vici: Provide a command dispatcher handling request and event registration

src/libcharon/plugins/vici/vici_builder.c

@@ -0,0 +1,253 @@
+/*
+ * Copyright (C) 2014 Martin Willi
+ * Copyright (C) 2014 revosec AG
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+#include "vici_builder.h"
+
+#include <bio/bio_writer.h>
+
+typedef struct private_vici_builder_t private_vici_builder_t;
+
+/**
+ * Private data of an vici_builder_t object.
+ */
+struct private_vici_builder_t {
+
+	/**
+	 * Public vici_builder_t interface.
+	 */
+	vici_builder_t public;
+
+	/**
+	 * Writer for elements
+	 */
+	bio_writer_t *writer;
+
+	/**
+	 * Errors encountered
+	 */
+	u_int error;
+
+	/**
+	 * Section nesting level
+	 */
+	u_int section;
+
+	/**
+	 * In list element?
+	 */
+	bool list;
+};
+
+METHOD(vici_builder_t, add, void,
+	private_vici_builder_t *this, vici_type_t type, ...)
+{
+	va_list args;
+	char *name = NULL;
+	chunk_t value = chunk_empty;
+
+	va_start(args, type);
+	switch (type)
+	{
+		case VICI_SECTION_END:
+		case VICI_LIST_END:
+		case VICI_END:
+			break;
+		case VICI_LIST_START:
+		case VICI_SECTION_START:
+			name = va_arg(args, char*);
+			break;
+		case VICI_KEY_VALUE:
+			name = va_arg(args, char*);
+			value = va_arg(args, chunk_t);
+			break;
+		case VICI_LIST_ITEM:
+			value = va_arg(args, chunk_t);
+			break;
+		default:
+			va_end(args);
+			this->error++;
+			return;
+	}
+	va_end(args);
+
+	if (value.len > 0xffff)
+	{
+		this->error++;
+		return;
+	}
+	if (!vici_verify_type(type, this->section, this->list))
+	{
+		this->error++;
+		return;
+	}
+	if (type != VICI_END)
+	{
+		this->writer->write_uint8(this->writer, type);
+	}
+	switch (type)
+	{
+		case VICI_SECTION_START:
+			this->writer->write_data8(this->writer, chunk_from_str(name));
+			this->section++;
+			break;
+		case VICI_SECTION_END:
+			this->section--;
+			break;
+		case VICI_KEY_VALUE:
+			this->writer->write_data8(this->writer, chunk_from_str(name));
+			this->writer->write_data16(this->writer, value);
+			break;
+		case VICI_LIST_START:
+			this->writer->write_data8(this->writer, chunk_from_str(name));
+			this->list = TRUE;
+			break;
+		case VICI_LIST_ITEM:
+			this->writer->write_data16(this->writer, value);
+			break;
+		case VICI_LIST_END:
+			this->list = FALSE;
+			break;
+		default:
+			this->error++;
+			break;
+	}
+}
+
+METHOD(vici_builder_t, vadd_kv, void,
+	private_vici_builder_t *this, char *key, char *fmt, va_list args)
+{
+	char buf[2048];
+	ssize_t len;
+
+	len = vsnprintf(buf, sizeof(buf), fmt, args);
+	if (len < 0 || len >= sizeof(buf))
+	{
+		DBG1(DBG_ENC, "vici builder format buffer exceeds limit");
+		this->error++;
+	}
+	else
+	{
+		add(this, VICI_KEY_VALUE, key, chunk_create(buf, len));
+	}
+}
+
+METHOD(vici_builder_t, add_kv, void,
+	private_vici_builder_t *this, char *key, char *fmt, ...)
+{
+	va_list args;
+
+	va_start(args, fmt);
+	vadd_kv(this, key, fmt, args);
+	va_end(args);
+}
+
+
+METHOD(vici_builder_t, vadd_li, void,
+	private_vici_builder_t *this, char *fmt, va_list args)
+{
+	char buf[2048];
+	ssize_t len;
+
+	len = vsnprintf(buf, sizeof(buf), fmt, args);
+	if (len < 0 || len >= sizeof(buf))
+	{
+		DBG1(DBG_ENC, "vici builder format buffer exceeds limit");
+		this->error++;
+	}
+	else
+	{
+		add(this, VICI_LIST_ITEM, chunk_create(buf, len));
+	}
+}
+
+METHOD(vici_builder_t, add_li, void,
+	private_vici_builder_t *this, char *fmt, ...)
+{
+	va_list args;
+
+	va_start(args, fmt);
+	vadd_li(this, fmt, args);
+	va_end(args);
+}
+
+METHOD(vici_builder_t, begin_section, void,
+	private_vici_builder_t *this, char *name)
+{
+	add(this, VICI_SECTION_START, name);
+}
+
+METHOD(vici_builder_t, end_section, void,
+	private_vici_builder_t *this)
+{
+	add(this, VICI_SECTION_END);
+}
+
+METHOD(vici_builder_t, begin_list, void,
+	private_vici_builder_t *this, char *name)
+{
+	add(this, VICI_LIST_START, name);
+}
+
+METHOD(vici_builder_t, end_list, void,
+	private_vici_builder_t *this)
+{
+	add(this, VICI_LIST_END);
+}
+
+METHOD(vici_builder_t, finalize, vici_message_t*,
+	private_vici_builder_t *this)
+{
+	vici_message_t *product;
+
+	if (this->error || this->section || this->list)
+	{
+		DBG1(DBG_ENC, "vici builder error: %u errors (section: %u, list %u)",
+			 this->error, this->section, this->list);
+		this->writer->destroy(this->writer);
+		free(this);
+		return NULL;
+	}
+	product = vici_message_create_from_data(
+								this->writer->extract_buf(this->writer), TRUE);
+	this->writer->destroy(this->writer);
+	free(this);
+	return product;
+}
+
+/**
+ * See header
+ */
+vici_builder_t *vici_builder_create()
+{
+	private_vici_builder_t *this;
+
+	INIT(this,
+		.public = {
+			.add = _add,
+			.add_kv = _add_kv,
+			.vadd_kv = _vadd_kv,
+			.add_li = _add_li,
+			.vadd_li = _vadd_li,
+			.begin_section = _begin_section,
+			.end_section = _end_section,
+			.begin_list = _begin_list,
+			.end_list = _end_list,
+			.finalize = _finalize,
+		},
+		.writer = bio_writer_create(0),
+	);
+
+	return &this->public;
+}