3 files changed, 209 insertions, 0 deletions
diff --git a/src/feature/api/tor_api.c b/src/feature/api/tor_api.c
new file mode 100644
index 0000000000..efedf2dc78
--- /dev/null
+++ b/src/feature/api/tor_api.c
@@ -0,0 +1,88 @@
+/* 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.c
+ **/
+
+#include "or/tor_api.h"
+#include "or/tor_api_internal.h"
+
+// Include this after the above headers, to insure that they don't
+// depend on anything else.
+#include "orconfig.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+// We don't want to use tor_malloc and tor_free here, since this needs
+// to run before anything is initialized at all, and ought to run when
+// we're not linked to anything at all.
+
+#define raw_malloc malloc
+#define raw_free free
+
+tor_main_configuration_t *
+tor_main_configuration_new(void)
+{
+  static const char *fake_argv[] = { "tor" };
+  tor_main_configuration_t *cfg = raw_malloc(sizeof(*cfg));
+  if (cfg == NULL)
+    return NULL;
+
+  memset(cfg, 0, sizeof(*cfg));
+
+  cfg->argc = 1;
+  cfg->argv = (char **) fake_argv;
+
+  return cfg;
+}
+
+int
+tor_main_configuration_set_command_line(tor_main_configuration_t *cfg,
+                                        int argc, char *argv[])
+{
+  if (cfg == NULL)
+    return -1;
+  cfg->argc = argc;
+  cfg->argv = argv;
+  return 0;
+}
+
+void
+tor_main_configuration_free(tor_main_configuration_t *cfg)
+{
+  if (cfg == NULL)
+    return;
+  raw_free(cfg);
+}
+
+/* Main entry point for the Tor process.  Called from main().
+ *
+ * This function is distinct from main() only so we can link main.c into
+ * the unittest binary without conflicting with the unittests' main.
+ *
+ * Some embedders have historically called this function; but that usage is
+ * deprecated: they should use tor_run_main() instead.
+ */
+int
+tor_main(int argc, char *argv[])
+{
+  tor_main_configuration_t *cfg = tor_main_configuration_new();
+  if (!cfg) {
+    puts("INTERNAL ERROR: Allocation failure. Cannot proceed");
+    return 1;
+  }
+  if (tor_main_configuration_set_command_line(cfg, argc, argv) < 0) {
+    puts("INTERNAL ERROR: Can't set command line. Cannot proceed.");
+    return 1;
+  }
+  int rv = tor_run_main(cfg);
+  tor_main_configuration_free(cfg);
+  return rv;
+}
+
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) */
+
diff --git a/src/feature/api/tor_api_internal.h b/src/feature/api/tor_api_internal.h
new file mode 100644
index 0000000000..2c392a68de
--- /dev/null
+++ b/src/feature/api/tor_api_internal.h
@@ -0,0 +1,20 @@
+/* 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 */
+
+#ifndef TOR_API_INTERNAL_H
+#define TOR_API_INTERNAL_H
+
+/* The contents of this type are private; don't mess with them from outside
+ * Tor. */
+struct tor_main_configuration_t {
+  /** As in main() */
+  int argc;
+  /** As in main(). This pointer is owned by the caller */
+  char **argv;
+};
+
+#endif /* !defined(TOR_API_INTERNAL_H) */
+