tinc/src/tincd.c
Guus Sliepen edebf579f2 Use the TCP socket infrastructure for control sockets.
The control socket code was completely different from how meta connections are
handled, resulting in lots of extra code to handle requests.  Also, not every
operating system has UNIX sockets, so we have to resort to another type of
sockets or pipes for those anyway.  To reduce code duplication and make control
sockets work the same on all platforms, we now just connect to the TCP port
where tincd is already listening on.

To authenticate, the program that wants to control a running tinc daemon must
send the contents of a cookie file. The cookie is a random 256 bits number that
is regenerated every time tincd starts. The cookie file should only be readable
by the same user that can start a tincd.

Instead of the binary-ish protocol previously used, we now use an ASCII
protocol similar to that of the meta connections, but this can still change.
2009-11-07 23:43:25 +01:00

459 lines
11 KiB
C

/*
tincd.c -- the main file for tincd
Copyright (C) 1998-2005 Ivo Timmermans
2000-2009 Guus Sliepen <guus@tinc-vpn.org>
2008 Max Rijevski <maksuf@gmail.com>
2009 Michael Tokarev <mjt@tls.msk.ru>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
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.
*/
#include "system.h"
/* Darwin (MacOS/X) needs the following definition... */
#ifndef _P1003_1B_VISIBLE
#define _P1003_1B_VISIBLE
#endif
#ifdef HAVE_SYS_MMAN_H
#include <sys/mman.h>
#endif
#include LZO1X_H
#ifndef HAVE_MINGW
#include <pwd.h>
#include <grp.h>
#include <time.h>
#endif
#include <getopt.h>
#include "conf.h"
#include "control.h"
#include "crypto.h"
#include "device.h"
#include "logger.h"
#include "net.h"
#include "netutl.h"
#include "process.h"
#include "protocol.h"
#include "utils.h"
#include "xalloc.h"
/* The name this program was run with. */
char *program_name = NULL;
/* If nonzero, display usage information and exit. */
bool show_help = false;
/* If nonzero, print the version on standard output and exit. */
bool show_version = false;
/* If nonzero, use null ciphers and skip all key exchanges. */
bool bypass_security = false;
/* If nonzero, disable swapping for this process. */
bool do_mlock = false;
/* If nonzero, chroot to netdir after startup. */
static bool do_chroot = false;
/* If !NULL, do setuid to given user after startup */
static const char *switchuser = NULL;
/* If nonzero, write log entries to a separate file. */
bool use_logfile = false;
char *identname = NULL; /* program name for syslog */
char *logfilename = NULL; /* log file location */
char *controlcookiename = NULL;
char **g_argv; /* a copy of the cmdline arguments */
static int status;
static struct option const long_options[] = {
{"config", required_argument, NULL, 'c'},
{"net", required_argument, NULL, 'n'},
{"help", no_argument, NULL, 1},
{"version", no_argument, NULL, 2},
{"no-detach", no_argument, NULL, 'D'},
{"debug", optional_argument, NULL, 'd'},
{"bypass-security", no_argument, NULL, 3},
{"mlock", no_argument, NULL, 'L'},
{"chroot", no_argument, NULL, 'R'},
{"user", required_argument, NULL, 'U'},
{"logfile", optional_argument, NULL, 4},
{"controlcookie", required_argument, NULL, 5},
{NULL, 0, NULL, 0}
};
#ifdef HAVE_MINGW
static struct WSAData wsa_state;
CRITICAL_SECTION mutex;
#endif
static void usage(bool status) {
if(status)
fprintf(stderr, "Try `%s --help\' for more information.\n",
program_name);
else {
printf("Usage: %s [option]...\n\n", program_name);
printf( " -c, --config=DIR Read configuration options from DIR.\n"
" -D, --no-detach Don't fork and detach.\n"
" -d, --debug[=LEVEL] Increase debug level or set it to LEVEL.\n"
" -n, --net=NETNAME Connect to net NETNAME.\n"
" -L, --mlock Lock tinc into main memory.\n"
" --logfile[=FILENAME] Write log entries to a logfile.\n"
" --controlcookie=FILENAME Write control socket cookie to FILENAME.\n"
" --bypass-security Disables meta protocol security, for debugging.\n"
" -R, --chroot chroot to NET dir at startup.\n"
" -U, --user=USER setuid to given USER at startup.\n" " --help Display this help and exit.\n"
" --version Output version information and exit.\n\n");
printf("Report bugs to tinc@tinc-vpn.org.\n");
}
}
static bool parse_options(int argc, char **argv) {
int r;
int option_index = 0;
while((r = getopt_long(argc, argv, "c:DLd::n:RU:", long_options, &option_index)) != EOF) {
switch (r) {
case 0: /* long option */
break;
case 'c': /* config file */
confbase = xstrdup(optarg);
break;
case 'D': /* no detach */
do_detach = false;
break;
case 'L': /* no detach */
#ifndef HAVE_MLOCKALL
logger(LOG_ERR, "%s not supported on this platform", "mlockall()");
return false;
#else
do_mlock = true;
break;
#endif
case 'd': /* inc debug level */
if(optarg)
debug_level = atoi(optarg);
else
debug_level++;
break;
case 'n': /* net name given */
netname = xstrdup(optarg);
break;
case 'R': /* chroot to NETNAME dir */
do_chroot = true;
break;
case 'U': /* setuid to USER */
switchuser = optarg;
break;
case 1: /* show help */
show_help = true;
break;
case 2: /* show version */
show_version = true;
break;
case 3: /* bypass security */
bypass_security = true;
break;
case 4: /* write log entries to a file */
use_logfile = true;
if(optarg)
logfilename = xstrdup(optarg);
break;
case 5: /* open control socket here */
controlcookiename = xstrdup(optarg);
break;
case '?':
usage(true);
return false;
default:
break;
}
}
return true;
}
/*
Set all files and paths according to netname
*/
static void make_names(void) {
#ifdef HAVE_MINGW
HKEY key;
char installdir[1024] = "";
long len = sizeof installdir;
#endif
if(netname)
xasprintf(&identname, "tinc.%s", netname);
else
identname = xstrdup("tinc");
#ifdef HAVE_MINGW
if(!RegOpenKeyEx(HKEY_LOCAL_MACHINE, "SOFTWARE\\tinc", 0, KEY_READ, &key)) {
if(!RegQueryValueEx(key, NULL, 0, 0, installdir, &len)) {
if(!logfilename)
xasprintf(&logfilename, "%s/log/%s.log", identname);
if(!confbase) {
if(netname)
xasprintf(&confbase, "%s/%s", installdir, netname);
else
xasprintf(&confbase, "%s", installdir);
}
if(!controlcookiename)
xasprintf(&controlcookiename, "%s/cookie", confbase);
}
RegCloseKey(key);
if(*installdir)
return;
}
#endif
if(!logfilename)
xasprintf(&logfilename, LOCALSTATEDIR "/log/%s.log", identname);
if(netname) {
if(!confbase)
xasprintf(&confbase, CONFDIR "/tinc/%s", netname);
else
logger(LOG_INFO, "Both netname and configuration directory given, using the latter...");
} else {
if(!confbase)
xasprintf(&confbase, CONFDIR "/tinc");
}
}
static void free_names() {
if (identname) free(identname);
if (netname) free(netname);
if (controlcookiename) free(controlcookiename);
if (logfilename) free(logfilename);
if (confbase) free(confbase);
}
static bool drop_privs() {
#ifdef HAVE_MINGW
if (switchuser) {
logger(LOG_ERR, "%s not supported on this platform", "-U");
return false;
}
if (do_chroot) {
logger(LOG_ERR, "%s not supported on this platform", "-R");
return false;
}
#else
uid_t uid = 0;
if (switchuser) {
struct passwd *pw = getpwnam(switchuser);
if (!pw) {
logger(LOG_ERR, "unknown user `%s'", switchuser);
return false;
}
uid = pw->pw_uid;
if (initgroups(switchuser, pw->pw_gid) != 0 ||
setgid(pw->pw_gid) != 0) {
logger(LOG_ERR, "System call `%s' failed: %s",
"initgroups", strerror(errno));
return false;
}
endgrent();
endpwent();
}
if (do_chroot) {
tzset(); /* for proper timestamps in logs */
if (chroot(confbase) != 0 || chdir("/") != 0) {
logger(LOG_ERR, "System call `%s' failed: %s",
"chroot", strerror(errno));
return false;
}
free(confbase);
confbase = xstrdup("");
}
if (switchuser)
if (setuid(uid) != 0) {
logger(LOG_ERR, "System call `%s' failed: %s",
"setuid", strerror(errno));
return false;
}
#endif
return true;
}
#ifdef HAVE_MINGW
# define setpriority(level) SetPriorityClass(GetCurrentProcess(), level)
#else
# define NORMAL_PRIORITY_CLASS 0
# define BELOW_NORMAL_PRIORITY_CLASS 10
# define HIGH_PRIORITY_CLASS -10
# define setpriority(level) nice(level)
#endif
int main(int argc, char **argv) {
program_name = argv[0];
if(!parse_options(argc, argv))
return 1;
make_names();
if(show_version) {
printf("%s version %s (built %s %s, protocol %d)\n", PACKAGE,
VERSION, __DATE__, __TIME__, PROT_CURRENT);
printf("Copyright (C) 1998-2009 Ivo Timmermans, Guus Sliepen and others.\n"
"See the AUTHORS file for a complete list.\n\n"
"tinc comes with ABSOLUTELY NO WARRANTY. This is free software,\n"
"and you are welcome to redistribute it under certain conditions;\n"
"see the file COPYING for details.\n");
return 0;
}
if(show_help) {
usage(false);
return 0;
}
#ifdef HAVE_MINGW
if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
logger(LOG_ERR, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
return 1;
}
#endif
openlogger("tinc", use_logfile?LOGMODE_FILE:LOGMODE_STDERR);
if(!event_init()) {
logger(LOG_ERR, "Error initializing libevent!");
return 1;
}
g_argv = argv;
init_configuration(&config_tree);
/* Slllluuuuuuurrrrp! */
srand(time(NULL));
crypto_init();
if(!read_server_config())
return 1;
if(lzo_init() != LZO_E_OK) {
logger(LOG_ERR, "Error initializing LZO compressor!");
return 1;
}
#ifdef HAVE_MINGW
if(!do_detach || !init_service())
return main2(argc, argv);
else
return 1;
}
int main2(int argc, char **argv) {
InitializeCriticalSection(&mutex);
EnterCriticalSection(&mutex);
#endif
if(!detach())
return 1;
#ifdef HAVE_MLOCKALL
/* Lock all pages into memory if requested.
* This has to be done after daemon()/fork() so it works for child.
* No need to do that in parent as it's very short-lived. */
if(do_mlock && mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
logger(LOG_ERR, "System call `%s' failed: %s", "mlockall",
strerror(errno));
return 1;
}
#endif
/* Setup sockets and open device. */
if(!setup_network())
goto end;
if(!init_control())
return 1;
/* Initiate all outgoing connections. */
try_outgoing_connections();
/* Change process priority */
char *priority = 0;
if(get_config_string(lookup_config(config_tree, "ProcessPriority"), &priority)) {
if(!strcasecmp(priority, "Normal"))
setpriority(NORMAL_PRIORITY_CLASS);
else if(!strcasecmp(priority, "Low"))
setpriority(BELOW_NORMAL_PRIORITY_CLASS);
else if(!strcasecmp(priority, "High"))
setpriority(HIGH_PRIORITY_CLASS);
else {
logger(LOG_ERR, "Invalid priority `%s`!", priority);
goto end;
}
}
/* drop privileges */
if (!drop_privs())
goto end;
/* Start main loop. It only exits when tinc is killed. */
status = main_loop();
/* Shutdown properly. */
ifdebug(CONNECTIONS)
dump_device_stats();
close_network_connections();
end:
logger(LOG_NOTICE, "Terminating");
exit_control();
crypto_exit();
exit_configuration(&config_tree);
free_names();
return status;
}