| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| #include "guacamole/error.h" |
| #include "guacamole/socket.h" |
| |
| #include <pthread.h> |
| #include <stddef.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| |
| #include <winsock2.h> |
| |
| /** |
| * Data associated with an open socket which uses the Windows Socket API. |
| */ |
| typedef struct guac_socket_wsa_data { |
| |
| /** |
| * The associated Windows socket handle. |
| */ |
| SOCKET sock; |
| |
| /** |
| * The number of bytes currently in the main write buffer. |
| */ |
| int written; |
| |
| /** |
| * The main write buffer. Bytes written go here before being flushed |
| * to the open socket. |
| */ |
| char out_buf[GUAC_SOCKET_OUTPUT_BUFFER_SIZE]; |
| |
| /** |
| * Lock which is acquired when an instruction is being written, and |
| * released when the instruction is finished being written. |
| */ |
| pthread_mutex_t socket_lock; |
| |
| /** |
| * Lock which protects access to the internal buffer of this socket, |
| * guaranteeing atomicity of writes and flushes. |
| */ |
| pthread_mutex_t buffer_lock; |
| |
| } guac_socket_wsa_data; |
| |
| /** |
| * Writes the entire contents of the given buffer to the SOCKET handle |
| * associated with the given socket, retrying as necessary until the whole |
| * buffer is written, and aborting if an error occurs. |
| * |
| * @param socket |
| * The guac_socket associated with the SOCKET handle to which the given |
| * buffer should be written. |
| * |
| * @param buf |
| * The buffer of data to write to the given guac_socket. |
| * |
| * @param count |
| * The number of bytes within the given buffer. |
| * |
| * @return |
| * The number of bytes written, which will be exactly the size of the given |
| * buffer, or a negative value if an error occurs. |
| */ |
| ssize_t guac_socket_wsa_write(guac_socket* socket, |
| const void* buf, size_t count) { |
| |
| guac_socket_wsa_data* data = (guac_socket_wsa_data*) socket->data; |
| const char* buffer = buf; |
| |
| /* Write until completely written */ |
| while (count > 0) { |
| |
| int retval = send(data->sock, buffer, count, 0); |
| |
| /* Record errors in guac_error */ |
| if (retval < 0) { |
| guac_error = GUAC_STATUS_SEE_ERRNO; |
| guac_error_message = "Error writing data to socket"; |
| return retval; |
| } |
| |
| /* Advance buffer as data retval */ |
| buffer += retval; |
| count -= retval; |
| |
| } |
| |
| return 0; |
| |
| } |
| |
| /** |
| * Attempts to read from the underlying SOCKET handle of the given guac_socket, |
| * populating the given buffer. |
| * |
| * @param socket |
| * The guac_socket being read from. |
| * |
| * @param buf |
| * The arbitrary buffer which we must populate with data. |
| * |
| * @param count |
| * The maximum number of bytes to read into the buffer. |
| * |
| * @return |
| * The number of bytes read, or -1 if an error occurs. |
| */ |
| static ssize_t guac_socket_wsa_read_handler(guac_socket* socket, |
| void* buf, size_t count) { |
| |
| guac_socket_wsa_data* data = (guac_socket_wsa_data*) socket->data; |
| |
| /* Read from socket */ |
| int retval = recv(data->sock, buf, count, 0); |
| |
| /* Record errors in guac_error */ |
| if (retval < 0) { |
| guac_error = GUAC_STATUS_SEE_ERRNO; |
| guac_error_message = "Error reading data from socket"; |
| } |
| |
| return retval; |
| |
| } |
| |
| /** |
| * Flushes the contents of the output buffer of the given socket immediately, |
| * without first locking access to the output buffer. This function must ONLY |
| * be called if the buffer lock has already been acquired. |
| * |
| * @param socket |
| * The guac_socket to flush. |
| * |
| * @return |
| * Zero if the flush operation was successful, non-zero otherwise. |
| */ |
| static ssize_t guac_socket_wsa_flush(guac_socket* socket) { |
| |
| guac_socket_wsa_data* data = (guac_socket_wsa_data*) socket->data; |
| |
| /* Flush remaining bytes in buffer */ |
| if (data->written > 0) { |
| |
| /* Write ALL bytes in buffer immediately */ |
| if (guac_socket_wsa_write(socket, data->out_buf, data->written)) |
| return 1; |
| |
| data->written = 0; |
| } |
| |
| return 0; |
| |
| } |
| |
| /** |
| * Flushes the internal buffer of the given guac_socket, writing all data |
| * to the underlying SOCKET handle. |
| * |
| * @param socket |
| * The guac_socket to flush. |
| * |
| * @return |
| * Zero if the flush operation was successful, non-zero otherwise. |
| */ |
| static ssize_t guac_socket_wsa_flush_handler(guac_socket* socket) { |
| |
| int retval; |
| guac_socket_wsa_data* data = (guac_socket_wsa_data*) socket->data; |
| |
| /* Acquire exclusive access to buffer */ |
| pthread_mutex_lock(&(data->buffer_lock)); |
| |
| /* Flush contents of buffer */ |
| retval = guac_socket_wsa_flush(socket); |
| |
| /* Relinquish exclusive access to buffer */ |
| pthread_mutex_unlock(&(data->buffer_lock)); |
| |
| return retval; |
| |
| } |
| |
| /** |
| * Writes the contents of the buffer to the output buffer of the given socket, |
| * flushing the output buffer as necessary, without first locking access to the |
| * output buffer. This function must ONLY be called if the buffer lock has |
| * already been acquired. |
| * |
| * @param socket |
| * The guac_socket to write the given buffer to. |
| * |
| * @param buf |
| * The buffer to write to the given socket. |
| * |
| * @param count |
| * The number of bytes in the given buffer. |
| * |
| * @return |
| * The number of bytes written, or a negative value if an error occurs |
| * during write. |
| */ |
| static ssize_t guac_socket_wsa_write_buffered(guac_socket* socket, |
| const void* buf, size_t count) { |
| |
| size_t original_count = count; |
| const char* current = buf; |
| guac_socket_wsa_data* data = (guac_socket_wsa_data*) socket->data; |
| |
| /* Append to buffer, flush if necessary */ |
| while (count > 0) { |
| |
| int chunk_size; |
| int remaining = sizeof(data->out_buf) - data->written; |
| |
| /* If no space left in buffer, flush and retry */ |
| if (remaining == 0) { |
| |
| /* Abort if error occurs during flush */ |
| if (guac_socket_wsa_flush(socket)) |
| return -1; |
| |
| /* Retry buffer append */ |
| continue; |
| |
| } |
| |
| /* Calculate size of chunk to be written to buffer */ |
| chunk_size = count; |
| if (chunk_size > remaining) |
| chunk_size = remaining; |
| |
| /* Update output buffer */ |
| memcpy(data->out_buf + data->written, current, chunk_size); |
| data->written += chunk_size; |
| |
| /* Update provided buffer */ |
| current += chunk_size; |
| count -= chunk_size; |
| |
| } |
| |
| /* All bytes have been written, possibly some to the internal buffer */ |
| return original_count; |
| |
| } |
| |
| /** |
| * Appends the provided data to the internal buffer for future writing. The |
| * actual write attempt will occur only upon flush, or when the internal buffer |
| * is full. |
| * |
| * @param socket |
| * The guac_socket being write to. |
| * |
| * @param buf |
| * The arbitrary buffer containing the data to be written. |
| * |
| * @param count |
| * The number of bytes contained within the buffer. |
| * |
| * @return |
| * The number of bytes written, or -1 if an error occurs. |
| */ |
| static ssize_t guac_socket_wsa_write_handler(guac_socket* socket, |
| const void* buf, size_t count) { |
| |
| int retval; |
| guac_socket_wsa_data* data = (guac_socket_wsa_data*) socket->data; |
| |
| /* Acquire exclusive access to buffer */ |
| pthread_mutex_lock(&(data->buffer_lock)); |
| |
| /* Write provided data to buffer */ |
| retval = guac_socket_wsa_write_buffered(socket, buf, count); |
| |
| /* Relinquish exclusive access to buffer */ |
| pthread_mutex_unlock(&(data->buffer_lock)); |
| |
| return retval; |
| |
| } |
| |
| /** |
| * Waits for data on the underlying SOCKET handle of the given socket to |
| * become available such that the next read operation will not block. |
| * |
| * @param socket |
| * The guac_socket to wait for. |
| * |
| * @param usec_timeout |
| * The maximum amount of time to wait for data, in microseconds, or -1 to |
| * potentially wait forever. |
| * |
| * @return |
| * A positive value on success, zero if the timeout elapsed and no data is |
| * available, or a negative value if an error occurs. |
| */ |
| static int guac_socket_wsa_select_handler(guac_socket* socket, |
| int usec_timeout) { |
| |
| guac_socket_wsa_data* data = (guac_socket_wsa_data*) socket->data; |
| |
| fd_set sockets; |
| struct timeval timeout; |
| int retval; |
| |
| /* Initialize fd_set with single underlying socket handle */ |
| FD_ZERO(&sockets); |
| FD_SET(data->sock, &sockets); |
| |
| /* No timeout if usec_timeout is negative */ |
| if (usec_timeout < 0) |
| retval = select(0, &sockets, NULL, NULL, NULL); |
| |
| /* Handle timeout if specified */ |
| else { |
| timeout.tv_sec = usec_timeout / 1000000; |
| timeout.tv_usec = usec_timeout % 1000000; |
| retval = select(0, &sockets, NULL, NULL, &timeout); |
| } |
| |
| /* Properly set guac_error */ |
| if (retval < 0) { |
| guac_error = GUAC_STATUS_SEE_ERRNO; |
| guac_error_message = "Error while waiting for data on socket"; |
| } |
| |
| if (retval == 0) { |
| guac_error = GUAC_STATUS_TIMEOUT; |
| guac_error_message = "Timeout while waiting for data on socket"; |
| } |
| |
| return retval; |
| |
| } |
| |
| /** |
| * Frees all implementation-specific data associated with the given socket, but |
| * not the socket object itself. |
| * |
| * @param socket |
| * The guac_socket whose associated data should be freed. |
| * |
| * @return |
| * Zero if the data was successfully freed, non-zero otherwise. This |
| * implementation always succeeds, and will always return zero. |
| */ |
| static int guac_socket_wsa_free_handler(guac_socket* socket) { |
| |
| guac_socket_wsa_data* data = (guac_socket_wsa_data*) socket->data; |
| |
| /* Destroy locks */ |
| pthread_mutex_destroy(&(data->socket_lock)); |
| pthread_mutex_destroy(&(data->buffer_lock)); |
| |
| /* Close socket */ |
| closesocket(data->sock); |
| |
| free(data); |
| return 0; |
| |
| } |
| |
| /** |
| * Acquires exclusive access to the given socket. |
| * |
| * @param socket |
| * The guac_socket to which exclusive access is required. |
| */ |
| static void guac_socket_wsa_lock_handler(guac_socket* socket) { |
| |
| guac_socket_wsa_data* data = (guac_socket_wsa_data*) socket->data; |
| |
| /* Acquire exclusive access to socket */ |
| pthread_mutex_lock(&(data->socket_lock)); |
| |
| } |
| |
| /** |
| * Relinquishes exclusive access to the given socket. |
| * |
| * @param socket |
| * The guac_socket to which exclusive access is no longer required. |
| */ |
| static void guac_socket_wsa_unlock_handler(guac_socket* socket) { |
| |
| guac_socket_wsa_data* data = (guac_socket_wsa_data*) socket->data; |
| |
| /* Relinquish exclusive access to socket */ |
| pthread_mutex_unlock(&(data->socket_lock)); |
| |
| } |
| |
| guac_socket* guac_socket_open_wsa(SOCKET sock) { |
| |
| pthread_mutexattr_t lock_attributes; |
| |
| /* Allocate socket and associated data */ |
| guac_socket* socket = guac_socket_alloc(); |
| guac_socket_wsa_data* data = malloc(sizeof(guac_socket_wsa_data)); |
| |
| /* Store socket as socket data */ |
| data->sock = sock; |
| data->written = 0; |
| socket->data = data; |
| |
| pthread_mutexattr_init(&lock_attributes); |
| pthread_mutexattr_setpshared(&lock_attributes, PTHREAD_PROCESS_SHARED); |
| |
| /* Init locks */ |
| pthread_mutex_init(&(data->socket_lock), &lock_attributes); |
| pthread_mutex_init(&(data->buffer_lock), &lock_attributes); |
| |
| /* Set read/write handlers */ |
| socket->read_handler = guac_socket_wsa_read_handler; |
| socket->write_handler = guac_socket_wsa_write_handler; |
| socket->select_handler = guac_socket_wsa_select_handler; |
| socket->lock_handler = guac_socket_wsa_lock_handler; |
| socket->unlock_handler = guac_socket_wsa_unlock_handler; |
| socket->flush_handler = guac_socket_wsa_flush_handler; |
| socket->free_handler = guac_socket_wsa_free_handler; |
| |
| return socket; |
| |
| } |
| |