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/* eurephia-auth.c -- Main OpenVPN plug-in functions.
* The API level between OpenVPN and eurephia-auth
*
* GPLv2 only - Copyright (C) 2008 - 2010
* David Sommerseth <dazo@users.sourceforge.net>
*
* 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; version 2
* of the License.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
/**
* @file eurephia-auth.c
* @author David Sommerseth <dazo@users.sourceforge.net>
* @date 2008-08-06
*
* @brief Implements the API which the OpenVPN plug-in interface requires
*
*/
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "openvpn-plugin.h"
#define EUREPHIA_FWINTF
#include <eurephiafw_struct.h>
#include <eurephia_context.h>
#include <eurephiadb.h>
#include <eurephia.h>
#include <eurephia_nullsafe.h>
#include <eurephia_values.h>
#include <environment.h>
#ifdef ENABLE_DEBUG /* To avoid compiler warnings when ENABLE_DEBUG is not defined */
/**
* Simple "converter" from OPENVPN_PLUGIN_* type IDs to string
*
* @param type int value, corresponding to an OPENVPN_PLUGIN_* type
*
* @return String containing the string version of the type
*/
static const char *plugin_type_name(const int type)
{
switch (type)
{
case OPENVPN_PLUGIN_UP:
return "PLUGIN_UP";
case OPENVPN_PLUGIN_DOWN:
return "PLUGIN_DOWN";
case OPENVPN_PLUGIN_ROUTE_UP:
return "PLUGIN_ROUTE_UP";
case OPENVPN_PLUGIN_IPCHANGE:
return "PLUGIN_IPCHANGE";
case OPENVPN_PLUGIN_TLS_VERIFY:
return "PLUGIN_TLS_VERIFY";
case OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY:
return "PLUGIN_AUTH_USER_PASS_VERIFY";
case OPENVPN_PLUGIN_CLIENT_CONNECT:
return "PLUGIN_CLIENT_CONNECT";
case OPENVPN_PLUGIN_CLIENT_DISCONNECT:
return "PLUGIN_CLIENT_DISCONNECT";
case OPENVPN_PLUGIN_LEARN_ADDRESS:
return "PLUGIN_LEARN_ADDRESS";
default:
return "(UNKNOWN PLUGIN CODE)";
}
}
/**
* Dumps the contents of the environmental table to the given FILE. This function is only available
* if DEBUG is defined during compilation. If SHOW_SECRETS is not defined, it will mask the contents
* of the password field, if found.
*
* @param f FILE * where the contents will be dumped
* @param prefix Adds a fixed prefix to each of the lines
* @param envp openvpn environmental table
*/
static void dump_env(FILE *f, const char *prefix, const char *envp[]) {
int i;
for (i = 0; envp[i]; i++) {
#ifdef SHOW_SECRETS
fprintf(f, "%s%s\n", prefix, envp[i]);
#else
fprintf(f, "%s%s\n", prefix ,
(strncmp(envp[i], "password=", 9) == 0) ? "password=xxxxxxx" : envp[i]);
#endif // SHOW_SECRETS
}
}
#endif // ENABLE_DEBUG
/**
* Simple function for converting a device name/type string to
* a OVPN_tunnelType constant
*/
static OVPN_tunnelType conv_str2tuntype(const char *str) {
if( str ) {
if( strncmp(str, "tun", 3) == 0 ) {
return tuntype_TUN;
} else if( strncmp(str, "tap", 3) == 0 ) {
return tuntype_TAP;
}
}
return tuntype_UNKN;
}
static inline int detect_tunnel_type(eurephiaCTX *ctx, const char const *env[]) {
char *devname = NULL;
char *devtype = NULL;
OVPN_tunnelType tuntype = tuntype_UNKN;
int forced = 0;
devname = GETENV_DEVNAME(ctx, env);
// Check if eurephia is configured to override the device type
devtype = eGet_value(ctx->dbc->config, "openvpn_devtype");
if( devtype ) {
tuntype = conv_str2tuntype(devtype);
if( tuntype == tuntype_UNKN ) {
eurephia_log(ctx, LOG_ERR, 0,
"Unkown openvpn_devtype configuration value: '%s'. "
"Will try to auto-detect the type for the %s device.",
devtype, devname);
free_nullsafe(ctx, devtype);
} else {
ctx->tuntype = tuntype;
forced = 1;
goto success;
}
}
// Check if we got the 'dev_type' environment variable
devtype = GETENV_DEVTYPE(ctx, env);
tuntype = conv_str2tuntype(devtype);
if( tuntype != tuntype_UNKN ) {
ctx->tuntype = tuntype;
goto success;
}
// If no 'dev_type', try to guess the dev-type based on the dev name
tuntype = conv_str2tuntype(devname);
if( tuntype != tuntype_UNKN ) {
ctx->tuntype = tuntype;
goto success;
}
// If we're here, it's an unknown device type
eurephia_log(ctx, LOG_FATAL, 0,
"Could not detect automatically which device type the %s device is. "
"You need to force the tunnel device type setting the 'openvpn_devtype' "
"configuration value.",
devname);
return 0;
success:
eurephia_log(ctx, LOG_INFO, 1,
"OpenVPN device type is %s %s on the %s device.",
(forced ? "forced to" : "detected as"),
(tuntype == tuntype_TUN ? "TUN" : "TAP"), devname);
free_nullsafe(ctx, devtype);
free_nullsafe(ctx, devname);
return 1;
}
/**
* Prepares a eurephiaCTX (context) for the openvpn process and tells openvpn which hooks eurephia
* will make use of.
*
* @param type_mask int pointer, containing the hooks eurephia will make use of
* @param argv arguments from the openvpn --plugin configuration option.
* @param envp openvpn environmental table
*
* @return Returns a pointer to the eurephiaCTX.
*/
OPENVPN_EXPORT openvpn_plugin_handle_t openvpn_plugin_open_v1(unsigned int *type_mask,
const char *argv[], const char *envp[])
{
eurephiaCTX *context = NULL;
#ifdef MEMWATCH
mwStatistics(3);
#warning MEMWATCH enabled
#endif
// Define what will trigger eurephia
*type_mask = OPENVPN_PLUGIN_MASK(OPENVPN_PLUGIN_UP)
| OPENVPN_PLUGIN_MASK(OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY)
| OPENVPN_PLUGIN_MASK(OPENVPN_PLUGIN_TLS_VERIFY)
| OPENVPN_PLUGIN_MASK(OPENVPN_PLUGIN_CLIENT_CONNECT)
| OPENVPN_PLUGIN_MASK(OPENVPN_PLUGIN_CLIENT_DISCONNECT)
| OPENVPN_PLUGIN_MASK(OPENVPN_PLUGIN_LEARN_ADDRESS);
// Setup a eurephia context
context = eurephiaInit(argv, envp);
context->tuntype = tuntype_UNKN; // Make sure tunnel type is unknown
return (openvpn_plugin_handle_t) context;
}
/**
* On each hook defined in openvpn_plugin_open_v1(), this function will be called when
* openvpn reaches that phase.
*
* @param handle Contains a pointer to the eurephiaCTX
* @param type What kind of event is openvpn processing now
* @param argv openvpn arguments for the current event
* @param envp openvpn environmental table
*
* @return Returns OPENVPN_PLUGIN_FUNC_SUCCESS on success, otherwise OPENVPN_PLUGIN_FUNC_ERROR
*/
OPENVPN_EXPORT int openvpn_plugin_func_v1(openvpn_plugin_handle_t handle,
const int type,
const char *argv[], const char *envp[])
{
eurephiaCTX *ctx = (eurephiaCTX *) handle;
int result = 0;
if( (ctx == NULL) || (ctx->dbc == NULL) || (ctx->dbc->dbhandle == NULL) ) {
return OPENVPN_PLUGIN_FUNC_ERROR;
}
DEBUG(ctx, 10, "openvpn_plugin_func_v1(ctx, %s, ...)", plugin_type_name(type));
#ifdef ENABLE_DEBUG
if( (ctx->log->loglevel >= 30) && (ctx->log->logfile != NULL) ) {
dump_env(ctx->log->logfile, "ENV: ", envp);
dump_env(ctx->log->logfile, "ARG: ", argv);
}
#endif
switch( type ) {
case OPENVPN_PLUGIN_UP:
result = detect_tunnel_type(ctx, envp); // Figure out what kind of tunnel type we got.
if( result == 0 ) {
// If we cannot identify the tunnel type, we will anyway reject
// OpenVPN from starting up. In that case, shutdown eurephia properly
eurephiaShutdown(ctx);
}
break;
case OPENVPN_PLUGIN_TLS_VERIFY: // Validate certificates
result = eurephia_tlsverify(ctx, envp, argv[1]);
break;
case OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY: // Validate user name and password
result = eurephia_userauth(ctx, envp);
break;
case OPENVPN_PLUGIN_CLIENT_CONNECT: // Register login
result = eurephia_connect(ctx, envp);
break;
case OPENVPN_PLUGIN_CLIENT_DISCONNECT: // Register logout
result = eurephia_disconnect(ctx, envp);
break;
case OPENVPN_PLUGIN_LEARN_ADDRESS: // Log IP address, MAC address and update firewall
result = eurephia_learn_address(ctx, argv[1], argv[2], envp);
break;
default: // This should normally not be reached at all
eurephia_log(ctx, LOG_FATAL, 0, "Unknown OPENVPN_PLUGIN type: %i", type);
break;
}
return (result == 1 ? OPENVPN_PLUGIN_FUNC_SUCCESS : OPENVPN_PLUGIN_FUNC_ERROR);
}
/**
* Called when openvpn is shutting down. This makes sure that eurephia disconnects,
* unloads drivers and frees the memory it has been using.
*
* @param handle Contains a pointer to the eurephiaCTX
*/
OPENVPN_EXPORT void openvpn_plugin_close_v1(openvpn_plugin_handle_t handle)
{
eurephiaCTX *ctx = (eurephiaCTX *) handle;
eurephiaShutdown(ctx);
}
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