mgmt: remove listen option from unix channel configuration

refs: #2188

Change-Id: I11adf075b03eab3d22f8160e5d619e3ed445dd29
diff --git a/daemon/mgmt/face-manager.cpp b/daemon/mgmt/face-manager.cpp
index e4286e8..daba08e 100644
--- a/daemon/mgmt/face-manager.cpp
+++ b/daemon/mgmt/face-manager.cpp
@@ -222,16 +222,14 @@
 void
 FaceManager::processSectionUnix(const ConfigSection& configSection, bool isDryRun)
 {
-  // ; the unix section contains settings of UNIX stream faces and channels
+  // ; the unix section contains settings of Unix stream faces and channels
   // unix
   // {
-  //   listen yes ; set to 'no' to disable UNIX stream listener, default 'yes'
-  //   path /var/run/nfd.sock ; UNIX stream listener path
+  //   path /var/run/nfd.sock ; Unix stream listener path
   // }
 
 #if defined(HAVE_UNIX_SOCKETS)
 
-  bool needToListen = true;
   std::string path = "/var/run/nfd.sock";
 
   for (ConfigSection::const_iterator i = configSection.begin();
@@ -242,10 +240,6 @@
         {
           path = i->second.get_value<std::string>();
         }
-      else if (i->first == "listen")
-        {
-          needToListen = parseYesNo(i, i->first, "unix");
-        }
       else
         {
           throw ConfigFile::Error("Unrecognized option \"" + i->first + "\" in \"unix\" section");
@@ -270,17 +264,14 @@
       shared_ptr<UnixStreamFactory> factory = make_shared<UnixStreamFactory>();
       shared_ptr<UnixStreamChannel> unixChannel = factory->createChannel(path);
 
-      if (needToListen)
-        {
-          // Should acceptFailed callback be used somehow?
-          unixChannel->listen(bind(&FaceTable::add, &m_faceTable, _1),
-                              UnixStreamChannel::ConnectFailedCallback());
-        }
+      // Should acceptFailed callback be used somehow?
+      unixChannel->listen(bind(&FaceTable::add, &m_faceTable, _1),
+                          UnixStreamChannel::ConnectFailedCallback());
 
       m_factories.insert(std::make_pair("unix", factory));
     }
 #else
-  throw ConfigFile::Error("NFD was compiled without UNIX sockets support, "
+  throw ConfigFile::Error("NFD was compiled without Unix sockets support, "
                           "cannot process \"unix\" section");
 #endif // HAVE_UNIX_SOCKETS
 
diff --git a/nfd.conf.sample.in b/nfd.conf.sample.in
index 210ecba..eb0de12 100644
--- a/nfd.conf.sample.in
+++ b/nfd.conf.sample.in
@@ -64,11 +64,12 @@
 ; The face_system section defines what faces and channels are created.
 face_system
 {
-  ; The unix section contains settings of UNIX stream faces and channels.
+  ; The unix section contains settings of Unix stream faces and channels.
+  ; Unix channel is always listening; delete unix section to disable
+  ; Unix stream faces and channels.
   unix
   {
-    listen yes ; set to 'no' to disable UNIX stream listener, default 'yes'
-    path /var/run/nfd.sock ; UNIX stream listener path
+    path /var/run/nfd.sock ; Unix stream listener path
   }
 
   ; The tcp section contains settings of TCP faces and channels.
diff --git a/tests/daemon/mgmt/face-manager.cpp b/tests/daemon/mgmt/face-manager.cpp
index 70d8d83..966844a 100644
--- a/tests/daemon/mgmt/face-manager.cpp
+++ b/tests/daemon/mgmt/face-manager.cpp
@@ -342,7 +342,6 @@
     "{\n"
     "  unix\n"
     "  {\n"
-    "    listen yes\n"
     "    path /tmp/nfd.sock\n"
     "  }\n"
     "}\n";
@@ -357,7 +356,6 @@
     "{\n"
     "  unix\n"
     "  {\n"
-    "    listen yes\n"
     "    path /var/run/nfd.sock\n"
     "  }\n"
     "}\n";
@@ -365,21 +363,6 @@
   BOOST_CHECK_NO_THROW(parseConfig(CONFIG, true));
 }
 
-BOOST_AUTO_TEST_CASE(TestProcessSectionUnixBadListen)
-{
-  const std::string CONFIG =
-    "face_system\n"
-    "{\n"
-    "  unix\n"
-    "  {\n"
-    "    listen hello\n"
-    "  }\n"
-    "}\n";
-  BOOST_CHECK_EXCEPTION(parseConfig(CONFIG, false), ConfigFile::Error,
-                        bind(&isExpectedException, _1,
-                             "Invalid value for option \"listen\" in \"unix\" section"));
-}
-
 BOOST_AUTO_TEST_CASE(TestProcessSectionUnixUnknownOption)
 {
   const std::string CONFIG =