Merge branch 'ticket30935' into ticket30935_merged

11 files changed, 346 insertions, 53 deletions

diff --git a/src/lib/conf/.may_include b/src/lib/conf/.may_include
index 4285c3dcb8..629e2f897d 100644
--- a/src/lib/conf/.may_include
+++ b/src/lib/conf/.may_include
@@ -1,2 +1,3 @@
 orconfig.h
 lib/cc/*.h
+lib/conf/*.h
diff --git a/src/lib/conf/confmacros.h b/src/lib/conf/confmacros.h
new file mode 100644
index 0000000000..aa89965e69
--- /dev/null
+++ b/src/lib/conf/confmacros.h
@@ -0,0 +1,67 @@
+/* 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 confmacros.h
+ * @brief Macro definitions for declaring configuration variables
+ **/
+
+#ifndef TOR_LIB_CONF_CONFMACROS_H
+#define TOR_LIB_CONF_CONFMACROS_H
+
+#include "orconfig.h"
+#include "lib/conf/conftesting.h"
+
+/**
+ * Used to indicate the end of an array of configuration variables.
+ **/
+#define END_OF_CONFIG_VARS                                      \
+  { .member = { .name = NULL } DUMMY_CONF_TEST_MEMBERS }
+
+/**
+ * Declare a config_var_t as a member named <b>membername</b> of the structure
+ * <b>structtype</b>, whose user-visible name is <b>varname</b>, whose
+ * type corresponds to the config_type_t member CONFIG_TYPE_<b>vartype</b>,
+ * and whose initial value is <b>intval</b>.
+ *
+ * Most modules that use this macro should wrap it in a local macro that
+ * sets structtype to the local configuration type.
+ **/
+#define CONFIG_VAR_ETYPE(structtype, varname, vartype, membername,      \
+                         varflags, initval)                             \
+  { .member =                                                           \
+    { .name = varname,                                                  \
+      .type = CONFIG_TYPE_ ## vartype,                                  \
+      .offset = offsetof(structtype, membername),                       \
+    },                                                                  \
+    .flags = varflags,                                                  \
+    .initvalue = initval                                                \
+    CONF_TEST_MEMBERS(structtype, vartype, membername)                  \
+  }
+
+/**
+ * As CONFIG_VAR_XTYPE, but declares a value using an extension type whose
+ * type definition is <b>vartype</b>_type_defn.
+ **/
+#define CONFIG_VAR_DEFN(structtype, varname, vartype, membername,       \
+                        varflags, initval)                              \
+  { .member =                                                           \
+      { .name = varname,                                                \
+      .type = CONFIG_TYPE_EXTENDED,                                     \
+      .type_def = &vartype ## _type_defn,                               \
+      .offset = offsetof(structtype, membername),                       \
+    },                                                                  \
+    .flags = varflags,                                                  \
+    .initvalue = initval                                                \
+    CONF_TEST_MEMBERS(structtype, vartype, membername)                  \
+  }
+
+#define CONFIG_VAR_OBSOLETE(varname)            \
+  { .member = { .name = varname, .type = CONFIG_TYPE_OBSOLETE },        \
+    .flags = CVFLAG_OBSOLETE                                            \
+  }
+
+#endif /* !defined(TOR_LIB_CONF_CONFMACROS_H) */
diff --git a/src/lib/conf/conftesting.h b/src/lib/conf/conftesting.h
new file mode 100644
index 0000000000..a40c9bc97c
--- /dev/null
+++ b/src/lib/conf/conftesting.h
@@ -0,0 +1,86 @@
+/* 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 conftesting.h
+ * @brief Macro and type declarations for testing
+ **/
+
+#ifndef TOR_LIB_CONF_CONFTESTING_H
+#define TOR_LIB_CONF_CONFTESTING_H
+
+#ifdef TOR_UNIT_TESTS
+/**
+ * Union used when building in test mode typechecking the members of a type
+ * used with confparse.c.  See CONF_CHECK_VAR_TYPE for a description of how
+ * it is used. */
+typedef union {
+  char **STRING;
+  char **FILENAME;
+  int *POSINT; /* yes, this is really an int, and not an unsigned int.  For
+                * historical reasons, many configuration values are restricted
+                * to the range [0,INT_MAX], and stored in signed ints.
+                */
+  uint64_t *UINT64;
+  int *INT;
+  int *INTERVAL;
+  int *MSEC_INTERVAL;
+  uint64_t *MEMUNIT;
+  double *DOUBLE;
+  int *BOOL;
+  int *AUTOBOOL;
+  time_t *ISOTIME;
+  struct smartlist_t **CSV;
+  int *CSV_INTERVAL;
+  struct config_line_t **LINELIST;
+  struct config_line_t **LINELIST_S;
+  struct config_line_t **LINELIST_V;
+  // XXXX this doesn't belong at this level of abstraction.
+  struct routerset_t **ROUTERSET;
+} confparse_dummy_values_t;
+#endif /* defined(TOR_UNIT_TESTS) */
+
+/* Macros to define extra members inside config_var_t fields, and at the
+ * end of a list of them.
+ */
+#ifdef TOR_UNIT_TESTS
+/* This is a somewhat magic type-checking macro for users of confparse.c.
+ * It initializes a union member "confparse_dummy_values_t.conftype" with
+ * the address of a static member "tp_dummy.member".   This
+ * will give a compiler warning unless the member field is of the correct
+ * type.
+ *
+ * (This warning is mandatory, because a type mismatch here violates the type
+ * compatibility constraint for simple assignment, and requires a diagnostic,
+ * according to the C spec.)
+ *
+ * For example, suppose you say:
+ *     "CONF_CHECK_VAR_TYPE(or_options_t, STRING, Address)".
+ * Then this macro will evaluate to:
+ *     { .STRING = &or_options_t_dummy.Address }
+ * And since confparse_dummy_values_t.STRING has type "char **", that
+ * expression will create a warning unless or_options_t.Address also
+ * has type "char *".
+ */
+#define CONF_CHECK_VAR_TYPE(tp, conftype, member)       \
+  { . conftype = &tp ## _dummy . member }
+#define CONF_TEST_MEMBERS(tp, conftype, member) \
+  , .var_ptr_dummy=CONF_CHECK_VAR_TYPE(tp, conftype, member)
+#define DUMMY_CONF_TEST_MEMBERS , .var_ptr_dummy={ .INT=NULL }
+#define DUMMY_TYPECHECK_INSTANCE(tp)            \
+  static tp tp ## _dummy
+
+#else /* !(defined(TOR_UNIT_TESTS)) */
+
+#define CONF_TEST_MEMBERS(tp, conftype, member)
+/* Repeatedly declarable incomplete struct to absorb redundant semicolons */
+#define DUMMY_TYPECHECK_INSTANCE(tp)            \
+  struct tor_semicolon_eater
+#define DUMMY_CONF_TEST_MEMBERS
+
+#endif /* defined(TOR_UNIT_TESTS) */
+
+#endif /* !defined(TOR_LIB_CONF_CONFTESTING_H) */
diff --git a/src/lib/conf/conftypes.h b/src/lib/conf/conftypes.h
index cddfeff2fd..3b754e07be 100644
--- a/src/lib/conf/conftypes.h
+++ b/src/lib/conf/conftypes.h
@@ -29,6 +29,9 @@
 #define TOR_SRC_LIB_CONF_CONFTYPES_H
 
 #include "lib/cc/torint.h"
+#ifdef TOR_UNIT_TESTS
+#include "lib/conf/conftesting.h"
+#endif
 
 /** Enumeration of types which option values can take */
 typedef enum config_type_t {
@@ -59,9 +62,6 @@ typedef enum config_type_t {
   CONFIG_TYPE_LINELIST_V,   /**< Catch-all "virtual" option to summarize
                              * context-sensitive config lines when fetching.
                              */
-  // XXXX this doesn't belong at this level of abstraction.
-  CONFIG_TYPE_ROUTERSET,    /**< A list of router names, addrs, and fps,
-                             * parsed into a routerset_t. */
   CONFIG_TYPE_OBSOLETE,     /**< Obsolete (ignored) option. */
   CONFIG_TYPE_EXTENDED,     /**< Extended type; definition will appear in
                              * pointer. */
@@ -105,35 +105,34 @@ typedef struct struct_magic_decl_t {
   int magic_offset;
 } struct_magic_decl_t;
 
-#ifdef TOR_UNIT_TESTS
 /**
- * Union used when building in test mode typechecking the members of a type
- * used with confparse.c.  See CONF_CHECK_VAR_TYPE for a description of how
- * it is used. */
-typedef union {
-  char **STRING;
-  char **FILENAME;
-  int *POSINT; /* yes, this is really an int, and not an unsigned int.  For
-                * historical reasons, many configuration values are restricted
-                * to the range [0,INT_MAX], and stored in signed ints.
-                */
-  uint64_t *UINT64;
-  int *INT;
-  int *INTERVAL;
-  int *MSEC_INTERVAL;
-  uint64_t *MEMUNIT;
-  double *DOUBLE;
-  int *BOOL;
-  int *AUTOBOOL;
-  time_t *ISOTIME;
-  struct smartlist_t **CSV;
-  int *CSV_INTERVAL;
-  struct config_line_t **LINELIST;
-  struct config_line_t **LINELIST_S;
-  struct config_line_t **LINELIST_V;
-  // XXXX this doesn't belong at this level of abstraction.
-  struct routerset_t **ROUTERSET;
-} confparse_dummy_values_t;
-#endif /* defined(TOR_UNIT_TESTS) */
+ * Flag to indicate that an option is obsolete. Any attempt to set or
+ * fetch this option should produce a warning.
+ **/
+#define CVFLAG_OBSOLETE  (1u<<0)
+/**
+ * Flag to indicate that an option is undumpable. An undumpable option is
+ * never saved to disk, and is prefixed with __.
+ **/
+#define CVFLAG_NODUMP    (1u<<1)
+/**
+ * Flag to indicate that an option is "invisible". An invisible option
+ * is always undumpable, and we don't tell the controller about it.
+ **/
+#define CVFLAG_INVISIBLE (1u<<2)
+
+/** A variable allowed in the configuration file or on the command line. */
+typedef struct config_var_t {
+  struct_member_t member; /** A struct member corresponding to this
+                           * variable. */
+  const char *initvalue; /**< String (or null) describing initial value. */
+  uint32_t flags; /**< One or more flags describing special handling for this
+                   * variable */
+#ifdef TOR_UNIT_TESTS
+  /** Used for compiler-magic to typecheck the corresponding field in the
+   * corresponding struct. Only used in unit test mode, at compile-time. */
+  confparse_dummy_values_t var_ptr_dummy;
+#endif
+} config_var_t;
 
 #endif /* !defined(TOR_SRC_LIB_CONF_CONFTYPES_H) */
diff --git a/src/lib/conf/include.am b/src/lib/conf/include.am
index 25355697d2..cb7126184d 100644
--- a/src/lib/conf/include.am
+++ b/src/lib/conf/include.am
@@ -1,4 +1,6 @@
 
 # ADD_C_FILE: INSERT HEADERS HERE.
 noinst_HEADERS +=				\
-	src/lib/conf/conftypes.h
+	src/lib/conf/conftesting.h              \
+	src/lib/conf/conftypes.h                \
+	src/lib/conf/confmacros.h
diff --git a/src/lib/confmgt/structvar.c b/src/lib/confmgt/structvar.c
index 38f8e5dd7a..97a8fb3633 100644
--- a/src/lib/confmgt/structvar.c
+++ b/src/lib/confmgt/structvar.c
@@ -202,6 +202,19 @@ struct_var_kvencode(const void *object, const struct_member_t *member)
 }
 
 /**
+ * Mark the field in <b>object</b> determined by <b>member</b> -- a variable
+ * that ordinarily would be extended by assignment -- as "fragile", so that it
+ * will get replaced by the next assignment instead.
+ */
+void
+struct_var_mark_fragile(void *object, const struct_member_t *member)
+{
+  void *p = struct_get_mptr(object, member);
+  const var_type_def_t *def = get_type_def(member);
+  return typed_var_mark_fragile_ex(p, def);
+}
+
+/**
  * Return the official name of this struct member.
  **/
 const char *
@@ -224,3 +237,27 @@ struct_var_get_typename(const struct_member_t *member)
 
   return def ? def->name : NULL;
 }
+
+bool
+struct_var_is_cumulative(const struct_member_t *member)
+{
+  const var_type_def_t *def = get_type_def(member);
+
+  return def ? def->is_cumulative : false;
+}
+
+bool
+struct_var_is_settable(const struct_member_t *member)
+{
+  const var_type_def_t *def = get_type_def(member);
+
+  return def ? !def->is_unsettable : true;
+}
+
+bool
+struct_var_is_contained(const struct_member_t *member)
+{
+  const var_type_def_t *def = get_type_def(member);
+
+  return def ? def->is_contained : false;
+}
diff --git a/src/lib/confmgt/structvar.h b/src/lib/confmgt/structvar.h
index 92b9b6fc71..e6dbc6d6ec 100644
--- a/src/lib/confmgt/structvar.h
+++ b/src/lib/confmgt/structvar.h
@@ -40,9 +40,14 @@ bool struct_var_eq(const void *a, const void *b,
                    const struct struct_member_t *member);
 bool struct_var_ok(const void *object,
                    const struct struct_member_t *member);
+void struct_var_mark_fragile(void *object,
+                             const struct struct_member_t *member);
 
 const char *struct_var_get_name(const struct struct_member_t *member);
 const char *struct_var_get_typename(const struct struct_member_t *member);
+bool struct_var_is_cumulative(const struct struct_member_t *member);
+bool struct_var_is_settable(const struct struct_member_t *member);
+bool struct_var_is_contained(const struct struct_member_t *member);
 
 int struct_var_kvassign(void *object, const struct config_line_t *line,
                         char **errmsg,
diff --git a/src/lib/confmgt/type_defs.c b/src/lib/confmgt/type_defs.c
index 62b4c1019d..f8b2681aa0 100644
--- a/src/lib/confmgt/type_defs.c
+++ b/src/lib/confmgt/type_defs.c
@@ -620,12 +620,22 @@ linelist_copy(void *target, const void *value, const void *params)
   return 0;
 }
 
+static void
+linelist_mark_fragile(void *target, const void *params)
+{
+  (void)params;
+  config_line_t **ptr = (config_line_t **)target;
+  if (*ptr)
+    (*ptr)->fragile = 1;
+}
+
 static const var_type_fns_t linelist_fns = {
   .kv_parse = linelist_kv_parse,
   .kv_encode = linelist_kv_encode,
   .clear = linelist_clear,
   .eq = linelist_eq,
   .copy = linelist_copy,
+  .mark_fragile = linelist_mark_fragile,
 };
 
 static const var_type_fns_t linelist_v_fns = {
@@ -634,6 +644,7 @@ static const var_type_fns_t linelist_v_fns = {
   .clear = linelist_clear,
   .eq = linelist_eq,
   .copy = linelist_copy,
+  .mark_fragile = linelist_mark_fragile,
 };
 
 static const var_type_fns_t linelist_s_fns = {
@@ -690,26 +701,40 @@ static const var_type_fns_t ignore_fns = {
  * Table mapping conf_type_t values to var_type_def_t objects.
  **/
 static const var_type_def_t type_definitions_table[] = {
-  [CONFIG_TYPE_STRING] = { "String", &string_fns, NULL },
-  [CONFIG_TYPE_FILENAME] = { "Filename", &string_fns, NULL },
-  [CONFIG_TYPE_INT] = { "SignedInteger", &int_fns, &INT_PARSE_UNRESTRICTED },
-  [CONFIG_TYPE_POSINT] = { "Integer", &int_fns, &INT_PARSE_POSINT },
-  [CONFIG_TYPE_UINT64] = { "Integer", &uint64_fns, NULL, },
-  [CONFIG_TYPE_MEMUNIT] = { "DataSize", &memunit_fns, &memory_units },
-  [CONFIG_TYPE_INTERVAL] = { "TimeInterval", &interval_fns, &time_units },
-  [CONFIG_TYPE_MSEC_INTERVAL] = { "TimeMsecInterval", &interval_fns,
-                                  &time_msec_units },
-  [CONFIG_TYPE_DOUBLE] = { "Float", &double_fns, NULL },
-  [CONFIG_TYPE_BOOL] = { "Boolean", &enum_fns, &enum_table_bool },
-  [CONFIG_TYPE_AUTOBOOL] = { "Boolean+Auto", &enum_fns, &enum_table_autobool },
-  [CONFIG_TYPE_ISOTIME] = { "Time", &time_fns, NULL },
-  [CONFIG_TYPE_CSV] = { "CommaList", &csv_fns, NULL },
-  [CONFIG_TYPE_CSV_INTERVAL] = { "TimeInterval", &legacy_csv_interval_fns,
-                                 NULL },
-  [CONFIG_TYPE_LINELIST] = { "LineList", &linelist_fns, NULL },
-  [CONFIG_TYPE_LINELIST_S] = { "Dependent", &linelist_s_fns, NULL },
-  [CONFIG_TYPE_LINELIST_V] = { "Virtual", &linelist_v_fns, NULL },
-  [CONFIG_TYPE_OBSOLETE] = { "Obsolete", &ignore_fns, NULL }
+  [CONFIG_TYPE_STRING] = { .name="String", .fns=&string_fns },
+  [CONFIG_TYPE_FILENAME] = { .name="Filename", .fns=&string_fns },
+  [CONFIG_TYPE_INT] = { .name="SignedInteger", .fns=&int_fns,
+                        .params=&INT_PARSE_UNRESTRICTED },
+  [CONFIG_TYPE_POSINT] = { .name="Integer", .fns=&int_fns,
+                           .params=&INT_PARSE_POSINT },
+  [CONFIG_TYPE_UINT64] = { .name="Integer", .fns=&uint64_fns, },
+  [CONFIG_TYPE_MEMUNIT] = { .name="DataSize", .fns=&memunit_fns,
+                            .params=&memory_units },
+  [CONFIG_TYPE_INTERVAL] = { .name="TimeInterval", .fns=&interval_fns,
+                             .params=&time_units },
+  [CONFIG_TYPE_MSEC_INTERVAL] = { .name="TimeMsecInterval",
+                                  .fns=&interval_fns,
+                                  .params=&time_msec_units },
+  [CONFIG_TYPE_DOUBLE] = { .name="Float", .fns=&double_fns, },
+  [CONFIG_TYPE_BOOL] = { .name="Boolean", .fns=&enum_fns,
+                         .params=&enum_table_bool },
+  [CONFIG_TYPE_AUTOBOOL] = { .name="Boolean+Auto", .fns=&enum_fns,
+                             .params=&enum_table_autobool },
+  [CONFIG_TYPE_ISOTIME] = { .name="Time", .fns=&time_fns, },
+  [CONFIG_TYPE_CSV] = { .name="CommaList", .fns=&csv_fns, },
+  [CONFIG_TYPE_CSV_INTERVAL] = { .name="TimeInterval",
+                                 .fns=&legacy_csv_interval_fns, },
+  [CONFIG_TYPE_LINELIST] = { .name="LineList", .fns=&linelist_fns,
+                             .is_cumulative=true},
+  [CONFIG_TYPE_LINELIST_S] = { .name="Dependent", .fns=&linelist_s_fns,
+                               .is_cumulative=true,
+                               .is_contained=true, },
+  [CONFIG_TYPE_LINELIST_V] = { .name="Virtual", .fns=&linelist_v_fns,
+                               .is_cumulative=true,
+                               .is_unsettable=true },
+  [CONFIG_TYPE_OBSOLETE] = { .name="Obsolete", .fns=&ignore_fns,
+                             .is_unsettable=true,
+                             .is_contained=true, }
 };
 
 /**
diff --git a/src/lib/confmgt/typedvar.c b/src/lib/confmgt/typedvar.c
index c2b9b45725..3cba075390 100644
--- a/src/lib/confmgt/typedvar.c
+++ b/src/lib/confmgt/typedvar.c
@@ -210,6 +210,51 @@ typed_var_ok_ex(const void *value, const var_type_def_t *def)
   return true;
 }
 
+/**
+ * Mark <b>value</b> -- a variable that ordinarily would be extended by
+ * assignment -- as "fragile", so that it will get replaced by the next
+ * assignment instead.
+ **/
+void
+typed_var_mark_fragile_ex(void *value, const var_type_def_t *def)
+{
+  if (BUG(!def)) {
+    return; // LCOV_EXCL_LINE
+  }
+
+  if (def->fns->mark_fragile)
+    def->fns->mark_fragile(value, def->params);
+}
+
+/**
+ * Return true iff multiple assignments to a variable will extend its
+ * value, rather than replacing it.
+ **/
+bool
+var_type_is_cumulative(const var_type_def_t *def)
+{
+  return def->is_cumulative;
+}
+
+/**
+ * Return true iff this variable type is always contained in another variable,
+ * and as such doesn't need to be dumped or copied independently.
+ **/
+bool
+var_type_is_contained(const var_type_def_t *def)
+{
+  return def->is_contained;
+}
+
+/**
+ * Return true iff this type can not be assigned directly by the user.
+ **/
+bool
+var_type_is_settable(const var_type_def_t *def)
+{
+  return ! def->is_unsettable;
+}
+
 /* =====
  * The functions below take a config_type_t instead of a var_type_def_t.
  * I'd like to deprecate them eventually and use var_type_def_t everywhere,
diff --git a/src/lib/confmgt/typedvar.h b/src/lib/confmgt/typedvar.h
index 720ad54fc6..2e36f9d673 100644
--- a/src/lib/confmgt/typedvar.h
+++ b/src/lib/confmgt/typedvar.h
@@ -46,4 +46,10 @@ int typed_var_kvassign_ex(void *target, const struct config_line_t *line,
 struct config_line_t *typed_var_kvencode_ex(const char *key, const void *value,
                                             const var_type_def_t *def);
 
+void typed_var_mark_fragile_ex(void *value, const var_type_def_t *def);
+
+bool var_type_is_cumulative(const var_type_def_t *def);
+bool var_type_is_contained(const var_type_def_t *def);
+bool var_type_is_settable(const var_type_def_t *def);
+
 #endif /* !defined(TOR_LIB_CONFMGT_TYPEDVAR_H) */
diff --git a/src/lib/confmgt/var_type_def_st.h b/src/lib/confmgt/var_type_def_st.h
index d142ee1104..4157cb8ff6 100644
--- a/src/lib/confmgt/var_type_def_st.h
+++ b/src/lib/confmgt/var_type_def_st.h
@@ -122,6 +122,15 @@ struct var_type_fns_t {
    * values are valid.
    **/
   bool (*ok)(const void *value, const void *params);
+  /**
+   * Mark a value of this variable as "fragile", so that future attempts to
+   * assign to this variable will replace rather than extending it.
+   *
+   * The default implementation for this function does nothing.
+   *
+   * Only meaningful for types with is_cumulative set.
+   **/
+  void (*mark_fragile)(void *value, const void *params);
 };
 
 /**
@@ -142,6 +151,17 @@ struct var_type_def_t {
    * calling the functions in this type's function table.
    */
   const void *params;
+
+  /** True iff a variable of this type can never be set directly by name. */
+  bool is_unsettable;
+  /** True iff a variable of this type is always contained in another
+   * variable, and as such doesn't need to be dumped or copied
+   * independently. */
+  bool is_contained;
+  /** True iff a variable of this type can be set more than once without
+   * destroying older values. Such variables should implement "mark_fragile".
+   */
+  bool is_cumulative;
 };
 
 #endif /* !defined(TOR_LIB_CONFMGT_VAR_TYPE_DEF_ST_H) */