diff options
author | Alberto Gonzalez Iniesta <agi@inittab.org> | 2012-11-05 16:28:09 +0100 |
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committer | Alberto Gonzalez Iniesta <agi@inittab.org> | 2012-11-05 16:28:09 +0100 |
commit | 8dd0350e1607aa30f7a043c8d5ec7a7eeb874115 (patch) | |
tree | 566d0620eb693320cb121dfd93a5675fa704a30b /plugin/down-root | |
parent | 349cfa7acb95abe865209a28e417ec74b56f9bba (diff) |
Imported Upstream version 2.3_rc1
Diffstat (limited to 'plugin/down-root')
-rwxr-xr-x | plugin/down-root/Makefile | 17 | ||||
-rw-r--r-- | plugin/down-root/README | 29 | ||||
-rw-r--r-- | plugin/down-root/down-root.c | 553 |
3 files changed, 0 insertions, 599 deletions
diff --git a/plugin/down-root/Makefile b/plugin/down-root/Makefile deleted file mode 100755 index 5ce4ffb..0000000 --- a/plugin/down-root/Makefile +++ /dev/null @@ -1,17 +0,0 @@ -# -# Build the OpenVPN down-root plugin module. -# - -# This directory is where we will look for openvpn-plugin.h -INCLUDE=-I../.. - -CC_FLAGS=-O2 -Wall - -down-root.so : down-root.o - gcc ${CC_FLAGS} -fPIC -shared -Wl,-soname,openvpn-down-root.so -o openvpn-down-root.so down-root.o -lc - -down-root.o : down-root.c - gcc ${CC_FLAGS} -fPIC -c ${INCLUDE} down-root.c - -clean : - rm -f *.o *.so diff --git a/plugin/down-root/README b/plugin/down-root/README deleted file mode 100644 index d337ffe..0000000 --- a/plugin/down-root/README +++ /dev/null @@ -1,29 +0,0 @@ -down-root -- an OpenVPN Plugin Module - -SYNOPSIS - -The down-root module allows an OpenVPN configuration to -call a down script with root privileges, even when privileges -have been dropped using --user/--group/--chroot. - -This module uses a split privilege execution model which will -fork() before OpenVPN drops root privileges, at the point where -the --up script is usually called. The module will then remain -in a wait state until it receives a message from OpenVPN via -pipe to execute the down script. Thus, the down script will be -run in the same execution environment as the up script. - -BUILD - -Build this module with the "make" command. The plugin -module will be named openvpn-down-root.so - -USAGE - -To use this module, add to your OpenVPN config file: - - plugin openvpn-down-root.so "command ..." - -CAVEATS - -This module will only work on *nix systems, not Windows. diff --git a/plugin/down-root/down-root.c b/plugin/down-root/down-root.c deleted file mode 100644 index fced23b..0000000 --- a/plugin/down-root/down-root.c +++ /dev/null @@ -1,553 +0,0 @@ -/* - * 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) 2002-2010 OpenVPN Technologies, 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 (see the file COPYING included with this - * distribution); if not, write to the Free Software Foundation, Inc., - * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - */ - -/* - * OpenVPN plugin module to do privileged down-script execution. - */ - -#include <stdio.h> -#include <string.h> -#include <unistd.h> -#include <stdlib.h> -#include <sys/types.h> -#include <sys/socket.h> -#include <sys/wait.h> -#include <fcntl.h> -#include <signal.h> -#include <syslog.h> - -#include "openvpn-plugin.h" - -#define DEBUG(verb) ((verb) >= 7) - -/* Command codes for foreground -> background communication */ -#define COMMAND_RUN_SCRIPT 0 -#define COMMAND_EXIT 1 - -/* Response codes for background -> foreground communication */ -#define RESPONSE_INIT_SUCCEEDED 10 -#define RESPONSE_INIT_FAILED 11 -#define RESPONSE_SCRIPT_SUCCEEDED 12 -#define RESPONSE_SCRIPT_FAILED 13 - -/* Background process function */ -static void down_root_server (const int fd, char *command, const char *argv[], const char *envp[], const int verb); - -/* - * Plugin state, used by foreground - */ -struct down_root_context -{ - /* Foreground's socket to background process */ - int foreground_fd; - - /* Process ID of background process */ - pid_t background_pid; - - /* Verbosity level of OpenVPN */ - int verb; - - /* down command */ - char *command; -}; - -/* - * Given an environmental variable name, search - * the envp array for its value, returning it - * if found or NULL otherwise. - */ -static const char * -get_env (const char *name, const char *envp[]) -{ - if (envp) - { - int i; - const int namelen = strlen (name); - for (i = 0; envp[i]; ++i) - { - if (!strncmp (envp[i], name, namelen)) - { - const char *cp = envp[i] + namelen; - if (*cp == '=') - return cp + 1; - } - } - } - return NULL; -} - -/* - * Return the length of a string array - */ -static int -string_array_len (const char *array[]) -{ - int i = 0; - if (array) - { - while (array[i]) - ++i; - } - return i; -} - -/* - * Socket read/write functions. - */ - -static int -recv_control (int fd) -{ - unsigned char c; - const ssize_t size = read (fd, &c, sizeof (c)); - if (size == sizeof (c)) - return c; - else - return -1; -} - -static int -send_control (int fd, int code) -{ - unsigned char c = (unsigned char) code; - const ssize_t size = write (fd, &c, sizeof (c)); - if (size == sizeof (c)) - return (int) size; - else - return -1; -} - -/* - * Daemonize if "daemon" env var is true. - * Preserve stderr across daemonization if - * "daemon_log_redirect" env var is true. - */ -static void -daemonize (const char *envp[]) -{ - const char *daemon_string = get_env ("daemon", envp); - if (daemon_string && daemon_string[0] == '1') - { - const char *log_redirect = get_env ("daemon_log_redirect", envp); - int fd = -1; - if (log_redirect && log_redirect[0] == '1') - fd = dup (2); - if (daemon (0, 0) < 0) - { - fprintf (stderr, "DOWN-ROOT: daemonization failed\n"); - } - else if (fd >= 3) - { - dup2 (fd, 2); - close (fd); - } - } -} - -/* - * Close most of parent's fds. - * Keep stdin/stdout/stderr, plus one - * other fd which is presumed to be - * our pipe back to parent. - * Admittedly, a bit of a kludge, - * but posix doesn't give us a kind - * of FD_CLOEXEC which will stop - * fds from crossing a fork(). - */ -static void -close_fds_except (int keep) -{ - int i; - closelog (); - for (i = 3; i <= 100; ++i) - { - if (i != keep) - close (i); - } -} - -/* - * Usually we ignore signals, because our parent will - * deal with them. - */ -static void -set_signals (void) -{ - signal (SIGTERM, SIG_DFL); - - signal (SIGINT, SIG_IGN); - signal (SIGHUP, SIG_IGN); - signal (SIGUSR1, SIG_IGN); - signal (SIGUSR2, SIG_IGN); - signal (SIGPIPE, SIG_IGN); -} - -/* - * convert system() return into a success/failure value - */ -int -system_ok (int stat) -{ -#ifdef WIN32 - return stat == 0; -#else - return stat != -1 && WIFEXITED (stat) && WEXITSTATUS (stat) == 0; -#endif -} - -static char * -build_command_line (const char *argv[]) -{ - int size = 0; - int n = 0; - int i; - char *string; - - /* precompute size */ - if (argv) - { - for (i = 0; argv[i]; ++i) - { - size += (strlen (argv[i]) + 1); /* string length plus trailing space */ - ++n; - } - } - ++size; /* for null terminator */ - - /* allocate memory */ - string = (char *) malloc (size); - if (!string) - { - fprintf (stderr, "DOWN-ROOT: out of memory\n"); - exit (1); - } - string[0] = '\0'; - - /* build string */ - for (i = 0; i < n; ++i) - { - strcat (string, argv[i]); - if (i + 1 < n) - strcat (string, " "); - } - return string; -} - -static void -free_context (struct down_root_context *context) -{ - if (context) - { - if (context->command) - free (context->command); - free (context); - } -} - -OPENVPN_EXPORT openvpn_plugin_handle_t -openvpn_plugin_open_v1 (unsigned int *type_mask, const char *argv[], const char *envp[]) -{ - struct down_root_context *context; - - /* - * Allocate our context - */ - context = (struct down_root_context *) calloc (1, sizeof (struct down_root_context)); - if (!context) - goto error; - context->foreground_fd = -1; - - /* - * Intercept the --up and --down callbacks - */ - *type_mask = OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_UP) | OPENVPN_PLUGIN_MASK (OPENVPN_PLUGIN_DOWN); - - /* - * Make sure we have two string arguments: the first is the .so name, - * the second is the script command. - */ - if (string_array_len (argv) < 2) - { - fprintf (stderr, "DOWN-ROOT: need down script command\n"); - goto error; - } - - /* - * Save our argument in context - */ - context->command = build_command_line (&argv[1]); - - /* - * Get verbosity level from environment - */ - { - const char *verb_string = get_env ("verb", envp); - if (verb_string) - context->verb = atoi (verb_string); - } - - return (openvpn_plugin_handle_t) context; - - error: - free_context (context); - return NULL; -} - -OPENVPN_EXPORT int -openvpn_plugin_func_v1 (openvpn_plugin_handle_t handle, const int type, const char *argv[], const char *envp[]) -{ - struct down_root_context *context = (struct down_root_context *) handle; - - if (type == OPENVPN_PLUGIN_UP && context->foreground_fd == -1) /* fork off a process to hold onto root */ - { - pid_t pid; - int fd[2]; - - /* - * Make a socket for foreground and background processes - * to communicate. - */ - if (socketpair (PF_UNIX, SOCK_DGRAM, 0, fd) == -1) - { - fprintf (stderr, "DOWN-ROOT: socketpair call failed\n"); - return OPENVPN_PLUGIN_FUNC_ERROR; - } - - /* - * Fork off the privileged process. It will remain privileged - * even after the foreground process drops its privileges. - */ - pid = fork (); - - if (pid) - { - int status; - - /* - * Foreground Process - */ - - context->background_pid = pid; - - /* close our copy of child's socket */ - close (fd[1]); - - /* don't let future subprocesses inherit child socket */ - if (fcntl (fd[0], F_SETFD, FD_CLOEXEC) < 0) - fprintf (stderr, "DOWN-ROOT: Set FD_CLOEXEC flag on socket file descriptor failed\n"); - - /* wait for background child process to initialize */ - status = recv_control (fd[0]); - if (status == RESPONSE_INIT_SUCCEEDED) - { - context->foreground_fd = fd[0]; - return OPENVPN_PLUGIN_FUNC_SUCCESS; - } - } - else - { - /* - * Background Process - */ - - /* close all parent fds except our socket back to parent */ - close_fds_except (fd[1]); - - /* Ignore most signals (the parent will receive them) */ - set_signals (); - - /* Daemonize if --daemon option is set. */ - daemonize (envp); - - /* execute the event loop */ - down_root_server (fd[1], context->command, argv, envp, context->verb); - - close (fd[1]); - exit (0); - return 0; /* NOTREACHED */ - } - } - else if (type == OPENVPN_PLUGIN_DOWN && context->foreground_fd >= 0) - { - if (send_control (context->foreground_fd, COMMAND_RUN_SCRIPT) == -1) - { - fprintf (stderr, "DOWN-ROOT: Error sending script execution signal to background process\n"); - } - else - { - const int status = recv_control (context->foreground_fd); - if (status == RESPONSE_SCRIPT_SUCCEEDED) - return OPENVPN_PLUGIN_FUNC_SUCCESS; - if (status == -1) - fprintf (stderr, "DOWN-ROOT: Error receiving script execution confirmation from background process\n"); - } - } - return OPENVPN_PLUGIN_FUNC_ERROR; -} - -OPENVPN_EXPORT void -openvpn_plugin_close_v1 (openvpn_plugin_handle_t handle) -{ - struct down_root_context *context = (struct down_root_context *) handle; - - if (DEBUG (context->verb)) - fprintf (stderr, "DOWN-ROOT: close\n"); - - if (context->foreground_fd >= 0) - { - /* tell background process to exit */ - if (send_control (context->foreground_fd, COMMAND_EXIT) == -1) - fprintf (stderr, "DOWN-ROOT: Error signaling background process to exit\n"); - - /* wait for background process to exit */ - if (context->background_pid > 0) - waitpid (context->background_pid, NULL, 0); - - close (context->foreground_fd); - context->foreground_fd = -1; - } - - free_context (context); -} - -OPENVPN_EXPORT void -openvpn_plugin_abort_v1 (openvpn_plugin_handle_t handle) -{ - struct down_root_context *context = (struct down_root_context *) handle; - - if (context && context->foreground_fd >= 0) - { - /* tell background process to exit */ - send_control (context->foreground_fd, COMMAND_EXIT); - close (context->foreground_fd); - context->foreground_fd = -1; - } -} - -/* - * Background process -- runs with privilege. - */ -static void -down_root_server (const int fd, char *command, const char *argv[], const char *envp[], const int verb) -{ - const char *p[3]; - char *command_line = NULL; - char *argv_cat = NULL; - int i; - - /* - * Do initialization - */ - if (DEBUG (verb)) - fprintf (stderr, "DOWN-ROOT: BACKGROUND: INIT command='%s'\n", command); - - /* - * Tell foreground that we initialized successfully - */ - if (send_control (fd, RESPONSE_INIT_SUCCEEDED) == -1) - { - fprintf (stderr, "DOWN-ROOT: BACKGROUND: write error on response socket [1]\n"); - goto done; - } - - /* - * Build command line - */ - if (string_array_len (argv) >= 2) - argv_cat = build_command_line (&argv[1]); - else - argv_cat = build_command_line (NULL); - p[0] = command; - p[1] = argv_cat; - p[2] = NULL; - command_line = build_command_line (p); - - /* - * Save envp in environment - */ - for (i = 0; envp[i]; ++i) - { - putenv ((char *)envp[i]); - } - - /* - * Event loop - */ - while (1) - { - int command_code; - int status; - - /* get a command from foreground process */ - command_code = recv_control (fd); - - if (DEBUG (verb)) - fprintf (stderr, "DOWN-ROOT: BACKGROUND: received command code: %d\n", command_code); - - switch (command_code) - { - case COMMAND_RUN_SCRIPT: - status = system (command_line); - if (system_ok (status)) /* Succeeded */ - { - if (send_control (fd, RESPONSE_SCRIPT_SUCCEEDED) == -1) - { - fprintf (stderr, "DOWN-ROOT: BACKGROUND: write error on response socket [2]\n"); - goto done; - } - } - else /* Failed */ - { - if (send_control (fd, RESPONSE_SCRIPT_FAILED) == -1) - { - fprintf (stderr, "DOWN-ROOT: BACKGROUND: write error on response socket [3]\n"); - goto done; - } - } - break; - - case COMMAND_EXIT: - goto done; - - case -1: - fprintf (stderr, "DOWN-ROOT: BACKGROUND: read error on command channel\n"); - goto done; - - default: - fprintf (stderr, "DOWN-ROOT: BACKGROUND: unknown command code: code=%d, exiting\n", - command_code); - goto done; - } - } - - done: - if (argv_cat) - free (argv_cat); - if (command_line) - free (command_line); - if (DEBUG (verb)) - fprintf (stderr, "DOWN-ROOT: BACKGROUND: EXIT\n"); - - return; -} |