From f3c853bad6b3070e11374bea3b157e214b0be237 Mon Sep 17 00:00:00 2001
From: Simone Basso <bassosimone@gmail.com>
Date: Fri, 3 Feb 2023 18:18:14 +0100
Subject: [PATCH] fix(torembed): use embedded control conn  (#1074)

See https://github.com/ooni/probe/issues/2405#issuecomment-1416088377
---
 internal/tunnel/torembed.go  | 9 +++++----
 internal/tunnel/tormobile.go | 7 +++++++
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/internal/tunnel/torembed.go b/internal/tunnel/torembed.go
index a55a6183c4..df7bf67991 100644
--- a/internal/tunnel/torembed.go
+++ b/internal/tunnel/torembed.go
@@ -29,9 +29,10 @@ func getTorStartConf(config *Config, dataDir string, extraArgs []string) (*tor.S
 	config.logger().Infof("tunnel: tor: exec: <internal/libtor> %s %s",
 		dataDir, strings.Join(extraArgs, " "))
 	return &tor.StartConf{
-		ProcessCreator: creator,
-		DataDir:        dataDir,
-		ExtraArgs:      extraArgs,
-		NoHush:         true,
+		ProcessCreator:         creator,
+		UseEmbeddedControlConn: true,
+		DataDir:                dataDir,
+		ExtraArgs:              extraArgs,
+		NoHush:                 true,
 	}, nil
 }
diff --git a/internal/tunnel/tormobile.go b/internal/tunnel/tormobile.go
index c67f513824..651ed325d8 100644
--- a/internal/tunnel/tormobile.go
+++ b/internal/tunnel/tormobile.go
@@ -20,6 +20,13 @@ func getTorStartConf(config *Config, dataDir string, extraArgs []string) (*tor.S
 	config.logger().Infof("tunnel: tor: exec: <ooni/go-libtor> %s %s",
 		dataDir, strings.Join(extraArgs, " "))
 	return &tor.StartConf{
+		// Implementation note: go-libtor leaks a file descriptor when you set
+		// UseEmbeddedControlConn, as documented by
+		//
+		//	https://github.com/ooni/probe/issues/2405
+		//
+		// This is why we're not using this field for now. The above mentioned
+		// issue also refers to what a possible fix would look like.
 		ProcessCreator: libtor.Creator,
 		DataDir:        dataDir,
 		ExtraArgs:      extraArgs,