From dc4cd669fcf90e758927d5ebbc79d3fb1547c597 Mon Sep 17 00:00:00 2001
From: Fabricio Voznika <fvoznika@google.com>
Date: Wed, 3 Aug 2022 14:30:26 -0700
Subject: [PATCH] Add sinks to `runsc trace metadata` output

Updates #4805

PiperOrigin-RevId: 465150097
---
 pkg/sentry/seccheck/config.go        |  2 +-
 pkg/sentry/seccheck/metadata.go      | 12 +++++++-----
 pkg/sentry/seccheck/metadata_test.go |  2 +-
 runsc/cmd/trace/metadata.go          |  5 +++++
 test/trace/config/config.go          | 19 ++++++++++++++++---
 5 files changed, 30 insertions(+), 10 deletions(-)

diff --git a/pkg/sentry/seccheck/config.go b/pkg/sentry/seccheck/config.go
index 54a865457..81e505d62 100644
--- a/pkg/sentry/seccheck/config.go
+++ b/pkg/sentry/seccheck/config.go
@@ -225,7 +225,7 @@ func setFields(names []string, fields []FieldDesc) (FieldMask, error) {
 }
 
 func findSinkDesc(name string) (SinkDesc, error) {
-	if desc, ok := sinks[name]; ok {
+	if desc, ok := Sinks[name]; ok {
 		return desc, nil
 	}
 	return SinkDesc{}, fmt.Errorf("sink %q not found", name)
diff --git a/pkg/sentry/seccheck/metadata.go b/pkg/sentry/seccheck/metadata.go
index 2e19ec65c..2267608ac 100644
--- a/pkg/sentry/seccheck/metadata.go
+++ b/pkg/sentry/seccheck/metadata.go
@@ -61,11 +61,13 @@ const (
 	FieldSentryExecveBinaryInfo Field = iota
 )
 
-// Points is a map with all the Points registered in the system.
+// Points is a map with all the trace points registered in the system.
 var Points = map[string]PointDesc{}
-var sinks = map[string]SinkDesc{}
 
-// defaultContextFields are the fields present in most Points.
+// Sinks is a map with all the sinks registered in the system.
+var Sinks = map[string]SinkDesc{}
+
+// defaultContextFields are the fields present in most trace points.
 var defaultContextFields = []FieldDesc{
 	{
 		ID:   FieldCtxtTime,
@@ -122,10 +124,10 @@ type SinkDesc struct {
 
 // RegisterSink registers a new sink to make it discoverable.
 func RegisterSink(sink SinkDesc) {
-	if _, ok := sinks[sink.Name]; ok {
+	if _, ok := Sinks[sink.Name]; ok {
 		panic(fmt.Sprintf("Sink %q already registered", sink.Name))
 	}
-	sinks[sink.Name] = sink
+	Sinks[sink.Name] = sink
 }
 
 // PointDesc describes a Point that is available to be configured.
diff --git a/pkg/sentry/seccheck/metadata_test.go b/pkg/sentry/seccheck/metadata_test.go
index 7dafe471b..0ef031141 100644
--- a/pkg/sentry/seccheck/metadata_test.go
+++ b/pkg/sentry/seccheck/metadata_test.go
@@ -21,7 +21,7 @@ import (
 func TestSinkRegistration(t *testing.T) {
 	sink := SinkDesc{Name: "test"}
 	RegisterSink(sink)
-	if _, ok := sinks["test"]; !ok {
+	if _, ok := Sinks["test"]; !ok {
 		t.Errorf("sink registration failed")
 	}
 
diff --git a/runsc/cmd/trace/metadata.go b/runsc/cmd/trace/metadata.go
index 868f3ffff..28b21fa1f 100644
--- a/runsc/cmd/trace/metadata.go
+++ b/runsc/cmd/trace/metadata.go
@@ -64,6 +64,11 @@ func (l *metadata) Execute(context.Context, *flag.FlagSet, ...interface{}) subco
 		ctxFields := fieldNames(pt.ContextFields)
 		fmt.Printf("Name: %s, optional fields: [%s], context fields: [%s]\n", pt.Name, strings.Join(optFields, "|"), strings.Join(ctxFields, "|"))
 	}
+	fmt.Printf("\nSINKS (%d)\n", len(seccheck.Sinks))
+	for _, sink := range seccheck.Sinks {
+		fmt.Printf("Name: %s\n", sink.Name)
+	}
+
 	return subcommands.ExitSuccess
 }
 
diff --git a/test/trace/config/config.go b/test/trace/config/config.go
index c3f4343d7..94861be0a 100644
--- a/test/trace/config/config.go
+++ b/test/trace/config/config.go
@@ -61,14 +61,24 @@ func (b *Builder) LoadAllPoints(runscPath string) error {
 	// The command above produces an output like the following:
 	//   POINTS (907)
 	//   Name: container/start, optional fields: [], context fields: [time|thread_id]
+	//
+	//   SINKS (2)
+	//   Name: remote
 	scanner := bufio.NewScanner(bytes.NewReader(out))
 	if !scanner.Scan() {
 		return fmt.Errorf("%q returned empty", cmd)
 	}
-	if !scanner.Scan() {
-		return fmt.Errorf("%q returned empty", cmd)
+	if line := scanner.Text(); !strings.HasPrefix(line, "POINTS (") {
+		return fmt.Errorf("%q missing POINTS header: %q", cmd, line)
 	}
-	for line := scanner.Text(); scanner.Scan(); line = scanner.Text() {
+	for scanner.Scan() {
+		line := scanner.Text()
+		if len(line) == 0 {
+			continue // Skip empty lines.
+		}
+		if strings.HasPrefix(line, "SINKS (") {
+			break // Starting SINKS section, POINTS section is over.
+		}
 		elems := strings.Split(line, ",")
 		if len(elems) != 3 {
 			return fmt.Errorf("invalid line: %q", line)
@@ -88,6 +98,9 @@ func (b *Builder) LoadAllPoints(runscPath string) error {
 			ContextFields:  ctxFields,
 		})
 	}
+	if len(b.points) == 0 {
+		return fmt.Errorf("%q returned no points", cmd)
+	}
 	return scanner.Err()
 }