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Diffstat (limited to 'plugin/down-root/down-root.c')
-rw-r--r--plugin/down-root/down-root.c553
1 files changed, 0 insertions, 553 deletions
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;
-}
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