Make sure Lua values are actually tables before accessing them (fix #44)

config.go

@@ -3,6 +3,7 @@ package main
 
 import (
 	"errors"
+	"log"
 
 	lua "github.com/yuin/gopher-lua"
 )
@@ -57,12 +58,16 @@ func getTableFromTable(L *lua.LState, lobj lua.LValue, key string, out *lua.LVal
 
 // parseConfig parses the JSON configuration file at 'path' and stores the contents in 'config'
 func parseConfig(path string, config *Configuration) {
+	log.Printf("Loading config from : %s ...", path)
 	// Lua state setup
 	L := lua.NewState()
 	defer L.Close()
 
 	L.DoFile(path)
 	table := L.Get(-1)                    // Get the table returned by the config file
+	if table.Type().String() != "table" { // Make sure value returned is of type 'table'
+		log.Fatalf("config is of type : '%s', not 'table'", table.Type().String())
+	}
 
 	// Main config
 	if _, err := getStringFromTable(L, table, "sites_dir", &config.sites_dir); err != nil {
@@ -74,7 +79,10 @@ func parseConfig(path string, config *Configuration) {
 
 	// Matrix config
 	var matrix lua.LValue
-	getTableFromTable(L, table, "matrix", &matrix)
+	getTableFromTable(L, table, "matrix", &matrix) // Get the 'matrix' sub table
+	if matrix.Type().String() != "table" {         // Make sure 'config.matrix' is of type 'table'
+		log.Fatalf("config.matrix is of type : '%s', not 'table'", matrix.Type().String())
+	}
 	if _, err := getStringFromTable(L, matrix, "homeserver", &config.matrix.homeserver); err != nil {
 		panic(err)
 	}

site.go

@@ -48,32 +48,38 @@ func getSite(name string) (Site, bool, error) {
 // getConfig parses a site's configuration file.
 func (site *Site) getConfig() (bool, error) {
 	path := fmt.Sprintf("%s/%s/deploy_config.lua", configuration.sites_dir, site.name)
+	warning := fmt.Sprintf("%s%s : Site config warning : ", Circles["orange"], site.getName())
 	// Make sure config file exists
 	if exists, _ := fileExists(path); !exists {
 		return false, nil
 	}
+	log.Printf("Loading per-site config %s", path)
 	// Lua state setup
 	L := lua.NewState()
 	defer L.Close()
 
 	L.DoFile(path)                        // Load the config
 	table := L.Get(-1)                    // Get the table returned by the config file
+	if table.Type().String() != "table" { // Make sure 'config' is of type 'table'
+		err := fmt.Sprintf("Value returned by config is of type '%s', not 'table'", table.Type().String())
+		sendMessage(MatrixMessage{text: warning + err})
+		return false, errors.New(err)
+	}
 
 	// Parse the config
 	config := SiteConfig{}
-	log.Printf("Loading per-site config %s", path)
 
-	warning := fmt.Sprintf("%s%s : Site config warning : ", Circles["orange"], site.getName())
+	if _, err := getStringFromTable(L, table, "name", &config.name); err != nil { // name
-
-	if _, err := getStringFromTable(L, table, "name", &config.name); err != nil { // Name
 		sendMessage(MatrixMessage{text: warning + fmt.Sprint(err)})
 	}
-	if _, err := getIntFromTable(L, table, "port", &config.port); err != nil { // Port
+	if _, err := getIntFromTable(L, table, "port", &config.port); err != nil { // port
+		sendMessage(MatrixMessage{text: warning + fmt.Sprint(err)})
+	}
+	raw_gitt := L.GetTable(table, lua.LString("git")) // git
+	if gitt, ok := L.GetTable(table, lua.LString("git")).(*lua.LTable); ok {
+		if _, err := getStringFromTable(L, gitt, "branch", &config.git.branch); err != nil { // git.branch
 			sendMessage(MatrixMessage{text: warning + fmt.Sprint(err)})
 		}
-	raw_gitt := L.GetTable(table, lua.LString("git")) // Attempt to get 'git' table
-	if gitt, ok := raw_gitt.(*lua.LTable); ok {
-		getStringFromTable(L, gitt, "branch", &config.git.branch)
 	} else if _, ok := raw_gitt.(*lua.LNilType); !ok { // If 'git' is neither a table or nil (undefined),
 		sendMessage(MatrixMessage{text: warning + "'git' is neither a table or nil!"})
 	}