From dd8717797e51675b611a99efac9ada2e96b18696 Mon Sep 17 00:00:00 2001
From: Nick Craig-Wood <nick@craig-wood.com>
Date: Tue, 8 Sep 2015 21:01:26 +0100
Subject: [PATCH] Implement --dump-headers and --dump-bodies debug flags

---
 fs/config.go  | 12 +++++++++++-
 fs/loghttp.go | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+), 1 deletion(-)
 create mode 100644 fs/loghttp.go

diff --git a/fs/config.go b/fs/config.go
index e751cd852..172031a9f 100644
--- a/fs/config.go
+++ b/fs/config.go
@@ -50,6 +50,8 @@ var (
 	dryRun         = pflag.BoolP("dry-run", "n", false, "Do a trial run with no permanent changes")
 	connectTimeout = pflag.DurationP("contimeout", "", 60*time.Second, "Connect timeout")
 	timeout        = pflag.DurationP("timeout", "", 5*60*time.Second, "IO idle timeout")
+	dumpHeaders    = pflag.BoolP("dump-headers", "", false, "Dump HTTP headers - may contain sensitive info")
+	dumpBodies     = pflag.BoolP("dump-bodies", "", false, "Dump HTTP headers and bodies - may contain sensitive info")
 	bwLimit        SizeSuffix
 )
 
@@ -155,11 +157,13 @@ type ConfigInfo struct {
 	Transfers      int
 	ConnectTimeout time.Duration // Connect timeout
 	Timeout        time.Duration // Data channel timeout
+	DumpHeaders    bool
+	DumpBodies     bool
 }
 
 // Transport returns an http.RoundTripper with the correct timeouts
 func (ci *ConfigInfo) Transport() http.RoundTripper {
-	return &httpclient.Transport{
+	t := &httpclient.Transport{
 		Proxy:               http.ProxyFromEnvironment,
 		MaxIdleConnsPerHost: ci.Checkers + ci.Transfers + 1,
 
@@ -182,6 +186,10 @@ func (ci *ConfigInfo) Transport() http.RoundTripper {
 		// Write operation on the request connection.
 		ReadWriteTimeout: ci.Timeout,
 	}
+	if ci.DumpHeaders || ci.DumpBodies {
+		return NewLoggedTransport(t, ci.DumpBodies)
+	}
+	return t
 }
 
 // Transport returns an http.Client with the correct timeouts
@@ -227,6 +235,8 @@ func LoadConfig() {
 	Config.ConnectTimeout = *connectTimeout
 	Config.CheckSum = *checkSum
 	Config.SizeOnly = *sizeOnly
+	Config.DumpHeaders = *dumpHeaders
+	Config.DumpBodies = *dumpBodies
 
 	ConfigPath = *configFile
 
diff --git a/fs/loghttp.go b/fs/loghttp.go
new file mode 100644
index 000000000..e3fbe88d7
--- /dev/null
+++ b/fs/loghttp.go
@@ -0,0 +1,54 @@
+// A logging http transport
+
+package fs
+
+import (
+	"log"
+	"net/http"
+	"net/http/httputil"
+)
+
+const separator = "------------------------------------------------------------"
+
+// An http transport which logs the traffic
+type loggedTransport struct {
+	wrapped http.RoundTripper
+	logBody bool
+}
+
+// NewLoggedTransport wraps the transport passed in and logs all roundtrips
+// including the body if logBody is set.
+func NewLoggedTransport(transport http.RoundTripper, logBody bool) *loggedTransport {
+	return &loggedTransport{
+		wrapped: transport,
+		logBody: logBody,
+	}
+}
+
+// CancelRequest cancels an in-flight request by closing its
+// connection. CancelRequest should only be called after RoundTrip has
+// returned.
+func (t *loggedTransport) CancelRequest(req *http.Request) {
+	if wrapped, ok := t.wrapped.(interface {
+		CancelRequest(*http.Request)
+	}); ok {
+		log.Printf("CANCEL REQUEST %v", req)
+		wrapped.CancelRequest(req)
+	}
+}
+
+// RoundTrip implements the RoundTripper interface.
+func (t *loggedTransport) RoundTrip(req *http.Request) (resp *http.Response, err error) {
+	buf, _ := httputil.DumpRequest(req, t.logBody)
+	log.Println(separator)
+	log.Println("HTTP REQUEST")
+	log.Println(string(buf))
+	log.Println(separator)
+	resp, err = t.wrapped.RoundTrip(req)
+	buf, _ = httputil.DumpResponse(resp, t.logBody)
+	log.Println(separator)
+	log.Println("HTTP RESPONSE")
+	log.Println(string(buf))
+	log.Println(separator)
+	return resp, err
+}