diff options
author | Arne Schwabe <arne@rfc2549.org> | 2015-04-15 00:17:26 +0200 |
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committer | Arne Schwabe <arne@rfc2549.org> | 2015-04-15 00:20:23 +0200 |
commit | c3ae4aaac9f0b168aed063d3e86c5196608eaba1 (patch) | |
tree | 1a18e7d8751d4dd3682d82d12c8441b335112984 /main/openvpn/src/plugins/down-root/down-root.c | |
parent | 5e42114d22faefe7c272b1b498fdf5640da494c7 (diff) |
Move more to git, add submodules, fix build script, change hgignore to gitignore
Diffstat (limited to 'main/openvpn/src/plugins/down-root/down-root.c')
m--------- | main/openvpn | 0 | ||||
-rw-r--r-- | main/openvpn/src/plugins/down-root/down-root.c | 547 |
2 files changed, 0 insertions, 547 deletions
diff --git a/main/openvpn b/main/openvpn new file mode 160000 +Subproject 7aaf01766f9718375986600216607aeb6397200 diff --git a/main/openvpn/src/plugins/down-root/down-root.c b/main/openvpn/src/plugins/down-root/down-root.c deleted file mode 100644 index 6931becf..00000000 --- a/main/openvpn/src/plugins/down-root/down-root.c +++ /dev/null @@ -1,547 +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) 2002-2013 OpenVPN Technologies, Inc. <sales@openvpn.net> - * Copyright (C) 2013 David Sommerseth <davids@redhat.com> - * - * 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. - */ - -#ifdef HAVE_CONFIG_H -#include <config.h> -#endif - -#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 <errno.h> -#include <err.h> - -#include <openvpn-plugin.h> - -#define DEBUG(verb) ((verb) >= 7) - -/* Command codes for foreground -> background communication */ -#define COMMAND_RUN_SCRIPT 1 -#define COMMAND_EXIT 2 - -/* 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 * const * argv, char * const *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) - { - warn ("DOWN-ROOT: daemonization failed"); - } - 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); -} - - -static void -free_context (struct down_root_context *context) -{ - if (context) - { - if (context->command) - { - free (context->command); - } - free (context); - } -} - -/* Run the script using execve(). As execve() replaces the - * current process with the new one, do a fork first before - * calling execve() - */ -static int -run_script(char * const *argv, char * const *envp) -{ - pid_t pid; - int ret = 0; - - pid = fork(); - if (pid == (pid_t)0) /* child side */ - { - execve(argv[0], argv, envp); - /* If execve() fails to run, exit child with exit code 127 */ - err(127, "DOWN-ROOT: Failed execute: %s", argv[0]); - } - else if (pid < (pid_t)0 ) - { - warn ("DOWN-ROOT: Failed to fork child to run %s", argv[0]); - return -1; - } - else /* parent side */ - { - if( waitpid (pid, &ret, 0) != pid ) - { - /* waitpid does not return error information via errno */ - fprintf(stderr, "DOWN-ROOT: waitpid() failed, don't know exit code of child (%s)\n", argv[0]); - return -1; - } - } - return ret; -} - -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; - int i = 0; - - /* - * Allocate our context - */ - context = (struct down_root_context *) calloc (1, sizeof (struct down_root_context)); - if (!context) - { - warn ("DOWN-ROOT: Could not allocate memory for plug-in 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 the arguments in our context - */ - context->command = calloc(string_array_len(argv), sizeof(char *)); - if (!context->command) - { - warn ("DOWN-ROOT: Could not allocate memory for command array"); - goto error; - } - - /* Ignore argv[0], as it contains just the plug-in file name */ - for (i = 1; i < string_array_len(argv); i++) - { - context->command[i-1] = (char *) argv[i]; - } - - /* - * 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) - { - warn ("DOWN-ROOT: socketpair call failed"); - 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) - { - warn ("DOWN-ROOT: Set FD_CLOEXEC flag on socket file descriptor failed"); - } - - /* 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, (char * const *) 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) - { - warn ("DOWN-ROOT: Error sending script execution signal to background process"); - } - else - { - const int status = recv_control (context->foreground_fd); - if (status == RESPONSE_SCRIPT_SUCCEEDED) - return OPENVPN_PLUGIN_FUNC_SUCCESS; - if (status == -1) - { - warn ("DOWN-ROOT: Error receiving script execution confirmation from background process"); - } - } - } - 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) - { - warn ("DOWN-ROOT: Error signalling background process to exit"); - } - - /* 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 * const *argv, char * const *envp, const int verb) -{ - /* - * Do initialization - */ - if (DEBUG (verb)) - fprintf (stderr, "DOWN-ROOT: BACKGROUND: INIT command='%s'\n", argv[0]); - - /* - * Tell foreground that we initialized successfully - */ - if (send_control (fd, RESPONSE_INIT_SUCCEEDED) == -1) - { - warn ("DOWN-ROOT: BACKGROUND: write error on response socket [1]"); - goto done; - } - - /* - * Event loop - */ - while (1) - { - int command_code; - int exit_code = -1; - - /* 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: - if ( (exit_code = run_script(argv, envp)) == 0 ) /* Succeeded */ - { - if (send_control (fd, RESPONSE_SCRIPT_SUCCEEDED) == -1) - { - warn ("DOWN-ROOT: BACKGROUND: write error on response socket [2]"); - goto done; - } - } - else /* Failed */ - { - fprintf(stderr, "DOWN-ROOT: BACKGROUND: %s exited with exit code %i\n", argv[0], exit_code); - if (send_control (fd, RESPONSE_SCRIPT_FAILED) == -1) - { - warn ("DOWN-ROOT: BACKGROUND: write error on response socket [3]"); - goto done; - } - } - break; - - case COMMAND_EXIT: - goto done; - - case -1: - warn ("DOWN-ROOT: BACKGROUND: read error on command channel"); - goto done; - - default: - fprintf (stderr, "DOWN-ROOT: BACKGROUND: unknown command code: code=%d, exiting\n", - command_code); - goto done; - } - } - -done: - if (DEBUG (verb)) - fprintf (stderr, "DOWN-ROOT: BACKGROUND: EXIT\n"); - - return; -} - - -/* -Local variables: -c-file-style: "bsd" -c-basic-offset: 4 -indent-tabs-mode: nil -End: -*/ |