osquery-1/osquery/sql/virtual_table.h

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2.5 KiB
C++

/*
* Copyright (c) 2014, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*
*/
#pragma once
#include <unordered_map>
#include <osquery/tables.h>
#include "osquery/core/conversions.h"
#include "osquery/sql/sqlite_util.h"
namespace osquery {
/**
* @brief osquery virtual table connection.
*
* This object is the SQLite database's virtual table context.
* When the virtual table is created/connected the name and columns are
* retrieved via the TablePlugin call API. The details are kept in this context
* so column parsing and row walking does not require additional Registry calls.
*
* When tables are accessed as the result of an SQL statement a QueryContext is
* created to represent metadata that can be used by the virtual table
* implementation code. Thus the code that generates rows can choose to emit
* additional data, restrict based on constraints, or potentially yield from
* a cache or choose not to generate certain columns.
*/
struct VirtualTableContent {
/// Friendly name for the table.
TableName name;
/// Table column structure, retrieved once via the TablePlugin call API.
TableColumns columns;
/// Transient set of virtual table access constraints.
std::unordered_map<size_t, ConstraintSet> constraints;
};
/**
* @brief osquery cursor object.
*
* Only used in the SQLite virtual table module methods.
*/
struct BaseCursor {
/// SQLite virtual table cursor.
sqlite3_vtab_cursor base;
/// Track cursors for optional planner output.
size_t id{0};
/// Table data generated from last access.
QueryData data;
/// Current cursor position.
size_t row{0};
/// Total number of rows.
size_t n{0};
};
/**
* @brief osquery virtual table object
*
* Only used in the SQLite virtual table module methods.
* This adds each table plugin class to the state tracking in SQLite.
*/
struct VirtualTable {
sqlite3_vtab base;
VirtualTableContent *content{nullptr};
};
/// Attach a table plugin name to an in-memory SQLite database.
Status attachTableInternal(const std::string &name,
const std::string &statement,
sqlite3 *db);
/// Detach (drop) a table.
Status detachTableInternal(const std::string &name, sqlite3 *db);
/// Attach all table plugins to an in-memory SQLite database.
void attachVirtualTables(sqlite3 *db);
}