Add a verbose flag.

Add a verbose flag -v which implies printing additional info. This is
passed down to lua during load_rules and sets the per-module verbose
value for the compiler and parser modules.

Later commits will use this to print additional info when loading rules.

userspace/falco/falco.cpp

@@ -55,6 +55,7 @@ static void usage()
            " -r <rules_file>               Rules file (defaults to value set in configuration file, or /etc/falco_rules.yaml).\n"
 	   " -L                            Show the name and description of all rules and exit.\n"
 	   " -l <rule>                     Show the name and description of the rule with name <rule> and exit.\n"
+	   " -v                            Verbose output.\n"
 	   "\n"
     );
 }
@@ -253,6 +254,7 @@ int falco_init(int argc, char **argv)
 	string pidfilename = "/var/run/falco.pid";
 	bool describe_all_rules = false;
 	string describe_rule = "";
+	bool verbose = false;
 
 	static struct option long_options[] =
 	{
@@ -272,7 +274,7 @@ int falco_init(int argc, char **argv)
 		// Parse the args
 		//
 		while((op = getopt_long(argc, argv,
-                                        "c:ho:e:r:dp:Ll:",
+                                        "c:ho:e:r:dp:Ll:v",
                                         long_options, &long_index)) != -1)
 		{
 			switch(op)
@@ -301,6 +303,9 @@ int falco_init(int argc, char **argv)
 			case 'L':
 				describe_all_rules = true;
 				break;
+			case 'v':
+				verbose = true;
+				break;
 			case 'l':
 				describe_rule = optarg;
 				break;
@@ -397,7 +402,7 @@ int falco_init(int argc, char **argv)
 
 
 		inspector->set_drop_event_flags(EF_DROP_FALCO);
-		rules->load_rules(config.m_rules_filename);
+		rules->load_rules(config.m_rules_filename, verbose);
 		inspector->set_filter(rules->get_filter());
 		falco_logger::log(LOG_INFO, "Parsed rules from file " + config.m_rules_filename + "\n");
 

userspace/falco/lua/compiler.lua

@@ -1,6 +1,13 @@
 local parser = require("parser")
 local compiler = {}
 
+compiler.verbose = false
+
+function compiler.set_verbose(verbose)
+   compiler.verbose = verbose
+   parser.set_verbose(verbose)
+end
+
 function map(f, arr)
    local res = {}
    for i,v in ipairs(arr) do

userspace/falco/lua/parser.lua

@@ -11,6 +11,12 @@
 
 local parser = {}
 
+parser.verbose = false
+
+function parser.set_verbose(verbose)
+   parser.verbose = verbose
+end
+
 local lpeg = require "lpeg"
 
 lpeg.locale(lpeg)

userspace/falco/lua/rule_loader.lua

@@ -117,7 +117,9 @@ end
 -- to a rule.
 local state = {macros={}, lists={}, filter_ast=nil, rules_by_name={}, n_rules=0, rules_by_idx={}}
 
-function load_rules(filename)
+function load_rules(filename, verbose)
+
+   compiler.set_verbose(verbose)
 
    local f = assert(io.open(filename, "r"))
    local s = f:read("*all")

userspace/falco/rules.cpp

@@ -40,7 +40,7 @@ void falco_rules::load_compiler(string lua_main_filename)
 	}
 }
 
-void falco_rules::load_rules(string rules_filename)
+void falco_rules::load_rules(string rules_filename, bool verbose)
 {
 	lua_getglobal(m_ls, m_lua_load_rules.c_str());
 	if(lua_isfunction(m_ls, -1))
@@ -82,7 +82,8 @@ void falco_rules::load_rules(string rules_filename)
 		lua_setglobal(m_ls, m_lua_ignored_syscalls.c_str());
 
 		lua_pushstring(m_ls, rules_filename.c_str());
-		if(lua_pcall(m_ls, 1, 0, 0) != 0)
+		lua_pushboolean(m_ls, (verbose ? 1 : 0));
+		if(lua_pcall(m_ls, 2, 0, 0) != 0)
 		{
 			const char* lerr = lua_tostring(m_ls, -1);
 			string err = "Error loading rules:" + string(lerr);

userspace/falco/rules.h

@@ -8,7 +8,7 @@ class falco_rules
  public:
 	falco_rules(sinsp* inspector, lua_State *ls, string lua_main_filename);
 	~falco_rules();
-	void load_rules(string rules_filename);
+	void load_rules(string rules_filename, bool verbose);
 	void describe_rule(string *rule);
 	sinsp_filter* get_filter();