1 files changed, 1196 insertions, 0 deletions

diff --git a/usr.sbin/pppd/ipcp.c b/usr.sbin/pppd/ipcp.c
new file mode 100644
index 000000000000..6c9abb15f2be
--- /dev/null
+++ b/usr.sbin/pppd/ipcp.c
@@ -0,0 +1,1196 @@
+/*
+ * ipcp.c - PPP IP 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.
+ */
+
+#ifndef lint
+static char rcsid[] = "$Id: ipcp.c,v 1.8 1994/05/26 06:37:34 paulus Exp $";
+#endif
+
+/*
+ * TODO:
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <syslog.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include "pppd.h"
+#include "ppp.h"
+#include "fsm.h"
+#include "ipcp.h"
+#include "pathnames.h"
+
+/* global vars */
+ipcp_options ipcp_wantoptions[NPPP];	/* Options that we want to request */
+ipcp_options ipcp_gotoptions[NPPP];	/* Options that peer ack'd */
+ipcp_options ipcp_allowoptions[NPPP];	/* Options we allow peer to request */
+ipcp_options ipcp_hisoptions[NPPP];	/* Options that we ack'd */
+
+extern char ifname[];
+extern char devname[];
+extern int baud_rate;
+
+/* local vars */
+static int cis_received[NPPP];		/* # Conf-Reqs received */
+
+/*
+ * Callbacks for fsm code.  (CI = Configuration Information)
+ */
+static void ipcp_resetci __ARGS((fsm *));	/* Reset our CI */
+static int  ipcp_cilen __ARGS((fsm *));	        /* Return length of our CI */
+static void ipcp_addci __ARGS((fsm *, u_char *, int *)); /* Add our CI */
+static int  ipcp_ackci __ARGS((fsm *, u_char *, int));	/* Peer ack'd our CI */
+static int  ipcp_nakci __ARGS((fsm *, u_char *, int));	/* Peer nak'd our CI */
+static int  ipcp_rejci __ARGS((fsm *, u_char *, int));	/* Peer rej'd our CI */
+static int  ipcp_reqci __ARGS((fsm *, u_char *, int *, int)); /* Rcv CI */
+static void ipcp_up __ARGS((fsm *));		/* We're UP */
+static void ipcp_down __ARGS((fsm *));		/* We're DOWN */
+static void ipcp_script __ARGS((fsm *, char *)); /* Run an up/down script */
+
+fsm ipcp_fsm[NPPP];		/* IPCP fsm structure */
+
+static fsm_callbacks ipcp_callbacks = { /* IPCP callback routines */
+    ipcp_resetci,		/* Reset our Configuration Information */
+    ipcp_cilen,			/* Length of our Configuration Information */
+    ipcp_addci,			/* Add our Configuration Information */
+    ipcp_ackci,			/* ACK our Configuration Information */
+    ipcp_nakci,			/* NAK our Configuration Information */
+    ipcp_rejci,			/* Reject our Configuration Information */
+    ipcp_reqci,			/* Request peer's Configuration Information */
+    ipcp_up,			/* Called when fsm reaches OPENED state */
+    ipcp_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 */
+    "IPCP"			/* String name of protocol */
+};
+
+/*
+ * Lengths of configuration options.
+ */
+#define CILEN_VOID	2
+#define CILEN_COMPRESS	4	/* min length for compression protocol opt. */
+#define CILEN_VJ	6	/* length for RFC1332 Van-Jacobson opt. */
+#define CILEN_ADDR	6	/* new-style single address option */
+#define CILEN_ADDRS	10	/* old-style dual address option */
+
+
+#define CODENAME(x)	((x) == CONFACK ? "ACK" : \
+			 (x) == CONFNAK ? "NAK" : "REJ")
+
+
+/*
+ * Make a string representation of a network IP address.
+ */
+char *
+ip_ntoa(ipaddr)
+u_long ipaddr;
+{
+    static char b[64];
+
+    ipaddr = ntohl(ipaddr);
+
+    sprintf(b, "%d.%d.%d.%d",
+	    (u_char)(ipaddr >> 24),
+	    (u_char)(ipaddr >> 16),
+	    (u_char)(ipaddr >> 8),
+	    (u_char)(ipaddr));
+    return b;
+}
+
+
+/*
+ * ipcp_init - Initialize IPCP.
+ */
+void
+ipcp_init(unit)
+    int unit;
+{
+    fsm *f = &ipcp_fsm[unit];
+    ipcp_options *wo = &ipcp_wantoptions[unit];
+    ipcp_options *ao = &ipcp_allowoptions[unit];
+
+    f->unit = unit;
+    f->protocol = IPCP;
+    f->callbacks = &ipcp_callbacks;
+    fsm_init(&ipcp_fsm[unit]);
+
+    wo->neg_addr = 1;
+    wo->old_addrs = 0;
+    wo->ouraddr = 0;
+    wo->hisaddr = 0;
+
+    wo->neg_vj = 1;
+    wo->old_vj = 0;
+    wo->vj_protocol = IPCP_VJ_COMP;
+    wo->maxslotindex = MAX_STATES - 1; /* really max index */
+    wo->cflag = 1;
+
+    /* max slots and slot-id compression are currently hardwired in */
+    /* ppp_if.c to 16 and 1, this needs to be changed (among other */
+    /* things) gmc */
+
+    ao->neg_addr = 1;
+    ao->neg_vj = 1;
+    ao->maxslotindex = MAX_STATES - 1;
+    ao->cflag = 1;
+}
+
+
+/*
+ * ipcp_open - IPCP is allowed to come up.
+ */
+void
+ipcp_open(unit)
+    int unit;
+{
+    fsm_open(&ipcp_fsm[unit]);
+}
+
+
+/*
+ * ipcp_close - Take IPCP down.
+ */
+void
+ipcp_close(unit)
+    int unit;
+{
+    fsm_close(&ipcp_fsm[unit]);
+}
+
+
+/*
+ * ipcp_lowerup - The lower layer is up.
+ */
+void
+ipcp_lowerup(unit)
+    int unit;
+{
+    fsm_lowerup(&ipcp_fsm[unit]);
+}
+
+
+/*
+ * ipcp_lowerdown - The lower layer is down.
+ */
+void
+ipcp_lowerdown(unit)
+    int unit;
+{
+    fsm_lowerdown(&ipcp_fsm[unit]);
+}
+
+
+/*
+ * ipcp_input - Input IPCP packet.
+ */
+void
+ipcp_input(unit, p, len)
+    int unit;
+    u_char *p;
+    int len;
+{
+    fsm_input(&ipcp_fsm[unit], p, len);
+}
+
+
+/*
+ * ipcp_protrej - A Protocol-Reject was received for IPCP.
+ *
+ * Pretend the lower layer went down, so we shut up.
+ */
+void
+ipcp_protrej(unit)
+    int unit;
+{
+    fsm_lowerdown(&ipcp_fsm[unit]);
+}
+
+
+/*
+ * ipcp_resetci - Reset our CI.
+ */
+static void
+ipcp_resetci(f)
+    fsm *f;
+{
+    ipcp_options *wo = &ipcp_wantoptions[f->unit];
+
+    wo->req_addr = wo->neg_addr && ipcp_allowoptions[f->unit].neg_addr;
+    if (wo->ouraddr == 0)
+	wo->accept_local = 1;
+    if (wo->hisaddr == 0)
+	wo->accept_remote = 1;
+    ipcp_gotoptions[f->unit] = *wo;
+    cis_received[f->unit] = 0;
+}
+
+
+/*
+ * ipcp_cilen - Return length of our CI.
+ */
+static int
+ipcp_cilen(f)
+    fsm *f;
+{
+    ipcp_options *go = &ipcp_gotoptions[f->unit];
+
+#define LENCIVJ(neg, old)	(neg ? (old? CILEN_COMPRESS : CILEN_VJ) : 0)
+#define LENCIADDR(neg, old)	(neg ? (old? CILEN_ADDRS : CILEN_ADDR) : 0)
+
+    return (LENCIADDR(go->neg_addr, go->old_addrs) +
+	    LENCIVJ(go->neg_vj, go->old_vj));
+}
+
+
+/*
+ * ipcp_addci - Add our desired CIs to a packet.
+ */
+static void
+ipcp_addci(f, ucp, lenp)
+    fsm *f;
+    u_char *ucp;
+    int *lenp;
+{
+    ipcp_options *wo = &ipcp_wantoptions[f->unit];
+    ipcp_options *go = &ipcp_gotoptions[f->unit];
+    ipcp_options *ho = &ipcp_hisoptions[f->unit];
+    int len = *lenp;
+
+#define ADDCIVJ(opt, neg, val, old, maxslotindex, cflag) \
+    if (neg) { \
+	int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
+	if (len >= vjlen) { \
+	    PUTCHAR(opt, ucp); \
+	    PUTCHAR(vjlen, ucp); \
+	    PUTSHORT(val, ucp); \
+	    if (!old) { \
+		PUTCHAR(maxslotindex, ucp); \
+		PUTCHAR(cflag, ucp); \
+	    } \
+	    len -= vjlen; \
+	} else \
+	    neg = 0; \
+    }
+
+#define ADDCIADDR(opt, neg, old, val1, val2) \
+    if (neg) { \
+	int addrlen = (old? CILEN_ADDRS: CILEN_ADDR); \
+	if (len >= addrlen) { \
+	    u_long l; \
+	    PUTCHAR(opt, ucp); \
+	    PUTCHAR(addrlen, ucp); \
+	    l = ntohl(val1); \
+	    PUTLONG(l, ucp); \
+	    if (old) { \
+		l = ntohl(val2); \
+		PUTLONG(l, ucp); \
+	    } \
+	    len -= addrlen; \
+	} else \
+	    neg = 0; \
+    }
+
+    /*
+     * First see if we want to change our options to the old
+     * forms because we have received old forms from the peer.
+     */
+    if (wo->neg_addr && !go->neg_addr && !go->old_addrs) {
+	/* use the old style of address negotiation */
+	go->neg_addr = 1;
+	go->old_addrs = 1;
+    }
+    if (wo->neg_vj && !go->neg_vj && !go->old_vj) {
+	/* try an older style of VJ negotiation */
+	if (cis_received[f->unit] == 0) {
+	    /* keep trying the new style until we see some CI from the peer */
+	    go->neg_vj = 1;
+	} else {
+	    /* use the old style only if the peer did */
+	    if (ho->neg_vj && ho->old_vj) {
+		go->neg_vj = 1;
+		go->old_vj = 1;
+		go->vj_protocol = ho->vj_protocol;
+	    }
+	}
+    }
+
+    ADDCIADDR((go->old_addrs? CI_ADDRS: CI_ADDR), go->neg_addr,
+	      go->old_addrs, go->ouraddr, go->hisaddr);
+
+    ADDCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
+	    go->maxslotindex, go->cflag);
+
+    *lenp -= len;
+}
+
+
+/*
+ * ipcp_ackci - Ack our CIs.
+ *
+ * Returns:
+ *	0 - Ack was bad.
+ *	1 - Ack was good.
+ */
+static int
+ipcp_ackci(f, p, len)
+    fsm *f;
+    u_char *p;
+    int len;
+{
+    ipcp_options *go = &ipcp_gotoptions[f->unit];
+    u_short cilen, citype, cishort;
+    u_long cilong;
+    u_char cimaxslotindex, cicflag;
+
+    /*
+     * 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.
+     */
+
+#define ACKCIVJ(opt, neg, val, old, maxslotindex, cflag) \
+    if (neg) { \
+	int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
+	if ((len -= vjlen) < 0) \
+	    goto bad; \
+	GETCHAR(citype, p); \
+	GETCHAR(cilen, p); \
+	if (cilen != vjlen || \
+	    citype != opt)  \
+	    goto bad; \
+	GETSHORT(cishort, p); \
+	if (cishort != val) \
+	    goto bad; \
+	if (!old) { \
+	    GETCHAR(cimaxslotindex, p); \
+	    if (cimaxslotindex != maxslotindex) \
+		goto bad; \
+	    GETCHAR(cicflag, p); \
+	    if (cicflag != cflag) \
+		goto bad; \
+	} \
+    }
+
+#define ACKCIADDR(opt, neg, old, val1, val2) \
+    if (neg) { \
+	int addrlen = (old? CILEN_ADDRS: CILEN_ADDR); \
+	u_long l; \
+	if ((len -= addrlen) < 0) \
+	    goto bad; \
+	GETCHAR(citype, p); \
+	GETCHAR(cilen, p); \
+	if (cilen != addrlen || \
+	    citype != opt) \
+	    goto bad; \
+	GETLONG(l, p); \
+	cilong = htonl(l); \
+	if (val1 != cilong) \
+	    goto bad; \
+	if (old) { \
+	    GETLONG(l, p); \
+	    cilong = htonl(l); \
+	    if (val2 != cilong) \
+		goto bad; \
+	} \
+    }
+
+    ACKCIADDR((go->old_addrs? CI_ADDRS: CI_ADDR), go->neg_addr,
+	      go->old_addrs, go->ouraddr, go->hisaddr);
+
+    ACKCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
+	    go->maxslotindex, go->cflag);
+
+    /*
+     * If there are any remaining CIs, then this packet is bad.
+     */
+    if (len != 0)
+	goto bad;
+    return (1);
+
+bad:
+    IPCPDEBUG((LOG_INFO, "ipcp_ackci: received bad Ack!"));
+    return (0);
+}
+
+/*
+ * ipcp_nakci - Peer has sent a NAK for some of our CIs.
+ * This should not modify any state if the Nak is bad
+ * or if IPCP is in the OPENED state.
+ *
+ * Returns:
+ *	0 - Nak was bad.
+ *	1 - Nak was good.
+ */
+static int
+ipcp_nakci(f, p, len)
+    fsm *f;
+    u_char *p;
+    int len;
+{
+    ipcp_options *go = &ipcp_gotoptions[f->unit];
+    u_char cimaxslotindex, cicflag;
+    u_char citype, cilen, *next;
+    u_short cishort;
+    u_long ciaddr1, ciaddr2, l;
+    ipcp_options no;		/* options we've seen Naks for */
+    ipcp_options try;		/* options to request next time */
+
+    BZERO(&no, sizeof(no));
+    try = *go;
+
+    /*
+     * Any Nak'd 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.
+     */
+#define NAKCIADDR(opt, neg, old, code) \
+    if (go->neg && \
+	len >= (cilen = (old? CILEN_ADDRS: CILEN_ADDR)) && \
+	p[1] == cilen && \
+	p[0] == opt) { \
+	len -= cilen; \
+	INCPTR(2, p); \
+	GETLONG(l, p); \
+	ciaddr1 = htonl(l); \
+	if (old) { \
+	    GETLONG(l, p); \
+	    ciaddr2 = htonl(l); \
+	    no.old_addrs = 1; \
+	} else \
+	    ciaddr2 = 0; \
+	no.neg = 1; \
+	code \
+    }
+
+#define NAKCIVJ(opt, neg, code) \
+    if (go->neg && \
+	((cilen = p[1]) == CILEN_COMPRESS || cilen == CILEN_VJ) && \
+	len >= cilen && \
+	p[0] == opt) { \
+	len -= cilen; \
+	INCPTR(2, p); \
+	GETSHORT(cishort, p); \
+	no.neg = 1; \
+        code \
+    }
+
+    /*
+     * Accept the peer's idea of {our,his} address, if different
+     * from our idea, only if the accept_{local,remote} flag is set.
+     */
+    NAKCIADDR(CI_ADDR, neg_addr, go->old_addrs,
+	      if (go->accept_local && ciaddr1) { /* Do we know our address? */
+		  try.ouraddr = ciaddr1;
+		  IPCPDEBUG((LOG_INFO, "local IP address %s",
+			     ip_ntoa(ciaddr1)));
+	      }
+	      if (go->accept_remote && ciaddr2) { /* Does he know his? */
+		  try.hisaddr = ciaddr2;
+		  IPCPDEBUG((LOG_INFO, "remote IP address %s",
+			     ip_ntoa(ciaddr2)));
+	      }
+	      );
+
+    /*
+     * Accept the peer's value of maxslotindex provided that it
+     * is less than what we asked for.  Turn off slot-ID compression
+     * if the peer wants.  Send old-style compress-type option if
+     * the peer wants.
+     */
+    NAKCIVJ(CI_COMPRESSTYPE, neg_vj,
+	    if (cilen == CILEN_VJ) {
+		GETCHAR(cimaxslotindex, p);
+		GETCHAR(cicflag, p);
+		if (cishort == IPCP_VJ_COMP) {
+		    try.old_vj = 0;
+		    if (cimaxslotindex < go->maxslotindex)
+			try.maxslotindex = cimaxslotindex;
+		    if (!cicflag)
+			try.cflag = 0;
+		} else {
+		    try.neg_vj = 0;
+		}
+	    } else {
+		if (cishort == IPCP_VJ_COMP || cishort == IPCP_VJ_COMP_OLD) {
+		    try.old_vj = 1;
+		    try.vj_protocol = cishort;
+		} else {
+		    try.neg_vj = 0;
+		}
+	    }
+	    );
+
+    /*
+     * There may be remaining CIs, if the peer is requesting negotiation
+     * on an option that we didn't include in our request packet.
+     * If they want to negotiate about IP addresses, we comply.
+     * If they want us to ask for compression, we refuse.
+     */
+    while (len > CILEN_VOID) {
+	GETCHAR(citype, p);
+	GETCHAR(cilen, p);
+	if( (len -= cilen) < 0 )
+	    goto bad;
+	next = p + cilen - 2;
+
+	switch (citype) {
+	case CI_COMPRESSTYPE:
+	    if (go->neg_vj || no.neg_vj ||
+		(cilen != CILEN_VJ && cilen != CILEN_COMPRESS))
+		goto bad;
+	    no.neg_vj = 1;
+	    break;
+	case CI_ADDRS:
+	    if (go->neg_addr && go->old_addrs || no.old_addrs
+		|| cilen != CILEN_ADDRS)
+		goto bad;
+	    try.neg_addr = 1;
+	    try.old_addrs = 1;
+	    GETLONG(l, p);
+	    ciaddr1 = htonl(l);
+	    if (ciaddr1 && go->accept_local)
+		try.ouraddr = ciaddr1;
+	    GETLONG(l, p);
+	    ciaddr2 = htonl(l);
+	    if (ciaddr2 && go->accept_remote)
+		try.hisaddr = ciaddr2;
+	    no.old_addrs = 1;
+	    break;
+	case CI_ADDR:
+	    if (go->neg_addr || no.neg_addr || cilen != CILEN_ADDR)
+		goto bad;
+	    try.neg_addr = 1;
+	    try.old_addrs = 0;
+	    GETLONG(l, p);
+	    ciaddr1 = htonl(l);
+	    if (ciaddr1 && go->accept_local)
+		try.ouraddr = ciaddr1;
+	    no.neg_addr = 1;
+	    break;
+	default:
+	    goto bad;
+	}
+	p = next;
+    }
+
+    /* If there is still anything left, this packet is bad. */
+    if (len != 0)
+	goto bad;
+
+    /*
+     * OK, the Nak is good.  Now we can update state.
+     */
+    if (f->state != OPENED)
+	*go = try;
+
+    return 1;
+
+bad:
+    IPCPDEBUG((LOG_INFO, "ipcp_nakci: received bad Nak!"));
+    return 0;
+}
+
+
+/*
+ * ipcp_rejci - Reject some of our CIs.
+ */
+static int
+ipcp_rejci(f, p, len)
+    fsm *f;
+    u_char *p;
+    int len;
+{
+    ipcp_options *go = &ipcp_gotoptions[f->unit];
+    u_char cimaxslotindex, ciflag, cilen;
+    u_short cishort;
+    u_long cilong;
+    ipcp_options try;		/* options to request next time */
+
+    try = *go;
+    /*
+     * 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.
+     */
+#define REJCIADDR(opt, neg, old, val1, val2) \
+    if (go->neg && \
+	len >= (cilen = old? CILEN_ADDRS: CILEN_ADDR) && \
+	p[1] == cilen && \
+	p[0] == opt) { \
+	u_long l; \
+	len -= cilen; \
+	INCPTR(2, p); \
+	GETLONG(l, p); \
+	cilong = htonl(l); \
+	/* Check rejected value. */ \
+	if (cilong != val1) \
+	    goto bad; \
+	if (old) { \
+	    GETLONG(l, p); \
+	    cilong = htonl(l); \
+	    /* Check rejected value. */ \
+	    if (cilong != val2) \
+		goto bad; \
+	} \
+	try.neg = 0; \
+    }
+
+#define REJCIVJ(opt, neg, val, old, maxslot, cflag) \
+    if (go->neg && \
+	p[1] == (old? CILEN_COMPRESS : CILEN_VJ) && \
+	len >= p[1] && \
+	p[0] == opt) { \
+	len -= p[1]; \
+	INCPTR(2, p); \
+	GETSHORT(cishort, p); \
+	/* Check rejected value. */  \
+	if (cishort != val) \
+	    goto bad; \
+	if (!old) { \
+	   GETCHAR(cimaxslotindex, p); \
+	   if (cimaxslotindex != maxslot) \
+	     goto bad; \
+	   GETCHAR(ciflag, p); \
+	   if (ciflag != cflag) \
+	     goto bad; \
+        } \
+	try.neg = 0; \
+     }
+
+    REJCIADDR((go->old_addrs? CI_ADDRS: CI_ADDR), neg_addr,
+	      go->old_addrs, go->ouraddr, go->hisaddr);
+
+    REJCIVJ(CI_COMPRESSTYPE, neg_vj, go->vj_protocol, go->old_vj,
+	    go->maxslotindex, go->cflag);
+
+    /*
+     * If there are any remaining CIs, then this packet is bad.
+     */
+    if (len != 0)
+	goto bad;
+    /*
+     * Now we can update state.
+     */
+    if (f->state != OPENED)
+	*go = try;
+    return 1;
+
+bad:
+    IPCPDEBUG((LOG_INFO, "ipcp_rejci: received bad Reject!"));
+    return 0;
+}
+
+
+/*
+ * ipcp_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.
+ */
+static int
+ipcp_reqci(f, inp, len, reject_if_disagree)
+    fsm *f;
+    u_char *inp;		/* Requested CIs */
+    int *len;			/* Length of requested CIs */
+    int reject_if_disagree;
+{
+    ipcp_options *wo = &ipcp_wantoptions[f->unit];
+    ipcp_options *ho = &ipcp_hisoptions[f->unit];
+    ipcp_options *ao = &ipcp_allowoptions[f->unit];
+    ipcp_options *go = &ipcp_gotoptions[f->unit];
+    u_char *cip, *next;		/* Pointer to current and next CIs */
+    u_short cilen, citype;	/* Parsed len, type */
+    u_short cishort;		/* Parsed short value */
+    u_long tl, ciaddr1, ciaddr2;/* 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 */
+    u_char maxslotindex, cflag;
+
+    /*
+     * 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? */
+	    IPCPDEBUG((LOG_INFO, "ipcp_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 */
+	case CI_ADDRS:
+	    IPCPDEBUG((LOG_INFO, "ipcp: received ADDRS "));
+	    if (!ao->neg_addr ||
+		cilen != CILEN_ADDRS) {	/* Check CI length */
+		orc = CONFREJ;		/* Reject CI */
+		break;
+	    }
+
+	    /*
+	     * If he has no address, or if we both have his address but
+	     * disagree about it, then NAK it with our idea.
+	     * In particular, if we don't know his address, but he does,
+	     * then accept it.
+	     */
+	    GETLONG(tl, p);		/* Parse source address (his) */
+	    ciaddr1 = htonl(tl);
+	    IPCPDEBUG((LOG_INFO, "(%s:", ip_ntoa(ciaddr1)));
+	    if (ciaddr1 != wo->hisaddr
+		&& (ciaddr1 == 0 || !wo->accept_remote)) {
+		orc = CONFNAK;
+		if (!reject_if_disagree) {
+		    DECPTR(sizeof (long), p);
+		    tl = ntohl(wo->hisaddr);
+		    PUTLONG(tl, p);
+		}
+	    }
+
+	    /*
+	     * If he doesn't know our address, or if we both have our address
+	     * but disagree about it, then NAK it with our idea.
+	     */
+	    GETLONG(tl, p);		/* Parse desination address (ours) */
+	    ciaddr2 = htonl(tl);
+	    IPCPDEBUG((LOG_INFO, "%s)", ip_ntoa(ciaddr2)));
+	    if (ciaddr2 != wo->ouraddr) {
+		if (ciaddr2 == 0 || !wo->accept_local) {
+		    orc = CONFNAK;
+		    if (!reject_if_disagree) {
+			DECPTR(sizeof (long), p);
+			tl = ntohl(wo->ouraddr);
+			PUTLONG(tl, p);
+		    }
+		} else {
+		    go->ouraddr = ciaddr2;	/* accept peer's idea */
+		}
+	    }
+
+	    ho->neg_addr = 1;
+	    ho->old_addrs = 1;
+	    ho->hisaddr = ciaddr1;
+	    ho->ouraddr = ciaddr2;
+	    break;
+
+	case CI_ADDR:
+	    IPCPDEBUG((LOG_INFO, "ipcp: received ADDR "));
+
+	    if (!ao->neg_addr ||
+		cilen != CILEN_ADDR) {	/* Check CI length */
+		orc = CONFREJ;		/* Reject CI */
+		break;
+	    }
+
+	    /*
+	     * If he has no address, or if we both have his address but
+	     * disagree about it, then NAK it with our idea.
+	     * In particular, if we don't know his address, but he does,
+	     * then accept it.
+	     */
+	    GETLONG(tl, p);	/* Parse source address (his) */
+	    ciaddr1 = htonl(tl);
+	    IPCPDEBUG((LOG_INFO, "(%s)", ip_ntoa(ciaddr1)));
+	    if (ciaddr1 != wo->hisaddr
+		&& (ciaddr1 == 0 || !wo->accept_remote)) {
+		orc = CONFNAK;
+		if (!reject_if_disagree) {
+		    DECPTR(sizeof (long), p);
+		    tl = ntohl(wo->hisaddr);
+		    PUTLONG(tl, p);
+		}
+	    }
+	
+	    ho->neg_addr = 1;
+	    ho->hisaddr = ciaddr1;
+	    break;
+	
+	case CI_COMPRESSTYPE:
+	    IPCPDEBUG((LOG_INFO, "ipcp: received COMPRESSTYPE "));
+	    if (!ao->neg_vj ||
+		(cilen != CILEN_VJ && cilen != CILEN_COMPRESS)) {
+		orc = CONFREJ;
+		break;
+	    }
+	    GETSHORT(cishort, p);
+	    IPCPDEBUG((LOG_INFO, "(%d)", cishort));
+
+	    if (!(cishort == IPCP_VJ_COMP ||
+		  (cishort == IPCP_VJ_COMP_OLD && cilen == CILEN_COMPRESS))) {
+		orc = CONFREJ;
+		break;
+	    }
+
+	    ho->neg_vj = 1;
+	    ho->vj_protocol = cishort;
+	    if (cilen == CILEN_VJ) {
+		GETCHAR(maxslotindex, p);
+		if (maxslotindex > ao->maxslotindex) { 
+		    orc = CONFNAK;
+		    if (!reject_if_disagree){
+			DECPTR(1, p);
+			PUTCHAR(ao->maxslotindex, p);
+		    }
+		}
+		GETCHAR(cflag, p);
+		if (cflag && !ao->cflag) {
+		    orc = CONFNAK;
+		    if (!reject_if_disagree){
+			DECPTR(1, p);
+			PUTCHAR(wo->cflag, p);
+		    }
+		}
+		ho->maxslotindex = maxslotindex;
+		ho->cflag = wo->cflag;
+	    } else {
+		ho->old_vj = 1;
+		ho->maxslotindex = MAX_STATES - 1;
+		ho->cflag = 1;
+	    }
+	    break;
+
+	default:
+	    orc = CONFREJ;
+	    break;
+	}
+
+endswitch:
+	IPCPDEBUG((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 */
+	    else {
+		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 CI_ADDR option appended.  We assume the
+     * input buffer is long enough that we can append the extra
+     * option safely.
+     */
+    if (rc != CONFREJ && !ho->neg_addr &&
+	wo->req_addr && !reject_if_disagree) {
+	if (rc == CONFACK) {
+	    rc = CONFNAK;
+	    ucp = inp;			/* reset pointer */
+	    wo->req_addr = 0;		/* don't ask again */
+	}
+	PUTCHAR(CI_ADDR, ucp);
+	PUTCHAR(CILEN_ADDR, ucp);
+	tl = ntohl(wo->hisaddr);
+	PUTLONG(tl, ucp);
+    }
+
+    *len = ucp - inp;			/* Compute output length */
+    IPCPDEBUG((LOG_INFO, "ipcp: returning Configure-%s", CODENAME(rc)));
+    return (rc);			/* Return final code */
+}
+
+
+/*
+ * ipcp_up - IPCP has come UP.
+ *
+ * Configure the IP network interface appropriately and bring it up.
+ */
+static void
+ipcp_up(f)
+    fsm *f;
+{
+    u_long mask;
+    ipcp_options *ho = &ipcp_hisoptions[f->unit];
+    ipcp_options *go = &ipcp_gotoptions[f->unit];
+
+    IPCPDEBUG((LOG_INFO, "ipcp: up"));
+    go->default_route = 0;
+    go->proxy_arp = 0;
+
+    /*
+     * We must have a non-zero IP address for both ends of the link.
+     */
+    if (!ho->neg_addr)
+	ho->hisaddr = ipcp_wantoptions[f->unit].hisaddr;
+
+    if (ho->hisaddr == 0) {
+	syslog(LOG_ERR, "Could not determine remote IP address");
+	ipcp_close(f->unit);
+	return;
+    }
+    if (go->ouraddr == 0) {
+	syslog(LOG_ERR, "Could not determine local IP address");
+	ipcp_close(f->unit);
+	return;
+    }
+
+    /*
+     * Check that the peer is allowed to use the IP address it wants.
+     */
+    if (!auth_ip_addr(f->unit, ho->hisaddr)) {
+	syslog(LOG_ERR, "Peer is not authorized to use remote address %s",
+	       ip_ntoa(ho->hisaddr));
+	ipcp_close(f->unit);
+	return;
+    }
+
+    syslog(LOG_NOTICE, "local  IP address %s", ip_ntoa(go->ouraddr));
+    syslog(LOG_NOTICE, "remote IP address %s", ip_ntoa(ho->hisaddr));
+
+    /*
+     * Set IP addresses and (if specified) netmask.
+     */
+    mask = GetMask(go->ouraddr);
+    if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {
+	IPCPDEBUG((LOG_WARNING, "sifaddr failed"));
+	ipcp_close(f->unit);
+	return;
+    }
+
+    /* set tcp compression */
+    sifvjcomp(f->unit, ho->neg_vj, ho->cflag, ho->maxslotindex);
+
+    /* bring the interface up for IP */
+    if (!sifup(f->unit)) {
+	IPCPDEBUG((LOG_WARNING, "sifup failed"));
+	ipcp_close(f->unit);
+	return;
+    }
+
+    /* assign a default route through the interface if required */
+    if (ipcp_wantoptions[f->unit].default_route) 
+	if (sifdefaultroute(f->unit, ho->hisaddr))
+	    go->default_route = 1;
+
+    /* Make a proxy ARP entry if requested. */
+    if (ipcp_wantoptions[f->unit].proxy_arp)
+	if (sifproxyarp(f->unit, ho->hisaddr))
+	    go->proxy_arp = 1;
+
+    /*
+     * Execute the ip-up script, like this:
+     *	/etc/ppp/ip-up interface tty speed local-IP remote-IP
+     */
+    ipcp_script(f, _PATH_IPUP);
+
+}
+
+
+/*
+ * ipcp_down - IPCP has gone DOWN.
+ *
+ * Take the IP network interface down, clear its addresses
+ * and delete routes through it.
+ */
+static void
+ipcp_down(f)
+    fsm *f;
+{
+    u_long ouraddr, hisaddr;
+
+    IPCPDEBUG((LOG_INFO, "ipcp: down"));
+
+    ouraddr = ipcp_gotoptions[f->unit].ouraddr;
+    hisaddr = ipcp_hisoptions[f->unit].hisaddr;
+    if (ipcp_gotoptions[f->unit].proxy_arp)
+	cifproxyarp(f->unit, hisaddr);
+    if (ipcp_gotoptions[f->unit].default_route) 
+	cifdefaultroute(f->unit, hisaddr);
+    sifdown(f->unit);
+    cifaddr(f->unit, ouraddr, hisaddr);
+
+    /* Execute the ip-down script */
+    ipcp_script(f, _PATH_IPDOWN);
+}
+
+
+/*
+ * ipcp_script - Execute a script with arguments
+ * interface-name tty-name speed local-IP remote-IP.
+ */
+static void
+ipcp_script(f, script)
+    fsm *f;
+    char *script;
+{
+    char strspeed[32], strlocal[32], strremote[32];
+    char *argv[8];
+
+    sprintf(strspeed, "%d", baud_rate);
+    strcpy(strlocal, ip_ntoa(ipcp_gotoptions[f->unit].ouraddr));
+    strcpy(strremote, ip_ntoa(ipcp_hisoptions[f->unit].hisaddr));
+
+    argv[0] = script;
+    argv[1] = ifname;
+    argv[2] = devname;
+    argv[3] = strspeed;
+    argv[4] = strlocal;
+    argv[5] = strremote;
+    argv[6] = NULL;
+    run_program(script, argv, 0);
+}
+
+/*
+ * ipcp_printpkt - print the contents of an IPCP packet.
+ */
+char *ipcp_codenames[] = {
+    "ConfReq", "ConfAck", "ConfNak", "ConfRej",
+    "TermReq", "TermAck", "CodeRej"
+};
+
+int
+ipcp_printpkt(p, plen, printer, arg)
+    u_char *p;
+    int plen;
+    void (*printer)();
+    void *arg;
+{
+    int code, id, len, olen;
+    u_char *pstart, *optend;
+    u_short cishort;
+    u_long 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(ipcp_codenames) / sizeof(char *))
+	printer(arg, " %s", ipcp_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 < 2 || olen > len) {
+		break;
+	    }
+	    printer(arg, " <");
+	    len -= olen;
+	    optend = p + olen;
+	    switch (code) {
+	    case CI_ADDRS:
+		if (olen == CILEN_ADDRS) {
+		    p += 2;
+		    GETLONG(cilong, p);
+		    printer(arg, "addrs %s", ip_ntoa(htonl(cilong)));
+		    GETLONG(cilong, p);
+		    printer(arg, " %s", ip_ntoa(htonl(cilong)));
+		}
+		break;
+	    case CI_COMPRESSTYPE:
+		if (olen >= CILEN_COMPRESS) {
+		    p += 2;
+		    GETSHORT(cishort, p);
+		    printer(arg, "compress ");
+		    switch (cishort) {
+		    case IPCP_VJ_COMP:
+			printer(arg, "VJ");
+			break;
+		    case IPCP_VJ_COMP_OLD:
+			printer(arg, "old-VJ");
+			break;
+		    default:
+			printer(arg, "0x%x", cishort);
+		    }
+		}
+		break;
+	    case CI_ADDR:
+		if (olen == CILEN_ADDR) {
+		    p += 2;
+		    GETLONG(cilong, p);
+		    printer(arg, "addr %s", ip_ntoa(htonl(cilong)));
+		}
+		break;
+	    }
+	    while (p < optend) {
+		GETCHAR(code, p);
+		printer(arg, " %.2x", code);
+	    }
+	    printer(arg, ">");
+	}
+	break;
+    }
+
+    /* print the rest of the bytes in the packet */
+    for (; len > 0; --len) {
+	GETCHAR(code, p);
+	printer(arg, " %.2x", code);
+    }
+
+    return p - pstart;
+}