744     argv[2] = devnam;
   1745     argv[3] = strspeed;
   1746     argv[4] = strlocal;
   1747     argv[5] = strremote;
   1748     argv[6] = ipparam;
   1749     argv[7] = NULL;
   1750     ipcp_script_pid = run_program(script, argv, 0, ipcp_script_done, NULL);
   1751 }
   1752 
   1753 /*
   1754  * create_resolv - create the replacement resolv.conf file
   1755  */
   1756 static void
   1757 create_resolv(peerdns1, peerdns2)
   1758     u_int32_t peerdns1, peerdns2;
   1759 {
   1760     FILE *f;
   1761 
   1762     f = fopen(_PATH_RESOLV, "w");
   1763     if (f == NULL) {
   1764 	error("Failed to create %s: %m", _PATH_RESOLV);
   1765 	return;
   1766     }
   1767 
   1768     if (peerdns1)
   1769 	if (fprintf(f, "nameserver %s\n", ip_ntoa(peerdns1)) <= 0)
   1770 	    error("Write failed to %s: %m", _PATH_RESOLV);
   1771 
   1772     if (peerdns2)
   1773 	if (fprintf(f, "nameserver %s\n", ip_ntoa(peerdns2)) <= 0)
   1774 	    error("Write failed to %s: %m", _PATH_RESOLV);
   1775 
   1776     if (fclose(f) != 0)
   1777 	error("Failed to close %s: %m", _PATH_RESOLV);
   1778 }
   1779 
   1780 /*
   1781  * ipcp_printpkt - print the contents of an IPCP packet.
   1782  */
   1783 static int
   1784 ipcp_printpkt(p, plen, printer, arg)
   1785     u_char *p;
   1786     int plen;
   1787     void (*printer) __P((void *, const char *, ...));
   1788     void *arg;
   1789 {
   1790     int code, id, len, olen;
   1791     u_char *pstart, *optend;
   1792     u_short cishort;
   1793     u_int32_t cilong;
   1794 
   1795     if (plen < HEADERLEN)
   1796 	return 0;
   1797     pstart = p;
   1798     GETCHAR(code, p);
   1799     GETCHAR(id, p);
   1800     GETSHORT(len, p);
   1801     if (len < HEADERLEN || len > plen)
   1802 	return 0;
   1803 
   1804     printer(arg, " %s id=0x%x", code_name(code, 1), id);
   1805     len -= HEADERLEN;
   1806     switch (code) {
   1807     case CODE_CONFREQ:
   1808     case CODE_CONFACK:
   1809     case CODE_CONFNAK:
   1810     case CODE_CONFREJ:
   1811 	/* print option list */
   1812 	while (len >= 2) {
   1813 	    GETCHAR(code, p);
   1814 	    GETCHAR(olen, p);
   1815 	    p -= 2;
   1816 	    if (olen < 2 || olen > len) {
   1817 		break;
   1818 	    }
   1819 	    printer(arg, " <");
   1820 	    len -= olen;
   1821 	    optend = p + olen;
   1822 	    switch (code) {
   1823 	    case CI_ADDRS:
   1824 		if (olen == CILEN_ADDRS) {
   1825 		    p += 2;
   1826 		    GETNLONG(cilong, p);
   1827 		    printer(arg, "addrs %I", cilong);
   1828 		    GETNLONG(cilong, p);
   1829 		    printer(arg, " %I", cilong);
   1830 		}
   1831 		break;
   1832 	    case CI_COMPRESSTYPE:
   1833 		if (olen >= CILEN_COMPRESS) {
   1834 		    p += 2;
   1835 		    GETSHORT(cishort, p);
   1836 		    printer(arg, "compress ");
   1837 		    switch (cishort) {
   1838 		    case IPCP_VJ_COMP:
   1839 			printer(arg, "VJ");
   1840 			break;
   1841 		    case IPCP_VJ_COMP_OLD:
   1842 			printer(arg, "old-VJ");
   1843 			break;
   1844 		    default:
   1845 			printer(arg, "0x%x", cishort);
   1846 		    }
   1847 		}
   1848 		break;
   1849 	    case CI_ADDR:
   1850 		if (olen == CILEN_ADDR) {
   1851 		    p += 2;
   1852 		    GETNLONG(cilong, p);
   1853 		    printer(arg, "addr %I", cilong);
   1854 		}
   1855 		break;
   1856 	    case CI_MS_DNS1:
   1857 	    case CI_MS_DNS2:
   1858 	        p += 2;
   1859 		GETNLONG(cilong, p);
   1860 		printer(arg, "ms-dns%d %I", (code == CI_MS_DNS1 ? 1 : 2),
   1861 		    cilong);
   1862 		break;
   1863 	    case CI_MS_WINS1:
   1864 	    case CI_MS_WINS2:
   1865 	        p += 2;
   1866 		GETNLONG(cilong, p);
   1867 		printer(arg, "ms-wins%d %I", (code == CI_MS_WINS1 ? 1 : 2),
   1868 		    cilong);
   1869 		break;
   1870 	    case CI_SUBNET:
   1871 		p += 2;
   1872 		GETNLONG(cilong, p);
   1873 		printer(arg, "subnet %I", cilong);
   1874 		break;
   1875 	    }
   1876 	    while (p < optend) {
   1877 		GETCHAR(code, p);
   1878 		printer(arg, " %.2x", code);
   1879 	    }
   1880 	    printer(arg, ">");
   1881 	}
   1882 	break;
   1883 
   1884     case CODE_TERMACK:
   1885     case CODE_TERMREQ:
   1886 	if (len > 0 && *p >= ' ' && *p < 0x7f) {
   1887 	    printer(arg, " ");
   1888 	    print_string((char *)p, len, printer, arg);
   1889 	    p += len;
   1890 	    len = 0;
   1891 	}
   1892 	break;
   1893     }
   1894 
   1895     /* print the rest of the bytes in the packet */
   1896     for (; len > 0; --len) {
   1897 	GETCHAR(code, p);
   1898 	printer(arg, " %.2x", code);
   1899     }
   1900 
   1901     return p - pstart;
   1902 }
   1903 
   1904 char *
   1905 tcp_flag_decode(val)
   1906     int val;
   1907 {
   1908     static char buf[32];
   1909     char *cp = buf;
   1910 
   1911     if (val & TH_URG)
   1912 	*cp++ = 'U';
   1913     if (val & TH_ACK)
   1914 	*cp++ = 'A';
   1915     if (val & TH_PUSH)
   1916 	*cp++ = 'P';
   1917     if (val & TH_RST)
   1918 	*cp++ = 'R';
   1919     if (val & TH_SYN)
   1920 	*cp++ = 'S';
   1921     if (val & TH_FIN)
   1922 	*cp++ = 'F';
   1923     if (cp != buf)
   1924 	*cp++ = ' ';
   1925     *cp = '\0';
   1926     return buf;
   1927 }
   1928 
   1929 /*
   1930  * ip_active_pkt - see if this IP packet is worth bringing the link up for.
   1931  * We don't bring the link up for IP fragments or for TCP FIN packets
   1932  * with no data.
   1933  */
   1934 
   1935 static int
   1936 ip_active_pkt(pkt, len)
   1937     u_char *pkt;
   1938     int len;
   1939 {
   1940     u_char *tcp;
   1941     struct protoent *pep;
   1942     int val;
   1943     int hlen;
   1944     char buf[32], *cp;
   1945     u_int32_t src, dst;
   1946 
   1947     len -= PPP_HDRLEN;
   1948     pkt += PPP_HDRLEN;
   1949     if (len < IP_HDRLEN) {
   1950 	dbglog("IP packet of length %d is not activity", len);
   1951 	return 0;
   1952     }
   1953     src = get_ipsrc(pkt);
   1954     dst = get_ipdst(pkt);
   1955     if ((get_ipoff(pkt) & IP_OFFMASK) != 0) {
   1956 	dbglog("IP fragment from %I->%I is not activity", src, dst);
   1957 	return 0;
   1958     }
   1959     val = get_ipproto(pkt);
   1960     if (val != IPPROTO_TCP) {
   1961 	if (debug) {
   1962 	    if ((pep = getprotobynumber(val)) != NULL) {
   1963 		cp = pep->p_name;
   1964 	    } else {
   1965 		(void) slprintf(buf, sizeof (buf), "IP proto %d", val);
   1966 		cp = buf;
   1967 	    }
   1968 	    info("%s from %I->%I is activity", cp, src, dst);
   1969 	}
   1970 	return 1;
   1971     }
   1972     hlen = get_iphl(pkt) * 4;
   1973     if (len < hlen + TCP_HDRLEN) {
   1974 	dbglog("Bad TCP length %d<%d+%d %I->%I is not activity", len, hlen,
   1975 	    TCP_HDRLEN, src, dst);
   1976 	return 0;
   1977     }
   1978     tcp = pkt + hlen;
   1979     val = get_tcpflags(tcp);
   1980     hlen += get_tcpoff(tcp) * 4;
   1981     if ((val & TH_FIN) != 0 && len == hlen) {
   1982 	dbglog("Empty TCP FIN %I->%I is not activity", src, dst);
   1983 	return 0;
   1984     }
   1985     info("TCP %d data %s%I->%I is activity", len - hlen,
   1986 	tcp_flag_decode(get_tcpflags(tcp)), src, dst);
   1987     return 1;
   1988 }
   1989 
   1990 static void
   1991 ipcp_print_stat(unit, strptr)
   1992     int unit;
   1993     FILE *strptr;
   1994 {
   1995     ipcp_options *go = &ipcp_gotoptions[unit];
   1996     ipcp_options *ho = &ipcp_hisoptions[unit];
   1997     char *proto_name = ipcp_protent.name;
   1998 
   1999     if (!ipcp_protent.enabled_flag) {
   2000 	(void) flprintf(strptr, "%s disabled\n", proto_name);
   2001 	return;
   2002     }
   2003 
   2004     (void) flprintf(strptr, "%s state: %s", proto_name,
   2005 	fsm_state(ipcp_fsm[unit].state));
   2006     (void) flprintf(strptr, "%s local %I  remote %I", proto_name, go->ouraddr,
   2007 	ho->ouraddr);
   2008 }
   2009