auth.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* auth.c - PPP authentication and phase control.
*
* Copyright 2000-2002 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*
* 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.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#define RCSID "$Id: auth.c,v 1.65 2000/04/15 01:27:10 masputra Exp $"
/* Pull in crypt() definition. */
#define __EXTENSIONS__
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>
#include <pwd.h>
#include <grp.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <utmp.h>
#include <fcntl.h>
#if defined(_PATH_LASTLOG) && (defined(_linux_) || defined(__linux__))
#include <lastlog.h>
#endif
#if defined(_linux_) || defined(__linux__)
#include <crypt.h>
#endif
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
/* Backward compatibility with old Makefiles */
#if defined(USE_PAM) && !defined(ALLOW_PAM)
#define ALLOW_PAM
#endif
#ifdef ALLOW_PAM
#include <security/pam_appl.h>
#endif
#ifdef HAS_SHADOW
#include <shadow.h>
#ifndef PW_PPP
#define PW_PPP PW_LOGIN
#endif
#endif
#include "pppd.h"
#include "fsm.h"
#include "lcp.h"
#include "ipcp.h"
#include "upap.h"
#include "chap.h"
#ifdef CBCP_SUPPORT
#include "cbcp.h"
#endif
#include "pathnames.h"
#if !defined(lint) && !defined(_lint)
static const char rcsid[] = RCSID;
#endif
/* Bits in scan_authfile return value */
#define NONWILD_SERVER 1
#define NONWILD_CLIENT 2
#define ISWILD(word) (word[0] == '*' && word[1] == '\0')
/* The name by which the peer authenticated itself to us. */
char peer_authname[MAXNAMELEN];
/* 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;
/* List of addresses which the peer may use. */
static struct permitted_ip *addresses[NUM_PPP];
/* 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;
/* Source of those extra options. */
static const char *extra_opt_filename;
static int extra_opt_line;
/* 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;
/* Set if we got the contents of passwd[] from the pap-secrets file. */
static int passwd_from_file;
/* 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;
/*
* This is set by scan_authfile if a client matches, but server doesn't
* (possible configuration error).
*/
static char scan_server_match_failed[MAXWORDLEN];
/*
* Option variables.
*/
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 */
#ifdef CHAPMS
bool refuse_mschap = 0; /* Don't wanna auth. ourself with MS-CHAPv1 */
#else
bool refuse_mschap = 1; /* Never auth. ourself with MS-CHAPv1 */
#endif
#ifdef CHAPMSV2
bool refuse_mschapv2 = 0; /* Don't wanna auth. ourself with MS-CHAPv2 */
#else
bool refuse_mschapv2 = 1; /* Never auth. ourself with MS-CHAPv2 */
#endif
#ifdef USE_PAM
bool use_pam = 1; /* Enable use of PAM by default */
#else
bool use_pam = 0; /* Disable use of PAM by default */
#endif
/* Bits in auth_pending[] */
#define PAP_WITHPEER 1
#define PAP_PEER 2
#define CHAP_WITHPEER 4
#define CHAP_PEER 8
/* Prototypes for procedures local to this file. */
static void network_phase __P((int));
static void check_idle __P((void *));
static void connect_time_expired __P((void *));
static int plogin __P((char *, char *, char **));
static void plogout __P((void));
static int null_login __P((int));
static int get_pap_passwd __P((char *));
static int have_pap_secret __P((int *));
static int have_chap_secret __P((char *, char *, int, int *));
static int ip_addr_check __P((u_int32_t, struct permitted_ip *));
static int scan_authfile __P((FILE *, char *, char *, char *,
struct wordlist **, struct wordlist **,
char *));
static void free_wordlist __P((struct wordlist *));
static void auth_script __P((char *));
static void auth_script_done __P((void *, int));
static void set_allowed_addrs __P((int, struct wordlist *, struct wordlist *));
static int some_ip_ok __P((struct wordlist *));
static int setupapfile __P((char **, option_t *));
static int privgroup __P((char **, option_t *));
static int set_noauth_addr __P((char **, option_t *));
static void check_access __P((FILE *, char *));
/*
* 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 peer IP address(es) usable without authentication",
OPT_PRIV },
#ifdef CHAPMS
{ "require-mschap", o_bool, &lcp_wantoptions[0].neg_mschap,
"Require MS-CHAPv1 authentication from peer", 1, &auth_required },
{ "refuse-mschap", o_bool, &refuse_mschap,
"Don't agree to authenticate to peer with MS-CHAPv1", 1 },
#endif
#ifdef CHAPMSV2
{ "require-mschapv2", o_bool, &lcp_wantoptions[0].neg_mschapv2,
"Require MS-CHAPv2 authentication from peer", 1, &auth_required },
{ "refuse-mschapv2", o_bool, &refuse_mschapv2,
"Don't agree to authenticate to peer with MS-CHAPv2", 1 },
#endif
#ifdef ALLOW_PAM
{ "pam", o_bool, &use_pam,
"Enable use of Pluggable Authentication Modules", OPT_PRIV|1 },
{ "nopam", o_bool, &use_pam,
"Disable use of Pluggable Authentication Modules", OPT_PRIV|0 },
#endif
{ NULL }
};
/*
* setupapfile - specifies UPAP info for authenticating with peer.
*/
/*ARGSUSED*/
static int
setupapfile(argv, opt)
char **argv;
option_t *opt;
{
FILE * ufile;
int l;
lcp_allowoptions[0].neg_upap = 1;
/* open user info file */
(void) seteuid(getuid());
ufile = fopen(*argv, "r");
(void) 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;
}
(void) 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);
}
/*
* privgroup - allow members of the group to have privileged access.
*/
/*ARGSUSED*/
static int
privgroup(argv, opt)
char **argv;
option_t *opt;
{
struct group *g;
int i;
g = getgrnam(*argv);
if (g == NULL) {
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;
}
/*
* set_noauth_addr - set address(es) that can be used without authentication.
* Equivalent to specifying an entry like `"" * "" addr' in pap-secrets.
*/
/*ARGSUSED*/
static int
set_noauth_addr(argv, opt)
char **argv;
option_t *opt;
{
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;
(void) strcpy(wp->word, addr);
noauth_addrs = wp;
return 1;
}
/*
* An Open on LCP has requested a change from Dead to Establish phase.
* Do what's necessary to bring the physical layer up.
*/
/*ARGSUSED*/
void
link_required(unit)
int unit;
{
}
/*
* LCP has terminated the link; go to the Dead phase and take the
* physical layer down.
*/
/*ARGSUSED*/
void
link_terminated(unit)
int unit;
{
const char *pn1, *pn2;
if (phase == PHASE_DEAD)
return;
if (pap_logout_hook != NULL) {
(*pap_logout_hook)();
} else {
if (logged_in)
plogout();
}
new_phase(PHASE_DEAD);
if (peer_nak_auth) {
if ((pn1 = protocol_name(nak_auth_orig)) == NULL)
pn1 = "?";
if ((pn2 = protocol_name(nak_auth_proto)) == NULL)
pn2 = "?";
warn("Peer sent Configure-Nak for 0x%x (%s) to suggest 0x%x (%s)",
nak_auth_orig, pn1, nak_auth_proto, pn2);
}
if (unsolicited_nak_auth) {
if ((pn1 = protocol_name(unsolicit_auth_proto)) == NULL)
pn1 = "?";
warn("Peer unexpectedly asked us to authenticate with 0x%x (%s)",
unsolicit_auth_proto, pn1);
}
if (peer_reject_auth) {
if ((pn1 = protocol_name(reject_auth_proto)) == NULL)
pn1 = "?";
warn("Peer rejected our demand for 0x%x (%s)",
reject_auth_proto, pn1);
}
if (naked_peers_auth) {
if ((pn1 = protocol_name(naked_auth_orig)) == NULL)
pn1 = "?";
if ((pn2 = protocol_name(naked_auth_proto)) == NULL)
pn2 = "?";
warn("We set Configure-Nak for 0x%x (%s) to suggest 0x%x (%s)",
naked_auth_orig, pn1, naked_auth_proto, pn2);
}
if (rejected_peers_auth) {
if ((pn1 = protocol_name(rejected_auth_proto)) == NULL)
pn1 = "?";
warn("We rejected the peer's demand for 0x%x (%s)",
rejected_auth_proto, pn1);
}
peer_nak_auth = unsolicited_nak_auth = peer_reject_auth =
rejected_peers_auth = naked_peers_auth = 0;
nak_auth_proto = nak_auth_orig = unsolicit_auth_proto = reject_auth_proto =
rejected_auth_proto = naked_auth_orig = naked_auth_proto = 0;
notice("Connection terminated.");
}
/*
* LCP has gone down; it will either die or try to re-establish.
*/
void
link_down(unit)
int unit;
{
int i;
struct protent *protp;
auth_state = s_down;
if (auth_script_state == s_up && auth_script_pid == 0) {
update_link_stats(unit);
auth_script_state = s_down;
auth_script(_PATH_AUTHDOWN);
}
for (i = 0; (protp = 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;
num_np_up = 0;
if (phase != PHASE_DEAD)
new_phase(PHASE_TERMINATE);
}
/*
* The link is established.
* Proceed to the Dead, Authenticate or Network phase as appropriate.
*/
void
link_established(unit)
int unit;
{
int auth;
lcp_options *wo = &lcp_wantoptions[unit];
lcp_options *go = &lcp_gotoptions[unit];
lcp_options *ho = &lcp_hisoptions[unit];
int i;
struct protent *protp;
/*
* Tell higher-level protocols that LCP is up.
*/
for (i = 0; (protp = protocols[i]) != NULL; ++i)
if (protp->protocol != PPP_LCP && protp->enabled_flag
&& protp->lowerup != NULL)
(*protp->lowerup)(unit);
if (auth_required && !(go->neg_chap || go->neg_mschap ||
go->neg_mschapv2 || go->neg_upap)) {
/*
* We wanted the peer to authenticate itself, and it refused:
* if we have some address(es) it can use without auth, fine,
* otherwise 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 (noauth_addrs != NULL) {
set_allowed_addrs(unit, noauth_addrs, NULL);
} else if (!wo->neg_upap || !null_login(unit)) {
warn("peer refused to authenticate: terminating link");
lcp_close(unit, "peer refused to authenticate");
status = EXIT_PEER_AUTH_FAILED;
return;
}
}
new_phase(PHASE_AUTHENTICATE);
auth = 0;
if (go->neg_chap || go->neg_mschap || go->neg_mschapv2) {
if (go->neg_chap) {
if (debug)
dbglog("Authenticating peer with standard CHAP");
go->chap_mdtype = CHAP_DIGEST_MD5;
} else if (go->neg_mschap) {
if (debug)
dbglog("Authenticating peer with MS-CHAPv1");
go->chap_mdtype = CHAP_MICROSOFT;
} else {
if (debug)
dbglog("Authenticating peer with MS-CHAPv2");
go->chap_mdtype = CHAP_MICROSOFT_V2;
}
ChapAuthPeer(unit, our_name, go->chap_mdtype);
auth |= CHAP_PEER;
} else if (go->neg_upap) {
if (debug)
dbglog("Authenticating peer with PAP");
upap_authpeer(unit);
auth |= PAP_PEER;
}
if (ho->neg_chap || ho->neg_mschap || ho->neg_mschapv2) {
switch (ho->chap_mdtype) {
case CHAP_DIGEST_MD5:
if (debug)
dbglog("Authenticating to peer with standard CHAP");
break;
case CHAP_MICROSOFT:
if (debug)
dbglog("Authenticating to peer with MS-CHAPv1");
break;
case CHAP_MICROSOFT_V2:
if (debug)
dbglog("Authenticating to peer with MS-CHAPv2");
break;
default:
if (debug)
dbglog("Authenticating to peer with CHAP 0x%x", ho->chap_mdtype);
break;
}
ChapAuthWithPeer(unit, user, ho->chap_mdtype);
auth |= CHAP_WITHPEER;
} else if (ho->neg_upap) {
if (passwd[0] == '\0') {
passwd_from_file = 1;
if (!get_pap_passwd(passwd))
error("No secret found for PAP login");
}
if (debug)
dbglog("Authenticating to peer with PAP");
upap_authwithpeer(unit, user, passwd);
auth |= PAP_WITHPEER;
}
auth_pending[unit] = auth;
if (!auth)
network_phase(unit);
}
/*
* Proceed to the network phase.
*/
static void
network_phase(unit)
int unit;
{
lcp_options *go = &lcp_gotoptions[unit];
/*
* If the peer had to authenticate, run the auth-up script now.
*/
if (go->neg_chap || go->neg_mschap || go->neg_mschapv2 || go->neg_upap) {
auth_state = s_up;
if (auth_script_state == s_down && auth_script_pid == 0) {
auth_script_state = s_up;
auth_script(_PATH_AUTHUP);
}
}
/*
* Process extra options from the secrets file
*/
if (extra_options != NULL) {
option_source = (char *)extra_opt_filename;
option_line = extra_opt_line;
(void) options_from_list(extra_options, 1);
free_wordlist(extra_options);
extra_options = NULL;
}
#ifdef CBCP_SUPPORT
/*
* If we negotiated callback, do it now.
*/
if (go->neg_cbcp) {
new_phase(PHASE_CALLBACK);
(*cbcp_protent.open)(unit);
return;
}
#endif
start_networks();
}
void
start_networks()
{
int i;
struct protent *protp;
new_phase(PHASE_NETWORK);
#ifdef HAVE_MULTILINK
if (multilink) {
if (mp_join_bundle()) {
if (updetach && !nodetach)
detach();
return;
}
}
#endif /* HAVE_MULTILINK */
#if 0
if (!demand)
set_filters(&pass_filter, &active_filter);
#endif
for (i = 0; (protp = protocols[i]) != NULL; ++i)
if (protp->protocol < 0xC000 && protp->enabled_flag
&& protp->open != NULL) {
(*protp->open)(0);
if (protp->protocol != PPP_CCP)
++num_np_open;
}
if (num_np_open == 0)
/* nothing to do */
lcp_close(0, "No network protocols running");
}
/*
* The peer has failed to authenticate himself using `protocol'.
*/
/*ARGSUSED*/
void
auth_peer_fail(unit, protocol)
int unit, protocol;
{
/*
* Authentication failure: take the link down
*/
lcp_close(unit, "Authentication failed");
status = EXIT_PEER_AUTH_FAILED;
}
/*
* The peer has been successfully authenticated using `protocol'.
*/
void
auth_peer_success(unit, protocol, name, namelen)
int unit, protocol;
char *name;
int namelen;
{
int bit;
switch (protocol) {
case PPP_CHAP:
bit = CHAP_PEER;
break;
case PPP_PAP:
bit = PAP_PEER;
break;
default:
warn("auth_peer_success: unknown protocol %x", protocol);
return;
}
/*
* Save the authenticated name of the peer for later.
*/
if (namelen > sizeof(peer_authname) - 1)
namelen = sizeof(peer_authname) - 1;
BCOPY(name, peer_authname, namelen);
peer_authname[namelen] = '\0';
script_setenv("PEERNAME", peer_authname, 0);
/*
* If there is no more authentication still to be done,
* proceed to the network (or callback) phase.
*/
if ((auth_pending[unit] &= ~bit) == 0)
network_phase(unit);
}
/*
* We have failed to authenticate ourselves to the peer using `protocol'.
*/
/*ARGSUSED*/
void
auth_withpeer_fail(unit, protocol)
int unit, protocol;
{
if (passwd_from_file)
BZERO(passwd, MAXSECRETLEN);
/*
* We've failed to authenticate ourselves to our peer.
* Some servers keep sending CHAP challenges, but there
* is no point in persisting without any way to get updated
* authentication secrets.
*/
lcp_close(unit, "Failed to authenticate ourselves to peer");
status = EXIT_AUTH_TOPEER_FAILED;
}
/*
* We have successfully authenticated ourselves with the peer using `protocol'.
*/
void
auth_withpeer_success(unit, protocol)
int unit, protocol;
{
int bit;
switch (protocol) {
case PPP_CHAP:
bit = CHAP_WITHPEER;
break;
case PPP_PAP:
if (passwd_from_file)
BZERO(passwd, MAXSECRETLEN);
bit = PAP_WITHPEER;
break;
default:
warn("auth_withpeer_success: unknown protocol %x", protocol);
bit = 0;
}
/*
* If there is no more authentication still being done,
* proceed to the network (or callback) phase.
*/
if ((auth_pending[unit] &= ~bit) == 0)
network_phase(unit);
}
/*
* np_up - a network protocol has come up.
*/
/*ARGSUSED*/
void
np_up(unit, proto)
int unit, proto;
{
int tlim;
if (num_np_up == 0) {
/*
* At this point we consider that the link has come up successfully.
*/
status = EXIT_OK;
unsuccess = 0;
peer_nak_auth = unsolicited_nak_auth = peer_reject_auth =
rejected_peers_auth = naked_peers_auth = 0;
nak_auth_proto = nak_auth_orig = unsolicit_auth_proto =
reject_auth_proto = rejected_auth_proto = naked_auth_orig =
naked_auth_proto = 0;
new_phase(PHASE_RUNNING);
if (idle_time_hook != NULL)
tlim = (*idle_time_hook)(NULL);
else
tlim = idle_time_limit;
if (tlim > 0)
TIMEOUT(check_idle, NULL, tlim);
/*
* Set a timeout to close the connection once the maximum
* connect time has expired.
*/
if (maxconnect > 0) {
TIMEOUT(connect_time_expired, &lcp_fsm[unit], maxconnect);
/*
* Tell LCP to send Time-Remaining packets. One should be
* sent out now, at maxconnect-300, at maxconnect-120, and
* again at maxconnect-30.
*/
lcp_settimeremaining(unit, maxconnect, maxconnect);
if (maxconnect > 300)
lcp_settimeremaining(unit, maxconnect, 300);
if (maxconnect > 120)
lcp_settimeremaining(unit, maxconnect, 120);
if (maxconnect > 30)
lcp_settimeremaining(unit, maxconnect, 30);
}
/*
* Detach now, if the updetach option was given.
*/
if (updetach && !nodetach)
detach();
}
++num_np_up;
}
/*
* np_down - a network protocol has gone down.
*/
/*ARGSUSED*/
void
np_down(unit, proto)
int unit, proto;
{
if (--num_np_up == 0) {
UNTIMEOUT(check_idle, NULL);
new_phase(PHASE_NETWORK);
}
}
/*
* np_finished - a network protocol has finished using the link.
*/
/*ARGSUSED*/
void
np_finished(unit, proto)
int 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.
*/
/*ARGSUSED*/
static void
check_idle(arg)
void *arg;
{
struct ppp_idle idle;
time_t itime;
int tlim;
if (!get_idle_time(0, &idle))
return;
if (idle_time_hook != NULL) {
tlim = (*idle_time_hook)(&idle);
} else {
itime = MIN(idle.xmit_idle, idle.recv_idle);
tlim = idle_time_limit - itime;
}
if (tlim <= 0) {
/* link is idle: shut it down. */
notice("Terminating connection due to lack of activity.");
lcp_close(0, "Link inactive");
need_holdoff = 0;
status = EXIT_IDLE_TIMEOUT;
} else {
TIMEOUT(check_idle, NULL, tlim);
}
}
/*
* connect_time_expired - log a message and close the connection.
*/
/*ARGSUSED*/
static void
connect_time_expired(arg)
void *arg;
{
fsm *f = (fsm *)arg;
info("Connect time expired");
lcp_close(f->unit, "Connect time expired"); /* Close connection */
status = EXIT_CONNECT_TIME;
}
/*
* auth_check_options - called to check authentication options.
*/
void
auth_check_options()
{
lcp_options *wo = &lcp_wantoptions[0];
int can_auth;
int lacks_ip;
/* Default our_name to hostname, and user to our_name */
if (our_name[0] == '\0' || usehostname)
(void) strlcpy(our_name, hostname, sizeof(our_name));
if (user[0] == '\0')
(void) strlcpy(user, our_name, sizeof(user));
/*
* If we have a default route, require the peer to authenticate
* unless the noauth option was given or the real user is root.
*/
if (!auth_required && !allow_any_ip && have_route_to(0) && !privileged) {
auth_required = 1;
default_auth = 1;
}
/* If authentication is required, ask peer for CHAP or PAP. */
if (auth_required) {
if (!wo->neg_chap && !wo->neg_mschap && !wo->neg_mschapv2 &&
!wo->neg_upap) {
wo->neg_chap = 1;
#ifdef CHAPMS
wo->neg_mschap = 1;
#endif
#ifdef CHAPMSV2
wo->neg_mschapv2 = 1;
#endif
wo->chap_mdtype = CHAP_DIGEST_MD5;
wo->neg_upap = 1;
}
} else {
wo->neg_chap = 0;
wo->neg_mschap = 0;
wo->neg_mschapv2 = 0;
wo->neg_upap = 0;
}
/*
* Check whether we have appropriate secrets to use
* to authenticate the peer.
*/
lacks_ip = 0;
can_auth = wo->neg_upap && (uselogin || have_pap_secret(&lacks_ip));
if (!can_auth && (wo->neg_chap || wo->neg_mschap || wo->neg_mschapv2)) {
can_auth = have_chap_secret((explicit_remote? remote_name: NULL),
our_name, 1, &lacks_ip);
}
if (auth_required && !can_auth && noauth_addrs == NULL) {
if (default_auth) {
option_error(
"By default the remote system is required to authenticate itself");
option_error(
"(because this system has a default route to the Internet)");
} else if (explicit_remote)
option_error(
"The remote system (%s) is required to authenticate itself",
remote_name);
else
option_error(
"The remote system is required to authenticate itself");
option_error(
"but I couldn't find any suitable secret (password) for it to use to do so.");
if (lacks_ip)
option_error(
"(None of the available passwords would let it use an IP address.)");
exit(1);
}
}
/*
* 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(unit)
int unit;
{
lcp_options *go = &lcp_gotoptions[unit];
lcp_options *ao = &lcp_allowoptions[unit];
int havesecret;
ao->neg_upap = !refuse_pap && (passwd[0] != '\0' || get_pap_passwd(NULL));
havesecret = passwd[0] != '\0' ||
have_chap_secret(user, (explicit_remote? remote_name: NULL), 0, NULL);
ao->neg_chap = !refuse_chap && havesecret;
ao->neg_mschap = !refuse_mschap && havesecret;
ao->neg_mschapv2 = !refuse_mschapv2 && havesecret;
if (ao->neg_chap)
ao->chap_mdtype = CHAP_DIGEST_MD5;
else if (ao->neg_mschap)
ao->chap_mdtype = CHAP_MICROSOFT;
else
ao->chap_mdtype = CHAP_MICROSOFT_V2;
if (go->neg_upap && !uselogin && !have_pap_secret(NULL))
go->neg_upap = 0;
if (go->neg_chap || go->neg_mschap || go->neg_mschapv2) {
havesecret = have_chap_secret((explicit_remote? remote_name: NULL),
our_name, 1, NULL);
if (!havesecret)
go->neg_chap = go->neg_mschap = go->neg_mschapv2 = 0;
else if (go->neg_chap)
go->chap_mdtype = CHAP_DIGEST_MD5;
else if (go->neg_mschap)
go->chap_mdtype = CHAP_MICROSOFT;
else
go->chap_mdtype = CHAP_MICROSOFT_V2;
}
}
/*
* 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(unit, auser, userlen, apasswd, passwdlen, msg)
int unit;
char *auser;
int userlen;
char *apasswd;
int passwdlen;
char **msg;
{
int ret;
char *filename;
FILE *f;
struct wordlist *addrs = NULL, *opts = NULL;
char passwd[256], user[256];
char secret[MAXWORDLEN];
static int attempts = 0;
/*
* Make copies of apasswd and auser, then null-terminate them.
* If there are unprintable characters in the password, make
* them visible.
*/
(void) slprintf(passwd, sizeof(passwd), "%.*v", passwdlen, apasswd);
(void) slprintf(user, sizeof(user), "%.*v", userlen, auser);
*msg = "";
/*
* Check if a plugin wants to handle this.
*/
if (pap_auth_hook != NULL) {
/* Set a default and allow the plug-in to change it. */
extra_opt_filename = "plugin";
extra_opt_line = 0;
ret = (*pap_auth_hook)(user, passwd, msg, &addrs, &opts);
if (ret >= 0) {
if (ret > 0)
set_allowed_addrs(unit, addrs, opts);
BZERO(passwd, sizeof(passwd));
if (addrs != NULL)
free_wordlist(addrs);
return ret? UPAP_AUTHACK: UPAP_AUTHNAK;
}
}
/*
* Open the file of pap secrets and scan for a suitable secret
* for authenticating this user.
*/
filename = _PATH_UPAPFILE;
addrs = opts = NULL;
ret = UPAP_AUTHNAK;
f = fopen(filename, "r");
if (f == NULL) {
error("Can't open PAP password file %s: %m", filename);
} else {
check_access(f, filename);
if (scan_authfile(f, user, our_name, secret, &addrs, &opts, filename) < 0) {
warn("no PAP secret found for %s", user);
if (scan_server_match_failed[0] != '\0')
warn("possible configuration error: local name is %q, but "
"found %q instead", our_name, scan_server_match_failed);
} else if (secret[0] != '\0') {
/* password given in pap-secrets - must match */
if ((!cryptpap && strcmp(passwd, secret) == 0)
|| strcmp(crypt(passwd, secret), secret) == 0)
ret = UPAP_AUTHACK;
else
warn("PAP authentication failure for %s", user);
} else if (uselogin) {
/* empty password in pap-secrets and login option */
ret = plogin(user, passwd, msg);
if (ret == UPAP_AUTHNAK)
warn("PAP login failure for %s", user);
} else {
/* empty password in pap-secrets and login option not used */
ret = UPAP_AUTHACK;
}
(void) fclose(f);
}
if (ret == UPAP_AUTHNAK) {
if (**msg == '\0')
*msg = "Login incorrect";
/*
* 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) {
warn("%d LOGIN FAILURES ON %s, %s", attempts, devnam, user);
lcp_close(unit, "login failed");
}
if (attempts > 3)
(void) sleep((u_int) (attempts - 3) * 5);
if (opts != NULL)
free_wordlist(opts);
} else {
attempts = 0; /* Reset count */
if (**msg == '\0')
*msg = "Login ok";
set_allowed_addrs(unit, addrs, opts);
}
if (addrs != NULL)
free_wordlist(addrs);
BZERO(passwd, sizeof(passwd));
BZERO(secret, sizeof(secret));
return ret;
}
/*
* This function is needed for PAM.
*/
#ifdef ALLOW_PAM
/* Static variables used to communicate between the conversation function
* and the server_login function
*/
static char *PAM_username;
static char *PAM_password;
static int PAM_error = 0;
static pam_handle_t *pamh = NULL;
/* PAM conversation function
* Here we assume (for now, at least) that echo on means login name, and
* echo off means password.
*/
/*ARGSUSED*/
static int PAM_conv (int num_msg,
#ifndef SOL2
const
#endif
struct pam_message **msg, struct pam_response **resp, void *appdata_ptr)
{
int replies = 0;
struct pam_response *reply = NULL;
#define COPY_STRING(s) (s) ? strdup(s) : NULL
reply = malloc(sizeof(struct pam_response) * num_msg);
if (reply == NULL)
return PAM_CONV_ERR;
for (replies = 0; replies < num_msg; replies++) {
switch (msg[replies]->msg_style) {
case PAM_PROMPT_ECHO_ON:
reply[replies].resp_retcode = PAM_SUCCESS;
reply[replies].resp = COPY_STRING(PAM_username);
/* PAM frees resp */
break;
case PAM_PROMPT_ECHO_OFF:
reply[replies].resp_retcode = PAM_SUCCESS;
reply[replies].resp = COPY_STRING(PAM_password);
/* PAM frees resp */
break;
case PAM_TEXT_INFO:
/* fall through */
case PAM_ERROR_MSG:
/* ignore it, but pam still wants a NULL response... */
reply[replies].resp_retcode = PAM_SUCCESS;
reply[replies].resp = NULL;
break;
default:
/* Must be an error of some sort... */
free (reply);
PAM_error = 1;
return PAM_CONV_ERR;
}
}
*resp = reply;
return PAM_SUCCESS;
}
static struct pam_conv PAM_conversation = {
PAM_conv, NULL
};
#endif /* ALLOW_PAM */
/*
* 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(user, passwd, msg)
char *user;
char *passwd;
char **msg;
{
char *tty;
#ifdef HAS_SHADOW
struct spwd *spwd;
#endif
struct passwd *pw = NULL;
#ifdef ALLOW_PAM
int pam_error;
if (use_pam) {
if (debug)
dbglog("using PAM for user authentication");
pam_error = pam_start ("ppp", user, &PAM_conversation, &pamh);
if (pam_error != PAM_SUCCESS) {
*msg = (char *) pam_strerror (pamh, pam_error);
reopen_log();
return UPAP_AUTHNAK;
}
/*
* Define the fields for the credential validation
*/
PAM_username = user;
PAM_password = passwd;
PAM_error = 0;
/* this might be useful to some modules; required for Solaris */
tty = devnam;
if (*tty == '\0')
tty = ppp_devnam;
(void) pam_set_item(pamh, PAM_TTY, tty);
#ifdef PAM_RHOST
(void) pam_set_item(pamh, PAM_RHOST, "");
#endif
/*
* Validate the user
*/
pam_error = pam_authenticate (pamh, PAM_SILENT);
if (pam_error == PAM_SUCCESS && !PAM_error) {
pam_error = pam_acct_mgmt (pamh, PAM_SILENT);
if (pam_error == PAM_SUCCESS)
(void) pam_open_session (pamh, PAM_SILENT);
}
*msg = (char *) pam_strerror (pamh, pam_error);
/*
* Clean up the mess
*/
reopen_log(); /* apparently the PAM stuff does closelog() */
PAM_username = NULL;
PAM_password = NULL;
if (pam_error != PAM_SUCCESS)
return UPAP_AUTHNAK;
} else
#endif /* ALLOW_PAM */
{
if (debug) {
#ifdef HAS_SHADOW
dbglog("using passwd/shadow for user authentication");
#else
dbglog("using passwd for user authentication");
#endif
}
/*
* Use the non-PAM methods directly
*/
pw = getpwnam(user);
endpwent();
if (pw == NULL)
return (UPAP_AUTHNAK);
#ifdef HAS_SHADOW
spwd = getspnam(user);
endspent();
if (spwd != NULL) {
/* check the age of the password entry */
long now = time(NULL) / 86400L;
if ((spwd->sp_expire > 0 && now >= spwd->sp_expire)
|| ((spwd->sp_max >= 0 && spwd->sp_max < 10000)
&& spwd->sp_lstchg >= 0
&& now >= spwd->sp_lstchg + spwd->sp_max)) {
warn("Password for %s has expired", user);
return (UPAP_AUTHNAK);
}
pw->pw_passwd = spwd->sp_pwdp;
}
#endif
/*
* If no passwd, don't let them login.
*/
if (pw->pw_passwd == NULL || strlen(pw->pw_passwd) < 2 ||
strcmp(crypt(passwd, pw->pw_passwd), pw->pw_passwd) != 0)
return (UPAP_AUTHNAK);
}
/*
* Write a wtmp entry for this user.
*/
tty = devnam;
if (strncmp(tty, "/dev/", 5) == 0)
tty += 5;
logwtmp(tty, user, remote_name); /* Add wtmp login entry */
#ifdef _PATH_LASTLOG
if (!use_pam && pw != (struct passwd *)NULL) {
struct lastlog ll;
int fd;
if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) >= 0) {
(void)lseek(fd, (off_t)(pw->pw_uid * sizeof(ll)), SEEK_SET);
BZERO((void *)&ll, sizeof(ll));
(void)time(&ll.ll_time);
(void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
(void)write(fd, (char *)&ll, sizeof(ll));
(void)close(fd);
}
}
#endif /* _PATH_LASTLOG */
info("user %s logged in", user);
logged_in = 1;
return (UPAP_AUTHACK);
}
/*
* plogout - Logout the user.
*/
static void
plogout()
{
char *tty;
#ifdef ALLOW_PAM
int pam_error;
if (use_pam) {
if (pamh != NULL) {
pam_error = pam_close_session (pamh, PAM_SILENT);
(void) pam_end (pamh, pam_error);
pamh = NULL;
}
/* Apparently the pam stuff does closelog(). */
reopen_log();
} else
#endif /* ALLOW_PAM */
{
tty = devnam;
if (strncmp(tty, "/dev/", 5) == 0)
tty += 5;
/* Wipe out utmp logout entry */
logwtmp(tty, "", "");
}
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(unit)
int unit;
{
char *filename;
FILE *f;
int i, ret;
struct wordlist *addrs, *opts;
char secret[MAXWORDLEN];
/*
* Open the file of pap secrets and scan for a suitable secret.
*/
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, &opts, filename);
ret = i >= 0 && secret[0] == '\0';
BZERO(secret, sizeof(secret));
if (ret)
set_allowed_addrs(unit, addrs, opts);
else if (opts != NULL)
free_wordlist(opts);
if (addrs != NULL)
free_wordlist(addrs);
(void) fclose(f);
return ret;
}
/*
* 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.
* Assumes passwd points to MAXSECRETLEN bytes of space (if non-null).
*/
static int
get_pap_passwd(passwd)
char *passwd;
{
char *filename;
FILE *f;
int ret;
char secret[MAXWORDLEN];
/*
* Check whether a plugin wants to supply this.
*/
if (pap_passwd_hook != NULL) {
ret = (*pap_passwd_hook)(user, passwd);
if (ret >= 0)
return ret;
}
filename = _PATH_UPAPFILE;
f = fopen(filename, "r");
if (f == NULL)
return 0;
check_access(f, filename);
ret = scan_authfile(f, user,
(remote_name[0] != '\0' ? remote_name: NULL),
secret, NULL, NULL, filename);
(void) fclose(f);
if (ret < 0)
return 0;
if (passwd != NULL)
(void) strlcpy(passwd, secret, MAXSECRETLEN);
BZERO(secret, sizeof(secret));
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(lacks_ipp)
int *lacks_ipp;
{
FILE *f;
int ret;
char *filename;
struct wordlist *addrs;
/* let the plugin decide, if there is one */
if (pap_check_hook != NULL) {
ret = (*pap_check_hook)();
if (ret >= 0)
return ret;
}
filename = _PATH_UPAPFILE;
f = fopen(filename, "r");
if (f == NULL)
return 0;
ret = scan_authfile(f, (explicit_remote? remote_name: NULL), our_name,
NULL, &addrs, NULL, filename);
(void) fclose(f);
if (ret >= 0 && !some_ip_ok(addrs)) {
if (lacks_ipp != NULL)
*lacks_ipp = 1;
ret = -1;
}
if (addrs != NULL)
free_wordlist(addrs);
return ret >= 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 or both can be the null string, meaning we don't know the
* identity yet.
*/
static int
have_chap_secret(client, server, need_ip, lacks_ipp)
char *client;
char *server;
int need_ip;
int *lacks_ipp;
{
FILE *f;
int ret;
char *filename;
struct wordlist *addrs;
filename = _PATH_CHAPFILE;
f = fopen(filename, "r");
if (f == NULL)
return 0;
if (client != NULL && client[0] == '\0')
client = NULL;
if (server != NULL && server[0] == '\0')
server = NULL;
ret = scan_authfile(f, client, server, NULL, &addrs, NULL, filename);
(void) fclose(f);
if (ret >= 0 && need_ip && !some_ip_ok(addrs)) {
if (lacks_ipp != NULL)
*lacks_ipp = 1;
ret = -1;
}
if (addrs != NULL)
free_wordlist(addrs);
return ret >= 0;
}
/*
* get_secret - open the CHAP secret file and return the secret
* for authenticating the given client on the given server.
*
* "am_server" means that we're the authenticator (demanding
* identity from the peer).
*
* "!am_server" means that we're the authenticatee (supplying
* identity to the peer).
*/
int
get_secret(unit, client, server, secret, secret_len, am_server)
int unit;
char *client;
char *server;
char *secret;
int *secret_len;
int am_server;
{
FILE *f;
int ret, len;
char *filename;
struct wordlist *addrs, *opts;
char secbuf[MAXWORDLEN];
/*
* Support the 'password' option on authenticatee only in order to
* avoid obvious security problem (authenticator and authenticatee
* within a given implementation must never share secrets).
*/
if (!am_server && passwd[0] != '\0') {
(void) strlcpy(secbuf, passwd, sizeof(secbuf));
} else {
filename = _PATH_CHAPFILE;
addrs = NULL;
secbuf[0] = '\0';
f = fopen(filename, "r");
if (f == NULL) {
error("Can't open chap secret file %s: %m", filename);
return 0;
}
check_access(f, filename);
ret = scan_authfile(f, client, server, secbuf, &addrs, &opts,
filename);
(void) fclose(f);
if (ret < 0) {
if (scan_server_match_failed[0] != '\0')
warn("possible configuration error: local name is %q, but "
"found %q instead", our_name, scan_server_match_failed);
return 0;
}
/* Only the authenticator cares about limiting peer addresses. */
if (am_server)
set_allowed_addrs(unit, addrs, opts);
else if (opts != NULL)
free_wordlist(opts);
if (addrs != NULL)
free_wordlist(addrs);
}
len = strlen(secbuf);
if (len > MAXSECRETLEN) {
error("Secret for %s on %s is too long", client, server);
len = MAXSECRETLEN;
}
/* Do not leave a temporary copy of the secret on the stack. */
BCOPY(secbuf, secret, len);
BZERO(secbuf, sizeof(secbuf));
*secret_len = len;
return 1;
}
/*
* set_allowed_addrs() - set the list of allowed addresses.
* The caller must also look for `--' indicating options to apply for
* this peer and leaves the following words in extra_options.
*/
static void
set_allowed_addrs(unit, addrs, opts)
int unit;
struct wordlist *addrs;
struct wordlist *opts;
{
int n;
struct wordlist *ap, **pap;
struct permitted_ip *ip;
char *ptr_word, *ptr_mask;
struct hostent *hp;
struct netent *np;
u_int32_t a, mask, newmask, ah, offset;
struct ipcp_options *wo = &ipcp_wantoptions[unit];
u_int32_t suggested_ip = 0;
int err_num;
if (addresses[unit] != NULL)
free(addresses[unit]);
addresses[unit] = NULL;
if (extra_options != NULL)
free_wordlist(extra_options);
extra_options = opts;
/*
* Count the number of IP addresses given.
*/
for (n = 0, pap = &addrs; (ap = *pap) != NULL; pap = &ap->next)
++n;
if (n == 0)
return;
ip = (struct permitted_ip *) malloc((n + 1) * sizeof(struct permitted_ip));
if (ip == NULL)
return;
n = 0;
for (ap = addrs; ap != NULL; ap = ap->next) {
/* "-" means no addresses authorized, "*" means any address allowed */
ptr_word = ap->word;
if (strcmp(ptr_word, "-") == 0)
break;
if (strcmp(ptr_word, "*") == 0) {
ip[n].permit = 1;
ip[n].base = ip[n].mask = 0;
++n;
break;
}
ip[n].permit = 1;
if (*ptr_word == '!') {
ip[n].permit = 0;
++ptr_word;
}
mask = ~ (u_int32_t) 0;
offset = 0;
ptr_mask = strchr (ptr_word, '/');
if (ptr_mask != NULL) {
int bit_count;
char *endp;
bit_count = (int) strtol (ptr_mask+1, &endp, 10);
if (bit_count <= 0 || bit_count > 32) {
warn("invalid address length %v in authorized address list",
ptr_mask+1);
continue;
}
bit_count = 32 - bit_count; /* # bits in host part */
if (*endp == '+') {
offset = ifunit + 1;
++endp;
}
if (*endp != '\0') {
warn("invalid address length syntax: %v", ptr_mask+1);
continue;
}
*ptr_mask = '\0';
mask <<= bit_count;
}
/* Try to interpret value as host name or numeric address first */
hp = getipnodebyname(ptr_word, AF_INET, 0, &err_num);
if (hp != NULL) {
(void) memcpy(&a, hp->h_addr, sizeof(a));
freehostent(hp);
} else {
char *cp = ptr_word + strlen(ptr_word);
if (cp > ptr_word)
cp--;
if (*cp == '+') {
offset = ifunit + 1;
*cp = '\0';
}
np = getnetbyname (ptr_word);
if (np != NULL && np->n_addrtype == AF_INET) {
ah = np->n_net;
newmask = (u_int32_t)~0;
if ((ah & 0xff000000ul) == 0)
ah <<= 8, newmask <<= 8;
if ((ah & 0xff000000ul) == 0)
ah <<= 8, newmask <<= 8;
if ((ah & 0xff000000ul) == 0)
ah <<= 8, newmask <<= 8;
if (ptr_mask == NULL)
mask = newmask;
a = htonl(ah);
}
}
if (ptr_mask != NULL)
*ptr_mask = '/';
if (a == (u_int32_t)-1L) {
warn("unknown host %s in auth. address list", ap->word);
continue;
}
if (offset != 0) {
if (offset >= ~mask) {
warn("interface unit %d too large for subnet %v",
ifunit, ptr_word);
continue;
}
a = htonl((ntohl(a) & mask) + offset);
mask = ~(u_int32_t)0;
}
ip[n].mask = htonl(mask);
ip[n].base = a & ip[n].mask;
++n;
if (~mask == 0 && suggested_ip == 0)
suggested_ip = a;
}
/* Sentinel value at end of list */
ip[n].permit = 0; /* make the last entry forbid all addresses */
ip[n].base = 0; /* to terminate the list */
ip[n].mask = 0;
addresses[unit] = ip;
/*
* If the address given for the peer isn't authorized, or if
* the user hasn't given one, AND there is an authorized address
* which is a single host, then use that if we find one.
*/
if (suggested_ip != 0
&& (wo->hisaddr == 0 || !auth_ip_addr(unit, wo->hisaddr)))
wo->hisaddr = suggested_ip;
}
/*
* 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(unit, addr)
int unit;
u_int32_t addr;
{
int ok;
/* don't allow loopback or multicast address */
if (bad_ip_adrs(addr))
return 0;
if (addresses[unit] != NULL) {
ok = ip_addr_check(addr, addresses[unit]);
if (ok >= 0)
return ok;
}
if (auth_required)
return 0; /* no addresses authorized */
return allow_any_ip || privileged || !have_route_to(addr);
}
static int
ip_addr_check(addr, addrs)
u_int32_t addr;
struct permitted_ip *addrs;
{
/* This loop is safe because of the sentinel value in set_allowed_addrs */
for (; ; ++addrs)
if ((addr & addrs->mask) == addrs->base)
return addrs->permit;
}
/*
* 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(addr)
u_int32_t addr;
{
addr = ntohl(addr);
return
#ifndef ALLOW_127_NET
(addr >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
#endif
#ifndef ALLOW_0_NET
((addr >> IN_CLASSA_NSHIFT) == 0 && addr != 0) ||
#endif
IN_MULTICAST(addr) || IN_BADCLASS(addr);
}
/*
* some_ip_ok - check a wordlist to see if it authorizes any
* IP address(es).
*/
static int
some_ip_ok(addrs)
struct wordlist *addrs;
{
for (; addrs != NULL; 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(f, filename)
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. If opts is NULL, these are just
* discarded. Otherwise, the extra_opt_* variables are set to
* indicate the source of the options.
*
* We assume secret is NULL or points to MAXWORDLEN bytes of space.
*/
static int
scan_authfile(f, client, server, secret, addrs, opts, filename)
FILE *f;
char *client;
char *server;
char *secret;
struct wordlist **addrs;
struct wordlist **opts;
char *filename;
{
int newline, xxx, sline;
int got_flag, best_flag;
FILE *sf;
struct wordlist *ap, *addr_list, *alist, **app;
char word[MAXWORDLEN];
char atfile[MAXWORDLEN];
char lsecret[MAXWORDLEN];
scan_server_match_failed[0] = '\0';
if (addrs != NULL)
*addrs = NULL;
if (opts != NULL)
*opts = NULL;
addr_list = NULL;
option_line = 0;
if (!getword(f, word, &newline, filename)) {
if (debug)
dbglog("%s is apparently empty", 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 */
sline = option_line;
/*
* 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 (!ISWILD(word)) {
if (server != NULL && strcmp(word, server) != 0) {
(void) strcpy(scan_server_match_failed, word);
continue;
}
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.
* Because the secrets files are modifiable only by root,
* it's safe to open this file as root. One small addition --
* if open fails, we try as the regular user; just in case
* it's over NFS and not root-equivalent.
*/
if (word[0] == '@') {
(void) strlcpy(atfile, word+1, sizeof(atfile));
if ((sf = fopen(atfile, "r")) == NULL) {
(void) seteuid(getuid());
sf = fopen(atfile, "r");
(void) seteuid(0);
}
if (sf == NULL) {
warn("can't open indirect secret file %s: %m", atfile);
continue;
}
check_access(sf, atfile);
if (!getword(sf, word, &xxx, atfile)) {
warn("no secret in indirect secret file %s", atfile);
(void) fclose(sf);
continue;
}
(void) fclose(sf);
}
if (secret != NULL)
(void) strlcpy(lsecret, word, sizeof(lsecret));
/*
* Now read address authorization info and make a wordlist.
*/
app = &alist;
for (;;) {
if (!getword(f, word, &newline, filename) || newline)
break;
ap = (struct wordlist *) malloc(sizeof(struct wordlist));
if (ap == NULL)
novm("authorized addresses");
ap->word = strdup(word);
if (ap->word == NULL)
novm("authorized addresses");
*app = ap;
app = &ap->next;
}
*app = NULL;
/*
* This is the best so far; remember it.
*/
best_flag = got_flag;
if (addr_list != NULL)
free_wordlist(addr_list);
addr_list = alist;
if (secret != NULL)
(void) strlcpy(secret, lsecret, MAXWORDLEN);
if (opts != NULL) {
extra_opt_filename = filename;
extra_opt_line = sline;
}
if (!newline)
break;
}
/* scan for a -- word indicating the start of options */
for (app = &addr_list; (ap = *app) != NULL; app = &ap->next)
if (strcmp(ap->word, "--") == 0)
break;
/* ap = start of options */
if (ap != NULL) {
ap = ap->next; /* first option */
free(*app); /* free the "--" word */
*app = NULL; /* terminate addr list */
}
if (opts != NULL)
*opts = ap;
else if (ap != NULL)
free_wordlist(ap);
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(wp)
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.
*/
/*ARGSUSED*/
static void
auth_script_done(arg, status)
void *arg;
int status;
{
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(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 {
(void) slprintf(struid, sizeof(struid), "%d", getuid());
user_name = struid;
}
(void) 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);
}