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SDA-3148 refactoring, cleanup and comments
This commit is contained in:
Mattias Gustavsson
parent
3ddcbe1bd5
commit
2011b02bbc
@ -47,12 +47,18 @@ void ipc_server_stop( ipc_server_t* server );
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#pragma comment(lib, "advapi32.lib")
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// TODO: placeholder until implementing logging
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#define IPC_LOG printf
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// Named pipes are on the form "\\.\pipe\name" but we don't want the user to have
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// to specify all that, so we expand what they pass in from "name" to "\\.\pipe\name"
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bool expand_pipe_name( char const* pipe_name, char* buffer, size_t capacity ) {
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int result = snprintf( buffer, capacity, "\\\\.\\pipe\\%s", pipe_name );
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return result >= 0 && result < (int) capacity;
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}
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// Returns true if a pipe of the specified name exists, false if none exists
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bool pipe_exists( const char* pipe_name ) {
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WIN32_FIND_DATAA data;
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memset( &data, 0, sizeof( data ) );
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@ -73,29 +79,39 @@ bool pipe_exists( const char* pipe_name ) {
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}
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// This holds data related to a single client instance
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struct ipc_client_t {
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HANDLE pipe;
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HANDLE pipe; // The named pipe to communicate over
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};
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// Establishes a connection to the specified named pipe
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// Returns NULL if a connection could not be established
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ipc_client_t* ipc_client_connect( char const* pipe_name ) {
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// Make sure a pipe with the specified name exists
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if( !pipe_exists( pipe_name ) ) {
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// Retry once if pipe was not found
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// Retry once if pipe was not found - this would be very rare, but will make it more robust
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Sleep( 1000 );
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if( !pipe_exists( pipe_name ) ) {
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printf( "Named pipe does not exist\n" );
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IPC_LOG( "Named pipe does not exist\n" );
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return NULL;
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}
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}
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// Expand the pipe name to the valid form eg. "\\.\pipe\name"
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char expanded_pipe_name[ MAX_PATH ];
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if( !expand_pipe_name( pipe_name, expanded_pipe_name, sizeof( expanded_pipe_name ) ) ) {
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printf( "Pipe name too long\n" );
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IPC_LOG( "Pipe name too long\n" );
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return NULL;
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}
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// A named pipe has a maximum number of connections. When a client disconnect, it
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// can take a while for the disconnect to register on the server side, so we need
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// to handle the case where the pipe is busy. In practice, this should be rare,
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// but for robustness we handle it anyway.
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HANDLE pipe = NULL;
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for( ; ; ) { // Keep trying to connect while pipe is busy
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for( ; ; ) { // This loop will typically not run more than two iterations, due to multiple exit points
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pipe = CreateFileA(
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expanded_pipe_name, // pipe name
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GENERIC_READ | // read and write access
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@ -106,12 +122,12 @@ ipc_client_t* ipc_client_connect( char const* pipe_name ) {
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0, // default attributes
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NULL ); // no template file
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// Break if the pipe handle is valid.
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// Break if the pipe handle is valid - a connection is now established
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if( pipe != INVALID_HANDLE_VALUE ) {
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break;
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}
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// Retry once if pipe was not found
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// Retry once if pipe was not found. Very rare that this would happen, but we're going for stability
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if( GetLastError() == ERROR_FILE_NOT_FOUND ) {
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Sleep( 1000 );
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pipe = CreateFileA(
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@ -123,40 +139,53 @@ ipc_client_t* ipc_client_connect( char const* pipe_name ) {
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OPEN_EXISTING, // opens existing pipe
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0, // default attributes
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NULL ); // no template file
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// Break if the pipe handle is valid.
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// Break if the pipe handle is valid - a connection is now established
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if( pipe != INVALID_HANDLE_VALUE ) {
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break;
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}
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}
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// Exit if an error other than ERROR_PIPE_BUSY occurs.
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// If we get an error other than ERROR_PIPE_BUSY, we fail to establish a connection.
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// In the case of ERROR_PIPE_BUSY we will wait for the pipe not to be busy (see below)
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if( GetLastError() != ERROR_PIPE_BUSY ) {
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printf( "Could not open pipe. LastError=%d\n", GetLastError() );
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IPC_LOG( "Could not open pipe. LastError=%d\n", GetLastError() );
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return NULL;
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}
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// All pipe instances are busy, so wait for 20 seconds.
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if( !WaitNamedPipeA( expanded_pipe_name, 20000 ) ) {
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// In the specific case of getting an ERROR_FILE_NOT_FOUND, we try doing the
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// wait one more time. The reason this would happen is if the server was just restarting
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// at the start of the call to ipc_client_connect, and thus the check if the pipe exist
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// passed, but when we got to the wait, the pipe was closed down and not yet started up
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// again. Waiting briefly and then trying again will ensure that we handle this rare case
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// of the server being restarted, but it will be very very rare.
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if( GetLastError() == ERROR_FILE_NOT_FOUND ) {
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// retry once just in case pipe was not created yet
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Sleep(1000);
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if( !WaitNamedPipeA( expanded_pipe_name, 20000 ) ) {
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printf( "Could not open pipe on second attempt: 20 second wait timed out. LastError=%d\n", GetLastError() );
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IPC_LOG( "Could not open pipe on second attempt: 20 second wait timed out. LastError=%d\n", GetLastError() );
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return NULL;
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}
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} else {
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printf( "Could not open pipe: 20 second wait timed out. LastError=%d\n", GetLastError() );
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IPC_LOG( "Could not open pipe: 20 second wait timed out. LastError=%d\n", GetLastError() );
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return NULL;
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}
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}
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}
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// A fully working connection has been set up, return it to the caller
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ipc_client_t* connection = (ipc_client_t*) malloc( sizeof( ipc_client_t ) );
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connection->pipe = pipe;
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return connection;
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}
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// Disconnect the client from the server, and release the resources used by it
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// This will allow the server to eventually recycle and reuse that connection slot,
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// but in some cases it can take a brief period of time for that to happen
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void ipc_client_disconnect( ipc_client_t* connection ) {
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FlushFileBuffers( connection->pipe );
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DisconnectNamedPipe( connection->pipe );
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@ -165,6 +194,13 @@ void ipc_client_disconnect( ipc_client_t* connection ) {
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}
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// Wait for data to be available on the named pipe, and once it is, read it into the
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// provided buffer. Returns a status enum for success or failure, or for the case
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// where more data was cued up on the server side than could be received in one call,
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// in which case the ipc_client_receive function should be called again to complete
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// the retrieval of the message. The function will wait indefinitely, until either
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// a message is available, or the pipe is closed.
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// TODO: consider a timeout for the wait, to allow for more robust client implementations
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ipc_receive_status_t ipc_client_receive( ipc_client_t* connection, char* output, int output_size, int* received_size ) {
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DWORD size_read = 0;
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BOOL success = ReadFile(
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@ -175,7 +211,7 @@ ipc_receive_status_t ipc_client_receive( ipc_client_t* connection, char* output,
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NULL ); // not overlapped
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if( !success && GetLastError() != ERROR_MORE_DATA ) {
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printf( "ReadFile from pipe failed. LastError=%d\n", GetLastError() );
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IPC_LOG( "ReadFile from pipe failed. LastError=%d\n", GetLastError() );
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return IPC_RECEIVE_STATUS_ERROR;
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}
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@ -191,21 +227,14 @@ ipc_receive_status_t ipc_client_receive( ipc_client_t* connection, char* output,
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}
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// Sends the specified message (as a zero-terminated string) to the server
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// Will wait for the server to receive the message, and how long that wait
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// is will depend on if the server is busy when the message is sent.
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// TODO: consider a timeout for the wait, to allow for more robust client implementations
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bool ipc_client_send( ipc_client_t* connection, char const* message ) {
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DWORD mode = PIPE_READMODE_MESSAGE;
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BOOL success = SetNamedPipeHandleState(
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connection->pipe, // pipe handle
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&mode, // new pipe mode
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NULL, // don't set maximum bytes
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NULL ); // don't set maximum time
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if( !success ) {
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printf( "SetNamedPipeHandleState failed. LastError=%d\n", GetLastError() );
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return false;
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}
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// Send a message to the pipe server.
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DWORD written = 0;
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success = WriteFile(
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BOOL success = WriteFile(
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connection->pipe, // pipe handle
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message, // message
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(DWORD) strlen( message ) + 1, // message length
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@ -213,7 +242,7 @@ bool ipc_client_send( ipc_client_t* connection, char const* message ) {
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NULL ); // not overlapped
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if( !success ) {
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printf( "WriteFile to pipe failed. LastError=%d\n", GetLastError() );
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IPC_LOG( "WriteFile to pipe failed. LastError=%d\n", GetLastError() );
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return false;
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}
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@ -221,186 +250,229 @@ bool ipc_client_send( ipc_client_t* connection, char const* message ) {
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}
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// This holds the data for a single server-side client thread
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typedef struct ipc_client_thread_t {
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BOOL recycle;
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ipc_server_t* server;
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HANDLE thread;
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HANDLE thread_started_event;
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HANDLE pipe;
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OVERLAPPED io;
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int exit_flag;
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BOOL recycle; // When a client disconnect, this flag is set to TRUE so the slot can be reused
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ipc_request_handler_t request_handler; // When a request is recieved from a client, the server calls this handler
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void* user_data; // When the request_handler is called, this user_data field is passed along with it
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int exit_flag; // Set by the server to signal that the client thread should exit
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HANDLE thread; // Handle to this client thread, used by server to wait for it to exit (on server shutdown)
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HANDLE pipe; // The named pipe instance allocated to this client
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OVERLAPPED io; // We are using non-blocking I/O so the server can cancel pending read/write operations on shutdown
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} ipc_client_thread_t;
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// Typically, we should only ever have one connections, so this is probably overkill, but
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// it doesn't hurt
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#define MAX_CLIENT_CONNECTIONS 32
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// This holds the data for an ipc server instance
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struct ipc_server_t {
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char expanded_pipe_name[ MAX_PATH ];
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PSID sid;
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PACL acl;
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PSECURITY_DESCRIPTOR sd;
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HANDLE thread;
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HANDLE thread_started_event;
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HANDLE pipe;
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OVERLAPPED io;
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int exit_flag;
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ipc_request_handler_t request_handler;
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void* user_data;
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ipc_client_thread_t client_threads[ MAX_CLIENT_CONNECTIONS ];
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int client_threads_count;
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char expanded_pipe_name[ MAX_PATH ]; // Holds the result of expanding from the "name" form to the "\\.\pipe\name" form
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HANDLE thread; // Handle to the main server thread, used to wait for thread exit on server shutdown
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HANDLE thread_started_event; // When the main server thread is started, ipc_server_start needs to wait until it is ready to accept connections before returning to the caller
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HANDLE pipe; // The server pipe instance currently used to listen for connections, will be handed to client thread when connection is made
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OVERLAPPED io; // We are using non-blocking I/O so the server can cancel pending ConnectNamedPipe operations on shutdown
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int exit_flag; // Set by the ipc_server_stop to signal that the main server thread should exit
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ipc_request_handler_t request_handler; // When a request is recieved from a client, the server calls this handler
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void* user_data; // When the request_handler is called, this user_data field is passed along with it
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ipc_client_thread_t client_threads[ MAX_CLIENT_CONNECTIONS ]; // Array of client instances, an instance is only in use if its `recycle` flag is FALSE
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int client_threads_count; // Number of slots used on the `client_threads` array (but a slot may or may not be in use depending on its `recycle` flag)
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};
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// This routine is a thread processing function to read from and reply to a client
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// via the open pipe connection passed from the main loop. Note this allows
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// the main loop to continue executing, potentially creating more threads of
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// this procedure to run concurrently, depending on the number of incoming
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// client connections.
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// When a client connects to the server, the server creates a new thread to handle that connection,
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// and this is the function running on that thread. It basically just sits in a loop, doing a Read
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// from the pipe and waiting until it gets a message. Then it will call the user supplied request
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// handler, and then it does a Write on the pipe to send the response it got from the request handler
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// to the pipe.
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DWORD WINAPI ipc_client_thread( LPVOID param ) {
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// Print verbose messages. In production code, this should be for debugging only.
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//printf( "ipc_client_thread created, receiving and processing messages.\n" );
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ipc_client_thread_t* context = (ipc_client_thread_t*) param;
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// The thread's parameter is a handle to a pipe object instance.
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ipc_client_thread_t* context= (ipc_client_thread_t*) param;
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ipc_server_t* server = context->server;
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HANDLE hPipe = context->pipe;
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HANDLE hEvent = CreateEvent(
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// Create the event used to wait for Read/Write operations to complete
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HANDLE io_event = CreateEvent(
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NULL, // default security attributes
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TRUE, // manual-reset event
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FALSE, // initial state is nonsignaled
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NULL // object name
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);
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//printf( "Thread started\n" );
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SetEvent( context->thread_started_event );
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// Loop until done reading
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for( ; ; ) {
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CHAR pchRequest[ IPC_MESSAGE_MAX_LENGTH ];
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for( ; ; ) {
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// Read client requests from the pipe. This simplistic code only allows messages
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// up to IPC_MESSAGE_MAX_LENGTH characters in length.
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//printf( "ipc_client_thread: reading.\n" );
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DWORD cbBytesRead = 0;
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// Main request-response loop. Will run until exit requested or an eror occurs
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while( !context->exit_flag ) {
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// Read loop, keeps trying to read until data arrives or an error occurs (including a shutdown
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// cancelling the read operation)
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char request[ IPC_MESSAGE_MAX_LENGTH ]; // buffer to hold incoming data
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DWORD bytes_read = 0;
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BOOL success = FALSE;
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bool read_pending = true;
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while( read_pending ) {
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// Set up non-blocking I/O
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memset( &context->io, 0, sizeof( context->io ) );
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ResetEvent( hEvent );
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context->io.hEvent = hEvent;
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BOOL fSuccess = ReadFile(
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hPipe, // handle to pipe
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pchRequest, // buffer to receive data
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IPC_MESSAGE_MAX_LENGTH * sizeof( CHAR ), // size of buffer
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&cbBytesRead, // number of bytes read
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ResetEvent( io_event );
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context->io.hEvent = io_event;
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// Read client requests from the pipe in a non-blocking call
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success = ReadFile(
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context->pipe, // handle to pipe
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request, // buffer to receive data
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IPC_MESSAGE_MAX_LENGTH, // size of buffer
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&bytes_read, // number of bytes read
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&context->io ); // overlapped I/O
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//printf( "ipc_client_thread: read.\n" );
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if( !fSuccess && GetLastError() == ERROR_IO_PENDING ) {
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if( WaitForSingleObject( hEvent, 500 ) == WAIT_TIMEOUT ) {
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// Check if the Read operation is in progress (ReadFile returns FALSE and the error is ERROR_IO_PENDING )
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if( !success && GetLastError() == ERROR_IO_PENDING ) {
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// Wait for the event to be triggered, but timeout after half a second and re-issue the Read
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// This is so the re-issued Read can detect if the pipe have been closed, and thus exit the thread
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if( WaitForSingleObject( io_event, 500 ) == WAIT_TIMEOUT ) {
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CancelIoEx( context->pipe, &context->io );
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continue;
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continue; // Make another Read call
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}
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fSuccess = GetOverlappedResult(
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hPipe, // handle to pipe
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// The wait did not timeout, so the Read operation should now be completed (or failed)
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success = GetOverlappedResult(
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context->pipe, // handle to pipe
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&context->io, // OVERLAPPED structure
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&cbBytesRead, // bytes transferred
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FALSE ); // wait
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&bytes_read, // bytes transferred
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FALSE ); // don't wait
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}
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if( !fSuccess || cbBytesRead == 0 ) {
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// The read have completed (successfully or not) so exit the read loop
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read_pending = false;
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}
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// If the Read was unsuccessful (or read no data), log the error and exit the thread
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// TODO: consider if there are better ways to deal with the error. There might not be,
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// but then the user-code calling client send/receive might need some robust retry code
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if( !success || bytes_read == 0 ) {
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if (GetLastError() == ERROR_BROKEN_PIPE) {
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//printf( "ipc_client_thread: client disconnected.\n" );
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//IPC_LOG( "ipc_client_thread: client disconnected.\n" );
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} else {
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printf( "ipc_client_thread ReadFile failed, LastError=%d.\n", GetLastError() );
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IPC_LOG( "ipc_client_thread ReadFile failed, LastError=%d.\n", GetLastError() );
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}
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goto exit_client_thread;
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}
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if( context->exit_flag ) {
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goto exit_client_thread;
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}
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break;
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}
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// Process the incoming message.
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char pchReply[ IPC_MESSAGE_MAX_LENGTH ];
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memset( pchReply, 0, sizeof( pchReply ) );
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server->request_handler( pchRequest, server->user_data, pchReply, sizeof( pchReply ) );
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pchReply[ IPC_MESSAGE_MAX_LENGTH - 1 ] = '\0'; // Force zero termination (truncate string)
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DWORD cbReplyBytes = (DWORD)strlen(pchReply) + 1;
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// Check if a server shutdown have requested this thread to be terminated, and exit if that's the case
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if( context->exit_flag ) {
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break;
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}
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// Write the reply to the pipe.
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//printf( "ipc_client_thread: writing.\n" );
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DWORD cbWritten = 0;
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BOOL fSuccess = WriteFile(
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hPipe, // handle to pipe
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pchReply, // buffer to write from
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cbReplyBytes, // number of bytes to write
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&cbWritten, // number of bytes written
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// Process the incoming message by calling the user-supplied request handler function
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char response[ IPC_MESSAGE_MAX_LENGTH ];
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memset( response, 0, sizeof( response ) );
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context->request_handler( request, context->user_data, response, sizeof( response ) );
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response[ sizeof( response ) - 1 ] = '\0'; // Force zero termination (truncate string)
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// TODO: Do we need to handle this better? Log it?
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DWORD response_length = (DWORD)strlen( response ) + 1;
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// Write the reply to the pipe
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DWORD bytes_written = 0;
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success = WriteFile(
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context->pipe, // handle to pipe
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response, // buffer to write from
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response_length, // number of bytes to write
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&bytes_written, // number of bytes written
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&context->io ); // overlapped I/O
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|
||||
//printf( "ipc_client_thread: writ.\n" );
|
||||
if( fSuccess || GetLastError() == ERROR_IO_PENDING ) {
|
||||
fSuccess = GetOverlappedResult(
|
||||
hPipe, // handle to pipe
|
||||
// If the write operation is in progress, we wait until it is done, or aborted due to server shutdown
|
||||
if( success || GetLastError() == ERROR_IO_PENDING ) {
|
||||
success = GetOverlappedResult(
|
||||
context->pipe, // handle to pipe
|
||||
&context->io, // OVERLAPPED structure
|
||||
&cbWritten, // bytes transferred
|
||||
FALSE); // wait
|
||||
&bytes_written, // bytes transferred
|
||||
TRUE ); // wait
|
||||
}
|
||||
|
||||
if( !fSuccess || cbReplyBytes != cbWritten ) {
|
||||
printf( ("ipc_client_thread WriteFile failed, LastError=%d.\n"), GetLastError());
|
||||
break;
|
||||
}
|
||||
|
||||
if( context->exit_flag ) {
|
||||
// If the Write was unsuccessful (or didn't manage to write the whole buffer), log the error and exit the thread
|
||||
if( !success || bytes_written != response_length ) {
|
||||
IPC_LOG( ("ipc_client_thread WriteFile failed, LastError=%d.\n"), GetLastError());
|
||||
break;
|
||||
}
|
||||
}
|
||||
exit_client_thread:
|
||||
//printf( "ipc_client_thread cleanup.\n" );
|
||||
|
||||
|
||||
// Flush the pipe to allow the client to read the pipe's contents
|
||||
// before disconnecting. Then disconnect the pipe, and close the
|
||||
// handle to this pipe instance.
|
||||
CloseHandle( hEvent );
|
||||
FlushFileBuffers( hPipe );
|
||||
DisconnectNamedPipe( hPipe );
|
||||
CloseHandle( hPipe );
|
||||
CloseHandle( io_event );
|
||||
FlushFileBuffers( context->pipe );
|
||||
DisconnectNamedPipe( context->pipe );
|
||||
CloseHandle( context->pipe );
|
||||
|
||||
// Mark this client slot for recycling for new connections
|
||||
context->pipe = INVALID_HANDLE_VALUE;
|
||||
context->recycle = TRUE;
|
||||
//printf( "ipc_client_thread exiting.\n" );
|
||||
return EXIT_SUCCESS;
|
||||
}
|
||||
|
||||
void ipc_stop_client_thread( ipc_client_thread_t* thread_context ) {
|
||||
thread_context->exit_flag = 1;
|
||||
CancelIoEx( thread_context->pipe, &thread_context->io );
|
||||
WaitForSingleObject( thread_context->thread, INFINITE );
|
||||
}
|
||||
|
||||
// When the `ipc_server_start` is called, it creates this thread which sits in a loop
|
||||
// and listens for new client connections, until exit is requested by a call to
|
||||
// `ipc_server_stop`. When a new connection is made, it will start another thread to
|
||||
// handle the I/O for that specific client. Then it will open a new listening pipe
|
||||
// instance for further connections.
|
||||
DWORD WINAPI ipc_server_thread( LPVOID param ) {
|
||||
ipc_server_t* server = (ipc_server_t*) param;
|
||||
|
||||
// TODO: logging
|
||||
//fp = fopen( "C:\\auto_update_poc\\log.txt", "w" );
|
||||
//setvbuf(fp, NULL, _IONBF, 0);
|
||||
|
||||
// Create security attribs, we need this so the server can run in session 0
|
||||
// while client runs as a normal user session
|
||||
SID_IDENTIFIER_AUTHORITY auth = { SECURITY_WORLD_SID_AUTHORITY };
|
||||
PSID sid;
|
||||
if( !AllocateAndInitializeSid( &auth, 1, SECURITY_WORLD_RID, 0, 0, 0, 0, 0, 0, 0, &sid ) ) {
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
EXPLICIT_ACCESS access = { 0 };
|
||||
access.grfAccessPermissions = FILE_ALL_ACCESS;
|
||||
access.grfAccessMode = SET_ACCESS;
|
||||
access.grfInheritance = NO_INHERITANCE;
|
||||
access.Trustee.TrusteeForm = TRUSTEE_IS_SID;
|
||||
access.Trustee.TrusteeType = TRUSTEE_IS_WELL_KNOWN_GROUP;
|
||||
access.Trustee.ptstrName = (LPTSTR)sid;
|
||||
PACL acl;
|
||||
if( SetEntriesInAcl(1, &access, NULL, &acl) != ERROR_SUCCESS ) {
|
||||
FreeSid(sid);
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
PSECURITY_DESCRIPTOR sd = (PSECURITY_DESCRIPTOR)LocalAlloc( LPTR, SECURITY_DESCRIPTOR_MIN_LENGTH );
|
||||
if( !sd ) {
|
||||
FreeSid( sid );
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
if( !InitializeSecurityDescriptor( sd, SECURITY_DESCRIPTOR_REVISION ) ) {
|
||||
LocalFree(sd);
|
||||
FreeSid(sid);
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
if( !SetSecurityDescriptorDacl( sd, TRUE, acl, FALSE ) ) {
|
||||
LocalFree( sd );
|
||||
FreeSid( sid );
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
SECURITY_ATTRIBUTES attribs;
|
||||
attribs.nLength = sizeof( SECURITY_ATTRIBUTES );
|
||||
attribs.lpSecurityDescriptor = server->sd;
|
||||
attribs.lpSecurityDescriptor = sd;
|
||||
attribs.bInheritHandle = -1;
|
||||
|
||||
// The main loop creates an instance of the named pipe and
|
||||
// then waits for a client to connect to it. When the client
|
||||
// connects, a thread is created to handle communications
|
||||
// with that client, and this loop is free to wait for the
|
||||
// next client connect request. It is an infinite loop.
|
||||
bool event_raised = false;
|
||||
// Create the event used to wait for ConnectNamedPipe operations to complete
|
||||
HANDLE io_event = CreateEvent(
|
||||
NULL, // default security attributes
|
||||
TRUE, // manual-reset event
|
||||
FALSE, // initial state is nonsignaled
|
||||
NULL // object name
|
||||
);
|
||||
|
||||
// The main loop creates an instance of the named pipe and then waits for a client
|
||||
// to connect to it. When the client connects, a thread is created to handle
|
||||
// communications with that client, and this loop is free to wait for the next client
|
||||
// connect request
|
||||
bool event_raised = false; // We make sure to only raise the server-thread-is-ready event once
|
||||
while( !server->exit_flag ) {
|
||||
//printf( "\nPipe Server: Main thread awaiting client connection on %s\n", server->expanded_pipe_name );
|
||||
// Create a pipe instance to listen for connections
|
||||
server->pipe = CreateNamedPipeA(
|
||||
server->expanded_pipe_name,// pipe name
|
||||
PIPE_ACCESS_DUPLEX | // read/write access
|
||||
FILE_FLAG_OVERLAPPED,
|
||||
FILE_FLAG_OVERLAPPED, // we use async I/O so that we can cancel ConnectNamedPipe operations
|
||||
PIPE_TYPE_MESSAGE | // message type pipe
|
||||
PIPE_READMODE_MESSAGE | // message-read mode
|
||||
PIPE_WAIT, // blocking mode
|
||||
@ -410,26 +482,26 @@ DWORD WINAPI ipc_server_thread( LPVOID param ) {
|
||||
0, // client time-out
|
||||
&attribs ); // default security attribute
|
||||
|
||||
// If we failed to create the pipe, we log the error and exit
|
||||
// TODO: Should we handle this some other way? perhaps report the error back to user
|
||||
if( server->pipe == INVALID_HANDLE_VALUE ) {
|
||||
printf( "CreateNamedPipe failed, LastError=%d.\n", GetLastError() );
|
||||
IPC_LOG( "CreateNamedPipe failed, LastError=%d.\n", GetLastError() );
|
||||
LocalFree( acl );
|
||||
LocalFree( sd );
|
||||
FreeSid( sid );
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
|
||||
// Signal to `ipc_server_start` that the server thread is now fully up and
|
||||
// running and accepting connections
|
||||
if( !event_raised ) {
|
||||
SetEvent( server->thread_started_event );
|
||||
event_raised = true;
|
||||
event_raised = true; // Make sure we don't signal the event again
|
||||
}
|
||||
|
||||
// Wait for the client to connect; if it succeeds,
|
||||
// the function returns a nonzero value. If the function
|
||||
// returns zero, GetLastError returns ERROR_PIPE_CONNECTED.
|
||||
// Wait for the client to connect, using async I/O operation, so ConnectNamedPipe returns immediately
|
||||
memset( &server->io, 0, sizeof( server->io ) );
|
||||
server->io.hEvent = CreateEvent(
|
||||
NULL, // default security attributes
|
||||
TRUE, // manual-reset event
|
||||
FALSE, // initial state is nonsignaled
|
||||
NULL // object name
|
||||
);
|
||||
server->io.hEvent = io_event;
|
||||
ConnectNamedPipe( server->pipe, &server->io );
|
||||
if( GetLastError() == ERROR_IO_PENDING ) {
|
||||
for( ; ; ) {
|
||||
@ -443,48 +515,58 @@ DWORD WINAPI ipc_server_thread( LPVOID param ) {
|
||||
} else if( GetLastError() != ERROR_PIPE_CONNECTED ) {
|
||||
if( GetLastError() != ERROR_OPERATION_ABORTED || server->exit_flag == 0 ) {
|
||||
// The client could not connect, so close the pipe.
|
||||
printf( "Connection failed. LastError=%d\n",GetLastError() );
|
||||
CloseHandle( server->io.hEvent );
|
||||
IPC_LOG( "Connection failed. LastError=%d\n",GetLastError() );
|
||||
break;
|
||||
}
|
||||
}
|
||||
CloseHandle( server->io.hEvent );
|
||||
|
||||
// Check if a server shutdown have requested this thread to be terminated, and exit if that's the case
|
||||
if( server->exit_flag ) {
|
||||
break;
|
||||
}
|
||||
|
||||
//printf( "Client connected, creating a processing thread.\n" );
|
||||
// Create a thread for this client.
|
||||
// Find a free client slot to recycle for this new client connection
|
||||
ipc_client_thread_t* context = NULL;
|
||||
for( int i = 0; i < server->client_threads_count; ++i ) {
|
||||
if( server->client_threads[ i ].recycle ) {
|
||||
context = &server->client_threads[ i ];
|
||||
}
|
||||
}
|
||||
// If there is no free slot to recycle, use a new slot if available
|
||||
if( !context ) {
|
||||
if( server->client_threads_count == MAX_CLIENT_CONNECTIONS ) {
|
||||
printf( "Too many connections\n" );
|
||||
if( server->client_threads_count < MAX_CLIENT_CONNECTIONS ) {
|
||||
context = &server->client_threads[ server->client_threads_count++ ];
|
||||
} else {
|
||||
// If we already reached the maximum number of connections, we have to bail out
|
||||
// This shouldn't really happen though, as the client should be kept in the wait
|
||||
// state by the pipe itself which is specified to accept only the same number of
|
||||
// connections
|
||||
// TODO: Perhaps better to just silently refuse the connection but stay alive?
|
||||
// or maybe kill the connection that has been idle for the longest time?
|
||||
IPC_LOG( "Too many connections\n" );
|
||||
LocalFree( acl );
|
||||
LocalFree( sd );
|
||||
FreeSid( sid );
|
||||
if( server->pipe != INVALID_HANDLE_VALUE ) {
|
||||
CloseHandle( server->pipe );
|
||||
server->pipe = INVALID_HANDLE_VALUE;
|
||||
}
|
||||
|
||||
CloseHandle( io_event );
|
||||
return EXIT_FAILURE;
|
||||
} else {
|
||||
context = &server->client_threads[ server->client_threads_count++ ];
|
||||
}
|
||||
}
|
||||
memset( context, 0, sizeof( *context ) );
|
||||
context->server = server;
|
||||
context->pipe = server->pipe;
|
||||
server->pipe = INVALID_HANDLE_VALUE;
|
||||
context->thread_started_event = CreateEvent(
|
||||
NULL, // default security attributes
|
||||
TRUE, // manual-reset event
|
||||
FALSE, // initial state is nonsignaled
|
||||
NULL // object name
|
||||
);
|
||||
|
||||
// Initialize the client slot
|
||||
memset( context, 0, sizeof( *context ) );
|
||||
context->request_handler = server->request_handler;
|
||||
context->user_data = server->user_data;
|
||||
context->pipe = server->pipe;
|
||||
|
||||
// We are handing the pipe over to the client thread, but will be creating a new one on
|
||||
// the next iteration through the loop
|
||||
server->pipe = INVALID_HANDLE_VALUE;
|
||||
|
||||
// Create a dedicated thread to handle this connection
|
||||
context->thread = CreateThread(
|
||||
NULL, // no security attribute
|
||||
0, // default stack size
|
||||
@ -493,126 +575,117 @@ DWORD WINAPI ipc_server_thread( LPVOID param ) {
|
||||
0, // not suspended
|
||||
NULL ); // returns thread ID
|
||||
|
||||
// If we failed to create thread, something's gone very wrong, so we need to bail
|
||||
if( context->thread == NULL ) {
|
||||
printf( "CreateThread failed, LastError=%d.\n", GetLastError() );
|
||||
IPC_LOG( "CreateThread failed, LastError=%d.\n", GetLastError() );
|
||||
LocalFree( acl );
|
||||
LocalFree( sd );
|
||||
FreeSid( sid );
|
||||
if( server->pipe != INVALID_HANDLE_VALUE ) {
|
||||
CloseHandle( server->pipe );
|
||||
server->pipe = INVALID_HANDLE_VALUE;
|
||||
}
|
||||
CloseHandle( io_event );
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
//printf( "Waiting for thread\n" );
|
||||
WaitForSingleObject( context->thread_started_event, INFINITE );
|
||||
}
|
||||
|
||||
// Cleanup thread resources before we exit
|
||||
LocalFree( acl );
|
||||
LocalFree( sd );
|
||||
FreeSid( sid );
|
||||
|
||||
if( server->pipe != INVALID_HANDLE_VALUE ) {
|
||||
CloseHandle( server->pipe );
|
||||
server->pipe = INVALID_HANDLE_VALUE;
|
||||
}
|
||||
|
||||
CloseHandle( io_event );
|
||||
return EXIT_SUCCESS;
|
||||
}
|
||||
|
||||
|
||||
// Starts a named pipe server with the specified pipe name, and starts listening for
|
||||
// client connections on a separate thread, so will return immediately. The server
|
||||
// thread will keep listening for connections until `ipc_server_stop` is called.
|
||||
ipc_server_t* ipc_server_start( char const* pipe_name, ipc_request_handler_t request_handler, void* user_data ) {
|
||||
|
||||
// Allocate the server instance and initialize it
|
||||
ipc_server_t* server = (ipc_server_t*) malloc( sizeof( ipc_server_t ) );
|
||||
memset( server, 0, sizeof( ipc_server_t ) );
|
||||
server->pipe = INVALID_HANDLE_VALUE;
|
||||
if( !expand_pipe_name( pipe_name, server->expanded_pipe_name, sizeof( server->expanded_pipe_name ) ) ) {
|
||||
printf( "Pipe name too long\n" );
|
||||
free( server );
|
||||
return NULL;
|
||||
}
|
||||
|
||||
// Create security attribs
|
||||
SID_IDENTIFIER_AUTHORITY auth = { SECURITY_WORLD_SID_AUTHORITY };
|
||||
if( !AllocateAndInitializeSid( &auth, 1, SECURITY_WORLD_RID, 0, 0, 0, 0, 0, 0, 0, &server->sid ) ) {
|
||||
free( server );
|
||||
return NULL;
|
||||
}
|
||||
|
||||
EXPLICIT_ACCESS access = { 0 };
|
||||
access.grfAccessPermissions = FILE_ALL_ACCESS;
|
||||
access.grfAccessMode = SET_ACCESS;
|
||||
access.grfInheritance = NO_INHERITANCE;
|
||||
access.Trustee.TrusteeForm = TRUSTEE_IS_SID;
|
||||
access.Trustee.TrusteeType = TRUSTEE_IS_WELL_KNOWN_GROUP;
|
||||
access.Trustee.ptstrName = (LPTSTR)server->sid;
|
||||
|
||||
if( SetEntriesInAcl(1, &access, NULL, &server->acl) != ERROR_SUCCESS ) {
|
||||
FreeSid( server->sid );
|
||||
free( server );
|
||||
return NULL;
|
||||
}
|
||||
|
||||
server->sd = (PSECURITY_DESCRIPTOR)LocalAlloc( LPTR, SECURITY_DESCRIPTOR_MIN_LENGTH );
|
||||
if( !server->sd ) {
|
||||
FreeSid( server->sid );
|
||||
free( server );
|
||||
return NULL;
|
||||
}
|
||||
|
||||
if( !InitializeSecurityDescriptor( server->sd, SECURITY_DESCRIPTOR_REVISION ) ) {
|
||||
LocalFree(server->sd);
|
||||
FreeSid( server->sid );
|
||||
free( server );
|
||||
return NULL;
|
||||
}
|
||||
|
||||
if( !SetSecurityDescriptorDacl( server->sd, TRUE, server->acl, FALSE ) ) {
|
||||
LocalFree( server->sd );
|
||||
FreeSid( server->sid );
|
||||
free( server );
|
||||
return NULL;
|
||||
}
|
||||
|
||||
server->request_handler = request_handler;
|
||||
server->user_data = user_data;
|
||||
|
||||
// Expand the pipe name to the valid form eg. "\\.\pipe\name"
|
||||
if( !expand_pipe_name( pipe_name, server->expanded_pipe_name, sizeof( server->expanded_pipe_name ) ) ) {
|
||||
IPC_LOG( "Pipe name too long\n" );
|
||||
free( server );
|
||||
return NULL;
|
||||
}
|
||||
|
||||
// Create the event used by the server thread to signal that it is up and running and accepting connections
|
||||
server->thread_started_event = CreateEvent(
|
||||
NULL, // default security attributes
|
||||
TRUE, // manual-reset event
|
||||
FALSE, // initial state is nonsignaled
|
||||
NULL // object name
|
||||
);
|
||||
DWORD threadId = 0;
|
||||
|
||||
// Start the server thread which accepts connections and starts dedicated client threads for each new connection
|
||||
server->thread = CreateThread(
|
||||
NULL, // default security attributes
|
||||
0, // use default stack size
|
||||
ipc_server_thread, // thread function name
|
||||
server, // argument to thread function
|
||||
0, // use default creation flags
|
||||
&threadId ); // returns the thread identifier
|
||||
NULL ); // returns the thread identifier
|
||||
|
||||
// If thread creation failed, return error
|
||||
if( server->thread == NULL ) {
|
||||
printf( "Failed to create server thread\n" );
|
||||
LocalFree( server->acl );
|
||||
LocalFree( server->sd );
|
||||
FreeSid( server->sid );
|
||||
IPC_LOG( "Failed to create server thread\n" );
|
||||
CloseHandle( server->thread_started_event );
|
||||
free( server );
|
||||
return NULL;
|
||||
}
|
||||
|
||||
// Wait for the server thread to be up and running and accepting connections
|
||||
if( WaitForSingleObject( server->thread_started_event, 10000 ) != WAIT_OBJECT_0 ) {
|
||||
printf( "Timeout waiting for client thread to start\n" );
|
||||
LocalFree( server->acl );
|
||||
LocalFree( server->sd );
|
||||
FreeSid( server->sid );
|
||||
// If it takes more than 10 seconds for the server thread to start up, something
|
||||
// has gone very wrong so we abort and return an error
|
||||
IPC_LOG( "Timeout waiting for client thread to start\n" );
|
||||
CloseHandle( server->thread_started_event );
|
||||
TerminateThread( server->thread, EXIT_FAILURE );
|
||||
free( server );
|
||||
return NULL;
|
||||
}
|
||||
|
||||
// Return the fully set up and ready server instance
|
||||
return server;
|
||||
}
|
||||
|
||||
|
||||
// Signals the server thread to stop, cancels all pending I/O operations on all
|
||||
// client threads, and release the resources used by the server
|
||||
void ipc_server_stop( ipc_server_t* server ) {
|
||||
server->exit_flag = 1;
|
||||
server->exit_flag = 1; // Signal server thread top stop
|
||||
if( server->pipe != INVALID_HANDLE_VALUE ) {
|
||||
CancelIoEx( server->pipe, &server->io );
|
||||
CancelIoEx( server->pipe, &server->io ); // Cancel pending ConnectNamedPipe operatios, if any
|
||||
}
|
||||
WaitForSingleObject( server->thread, INFINITE );
|
||||
LocalFree( server->acl );
|
||||
LocalFree( server->sd );
|
||||
FreeSid( server->sid );
|
||||
WaitForSingleObject( server->thread, INFINITE ); // Wait for server thread to exit
|
||||
|
||||
// Loop over all clients and terminate each one
|
||||
for( int i = 0; i < server->client_threads_count; ++i ) {
|
||||
if( !server->client_threads[ i ].recycle ) {
|
||||
ipc_stop_client_thread( &server->client_threads[ i ] );
|
||||
ipc_client_thread_t* client = &server->client_threads[ i ];
|
||||
if( !client->recycle ) { // A slot is only valid if `recycle` is FALSE
|
||||
client->exit_flag = 1; // Tell client thread to exit
|
||||
CancelIoEx( client->pipe, &client->io ); // Cancel any pending Read/Write operation
|
||||
WaitForSingleObject( client->thread, INFINITE ); // Wait for client thread to exit
|
||||
}
|
||||
}
|
||||
|
||||
// Free server resources
|
||||
CloseHandle( server->thread_started_event );
|
||||
free( server );
|
||||
}
|
||||
|
||||
|
||||
@ -1,8 +1,17 @@
|
||||
REM runs the tests in an infinite loop
|
||||
REM intended to be run manually and left running for a long time,
|
||||
REM as a final sanity check to make sure the tests are stable
|
||||
REM will exit if any tests fail
|
||||
@echo off
|
||||
echo runs the tests in an infinite loop
|
||||
echo intended to be run manually and left running for a long time,
|
||||
echo as a final sanity check to make sure the tests are stable
|
||||
echo will exit if any tests fail
|
||||
set started=%date% %time%
|
||||
:loop
|
||||
echo INITIATED AT %started%
|
||||
echo CURRENTLY AT %date% %time%
|
||||
call npm run test
|
||||
if %ERRORLEVEL% NEQ 0 goto :eof
|
||||
if %ERRORLEVEL% NEQ 0 (
|
||||
echo.
|
||||
echo INITIATED AT %started%
|
||||
echo TERMINATED AT %date% %time%
|
||||
goto :eof
|
||||
)
|
||||
goto :loop
|
||||
Loading…
Reference in New Issue
Block a user