From 2973de6fe1ec9e2cfe4fd54c764df493843de085 Mon Sep 17 00:00:00 2001
From: Zhang Bo <bozhang@ebay.com>
Date: Fri, 10 Nov 2023 01:28:12 -0700
Subject: [PATCH] add magic number to avoid unexpected collison
---
agent/agent.go | 10 +++++++++-
internal/cmd/shared.go | 3 +++
internal/internal.go | 5 ++++-
3 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/agent/agent.go b/agent/agent.go
index 07a3e80b..d9cbaecb 100644
--- a/agent/agent.go
+++ b/agent/agent.go
@@ -207,6 +207,14 @@ func formatBytes(val uint64) string {
}
func handle(conn io.ReadWriter, msg []byte) error {
+ reader := bufio.NewReader(conn)
+ magic, err := binary.ReadVarint(reader)
+ if err != nil {
+ return err
+ }
+ if magic != internal.MAGIC {
+ return fmt.Errorf("gops: invalid magic number: %v", magic)
+ }
switch msg[0] {
case signal.StackTrace:
return pprof.Lookup("goroutine").WriteTo(conn, 2)
@@ -286,7 +294,7 @@ func handle(conn io.ReadWriter, msg []byte) error {
time.Sleep(5 * time.Second)
trace.Stop()
case signal.SetGCPercent:
- perc, err := binary.ReadVarint(bufio.NewReader(conn))
+ perc, err := binary.ReadVarint(reader)
if err != nil {
return err
}
diff --git a/internal/cmd/shared.go b/internal/cmd/shared.go
index fc11e6b2..8e54ca1d 100644
--- a/internal/cmd/shared.go
+++ b/internal/cmd/shared.go
@@ -306,6 +306,9 @@ func cmdLazy(addr net.TCPAddr, c byte, params ...byte) (io.Reader, error) {
return nil, err
}
buf := []byte{c}
+ magic := make([]byte, binary.MaxVarintLen64)
+ binary.PutVarint(magic, internal.MAGIC)
+ buf = append(buf, magic...)
buf = append(buf, params...)
if _, err := conn.Write(buf); err != nil {
return nil, err
diff --git a/internal/internal.go b/internal/internal.go
index 7e3492aa..376b1d71 100644
--- a/internal/internal.go
+++ b/internal/internal.go
@@ -13,7 +13,10 @@ import (
"strings"
)
-const gopsConfigDirEnvKey = "GOPS_CONFIG_DIR"
+const (
+ goipsConfigDirEnvKey = "GOPS_CONFIG_DIR"
+ MAGIC = 0xabcdefedcba
+)
func ConfigDir() (string, error) {
if configDir := os.Getenv(gopsConfigDirEnvKey); configDir != "" {