diff options
Diffstat (limited to 'winsup/cygwin/cygserver.cc')
| -rwxr-xr-x | winsup/cygwin/cygserver.cc | 546 |
1 files changed, 546 insertions, 0 deletions
diff --git a/winsup/cygwin/cygserver.cc b/winsup/cygwin/cygserver.cc new file mode 100755 index 00000000000..34141d3bfa7 --- /dev/null +++ b/winsup/cygwin/cygserver.cc @@ -0,0 +1,546 @@ +/* cygserver.cc + + Copyright 2001 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 "wincap.h" + +#include "getopt.h" + +#include "cygwin/cygserver_transport.h" +#include "cygwin/cygserver.h" +#include "cygserver_shm.h" + + +GENERIC_MAPPING access_mapping; +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) +{ + 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; + } + + ret_val = 0; + +out: + if (local_handle && from_process != GetCurrentProcess ()) + CloseHandle (local_handle); + + 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) +{ + return check_and_dup_handle(from_process,to_process,from_process_token,access,from_handle,to_handle_ptr,FALSE); +} + +void +client_request_attach_tty::serve(transport_layer_base *conn) +{ + 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; + } + +#ifdef DEBUG + printf ("%d:(%d,%d) -> %d\n", req.master_pid, + req.from_master, req.to_master, + req.pid); +#endif + + from_process_handle = OpenProcess (PROCESS_DUP_HANDLE, FALSE, req.master_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; + } + + transport->impersonate_client (); + + rc = OpenThreadToken (GetCurrentThread (), + TOKEN_QUERY, + TRUE, + &token_handle); + + transport->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) != 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) != 0) + { + printf ("error duplicating to_master handle (%lu)\n", GetLastError ()); + header.error_code = EACCES; + goto out; + } + } + +#ifdef DEBUG + printf ("%d -> %d(%d,%d)\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) +{ + 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: + class server_request *next; + server_request (transport_layer_base *newconn); + void process (); + private: + char request_buffer [MAX_REQUEST_SIZE]; + transport_layer_base *conn; +}; + +class server_request_queue +{ + public: + CRITICAL_SECTION queuelock; + HANDLE event; + server_request * request; + bool active; + unsigned int initial_workers; + unsigned int running; + void create_workers (); + void cleanup (); + void add (transport_layer_base *conn); +}; +class server_request_queue request_queue; + +void +client_request_shutdown::serve (transport_layer_base *conn) +{ + /* 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) +{ + conn = newconn; + next = NULL; +} + +void +server_request::process () +{ + ssize_t bytes_read, bytes_written; + struct request_header* req_ptr = (struct request_header*) &request_buffer; + client_request *req = NULL; + 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; + } + 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_get (); break; + default: + req = new client_request (CYGSERVER_REQUEST_INVALID); + req->header.error_code = ENOSYS; + printf ("Bad client request - returning ENOSYS\n"); + } + + if (req->header.cb != req_ptr->cb) + { + 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) + { + printf ("error reading from connection (%lu)\n", GetLastError ()); + goto out; + } + 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); + + if ((bytes_written = conn->write ((char *)&req->header, sizeof (req->header))) + != sizeof(req->header) || + (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; + } + + printf("Sent reply, size (%ld)\n",bytes_written); + +out: + conn->close (); + delete conn; + if (req) + delete (req); +} + +DWORD WINAPI +worker_function( LPVOID LpParam ) +{ + class server_request_queue *queue = (class server_request_queue *) LpParam; + class server_request *request; + /* FIXME use a threadsafe pop instead for speed? */ + while (queue->active) + { + EnterCriticalSection (&queue->queuelock); + while (!queue->request && queue->active) + { + LeaveCriticalSection (&queue->queuelock); + DWORD rc = WaitForSingleObject (queue->event,INFINITE); + if (rc == WAIT_FAILED) + { + printf("Wait for event failed\n"); + queue->running--; + ExitThread (0); + } + EnterCriticalSection (&queue->queuelock); + } + if (!queue->active) + { + queue->running--; + LeaveCriticalSection (&queue->queuelock); + ExitThread (0); + } + /* not needed, but it is efficient */ + request = (class server_request *)InterlockedExchangePointer (&queue->request, queue->request->next); + LeaveCriticalSection (&queue->queuelock); + request->process (); + delete request; + } + queue->running--; + ExitThread (0); +} + +void +server_request_queue::create_workers() +{ + InitializeCriticalSection (&queuelock); + if ((event = CreateEvent (NULL, FALSE, FALSE, NULL)) == NULL) + { + printf ("Failed to create event queue (%lu), terminating\n", GetLastError ()); + exit (1); + } + active = true; + + /* FIXME: Use a stack pair and create threads on the fly whenever + * we have to to service a request. + */ + for (unsigned int i=0; i<initial_workers; i++) + { + HANDLE hThread; + DWORD tid; + hThread = CreateThread (NULL, 0, worker_function, this, 0, &tid); + if (hThread == NULL) + { + printf ("Failed to create thread (%lu), terminating\n", GetLastError ()); + exit (1); + } + CloseHandle (hThread); + running++; + } +} + +void +server_request_queue::cleanup () +{ + /* harvest the threads */ + active = false; + if (!running) + return; + printf ("Waiting for current connections to terminate\n"); + for (int n=running; n; n--) + PulseEvent (event); + while (running) + sleep (1); + DeleteCriticalSection (&queuelock); + CloseHandle (event); +} + +void +server_request_queue::add (transport_layer_base *conn) +{ + /* safe to not "Try" because workers don't hog this, they wait on the event + */ + EnterCriticalSection (&queuelock); + if (!running) + { + printf ("No worker threads to handle request!\n"); + conn->close (); + delete conn; + } + server_request * listrequest; + if (!request) + { + request = new server_request (conn); + listrequest = request; + } + else + { + /* add to the queue end. */ + listrequest = request; + while (listrequest->next) + listrequest = listrequest->next; + listrequest->next = new server_request (conn); + listrequest = listrequest->next; + } + PulseEvent (event); + LeaveCriticalSection (&queuelock); +} + +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); + } + + transport->listen (); + request_queue.initial_workers = 10; + request_queue.create_workers(); + while (request_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 && request_queue.active) + request_queue.add (new_conn); + } + printf ("No longer accepting requests.\n"); + request_queue.cleanup (); + transport->close (); +} |