text: /*****************************************************************************
  * auth.c - Network Authentication and Phase Control program file.
  *
  * Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
  * Copyright (c) 1997 by Global Election Systems Inc.  All rights reserved.
  *
  * 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.
  *   Ported from public pppd code.
  *****************************************************************************/
  /*
   * auth.c - PPP authentication and phase control.
   *
   * Copyright (c) 1993 The Australian National 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 the Australian National 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.
   *
   * 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.h"
  #include "pppdebug.h"
  
  #include "fsm.h"
  #include "lcp.h"
  #include "pap.h"
  #include "chap.h"
  #include "auth.h"
  #include "ipcp.h"
  
  #if CBCP_SUPPORT
  #include "cbcp.h"
  #endif /* CBCP_SUPPORT */
  
  #include "lwip/inet.h"
  
  #include <string.h>
  
  #if 0 /* UNUSED */
  /* Bits in scan_authfile return value */
  #define NONWILD_SERVER  1
  #define NONWILD_CLIENT  2
  
  #define ISWILD(word)  (word[0] == '*' && word[1] == 0)
  #endif /* UNUSED */
  
  #if PAP_SUPPORT || CHAP_SUPPORT
  /* The name by which the peer authenticated itself to us. */
  static char peer_authname[MAXNAMELEN];
  #endif /* PAP_SUPPORT || CHAP_SUPPORT */
  
  /* Records which authentication operations haven't completed yet. */
  static int auth_pending[NUM_PPP];
  
  /* Set if we have successfully called plogin() */
  static int logged_in;
  
  /* Set if we have run the /etc/ppp/auth-up script. */
  static int did_authup; /* @todo, we don't need this in lwip*/
  
  /* List of addresses which the peer may use. */
  static struct wordlist *addresses[NUM_PPP];
  
  #if 0 /* UNUSED */
  /* Wordlist giving addresses which the peer may use
     without authenticating itself. */
  static struct wordlist *noauth_addrs;
  
  /* Extra options to apply, from the secrets file entry for the peer. */
  static struct wordlist *extra_options;
  #endif /* UNUSED */
  
  /* Number of network protocols which we have opened. */
  static int num_np_open;
  
  /* Number of network protocols which have come up. */
  static int num_np_up;
  
  #if PAP_SUPPORT || CHAP_SUPPORT
  /* Set if we got the contents of passwd[] from the pap-secrets file. */
  static int passwd_from_file;
  #endif /* PAP_SUPPORT || CHAP_SUPPORT */
  
  #if 0 /* UNUSED */
  /* Set if we require authentication only because we have a default route. */
  static bool default_auth;
  
  /* Hook to enable a plugin to control the idle time limit */
  int (*idle_time_hook) __P((struct ppp_idle *)) = NULL;
  
  /* Hook for a plugin to say whether we can possibly authenticate any peer */
  int (*pap_check_hook) __P((void)) = NULL;
  
  /* Hook for a plugin to check the PAP user and password */
  int (*pap_auth_hook) __P((char *user, char *passwd, char **msgp,
          struct wordlist **paddrs,
          struct wordlist **popts)) = NULL;
  
  /* Hook for a plugin to know about the PAP user logout */
  void (*pap_logout_hook) __P((void)) = NULL;
  
  /* Hook for a plugin to get the PAP password for authenticating us */
  int (*pap_passwd_hook) __P((char *user, char *passwd)) = NULL;
  
  /*
   * This is used to ensure that we don't start an auth-up/down
   * script while one is already running.
   */
  enum script_state {
      s_down,
      s_up
  };
  
  static enum script_state auth_state = s_down;
  static enum script_state auth_script_state = s_down;
  static pid_t auth_script_pid = 0;
  
  /*
   * Option variables.
   * lwip: some of these are present in the ppp_settings structure
   */
  bool uselogin = 0;            /* Use /etc/passwd for checking PAP */
  bool cryptpap = 0;            /* Passwords in pap-secrets are encrypted */
  bool refuse_pap = 0;          /* Don't wanna auth. ourselves with PAP */
  bool refuse_chap = 0;         /* Don't wanna auth. ourselves with CHAP */
  bool usehostname = 0;         /* Use hostname for our_name */
  bool auth_required = 0;       /* Always require authentication from peer */
  bool allow_any_ip = 0;        /* Allow peer to use any IP address */
  bool explicit_remote = 0;     /* User specified explicit remote name */
  char remote_name[MAXNAMELEN]; /* Peer's name for authentication */
  
  #endif /* UNUSED */
  
  /* Bits in auth_pending[] */
  #define PAP_WITHPEER    1
  #define PAP_PEER        2
  #define CHAP_WITHPEER   4
  #define CHAP_PEER       8
  
  /* @todo, move this somewhere */
  /* Used for storing a sequence of words.  Usually malloced. */
  struct wordlist {
    struct wordlist *next;
    char        word[1];
  };
  
  
  extern char *crypt (const char *, const char *);
  
  /* Prototypes for procedures local to this file. */
  
  static void network_phase (int);
  static void check_idle (void *);
  static void connect_time_expired (void *);
  #if 0
  static int  plogin (char *, char *, char **, int *);
  #endif
  static void plogout (void);
  static int  null_login (int);
  static int  get_pap_passwd (int, char *, char *);
  static int  have_pap_secret (void);
  static int  have_chap_secret (char *, char *, u32_t);
  static int  ip_addr_check (u32_t, struct wordlist *);
  
  #if 0 /* PAP_SUPPORT || CHAP_SUPPORT */
  static int  scan_authfile (FILE *, char *, char *, char *,
               struct wordlist **, struct wordlist **,
               char *);
  static void free_wordlist (struct wordlist *);
  static void auth_script (char *);
  static void auth_script_done (void *);
  static void set_allowed_addrs (int unit, struct wordlist *addrs);
  static int  some_ip_ok (struct wordlist *);
  static int  setupapfile (char **);
  static int  privgroup (char **);
  static int  set_noauth_addr (char **);
  static void check_access (FILE *, char *);
  #endif /* 0 */ /* PAP_SUPPORT || CHAP_SUPPORT */
  
  #if 0 /* UNUSED */
  /*
   * Authentication-related options.
   */
  option_t auth_options[] = {
      { "require-pap", o_bool, &lcp_wantoptions[0].neg_upap,
        "Require PAP authentication from peer", 1, &auth_required },
      { "+pap", o_bool, &lcp_wantoptions[0].neg_upap,
        "Require PAP authentication from peer", 1, &auth_required },
      { "refuse-pap", o_bool, &refuse_pap,
        "Don't agree to auth to peer with PAP", 1 },
      { "-pap", o_bool, &refuse_pap,
        "Don't allow PAP authentication with peer", 1 },
      { "require-chap", o_bool, &lcp_wantoptions[0].neg_chap,
        "Require CHAP authentication from peer", 1, &auth_required },
      { "+chap", o_bool, &lcp_wantoptions[0].neg_chap,
        "Require CHAP authentication from peer", 1, &auth_required },
      { "refuse-chap", o_bool, &refuse_chap,
        "Don't agree to auth to peer with CHAP", 1 },
      { "-chap", o_bool, &refuse_chap,
        "Don't allow CHAP authentication with peer", 1 },
      { "name", o_string, our_name,
        "Set local name for authentication",
        OPT_PRIV|OPT_STATIC, NULL, MAXNAMELEN },
      { "user", o_string, user,
        "Set name for auth with peer", OPT_STATIC, NULL, MAXNAMELEN },
      { "usehostname", o_bool, &usehostname,
        "Must use hostname for authentication", 1 },
      { "remotename", o_string, remote_name,
        "Set remote name for authentication", OPT_STATIC,
        &explicit_remote, MAXNAMELEN },
      { "auth", o_bool, &auth_required,
        "Require authentication from peer", 1 },
      { "noauth", o_bool, &auth_required,
        "Don't require peer to authenticate", OPT_PRIV, &allow_any_ip },
      {  "login", o_bool, &uselogin,
        "Use system password database for PAP", 1 },
      { "papcrypt", o_bool, &cryptpap,
        "PAP passwords are encrypted", 1 },
      { "+ua", o_special, (void *)setupapfile,
        "Get PAP user and password from file" },
      { "password", o_string, passwd,
        "Password for authenticating us to the peer", OPT_STATIC,
        NULL, MAXSECRETLEN },
      { "privgroup", o_special, (void *)privgroup,
        "Allow group members to use privileged options", OPT_PRIV },
      { "allow-ip", o_special, (void *)set_noauth_addr,
        "Set IP address(es) which can be used without authentication",
        OPT_PRIV },
      { NULL }
  };
  #endif /* UNUSED */
  #if 0 /* UNUSED */
  /*
   * setupapfile - specifies UPAP info for authenticating with peer.
   */
  static int
  setupapfile(char **argv)
  {
      FILE * ufile;
      int l;
  
      lcp_allowoptions[0].neg_upap = 1;
  
      /* open user info file */
      seteuid(getuid());
      ufile = fopen(*argv, "r");
      seteuid(0);
      if (ufile == NULL) {
        option_error("unable to open user login data file %s", *argv);
        return 0;
      }
      check_access(ufile, *argv);
  
      /* get username */
      if (fgets(user, MAXNAMELEN - 1, ufile) == NULL
          || fgets(passwd, MAXSECRETLEN - 1, ufile) == NULL){
        option_error("unable to read user login data file %s", *argv);
        return 0;
      }
      fclose(ufile);
  
      /* get rid of newlines */
      l = strlen(user);
      if (l > 0 && user[l-1] == '\n')
        user[l-1] = 0;
      l = strlen(passwd);
      if (l > 0 && passwd[l-1] == '\n')
        passwd[l-1] = 0;
  
      return (1);
  }
  #endif /* UNUSED */
  
  #if 0 /* UNUSED */
  /*
   * privgroup - allow members of the group to have privileged access.
   */
  static int
  privgroup(char **argv)
  {
      struct group *g;
      int i;
  
      g = getgrnam(*argv);
      if (g == 0) {
        option_error("group %s is unknown", *argv);
        return 0;
      }
      for (i = 0; i < ngroups; ++i) {
        if (groups[i] == g->gr_gid) {
          privileged = 1;
          break;
        }
      }
      return 1;
  }
  #endif
  
  #if 0 /* UNUSED */
  /*
   * set_noauth_addr - set address(es) that can be used without authentication.
   * Equivalent to specifying an entry like `"" * "" addr' in pap-secrets.
   */
  static int
  set_noauth_addr(char **argv)
  {
      char *addr = *argv;
      int l = strlen(addr);
      struct wordlist *wp;
  
      wp = (struct wordlist *) malloc(sizeof(struct wordlist) + l + 1);
      if (wp == NULL)
        novm("allow-ip argument");
      wp->word = (char *) (wp + 1);
      wp->next = noauth_addrs;
      BCOPY(addr, wp->word, l);
      noauth_addrs = wp;
      return 1;
  }
  #endif /* UNUSED */
  
  /*
   * An Open on LCP has requested a change from Dead to Establish phase.
   * Do what's necessary to bring the physical layer up.
   */
  void
  link_required(int unit)
  {
    LWIP_UNUSED_ARG(unit);
  
    AUTHDEBUG(LOG_INFO, ("link_required: %d\n", unit));
  }
  
  /*
   * LCP has terminated the link; go to the Dead phase and take the
   * physical layer down.
   */
  void
  link_terminated(int unit)
  {
    AUTHDEBUG(LOG_INFO, ("link_terminated: %d\n", unit));
    if (lcp_phase[unit] == PHASE_DEAD) {
      return;
    }
    if (logged_in) {
      plogout();
    }
    lcp_phase[unit] = PHASE_DEAD;
    AUTHDEBUG(LOG_NOTICE, ("Connection terminated.\n"));
    pppLinkTerminated(unit);
  }
  
  /*
   * LCP has gone down; it will either die or try to re-establish.
   */
  void
  link_down(int unit)
  {
    int i;
    struct protent *protp;
  
    AUTHDEBUG(LOG_INFO, ("link_down: %d\n", unit));
  
    if (did_authup) {
      /* XXX Do link down processing. */
      did_authup = 0;
    }
    for (i = 0; (protp = ppp_protocols[i]) != NULL; ++i) {
      if (!protp->enabled_flag) {
        continue;
      }
      if (protp->protocol != PPP_LCP && protp->lowerdown != NULL) {
        (*protp->lowerdown)(unit);
      }
      if (protp->protocol < 0xC000 && protp->close != NULL) {
        (*protp->close)(unit, "LCP down");
      }
    }
    num_np_open = 0;  /* number of network protocols we have opened */
    num_np_up = 0;    /* Number of network protocols which have come up */
  
    if (lcp_phase[unit] != PHASE_DEAD) {
      lcp_phase[unit] = PHASE_TERMINATE;
    }
    pppLinkDown(unit);
  }
  
  /*
   * The link is established.
   * Proceed to the Dead, Authenticate or Network phase as appropriate.
   */
  void
  link_established(int unit)
  {
    int auth;
    int i;
    struct protent *protp;
    lcp_options *wo = &lcp_wantoptions[unit];
    lcp_options *go = &lcp_gotoptions[unit];
  #if PAP_SUPPORT || CHAP_SUPPORT
    lcp_options *ho = &lcp_hisoptions[unit];
  #endif /* PAP_SUPPORT || CHAP_SUPPORT */
  
    AUTHDEBUG(LOG_INFO, ("link_established: unit %d; Lowering up all protocols...\n", unit));
    /*
     * Tell higher-level protocols that LCP is up.
     */
    for (i = 0; (protp = ppp_protocols[i]) != NULL; ++i) {
      if (protp->protocol != PPP_LCP && protp->enabled_flag && protp->lowerup != NULL) {
        (*protp->lowerup)(unit);
      }
    }
    if (ppp_settings.auth_required && !(go->neg_chap || go->neg_upap)) {
      /*
       * We wanted the peer to authenticate itself, and it refused:
       * treat it as though it authenticated with PAP using a username
       * of "" and a password of "".  If that's not OK, boot it out.
       */
      if (!wo->neg_upap || !null_login(unit)) {
        AUTHDEBUG(LOG_WARNING, ("peer refused to authenticate\n"));
        lcp_close(unit, "peer refused to authenticate");
        return;
      }
    }
  
    lcp_phase[unit] = PHASE_AUTHENTICATE;
    auth = 0;
  #if CHAP_SUPPORT
    if (go->neg_chap) {
      ChapAuthPeer(unit, ppp_settings.our_name, go->chap_mdtype);
      auth |= CHAP_PEER;
    } 
  #endif /* CHAP_SUPPORT */
  #if PAP_SUPPORT && CHAP_SUPPORT
    else
  #endif /* PAP_SUPPORT && CHAP_SUPPORT */
  #if PAP_SUPPORT
    if (go->neg_upap) {
      upap_authpeer(unit);
      auth |= PAP_PEER;
    }
  #endif /* PAP_SUPPORT */
  #if CHAP_SUPPORT
    if (ho->neg_chap) {
      ChapAuthWithPeer(unit, ppp_settings.user, ho->chap_mdtype);
      auth |= CHAP_WITHPEER;
    }
  #endif /* CHAP_SUPPORT */
  #if PAP_SUPPORT && CHAP_SUPPORT
    else
  #endif /* PAP_SUPPORT && CHAP_SUPPORT */
  #if PAP_SUPPORT
    if (ho->neg_upap) {
      if (ppp_settings.passwd[0] == 0) {
        passwd_from_file = 1;
        if (!get_pap_passwd(unit, ppp_settings.user, ppp_settings.passwd)) {
          AUTHDEBUG(LOG_ERR, ("No secret found for PAP login\n"));
        }
      }
      upap_authwithpeer(unit, ppp_settings.user, ppp_settings.passwd);
      auth |= PAP_WITHPEER;
    }
  #endif /* PAP_SUPPORT */
    auth_pending[unit] = auth;
  
    if (!auth) {
      network_phase(unit);
    }
  }
  
  /*
   * Proceed to the network phase.
   */
  static void
  network_phase(int unit)
  {
    int i;
    struct protent *protp;
    lcp_options *go = &lcp_gotoptions[unit];
  
    /*
     * If the peer had to authenticate, run the auth-up script now.
     */
    if ((go->neg_chap || go->neg_upap) && !did_authup) {
      /* XXX Do setup for peer authentication. */
      did_authup = 1;
    }
  
  #if CBCP_SUPPORT
    /*
     * If we negotiated callback, do it now.
     */
    if (go->neg_cbcp) {
      lcp_phase[unit] = PHASE_CALLBACK;
      (*cbcp_protent.open)(unit);
      return;
    }
  #endif /* CBCP_SUPPORT */
  
    lcp_phase[unit] = PHASE_NETWORK;
    for (i = 0; (protp = ppp_protocols[i]) != NULL; ++i) {
      if (protp->protocol < 0xC000 && protp->enabled_flag && protp->open != NULL) {
        (*protp->open)(unit);
        if (protp->protocol != PPP_CCP) {
          ++num_np_open;
        }
      }
    }
  
    if (num_np_open == 0) {
      /* nothing to do */
      lcp_close(0, "No network protocols running");
    }
  }
  /* @todo: add void start_networks(void) here (pppd 2.3.11) */
  
  /*
   * The peer has failed to authenticate himself using `protocol'.
   */
  void
  auth_peer_fail(int unit, u16_t protocol)
  {
    LWIP_UNUSED_ARG(protocol);
  
    AUTHDEBUG(LOG_INFO, ("auth_peer_fail: %d proto=%X\n", unit, protocol));
    /*
     * Authentication failure: take the link down
     */
    lcp_close(unit, "Authentication failed");
  }
  
  
  #if PAP_SUPPORT || CHAP_SUPPORT
  /*
   * The peer has been successfully authenticated using `protocol'.
   */
  void
  auth_peer_success(int unit, u16_t protocol, char *name, int namelen)
  {
    int pbit;
  
    AUTHDEBUG(LOG_INFO, ("auth_peer_success: %d proto=%X\n", unit, protocol));
    switch (protocol) {
      case PPP_CHAP:
        pbit = CHAP_PEER;
        break;
      case PPP_PAP:
        pbit = PAP_PEER;
        break;
      default:
        AUTHDEBUG(LOG_WARNING, ("auth_peer_success: unknown protocol %x\n", protocol));
        return;
    }
  
    /*
     * Save the authenticated name of the peer for later.
     */
    if (namelen > (int)sizeof(peer_authname) - 1) {
      namelen = sizeof(peer_authname) - 1;
    }
    BCOPY(name, peer_authname, namelen);
    peer_authname[namelen] = 0;
    
    /*
     * If there is no more authentication still to be done,
     * proceed to the network (or callback) phase.
     */
    if ((auth_pending[unit] &= ~pbit) == 0) {
      network_phase(unit);
    }
  }
  
  /*
   * We have failed to authenticate ourselves to the peer using `protocol'.
   */
  void
  auth_withpeer_fail(int unit, u16_t protocol)
  {
    int errCode = PPPERR_AUTHFAIL;
  
    LWIP_UNUSED_ARG(protocol);
  
    AUTHDEBUG(LOG_INFO, ("auth_withpeer_fail: %d proto=%X\n", unit, protocol));
    if (passwd_from_file) {
      BZERO(ppp_settings.passwd, MAXSECRETLEN);
    }
  
    /*
     * We've failed to authenticate ourselves to our peer.
     * He'll probably take the link down, and there's not much
     * we can do except wait for that.
     */
    pppIOCtl(unit, PPPCTLS_ERRCODE, &errCode);
    lcp_close(unit, "Failed to authenticate ourselves to peer");
  }
  
  /*
   * We have successfully authenticated ourselves with the peer using `protocol'.
   */
  void
  auth_withpeer_success(int unit, u16_t protocol)
  {
    int pbit;
  
    AUTHDEBUG(LOG_INFO, ("auth_withpeer_success: %d proto=%X\n", unit, protocol));
    switch (protocol) {
      case PPP_CHAP:
        pbit = CHAP_WITHPEER;
        break;
      case PPP_PAP:
        if (passwd_from_file) {
          BZERO(ppp_settings.passwd, MAXSECRETLEN);
        }
        pbit = PAP_WITHPEER;
        break;
      default:
        AUTHDEBUG(LOG_WARNING, ("auth_peer_success: unknown protocol %x\n", protocol));
        pbit = 0;
    }
  
    /*
     * If there is no more authentication still being done,
     * proceed to the network (or callback) phase.
     */
    if ((auth_pending[unit] &= ~pbit) == 0) {
      network_phase(unit);
    }
  }
  #endif /* PAP_SUPPORT || CHAP_SUPPORT */
  
  
  /*
   * np_up - a network protocol has come up.
   */
  void
  np_up(int unit, u16_t proto)
  {
    LWIP_UNUSED_ARG(unit);
    LWIP_UNUSED_ARG(proto);
  
    AUTHDEBUG(LOG_INFO, ("np_up: %d proto=%X\n", unit, proto));
    if (num_np_up == 0) {
      AUTHDEBUG(LOG_INFO, ("np_up: maxconnect=%d idle_time_limit=%d\n",ppp_settings.maxconnect,ppp_settings.idle_time_limit));
      /*
       * At this point we consider that the link has come up successfully.
       */
      if (ppp_settings.idle_time_limit > 0) {
        TIMEOUT(check_idle, NULL, ppp_settings.idle_time_limit);
      }
  
      /*
       * Set a timeout to close the connection once the maximum
       * connect time has expired.
       */
      if (ppp_settings.maxconnect > 0) {
        TIMEOUT(connect_time_expired, 0, ppp_settings.maxconnect);
      }
    }
    ++num_np_up;
  }
  
  /*
   * np_down - a network protocol has gone down.
   */
  void
  np_down(int unit, u16_t proto)
  {
    LWIP_UNUSED_ARG(unit);
    LWIP_UNUSED_ARG(proto);
  
    AUTHDEBUG(LOG_INFO, ("np_down: %d proto=%X\n", unit, proto));
    if (--num_np_up == 0 && ppp_settings.idle_time_limit > 0) {
      UNTIMEOUT(check_idle, NULL);
    }
  }
  
  /*
   * np_finished - a network protocol has finished using the link.
   */
  void
  np_finished(int unit, u16_t proto)
  {
    LWIP_UNUSED_ARG(unit);
    LWIP_UNUSED_ARG(proto);
  
    AUTHDEBUG(LOG_INFO, ("np_finished: %d proto=%X\n", unit, proto));
    if (--num_np_open <= 0) {
      /* no further use for the link: shut up shop. */
      lcp_close(0, "No network protocols running");
    }
  }
  
  /*
   * check_idle - check whether the link has been idle for long
   * enough that we can shut it down.
   */
  static void
  check_idle(void *arg)
  {
    struct ppp_idle idle;
    u_short itime;
    
    LWIP_UNUSED_ARG(arg);
    if (!get_idle_time(0, &idle)) {
      return;
    }
    itime = LWIP_MIN(idle.xmit_idle, idle.recv_idle);
    if (itime >= ppp_settings.idle_time_limit) {
      /* link is idle: shut it down. */
      AUTHDEBUG(LOG_INFO, ("Terminating connection due to lack of activity.\n"));
      lcp_close(0, "Link inactive");
    } else {
      TIMEOUT(check_idle, NULL, ppp_settings.idle_time_limit - itime);
    }
  }
  
  /*
   * connect_time_expired - log a message and close the connection.
   */
  static void
  connect_time_expired(void *arg)
  {
    LWIP_UNUSED_ARG(arg);
  
    AUTHDEBUG(LOG_INFO, ("Connect time expired\n"));
    lcp_close(0, "Connect time expired");   /* Close connection */
  }
  
  #if 0 /* UNUSED */
  /*
   * auth_check_options - called to check authentication options.
   */
  void
  auth_check_options(void)
  {
    lcp_options *wo = &lcp_wantoptions[0];
    int can_auth;
    ipcp_options *ipwo = &ipcp_wantoptions[0];
    u32_t remote;
  
    /* Default our_name to hostname, and user to our_name */
    if (ppp_settings.our_name[0] == 0 || ppp_settings.usehostname) {
        strcpy(ppp_settings.our_name, ppp_settings.hostname);
    }
  
    if (ppp_settings.user[0] == 0) {
      strcpy(ppp_settings.user, ppp_settings.our_name);
    }
  
    /* If authentication is required, ask peer for CHAP or PAP. */
    if (ppp_settings.auth_required && !wo->neg_chap && !wo->neg_upap) {
      wo->neg_chap = 1;
      wo->neg_upap = 1;
    }
    
    /*
     * Check whether we have appropriate secrets to use
     * to authenticate the peer.
     */
    can_auth = wo->neg_upap && have_pap_secret();
    if (!can_auth && wo->neg_chap) {
      remote = ipwo->accept_remote? 0: ipwo->hisaddr;
      can_auth = have_chap_secret(ppp_settings.remote_name, ppp_settings.our_name, remote);
    }
  
    if (ppp_settings.auth_required && !can_auth) {
      ppp_panic("No auth secret");
    }
  }
  #endif /* UNUSED */
  
  /*
   * auth_reset - called when LCP is starting negotiations to recheck
   * authentication options, i.e. whether we have appropriate secrets
   * to use for authenticating ourselves and/or the peer.
   */
  void
  auth_reset(int unit)
  {
    lcp_options *go = &lcp_gotoptions[unit];
    lcp_options *ao = &lcp_allowoptions[0];
    ipcp_options *ipwo = &ipcp_wantoptions[0];
    u32_t remote;
  
    AUTHDEBUG(LOG_INFO, ("auth_reset: %d\n", unit));
    ao->neg_upap = !ppp_settings.refuse_pap && (ppp_settings.passwd[0] != 0 || get_pap_passwd(unit, NULL, NULL));
    ao->neg_chap = !ppp_settings.refuse_chap && ppp_settings.passwd[0] != 0 /*have_chap_secret(ppp_settings.user, ppp_settings.remote_name, (u32_t)0)*/;
  
    if (go->neg_upap && !have_pap_secret()) {
      go->neg_upap = 0;
    }
    if (go->neg_chap) {
      remote = ipwo->accept_remote? 0: ipwo->hisaddr;
      if (!have_chap_secret(ppp_settings.remote_name, ppp_settings.our_name, remote)) {
        go->neg_chap = 0;
      }
    }
  }
  
  #if PAP_SUPPORT
  /*
   * check_passwd - Check the user name and passwd against the PAP secrets
   * file.  If requested, also check against the system password database,
   * and login the user if OK.
   *
   * returns:
   *  UPAP_AUTHNAK: Authentication failed.
   *  UPAP_AUTHACK: Authentication succeeded.
   * In either case, msg points to an appropriate message.
   */
  u_char
  check_passwd( int unit, char *auser, int userlen, char *apasswd, int passwdlen, char **msg, int *msglen)
  {
  #if 1 /* XXX Assume all entries OK. */
    LWIP_UNUSED_ARG(unit);
    LWIP_UNUSED_ARG(auser);
    LWIP_UNUSED_ARG(userlen);
    LWIP_UNUSED_ARG(apasswd);
    LWIP_UNUSED_ARG(passwdlen);
    LWIP_UNUSED_ARG(msglen);
    *msg = (char *) 0;
    return UPAP_AUTHACK;     /* XXX Assume all entries OK. */
  #else
    u_char ret = 0;
    struct wordlist *addrs = NULL;
    char passwd[256], user[256];
    char secret[MAXWORDLEN];
    static u_short attempts = 0;
    
    /*
     * Make copies of apasswd and auser, then null-terminate them.
     */
    BCOPY(apasswd, passwd, passwdlen);
    passwd[passwdlen] = '\0';
    BCOPY(auser, user, userlen);
    user[userlen] = '\0';
    *msg = (char *) 0;
  
    /* XXX Validate user name and password. */
    ret = UPAP_AUTHACK;     /* XXX Assume all entries OK. */
        
    if (ret == UPAP_AUTHNAK) {
      if (*msg == (char *) 0) {
        *msg = "Login incorrect";
      }
      *msglen = strlen(*msg);
      /*
       * Frustrate passwd stealer programs.
       * Allow 10 tries, but start backing off after 3 (stolen from login).
       * On 10'th, drop the connection.
       */
      if (attempts++ >= 10) {
        AUTHDEBUG(LOG_WARNING, ("%d LOGIN FAILURES BY %s\n", attempts, user));
        /*ppp_panic("Excess Bad Logins");*/
      }
      if (attempts > 3) {
        /* @todo: this was sleep(), i.e. seconds, not milliseconds
         * I don't think we really need this in lwIP - we would block tcpip_thread!
         */
        /*sys_msleep((attempts - 3) * 5);*/
      }
      if (addrs != NULL) {
        free_wordlist(addrs);
      }
    } else {
      attempts = 0; /* Reset count */
      if (*msg == (char *) 0) {
        *msg = "Login ok";
      }
      *msglen = strlen(*msg);
      set_allowed_addrs(unit, addrs);
    }
  
    BZERO(passwd, sizeof(passwd));
    BZERO(secret, sizeof(secret));
  
    return ret;
  #endif
  }
  #endif /* PAP_SUPPORT */
  
  #if 0 /* UNUSED */
  /*
   * This function is needed for PAM.
   */
  
  #ifdef USE_PAM
  
  /* lwip does not support PAM*/
  
  #endif  /* USE_PAM */
  
  #endif /* UNUSED */
  
  
  #if 0 /* UNUSED */
  /*
   * plogin - Check the user name and password against the system
   * password database, and login the user if OK.
   *
   * returns:
   *  UPAP_AUTHNAK: Login failed.
   *  UPAP_AUTHACK: Login succeeded.
   * In either case, msg points to an appropriate message.
   */
  static int
  plogin(char *user, char *passwd, char **msg, int *msglen)
  {
  
    LWIP_UNUSED_ARG(user);
    LWIP_UNUSED_ARG(passwd);
    LWIP_UNUSED_ARG(msg);
    LWIP_UNUSED_ARG(msglen);
  
  
   /* The new lines are here align the file when 
    * compared against the pppd 2.3.11 code */
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
    /* XXX Fail until we decide that we want to support logins. */
    return (UPAP_AUTHNAK);
  }
  #endif
  
  
  
  /*
   * plogout - Logout the user.
   */
  static void
  plogout(void)
  {
    logged_in = 0;
  }
  
  /*
   * null_login - Check if a username of "" and a password of "" are
   * acceptable, and iff so, set the list of acceptable IP addresses
   * and return 1.
   */
  static int
  null_login(int unit)
  {
    LWIP_UNUSED_ARG(unit);
    /* XXX Fail until we decide that we want to support logins. */
    return 0;
  }
  
  
  /*
   * get_pap_passwd - get a password for authenticating ourselves with
   * our peer using PAP.  Returns 1 on success, 0 if no suitable password
   * could be found.
   */
  static int
  get_pap_passwd(int unit, char *user, char *passwd)
  {
    LWIP_UNUSED_ARG(unit);
  /* normally we would reject PAP if no password is provided,
     but this causes problems with some providers (like CHT in Taiwan)
     who incorrectly request PAP and expect a bogus/empty password, so
     always provide a default user/passwd of "none"/"none"
  
     @todo: This should be configured by the user, instead of being hardcoded here!
  */
    if(user) {
      strcpy(user, "none");
    }
    if(passwd) {
      strcpy(passwd, "none");
    }
    return 1;
  }
  
  /*
   * have_pap_secret - check whether we have a PAP file with any
   * secrets that we could possibly use for authenticating the peer.
   */
  static int
  have_pap_secret(void)
  {
    /* XXX Fail until we set up our passwords. */
    return 0;
  }
  
  /*
   * have_chap_secret - check whether we have a CHAP file with a
   * secret that we could possibly use for authenticating `client'
   * on `server'.  Either can be the null string, meaning we don't
   * know the identity yet.
   */
  static int
  have_chap_secret(char *client, char *server, u32_t remote)
  {
    LWIP_UNUSED_ARG(client);
    LWIP_UNUSED_ARG(server);
    LWIP_UNUSED_ARG(remote);
  
    /* XXX Fail until we set up our passwords. */
    return 0;
  }
  #if CHAP_SUPPORT
  
  /*
   * get_secret - open the CHAP secret file and return the secret
   * for authenticating the given client on the given server.
   * (We could be either client or server).
   */
  int
  get_secret(int unit, char *client, char *server, char *secret, int *secret_len, int save_addrs)
  {
  #if 1
    int len;
    struct wordlist *addrs;
  
    LWIP_UNUSED_ARG(unit);
    LWIP_UNUSED_ARG(server);
    LWIP_UNUSED_ARG(save_addrs);
  
    addrs = NULL;
  
    if(!client || !client[0] || strcmp(client, ppp_settings.user)) {
      return 0;
    }
  
    len = (int)strlen(ppp_settings.passwd);
    if (len > MAXSECRETLEN) {
      AUTHDEBUG(LOG_ERR, ("Secret for %s on %s is too long\n", client, server));
      len = MAXSECRETLEN;
    }
  
    BCOPY(ppp_settings.passwd, secret, len);
    *secret_len = len;
  
    return 1;
  #else
    int ret = 0, len;
    struct wordlist *addrs;
    char secbuf[MAXWORDLEN];
    
    addrs = NULL;
    secbuf[0] = 0;
  
    /* XXX Find secret. */
    if (ret < 0) {
      return 0;
    }
  
    if (save_addrs) {
      set_allowed_addrs(unit, addrs);
    }
  
    len = strlen(secbuf);
    if (len > MAXSECRETLEN) {
      AUTHDEBUG(LOG_ERR, ("Secret for %s on %s is too long\n", client, server));
      len = MAXSECRETLEN;
    }
  
    BCOPY(secbuf, secret, len);
    BZERO(secbuf, sizeof(secbuf));
    *secret_len = len;
  
    return 1;
  #endif
  }
  #endif /* CHAP_SUPPORT */
  
  
  #if 0 /* PAP_SUPPORT || CHAP_SUPPORT */
  /*
   * set_allowed_addrs() - set the list of allowed addresses.
   */
  static void
  set_allowed_addrs(int unit, struct wordlist *addrs)
  {
    if (addresses[unit] != NULL) {
      free_wordlist(addresses[unit]);
    }
    addresses[unit] = addrs;
  
  #if 0
    /*
     * If there's only one authorized address we might as well
     * ask our peer for that one right away
     */
    if (addrs != NULL && addrs->next == NULL) {
      char *p = addrs->word;
      struct ipcp_options *wo = &ipcp_wantoptions[unit];
      u32_t a;
      struct hostent *hp;
      
      if (wo->hisaddr == 0 && *p != '!' && *p != '-' && strchr(p, '/') == NULL) {
        hp = gethostbyname(p);
        if (hp != NULL && hp->h_addrtype == AF_INET) {
          a = *(u32_t *)hp->h_addr;
        } else {
          a = inet_addr(p);
        }
        if (a != (u32_t) -1) {
          wo->hisaddr = a;
        }
      }
    }
  #endif
  }
  #endif /* 0 */ /* PAP_SUPPORT || CHAP_SUPPORT */
  
  /*
   * auth_ip_addr - check whether the peer is authorized to use
   * a given IP address.  Returns 1 if authorized, 0 otherwise.
   */
  int
  auth_ip_addr(int unit, u32_t addr)
  {
    return ip_addr_check(addr, addresses[unit]);
  }
  
  static int /* @todo: integrate this funtion into auth_ip_addr()*/
  ip_addr_check(u32_t addr, struct wordlist *addrs)
  {
    /* don't allow loopback or multicast address */
    if (bad_ip_adrs(addr)) {
      return 0;
    }
  
    if (addrs == NULL) {
      return !ppp_settings.auth_required; /* no addresses authorized */
    }
  
    /* XXX All other addresses allowed. */
    return 1;
  }
  
  /*
   * bad_ip_adrs - return 1 if the IP address is one we don't want
   * to use, such as an address in the loopback net or a multicast address.
   * addr is in network byte order.
   */
  int
  bad_ip_adrs(u32_t addr)
  {
    addr = ntohl(addr);
    return (addr >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET
        || IN_MULTICAST(addr) || IN_BADCLASS(addr);
  }
  
  #if 0 /* UNUSED */ /* PAP_SUPPORT || CHAP_SUPPORT */
  /*
   * some_ip_ok - check a wordlist to see if it authorizes any
   * IP address(es).
   */
  static int
  some_ip_ok(struct wordlist *addrs)
  {
      for (; addrs != 0; addrs = addrs->next) {
        if (addrs->word[0] == '-')
          break;
        if (addrs->word[0] != '!')
          return 1; /* some IP address is allowed */
      }
      return 0;
  }
  
  /*
   * check_access - complain if a secret file has too-liberal permissions.
   */
  static void
  check_access(FILE *f, char *filename)
  {
      struct stat sbuf;
  
      if (fstat(fileno(f), &sbuf) < 0) {
        warn("cannot stat secret file %s: %m", filename);
      } else if ((sbuf.st_mode & (S_IRWXG | S_IRWXO)) != 0) {
        warn("Warning - secret file %s has world and/or group access",
              filename);
      }
  }
  
  
  /*
   * scan_authfile - Scan an authorization file for a secret suitable
   * for authenticating `client' on `server'.  The return value is -1
   * if no secret is found, otherwise >= 0.  The return value has
   * NONWILD_CLIENT set if the secret didn't have "*" for the client, and
   * NONWILD_SERVER set if the secret didn't have "*" for the server.
   * Any following words on the line up to a "--" (i.e. address authorization
   * info) are placed in a wordlist and returned in *addrs.  Any
   * following words (extra options) are placed in a wordlist and
   * returned in *opts.
   * We assume secret is NULL or points to MAXWORDLEN bytes of space.
   */
  static int
  scan_authfile(FILE *f, char *client, char *server, char *secret, struct wordlist **addrs, struct wordlist **opts, char *filename)
  {
    /* We do not (currently) need this in lwip  */
    return 0; /* dummy */
  }
  /*
   * free_wordlist - release memory allocated for a wordlist.
   */
  static void
  free_wordlist(struct wordlist *wp)
  {
    struct wordlist *next;
  
    while (wp != NULL) {
      next = wp->next;
      free(wp);
      wp = next;
    }
  }
  
  /*
   * auth_script_done - called when the auth-up or auth-down script
   * has finished.
   */
  static void
  auth_script_done(void *arg)
  {
      auth_script_pid = 0;
      switch (auth_script_state) {
      case s_up:
        if (auth_state == s_down) {
          auth_script_state = s_down;
          auth_script(_PATH_AUTHDOWN);
        }
        break;
      case s_down:
        if (auth_state == s_up) {
          auth_script_state = s_up;
          auth_script(_PATH_AUTHUP);
        }
        break;
      }
  }
  
  /*
   * auth_script - execute a script with arguments
   * interface-name peer-name real-user tty speed
   */
  static void
  auth_script(char *script)
  {
      char strspeed[32];
      struct passwd *pw;
      char struid[32];
      char *user_name;
      char *argv[8];
  
      if ((pw = getpwuid(getuid())) != NULL && pw->pw_name != NULL)
        user_name = pw->pw_name;
      else {
        slprintf(struid, sizeof(struid), "%d", getuid());
        user_name = struid;
      }
      slprintf(strspeed, sizeof(strspeed), "%d", baud_rate);
  
      argv[0] = script;
      argv[1] = ifname;
      argv[2] = peer_authname;
      argv[3] = user_name;
      argv[4] = devnam;
      argv[5] = strspeed;
      argv[6] = NULL;
  
      auth_script_pid = run_program(script, argv, 0, auth_script_done, NULL);
  }
  #endif  /* 0 */ /* PAP_SUPPORT || CHAP_SUPPORT */
  #endif /* PPP_SUPPORT */
  