Move literally everything out of src/or

This commit won't build yet -- it just puts everything in a slightly
more logical place.

The reasoning here is that "src/core" will hold the stuff that every (or
nearly every) tor instance will need in order to do onion routing.
Other features (including some necessary ones) will live in
"src/feature".  The "src/app" directory will hold the stuff needed
to have Tor be an application you can actually run.

This commit DOES NOT refactor the former contents of src/or into a
logical set of acyclic libraries, or change any code at all.  That
will have to come in the future.

We will continue to move things around and split them in the future,
but I hope this lays a reasonable groundwork for doing so.

1 files changed, 101 insertions, 0 deletions

diff --git a/src/feature/api/tor_api.h b/src/feature/api/tor_api.h
new file mode 100644
index 0000000000..ead9493c1f
--- /dev/null
+++ b/src/feature/api/tor_api.h
@@ -0,0 +1,101 @@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file tor_api.h
+ * \brief Public C API for the Tor network service.
+ *
+ * This interface is intended for use by programs that need to link Tor as
+ * a library, and launch it in a separate thread.  If you have the ability
+ * to run Tor as a separate executable, you should probably do that instead
+ * of embedding it as a library.
+ *
+ * To use this API, first construct a tor_main_configuration_t object using
+ * tor_main_configuration_new().  Then, you use one or more other function
+ * calls (such as tor_main_configuration_set_command_line() to configure how
+ * Tor should be run.  Finally, you pass the configuration object to
+ * tor_run_main().
+ *
+ * At this point, tor_run_main() will block its thread to run a Tor daemon;
+ * when the Tor daemon exits, it will return.  See notes on bugs and
+ * limitations below.
+ *
+ * There is no other public C API to Tor: calling any C Tor function not
+ * documented in this file is not guaranteed to be stable.
+ **/
+
+#ifndef TOR_API_H
+#define TOR_API_H
+
+typedef struct tor_main_configuration_t tor_main_configuration_t;
+
+/**
+ * Create and return a new tor_main_configuration().
+ */
+tor_main_configuration_t *tor_main_configuration_new(void);
+
+/**
+ * Set the command-line arguments in <b>cfg</b>.
+ *
+ * The <b>argc</b> and <b>argv</b> values here are as for main().  The
+ * contents of the argv pointer must remain unchanged until tor_run_main() has
+ * finished and you call tor_main_configuration_free().
+ *
+ * Return 0 on success, -1 on failure.
+ */
+int tor_main_configuration_set_command_line(tor_main_configuration_t *cfg,
+                                            int argc, char *argv[]);
+
+/**
+ * Release all storage held in <b>cfg</b>.
+ *
+ * Once you have passed a tor_main_configuration_t to tor_run_main(), you
+ * must not free it until tor_run_main() has finished.
+ */
+void tor_main_configuration_free(tor_main_configuration_t *cfg);
+
+/**
+ * Run the tor process, as if from the command line.
+ *
+ * The command line arguments from tor_main_configuration_set_command_line()
+ * are taken as if they had been passed to main().
+ *
+ * This function will not return until Tor is done running.  It returns zero
+ * on success, and nonzero on failure.
+ *
+ * If you want to control when Tor exits, make sure to configure a control
+ * socket. The OwningControllerFD option may be helpful there.
+ *
+ * BUG 23847: Sometimes, if you call tor_main a second time (after it has
+ * returned), Tor may crash or behave strangely.  We have fixed all issues of
+ * this type that we could find, but more may remain.
+ *
+ * LIMITATION: You cannot run more than one instance of Tor in the same
+ * process at the same time. Concurrent calls will cause undefined behavior.
+ * We do not currently have plans to change this.
+ *
+ * LIMITATION: While we will try to fix any problems found here, you
+ * should be aware that Tor was originally written to run as its own
+ * process, and that the functionality of this file was added later.  If
+ * you find any bugs or strange behavior, please report them, and we'll
+ * try to straighten them out.
+ */
+int tor_run_main(const tor_main_configuration_t *);
+
+/**
+ * Run the tor process, as if from the command line.
+ *
+ * @deprecated Using this function from outside Tor is deprecated; you should
+ * use tor_run_main() instead.
+ *
+ * BUGS: This function has all the same bugs as tor_run_main().
+ *
+ * LIMITATIONS: This function has all the limitations of tor_run_main().
+ */
+int tor_main(int argc, char **argv);
+
+#endif /* !defined(TOR_API_H) */
+