Logo Search packages:      
Sourcecode: isdnutils version File versions  Download package

auth.c

/*
 * auth.c - PPP authentication and phase control.
 *
 * Fairly patched version for isdn4linux
 * copyright (c) 1995,1996,1997 of all patches by Michael Hipp
 * still no warranties (see disclaimer)
 *
 * Copyright (c) 1993 The Australian National University.
 * All rights reserved.
 *
 * 2000-07-25 Callback improvements by richard.kunze@web.de 
 *
 * 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.
 */

char auth_rcsid[] = "$Id: auth.c,v 1.21 2002/07/06 00:34:08 keil Exp $";

#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <syslog.h>
#include <pwd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#if defined __GLIBC__ && __GLIBC__ >= 2
# include <crypt.h>
#endif

#include "config.h"
#ifdef HAVE_SHADOW_H
#include <shadow.h>
#endif

#ifdef RADIUS
#include <radiusclient.h>
int  radius_pap_auth __P((int, char *, char *, char **, int *));
extern int auth_order ;
extern int idle_time_limit ;
extern int default_idle_time_limit ;
extern int session_time_limit ;
extern int default_session_time_limit ;
#endif

#include "fsm.h"
#include "ipppd.h"
#include "lcp.h"
#include "upap.h"
#include "chap.h"
#include "cbcp.h"
#include "ipcp.h"
#include "ipxcp.h"

#include "ccp.h"
#include "pathnames.h"

#if defined(sun) && defined(sparc)
#include <alloca.h>
#endif /*sparc*/

/* Bits in scan_authfile return value */
#define NONWILD_SERVER        1
#define NONWILD_CLIENT        2

#define ISWILD(word)        (word[0] == '*' && word[1] == 0)

#define FALSE        0
#define TRUE        1

/* Bits in auth_pending[] */
#define UPAP_WITHPEER    1
#define UPAP_PEER        2
#define CHAP_WITHPEER    4
#define CHAP_PEER        8

/* Prototypes */
void check_access __P((FILE *, char *));

static void network_phase __P((int));
static void callback_phase __P((int));
static int  link_lastlink(int);
static int  check_login __P((char *, char *, char **, int *,int));
static void do_logout __P((int));
static int  null_login __P((int));
static int  get_upap_passwd __P((void));
static int  have_upap_secret __P((void));
static int  have_chap_secret __P((char *, char *));
static int  scan_authfile __P((FILE *, char *, char *, char *,
        struct wordlist **, char *));
static void free_wordlist __P((struct wordlist *));
static void auth_script __P((int,char *,int));

/*
 * 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)
{
}

/*
 * LCP has terminated the link; go to the Dead phase and take the
 * physical layer down.
 */
void link_terminated(int linkunit)
{

#ifdef RADIUS
      extern u_int32_t  default_hisaddr;
      extern u_int32_t  default_ouraddr;  
      extern u_int32_t  default_netmask;
      struct in_addr hisifaddr;
      struct in_addr ourifaddr;
#endif
      
      if(lns[linkunit].auth_up_script)
            auth_script(linkunit,_PATH_AUTHDOWN,0);
      if (lns[linkunit].phase == PHASE_DEAD)
            return;
      if (lns[linkunit].logged_in) {
            do_logout(linkunit);
            lns[linkunit].logged_in = 0;
      }
#ifdef RADIUS
      if (lns[linkunit].radius_in )
      {
            lns[linkunit].radius_in = FALSE ;
            if ( useradacct ) 
                  radius_acct_stop(linkunit) ;
      }
      /* reset some parameters to their default (option-parsed) values */
      session_time_limit = default_session_time_limit ;
      idle_time_limit = default_idle_time_limit ;
      /* and reset IP addresses to their default values */
      hisifaddr.s_addr = default_hisaddr ? default_hisaddr : ipcp_wantoptions[linkunit].hisaddr ;
      ourifaddr.s_addr = default_ouraddr ? default_ouraddr : ipcp_wantoptions[linkunit].ouraddr ;
      syslog(LOG_DEBUG,
            "reseting remote ippp interface addresses for linkunit %d [ifunit %d] to %s:%s\n",
                        linkunit,
                        lns[linkunit].ifunit,
                        inet_ntoa(ourifaddr),
                        inet_ntoa(hisifaddr)
            );
      sifaddr(linkunit,
            default_ouraddr ? default_ouraddr :ipcp_wantoptions[linkunit].ouraddr,
            default_hisaddr ? default_hisaddr : ipcp_wantoptions[linkunit].hisaddr,
            default_netmask ? default_netmask : 0xffffffff);
#endif
      lns[linkunit].phase = PHASE_DEAD;
      syslog(LOG_NOTICE, "Connection terminated.");
}

/*
 * LCP has gone down; it will either die or try to re-establish.
 */
void link_down(int unit)
{
      if(lns[unit].ccp_l_unit >= 0) {
            (*ccp_link_protent.lowerdown)(lns[unit].ccp_l_unit);
            (*ccp_link_protent.close)(lns[unit].ccp_l_unit,"link went down");
            ccp_freeunit(lns[unit].ccp_l_unit);
            lns[unit].ccp_l_unit = -1;
      }
      if(link_lastlink(unit)) {
            if(lns[unit].ccp_unit >= 0) {
                  (*ccp_protent.lowerdown)(lns[unit].ccp_unit);
                  (*ccp_protent.close)(lns[unit].ccp_unit,"link went down");
                  ccp_freeunit(lns[unit].ccp_unit);
                  lns[unit].ccp_unit = -1;
            }
            if(lns[unit].ipcp_unit >= 0) {
                  (*ipcp_protent.lowerdown)(lns[unit].ipcp_unit);
                  (*ipcp_protent.close)(lns[unit].ipcp_unit,"link went down");
                  ipcp_freeunit(lns[unit].ipcp_unit);
                  lns[unit].ipcp_unit = -1;
            }
            if(lns[unit].cbcp_unit >= 0) {
                  (*cbcp_protent.lowerdown)(lns[unit].cbcp_unit);
                  (*cbcp_protent.close)(lns[unit].cbcp_unit,"link went down");
                  lns[unit].cbcp_unit = -1;
            }
            if(lns[unit].ipxcp_unit >= 0)
            {
                  (*ipxcp_protent.lowerdown)(lns[unit].ipxcp_unit);
                  (*ipxcp_protent.close)(lns[unit].ipxcp_unit,"link went down");
                  ipxcp_freeunit(lns[unit].ipxcp_unit);
                  lns[unit].ipxcp_unit = -1;      
            }
      }
      else {
            struct link_struct *q;
            int i; /* bugcheck, stop after 1024 links */
            for(i=1024,q=lns[unit].bundle_next;i && q!=&lns[unit];q=q->bundle_next,i--) {
                  if(q->bundle_next == &lns[unit])
                  break;
            }
            if(!i || q == &lns[unit]) {
                  syslog(LOG_ERR,"Error on 'unbundling' link");
            }
            else {
                  /*
                   * maybe the dead link was our communication link -> set a valid 'fd'
                   */
                  ipcp_fsm[lns[unit].ipcp_unit].unit = q->unit;
                  ccp_fsm[lns[unit].ccp_unit].unit = q->unit; 
                  ipxcp_fsm[lns[unit].ipxcp_unit].unit = q->unit;
                  q->bundle_next = lns[unit].bundle_next;
                  lns[unit].bundle_next = &lns[unit];
            }
      }
      lns[unit].phase = PHASE_TERMINATE;
}

/* 
 * check whether 'unit' is the last in the bundle
 */
static int link_lastlink(int unit)
{
      if(lns[unit].bundle_next == &lns[unit])
            return 1;
      else
            return 0;
}


/*
 * The link is established.
 * Proceed to the Dead, Authenticate or Network phase as appropriate.
 */
void link_established(int linkunit)
{
      int auth;
      lcp_options *wo = &lcp_wantoptions[ lns[linkunit].lcp_unit ];
      lcp_options *go = &lcp_gotoptions[ lns[linkunit].lcp_unit ];
      lcp_options *ho = &lcp_hisoptions[ lns[linkunit].lcp_unit ];
      
      if (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(linkunit)) {
                  syslog(LOG_WARNING, "peer refused to authenticate");
                  lcp_close(lns[linkunit].lcp_unit,"peer refused to authenticate");
                  lns[linkunit].phase = PHASE_TERMINATE;
                  return;
            }
      }

      lns[linkunit].phase = PHASE_AUTHENTICATE;
      auth = 0;
      if (go->neg_chap) {
            ChapAuthPeer(lns[linkunit].chap_unit, our_name, go->chap_mdtype);
            auth |= CHAP_PEER;
      } else if (go->neg_upap) {
            upap_authpeer(lns[linkunit].upap_unit);
            auth |= UPAP_PEER;
      }
      if (ho->neg_chap) {
            ChapAuthWithPeer(lns[linkunit].chap_unit, our_name, ho->chap_mdtype);
            auth |= CHAP_WITHPEER;
      } else if (ho->neg_upap) {
            upap_authwithpeer(lns[linkunit].upap_unit, user, passwd);
            auth |= UPAP_WITHPEER;
      }
      lns[linkunit].auth_pending = auth;
      if (!auth)
            callback_phase(linkunit);
}

/*
 * Proceed to the network phase.
 */
static void network_phase(int linkunit)
{
  int lcp_unit = lns[linkunit].lcp_unit;
  lcp_options *go=&lcp_gotoptions[lcp_unit],*ho=&lcp_hisoptions[lcp_unit];
  int higher_up = 1;
  int discr,i;

  if(go->neg_mpmrru || go->neg_mpshortseq)
      go->neg_mp = 1;
  if(ho->neg_mpmrru || ho->neg_mpshortseq) 
      ho->neg_mp = 1;

  syslog(LOG_INFO,"MPPP negotiation, He: %s We: %s",go->neg_mp?"Yes":"No",ho->neg_mp?"Yes":"No");

  if(go->neg_mp && ho->neg_mp)
      for(i=0;i<numdev && higher_up;i++)
      {
        if(i != linkunit && lns[i].phase == PHASE_NETWORK)
        {
            if(lcp_gotoptions[i].neg_mp  && lcp_hisoptions[i].neg_mp)
            {
              discr = lcp_hisoptions[i].neg_mpdiscr ? 1 : 0;
              if(ho->neg_mpdiscr)
                  discr++;

              syslog(LOG_INFO,"ipppd[%d]: discr: %d\n",linkunit,discr);

              switch(discr)            
              {
                  case 1: /* one peer has a discriminator, the other not */
                    break; 
                  case 2:
                    /*
                     * maybe, we should check our side, too 
                     * (but currently we use always the same discriminator)
                     */
                    if(ho->mp_alen != lcp_hisoptions[i].mp_alen || ho->mp_class != lcp_hisoptions[i].mp_class)
                        break;
                    syslog(LOG_INFO,"ipppd[%d]: passed 1\n",linkunit);
                    if(memcmp(ho->mp_addr,lcp_hisoptions[i].mp_addr,ho->mp_alen))
                        break;
                    syslog(LOG_INFO,"ipppd[%d]: passed 2\n",linkunit);
                  case 0:
                     /* 
                        * login check when peer has authentification
                        */
                    if(go->neg_chap)
                    {
                        syslog(LOG_INFO,"ipppd[%d]: chap-check: NOT IMPLEMENTED YET\n",linkunit);
                    }
                    else if(go->neg_upap)
                    {
                        int l;
                        syslog(LOG_INFO,"ipppd[%d]: pap-check\n",linkunit);
                        if((l=upap[lns[linkunit].upap_unit].us_ruserlen) == upap[lns[i].upap_unit].us_ruserlen)
                          if(strncmp(upap[lns[linkunit].upap_unit].us_ruser,upap[lns[i].upap_unit].us_ruser,l))
                          {
                              syslog(LOG_INFO,"Making no bundle because of different login names");
                              break;
                          }
                    }
                    syslog(LOG_INFO,"ipppd[%d]: pap/chap-check passed\n",linkunit);
                    higher_up = 0;
                    /* 
                     * ok: found a valid bundle
                     */
                    syslog(LOG_INFO,"ok, found a valid bundle with linkunit %d",i);
                    lns[linkunit].bundle_next = lns[i].bundle_next;
                    lns[i].bundle_next = &lns[linkunit];
                    lns[linkunit].ifunit = lns[i].ifunit;
                    lns[linkunit].master = i;
                    lns[linkunit].ipcp_unit = lns[i].ipcp_unit; /* use fsm state of other link */
                    /* 
                     * same fsm state for ccp, too???
                     */
                    lns[linkunit].ccp_unit = lns[i].ccp_unit; 
                    lns[linkunit].ipxcp_unit = lns[i].ipxcp_unit;
                    lns[linkunit].phase = PHASE_NETWORK;
                    /* 
                     * bundle the links on driver layer
                     */
                    syslog(LOG_INFO,"bundle: %d",
                         sifbundle(linkunit,i)); /* sets MP Flags */
                    break;
              }
            }
        }
      }

  if(higher_up) /* no bundle -> kick higher layers */
  {
      if(go->neg_mp && ho->neg_mp)
        enable_mp(linkunit,0x0);

            if(ipcp_protent.enabled_flag) {
                        int ipcp_unit = lns[linkunit].ipcp_unit = ipcp_getunit(linkunit);
                        if(ipcp_unit >= 0) {
                                    if(useifip)
                                                setifip(lns[linkunit].ipcp_unit);
                                    if(usefirstip && lns[linkunit].addresses) {
                                                ipcp_options *wo = &ipcp_wantoptions[ipcp_unit];
                                                struct hostent *hp = gethostbyname(lns[linkunit].addresses->word);
                                                if (hp != NULL && hp->h_addrtype == AF_INET) {
                                                            wo->hisaddr = *(u_int32_t *)hp->h_addr;
                                                }
                                    }
                                    (*ipcp_protent.lowerup)(lns[linkunit].ipcp_unit);
                                    (*ipcp_protent.open)(lns[linkunit].ipcp_unit);
                        }
            }
            if(ipxcp_protent.enabled_flag) {
                        lns[linkunit].ipxcp_unit = ipxcp_getunit(linkunit);
                        (*ipxcp_protent.lowerup)(lns[linkunit].ipxcp_unit);
                        (*ipxcp_protent.open)(lns[linkunit].ipxcp_unit);
            }
            if(ccp_link_protent.enabled_flag) {
                  syslog(LOG_NOTICE,"linkCCP enabled! Trying CCP.\n");
                  lns[linkunit].ccp_unit = ccp_getunit(linkunit,PPP_LINK_CCP);
                  (*ccp_link_protent.lowerup)(lns[linkunit].ccp_unit);
                  (*ccp_link_protent.open)(lns[linkunit].ccp_unit);
            }
            if(ccp_protent.enabled_flag) {
                  syslog(LOG_NOTICE,"CCP enabled! Trying CCP.\n");
                  lns[linkunit].ccp_unit = ccp_getunit(linkunit,PPP_CCP);
                  (*ccp_protent.lowerup)(lns[linkunit].ccp_unit);
                  (*ccp_protent.open)(lns[linkunit].ccp_unit);
            }
      lns[linkunit].phase = PHASE_NETWORK;
  }

  if(ccp_link_protent.enabled_flag) {
    syslog(LOG_NOTICE,"linkCCP enabled! Trying CCP.\n");
    lns[linkunit].ccp_l_unit = ccp_getunit(linkunit,PPP_LINK_CCP);
    (*ccp_link_protent.lowerup)(lns[linkunit].ccp_l_unit);
    (*ccp_link_protent.open)(lns[linkunit].ccp_l_unit);
  }
}

/*
 * Proceed to the callback phase which may be empty.
 */
static void callback_phase(int linkunit)
{
  lcp_options *go = &lcp_gotoptions[ lns[linkunit].lcp_unit ];
  
  /* hack here: remote is always the server for callback */
  if (go->neg_callback && !(lns[linkunit].pci.calltype & CALLTYPE_INCOMING)) {
    /* Do CBCP if we did negotiate CBCP, take the lionk
       down and wait for callback if we negotiated RFC
       1570 style callback */
    if (go->cbopt.type == CB_CBCP) {
      lns[linkunit].phase = PHASE_CALLBACK;
      /* cbcp always corresponds to a link */
      lns[linkunit].cbcp_unit = linkunit; 
      cbcp[ lns[linkunit].cbcp_unit ].us_unit = linkunit;
      (*cbcp_protent.lowerup)(lns[linkunit].cbcp_unit);
      (*cbcp_protent.open)(lns[linkunit].cbcp_unit);
    } else {
      lns[linkunit].phase = PHASE_TERMINATE;
    }
  } else {
    network_phase(linkunit);
  }
}

/*
 * The peer has failed to authenticate himself using `protocol'.
 */
void auth_peer_fail(int unit,int protocol, int reason)
{
      /*
       * Authentication failure: take the link down
       */
      lcp_close(lns[unit].lcp_unit,"auth failure");
      lns[unit].phase = PHASE_TERMINATE;
      auth_script(unit, _PATH_AUTHFAIL, reason);
}

/*
 * The peer has been successfully authenticated using `protocol'.
 */
void auth_peer_success(int linkunit,int protocol)
{
      int bit;

            switch (protocol) {
                        case PPP_CHAP:
                                    bit = CHAP_PEER;
                                    break;
                        case PPP_PAP:
                                    bit = UPAP_PEER;
                                    break;
                        default:
                                    syslog(LOG_WARNING, "auth_peer_success: unknown protocol %x",protocol);
                                    return;
      }

      /*
       * If there is no more authentication still to be done,
       * proceed to the network phase. (via callback phase)
       */
      if ((lns[linkunit].auth_pending &= ~bit) == 0 &&
             lns[linkunit].phase == PHASE_AUTHENTICATE) {
            callback_phase(linkunit);
      }
}

/*
 * We have failed to authenticate ourselves to the peer using `protocol'.
 */
void auth_withpeer_fail(int unit,int protocol,int reason)
{
      /*
       * 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.
       */
      auth_script(unit, _PATH_AUTHFAIL, reason);
}

/*
 * We have successfully authenticated ourselves with the peer using `protocol'.
 */
void auth_withpeer_success(int linkunit,int protocol)
{
      int bit;

      switch (protocol) {
            case PPP_CHAP:
                  bit = CHAP_WITHPEER;
                  break;
            case PPP_PAP:
                  bit = UPAP_WITHPEER;
                  break;
            default:
                  syslog(LOG_WARNING, "auth_peer_success: unknown protocol %x",protocol);
                  bit = 0;
      }

      /*
       * If there is no more authentication still being done,
       * proceed to the network phase.
       */
      if ((lns[linkunit].auth_pending &= ~bit) == 0 && 
           lns[linkunit].phase == PHASE_AUTHENTICATE)
                  callback_phase(linkunit);
}

/*
 * check_auth_options - called to check authentication options.
 */
void check_auth_options()
{
      int i;

      lcp_options *wo = &lcp_wantoptions[0];
      lcp_options *ao = &lcp_allowoptions[0];

      /* Default our_name to hostname, and user to our_name */
      if (our_name[0] == 0 || usehostname)
            strcpy(our_name, hostname);
      if (user[0] == 0)
            strcpy(user, our_name);

      /* If authentication is required, ask peer for CHAP or PAP. */
      if (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 ourselves and/or the peer.
       */
#ifdef RADIUS
      if (ao->neg_upap && passwd[0] == 0 && !get_upap_passwd() 
            && !useradius ) {
#else
      if (ao->neg_upap && passwd[0] == 0 && !get_upap_passwd()) {
#endif
            syslog(LOG_INFO,"info: no PAP secret entry for this user!\n");
            ao->neg_upap = 0;
      }
#ifdef RADIUS
      if (wo->neg_upap && !uselogin && !ask_passwd && !fdpasswd &&
            !have_upap_secret() && !useradius )
#else
      if (wo->neg_upap && !uselogin && !ask_passwd && !fdpasswd &&
            !have_upap_secret())
#endif
            wo->neg_upap = 0;
#ifdef RADIUS
      if (ao->neg_chap && !ask_passwd && !fdpasswd &&
            !have_chap_secret(our_name, remote_name) && !useradius ) {
#else
      if (ao->neg_chap && !ask_passwd && !fdpasswd &&
            !have_chap_secret(our_name, remote_name)) {
#endif
            syslog(LOG_INFO,"info: no CHAP secret entry for this user!\n");
            ao->neg_chap = 0;
      }
#ifdef RADIUS
      if (wo->neg_chap && !ask_passwd && !fdpasswd &&
            !have_chap_secret(remote_name, our_name) && !useradius )
#else
      if (wo->neg_chap && !ask_passwd && !fdpasswd &&
            !have_chap_secret(remote_name, our_name))
#endif
            wo->neg_chap = 0;

      if (auth_required && !wo->neg_chap && !wo->neg_upap) {
            fprintf(stderr,"ipppd: peer authentication required but no authentication files accessible\n or user %s not found in auth files",user);
            exit(1);
      }

      for(i=1;i<NUM_PPP;i++) /* duplicate options */
      {
        lcp_wantoptions[i].neg_upap = lcp_wantoptions[0].neg_upap;
        lcp_wantoptions[i].neg_chap = lcp_wantoptions[0].neg_chap;
        lcp_allowoptions[i].neg_upap = lcp_allowoptions[0].neg_upap;
        lcp_allowoptions[i].neg_chap = lcp_allowoptions[0].neg_chap;
      }

}

/*
 * reload PW
 */
void auth_reload_upap_pw(void)
{
  if(lcp_allowoptions[0].neg_upap)
    get_upap_passwd();
}

/*
 * 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.
 */
int check_passwd(int linkunit,char *auser,int userlen,char *apasswd,
      int passwdlen,char **msg,int *msglen)
{
      int ret;
      char *filename;
      FILE *f;
      struct wordlist *addrs;
      char passwd[256], user[256];
      char secret[MAXWORDLEN];

      /*
       * Make copies of apasswd and auser, then null-terminate them.
       */
      BCOPY(apasswd, passwd, passwdlen);
      passwd[passwdlen] = '\0';
      BCOPY(auser, user, userlen);
      user[userlen] = '\0';

      syslog(LOG_INFO,"Check_passwd called with user=%s\n",user);

      snprintf(lns[linkunit].peer_authname,sizeof(lns[0].peer_authname), "%s", user);

      /*
       * Open the file of upap secrets and scan for a suitable secret
       * for authenticating this user.
       */
      filename = _PATH_UPAPFILE;
      addrs = NULL;
      ret = UPAP_AUTHACK;
      f = fopen(filename, "r");
      if (f == NULL) {
            if (!uselogin ) {
                  syslog(LOG_ERR, "Can't open PAP password file %s: %m", filename);
                  ret = UPAP_AUTHNAK;
            }
      } else {
            check_access(f, filename);
            if (scan_authfile(f, user, our_name, secret, &addrs, filename) < 0
                  || (secret[0] != 0 && (cryptpap || strcmp(passwd, secret) != 0)
                        && strcmp(crypt(passwd, secret), secret) != 0)) {
                  syslog(LOG_WARNING, "PAP authentication failure for %s", user);
                  ret = UPAP_AUTHNAK;
            }
            fclose(f);
      }

      if (uselogin && ret == UPAP_AUTHACK) {
            ret = check_login(user, passwd, msg, msglen,linkunit);
            if (ret == UPAP_AUTHNAK) {
                  syslog(LOG_WARNING, "PAP login failure for %s", user);
            }
            else
                  lns[linkunit].logged_in = TRUE;
      }

      if (ret == UPAP_AUTHNAK) {
            *msg = "Login incorrect";
            *msglen = strlen(*msg);
            if (lns[linkunit].attempts++ >= 10) {
                  syslog(LOG_WARNING, "%d LOGIN FAILURES ON %s, %s",
                  lns[linkunit].attempts, lns[linkunit].devnam, user);
                  lcp_close(lns[linkunit].lcp_unit,"max auth exceed");
                  lns[linkunit].phase = PHASE_TERMINATE;
            }
#if 0
            if (attempts > 3)
                  sleep((u_int) (attempts - 3) * 5);
#endif
            if (addrs != NULL)
                  free_wordlist(addrs);
      } else {
            lns[linkunit].attempts = 0;                        /* Reset count */
            *msg = "Login ok";
            *msglen = strlen(*msg);
            if (lns[linkunit].addresses != NULL)
                  free_wordlist(lns[linkunit].addresses);
            lns[linkunit].addresses = addrs;
            auth_script(linkunit,_PATH_AUTHUP,0);
            lns[linkunit].auth_up_script = 1;
      }
      return ret;
}

#ifdef RADIUS
/*
 * Name: radius_check_passwd 
 *
 * Purpose: Check the user name and passwd against RADIUS server
 *        and acording to configuration also perform standard check_passwd
 *
 * returns:
 *        UPAP_AUTHNAK: Authentication failed.
 *        UPAP_AUTHACK: Authentication succeeded.
 * In either case, msg points to an appropriate message.
 */
int radius_check_passwd(linkunit,auser,userlen,apasswd,passwdlen,msg,msglen)
      int linkunit ;
      char *auser ;
      int userlen ;
      char *apasswd ;
      int passwdlen ;
      char **msg ;
      int *msglen ;                 
{
      int ret;
      char passwd[256], user[256];

      /*
      * Make copies of apasswd and auser, then null-terminate them.
      */
      BCOPY(apasswd, passwd, passwdlen);
      passwd[passwdlen] = '\0';
      BCOPY(auser, user, userlen);
      user[userlen] = '\0';
      snprintf(lns[linkunit].peer_authname,sizeof(lns[0].peer_authname), "%s", user);

      ret = UPAP_AUTHACK;

      if ( useradius )
      {
            if ( auth_order & AUTH_RADIUS_FST )
            {
                  ret = radius_pap_auth( linkunit, user, passwd, msg, msglen );
                  if ((ret == UPAP_AUTHNAK) && (auth_order & AUTH_LOCAL_SND))
                  {
                        ret = check_passwd (linkunit,auser,userlen,apasswd,passwdlen,msg,msglen) ;
                  }
            }
            else if ( auth_order & AUTH_LOCAL_FST )
            {
                  ret = check_passwd (linkunit,auser,userlen,apasswd,passwdlen,msg,msglen) ;
                  if ((auth_order & AUTH_RADIUS_SND) && (ret == UPAP_AUTHNAK))
                  {
                        ret = radius_pap_auth( linkunit, user, passwd, msg, msglen );
                  }
            }
      } 
      else
      {
            ret = check_passwd (linkunit,auser,userlen,apasswd,passwdlen,msg,msglen) ;
      }

      if (ret == UPAP_AUTHNAK) 
      {
            *msg = "Login incorrect";
            *msglen = strlen(*msg);
            if (lns[linkunit].attempts++ >= 10)
            {
                  syslog(LOG_WARNING, "%d LOGIN FAILURES ON %s, %s",
                        lns[linkunit].attempts, 
                        lns[linkunit].devnam, user);
                        lcp_close(lns[linkunit].lcp_unit,
                        "max auth exceed");
                  lns[linkunit].phase = PHASE_TERMINATE;
/* should I die here it must be something wrong here then */
/* then outside script can reestablish ipppd            */
            }

      } 
      else 
      {
            lns[linkunit].attempts = 0;         /* Reset count */
            *msg = "Login ok";
            *msglen = strlen(*msg);
      }

      return ret;
}
#endif

/*
 * check_login - 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 check_login(char *user,char *passwd,char **msg,int *msglen,int unit)
{
      struct passwd *pw;
      char *epasswd;
      char *tty;

#ifdef HAVE_SHADOW_H
      struct spwd *spwd;
      extern int isexpired (struct passwd *, struct spwd *);
#endif

      if ((pw = getpwnam(user)) == NULL) {
            return (UPAP_AUTHNAK);
       }

#ifdef HAVE_SHADOW_H
      /* try to deal with shadow */
      spwd = getspnam(user);
      if (spwd) {
         /* check the age of the password entry */
         if (isexpired(pw, spwd)) {
               syslog(LOG_WARNING,"Expired password for %s",user);
               return (UPAP_AUTHNAK);
         }
         pw->pw_passwd = spwd->sp_pwdp;
      }
      endspent();
#endif

       /*
        * XXX If no passwd, let them login without one.
        */
      if (!pw->pw_passwd || *pw->pw_passwd == '\0') {
            return (UPAP_AUTHACK);
       }

      epasswd = crypt(passwd, pw->pw_passwd);
      if (strcmp(epasswd, pw->pw_passwd)) {
         return (UPAP_AUTHNAK);
      }

      syslog(LOG_INFO, "user %s logged in", user);

      /*
       * Write a wtmp entry for this user.
       */
      tty = lns[unit].devnam;
      if (strncmp(tty, "/dev/", 5) == 0)
            tty += 5;
      logwtmputmp(unit, tty, user, "");                /* Add wtmp login entry */

      return (UPAP_AUTHACK);
}

/*
 * logout - Logout the user.
 */
static void do_logout(int unit)
{
      char *tty;

      tty = lns[unit].devnam;
      if (strncmp(tty, "/dev/", 5) == 0)
            tty += 5;
      logwtmputmp(unit, tty, "", "");                /* Wipe out wtmp logout entry */
}


/*
 * 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)
{
      char *filename;
      FILE *f;
      int i, ret;
      struct wordlist *addrs;
      char secret[MAXWORDLEN];

      /*
       * Open the file of upap secrets and scan for a suitable secret.
       * We don't accept a wildcard client.
       */
      filename = _PATH_UPAPFILE;
      addrs = NULL;
      f = fopen(filename, "r");
      if (f == NULL)
            return 0;
      check_access(f, filename);

      i = scan_authfile(f, "", our_name, secret, &addrs, filename);
      ret = i >= 0 && (i & NONWILD_CLIENT) != 0 && secret[0] == 0;

      if (ret) {
            if (lns[unit].addresses != NULL)
                  free_wordlist(lns[unit].addresses);
            lns[unit].addresses = addrs;
      }

      fclose(f);
      return ret;
}


/*
 * get_upap_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_upap_passwd(void)
{
      char *filename;
      FILE *f;
      struct wordlist *addrs;
      char secret[MAXWORDLEN];

      if ((ask_passwd || fdpasswd) && passwd[0])
            return 1;
      filename = _PATH_UPAPFILE;
      addrs = NULL;
      f = fopen(filename, "r");
      if (f == NULL)
            return 0;
      check_access(f, filename);
      if (scan_authfile(f, user, remote_name, secret, NULL, filename) < 0)
            return 0;
      strncpy(passwd, secret, MAXSECRETLEN);
      passwd[MAXSECRETLEN-1] = 0;
      return 1;
}


/*
 * have_upap_secret - check whether we have a PAP file with any
 * secrets that we could possibly use for authenticating the peer.
 */
static int have_upap_secret(void)
{
      FILE *f;
      int ret;
      char *filename;

      filename = _PATH_UPAPFILE;
      f = fopen(filename, "r");
      if (f == NULL)
            return 0;

      ret = scan_authfile(f, NULL, our_name, NULL, NULL, filename);
      fclose(f);
      if (ret < 0)
            return 0;

      return 1;
}


/*
 * 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)
{
      FILE *f;
      int ret;
      char *filename;

      filename = _PATH_CHAPFILE;
      f = fopen(filename, "r");
      if (f == NULL)
            return 0;

      if (client[0] == 0)
            client = NULL;
      else if (server[0] == 0)
            server = NULL;

      ret = scan_authfile(f, client, server, NULL, NULL, filename);
      fclose(f);
      if (ret < 0)
            return 0;

      return 1;
}


/*
 * 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(unit, client, server, secret, secret_len, save_addrs)
      int unit;
      char *client;
      char *server;
      char *secret;
      int *secret_len;
      int save_addrs;
{
      FILE *f;
      int ret, len;
      char *filename;
      struct wordlist *addrs;
      char secbuf[MAXWORDLEN];

      if ((ask_passwd || fdpasswd) && passwd[0]) {
            len = strlen(passwd);
            BCOPY(passwd, secret, len);
            *secret_len = len;
            return 1;
      }
      filename = _PATH_CHAPFILE;
      addrs = NULL;
      secbuf[0] = 0;

      f = fopen(filename, "r");
      if (f == NULL) {
            syslog(LOG_ERR, "Can't open chap secret file %s: %m", filename);
            return 0;
      }
      check_access(f, filename);

      ret = scan_authfile(f, client, server, secbuf, &addrs, filename);
      fclose(f);
      if (ret < 0)
            return 0;

      if (save_addrs) {
            if (lns[unit].addresses != NULL)
                  free_wordlist(lns[unit].addresses);
            lns[unit].addresses = addrs;
      }

      len = strlen(secbuf);
      if (len > MAXSECRETLEN) {
            syslog(LOG_ERR, "Secret for %s on %s is too long", client, server);
            len = MAXSECRETLEN;
      }
      BCOPY(secbuf, secret, len);
      *secret_len = len;

      return 1;
}

/*
 * 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,u_int32_t addr)
{
      u_int32_t a;
      int       accept;
      u_int32_t mask;
      u_char    *ptr_word, *ptr_mask;
      struct hostent *hp;
      struct netent *np;
      struct wordlist *addrs;

      /* don't allow loopback or multicast address */
      if (bad_ip_adrs(addr))
            return 0;

      if ((addrs = lns[unit].addresses) == NULL)
            return 1;                /* no restriction */

      for (; addrs != NULL; addrs = addrs->next) {
            /* "-" means no addresses authorized */
            ptr_word = addrs->word;
            if (strcmp(ptr_word, "-") == 0)
                  break;

            /* "*" means any addresses authorized */
            if (strcmp(ptr_word, "*") == 0)
                  return 1;

            accept = 1;

            if (*ptr_word == '!') {
                  accept = 0;
                  ++ptr_word;
            }

            ptr_mask = strchr (ptr_word, '/');
            if (ptr_mask == NULL)
                  mask = 0xFFFFFFFFUL;
            else {
                  int bit_count;
                  *ptr_mask = '\0';
                  bit_count = (int) strtol (ptr_mask, (char **) 0, 10);
                  if (bit_count <= 0 || bit_count > 32) {
                        syslog (LOG_WARNING,
                                    "invalid address length %s in auth. address list",
                                    ptr_mask);
                        *ptr_mask = '/';
                         continue;
                  }
                  mask = ~((1UL << (32 - bit_count)) - 1UL);
             }

            hp = gethostbyname(ptr_word);
            if (hp != NULL && hp->h_addrtype == AF_INET) {
                  a    = *(u_int32_t *)hp->h_addr;
                  mask = -1L;
            } else {
                  np = getnetbyname (ptr_word);
                  if (np != NULL && np->n_addrtype == AF_INET)
                        a = htonl ((unsigned long)np->n_net);
                  else
                        a = inet_addr (ptr_word);
            }

            if (ptr_mask)
                  *ptr_mask = '/';

            if (a == (u_int32_t)-1L)
                  syslog (LOG_WARNING,
                              "unknown host %s in auth. address list",
                              addrs->word);
            else
                  if (((addr ^ a) & mask) == 0)
                        return accept;
        }
       return 0;                        /* not in list => can't have it */
}

/*
 * 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(u_int32_t addr)
{
      addr = ntohl(addr);
      return (addr >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET
            || IN_MULTICAST(addr) || IN_BADCLASS(addr);
}

/*
 * check_access - complain if a secret file has too-liberal permissions.
 */
void check_access(FILE *f,char *filename)
{
      struct stat sbuf;

      if (fstat(fileno(f), &sbuf) < 0) {
            syslog(LOG_WARNING, "cannot stat secret file %s: %m", filename);
      } else if ((sbuf.st_mode & (S_IRWXG | S_IRWXO)) != 0) {
            syslog(LOG_WARNING, "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 (i.e. address authorization
 * info) are placed in a wordlist and returned in *addrs.  
 */
static int scan_authfile(FILE *f,char *client,char *server,char *secret,struct wordlist ** addrs,char *filename)
{
      int newline, xxx;
      int got_flag, best_flag;
      FILE *sf;
      struct wordlist *ap, *addr_list, *addr_last;
      char word[MAXWORDLEN];
      char atfile[MAXWORDLEN];

      if (addrs != NULL)
            *addrs = NULL;
      addr_list = NULL;
      if (!getword(f, word, &newline, filename))
            return -1;                /* file is empty??? */
      newline = 1;
      best_flag = -1;
      for (;;) {
            /*
             * Skip until we find a word at the start of a line.
             */
            while (!newline && getword(f, word, &newline, filename))
                  ;
            if (!newline)
                  break;                /* got to end of file */

            /*
             * Got a client - check if it's a match or a wildcard.
             */
            got_flag = 0;
            if (client != NULL && strcmp(word, client) != 0 && !ISWILD(word)) {
                  newline = 0;
                  continue;
            }
            if (!ISWILD(word))
                  got_flag = NONWILD_CLIENT;

            /*
             * Now get a server and check if it matches.
             */
            if (!getword(f, word, &newline, filename))
                  break;
            if (newline)
                  continue;
            if (server != NULL && strcmp(word, server) != 0 && !ISWILD(word))
                  continue;
            if (!ISWILD(word))
                  got_flag |= NONWILD_SERVER;

            /*
             * Got some sort of a match - see if it's better than what
             * we have already.
             */
            if (got_flag <= best_flag)
                  continue;

            /*
             * Get the secret.
             */
            if (!getword(f, word, &newline, filename))
                  break;
            if (newline)
                  continue;

            /*
             * Special syntax: @filename means read secret from file.
             */
            if (word[0] == '@') {
                  strcpy(atfile, word+1);
                  if ((sf = fopen(atfile, "r")) == NULL) {
                        syslog(LOG_WARNING, "can't open indirect secret file %s",
                                 atfile);
                        continue;
                  }
                  check_access(sf, atfile);
                  if (!getword(sf, word, &xxx, atfile)) {
                        syslog(LOG_WARNING, "no secret in indirect secret file %s",
                                 atfile);
                        fclose(sf);
                        continue;
                  }
                  fclose(sf);
            }
            if (secret != NULL)
                  strcpy(secret, word);
                        
            best_flag = got_flag;

            /*
             * Now read address authorization info and make a wordlist.
             */
            if (addr_list)
                  free_wordlist(addr_list);
            addr_list = addr_last = NULL;
            for (;;) {
                  if (!getword(f, word, &newline, filename) || newline)
                        break;
                  ap = (struct wordlist *) malloc(sizeof(struct wordlist) + strlen(word));
                  if (ap == NULL)
                        novm("authorized addresses");
                  ap->next = NULL;
                  strcpy(ap->word, word);
                  if (addr_list == NULL)
                        addr_list = ap;
                  else
                        addr_last->next = ap;
                  addr_last = ap;
            }
            if (!newline)
                  break;
      }

      if (addrs != NULL)
            *addrs = addr_list;
      else if (addr_list != NULL)
            free_wordlist(addr_list);

      return best_flag;
}

/*
 * 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 - execute a script with arguments
 * interface-name peer-name real-user tty speed remote-number [fail-reason]
 */
static void auth_script(int linkunit,char *script,int error_reason)
{
      char strspeed[32];
      struct passwd *pw;
      char struid[32];
      char *user_name;
      char *argv[9];

      if ((pw = getpwuid(getuid())) != NULL && pw->pw_name != NULL)
            user_name = pw->pw_name;
      else {
            sprintf(struid, "%d", getuid());
            user_name = struid;
      }
      sprintf(strspeed, "%d", 64000);

      argv[0] = script;
      argv[1] = lns[linkunit].ifname;
      argv[2] = lns[linkunit].peer_authname;
      argv[3] = user_name;
      argv[4] = lns[linkunit].devnam;
      argv[5] = strspeed;
      argv[6] = lns[linkunit].pci.remote_num;
      argv[7] = NULL;
      if (error_reason) {
        sprintf(struid,"%d",error_reason);
        argv[7] = struid;
        argv[8] = NULL;
      }
      run_program(script, argv, debug,linkunit);
}




Generated by  Doxygen 1.6.0   Back to index