/*
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#elif defined(_MSC_VER)
#include "config-msvc.h"
#endif
#include "syshead.h"
#include "buffer.h"
#include "error.h"
#include "misc.h"
#include "win32.h"
#include "memdbg.h"
#include "platform.h"
/* Redefine the top level directory of the filesystem
* to restrict access to files for security */
void
platform_chroot(const char *path)
{
if (path)
{
#ifdef HAVE_CHROOT
const char *top = "/";
if (chroot(path))
{
msg(M_ERR, "chroot to '%s' failed", path);
}
if (platform_chdir(top))
{
msg(M_ERR, "cd to '%s' failed", top);
}
msg(M_INFO, "chroot to '%s' and cd to '%s' succeeded", path, top);
#else /* ifdef HAVE_CHROOT */
msg(M_FATAL, "Sorry but I can't chroot to '%s' because this operating system doesn't appear to support the chroot() system call", path);
#endif
}
}
/* Get/Set UID of process */
bool
platform_user_get(const char *username, struct platform_state_user *state)
{
bool ret = false;
CLEAR(*state);
if (username)
{
#if defined(HAVE_GETPWNAM) && defined(HAVE_SETUID)
state->pw = getpwnam(username);
if (!state->pw)
{
msg(M_ERR, "failed to find UID for user %s", username);
}
state->username = username;
ret = true;
#else /* if defined(HAVE_GETPWNAM) && defined(HAVE_SETUID) */
msg(M_FATAL, "cannot get UID for user %s -- platform lacks getpwname() or setuid() system calls", username);
#endif
}
return ret;
}
void
platform_user_set(const struct platform_state_user *state)
{
#if defined(HAVE_GETPWNAM) && defined(HAVE_SETUID)
if (state->username && state->pw)
{
if (setuid(state->pw->pw_uid))
{
msg(M_ERR, "setuid('%s') failed", state->username);
}
msg(M_INFO, "UID set to %s", state->username);
}
#endif
}
/* Get/Set GID of process */
bool
platform_group_get(const char *groupname, struct platform_state_group *state)
{
bool ret = false;
CLEAR(*state);
if (groupname)
{
#if defined(HAVE_GETGRNAM) && defined(HAVE_SETGID)
state->gr = getgrnam(groupname);
if (!state->gr)
{
msg(M_ERR, "failed to find GID for group %s", groupname);
}
state->groupname = groupname;
ret = true;
#else /* if defined(HAVE_GETGRNAM) && defined(HAVE_SETGID) */
msg(M_FATAL, "cannot get GID for group %s -- platform lacks getgrnam() or setgid() system calls", groupname);
#endif
}
return ret;
}
void
platform_group_set(const struct platform_state_group *state)
{
#if defined(HAVE_GETGRNAM) && defined(HAVE_SETGID)
if (state->groupname && state->gr)
{
if (setgid(state->gr->gr_gid))
{
msg(M_ERR, "setgid('%s') failed", state->groupname);
}
msg(M_INFO, "GID set to %s", state->groupname);
#ifdef HAVE_SETGROUPS
{
gid_t gr_list[1];
gr_list[0] = state->gr->gr_gid;
if (setgroups(1, gr_list))
{
msg(M_ERR, "setgroups('%s') failed", state->groupname);
}
}
#endif
}
#endif
}
/* Change process priority */
void
platform_nice(int niceval)
{
if (niceval)
{
#ifdef HAVE_NICE
errno = 0;
if (nice(niceval) < 0 && errno != 0)
{
msg(M_WARN | M_ERRNO, "WARNING: nice %d failed", niceval);
}
else
{
msg(M_INFO, "nice %d succeeded", niceval);
}
#else /* ifdef HAVE_NICE */
msg(M_WARN, "WARNING: nice %d failed (function not implemented)", niceval);
#endif
}
}
/* Get current PID */
unsigned int
platform_getpid(void)
{
#ifdef _WIN32
return (unsigned int) GetCurrentProcessId();
#else
#ifdef HAVE_GETPID
return (unsigned int) getpid();
#else
return 0;
#endif
#endif
}
/* Disable paging */
void
platform_mlockall(bool print_msg)
{
#ifdef HAVE_MLOCKALL
if (mlockall(MCL_CURRENT | MCL_FUTURE))
{
msg(M_WARN | M_ERRNO, "WARNING: mlockall call failed");
}
else if (print_msg)
{
msg(M_INFO, "mlockall call succeeded");
}
#else /* ifdef HAVE_MLOCKALL */
msg(M_WARN, "WARNING: mlockall call failed (function not implemented)");
#endif
}
/*
* Wrapper for chdir library function
*/
int
platform_chdir(const char *dir)
{
#ifdef HAVE_CHDIR
#ifdef _WIN32
int res;
struct gc_arena gc = gc_new();
res = _wchdir(wide_string(dir, &gc));
gc_free(&gc);
return res;
#else /* ifdef _WIN32 */
return chdir(dir);
#endif
#else /* ifdef HAVE_CHDIR */
return -1;
#endif
}
/*
* convert execve() return into a success/failure value
*/
bool
platform_system_ok(int stat)
{
#ifdef _WIN32
return stat == 0;
#else
return stat != -1 && WIFEXITED(stat) && WEXITSTATUS(stat) == 0;
#endif
}
int
platform_access(const char *path, int mode)
{
#ifdef _WIN32
struct gc_arena gc = gc_new();
int ret = _waccess(wide_string(path, &gc), mode & ~X_OK);
gc_free(&gc);
return ret;
#else
return access(path, mode);
#endif
}
/*
* Go to sleep for n milliseconds.
*/
void
platform_sleep_milliseconds(unsigned int n)
{
#ifdef _WIN32
Sleep(n);
#else
struct timeval tv;
tv.tv_sec = n / 1000;
tv.tv_usec = (n % 1000) * 1000;
select(0, NULL, NULL, NULL, &tv);
#endif
}
/*
* Go to sleep indefinitely.
*/
void
platform_sleep_until_signal(void)
{
#ifdef _WIN32
ASSERT(0);
#else
select(0, NULL, NULL, NULL, NULL);
#endif
}
/* delete a file, return true if succeeded */
bool
platform_unlink(const char *filename)
{
#if defined(_WIN32)
struct gc_arena gc = gc_new();
BOOL ret = DeleteFileW(wide_string(filename, &gc));
gc_free(&gc);
return (ret != 0);
#elif defined(HAVE_UNLINK)
return (unlink(filename) == 0);
#else /* if defined(_WIN32) */
return false;
#endif
}
FILE *
platform_fopen(const char *path, const char *mode)
{
#ifdef _WIN32
struct gc_arena gc = gc_new();
FILE *f = _wfopen(wide_string(path, &gc), wide_string(mode, &gc));
gc_free(&gc);
return f;
#else
return fopen(path, mode);
#endif
}
int
platform_open(const char *path, int flags, int mode)
{
#ifdef _WIN32
struct gc_arena gc = gc_new();
int fd = _wopen(wide_string(path, &gc), flags, mode);
gc_free(&gc);
return fd;
#else
return open(path, flags, mode);
#endif
}
int
platform_stat(const char *path, platform_stat_t *buf)
{
#ifdef _WIN32
struct gc_arena gc = gc_new();
int res = _wstat(wide_string(path, &gc), buf);
gc_free(&gc);
return res;
#else
return stat(path, buf);
#endif
}
/* create a temporary filename in directory */
const char *
platform_create_temp_file(const char *directory, const char *prefix, struct gc_arena *gc)
{
int fd;
const char *retfname = NULL;
unsigned int attempts = 0;
char fname[256] = { 0 };
const char *fname_fmt = PACKAGE "_%.*s_%08lx%08lx.tmp";
const int max_prefix_len = sizeof(fname) - (sizeof(PACKAGE) + 7 + (2 * 8));
while (attempts < 6)
{
++attempts;
if (!openvpn_snprintf(fname, sizeof(fname), fname_fmt, max_prefix_len,
prefix, (unsigned long) get_random(),
(unsigned long) get_random()))
{
msg(M_WARN, "ERROR: temporary filename too long");
return NULL;
}
retfname = platform_gen_path(directory, fname, gc);
if (!retfname)
{
msg(M_WARN, "Failed to create temporary filename and path");
return NULL;
}
/* Atomically create the file. Errors out if the file already
* exists. */
fd = platform_open(retfname, O_CREAT | O_EXCL | O_WRONLY, S_IRUSR | S_IWUSR);
if (fd != -1)
{
close(fd);
return retfname;
}
else if (fd == -1 && errno != EEXIST)
{
/* Something else went wrong, no need to retry. */
msg(M_WARN | M_ERRNO, "Could not create temporary file '%s'",
retfname);
return NULL;
}
}
msg(M_WARN, "Failed to create temporary file after %i attempts", attempts);
return NULL;
}
/*
* Put a directory and filename together.
*/
const char *
platform_gen_path(const char *directory, const char *filename,
struct gc_arena *gc)
{
#ifdef _WIN32
const int CC_PATH_RESERVED = CC_LESS_THAN|CC_GREATER_THAN|CC_COLON
|CC_DOUBLE_QUOTE|CC_SLASH|CC_BACKSLASH|CC_PIPE|CC_QUESTION_MARK|CC_ASTERISK;
#else
const int CC_PATH_RESERVED = CC_SLASH;
#endif
if (!gc)
{
return NULL; /* Would leak memory otherwise */
}
const char *safe_filename = string_mod_const(filename, CC_PRINT, CC_PATH_RESERVED, '_', gc);
if (safe_filename
&& strcmp(safe_filename, ".")
&& strcmp(safe_filename, "..")
#ifdef _WIN32
&& win_safe_filename(safe_filename)
#endif
)
{
const size_t outsize = strlen(safe_filename) + (directory ? strlen(directory) : 0) + 16;
struct buffer out = alloc_buf_gc(outsize, gc);
char dirsep[2];
dirsep[0] = OS_SPECIFIC_DIRSEP;
dirsep[1] = '\0';
if (directory)
{
buf_printf(&out, "%s%s", directory, dirsep);
}
buf_printf(&out, "%s", safe_filename);
return BSTR(&out);
}
else
{
return NULL;
}
}
bool
platform_absolute_pathname(const char *pathname)
{
if (pathname)
{
const int c = pathname[0];
#ifdef _WIN32
return c == '\\' || (isalpha(c) && pathname[1] == ':' && pathname[2] == '\\');
#else
return c == '/';
#endif
}
else
{
return false;
}
}
/* return true if filename can be opened for read */
bool
platform_test_file(const char *filename)
{
bool ret = false;
if (filename)
{
FILE *fp = platform_fopen(filename, "r");
if (fp)
{
fclose(fp);
ret = true;
}
else
{
if (openvpn_errno() == EACCES)
{
msg( M_WARN | M_ERRNO, "Could not access file '%s'", filename);
}
}
}
dmsg(D_TEST_FILE, "TEST FILE '%s' [%d]",
filename ? filename : "UNDEF",
ret);
return ret;
}