From b22bde4a7d68c41a138a003d772c27d063075e2f Mon Sep 17 00:00:00 2001
From: Bryan Boreham <bjboreham@gmail.com>
Date: Tue, 16 Jul 2019 16:23:34 +0000
Subject: [PATCH] fix(probe): Update tcptracer-bpf package to cure out-of-order
 events

Avoid ebpf events out of order by adding offset to time.
---
 .../tcptracer-bpf/pkg/tracer/event.go         | 12 +++++++--
 .../weaveworks/tcptracer-bpf/tests/tracer.go  | 27 ++++++++++++-------
 vendor/manifest                               |  2 +-
 3 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/vendor/github.com/weaveworks/tcptracer-bpf/pkg/tracer/event.go b/vendor/github.com/weaveworks/tcptracer-bpf/pkg/tracer/event.go
index cd874297b..2ee9a2507 100644
--- a/vendor/github.com/weaveworks/tcptracer-bpf/pkg/tracer/event.go
+++ b/vendor/github.com/weaveworks/tcptracer-bpf/pkg/tracer/event.go
@@ -1,3 +1,5 @@
+// +build linux
+
 package tracer
 
 import (
@@ -37,9 +39,15 @@ func tcpV4ToGo(data *[]byte) (ret TcpV4) {
 	return
 }
 
+// Offset added to all timestamps, to hold back events so they are less
+// likely to be reported out of order. Value is in nanoseconds.
+var (
+	TimestampOffset uint64 = 100000
+)
+
 func tcpV4Timestamp(data *[]byte) uint64 {
 	eventC := (*C.struct_tcp_ipv4_event_t)(unsafe.Pointer(&(*data)[0]))
-	return uint64(eventC.timestamp)
+	return uint64(eventC.timestamp) + TimestampOffset
 }
 
 func tcpV6ToGo(data *[]byte) (ret TcpV6) {
@@ -72,5 +80,5 @@ func tcpV6ToGo(data *[]byte) (ret TcpV6) {
 
 func tcpV6Timestamp(data *[]byte) uint64 {
 	eventC := (*C.struct_tcp_ipv6_event_t)(unsafe.Pointer(&(*data)[0]))
-	return uint64(eventC.timestamp)
+	return uint64(eventC.timestamp) + TimestampOffset
 }
diff --git a/vendor/github.com/weaveworks/tcptracer-bpf/tests/tracer.go b/vendor/github.com/weaveworks/tcptracer-bpf/tests/tracer.go
index fe7d9dac5..48dbb8727 100644
--- a/vendor/github.com/weaveworks/tcptracer-bpf/tests/tracer.go
+++ b/vendor/github.com/weaveworks/tcptracer-bpf/tests/tracer.go
@@ -11,6 +11,15 @@ import (
 	"github.com/weaveworks/tcptracer-bpf/pkg/tracer"
 )
 
+const (
+	OK = iota
+	BAD_ARGUMENTS
+	TRACER_INSERT_FAILED
+	PROCESS_NOT_FOUND
+	TCP_EVENT_LATE
+	TCP_EVENTS_LOST
+)
+
 var watchFdInstallPids string
 
 type tcpEventTracer struct {
@@ -29,7 +38,7 @@ func (t *tcpEventTracer) TCPEventV4(e tracer.TcpV4) {
 
 	if t.lastTimestampV4 > e.Timestamp {
 		fmt.Printf("ERROR: late event!\n")
-		os.Exit(1)
+		os.Exit(TCP_EVENT_LATE)
 	}
 
 	t.lastTimestampV4 = e.Timestamp
@@ -41,7 +50,7 @@ func (t *tcpEventTracer) TCPEventV6(e tracer.TcpV6) {
 
 	if t.lastTimestampV6 > e.Timestamp {
 		fmt.Printf("ERROR: late event!\n")
-		os.Exit(1)
+		os.Exit(TCP_EVENT_LATE)
 	}
 
 	t.lastTimestampV6 = e.Timestamp
@@ -49,12 +58,12 @@ func (t *tcpEventTracer) TCPEventV6(e tracer.TcpV6) {
 
 func (t *tcpEventTracer) LostV4(count uint64) {
 	fmt.Printf("ERROR: lost %d events!\n", count)
-	os.Exit(1)
+	os.Exit(TCP_EVENTS_LOST)
 }
 
 func (t *tcpEventTracer) LostV6(count uint64) {
 	fmt.Printf("ERROR: lost %d events!\n", count)
-	os.Exit(1)
+	os.Exit(TCP_EVENTS_LOST)
 }
 
 func init() {
@@ -66,13 +75,13 @@ func init() {
 func main() {
 	if flag.NArg() > 1 {
 		flag.Usage()
-		os.Exit(1)
+		os.Exit(BAD_ARGUMENTS)
 	}
 
 	t, err := tracer.NewTracer(&tcpEventTracer{})
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "%v\n", err)
-		os.Exit(1)
+		os.Exit(TRACER_INSERT_FAILED)
 	}
 
 	t.Start()
@@ -85,14 +94,12 @@ func main() {
 		pid, err := strconv.ParseUint(p, 10, 32)
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "Invalid pid: %v\n", err)
-			os.Exit(1)
+			os.Exit(PROCESS_NOT_FOUND)
 		}
 		fmt.Printf("Monitor fdinstall events for pid %d\n", pid)
 		t.AddFdInstallWatcher(uint32(pid))
 	}
-
-	fmt.Printf("Ready\n")
-
+	
 	sig := make(chan os.Signal, 1)
 	signal.Notify(sig, os.Interrupt, os.Kill)
 
diff --git a/vendor/manifest b/vendor/manifest
index 48600d8bb..efde051d6 100644
--- a/vendor/manifest
+++ b/vendor/manifest
@@ -2037,7 +2037,7 @@
 			"importpath": "github.com/weaveworks/tcptracer-bpf",
 			"repository": "https://github.com/weaveworks/tcptracer-bpf",
 			"vcs": "git",
-			"revision": "6dca783d10f7ba0c8fe707e5e210a8d3114af4c0",
+			"revision": "cd53e7c84baca8cc63cb689185b93a14b0169848",
 			"branch": "master",
 			"notests": true
 		},