wiki:user/catalyst

Version 3 (modified by catalyst, 7 months ago) (diff)

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Notes on Tor Browser debugging

Stuff to delete to reset on Linux:

  • Browser/TorBrowser/Data/Tor/{cached*,state,torrc}
  • Browser/TorBrowser/Data/Browser/profile.default/prefs.js

Clock skew testing

The faketime package in Ubuntu 16.04 is too old to know about CLOCK_MONOTONIC_COARSE but tor uses it. This causes startup to fail in the faketime library. Also if asan is active, its runtime must be listed first in LD_PRELOAD, which prevents using the normal faketime wrapper script.

Signs of client clock in the future

Stuck at 80% (Connecting to the Tor network) or 85% (Finishing handshake with first hop).

Repetitive logs such as

Sep 18 18:53:04.000 [debug] update_guard_selection_choice(): Staying with guard context "default" (no change)
Sep 18 18:53:04.000 [info] sampled_guards_update_from_consensus(): Not updating the sample guard set; we have no live consensus.
Sep 18 18:53:04.000 [info] sample_reachable_filtered_entry_guards(): Trying to sample a reachable guard: We know of 0 in the USABLE_FILTERED set.
Sep 18 18:53:04.000 [info] sample_reachable_filtered_entry_guards():   (That isn't enough. Trying to expand the sample.)
Sep 18 18:53:04.000 [info] entry_guards_expand_sample(): Not expanding the sample guard set; we have no live consensus.

or

Sep 19 16:56:50.000 [info] sample_reachable_filtered_entry_guards(): Trying to sample a reachable guard: We know of 0 in the USABLE_FILTERED set.
Sep 19 16:56:50.000 [info] sample_reachable_filtered_entry_guards():   (That isn't enough. Trying to expand the sample.)
Sep 19 16:56:50.000 [info] entry_guards_expand_sample(): Not expanding the sample guard set; we have no live consensus.
Sep 19 16:56:50.000 [info] sample_reachable_filtered_entry_guards():   (After filters [17], we have 0 guards to consider.)
Sep 19 16:56:50.000 [info] select_entry_guard_for_circuit(): Absolutely no sampled guards were available. Marking all guards for retry and starting from top again.
Sep 19 16:56:50.000 [warn] Failed to find node for hop #1 of our path. Discarding this circuit.
Sep 19 16:56:50.000 [info] onion_populate_cpath(): Generating cpath hop failed.