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libc/winsup/cygserver/cygserver.cc

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/* cygserver.cc
Written by Egor Duda <deo@logos-m.ru>
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#ifdef __OUTSIDE_CYGWIN__
#include "woutsup.h"
#include <sys/types.h>
#include <assert.h>
#include <errno.h>
#include <ctype.h>
#include <getopt.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "cygwin_version.h"
#include "cygserver.h"
#include "process.h"
#include "transport.h"
#include "cygserver_ipc.h"
#include "cygserver_msg.h"
#include "cygserver_sem.h"
#define DEF_CONFIG_FILE "" SYSCONFDIR "/cygserver.conf"
#define SERVER_VERSION "1.20"
GENERIC_MAPPING access_mapping;
static bool
setup_privileges ()
{
BOOL rc, ret_val;
HANDLE hToken = NULL;
TOKEN_PRIVILEGES sPrivileges;
rc = OpenProcessToken (GetCurrentProcess () , TOKEN_ALL_ACCESS , &hToken) ;
if (!rc)
{
debug ("error opening process token (err %u)", GetLastError ());
return false;
}
rc = LookupPrivilegeValue (NULL, SE_DEBUG_NAME, &sPrivileges.Privileges[0].Luid);
if (!rc)
{
debug ("error getting privilege luid (err %u)", GetLastError ());
ret_val = false;
goto out;
}
sPrivileges.PrivilegeCount = 1 ;
sPrivileges.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED ;
rc = AdjustTokenPrivileges (hToken, FALSE, &sPrivileges, 0, NULL, NULL) ;
if (!rc)
{
debug ("error adjusting privilege level. (err %u)", GetLastError ());
ret_val = false;
goto out;
}
access_mapping.GenericRead = FILE_READ_DATA;
access_mapping.GenericWrite = FILE_WRITE_DATA;
access_mapping.GenericExecute = 0;
access_mapping.GenericAll = FILE_READ_DATA | FILE_WRITE_DATA;
ret_val = true;
out:
CloseHandle (hToken);
return ret_val;
}
int
check_and_dup_handle (HANDLE from_process, HANDLE to_process,
HANDLE from_process_token,
DWORD access,
HANDLE from_handle,
HANDLE *to_handle_ptr, BOOL bInheritHandle = FALSE)
{
HANDLE local_handle = NULL;
int ret_val = EACCES;
char sd_buf [1024];
PSECURITY_DESCRIPTOR sd = (PSECURITY_DESCRIPTOR) &sd_buf;
DWORD bytes_needed;
PRIVILEGE_SET ps;
DWORD ps_len = sizeof (ps);
BOOL status;
if (from_process != GetCurrentProcess ())
{
if (!DuplicateHandle (from_process, from_handle,
GetCurrentProcess (), &local_handle,
0, bInheritHandle,
DUPLICATE_SAME_ACCESS))
{
log (LOG_ERR, "error getting handle(%p) to server (err %u)",
from_handle, GetLastError ());
goto out;
}
} else
local_handle = from_handle;
if (!GetKernelObjectSecurity (local_handle,
(OWNER_SECURITY_INFORMATION
| GROUP_SECURITY_INFORMATION
| DACL_SECURITY_INFORMATION),
sd, sizeof (sd_buf), &bytes_needed))
{
log (LOG_ERR, "error getting handle SD (err %u)", GetLastError ());
goto out;
}
MapGenericMask (&access, &access_mapping);
if (!AccessCheck (sd, from_process_token, access, &access_mapping,
&ps, &ps_len, &access, &status))
{
log (LOG_ERR, "error checking access rights (err %u)", GetLastError ());
goto out;
}
if (!status)
{
log (LOG_ERR, "access to object denied");
goto out;
}
if (!DuplicateHandle (from_process, from_handle,
to_process, to_handle_ptr,
access, bInheritHandle, 0))
{
log (LOG_ERR, "error getting handle to client (err %u)", GetLastError ());
goto out;
}
debug ("Duplicated %p to %p", from_handle, *to_handle_ptr);
ret_val = 0;
out:
if (local_handle && from_process != GetCurrentProcess ())
CloseHandle (local_handle);
return (ret_val);
}
/*
* client_request_attach_tty::serve ()
*/
void
client_request_attach_tty::serve (transport_layer_base *const conn,
process_cache *)
{
assert (conn);
assert (!error_code ());
if (msglen () != sizeof (req))
{
log (LOG_ERR, "bad request body length: expecting %lu bytes, got %lu",
sizeof (req), msglen ());
error_code (EINVAL);
msglen (0);
return;
}
msglen (0); // Until we fill in some fields.
debug ("pid %d:(%p,%p) -> pid %d", req.master_pid, req.from_master,
req.to_master, req.pid);
debug ("opening process %d", req.master_pid);
const HANDLE from_process_handle =
OpenProcess (PROCESS_DUP_HANDLE, FALSE, req.master_pid);
if (!from_process_handle)
{
log (LOG_ERR, "error opening `from' process (err %u)", GetLastError ());
error_code (EACCES);
return;
}
debug ("opening process %d", req.pid);
const HANDLE to_process_handle =
OpenProcess (PROCESS_DUP_HANDLE, FALSE, req.pid);
if (!to_process_handle)
{
log (LOG_ERR, "error opening `to' process (err %u)", GetLastError ());
CloseHandle (from_process_handle);
error_code (EACCES);
return;
}
debug ("Impersonating client");
if (!conn->impersonate_client ())
{
CloseHandle (from_process_handle);
CloseHandle (to_process_handle);
error_code (EACCES);
return;
}
HANDLE token_handle = NULL;
debug ("about to open thread token");
const DWORD rc = OpenThreadToken (GetCurrentThread (),
TOKEN_QUERY,
TRUE,
&token_handle);
debug ("opened thread token, rc=%u", rc);
if (!conn->revert_to_self ())
{
CloseHandle (from_process_handle);
CloseHandle (to_process_handle);
error_code (EACCES);
return;
}
if (!rc)
{
log (LOG_ERR, "error opening thread token (err %u)", GetLastError ());
CloseHandle (from_process_handle);
CloseHandle (to_process_handle);
error_code (EACCES);
return;
}
// From this point on, a reply body is returned to the client.
const HANDLE from_master = req.from_master;
const HANDLE to_master = req.to_master;
req.from_master = NULL;
req.to_master = NULL;
msglen (sizeof (req));
if (from_master)
if (check_and_dup_handle (from_process_handle, to_process_handle,
token_handle,
GENERIC_READ,
from_master,
&req.from_master, TRUE) != 0)
{
log (LOG_ERR, "error duplicating from_master handle (err %u)",
GetLastError ());
error_code (EACCES);
}
if (to_master)
if (check_and_dup_handle (from_process_handle, to_process_handle,
token_handle,
GENERIC_WRITE,
to_master,
&req.to_master, TRUE) != 0)
{
log (LOG_ERR, "error duplicating to_master handle (err %u)",
GetLastError ());
error_code (EACCES);
}
CloseHandle (from_process_handle);
CloseHandle (to_process_handle);
CloseHandle (token_handle);
debug ("%u(%p, %p) -> %u(%p,%p)", req.master_pid, from_master, to_master,
req.pid, req.from_master, req.to_master);
return;
}
void
client_request_get_version::serve (transport_layer_base *, process_cache *)
{
assert (!error_code ());
if (msglen ())
log (LOG_ERR, "unexpected request body ignored: %lu bytes", msglen ());
msglen (sizeof (version));
version.major = CYGWIN_SERVER_VERSION_MAJOR;
version.api = CYGWIN_SERVER_VERSION_API;
version.minor = CYGWIN_SERVER_VERSION_MINOR;
version.patch = CYGWIN_SERVER_VERSION_PATCH;
}
class server_request : public queue_request
{
public:
server_request (transport_layer_base *const conn, process_cache *const cache)
: _conn (conn), _cache (cache)
{}
virtual ~server_request ()
{
delete _conn;
}
virtual void process ()
{
client_request::handle_request (_conn, _cache);
}
private:
transport_layer_base *const _conn;
process_cache *const _cache;
};
class server_submission_loop : public queue_submission_loop
{
public:
server_submission_loop (threaded_queue *const queue,
transport_layer_base *const transport,
process_cache *const cache)
: queue_submission_loop (queue, false),
_transport (transport),
_cache (cache)
{
assert (_transport);
assert (_cache);
}
private:
transport_layer_base *const _transport;
process_cache *const _cache;
virtual void request_loop ();
};
/* FIXME: this is a little ugly. What we really want is to wait on
* two objects: one for the pipe/socket, and one for being told to
* shutdown. Otherwise this will stay a problem (we won't actually
* shutdown until the request _AFTER_ the shutdown request. And
* sending ourselves a request is ugly
*/
void
server_submission_loop::request_loop ()
{
/* I'd like the accepting thread's priority to be above any "normal"
* thread in the system to avoid overflowing the listen queue (for
* sockets; similar issues exist for named pipes); but, for example,
* a normal priority thread in a foregrounded process is boosted to
* THREAD_PRIORITY_HIGHEST (AFAICT). Thus try to set the current
* thread's priority to a level one above that. This fails on
* win9x/ME so assume any failure in that call is due to that and
* simply call again at one priority level lower.
* FIXME: This looks weird and is an issue on NT, too. Per MSDN,
* THREAD_PRIORITY_HIGHEST + 1 is only a valid priority level if
* the priority class is set to REALTIME_PRIORITY_CLASS.
*/
if (!SetThreadPriority (GetCurrentThread (), THREAD_PRIORITY_HIGHEST + 1))
if (!SetThreadPriority (GetCurrentThread (), THREAD_PRIORITY_HIGHEST))
debug ("failed to raise accept thread priority (err %u)",
GetLastError ());
while (_running)
{
bool recoverable = false;
transport_layer_base *const conn = _transport->accept (&recoverable);
if (!conn && !recoverable)
{
log (LOG_ERR, "fatal error on IPC transport: closing down");
return;
}
// EINTR probably implies a shutdown request; so back off for a
// moment to let the main thread take control, otherwise the
// server spins here receiving EINTR repeatedly since the signal
// handler in the main thread doesn't get a chance to be called.
if (!conn && errno == EINTR)
{
if (!SetThreadPriority (GetCurrentThread (), THREAD_PRIORITY_NORMAL))
debug ("failed to reset thread priority (err %u)",
GetLastError ());
Sleep (0);
if (!SetThreadPriority (GetCurrentThread (),
THREAD_PRIORITY_HIGHEST + 1))
if (!SetThreadPriority (GetCurrentThread (),
THREAD_PRIORITY_HIGHEST))
debug ("failed to raise thread priority (err %u)",
GetLastError ());
}
if (conn)
_queue->add (new server_request (conn, _cache));
}
}
client_request_shutdown::client_request_shutdown ()
: client_request (CYGSERVER_REQUEST_SHUTDOWN)
{
}
void
client_request_shutdown::serve (transport_layer_base *, process_cache *)
{
assert (!error_code ());
if (msglen ())
log (LOG_ERR, "unexpected request body ignored: %lu bytes", msglen ());
/* FIXME: link upwards, and then this becomes a trivial method call to
* only shutdown _this queue_
*/
kill (getpid (), SIGINT);
msglen (0);
}
static sig_atomic_t shutdown_server = false;
static void
handle_signal (const int signum)
{
/* any signal makes us die :} */
shutdown_server = true;
}
/*
* print_usage ()
*/
static void
print_usage (const char *const pgm)
{
log (LOG_NOTICE, "Usage: %s [OPTIONS]\n"
"\n"
"Cygwin background service daemon\n"
"\n"
"Configuration option:\n"
"\n"
" -f, --config-file <file> Use <file> as config file. Default is\n"
" " DEF_CONFIG_FILE "\n"
"\n"
"Performance options:\n"
"\n"
" -c, --cleanup-threads <num> Number of cleanup threads to use.\n"
" -p, --process-cache <num> Size of process cache.\n"
" -r, --request-threads <num> Number of request threads to use.\n"
"\n"
"Logging options:\n"
"\n"
" -d, --debug Log debug messages to stderr.\n"
" -e, --stderr Log to stderr (default if stderr is a tty).\n"
" -E, --no-stderr Don't log to stderr (see -y, -Y options).\n"
" -l, --log-level <level> Verbosity of logging (1..7). Default: 6\n"
" -y, --syslog Log to syslog (default if stderr is no tty).\n"
" -Y, --no-syslog Don't log to syslog (See -e, -E options).\n"
"\n"
"Support options:\n"
"\n"
" -m, --no-sharedmem Don't start XSI Shared Memory support.\n"
" -q, --no-msgqueues Don't start XSI Message Queue support.\n"
" -s, --no-semaphores Don't start XSI Semaphore support.\n"
"\n"
"Miscellaneous:\n"
"\n"
" -S, --shutdown Shutdown the daemon.\n"
" -h, --help Output usage information and exit.\n"
" -V, --version Output version information and exit.\n"
, pgm);
}
/*
* print_version ()
*/
static void
print_version ()
{
log (LOG_INFO,
"cygserver (cygwin) %d.%d.%d\n"
"Cygwin background service daemon\n"
"Copyright (C) 2001 - %s Cygwin Authors\n"
"This is free software; see the source for copying conditions. There is NO\n"
"warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.",
CYGWIN_VERSION_DLL_MAJOR / 1000,
CYGWIN_VERSION_DLL_MAJOR % 1000,
CYGWIN_VERSION_DLL_MINOR,
strrchr (__DATE__, ' ') + 1);
}
/*
* main ()
*/
int
main (const int argc, char *argv[])
{
const struct option longopts[] = {
{"cleanup-threads", required_argument, NULL, 'c'},
{"debug", no_argument, NULL, 'd'},
{"stderr", no_argument, NULL, 'e'},
{"no-stderr", no_argument, NULL, 'E'},
{"config-file", required_argument, NULL, 'f'},
{"help", no_argument, NULL, 'h'},
{"log-level", required_argument, NULL, 'l'},
{"no-sharedmem", no_argument, NULL, 'm'},
{"process-cache", required_argument, NULL, 'p'},
{"no-msgqueues", no_argument, NULL, 'q'},
{"request-threads", required_argument, NULL, 'r'},
{"no-semaphores", no_argument, NULL, 's'},
{"shutdown", no_argument, NULL, 'S'},
{"version", no_argument, NULL, 'V'},
{"syslog", no_argument, NULL, 'y'},
{"no-syslog", no_argument, NULL, 'Y'},
{0, no_argument, NULL, 0}
};
const char opts[] = "c:deEf:hl:mp:qr:sSVyY";
int32_t cleanup_threads = 0;
int32_t request_threads = 0;
int32_t process_cache_size = 0;
bool shutdown = false;
const char *config_file = DEF_CONFIG_FILE;
bool force_config_file = false;
tun_bool_t option_log_stderr = TUN_UNDEF;
tun_bool_t option_log_syslog = TUN_UNDEF;
char *c = NULL;
/* Check if we have a terminal. If so, default to stderr logging,
otherwise default to syslog logging. This must be done early
to allow default logging already in option processing state. */
openlog ("cygserver", LOG_PID, LOG_KERN);
if (isatty (2))
log_stderr = TUN_TRUE;
else
log_syslog = TUN_TRUE;
int opt;
securityinit ();
opterr = 0;
while ((opt = getopt_long (argc, argv, opts, longopts, NULL)) != EOF)
switch (opt)
{
case 'c':
c = NULL;
cleanup_threads = strtol (optarg, &c, 10);
if (cleanup_threads <= 0 || cleanup_threads > 32 || (c && *c))
panic ("Number of cleanup threads must be between 1 and 32");
break;
case 'd':
log_debug = TUN_TRUE;
break;
case 'e':
option_log_stderr = TUN_TRUE;
break;
case 'E':
option_log_stderr = TUN_FALSE;
break;
case 'f':
config_file = optarg;
force_config_file = true;
break;
case 'h':
print_usage (getprogname ());
return 0;
case 'l':
c = NULL;
log_level = strtoul (optarg, &c, 10);
if (!log_level || log_level > 7 || (c && *c))
panic ("Log level must be between 1 and 7");
break;
case 'm':
support_sharedmem = TUN_FALSE;
break;
case 'p':
c = NULL;
process_cache_size = strtol (optarg, &c, 10);
if (process_cache_size <= 0 || process_cache_size > 310 || (c && *c))
panic ("Size of process cache must be between 1 and 310");
break;
case 'q':
support_msgqueues = TUN_FALSE;
break;
case 'r':
c = NULL;
request_threads = strtol (optarg, &c, 10);
if (request_threads <= 0 || request_threads > 310 || (c && *c))
panic ("Number of request threads must be between 1 and 310");
break;
case 's':
support_semaphores = TUN_FALSE;
break;
case 'S':
shutdown = true;
break;
case 'V':
print_version ();
return 0;
case 'y':
option_log_syslog = TUN_TRUE;
break;
case 'Y':
option_log_syslog = TUN_FALSE;
break;
case '?':
panic ("unknown option -- %c\n"
"Try `%s --help' for more information.", optopt, getprogname ());
}
if (optind != argc)
panic ("Too many arguments");
if (shutdown)
{
/* Setting `cygserver_running' stops the request code making a
* version request, which is not much to the point.
*/
cygserver_running = CYGSERVER_OK;
client_request_shutdown req;
if (req.make_request () == -1 || req.error_code ())
panic("Shutdown request failed: %s", strerror (req.error_code ()));
// FIXME: It would be nice to wait here for the daemon to exit.
return 0;
}
SIGHANDLE (SIGHUP);
SIGHANDLE (SIGINT);
SIGHANDLE (SIGTERM);
tunable_param_init (config_file, force_config_file);
loginit (option_log_stderr, option_log_syslog);
log (LOG_INFO, "daemon starting up");
if (!cleanup_threads)
TUNABLE_INT_FETCH ("kern.srv.cleanup_threads", &cleanup_threads);
if (!cleanup_threads)
cleanup_threads = 2;
if (!request_threads)
TUNABLE_INT_FETCH ("kern.srv.request_threads", &request_threads);
if (!request_threads)
request_threads = 10;
if (!process_cache_size)
TUNABLE_INT_FETCH ("kern.srv.process_cache_size", &process_cache_size);
if (!process_cache_size)
process_cache_size = 62;
if (support_sharedmem == TUN_UNDEF)
TUNABLE_BOOL_FETCH ("kern.srv.sharedmem", &support_sharedmem);
if (support_sharedmem == TUN_UNDEF)
support_sharedmem = TUN_TRUE;
if (support_msgqueues == TUN_UNDEF)
TUNABLE_BOOL_FETCH ("kern.srv.msgqueues", &support_msgqueues);
if (support_msgqueues == TUN_UNDEF)
support_msgqueues = TUN_TRUE;
if (support_semaphores == TUN_UNDEF)
TUNABLE_BOOL_FETCH ("kern.srv.semaphores", &support_semaphores);
if (support_semaphores == TUN_UNDEF)
support_semaphores = TUN_TRUE;
if (!setup_privileges ())
panic ("Setting process privileges failed.");
ipcinit ();
/*XXXXX*/
threaded_queue request_queue (request_threads);
transport_layer_base *const transport = create_server_transport ();
assert (transport);
if (transport->listen () == -1)
return 1;
process_cache cache (process_cache_size, cleanup_threads);
server_submission_loop submission_loop (&request_queue, transport, &cache);
request_queue.add_submission_loop (&submission_loop);
cache.start ();
request_queue.start ();
log (LOG_NOTICE, "Initialization complete. Waiting for requests.");
/* TODO: wait on multiple objects - the thread handle for each
* request loop + all the process handles. This should be done by
* querying the request_queue and the process cache for all their
* handles, and then waiting for (say) 30 seconds. after that we
* recreate the list of handles to wait on, and wait again. the
* point of all this abstraction is that we can trivially server
* both sockets and pipes simply by making a new transport, and then
* calling request_queue.process_requests (transport2);
*/
/* WaitForMultipleObjects abort && request_queue && process_queue && signal
-- if signal event then retrigger it
*/
while (!shutdown_server && request_queue.running () && cache.running ())
{
pause ();
if (ipcunload ())
{
shutdown_server = false;
log (LOG_WARNING, "Shutdown request received but ignored. "
"Dependent processes still running.");
}
}
log (LOG_INFO, "Shutdown request received - new requests will be denied");
request_queue.stop ();
log (LOG_INFO, "All pending requests processed");
delete transport;
log (LOG_INFO, "No longer accepting requests - cygwin will operate in daemonless mode");
cache.stop ();
log (LOG_INFO, "All outstanding process-cache activities completed");
log (LOG_NOTICE, "Shutdown finished.");
return 0;
}
#endif /* __OUTSIDE_CYGWIN__ */
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