1 files changed, 377 insertions, 0 deletions
diff --git a/src/tcp_socket.c b/src/tcp_socket.c
new file mode 100644
index 000000000..bfed4dc56
--- /dev/null
+++ b/src/tcp_socket.c
@@ -0,0 +1,377 @@
+/*
+ * Copyright (C) 2003-2011 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "tcp_socket.h"
+#include "fifo_buffer.h"
+#include "io_thread.h"
+#include "glib_socket.h"
+
+#include <assert.h>
+#include <string.h>
+
+#ifdef WIN32
+#include <ws2tcpip.h>
+#include <winsock.h>
+#else
+#include <sys/socket.h>
+#include <netinet/in.h>
+#endif
+
+struct tcp_socket {
+	const struct tcp_socket_handler *handler;
+	void *handler_ctx;
+
+	GMutex *mutex;
+
+	GIOChannel *channel;
+	GSource *in_source, *out_source;
+
+	struct fifo_buffer *input, *output;
+};
+
+static gboolean
+tcp_event(GIOChannel *source, GIOCondition condition, gpointer data);
+
+static void
+tcp_socket_schedule_read(struct tcp_socket *s)
+{
+	assert(s->input != NULL);
+	assert(!fifo_buffer_is_full(s->input));
+
+	if (s->in_source != NULL)
+		return;
+
+	s->in_source = g_io_create_watch(s->channel,
+					 G_IO_IN|G_IO_ERR|G_IO_HUP);
+	g_source_set_callback(s->in_source, (GSourceFunc)tcp_event, s, NULL);
+	g_source_attach(s->in_source, io_thread_context());
+}
+
+static void
+tcp_socket_unschedule_read(struct tcp_socket *s)
+{
+	if (s->in_source == NULL)
+		return;
+
+	g_source_destroy(s->in_source);
+	g_source_unref(s->in_source);
+	s->in_source = NULL;
+}
+
+static void
+tcp_socket_schedule_write(struct tcp_socket *s)
+{
+	assert(s->output != NULL);
+	assert(!fifo_buffer_is_empty(s->output));
+
+	if (s->out_source != NULL)
+		return;
+
+	s->out_source = g_io_create_watch(s->channel, G_IO_OUT);
+	g_source_set_callback(s->out_source, (GSourceFunc)tcp_event, s, NULL);
+	g_source_attach(s->out_source, io_thread_context());
+}
+
+static void
+tcp_socket_unschedule_write(struct tcp_socket *s)
+{
+	if (s->out_source == NULL)
+		return;
+
+	g_source_destroy(s->out_source);
+	g_source_unref(s->out_source);
+	s->out_source = NULL;
+}
+
+/**
+ * Close the socket.  Caller must lock the mutex.
+ */
+static void
+tcp_socket_close(struct tcp_socket *s)
+{
+	tcp_socket_unschedule_read(s);
+	tcp_socket_unschedule_write(s);
+
+	if (s->channel != NULL) {
+		g_io_channel_unref(s->channel);
+		s->channel = NULL;
+	}
+
+	if (s->input != NULL) {
+		fifo_buffer_free(s->input);
+		s->input = NULL;
+	}
+
+	if (s->output != NULL) {
+		fifo_buffer_free(s->output);
+		s->output = NULL;
+	}
+}
+
+static gpointer
+tcp_socket_close_callback(gpointer data)
+{
+	struct tcp_socket *s = data;
+
+	g_mutex_lock(s->mutex);
+	tcp_socket_close(s);
+	g_mutex_unlock(s->mutex);
+
+	return NULL;
+}
+
+static void
+tcp_socket_close_indirect(struct tcp_socket *s)
+{
+	io_thread_call(tcp_socket_close_callback, s);
+
+	assert(s->channel == NULL);
+	assert(s->in_source == NULL);
+	assert(s->out_source == NULL);
+}
+
+static void
+tcp_handle_input(struct tcp_socket *s)
+{
+	size_t length;
+	const void *p = fifo_buffer_read(s->input, &length);
+	if (p == NULL)
+		return;
+
+	g_mutex_unlock(s->mutex);
+	size_t consumed = s->handler->data(p, length, s->handler_ctx);
+	g_mutex_lock(s->mutex);
+	if (consumed > 0 && s->input != NULL)
+		fifo_buffer_consume(s->input, consumed);
+}
+
+static bool
+tcp_in_event(struct tcp_socket *s)
+{
+	assert(s != NULL);
+	assert(s->channel != NULL);
+
+	g_mutex_lock(s->mutex);
+
+	size_t max_length;
+	void *p = fifo_buffer_write(s->input, &max_length);
+	if (p == NULL) {
+		GError *error = g_error_new_literal(tcp_socket_quark(), 0,
+						    "buffer overflow");
+		tcp_socket_close(s);
+		g_mutex_unlock(s->mutex);
+		s->handler->error(error, s->handler_ctx);
+		return false;
+	}
+
+	gsize bytes_read;
+	GError *error = NULL;
+	GIOStatus status = g_io_channel_read_chars(s->channel,
+						   p, max_length,
+						   &bytes_read, &error);
+	switch (status) {
+	case G_IO_STATUS_NORMAL:
+		fifo_buffer_append(s->input, bytes_read);
+		tcp_handle_input(s);
+		g_mutex_unlock(s->mutex);
+		return true;
+
+	case G_IO_STATUS_AGAIN:
+		/* try again later */
+		g_mutex_unlock(s->mutex);
+		return true;
+
+	case G_IO_STATUS_EOF:
+		/* peer disconnected */
+		tcp_socket_close(s);
+		g_mutex_unlock(s->mutex);
+		s->handler->disconnected(s->handler_ctx);
+		return false;
+
+	case G_IO_STATUS_ERROR:
+		/* I/O error */
+		tcp_socket_close(s);
+		g_mutex_unlock(s->mutex);
+		s->handler->error(error, s->handler_ctx);
+		return false;
+	}
+
+	/* unreachable */
+	assert(false);
+	return true;
+}
+
+static bool
+tcp_out_event(struct tcp_socket *s)
+{
+	assert(s != NULL);
+	assert(s->channel != NULL);
+
+	g_mutex_lock(s->mutex);
+
+	size_t length;
+	const void *p = fifo_buffer_read(s->output, &length);
+	if (p == NULL) {
+		/* no more data in the output buffer, remove the
+		   output event */
+		tcp_socket_unschedule_write(s);
+		g_mutex_unlock(s->mutex);
+		return false;
+	}
+
+	gsize bytes_written;
+	GError *error = NULL;
+	GIOStatus status = g_io_channel_write_chars(s->channel, p, length,
+						    &bytes_written, &error);
+	switch (status) {
+	case G_IO_STATUS_NORMAL:
+		fifo_buffer_consume(s->output, bytes_written);
+		g_mutex_unlock(s->mutex);
+		return true;
+
+	case G_IO_STATUS_AGAIN:
+		tcp_socket_schedule_write(s);
+		g_mutex_unlock(s->mutex);
+		return true;
+
+	case G_IO_STATUS_EOF:
+		/* peer disconnected */
+		tcp_socket_close(s);
+		g_mutex_unlock(s->mutex);
+		s->handler->disconnected(s->handler_ctx);
+		return false;
+
+	case G_IO_STATUS_ERROR:
+		/* I/O error */
+		tcp_socket_close(s);
+		g_mutex_unlock(s->mutex);
+		s->handler->error(error, s->handler_ctx);
+		return false;
+	}
+
+	/* unreachable */
+	g_mutex_unlock(s->mutex);
+	assert(false);
+	return true;
+}
+
+static gboolean
+tcp_event(G_GNUC_UNUSED GIOChannel *source, GIOCondition condition,
+	  gpointer data)
+{
+	struct tcp_socket *s = data;
+
+	assert(source == s->channel);
+
+	switch (condition) {
+	case G_IO_IN:
+	case G_IO_PRI:
+		return tcp_in_event(s);
+
+	case G_IO_OUT:
+		return tcp_out_event(s);
+
+	case G_IO_ERR:
+	case G_IO_HUP:
+	case G_IO_NVAL:
+		tcp_socket_close(s);
+		s->handler->disconnected(s->handler_ctx);
+		return false;
+	}
+
+	/* unreachable */
+	assert(false);
+	return false;
+}
+
+struct tcp_socket *
+tcp_socket_new(int fd,
+	       const struct tcp_socket_handler *handler, void *ctx)
+{
+	assert(fd >= 0);
+	assert(handler != NULL);
+	assert(handler->data != NULL);
+	assert(handler->error != NULL);
+	assert(handler->disconnected != NULL);
+
+	struct tcp_socket *s = g_new(struct tcp_socket, 1);
+	s->handler = handler;
+	s->handler_ctx = ctx;
+	s->mutex = g_mutex_new();
+
+	g_mutex_lock(s->mutex);
+
+	s->channel = g_io_channel_new_socket(fd);
+	/* GLib is responsible for closing the file descriptor */
+	g_io_channel_set_close_on_unref(s->channel, true);
+	/* NULL encoding means the stream is binary safe */
+	g_io_channel_set_encoding(s->channel, NULL, NULL);
+	/* no buffering */
+	g_io_channel_set_buffered(s->channel, false);
+
+	s->input = fifo_buffer_new(4096);
+	s->output = fifo_buffer_new(4096);
+
+	s->in_source = NULL;
+	s->out_source = NULL;
+
+	tcp_socket_schedule_read(s);
+
+	g_mutex_unlock(s->mutex);
+
+	return s;
+}
+
+void
+tcp_socket_free(struct tcp_socket *s)
+{
+	tcp_socket_close_indirect(s);
+	g_mutex_free(s->mutex);
+	g_free(s);
+}
+
+bool
+tcp_socket_send(struct tcp_socket *s, const void *data, size_t length)
+{
+	assert(s != NULL);
+
+	g_mutex_lock(s->mutex);
+
+	if (s->output == NULL || s->channel == NULL) {
+		/* already disconnected */
+		g_mutex_unlock(s->mutex);
+		return false;
+	}
+
+	size_t max_length;
+	void *p = fifo_buffer_write(s->output, &max_length);
+	if (p == NULL || max_length < length) {
+		/* buffer is full */
+		g_mutex_unlock(s->mutex);
+		return false;
+	}
+
+	memcpy(p, data, length);
+	fifo_buffer_append(s->output, length);
+	tcp_socket_schedule_write(s);
+
+	g_mutex_unlock(s->mutex);
+	return true;
+}
+