rlm_ldap.c

RADIUS认证协议

/*
 * rlm_ldap.c	LDAP authorization and authentication module.
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * This module is based on LDAP patch to Cistron radiusd by James Golovich
 * <[e-mail]>, which in turn was based mostly on a Mysql+Cistron patch
 * from <[e-mail]>
 *
 * 17 Jan 2000,	Adrian Pavlykevych <[e-mail]>
 *	- OpenLDAP SDK porting, basic TLS support, LDAP authorization,
 *	  fault tolerance with multiple LDAP server support
 * 24 May 2000,	Adrian Pavlykevych <[e-mail]>
 *	- Converting to new configuration file format, futher improvements
 *	  in fault tolerance, threaded operation
 * 12 Dec 2000,	Adrian Pavlykevych <[e-mail]>
 *	- Added preliminary support for multiple instances
 * 	- moved all instance configuration into dynamicly allocated structure
 *	- Removed connection maintenance thread and all attempts for multihreading
 *	  the module itself. OpenLDAP SDK is not thread safe when used with shared
 *	  LDAP connection.
 *	- Added configuration option for defining LDAP attribute of user object,
 *	  which controls remote access.
 * 16 Feb 2001, Hannu Laurila <[e-mail]>
 * 	- LDAP<->RADIUS attribute mappings are now read from a file
 *  	- Support for generic RADIUS check and reply attribute.
 * Jun 2001, Kostas Kalevras <[e-mail]>
 *	- Fix: check and reply attributes from LDAP _replace_ existing ones
 *	- Added "default_profile" directive, which points to radiusProfile
 *	  object, which contains default values for RADIUS users
 *	- Added "profile_attribute" directive, which specifies user object
 *	  attribute pointing to radiusProfile object.
 * Nov 2001, Kostas Kalevras <[e-mail]>
 *	- Added support for adding the user password to the check. Based on
 *	  the password_header directive rlm_ldap will strip the
 *	  password header if needed. This will make support for CHAP much easier.
 *	- Added module messages when we reject a user.
 *	- Added ldap_groupcmp to allow searching for user group membership.
 *	- Added ldap_xlat to allow ldap urls in xlat strings. Something like:
 *	  %{ldap:ldap:///dc=company,dc=com?cn?sub?uid=user}
 * Nov 2001, Gordon Tetlow <[e-mail]>
 *	- Do an xlat on the access_group attribute.
 * Dec 2001, Kostas Kalevras <[e-mail]>
 *	- Added ldap caching for the default/regular profiles and group entries.
 *	- Fixed a memory leak in ldap_xlat.
 *	- Removed dict_attrbyname from ldap_pairget. They are not needed.
 *	- Moved the radius_xlat's for filter and basedn in ldap_authenticate() to
 *	  the right place.
 *	- Made the module thread safe. We create a connection pool and each thread
 *	  will call ldap_get_conn to lock one of the ldap connections and release with
 *	  a call to ldap_release_conn when it has finished.
 *	- Request only the user attributes that interest us (radius attributes,regular
 *	  profile,user password and access attribute).
 * Mar 2002, Kostas Kalevras <[e-mail]>
 *	- Fixed a bug where the ldap server will kill the idle connections from the ldap
 *	  connection pool. We now check if ldap_search returns LDAP_SERVER_DOWN and try to
 *	  reconnect if it does. Bug noted by Dan Perik <[e-mail]>
 * May 2002, Kostas Kalevras <[e-mail]>
 *	- Instead of the Group attribute we now have the Ldap-Group attribute, to avoid
 *	  collisions with other modules
 *	- If perform_search fails check the ld != NULL before using it. Based on a bug report
 *	  by John <[e-mail]>
 * Jun 2002, Kostas Kalevras <[e-mail]>
 *	- Add the ability to do a paircmp on the check items. Add a compare_check_items boolean
 *	  configuration directive which defaults to no. If it is set then we will do a compare
 *	- Add another configuration directive. access_attr_used_for_allow. If it is set to yes
 *	  then the access_attr will be used to allow user access. If it is set to no then it will
 *	  be used to deny user access.
 *	- Remember to free inst->atts in ldap_detach()
 *	- Add a forgotten ldap_free_urldesc in ldap_xlat()
 *	- Add a variable locked in the LDAP_CONN structure. We use this to avoid deadlocks. The mutex
 *	  we are using is of type fast and can deadlock if the same thread tries to relock it. That
 *	  could happen in case of calls to xlat.
 *	- When ldap_search returns NO_SUCH_OBJECT don't return fail but notfound
 * Jul 2002, Kostas Kalevras <[e-mail]>
 *	- Fix the logic when we get an LDAP_SERVER_DOWN or we have conn->ld == NULL in perform_search
 *	- Try to minimize the penalty of having the ldap server go down. The comments before
 *	  MAX_FAILED_CONNS_* definitions should explain things.
 *	- Check for a number of error codes from ldap_search and log corresponding error messages
 *	  We should only reconnect when that can help things.
 *	- In ldap_groupcmp instead of first searching for the group object and then checking user
 *	  group membership combine them in one ldap search operation. That should make group
 *	  membership checks a lot faster.
 *	- Remember to do ldap_release_conn and ldap_msgfree when we do paircmp and the result is reject
 * Aug 2002, Kostas Kalevras <[e-mail]>
 *	- Add support for group membership attribute inside the user entry in ldap_groupcmp. The attribute
 *	  can either contain the name or the DN of the group. Added the groupmembership_attribute
 *	  configuration directive
 *	- Move the ldap_{get,release}_conn in ldap_groupcmp so that we hold a connection for the minimum time.
 *	- Now that ldap_groupcmp is complete we really don't need access_group. Removed it.
 *	- Remember to free groupmembership_attribute in ldap_detach
 *	- Don't delete existing generic attributes in ldap_pairget when adding new ones. Since generic attributes
 *	  have operators we don't need to try to be cleaver.
 * Sep 2002, Kostas Kalevras <[e-mail]>
 *	- Fix a crash in ldap_pairget when the attribute value is larger than the buffer size
 *	  Bug report by Stefan Radovanovici <[e-mail]>
 *	- If we add a check item then use the == operator. Based on an idea by Allister Maguire <[e-mail]>
 *	- Only add a failure message for bind as user failed in ldap_authenticate if the result of ldap_connect was
 *	  RLM_MODULE_REJECT
 *	- Make tls_mode a configurable option. Patch from John <[e-mail]>
 *	- Allow multiple regular profiles for an entry
 * Oct 2002, Kostas Kalevras <[e-mail]>
 *	- Disable cache after searching for the default profile
 *	- Use the MAX_FAILED_CONNS_* in ldap_authenticate() when calling ldap_connect()
 * Nov 2002, Kostas Kalevras <[e-mail]>
 *	- Set LDAP version to V3 before binding. Now freeradius should work with openldap21
 * Dec 2002, Kostas Kalevras <[e-mail]>
 *	- Set default values for the server and basedn parameters
 * Feb 2003, Kostas Kalevras <[e-mail]>
 *	- Add support for ldap_initialize. That way we can specify the server as an ldap url.
 *	  Based on ideas from Derrik Pates <[e-mail]>
 * Mar 2003, Kostas Kalevras <[e-mail]>
 * 	- Add an ldap_escape_func. Escape the * character from the filter so that we can avoid
 * 	  the trivial DoS of username=*
 * 	- Remove the caching code. It does not exist in openldap21.
 *	  Based on a report from Mike Denka <[e-mail]>
 * May 2003, Kostas Kalevras <[e-mail]>
 *	- Don't do a double free on the attribute maps. Bug noted by Derrik Pates <[e-mail]>
 *	- Apply a patch from Alexander M. Pravking <[e-mail]> to do an xlat on the
 *	  retrieved attributes.
 * Aug 2003, Kostas Kalevras <[e-mail]>
 *	- In case of a bad search filter, print out the corresponding filter
 * Sep 2003, Kostas Kalevras <[e-mail]>
 *	- Compile even if we don't have pthread's
 * Oct 2003, Kostas Kalevras <[e-mail]>
 *	- Add a new configuration directive, base_filter which is used for base scope searches
 *	  (When searching for the default/regular profiles for example)
 * Nov 2003, Kostas Kalevras <[e-mail]>
 *	- Add a new configuration directive, do_xlat (default: yes). If set we use pairxlatmove
 *	  on the radius attributes, else we fall back to the plain old pairadd. That way people
 *	  can fall back on the 0.8.1 behaviour without making changes to their ldap database or
 *	  gain a little performance by not using pairxlatmove
 * Dec 2003, Kostas Kalevras <[e-mail]>
 *	- Add a patch from Jon Miner <[e-mail]> to add the ability to configure
 *	  various LDAP TLS options
 *	- Only call pairfree if we are using pairxlatmove not for pairadd
 * Mar 2004, Kostas Kalevras <[e-mail]>
 *	- If we are passed an empty password log a module failure message not an error message
 * Apr 2004, Kostas Kalveras <[e-mail]>
 *	- Add a patch from Tarun Bhushan <[e-mail]> to add a tls_mode boolean
 *	  directive so that we can enable TLS connetions even if port is not set to 636
 *	- Add an error message if ldap_initialize() is not available and we are passed a URL like
 *	  'server' directive.
 *	- Add a per instance Ldap-Group attribute (of the form <instance>-Ldap-Group) and register
 *	  a corresponding ldap_groupcmp function
 *	- Small change to ldap_get_conn to fix problems on some platforms
 */
static const char rcsid[] = "$Id: rlm_ldap.c,v 1.122.2.7 2005/08/29 16:09:56 aland Exp $";

#include "autoconf.h"

#include	<sys/types.h>
#include	<sys/socket.h>
#include	<sys/time.h>
#include	<netinet/in.h>

#include	<stdio.h>
#include	<stdlib.h>
#include	<netdb.h>
#include	<pwd.h>
#include	<time.h>
#include	<ctype.h>
#include	<string.h>

#include	<lber.h>
#include        <ldap.h>

#include	<errno.h>
#include	<unistd.h>
#include	<pthread.h>

#include        "libradius.h"
#include	"radiusd.h"
#include	"conffile.h"
#include	"modules.h"
#include	"rad_assert.h"

#ifndef HAVE_PTHREAD_H
/*
 *      This is a lot simpler than putting ifdef's around
 *      every use of the pthread functions.
 */
#define pthread_mutex_lock(a)
#define pthread_mutex_unlock(a)
#define pthread_mutex_init(a,b)
#define pthread_mutex_destroy(a)
#endif


#define MAX_FILTER_STR_LEN	1024
#define TIMELIMIT 5

/*
 * These are used in case ldap_search returns LDAP_SERVER_DOWN
 * In that case we do conn->failed_conns++ and then check it:
 * If conn->failed_conns <= MAX_FAILED_CONNS_START then we try
 * to reconnect
 * conn->failed_conns is also checked on entrance in perform_search:
 * If conn->failed_conns > MAX_FAILED_CONNS_START then we don't
 * try to do anything and we just do conn->failed_conns++ and
 * return RLM_MODULE_FAIL
 * if conn->failed_conns >= MAX_FAILED_CONNS_END then we give it
 * another chance and we set it to MAX_FAILED_CONNS_RESTART and
 * try to reconnect.
 *
 *
 * We are assuming that the majority of the LDAP_SERVER_DOWN cases
 * will either be an ldap connection timeout or a temporary ldap
 * server problem.
 * As a result we make a few attempts to reconnect hoping that the problem
 * will soon go away. If it does not go away then we just return
 * RLM_MODULE_FAIL on entrance in perform_search until conn->failed_conns
 * gets to MAX_FAILED_CONNS_END. After that we give it one more chance by
 * going back to MAX_FAILED_CONNS_RESTART
 *
 */

#define MAX_FAILED_CONNS_END		20
#define MAX_FAILED_CONNS_RESTART	4
#define MAX_FAILED_CONNS_START		5

#ifdef NOVELL_UNIVERSAL_PASSWORD

/* Universal Password Length */
#define UNIVERSAL_PASS_LEN 256

int nmasldap_get_password(
	LDAP	 *ld,
	char     *objectDN,
	size_t   *pwdSize,	/* in bytes */
	char     *pwd );

#endif

/* linked list of mappings between RADIUS attributes and LDAP attributes */
struct TLDAP_RADIUS {
	char*                 attr;
	char*                 radius_attr;
	struct TLDAP_RADIUS*  next;
};
typedef struct TLDAP_RADIUS TLDAP_RADIUS;

typedef struct ldap_conn {
	LDAP		*ld;
	char		bound;
	char		locked;
	int		failed_conns;
#ifdef HAVE_PTHREAD_H
	pthread_mutex_t	mutex;
#endif
} LDAP_CONN;

typedef struct {
	char           *server;
	int             port;
	int             timelimit;
	struct timeval  net_timeout;
	struct timeval  timeout;
	int             debug;
	int             tls_mode;
	int		start_tls;
	int		num_conns;
	int		do_comp;
	int		do_xlat;
	int		default_allow;
	int		failed_conns;
	int		is_url;
	char           *login;
	char           *password;
	char           *filter;
	char           *base_filter;
	char           *basedn;
	char           *default_profile;
	char           *profile_attr;
	char           *access_attr;
	char           *passwd_hdr;
	char           *passwd_attr;
	char           *dictionary_mapping;
	char	       *groupname_attr;
	char	       *groupmemb_filt;
	char           *groupmemb_attr;
	char		**atts;
	TLDAP_RADIUS   *check_item_map;
	TLDAP_RADIUS   *reply_item_map;
	LDAP_CONN	*conns;
#ifdef NOVELL
	LDAP_CONN *apc_conns;
#endif
	int             ldap_debug; /* Debug flag for LDAP SDK */
	char		*xlat_name; /* name used to xlat */
	char		*tls_cacertfile;
	char		*tls_cacertdir;
	char		*tls_certfile;
	char		*tls_keyfile;
	char		*tls_randfile;
	char		*tls_require_cert;
#ifdef NOVELL
	int			edir_account_policy_check;
#endif
}               ldap_instance;

/* The default setting for TLS Certificate Verification */
#define TLS_DEFAULT_VERIFY "allow"

static CONF_PARSER module_config[] = {
	{"server", PW_TYPE_STRING_PTR, offsetof(ldap_instance,server), NULL, "localhost"},
	{"port", PW_TYPE_INTEGER, offsetof(ldap_instance,port), NULL, "389"},
	/* wait forever on network activity */
	{"net_timeout", PW_TYPE_INTEGER, offsetof(ldap_instance,net_timeout.tv_sec), NULL, "10"},
	/* wait forever for search results */
	{"timeout", PW_TYPE_INTEGER, offsetof(ldap_instance,timeout.tv_sec), NULL, "20"},
	/* allow server unlimited time for search (server-side limit) */
	{"timelimit", PW_TYPE_INTEGER, offsetof(ldap_instance,timelimit), NULL, "20"},
	{"identity", PW_TYPE_STRING_PTR, offsetof(ldap_instance,login), NULL, ""},
	{"tls_mode", PW_TYPE_BOOLEAN, offsetof(ldap_instance,tls_mode), NULL, "no"},
	{"start_tls", PW_TYPE_BOOLEAN, offsetof(ldap_instance,start_tls), NULL, "no"},
	{"tls_cacertfile", PW_TYPE_STRING_PTR, offsetof(ldap_instance,tls_cacertfile), NULL, NULL},
	{"tls_cacertdir", PW_TYPE_STRING_PTR, offsetof(ldap_instance,tls_cacertdir), NULL, NULL},
	{"tls_certfile", PW_TYPE_STRING_PTR, offsetof(ldap_instance,tls_certfile), NULL, NULL},
	{"tls_keyfile", PW_TYPE_STRING_PTR, offsetof(ldap_instance,tls_keyfile), NULL, NULL},
	{"tls_randfile", PW_TYPE_STRING_PTR, offsetof(ldap_instance,tls_randfile), NULL, NULL},
	{"tls_require_cert", PW_TYPE_STRING_PTR, offsetof(ldap_instance,tls_require_cert), NULL, TLS_DEFAULT_VERIFY},
	{"password", PW_TYPE_STRING_PTR, offsetof(ldap_instance,password), NULL, ""},
	{"basedn", PW_TYPE_STRING_PTR, offsetof(ldap_instance,basedn), NULL, "o=notexist"},
	{"filter", PW_TYPE_STRING_PTR, offsetof(ldap_instance,filter), NULL, "(uid=%u)"},
	{"base_filter", PW_TYPE_STRING_PTR, offsetof(ldap_instance,base_filter), NULL, "(objectclass=radiusprofile)"},
	{"default_profile", PW_TYPE_STRING_PTR, offsetof(ldap_instance,default_profile), NULL, NULL},
	{"profile_attribute", PW_TYPE_STRING_PTR, offsetof(ldap_instance,profile_attr), NULL, NULL},
	{"password_header", PW_TYPE_STRING_PTR, offsetof(ldap_instance,passwd_hdr), NULL, NULL},
	{"password_attribute", PW_TYPE_STRING_PTR, offsetof(ldap_instance,passwd_attr), NULL, NULL},
	/* LDAP attribute name that controls remote access */
	{"access_attr", PW_TYPE_STRING_PTR, offsetof(ldap_instance,access_attr), NULL, NULL},
	/* file with mapping between LDAP and RADIUS attributes */
	{"groupname_attribute", PW_TYPE_STRING_PTR, offsetof(ldap_instance,groupname_attr), NULL, "cn"},
	{"groupmembership_filter", PW_TYPE_STRING_PTR, offsetof(ldap_instance,groupmemb_filt), NULL, "(|(&(objectClass=GroupOfNames)(member=%{Ldap-UserDn}))(&(objectClass=GroupOfUniqueNames)(uniquemember=%{Ldap-UserDn})))"},
	{"groupmembership_attribute", PW_TYPE_STRING_PTR, offsetof(ldap_instance,groupmemb_attr), NULL, NULL},
	{"dictionary_mapping", PW_TYPE_STRING_PTR, offsetof(ldap_instance,dictionary_mapping), NULL, "${confdir}/ldap.attrmap"},
	{"ldap_debug", PW_TYPE_INTEGER, offsetof(ldap_instance,ldap_debug), NULL, "0x0000"},
	{"ldap_connections_number", PW_TYPE_INTEGER, offsetof(ldap_instance,num_conns), NULL, "5"},
	{"compare_check_items", PW_TYPE_BOOLEAN, offsetof(ldap_instance,do_comp), NULL, "no"},
	{"access_attr_used_for_allow", PW_TYPE_BOOLEAN, offsetof(ldap_instance,default_allow), NULL, "yes"},
	{"do_xlat", PW_TYPE_BOOLEAN, offsetof(ldap_instance,do_xlat), NULL, "yes"},
#ifdef NOVELL
	{"edir_account_policy_check", PW_TYPE_BOOLEAN, offsetof(ldap_instance,edir_account_policy_check), NULL, "yes"},
#endif

	{NULL, -1, 0, NULL, NULL}
};

#define ld_valid                ld_options.ldo_valid
#define LDAP_VALID_SESSION      0x2
#define LDAP_VALID(ld)  ( (ld)->ld_valid == LDAP_VALID_SESSION )

#ifdef FIELDCPY
static void     fieldcpy(char *, char **);
#endif
static VALUE_PAIR *ldap_pairget(LDAP *, LDAPMessage *, TLDAP_RADIUS *,VALUE_PAIR **,char);
static int ldap_groupcmp(void *, REQUEST *, VALUE_PAIR *, VALUE_PAIR *, VALUE_PAIR *, VALUE_PAIR **);
static int ldap_xlat(void *, REQUEST *, char *, char *, size_t, RADIUS_ESCAPE_STRING);
static LDAP    *ldap_connect(void *instance, const char *, const char *, int, int *, char **);
static int     read_mappings(ldap_instance* inst);

static inline int ldap_get_conn(LDAP_CONN *conns,LDAP_CONN **ret,void *instance)
{
	ldap_instance *inst = instance;
	register int i = 0;

	for(i=0;i<inst->num_conns;i++){
		DEBUG("rlm_ldap: ldap_get_conn: Checking Id: %d",i);
		if (conns[i].locked == 0 && pthread_mutex_trylock(&(conns[i].mutex)) == 0){
			*ret = &conns[i];
			conns[i].locked = 1;
			DEBUG("rlm_ldap: ldap_get_conn: Got Id: %d",i);