rlm_unix.c

free radius编程。完成AAA的实现

/*
 * rlm_unix.c	authentication: Unix user authentication
 *		accounting:     Functions to write radwtmp file.
 *		Also contains handler for "Group".
 *
 * Version:	$Id: rlm_unix.c,v 1.63 2004/02/26 19:04:37 aland Exp $
 *
 *   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
 *
 * Copyright 2000  The FreeRADIUS server project
 * Copyright 2000  Jeff Carneal <[e-mail]>
 * Copyright 2000  Alan Curry <[e-mail]>
 */
static const char rcsid[] = "$Id: rlm_unix.c,v 1.63 2004/02/26 19:04:37 aland Exp $";

#include	"autoconf.h"
#include	"libradius.h"

#include	<stdlib.h>
#include	<string.h>
#include	<grp.h>
#include	<pwd.h>
#include	<sys/types.h>
#include	<sys/stat.h>

#include "config.h"

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

#ifdef OSFC2
#  include	<sys/security.h>
#  include	<prot.h>
#endif

#ifdef OSFSIA
#  include	<sia.h>
#  include	<siad.h>
#endif

#include	"radiusd.h"
#include	"modules.h"
#include	"sysutmp.h"
#include	"cache.h"
#include	"conffile.h"
#include	"compat.h"

static char trans[64] =
   "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
#define ENC(c) trans[c]

struct unix_instance {
	int cache_passwd;
	const char *passwd_file;
	const char *shadow_file;
	const char *group_file;
	const char *radwtmp;
	int usegroup;
	struct pwcache *cache;
	time_t cache_reload;
	time_t next_reload;
	time_t last_reload;
};

static CONF_PARSER module_config[] = {
	/*
	 *	Cache the password by default.
	 */
	{ "cache",    PW_TYPE_BOOLEAN,
	  offsetof(struct unix_instance,cache_passwd), NULL, "no" },
	{ "passwd",   PW_TYPE_STRING_PTR,
	  offsetof(struct unix_instance,passwd_file), NULL,  NULL },
	{ "shadow",   PW_TYPE_STRING_PTR,
	  offsetof(struct unix_instance,shadow_file), NULL,  NULL },
	{ "group",    PW_TYPE_STRING_PTR,
	  offsetof(struct unix_instance,group_file), NULL,   NULL },
	{ "radwtmp",  PW_TYPE_STRING_PTR,
	  offsetof(struct unix_instance,radwtmp), NULL,   "NULL" },
	{ "usegroup", PW_TYPE_BOOLEAN,
	  offsetof(struct unix_instance,usegroup), NULL,     "no" },
	{ "cache_reload", PW_TYPE_INTEGER,
	  offsetof(struct unix_instance,cache_reload), NULL, "600" },

	{ NULL, -1, 0, NULL, NULL }		/* end the list */
};

/*
 * groupcmp is part of autz. But it uses the data from an auth instance. So
 * here is where it gets it. By default this will be the first configured
 * auth instance. That can be changed by putting "usegroup = yes" inside an
 * auth instance to explicitly bind all Group checks to it.
 */

/* binds "Group=" to an instance (a particular passwd file) */
static struct unix_instance *group_inst;

/* Tells if the above binding was explicit (usegroup=yes specified in config
 * file) or not ("Group=" was bound to the first instance of rlm_unix */
static int group_inst_explicit;

#ifdef HAVE_GETSPNAM
#if defined(M_UNIX)
static inline const char *get_shadow_name(shadow_pwd_t *spwd) {
	if (spwd == NULL) return NULL;
	return (spwd->pw_name);
}

static inline const char *get_shadow_encrypted_pwd(shadow_pwd_t *spwd) {
	if (spwd == NULL) return NULL;
	return (spwd->pw_passwd);
}
#else /* M_UNIX */
	static inline const char *get_shadow_name(shadow_pwd_t *spwd) {
		if (spwd == NULL) return NULL;
		return (spwd->sp_namp);
	}
	static inline const char *get_shadow_encrypted_pwd(shadow_pwd_t *spwd) {
		if (spwd == NULL) return NULL;
		return (spwd->sp_pwdp);
	}
#endif	/* M_UNIX */
#endif	/* HAVE_GETSPNAM */

static struct passwd *fgetpwnam(const char *fname, const char *name) {
	FILE		*file = fopen(fname, "ro");
	struct passwd	*pwd = NULL;

	if(file == NULL) return NULL;
	do {
		pwd = fgetpwent(file);
		if(pwd == NULL) {
			fclose(file);
			return NULL;
		}
	} while (strcmp(name, pwd->pw_name) != 0);

	fclose(file);
	return pwd;
}

static struct group *fgetgrnam(const char *fname, const char *name) {
	FILE		*file = fopen(fname, "ro");
	struct group	*grp = NULL;

	if(file == NULL) return NULL;

	do {
		grp = fgetgrent(file);
		if(grp == NULL) {
			fclose(file);
			return NULL;
		}
	} while(strcmp(name, grp->gr_name) != 0);
	fclose(file);
	return grp;
}

#ifdef HAVE_GETSPNAM

static shadow_pwd_t *fgetspnam(const char *fname, const char *name) {
	FILE		*file = fopen(fname, "ro");
	shadow_pwd_t	*spwd = NULL;

	if(file == NULL) return NULL;
	do {
		spwd = fgetspent(file);
		if(spwd == NULL) {
			fclose(file);
			return NULL;
		}
	} while(strcmp(name, get_shadow_name(spwd)) != 0);
	fclose(file);
	return spwd;
}

#endif

/*
 *	The Group = handler.
 */
static int groupcmp(void *instance, REQUEST *req, VALUE_PAIR *request,
		    VALUE_PAIR *check, VALUE_PAIR *check_pairs,
		    VALUE_PAIR **reply_pairs)
{
	struct passwd	*pwd;
	struct group	*grp;
	char		**member;
	char		*username;
	int		retval;
	VALUE_PAIR	*vp;

	instance = instance;
	check_pairs = check_pairs;
	reply_pairs = reply_pairs;

	if (!group_inst) {
		radlog(L_ERR, "groupcmp: no group list known.");
		return 1;
	}

	/*
	 *	No user name, doesn't compare.
	 */
	vp = pairfind(request, PW_STRIPPED_USER_NAME);
	if (!vp) {
		vp = pairfind(request, PW_USER_NAME);
		if (!vp) {
			return -1;
		}
	}
	username = (char *)vp->strvalue;

	if (group_inst->cache_passwd &&
	    (retval = H_groupcmp(group_inst->cache, check, username)) != -2)
		return retval;

	if (group_inst->passwd_file)
		pwd = fgetpwnam(group_inst->passwd_file, username);
	else
		pwd = getpwnam(username);
	if (pwd == NULL)
		return -1;

	if (group_inst->group_file)
		grp = fgetgrnam(group_inst->group_file, (char *)check->strvalue);
	else
		grp = getgrnam((char *)check->strvalue);
	if (grp == NULL)
		return -1;

	retval = (pwd->pw_gid == grp->gr_gid) ? 0 : -1;
	if (retval < 0) {
		for (member = grp->gr_mem; *member && retval; member++) {
			if (strcmp(*member, pwd->pw_name) == 0)
				retval = 0;
		}
	}
	return retval;
}


/*
 *	FIXME:	We really should have an 'init' which makes
 *	System auth == Unix
 */
static int unix_init(void)
{
	/* FIXME - delay these until a group file has been read so we know
	 * groupcmp can actually do something */
	paircompare_register(PW_GROUP, PW_USER_NAME, groupcmp, NULL);
#ifdef PW_GROUP_NAME /* compat */
	paircompare_register(PW_GROUP_NAME, PW_USER_NAME, groupcmp, NULL);
#endif
	return 0;
}

static int unix_instantiate(CONF_SECTION *conf, void **instance)
{
	struct unix_instance *inst;

	/*
	 *	Allocate room for the instance.
	 */
	inst = *instance = rad_malloc(sizeof(*inst));
	if (!inst) {
		return -1;
	}
	memset(inst, 0, sizeof(*inst));

	/*
	 *	Parse the configuration, failing if we can't do so.
	 */
	if (cf_section_parse(conf, inst, module_config) < 0) {
		free(inst);
		return -1;
	}

	if (inst->cache_passwd) {
		radlog(L_INFO, "HASH:  Reinitializing hash structures "
			"and lists for caching...");
		if ((inst->cache = unix_buildpwcache(inst->passwd_file,
						     inst->shadow_file,
						     inst->group_file))==NULL)
                {
			radlog(L_ERR, "HASH:  unable to create user "
				"hash table.  disable caching and run debugs");
			if (inst->passwd_file)
				free((char *) inst->passwd_file);
			if (inst->shadow_file)
				free((char *) inst->shadow_file);
			if (inst->group_file)
				free((char *) inst->group_file);
			if (inst->radwtmp)
				free((char *) inst->radwtmp);
			free(inst);
			return -1;
		}

		if (inst->cache_reload) {
			inst->last_reload = 0;
			inst->next_reload = time(NULL) + inst->cache_reload;
		}
	} else {
		inst->cache = NULL;
	}

	if (inst->usegroup) {
		if (group_inst_explicit) {
			radlog(L_ERR, "Only one group list may be active");
		} else {
			group_inst = inst;
			group_inst_explicit = 1;
		}
	} else if (!group_inst) {
		group_inst = inst;
	}
#undef inst

	return 0;
}

/*
 *	Detach.
 */
static int unix_detach(void *instance)
{
#define inst ((struct unix_instance *)instance)
	if (group_inst == inst) {
		group_inst = NULL;
		group_inst_explicit = 0;
	}
	if (inst->passwd_file)
		free((char *) inst->passwd_file);
	if (inst->shadow_file)
		free((char *) inst->shadow_file);
	if (inst->group_file)
		free((char *) inst->group_file);
	if (inst->radwtmp)
		free((char *) inst->radwtmp);
	if (inst->cache) {
		unix_freepwcache(inst->cache);
	}
#undef inst
	free(instance);
	return 0;
}

static int unix_destroy(void)
{
	paircompare_unregister(PW_GROUP, groupcmp);
#ifdef PW_GROUP_NAME
	paircompare_unregister(PW_GROUP_NAME, groupcmp);
#endif
	return 0;
}


/*
 *	Check the users password against the standard UNIX
 *	password table.
 */
static int unix_authenticate(void *instance, REQUEST *request)
{
#define inst ((struct unix_instance *)instance)
	char *name, *passwd;
	struct passwd	*pwd;
	const char	*encrypted_pass;
	int		ret;
#ifdef HAVE_GETSPNAM
	shadow_pwd_t	*spwd = NULL;
#endif
#ifdef OSFC2
	struct pr_passwd *pr_pw;
#endif
#ifdef OSFSIA
	char		*info[2];
	char		*progname = "radius";
	SIAENTITY	*ent = NULL;
#endif
#ifdef HAVE_GETUSERSHELL
	char		*shell;
#endif

	/* See if we should refresh the cache */
	if (inst->cache && inst->cache_reload
	 && (inst->next_reload < request->timestamp)) {
		/* Time to refresh, maybe ? */
		int must_reload = 0;
		struct stat statbuf;

		DEBUG2("rlm_users : Time to refresh cache.");
		/* Check if any of the files has changed */
		if (inst->passwd_file
		 && (stat(inst->passwd_file, &statbuf) != -1)
		 && (statbuf.st_mtime > inst->last_reload)) {
			must_reload++;
		}

		if (inst->shadow_file
		 && (stat(inst->shadow_file, &statbuf) != -1)
		 && (statbuf.st_mtime > inst->last_reload)) {
			must_reload++;
		}

		if (inst->group_file
		 && (stat(inst->group_file, &statbuf) != -1)
		 && (statbuf.st_mtime > inst->last_reload)) {
			must_reload++;
		}