Add config object for dirauth; move one option there.

I've chosen the "AuthDirMaxServersPerAddr" option here for
simplicity, since it is used literally nowhere else besides the dirauth
module.  Once we have all the infrastructure in place for this, we
can move more options into this structure.

src/app/config/config.c

@@ -337,7 +337,6 @@ static const config_var_t option_vars_[] = {
   OBSOLETE("AuthDirRejectUnlisted"),
   OBSOLETE("AuthDirListBadDirs"),
   V(AuthDirListBadExits,         BOOL,     "0"),
-  V(AuthDirMaxServersPerAddr,    POSINT,     "2"),
   OBSOLETE("AuthDirMaxServersPerAuthAddr"),
   V(AuthDirHasIPv6Connectivity,  BOOL,     "0"),
   VAR("AuthoritativeDirectory",  BOOL, AuthoritativeDir,    "0"),

src/app/config/or_options_st.h

@@ -467,8 +467,6 @@ struct or_options_t {
 
   int AuthDirListBadExits; /**< True iff we should list bad exits,
                             * and vote for all other exits as good. */
-  int AuthDirMaxServersPerAddr; /**< Do not permit more than this
-                                 * number of servers per IP address. */
   int AuthDirHasIPv6Connectivity; /**< Boolean: are we on IPv6?  */
   int AuthDirPinKeys; /**< Boolean: Do we enforce key-pinning? */
 

src/core/include.am

@@ -355,6 +355,8 @@ noinst_HEADERS +=					\
 	src/feature/dirauth/bridgeauth.h		\
 	src/feature/dirauth/bwauth.h			\
 	src/feature/dirauth/dirauth_config.h		\
+	src/feature/dirauth/dirauth_options.inc		\
+	src/feature/dirauth/dirauth_options_st.h	\
 	src/feature/dirauth/dirauth_periodic.h		\
 	src/feature/dirauth/dirauth_sys.h		\
 	src/feature/dirauth/dircollate.h		\

src/feature/dirauth/.may_include

@@ -1 +1,2 @@
 *.h
+feature/dirauth/*.inc

src/feature/dirauth/dirauth_config.c

@@ -15,6 +15,7 @@
 
 #include "lib/encoding/confline.h"
 #include "lib/confmgt/confmgt.h"
+#include "lib/conf/confdecl.h"
 
 /* Required for dirinfo_type_t in or_options_t */
 #include "core/or/or.h"
@@ -28,6 +29,7 @@
 #include "feature/dirauth/dirauth_periodic.h"
 #include "feature/dirauth/dirvote.h"
 #include "feature/dirauth/guardfraction.h"
+#include "feature/dirauth/dirauth_options_st.h"
 
 /* Copied from config.c, we will refactor later in 29211. */
 #define REJECT(arg) \
@@ -438,3 +440,23 @@ options_act_dirauth_stats(const or_options_t *old_options,
 
   return 0;
 }
+
+/* Declare the options field table for dirauth_options */
+#define CONF_CONTEXT TABLE
+#include "feature/dirauth/dirauth_options.inc"
+#undef CONF_CONTEXT
+
+/** Magic number for dirauth_options_t. */
+#define DIRAUTH_OPTIONS_MAGIC 0x41757448
+
+/**
+ * Declare the configuration options for the dirauth module.
+ **/
+const config_format_t dirauth_options_fmt = {
+  .size = sizeof(dirauth_options_t),
+  .magic = { "dirauth_options_t",
+             DIRAUTH_OPTIONS_MAGIC,
+             offsetof(dirauth_options_t, magic) },
+  .vars = dirauth_options_t_vars,
+};
+

src/feature/dirauth/dirauth_config.h

@@ -39,6 +39,8 @@ int options_act_dirauth_mtbf(const struct or_options_t *old_options);
 int options_act_dirauth_stats(const struct or_options_t *old_options,
                               bool *print_notice_out);
 
+extern const struct config_format_t dirauth_options_fmt;
+
 #else /* !defined(HAVE_MODULE_DIRAUTH) */
 
 /** When tor is compiled with the dirauth module disabled, it can't be

src/feature/dirauth/dirauth_options.inc

@@ -0,0 +1,18 @@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2019, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * @file dirauth_options.inc
+ * @brief Declare configuration options for the crypto_ops module.
+ **/
+
+/** Holds configuration about our directory authority options. */
+BEGIN_CONF_STRUCT(dirauth_options_t)
+
+/** Do not permit more than this number of servers per IP address. */
+CONF_VAR(AuthDirMaxServersPerAddr, POSINT, 0, "2")
+
+END_CONF_STRUCT(dirauth_options_t)

src/feature/dirauth/dirauth_options_st.h

@@ -0,0 +1,22 @@
+/* Copyright (c) 2001 Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2019, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * @file dirauth_options_st.h
+ * @brief Structure dirauth_options_t to hold directory authority options.
+ **/
+
+#ifndef TOR_FEATURE_DIRAUTH_DIRAUTH_OPTIONS_ST_H
+#define TOR_FEATURE_DIRAUTH_DIRAUTH_OPTIONS_ST_H
+
+#include "lib/conf/confdecl.h"
+#define CONF_CONTEXT STRUCT
+#include "feature/dirauth/dirauth_options.inc"
+#undef CONF_CONTEXT
+
+typedef struct dirauth_options_t dirauth_options_t;
+
+#endif /* !defined(TOR_FEATURE_DIRAUTH_DIRAUTH_OPTIONS_ST_H) */

src/feature/dirauth/dirauth_stub.c

@@ -11,9 +11,23 @@
 
 #include "orconfig.h"
 #include "feature/dirauth/dirauth_sys.h"
+#include "lib/conf/conftypes.h"
+#include "lib/conf/confdecl.h"
+#include "lib/subsys/subsys.h"
+
+/* Declare the options field table for dirauth_options */
+#define CONF_CONTEXT STUB_TABLE
+#include "feature/dirauth/dirauth_options.inc"
+#undef CONF_CONTEXT
+
+static const config_format_t dirauth_options_stub_fmt = {
+  .vars = dirauth_options_t_vars,
+};
 
 const struct subsys_fns_t sys_dirauth = {
   .name = "dirauth",
   .supported = false,
   .level = 70,
+
+  .options_format = &dirauth_options_stub_fmt
 };

src/feature/dirauth/dirauth_sys.c

@@ -17,9 +17,14 @@
 #include "feature/dirauth/dirauth_periodic.h"
 #include "feature/dirauth/keypin.h"
 #include "feature/dirauth/process_descs.h"
+#include "feature/dirauth/dirauth_config.h"
+
+#include "feature/dirauth/dirauth_options_st.h"
 
 #include "lib/subsys/subsys.h"
 
+static const dirauth_options_t *global_dirauth_options;
+
 static int
 subsys_dirauth_initialize(void)
 {
@@ -34,6 +39,22 @@ subsys_dirauth_shutdown(void)
   dirvote_free_all();
   dirserv_clear_measured_bw_cache();
   keypin_close_journal();
+  global_dirauth_options = NULL;
+}
+
+const dirauth_options_t *
+dirauth_get_options(void)
+{
+  tor_assert(global_dirauth_options);
+  return global_dirauth_options;
+}
+
+static int
+dirauth_set_options(void *arg)
+{
+  dirauth_options_t *opts = arg;
+  global_dirauth_options = opts;
+  return 0;
 }
 
 const struct subsys_fns_t sys_dirauth = {
@@ -42,4 +63,7 @@ const struct subsys_fns_t sys_dirauth = {
   .level = 70,
   .initialize = subsys_dirauth_initialize,
   .shutdown = subsys_dirauth_shutdown,
+
+  .options_format = &dirauth_options_fmt,
+  .set_options = dirauth_set_options,
 };

src/feature/dirauth/dirauth_sys.h

@@ -12,6 +12,9 @@
 #ifndef DIRAUTH_SYS_H
 #define DIRAUTH_SYS_H
 
+struct dirauth_options_t;
+const struct dirauth_options_t *dirauth_get_options(void);
+
 extern const struct subsys_fns_t sys_dirauth;
 
 #endif /* !defined(DIRAUTH_SYS_H) */

src/feature/dirauth/dirvote.c

@@ -41,10 +41,12 @@
 #include "feature/dirauth/dirvote.h"
 #include "feature/dirauth/authmode.h"
 #include "feature/dirauth/shared_random_state.h"
+#include "feature/dirauth/dirauth_sys.h"
 
 #include "feature/nodelist/authority_cert_st.h"
 #include "feature/dircache/cached_dir_st.h"
 #include "feature/dirclient/dir_server_st.h"
+#include "feature/dirauth/dirauth_options_st.h"
 #include "feature/nodelist/document_signature_st.h"
 #include "feature/nodelist/microdesc_st.h"
 #include "feature/nodelist/networkstatus_st.h"
@@ -4228,7 +4230,7 @@ compare_routerinfo_by_ip_and_bw_(const void **a, const void **b)
 static digestmap_t *
 get_possible_sybil_list(const smartlist_t *routers)
 {
-  const or_options_t *options = get_options();
+  const dirauth_options_t *options = dirauth_get_options();
   digestmap_t *omit_as_sybil;
   smartlist_t *routers_by_ip = smartlist_new();
   uint32_t last_addr;