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      1 /*
      2  * ipcp.c - PPP IP Control Protocol.
      3  *
      4  * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  *
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  *
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in
     15  *    the documentation and/or other materials provided with the
     16  *    distribution.
     17  *
     18  * 3. The name "Carnegie Mellon University" must not be used to
     19  *    endorse or promote products derived from this software without
     20  *    prior written permission. For permission or any legal
     21  *    details, please contact
     22  *      Office of Technology Transfer
     23  *      Carnegie Mellon University
     24  *      5000 Forbes Avenue
     25  *      Pittsburgh, PA  15213-3890
     26  *      (412) 268-4387, fax: (412) 268-7395
     27  *      tech-transfer (at) andrew.cmu.edu
     28  *
     29  * 4. Redistributions of any form whatsoever must retain the following
     30  *    acknowledgment:
     31  *    "This product includes software developed by Computing Services
     32  *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
     33  *
     34  * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
     35  * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
     36  * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
     37  * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     38  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
     39  * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
     40  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     41  */
     42 
     43 #define RCSID	"$Id: ipcp.c,v 1.69 2004/11/13 12:03:26 paulus Exp $"
     44 
     45 /*
     46  * TODO:
     47  */
     48 
     49 #include <stdio.h>
     50 #include <string.h>
     51 #include <stdlib.h>
     52 #include <netdb.h>
     53 #include <sys/param.h>
     54 #include <sys/types.h>
     55 #include <sys/socket.h>
     56 #include <netinet/in.h>
     57 #include <arpa/inet.h>
     58 
     59 #include "pppd.h"
     60 #include "fsm.h"
     61 #include "ipcp.h"
     62 #include "pathnames.h"
     63 
     64 static const char rcsid[] = RCSID;
     65 
     66 /* global vars */
     67 ipcp_options ipcp_wantoptions[NUM_PPP];	/* Options that we want to request */
     68 ipcp_options ipcp_gotoptions[NUM_PPP];	/* Options that peer ack'd */
     69 ipcp_options ipcp_allowoptions[NUM_PPP]; /* Options we allow peer to request */
     70 ipcp_options ipcp_hisoptions[NUM_PPP];	/* Options that we ack'd */
     71 
     72 u_int32_t netmask = 0;		/* IP netmask to set on interface */
     73 
     74 bool	disable_defaultip = 0;	/* Don't use hostname for default IP adrs */
     75 
     76 /* Hook for a plugin to know when IP protocol has come up */
     77 void (*ip_up_hook) __P((void)) = NULL;
     78 
     79 /* Hook for a plugin to know when IP protocol has come down */
     80 void (*ip_down_hook) __P((void)) = NULL;
     81 
     82 /* Hook for a plugin to choose the remote IP address */
     83 void (*ip_choose_hook) __P((u_int32_t *)) = NULL;
     84 
     85 /* Notifiers for when IPCP goes up and down */
     86 struct notifier *ip_up_notifier = NULL;
     87 struct notifier *ip_down_notifier = NULL;
     88 
     89 /* local vars */
     90 static int default_route_set[NUM_PPP];	/* Have set up a default route */
     91 static int proxy_arp_set[NUM_PPP];	/* Have created proxy arp entry */
     92 static bool usepeerdns;			/* Ask peer for DNS addrs */
     93 static int ipcp_is_up;			/* have called np_up() */
     94 static int ipcp_is_open;		/* haven't called np_finished() */
     95 static bool ask_for_local;		/* request our address from peer */
     96 static char vj_value[8];		/* string form of vj option value */
     97 static char netmask_str[20];		/* string form of netmask value */
     98 
     99 /*
    100  * Callbacks for fsm code.  (CI = Configuration Information)
    101  */
    102 static void ipcp_resetci __P((fsm *));	/* Reset our CI */
    103 static int  ipcp_cilen __P((fsm *));	        /* Return length of our CI */
    104 static void ipcp_addci __P((fsm *, u_char *, int *)); /* Add our CI */
    105 static int  ipcp_ackci __P((fsm *, u_char *, int));	/* Peer ack'd our CI */
    106 static int  ipcp_nakci __P((fsm *, u_char *, int, int));/* Peer nak'd our CI */
    107 static int  ipcp_rejci __P((fsm *, u_char *, int));	/* Peer rej'd our CI */
    108 static int  ipcp_reqci __P((fsm *, u_char *, int *, int)); /* Rcv CI */
    109 static void ipcp_up __P((fsm *));		/* We're UP */
    110 static void ipcp_down __P((fsm *));		/* We're DOWN */
    111 static void ipcp_finished __P((fsm *));	/* Don't need lower layer */
    112 
    113 fsm ipcp_fsm[NUM_PPP];		/* IPCP fsm structure */
    114 
    115 static fsm_callbacks ipcp_callbacks = { /* IPCP callback routines */
    116     ipcp_resetci,		/* Reset our Configuration Information */
    117     ipcp_cilen,			/* Length of our Configuration Information */
    118     ipcp_addci,			/* Add our Configuration Information */
    119     ipcp_ackci,			/* ACK our Configuration Information */
    120     ipcp_nakci,			/* NAK our Configuration Information */
    121     ipcp_rejci,			/* Reject our Configuration Information */
    122     ipcp_reqci,			/* Request peer's Configuration Information */
    123     ipcp_up,			/* Called when fsm reaches OPENED state */
    124     ipcp_down,			/* Called when fsm leaves OPENED state */
    125     NULL,			/* Called when we want the lower layer up */
    126     ipcp_finished,		/* Called when we want the lower layer down */
    127     NULL,			/* Called when Protocol-Reject received */
    128     NULL,			/* Retransmission is necessary */
    129     NULL,			/* Called to handle protocol-specific codes */
    130     "IPCP"			/* String name of protocol */
    131 };
    132 
    133 /*
    134  * Command-line options.
    135  */
    136 static int setvjslots __P((char **));
    137 static int setdnsaddr __P((char **));
    138 static int setwinsaddr __P((char **));
    139 static int setnetmask __P((char **));
    140 int setipaddr __P((char *, char **, int));
    141 static void printipaddr __P((option_t *, void (*)(void *, char *,...),void *));
    142 
    143 static option_t ipcp_option_list[] = {
    144     { "noip", o_bool, &ipcp_protent.enabled_flag,
    145       "Disable IP and IPCP" },
    146     { "-ip", o_bool, &ipcp_protent.enabled_flag,
    147       "Disable IP and IPCP", OPT_ALIAS },
    148 
    149     { "novj", o_bool, &ipcp_wantoptions[0].neg_vj,
    150       "Disable VJ compression", OPT_A2CLR, &ipcp_allowoptions[0].neg_vj },
    151     { "-vj", o_bool, &ipcp_wantoptions[0].neg_vj,
    152       "Disable VJ compression", OPT_ALIAS | OPT_A2CLR,
    153       &ipcp_allowoptions[0].neg_vj },
    154 
    155     { "novjccomp", o_bool, &ipcp_wantoptions[0].cflag,
    156       "Disable VJ connection-ID compression", OPT_A2CLR,
    157       &ipcp_allowoptions[0].cflag },
    158     { "-vjccomp", o_bool, &ipcp_wantoptions[0].cflag,
    159       "Disable VJ connection-ID compression", OPT_ALIAS | OPT_A2CLR,
    160       &ipcp_allowoptions[0].cflag },
    161 
    162     { "vj-max-slots", o_special, (void *)setvjslots,
    163       "Set maximum VJ header slots",
    164       OPT_PRIO | OPT_A2STRVAL | OPT_STATIC, vj_value },
    165 
    166     { "ipcp-accept-local", o_bool, &ipcp_wantoptions[0].accept_local,
    167       "Accept peer's address for us", 1 },
    168     { "ipcp-accept-remote", o_bool, &ipcp_wantoptions[0].accept_remote,
    169       "Accept peer's address for it", 1 },
    170 
    171     { "ipparam", o_string, &ipparam,
    172       "Set ip script parameter", OPT_PRIO },
    173 
    174     { "noipdefault", o_bool, &disable_defaultip,
    175       "Don't use name for default IP adrs", 1 },
    176 
    177     { "ms-dns", 1, (void *)setdnsaddr,
    178       "DNS address for the peer's use" },
    179     { "ms-wins", 1, (void *)setwinsaddr,
    180       "Nameserver for SMB over TCP/IP for peer" },
    181 
    182     { "ipcp-restart", o_int, &ipcp_fsm[0].timeouttime,
    183       "Set timeout for IPCP", OPT_PRIO },
    184     { "ipcp-max-terminate", o_int, &ipcp_fsm[0].maxtermtransmits,
    185       "Set max #xmits for term-reqs", OPT_PRIO },
    186     { "ipcp-max-configure", o_int, &ipcp_fsm[0].maxconfreqtransmits,
    187       "Set max #xmits for conf-reqs", OPT_PRIO },
    188     { "ipcp-max-failure", o_int, &ipcp_fsm[0].maxnakloops,
    189       "Set max #conf-naks for IPCP", OPT_PRIO },
    190 
    191     { "defaultroute", o_bool, &ipcp_wantoptions[0].default_route,
    192       "Add default route", OPT_ENABLE|1, &ipcp_allowoptions[0].default_route },
    193     { "nodefaultroute", o_bool, &ipcp_allowoptions[0].default_route,
    194       "disable defaultroute option", OPT_A2CLR,
    195       &ipcp_wantoptions[0].default_route },
    196     { "-defaultroute", o_bool, &ipcp_allowoptions[0].default_route,
    197       "disable defaultroute option", OPT_ALIAS | OPT_A2CLR,
    198       &ipcp_wantoptions[0].default_route },
    199 
    200     { "proxyarp", o_bool, &ipcp_wantoptions[0].proxy_arp,
    201       "Add proxy ARP entry", OPT_ENABLE|1, &ipcp_allowoptions[0].proxy_arp },
    202     { "noproxyarp", o_bool, &ipcp_allowoptions[0].proxy_arp,
    203       "disable proxyarp option", OPT_A2CLR,
    204       &ipcp_wantoptions[0].proxy_arp },
    205     { "-proxyarp", o_bool, &ipcp_allowoptions[0].proxy_arp,
    206       "disable proxyarp option", OPT_ALIAS | OPT_A2CLR,
    207       &ipcp_wantoptions[0].proxy_arp },
    208 
    209     { "usepeerdns", o_bool, &usepeerdns,
    210       "Ask peer for DNS address(es)", 1 },
    211 
    212     { "netmask", o_special, (void *)setnetmask,
    213       "set netmask", OPT_PRIO | OPT_A2STRVAL | OPT_STATIC, netmask_str },
    214 
    215     { "ipcp-no-addresses", o_bool, &ipcp_wantoptions[0].old_addrs,
    216       "Disable old-style IP-Addresses usage", OPT_A2CLR,
    217       &ipcp_allowoptions[0].old_addrs },
    218     { "ipcp-no-address", o_bool, &ipcp_wantoptions[0].neg_addr,
    219       "Disable IP-Address usage", OPT_A2CLR,
    220       &ipcp_allowoptions[0].neg_addr },
    221 
    222     { "IP addresses", o_wild, (void *) &setipaddr,
    223       "set local and remote IP addresses",
    224       OPT_NOARG | OPT_A2PRINTER, (void *) &printipaddr },
    225 
    226     { NULL }
    227 };
    228 
    229 /*
    230  * Protocol entry points from main code.
    231  */
    232 static void ipcp_init __P((int));
    233 static void ipcp_open __P((int));
    234 static void ipcp_close __P((int, char *));
    235 static void ipcp_lowerup __P((int));
    236 static void ipcp_lowerdown __P((int));
    237 static void ipcp_input __P((int, u_char *, int));
    238 static void ipcp_protrej __P((int));
    239 static int  ipcp_printpkt __P((u_char *, int,
    240 			       void (*) __P((void *, char *, ...)), void *));
    241 static void ip_check_options __P((void));
    242 static int  ip_demand_conf __P((int));
    243 static int  ip_active_pkt __P((u_char *, int));
    244 static void create_resolv __P((u_int32_t, u_int32_t));
    245 
    246 struct protent ipcp_protent = {
    247     PPP_IPCP,
    248     ipcp_init,
    249     ipcp_input,
    250     ipcp_protrej,
    251     ipcp_lowerup,
    252     ipcp_lowerdown,
    253     ipcp_open,
    254     ipcp_close,
    255     ipcp_printpkt,
    256     NULL,
    257     1,
    258     "IPCP",
    259     "IP",
    260     ipcp_option_list,
    261     ip_check_options,
    262     ip_demand_conf,
    263     ip_active_pkt
    264 };
    265 
    266 static void ipcp_clear_addrs __P((int, u_int32_t, u_int32_t));
    267 static void ipcp_script __P((char *));		/* Run an up/down script */
    268 static void ipcp_script_done __P((void *));
    269 
    270 /*
    271  * Lengths of configuration options.
    272  */
    273 #define CILEN_VOID	2
    274 #define CILEN_COMPRESS	4	/* min length for compression protocol opt. */
    275 #define CILEN_VJ	6	/* length for RFC1332 Van-Jacobson opt. */
    276 #define CILEN_ADDR	6	/* new-style single address option */
    277 #define CILEN_ADDRS	10	/* old-style dual address option */
    278 
    279 
    280 #define CODENAME(x)	((x) == CONFACK ? "ACK" : \
    281 			 (x) == CONFNAK ? "NAK" : "REJ")
    282 
    283 /*
    284  * This state variable is used to ensure that we don't
    285  * run an ipcp-up/down script while one is already running.
    286  */
    287 static enum script_state {
    288     s_down,
    289     s_up,
    290 } ipcp_script_state;
    291 static pid_t ipcp_script_pid;
    292 
    293 /*
    294  * Make a string representation of a network IP address.
    295  */
    296 char *
    297 ip_ntoa(ipaddr)
    298 u_int32_t ipaddr;
    299 {
    300     static char b[64];
    301 
    302     slprintf(b, sizeof(b), "%I", ipaddr);
    303     return b;
    304 }
    305 
    306 /*
    307  * Option parsing.
    308  */
    309 
    310 /*
    311  * setvjslots - set maximum number of connection slots for VJ compression
    312  */
    313 static int
    314 setvjslots(argv)
    315     char **argv;
    316 {
    317     int value;
    318 
    319     if (!int_option(*argv, &value))
    320 	return 0;
    321     if (value < 2 || value > 16) {
    322 	option_error("vj-max-slots value must be between 2 and 16");
    323 	return 0;
    324     }
    325     ipcp_wantoptions [0].maxslotindex =
    326         ipcp_allowoptions[0].maxslotindex = value - 1;
    327     slprintf(vj_value, sizeof(vj_value), "%d", value);
    328     return 1;
    329 }
    330 
    331 /*
    332  * setdnsaddr - set the dns address(es)
    333  */
    334 static int
    335 setdnsaddr(argv)
    336     char **argv;
    337 {
    338     u_int32_t dns;
    339     struct hostent *hp;
    340 
    341     dns = inet_addr(*argv);
    342     if (dns == (u_int32_t) -1) {
    343 	if ((hp = gethostbyname(*argv)) == NULL) {
    344 	    option_error("invalid address parameter '%s' for ms-dns option",
    345 			 *argv);
    346 	    return 0;
    347 	}
    348 	dns = *(u_int32_t *)hp->h_addr;
    349     }
    350 
    351     /* We take the last 2 values given, the 2nd-last as the primary
    352        and the last as the secondary.  If only one is given it
    353        becomes both primary and secondary. */
    354     if (ipcp_allowoptions[0].dnsaddr[1] == 0)
    355 	ipcp_allowoptions[0].dnsaddr[0] = dns;
    356     else
    357 	ipcp_allowoptions[0].dnsaddr[0] = ipcp_allowoptions[0].dnsaddr[1];
    358 
    359     /* always set the secondary address value. */
    360     ipcp_allowoptions[0].dnsaddr[1] = dns;
    361 
    362     return (1);
    363 }
    364 
    365 /*
    366  * setwinsaddr - set the wins address(es)
    367  * This is primrarly used with the Samba package under UNIX or for pointing
    368  * the caller to the existing WINS server on a Windows NT platform.
    369  */
    370 static int
    371 setwinsaddr(argv)
    372     char **argv;
    373 {
    374     u_int32_t wins;
    375     struct hostent *hp;
    376 
    377     wins = inet_addr(*argv);
    378     if (wins == (u_int32_t) -1) {
    379 	if ((hp = gethostbyname(*argv)) == NULL) {
    380 	    option_error("invalid address parameter '%s' for ms-wins option",
    381 			 *argv);
    382 	    return 0;
    383 	}
    384 	wins = *(u_int32_t *)hp->h_addr;
    385     }
    386 
    387     /* We take the last 2 values given, the 2nd-last as the primary
    388        and the last as the secondary.  If only one is given it
    389        becomes both primary and secondary. */
    390     if (ipcp_allowoptions[0].winsaddr[1] == 0)
    391 	ipcp_allowoptions[0].winsaddr[0] = wins;
    392     else
    393 	ipcp_allowoptions[0].winsaddr[0] = ipcp_allowoptions[0].winsaddr[1];
    394 
    395     /* always set the secondary address value. */
    396     ipcp_allowoptions[0].winsaddr[1] = wins;
    397 
    398     return (1);
    399 }
    400 
    401 /*
    402  * setipaddr - Set the IP address
    403  * If doit is 0, the call is to check whether this option is
    404  * potentially an IP address specification.
    405  * Not static so that plugins can call it to set the addresses
    406  */
    407 int
    408 setipaddr(arg, argv, doit)
    409     char *arg;
    410     char **argv;
    411     int doit;
    412 {
    413     struct hostent *hp;
    414     char *colon;
    415     u_int32_t local, remote;
    416     ipcp_options *wo = &ipcp_wantoptions[0];
    417     static int prio_local = 0, prio_remote = 0;
    418 
    419     /*
    420      * IP address pair separated by ":".
    421      */
    422     if ((colon = strchr(arg, ':')) == NULL)
    423 	return 0;
    424     if (!doit)
    425 	return 1;
    426 
    427     /*
    428      * If colon first character, then no local addr.
    429      */
    430     if (colon != arg && option_priority >= prio_local) {
    431 	*colon = '\0';
    432 	if ((local = inet_addr(arg)) == (u_int32_t) -1) {
    433 	    if ((hp = gethostbyname(arg)) == NULL) {
    434 		option_error("unknown host: %s", arg);
    435 		return 0;
    436 	    }
    437 	    local = *(u_int32_t *)hp->h_addr;
    438 	}
    439 	if (bad_ip_adrs(local)) {
    440 	    option_error("bad local IP address %s", ip_ntoa(local));
    441 	    return 0;
    442 	}
    443 	if (local != 0)
    444 	    wo->ouraddr = local;
    445 	*colon = ':';
    446 	prio_local = option_priority;
    447     }
    448 
    449     /*
    450      * If colon last character, then no remote addr.
    451      */
    452     if (*++colon != '\0' && option_priority >= prio_remote) {
    453 	if ((remote = inet_addr(colon)) == (u_int32_t) -1) {
    454 	    if ((hp = gethostbyname(colon)) == NULL) {
    455 		option_error("unknown host: %s", colon);
    456 		return 0;
    457 	    }
    458 	    remote = *(u_int32_t *)hp->h_addr;
    459 	    if (remote_name[0] == 0)
    460 		strlcpy(remote_name, colon, sizeof(remote_name));
    461 	}
    462 	if (bad_ip_adrs(remote)) {
    463 	    option_error("bad remote IP address %s", ip_ntoa(remote));
    464 	    return 0;
    465 	}
    466 	if (remote != 0)
    467 	    wo->hisaddr = remote;
    468 	prio_remote = option_priority;
    469     }
    470 
    471     return 1;
    472 }
    473 
    474 static void
    475 printipaddr(opt, printer, arg)
    476     option_t *opt;
    477     void (*printer) __P((void *, char *, ...));
    478     void *arg;
    479 {
    480 	ipcp_options *wo = &ipcp_wantoptions[0];
    481 
    482 	if (wo->ouraddr != 0)
    483 		printer(arg, "%I", wo->ouraddr);
    484 	printer(arg, ":");
    485 	if (wo->hisaddr != 0)
    486 		printer(arg, "%I", wo->hisaddr);
    487 }
    488 
    489 /*
    490  * setnetmask - set the netmask to be used on the interface.
    491  */
    492 static int
    493 setnetmask(argv)
    494     char **argv;
    495 {
    496     u_int32_t mask;
    497     int n;
    498     char *p;
    499 
    500     /*
    501      * Unfortunately, if we use inet_addr, we can't tell whether
    502      * a result of all 1s is an error or a valid 255.255.255.255.
    503      */
    504     p = *argv;
    505     n = parse_dotted_ip(p, &mask);
    506 
    507     mask = htonl(mask);
    508 
    509     if (n == 0 || p[n] != 0 || (netmask & ~mask) != 0) {
    510 	option_error("invalid netmask value '%s'", *argv);
    511 	return 0;
    512     }
    513 
    514     netmask = mask;
    515     slprintf(netmask_str, sizeof(netmask_str), "%I", mask);
    516 
    517     return (1);
    518 }
    519 
    520 int
    521 parse_dotted_ip(p, vp)
    522     char *p;
    523     u_int32_t *vp;
    524 {
    525     int n;
    526     u_int32_t v, b;
    527     char *endp, *p0 = p;
    528 
    529     v = 0;
    530     for (n = 3;; --n) {
    531 	b = strtoul(p, &endp, 0);
    532 	if (endp == p)
    533 	    return 0;
    534 	if (b > 255) {
    535 	    if (n < 3)
    536 		return 0;
    537 	    /* accept e.g. 0xffffff00 */
    538 	    *vp = b;
    539 	    return endp - p0;
    540 	}
    541 	v |= b << (n * 8);
    542 	p = endp;
    543 	if (n == 0)
    544 	    break;
    545 	if (*p != '.')
    546 	    return 0;
    547 	++p;
    548     }
    549     *vp = v;
    550     return p - p0;
    551 }
    552 
    553 
    554 /*
    555  * ipcp_init - Initialize IPCP.
    556  */
    557 static void
    558 ipcp_init(unit)
    559     int unit;
    560 {
    561     fsm *f = &ipcp_fsm[unit];
    562     ipcp_options *wo = &ipcp_wantoptions[unit];
    563     ipcp_options *ao = &ipcp_allowoptions[unit];
    564 
    565     f->unit = unit;
    566     f->protocol = PPP_IPCP;
    567     f->callbacks = &ipcp_callbacks;
    568     fsm_init(&ipcp_fsm[unit]);
    569 
    570     memset(wo, 0, sizeof(*wo));
    571     memset(ao, 0, sizeof(*ao));
    572 
    573     wo->neg_addr = wo->old_addrs = 1;
    574     wo->neg_vj = 1;
    575     wo->vj_protocol = IPCP_VJ_COMP;
    576     wo->maxslotindex = MAX_STATES - 1; /* really max index */
    577     wo->cflag = 1;
    578 
    579 
    580     /* max slots and slot-id compression are currently hardwired in */
    581     /* ppp_if.c to 16 and 1, this needs to be changed (among other */
    582     /* things) gmc */
    583 
    584     ao->neg_addr = ao->old_addrs = 1;
    585     ao->neg_vj = 1;
    586     ao->maxslotindex = MAX_STATES - 1;
    587     ao->cflag = 1;
    588 
    589     /*
    590      * XXX These control whether the user may use the proxyarp
    591      * and defaultroute options.
    592      */
    593     ao->proxy_arp = 1;
    594     ao->default_route = 1;
    595 }
    596 
    597 
    598 /*
    599  * ipcp_open - IPCP is allowed to come up.
    600  */
    601 static void
    602 ipcp_open(unit)
    603     int unit;
    604 {
    605     fsm_open(&ipcp_fsm[unit]);
    606     ipcp_is_open = 1;
    607 }
    608 
    609 
    610 /*
    611  * ipcp_close - Take IPCP down.
    612  */
    613 static void
    614 ipcp_close(unit, reason)
    615     int unit;
    616     char *reason;
    617 {
    618     fsm_close(&ipcp_fsm[unit], reason);
    619 }
    620 
    621 
    622 /*
    623  * ipcp_lowerup - The lower layer is up.
    624  */
    625 static void
    626 ipcp_lowerup(unit)
    627     int unit;
    628 {
    629     fsm_lowerup(&ipcp_fsm[unit]);
    630 }
    631 
    632 
    633 /*
    634  * ipcp_lowerdown - The lower layer is down.
    635  */
    636 static void
    637 ipcp_lowerdown(unit)
    638     int unit;
    639 {
    640     fsm_lowerdown(&ipcp_fsm[unit]);
    641 }
    642 
    643 
    644 /*
    645  * ipcp_input - Input IPCP packet.
    646  */
    647 static void
    648 ipcp_input(unit, p, len)
    649     int unit;
    650     u_char *p;
    651     int len;
    652 {
    653     fsm_input(&ipcp_fsm[unit], p, len);
    654 }
    655 
    656 
    657 /*
    658  * ipcp_protrej - A Protocol-Reject was received for IPCP.
    659  *
    660  * Pretend the lower layer went down, so we shut up.
    661  */
    662 static void
    663 ipcp_protrej(unit)
    664     int unit;
    665 {
    666     fsm_lowerdown(&ipcp_fsm[unit]);
    667 }
    668 
    669 
    670 /*
    671  * ipcp_resetci - Reset our CI.
    672  * Called by fsm_sconfreq, Send Configure Request.
    673  */
    674 static void
    675 ipcp_resetci(f)
    676     fsm *f;
    677 {
    678     ipcp_options *wo = &ipcp_wantoptions[f->unit];
    679     ipcp_options *go = &ipcp_gotoptions[f->unit];
    680     ipcp_options *ao = &ipcp_allowoptions[f->unit];
    681 
    682     wo->req_addr = (wo->neg_addr || wo->old_addrs) &&
    683 	(ao->neg_addr || ao->old_addrs);
    684     if (wo->ouraddr == 0)
    685 	wo->accept_local = 1;
    686     if (wo->hisaddr == 0)
    687 	wo->accept_remote = 1;
    688     wo->req_dns1 = usepeerdns;	/* Request DNS addresses from the peer */
    689     wo->req_dns2 = usepeerdns;
    690     *go = *wo;
    691     if (!ask_for_local)
    692 	go->ouraddr = 0;
    693     if (ip_choose_hook) {
    694 	ip_choose_hook(&wo->hisaddr);
    695 	if (wo->hisaddr) {
    696 	    wo->accept_remote = 0;
    697 	}
    698     }
    699     BZERO(&ipcp_hisoptions[f->unit], sizeof(ipcp_options));
    700 }
    701 
    702 
    703 /*
    704  * ipcp_cilen - Return length of our CI.
    705  * Called by fsm_sconfreq, Send Configure Request.
    706  */
    707 static int
    708 ipcp_cilen(f)
    709     fsm *f;
    710 {
    711     ipcp_options *go = &ipcp_gotoptions[f->unit];
    712     ipcp_options *wo = &ipcp_wantoptions[f->unit];
    713     ipcp_options *ho = &ipcp_hisoptions[f->unit];
    714 
    715 #define LENCIADDRS(neg)		(neg ? CILEN_ADDRS : 0)
    716 #define LENCIVJ(neg, old)	(neg ? (old? CILEN_COMPRESS : CILEN_VJ) : 0)
    717 #define LENCIADDR(neg)		(neg ? CILEN_ADDR : 0)
    718 #define LENCIDNS(neg)		(neg ? (CILEN_ADDR) : 0)
    719 
    720     /*
    721      * First see if we want to change our options to the old
    722      * forms because we have received old forms from the peer.
    723      */
    724     if (go->neg_addr && go->old_addrs && !ho->neg_addr && ho->old_addrs)
    725 	go->neg_addr = 0;
    726     if (wo->neg_vj && !go->neg_vj && !go->old_vj) {
    727 	/* try an older style of VJ negotiation */
    728 	/* use the old style only if the peer did */
    729 	if (ho->neg_vj && ho->old_vj) {
    730 	    go->neg_vj = 1;
    731 	    go->old_vj = 1;
    732 	    go->vj_protocol = ho->vj_protocol;
    733 	}
    734     }
    735 
    736     return (LENCIADDRS(!go->neg_addr && go->old_addrs) +
    737 	    LENCIVJ(go->neg_vj, go->old_vj) +
    738 	    LENCIADDR(go->neg_addr) +
    739 	    LENCIDNS(go->req_dns1) +
    740 	    LENCIDNS(go->req_dns2)) ;
    741 }
    742 
    743 
    744 /*
    745  * ipcp_addci - Add our desired CIs to a packet.
    746  * Called by fsm_sconfreq, Send Configure Request.
    747  */
    748 static void
    749 ipcp_addci(f, ucp, lenp)
    750     fsm *f;
    751     u_char *ucp;
    752     int *lenp;
    753 {
    754     ipcp_options *go = &ipcp_gotoptions[f->unit];
    755     int len = *lenp;
    756 
    757 #define ADDCIADDRS(opt, neg, val1, val2) \
    758     if (neg) { \
    759 	if (len >= CILEN_ADDRS) { \
    760 	    u_int32_t l; \
    761 	    PUTCHAR(opt, ucp); \
    762 	    PUTCHAR(CILEN_ADDRS, ucp); \
    763 	    l = ntohl(val1); \
    764 	    PUTLONG(l, ucp); \
    765 	    l = ntohl(val2); \
    766 	    PUTLONG(l, ucp); \
    767 	    len -= CILEN_ADDRS; \
    768 	} else \
    769 	    go->old_addrs = 0; \
    770     }
    771 
    772 #define ADDCIVJ(opt, neg, val, old, maxslotindex, cflag) \
    773     if (neg) { \
    774 	int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
    775 	if (len >= vjlen) { \
    776 	    PUTCHAR(opt, ucp); \
    777 	    PUTCHAR(vjlen, ucp); \
    778 	    PUTSHORT(val, ucp); \
    779 	    if (!old) { \
    780 		PUTCHAR(maxslotindex, ucp); \
    781 		PUTCHAR(cflag, ucp); \
    782 	    } \
    783 	    len -= vjlen; \
    784 	} else \
    785 	    neg = 0; \
    786     }
    787 
    788 #define ADDCIADDR(opt, neg, val) \
    789     if (neg) { \
    790 	if (len >= CILEN_ADDR) { \
    791 	    u_int32_t l; \
    792 	    PUTCHAR(opt, ucp); \
    793 	    PUTCHAR(CILEN_ADDR, ucp); \
    794 	    l = ntohl(val); \
    795 	    PUTLONG(l, ucp); \
    796 	    len -= CILEN_ADDR; \
    797 	} else \
    798 	    neg = 0; \
    799     }
    800 
    801 #define ADDCIDNS(opt, neg, addr) \
    802     if (neg) { \
    803 	if (len >= CILEN_ADDR) { \
    804 	    u_int32_t l; \
    805 	    PUTCHAR(opt, ucp); \
    806 	    PUTCHAR(CILEN_ADDR, ucp); \
    807 	    l = ntohl(addr); \
    808 	    PUTLONG(l, ucp); \
    809 	    len -= CILEN_ADDR; \
    810 	} else \
    811 	    neg = 0; \
    812     }
    813 
    814     ADDCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs, go->ouraddr,
    815 	       go->hisaddr);
    816 
    817     ADDCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
    818 	    go->maxslotindex, go->cflag);
    819 
    820     ADDCIADDR(CI_ADDR, go->neg_addr, go->ouraddr);
    821 
    822     ADDCIDNS(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]);
    823 
    824     ADDCIDNS(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
    825 
    826     *lenp -= len;
    827 }
    828 
    829 
    830 /*
    831  * ipcp_ackci - Ack our CIs.
    832  * Called by fsm_rconfack, Receive Configure ACK.
    833  *
    834  * Returns:
    835  *	0 - Ack was bad.
    836  *	1 - Ack was good.
    837  */
    838 static int
    839 ipcp_ackci(f, p, len)
    840     fsm *f;
    841     u_char *p;
    842     int len;
    843 {
    844     ipcp_options *go = &ipcp_gotoptions[f->unit];
    845     u_short cilen, citype, cishort;
    846     u_int32_t cilong;
    847     u_char cimaxslotindex, cicflag;
    848 
    849     /*
    850      * CIs must be in exactly the same order that we sent...
    851      * Check packet length and CI length at each step.
    852      * If we find any deviations, then this packet is bad.
    853      */
    854 
    855 #define ACKCIADDRS(opt, neg, val1, val2) \
    856     if (neg) { \
    857 	u_int32_t l; \
    858 	if ((len -= CILEN_ADDRS) < 0) \
    859 	    goto bad; \
    860 	GETCHAR(citype, p); \
    861 	GETCHAR(cilen, p); \
    862 	if (cilen != CILEN_ADDRS || \
    863 	    citype != opt) \
    864 	    goto bad; \
    865 	GETLONG(l, p); \
    866 	cilong = htonl(l); \
    867 	if (val1 != cilong) \
    868 	    goto bad; \
    869 	GETLONG(l, p); \
    870 	cilong = htonl(l); \
    871 	if (val2 != cilong) \
    872 	    goto bad; \
    873     }
    874 
    875 #define ACKCIVJ(opt, neg, val, old, maxslotindex, cflag) \
    876     if (neg) { \
    877 	int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
    878 	if ((len -= vjlen) < 0) \
    879 	    goto bad; \
    880 	GETCHAR(citype, p); \
    881 	GETCHAR(cilen, p); \
    882 	if (cilen != vjlen || \
    883 	    citype != opt)  \
    884 	    goto bad; \
    885 	GETSHORT(cishort, p); \
    886 	if (cishort != val) \
    887 	    goto bad; \
    888 	if (!old) { \
    889 	    GETCHAR(cimaxslotindex, p); \
    890 	    if (cimaxslotindex != maxslotindex) \
    891 		goto bad; \
    892 	    GETCHAR(cicflag, p); \
    893 	    if (cicflag != cflag) \
    894 		goto bad; \
    895 	} \
    896     }
    897 
    898 #define ACKCIADDR(opt, neg, val) \
    899     if (neg) { \
    900 	u_int32_t l; \
    901 	if ((len -= CILEN_ADDR) < 0) \
    902 	    goto bad; \
    903 	GETCHAR(citype, p); \
    904 	GETCHAR(cilen, p); \
    905 	if (cilen != CILEN_ADDR || \
    906 	    citype != opt) \
    907 	    goto bad; \
    908 	GETLONG(l, p); \
    909 	cilong = htonl(l); \
    910 	if (val != cilong) \
    911 	    goto bad; \
    912     }
    913 
    914 #define ACKCIDNS(opt, neg, addr) \
    915     if (neg) { \
    916 	u_int32_t l; \
    917 	if ((len -= CILEN_ADDR) < 0) \
    918 	    goto bad; \
    919 	GETCHAR(citype, p); \
    920 	GETCHAR(cilen, p); \
    921 	if (cilen != CILEN_ADDR || citype != opt) \
    922 	    goto bad; \
    923 	GETLONG(l, p); \
    924 	cilong = htonl(l); \
    925 	if (addr != cilong) \
    926 	    goto bad; \
    927     }
    928 
    929     ACKCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs, go->ouraddr,
    930 	       go->hisaddr);
    931 
    932     ACKCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
    933 	    go->maxslotindex, go->cflag);
    934 
    935     ACKCIADDR(CI_ADDR, go->neg_addr, go->ouraddr);
    936 
    937     ACKCIDNS(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]);
    938 
    939     ACKCIDNS(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
    940 
    941     /*
    942      * If there are any remaining CIs, then this packet is bad.
    943      */
    944     if (len != 0)
    945 	goto bad;
    946     return (1);
    947 
    948 bad:
    949     IPCPDEBUG(("ipcp_ackci: received bad Ack!"));
    950     return (0);
    951 }
    952 
    953 /*
    954  * ipcp_nakci - Peer has sent a NAK for some of our CIs.
    955  * This should not modify any state if the Nak is bad
    956  * or if IPCP is in the OPENED state.
    957  * Calback from fsm_rconfnakrej - Receive Configure-Nak or Configure-Reject.
    958  *
    959  * Returns:
    960  *	0 - Nak was bad.
    961  *	1 - Nak was good.
    962  */
    963 static int
    964 ipcp_nakci(f, p, len, treat_as_reject)
    965     fsm *f;
    966     u_char *p;
    967     int len;
    968     int treat_as_reject;
    969 {
    970     ipcp_options *go = &ipcp_gotoptions[f->unit];
    971     u_char cimaxslotindex, cicflag;
    972     u_char citype, cilen, *next;
    973     u_short cishort;
    974     u_int32_t ciaddr1, ciaddr2, l, cidnsaddr;
    975     ipcp_options no;		/* options we've seen Naks for */
    976     ipcp_options try;		/* options to request next time */
    977 
    978     BZERO(&no, sizeof(no));
    979     try = *go;
    980 
    981     /*
    982      * Any Nak'd CIs must be in exactly the same order that we sent.
    983      * Check packet length and CI length at each step.
    984      * If we find any deviations, then this packet is bad.
    985      */
    986 #define NAKCIADDRS(opt, neg, code) \
    987     if ((neg) && \
    988 	(cilen = p[1]) == CILEN_ADDRS && \
    989 	len >= cilen && \
    990 	p[0] == opt) { \
    991 	len -= cilen; \
    992 	INCPTR(2, p); \
    993 	GETLONG(l, p); \
    994 	ciaddr1 = htonl(l); \
    995 	GETLONG(l, p); \
    996 	ciaddr2 = htonl(l); \
    997 	no.old_addrs = 1; \
    998 	code \
    999     }
   1000 
   1001 #define NAKCIVJ(opt, neg, code) \
   1002     if (go->neg && \
   1003 	((cilen = p[1]) == CILEN_COMPRESS || cilen == CILEN_VJ) && \
   1004 	len >= cilen && \
   1005 	p[0] == opt) { \
   1006 	len -= cilen; \
   1007 	INCPTR(2, p); \
   1008 	GETSHORT(cishort, p); \
   1009 	no.neg = 1; \
   1010         code \
   1011     }
   1012 
   1013 #define NAKCIADDR(opt, neg, code) \
   1014     if (go->neg && \
   1015 	(cilen = p[1]) == CILEN_ADDR && \
   1016 	len >= cilen && \
   1017 	p[0] == opt) { \
   1018 	len -= cilen; \
   1019 	INCPTR(2, p); \
   1020 	GETLONG(l, p); \
   1021 	ciaddr1 = htonl(l); \
   1022 	no.neg = 1; \
   1023 	code \
   1024     }
   1025 
   1026 #define NAKCIDNS(opt, neg, code) \
   1027     if (go->neg && \
   1028 	((cilen = p[1]) == CILEN_ADDR) && \
   1029 	len >= cilen && \
   1030 	p[0] == opt) { \
   1031 	len -= cilen; \
   1032 	INCPTR(2, p); \
   1033 	GETLONG(l, p); \
   1034 	cidnsaddr = htonl(l); \
   1035 	no.neg = 1; \
   1036 	code \
   1037     }
   1038 
   1039     /*
   1040      * Accept the peer's idea of {our,his} address, if different
   1041      * from our idea, only if the accept_{local,remote} flag is set.
   1042      */
   1043     NAKCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs,
   1044 	       if (treat_as_reject) {
   1045 		   try.old_addrs = 0;
   1046 	       } else {
   1047 		   if (go->accept_local && ciaddr1) {
   1048 		       /* take his idea of our address */
   1049 		       try.ouraddr = ciaddr1;
   1050 		   }
   1051 		   if (go->accept_remote && ciaddr2) {
   1052 		       /* take his idea of his address */
   1053 		       try.hisaddr = ciaddr2;
   1054 		   }
   1055 	       }
   1056 	);
   1057 
   1058     /*
   1059      * Accept the peer's value of maxslotindex provided that it
   1060      * is less than what we asked for.  Turn off slot-ID compression
   1061      * if the peer wants.  Send old-style compress-type option if
   1062      * the peer wants.
   1063      */
   1064     NAKCIVJ(CI_COMPRESSTYPE, neg_vj,
   1065 	    if (treat_as_reject) {
   1066 		try.neg_vj = 0;
   1067 	    } else if (cilen == CILEN_VJ) {
   1068 		GETCHAR(cimaxslotindex, p);
   1069 		GETCHAR(cicflag, p);
   1070 		if (cishort == IPCP_VJ_COMP) {
   1071 		    try.old_vj = 0;
   1072 		    if (cimaxslotindex < go->maxslotindex)
   1073 			try.maxslotindex = cimaxslotindex;
   1074 		    if (!cicflag)
   1075 			try.cflag = 0;
   1076 		} else {
   1077 		    try.neg_vj = 0;
   1078 		}
   1079 	    } else {
   1080 		if (cishort == IPCP_VJ_COMP || cishort == IPCP_VJ_COMP_OLD) {
   1081 		    try.old_vj = 1;
   1082 		    try.vj_protocol = cishort;
   1083 		} else {
   1084 		    try.neg_vj = 0;
   1085 		}
   1086 	    }
   1087 	    );
   1088 
   1089     NAKCIADDR(CI_ADDR, neg_addr,
   1090 	      if (treat_as_reject) {
   1091 		  try.neg_addr = 0;
   1092 		  try.old_addrs = 0;
   1093 	      } else if (go->accept_local && ciaddr1) {
   1094 		  /* take his idea of our address */
   1095 		  try.ouraddr = ciaddr1;
   1096 	      }
   1097 	      );
   1098 
   1099     NAKCIDNS(CI_MS_DNS1, req_dns1,
   1100 	     if (treat_as_reject) {
   1101 		 try.req_dns1 = 0;
   1102 	     } else {
   1103 		 try.dnsaddr[0] = cidnsaddr;
   1104 	     }
   1105 	     );
   1106 
   1107     NAKCIDNS(CI_MS_DNS2, req_dns2,
   1108 	     if (treat_as_reject) {
   1109 		 try.req_dns2 = 0;
   1110 	     } else {
   1111 		 try.dnsaddr[1] = cidnsaddr;
   1112 	     }
   1113 	     );
   1114 
   1115     /*
   1116      * There may be remaining CIs, if the peer is requesting negotiation
   1117      * on an option that we didn't include in our request packet.
   1118      * If they want to negotiate about IP addresses, we comply.
   1119      * If they want us to ask for compression, we refuse.
   1120      */
   1121     while (len >= CILEN_VOID) {
   1122 	GETCHAR(citype, p);
   1123 	GETCHAR(cilen, p);
   1124 	if ( cilen < CILEN_VOID || (len -= cilen) < 0 )
   1125 	    goto bad;
   1126 	next = p + cilen - 2;
   1127 
   1128 	switch (citype) {
   1129 	case CI_COMPRESSTYPE:
   1130 	    if (go->neg_vj || no.neg_vj ||
   1131 		(cilen != CILEN_VJ && cilen != CILEN_COMPRESS))
   1132 		goto bad;
   1133 	    no.neg_vj = 1;
   1134 	    break;
   1135 	case CI_ADDRS:
   1136 	    if ((!go->neg_addr && go->old_addrs) || no.old_addrs
   1137 		|| cilen != CILEN_ADDRS)
   1138 		goto bad;
   1139 	    try.neg_addr = 0;
   1140 	    GETLONG(l, p);
   1141 	    ciaddr1 = htonl(l);
   1142 	    if (ciaddr1 && go->accept_local)
   1143 		try.ouraddr = ciaddr1;
   1144 	    GETLONG(l, p);
   1145 	    ciaddr2 = htonl(l);
   1146 	    if (ciaddr2 && go->accept_remote)
   1147 		try.hisaddr = ciaddr2;
   1148 	    no.old_addrs = 1;
   1149 	    break;
   1150 	case CI_ADDR:
   1151 	    if (go->neg_addr || no.neg_addr || cilen != CILEN_ADDR)
   1152 		goto bad;
   1153 	    try.old_addrs = 0;
   1154 	    GETLONG(l, p);
   1155 	    ciaddr1 = htonl(l);
   1156 	    if (ciaddr1 && go->accept_local)
   1157 		try.ouraddr = ciaddr1;
   1158 	    if (try.ouraddr != 0)
   1159 		try.neg_addr = 1;
   1160 	    no.neg_addr = 1;
   1161 	    break;
   1162 	}
   1163 	p = next;
   1164     }
   1165 
   1166     /*
   1167      * OK, the Nak is good.  Now we can update state.
   1168      * If there are any remaining options, we ignore them.
   1169      */
   1170     if (f->state != OPENED)
   1171 	*go = try;
   1172 
   1173     return 1;
   1174 
   1175 bad:
   1176     IPCPDEBUG(("ipcp_nakci: received bad Nak!"));
   1177     return 0;
   1178 }
   1179 
   1180 
   1181 /*
   1182  * ipcp_rejci - Reject some of our CIs.
   1183  * Callback from fsm_rconfnakrej.
   1184  */
   1185 static int
   1186 ipcp_rejci(f, p, len)
   1187     fsm *f;
   1188     u_char *p;
   1189     int len;
   1190 {
   1191     ipcp_options *go = &ipcp_gotoptions[f->unit];
   1192     u_char cimaxslotindex, ciflag, cilen;
   1193     u_short cishort;
   1194     u_int32_t cilong;
   1195     ipcp_options try;		/* options to request next time */
   1196 
   1197     try = *go;
   1198     /*
   1199      * Any Rejected CIs must be in exactly the same order that we sent.
   1200      * Check packet length and CI length at each step.
   1201      * If we find any deviations, then this packet is bad.
   1202      */
   1203 #define REJCIADDRS(opt, neg, val1, val2) \
   1204     if ((neg) && \
   1205 	(cilen = p[1]) == CILEN_ADDRS && \
   1206 	len >= cilen && \
   1207 	p[0] == opt) { \
   1208 	u_int32_t l; \
   1209 	len -= cilen; \
   1210 	INCPTR(2, p); \
   1211 	GETLONG(l, p); \
   1212 	cilong = htonl(l); \
   1213 	/* Check rejected value. */ \
   1214 	if (cilong != val1) \
   1215 	    goto bad; \
   1216 	GETLONG(l, p); \
   1217 	cilong = htonl(l); \
   1218 	/* Check rejected value. */ \
   1219 	if (cilong != val2) \
   1220 	    goto bad; \
   1221 	try.old_addrs = 0; \
   1222     }
   1223 
   1224 #define REJCIVJ(opt, neg, val, old, maxslot, cflag) \
   1225     if (go->neg && \
   1226 	p[1] == (old? CILEN_COMPRESS : CILEN_VJ) && \
   1227 	len >= p[1] && \
   1228 	p[0] == opt) { \
   1229 	len -= p[1]; \
   1230 	INCPTR(2, p); \
   1231 	GETSHORT(cishort, p); \
   1232 	/* Check rejected value. */  \
   1233 	if (cishort != val) \
   1234 	    goto bad; \
   1235 	if (!old) { \
   1236 	   GETCHAR(cimaxslotindex, p); \
   1237 	   if (cimaxslotindex != maxslot) \
   1238 	     goto bad; \
   1239 	   GETCHAR(ciflag, p); \
   1240 	   if (ciflag != cflag) \
   1241 	     goto bad; \
   1242         } \
   1243 	try.neg = 0; \
   1244      }
   1245 
   1246 #define REJCIADDR(opt, neg, val) \
   1247     if (go->neg && \
   1248 	(cilen = p[1]) == CILEN_ADDR && \
   1249 	len >= cilen && \
   1250 	p[0] == opt) { \
   1251 	u_int32_t l; \
   1252 	len -= cilen; \
   1253 	INCPTR(2, p); \
   1254 	GETLONG(l, p); \
   1255 	cilong = htonl(l); \
   1256 	/* Check rejected value. */ \
   1257 	if (cilong != val) \
   1258 	    goto bad; \
   1259 	try.neg = 0; \
   1260     }
   1261 
   1262 #define REJCIDNS(opt, neg, dnsaddr) \
   1263     if (go->neg && \
   1264 	((cilen = p[1]) == CILEN_ADDR) && \
   1265 	len >= cilen && \
   1266 	p[0] == opt) { \
   1267 	u_int32_t l; \
   1268 	len -= cilen; \
   1269 	INCPTR(2, p); \
   1270 	GETLONG(l, p); \
   1271 	cilong = htonl(l); \
   1272 	/* Check rejected value. */ \
   1273 	if (cilong != dnsaddr) \
   1274 	    goto bad; \
   1275 	try.neg = 0; \
   1276     }
   1277 
   1278 
   1279     REJCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs,
   1280 	       go->ouraddr, go->hisaddr);
   1281 
   1282     REJCIVJ(CI_COMPRESSTYPE, neg_vj, go->vj_protocol, go->old_vj,
   1283 	    go->maxslotindex, go->cflag);
   1284 
   1285     REJCIADDR(CI_ADDR, neg_addr, go->ouraddr);
   1286 
   1287     REJCIDNS(CI_MS_DNS1, req_dns1, go->dnsaddr[0]);
   1288 
   1289     REJCIDNS(CI_MS_DNS2, req_dns2, go->dnsaddr[1]);
   1290 
   1291     /*
   1292      * If there are any remaining CIs, then this packet is bad.
   1293      */
   1294     if (len != 0)
   1295 	goto bad;
   1296     /*
   1297      * Now we can update state.
   1298      */
   1299     if (f->state != OPENED)
   1300 	*go = try;
   1301     return 1;
   1302 
   1303 bad:
   1304     IPCPDEBUG(("ipcp_rejci: received bad Reject!"));
   1305     return 0;
   1306 }
   1307 
   1308 
   1309 /*
   1310  * ipcp_reqci - Check the peer's requested CIs and send appropriate response.
   1311  * Callback from fsm_rconfreq, Receive Configure Request
   1312  *
   1313  * Returns: CONFACK, CONFNAK or CONFREJ and input packet modified
   1314  * appropriately.  If reject_if_disagree is non-zero, doesn't return
   1315  * CONFNAK; returns CONFREJ if it can't return CONFACK.
   1316  */
   1317 static int
   1318 ipcp_reqci(f, inp, len, reject_if_disagree)
   1319     fsm *f;
   1320     u_char *inp;		/* Requested CIs */
   1321     int *len;			/* Length of requested CIs */
   1322     int reject_if_disagree;
   1323 {
   1324     ipcp_options *wo = &ipcp_wantoptions[f->unit];
   1325     ipcp_options *ho = &ipcp_hisoptions[f->unit];
   1326     ipcp_options *ao = &ipcp_allowoptions[f->unit];
   1327     u_char *cip, *next;		/* Pointer to current and next CIs */
   1328     u_short cilen, citype;	/* Parsed len, type */
   1329     u_short cishort;		/* Parsed short value */
   1330     u_int32_t tl, ciaddr1, ciaddr2;/* Parsed address values */
   1331     int rc = CONFACK;		/* Final packet return code */
   1332     int orc;			/* Individual option return code */
   1333     u_char *p;			/* Pointer to next char to parse */
   1334     u_char *ucp = inp;		/* Pointer to current output char */
   1335     int l = *len;		/* Length left */
   1336     u_char maxslotindex, cflag;
   1337     int d;
   1338 
   1339     /*
   1340      * Reset all his options.
   1341      */
   1342     BZERO(ho, sizeof(*ho));
   1343 
   1344     /*
   1345      * Process all his options.
   1346      */
   1347     next = inp;
   1348     while (l) {
   1349 	orc = CONFACK;			/* Assume success */
   1350 	cip = p = next;			/* Remember begining of CI */
   1351 	if (l < 2 ||			/* Not enough data for CI header or */
   1352 	    p[1] < 2 ||			/*  CI length too small or */
   1353 	    p[1] > l) {			/*  CI length too big? */
   1354 	    IPCPDEBUG(("ipcp_reqci: bad CI length!"));
   1355 	    orc = CONFREJ;		/* Reject bad CI */
   1356 	    cilen = l;			/* Reject till end of packet */
   1357 	    l = 0;			/* Don't loop again */
   1358 	    goto endswitch;
   1359 	}
   1360 	GETCHAR(citype, p);		/* Parse CI type */
   1361 	GETCHAR(cilen, p);		/* Parse CI length */
   1362 	l -= cilen;			/* Adjust remaining length */
   1363 	next += cilen;			/* Step to next CI */
   1364 
   1365 	switch (citype) {		/* Check CI type */
   1366 	case CI_ADDRS:
   1367 	    if (!ao->old_addrs || ho->neg_addr ||
   1368 		cilen != CILEN_ADDRS) {	/* Check CI length */
   1369 		orc = CONFREJ;		/* Reject CI */
   1370 		break;
   1371 	    }
   1372 
   1373 	    /*
   1374 	     * If he has no address, or if we both have his address but
   1375 	     * disagree about it, then NAK it with our idea.
   1376 	     * In particular, if we don't know his address, but he does,
   1377 	     * then accept it.
   1378 	     */
   1379 	    GETLONG(tl, p);		/* Parse source address (his) */
   1380 	    ciaddr1 = htonl(tl);
   1381 	    if (ciaddr1 != wo->hisaddr
   1382 		&& (ciaddr1 == 0 || !wo->accept_remote)) {
   1383 		orc = CONFNAK;
   1384 		if (!reject_if_disagree) {
   1385 		    DECPTR(sizeof(u_int32_t), p);
   1386 		    tl = ntohl(wo->hisaddr);
   1387 		    PUTLONG(tl, p);
   1388 		}
   1389 	    } else if (ciaddr1 == 0 && wo->hisaddr == 0) {
   1390 		/*
   1391 		 * If neither we nor he knows his address, reject the option.
   1392 		 */
   1393 		orc = CONFREJ;
   1394 		wo->req_addr = 0;	/* don't NAK with 0.0.0.0 later */
   1395 		break;
   1396 	    }
   1397 
   1398 	    /*
   1399 	     * If he doesn't know our address, or if we both have our address
   1400 	     * but disagree about it, then NAK it with our idea.
   1401 	     */
   1402 	    GETLONG(tl, p);		/* Parse desination address (ours) */
   1403 	    ciaddr2 = htonl(tl);
   1404 	    if (ciaddr2 != wo->ouraddr) {
   1405 		if (ciaddr2 == 0 || !wo->accept_local) {
   1406 		    orc = CONFNAK;
   1407 		    if (!reject_if_disagree) {
   1408 			DECPTR(sizeof(u_int32_t), p);
   1409 			tl = ntohl(wo->ouraddr);
   1410 			PUTLONG(tl, p);
   1411 		    }
   1412 		} else {
   1413 		    wo->ouraddr = ciaddr2;	/* accept peer's idea */
   1414 		}
   1415 	    }
   1416 
   1417 	    ho->old_addrs = 1;
   1418 	    ho->hisaddr = ciaddr1;
   1419 	    ho->ouraddr = ciaddr2;
   1420 	    break;
   1421 
   1422 	case CI_ADDR:
   1423 	    if (!ao->neg_addr || ho->old_addrs ||
   1424 		cilen != CILEN_ADDR) {	/* Check CI length */
   1425 		orc = CONFREJ;		/* Reject CI */
   1426 		break;
   1427 	    }
   1428 
   1429 	    /*
   1430 	     * If he has no address, or if we both have his address but
   1431 	     * disagree about it, then NAK it with our idea.
   1432 	     * In particular, if we don't know his address, but he does,
   1433 	     * then accept it.
   1434 	     */
   1435 	    GETLONG(tl, p);	/* Parse source address (his) */
   1436 	    ciaddr1 = htonl(tl);
   1437 	    if (ciaddr1 != wo->hisaddr
   1438 		&& (ciaddr1 == 0 || !wo->accept_remote)) {
   1439 		orc = CONFNAK;
   1440 		if (!reject_if_disagree) {
   1441 		    DECPTR(sizeof(u_int32_t), p);
   1442 		    tl = ntohl(wo->hisaddr);
   1443 		    PUTLONG(tl, p);
   1444 		}
   1445 	    } else if (ciaddr1 == 0 && wo->hisaddr == 0) {
   1446 		/*
   1447 		 * Don't ACK an address of 0.0.0.0 - reject it instead.
   1448 		 */
   1449 		orc = CONFREJ;
   1450 		wo->req_addr = 0;	/* don't NAK with 0.0.0.0 later */
   1451 		break;
   1452 	    }
   1453 
   1454 	    ho->neg_addr = 1;
   1455 	    ho->hisaddr = ciaddr1;
   1456 	    break;
   1457 
   1458 	case CI_MS_DNS1:
   1459 	case CI_MS_DNS2:
   1460 	    /* Microsoft primary or secondary DNS request */
   1461 	    d = citype == CI_MS_DNS2;
   1462 
   1463 	    /* If we do not have a DNS address then we cannot send it */
   1464 	    if (ao->dnsaddr[d] == 0 ||
   1465 		cilen != CILEN_ADDR) {	/* Check CI length */
   1466 		orc = CONFREJ;		/* Reject CI */
   1467 		break;
   1468 	    }
   1469 	    GETLONG(tl, p);
   1470 	    if (htonl(tl) != ao->dnsaddr[d]) {
   1471                 DECPTR(sizeof(u_int32_t), p);
   1472 		tl = ntohl(ao->dnsaddr[d]);
   1473 		PUTLONG(tl, p);
   1474 		orc = CONFNAK;
   1475             }
   1476             break;
   1477 
   1478 	case CI_MS_WINS1:
   1479 	case CI_MS_WINS2:
   1480 	    /* Microsoft primary or secondary WINS request */
   1481 	    d = citype == CI_MS_WINS2;
   1482 
   1483 	    /* If we do not have a DNS address then we cannot send it */
   1484 	    if (ao->winsaddr[d] == 0 ||
   1485 		cilen != CILEN_ADDR) {	/* Check CI length */
   1486 		orc = CONFREJ;		/* Reject CI */
   1487 		break;
   1488 	    }
   1489 	    GETLONG(tl, p);
   1490 	    if (htonl(tl) != ao->winsaddr[d]) {
   1491                 DECPTR(sizeof(u_int32_t), p);
   1492 		tl = ntohl(ao->winsaddr[d]);
   1493 		PUTLONG(tl, p);
   1494 		orc = CONFNAK;
   1495             }
   1496             break;
   1497 
   1498 	case CI_COMPRESSTYPE:
   1499 	    if (!ao->neg_vj ||
   1500 		(cilen != CILEN_VJ && cilen != CILEN_COMPRESS)) {
   1501 		orc = CONFREJ;
   1502 		break;
   1503 	    }
   1504 	    GETSHORT(cishort, p);
   1505 
   1506 	    if (!(cishort == IPCP_VJ_COMP ||
   1507 		  (cishort == IPCP_VJ_COMP_OLD && cilen == CILEN_COMPRESS))) {
   1508 		orc = CONFREJ;
   1509 		break;
   1510 	    }
   1511 
   1512 	    ho->neg_vj = 1;
   1513 	    ho->vj_protocol = cishort;
   1514 	    if (cilen == CILEN_VJ) {
   1515 		GETCHAR(maxslotindex, p);
   1516 		if (maxslotindex > ao->maxslotindex) {
   1517 		    orc = CONFNAK;
   1518 		    if (!reject_if_disagree){
   1519 			DECPTR(1, p);
   1520 			PUTCHAR(ao->maxslotindex, p);
   1521 		    }
   1522 		}
   1523 		GETCHAR(cflag, p);
   1524 		if (cflag && !ao->cflag) {
   1525 		    orc = CONFNAK;
   1526 		    if (!reject_if_disagree){
   1527 			DECPTR(1, p);
   1528 			PUTCHAR(wo->cflag, p);
   1529 		    }
   1530 		}
   1531 		ho->maxslotindex = maxslotindex;
   1532 		ho->cflag = cflag;
   1533 	    } else {
   1534 		ho->old_vj = 1;
   1535 		ho->maxslotindex = MAX_STATES - 1;
   1536 		ho->cflag = 1;
   1537 	    }
   1538 	    break;
   1539 
   1540 	default:
   1541 	    orc = CONFREJ;
   1542 	    break;
   1543 	}
   1544 endswitch:
   1545 	if (orc == CONFACK &&		/* Good CI */
   1546 	    rc != CONFACK)		/*  but prior CI wasnt? */
   1547 	    continue;			/* Don't send this one */
   1548 
   1549 	if (orc == CONFNAK) {		/* Nak this CI? */
   1550 	    if (reject_if_disagree)	/* Getting fed up with sending NAKs? */
   1551 		orc = CONFREJ;		/* Get tough if so */
   1552 	    else {
   1553 		if (rc == CONFREJ)	/* Rejecting prior CI? */
   1554 		    continue;		/* Don't send this one */
   1555 		if (rc == CONFACK) {	/* Ack'd all prior CIs? */
   1556 		    rc = CONFNAK;	/* Not anymore... */
   1557 		    ucp = inp;		/* Backup */
   1558 		}
   1559 	    }
   1560 	}
   1561 
   1562 	if (orc == CONFREJ &&		/* Reject this CI */
   1563 	    rc != CONFREJ) {		/*  but no prior ones? */
   1564 	    rc = CONFREJ;
   1565 	    ucp = inp;			/* Backup */
   1566 	}
   1567 
   1568 	/* Need to move CI? */
   1569 	if (ucp != cip)
   1570 	    BCOPY(cip, ucp, cilen);	/* Move it */
   1571 
   1572 	/* Update output pointer */
   1573 	INCPTR(cilen, ucp);
   1574     }
   1575 
   1576     /*
   1577      * If we aren't rejecting this packet, and we want to negotiate
   1578      * their address, and they didn't send their address, then we
   1579      * send a NAK with a CI_ADDR option appended.  We assume the
   1580      * input buffer is long enough that we can append the extra
   1581      * option safely.
   1582      */
   1583     if (rc != CONFREJ && !ho->neg_addr && !ho->old_addrs &&
   1584 	wo->req_addr && !reject_if_disagree) {
   1585 	if (rc == CONFACK) {
   1586 	    rc = CONFNAK;
   1587 	    ucp = inp;			/* reset pointer */
   1588 	    wo->req_addr = 0;		/* don't ask again */
   1589 	}
   1590 	PUTCHAR(CI_ADDR, ucp);
   1591 	PUTCHAR(CILEN_ADDR, ucp);
   1592 	tl = ntohl(wo->hisaddr);
   1593 	PUTLONG(tl, ucp);
   1594     }
   1595 
   1596     *len = ucp - inp;			/* Compute output length */
   1597     IPCPDEBUG(("ipcp: returning Configure-%s", CODENAME(rc)));
   1598     return (rc);			/* Return final code */
   1599 }
   1600 
   1601 
   1602 /*
   1603  * ip_check_options - check that any IP-related options are OK,
   1604  * and assign appropriate defaults.
   1605  */
   1606 static void
   1607 ip_check_options()
   1608 {
   1609     struct hostent *hp;
   1610     u_int32_t local;
   1611     ipcp_options *wo = &ipcp_wantoptions[0];
   1612 
   1613     /*
   1614      * Default our local IP address based on our hostname.
   1615      * If local IP address already given, don't bother.
   1616      */
   1617     if (wo->ouraddr == 0 && !disable_defaultip) {
   1618 	/*
   1619 	 * Look up our hostname (possibly with domain name appended)
   1620 	 * and take the first IP address as our local IP address.
   1621 	 * If there isn't an IP address for our hostname, too bad.
   1622 	 */
   1623 	wo->accept_local = 1;	/* don't insist on this default value */
   1624 	if ((hp = gethostbyname(hostname)) != NULL) {
   1625 	    local = *(u_int32_t *)hp->h_addr;
   1626 	    if (local != 0 && !bad_ip_adrs(local))
   1627 		wo->ouraddr = local;
   1628 	}
   1629     }
   1630     ask_for_local = wo->ouraddr != 0 || !disable_defaultip;
   1631 }
   1632 
   1633 
   1634 /*
   1635  * ip_demand_conf - configure the interface as though
   1636  * IPCP were up, for use with dial-on-demand.
   1637  */
   1638 static int
   1639 ip_demand_conf(u)
   1640     int u;
   1641 {
   1642     ipcp_options *wo = &ipcp_wantoptions[u];
   1643 
   1644     if (wo->hisaddr == 0) {
   1645 	/* make up an arbitrary address for the peer */
   1646 	wo->hisaddr = htonl(0x0a707070 + ifunit);
   1647 	wo->accept_remote = 1;
   1648     }
   1649     if (wo->ouraddr == 0) {
   1650 	/* make up an arbitrary address for us */
   1651 	wo->ouraddr = htonl(0x0a404040 + ifunit);
   1652 	wo->accept_local = 1;
   1653 	ask_for_local = 0;	/* don't tell the peer this address */
   1654     }
   1655     if (!sifaddr(u, wo->ouraddr, wo->hisaddr, GetMask(wo->ouraddr)))
   1656 	return 0;
   1657     if (!sifup(u))
   1658 	return 0;
   1659     if (!sifnpmode(u, PPP_IP, NPMODE_QUEUE))
   1660 	return 0;
   1661     if (wo->default_route)
   1662 	if (sifdefaultroute(u, wo->ouraddr, wo->hisaddr))
   1663 	    default_route_set[u] = 1;
   1664     if (wo->proxy_arp)
   1665 	if (sifproxyarp(u, wo->hisaddr))
   1666 	    proxy_arp_set[u] = 1;
   1667 
   1668     notice("local  IP address %I", wo->ouraddr);
   1669     notice("remote IP address %I", wo->hisaddr);
   1670 
   1671     return 1;
   1672 }
   1673 
   1674 
   1675 /*
   1676  * ipcp_up - IPCP has come UP.
   1677  *
   1678  * Configure the IP network interface appropriately and bring it up.
   1679  */
   1680 static void
   1681 ipcp_up(f)
   1682     fsm *f;
   1683 {
   1684     u_int32_t mask;
   1685     ipcp_options *ho = &ipcp_hisoptions[f->unit];
   1686     ipcp_options *go = &ipcp_gotoptions[f->unit];
   1687     ipcp_options *wo = &ipcp_wantoptions[f->unit];
   1688 
   1689     IPCPDEBUG(("ipcp: up"));
   1690 
   1691     /*
   1692      * We must have a non-zero IP address for both ends of the link.
   1693      */
   1694     if (!ho->neg_addr && !ho->old_addrs)
   1695 	ho->hisaddr = wo->hisaddr;
   1696 
   1697     if (!(go->neg_addr || go->old_addrs) && (wo->neg_addr || wo->old_addrs)
   1698 	&& wo->ouraddr != 0) {
   1699 	error("Peer refused to agree to our IP address");
   1700 	ipcp_close(f->unit, "Refused our IP address");
   1701 	return;
   1702     }
   1703     if (go->ouraddr == 0) {
   1704 	error("Could not determine local IP address");
   1705 	ipcp_close(f->unit, "Could not determine local IP address");
   1706 	return;
   1707     }
   1708     if (ho->hisaddr == 0) {
   1709 	ho->hisaddr = htonl(0x0a404040 + ifunit);
   1710 	warn("Could not determine remote IP address: defaulting to %I",
   1711 	     ho->hisaddr);
   1712     }
   1713     script_setenv("IPLOCAL", ip_ntoa(go->ouraddr), 0);
   1714     script_setenv("IPREMOTE", ip_ntoa(ho->hisaddr), 1);
   1715 
   1716     if (go->dnsaddr[0])
   1717 	script_setenv("DNS1", ip_ntoa(go->dnsaddr[0]), 0);
   1718     if (go->dnsaddr[1])
   1719 	script_setenv("DNS2", ip_ntoa(go->dnsaddr[1]), 0);
   1720     if (usepeerdns && (go->dnsaddr[0] || go->dnsaddr[1])) {
   1721 	script_setenv("USEPEERDNS", "1", 0);
   1722 	create_resolv(go->dnsaddr[0], go->dnsaddr[1]);
   1723     }
   1724 
   1725     /*
   1726      * Check that the peer is allowed to use the IP address it wants.
   1727      */
   1728     if (!auth_ip_addr(f->unit, ho->hisaddr)) {
   1729 	error("Peer is not authorized to use remote address %I", ho->hisaddr);
   1730 	ipcp_close(f->unit, "Unauthorized remote IP address");
   1731 	return;
   1732     }
   1733 
   1734     /* set tcp compression */
   1735     sifvjcomp(f->unit, ho->neg_vj, ho->cflag, ho->maxslotindex);
   1736 
   1737     /*
   1738      * If we are doing dial-on-demand, the interface is already
   1739      * configured, so we put out any saved-up packets, then set the
   1740      * interface to pass IP packets.
   1741      */
   1742     if (demand) {
   1743 	if (go->ouraddr != wo->ouraddr || ho->hisaddr != wo->hisaddr) {
   1744 	    ipcp_clear_addrs(f->unit, wo->ouraddr, wo->hisaddr);
   1745 	    if (go->ouraddr != wo->ouraddr) {
   1746 		warn("Local IP address changed to %I", go->ouraddr);
   1747 		script_setenv("OLDIPLOCAL", ip_ntoa(wo->ouraddr), 0);
   1748 		wo->ouraddr = go->ouraddr;
   1749 	    } else
   1750 		script_unsetenv("OLDIPLOCAL");
   1751 	    if (ho->hisaddr != wo->hisaddr) {
   1752 		warn("Remote IP address changed to %I", ho->hisaddr);
   1753 		script_setenv("OLDIPREMOTE", ip_ntoa(wo->hisaddr), 0);
   1754 		wo->hisaddr = ho->hisaddr;
   1755 	    } else
   1756 		script_unsetenv("OLDIPREMOTE");
   1757 
   1758 	    /* Set the interface to the new addresses */
   1759 	    mask = GetMask(go->ouraddr);
   1760 	    if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
   1761 		if (debug)
   1762 		    warn("Interface configuration failed");
   1763 		ipcp_close(f->unit, "Interface configuration failed");
   1764 		return;
   1765 	    }
   1766 
   1767 	    /* assign a default route through the interface if required */
   1768 	    if (ipcp_wantoptions[f->unit].default_route)
   1769 		if (sifdefaultroute(f->unit, go->ouraddr, ho->hisaddr))
   1770 		    default_route_set[f->unit] = 1;
   1771 
   1772 	    /* Make a proxy ARP entry if requested. */
   1773 	    if (ipcp_wantoptions[f->unit].proxy_arp)
   1774 		if (sifproxyarp(f->unit, ho->hisaddr))
   1775 		    proxy_arp_set[f->unit] = 1;
   1776 
   1777 	}
   1778 	demand_rexmit(PPP_IP);
   1779 	sifnpmode(f->unit, PPP_IP, NPMODE_PASS);
   1780 
   1781     } else {
   1782 	/*
   1783 	 * Set IP addresses and (if specified) netmask.
   1784 	 */
   1785 	mask = GetMask(go->ouraddr);
   1786 
   1787 #if !(defined(SVR4) && (defined(SNI) || defined(__USLC__)))
   1788 	if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
   1789 	    if (debug)
   1790 		warn("Interface configuration failed");
   1791 	    ipcp_close(f->unit, "Interface configuration failed");
   1792 	    return;
   1793 	}
   1794 #endif
   1795 
   1796 	/* bring the interface up for IP */
   1797 	if (!sifup(f->unit)) {
   1798 	    if (debug)
   1799 		warn("Interface failed to come up");
   1800 	    ipcp_close(f->unit, "Interface configuration failed");
   1801 	    return;
   1802 	}
   1803 
   1804 #if (defined(SVR4) && (defined(SNI) || defined(__USLC__)))
   1805 	if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
   1806 	    if (debug)
   1807 		warn("Interface configuration failed");
   1808 	    ipcp_close(f->unit, "Interface configuration failed");
   1809 	    return;
   1810 	}
   1811 #endif
   1812 	sifnpmode(f->unit, PPP_IP, NPMODE_PASS);
   1813 
   1814 	/* assign a default route through the interface if required */
   1815 	if (ipcp_wantoptions[f->unit].default_route)
   1816 	    if (sifdefaultroute(f->unit, go->ouraddr, ho->hisaddr))
   1817 		default_route_set[f->unit] = 1;
   1818 
   1819 	/* Make a proxy ARP entry if requested. */
   1820 	if (ipcp_wantoptions[f->unit].proxy_arp)
   1821 	    if (sifproxyarp(f->unit, ho->hisaddr))
   1822 		proxy_arp_set[f->unit] = 1;
   1823 
   1824 	ipcp_wantoptions[0].ouraddr = go->ouraddr;
   1825 
   1826 	notice("local  IP address %I", go->ouraddr);
   1827 	notice("remote IP address %I", ho->hisaddr);
   1828 	if (go->dnsaddr[0])
   1829 	    notice("primary   DNS address %I", go->dnsaddr[0]);
   1830 	if (go->dnsaddr[1])
   1831 	    notice("secondary DNS address %I", go->dnsaddr[1]);
   1832     }
   1833 
   1834     reset_link_stats(f->unit);
   1835 
   1836     np_up(f->unit, PPP_IP);
   1837     ipcp_is_up = 1;
   1838 
   1839     notify(ip_up_notifier, 0);
   1840     if (ip_up_hook)
   1841 	ip_up_hook();
   1842 
   1843     /*
   1844      * Execute the ip-up script, like this:
   1845      *	/etc/ppp/ip-up interface tty speed local-IP remote-IP
   1846      */
   1847     if (ipcp_script_state == s_down && ipcp_script_pid == 0) {
   1848 	ipcp_script_state = s_up;
   1849 	ipcp_script(_PATH_IPUP);
   1850     }
   1851 }
   1852 
   1853 
   1854 /*
   1855  * ipcp_down - IPCP has gone DOWN.
   1856  *
   1857  * Take the IP network interface down, clear its addresses
   1858  * and delete routes through it.
   1859  */
   1860 static void
   1861 ipcp_down(f)
   1862     fsm *f;
   1863 {
   1864     IPCPDEBUG(("ipcp: down"));
   1865     /* XXX a bit IPv4-centric here, we only need to get the stats
   1866      * before the interface is marked down. */
   1867     /* XXX more correct: we must get the stats before running the notifiers,
   1868      * at least for the radius plugin */
   1869     update_link_stats(f->unit);
   1870     notify(ip_down_notifier, 0);
   1871     if (ip_down_hook)
   1872 	ip_down_hook();
   1873     if (ipcp_is_up) {
   1874 	ipcp_is_up = 0;
   1875 	np_down(f->unit, PPP_IP);
   1876     }
   1877     sifvjcomp(f->unit, 0, 0, 0);
   1878 
   1879     print_link_stats(); /* _after_ running the notifiers and ip_down_hook(),
   1880 			 * because print_link_stats() sets link_stats_valid
   1881 			 * to 0 (zero) */
   1882 
   1883     /*
   1884      * If we are doing dial-on-demand, set the interface
   1885      * to queue up outgoing packets (for now).
   1886      */
   1887     if (demand) {
   1888 	sifnpmode(f->unit, PPP_IP, NPMODE_QUEUE);
   1889     } else {
   1890 	sifnpmode(f->unit, PPP_IP, NPMODE_DROP);
   1891 	sifdown(f->unit);
   1892 	ipcp_clear_addrs(f->unit, ipcp_gotoptions[f->unit].ouraddr,
   1893 			 ipcp_hisoptions[f->unit].hisaddr);
   1894     }
   1895 
   1896     /* Execute the ip-down script */
   1897     if (ipcp_script_state == s_up && ipcp_script_pid == 0) {
   1898 	ipcp_script_state = s_down;
   1899 	ipcp_script(_PATH_IPDOWN);
   1900     }
   1901 }
   1902 
   1903 
   1904 /*
   1905  * ipcp_clear_addrs() - clear the interface addresses, routes,
   1906  * proxy arp entries, etc.
   1907  */
   1908 static void
   1909 ipcp_clear_addrs(unit, ouraddr, hisaddr)
   1910     int unit;
   1911     u_int32_t ouraddr;  /* local address */
   1912     u_int32_t hisaddr;  /* remote address */
   1913 {
   1914     if (proxy_arp_set[unit]) {
   1915 	cifproxyarp(unit, hisaddr);
   1916 	proxy_arp_set[unit] = 0;
   1917     }
   1918     if (default_route_set[unit]) {
   1919 	cifdefaultroute(unit, ouraddr, hisaddr);
   1920 	default_route_set[unit] = 0;
   1921     }
   1922     cifaddr(unit, ouraddr, hisaddr);
   1923 }
   1924 
   1925 
   1926 /*
   1927  * ipcp_finished - possibly shut down the lower layers.
   1928  */
   1929 static void
   1930 ipcp_finished(f)
   1931     fsm *f;
   1932 {
   1933 	if (ipcp_is_open) {
   1934 		ipcp_is_open = 0;
   1935 		np_finished(f->unit, PPP_IP);
   1936 	}
   1937 }
   1938 
   1939 
   1940 /*
   1941  * ipcp_script_done - called when the ip-up or ip-down script
   1942  * has finished.
   1943  */
   1944 static void
   1945 ipcp_script_done(arg)
   1946     void *arg;
   1947 {
   1948     ipcp_script_pid = 0;
   1949     switch (ipcp_script_state) {
   1950     case s_up:
   1951 	if (ipcp_fsm[0].state != OPENED) {
   1952 	    ipcp_script_state = s_down;
   1953 	    ipcp_script(_PATH_IPDOWN);
   1954 	}
   1955 	break;
   1956     case s_down:
   1957 	if (ipcp_fsm[0].state == OPENED) {
   1958 	    ipcp_script_state = s_up;
   1959 	    ipcp_script(_PATH_IPUP);
   1960 	}
   1961 	break;
   1962     }
   1963 }
   1964 
   1965 
   1966 /*
   1967  * ipcp_script - Execute a script with arguments
   1968  * interface-name tty-name speed local-IP remote-IP.
   1969  */
   1970 static void
   1971 ipcp_script(script)
   1972     char *script;
   1973 {
   1974     char strspeed[32], strlocal[32], strremote[32];
   1975     char *argv[8];
   1976 
   1977     slprintf(strspeed, sizeof(strspeed), "%d", baud_rate);
   1978     slprintf(strlocal, sizeof(strlocal), "%I", ipcp_gotoptions[0].ouraddr);
   1979     slprintf(strremote, sizeof(strremote), "%I", ipcp_hisoptions[0].hisaddr);
   1980 
   1981     argv[0] = script;
   1982     argv[1] = ifname;
   1983     argv[2] = devnam;
   1984     argv[3] = strspeed;
   1985     argv[4] = strlocal;
   1986     argv[5] = strremote;
   1987     argv[6] = ipparam;
   1988     argv[7] = NULL;
   1989     ipcp_script_pid = run_program(script, argv, 0, ipcp_script_done, NULL);
   1990 }
   1991 
   1992 /*
   1993  * create_resolv - create the replacement resolv.conf file
   1994  */
   1995 static void
   1996 create_resolv(peerdns1, peerdns2)
   1997     u_int32_t peerdns1, peerdns2;
   1998 {
   1999 #ifndef ANDROID_CHANGES
   2000     FILE *f;
   2001 
   2002     f = fopen(_PATH_RESOLV, "w");
   2003     if (f == NULL) {
   2004 	error("Failed to create %s: %m", _PATH_RESOLV);
   2005 	return;
   2006     }
   2007 
   2008     if (peerdns1)
   2009 	fprintf(f, "nameserver %s\n", ip_ntoa(peerdns1));
   2010 
   2011     if (peerdns2)
   2012 	fprintf(f, "nameserver %s\n", ip_ntoa(peerdns2));
   2013 
   2014     if (ferror(f))
   2015 	error("Write failed to %s: %m", _PATH_RESOLV);
   2016 
   2017     fclose(f);
   2018 #endif
   2019 }
   2020 
   2021 /*
   2022  * ipcp_printpkt - print the contents of an IPCP packet.
   2023  */
   2024 static char *ipcp_codenames[] = {
   2025     "ConfReq", "ConfAck", "ConfNak", "ConfRej",
   2026     "TermReq", "TermAck", "CodeRej"
   2027 };
   2028 
   2029 static int
   2030 ipcp_printpkt(p, plen, printer, arg)
   2031     u_char *p;
   2032     int plen;
   2033     void (*printer) __P((void *, char *, ...));
   2034     void *arg;
   2035 {
   2036     int code, id, len, olen;
   2037     u_char *pstart, *optend;
   2038     u_short cishort;
   2039     u_int32_t cilong;
   2040 
   2041     if (plen < HEADERLEN)
   2042 	return 0;
   2043     pstart = p;
   2044     GETCHAR(code, p);
   2045     GETCHAR(id, p);
   2046     GETSHORT(len, p);
   2047     if (len < HEADERLEN || len > plen)
   2048 	return 0;
   2049 
   2050     if (code >= 1 && code <= sizeof(ipcp_codenames) / sizeof(char *))
   2051 	printer(arg, " %s", ipcp_codenames[code-1]);
   2052     else
   2053 	printer(arg, " code=0x%x", code);
   2054     printer(arg, " id=0x%x", id);
   2055     len -= HEADERLEN;
   2056     switch (code) {
   2057     case CONFREQ:
   2058     case CONFACK:
   2059     case CONFNAK:
   2060     case CONFREJ:
   2061 	/* print option list */
   2062 	while (len >= 2) {
   2063 	    GETCHAR(code, p);
   2064 	    GETCHAR(olen, p);
   2065 	    p -= 2;
   2066 	    if (olen < 2 || olen > len) {
   2067 		break;
   2068 	    }
   2069 	    printer(arg, " <");
   2070 	    len -= olen;
   2071 	    optend = p + olen;
   2072 	    switch (code) {
   2073 	    case CI_ADDRS:
   2074 		if (olen == CILEN_ADDRS) {
   2075 		    p += 2;
   2076 		    GETLONG(cilong, p);
   2077 		    printer(arg, "addrs %I", htonl(cilong));
   2078 		    GETLONG(cilong, p);
   2079 		    printer(arg, " %I", htonl(cilong));
   2080 		}
   2081 		break;
   2082 	    case CI_COMPRESSTYPE:
   2083 		if (olen >= CILEN_COMPRESS) {
   2084 		    p += 2;
   2085 		    GETSHORT(cishort, p);
   2086 		    printer(arg, "compress ");
   2087 		    switch (cishort) {
   2088 		    case IPCP_VJ_COMP:
   2089 			printer(arg, "VJ");
   2090 			break;
   2091 		    case IPCP_VJ_COMP_OLD:
   2092 			printer(arg, "old-VJ");
   2093 			break;
   2094 		    default:
   2095 			printer(arg, "0x%x", cishort);
   2096 		    }
   2097 		}
   2098 		break;
   2099 	    case CI_ADDR:
   2100 		if (olen == CILEN_ADDR) {
   2101 		    p += 2;
   2102 		    GETLONG(cilong, p);
   2103 		    printer(arg, "addr %I", htonl(cilong));
   2104 		}
   2105 		break;
   2106 	    case CI_MS_DNS1:
   2107 	    case CI_MS_DNS2:
   2108 	        p += 2;
   2109 		GETLONG(cilong, p);
   2110 		printer(arg, "ms-dns%d %I", code - CI_MS_DNS1 + 1,
   2111 			htonl(cilong));
   2112 		break;
   2113 	    case CI_MS_WINS1:
   2114 	    case CI_MS_WINS2:
   2115 	        p += 2;
   2116 		GETLONG(cilong, p);
   2117 		printer(arg, "ms-wins %I", htonl(cilong));
   2118 		break;
   2119 	    }
   2120 	    while (p < optend) {
   2121 		GETCHAR(code, p);
   2122 		printer(arg, " %.2x", code);
   2123 	    }
   2124 	    printer(arg, ">");
   2125 	}
   2126 	break;
   2127 
   2128     case TERMACK:
   2129     case TERMREQ:
   2130 	if (len > 0 && *p >= ' ' && *p < 0x7f) {
   2131 	    printer(arg, " ");
   2132 	    print_string((char *)p, len, printer, arg);
   2133 	    p += len;
   2134 	    len = 0;
   2135 	}
   2136 	break;
   2137     }
   2138 
   2139     /* print the rest of the bytes in the packet */
   2140     for (; len > 0; --len) {
   2141 	GETCHAR(code, p);
   2142 	printer(arg, " %.2x", code);
   2143     }
   2144 
   2145     return p - pstart;
   2146 }
   2147 
   2148 /*
   2149  * ip_active_pkt - see if this IP packet is worth bringing the link up for.
   2150  * We don't bring the link up for IP fragments or for TCP FIN packets
   2151  * with no data.
   2152  */
   2153 #define IP_HDRLEN	20	/* bytes */
   2154 #define IP_OFFMASK	0x1fff
   2155 #ifndef IPPROTO_TCP
   2156 #define IPPROTO_TCP	6
   2157 #endif
   2158 #define TCP_HDRLEN	20
   2159 #define TH_FIN		0x01
   2160 
   2161 /*
   2162  * We use these macros because the IP header may be at an odd address,
   2163  * and some compilers might use word loads to get th_off or ip_hl.
   2164  */
   2165 
   2166 #define net_short(x)	(((x)[0] << 8) + (x)[1])
   2167 #define get_iphl(x)	(((unsigned char *)(x))[0] & 0xF)
   2168 #define get_ipoff(x)	net_short((unsigned char *)(x) + 6)
   2169 #define get_ipproto(x)	(((unsigned char *)(x))[9])
   2170 #define get_tcpoff(x)	(((unsigned char *)(x))[12] >> 4)
   2171 #define get_tcpflags(x)	(((unsigned char *)(x))[13])
   2172 
   2173 static int
   2174 ip_active_pkt(pkt, len)
   2175     u_char *pkt;
   2176     int len;
   2177 {
   2178     u_char *tcp;
   2179     int hlen;
   2180 
   2181     len -= PPP_HDRLEN;
   2182     pkt += PPP_HDRLEN;
   2183     if (len < IP_HDRLEN)
   2184 	return 0;
   2185     if ((get_ipoff(pkt) & IP_OFFMASK) != 0)
   2186 	return 0;
   2187     if (get_ipproto(pkt) != IPPROTO_TCP)
   2188 	return 1;
   2189     hlen = get_iphl(pkt) * 4;
   2190     if (len < hlen + TCP_HDRLEN)
   2191 	return 0;
   2192     tcp = pkt + hlen;
   2193     if ((get_tcpflags(tcp) & TH_FIN) != 0 && len == hlen + get_tcpoff(tcp) * 4)
   2194 	return 0;
   2195     return 1;
   2196 }
   2197