error handling + support offlinehttp in flow templates (#4653)

pkg/templates/compile.go

@@ -183,8 +183,9 @@ func (template *Template) compileProtocolRequests(options *protocols.ExecutorOpt
 			requests = append(requests, template.convertRequestToProtocolsRequest(template.RequestsJavascript)...)
 		}
 	}
-	template.Executer = tmplexec.NewTemplateExecuter(requests, options)
-	return nil
+	var err error
+	template.Executer, err = tmplexec.NewTemplateExecuter(requests, options)
+	return err
 }
 
 // convertRequestToProtocolsRequest is a convenience wrapper to convert
@@ -228,8 +229,13 @@ mainLoop:
 	}
 	if len(operatorsList) > 0 {
 		options.Operators = operatorsList
-		template.Executer = tmplexec.NewTemplateExecuter([]protocols.Request{&offlinehttp.Request{}}, options)
-		return nil
+		var err error
+		template.Executer, err = tmplexec.NewTemplateExecuter([]protocols.Request{&offlinehttp.Request{}}, options)
+		if err != nil {
+			// it seems like flow executor cannot be used for offline http matching (ex:http(1) && http(2))
+			return ErrIncompatibleWithOfflineMatching
+		}
+		return err
 	}
 
 	return ErrIncompatibleWithOfflineMatching

pkg/tmplexec/exec.go

@@ -31,7 +31,7 @@ type TemplateExecuter struct {
 var _ protocols.Executer = &TemplateExecuter{}
 
 // NewTemplateExecuter creates a new request TemplateExecuter for list of requests
-func NewTemplateExecuter(requests []protocols.Request, options *protocols.ExecutorOptions) *TemplateExecuter {
+func NewTemplateExecuter(requests []protocols.Request, options *protocols.ExecutorOptions) (*TemplateExecuter, error) {
 	isMultiProto := false
 	lastProto := ""
 	for _, request := range requests {
@@ -47,7 +47,11 @@ func NewTemplateExecuter(requests []protocols.Request, options *protocols.Execut
 		// we use a dummy input here because goal of flow executor at this point is to just check
 		// syntax and other things are correct before proceeding to actual execution
 		// during execution new instance of flow will be created as it is tightly coupled with lot of executor options
-		e.engine = flow.NewFlowExecutor(requests, scan.NewScanContext(contextargs.NewWithInput("dummy")), options, e.results)
+		var err error
+		e.engine, err = flow.NewFlowExecutor(requests, scan.NewScanContext(contextargs.NewWithInput("dummy")), options, e.results)
+		if err != nil {
+			return nil, fmt.Errorf("could not create flow executor: %s", err)
+		}
 	} else {
 		// Review:
 		// multiproto engine is only used if there is more than one protocol in template
@@ -58,8 +62,7 @@ func NewTemplateExecuter(requests []protocols.Request, options *protocols.Execut
 			e.engine = generic.NewGenericEngine(requests, options, e.results)
 		}
 	}
-
-	return e
+	return e, nil
 }
 
 // Compile compiles the execution generators preparing any requests possible.
@@ -146,7 +149,7 @@ func (e *TemplateExecuter) Execute(ctx *scan.ScanContext) (bool, error) {
 			}
 		}
 	}
-	var err error
+	var errx error
 
 	// Note: this is required for flow executor
 	// flow executer is tightly coupled with lot of executor options
@@ -155,20 +158,24 @@ func (e *TemplateExecuter) Execute(ctx *scan.ScanContext) (bool, error) {
 	// so in compile step earlier we compile it to validate javascript syntax and other things
 	// and while executing we create new instance of flow executor everytime
 	if e.options.Flow != "" {
-		flowexec := flow.NewFlowExecutor(e.requests, ctx, e.options, results)
+		flowexec, err := flow.NewFlowExecutor(e.requests, ctx, e.options, results)
+		if err != nil {
+			ctx.LogError(err)
+			return false, fmt.Errorf("could not create flow executor: %s", err)
+		}
 		if err := flowexec.Compile(); err != nil {
 			ctx.LogError(err)
 			return false, err
 		}
-		err = flowexec.ExecuteWithResults(ctx)
+		errx = flowexec.ExecuteWithResults(ctx)
 	} else {
-		err = e.engine.ExecuteWithResults(ctx)
+		errx = e.engine.ExecuteWithResults(ctx)
 	}
 
 	if lastMatcherEvent != nil {
 		writeFailureCallback(lastMatcherEvent, e.options.Options.MatcherStatus)
 	}
-	return results.Load(), err
+	return results.Load(), errx
 }
 
 // ExecuteWithResults executes the protocol requests and returns results instead of writing them.

pkg/tmplexec/flow/flow_executor.go

@@ -55,7 +55,7 @@ type FlowExecutor struct {
 // NewFlowExecutor creates a new flow executor from a list of requests
 // Note: Unlike other engine for every target x template flow needs to be compiled and executed everytime
 // unlike other engines where we compile once and execute multiple times
-func NewFlowExecutor(requests []protocols.Request, ctx *scan.ScanContext, options *protocols.ExecutorOptions, results *atomic.Bool) *FlowExecutor {
+func NewFlowExecutor(requests []protocols.Request, ctx *scan.ScanContext, options *protocols.ExecutorOptions, results *atomic.Bool) (*FlowExecutor, error) {
 	allprotos := make(map[string][]protocols.Request)
 	for _, req := range requests {
 		switch req.Type() {
@@ -79,9 +79,11 @@ func NewFlowExecutor(requests []protocols.Request, ctx *scan.ScanContext, option
 			allprotos[templateTypes.CodeProtocol.String()] = append(allprotos[templateTypes.CodeProtocol.String()], req)
 		case templateTypes.JavascriptProtocol:
 			allprotos[templateTypes.JavascriptProtocol.String()] = append(allprotos[templateTypes.JavascriptProtocol.String()], req)
+		case templateTypes.OfflineHTTPProtocol:
+			// offlinehttp is run in passive mode but templates are same so instead of using offlinehttp() we use http() in flow
+			allprotos[templateTypes.HTTPProtocol.String()] = append(allprotos[templateTypes.OfflineHTTPProtocol.String()], req)
 		default:
-			ctx.LogError(fmt.Errorf("invalid request type %s", req.Type().String()))
-			return nil
+			return nil, fmt.Errorf("invalid request type %s", req.Type().String())
 		}
 	}
 	f := &FlowExecutor{
@@ -96,7 +98,7 @@ func NewFlowExecutor(requests []protocols.Request, ctx *scan.ScanContext, option
 		jsVM:           protocolstate.NewJSRuntime(),
 		ctx:            ctx,
 	}
-	return f
+	return f, nil
 }
 
 // Compile compiles js program and registers all functions