1 files changed, 135 insertions, 0 deletions
diff --git a/src/uvt_tty_null.c b/src/uvt_tty_null.c
new file mode 100644
index 0000000..0c04942
--- /dev/null
+++ b/src/uvt_tty_null.c
@@ -0,0 +1,135 @@
+/*
+ * UVT - Userspace Virtual Terminals
+ *
+ * Copyright (c) 2011-2013 David Herrmann <dh.herrmann@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/*
+ * Null TTY
+ * This tty simply discards all incoming messages and never produces any
+ * outgoing messages. Ioctls return static data or fail with some generic error
+ * code if they would modify internal state that we cannot emulate easily.
+ */
+
+#include <eloop.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include "shl_llog.h"
+#include "uvt.h"
+#include "uvt_internal.h"
+
+#define LLOG_SUBSYSTEM "uvt_tty_null"
+
+struct uvt_tty_null {
+	unsigned long ref;
+	struct uvt_ctx *ctx;
+	llog_submit_t llog;
+	void *llog_data;
+};
+
+static void tty_null_ref(void *data)
+{
+	uvt_tty_null_ref(data);
+}
+
+static void tty_null_unref(void *data)
+{
+	uvt_tty_null_unref(data);
+}
+
+static int tty_null_register_cb(void *data, uvt_tty_cb cb, void *cb_data)
+{
+	return 0;
+}
+
+static void tty_null_unregister_cb(void *data, uvt_tty_cb cb, void *cb_data)
+{
+}
+
+static int tty_null_read(void *data, uint8_t *buf, size_t size)
+{
+	return -EAGAIN;
+}
+
+static int tty_null_write(void *data, const uint8_t *buf, size_t size)
+{
+	return size;
+}
+
+static unsigned int tty_null_poll(void *data)
+{
+	return UVT_TTY_WRITE;
+}
+
+const struct uvt_tty_ops uvt_tty_null_ops = {
+	.ref = tty_null_ref,
+	.unref = tty_null_unref,
+	.register_cb = tty_null_register_cb,
+	.unregister_cb = tty_null_unregister_cb,
+
+	.read = tty_null_read,
+	.write = tty_null_write,
+	.poll = tty_null_poll,
+};
+
+int uvt_tty_null_new(struct uvt_tty_null **out, struct uvt_ctx *ctx)
+{
+	struct uvt_tty_null *tty;
+
+	if (!ctx)
+		return -EINVAL;
+	if (!out)
+		return llog_EINVAL(ctx);
+
+	tty = malloc(sizeof(*tty));
+	if (!tty)
+		return llog_ENOMEM(ctx);
+	memset(tty, 0, sizeof(*tty));
+	tty->ref = 1;
+	tty->ctx = ctx;
+	tty->llog = tty->ctx->llog;
+	tty->llog_data = tty->ctx->llog_data;
+
+	uvt_ctx_ref(tty->ctx);
+	*out = tty;
+	return 0;
+}
+
+void uvt_tty_null_ref(struct uvt_tty_null *tty)
+{
+	if (!tty || !tty->ref)
+		return;
+
+	++tty->ref;
+}
+
+void uvt_tty_null_unref(struct uvt_tty_null *tty)
+{
+	if (!tty || !tty->ref || --tty->ref)
+		return;
+
+	uvt_ctx_unref(tty->ctx);
+	free(tty);
+}