newlib-cygwin/winsup/cygserver/cygserver.cc

550 lines
15 KiB
C++

/* cygserver.cc
Copyright 2001, 2002 Red Hat Inc.
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. */
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <windows.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <signal.h>
#include <stdlib.h>
#include "wincap.h"
#include "cygwin_version.h"
#include "getopt.h"
#include "cygwin/cygserver_transport.h"
#include "cygwin/cygserver_transport_pipes.h"
#include "cygwin/cygserver_transport_sockets.h"
#include "threaded_queue.h"
#include "cygwin/cygserver_process.h"
#include "cygwin/cygserver.h"
#include "cygserver_shm.h"
/* for quieter operation, set to 0 */
#define DEBUG 0
#define debug_printf if (DEBUG) printf
GENERIC_MAPPING access_mapping;
static class transport_layer_base *transport;
DWORD request_count = 0;
BOOL
setup_privileges ()
{
BOOL rc, ret_val;
HANDLE hToken = NULL;
TOKEN_PRIVILEGES sPrivileges;
rc = OpenProcessToken (GetCurrentProcess() , TOKEN_ALL_ACCESS , &hToken) ;
if (!rc)
{
printf ("error opening process token (%lu)\n", GetLastError ());
ret_val = FALSE;
goto out;
}
rc = LookupPrivilegeValue (NULL, SE_DEBUG_NAME, &sPrivileges.Privileges[0].Luid);
if (!rc)
{
printf ("error getting prigilege luid (%lu)\n", 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)
{
printf ("error adjusting prigilege level. (%lu)\n", 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))
{
printf ("error getting handle(%u) to server (%lu)\n", (unsigned int)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))
{
printf ("error getting handle SD (%lu)\n", GetLastError ());
goto out;
}
MapGenericMask (&access, &access_mapping);
if (!AccessCheck (sd, from_process_token, access, &access_mapping,
&ps, &ps_len, &access, &status))
{
printf ("error checking access rights (%lu)\n", GetLastError ());
goto out;
}
if (!status)
{
printf ("access to object denied\n");
goto out;
}
if (!DuplicateHandle (from_process, from_handle,
to_process, to_handle_ptr,
access, bInheritHandle, 0))
{
printf ("error getting handle to client (%lu)\n", GetLastError ());
goto out;
}
debug_printf ("Duplicated %p to %p\n", from_handle, *to_handle_ptr);
ret_val = 0;
out:
if (local_handle && from_process != GetCurrentProcess ())
CloseHandle (local_handle);
return (ret_val);
}
void
client_request::serve (transport_layer_base *conn, class process_cache *cache)
{
printf ("*****************************************\n"
"A call to the base client_request class has occured\n"
"This indicates a mismatch in a virtual function definition somewhere\n");
exit (1);
}
void
client_request_attach_tty::serve(transport_layer_base *conn, class process_cache *cache)
{
HANDLE from_process_handle = NULL;
HANDLE to_process_handle = NULL;
HANDLE token_handle = NULL;
DWORD rc;
if (header.cb != sizeof (req))
{
header.error_code = EINVAL;
return;
}
debug_printf ("pid %ld:(%p,%p) -> pid %ld\n", req.master_pid,
req.from_master, req.to_master,
req.pid);
debug_printf ("opening process %ld\n", req.master_pid);
from_process_handle = OpenProcess (PROCESS_DUP_HANDLE, FALSE, req.master_pid);
debug_printf ("opening process %ld\n", req.pid);
to_process_handle = OpenProcess (PROCESS_DUP_HANDLE, FALSE, req.pid);
if (!from_process_handle || !to_process_handle)
{
printf ("error opening process (%lu)\n", GetLastError ());
header.error_code = EACCES;
goto out;
}
debug_printf ("Impersonating client\n");
conn->impersonate_client ();
debug_printf ("about to open thread token\n");
rc = OpenThreadToken (GetCurrentThread (),
TOKEN_QUERY,
TRUE,
&token_handle);
debug_printf ("opened thread token, rc=%lu\n", rc);
conn->revert_to_self ();
if (!rc)
{
printf ("error opening thread token (%lu)\n", GetLastError ());
header.error_code = EACCES;
goto out;
}
if (check_and_dup_handle (from_process_handle, to_process_handle,
token_handle,
GENERIC_READ,
req.from_master,
&req.from_master, TRUE) != 0)
{
printf ("error duplicating from_master handle (%lu)\n", GetLastError ());
header.error_code = EACCES;
goto out;
}
if (req.to_master)
{
if (check_and_dup_handle (from_process_handle, to_process_handle,
token_handle,
GENERIC_WRITE,
req.to_master,
&req.to_master, TRUE) != 0)
{
printf ("error duplicating to_master handle (%lu)\n", GetLastError ());
header.error_code = EACCES;
goto out;
}
}
#if DEBUG
printf ("%ld -> %ld(%p,%p)\n", req.master_pid, req.pid,
req.from_master, req.to_master);
#endif
header.error_code = 0;
out:
if (from_process_handle)
CloseHandle (from_process_handle);
if (to_process_handle)
CloseHandle (to_process_handle);
if (token_handle)
CloseHandle (token_handle);
}
void
client_request_get_version::serve(transport_layer_base *conn, class process_cache *cache)
{
if (header.cb != sizeof (version))
{
header.error_code = EINVAL;
return;
}
header.error_code = 0;
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 *newconn, class process_cache *newcache);
virtual void process ();
private:
char request_buffer [MAX_REQUEST_SIZE];
transport_layer_base *conn;
class process_cache *cache;
};
class server_process_param : public queue_process_param
{
public:
transport_layer_base *transport;
server_process_param () : queue_process_param (false) {};
};
class server_request_queue : public threaded_queue
{
public:
class process_cache *cache;
void process_requests (transport_layer_base *transport);
virtual void add (transport_layer_base *conn);
};
class server_request_queue request_queue;
static DWORD WINAPI
request_loop (LPVOID LpParam)
{
class server_process_param *params = (server_process_param *) LpParam;
class server_request_queue *queue = (server_request_queue *) params->queue;
class transport_layer_base * transport = params->transport;
while (queue->active)
{
transport_layer_base * new_conn = transport->accept ();
/* 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
*/
if (new_conn && queue->active)
queue->add (new_conn);
}
return 0;
}
/* TODO: check we are not being asked to service a already serviced transport */
void
server_request_queue::process_requests (transport_layer_base *transport)
{
class server_process_param *params = new server_process_param;
params->transport = transport;
threaded_queue::process_requests (params, request_loop);
}
void
client_request_shutdown::serve (transport_layer_base *conn, class process_cache *cache)
{
/* FIXME: link upwards, and then this becomes a trivial method call to
* only shutdown _this queue_
*/
/* tell the main thread to shutdown */
request_queue.active=false;
}
server_request::server_request (transport_layer_base *newconn, class process_cache *newcache)
{
conn = newconn;
cache = newcache;
}
void
server_request::process ()
{
ssize_t bytes_read, bytes_written;
struct request_header* req_ptr = (struct request_header*) &request_buffer;
client_request *req = NULL;
debug_printf ("about to read\n");
bytes_read = conn->read (request_buffer, sizeof (struct request_header));
if (bytes_read != sizeof (struct request_header))
{
printf ("error reading from connection (%lu)\n", GetLastError ());
goto out;
}
debug_printf ("got header (%ld)\n", bytes_read);
switch (req_ptr->req_id)
{
case CYGSERVER_REQUEST_GET_VERSION:
req = new client_request_get_version (); break;
case CYGSERVER_REQUEST_ATTACH_TTY:
req = new client_request_attach_tty (); break;
case CYGSERVER_REQUEST_SHUTDOWN:
req = new client_request_shutdown (); break;
case CYGSERVER_REQUEST_SHM_GET:
req = new client_request_shm (); break;
default:
req = new client_request (CYGSERVER_REQUEST_INVALID, 0);
req->header.error_code = ENOSYS;
debug_printf ("Bad client request - returning ENOSYS\n");
}
if (req->header.cb != req_ptr->cb)
{
debug_printf ("Mismatch in request buffer sizes\n");
goto out;
}
if (req->header.cb)
{
bytes_read = conn->read (req->buffer, req->header.cb);
if (bytes_read != req->header.cb)
{
debug_printf ("error reading from connection (%lu)\n", GetLastError ());
goto out;
}
debug_printf ("got body (%ld)\n",bytes_read);
}
/* this is not allowed to fail. We must return ENOSYS at a minimum to the client */
req->serve (conn, cache);
if ((bytes_written = conn->write ((char *)&req->header, sizeof (req->header)))
!= sizeof(req->header) || (req->header.cb &&
(bytes_written = conn->write (req->buffer, req->header.cb)) != req->header.cb))
{
req->header.error_code = -1;
printf ("error writing to connection (%lu)\n", GetLastError ());
goto out;
}
debug_printf("Sent reply, size (%ld)\n",bytes_written);
printf (".");
out:
conn->close ();
delete conn;
if (req)
delete (req);
}
void
server_request_queue::add (transport_layer_base *conn)
{
/* safe to not "Try" because workers don't hog this, they wait on the event
*/
/* every derived ::add must enter the section! */
EnterCriticalSection (&queuelock);
if (!running)
{
conn->close ();
delete conn;
LeaveCriticalSection (&queuelock);
return;
}
queue_request * listrequest = new server_request (conn, cache);
threaded_queue::add (listrequest);
LeaveCriticalSection (&queuelock);
}
void
handle_signal (int signal)
{
/* any signal makes us die :} */
/* FIXME: link upwards, and then this becomes a trivial method call to
* only shutdown _this queue_
*/
/* tell the main thread to shutdown */
request_queue.active=false;
}
struct option longopts[] = {
{"shutdown", no_argument, NULL, 's'},
{0, no_argument, NULL, 0}
};
char opts[] = "s";
int
main (int argc, char **argv)
{
int shutdown=0;
char i;
while ((i = getopt_long (argc, argv, opts, longopts, NULL)) != EOF)
switch (i)
{
case 's':
shutdown = 1;
break;
default:
break;
/*NOTREACHED*/
}
wincap.init();
if (wincap.has_security ())
setup_privileges ();
transport = create_server_transport ();
if (shutdown)
{
if (!transport->connect())
{
printf ("couldn't establish connection with server\n");
exit (1);
}
client_request_shutdown *request =
new client_request_shutdown ();
request->send (transport);
transport->close();
delete transport;
delete request;
exit(0);
}
char version[200];
/* Cygwin dll release */
snprintf (version, 200, "%d.%d.%d(%d.%d/%d/%d)-(%d.%d.%d.%d) %s",
cygwin_version.dll_major / 1000,
cygwin_version.dll_major % 1000,
cygwin_version.dll_minor,
cygwin_version.api_major,
cygwin_version.api_minor,
cygwin_version.shared_data,
CYGWIN_SERVER_VERSION_MAJOR,
CYGWIN_SERVER_VERSION_API,
CYGWIN_SERVER_VERSION_MINOR,
CYGWIN_SERVER_VERSION_PATCH,
cygwin_version.mount_registry,
cygwin_version.dll_build_date);
setbuf (stdout, NULL);
printf ("daemon version %s starting up", version);
if (signal (SIGQUIT, handle_signal) == SIG_ERR)
{
printf ("\ncould not install signal handler (%d)- aborting startup\n", errno);
exit (1);
}
printf (".");
transport->listen ();
printf (".");
class process_cache cache (2);
request_queue.initial_workers = 10;
request_queue.cache = &cache;
request_queue.create_workers ();
printf (".");
request_queue.process_requests (transport);
printf (".");
cache.create_workers ();
printf (".");
cache.process_requests ();
printf (".complete\n");
/* 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 (1 && request_queue.active)
{
sleep (1);
}
printf ("\nShutdown request recieved - new requests will be denied\n");
request_queue.cleanup ();
printf ("All pending requests processed\n");
transport->close ();
printf ("No longer accepting requests - cygwin will operate in daemonless mode\n");
cache.cleanup ();
printf ("All outstanding process-cache activities completed\n");
printf ("daemon shutdown\n");
}