From 46bdf0692fca50d74c964701f163cc0df58ba76b Mon Sep 17 00:00:00 2001 From: Michael Jumper Date: Mon, 2 May 2016 00:11:38 -0700 Subject: [PATCH] GUACAMOLE-25: Delay sending of "ack" until RDP has opened the AUDIO_INPUT stream. Close audio stream with another "ack" when RDP has closed the AUDIO_INPUT stream. --- src/protocols/rdp/audio_input.c | 97 +++++++++++++++++++++++++++++++-- src/protocols/rdp/audio_input.h | 39 +++++++++++++ 2 files changed, 131 insertions(+), 5 deletions(-) diff --git a/src/protocols/rdp/audio_input.c b/src/protocols/rdp/audio_input.c index 8839d35b..93c492b9 100644 --- a/src/protocols/rdp/audio_input.c +++ b/src/protocols/rdp/audio_input.c @@ -30,19 +30,22 @@ #include #include +#include int guac_rdp_audio_handler(guac_user* user, guac_stream* stream, char* mimetype) { + guac_client* client = user->client; + guac_rdp_client* rdp_client = (guac_rdp_client*) client->data; + /* FIXME: Assuming mimetype of "audio/L16;rate=44100,channels=2" */ /* Init stream data */ stream->blob_handler = guac_rdp_audio_blob_handler; stream->end_handler = guac_rdp_audio_end_handler; - guac_protocol_send_ack(user->socket, stream, - "OK", GUAC_PROTOCOL_STATUS_SUCCESS); - guac_socket_flush(user->socket); + /* Associate stream with audio buffer */ + guac_rdp_audio_buffer_set_stream(rdp_client->audio_input, user, stream); return 0; @@ -83,13 +86,72 @@ void guac_rdp_audio_load_plugin(rdpContext* context) { } guac_rdp_audio_buffer* guac_rdp_audio_buffer_alloc() { - return calloc(1, sizeof(guac_rdp_audio_buffer)); + guac_rdp_audio_buffer* buffer = calloc(1, sizeof(guac_rdp_audio_buffer)); + pthread_mutex_init(&(buffer->lock), NULL); + return buffer; +} + +/** + * Sends an "ack" instruction over the socket associated with the Guacamole + * stream over which audio data is being received. The "ack" instruction will + * only be sent if the Guacamole audio stream has been established (through + * receipt of an "audio" instruction), is still open (has not received an "end" + * instruction nor been associated with an "ack" having an error code), and is + * associated with an active RDP AUDIO_INPUT channel. + * + * @param audio_buffer + * The audio buffer associated with the guac_stream for which the "ack" + * instruction should be sent, if any. If there is no associated + * guac_stream, this function has no effect. + * + * @param message + * An arbitrary human-readable message to send along with the "ack". + * + * @param status + * The Guacamole protocol status code to send with the "ack". This should + * be GUAC_PROTOCOL_STATUS_SUCCESS if the audio stream has been set up + * successfully or GUAC_PROTOCOL_STATUS_RESOURCE_CLOSED if the audio stream + * has been closed (but may usable again if reopened). + */ +static void guac_rdp_audio_buffer_ack(guac_rdp_audio_buffer* audio_buffer, + const char* message, guac_protocol_status status) { + + guac_user* user = audio_buffer->user; + guac_stream* stream = audio_buffer->stream; + + /* Do not send ack unless both sides of the audio stream are ready */ + if (user == NULL || stream == NULL || audio_buffer->packet == NULL) + return; + + /* Send ack instruction */ + guac_protocol_send_ack(user->socket, stream, message, status); + guac_socket_flush(user->socket); + +} + +void guac_rdp_audio_buffer_set_stream(guac_rdp_audio_buffer* audio_buffer, + guac_user* user, guac_stream* stream) { + + pthread_mutex_lock(&(audio_buffer->lock)); + + /* Associate received stream */ + audio_buffer->user = user; + audio_buffer->stream = stream; + + /* Acknowledge stream creation (if buffer is ready to receive) */ + guac_rdp_audio_buffer_ack(audio_buffer, + "OK", GUAC_PROTOCOL_STATUS_SUCCESS); + + pthread_mutex_unlock(&(audio_buffer->lock)); + } void guac_rdp_audio_buffer_begin(guac_rdp_audio_buffer* audio_buffer, int packet_size, guac_rdp_audio_buffer_flush_handler* flush_handler, void* data) { + pthread_mutex_lock(&(audio_buffer->lock)); + /* Reset buffer state to provided values */ audio_buffer->bytes_written = 0; audio_buffer->packet_size = packet_size; @@ -100,14 +162,24 @@ void guac_rdp_audio_buffer_begin(guac_rdp_audio_buffer* audio_buffer, free(audio_buffer->packet); audio_buffer->packet = malloc(packet_size); + /* Acknowledge stream creation (if stream is ready to receive) */ + guac_rdp_audio_buffer_ack(audio_buffer, + "OK", GUAC_PROTOCOL_STATUS_SUCCESS); + + pthread_mutex_unlock(&(audio_buffer->lock)); + } void guac_rdp_audio_buffer_write(guac_rdp_audio_buffer* audio_buffer, char* buffer, int length) { + pthread_mutex_lock(&(audio_buffer->lock)); + /* Ignore packet if there is no buffer */ - if (audio_buffer->packet_size == 0 || audio_buffer->packet == NULL) + if (audio_buffer->packet_size == 0 || audio_buffer->packet == NULL) { + pthread_mutex_unlock(&(audio_buffer->lock)); return; + } /* Continuously write packets until no data remains */ while (length > 0) { @@ -146,10 +218,22 @@ void guac_rdp_audio_buffer_write(guac_rdp_audio_buffer* audio_buffer, } /* end packet write loop */ + pthread_mutex_unlock(&(audio_buffer->lock)); + } void guac_rdp_audio_buffer_end(guac_rdp_audio_buffer* audio_buffer) { + pthread_mutex_lock(&(audio_buffer->lock)); + + /* The stream is now closed */ + guac_rdp_audio_buffer_ack(audio_buffer, + "CLOSED", GUAC_PROTOCOL_STATUS_RESOURCE_CLOSED); + + /* Unset user and stream */ + audio_buffer->user = NULL; + audio_buffer->stream = NULL; + /* Reset buffer state */ audio_buffer->bytes_written = 0; audio_buffer->packet_size = 0; @@ -159,9 +243,12 @@ void guac_rdp_audio_buffer_end(guac_rdp_audio_buffer* audio_buffer) { free(audio_buffer->packet); audio_buffer->packet = NULL; + pthread_mutex_unlock(&(audio_buffer->lock)); + } void guac_rdp_audio_buffer_free(guac_rdp_audio_buffer* audio_buffer) { + pthread_mutex_destroy(&(audio_buffer->lock)); free(audio_buffer->packet); free(audio_buffer); } diff --git a/src/protocols/rdp/audio_input.h b/src/protocols/rdp/audio_input.h index c89de153..776f0a52 100644 --- a/src/protocols/rdp/audio_input.h +++ b/src/protocols/rdp/audio_input.h @@ -23,8 +23,11 @@ #include "config.h" #include +#include #include +#include + /** * Handler which is invoked when a guac_rdp_audio_buffer's internal packet * buffer has reached capacity and must be flushed. @@ -51,6 +54,24 @@ typedef void guac_rdp_audio_buffer_flush_handler(char* buffer, int length, */ typedef struct guac_rdp_audio_buffer { + /** + * Lock which is acquired/released to ensure accesses to the audio buffer + * are atomic. + */ + pthread_mutex_t lock; + + /** + * The user from which this audio buffer will receive data. If no user has + * yet opened an associated audio stream, this will be NULL. + */ + guac_user* user; + + /** + * The stream from which this audio buffer will receive data. If no user + * has yet opened an associated audio stream, this will be NULL. + */ + guac_stream* stream; + /** * The size that each audio packet must be, in bytes. The packet buffer * within this structure will be at least this size. @@ -91,6 +112,24 @@ typedef struct guac_rdp_audio_buffer { */ guac_rdp_audio_buffer* guac_rdp_audio_buffer_alloc(); +/** + * Associates the given audio buffer with the underlying audio stream which + * has been received from the given Guacamole user. Once both the Guacamole + * audio stream and the RDP audio stream are ready, an appropriate "ack" + * message will be sent. + * + * @param audio_buffer + * The audio buffer associated with the audio stream just received. + * + * @param user + * The Guacamole user that created the audio stream. + * + * @param stream + * The guac_stream object representing the audio stream. + */ +void guac_rdp_audio_buffer_set_stream(guac_rdp_audio_buffer* audio_buffer, + guac_user* user, guac_stream* stream); + /** * Begins handling of audio data received via guac_rdp_audio_buffer_write() and * allocates the necessary underlying packet buffer. Audio packets of exactly