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76f64f5d79
Properly parse multi-document yaml files e.g. blocks separated by ---. This is easily handled by lyaml itself--you just need to pass the option all = true to yaml.load, and each document will be provided as a table. This does break the table iteration a bit, so some more refactoring: - Create a load_state table that holds context like the current - document index, the required_engine_version, etc. - Pull out the parts that parse a single document to load_rules_doc(), which is given the table for a single document + load_state. - Simplify get_orig_yaml_obj to just provide a single row index and - return all rows from that point to the next blank line or line starting with '-' Signed-off-by: Mark Stemm <mark.stemm@gmail.com>
840 lines
25 KiB
Lua
840 lines
25 KiB
Lua
-- Copyright (C) 2016-2018 Draios Inc dba Sysdig.
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--
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-- This file is part of falco.
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--
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-- Licensed under the Apache License, Version 2.0 (the "License");
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-- you may not use this file except in compliance with the License.
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-- You may obtain a copy of the License at
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--
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-- http://www.apache.org/licenses/LICENSE-2.0
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--
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-- Unless required by applicable law or agreed to in writing, software
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-- distributed under the License is distributed on an "AS IS" BASIS,
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-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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-- See the License for the specific language governing permissions and
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-- limitations under the License.
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--
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--[[
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Compile and install falco rules.
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This module exports functions that are called from falco c++-side to compile and install a set of rules.
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--]]
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local sinsp_rule_utils = require "sinsp_rule_utils"
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local compiler = require "compiler"
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local yaml = require"lyaml"
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--[[
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Traverse AST, adding the passed-in 'index' to each node that contains a relational expression
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--]]
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local function mark_relational_nodes(ast, index)
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local t = ast.type
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if t == "BinaryBoolOp" then
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mark_relational_nodes(ast.left, index)
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mark_relational_nodes(ast.right, index)
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elseif t == "UnaryBoolOp" then
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mark_relational_nodes(ast.argument, index)
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elseif t == "BinaryRelOp" then
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ast.index = index
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elseif t == "UnaryRelOp" then
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ast.index = index
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else
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error ("Unexpected type in mark_relational_nodes: "..t)
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end
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end
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function map(f, arr)
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local res = {}
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for i,v in ipairs(arr) do
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res[i] = f(v)
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end
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return res
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end
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-- Permissive for case and for common abbreviations.
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priorities = {
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Emergency=0, Alert=1, Critical=2, Error=3, Warning=4, Notice=5, Informational=5, Debug=7,
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emergency=0, alert=1, critical=2, error=3, warning=4, notice=5, informational=5, debug=7,
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EMERGENCY=0, ALERT=1, CRITICAL=2, ERROR=3, WARNING=4, NOTICE=5, INFORMATIONAL=5, DEBUG=7,
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INFO=5, info=5
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}
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--[[
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Take a filter AST and set it up in the libsinsp runtime, using the filter API.
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--]]
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local function install_filter(node, filter_api_lib, lua_parser, parent_bool_op)
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local t = node.type
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if t == "BinaryBoolOp" then
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-- "nesting" (the runtime equivalent of placing parens in syntax) is
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-- never necessary when we have identical successive operators. so we
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-- avoid it as a runtime performance optimization.
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if (not(node.operator == parent_bool_op)) then
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filter_api_lib.nest(lua_parser) -- io.write("(")
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end
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install_filter(node.left, filter_api_lib, lua_parser, node.operator)
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filter_api_lib.bool_op(lua_parser, node.operator) -- io.write(" "..node.operator.." ")
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install_filter(node.right, filter_api_lib, lua_parser, node.operator)
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if (not (node.operator == parent_bool_op)) then
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filter_api_lib.unnest(lua_parser) -- io.write(")")
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end
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elseif t == "UnaryBoolOp" then
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filter_api_lib.nest(lua_parser) --io.write("(")
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filter_api_lib.bool_op(lua_parser, node.operator) -- io.write(" "..node.operator.." ")
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install_filter(node.argument, filter_api_lib, lua_parser)
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filter_api_lib.unnest(lua_parser) -- io.write(")")
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elseif t == "BinaryRelOp" then
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if (node.operator == "in" or node.operator == "pmatch") then
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elements = map(function (el) return el.value end, node.right.elements)
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filter_api_lib.rel_expr(lua_parser, node.left.value, node.operator, elements, node.index)
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else
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filter_api_lib.rel_expr(lua_parser, node.left.value, node.operator, node.right.value, node.index)
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end
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-- io.write(node.left.value.." "..node.operator.." "..node.right.value)
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elseif t == "UnaryRelOp" then
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filter_api_lib.rel_expr(lua_parser, node.argument.value, node.operator, node.index)
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--io.write(node.argument.value.." "..node.operator)
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else
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error ("Unexpected type in install_filter: "..t)
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end
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end
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function set_output(output_format, state)
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if(output_ast.type == "OutputFormat") then
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local format
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else
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error ("Unexpected type in set_output: ".. output_ast.type)
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end
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end
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-- Note that the rules_by_name and rules_by_idx refer to the same rule
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-- object. The by_name index is used for things like describing rules,
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-- and the by_idx index is used to map the relational node index back
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-- to a rule.
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local state = {macros={}, lists={}, filter_ast=nil, rules_by_name={},
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skipped_rules_by_name={}, macros_by_name={}, lists_by_name={},
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n_rules=0, rules_by_idx={}, ordered_rule_names={}, ordered_macro_names={}, ordered_list_names={}}
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local function reset_rules(rules_mgr)
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falco_rules.clear_filters(rules_mgr)
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state.n_rules = 0
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state.rules_by_idx = {}
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state.macros = {}
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state.lists = {}
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end
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-- From http://lua-users.org/wiki/TableUtils
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--
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function table.val_to_str ( v )
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if "string" == type( v ) then
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v = string.gsub( v, "\n", "\\n" )
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if string.match( string.gsub(v,"[^'\"]",""), '^"+$' ) then
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return "'" .. v .. "'"
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end
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return '"' .. string.gsub(v,'"', '\\"' ) .. '"'
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else
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return "table" == type( v ) and table.tostring( v ) or
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tostring( v )
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end
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end
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function table.key_to_str ( k )
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if "string" == type( k ) and string.match( k, "^[_%a][_%a%d]*$" ) then
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return k
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else
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return "[" .. table.val_to_str( k ) .. "]"
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end
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end
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function table.tostring( tbl )
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local result, done = {}, {}
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for k, v in ipairs( tbl ) do
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table.insert( result, table.val_to_str( v ) )
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done[ k ] = true
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end
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for k, v in pairs( tbl ) do
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if not done[ k ] then
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table.insert( result,
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table.key_to_str( k ) .. "=" .. table.val_to_str( v ) )
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end
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end
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return "{" .. table.concat( result, "," ) .. "}"
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end
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-- Split rules_content by lines and also remember the line numbers for
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-- each top -level object. Returns a table of lines and a table of
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-- line numbers for objects.
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function split_lines(rules_content)
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lines = {}
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indices = {}
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idx = 1
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last_pos = 1
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pos = string.find(rules_content, "\n", 1, true)
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while pos ~= nil do
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line = string.sub(rules_content, last_pos, pos-1)
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if line ~= "" then
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lines[#lines+1] = line
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if string.len(line) >= 3 and string.sub(line, 1, 3) == "---" then
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-- Document marker, skip
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elseif string.sub(line, 1, 1) == '-' then
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indices[#indices+1] = idx
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end
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idx = idx + 1
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end
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last_pos = pos+1
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pos = string.find(rules_content, "\n", pos+1, true)
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end
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if last_pos < string.len(rules_content) then
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line = string.sub(rules_content, last_pos)
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lines[#lines+1] = line
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if string.sub(line, 1, 1) == '-' then
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indices[#indices+1] = idx
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end
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idx = idx + 1
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end
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-- Add a final index for last line in document
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indices[#indices+1] = idx
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return lines, indices
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end
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function get_orig_yaml_obj(rules_lines, row)
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local ret = ""
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idx = row
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while (idx <= #rules_lines) do
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ret = ret..rules_lines[idx].."\n"
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idx = idx + 1
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if idx > #rules_lines or rules_lines[idx] == "" or string.sub(rules_lines[idx], 1, 1) == '-' then
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break
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end
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end
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return ret
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end
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function get_lines(rules_lines, row, num_lines)
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local ret = ""
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idx = row
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while (idx < (row + num_lines) and idx <= #rules_lines) do
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ret = ret..rules_lines[idx].."\n"
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idx = idx + 1
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end
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return ret
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end
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function build_error(rules_lines, row, num_lines, err)
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local ret = err.."\n---\n"..get_lines(rules_lines, row, num_lines).."---"
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return ret
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end
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function build_error_with_context(ctx, err)
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local ret = err.."\n---\n"..ctx.."---"
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return ret
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end
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function load_rules_doc(rules_mgr, doc, load_state)
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-- Iterate over yaml list. In this pass, all we're doing is
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-- populating the set of rules, macros, and lists. We're not
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-- expanding/compiling anything yet. All that will happen in a
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-- second pass
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for i,v in ipairs(doc) do
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load_state.cur_item_idx = load_state.cur_item_idx + 1
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-- Save back the original object as it appeared in the file. Will be used to provide context.
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local context = get_orig_yaml_obj(load_state.lines,
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load_state.indices[load_state.cur_item_idx])
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if (not (type(v) == "table")) then
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return false, build_error_with_context(context, "Unexpected element of type " ..type(v)..". Each element should be a yaml associative array.")
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end
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v['context'] = context
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if (v['required_engine_version']) then
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load_state.required_engine_version = v['required_engine_version']
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if type(load_state.required_engine_version) ~= "number" then
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return false, build_error_with_context(v['context'], "Value of required_engine_version must be a number")
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end
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if falco_rules.engine_version(rules_mgr) < v['required_engine_version'] then
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return false, build_error_with_context(v['context'], "Rules require engine version "..v['required_engine_version']..", but engine version is "..falco_rules.engine_version(rules_mgr))
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end
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elseif (v['macro']) then
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if (v['macro'] == nil or type(v['macro']) == "table") then
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return false, build_error_with_context(v['context'], "Macro name is empty")
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end
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if v['source'] == nil then
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v['source'] = "syscall"
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end
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if state.macros_by_name[v['macro']] == nil then
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state.ordered_macro_names[#state.ordered_macro_names+1] = v['macro']
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end
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for j, field in ipairs({'condition'}) do
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if (v[field] == nil) then
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return false, build_error_with_context(v['context'], "Macro must have property "..field)
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end
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end
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-- Possibly append to the condition field of an existing macro
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append = false
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if v['append'] then
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append = v['append']
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end
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if append then
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if state.macros_by_name[v['macro']] == nil then
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return false, build_error_with_context(v['context'], "Macro " ..v['macro'].. " has 'append' key but no macro by that name already exists")
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end
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state.macros_by_name[v['macro']]['condition'] = state.macros_by_name[v['macro']]['condition'] .. " " .. v['condition']
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-- Add the current object to the context of the base macro
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state.macros_by_name[v['macro']]['context'] = state.macros_by_name[v['macro']]['context'].."\n"..v['context']
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else
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state.macros_by_name[v['macro']] = v
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end
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elseif (v['list']) then
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if (v['list'] == nil or type(v['list']) == "table") then
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return false, build_error_with_context(v['context'], "List name is empty")
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end
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if state.lists_by_name[v['list']] == nil then
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state.ordered_list_names[#state.ordered_list_names+1] = v['list']
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end
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for j, field in ipairs({'items'}) do
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if (v[field] == nil) then
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return false, build_error_with_context(v['context'], "List must have property "..field)
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end
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end
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-- Possibly append to an existing list
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append = false
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if v['append'] then
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append = v['append']
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end
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if append then
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if state.lists_by_name[v['list']] == nil then
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return false, build_error_with_context(v['context'], "List " ..v['list'].. " has 'append' key but no list by that name already exists")
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end
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for j, elem in ipairs(v['items']) do
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table.insert(state.lists_by_name[v['list']]['items'], elem)
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end
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else
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state.lists_by_name[v['list']] = v
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end
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elseif (v['rule']) then
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if (v['rule'] == nil or type(v['rule']) == "table") then
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return false, build_error_with_context(v['context'], "Rule name is empty")
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end
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-- By default, if a rule's condition refers to an unknown
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-- filter like evt.type, etc the loader throws an error.
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if v['skip-if-unknown-filter'] == nil then
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v['skip-if-unknown-filter'] = false
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end
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if v['source'] == nil then
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v['source'] = "syscall"
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end
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-- Possibly append to the condition field of an existing rule
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append = false
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if v['append'] then
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append = v['append']
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end
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if append then
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-- For append rules, all you need is the condition
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for j, field in ipairs({'condition'}) do
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if (v[field] == nil) then
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return false, build_error_with_context(v['context'], "Rule must have property "..field)
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end
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end
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if state.rules_by_name[v['rule']] == nil then
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if state.skipped_rules_by_name[v['rule']] == nil then
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return false, build_error_with_context(v['context'], "Rule " ..v['rule'].. " has 'append' key but no rule by that name already exists")
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end
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else
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state.rules_by_name[v['rule']]['condition'] = state.rules_by_name[v['rule']]['condition'] .. " " .. v['condition']
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-- Add the current object to the context of the base rule
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state.rules_by_name[v['rule']]['context'] = state.rules_by_name[v['rule']]['context'].."\n"..v['context']
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end
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else
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for j, field in ipairs({'condition', 'output', 'desc', 'priority'}) do
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if (v[field] == nil) then
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return false, build_error_with_context(v['context'], "Rule must have property "..field)
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end
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end
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-- Convert the priority-as-string to a priority-as-number now
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v['priority_num'] = priorities[v['priority']]
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if v['priority_num'] == nil then
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error("Invalid priority level: "..v['priority'])
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end
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if v['priority_num'] <= load_state.min_priority then
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-- Note that we can overwrite rules, but the rules are still
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-- loaded in the order in which they first appeared,
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-- potentially across multiple files.
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if state.rules_by_name[v['rule']] == nil then
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state.ordered_rule_names[#state.ordered_rule_names+1] = v['rule']
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end
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-- The output field might be a folded-style, which adds a
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-- newline to the end. Remove any trailing newlines.
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v['output'] = compiler.trim(v['output'])
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state.rules_by_name[v['rule']] = v
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else
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state.skipped_rules_by_name[v['rule']] = v
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end
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end
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else
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-- Remove the context from the table, so the table is exactly what was parsed
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local context = v['context']
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v['context'] = nil
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return false, build_error_with_context(context, "Unknown rule object: "..table.tostring(v))
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end
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end
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return true, ""
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end
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function load_rules(sinsp_lua_parser,
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json_lua_parser,
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rules_content,
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rules_mgr,
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verbose,
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all_events,
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extra,
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replace_container_info,
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min_priority)
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local load_state = {lines={}, indices={}, cur_item_idx=0, min_priority=min_priority, required_engine_version=0}
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load_state.lines, load_state.indices = split_lines(rules_content)
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local status, docs = pcall(yaml.load, rules_content, { all = true })
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if status == false then
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local pat = "^([%d]+):([%d]+): "
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-- docs is actually an error string
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local row = 0
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local col = 0
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row, col = string.match(docs, pat)
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if row ~= nil and col ~= nil then
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docs = string.gsub(docs, pat, "")
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end
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row = tonumber(row)
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col = tonumber(col)
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return false, build_error(load_state.lines, row, 3, docs)
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end
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if docs == nil then
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-- An empty rules file is acceptable
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return true, load_state.required_engine_version
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end
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|
if type(docs) ~= "table" then
|
|
return false, build_error(load_state.lines, 1, 1, "Rules content is not yaml")
|
|
end
|
|
|
|
for docidx, doc in ipairs(docs) do
|
|
|
|
if type(doc) ~= "table" then
|
|
return false, build_error(load_state.lines, 1, 1, "Rules content is not yaml")
|
|
end
|
|
|
|
-- Look for non-numeric indices--implies that document is not array
|
|
-- of objects.
|
|
for key, val in pairs(doc) do
|
|
if type(key) ~= "number" then
|
|
return false, build_error(load_state.lines, 1, 1, "Rules content is not yaml array of objects")
|
|
end
|
|
end
|
|
|
|
res, errstr = load_rules_doc(rules_mgr, doc, load_state)
|
|
|
|
if not res then
|
|
return res, errstr
|
|
end
|
|
end
|
|
|
|
-- We've now loaded all the rules, macros, and lists. Now
|
|
-- compile/expand the rules, macros, and lists. We use
|
|
-- ordered_rule_{lists,macros,names} to compile them in the order
|
|
-- in which they appeared in the file(s).
|
|
reset_rules(rules_mgr)
|
|
|
|
for i, name in ipairs(state.ordered_list_names) do
|
|
|
|
local v = state.lists_by_name[name]
|
|
|
|
-- list items are represented in yaml as a native list, so no
|
|
-- parsing necessary
|
|
local items = {}
|
|
|
|
-- List items may be references to other lists, so go through
|
|
-- the items and expand any references to the items in the list
|
|
for i, item in ipairs(v['items']) do
|
|
if (state.lists[item] == nil) then
|
|
items[#items+1] = item
|
|
else
|
|
for i, exp_item in ipairs(state.lists[item].items) do
|
|
items[#items+1] = exp_item
|
|
end
|
|
end
|
|
end
|
|
|
|
state.lists[v['list']] = {["items"] = items, ["used"] = false}
|
|
end
|
|
|
|
for _, name in ipairs(state.ordered_macro_names) do
|
|
|
|
local v = state.macros_by_name[name]
|
|
|
|
local status, ast = compiler.compile_macro(v['condition'], state.macros, state.lists)
|
|
|
|
if status == false then
|
|
return false, build_error_with_context(v['context'], ast)
|
|
end
|
|
|
|
if v['source'] == "syscall" then
|
|
if not all_events then
|
|
sinsp_rule_utils.check_for_ignored_syscalls_events(ast, 'macro', v['condition'])
|
|
end
|
|
end
|
|
|
|
state.macros[v['macro']] = {["ast"] = ast.filter.value, ["used"] = false}
|
|
end
|
|
|
|
for _, name in ipairs(state.ordered_rule_names) do
|
|
|
|
local v = state.rules_by_name[name]
|
|
|
|
warn_evttypes = true
|
|
if v['warn_evttypes'] ~= nil then
|
|
warn_evttypes = v['warn_evttypes']
|
|
end
|
|
|
|
local status, filter_ast, filters = compiler.compile_filter(v['rule'], v['condition'],
|
|
state.macros, state.lists)
|
|
|
|
if status == false then
|
|
return false, build_error_with_context(v['context'], filter_ast)
|
|
end
|
|
|
|
local evtttypes = {}
|
|
local syscallnums = {}
|
|
|
|
if v['source'] == "syscall" then
|
|
if not all_events then
|
|
sinsp_rule_utils.check_for_ignored_syscalls_events(filter_ast, 'rule', v['rule'])
|
|
end
|
|
|
|
evttypes, syscallnums = sinsp_rule_utils.get_evttypes_syscalls(name, filter_ast, v['condition'], warn_evttypes, verbose)
|
|
end
|
|
|
|
-- If a filter in the rule doesn't exist, either skip the rule
|
|
-- or raise an error, depending on the value of
|
|
-- skip-if-unknown-filter.
|
|
for filter, _ in pairs(filters) do
|
|
found = false
|
|
|
|
if defined_noarg_filters[filter] ~= nil then
|
|
found = true
|
|
else
|
|
bracket_idx = string.find(filter, "[", 1, true)
|
|
|
|
if bracket_idx ~= nil then
|
|
subfilter = string.sub(filter, 1, bracket_idx-1)
|
|
|
|
if defined_arg_filters[subfilter] ~= nil then
|
|
found = true
|
|
end
|
|
end
|
|
|
|
if not found then
|
|
dot_idx = string.find(filter, ".", 1, true)
|
|
|
|
while dot_idx ~= nil do
|
|
subfilter = string.sub(filter, 1, dot_idx-1)
|
|
|
|
if defined_arg_filters[subfilter] ~= nil then
|
|
found = true
|
|
break
|
|
end
|
|
|
|
dot_idx = string.find(filter, ".", dot_idx+1, true)
|
|
end
|
|
end
|
|
end
|
|
|
|
if not found then
|
|
if v['skip-if-unknown-filter'] then
|
|
if verbose then
|
|
print("Skipping rule \""..v['rule'].."\" that contains unknown filter "..filter)
|
|
end
|
|
goto next_rule
|
|
else
|
|
error("Rule \""..v['rule'].."\" contains unknown filter "..filter)
|
|
end
|
|
end
|
|
end
|
|
|
|
if (filter_ast.type == "Rule") then
|
|
state.n_rules = state.n_rules + 1
|
|
|
|
state.rules_by_idx[state.n_rules] = v
|
|
|
|
-- Store the index of this formatter in each relational expression that
|
|
-- this rule contains.
|
|
-- This index will eventually be stamped in events passing this rule, and
|
|
-- we'll use it later to determine which output to display when we get an
|
|
-- event.
|
|
mark_relational_nodes(filter_ast.filter.value, state.n_rules)
|
|
|
|
if (v['tags'] == nil) then
|
|
v['tags'] = {}
|
|
end
|
|
if v['source'] == "syscall" then
|
|
install_filter(filter_ast.filter.value, filter, sinsp_lua_parser)
|
|
-- Pass the filter and event types back up
|
|
falco_rules.add_filter(rules_mgr, v['rule'], evttypes, syscallnums, v['tags'])
|
|
|
|
elseif v['source'] == "k8s_audit" then
|
|
install_filter(filter_ast.filter.value, k8s_audit_filter, json_lua_parser)
|
|
|
|
falco_rules.add_k8s_audit_filter(rules_mgr, v['rule'], v['tags'])
|
|
end
|
|
|
|
-- Rule ASTs are merged together into one big AST, with "OR" between each
|
|
-- rule.
|
|
if (state.filter_ast == nil) then
|
|
state.filter_ast = filter_ast.filter.value
|
|
else
|
|
state.filter_ast = { type = "BinaryBoolOp", operator = "or", left = state.filter_ast, right = filter_ast.filter.value }
|
|
end
|
|
|
|
-- Enable/disable the rule
|
|
if (v['enabled'] == nil) then
|
|
v['enabled'] = true
|
|
end
|
|
|
|
if (v['enabled'] == false) then
|
|
falco_rules.enable_rule(rules_mgr, v['rule'], 0)
|
|
else
|
|
falco_rules.enable_rule(rules_mgr, v['rule'], 1)
|
|
end
|
|
|
|
-- If the format string contains %container.info, replace it
|
|
-- with extra. Otherwise, add extra onto the end of the format
|
|
-- string.
|
|
if v['source'] == "syscall" then
|
|
if string.find(v['output'], "%container.info", nil, true) ~= nil then
|
|
|
|
-- There may not be any extra, or we're not supposed
|
|
-- to replace it, in which case we use the generic
|
|
-- "%container.name (id=%container.id)"
|
|
if replace_container_info == false then
|
|
v['output'] = string.gsub(v['output'], "%%container.info", "%%container.name (id=%%container.id)")
|
|
if extra ~= "" then
|
|
v['output'] = v['output'].." "..extra
|
|
end
|
|
else
|
|
safe_extra = string.gsub(extra, "%%", "%%%%")
|
|
v['output'] = string.gsub(v['output'], "%%container.info", safe_extra)
|
|
end
|
|
else
|
|
-- Just add the extra to the end
|
|
if extra ~= "" then
|
|
v['output'] = v['output'].." "..extra
|
|
end
|
|
end
|
|
end
|
|
|
|
-- Ensure that the output field is properly formatted by
|
|
-- creating a formatter from it. Any error will be thrown
|
|
-- up to the top level.
|
|
formatter = formats.formatter(v['source'], v['output'])
|
|
formats.free_formatter(v['source'], formatter)
|
|
else
|
|
return false, build_error_with_context(v['context'], "Unexpected type in load_rule: "..filter_ast.type)
|
|
end
|
|
|
|
::next_rule::
|
|
end
|
|
|
|
if verbose then
|
|
-- Print info on any dangling lists or macros that were not used anywhere
|
|
for name, macro in pairs(state.macros) do
|
|
if macro.used == false then
|
|
print("Warning: macro "..name.." not refered to by any rule/macro")
|
|
end
|
|
end
|
|
|
|
for name, list in pairs(state.lists) do
|
|
if list.used == false then
|
|
print("Warning: list "..name.." not refered to by any rule/macro/list")
|
|
end
|
|
end
|
|
end
|
|
|
|
io.flush()
|
|
|
|
return true, load_state.required_engine_version
|
|
end
|
|
|
|
local rule_fmt = "%-50s %s"
|
|
|
|
-- http://lua-users.org/wiki/StringRecipes, with simplifications and bugfixes
|
|
local function wrap(str, limit, indent)
|
|
indent = indent or ""
|
|
limit = limit or 72
|
|
local here = 1
|
|
return str:gsub("(%s+)()(%S+)()",
|
|
function(sp, st, word, fi)
|
|
if fi-here > limit then
|
|
here = st
|
|
return "\n"..indent..word
|
|
end
|
|
end)
|
|
end
|
|
|
|
local function describe_single_rule(name)
|
|
if (state.rules_by_name[name] == nil) then
|
|
error ("No such rule: "..name)
|
|
end
|
|
|
|
-- Wrap the description into an multiple lines each of length ~ 60
|
|
-- chars, with indenting to line up with the first line.
|
|
local wrapped = wrap(state.rules_by_name[name]['desc'], 60, string.format(rule_fmt, "", ""))
|
|
|
|
local line = string.format(rule_fmt, name, wrapped)
|
|
print(line)
|
|
print()
|
|
end
|
|
|
|
-- If name is nil, describe all rules
|
|
function describe_rule(name)
|
|
|
|
print()
|
|
local line = string.format(rule_fmt, "Rule", "Description")
|
|
print(line)
|
|
line = string.format(rule_fmt, "----", "-----------")
|
|
print(line)
|
|
|
|
if name == nil then
|
|
for rulename, rule in pairs(state.rules_by_name) do
|
|
describe_single_rule(rulename)
|
|
end
|
|
else
|
|
describe_single_rule(name)
|
|
end
|
|
end
|
|
|
|
local rule_output_counts = {total=0, by_priority={}, by_name={}}
|
|
|
|
function on_event(rule_id)
|
|
|
|
if state.rules_by_idx[rule_id] == nil then
|
|
error ("rule_loader.on_event(): event with invalid rule_id: ", rule_id)
|
|
end
|
|
|
|
rule_output_counts.total = rule_output_counts.total + 1
|
|
local rule = state.rules_by_idx[rule_id]
|
|
|
|
if rule_output_counts.by_priority[rule.priority] == nil then
|
|
rule_output_counts.by_priority[rule.priority] = 1
|
|
else
|
|
rule_output_counts.by_priority[rule.priority] = rule_output_counts.by_priority[rule.priority] + 1
|
|
end
|
|
|
|
if rule_output_counts.by_name[rule.rule] == nil then
|
|
rule_output_counts.by_name[rule.rule] = 1
|
|
else
|
|
rule_output_counts.by_name[rule.rule] = rule_output_counts.by_name[rule.rule] + 1
|
|
end
|
|
|
|
-- Prefix output with '*' so formatting is permissive
|
|
output = "*"..rule.output
|
|
|
|
return rule.rule, rule.priority_num, output
|
|
end
|
|
|
|
function print_stats()
|
|
print("Events detected: "..rule_output_counts.total)
|
|
print("Rule counts by severity:")
|
|
for priority, count in pairs(rule_output_counts.by_priority) do
|
|
print (" "..priority..": "..count)
|
|
end
|
|
|
|
print("Triggered rules by rule name:")
|
|
for name, count in pairs(rule_output_counts.by_name) do
|
|
print (" "..name..": "..count)
|
|
end
|
|
end
|
|
|
|
|
|
|