MFC r1.6 r1.30 r1.28 (HEAD):

[dragonfly.git] / usr.sbin / pppd / ipxcp.c

/*
 * ipxcp.c - PPP IPX Control Protocol.
 *
 * Copyright (c) 1989 Carnegie Mellon University.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by Carnegie Mellon University.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * $FreeBSD: src/usr.sbin/pppd/ipxcp.c,v 1.5 1999/08/28 01:19:03 peter Exp $
 * $DragonFly: src/usr.sbin/pppd/ipxcp.c,v 1.4 2005/11/24 23:42:54 swildner Exp $
 */

#ifdef IPX_CHANGE

/*
 * TODO:
 */

#include <stdio.h>
#include <string.h>
#include <syslog.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>

#include "pppd.h"
#include "fsm.h"
#include "ipxcp.h"
#include "pathnames.h"

/* global vars */
ipxcp_options ipxcp_wantoptions[NUM_PPP];       /* Options that we want to request */
ipxcp_options ipxcp_gotoptions[NUM_PPP];        /* Options that peer ack'd */
ipxcp_options ipxcp_allowoptions[NUM_PPP];      /* Options we allow peer to request */
ipxcp_options ipxcp_hisoptions[NUM_PPP];        /* Options that we ack'd */

#define wo (&ipxcp_wantoptions[0])
#define ao (&ipxcp_allowoptions[0])
#define go (&ipxcp_gotoptions[0])
#define ho (&ipxcp_hisoptions[0])

/*
 * Callbacks for fsm code.  (CI = Configuration Information)
 */
static void ipxcp_resetci(fsm *);       /* Reset our CI */
static int  ipxcp_cilen(fsm *);         /* Return length of our CI */
static void ipxcp_addci(fsm *, u_char *, int *); /* Add our CI */
static int  ipxcp_ackci(fsm *, u_char *, int);  /* Peer ack'd our CI */
static int  ipxcp_nakci(fsm *, u_char *, int);  /* Peer nak'd our CI */
static int  ipxcp_rejci(fsm *, u_char *, int);  /* Peer rej'd our CI */
static int  ipxcp_reqci(fsm *, u_char *, int *, int); /* Rcv CI */
static void ipxcp_up(fsm *);            /* We're UP */
static void ipxcp_down(fsm *);          /* We're DOWN */
static void ipxcp_script(fsm *, char *); /* Run an up/down script */

fsm ipxcp_fsm[NUM_PPP];         /* IPXCP fsm structure */

static fsm_callbacks ipxcp_callbacks = { /* IPXCP callback routines */
    ipxcp_resetci,              /* Reset our Configuration Information */
    ipxcp_cilen,                /* Length of our Configuration Information */
    ipxcp_addci,                /* Add our Configuration Information */
    ipxcp_ackci,                /* ACK our Configuration Information */
    ipxcp_nakci,                /* NAK our Configuration Information */
    ipxcp_rejci,                /* Reject our Configuration Information */
    ipxcp_reqci,                /* Request peer's Configuration Information */
    ipxcp_up,                   /* Called when fsm reaches OPENED state */
    ipxcp_down,                 /* Called when fsm leaves OPENED state */
    NULL,                       /* Called when we want the lower layer up */
    NULL,                       /* Called when we want the lower layer down */
    NULL,                       /* Called when Protocol-Reject received */
    NULL,                       /* Retransmission is necessary */
    NULL,                       /* Called to handle protocol-specific codes */
    "IPXCP"                     /* String name of protocol */
};

/*
 * Protocol entry points.
 */

static void ipxcp_init(int);
static void ipxcp_open(int);
static void ipxcp_close(int, char *);
static void ipxcp_lowerup(int);
static void ipxcp_lowerdown(int);
static void ipxcp_input(int, u_char *, int);
static void ipxcp_protrej(int);
static int  ipxcp_printpkt(u_char *, int,
                                void (*)(void *, char *, ...), void *);

struct protent ipxcp_protent = {
    PPP_IPXCP,
    ipxcp_init,
    ipxcp_input,
    ipxcp_protrej,
    ipxcp_lowerup,
    ipxcp_lowerdown,
    ipxcp_open,
    ipxcp_close,
    ipxcp_printpkt,
    NULL,
    0,
    "IPXCP",
    NULL,
    NULL,
    NULL
};

/*
 * Lengths of configuration options.
 */

#define CILEN_VOID      2
#define CILEN_COMPLETE  2       /* length of complete option */
#define CILEN_NETN      6       /* network number length option */
#define CILEN_NODEN     8       /* node number length option */
#define CILEN_PROTOCOL  4       /* Minimum length of routing protocol */
#define CILEN_NAME      3       /* Minimum length of router name */
#define CILEN_COMPRESS  4       /* Minimum length of compression protocol */

#define CODENAME(x)     ((x) == CONFACK ? "ACK" : \
                         (x) == CONFNAK ? "NAK" : "REJ")

/* Used in printing the node number */
#define NODE(base) base[0], base[1], base[2], base[3], base[4], base[5]

/* Used to generate the proper bit mask */
#define BIT(num)   (1 << (num))

/*
 * Convert from internal to external notation
 */

static short int
to_external(short int internal)
{
    short int  external;

    if (internal & IPX_NONE)
        external = IPX_NONE;
    else
        external = RIP_SAP;

    return external;
}

/*
 * Make a string representation of a network IP address.
 */

char *
ipx_ntoa(u_int32_t ipxaddr)
{
    static char b[64];
    sprintf(b, "%x", ipxaddr);
    return b;
}


/*
 * ipxcp_init - Initialize IPXCP.
 */
static void
ipxcp_init(int unit)
{
    fsm *f = &ipxcp_fsm[unit];

    f->unit      = unit;
    f->protocol  = PPP_IPXCP;
    f->callbacks = &ipxcp_callbacks;
    fsm_init(&ipxcp_fsm[unit]);

    memset (wo->name,     0, sizeof (wo->name));
    memset (wo->our_node, 0, sizeof (wo->our_node));
    memset (wo->his_node, 0, sizeof (wo->his_node));

    wo->neg_nn         = 1;
    wo->neg_complete   = 1;
    wo->network        = 0;

    ao->neg_node       = 1;
    ao->neg_nn         = 1;
    ao->neg_name       = 1;
    ao->neg_complete   = 1;
    ao->neg_router     = 1;

    ao->accept_local   = 0;
    ao->accept_remote  = 0;
    ao->accept_network = 0;

    wo->tried_rip      = 0;
    wo->tried_nlsp     = 0;
}

/*
 * Copy the node number
 */

static void
copy_node(u_char *src, u_char *dst)
{
    memcpy (dst, src, sizeof (ipxcp_wantoptions[0].our_node));
}

/*
 * Compare node numbers
 */

static int
compare_node(u_char *src, u_char *dst)
{
    return memcmp (dst, src, sizeof (ipxcp_wantoptions[0].our_node)) == 0;
}

/*
 * Is the node number zero?
 */

static int
zero_node(u_char *node)
{
    int indx;
    for (indx = 0; indx < sizeof (ipxcp_wantoptions[0].our_node); ++indx)
        if (node [indx] != 0)
            return 0;
    return 1;
}

/*
 * Increment the node number
 */

static void
inc_node(u_char *node)
{
    u_char   *outp;
    u_int32_t magic_num;

    outp      = node;
    magic_num = magic();
    *outp++   = '\0';
    *outp++   = '\0';
    PUTLONG (magic_num, outp);
}

/*
 * ipxcp_open - IPXCP is allowed to come up.
 */
static void
ipxcp_open(int unit)
{
    fsm_open(&ipxcp_fsm[unit]);
}

/*
 * ipxcp_close - Take IPXCP down.
 */
static void
ipxcp_close(int unit, char *reason)
{
    fsm_close(&ipxcp_fsm[unit], reason);
}


/*
 * ipxcp_lowerup - The lower layer is up.
 */
static void
ipxcp_lowerup(int unit)
{
    fsm_lowerup(&ipxcp_fsm[unit]);
}


/*
 * ipxcp_lowerdown - The lower layer is down.
 */
static void
ipxcp_lowerdown(int unit)
{
    fsm_lowerdown(&ipxcp_fsm[unit]);
}


/*
 * ipxcp_input - Input IPXCP packet.
 */
static void
ipxcp_input(int unit, u_char *p, int len)
{
    fsm_input(&ipxcp_fsm[unit], p, len);
}


/*
 * ipxcp_protrej - A Protocol-Reject was received for IPXCP.
 *
 * Pretend the lower layer went down, so we shut up.
 */
static void
ipxcp_protrej(int unit)
{
    fsm_lowerdown(&ipxcp_fsm[unit]);
}


/*
 * ipxcp_resetci - Reset our CI.
 */
static void
ipxcp_resetci(fsm *f)
{
    wo->req_node = wo->neg_node && ao->neg_node;
    wo->req_nn   = wo->neg_nn   && ao->neg_nn;

    if (wo->our_network == 0) {
        wo->neg_node       = 1;
        ao->accept_network = 1;
    }
/*
 * If our node number is zero then change it.
 */
    if (zero_node (wo->our_node)) {
        inc_node (wo->our_node);
        ao->accept_local = 1;
        wo->neg_node     = 1;
    }
/*
 * If his node number is zero then change it.
 */
    if (zero_node (wo->his_node)) {
        inc_node (wo->his_node);
        ao->accept_remote = 1;
    }
/*
 * If no routing agent was specified then we do RIP/SAP according to the
 * RFC documents. If you have specified something then OK. Otherwise, we
 * do RIP/SAP.
 */
    if (ao->router == 0) {
        ao->router |= BIT(RIP_SAP);
        wo->router |= BIT(RIP_SAP);
    }

    /* Always specify a routing protocol unless it was REJected. */
    wo->neg_router = 1;
/*
 * Start with these default values
 */
    *go = *wo;
}

/*
 * ipxcp_cilen - Return length of our CI.
 */

static int
ipxcp_cilen(fsm *f)
{
    int len;

    len  = go->neg_nn       ? CILEN_NETN     : 0;
    len += go->neg_node     ? CILEN_NODEN    : 0;
    len += go->neg_name     ? CILEN_NAME + strlen (go->name) - 1 : 0;

    /* RFC says that defaults should not be included. */
    if (go->neg_router && to_external(go->router) != RIP_SAP)
        len += CILEN_PROTOCOL;

    return (len);
}


/*
 * ipxcp_addci - Add our desired CIs to a packet.
 */
static void
ipxcp_addci(fsm *f, u_char *ucp, int *lenp)
{
/*
 * Add the options to the record.
 */
    if (go->neg_nn) {
        PUTCHAR (IPX_NETWORK_NUMBER, ucp);
        PUTCHAR (CILEN_NETN, ucp);
        PUTLONG (go->our_network, ucp);
    }

    if (go->neg_node) {
        int indx;
        PUTCHAR (IPX_NODE_NUMBER, ucp);
        PUTCHAR (CILEN_NODEN, ucp);
        for (indx = 0; indx < sizeof (go->our_node); ++indx)
            PUTCHAR (go->our_node[indx], ucp);
    }

    if (go->neg_name) {
        int cilen = strlen (go->name);
        int indx;
        PUTCHAR (IPX_ROUTER_NAME, ucp);
        PUTCHAR (CILEN_NAME + cilen - 1, ucp);
        for (indx = 0; indx < cilen; ++indx)
            PUTCHAR (go->name [indx], ucp);
    }

    if (go->neg_router) {
        short external = to_external (go->router);
        if (external != RIP_SAP) {
            PUTCHAR  (IPX_ROUTER_PROTOCOL, ucp);
            PUTCHAR  (CILEN_PROTOCOL,      ucp);
            PUTSHORT (external,            ucp);
        }
    }
}

/*
 * ipxcp_ackci - Ack our CIs.
 *
 * Returns:
 *      0 - Ack was bad.
 *      1 - Ack was good.
 */
static int
ipxcp_ackci(fsm *f, u_char *p, int len)
{
    u_short cilen, citype, cishort;
    u_char cichar;
    u_int32_t cilong;

#define ACKCIVOID(opt, neg) \
    if (neg) { \
        if ((len -= CILEN_VOID) < 0) \
            break; \
        GETCHAR(citype, p); \
        GETCHAR(cilen, p); \
        if (cilen != CILEN_VOID || \
            citype != opt) \
            break; \
    }

#define ACKCICOMPLETE(opt,neg)  ACKCIVOID(opt, neg)

#define ACKCICHARS(opt, neg, val, cnt) \
    if (neg) { \
        int indx, count = cnt; \
        len -= (count + 2); \
        if (len < 0) \
            break; \
        GETCHAR(citype, p); \
        GETCHAR(cilen, p); \
        if (cilen != (count + 2) || \
            citype != opt) \
            break; \
        for (indx = 0; indx < count; ++indx) {\
            GETCHAR(cichar, p); \
            if (cichar != ((u_char *) &val)[indx]) \
               break; \
        }\
        if (indx != count) \
            break; \
    }

#define ACKCINODE(opt,neg,val) ACKCICHARS(opt,neg,val,sizeof(val))
#define ACKCINAME(opt,neg,val) ACKCICHARS(opt,neg,val,strlen(val))

#define ACKCINETWORK(opt, neg, val) \
    if (neg) { \
        if ((len -= CILEN_NETN) < 0) \
            break; \
        GETCHAR(citype, p); \
        GETCHAR(cilen, p); \
        if (cilen != CILEN_NETN || \
            citype != opt) \
            break; \
        GETLONG(cilong, p); \
        if (cilong != val) \
            break; \
    }

#define ACKCIPROTO(opt, neg, val) \
    if (neg) { \
        if (len < 2) \
            break; \
        GETCHAR(citype, p); \
        GETCHAR(cilen, p); \
        if (cilen != CILEN_PROTOCOL || citype != opt) \
            break; \
        len -= cilen; \
        if (len < 0) \
            break; \
        GETSHORT(cishort, p); \
        if (cishort != to_external (val) || cishort == RIP_SAP) \
            break; \
      }
/*
 * Process the ACK frame in the order in which the frame was assembled
 */
    do {
        ACKCINETWORK  (IPX_NETWORK_NUMBER,  go->neg_nn,     go->our_network);
        ACKCINODE     (IPX_NODE_NUMBER,     go->neg_node,   go->our_node);
        ACKCINAME     (IPX_ROUTER_NAME,     go->neg_name,   go->name);
        ACKCIPROTO    (IPX_ROUTER_PROTOCOL, go->neg_router, go->router);
        ACKCIPROTO    (IPX_ROUTER_PROTOCOL, go->neg_router, go->router);
        ACKCIPROTO    (IPX_ROUTER_PROTOCOL, go->neg_router, go->router);
/*
 * This is the end of the record.
 */
        if (len == 0)
            return (1);
    } while (0);
/*
 * The frame is invalid
 */
    IPXCPDEBUG((LOG_INFO, "ipxcp_ackci: received bad Ack!"));
    return (0);
}

/*
 * ipxcp_nakci - Peer has sent a NAK for some of our CIs.
 * This should not modify any state if the Nak is bad
 * or if IPXCP is in the OPENED state.
 *
 * Returns:
 *      0 - Nak was bad.
 *      1 - Nak was good.
 */

static int
ipxcp_nakci(fsm *f, u_char *p, int len)
{
    u_char citype, cilen, *next;
    u_short s;
    u_int32_t l;
    ipxcp_options no;           /* options we've seen Naks for */
    ipxcp_options try;          /* options to request next time */

    BZERO(&no, sizeof(no));
    try = *go;

    while (len > CILEN_VOID) {
        GETCHAR (citype, p);
        GETCHAR (cilen,  p);
        len -= cilen;
        if (len < 0)
            goto bad;
        next = &p [cilen - CILEN_VOID];

        switch (citype) {
        case IPX_NETWORK_NUMBER:
            if (!go->neg_nn || no.neg_nn || (cilen != CILEN_NETN))
                goto bad;
            no.neg_nn = 1;

            GETLONG(l, p);
            IPXCPDEBUG((LOG_INFO, "local IP address %d", l));
            if (l && ao->accept_network)
                try.our_network = l;
            break;

        case IPX_NODE_NUMBER:
            if (!go->neg_node || no.neg_node || (cilen != CILEN_NODEN))
                goto bad;
            no.neg_node = 1;

            IPXCPDEBUG((LOG_INFO,
                        "local node number %02X%02X%02X%02X%02X%02X",
                        NODE(p)));

            if (!zero_node (p) && ao->accept_local &&
                ! compare_node (p, ho->his_node))
                copy_node (p, try.our_node);
            break;

            /* This has never been sent. Ignore the NAK frame */
        case IPX_COMPRESSION_PROTOCOL:
            goto bad;

        case IPX_ROUTER_PROTOCOL:
            if (!go->neg_router || (cilen < CILEN_PROTOCOL))
                goto bad;

            GETSHORT (s, p);
            if (s > 15)         /* This is just bad, but ignore for now. */
                break;

            s = BIT(s);
            if (no.router & s)  /* duplicate NAKs are always bad */
                goto bad;

            if (no.router == 0) /* Reset on first NAK only */
                try.router = 0;

            no.router      |= s;
            try.router     |= s;
            try.neg_router  = 1;

            IPXCPDEBUG((LOG_INFO, "Router protocol number %d", s));
            break;

            /* These, according to the RFC, must never be NAKed. */
        case IPX_ROUTER_NAME:
        case IPX_COMPLETE:
            goto bad;

            /* These are for options which we have not seen. */
        default:
            break;
        }
        p = next;
    }

    /* If there is still anything left, this packet is bad. */
    if (len != 0)
        goto bad;

    /*
     * Do not permit the peer to force a router protocol which we do not
     * support. However, default to the condition that will accept "NONE".
     */
    try.router &= (ao->router | BIT(IPX_NONE));
    if (try.router == 0 && ao->router != 0)
        try.router = BIT(IPX_NONE);

    if (try.router != 0)
        try.neg_router = 1;
    
    /*
     * OK, the Nak is good.  Now we can update state.
     */
    if (f->state != OPENED)
        *go = try;

    return 1;

bad:
    IPXCPDEBUG((LOG_INFO, "ipxcp_nakci: received bad Nak!"));
    return 0;
}

/*
 * ipxcp_rejci - Reject some of our CIs.
 */
static int
ipxcp_rejci(fsm *f, u_char *p, int len)
{
    u_short cilen, citype, cishort;
    u_char cichar;
    u_int32_t cilong;
    ipxcp_options try;          /* options to request next time */

#define REJCINETWORK(opt, neg, val) \
    if (neg && p[0] == opt) { \
        if ((len -= CILEN_NETN) < 0) \
            break; \
        GETCHAR(citype, p); \
        GETCHAR(cilen, p); \
        if (cilen != CILEN_NETN || \
            citype != opt) \
            break; \
        GETLONG(cilong, p); \
        if (cilong != val) \
            break; \
        IPXCPDEBUG((LOG_INFO,"ipxcp_rejci rejected long opt %d", opt)); \
        neg = 0; \
    }

#define REJCICHARS(opt, neg, val, cnt) \
    if (neg && p[0] == opt) { \
        int indx, count = cnt; \
        len -= (count + 2); \
        if (len < 0) \
            break; \
        GETCHAR(citype, p); \
        GETCHAR(cilen, p); \
        if (cilen != (count + 2) || \
            citype != opt) \
            break; \
        for (indx = 0; indx < count; ++indx) {\
            GETCHAR(cichar, p); \
            if (cichar != ((u_char *) &val)[indx]) \
               break; \
        }\
        if (indx != count) \
            break; \
        IPXCPDEBUG((LOG_INFO,"ipxcp_rejci rejected opt %d", opt)); \
        neg = 0; \
    }

#define REJCINODE(opt,neg,val) REJCICHARS(opt,neg,val,sizeof(val))
#define REJCINAME(opt,neg,val) REJCICHARS(opt,neg,val,strlen(val))

#define REJCIVOID(opt, neg) \
    if (neg && p[0] == opt) { \
        if ((len -= CILEN_VOID) < 0) \
            break; \
        GETCHAR(citype, p); \
        GETCHAR(cilen, p); \
        if (cilen != CILEN_VOID || citype != opt) \
            break; \
        IPXCPDEBUG((LOG_INFO, "ipxcp_rejci rejected void opt %d", opt)); \
        neg = 0; \
    }

/* a reject for RIP/SAP is invalid since we don't send it and you can't
   reject something which is not sent. (You can NAK, but you can't REJ.) */
#define REJCIPROTO(opt, neg, val, bit) \
    if (neg && p[0] == opt) { \
        if ((len -= CILEN_PROTOCOL) < 0) \
            break; \
        GETCHAR(citype, p); \
        GETCHAR(cilen, p); \
        if (cilen != CILEN_PROTOCOL) \
            break; \
        GETSHORT(cishort, p); \
        if (cishort != to_external (val) || cishort == RIP_SAP) \
            break; \
        IPXCPDEBUG((LOG_INFO, "ipxcp_rejci short opt %d", opt)); \
        neg = 0; \
    }
/*
 * Any Rejected CIs must be in exactly the same order that we sent.
 * Check packet length and CI length at each step.
 * If we find any deviations, then this packet is bad.
 */
    try = *go;

    do {
        REJCINETWORK (IPX_NETWORK_NUMBER,  try.neg_nn,     try.our_network);
        REJCINODE    (IPX_NODE_NUMBER,     try.neg_node,   try.our_node);
        REJCINAME    (IPX_ROUTER_NAME,     try.neg_name,   try.name);
        REJCIPROTO   (IPX_ROUTER_PROTOCOL, try.neg_router, try.router, 0);
/*
 * This is the end of the record.
 */
        if (len == 0) {
            if (f->state != OPENED)
                *go = try;
            return (1);
        }
    } while (0);
/*
 * The frame is invalid at this point.
 */
    IPXCPDEBUG((LOG_INFO, "ipxcp_rejci: received bad Reject!"));
    return 0;
}

/*
 * ipxcp_reqci - Check the peer's requested CIs and send appropriate response.
 *
 * Returns: CONFACK, CONFNAK or CONFREJ and input packet modified
 * appropriately.  If reject_if_disagree is non-zero, doesn't return
 * CONFNAK; returns CONFREJ if it can't return CONFACK.
 *
 * Parameters:
 *      inp:    Requested CIs
 *      len:    Length of requested CIs
 */
static int
ipxcp_reqci(fsm *f, u_char *inp, int *len, int reject_if_disagree)
{
    u_char *cip, *next;         /* Pointer to current and next CIs */
    u_short cilen, citype;      /* Parsed len, type */
    u_short cishort;            /* Parsed short value */
    u_int32_t cinetwork;        /* Parsed address values */
    int rc = CONFACK;           /* Final packet return code */
    int orc;                    /* Individual option return code */
    u_char *p;                  /* Pointer to next char to parse */
    u_char *ucp = inp;          /* Pointer to current output char */
    int l = *len;               /* Length left */

    /*
     * Reset all his options.
     */
    BZERO(ho, sizeof(*ho));
    
    /*
     * Process all his options.
     */
    next = inp;
    while (l) {
        orc = CONFACK;                  /* Assume success */
        cip = p = next;                 /* Remember begining of CI */
        if (l < 2 ||                    /* Not enough data for CI header or */
            p[1] < 2 ||                 /*  CI length too small or */
            p[1] > l) {                 /*  CI length too big? */
            IPXCPDEBUG((LOG_INFO, "ipxcp_reqci: bad CI length!"));
            orc = CONFREJ;              /* Reject bad CI */
            cilen = l;                  /* Reject till end of packet */
            l = 0;                      /* Don't loop again */
            goto endswitch;
        }
        GETCHAR(citype, p);             /* Parse CI type */
        GETCHAR(cilen, p);              /* Parse CI length */
        l -= cilen;                     /* Adjust remaining length */
        next += cilen;                  /* Step to next CI */

        switch (citype) {               /* Check CI type */
/*
 * The network number must match. Choose the larger of the two.
 */
        case IPX_NETWORK_NUMBER:
            IPXCPDEBUG((LOG_INFO, "ipxcp: received Network Number request"));
            
            /* if we wont negotiate the network number or the length is wrong
               then reject the option */
            if ( !ao->neg_nn || cilen != CILEN_NETN ) {
                orc = CONFREJ;
                break;          
            }
            GETLONG(cinetwork, p);
            IPXCPDEBUG((LOG_INFO,"Remote proposed IPX network number is %8Lx",tl));

            /* If the network numbers match then acknowledge them. */
            if (cinetwork != 0) {
                ho->his_network = cinetwork;
                ho->neg_nn      = 1;
                if (wo->our_network == cinetwork)
                    break;
/*
 * If the network number is not given or we don't accept their change or
 * the network number is too small then NAK it.
 */
                if (! ao->accept_network || cinetwork < wo->our_network) {
                    DECPTR (sizeof (u_int32_t), p);
                    PUTLONG (wo->our_network, p);
                    orc = CONFNAK;
                }
                break;
            }
/*
 * The peer sent '0' for the network. Give it ours if we have one.
 */
            if (go->our_network != 0) {
                DECPTR (sizeof (u_int32_t), p);
                PUTLONG (wo->our_network, p);
                orc = CONFNAK;
/*
 * We don't have one. Reject the value.
 */
            } else
                orc = CONFREJ;

            break;
/*
 * The node number is required
 */
        case IPX_NODE_NUMBER:
            IPXCPDEBUG((LOG_INFO, "ipxcp: received Node Number request"));

            /* if we wont negotiate the node number or the length is wrong
               then reject the option */
            if ( cilen != CILEN_NODEN ) {
                orc = CONFREJ;
                break;
            }

            copy_node (p, ho->his_node);
            ho->neg_node = 1;
/*
 * If the remote does not have a number and we do then NAK it with the value
 * which we have for it. (We never have a default value of zero.)
 */
            if (zero_node (ho->his_node)) {
                orc = CONFNAK;
                copy_node (wo->his_node, p);
                INCPTR (sizeof (wo->his_node), p);
                break;
            }
/*
 * If you have given me the expected network node number then I'll accept
 * it now.
 */
            if (compare_node (wo->his_node, ho->his_node)) {
                orc = CONFACK;
                ho->neg_node = 1;
                INCPTR (sizeof (wo->his_node), p);
                break;
            }
/*
 * If his node number is the same as ours then ask him to try the next
 * value.
 */
            if (compare_node (ho->his_node, go->our_node)) {
                inc_node (ho->his_node);
                orc = CONFNAK;
                copy_node (ho->his_node, p);
                INCPTR (sizeof (wo->his_node), p);
                break;
            }
/*
 * If we don't accept a new value then NAK it.
 */
            if (! ao->accept_remote) {
                copy_node (wo->his_node, p);
                INCPTR (sizeof (wo->his_node), p);
                orc = CONFNAK;
                break;
            }
            orc = CONFACK;
            ho->neg_node = 1;
            INCPTR (sizeof (wo->his_node), p);
            break;
/*
 * Compression is not desired at this time. It is always rejected.
 */
        case IPX_COMPRESSION_PROTOCOL:
            IPXCPDEBUG((LOG_INFO, "ipxcp: received Compression Protocol request "));
            orc = CONFREJ;
            break;
/*
 * The routing protocol is a bitmask of various types. Any combination
 * of the values RIP_SAP and NLSP are permissible. 'IPX_NONE' for no
 * routing protocol must be specified only once.
 */
        case IPX_ROUTER_PROTOCOL:
            if ( !ao->neg_router || cilen < CILEN_PROTOCOL ) {
                orc = CONFREJ;
                break;          
            }

            GETSHORT (cishort, p);
            IPXCPDEBUG((LOG_INFO,
                        "Remote router protocol number 0x%04x",
                        cishort));

            if (wo->neg_router == 0) {
                wo->neg_router = 1;
                wo->router     = BIT(IPX_NONE);
            }

            if ((cishort == IPX_NONE && ho->router != 0) ||
                (ho->router & BIT(IPX_NONE))) {
                orc = CONFREJ;
                break;
            }

            cishort = BIT(cishort);
            if (ho->router & cishort) {
                orc = CONFREJ;
                break;
            }

            ho->router    |= cishort;
            ho->neg_router = 1;

            /* Finally do not allow a router protocol which we do not
               support. */

            if ((cishort & (ao->router | BIT(IPX_NONE))) == 0) {
                int protocol;

                if (cishort == BIT(NLSP) &&
                    (ao->router & BIT(RIP_SAP)) &&
                    !wo->tried_rip) {
                    protocol      = RIP_SAP;
                    wo->tried_rip = 1;
                } else
                    protocol = IPX_NONE;

                DECPTR (sizeof (u_int16_t), p);
                PUTSHORT (protocol, p);
                orc = CONFNAK;
            }
            break;
/*
 * The router name is advisorary. Just accept it if it is not too large.
 */
        case IPX_ROUTER_NAME:
            IPXCPDEBUG((LOG_INFO, "ipxcp: received Router Name request"));
            if (cilen >= CILEN_NAME) {
                int name_size = cilen - CILEN_NAME;
                if (name_size > sizeof (ho->name))
                    name_size = sizeof (ho->name) - 1;
                memset (ho->name, 0, sizeof (ho->name));
                memcpy (ho->name, p, name_size);
                ho->name [name_size] = '\0';
                ho->neg_name = 1;
                orc = CONFACK;
                break;
            }
            orc = CONFREJ;
            break;
/*
 * This is advisorary.
 */
        case IPX_COMPLETE:
            IPXCPDEBUG((LOG_INFO, "ipxcp: received Complete request"));
            if (cilen != CILEN_COMPLETE)
                orc = CONFREJ;
            else {
                ho->neg_complete = 1;
                orc = CONFACK;
            }
            break;
/*
 * All other entries are not known at this time.
 */
        default:
            IPXCPDEBUG((LOG_INFO, "ipxcp: received Complete request"));
            orc = CONFREJ;
            break;
        }

endswitch:
        IPXCPDEBUG((LOG_INFO, " (%s)\n", CODENAME(orc)));

        if (orc == CONFACK &&           /* Good CI */
            rc != CONFACK)              /*  but prior CI wasnt? */
            continue;                   /* Don't send this one */

        if (orc == CONFNAK) {           /* Nak this CI? */
            if (reject_if_disagree)     /* Getting fed up with sending NAKs? */
                orc = CONFREJ;          /* Get tough if so */
            if (rc == CONFREJ)          /* Rejecting prior CI? */
                continue;               /* Don't send this one */
            if (rc == CONFACK) {        /* Ack'd all prior CIs? */
                rc  = CONFNAK;          /* Not anymore... */
                ucp = inp;              /* Backup */
            }
        }

        if (orc == CONFREJ &&           /* Reject this CI */
            rc != CONFREJ) {            /*  but no prior ones? */
            rc = CONFREJ;
            ucp = inp;                  /* Backup */
        }

        /* Need to move CI? */
        if (ucp != cip)
            BCOPY(cip, ucp, cilen);     /* Move it */

        /* Update output pointer */
        INCPTR(cilen, ucp);
    }

    /*
     * If we aren't rejecting this packet, and we want to negotiate
     * their address, and they didn't send their address, then we
     * send a NAK with a IPX_NODE_NUMBER option appended. We assume the
     * input buffer is long enough that we can append the extra
     * option safely.
     */

    if (rc != CONFREJ && !ho->neg_node &&
        wo->req_nn && !reject_if_disagree) {
        if (rc == CONFACK) {
            rc = CONFNAK;
            wo->req_nn = 0;             /* don't ask again */
            ucp = inp;                  /* reset pointer */
        }

        if (zero_node (wo->his_node))
            inc_node (wo->his_node);

        PUTCHAR (IPX_NODE_NUMBER, ucp);
        PUTCHAR (CILEN_NODEN, ucp);
        copy_node (wo->his_node, ucp);
        INCPTR (sizeof (wo->his_node), ucp);
    }

    *len = ucp - inp;                   /* Compute output length */
    IPXCPDEBUG((LOG_INFO, "ipxcp: returning Configure-%s", CODENAME(rc)));
    return (rc);                        /* Return final code */
}

/*
 * ipxcp_up - IPXCP has come UP.
 *
 * Configure the IP network interface appropriately and bring it up.
 */

static void
ipxcp_up(fsm *f)
{
    int unit = f->unit;

    IPXCPDEBUG((LOG_INFO, "ipxcp: up"));

    /* The default router protocol is RIP/SAP. */
    if (ho->router == 0)
        ho->router = BIT(RIP_SAP);

    if (go->router == 0)
        go->router = BIT(RIP_SAP);

    /* Fetch the network number */
    if (!ho->neg_nn)
        ho->his_network = wo->his_network;

    if (!ho->neg_node)
        copy_node (wo->his_node, ho->his_node);

    if (!wo->neg_node && !go->neg_node)
        copy_node (wo->our_node, go->our_node);

    if (zero_node (go->our_node)) {
        static char errmsg[] = "Could not determine local IPX node address";
        IPXCPDEBUG((LOG_ERR, errmsg));
        ipxcp_close(f->unit, errmsg);
        return;
    }

    go->network = go->our_network;
    if (ho->his_network != 0 && ho->his_network > go->network)
        go->network = ho->his_network;

    if (go->network == 0) {
        static char errmsg[] = "Can not determine network number";
        IPXCPDEBUG((LOG_ERR, errmsg));
        ipxcp_close (unit, errmsg);
        return;
    }

    /* bring the interface up */
    if (!sifup(unit)) {
        IPXCPDEBUG((LOG_WARNING, "sifup failed"));
        ipxcp_close(unit, "Interface configuration failed");
        return;
    }

    /* set the network number for IPX */
    if (!sipxfaddr(unit, go->network, go->our_node)) {
        IPXCPDEBUG((LOG_WARNING, "sipxfaddr failed"));
        ipxcp_close(unit, "Interface configuration failed");
        return;
    }

    /*
     * Execute the ipx-up script, like this:
     *  /etc/ppp/ipx-up interface tty speed local-IPX remote-IPX
     */

    ipxcp_script (f, _PATH_IPXUP);
}

/*
 * ipxcp_down - IPXCP has gone DOWN.
 *
 * Take the IP network interface down, clear its addresses
 * and delete routes through it.
 */

static void
ipxcp_down(fsm *f)
{
    IPXCPDEBUG((LOG_INFO, "ipxcp: down"));

    cipxfaddr (f->unit);
    sifdown(f->unit);
    ipxcp_script (f, _PATH_IPXDOWN);
}


/*
 * ipxcp_script - Execute a script with arguments
 * interface-name tty-name speed local-IPX remote-IPX networks.
 */
static void
ipxcp_script(fsm *f, char *script)
{
    char strspeed[32],   strlocal[32],     strremote[32];
    char strnetwork[32], strpid[32];
    char *argv[14],      strproto_lcl[32], strproto_rmt[32];

    sprintf (strpid,   "%d", getpid());
    sprintf (strspeed, "%d", baud_rate);

    strproto_lcl[0] = '\0';
    if (go->neg_router && ((go->router & BIT(IPX_NONE)) == 0)) {
        if (go->router & BIT(RIP_SAP))
            strcpy (strproto_lcl, "RIP ");
        if (go->router & BIT(NLSP))
            strcat (strproto_lcl, "NLSP ");
    }

    if (strproto_lcl[0] == '\0')
        strcpy (strproto_lcl, "NONE ");

    strproto_lcl[strlen (strproto_lcl)-1] = '\0';

    strproto_rmt[0] = '\0';
    if (ho->neg_router && ((ho->router & BIT(IPX_NONE)) == 0)) {
        if (ho->router & BIT(RIP_SAP))
            strcpy (strproto_rmt, "RIP ");
        if (ho->router & BIT(NLSP))
            strcat (strproto_rmt, "NLSP ");
    }

    if (strproto_rmt[0] == '\0')
        strcpy (strproto_rmt, "NONE ");

    strproto_rmt[strlen (strproto_rmt)-1] = '\0';

    strcpy (strnetwork, ipx_ntoa (go->network));

    sprintf (strlocal,
             "%02X%02X%02X%02X%02X%02X",
             NODE(go->our_node));

    sprintf (strremote,
             "%02X%02X%02X%02X%02X%02X",
             NODE(ho->his_node));

    argv[0]  = script;
    argv[1]  = ifname;
    argv[2]  = devnam;
    argv[3]  = strspeed;
    argv[4]  = strnetwork;
    argv[5]  = strlocal;
    argv[6]  = strremote;
    argv[7]  = strproto_lcl;
    argv[8]  = strproto_rmt;
    argv[9]  = go->name;
    argv[10] = ho->name;
    argv[11] = ipparam;
    argv[12] = strpid;
    argv[13] = NULL;
    run_program(script, argv, 0);
}

/*
 * ipxcp_printpkt - print the contents of an IPXCP packet.
 */
static char *ipxcp_codenames[] = {
    "ConfReq", "ConfAck", "ConfNak", "ConfRej",
    "TermReq", "TermAck", "CodeRej"
};

static int
ipxcp_printpkt(u_char *p, int plen, void (*printer)(void *, char *, ...),
               void *arg)
{
    int code, id, len, olen;
    u_char *pstart, *optend;
    u_short cishort;
    u_int32_t cilong;

    if (plen < HEADERLEN)
        return 0;
    pstart = p;
    GETCHAR(code, p);
    GETCHAR(id, p);
    GETSHORT(len, p);
    if (len < HEADERLEN || len > plen)
        return 0;

    if (code >= 1 && code <= sizeof(ipxcp_codenames) / sizeof(char *))
        printer(arg, " %s", ipxcp_codenames[code-1]);
    else
        printer(arg, " code=0x%x", code);
    printer(arg, " id=0x%x", id);
    len -= HEADERLEN;
    switch (code) {
    case CONFREQ:
    case CONFACK:
    case CONFNAK:
    case CONFREJ:
        /* print option list */
        while (len >= 2) {
            GETCHAR(code, p);
            GETCHAR(olen, p);
            p -= 2;
            if (olen < CILEN_VOID || olen > len) {
                break;
            }
            printer(arg, " <");
            len -= olen;
            optend = p + olen;
            switch (code) {
            case IPX_NETWORK_NUMBER:
                if (olen == CILEN_NETN) {
                    p += 2;
                    GETLONG(cilong, p);
                    printer (arg, "network %s", ipx_ntoa (cilong));
                }
                break;
            case IPX_NODE_NUMBER:
                if (olen == CILEN_NODEN) {
                    p += 2;
                    printer (arg, "node ");
                    while (p < optend) {
                        GETCHAR(code, p);
                        printer(arg, "%.2x", (int) (unsigned int) (unsigned char) code);
                    }
                }
                break;
            case IPX_COMPRESSION_PROTOCOL:
                if (olen == CILEN_COMPRESS) {
                    p += 2;
                    GETSHORT (cishort, p);
                    printer (arg, "compression %d", (int) cishort);
                }
                break;
            case IPX_ROUTER_PROTOCOL:
                if (olen == CILEN_PROTOCOL) {
                    p += 2;
                    GETSHORT (cishort, p);
                    printer (arg, "router proto %d", (int) cishort);
                }
                break;
            case IPX_ROUTER_NAME:
                if (olen >= CILEN_NAME) {
                    p += 2;
                    printer (arg, "router name \"");
                    while (p < optend) {
                        GETCHAR(code, p);
                        if (code >= 0x20 && code <= 0x7E)
                            printer (arg, "%c", (int) (unsigned int) (unsigned char) code);
                        else
                            printer (arg, " \\%.2x", (int) (unsigned int) (unsigned char) code);
                    }
                    printer (arg, "\"");
                }
                break;
            case IPX_COMPLETE:
                if (olen == CILEN_COMPLETE) {
                    p += 2;
                    printer (arg, "complete");
                }
                break;
            default:
                break;
            }

            while (p < optend) {
                GETCHAR(code, p);
                printer(arg, " %.2x", (int) (unsigned int) (unsigned char) code);
            }
            printer(arg, ">");
        }
        break;

    case TERMACK:
    case TERMREQ:
        if (len > 0 && *p >= ' ' && *p < 0x7f) {
            printer(arg, " ");
            print_string(p, len, printer, arg);
            p += len;
            len = 0;
        }
        break;
    }

    /* print the rest of the bytes in the packet */
    for (; len > 0; --len) {
        GETCHAR(code, p);
        printer(arg, " %.2x", (int) (unsigned int) (unsigned char) code);
    }

    return p - pstart;
}
#endif /* ifdef IPX_CHANGE */