You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@mynewt.apache.org by ma...@apache.org on 2016/09/30 00:30:45 UTC

[02/51] [abbrv] [partial] incubator-mynewt-core git commit: net/ip/lwip_base; LwIP.

http://git-wip-us.apache.org/repos/asf/incubator-mynewt-core/blob/f5a0f2a0/net/ip/lwip_base/src/netif/ppp/lcp.c
----------------------------------------------------------------------
diff --git a/net/ip/lwip_base/src/netif/ppp/lcp.c b/net/ip/lwip_base/src/netif/ppp/lcp.c
new file mode 100644
index 0000000..90ed183
--- /dev/null
+++ b/net/ip/lwip_base/src/netif/ppp/lcp.c
@@ -0,0 +1,2790 @@
+/*
+ * lcp.c - PPP Link Control Protocol.
+ *
+ * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The name "Carnegie Mellon University" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For permission or any legal
+ *    details, please contact
+ *      Office of Technology Transfer
+ *      Carnegie Mellon University
+ *      5000 Forbes Avenue
+ *      Pittsburgh, PA  15213-3890
+ *      (412) 268-4387, fax: (412) 268-7395
+ *      tech-transfer@andrew.cmu.edu
+ *
+ * 4. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by Computing Services
+ *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
+ *
+ * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
+ * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
+ * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
+ * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "netif/ppp/ppp_opts.h"
+#if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */
+
+/*
+ * @todo:
+ */
+
+#if 0 /* UNUSED */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#endif /* UNUSED */
+
+#include "netif/ppp/ppp_impl.h"
+
+#include "netif/ppp/fsm.h"
+#include "netif/ppp/lcp.h"
+#if CHAP_SUPPORT
+#include "netif/ppp/chap-new.h"
+#endif /* CHAP_SUPPORT */
+#include "netif/ppp/magic.h"
+
+/*
+ * When the link comes up we want to be able to wait for a short while,
+ * or until seeing some input from the peer, before starting to send
+ * configure-requests.  We do this by delaying the fsm_lowerup call.
+ */
+/* steal a bit in fsm flags word */
+#define DELAYED_UP	0x80
+
+static void lcp_delayed_up(void *arg);
+
+/*
+ * LCP-related command-line options.
+ */
+#if 0 /* UNUSED */
+int	lcp_echo_interval = 0; 	/* Interval between LCP echo-requests */
+int	lcp_echo_fails = 0;	/* Tolerance to unanswered echo-requests */
+#endif /* UNUSED */
+
+#if 0 /* UNUSED */
+/* options */
+static u_int lcp_echo_interval      = LCP_ECHOINTERVAL; /* Interval between LCP echo-requests */
+static u_int lcp_echo_fails         = LCP_MAXECHOFAILS; /* Tolerance to unanswered echo-requests */
+#endif /* UNUSED */
+
+#if 0 /* UNUSED */
+#if PPP_LCP_ADAPTIVE
+bool	lcp_echo_adaptive = 0;	/* request echo only if the link was idle */
+#endif
+bool	lax_recv = 0;		/* accept control chars in asyncmap */
+bool	noendpoint = 0;		/* don't send/accept endpoint discriminator */
+#endif /* UNUSED */
+
+#if PPP_OPTIONS
+static int noopt (char **);
+#endif /* PPP_OPTIONS */
+
+#ifdef HAVE_MULTILINK
+static int setendpoint (char **);
+static void printendpoint (option_t *, void (*)(void *, char *, ...),
+			       void *);
+#endif /* HAVE_MULTILINK */
+
+#if PPP_OPTIONS
+static option_t lcp_option_list[] = {
+    /* LCP options */
+    { "-all", o_special_noarg, (void *)noopt,
+      "Don't request/allow any LCP options" },
+
+    { "noaccomp", o_bool, &lcp_wantoptions[0].neg_accompression,
+      "Disable address/control compression",
+      OPT_A2CLR, &lcp_allowoptions[0].neg_accompression },
+    { "-ac", o_bool, &lcp_wantoptions[0].neg_accompression,
+      "Disable address/control compression",
+      OPT_ALIAS | OPT_A2CLR, &lcp_allowoptions[0].neg_accompression },
+
+    { "asyncmap", o_uint32, &lcp_wantoptions[0].asyncmap,
+      "Set asyncmap (for received packets)",
+      OPT_OR, &lcp_wantoptions[0].neg_asyncmap },
+    { "-as", o_uint32, &lcp_wantoptions[0].asyncmap,
+      "Set asyncmap (for received packets)",
+      OPT_ALIAS | OPT_OR, &lcp_wantoptions[0].neg_asyncmap },
+    { "default-asyncmap", o_uint32, &lcp_wantoptions[0].asyncmap,
+      "Disable asyncmap negotiation",
+      OPT_OR | OPT_NOARG | OPT_VAL(~0U) | OPT_A2CLR,
+      &lcp_allowoptions[0].neg_asyncmap },
+    { "-am", o_uint32, &lcp_wantoptions[0].asyncmap,
+      "Disable asyncmap negotiation",
+      OPT_ALIAS | OPT_OR | OPT_NOARG | OPT_VAL(~0U) | OPT_A2CLR,
+      &lcp_allowoptions[0].neg_asyncmap },
+
+    { "nomagic", o_bool, &lcp_wantoptions[0].neg_magicnumber,
+      "Disable magic number negotiation (looped-back line detection)",
+      OPT_A2CLR, &lcp_allowoptions[0].neg_magicnumber },
+    { "-mn", o_bool, &lcp_wantoptions[0].neg_magicnumber,
+      "Disable magic number negotiation (looped-back line detection)",
+      OPT_ALIAS | OPT_A2CLR, &lcp_allowoptions[0].neg_magicnumber },
+
+    { "mru", o_int, &lcp_wantoptions[0].mru,
+      "Set MRU (maximum received packet size) for negotiation",
+      OPT_PRIO, &lcp_wantoptions[0].neg_mru },
+    { "default-mru", o_bool, &lcp_wantoptions[0].neg_mru,
+      "Disable MRU negotiation (use default 1500)",
+      OPT_PRIOSUB | OPT_A2CLR, &lcp_allowoptions[0].neg_mru },
+    { "-mru", o_bool, &lcp_wantoptions[0].neg_mru,
+      "Disable MRU negotiation (use default 1500)",
+      OPT_ALIAS | OPT_PRIOSUB | OPT_A2CLR, &lcp_allowoptions[0].neg_mru },
+
+    { "mtu", o_int, &lcp_allowoptions[0].mru,
+      "Set our MTU", OPT_LIMITS, NULL, MAXMRU, MINMRU },
+
+    { "nopcomp", o_bool, &lcp_wantoptions[0].neg_pcompression,
+      "Disable protocol field compression",
+      OPT_A2CLR, &lcp_allowoptions[0].neg_pcompression },
+    { "-pc", o_bool, &lcp_wantoptions[0].neg_pcompression,
+      "Disable protocol field compression",
+      OPT_ALIAS | OPT_A2CLR, &lcp_allowoptions[0].neg_pcompression },
+
+    { "passive", o_bool, &lcp_wantoptions[0].passive,
+      "Set passive mode", 1 },
+    { "-p", o_bool, &lcp_wantoptions[0].passive,
+      "Set passive mode", OPT_ALIAS | 1 },
+
+    { "silent", o_bool, &lcp_wantoptions[0].silent,
+      "Set silent mode", 1 },
+
+    { "lcp-echo-failure", o_int, &lcp_echo_fails,
+      "Set number of consecutive echo failures to indicate link failure",
+      OPT_PRIO },
+    { "lcp-echo-interval", o_int, &lcp_echo_interval,
+      "Set time in seconds between LCP echo requests", OPT_PRIO },
+#if PPP_LCP_ADAPTIVE
+    { "lcp-echo-adaptive", o_bool, &lcp_echo_adaptive,
+      "Suppress LCP echo requests if traffic was received", 1 },
+#endif
+    { "lcp-restart", o_int, &lcp_fsm[0].timeouttime,
+      "Set time in seconds between LCP retransmissions", OPT_PRIO },
+    { "lcp-max-terminate", o_int, &lcp_fsm[0].maxtermtransmits,
+      "Set maximum number of LCP terminate-request transmissions", OPT_PRIO },
+    { "lcp-max-configure", o_int, &lcp_fsm[0].maxconfreqtransmits,
+      "Set maximum number of LCP configure-request transmissions", OPT_PRIO },
+    { "lcp-max-failure", o_int, &lcp_fsm[0].maxnakloops,
+      "Set limit on number of LCP configure-naks", OPT_PRIO },
+
+    { "receive-all", o_bool, &lax_recv,
+      "Accept all received control characters", 1 },
+
+#ifdef HAVE_MULTILINK
+    { "mrru", o_int, &lcp_wantoptions[0].mrru,
+      "Maximum received packet size for multilink bundle",
+      OPT_PRIO, &lcp_wantoptions[0].neg_mrru },
+
+    { "mpshortseq", o_bool, &lcp_wantoptions[0].neg_ssnhf,
+      "Use short sequence numbers in multilink headers",
+      OPT_PRIO | 1, &lcp_allowoptions[0].neg_ssnhf },
+    { "nompshortseq", o_bool, &lcp_wantoptions[0].neg_ssnhf,
+      "Don't use short sequence numbers in multilink headers",
+      OPT_PRIOSUB | OPT_A2CLR, &lcp_allowoptions[0].neg_ssnhf },
+
+    { "endpoint", o_special, (void *) setendpoint,
+      "Endpoint discriminator for multilink",
+      OPT_PRIO | OPT_A2PRINTER, (void *) printendpoint },
+#endif /* HAVE_MULTILINK */
+
+    { "noendpoint", o_bool, &noendpoint,
+      "Don't send or accept multilink endpoint discriminator", 1 },
+
+    {NULL}
+};
+#endif /* PPP_OPTIONS */
+
+/*
+ * Callbacks for fsm code.  (CI = Configuration Information)
+ */
+static void lcp_resetci(fsm *f);	/* Reset our CI */
+static int  lcp_cilen(fsm *f);		/* Return length of our CI */
+static void lcp_addci(fsm *f, u_char *ucp, int *lenp); /* Add our CI to pkt */
+static int  lcp_ackci(fsm *f, u_char *p, int len); /* Peer ack'd our CI */
+static int  lcp_nakci(fsm *f, u_char *p, int len, int treat_as_reject); /* Peer nak'd our CI */
+static int  lcp_rejci(fsm *f, u_char *p, int len); /* Peer rej'd our CI */
+static int  lcp_reqci(fsm *f, u_char *inp, int *lenp, int reject_if_disagree); /* Rcv peer CI */
+static void lcp_up(fsm *f);		/* We're UP */
+static void lcp_down(fsm *f);		/* We're DOWN */
+static void lcp_starting (fsm *);	/* We need lower layer up */
+static void lcp_finished (fsm *);	/* We need lower layer down */
+static int  lcp_extcode(fsm *f, int code, int id, u_char *inp, int len);
+static void lcp_rprotrej(fsm *f, u_char *inp, int len);
+
+/*
+ * routines to send LCP echos to peer
+ */
+
+static void lcp_echo_lowerup(ppp_pcb *pcb);
+static void lcp_echo_lowerdown(ppp_pcb *pcb);
+static void LcpEchoTimeout(void *arg);
+static void lcp_received_echo_reply(fsm *f, int id, u_char *inp, int len);
+static void LcpSendEchoRequest(fsm *f);
+static void LcpLinkFailure(fsm *f);
+static void LcpEchoCheck(fsm *f);
+
+static const fsm_callbacks lcp_callbacks = {	/* LCP callback routines */
+    lcp_resetci,		/* Reset our Configuration Information */
+    lcp_cilen,			/* Length of our Configuration Information */
+    lcp_addci,			/* Add our Configuration Information */
+    lcp_ackci,			/* ACK our Configuration Information */
+    lcp_nakci,			/* NAK our Configuration Information */
+    lcp_rejci,			/* Reject our Configuration Information */
+    lcp_reqci,			/* Request peer's Configuration Information */
+    lcp_up,			/* Called when fsm reaches OPENED state */
+    lcp_down,			/* Called when fsm leaves OPENED state */
+    lcp_starting,		/* Called when we want the lower layer up */
+    lcp_finished,		/* Called when we want the lower layer down */
+    NULL,			/* Called when Protocol-Reject received */
+    NULL,			/* Retransmission is necessary */
+    lcp_extcode,		/* Called to handle LCP-specific codes */
+    "LCP"			/* String name of protocol */
+};
+
+/*
+ * Protocol entry points.
+ * Some of these are called directly.
+ */
+
+static void lcp_init(ppp_pcb *pcb);
+static void lcp_input(ppp_pcb *pcb, u_char *p, int len);
+static void lcp_protrej(ppp_pcb *pcb);
+#if PRINTPKT_SUPPORT
+static int lcp_printpkt(const u_char *p, int plen,
+		void (*printer) (void *, const char *, ...), void *arg);
+#endif /* PRINTPKT_SUPPORT */
+
+const struct protent lcp_protent = {
+    PPP_LCP,
+    lcp_init,
+    lcp_input,
+    lcp_protrej,
+    lcp_lowerup,
+    lcp_lowerdown,
+    lcp_open,
+    lcp_close,
+#if PRINTPKT_SUPPORT
+    lcp_printpkt,
+#endif /* PRINTPKT_SUPPORT */
+#if PPP_DATAINPUT
+    NULL,
+#endif /* PPP_DATAINPUT */
+#if PRINTPKT_SUPPORT
+    "LCP",
+    NULL,
+#endif /* PRINTPKT_SUPPORT */
+#if PPP_OPTIONS
+    lcp_option_list,
+    NULL,
+#endif /* PPP_OPTIONS */
+#if DEMAND_SUPPORT
+    NULL,
+    NULL
+#endif /* DEMAND_SUPPORT */
+};
+
+/*
+ * Length of each type of configuration option (in octets)
+ */
+#define CILEN_VOID	2
+#define CILEN_CHAR	3
+#define CILEN_SHORT	4	/* CILEN_VOID + 2 */
+#if CHAP_SUPPORT
+#define CILEN_CHAP	5	/* CILEN_VOID + 2 + 1 */
+#endif /* CHAP_SUPPORT */
+#define CILEN_LONG	6	/* CILEN_VOID + 4 */
+#if LQR_SUPPORT
+#define CILEN_LQR	8	/* CILEN_VOID + 2 + 4 */
+#endif /* LQR_SUPPORT */
+#define CILEN_CBCP	3
+
+#define CODENAME(x)	((x) == CONFACK ? "ACK" : \
+			 (x) == CONFNAK ? "NAK" : "REJ")
+
+#if PPP_OPTIONS
+/*
+ * noopt - Disable all options (why?).
+ */
+static int
+noopt(argv)
+    char **argv;
+{
+    BZERO((char *) &lcp_wantoptions[0], sizeof (struct lcp_options));
+    BZERO((char *) &lcp_allowoptions[0], sizeof (struct lcp_options));
+
+    return (1);
+}
+#endif /* PPP_OPTIONS */
+
+#ifdef HAVE_MULTILINK
+static int
+setendpoint(argv)
+    char **argv;
+{
+    if (str_to_epdisc(&lcp_wantoptions[0].endpoint, *argv)) {
+	lcp_wantoptions[0].neg_endpoint = 1;
+	return 1;
+    }
+    option_error("Can't parse '%s' as an endpoint discriminator", *argv);
+    return 0;
+}
+
+static void
+printendpoint(opt, printer, arg)
+    option_t *opt;
+    void (*printer) (void *, char *, ...);
+    void *arg;
+{
+	printer(arg, "%s", epdisc_to_str(&lcp_wantoptions[0].endpoint));
+}
+#endif /* HAVE_MULTILINK */
+
+/*
+ * lcp_init - Initialize LCP.
+ */
+static void lcp_init(ppp_pcb *pcb) {
+    fsm *f = &pcb->lcp_fsm;
+    lcp_options *wo = &pcb->lcp_wantoptions;
+    lcp_options *ao = &pcb->lcp_allowoptions;
+
+    f->pcb = pcb;
+    f->protocol = PPP_LCP;
+    f->callbacks = &lcp_callbacks;
+
+    fsm_init(f);
+
+    BZERO(wo, sizeof(*wo));
+    wo->neg_mru = 1;
+    wo->mru = PPP_DEFMRU;
+    wo->neg_asyncmap = 1;
+    wo->neg_magicnumber = 1;
+    wo->neg_pcompression = 1;
+    wo->neg_accompression = 1;
+
+    BZERO(ao, sizeof(*ao));
+    ao->neg_mru = 1;
+    ao->mru = PPP_MAXMRU;
+    ao->neg_asyncmap = 1;
+#if CHAP_SUPPORT
+    ao->neg_chap = 1;
+    ao->chap_mdtype = CHAP_MDTYPE_SUPPORTED;
+#endif /* CHAP_SUPPORT */
+#if PAP_SUPPORT
+    ao->neg_upap = 1;
+#endif /* PAP_SUPPORT */
+#if EAP_SUPPORT
+    ao->neg_eap = 1;
+#endif /* EAP_SUPPORT */
+    ao->neg_magicnumber = 1;
+    ao->neg_pcompression = 1;
+    ao->neg_accompression = 1;
+    ao->neg_endpoint = 1;
+}
+
+
+/*
+ * lcp_open - LCP is allowed to come up.
+ */
+void lcp_open(ppp_pcb *pcb) {
+    fsm *f = &pcb->lcp_fsm;
+    lcp_options *wo = &pcb->lcp_wantoptions;
+
+    f->flags &= ~(OPT_PASSIVE | OPT_SILENT);
+    if (wo->passive)
+	f->flags |= OPT_PASSIVE;
+    if (wo->silent)
+	f->flags |= OPT_SILENT;
+    fsm_open(f);
+}
+
+
+/*
+ * lcp_close - Take LCP down.
+ */
+void lcp_close(ppp_pcb *pcb, const char *reason) {
+    fsm *f = &pcb->lcp_fsm;
+    int oldstate;
+
+    if (pcb->phase != PPP_PHASE_DEAD
+#ifdef HAVE_MULTILINK
+    && pcb->phase != PPP_PHASE_MASTER
+#endif /* HAVE_MULTILINK */
+    )
+	new_phase(pcb, PPP_PHASE_TERMINATE);
+
+    if (f->flags & DELAYED_UP) {
+	UNTIMEOUT(lcp_delayed_up, f);
+	f->state = PPP_FSM_STOPPED;
+    }
+    oldstate = f->state;
+
+    fsm_close(f, reason);
+    if (oldstate == PPP_FSM_STOPPED && (f->flags & (OPT_PASSIVE|OPT_SILENT|DELAYED_UP))) {
+	/*
+	 * This action is not strictly according to the FSM in RFC1548,
+	 * but it does mean that the program terminates if you do a
+	 * lcp_close() when a connection hasn't been established
+	 * because we are in passive/silent mode or because we have
+	 * delayed the fsm_lowerup() call and it hasn't happened yet.
+	 */
+	f->flags &= ~DELAYED_UP;
+	lcp_finished(f);
+    }
+}
+
+
+/*
+ * lcp_lowerup - The lower layer is up.
+ */
+void lcp_lowerup(ppp_pcb *pcb) {
+    lcp_options *wo = &pcb->lcp_wantoptions;
+    fsm *f = &pcb->lcp_fsm;
+    /*
+     * Don't use A/C or protocol compression on transmission,
+     * but accept A/C and protocol compressed packets
+     * if we are going to ask for A/C and protocol compression.
+     */
+    if (ppp_send_config(pcb, PPP_MRU, 0xffffffff, 0, 0) < 0
+	|| ppp_recv_config(pcb, PPP_MRU, (pcb->settings.lax_recv? 0: 0xffffffff),
+			   wo->neg_pcompression, wo->neg_accompression) < 0)
+	    return;
+    pcb->peer_mru = PPP_MRU;
+
+    if (pcb->settings.listen_time != 0) {
+	f->flags |= DELAYED_UP;
+	TIMEOUTMS(lcp_delayed_up, f, pcb->settings.listen_time);
+    } else
+	fsm_lowerup(f);
+}
+
+
+/*
+ * lcp_lowerdown - The lower layer is down.
+ */
+void lcp_lowerdown(ppp_pcb *pcb) {
+    fsm *f = &pcb->lcp_fsm;
+
+    if (f->flags & DELAYED_UP) {
+	f->flags &= ~DELAYED_UP;
+	UNTIMEOUT(lcp_delayed_up, f);
+    } else
+	fsm_lowerdown(f);
+}
+
+
+/*
+ * lcp_delayed_up - Bring the lower layer up now.
+ */
+static void lcp_delayed_up(void *arg) {
+    fsm *f = (fsm*)arg;
+
+    if (f->flags & DELAYED_UP) {
+	f->flags &= ~DELAYED_UP;
+	fsm_lowerup(f);
+    }
+}
+
+
+/*
+ * lcp_input - Input LCP packet.
+ */
+static void lcp_input(ppp_pcb *pcb, u_char *p, int len) {
+    fsm *f = &pcb->lcp_fsm;
+
+    if (f->flags & DELAYED_UP) {
+	f->flags &= ~DELAYED_UP;
+	UNTIMEOUT(lcp_delayed_up, f);
+	fsm_lowerup(f);
+    }
+    fsm_input(f, p, len);
+}
+
+/*
+ * lcp_extcode - Handle a LCP-specific code.
+ */
+static int lcp_extcode(fsm *f, int code, int id, u_char *inp, int len) {
+    ppp_pcb *pcb = f->pcb;
+    lcp_options *go = &pcb->lcp_gotoptions;
+    u_char *magp;
+
+    switch( code ){
+    case PROTREJ:
+	lcp_rprotrej(f, inp, len);
+	break;
+    
+    case ECHOREQ:
+	if (f->state != PPP_FSM_OPENED)
+	    break;
+	magp = inp;
+	PUTLONG(go->magicnumber, magp);
+	fsm_sdata(f, ECHOREP, id, inp, len);
+	break;
+    
+    case ECHOREP:
+	lcp_received_echo_reply(f, id, inp, len);
+	break;
+
+    case DISCREQ:
+    case IDENTIF:
+    case TIMEREM:
+	break;
+
+    default:
+	return 0;
+    }
+    return 1;
+}
+
+    
+/*
+ * lcp_rprotrej - Receive an Protocol-Reject.
+ *
+ * Figure out which protocol is rejected and inform it.
+ */
+static void lcp_rprotrej(fsm *f, u_char *inp, int len) {
+    int i;
+    const struct protent *protp;
+    u_short prot;
+#if PPP_PROTOCOLNAME
+    const char *pname;
+#endif /* PPP_PROTOCOLNAME */
+
+    if (len < 2) {
+	LCPDEBUG(("lcp_rprotrej: Rcvd short Protocol-Reject packet!"));
+	return;
+    }
+
+    GETSHORT(prot, inp);
+
+    /*
+     * Protocol-Reject packets received in any state other than the LCP
+     * OPENED state SHOULD be silently discarded.
+     */
+    if( f->state != PPP_FSM_OPENED ){
+	LCPDEBUG(("Protocol-Reject discarded: LCP in state %d", f->state));
+	return;
+    }
+
+#if PPP_PROTOCOLNAME
+    pname = protocol_name(prot);
+#endif /* PPP_PROTOCOLNAME */
+
+    /*
+     * Upcall the proper Protocol-Reject routine.
+     */
+    for (i = 0; (protp = protocols[i]) != NULL; ++i)
+	if (protp->protocol == prot) {
+#if PPP_PROTOCOLNAME
+	    if (pname != NULL)
+		ppp_dbglog("Protocol-Reject for '%s' (0x%x) received", pname,
+		       prot);
+	    else
+#endif /* PPP_PROTOCOLNAME */
+		ppp_dbglog("Protocol-Reject for 0x%x received", prot);
+	    (*protp->protrej)(f->pcb);
+	    return;
+	}
+
+#if PPP_PROTOCOLNAME
+    if (pname != NULL)
+	ppp_warn("Protocol-Reject for unsupported protocol '%s' (0x%x)", pname,
+	     prot);
+    else
+#endif /* #if PPP_PROTOCOLNAME */
+	ppp_warn("Protocol-Reject for unsupported protocol 0x%x", prot);
+}
+
+
+/*
+ * lcp_protrej - A Protocol-Reject was received.
+ */
+/*ARGSUSED*/
+static void lcp_protrej(ppp_pcb *pcb) {
+    /*
+     * Can't reject LCP!
+     */
+    ppp_error("Received Protocol-Reject for LCP!");
+    fsm_protreject(&pcb->lcp_fsm);
+}
+
+
+/*
+ * lcp_sprotrej - Send a Protocol-Reject for some protocol.
+ */
+void lcp_sprotrej(ppp_pcb *pcb, u_char *p, int len) {
+    fsm *f = &pcb->lcp_fsm;
+    /*
+     * Send back the protocol and the information field of the
+     * rejected packet.  We only get here if LCP is in the OPENED state.
+     */
+#if 0
+    p += 2;
+    len -= 2;
+#endif
+
+    fsm_sdata(f, PROTREJ, ++f->id,
+	      p, len);
+}
+
+
+/*
+ * lcp_resetci - Reset our CI.
+ */
+static void lcp_resetci(fsm *f) {
+    ppp_pcb *pcb = f->pcb;
+    lcp_options *wo = &pcb->lcp_wantoptions;
+    lcp_options *go = &pcb->lcp_gotoptions;
+    lcp_options *ao = &pcb->lcp_allowoptions;
+
+#if PPP_AUTH_SUPPORT
+
+    /* note: default value is true for allow options */
+    if (pcb->settings.user && pcb->settings.passwd) {
+#if PAP_SUPPORT
+      if (pcb->settings.refuse_pap) {
+        ao->neg_upap = 0;
+      }
+#endif /* PAP_SUPPORT */
+#if CHAP_SUPPORT
+      if (pcb->settings.refuse_chap) {
+        ao->chap_mdtype &= ~MDTYPE_MD5;
+      }
+#if MSCHAP_SUPPORT
+      if (pcb->settings.refuse_mschap) {
+        ao->chap_mdtype &= ~MDTYPE_MICROSOFT;
+      }
+      if (pcb->settings.refuse_mschap_v2) {
+        ao->chap_mdtype &= ~MDTYPE_MICROSOFT_V2;
+      }
+#endif /* MSCHAP_SUPPORT */
+      ao->neg_chap = (ao->chap_mdtype != MDTYPE_NONE);
+#endif /* CHAP_SUPPORT */
+#if EAP_SUPPORT
+      if (pcb->settings.refuse_eap) {
+        ao->neg_eap = 0;
+      }
+#endif /* EAP_SUPPORT */
+
+#if PPP_SERVER
+      /* note: default value is false for wanted options */
+      if (pcb->settings.auth_required) {
+#if PAP_SUPPORT
+        if (!pcb->settings.refuse_pap) {
+          wo->neg_upap = 1;
+        }
+#endif /* PAP_SUPPORT */
+#if CHAP_SUPPORT
+        if (!pcb->settings.refuse_chap) {
+          wo->chap_mdtype |= MDTYPE_MD5;
+        }
+#if MSCHAP_SUPPORT
+        if (!pcb->settings.refuse_mschap) {
+          wo->chap_mdtype |= MDTYPE_MICROSOFT;
+        }
+        if (!pcb->settings.refuse_mschap_v2) {
+          wo->chap_mdtype |= MDTYPE_MICROSOFT_V2;
+        }
+#endif /* MSCHAP_SUPPORT */
+        wo->neg_chap = (wo->chap_mdtype != MDTYPE_NONE);
+#endif /* CHAP_SUPPORT */
+#if EAP_SUPPORT
+        if (!pcb->settings.refuse_eap) {
+          wo->neg_eap = 1;
+        }
+#endif /* EAP_SUPPORT */
+      }
+#endif /* PPP_SERVER */
+
+    } else {
+#if PAP_SUPPORT
+      ao->neg_upap = 0;
+#endif /* PAP_SUPPORT */
+#if CHAP_SUPPORT
+      ao->neg_chap = 0;
+      ao->chap_mdtype = MDTYPE_NONE;
+#endif /* CHAP_SUPPORT */
+#if EAP_SUPPORT
+      ao->neg_eap = 0;
+#endif /* EAP_SUPPORT */
+    }
+
+    PPPDEBUG(LOG_DEBUG, ("ppp: auth protocols:"));
+#if PAP_SUPPORT
+    PPPDEBUG(LOG_DEBUG, (" PAP=%d", ao->neg_upap));
+#endif /* PAP_SUPPORT */
+#if CHAP_SUPPORT
+    PPPDEBUG(LOG_DEBUG, (" CHAP=%d CHAP_MD5=%d", ao->neg_chap, !!(ao->chap_mdtype&MDTYPE_MD5)));
+#if MSCHAP_SUPPORT
+    PPPDEBUG(LOG_DEBUG, (" CHAP_MS=%d CHAP_MS2=%d", !!(ao->chap_mdtype&MDTYPE_MICROSOFT), !!(ao->chap_mdtype&MDTYPE_MICROSOFT_V2)));
+#endif /* MSCHAP_SUPPORT */
+#endif /* CHAP_SUPPORT */
+#if EAP_SUPPORT
+    PPPDEBUG(LOG_DEBUG, (" EAP=%d", ao->neg_eap));
+#endif /* EAP_SUPPORT */
+    PPPDEBUG(LOG_DEBUG, ("\n"));
+
+#endif /* PPP_AUTH_SUPPORT */
+
+    wo->magicnumber = magic();
+    wo->numloops = 0;
+    *go = *wo;
+#ifdef HAVE_MULTILINK
+    if (!multilink) {
+	go->neg_mrru = 0;
+#endif /* HAVE_MULTILINK */
+	go->neg_ssnhf = 0;
+	go->neg_endpoint = 0;
+#ifdef HAVE_MULTILINK
+    }
+#endif /* HAVE_MULTILINK */
+    if (pcb->settings.noendpoint)
+	ao->neg_endpoint = 0;
+    pcb->peer_mru = PPP_MRU;
+#if 0 /* UNUSED */
+    auth_reset(pcb);
+#endif /* UNUSED */
+}
+
+
+/*
+ * lcp_cilen - Return length of our CI.
+ */
+static int lcp_cilen(fsm *f) {
+    ppp_pcb *pcb = f->pcb;
+    lcp_options *go = &pcb->lcp_gotoptions;
+
+#define LENCIVOID(neg)	((neg) ? CILEN_VOID : 0)
+#if CHAP_SUPPORT
+#define LENCICHAP(neg)	((neg) ? CILEN_CHAP : 0)
+#endif /* CHAP_SUPPORT */
+#define LENCISHORT(neg)	((neg) ? CILEN_SHORT : 0)
+#define LENCILONG(neg)	((neg) ? CILEN_LONG : 0)
+#if LQR_SUPPORT
+#define LENCILQR(neg)	((neg) ? CILEN_LQR: 0)
+#endif /* LQR_SUPPORT */
+#define LENCICBCP(neg)	((neg) ? CILEN_CBCP: 0)
+    /*
+     * NB: we only ask for one of CHAP, UPAP, or EAP, even if we will
+     * accept more than one.  We prefer EAP first, then CHAP, then
+     * PAP.
+     */
+    return (LENCISHORT(go->neg_mru && go->mru != PPP_DEFMRU) +
+	    LENCILONG(go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF) +
+#if EAP_SUPPORT
+	    LENCISHORT(go->neg_eap) +
+#endif /* EAP_SUPPORT */
+#if CHAP_SUPPORT /* cannot be improved, embedding a directive within macro arguments is not portable */
+#if EAP_SUPPORT
+	    LENCICHAP(!go->neg_eap && go->neg_chap) +
+#endif /* EAP_SUPPORT */
+#if !EAP_SUPPORT
+	    LENCICHAP(go->neg_chap) +
+#endif /* !EAP_SUPPORT */
+#endif /* CHAP_SUPPORT */
+#if PAP_SUPPORT /* cannot be improved, embedding a directive within macro arguments is not portable */
+#if EAP_SUPPORT && CHAP_SUPPORT
+	    LENCISHORT(!go->neg_eap && !go->neg_chap && go->neg_upap) +
+#endif /* EAP_SUPPORT && CHAP_SUPPORT */
+#if EAP_SUPPORT && !CHAP_SUPPORT
+	    LENCISHORT(!go->neg_eap && go->neg_upap) +
+#endif /* EAP_SUPPORT && !CHAP_SUPPORT */
+#if !EAP_SUPPORT && CHAP_SUPPORT
+	    LENCISHORT(!go->neg_chap && go->neg_upap) +
+#endif /* !EAP_SUPPORT && CHAP_SUPPORT */
+#if !EAP_SUPPORT && !CHAP_SUPPORT
+	    LENCISHORT(go->neg_upap) +
+#endif /* !EAP_SUPPORT && !CHAP_SUPPORT */
+#endif /* PAP_SUPPORT */
+#if LQR_SUPPORT
+	    LENCILQR(go->neg_lqr) +
+#endif /* LQR_SUPPORT */
+	    LENCICBCP(go->neg_cbcp) +
+	    LENCILONG(go->neg_magicnumber) +
+	    LENCIVOID(go->neg_pcompression) +
+	    LENCIVOID(go->neg_accompression) +
+#ifdef HAVE_MULTILINK
+	    LENCISHORT(go->neg_mrru) +
+#endif /* HAVE_MULTILINK */
+	    LENCIVOID(go->neg_ssnhf) +
+	    (go->neg_endpoint? CILEN_CHAR + go->endpoint.length: 0));
+}
+
+
+/*
+ * lcp_addci - Add our desired CIs to a packet.
+ */
+static void lcp_addci(fsm *f, u_char *ucp, int *lenp) {
+    ppp_pcb *pcb = f->pcb;
+    lcp_options *go = &pcb->lcp_gotoptions;
+    u_char *start_ucp = ucp;
+
+#define ADDCIVOID(opt, neg) \
+    if (neg) { \
+	PUTCHAR(opt, ucp); \
+	PUTCHAR(CILEN_VOID, ucp); \
+    }
+#define ADDCISHORT(opt, neg, val) \
+    if (neg) { \
+	PUTCHAR(opt, ucp); \
+	PUTCHAR(CILEN_SHORT, ucp); \
+	PUTSHORT(val, ucp); \
+    }
+#if CHAP_SUPPORT
+#define ADDCICHAP(opt, neg, val) \
+    if (neg) { \
+	PUTCHAR((opt), ucp); \
+	PUTCHAR(CILEN_CHAP, ucp); \
+	PUTSHORT(PPP_CHAP, ucp); \
+	PUTCHAR((CHAP_DIGEST(val)), ucp); \
+    }
+#endif /* CHAP_SUPPORT */
+#define ADDCILONG(opt, neg, val) \
+    if (neg) { \
+	PUTCHAR(opt, ucp); \
+	PUTCHAR(CILEN_LONG, ucp); \
+	PUTLONG(val, ucp); \
+    }
+#if LQR_SUPPORT
+#define ADDCILQR(opt, neg, val) \
+    if (neg) { \
+	PUTCHAR(opt, ucp); \
+	PUTCHAR(CILEN_LQR, ucp); \
+	PUTSHORT(PPP_LQR, ucp); \
+	PUTLONG(val, ucp); \
+    }
+#endif /* LQR_SUPPORT */
+#define ADDCICHAR(opt, neg, val) \
+    if (neg) { \
+	PUTCHAR(opt, ucp); \
+	PUTCHAR(CILEN_CHAR, ucp); \
+	PUTCHAR(val, ucp); \
+    }
+#define ADDCIENDP(opt, neg, class, val, len) \
+    if (neg) { \
+	int i; \
+	PUTCHAR(opt, ucp); \
+	PUTCHAR(CILEN_CHAR + len, ucp); \
+	PUTCHAR(class, ucp); \
+	for (i = 0; i < len; ++i) \
+	    PUTCHAR(val[i], ucp); \
+    }
+
+    ADDCISHORT(CI_MRU, go->neg_mru && go->mru != PPP_DEFMRU, go->mru);
+    ADDCILONG(CI_ASYNCMAP, go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF,
+	      go->asyncmap);
+#if EAP_SUPPORT
+    ADDCISHORT(CI_AUTHTYPE, go->neg_eap, PPP_EAP);
+#endif /* EAP_SUPPORT */
+#if CHAP_SUPPORT /* cannot be improved, embedding a directive within macro arguments is not portable */
+#if EAP_SUPPORT
+    ADDCICHAP(CI_AUTHTYPE, !go->neg_eap && go->neg_chap, go->chap_mdtype);
+#endif /* EAP_SUPPORT */
+#if !EAP_SUPPORT
+    ADDCICHAP(CI_AUTHTYPE, go->neg_chap, go->chap_mdtype);
+#endif /* !EAP_SUPPORT */
+#endif /* CHAP_SUPPORT */
+#if PAP_SUPPORT /* cannot be improved, embedding a directive within macro arguments is not portable */
+#if EAP_SUPPORT && CHAP_SUPPORT
+    ADDCISHORT(CI_AUTHTYPE, !go->neg_eap && !go->neg_chap && go->neg_upap, PPP_PAP);
+#endif /* EAP_SUPPORT && CHAP_SUPPORT */
+#if EAP_SUPPORT && !CHAP_SUPPORT
+    ADDCISHORT(CI_AUTHTYPE, !go->neg_eap && go->neg_upap, PPP_PAP);
+#endif /* EAP_SUPPORT && !CHAP_SUPPORT */
+#if !EAP_SUPPORT && CHAP_SUPPORT
+    ADDCISHORT(CI_AUTHTYPE, !go->neg_chap && go->neg_upap, PPP_PAP);
+#endif /* !EAP_SUPPORT && CHAP_SUPPORT */
+#if !EAP_SUPPORT && !CHAP_SUPPORT
+    ADDCISHORT(CI_AUTHTYPE, go->neg_upap, PPP_PAP);
+#endif /* !EAP_SUPPORT && !CHAP_SUPPORT */
+#endif /* PAP_SUPPORT */
+#if LQR_SUPPORT
+    ADDCILQR(CI_QUALITY, go->neg_lqr, go->lqr_period);
+#endif /* LQR_SUPPORT */
+    ADDCICHAR(CI_CALLBACK, go->neg_cbcp, CBCP_OPT);
+    ADDCILONG(CI_MAGICNUMBER, go->neg_magicnumber, go->magicnumber);
+    ADDCIVOID(CI_PCOMPRESSION, go->neg_pcompression);
+    ADDCIVOID(CI_ACCOMPRESSION, go->neg_accompression);
+#ifdef HAVE_MULTILINK
+    ADDCISHORT(CI_MRRU, go->neg_mrru, go->mrru);
+#endif
+    ADDCIVOID(CI_SSNHF, go->neg_ssnhf);
+    ADDCIENDP(CI_EPDISC, go->neg_endpoint, go->endpoint.class_,
+	      go->endpoint.value, go->endpoint.length);
+
+    if (ucp - start_ucp != *lenp) {
+	/* this should never happen, because peer_mtu should be 1500 */
+	ppp_error("Bug in lcp_addci: wrong length");
+    }
+}
+
+
+/*
+ * lcp_ackci - Ack our CIs.
+ * This should not modify any state if the Ack is bad.
+ *
+ * Returns:
+ *	0 - Ack was bad.
+ *	1 - Ack was good.
+ */
+static int lcp_ackci(fsm *f, u_char *p, int len) {
+    ppp_pcb *pcb = f->pcb;
+    lcp_options *go = &pcb->lcp_gotoptions;
+    u_char cilen, citype, cichar;
+    u_short cishort;
+    u32_t cilong;
+
+    /*
+     * 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 ACKCIVOID(opt, neg) \
+    if (neg) { \
+	if ((len -= CILEN_VOID) < 0) \
+	    goto bad; \
+	GETCHAR(citype, p); \
+	GETCHAR(cilen, p); \
+	if (cilen != CILEN_VOID || \
+	    citype != opt) \
+	    goto bad; \
+    }
+#define ACKCISHORT(opt, neg, val) \
+    if (neg) { \
+	if ((len -= CILEN_SHORT) < 0) \
+	    goto bad; \
+	GETCHAR(citype, p); \
+	GETCHAR(cilen, p); \
+	if (cilen != CILEN_SHORT || \
+	    citype != opt) \
+	    goto bad; \
+	GETSHORT(cishort, p); \
+	if (cishort != val) \
+	    goto bad; \
+    }
+#define ACKCICHAR(opt, neg, val) \
+    if (neg) { \
+	if ((len -= CILEN_CHAR) < 0) \
+	    goto bad; \
+	GETCHAR(citype, p); \
+	GETCHAR(cilen, p); \
+	if (cilen != CILEN_CHAR || \
+	    citype != opt) \
+	    goto bad; \
+	GETCHAR(cichar, p); \
+	if (cichar != val) \
+	    goto bad; \
+    }
+#if CHAP_SUPPORT
+#define ACKCICHAP(opt, neg, val) \
+    if (neg) { \
+	if ((len -= CILEN_CHAP) < 0) \
+	    goto bad; \
+	GETCHAR(citype, p); \
+	GETCHAR(cilen, p); \
+	if (cilen != CILEN_CHAP || \
+	    citype != (opt)) \
+	    goto bad; \
+	GETSHORT(cishort, p); \
+	if (cishort != PPP_CHAP) \
+	    goto bad; \
+	GETCHAR(cichar, p); \
+	if (cichar != (CHAP_DIGEST(val))) \
+	  goto bad; \
+    }
+#endif /* CHAP_SUPPORT */
+#define ACKCILONG(opt, neg, val) \
+    if (neg) { \
+	if ((len -= CILEN_LONG) < 0) \
+	    goto bad; \
+	GETCHAR(citype, p); \
+	GETCHAR(cilen, p); \
+	if (cilen != CILEN_LONG || \
+	    citype != opt) \
+	    goto bad; \
+	GETLONG(cilong, p); \
+	if (cilong != val) \
+	    goto bad; \
+    }
+#if LQR_SUPPORT
+#define ACKCILQR(opt, neg, val) \
+    if (neg) { \
+	if ((len -= CILEN_LQR) < 0) \
+	    goto bad; \
+	GETCHAR(citype, p); \
+	GETCHAR(cilen, p); \
+	if (cilen != CILEN_LQR || \
+	    citype != opt) \
+	    goto bad; \
+	GETSHORT(cishort, p); \
+	if (cishort != PPP_LQR) \
+	    goto bad; \
+	GETLONG(cilong, p); \
+	if (cilong != val) \
+	  goto bad; \
+    }
+#endif /* LQR_SUPPORT */
+#define ACKCIENDP(opt, neg, class, val, vlen) \
+    if (neg) { \
+	int i; \
+	if ((len -= CILEN_CHAR + vlen) < 0) \
+	    goto bad; \
+	GETCHAR(citype, p); \
+	GETCHAR(cilen, p); \
+	if (cilen != CILEN_CHAR + vlen || \
+	    citype != opt) \
+	    goto bad; \
+	GETCHAR(cichar, p); \
+	if (cichar != class) \
+	    goto bad; \
+	for (i = 0; i < vlen; ++i) { \
+	    GETCHAR(cichar, p); \
+	    if (cichar != val[i]) \
+		goto bad; \
+	} \
+    }
+
+    ACKCISHORT(CI_MRU, go->neg_mru && go->mru != PPP_DEFMRU, go->mru);
+    ACKCILONG(CI_ASYNCMAP, go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF,
+	      go->asyncmap);
+#if EAP_SUPPORT
+    ACKCISHORT(CI_AUTHTYPE, go->neg_eap, PPP_EAP);
+#endif /* EAP_SUPPORT */
+#if CHAP_SUPPORT /* cannot be improved, embedding a directive within macro arguments is not portable */
+#if EAP_SUPPORT
+    ACKCICHAP(CI_AUTHTYPE, !go->neg_eap && go->neg_chap, go->chap_mdtype);
+#endif /* EAP_SUPPORT */
+#if !EAP_SUPPORT
+    ACKCICHAP(CI_AUTHTYPE, go->neg_chap, go->chap_mdtype);
+#endif /* !EAP_SUPPORT */
+#endif /* CHAP_SUPPORT */
+#if PAP_SUPPORT /* cannot be improved, embedding a directive within macro arguments is not portable */
+#if EAP_SUPPORT && CHAP_SUPPORT
+    ACKCISHORT(CI_AUTHTYPE, !go->neg_eap && !go->neg_chap && go->neg_upap, PPP_PAP);
+#endif /* EAP_SUPPORT && CHAP_SUPPORT */
+#if EAP_SUPPORT && !CHAP_SUPPORT
+    ACKCISHORT(CI_AUTHTYPE, !go->neg_eap && go->neg_upap, PPP_PAP);
+#endif /* EAP_SUPPORT && !CHAP_SUPPORT */
+#if !EAP_SUPPORT && CHAP_SUPPORT
+    ACKCISHORT(CI_AUTHTYPE, !go->neg_chap && go->neg_upap, PPP_PAP);
+#endif /* !EAP_SUPPORT && CHAP_SUPPORT */
+#if !EAP_SUPPORT && !CHAP_SUPPORT
+    ACKCISHORT(CI_AUTHTYPE, go->neg_upap, PPP_PAP);
+#endif /* !EAP_SUPPORT && !CHAP_SUPPORT */
+#endif /* PAP_SUPPORT */
+#if LQR_SUPPORT
+    ACKCILQR(CI_QUALITY, go->neg_lqr, go->lqr_period);
+#endif /* LQR_SUPPORT */
+    ACKCICHAR(CI_CALLBACK, go->neg_cbcp, CBCP_OPT);
+    ACKCILONG(CI_MAGICNUMBER, go->neg_magicnumber, go->magicnumber);
+    ACKCIVOID(CI_PCOMPRESSION, go->neg_pcompression);
+    ACKCIVOID(CI_ACCOMPRESSION, go->neg_accompression);
+#ifdef HAVE_MULTILINK
+    ACKCISHORT(CI_MRRU, go->neg_mrru, go->mrru);
+#endif /* HAVE_MULTILINK */
+    ACKCIVOID(CI_SSNHF, go->neg_ssnhf);
+    ACKCIENDP(CI_EPDISC, go->neg_endpoint, go->endpoint.class_,
+	      go->endpoint.value, go->endpoint.length);
+
+    /*
+     * If there are any remaining CIs, then this packet is bad.
+     */
+    if (len != 0)
+	goto bad;
+    return (1);
+bad:
+    LCPDEBUG(("lcp_acki: received bad Ack!"));
+    return (0);
+}
+
+
+/*
+ * lcp_nakci - Peer has sent a NAK for some of our CIs.
+ * This should not modify any state if the Nak is bad
+ * or if LCP is in the OPENED state.
+ *
+ * Returns:
+ *	0 - Nak was bad.
+ *	1 - Nak was good.
+ */
+static int lcp_nakci(fsm *f, u_char *p, int len, int treat_as_reject) {
+    ppp_pcb *pcb = f->pcb;
+    lcp_options *go = &pcb->lcp_gotoptions;
+    lcp_options *wo = &pcb->lcp_wantoptions;
+    u_char citype, cichar, *next;
+    u_short cishort;
+    u32_t cilong;
+    lcp_options no;		/* options we've seen Naks for */
+    lcp_options try_;		/* options to request next time */
+    int looped_back = 0;
+    int cilen;
+
+    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 NAKCIVOID(opt, neg) \
+    if (go->neg && \
+	len >= CILEN_VOID && \
+	p[1] == CILEN_VOID && \
+	p[0] == opt) { \
+	len -= CILEN_VOID; \
+	INCPTR(CILEN_VOID, p); \
+	no.neg = 1; \
+	try_.neg = 0; \
+    }
+#if CHAP_SUPPORT
+#define NAKCICHAP(opt, neg, code) \
+    if (go->neg && \
+	len >= CILEN_CHAP && \
+	p[1] == CILEN_CHAP && \
+	p[0] == opt) { \
+	len -= CILEN_CHAP; \
+	INCPTR(2, p); \
+	GETSHORT(cishort, p); \
+	GETCHAR(cichar, p); \
+	no.neg = 1; \
+	code \
+    }
+#endif /* CHAP_SUPPORT */
+#define NAKCICHAR(opt, neg, code) \
+    if (go->neg && \
+	len >= CILEN_CHAR && \
+	p[1] == CILEN_CHAR && \
+	p[0] == opt) { \
+	len -= CILEN_CHAR; \
+	INCPTR(2, p); \
+	GETCHAR(cichar, p); \
+	no.neg = 1; \
+	code \
+    }
+#define NAKCISHORT(opt, neg, code) \
+    if (go->neg && \
+	len >= CILEN_SHORT && \
+	p[1] == CILEN_SHORT && \
+	p[0] == opt) { \
+	len -= CILEN_SHORT; \
+	INCPTR(2, p); \
+	GETSHORT(cishort, p); \
+	no.neg = 1; \
+	code \
+    }
+#define NAKCILONG(opt, neg, code) \
+    if (go->neg && \
+	len >= CILEN_LONG && \
+	p[1] == CILEN_LONG && \
+	p[0] == opt) { \
+	len -= CILEN_LONG; \
+	INCPTR(2, p); \
+	GETLONG(cilong, p); \
+	no.neg = 1; \
+	code \
+    }
+#if LQR_SUPPORT
+#define NAKCILQR(opt, neg, code) \
+    if (go->neg && \
+	len >= CILEN_LQR && \
+	p[1] == CILEN_LQR && \
+	p[0] == opt) { \
+	len -= CILEN_LQR; \
+	INCPTR(2, p); \
+	GETSHORT(cishort, p); \
+	GETLONG(cilong, p); \
+	no.neg = 1; \
+	code \
+    }
+#endif /* LQR_SUPPORT */
+#define NAKCIENDP(opt, neg) \
+    if (go->neg && \
+	len >= CILEN_CHAR && \
+	p[0] == opt && \
+	p[1] >= CILEN_CHAR && \
+	p[1] <= len) { \
+	len -= p[1]; \
+	INCPTR(p[1], p); \
+	no.neg = 1; \
+	try_.neg = 0; \
+    }
+
+    /*
+     * NOTE!  There must be no assignments to individual fields of *go in
+     * the code below.  Any such assignment is a BUG!
+     */
+    /*
+     * We don't care if they want to send us smaller packets than
+     * we want.  Therefore, accept any MRU less than what we asked for,
+     * but then ignore the new value when setting the MRU in the kernel.
+     * If they send us a bigger MRU than what we asked, accept it, up to
+     * the limit of the default MRU we'd get if we didn't negotiate.
+     */
+    if (go->neg_mru && go->mru != PPP_DEFMRU) {
+	NAKCISHORT(CI_MRU, neg_mru,
+		   if (cishort <= wo->mru || cishort <= PPP_DEFMRU)
+		       try_.mru = cishort;
+		   );
+    }
+
+    /*
+     * Add any characters they want to our (receive-side) asyncmap.
+     */
+    if (go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF) {
+	NAKCILONG(CI_ASYNCMAP, neg_asyncmap,
+		  try_.asyncmap = go->asyncmap | cilong;
+		  );
+    }
+
+    /*
+     * If they've nak'd our authentication-protocol, check whether
+     * they are proposing a different protocol, or a different
+     * hash algorithm for CHAP.
+     */
+    if ((0
+#if CHAP_SUPPORT
+        || go->neg_chap
+#endif /* CHAP_SUPPORT */
+#if PAP_SUPPORT
+        || go->neg_upap
+#endif /* PAP_SUPPORT */
+#if EAP_SUPPORT
+        || go->neg_eap
+#endif /* EAP_SUPPORT */
+        )
+	&& len >= CILEN_SHORT
+	&& p[0] == CI_AUTHTYPE && p[1] >= CILEN_SHORT && p[1] <= len) {
+	cilen = p[1];
+	len -= cilen;
+#if CHAP_SUPPORT
+	no.neg_chap = go->neg_chap;
+#endif /* CHAP_SUPPORT */
+#if PAP_SUPPORT
+	no.neg_upap = go->neg_upap;
+#endif /* PAP_SUPPORT */
+#if EAP_SUPPORT
+	no.neg_eap = go->neg_eap;
+#endif /* EAP_SUPPORT */
+	INCPTR(2, p);
+	GETSHORT(cishort, p);
+
+#if PAP_SUPPORT
+	if (cishort == PPP_PAP && cilen == CILEN_SHORT) {
+#if EAP_SUPPORT
+	    /* If we were asking for EAP, then we need to stop that. */
+	    if (go->neg_eap)
+		try_.neg_eap = 0;
+	    else
+#endif /* EAP_SUPPORT */
+
+#if CHAP_SUPPORT
+	    /* If we were asking for CHAP, then we need to stop that. */
+	    if (go->neg_chap)
+		try_.neg_chap = 0;
+	    else
+#endif /* CHAP_SUPPORT */
+
+	    /*
+	     * If we weren't asking for CHAP or EAP, then we were asking for
+	     * PAP, in which case this Nak is bad.
+	     */
+		goto bad;
+	} else
+#endif /* PAP_SUPPORT */
+
+#if CHAP_SUPPORT
+	if (cishort == PPP_CHAP && cilen == CILEN_CHAP) {
+	    GETCHAR(cichar, p);
+#if EAP_SUPPORT
+	    /* Stop asking for EAP, if we were. */
+	    if (go->neg_eap) {
+		try_.neg_eap = 0;
+		/* Try to set up to use their suggestion, if possible */
+		if (CHAP_CANDIGEST(go->chap_mdtype, cichar))
+		    try_.chap_mdtype = CHAP_MDTYPE_D(cichar);
+	    } else
+#endif /* EAP_SUPPORT */
+	    if (go->neg_chap) {
+		/*
+		 * We were asking for our preferred algorithm, they must
+		 * want something different.
+		 */
+		if (cichar != CHAP_DIGEST(go->chap_mdtype)) {
+		    if (CHAP_CANDIGEST(go->chap_mdtype, cichar)) {
+			/* Use their suggestion if we support it ... */
+			try_.chap_mdtype = CHAP_MDTYPE_D(cichar);
+		    } else {
+			/* ... otherwise, try our next-preferred algorithm. */
+			try_.chap_mdtype &= ~(CHAP_MDTYPE(try_.chap_mdtype));
+			if (try_.chap_mdtype == MDTYPE_NONE) /* out of algos */
+			    try_.neg_chap = 0;
+		    }
+		} else {
+		    /*
+		     * Whoops, they Nak'd our algorithm of choice
+		     * but then suggested it back to us.
+		     */
+		    goto bad;
+		}
+	    } else {
+		/*
+		 * Stop asking for PAP if we were asking for it.
+		 */
+#if PAP_SUPPORT
+		try_.neg_upap = 0;
+#endif /* PAP_SUPPORT */
+	    }
+
+	} else
+#endif /* CHAP_SUPPORT */
+	{
+
+#if EAP_SUPPORT
+	    /*
+	     * If we were asking for EAP, and they're Conf-Naking EAP,
+	     * well, that's just strange.  Nobody should do that.
+	     */
+	    if (cishort == PPP_EAP && cilen == CILEN_SHORT && go->neg_eap)
+		ppp_dbglog("Unexpected Conf-Nak for EAP");
+
+	    /*
+	     * We don't recognize what they're suggesting.
+	     * Stop asking for what we were asking for.
+	     */
+	    if (go->neg_eap)
+		try_.neg_eap = 0;
+	    else
+#endif /* EAP_SUPPORT */
+
+#if CHAP_SUPPORT
+	    if (go->neg_chap)
+		try_.neg_chap = 0;
+	    else
+#endif /* CHAP_SUPPORT */
+
+#if PAP_SUPPORT
+	    if(1)
+		try_.neg_upap = 0;
+	    else
+#endif /* PAP_SUPPORT */
+	    {}
+
+	    p += cilen - CILEN_SHORT;
+	}
+    }
+
+#if LQR_SUPPORT
+    /*
+     * If they can't cope with our link quality protocol, we'll have
+     * to stop asking for LQR.  We haven't got any other protocol.
+     * If they Nak the reporting period, take their value XXX ?
+     */
+    NAKCILQR(CI_QUALITY, neg_lqr,
+	     if (cishort != PPP_LQR)
+		 try_.neg_lqr = 0;
+	     else
+		 try_.lqr_period = cilong;
+	     );
+#endif /* LQR_SUPPORT */
+
+    /*
+     * Only implementing CBCP...not the rest of the callback options
+     */
+    NAKCICHAR(CI_CALLBACK, neg_cbcp,
+              try_.neg_cbcp = 0;
+              (void)cichar; /* if CHAP support is not compiled, cichar is set but not used, which makes some compilers complaining */
+              );
+
+    /*
+     * Check for a looped-back line.
+     */
+    NAKCILONG(CI_MAGICNUMBER, neg_magicnumber,
+	      try_.magicnumber = magic();
+	      looped_back = 1;
+	      );
+
+    /*
+     * Peer shouldn't send Nak for protocol compression or
+     * address/control compression requests; they should send
+     * a Reject instead.  If they send a Nak, treat it as a Reject.
+     */
+    NAKCIVOID(CI_PCOMPRESSION, neg_pcompression);
+    NAKCIVOID(CI_ACCOMPRESSION, neg_accompression);
+
+#ifdef HAVE_MULTILINK
+    /*
+     * Nak for MRRU option - accept their value if it is smaller
+     * than the one we want.
+     */
+    if (go->neg_mrru) {
+	NAKCISHORT(CI_MRRU, neg_mrru,
+		   if (treat_as_reject)
+		       try_.neg_mrru = 0;
+		   else if (cishort <= wo->mrru)
+		       try_.mrru = cishort;
+		   );
+    }
+#else /* HAVE_MULTILINK */
+    LWIP_UNUSED_ARG(treat_as_reject);
+#endif /* HAVE_MULTILINK */
+
+    /*
+     * Nak for short sequence numbers shouldn't be sent, treat it
+     * like a reject.
+     */
+    NAKCIVOID(CI_SSNHF, neg_ssnhf);
+
+    /*
+     * Nak of the endpoint discriminator option is not permitted,
+     * treat it like a reject.
+     */
+    NAKCIENDP(CI_EPDISC, neg_endpoint);
+
+    /*
+     * There may be remaining CIs, if the peer is requesting negotiation
+     * on an option that we didn't include in our request packet.
+     * If we see an option that we requested, or one we've already seen
+     * in this packet, then this packet is bad.
+     * If we wanted to respond by starting to negotiate on the requested
+     * option(s), we could, but we don't, because except for the
+     * authentication type and quality protocol, if we are not negotiating
+     * an option, it is because we were told not to.
+     * For the authentication type, the Nak from the peer means
+     * `let me authenticate myself with you' which is a bit pointless.
+     * For the quality protocol, the Nak means `ask me to send you quality
+     * reports', but if we didn't ask for them, we don't want them.
+     * An option we don't recognize represents the peer asking to
+     * negotiate some option we don't support, so ignore it.
+     */
+    while (len >= CILEN_VOID) {
+	GETCHAR(citype, p);
+	GETCHAR(cilen, p);
+	if (cilen < CILEN_VOID || (len -= cilen) < 0)
+	    goto bad;
+	next = p + cilen - 2;
+
+	switch (citype) {
+	case CI_MRU:
+	    if ((go->neg_mru && go->mru != PPP_DEFMRU)
+		|| no.neg_mru || cilen != CILEN_SHORT)
+		goto bad;
+	    GETSHORT(cishort, p);
+	    if (cishort < PPP_DEFMRU) {
+		try_.neg_mru = 1;
+		try_.mru = cishort;
+	    }
+	    break;
+	case CI_ASYNCMAP:
+	    if ((go->neg_asyncmap && go->asyncmap != 0xFFFFFFFF)
+		|| no.neg_asyncmap || cilen != CILEN_LONG)
+		goto bad;
+	    break;
+	case CI_AUTHTYPE:
+	    if (0
+#if CHAP_SUPPORT
+                || go->neg_chap || no.neg_chap
+#endif /* CHAP_SUPPORT */
+#if PAP_SUPPORT
+                || go->neg_upap || no.neg_upap
+#endif /* PAP_SUPPORT */
+#if EAP_SUPPORT
+		|| go->neg_eap || no.neg_eap
+#endif /* EAP_SUPPORT */
+		)
+		goto bad;
+	    break;
+	case CI_MAGICNUMBER:
+	    if (go->neg_magicnumber || no.neg_magicnumber ||
+		cilen != CILEN_LONG)
+		goto bad;
+	    break;
+	case CI_PCOMPRESSION:
+	    if (go->neg_pcompression || no.neg_pcompression
+		|| cilen != CILEN_VOID)
+		goto bad;
+	    break;
+	case CI_ACCOMPRESSION:
+	    if (go->neg_accompression || no.neg_accompression
+		|| cilen != CILEN_VOID)
+		goto bad;
+	    break;
+#if LQR_SUPPORT
+	case CI_QUALITY:
+	    if (go->neg_lqr || no.neg_lqr || cilen != CILEN_LQR)
+		goto bad;
+	    break;
+#endif /* LQR_SUPPORT */
+#ifdef HAVE_MULTILINK
+	case CI_MRRU:
+	    if (go->neg_mrru || no.neg_mrru || cilen != CILEN_SHORT)
+		goto bad;
+	    break;
+#endif /* HAVE_MULTILINK */
+	case CI_SSNHF:
+	    if (go->neg_ssnhf || no.neg_ssnhf || cilen != CILEN_VOID)
+		goto bad;
+	    try_.neg_ssnhf = 1;
+	    break;
+	case CI_EPDISC:
+	    if (go->neg_endpoint || no.neg_endpoint || cilen < CILEN_CHAR)
+		goto bad;
+	    break;
+	default:
+	    break;
+	}
+	p = next;
+    }
+
+    /*
+     * OK, the Nak is good.  Now we can update state.
+     * If there are any options left we ignore them.
+     */
+    if (f->state != PPP_FSM_OPENED) {
+	if (looped_back) {
+	    if (++try_.numloops >= pcb->settings.lcp_loopbackfail) {
+		ppp_notice("Serial line is looped back.");
+		pcb->err_code = PPPERR_LOOPBACK;
+		lcp_close(f->pcb, "Loopback detected");
+	    }
+	} else
+	    try_.numloops = 0;
+	*go = try_;
+    }
+
+    return 1;
+
+bad:
+    LCPDEBUG(("lcp_nakci: received bad Nak!"));
+    return 0;
+}
+
+
+/*
+ * lcp_rejci - Peer has Rejected some of our CIs.
+ * This should not modify any state if the Reject is bad
+ * or if LCP is in the OPENED state.
+ *
+ * Returns:
+ *	0 - Reject was bad.
+ *	1 - Reject was good.
+ */
+static int lcp_rejci(fsm *f, u_char *p, int len) {
+    ppp_pcb *pcb = f->pcb;
+    lcp_options *go = &pcb->lcp_gotoptions;
+    u_char cichar;
+    u_short cishort;
+    u32_t cilong;
+    lcp_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 REJCIVOID(opt, neg) \
+    if (go->neg && \
+	len >= CILEN_VOID && \
+	p[1] == CILEN_VOID && \
+	p[0] == opt) { \
+	len -= CILEN_VOID; \
+	INCPTR(CILEN_VOID, p); \
+	try_.neg = 0; \
+    }
+#define REJCISHORT(opt, neg, val) \
+    if (go->neg && \
+	len >= CILEN_SHORT && \
+	p[1] == CILEN_SHORT && \
+	p[0] == opt) { \
+	len -= CILEN_SHORT; \
+	INCPTR(2, p); \
+	GETSHORT(cishort, p); \
+	/* Check rejected value. */ \
+	if (cishort != val) \
+	    goto bad; \
+	try_.neg = 0; \
+    }
+
+#if CHAP_SUPPORT && EAP_SUPPORT && PAP_SUPPORT
+#define REJCICHAP(opt, neg, val) \
+    if (go->neg && \
+	len >= CILEN_CHAP && \
+	p[1] == CILEN_CHAP && \
+	p[0] == opt) { \
+	len -= CILEN_CHAP; \
+	INCPTR(2, p); \
+	GETSHORT(cishort, p); \
+	GETCHAR(cichar, p); \
+	/* Check rejected value. */ \
+	if ((cishort != PPP_CHAP) || (cichar != (CHAP_DIGEST(val)))) \
+	    goto bad; \
+	try_.neg = 0; \
+	try_.neg_eap = try_.neg_upap = 0; \
+    }
+#endif /* CHAP_SUPPORT && EAP_SUPPORT && PAP_SUPPORT */
+
+#if CHAP_SUPPORT && !EAP_SUPPORT && PAP_SUPPORT
+#define REJCICHAP(opt, neg, val) \
+    if (go->neg && \
+	len >= CILEN_CHAP && \
+	p[1] == CILEN_CHAP && \
+	p[0] == opt) { \
+	len -= CILEN_CHAP; \
+	INCPTR(2, p); \
+	GETSHORT(cishort, p); \
+	GETCHAR(cichar, p); \
+	/* Check rejected value. */ \
+	if ((cishort != PPP_CHAP) || (cichar != (CHAP_DIGEST(val)))) \
+	    goto bad; \
+	try_.neg = 0; \
+	try_.neg_upap = 0; \
+    }
+#endif /* CHAP_SUPPORT && !EAP_SUPPORT && PAP_SUPPORT */
+
+#if CHAP_SUPPORT && EAP_SUPPORT && !PAP_SUPPORT
+#define REJCICHAP(opt, neg, val) \
+    if (go->neg && \
+	len >= CILEN_CHAP && \
+	p[1] == CILEN_CHAP && \
+	p[0] == opt) { \
+	len -= CILEN_CHAP; \
+	INCPTR(2, p); \
+	GETSHORT(cishort, p); \
+	GETCHAR(cichar, p); \
+	/* Check rejected value. */ \
+	if ((cishort != PPP_CHAP) || (cichar != (CHAP_DIGEST(val)))) \
+	    goto bad; \
+	try_.neg = 0; \
+	try_.neg_eap = 0; \
+    }
+#endif /* CHAP_SUPPORT && EAP_SUPPORT && !PAP_SUPPORT */
+
+#if CHAP_SUPPORT && !EAP_SUPPORT && !PAP_SUPPORT
+#define REJCICHAP(opt, neg, val) \
+    if (go->neg && \
+	len >= CILEN_CHAP && \
+	p[1] == CILEN_CHAP && \
+	p[0] == opt) { \
+	len -= CILEN_CHAP; \
+	INCPTR(2, p); \
+	GETSHORT(cishort, p); \
+	GETCHAR(cichar, p); \
+	/* Check rejected value. */ \
+	if ((cishort != PPP_CHAP) || (cichar != (CHAP_DIGEST(val)))) \
+	    goto bad; \
+	try_.neg = 0; \
+    }
+#endif /* CHAP_SUPPORT && !EAP_SUPPORT && !PAP_SUPPORT */
+
+#define REJCILONG(opt, neg, val) \
+    if (go->neg && \
+	len >= CILEN_LONG && \
+	p[1] == CILEN_LONG && \
+	p[0] == opt) { \
+	len -= CILEN_LONG; \
+	INCPTR(2, p); \
+	GETLONG(cilong, p); \
+	/* Check rejected value. */ \
+	if (cilong != val) \
+	    goto bad; \
+	try_.neg = 0; \
+    }
+#if LQR_SUPPORT
+#define REJCILQR(opt, neg, val) \
+    if (go->neg && \
+	len >= CILEN_LQR && \
+	p[1] == CILEN_LQR && \
+	p[0] == opt) { \
+	len -= CILEN_LQR; \
+	INCPTR(2, p); \
+	GETSHORT(cishort, p); \
+	GETLONG(cilong, p); \
+	/* Check rejected value. */ \
+	if (cishort != PPP_LQR || cilong != val) \
+	    goto bad; \
+	try_.neg = 0; \
+    }
+#endif /* LQR_SUPPORT */
+#define REJCICBCP(opt, neg, val) \
+    if (go->neg && \
+	len >= CILEN_CBCP && \
+	p[1] == CILEN_CBCP && \
+	p[0] == opt) { \
+	len -= CILEN_CBCP; \
+	INCPTR(2, p); \
+	GETCHAR(cichar, p); \
+	/* Check rejected value. */ \
+	if (cichar != val) \
+	    goto bad; \
+	try_.neg = 0; \
+    }
+#define REJCIENDP(opt, neg, class, val, vlen) \
+    if (go->neg && \
+	len >= CILEN_CHAR + vlen && \
+	p[0] == opt && \
+	p[1] == CILEN_CHAR + vlen) { \
+	int i; \
+	len -= CILEN_CHAR + vlen; \
+	INCPTR(2, p); \
+	GETCHAR(cichar, p); \
+	if (cichar != class) \
+	    goto bad; \
+	for (i = 0; i < vlen; ++i) { \
+	    GETCHAR(cichar, p); \
+	    if (cichar != val[i]) \
+		goto bad; \
+	} \
+	try_.neg = 0; \
+    }
+
+    REJCISHORT(CI_MRU, neg_mru, go->mru);
+    REJCILONG(CI_ASYNCMAP, neg_asyncmap, go->asyncmap);
+#if EAP_SUPPORT
+    REJCISHORT(CI_AUTHTYPE, neg_eap, PPP_EAP);
+    if (!go->neg_eap) {
+#endif /* EAP_SUPPORT */
+#if CHAP_SUPPORT
+	REJCICHAP(CI_AUTHTYPE, neg_chap, go->chap_mdtype);
+	if (!go->neg_chap) {
+#endif /* CHAP_SUPPORT */
+#if PAP_SUPPORT
+	    REJCISHORT(CI_AUTHTYPE, neg_upap, PPP_PAP);
+#endif /* PAP_SUPPORT */
+#if CHAP_SUPPORT
+	}
+#endif /* CHAP_SUPPORT */
+#if EAP_SUPPORT
+    }
+#endif /* EAP_SUPPORT */
+#if LQR_SUPPORT
+    REJCILQR(CI_QUALITY, neg_lqr, go->lqr_period);
+#endif /* LQR_SUPPORT */
+    REJCICBCP(CI_CALLBACK, neg_cbcp, CBCP_OPT);
+    REJCILONG(CI_MAGICNUMBER, neg_magicnumber, go->magicnumber);
+    REJCIVOID(CI_PCOMPRESSION, neg_pcompression);
+    REJCIVOID(CI_ACCOMPRESSION, neg_accompression);
+#ifdef HAVE_MULTILINK
+    REJCISHORT(CI_MRRU, neg_mrru, go->mrru);
+#endif /* HAVE_MULTILINK */
+    REJCIVOID(CI_SSNHF, neg_ssnhf);
+    REJCIENDP(CI_EPDISC, neg_endpoint, go->endpoint.class_,
+	      go->endpoint.value, go->endpoint.length);
+
+    /*
+     * If there are any remaining CIs, then this packet is bad.
+     */
+    if (len != 0)
+	goto bad;
+    /*
+     * Now we can update state.
+     */
+    if (f->state != PPP_FSM_OPENED)
+	*go = try_;
+    return 1;
+
+bad:
+    LCPDEBUG(("lcp_rejci: received bad Reject!"));
+    return 0;
+}
+
+
+/*
+ * lcp_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.
+ *
+ * inp = Requested CIs
+ * lenp = Length of requested CIs
+ */
+static int lcp_reqci(fsm *f, u_char *inp, int *lenp, int reject_if_disagree) {
+    ppp_pcb *pcb = f->pcb;
+    lcp_options *go = &pcb->lcp_gotoptions;
+    lcp_options *ho = &pcb->lcp_hisoptions;
+    lcp_options *ao = &pcb->lcp_allowoptions;
+    u_char *cip, *next;		/* Pointer to current and next CIs */
+    int cilen, citype, cichar;	/* Parsed len, type, char value */
+    u_short cishort;		/* Parsed short value */
+    u32_t cilong;		/* Parse long value */
+    int rc = CONFACK;		/* Final packet return code */
+    int orc;			/* Individual option return code */
+    u_char *p;			/* Pointer to next char to parse */
+    u_char *rejp;		/* Pointer to next char in reject frame */
+    struct pbuf *nakp;          /* Nak buffer */
+    u_char *nakoutp;		/* Pointer to next char in Nak frame */
+    int l = *lenp;		/* Length left */
+
+    /*
+     * Reset all his options.
+     */
+    BZERO(ho, sizeof(*ho));
+
+    /*
+     * Process all his options.
+     */
+    next = inp;
+    nakp = pbuf_alloc(PBUF_RAW, (u16_t)(PPP_CTRL_PBUF_MAX_SIZE), PPP_CTRL_PBUF_TYPE);
+    if(NULL == nakp)
+        return 0;
+    if(nakp->tot_len != nakp->len) {
+        pbuf_free(nakp);
+        return 0;
+    }
+
+    nakoutp = (u_char*)nakp->payload;
+    rejp = 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? */
+	    LCPDEBUG(("lcp_reqci: bad CI length!"));
+	    orc = CONFREJ;		/* Reject bad CI */
+	    cilen = l;			/* Reject till end of packet */
+	    l = 0;			/* Don't loop again */
+	    citype = 0;
+	    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_MRU:
+	    if (!ao->neg_mru ||		/* Allow option? */
+		cilen != CILEN_SHORT) {	/* Check CI length */
+		orc = CONFREJ;		/* Reject CI */
+		break;
+	    }
+	    GETSHORT(cishort, p);	/* Parse MRU */
+
+	    /*
+	     * He must be able to receive at least our minimum.
+	     * No need to check a maximum.  If he sends a large number,
+	     * we'll just ignore it.
+	     */
+	    if (cishort < PPP_MINMRU) {
+		orc = CONFNAK;		/* Nak CI */
+		PUTCHAR(CI_MRU, nakoutp);
+		PUTCHAR(CILEN_SHORT, nakoutp);
+		PUTSHORT(PPP_MINMRU, nakoutp);	/* Give him a hint */
+		break;
+	    }
+	    ho->neg_mru = 1;		/* Remember he sent MRU */
+	    ho->mru = cishort;		/* And remember value */
+	    break;
+
+	case CI_ASYNCMAP:
+	    if (!ao->neg_asyncmap ||
+		cilen != CILEN_LONG) {
+		orc = CONFREJ;
+		break;
+	    }
+	    GETLONG(cilong, p);
+
+	    /*
+	     * Asyncmap must have set at least the bits
+	     * which are set in lcp_allowoptions[unit].asyncmap.
+	     */
+	    if ((ao->asyncmap & ~cilong) != 0) {
+		orc = CONFNAK;
+		PUTCHAR(CI_ASYNCMAP, nakoutp);
+		PUTCHAR(CILEN_LONG, nakoutp);
+		PUTLONG(ao->asyncmap | cilong, nakoutp);
+		break;
+	    }
+	    ho->neg_asyncmap = 1;
+	    ho->asyncmap = cilong;
+	    break;
+
+	case CI_AUTHTYPE:
+	    if (cilen < CILEN_SHORT ||
+		!(0
+#if PAP_SUPPORT
+		|| ao->neg_upap
+#endif /* PAP_SUPPORT */
+#if CHAP_SUPPORT
+		|| ao->neg_chap
+#endif /* CHAP_SUPPORT */
+#if EAP_SUPPORT
+		|| ao->neg_eap
+#endif /* EAP_SUPPORT */
+		)) {
+		/*
+		 * Reject the option if we're not willing to authenticate.
+		 */
+		ppp_dbglog("No auth is possible");
+		orc = CONFREJ;
+		break;
+	    }
+	    GETSHORT(cishort, p);
+
+	    /*
+	     * Authtype must be PAP, CHAP, or EAP.
+	     *
+	     * Note: if more than one of ao->neg_upap, ao->neg_chap, and
+	     * ao->neg_eap are set, and the peer sends a Configure-Request
+	     * with two or more authenticate-protocol requests, then we will
+	     * reject the second request.
+	     * Whether we end up doing CHAP, UPAP, or EAP depends then on
+	     * the ordering of the CIs in the peer's Configure-Request.
+             */
+
+#if PAP_SUPPORT
+	    if (cishort == PPP_PAP) {
+		/* we've already accepted CHAP or EAP */
+		if (0
+#if CHAP_SUPPORT
+		    || ho->neg_chap
+#endif /* CHAP_SUPPORT */
+#if EAP_SUPPORT
+		    || ho->neg_eap
+#endif /* EAP_SUPPORT */
+		    || cilen != CILEN_SHORT) {
+		    LCPDEBUG(("lcp_reqci: rcvd AUTHTYPE PAP, rejecting..."));
+		    orc = CONFREJ;
+		    break;
+		}
+		if (!ao->neg_upap) {	/* we don't want to do PAP */
+		    orc = CONFNAK;	/* NAK it and suggest CHAP or EAP */
+		    PUTCHAR(CI_AUTHTYPE, nakoutp);
+#if EAP_SUPPORT
+		    if (ao->neg_eap) {
+			PUTCHAR(CILEN_SHORT, nakoutp);
+			PUTSHORT(PPP_EAP, nakoutp);
+		    } else {
+#endif /* EAP_SUPPORT */
+#if CHAP_SUPPORT
+			PUTCHAR(CILEN_CHAP, nakoutp);
+			PUTSHORT(PPP_CHAP, nakoutp);
+			PUTCHAR(CHAP_DIGEST(ao->chap_mdtype), nakoutp);
+#endif /* CHAP_SUPPORT */
+#if EAP_SUPPORT
+		    }
+#endif /* EAP_SUPPORT */
+		    break;
+		}
+		ho->neg_upap = 1;
+		break;
+	    }
+#endif /* PAP_SUPPORT */
+#if CHAP_SUPPORT
+	    if (cishort == PPP_CHAP) {
+		/* we've already accepted PAP or EAP */
+		if (
+#if PAP_SUPPORT
+		    ho->neg_upap ||
+#endif /* PAP_SUPPORT */
+#if EAP_SUPPORT
+		    ho->neg_eap ||
+#endif /* EAP_SUPPORT */
+		    cilen != CILEN_CHAP) {
+		    LCPDEBUG(("lcp_reqci: rcvd AUTHTYPE CHAP, rejecting..."));
+		    orc = CONFREJ;
+		    break;
+		}
+		if (!ao->neg_chap) {	/* we don't want to do CHAP */
+		    orc = CONFNAK;	/* NAK it and suggest EAP or PAP */
+		    PUTCHAR(CI_AUTHTYPE, nakoutp);
+		    PUTCHAR(CILEN_SHORT, nakoutp);
+#if EAP_SUPPORT
+		    if (ao->neg_eap) {
+			PUTSHORT(PPP_EAP, nakoutp);
+		    } else
+#endif /* EAP_SUPPORT */
+#if PAP_SUPPORT
+		    if(1) {
+			PUTSHORT(PPP_PAP, nakoutp);
+		    }
+		    else
+#endif /* PAP_SUPPORT */
+		    {}
+		    break;
+		}
+		GETCHAR(cichar, p);	/* get digest type */
+		if (!(CHAP_CANDIGEST(ao->chap_mdtype, cichar))) {
+		    /*
+		     * We can't/won't do the requested type,
+		     * suggest something else.
+		     */
+		    orc = CONFNAK;
+		    PUTCHAR(CI_AUTHTYPE, nakoutp);
+		    PUTCHAR(CILEN_CHAP, nakoutp);
+		    PUTSHORT(PPP_CHAP, nakoutp);
+		    PUTCHAR(CHAP_DIGEST(ao->chap_mdtype), nakoutp);
+		    break;
+		}
+		ho->chap_mdtype = CHAP_MDTYPE_D(cichar); /* save md type */
+		ho->neg_chap = 1;
+		break;
+	    }
+#endif /* CHAP_SUPPORT */
+#if EAP_SUPPORT
+	    if (cishort == PPP_EAP) {
+		/* we've already accepted CHAP or PAP */
+		if (
+#if CHAP_SUPPORT
+		    ho->neg_chap ||
+#endif /* CHAP_SUPPORT */
+#if PAP_SUPPORT
+		    ho->neg_upap ||
+#endif /* PAP_SUPPORT */
+		    cilen != CILEN_SHORT) {
+		    LCPDEBUG(("lcp_reqci: rcvd AUTHTYPE EAP, rejecting..."));
+		    orc = CONFREJ;
+		    break;
+		}
+		if (!ao->neg_eap) {	/* we don't want to do EAP */
+		    orc = CONFNAK;	/* NAK it and suggest CHAP or PAP */
+		    PUTCHAR(CI_AUTHTYPE, nakoutp);
+#if CHAP_SUPPORT
+		    if (ao->neg_chap) {
+			PUTCHAR(CILEN_CHAP, nakoutp);
+			PUTSHORT(PPP_CHAP, nakoutp);
+			PUTCHAR(CHAP_DIGEST(ao->chap_mdtype), nakoutp);
+		    } else
+#endif /* CHAP_SUPPORT */
+#if PAP_SUPPORT
+		    if(1) {
+			PUTCHAR(CILEN_SHORT, nakoutp);
+			PUTSHORT(PPP_PAP, nakoutp);
+		    } else
+#endif /* PAP_SUPPORT */
+		    {}
+		    break;
+		}
+		ho->neg_eap = 1;
+		break;
+	    }
+#endif /* EAP_SUPPORT */
+
+	    /*
+	     * We don't recognize the protocol they're asking for.
+	     * Nak it with something we're willing to do.
+	     * (At this point we know ao->neg_upap || ao->neg_chap ||
+	     * ao->neg_eap.)
+	     */
+	    orc = CONFNAK;
+	    PUTCHAR(CI_AUTHTYPE, nakoutp);
+
+#if EAP_SUPPORT
+	    if (ao->neg_eap) {
+		PUTCHAR(CILEN_SHORT, nakoutp);
+		PUTSHORT(PPP_EAP, nakoutp);
+	    } else
+#endif /* EAP_SUPPORT */
+#if CHAP_SUPPORT
+	    if (ao->neg_chap) {
+		PUTCHAR(CILEN_CHAP, nakoutp);
+		PUTSHORT(PPP_CHAP, nakoutp);
+		PUTCHAR(CHAP_DIGEST(ao->chap_mdtype), nakoutp);
+	    } else
+#endif /* CHAP_SUPPORT */
+#if PAP_SUPPORT
+	    if(1) {
+		PUTCHAR(CILEN_SHORT, nakoutp);
+		PUTSHORT(PPP_PAP, nakoutp);
+	    } else
+#endif /* PAP_SUPPORT */
+	    {}
+	    break;
+
+#if LQR_SUPPORT
+	case CI_QUALITY:
+	    if (!ao->neg_lqr ||
+		cilen != CILEN_LQR) {
+		orc = CONFREJ;
+		break;
+	    }
+
+	    GETSHORT(cishort, p);
+	    GETLONG(cilong, p);
+
+	    /*
+	     * Check the protocol and the reporting period.
+	     * XXX When should we Nak this, and what with?
+	     */
+	    if (cishort != PPP_LQR) {
+		orc = CONFNAK;
+		PUTCHAR(CI_QUALITY, nakoutp);
+		PUTCHAR(CILEN_LQR, nakoutp);
+		PUTSHORT(PPP_LQR, nakoutp);
+		PUTLONG(ao->lqr_period, nakoutp);
+		break;
+	    }
+	    break;
+#endif /* LQR_SUPPORT */
+
+	case CI_MAGICNUMBER:
+	    if (!(ao->neg_magicnumber || go->neg_magicnumber) ||
+		cilen != CILEN_LONG) {
+		orc = CONFREJ;
+		break;
+	    }
+	    GETLONG(cilong, p);
+
+	    /*
+	     * He must have a different magic number.
+	     */
+	    if (go->neg_magicnumber &&
+		cilong == go->magicnumber) {
+		cilong = magic();	/* Don't put magic() inside macro! */
+		orc = CONFNAK;
+		PUTCHAR(CI_MAGICNUMBER, nakoutp);
+		PUTCHAR(CILEN_LONG, nakoutp);
+		PUTLONG(cilong, nakoutp);
+		break;
+	    }
+	    ho->neg_magicnumber = 1;
+	    ho->magicnumber = cilong;
+	    break;
+
+
+	case CI_PCOMPRESSION:
+	    if (!ao->neg_pcompression ||
+		cilen != CILEN_VOID) {
+		orc = CONFREJ;
+		break;
+	    }
+	    ho->neg_pcompression = 1;
+	    break;
+
+	case CI_ACCOMPRESSION:
+	    if (!ao->neg_accompression ||
+		cilen != CILEN_VOID) {
+		orc = CONFREJ;
+		break;
+	    }
+	    ho->neg_accompression = 1;
+	    break;
+
+#ifdef HAVE_MULTILINK
+	case CI_MRRU:
+	    if (!ao->neg_mrru
+		|| !multilink
+		|| cilen != CILEN_SHORT) {
+		orc = CONFREJ;
+		break;
+	    }
+
+	    GETSHORT(cishort, p);
+	    /* possibly should insist on a minimum/maximum MRRU here */
+	    ho->neg_mrru = 1;
+	    ho->mrru = cishort;
+	    break;
+#endif /* HAVE_MULTILINK */
+
+	case CI_SSNHF:
+	    if (!ao->neg_ssnhf
+#ifdef HAVE_MULTILINK
+		|| !multilink
+#endif /* HAVE_MULTILINK */
+		|| cilen != CILEN_VOID) {
+		orc = CONFREJ;
+		break;
+	    }
+	    ho->neg_ssnhf = 1;
+	    break;
+
+	case CI_EPDISC:
+	    if (!ao->neg_endpoint ||
+		cilen < CILEN_CHAR ||
+		cilen > CILEN_CHAR + MAX_ENDP_LEN) {
+		orc = CONFREJ;
+		break;
+	    }
+	    GETCHAR(cichar, p);
+	    cilen -= CILEN_CHAR;
+	    ho->neg_endpoint = 1;
+	    ho->endpoint.class_ = cichar;
+	    ho->endpoint.length = cilen;
+	    MEMCPY(ho->endpoint.value, p, cilen);
+	    INCPTR(cilen, p);
+	    break;
+
+	default:
+	    LCPDEBUG(("lcp_reqci: rcvd unknown option %d", citype));
+	    orc = CONFREJ;
+	    break;
+	}
+
+endswitch:
+	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? */
+		&& citype != CI_MAGICNUMBER) {
+		orc = CONFREJ;		/* Get tough if so */
+	    } else {
+		if (rc == CONFREJ)	/* Rejecting prior CI? */
+		    continue;		/* Don't send this one */
+		rc = CONFNAK;
+	    }
+	}
+	if (orc == CONFREJ) {		/* Reject this CI */
+	    rc = CONFREJ;
+	    if (cip != rejp)		/* Need to move rejected CI? */
+		MEMCPY(rejp, cip, cilen); /* Move it */
+	    INCPTR(cilen, rejp);	/* Update output pointer */
+	}
+    }
+
+    /*
+     * If we wanted to send additional NAKs (for unsent CIs), the
+     * code would go here.  The extra NAKs would go at *nakoutp.
+     * At present there are no cases where we want to ask the
+     * peer to negotiate an option.
+     */
+
+    switch (rc) {
+    case CONFACK:
+	*lenp = next - inp;
+	break;
+    case CONFNAK:
+	/*
+	 * Copy the Nak'd options from the nak buffer to the caller's buffer.
+	 */
+	*lenp = nakoutp - (u_char*)nakp->payload;
+	MEMCPY(inp, nakp->payload, *lenp);
+	break;
+    case CONFREJ:
+	*lenp = rejp - inp;
+	break;
+    default:
+	break;
+    }
+
+    pbuf_free(nakp);
+    LCPDEBUG(("lcp_reqci: returning CONF%s.", CODENAME(rc)));
+    return (rc);			/* Return final code */
+}
+
+
+/*
+ * lcp_up - LCP has come UP.
+ */
+static void lcp_up(fsm *f) {
+    ppp_pcb *pcb = f->pcb;
+    lcp_options *wo = &pcb->lcp_wantoptions;
+    lcp_options *ho = &pcb->lcp_hisoptions;
+    lcp_options *go = &pcb->lcp_gotoptions;
+    lcp_options *ao = &pcb->lcp_allowoptions;
+    int mtu, mru;
+
+    if (!go->neg_magicnumber)
+	go->magicnumber = 0;
+    if (!ho->neg_magicnumber)
+	ho->magicnumber = 0;
+
+    /*
+     * Set our MTU to the smaller of the MTU we wanted and
+     * the MRU our peer wanted.  If we negotiated an MRU,
+     * set our MRU to the larger of value we wanted and
+     * the value we got in the negotiation.
+     * Note on the MTU: the link MTU can be the MRU the peer wanted,
+     * the interface MTU is set to the lowest of that, the
+     * MTU we want to use, and our link MRU.
+     */
+    mtu = ho->neg_mru? ho->mru: PPP_MRU;
+    mru = go->neg_mru? LWIP_MAX(wo->mru, go->mru): PPP_MRU;
+#ifdef HAVE_MULTILINK
+    if (!(multilink && go->neg_mrru && ho->neg_mrru))
+#endif /* HAVE_MULTILINK */
+	netif_set_mtu(pcb, LWIP_MIN(LWIP_MIN(mtu, mru), ao->mru));
+    ppp_send_config(pcb, mtu,
+		    (ho->neg_asyncmap? ho->asyncmap: 0xffffffff),
+		    ho->neg_pcompression, ho->neg_accompression);
+    ppp_recv_config(pcb, mru,
+		    (pcb->settings.lax_recv? 0: go->neg_asyncmap? go->asyncmap: 0xffffffff),
+		    go->neg_pcompression, go->neg_accompression);
+
+    if (ho->neg_mru)
+	pcb->peer_mru = ho->mru;
+
+    lcp_echo_lowerup(f->pcb);  /* Enable echo messages */
+
+    link_established(pcb);
+}
+
+
+/*
+ * lcp_down - LCP has gone DOWN.
+ *
+ * Alert other protocols.
+ */
+static void lcp_down(fsm *f) {
+    ppp_pcb *pcb = f->pcb;
+    lcp_options *go = &pcb->lcp_gotoptions;
+
+    lcp_echo_lowerdown(f->pcb);
+
+    link_down(pcb);
+
+    ppp_send_config(pcb, PPP_MRU, 0xffffffff, 0, 0);
+    ppp_recv_config(pcb, PPP_MRU,
+		    (go->neg_asyncmap? go->asyncmap: 0xffffffff),
+		    go->neg_pcompression, go->neg_accompression);
+    pcb->peer_mru = PPP_MRU;
+}
+
+
+/*
+ * lcp_starting - LCP needs the lower layer up.
+ */
+static void lcp_starting(fsm *f) {
+    ppp_pcb *pcb = f->pcb;
+    link_required(pcb);
+}
+
+
+/*
+ * lcp_finished - LCP has finished with the lower layer.
+ */
+static void lcp_finished(fsm *f) {
+    ppp_pcb *pcb = f->pcb;
+    link_terminated(pcb);
+}
+
+
+#if PRINTPKT_SUPPORT
+/*
+ * lcp_printpkt - print the contents of an LCP packet.
+ */
+static const char* const lcp_codenames[] = {
+    "ConfReq", "ConfAck", "ConfNak", "ConfRej",
+    "TermReq", "TermAck", "CodeRej", "ProtRej",
+    "EchoReq", "EchoRep", "DiscReq", "Ident",
+    "TimeRem"
+};
+
+static int lcp_printpkt(const u_char *p, int plen,
+		void (*printer) (void *, const char *, ...), void *arg) {
+    int code, id, len, olen, i;
+    const u_char *pstart, *optend;
+    u_short cishort;
+    u32_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 <= (int)LWIP_ARRAYSIZE(lcp_codenames))
+	printer(arg, " %s", lcp_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_MRU:
+		if (olen == CILEN_SHORT) {
+		    p += 2;
+		    GETSHORT(cishort, p);
+		    printer(arg, "mru %d", cishort);
+		}
+		break;
+	    case CI_ASYNCMAP:
+		if (olen == CILEN_LONG) {
+		    p += 2;
+		    GETLONG(cilong, p);
+		    printer(arg, "asyncmap 0x%x", cilong);
+		}
+		break;
+	    case CI_AUTHTYPE:
+		if (olen >= CILEN_SHORT) {
+		    p += 2;
+		    printer(arg, "auth ");
+		    GETSHORT(cishort, p);
+		    switch (cishort) {
+#if PAP_SUPPORT
+		    case PPP_PAP:
+			printer(arg, "pap");
+			break;
+#endif /* PAP_SUPPORT */
+#if CHAP_SUPPORT
+		    case PPP_CHAP:
+			printer(arg, "chap");
+			if (p < optend) {
+			    switch (*p) {
+			    case CHAP_MD5:
+				printer(arg, " MD5");
+				++p;
+				break;
+#if MSCHAP_SUPPORT
+			    case CHAP_MICROSOFT:
+				printer(arg, " MS");
+				++p;
+				break;
+
+			    case CHAP_MICROSOFT_V2:
+				printer(arg, " MS-v2");
+				++p;
+				break;
+#endif /* MSCHAP_SUPPORT */
+			    default:
+				break;
+			    }
+			}
+			break;
+#endif /* CHAP_SUPPORT */
+#if EAP_SUPPORT
+		    case PPP_EAP:
+			printer(arg, "eap");
+			break;
+#endif /* EAP_SUPPORT */
+		    default:
+			printer(arg, "0x%x", cishort);
+		    }
+		}
+		break;
+#if LQR_SUPPORT
+	    case CI_QUALITY:
+		if (olen >= CILEN_SHORT) {
+		    p += 2;
+		    printer(arg, "quality ");
+		    GETSHORT(cishort, p);
+		    switch (cishort) {
+		    case PPP_LQR:
+			printer(arg, "lqr");
+			break;
+		    default:
+			printer(arg, "0x%x", cishort);
+		    }
+		}
+		break;
+#endif /* LQR_SUPPORT */
+	    case CI_CALLBACK:
+		if (olen >= CILEN_CHAR) {
+		    p += 2;
+		    printer(arg, "callback ");
+		    GETCHAR(cishort, p);
+		    switch (cishort) {
+		    case CBCP_OPT:
+			printer(arg, "CBCP");
+			break;
+		    default:
+			printer(arg, "0x%x", cishort);
+		    }
+		}
+		break;
+	    case CI_MAGICNUMBER:
+		if (olen == CILEN_LONG) {
+		    p += 2;
+		    GETLONG(cilong, p);
+		    printer(arg, "magic 0x%x", cilong);
+		}
+		break;
+	    case CI_PCOMPRESSION:
+		if (olen == CILEN_VOID) {
+		    p += 2;
+		    printer(arg, "pcomp");
+		}
+		break;
+	    case CI_ACCOMPRESSION:
+		if (olen == CILEN_VOID) {
+		    p += 2;
+		    printer(arg, "accomp");
+		}
+		break;
+	    case CI_MRRU:
+		if (olen == CILEN_SHORT) {
+		    p += 2;
+		    GETSHORT(cishort, p);
+		    printer(arg, "mrru %d", cishort);
+		}
+		break;
+	    case CI_SSNHF:
+		if (olen == CILEN_VOID) {
+		    p += 2;
+		    printer(arg, "ssnhf");
+		}
+		break;
+	    case CI_EPDISC:
+#ifdef HAVE_MULTILINK
+		if (olen >= CILEN_CHAR) {
+		    struct epdisc epd;
+		    p += 2;
+		    GETCHAR(epd.class, p);
+		    epd.length = olen - CILEN_CHAR;
+		    if (epd.length > MAX_ENDP_LEN)
+			epd.length = MAX_ENDP_LEN;
+		    if (epd.length > 0) {
+			MEMCPY(epd.value, p, epd.length);
+			p += epd.length;
+		    }
+		    printer(arg, "endpoint [%s]", epdisc_to_str(&epd));
+		}
+#else
+		printer(arg, "endpoint");
+#endif
+		break;
+	    default:
+		break;
+	    }
+	    while (p < optend) {
+		GETCHAR(code, p);
+		printer(arg, " %.2x", code);
+	    }
+	    printer(arg, ">");
+	}
+	break;
+
+    case TERMACK:
+    case TERMREQ:
+	if (len > 0 && *p >= ' ' && *p < 0x7f) {
+	    printer(arg, " ");
+	    ppp_print_string(p, len, printer, arg);
+	    p += len;
+	    len = 0;
+	}
+	break;
+
+    case ECHOREQ:
+    case ECHOREP:
+    case DISCREQ:
+	if (len >= 4) {
+	    GETLONG(cilong, p);
+	    printer(arg, " magic=0x%x", cilong);
+	    len -= 4;
+	}
+	break;
+
+    case IDENTIF:
+    case TIMEREM:
+	if (len >= 4) {
+	    GETLONG(cilong, p);
+	    printer(arg, " magic=0x%x", cilong);
+	    len -= 4;
+	}
+	if (code == TIMEREM) {
+	    if (len < 4)
+		break;
+	    GETLONG(cilong, p);
+	    printer(arg, " seconds=%u", cilong);
+	    len -= 4;
+	}
+	if (len > 0) {
+	    printer(arg, " ");
+	    ppp_print_string(p, len, printer, arg);
+	    p += len;
+	    len = 0;
+	}
+	break;
+    default:
+	break;
+    }
+
+    /* print the rest of the bytes in the packet */
+    for (i = 0; i < len && i < 32; ++i) {
+	GETCHAR(code, p);
+	printer(arg, " %.2x", code);
+    }
+    if (i < len) {
+	printer(arg, " ...");
+	p += len - i;
+    }
+
+    return p - pstart;
+}
+#endif /* PRINTPKT_SUPPORT */
+
+/*
+ * Time to shut down the link because there is nothing out there.
+ */
+
+static void LcpLinkFailure(fsm *f) {
+    ppp_pcb *pcb = f->pcb;
+    if (f->state == PPP_FSM_OPENED) {
+	ppp_info("No response to %d echo-requests", pcb->lcp_echos_pending);
+        ppp_notice("Serial link appears to be disconnected.");
+	pcb->err_code = PPPERR_PEERDEAD;
+	lcp_close(pcb, "Peer not responding");
+    }
+}
+
+/*
+ * Timer expired for the LCP echo requests from this process.
+ */
+
+static void LcpEchoCheck(fsm *f) {
+    ppp_pcb *pcb = f->pcb;
+
+    LcpSendEchoRequest (f);
+    if (f->state != PPP_FSM_OPENED)
+	return;
+
+    /*
+     * Start the timer for the next interval.
+     */
+    if (pcb->lcp_echo_timer_running)
+	ppp_warn("assertion lcp_echo_timer_running==0 failed");
+    TIMEOUT (LcpEchoTimeout, f, pcb->settings.lcp_echo_interval);
+    pcb->lcp_echo_timer_running = 1;
+}
+
+/*
+ * LcpEchoTimeout - Timer expired on the LCP echo
+ */
+
+static void LcpEchoTimeout(void *arg) {
+    fsm *f = (fsm*)arg;
+    ppp_pcb *pcb = f->pcb;
+    if (pcb->lcp_echo_timer_running != 0) {
+        pcb->lcp_echo_timer_running = 0;
+        LcpEchoCheck ((fsm *) arg);
+    }
+}
+
+/*
+ * LcpEchoReply - LCP has received a reply to the echo
+ */
+
+static void lcp_received_echo_reply(fsm *f, int id, u_char *inp, int len) {
+    ppp_pcb *pcb = f->pcb;
+    lcp_options *go = &pcb->lcp_gotoptions;
+    u32_t magic_val;
+    LWIP_UNUSED_ARG(id);
+
+    /* Check the magic number - don't count replies from ourselves. */
+    if (len < 4) {
+	ppp_dbglog("lcp: received short Echo-Reply, length %d", len);
+	return;
+    }
+    GETLONG(magic_val, inp);
+    if (go->neg_magicnumber
+	&& magic_val == go->magicnumber) {
+	ppp_warn("appear to have received our own echo-reply!");
+	return;
+    }
+
+    /* Reset the number of outstanding echo frames */
+    pcb->lcp_echos_pending = 0;
+}
+
+/*
+ * LcpSendEchoRequest - Send an echo request frame to the peer
+ */
+
+static void LcpSendEchoRequest(fsm *f) {
+    ppp_pcb *pcb = f->pcb;
+    lcp_options *go = &pcb->lcp_gotoptions;
+    u32_t lcp_magic;
+    u_char pkt[4], *pktp;
+
+    /*
+     * Detect the failure of the peer at this point.
+     */
+    if (pcb->settings.lcp_echo_fails != 0) {
+        if (pcb->lcp_echos_pending >= pcb->settings.lcp_echo_fails) {
+            LcpLinkFailure(f);
+            pcb->lcp_echos_pending = 0;
+	}
+    }
+
+#if PPP_LCP_ADAPTIVE
+    /*
+     * If adaptive echos have been enabled, only send the echo request if
+     * no traffic was received since the last one.
+     */
+    if (pcb->settings.lcp_echo_adaptive) {
+	static unsigned int last_pkts_in = 0;
+
+#if PPP_STATS_SUPPORT
+	update_link_stats(f->unit);
+	link_stats_valid = 0;
+#endif /* PPP_STATS_SUPPORT */
+
+	if (link_stats.pkts_in != last_pkts_in) {
+	    last_pkts_in = link_stats.pkts_in;
+	    return;
+	}
+    }
+#endif
+
+    /*
+     * Make and send the echo request frame.
+     */
+    if (f->state == PPP_FSM_OPENED) {
+        lcp_magic = go->magicnumber;
+	pktp = pkt;
+	PUTLONG(lcp_magic, pktp);
+        fsm_sdata(f, ECHOREQ, pcb->lcp_echo_number++, pkt, pktp - pkt);
+	++pcb->lcp_echos_pending;
+    }
+}
+
+/*
+ * lcp_echo_lowerup - Start the timer for the LCP frame
+ */
+
+static void lcp_echo_lowerup(ppp_pcb *pcb) {
+    fsm *f = &pcb->lcp_fsm;
+
+    /* Clear the parameters for generating echo frames */
+    pcb->lcp_echos_pending      = 0;
+    pcb->lcp_echo_number        = 0;
+    pcb->lcp_echo_timer_running = 0;
+  
+    /* If a timeout interval is specified then start the timer */
+    if (pcb->settings.lcp_echo_interval != 0)
+        LcpEchoCheck (f);
+}
+
+/*
+ * lcp_echo_lowerdown - Stop the timer for the LCP frame
+ */
+
+static void lcp_echo_lowerdown(ppp_pcb *pcb) {
+    fsm *f = &pcb->lcp_fsm;
+
+    if (pcb->lcp_echo_timer_running != 0) {
+        UNTIMEOUT (LcpEchoTimeout, f);
+        pcb->lcp_echo_timer_running = 0;
+    }
+}
+
+#endif /* PPP_SUPPORT */

http://git-wip-us.apache.org/repos/asf/incubator-mynewt-core/blob/f5a0f2a0/net/ip/lwip_base/src/netif/ppp/magic.c
----------------------------------------------------------------------
diff --git a/net/ip/lwip_base/src/netif/ppp/magic.c b/net/ip/lwip_base/src/netif/ppp/magic.c
new file mode 100644
index 0000000..d0d87c5
--- /dev/null
+++ b/net/ip/lwip_base/src/netif/ppp/magic.c
@@ -0,0 +1,294 @@
+/*
+ * magic.c - PPP Magic Number routines.
+ *
+ * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The name "Carnegie Mellon University" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For permission or any legal
+ *    details, please contact
+ *      Office of Technology Transfer
+ *      Carnegie Mellon University
+ *      5000 Forbes Avenue
+ *      Pittsburgh, PA  15213-3890
+ *      (412) 268-4387, fax: (412) 268-7395
+ *      tech-transfer@andrew.cmu.edu
+ *
+ * 4. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by Computing Services
+ *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
+ *
+ * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
+ * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
+ * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
+ * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+/*****************************************************************************
+* randm.c - Random number generator program file.
+*
+* Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
+* Copyright (c) 1998 by Global Election Systems Inc.
+*
+* The authors hereby grant permission to use, copy, modify, distribute,
+* and license this software and its documentation for any purpose, provided
+* that existing copyright notices are retained in all copies and that this
+* notice and the following disclaimer are included verbatim in any
+* distributions. No written agreement, license, or royalty fee is required
+* for any of the authorized uses.
+*
+* THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
+* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+* IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*
+******************************************************************************
+* REVISION HISTORY
+*
+* 03-01-01 Marc Boucher <ma...@mbsi.ca>
+*   Ported to lwIP.
+* 98-06-03 Guy Lancaster <la...@acm.org>, Global Election Systems Inc.
+*   Extracted from avos.
+*****************************************************************************/
+
+#include "netif/ppp/ppp_opts.h"
+#if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */
+
+#include "netif/ppp/ppp_impl.h"
+#include "netif/ppp/magic.h"
+
+#if PPP_MD5_RANDM /* Using MD5 for better randomness if enabled */
+
+#include "netif/ppp/pppcrypt.h"
+
+#define MD5_HASH_SIZE 16
+static char magic_randpool[MD5_HASH_SIZE];   /* Pool of randomness. */
+static long magic_randcount;      /* Pseudo-random incrementer */
+static u32_t magic_randomseed;    /* Seed used for random number generation. */
+
+/*
+ * Churn the randomness pool on a random event.  Call this early and often
+ *  on random and semi-random system events to build randomness in time for
+ *  usage.  For randomly timed events, pass a null pointer and a zero length
+ *  and this will use the system timer and other sources to add randomness.
+ *  If new random data is available, pass a pointer to that and it will be
+ *  included.
+ *
+ * Ref: Applied Cryptography 2nd Ed. by Bruce Schneier p. 427
+ */
+static void magic_churnrand(char *rand_data, u32_t rand_len) {
+  lwip_md5_context md5_ctx;
+
+  /* LWIP_DEBUGF(LOG_INFO, ("magic_churnrand: %u@%P\n", rand_len, rand_data)); */
+  lwip_md5_init(&md5_ctx);
+  lwip_md5_starts(&md5_ctx);
+  lwip_md5_update(&md5_ctx, (u_char *)magic_randpool, sizeof(magic_randpool));
+  if (rand_data) {
+    lwip_md5_update(&md5_ctx, (u_char *)rand_data, rand_len);
+  } else {
+    struct {
+      /* INCLUDE fields for any system sources of randomness */
+      u32_t jiffies;
+#ifdef LWIP_RAND
+      u32_t rand;
+#endif /* LWIP_RAND */
+    } sys_data;
+    magic_randomseed += sys_jiffies();
+    sys_data.jiffies = magic_randomseed;
+#ifdef LWIP_RAND
+    sys_data.rand = LWIP_RAND();
+#endif /* LWIP_RAND */
+    /* Load sys_data fields here. */
+    lwip_md5_update(&md5_ctx, (u_char *)&sys_data, sizeof(sys_data));
+  }
+  lwip_md5_finish(&md5_ctx, (u_char *)magic_randpool);
+  lwip_md5_free(&md5_ctx);
+/*  LWIP_DEBUGF(LOG_INFO, ("magic_churnrand: -> 0\n")); */
+}
+
+/*
+ * Initialize the random number generator.
+ */
+void magic_init(void) {
+  magic_churnrand(NULL, 0);
+}
+
+/*
+ * Randomize our random seed value.
+ */
+void magic_randomize(void) {
+  magic_churnrand(NULL, 0);
+}
+
+/*
+ * magic_random_bytes - Fill a buffer with random bytes.
+ *
+ * Use the random pool to generate random data.  This degrades to pseudo
+ *  random when used faster than randomness is supplied using magic_churnrand().
+ * Note: It's important that there be sufficient randomness in magic_randpool
+ *  before this is called for otherwise the range of the result may be
+ *  narrow enough to make a search feasible.
+ *
+ * Ref: Applied Cryptography 2nd Ed. by Bruce Schneier p. 427
+ *
+ * XXX Why does he not just call magic_churnrand() for each block?  Probably
+ *  so that you don't ever publish the seed which could possibly help
+ *  predict future values.
+ * XXX Why don't we preserve md5 between blocks and just update it with
+ *  magic_randcount each time?  Probably there is a weakness but I wish that
+ *  it was documented.
+ */
+void magic_random_bytes(unsigned char *buf, u32_t buf_len) {
+  lwip_md5_context md5_ctx;
+  u_char tmp[MD5_HASH_SIZE];
+  u32_t n;
+
+  while (buf_len > 0) {
+    lwip_md5_init(&md5_ctx);
+    lwip_md5_starts(&md5_ctx);
+    lwip_md5_update(&md5_ctx, (u_char *)magic_randpool, sizeof(magic_randpool));
+    lwip_md5_update(&md5_ctx, (u_char *)&magic_randcount, sizeof(magic_randcount));
+    lwip_md5_finish(&md5_ctx, tmp);
+    lwip_md5_free(&md5_ctx);
+    magic_randcount++;
+    n = LWIP_MIN(buf_len, MD5_HASH_SIZE);
+    MEMCPY(buf, tmp, n);
+    buf += n;
+    buf_len -= n;
+  }
+}
+
+/*
+ * Return a new random number.
+ */
+u32_t magic(void) {
+  u32_t new_rand;
+
+  magic_random_bytes((unsigned char *)&new_rand, sizeof(new_rand));
+
+  return new_rand;
+}
+
+#else /* PPP_MD5_RANDM */
+
+/*****************************/
+/*** LOCAL DATA STRUCTURES ***/
+/*****************************/
+#ifndef LWIP_RAND
+static int  magic_randomized;       /* Set when truely randomized. */
+#endif /* LWIP_RAND */
+static u32_t magic_randomseed;      /* Seed used for random number generation. */
+
+
+/***********************************/
+/*** PUBLIC FUNCTION DEFINITIONS ***/
+/***********************************/
+
+/*
+ * Initialize the random number generator.
+ *
+ * Here we attempt to compute a random number seed but even if
+ * it isn't random, we'll randomize it later.
+ *
+ * The current method uses the fields from the real time clock,
+ * the idle process counter, the millisecond counter, and the
+ * hardware timer tick counter.  When this is invoked
+ * in startup(), then the idle counter and timer values may
+ * repeat after each boot and the real time clock may not be
+ * operational.  Thus we call it again on the first random
+ * event.
+ */
+void magic_init(void) {
+  magic_randomseed += sys_jiffies();
+#ifndef LWIP_RAND
+  /* Initialize the Borland random number generator. */
+  srand((unsigned)magic_randomseed);
+#endif /* LWIP_RAND */
+}
+
+/*
+ * magic_init - Initialize the magic number generator.
+ *
+ * Randomize our random seed value.  Here we use the fact that
+ * this function is called at *truely random* times by the polling
+ * and network functions.  Here we only get 16 bits of new random
+ * value but we use the previous value to randomize the other 16
+ * bits.
+ */
+void magic_randomize(void) {
+#ifndef LWIP_RAND
+  if (!magic_randomized) {
+    magic_randomized = !0;
+    magic_init();
+    /* The initialization function also updates the seed. */
+  } else {
+#endif /* LWIP_RAND */
+    magic_randomseed += sys_jiffies();
+#ifndef LWIP_RAND
+  }
+#endif /* LWIP_RAND */
+}
+
+/*
+ * Return a new random number.
+ *
+ * Here we use the Borland rand() function to supply a pseudo random
+ * number which we make truely random by combining it with our own
+ * seed which is randomized by truely random events.
+ * Thus the numbers will be truely random unless there have been no
+ * operator or network events in which case it will be pseudo random
+ * seeded by the real time clock.
+ */
+u32_t magic(void) {
+#ifdef LWIP_RAND
+  return LWIP_RAND() + magic_randomseed;
+#else /* LWIP_RAND */
+  return ((u32_t)rand() << 16) + (u32_t)rand() + magic_randomseed;
+#endif /* LWIP_RAND */
+}
+
+/*
+ * magic_random_bytes - Fill a buffer with random bytes.
+ */
+void magic_random_bytes(unsigned char *buf, u32_t buf_len) {
+  u32_t new_rand, n;
+
+  while (buf_len > 0) {
+    new_rand = magic();
+    n = LWIP_MIN(buf_len, sizeof(new_rand));
+    MEMCPY(buf, &new_rand, n);
+    buf += n;
+    buf_len -= n;
+  }
+}
+#endif /* PPP_MD5_RANDM */
+
+/*
+ * Return a new random number between 0 and (2^pow)-1 included.
+ */
+u32_t magic_pow(u8_t pow) {
+  return magic() & ~(~0UL<<pow);
+}
+
+#endif /* PPP_SUPPORT */