Sam Walsh
Forked from the DieterGraef Library
Fork of
F7_Ethernet
by 
Dieter Graef
Diff: lwip/netif/ppp/ipcp.c
- Revision:
- 0:d26c1b55cfca
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/lwip/netif/ppp/ipcp.c Sun Jun 19 16:23:40 2016 +0000
@@ -0,0 +1,1411 @@
+/** In contrast to pppd 2.3.1, DNS support has been added, proxy-ARP and
+ dial-on-demand has been stripped. */
+/*****************************************************************************
+* ipcp.c - Network PPP IP Control Protocol program file.
+*
+* Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
+* portions Copyright (c) 1997 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 <marc@mbsi.ca>
+* Ported to lwIP.
+* 97-12-08 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.
+* Original.
+*****************************************************************************/
+/*
+ * 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.
+ */
+
+#include "lwip/opt.h"
+
+#if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */
+
+#include "ppp_impl.h"
+#include "pppdebug.h"
+
+#include "auth.h"
+#include "fsm.h"
+#include "vj.h"
+#include "ipcp.h"
+
+#include "lwip/inet.h"
+
+#include <string.h>
+
+/* #define OLD_CI_ADDRS 1 */ /* Support deprecated address negotiation. */
+
+/* global vars */
+ipcp_options ipcp_wantoptions[NUM_PPP]; /* Options that we want to request */
+ipcp_options ipcp_gotoptions[NUM_PPP]; /* Options that peer ack'd */
+ipcp_options ipcp_allowoptions[NUM_PPP]; /* Options we allow peer to request */
+ipcp_options ipcp_hisoptions[NUM_PPP]; /* Options that we ack'd */
+
+/* local vars */
+static int default_route_set[NUM_PPP]; /* Have set up a default route */
+static int cis_received[NUM_PPP]; /* # Conf-Reqs received */
+
+
+/*
+ * Callbacks for fsm code. (CI = Configuration Information)
+ */
+static void ipcp_resetci (fsm *); /* Reset our CI */
+static int ipcp_cilen (fsm *); /* Return length of our CI */
+static void ipcp_addci (fsm *, u_char *, int *); /* Add our CI */
+static int ipcp_ackci (fsm *, u_char *, int); /* Peer ack'd our CI */
+static int ipcp_nakci (fsm *, u_char *, int); /* Peer nak'd our CI */
+static int ipcp_rejci (fsm *, u_char *, int); /* Peer rej'd our CI */
+static int ipcp_reqci (fsm *, u_char *, int *, int); /* Rcv CI */
+static void ipcp_up (fsm *); /* We're UP */
+static void ipcp_down (fsm *); /* We're DOWN */
+#if PPP_ADDITIONAL_CALLBACKS
+static void ipcp_script (fsm *, char *); /* Run an up/down script */
+#endif
+static void ipcp_finished (fsm *); /* Don't need lower layer */
+
+
+fsm ipcp_fsm[NUM_PPP]; /* 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 LS_OPENED state */
+ ipcp_down, /* Called when fsm leaves LS_OPENED state */
+ NULL, /* Called when we want the lower layer up */
+ ipcp_finished, /* 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 */
+};
+
+/*
+ * Protocol entry points from main code.
+ */
+static void ipcp_init (int);
+static void ipcp_open (int);
+static void ipcp_close (int, char *);
+static void ipcp_lowerup (int);
+static void ipcp_lowerdown (int);
+static void ipcp_input (int, u_char *, int);
+static void ipcp_protrej (int);
+
+
+struct protent ipcp_protent = {
+ PPP_IPCP,
+ ipcp_init,
+ ipcp_input,
+ ipcp_protrej,
+ ipcp_lowerup,
+ ipcp_lowerdown,
+ ipcp_open,
+ ipcp_close,
+#if PPP_ADDITIONAL_CALLBACKS
+ ipcp_printpkt,
+ NULL,
+#endif /* PPP_ADDITIONAL_CALLBACKS */
+ 1,
+ "IPCP",
+#if PPP_ADDITIONAL_CALLBACKS
+ ip_check_options,
+ NULL,
+ ip_active_pkt
+#endif /* PPP_ADDITIONAL_CALLBACKS */
+};
+
+static void ipcp_clear_addrs (int);
+
+/*
+ * 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")
+
+
+/*
+ * ipcp_init - Initialize IPCP.
+ */
+static void
+ipcp_init(int unit)
+{
+ fsm *f = &ipcp_fsm[unit];
+ ipcp_options *wo = &ipcp_wantoptions[unit];
+ ipcp_options *ao = &ipcp_allowoptions[unit];
+
+ f->unit = unit;
+ f->protocol = PPP_IPCP;
+ f->callbacks = &ipcp_callbacks;
+ fsm_init(&ipcp_fsm[unit]);
+
+ memset(wo, 0, sizeof(*wo));
+ memset(ao, 0, sizeof(*ao));
+
+ wo->neg_addr = 1;
+ wo->ouraddr = 0;
+#if VJ_SUPPORT
+ wo->neg_vj = 1;
+#else /* VJ_SUPPORT */
+ wo->neg_vj = 0;
+#endif /* VJ_SUPPORT */
+ wo->vj_protocol = IPCP_VJ_COMP;
+ wo->maxslotindex = MAX_SLOTS - 1;
+ wo->cflag = 0;
+ wo->default_route = 1;
+
+ ao->neg_addr = 1;
+#if VJ_SUPPORT
+ ao->neg_vj = 1;
+#else /* VJ_SUPPORT */
+ ao->neg_vj = 0;
+#endif /* VJ_SUPPORT */
+ ao->maxslotindex = MAX_SLOTS - 1;
+ ao->cflag = 1;
+ ao->default_route = 1;
+}
+
+
+/*
+ * ipcp_open - IPCP is allowed to come up.
+ */
+static void
+ipcp_open(int unit)
+{
+ fsm_open(&ipcp_fsm[unit]);
+}
+
+
+/*
+ * ipcp_close - Take IPCP down.
+ */
+static void
+ipcp_close(int unit, char *reason)
+{
+ fsm_close(&ipcp_fsm[unit], reason);
+}
+
+
+/*
+ * ipcp_lowerup - The lower layer is up.
+ */
+static void
+ipcp_lowerup(int unit)
+{
+ fsm_lowerup(&ipcp_fsm[unit]);
+}
+
+
+/*
+ * ipcp_lowerdown - The lower layer is down.
+ */
+static void
+ipcp_lowerdown(int unit)
+{
+ fsm_lowerdown(&ipcp_fsm[unit]);
+}
+
+
+/*
+ * ipcp_input - Input IPCP packet.
+ */
+static void
+ipcp_input(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.
+ */
+static void
+ipcp_protrej(int unit)
+{
+ fsm_lowerdown(&ipcp_fsm[unit]);
+}
+
+
+/*
+ * ipcp_resetci - Reset our CI.
+ */
+static void
+ipcp_resetci(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;
+ }
+ /* Request DNS addresses from the peer */
+ wo->req_dns1 = ppp_settings.usepeerdns;
+ wo->req_dns2 = ppp_settings.usepeerdns;
+ ipcp_gotoptions[f->unit] = *wo;
+ cis_received[f->unit] = 0;
+}
+
+
+/*
+ * ipcp_cilen - Return length of our CI.
+ */
+static int
+ipcp_cilen(fsm *f)
+{
+ ipcp_options *go = &ipcp_gotoptions[f->unit];
+ ipcp_options *wo = &ipcp_wantoptions[f->unit];
+ ipcp_options *ho = &ipcp_hisoptions[f->unit];
+
+#define LENCIVJ(neg, old) (neg ? (old? CILEN_COMPRESS : CILEN_VJ) : 0)
+#define LENCIADDR(neg, old) (neg ? (old? CILEN_ADDRS : CILEN_ADDR) : 0)
+#define LENCIDNS(neg) (neg ? (CILEN_ADDR) : 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;
+ }
+ }
+ }
+
+ return (LENCIADDR(go->neg_addr, go->old_addrs) +
+ LENCIVJ(go->neg_vj, go->old_vj) +
+ LENCIDNS(go->req_dns1) +
+ LENCIDNS(go->req_dns2));
+}
+
+
+/*
+ * ipcp_addci - Add our desired CIs to a packet.
+ */
+static void
+ipcp_addci(fsm *f, u_char *ucp, int *lenp)
+{
+ ipcp_options *go = &ipcp_gotoptions[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) { \
+ u32_t 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; \
+ } \
+ }
+
+#define ADDCIDNS(opt, neg, addr) \
+ if (neg) { \
+ if (len >= CILEN_ADDR) { \
+ u32_t l; \
+ PUTCHAR(opt, ucp); \
+ PUTCHAR(CILEN_ADDR, ucp); \
+ l = ntohl(addr); \
+ PUTLONG(l, ucp); \
+ len -= CILEN_ADDR; \
+ } else { \
+ neg = 0; \
+ } \
+ }
+
+ 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);
+
+ ADDCIDNS(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]);
+
+ ADDCIDNS(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
+
+ *lenp -= len;
+}
+
+
+/*
+ * ipcp_ackci - Ack our CIs.
+ *
+ * Returns:
+ * 0 - Ack was bad.
+ * 1 - Ack was good.
+ */
+static int
+ipcp_ackci(fsm *f, u_char *p, int len)
+{
+ ipcp_options *go = &ipcp_gotoptions[f->unit];
+ u_short cilen, citype, cishort;
+ u32_t 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); \
+ u32_t 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; \
+ } \
+ } \
+ }
+
+#define ACKCIDNS(opt, neg, addr) \
+ if (neg) { \
+ u32_t l; \
+ if ((len -= CILEN_ADDR) < 0) { \
+ goto bad; \
+ } \
+ GETCHAR(citype, p); \
+ GETCHAR(cilen, p); \
+ if (cilen != CILEN_ADDR || \
+ citype != opt) { \
+ goto bad; \
+ } \
+ GETLONG(l, p); \
+ cilong = htonl(l); \
+ if (addr != 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);
+
+ ACKCIDNS(CI_MS_DNS1, go->req_dns1, go->dnsaddr[0]);
+
+ ACKCIDNS(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
+
+ /*
+ * 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!\n"));
+ 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 LS_OPENED state.
+ *
+ * Returns:
+ * 0 - Nak was bad.
+ * 1 - Nak was good.
+ */
+static int
+ipcp_nakci(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;
+ u32_t ciaddr1, ciaddr2, l, cidnsaddr;
+ 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 \
+ }
+
+#define NAKCIDNS(opt, neg, code) \
+ if (go->neg && \
+ ((cilen = p[1]) == CILEN_ADDR) && \
+ len >= cilen && \
+ p[0] == opt) { \
+ len -= cilen; \
+ INCPTR(2, p); \
+ GETLONG(l, p); \
+ cidnsaddr = htonl(l); \
+ 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((go->old_addrs? CI_ADDRS: 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\n",
+ inet_ntoa(ciaddr1)));
+ }
+ if (go->accept_remote && ciaddr2) { /* Does he know his? */
+ try.hisaddr = ciaddr2;
+ IPCPDEBUG(LOG_INFO, ("remote IP address %s\n",
+ inet_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;
+ }
+ }
+ );
+
+ NAKCIDNS(CI_MS_DNS1, req_dns1,
+ try.dnsaddr[0] = cidnsaddr;
+ IPCPDEBUG(LOG_INFO, ("primary DNS address %s\n", inet_ntoa(cidnsaddr)));
+ );
+
+ NAKCIDNS(CI_MS_DNS2, req_dns2,
+ try.dnsaddr[1] = cidnsaddr;
+ IPCPDEBUG(LOG_INFO, ("secondary DNS address %s\n", inet_ntoa(cidnsaddr)));
+ );
+
+ /*
+ * 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.old_addrs = 0;
+ GETLONG(l, p);
+ ciaddr1 = htonl(l);
+ if (ciaddr1 && go->accept_local) {
+ try.ouraddr = ciaddr1;
+ }
+ if (try.ouraddr != 0) {
+ try.neg_addr = 1;
+ }
+ no.neg_addr = 1;
+ break;
+ }
+ 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 != LS_OPENED) {
+ *go = try;
+ }
+
+ return 1;
+
+bad:
+ IPCPDEBUG(LOG_INFO, ("ipcp_nakci: received bad Nak!\n"));
+ return 0;
+}
+
+
+/*
+ * ipcp_rejci - Reject some of our CIs.
+ */
+static int
+ipcp_rejci(fsm *f, u_char *p, int len)
+{
+ ipcp_options *go = &ipcp_gotoptions[f->unit];
+ u_char cimaxslotindex, ciflag, cilen;
+ u_short cishort;
+ u32_t 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) { \
+ u32_t 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; \
+ }
+
+#define REJCIDNS(opt, neg, dnsaddr) \
+ if (go->neg && \
+ ((cilen = p[1]) == CILEN_ADDR) && \
+ len >= cilen && \
+ p[0] == opt) { \
+ u32_t l; \
+ len -= cilen; \
+ INCPTR(2, p); \
+ GETLONG(l, p); \
+ cilong = htonl(l); \
+ /* Check rejected value. */ \
+ if (cilong != dnsaddr) { \
+ 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);
+
+ REJCIDNS(CI_MS_DNS1, req_dns1, go->dnsaddr[0]);
+
+ REJCIDNS(CI_MS_DNS2, req_dns2, go->dnsaddr[1]);
+
+ /*
+ * If there are any remaining CIs, then this packet is bad.
+ */
+ if (len != 0) {
+ goto bad;
+ }
+ /*
+ * Now we can update state.
+ */
+ if (f->state != LS_OPENED) {
+ *go = try;
+ }
+ return 1;
+
+bad:
+ IPCPDEBUG(LOG_INFO, ("ipcp_rejci: received bad Reject!\n"));
+ 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(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];
+#ifdef OLD_CI_ADDRS
+ ipcp_options *go = &ipcp_gotoptions[f->unit];
+#endif
+ u_char *cip, *next; /* Pointer to current and next CIs */
+ u_short cilen, citype; /* Parsed len, type */
+ u_short cishort; /* Parsed short value */
+ u32_t tl, ciaddr1; /* Parsed address values */
+#ifdef OLD_CI_ADDRS
+ u32_t ciaddr2; /* Parsed address values */
+#endif
+ 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;
+ int d;
+
+ cis_received[f->unit] = 1;
+
+ /*
+ * 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!\n"));
+ orc = CONFREJ; /* Reject bad CI */
+ cilen = (u_short)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 */
+#ifdef OLD_CI_ADDRS /* Need to save space... */
+ case CI_ADDRS:
+ IPCPDEBUG(LOG_INFO, ("ipcp_reqci: received ADDRS\n"));
+ 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, ("his addr %s\n", inet_ntoa(ciaddr1)));
+ if (ciaddr1 != wo->hisaddr
+ && (ciaddr1 == 0 || !wo->accept_remote)) {
+ orc = CONFNAK;
+ if (!reject_if_disagree) {
+ DECPTR(sizeof(u32_t), p);
+ tl = ntohl(wo->hisaddr);
+ PUTLONG(tl, p);
+ }
+ } else if (ciaddr1 == 0 && wo->hisaddr == 0) {
+ /*
+ * If neither we nor he knows his address, reject the option.
+ */
+ orc = CONFREJ;
+ wo->req_addr = 0; /* don't NAK with 0.0.0.0 later */
+ break;
+ }
+
+ /*
+ * 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, ("our addr %s\n", inet_ntoa(ciaddr2)));
+ if (ciaddr2 != wo->ouraddr) {
+ if (ciaddr2 == 0 || !wo->accept_local) {
+ orc = CONFNAK;
+ if (!reject_if_disagree) {
+ DECPTR(sizeof(u32_t), 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;
+#endif
+
+ case CI_ADDR:
+ if (!ao->neg_addr) {
+ IPCPDEBUG(LOG_INFO, ("ipcp_reqci: Reject ADDR not allowed\n"));
+ orc = CONFREJ; /* Reject CI */
+ break;
+ } else if (cilen != CILEN_ADDR) { /* Check CI length */
+ IPCPDEBUG(LOG_INFO, ("ipcp_reqci: Reject ADDR bad len\n"));
+ 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);
+ if (ciaddr1 != wo->hisaddr
+ && (ciaddr1 == 0 || !wo->accept_remote)) {
+ orc = CONFNAK;
+ if (!reject_if_disagree) {
+ DECPTR(sizeof(u32_t), p);
+ tl = ntohl(wo->hisaddr);
+ PUTLONG(tl, p);
+ }
+ IPCPDEBUG(LOG_INFO, ("ipcp_reqci: Nak ADDR %s\n", inet_ntoa(ciaddr1)));
+ } else if (ciaddr1 == 0 && wo->hisaddr == 0) {
+ /*
+ * Don't ACK an address of 0.0.0.0 - reject it instead.
+ */
+ IPCPDEBUG(LOG_INFO, ("ipcp_reqci: Reject ADDR %s\n", inet_ntoa(ciaddr1)));
+ orc = CONFREJ;
+ wo->req_addr = 0; /* don't NAK with 0.0.0.0 later */
+ break;
+ }
+
+ ho->neg_addr = 1;
+ ho->hisaddr = ciaddr1;
+ IPCPDEBUG(LOG_INFO, ("ipcp_reqci: ADDR %s\n", inet_ntoa(ciaddr1)));
+ break;
+
+ case CI_MS_DNS1:
+ case CI_MS_DNS2:
+ /* Microsoft primary or secondary DNS request */
+ d = citype == CI_MS_DNS2;
+
+ /* If we do not have a DNS address then we cannot send it */
+ if (ao->dnsaddr[d] == 0 ||
+ cilen != CILEN_ADDR) { /* Check CI length */
+ IPCPDEBUG(LOG_INFO, ("ipcp_reqci: Rejecting DNS%d Request\n", d+1));
+ orc = CONFREJ; /* Reject CI */
+ break;
+ }
+ GETLONG(tl, p);
+ if (htonl(tl) != ao->dnsaddr[d]) {
+ IPCPDEBUG(LOG_INFO, ("ipcp_reqci: Naking DNS%d Request %s\n",
+ d+1, inet_ntoa(tl)));
+ DECPTR(sizeof(u32_t), p);
+ tl = ntohl(ao->dnsaddr[d]);
+ PUTLONG(tl, p);
+ orc = CONFNAK;
+ }
+ IPCPDEBUG(LOG_INFO, ("ipcp_reqci: received DNS%d Request\n", d+1));
+ break;
+
+ case CI_MS_WINS1:
+ case CI_MS_WINS2:
+ /* Microsoft primary or secondary WINS request */
+ d = citype == CI_MS_WINS2;
+ IPCPDEBUG(LOG_INFO, ("ipcp_reqci: received WINS%d Request\n", d+1));
+
+ /* If we do not have a DNS address then we cannot send it */
+ if (ao->winsaddr[d] == 0 ||
+ cilen != CILEN_ADDR) { /* Check CI length */
+ orc = CONFREJ; /* Reject CI */
+ break;
+ }
+ GETLONG(tl, p);
+ if (htonl(tl) != ao->winsaddr[d]) {
+ DECPTR(sizeof(u32_t), p);
+ tl = ntohl(ao->winsaddr[d]);
+ PUTLONG(tl, p);
+ orc = CONFNAK;
+ }
+ break;
+
+ case CI_COMPRESSTYPE:
+ if (!ao->neg_vj) {
+ IPCPDEBUG(LOG_INFO, ("ipcp_reqci: Rejecting COMPRESSTYPE not allowed\n"));
+ orc = CONFREJ;
+ break;
+ } else if (cilen != CILEN_VJ && cilen != CILEN_COMPRESS) {
+ IPCPDEBUG(LOG_INFO, ("ipcp_reqci: Rejecting COMPRESSTYPE len=%d\n", cilen));
+ orc = CONFREJ;
+ break;
+ }
+ GETSHORT(cishort, p);
+
+ if (!(cishort == IPCP_VJ_COMP ||
+ (cishort == IPCP_VJ_COMP_OLD && cilen == CILEN_COMPRESS))) {
+ IPCPDEBUG(LOG_INFO, ("ipcp_reqci: Rejecting COMPRESSTYPE %d\n", cishort));
+ orc = CONFREJ;
+ break;
+ }
+
+ ho->neg_vj = 1;
+ ho->vj_protocol = cishort;
+ if (cilen == CILEN_VJ) {
+ GETCHAR(maxslotindex, p);
+ if (maxslotindex > ao->maxslotindex) {
+ IPCPDEBUG(LOG_INFO, ("ipcp_reqci: Naking VJ max slot %d\n", maxslotindex));
+ orc = CONFNAK;
+ if (!reject_if_disagree) {
+ DECPTR(1, p);
+ PUTCHAR(ao->maxslotindex, p);
+ }
+ }
+ GETCHAR(cflag, p);
+ if (cflag && !ao->cflag) {
+ IPCPDEBUG(LOG_INFO, ("ipcp_reqci: Naking VJ cflag %d\n", cflag));
+ orc = CONFNAK;
+ if (!reject_if_disagree) {
+ DECPTR(1, p);
+ PUTCHAR(wo->cflag, p);
+ }
+ }
+ ho->maxslotindex = maxslotindex;
+ ho->cflag = cflag;
+ } else {
+ ho->old_vj = 1;
+ ho->maxslotindex = MAX_SLOTS - 1;
+ ho->cflag = 1;
+ }
+ IPCPDEBUG(LOG_INFO, (
+ "ipcp_reqci: received COMPRESSTYPE p=%d old=%d maxslot=%d cflag=%d\n",
+ ho->vj_protocol, ho->old_vj, ho->maxslotindex, ho->cflag));
+ break;
+
+ default:
+ IPCPDEBUG(LOG_INFO, ("ipcp_reqci: Rejecting unknown CI type %d\n", 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? */
+ IPCPDEBUG(LOG_INFO, ("ipcp_reqci: Rejecting too many naks\n"));
+ 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) {
+ IPCPDEBUG(LOG_INFO, ("ipcp_reqci: Requesting peer address\n"));
+ 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 = (int)(ucp - inp); /* Compute output length */
+ IPCPDEBUG(LOG_INFO, ("ipcp_reqci: returning Configure-%s\n", CODENAME(rc)));
+ return (rc); /* Return final code */
+}
+
+
+#if 0
+/*
+ * ip_check_options - check that any IP-related options are OK,
+ * and assign appropriate defaults.
+ */
+static void
+ip_check_options(u_long localAddr)
+{
+ ipcp_options *wo = &ipcp_wantoptions[0];
+
+ /*
+ * Load our default IP address but allow the remote host to give us
+ * a new address.
+ */
+ if (wo->ouraddr == 0 && !ppp_settings.disable_defaultip) {
+ wo->accept_local = 1; /* don't insist on this default value */
+ wo->ouraddr = htonl(localAddr);
+ }
+}
+#endif
+
+
+/*
+ * ipcp_up - IPCP has come UP.
+ *
+ * Configure the IP network interface appropriately and bring it up.
+ */
+static void
+ipcp_up(fsm *f)
+{
+ u32_t mask;
+ ipcp_options *ho = &ipcp_hisoptions[f->unit];
+ ipcp_options *go = &ipcp_gotoptions[f->unit];
+ ipcp_options *wo = &ipcp_wantoptions[f->unit];
+
+ np_up(f->unit, PPP_IP);
+ IPCPDEBUG(LOG_INFO, ("ipcp: up\n"));
+
+ /*
+ * We must have a non-zero IP address for both ends of the link.
+ */
+ if (!ho->neg_addr) {
+ ho->hisaddr = wo->hisaddr;
+ }
+
+ if (ho->hisaddr == 0) {
+ IPCPDEBUG(LOG_ERR, ("Could not determine remote IP address\n"));
+ ipcp_close(f->unit, "Could not determine remote IP address");
+ return;
+ }
+ if (go->ouraddr == 0) {
+ IPCPDEBUG(LOG_ERR, ("Could not determine local IP address\n"));
+ ipcp_close(f->unit, "Could not determine local IP address");
+ return;
+ }
+
+ if (ppp_settings.usepeerdns && (go->dnsaddr[0] || go->dnsaddr[1])) {
+ /*pppGotDNSAddrs(go->dnsaddr[0], go->dnsaddr[1]);*/
+ }
+
+ /*
+ * Check that the peer is allowed to use the IP address it wants.
+ */
+ if (!auth_ip_addr(f->unit, ho->hisaddr)) {
+ IPCPDEBUG(LOG_ERR, ("Peer is not authorized to use remote address %s\n",
+ inet_ntoa(ho->hisaddr)));
+ ipcp_close(f->unit, "Unauthorized remote IP address");
+ return;
+ }
+
+ /* set tcp compression */
+ sifvjcomp(f->unit, ho->neg_vj, ho->cflag, ho->maxslotindex);
+
+ /*
+ * Set IP addresses and (if specified) netmask.
+ */
+ mask = GetMask(go->ouraddr);
+
+ if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask, go->dnsaddr[0], go->dnsaddr[1])) {
+ IPCPDEBUG(LOG_WARNING, ("sifaddr failed\n"));
+ ipcp_close(f->unit, "Interface configuration failed");
+ return;
+ }
+
+ /* bring the interface up for IP */
+ if (!sifup(f->unit)) {
+ IPCPDEBUG(LOG_WARNING, ("sifup failed\n"));
+ ipcp_close(f->unit, "Interface configuration failed");
+ return;
+ }
+
+ sifnpmode(f->unit, PPP_IP, NPMODE_PASS);
+
+ /* assign a default route through the interface if required */
+ if (ipcp_wantoptions[f->unit].default_route) {
+ if (sifdefaultroute(f->unit, go->ouraddr, ho->hisaddr)) {
+ default_route_set[f->unit] = 1;
+ }
+ }
+
+ IPCPDEBUG(LOG_NOTICE, ("local IP address %s\n", inet_ntoa(go->ouraddr)));
+ IPCPDEBUG(LOG_NOTICE, ("remote IP address %s\n", inet_ntoa(ho->hisaddr)));
+ if (go->dnsaddr[0]) {
+ IPCPDEBUG(LOG_NOTICE, ("primary DNS address %s\n", inet_ntoa(go->dnsaddr[0])));
+ }
+ if (go->dnsaddr[1]) {
+ IPCPDEBUG(LOG_NOTICE, ("secondary DNS address %s\n", inet_ntoa(go->dnsaddr[1])));
+ }
+}
+
+
+/*
+ * ipcp_down - IPCP has gone DOWN.
+ *
+ * Take the IP network interface down, clear its addresses
+ * and delete routes through it.
+ */
+static void
+ipcp_down(fsm *f)
+{
+ IPCPDEBUG(LOG_INFO, ("ipcp: down\n"));
+ np_down(f->unit, PPP_IP);
+ sifvjcomp(f->unit, 0, 0, 0);
+
+ sifdown(f->unit);
+ ipcp_clear_addrs(f->unit);
+}
+
+
+/*
+ * ipcp_clear_addrs() - clear the interface addresses, routes, etc.
+ */
+static void
+ipcp_clear_addrs(int unit)
+{
+ u32_t ouraddr, hisaddr;
+
+ ouraddr = ipcp_gotoptions[unit].ouraddr;
+ hisaddr = ipcp_hisoptions[unit].hisaddr;
+ if (default_route_set[unit]) {
+ cifdefaultroute(unit, ouraddr, hisaddr);
+ default_route_set[unit] = 0;
+ }
+ cifaddr(unit, ouraddr, hisaddr);
+}
+
+
+/*
+ * ipcp_finished - possibly shut down the lower layers.
+ */
+static void
+ipcp_finished(fsm *f)
+{
+ np_finished(f->unit, PPP_IP);
+}
+
+#if PPP_ADDITIONAL_CALLBACKS
+static int
+ipcp_printpkt(u_char *p, int plen, void (*printer) (void *, char *, ...), void *arg)
+{
+ LWIP_UNUSED_ARG(p);
+ LWIP_UNUSED_ARG(plen);
+ LWIP_UNUSED_ARG(printer);
+ LWIP_UNUSED_ARG(arg);
+ return 0;
+}
+
+/*
+ * ip_active_pkt - see if this IP packet is worth bringing the link up for.
+ * We don't bring the link up for IP fragments or for TCP FIN packets
+ * with no data.
+ */
+#define IP_HDRLEN 20 /* bytes */
+#define IP_OFFMASK 0x1fff
+#define IPPROTO_TCP 6
+#define TCP_HDRLEN 20
+#define TH_FIN 0x01
+
+/*
+ * We use these macros because the IP header may be at an odd address,
+ * and some compilers might use word loads to get th_off or ip_hl.
+ */
+
+#define net_short(x) (((x)[0] << 8) + (x)[1])
+#define get_iphl(x) (((unsigned char *)(x))[0] & 0xF)
+#define get_ipoff(x) net_short((unsigned char *)(x) + 6)
+#define get_ipproto(x) (((unsigned char *)(x))[9])
+#define get_tcpoff(x) (((unsigned char *)(x))[12] >> 4)
+#define get_tcpflags(x) (((unsigned char *)(x))[13])
+
+static int
+ip_active_pkt(u_char *pkt, int len)
+{
+ u_char *tcp;
+ int hlen;
+
+ len -= PPP_HDRLEN;
+ pkt += PPP_HDRLEN;
+ if (len < IP_HDRLEN) {
+ return 0;
+ }
+ if ((get_ipoff(pkt) & IP_OFFMASK) != 0) {
+ return 0;
+ }
+ if (get_ipproto(pkt) != IPPROTO_TCP) {
+ return 1;
+ }
+ hlen = get_iphl(pkt) * 4;
+ if (len < hlen + TCP_HDRLEN) {
+ return 0;
+ }
+ tcp = pkt + hlen;
+ if ((get_tcpflags(tcp) & TH_FIN) != 0 && len == hlen + get_tcpoff(tcp) * 4) {
+ return 0;
+ }
+ return 1;
+}
+#endif /* PPP_ADDITIONAL_CALLBACKS */
+
+#endif /* PPP_SUPPORT */