[tor-commits] [nyx/master] Notify when connection information is unavailable

[atagar at torproject.org]

commit e042022c117ad817d2ac8e974241c53d5c3448b9
Author: Damian Johnson <atagar at torproject.org>
Date:   Wed Jan 9 10:41:26 2019 -0800

    Notify when connection information is unavailable
    
    Provide a notice explaining why connection information is unavailable
    when the user's system lacks /proc content. Ususally Mac and BSD users.
    
      https://trac.torproject.org/projects/tor/ticket/24958
---
 nyx/tracker.py           |  9 ++++-----
 web/changelog/index.html |  1 +
 web/index.html           | 21 +++++++++++++++++++++
 3 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/nyx/tracker.py b/nyx/tracker.py
index b0ea9bb..f6880d2 100644
--- a/nyx/tracker.py
+++ b/nyx/tracker.py
@@ -510,13 +510,12 @@ class ConnectionTracker(Daemon):
     # resolution. Otherwise connection resolution by inference is the only game
     # in town.
 
-    self._resolvers = []
+    self._resolvers = [CustomResolver.INFERENCE] if stem.util.proc.is_available() else []
 
     if tor_controller().get_conf('DisableDebuggerAttachment', None) == '0':
-      self._resolvers = connection.system_resolvers()
-
-    if stem.util.proc.is_available():
-      self._resolvers = [CustomResolver.INFERENCE] + self._resolvers
+      self._resolvers = self._resolvers + connection.system_resolvers()
+    elif not self._resolvers:
+      stem.util.log.notice("Tor connection information is unavailable. This is fine, but if you would like to have it please see https://nyx.torproject.org/#no_connections")
 
     stem.util.log.info('Operating System: %s, Connection Resolvers: %s' % (os.uname()[0], ', '.join(self._resolvers)))
 
diff --git a/web/changelog/index.html b/web/changelog/index.html
index 0ba98c2..d49533e 100644
--- a/web/changelog/index.html
+++ b/web/changelog/index.html
@@ -77,6 +77,7 @@
             <li>Blank debug path caused us to crash (<a href="https://trac.torproject.org/projects/tor/ticket/27350">ticket</a>)</li>
             <li>Nyxrc <i>password</i> option for the controller credential (<a href="https://trac.torproject.org/projects/tor/ticket/28295">ticket</a>)</li>
             <li>Accept shorthand '--interface' arugments with a colon but no address (<a href="https://trac.torproject.org/projects/tor/ticket/28965">ticket</a>)</li>
+            <li>Notification when connection information is unavailable (<a href="https://trac.torproject.org/projects/tor/ticket/24958">ticket</a>)</li>
           </ul>
         </li>
 
diff --git a/web/index.html b/web/index.html
index 0ec396e..33332c2 100644
--- a/web/index.html
+++ b/web/index.html
@@ -280,6 +280,27 @@ E: Unable to locate package nyx</pre>
           </div>
         </li>
 
+        <li id="no_connections">
+          <span>Why can't I see Tor's connections?</span>
+          <div class="answer">
+            <p>Nyx can provide you with information about <a href="images/features/connections.png">tor's active connections</a>. This information is retrieved from your system's <b>/proc</b> content or tools such as <i>netstat</i> and <i>lsof</i>.</p>
+
+            <p>Unfortunately Tor inadvertently breaks the tools Nyx falls back to through a featurure called <a href="https://www.torproject.org/docs/tor-manual.html.en#DisableDebuggerAttachment"><b>DisableDebuggerAttachment</b></a>, which makes tor's process memory only readable by root.</p>
+
+            <p>This leaves you with three options...</p>
+
+            <ol>
+              <li><p>Use Nyx without connection data. <b>Nyx does not require connection information</b>, and aside a sparse connection list you probably won't even notice.</p></li>
+              <li><p>Run Nyx as root. <b>This is not recommended.</b></p></li>
+              <li><p>Turn off <a href="https://www.torproject.org/docs/tor-manual.html.en#DisableDebuggerAttachment"><b>DisableDebuggerAttachment</b></a> by adding the following to your <a href="https://www.torproject.org/docs/faq.html.en#torrc">torrc</a> and restarting tor...</p>
+                <pre>DisableDebuggerAttachment 0</pre>
+              </li>
+            </ol>
+
+            <p>Don't fret overly much about this decision. Nothing at play here is important - connection data is unimportant <b>and</b> DisableDebuggerAttachment's <a href="https://trac.torproject.org/projects/tor/ticket/3313">security benefit</a> is insignificant. Either decision is fine.</p>
+          </div>
+        </li>
+
         <li id="missing_relay_details">
           <span>Why are connections missing relay details?</span>
           <div class="answer">