[tbb-bugs] #26653 [Applications/Tor Browser]: Evaluate Tor's Embedding API when integrating Tor Launcher

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#26653: Evaluate Tor's Embedding API when integrating Tor Launcher
-------------------------------------------------+-------------------------
 Reporter:  sysrqb                               |          Owner:  tbb-
                                                 |  team
     Type:  task                                 |         Status:  new
 Priority:  Medium                               |      Milestone:
Component:  Applications/Tor Browser             |        Version:
 Severity:  Normal                               |     Resolution:
 Keywords:  tbb-mobile, TBA-a2,                  |  Actual Points:
  TorBrowserTeam201809                           |
Parent ID:  #24856                               |         Points:
 Reviewer:                                       |        Sponsor:
-------------------------------------------------+-------------------------

Comment (by sysrqb):

 Okay, this is looking good. #24204 is really nice.

 I created a test program that takes the standard tor command line as its
 own command line arguments, but it runs `tor_run_main()` twice, and calls
 `tor_configuration_set_command_line()` twice, too.

 First, it begins by taking the provided command line arguments and
 injecting `--verify-config` as the second argument (in a newly allocate
 argv). It then creates a control fd, and calls `tor_run_main()` using the
 modified command line for verifying the config is valid.

 After that returns, it resets the configuration using the original
 provided command line and calls `tor_run_main()` again using the original
 arguments. After tor starts, `SIGNAL TERM` is sent on the control FD.

 {{{
 $ ./threaded_verify_config --Log "notice stdout" --AvoidDiskWrites 1
 --SocksPort unix:${HOME}/test_socks --DisableNetwork 1
 Running with 'tor 0.3.5.0-alpha-dev'
 Sep 18 19:12:57.516 [notice] Tor 0.3.5.0-alpha-dev (git-b729bc202c74113c)
 running on Linux with Libevent 2.0.22-stable, NSS 3.36.1, Zlib 1.2.11,
 Liblzma N/A, and Libzstd N/A.
 Sep 18 19:12:57.516 [notice] Tor can't help you if you use it wrong! Learn
 how to be safe at https://www.torproject.org/download/download#warning
 Sep 18 19:12:57.516 [notice] This version is not a stable Tor release.
 Expect more bugs than usual.
 Sep 18 19:12:57.516 [notice] Configuration file "/usr/local/etc/tor/torrc"
 not present, using reasonable defaults.
 Configuration was valid
 Tor returned successfully
 Sep 18 19:12:57.572 [notice] Tor 0.3.5.0-alpha-dev (git-b729bc202c74113c)
 running on Linux with Libevent 2.0.22-stable, NSS 3.36.1, Zlib 1.2.11,
 Liblzma N/A, and Libzstd N/A.
 Sep 18 19:12:57.572 [notice] Tor can't help you if you use it wrong! Learn
 how to be safe at https://www.torproject.org/download/download#warning
 Sep 18 19:12:57.572 [notice] This version is not a stable Tor release.
 Expect more bugs than usual.
 Sep 18 19:12:57.572 [notice] Configuration file "/usr/local/etc/tor/torrc"
 not present, using reasonable defaults.
 Sep 18 19:12:57.575 [notice] DisableNetwork is set. Tor will not make or
 accept non-control network connections. Shutting down all existing
 connections.
 Sep 18 19:12:57.000 [notice] Bootstrapped 0%: Starting
 Sep 18 19:12:57.000 [notice] Starting with guard context "default"
 Sep 18 19:12:57.000 [notice] Delaying directory fetches: DisableNetwork is
 set.
 Sep 18 19:12:57.000 [notice] Catching signal TERM, exiting cleanly.
 Tor returned successfully
 }}}

 I compiled tor (with and without `--enable-restart-debugging`) with
 openssl:
 {{{
 $ ./configure --disable-asciidoc --enable-pic --enable-android --enable-
 fatal-warnings
 }}}
 and for fun, with NSS:
 {{{
 $ ./configure --disable-asciidoc --enable-pic --enable-android --enable-
 fatal-warnings --enable-nss
 }}}

 and I compiled the program using:
 {{{
 gcc -Wall -Werror -g -o threaded_verify_config -Isrc/feature/api
 src/tools/threaded_verify_config.c -lpthread -lz -lm -levent -lssl
 -lcrypto -ldl `make show-libs`
 }}}

 and with NSS:
 {{{
 gcc -Wall -Werror -g -o threaded_verify_config -Isrc/feature/api
 src/tools/threaded_verify_config.c -lpthread -lz -lm -levent -lssl3
 -lsmime3 -lnss3 -lnssutil3 -lplds4 -lplc4 -lnspr4 -lcrypto -ldl `make
 show-libs`
 }}}

 I put the program in src/tool/threaded_verify_config.c simply because it
 was easy.

 The test programs are available in branch `testing_26653` in my tor user
 repo. These don't fully bootstrap because `SIGNAL TERM` is sent as soon as
 the control fd is writable. I confirmed tor does fully bootstrap if it is
 not terminated immediately, though.

 Ex.
 {{{
 diff --git a/src/tools/threaded_verify_config.c
 b/src/tools/threaded_verify_config.c
 index 9ba637888..48b7249d8 100644
 --- a/src/tools/threaded_verify_config.c
 +++ b/src/tools/threaded_verify_config.c
 @@ -121,6 +121,7 @@ int main(const int argc, char *argv[]) {
      pfd[0].events = POLLIN;

      if (poll(pfd, 1, -1)) {
 +        sleep(60);
          read(ctx.control_fd, buf, 100);
          printf("%s", buf);
      }
 }}}

 https://gitweb.torproject.org/user/sysrqb/tor.git/commit/?h=testing_26653&id=621ef35eb5464bcf63857deebd2be6728483e8b6

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/26653#comment:4>
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