confparse.h

/* Copyright (c) 2001 Matej Pfajfar.
 * Copyright (c) 2001-2004, Roger Dingledine.
 * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
 * Copyright (c) 2007-2017, The Tor Project, Inc. */
/* See LICENSE for licensing information */

#ifndef TOR_CONFPARSE_H
#define TOR_CONFPARSE_H

typedef enum config_type_t {
  CONFIG_TYPE_STRING = 0,   
  CONFIG_TYPE_FILENAME,     
  CONFIG_TYPE_UINT,         
  CONFIG_TYPE_INT,          
  CONFIG_TYPE_PORT,         
  CONFIG_TYPE_INTERVAL,     
  CONFIG_TYPE_MSEC_INTERVAL,
  CONFIG_TYPE_MEMUNIT,      
  CONFIG_TYPE_DOUBLE,       
  CONFIG_TYPE_BOOL,         
  CONFIG_TYPE_AUTOBOOL,     
  CONFIG_TYPE_ISOTIME,      
  CONFIG_TYPE_CSV,          
  CONFIG_TYPE_CSV_INTERVAL, 
  CONFIG_TYPE_LINELIST,     
  CONFIG_TYPE_LINELIST_S,   
  CONFIG_TYPE_LINELIST_V,   
  CONFIG_TYPE_ROUTERSET,    
  CONFIG_TYPE_OBSOLETE,     
} config_type_t;

#ifdef TOR_UNIT_TESTS

typedef union {
  char **STRING;
  char **FILENAME;
  int *UINT; /* yes, really: Even though the confparse type is called
              * "UINT", it still uses the C int type -- it just enforces that
              * the values are in range [0,INT_MAX].
              */
  int *INT;
  int *PORT;
  int *INTERVAL;
  int *MSEC_INTERVAL;
  uint64_t *MEMUNIT;
  double *DOUBLE;
  int *BOOL;
  int *AUTOBOOL;
  time_t *ISOTIME;
  smartlist_t **CSV;
  int *CSV_INTERVAL;
  config_line_t **LINELIST;
  config_line_t **LINELIST_S;
  config_line_t **LINELIST_V;
  routerset_t **ROUTERSET;
} confparse_dummy_values_t;
#endif /* defined(TOR_UNIT_TESTS) */

typedef struct config_abbrev_t {
  const char *abbreviated;
  const char *full;
  int commandline_only;
  int warn;
} config_abbrev_t;

typedef struct config_deprecation_t {
  const char *name;
  const char *why_deprecated;
} config_deprecation_t;

/* Handy macro for declaring "In the config file or on the command line,
 * you can abbreviate <b>tok</b>s as <b>tok</b>". */
#define PLURAL(tok) { #tok, #tok "s", 0, 0 }

typedef struct config_var_t {
  const char *name; 
  config_type_t type; 
  off_t var_offset; 
  const char *initvalue; 
#ifdef TOR_UNIT_TESTS

  confparse_dummy_values_t var_ptr_dummy;
#endif
} config_var_t;

/* 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) \
  , CONF_CHECK_VAR_TYPE(tp, conftype, member)
#define END_OF_CONFIG_VARS                                      \
  { NULL, CONFIG_TYPE_OBSOLETE, 0, NULL, { .INT=NULL } }
#define DUMMY_TYPECHECK_INSTANCE(tp)            \
  static tp tp ## _dummy
#else /* !(defined(TOR_UNIT_TESTS)) */
#define CONF_TEST_MEMBERS(tp, conftype, member)
#define END_OF_CONFIG_VARS { NULL, CONFIG_TYPE_OBSOLETE, 0, NULL }
/* Repeatedly declarable incomplete struct to absorb redundant semicolons */
#define DUMMY_TYPECHECK_INSTANCE(tp)            \
  struct tor_semicolon_eater
#endif /* defined(TOR_UNIT_TESTS) */

typedef int (*validate_fn_t)(void*,void*,void*,int,char**);

typedef struct config_format_t {
  size_t size; 
  uint32_t magic; 
  off_t magic_offset; 
  config_abbrev_t *abbrevs; 
  const config_deprecation_t *deprecations; 
  config_var_t *vars; 
  validate_fn_t validate_fn; 
  config_var_t *extra;
} config_format_t;

#define CONFIG_CHECK(fmt, cfg) STMT_BEGIN                               \
    tor_assert(fmt && cfg);                                             \
    tor_assert((fmt)->magic ==                                          \
               *(uint32_t*)STRUCT_VAR_P(cfg,fmt->magic_offset));        \
  STMT_END

#define CAL_USE_DEFAULTS      (1u<<0)
#define CAL_CLEAR_FIRST       (1u<<1)
#define CAL_WARN_DEPRECATIONS (1u<<2)

void *config_new(const config_format_t *fmt);
void config_free_(const config_format_t *fmt, void *options);
#define config_free(fmt, options) do {                \
    config_free_((fmt), (options));                   \
    (options) = NULL;                                 \
  } while (0)

config_line_t *config_get_assigned_option(const config_format_t *fmt,
                                          const void *options, const char *key,
                                          int escape_val);
int config_is_same(const config_format_t *fmt,
                   const void *o1, const void *o2,
                   const char *name);
void config_init(const config_format_t *fmt, void *options);
void *config_dup(const config_format_t *fmt, const void *old);
char *config_dump(const config_format_t *fmt, const void *default_options,
                  const void *options, int minimal,
                  int comment_defaults);
int config_assign(const config_format_t *fmt, void *options,
                  config_line_t *list,
                  unsigned flags, char **msg);
config_var_t *config_find_option_mutable(config_format_t *fmt,
                                         const char *key);
const char *config_find_deprecation(const config_format_t *fmt,
                                     const char *key);
const config_var_t *config_find_option(const config_format_t *fmt,
                                       const char *key);
const char *config_expand_abbrev(const config_format_t *fmt,
                                 const char *option,
                                 int command_line, int warn_obsolete);
void warn_deprecated_option(const char *what, const char *why);

/* Helper macros to compare an option across two configuration objects */
#define CFG_EQ_BOOL(a,b,opt) ((a)->opt == (b)->opt)
#define CFG_EQ_INT(a,b,opt) ((a)->opt == (b)->opt)
#define CFG_EQ_STRING(a,b,opt) (!strcmp_opt((a)->opt, (b)->opt))
#define CFG_EQ_SMARTLIST(a,b,opt) smartlist_strings_eq((a)->opt, (b)->opt)
#define CFG_EQ_LINELIST(a,b,opt) config_lines_eq((a)->opt, (b)->opt)
#define CFG_EQ_ROUTERSET(a,b,opt) routerset_equal((a)->opt, (b)->opt)

#endif /* !defined(TOR_CONFPARSE_H) */