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Diffstat (limited to 'include/openvpn-plugin.h')
| -rw-r--r-- | include/openvpn-plugin.h | 883 |
1 files changed, 883 insertions, 0 deletions
diff --git a/include/openvpn-plugin.h b/include/openvpn-plugin.h new file mode 100644 index 0000000..e20f463 --- /dev/null +++ b/include/openvpn-plugin.h @@ -0,0 +1,883 @@ +/* include/openvpn-plugin.h. Generated from openvpn-plugin.h.in by configure. */ +/* + * OpenVPN -- An application to securely tunnel IP networks + * over a single TCP/UDP port, with support for SSL/TLS-based + * session authentication and key exchange, + * packet encryption, packet authentication, and + * packet compression. + * + * Copyright (C) 2002-2018 OpenVPN Inc <sales@openvpn.net> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + * + * 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. + */ + +#ifndef OPENVPN_PLUGIN_H_ +#define OPENVPN_PLUGIN_H_ + +#define OPENVPN_PLUGIN_VERSION 3 + +#ifdef ENABLE_CRYPTO_MBEDTLS +#include <mbedtls/x509_crt.h> +#ifndef __OPENVPN_X509_CERT_T_DECLARED +#define __OPENVPN_X509_CERT_T_DECLARED +typedef mbedtls_x509_crt openvpn_x509_cert_t; +#endif +#else /* ifdef ENABLE_CRYPTO_MBEDTLS */ +#include <openssl/x509.h> +#ifndef __OPENVPN_X509_CERT_T_DECLARED +#define __OPENVPN_X509_CERT_T_DECLARED +typedef X509 openvpn_x509_cert_t; +#endif +#endif + +#include <stdarg.h> +#include <stddef.h> + +#ifdef __cplusplus +extern "C" { +#endif + +/* Provide some basic version information to plug-ins at OpenVPN compile time + * This is will not be the complete version + */ +#define OPENVPN_VERSION_MAJOR 2 +#define OPENVPN_VERSION_MINOR 5 +#define OPENVPN_VERSION_PATCH "_beta3" + +/* + * Plug-in types. These types correspond to the set of script callbacks + * supported by OpenVPN. + * + * This is the general call sequence to expect when running in server mode: + * + * Initial Server Startup: + * + * FUNC: openvpn_plugin_open_v1 + * FUNC: openvpn_plugin_client_constructor_v1 (this is the top-level "generic" + * client template) + * FUNC: openvpn_plugin_func_v1 OPENVPN_PLUGIN_UP + * FUNC: openvpn_plugin_func_v1 OPENVPN_PLUGIN_ROUTE_UP + * + * New Client Connection: + * + * FUNC: openvpn_plugin_client_constructor_v1 + * FUNC: openvpn_plugin_func_v1 OPENVPN_PLUGIN_ENABLE_PF + * FUNC: openvpn_plugin_func_v1 OPENVPN_PLUGIN_TLS_VERIFY (called once for every cert + * in the server chain) + * FUNC: openvpn_plugin_func_v1 OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY + * FUNC: openvpn_plugin_func_v1 OPENVPN_PLUGIN_TLS_FINAL + * FUNC: openvpn_plugin_func_v1 OPENVPN_PLUGIN_IPCHANGE + * + * [If OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY returned OPENVPN_PLUGIN_FUNC_DEFERRED, + * we don't proceed until authentication is verified via auth_control_file] + * + * FUNC: openvpn_plugin_func_v1 OPENVPN_PLUGIN_CLIENT_CONNECT_V2 + * FUNC: openvpn_plugin_func_v1 OPENVPN_PLUGIN_LEARN_ADDRESS + * + * [Client session ensues] + * + * For each "TLS soft reset", according to reneg-sec option (or similar): + * + * FUNC: openvpn_plugin_func_v1 OPENVPN_PLUGIN_ENABLE_PF + * + * FUNC: openvpn_plugin_func_v1 OPENVPN_PLUGIN_TLS_VERIFY (called once for every cert + * in the server chain) + * FUNC: openvpn_plugin_func_v1 OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY + * FUNC: openvpn_plugin_func_v1 OPENVPN_PLUGIN_TLS_FINAL + * + * [If OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY returned OPENVPN_PLUGIN_FUNC_DEFERRED, + * we expect that authentication is verified via auth_control_file within + * the number of seconds defined by the "hand-window" option. Data channel traffic + * will continue to flow uninterrupted during this period.] + * + * [Client session continues] + * + * FUNC: openvpn_plugin_func_v1 OPENVPN_PLUGIN_CLIENT_DISCONNECT + * FUNC: openvpn_plugin_client_destructor_v1 + * + * [ some time may pass ] + * + * FUNC: openvpn_plugin_func_v1 OPENVPN_PLUGIN_LEARN_ADDRESS (this coincides with a + * lazy free of initial + * learned addr object) + * Server Shutdown: + * + * FUNC: openvpn_plugin_func_v1 OPENVPN_PLUGIN_DOWN + * FUNC: openvpn_plugin_client_destructor_v1 (top-level "generic" client) + * FUNC: openvpn_plugin_close_v1 + */ +#define OPENVPN_PLUGIN_UP 0 +#define OPENVPN_PLUGIN_DOWN 1 +#define OPENVPN_PLUGIN_ROUTE_UP 2 +#define OPENVPN_PLUGIN_IPCHANGE 3 +#define OPENVPN_PLUGIN_TLS_VERIFY 4 +#define OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY 5 +#define OPENVPN_PLUGIN_CLIENT_CONNECT 6 +#define OPENVPN_PLUGIN_CLIENT_DISCONNECT 7 +#define OPENVPN_PLUGIN_LEARN_ADDRESS 8 +#define OPENVPN_PLUGIN_CLIENT_CONNECT_V2 9 +#define OPENVPN_PLUGIN_TLS_FINAL 10 +#define OPENVPN_PLUGIN_ENABLE_PF 11 +#define OPENVPN_PLUGIN_ROUTE_PREDOWN 12 +#define OPENVPN_PLUGIN_CLIENT_CONNECT_DEFER 13 +#define OPENVPN_PLUGIN_CLIENT_CONNECT_DEFER_V2 14 +#define OPENVPN_PLUGIN_N 15 + +/* + * Build a mask out of a set of plug-in types. + */ +#define OPENVPN_PLUGIN_MASK(x) (1<<(x)) + +/* + * A pointer to a plugin-defined object which contains + * the object state. + */ +typedef void *openvpn_plugin_handle_t; + +/* + * Return value for openvpn_plugin_func_v1 function + */ +#define OPENVPN_PLUGIN_FUNC_SUCCESS 0 +#define OPENVPN_PLUGIN_FUNC_ERROR 1 +#define OPENVPN_PLUGIN_FUNC_DEFERRED 2 + +/* + * For Windows (needs to be modified for MSVC) + */ +#if defined(_WIN32) && !defined(OPENVPN_PLUGIN_H) +#define OPENVPN_EXPORT __declspec(dllexport) +#else +#define OPENVPN_EXPORT +#endif + +/* + * If OPENVPN_PLUGIN_H is defined, we know that we are being + * included in an OpenVPN compile, rather than a plugin compile. + */ +#ifdef OPENVPN_PLUGIN_H + +/* + * We are compiling OpenVPN. + */ +#define OPENVPN_PLUGIN_DEF typedef +#define OPENVPN_PLUGIN_FUNC(name) (*name) + +#else /* ifdef OPENVPN_PLUGIN_H */ + +/* + * We are compiling plugin. + */ +#define OPENVPN_PLUGIN_DEF OPENVPN_EXPORT +#define OPENVPN_PLUGIN_FUNC(name) name + +#endif + +/* + * Used by openvpn_plugin_func to return structured + * data. The plugin should allocate all structure + * instances, name strings, and value strings with + * malloc, since OpenVPN will assume that it + * can free the list by calling free() over the same. + */ +struct openvpn_plugin_string_list +{ + struct openvpn_plugin_string_list *next; + char *name; + char *value; +}; + + +/* openvpn_plugin_{open,func}_v3() related structs */ + +/** + * Defines version of the v3 plugin argument structs + * + * Whenever one or more of these structs are modified, this constant + * must be updated. A changelog should be appended in this comment + * as well, to make it easier to see what information is available + * in the different versions. + * + * Version Comment + * 1 Initial plugin v3 structures providing the same API as + * the v2 plugin interface, X509 certificate information + + * a logging API for plug-ins. + * + * 2 Added ssl_api member in struct openvpn_plugin_args_open_in + * which identifies the SSL implementation OpenVPN is compiled + * against. + * + * 3 Added ovpn_version, ovpn_version_major, ovpn_version_minor + * and ovpn_version_patch to provide the runtime version of + * OpenVPN to plug-ins. + * + * 4 Exported secure_memzero() as plugin_secure_memzero() + * + * 5 Exported openvpn_base64_encode() as plugin_base64_encode() + * Exported openvpn_base64_decode() as plugin_base64_decode() + */ +#define OPENVPN_PLUGINv3_STRUCTVER 5 + +/** + * Definitions needed for the plug-in callback functions. + */ +typedef enum +{ + PLOG_ERR = (1 << 0),/* Error condition message */ + PLOG_WARN = (1 << 1),/* General warning message */ + PLOG_NOTE = (1 << 2),/* Informational message */ + PLOG_DEBUG = (1 << 3),/* Debug message, displayed if verb >= 7 */ + + PLOG_ERRNO = (1 << 8),/* Add error description to message */ + PLOG_NOMUTE = (1 << 9), /* Mute setting does not apply for message */ + +} openvpn_plugin_log_flags_t; + + +#ifdef __GNUC__ +#if __USE_MINGW_ANSI_STDIO +#define _ovpn_chk_fmt(a, b) __attribute__ ((format(gnu_printf, (a), (b)))) +#else +#define _ovpn_chk_fmt(a, b) __attribute__ ((format(__printf__, (a), (b)))) +#endif +#else /* ifdef __GNUC__ */ +#define _ovpn_chk_fmt(a, b) +#endif + +typedef void (*plugin_log_t)(openvpn_plugin_log_flags_t flags, + const char *plugin_name, + const char *format, ...) _ovpn_chk_fmt (3, 4); + +typedef void (*plugin_vlog_t)(openvpn_plugin_log_flags_t flags, + const char *plugin_name, + const char *format, + va_list arglist) _ovpn_chk_fmt (3, 0); +/* #undef _ovpn_chk_fmt */ + +/** + * Export of secure_memzero() to be used inside plug-ins + * + * @param data Pointer to data to zeroise + * @param len Length of data, in bytes + * + */ +typedef void (*plugin_secure_memzero_t)(void *data, size_t len); + +/** + * Export of openvpn_base64_encode() to be used inside plug-ins + * + * @param data Pointer to data to BASE64 encode + * @param size Length of data, in bytes + * @param *str Pointer to the return buffer. This needed memory is + * allocated by openvpn_base64_encode() and needs to be free()d + * after use. + * + * @return int Returns the length of the buffer created, or -1 on error. + * + */ +typedef int (*plugin_base64_encode_t)(const void *data, int size, char **str); + +/** + * Export of openvpn_base64_decode() to be used inside plug-ins + * + * @param str Pointer to the BASE64 encoded data + * @param data Pointer to the buffer where save the decoded data + * @param size Size of the destination buffer + * + * @return int Returns the length of the decoded data, or -1 on error or + * if the destination buffer is too small. + * + */ +typedef int (*plugin_base64_decode_t)(const char *str, void *data, int size); + + +/** + * Used by the openvpn_plugin_open_v3() function to pass callback + * function pointers to the plug-in. + * + * plugin_log + * plugin_vlog : Use these functions to add information to the OpenVPN log file. + * Messages will only be displayed if the plugin_name parameter + * is set. PLOG_DEBUG messages will only be displayed with plug-in + * debug log verbosity (at the time of writing that's verb >= 7). + * + * plugin_secure_memzero + * : Use this function to securely wipe sensitive information from + * memory. This function is declared in a way that the compiler + * will not remove these function calls during the compiler + * optimization phase. + */ +struct openvpn_plugin_callbacks +{ + plugin_log_t plugin_log; + plugin_vlog_t plugin_vlog; + plugin_secure_memzero_t plugin_secure_memzero; + plugin_base64_encode_t plugin_base64_encode; + plugin_base64_decode_t plugin_base64_decode; +}; + +/** + * Used by the openvpn_plugin_open_v3() function to indicate to the + * plug-in what kind of SSL implementation OpenVPN uses. This is + * to avoid SEGV issues when OpenVPN is complied against mbed TLS + * and the plug-in against OpenSSL. + */ +typedef enum { + SSLAPI_NONE, + SSLAPI_OPENSSL, + SSLAPI_MBEDTLS +} ovpnSSLAPI; + +/** + * Arguments used to transport variables to the plug-in. + * The struct openvpn_plugin_args_open_in is only used + * by the openvpn_plugin_open_v3() function. + * + * STRUCT MEMBERS + * + * type_mask : Set by OpenVPN to the logical OR of all script + * types which this version of OpenVPN supports. + * + * argv : a NULL-terminated array of options provided to the OpenVPN + * "plug-in" directive. argv[0] is the dynamic library pathname. + * + * envp : a NULL-terminated array of OpenVPN-set environmental + * variables in "name=value" format. Note that for security reasons, + * these variables are not actually written to the "official" + * environmental variable store of the process. + * + * callbacks : a pointer to the plug-in callback function struct. + * + */ +struct openvpn_plugin_args_open_in +{ + const int type_mask; + const char **const argv; + const char **const envp; + struct openvpn_plugin_callbacks *callbacks; + const ovpnSSLAPI ssl_api; + const char *ovpn_version; + const unsigned int ovpn_version_major; + const unsigned int ovpn_version_minor; + const char *const ovpn_version_patch; +}; + + +/** + * Arguments used to transport variables from the plug-in back + * to the OpenVPN process. The struct openvpn_plugin_args_open_return + * is only used by the openvpn_plugin_open_v3() function. + * + * STRUCT MEMBERS + * + * type_mask : The plug-in should set this value to the logical OR of all script + * types which the plug-in wants to intercept. For example, if the + * script wants to intercept the client-connect and client-disconnect + * script types: + * + * type_mask = OPENVPN_PLUGIN_MASK(OPENVPN_PLUGIN_CLIENT_CONNECT) + * | OPENVPN_PLUGIN_MASK(OPENVPN_PLUGIN_CLIENT_DISCONNECT) + * + * handle : Pointer to a global plug-in context, created by the plug-in. This pointer + * is passed on to the other plug-in calls. + * + * return_list : used to return data back to OpenVPN. + * + */ +struct openvpn_plugin_args_open_return +{ + int type_mask; + openvpn_plugin_handle_t handle; + struct openvpn_plugin_string_list **return_list; +}; + +/** + * Arguments used to transport variables to and from the + * plug-in. The struct openvpn_plugin_args_func is only used + * by the openvpn_plugin_func_v3() function. + * + * STRUCT MEMBERS: + * + * type : one of the PLUGIN_x types. + * + * argv : a NULL-terminated array of "command line" options which + * would normally be passed to the script. argv[0] is the dynamic + * library pathname. + * + * envp : a NULL-terminated array of OpenVPN-set environmental + * variables in "name=value" format. Note that for security reasons, + * these variables are not actually written to the "official" + * environmental variable store of the process. + * + * handle : Pointer to a global plug-in context, created by the plug-in's openvpn_plugin_open_v3(). + * + * per_client_context : the per-client context pointer which was returned by + * openvpn_plugin_client_constructor_v1, if defined. + * + * current_cert_depth : Certificate depth of the certificate being passed over + * + * *current_cert : X509 Certificate object received from the client + * + */ +struct openvpn_plugin_args_func_in +{ + const int type; + const char **const argv; + const char **const envp; + openvpn_plugin_handle_t handle; + void *per_client_context; + int current_cert_depth; + openvpn_x509_cert_t *current_cert; +}; + + +/** + * Arguments used to transport variables to and from the + * plug-in. The struct openvpn_plugin_args_func is only used + * by the openvpn_plugin_func_v3() function. + * + * STRUCT MEMBERS: + * + * return_list : used to return data back to OpenVPN for further processing/usage by + * the OpenVPN executable. + * + */ +struct openvpn_plugin_args_func_return +{ + struct openvpn_plugin_string_list **return_list; +}; + +/* + * Multiple plugin modules can be cascaded, and modules can be + * used in tandem with scripts. The order of operation is that + * the module func() functions are called in the order that + * the modules were specified in the config file. If a script + * was specified as well, it will be called last. If the + * return code of the module/script controls an authentication + * function (such as tls-verify or auth-user-pass-verify), then + * every module and script must return success (0) in order for + * the connection to be authenticated. + * + * Notes: + * + * Plugins which use a privilege-separation model (by forking in + * their initialization function before the main OpenVPN process + * downgrades root privileges and/or executes a chroot) must + * daemonize after a fork if the "daemon" environmental variable is + * set. In addition, if the "daemon_log_redirect" variable is set, + * the plugin should preserve stdout/stderr across the daemon() + * syscall. See the daemonize() function in plugin/auth-pam/auth-pam.c + * for an example. + */ + +/* + * Prototypes for functions which OpenVPN plug-ins must define. + */ + +/* + * FUNCTION: openvpn_plugin_open_v2 + * + * REQUIRED: YES + * + * Called on initial plug-in load. OpenVPN will preserve plug-in state + * across SIGUSR1 restarts but not across SIGHUP restarts. A SIGHUP reset + * will cause the plugin to be closed and reopened. + * + * ARGUMENTS + * + * *type_mask : Set by OpenVPN to the logical OR of all script + * types which this version of OpenVPN supports. The plug-in + * should set this value to the logical OR of all script types + * which the plug-in wants to intercept. For example, if the + * script wants to intercept the client-connect and + * client-disconnect script types: + * + * *type_mask = OPENVPN_PLUGIN_MASK(OPENVPN_PLUGIN_CLIENT_CONNECT) + * | OPENVPN_PLUGIN_MASK(OPENVPN_PLUGIN_CLIENT_DISCONNECT) + * + * argv : a NULL-terminated array of options provided to the OpenVPN + * "plug-in" directive. argv[0] is the dynamic library pathname. + * + * envp : a NULL-terminated array of OpenVPN-set environmental + * variables in "name=value" format. Note that for security reasons, + * these variables are not actually written to the "official" + * environmental variable store of the process. + * + * return_list : used to return data back to OpenVPN. + * + * RETURN VALUE + * + * An openvpn_plugin_handle_t value on success, NULL on failure + */ +OPENVPN_PLUGIN_DEF openvpn_plugin_handle_t OPENVPN_PLUGIN_FUNC(openvpn_plugin_open_v2) + (unsigned int *type_mask, + const char *argv[], + const char *envp[], + struct openvpn_plugin_string_list **return_list); + +/* + * FUNCTION: openvpn_plugin_func_v2 + * + * Called to perform the work of a given script type. + * + * REQUIRED: YES + * + * ARGUMENTS + * + * handle : the openvpn_plugin_handle_t value which was returned by + * openvpn_plugin_open. + * + * type : one of the PLUGIN_x types + * + * argv : a NULL-terminated array of "command line" options which + * would normally be passed to the script. argv[0] is the dynamic + * library pathname. + * + * envp : a NULL-terminated array of OpenVPN-set environmental + * variables in "name=value" format. Note that for security reasons, + * these variables are not actually written to the "official" + * environmental variable store of the process. + * + * per_client_context : the per-client context pointer which was returned by + * openvpn_plugin_client_constructor_v1, if defined. + * + * return_list : used to return data back to OpenVPN. + * + * RETURN VALUE + * + * OPENVPN_PLUGIN_FUNC_SUCCESS on success, OPENVPN_PLUGIN_FUNC_ERROR on failure + * + * In addition, OPENVPN_PLUGIN_FUNC_DEFERRED may be returned by + * OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY, OPENVPN_PLUGIN_CLIENT_CONNECT and + * OPENVPN_PLUGIN_CLIENT_CONNECT_V2. This enables asynchronous + * authentication or client connect where the plugin (or one of its agents) + * may indicate authentication success/failure or client configuration some + * number of seconds after the return of the function handler. + * For OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY and OPENVPN_PLUGIN_CLIENT_CONNECT + * this is done by writing a single char to the file named by + * auth_control_file/client_connect_deferred_file + * in the environmental variable list (envp). + * + * In addition the OPENVPN_PLUGIN_CLIENT_CONNECT_DEFER and + * OPENVPN_PLUGIN_CLIENT_CONNECT_DEFER_V2 are called when OpenVPN tries to + * get the deferred result. For a V2 call implementing this function is + * required as information is not passed by files. For the normal version + * the call is optional. + * + * first char of auth_control_file: + * '0' -- indicates auth failure + * '1' -- indicates auth success + * + * OpenVPN will delete the auth_control_file after it goes out of scope. + * + * If an OPENVPN_PLUGIN_ENABLE_PF handler is defined and returns success + * for a particular client instance, packet filtering will be enabled for that + * instance. OpenVPN will then attempt to read the packet filter configuration + * from the temporary file named by the environmental variable pf_file. This + * file may be generated asynchronously and may be dynamically updated during the + * client session, however the client will be blocked from sending or receiving + * VPN tunnel packets until the packet filter file has been generated. OpenVPN + * will periodically test the packet filter file over the life of the client + * instance and reload when modified. OpenVPN will delete the packet filter file + * when the client instance goes out of scope. + * + * Packet filter file grammar: + * + * [CLIENTS DROP|ACCEPT] + * {+|-}common_name1 + * {+|-}common_name2 + * . . . + * [SUBNETS DROP|ACCEPT] + * {+|-}subnet1 + * {+|-}subnet2 + * . . . + * [END] + * + * Subnet: IP-ADDRESS | IP-ADDRESS/NUM_NETWORK_BITS + * + * CLIENTS refers to the set of clients (by their common-name) which + * this instance is allowed ('+') to connect to, or is excluded ('-') + * from connecting to. Note that in the case of client-to-client + * connections, such communication must be allowed by the packet filter + * configuration files of both clients. + * + * SUBNETS refers to IP addresses or IP address subnets which this + * instance may connect to ('+') or is excluded ('-') from connecting + * to. + * + * DROP or ACCEPT defines default policy when there is no explicit match + * for a common-name or subnet. The [END] tag must exist. A special + * purpose tag called [KILL] will immediately kill the client instance. + * A given client or subnet rule applies to both incoming and outgoing + * packets. + * + * See plugin/defer/simple.c for an example on using asynchronous + * authentication and client-specific packet filtering. + */ +OPENVPN_PLUGIN_DEF int OPENVPN_PLUGIN_FUNC(openvpn_plugin_func_v2) + (openvpn_plugin_handle_t handle, + const int type, + const char *argv[], + const char *envp[], + void *per_client_context, + struct openvpn_plugin_string_list **return_list); + + +/* + * FUNCTION: openvpn_plugin_open_v3 + * + * REQUIRED: YES + * + * Called on initial plug-in load. OpenVPN will preserve plug-in state + * across SIGUSR1 restarts but not across SIGHUP restarts. A SIGHUP reset + * will cause the plugin to be closed and reopened. + * + * ARGUMENTS + * + * version : fixed value, defines the API version of the OpenVPN plug-in API. The plug-in + * should validate that this value is matching the OPENVPN_PLUGINv3_STRUCTVER + * value. + * + * arguments : Structure with all arguments available to the plug-in. + * + * retptr : used to return data back to OpenVPN. + * + * RETURN VALUE + * + * OPENVPN_PLUGIN_FUNC_SUCCESS on success, OPENVPN_PLUGIN_FUNC_ERROR on failure + */ +OPENVPN_PLUGIN_DEF int OPENVPN_PLUGIN_FUNC(openvpn_plugin_open_v3) + (const int version, + struct openvpn_plugin_args_open_in const *arguments, + struct openvpn_plugin_args_open_return *retptr); + +/* + * FUNCTION: openvpn_plugin_func_v3 + * + * Called to perform the work of a given script type. + * + * REQUIRED: YES + * + * ARGUMENTS + * + * version : fixed value, defines the API version of the OpenVPN plug-in API. The plug-in + * should validate that this value is matching the OPENVPN_PLUGIN_VERSION value. + * + * handle : the openvpn_plugin_handle_t value which was returned by + * openvpn_plugin_open. + * + * return_list : used to return data back to OpenVPN. + * + * RETURN VALUE + * + * OPENVPN_PLUGIN_FUNC_SUCCESS on success, OPENVPN_PLUGIN_FUNC_ERROR on failure + * + * In addition, OPENVPN_PLUGIN_FUNC_DEFERRED may be returned by + * OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY. This enables asynchronous + * authentication where the plugin (or one of its agents) may indicate + * authentication success/failure some number of seconds after the return + * of the OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY handler by writing a single + * char to the file named by auth_control_file in the environmental variable + * list (envp). + * + * first char of auth_control_file: + * '0' -- indicates auth failure + * '1' -- indicates auth success + * + * OpenVPN will delete the auth_control_file after it goes out of scope. + * + * If an OPENVPN_PLUGIN_ENABLE_PF handler is defined and returns success + * for a particular client instance, packet filtering will be enabled for that + * instance. OpenVPN will then attempt to read the packet filter configuration + * from the temporary file named by the environmental variable pf_file. This + * file may be generated asynchronously and may be dynamically updated during the + * client session, however the client will be blocked from sending or receiving + * VPN tunnel packets until the packet filter file has been generated. OpenVPN + * will periodically test the packet filter file over the life of the client + * instance and reload when modified. OpenVPN will delete the packet filter file + * when the client instance goes out of scope. + * + * Packet filter file grammar: + * + * [CLIENTS DROP|ACCEPT] + * {+|-}common_name1 + * {+|-}common_name2 + * . . . + * [SUBNETS DROP|ACCEPT] + * {+|-}subnet1 + * {+|-}subnet2 + * . . . + * [END] + * + * Subnet: IP-ADDRESS | IP-ADDRESS/NUM_NETWORK_BITS + * + * CLIENTS refers to the set of clients (by their common-name) which + * this instance is allowed ('+') to connect to, or is excluded ('-') + * from connecting to. Note that in the case of client-to-client + * connections, such communication must be allowed by the packet filter + * configuration files of both clients. + * + * SUBNETS refers to IP addresses or IP address subnets which this + * instance may connect to ('+') or is excluded ('-') from connecting + * to. + * + * DROP or ACCEPT defines default policy when there is no explicit match + * for a common-name or subnet. The [END] tag must exist. A special + * purpose tag called [KILL] will immediately kill the client instance. + * A given client or subnet rule applies to both incoming and outgoing + * packets. + * + * See plugin/defer/simple.c for an example on using asynchronous + * authentication and client-specific packet filtering. + */ +OPENVPN_PLUGIN_DEF int OPENVPN_PLUGIN_FUNC(openvpn_plugin_func_v3) + (const int version, + struct openvpn_plugin_args_func_in const *arguments, + struct openvpn_plugin_args_func_return *retptr); + +/* + * FUNCTION: openvpn_plugin_close_v1 + * + * REQUIRED: YES + * + * ARGUMENTS + * + * handle : the openvpn_plugin_handle_t value which was returned by + * openvpn_plugin_open. + * + * Called immediately prior to plug-in unload. + */ +OPENVPN_PLUGIN_DEF void OPENVPN_PLUGIN_FUNC(openvpn_plugin_close_v1) + (openvpn_plugin_handle_t handle); + +/* + * FUNCTION: openvpn_plugin_abort_v1 + * + * REQUIRED: NO + * + * ARGUMENTS + * + * handle : the openvpn_plugin_handle_t value which was returned by + * openvpn_plugin_open. + * + * Called when OpenVPN is in the process of aborting due to a fatal error. + * Will only be called on an open context returned by a prior successful + * openvpn_plugin_open callback. + */ +OPENVPN_PLUGIN_DEF void OPENVPN_PLUGIN_FUNC(openvpn_plugin_abort_v1) + (openvpn_plugin_handle_t handle); + +/* + * FUNCTION: openvpn_plugin_client_constructor_v1 + * + * Called to allocate a per-client memory region, which + * is then passed to the openvpn_plugin_func_v2 function. + * This function is called every time the OpenVPN server + * constructs a client instance object, which normally + * occurs when a session-initiating packet is received + * by a new client, even before the client has authenticated. + * + * This function should allocate the private memory needed + * by the plugin to track individual OpenVPN clients, and + * return a void * to this memory region. + * + * REQUIRED: NO + * + * ARGUMENTS + * + * handle : the openvpn_plugin_handle_t value which was returned by + * openvpn_plugin_open. + * + * RETURN VALUE + * + * void * pointer to plugin's private per-client memory region, or NULL + * if no memory region is required. + */ +OPENVPN_PLUGIN_DEF void *OPENVPN_PLUGIN_FUNC(openvpn_plugin_client_constructor_v1) + (openvpn_plugin_handle_t handle); + +/* + * FUNCTION: openvpn_plugin_client_destructor_v1 + * + * This function is called on client instance object destruction. + * + * REQUIRED: NO + * + * ARGUMENTS + * + * handle : the openvpn_plugin_handle_t value which was returned by + * openvpn_plugin_open. + * + * per_client_context : the per-client context pointer which was returned by + * openvpn_plugin_client_constructor_v1, if defined. + */ +OPENVPN_PLUGIN_DEF void OPENVPN_PLUGIN_FUNC(openvpn_plugin_client_destructor_v1) + (openvpn_plugin_handle_t handle, void *per_client_context); + +/* + * FUNCTION: openvpn_plugin_select_initialization_point_v1 + * + * Several different points exist in OpenVPN's initialization sequence where + * the openvpn_plugin_open function can be called. While the default is + * OPENVPN_PLUGIN_INIT_PRE_DAEMON, this function can be used to select a + * different initialization point. For example, if your plugin needs to + * return configuration parameters to OpenVPN, use + * OPENVPN_PLUGIN_INIT_PRE_CONFIG_PARSE. + * + * REQUIRED: NO + * + * RETURN VALUE: + * + * An OPENVPN_PLUGIN_INIT_x value. + */ +#define OPENVPN_PLUGIN_INIT_PRE_CONFIG_PARSE 1 +#define OPENVPN_PLUGIN_INIT_PRE_DAEMON 2 /* default */ +#define OPENVPN_PLUGIN_INIT_POST_DAEMON 3 +#define OPENVPN_PLUGIN_INIT_POST_UID_CHANGE 4 + +OPENVPN_PLUGIN_DEF int OPENVPN_PLUGIN_FUNC(openvpn_plugin_select_initialization_point_v1) + (void); + +/* + * FUNCTION: openvpn_plugin_min_version_required_v1 + * + * This function is called by OpenVPN to query the minimum + * plugin interface version number required by the plugin. + * + * REQUIRED: NO + * + * RETURN VALUE + * + * The minimum OpenVPN plugin interface version number necessary to support + * this plugin. + */ +OPENVPN_PLUGIN_DEF int OPENVPN_PLUGIN_FUNC(openvpn_plugin_min_version_required_v1) + (void); + +/* + * Deprecated functions which are still supported for backward compatibility. + */ + +OPENVPN_PLUGIN_DEF openvpn_plugin_handle_t OPENVPN_PLUGIN_FUNC(openvpn_plugin_open_v1) + (unsigned int *type_mask, + const char *argv[], + const char *envp[]); + +OPENVPN_PLUGIN_DEF int OPENVPN_PLUGIN_FUNC(openvpn_plugin_func_v1) + (openvpn_plugin_handle_t handle, const int type, const char *argv[], const char *envp[]); + +#ifdef __cplusplus +} +#endif + +#endif /* OPENVPN_PLUGIN_H_ */ |