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Diffstat (limited to 'src/lib/confmgt/confmgt.c')
| -rw-r--r-- | src/lib/confmgt/confmgt.c | 1406 |
1 files changed, 1406 insertions, 0 deletions
diff --git a/src/lib/confmgt/confmgt.c b/src/lib/confmgt/confmgt.c new file mode 100644 index 0000000000..bf2764160e --- /dev/null +++ b/src/lib/confmgt/confmgt.c @@ -0,0 +1,1406 @@ +/* Copyright (c) 2001 Matej Pfajfar. + * Copyright (c) 2001-2004, Roger Dingledine. + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2020, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file confmgt.c + * + * \brief Back-end for parsing and generating key-value files, used to + * implement the torrc file format and the state file. + * + * This module is used by config.c to parse and encode torrc + * configuration files, and by statefile.c to parse and encode the + * $DATADIR/state file. + * + * To use this module, its callers provide an instance of + * config_format_t to describe the mappings from a set of configuration + * options to a number of fields in a C structure. With this mapping, + * the functions here can convert back and forth between the C structure + * specified, and a linked list of key-value pairs. + */ + +#define CONFMGT_PRIVATE +#include "orconfig.h" +#include "lib/confmgt/confmgt.h" + +#include "lib/confmgt/structvar.h" +#include "lib/confmgt/unitparse.h" +#include "lib/container/bitarray.h" +#include "lib/container/smartlist.h" +#include "lib/encoding/confline.h" +#include "lib/log/escape.h" +#include "lib/log/log.h" +#include "lib/log/util_bug.h" +#include "lib/string/compat_ctype.h" +#include "lib/string/printf.h" +#include "lib/string/util_string.h" + +#include "ext/siphash.h" + +/** + * A managed_var_t is an internal wrapper around a config_var_t in + * a config_format_t structure. It is used by config_mgr_t to + * keep track of which option goes with which structure. */ +typedef struct managed_var_t { + /** + * A pointer to the config_var_t for this option. + */ + const config_var_t *cvar; + /** + * The index of the object in which this option is stored. It is + * IDX_TOPLEVEL to indicate that the object is the top-level object. + **/ + int object_idx; +} managed_var_t; + +static void config_reset(const config_mgr_t *fmt, void *options, + const managed_var_t *var, int use_defaults); +static void config_mgr_register_fmt(config_mgr_t *mgr, + const config_format_t *fmt, + int object_idx); + +/** Release all storage held in a managed_var_t. */ +static void +managed_var_free_(managed_var_t *mv) +{ + if (!mv) + return; + tor_free(mv); +} +#define managed_var_free(mv) \ + FREE_AND_NULL(managed_var_t, managed_var_free_, (mv)) + +struct config_suite_t { + /** A list of configuration objects managed by a given configuration + * manager. They are stored in the same order as the config_format_t + * objects in the manager's list of subformats. */ + smartlist_t *configs; +}; + +/** + * Allocate a new empty config_suite_t. + **/ +static config_suite_t * +config_suite_new(void) +{ + config_suite_t *suite = tor_malloc_zero(sizeof(config_suite_t)); + suite->configs = smartlist_new(); + return suite; +} + +/** Release all storage held by a config_suite_t. (Does not free + * any configuration objects it holds; the caller must do that first.) */ +static void +config_suite_free_(config_suite_t *suite) +{ + if (!suite) + return; + smartlist_free(suite->configs); + tor_free(suite); +} + +#define config_suite_free(suite) \ + FREE_AND_NULL(config_suite_t, config_suite_free_, (suite)) + +struct config_mgr_t { + /** The 'top-level' configuration format. This one is used for legacy + * options that have not yet been assigned to different sub-modules. + * + * (NOTE: for now, this is the only config_format_t that a config_mgr_t + * contains. A subsequent commit will add more. XXXX) + */ + const config_format_t *toplevel; + /** + * List of second-level configuration format objects that this manager + * also knows about. + */ + smartlist_t *subconfigs; + /** A smartlist of managed_var_t objects for all configuration formats. */ + smartlist_t *all_vars; + /** A smartlist of config_abbrev_t objects for all configuration + * formats. These objects are used to track synonyms and abbreviations for + * different configuration options. */ + smartlist_t *all_abbrevs; + /** A smartlist of config_deprecation_t for all configuration formats. */ + smartlist_t *all_deprecations; + /** True if this manager has been frozen and cannot have any more formats + * added to it. A manager must be frozen before it can be used to construct + * or manipulate objects. */ + bool frozen; + /** A replacement for the magic number of the toplevel object. We override + * that number to make it unique for this particular config_mgr_t, so that + * an object constructed with one mgr can't be used with another, even if + * those managers' contents are equal. + */ + struct_magic_decl_t toplevel_magic; +}; + +#define IDX_TOPLEVEL (-1) + +/** Create a new config_mgr_t to manage a set of configuration objects to be + * wrapped under <b>toplevel_fmt</b>. */ +config_mgr_t * +config_mgr_new(const config_format_t *toplevel_fmt) +{ + config_mgr_t *mgr = tor_malloc_zero(sizeof(config_mgr_t)); + mgr->subconfigs = smartlist_new(); + mgr->all_vars = smartlist_new(); + mgr->all_abbrevs = smartlist_new(); + mgr->all_deprecations = smartlist_new(); + + config_mgr_register_fmt(mgr, toplevel_fmt, IDX_TOPLEVEL); + mgr->toplevel = toplevel_fmt; + + return mgr; +} + +/** Add a config_format_t to a manager, with a specified (unique) index. */ +static void +config_mgr_register_fmt(config_mgr_t *mgr, + const config_format_t *fmt, + int object_idx) +{ + int i; + + tor_assertf(!mgr->frozen, + "Tried to add a format to a configuration manager after " + "it had been frozen."); + + if (object_idx != IDX_TOPLEVEL) { + tor_assertf(! fmt->has_config_suite, + "Tried to register a toplevel format in a non-toplevel position"); + } + if (fmt->config_suite_offset) { + tor_assertf(fmt->has_config_suite, + "config_suite_offset was set, but has_config_suite was not."); + } + + tor_assertf(fmt != mgr->toplevel && + ! smartlist_contains(mgr->subconfigs, fmt), + "Tried to register an already-registered format."); + + /* register variables */ + for (i = 0; fmt->vars[i].member.name; ++i) { + managed_var_t *mv = tor_malloc_zero(sizeof(managed_var_t)); + mv->cvar = &fmt->vars[i]; + mv->object_idx = object_idx; + smartlist_add(mgr->all_vars, mv); + } + + /* register abbrevs */ + if (fmt->abbrevs) { + for (i = 0; fmt->abbrevs[i].abbreviated; ++i) { + smartlist_add(mgr->all_abbrevs, (void*)&fmt->abbrevs[i]); + } + } + + /* register deprecations. */ + if (fmt->deprecations) { + const config_deprecation_t *d; + for (d = fmt->deprecations; d->name; ++d) { + smartlist_add(mgr->all_deprecations, (void*)d); + } + } +} + +/** + * Add a new format to this configuration object. Asserts on failure. + * + * Returns an internal "index" value used to identify this format within + * all of those formats contained in <b>mgr</b>. This index value + * should not generally be used outside of this module. + **/ +int +config_mgr_add_format(config_mgr_t *mgr, + const config_format_t *fmt) +{ + tor_assert(mgr); + int idx = smartlist_len(mgr->subconfigs); + config_mgr_register_fmt(mgr, fmt, idx); + smartlist_add(mgr->subconfigs, (void *)fmt); + return idx; +} + +/** Return a pointer to the config_suite_t * pointer inside a + * configuration object; returns NULL if there is no such member. */ +static inline config_suite_t ** +config_mgr_get_suite_ptr(const config_mgr_t *mgr, void *toplevel) +{ + if (! mgr->toplevel->has_config_suite) + return NULL; + return STRUCT_VAR_P(toplevel, mgr->toplevel->config_suite_offset); +} + +/** + * Return a pointer to the configuration object within <b>toplevel</b> whose + * index is <b>idx</b>. + * + * NOTE: XXXX Eventually, there will be multiple objects supported within the + * toplevel object. For example, the or_options_t will contain pointers + * to configuration objects for other modules. This function gets + * the sub-object for a particular module. + */ +void * +config_mgr_get_obj_mutable(const config_mgr_t *mgr, void *toplevel, int idx) +{ + tor_assert(mgr); + tor_assert(toplevel); + if (idx == IDX_TOPLEVEL) + return toplevel; + + tor_assertf(idx >= 0 && idx < smartlist_len(mgr->subconfigs), + "Index %d is out of range.", idx); + config_suite_t **suite = config_mgr_get_suite_ptr(mgr, toplevel); + tor_assert(suite); + tor_assert(smartlist_len(mgr->subconfigs) == + smartlist_len((*suite)->configs)); + + return smartlist_get((*suite)->configs, idx); +} + +/** As config_mgr_get_obj_mutable(), but return a const pointer. */ +const void * +config_mgr_get_obj(const config_mgr_t *mgr, const void *toplevel, int idx) +{ + return config_mgr_get_obj_mutable(mgr, (void*)toplevel, idx); +} + +/** Sorting helper for smartlist of managed_var_t */ +static int +managed_var_cmp(const void **a, const void **b) +{ + const managed_var_t *mv1 = *(const managed_var_t**)a; + const managed_var_t *mv2 = *(const managed_var_t**)b; + + return strcasecmp(mv1->cvar->member.name, mv2->cvar->member.name); +} + +/** + * Mark a configuration manager as "frozen", so that no more formats can be + * added, and so that it can be used for manipulating configuration objects. + **/ +void +config_mgr_freeze(config_mgr_t *mgr) +{ + static uint64_t mgr_count = 0; + + smartlist_sort(mgr->all_vars, managed_var_cmp); + memcpy(&mgr->toplevel_magic, &mgr->toplevel->magic, + sizeof(struct_magic_decl_t)); + uint64_t magic_input[3] = { mgr->toplevel_magic.magic_val, + (uint64_t) (uintptr_t) mgr, + ++mgr_count }; + mgr->toplevel_magic.magic_val = + (uint32_t)siphash24g(magic_input, sizeof(magic_input)); + mgr->frozen = true; +} + +/** Release all storage held in <b>mgr</b> */ +void +config_mgr_free_(config_mgr_t *mgr) +{ + if (!mgr) + return; + SMARTLIST_FOREACH(mgr->all_vars, managed_var_t *, mv, managed_var_free(mv)); + smartlist_free(mgr->all_vars); + smartlist_free(mgr->all_abbrevs); + smartlist_free(mgr->all_deprecations); + smartlist_free(mgr->subconfigs); + memset(mgr, 0, sizeof(*mgr)); + tor_free(mgr); +} + +/** Return a new smartlist_t containing a config_var_t for every variable that + * <b>mgr</b> knows about. The elements of this smartlist do not need + * to be freed; they have the same lifespan as <b>mgr</b>. */ +smartlist_t * +config_mgr_list_vars(const config_mgr_t *mgr) +{ + smartlist_t *result = smartlist_new(); + tor_assert(mgr); + SMARTLIST_FOREACH(mgr->all_vars, managed_var_t *, mv, + smartlist_add(result, (void*) mv->cvar)); + return result; +} + +/** Return a new smartlist_t containing the names of all deprecated variables. + * The elements of this smartlist do not need to be freed; they have the same + * lifespan as <b>mgr</b>. + */ +smartlist_t * +config_mgr_list_deprecated_vars(const config_mgr_t *mgr) +{ + smartlist_t *result = smartlist_new(); + tor_assert(mgr); + SMARTLIST_FOREACH(mgr->all_deprecations, config_deprecation_t *, d, + smartlist_add(result, (char*)d->name)); + return result; +} + +/** + * Check the magic number on <b>object</b> to make sure it's a valid toplevel + * object, created with <b>mgr</b>. Exit with an assertion if it isn't. + **/ +void +config_check_toplevel_magic(const config_mgr_t *mgr, + const void *object) +{ + struct_check_magic(object, &mgr->toplevel_magic); +} + +/** Assert that the magic fields in <b>options</b> and its subsidiary + * objects are all okay. */ +static void +config_mgr_assert_magic_ok(const config_mgr_t *mgr, + const void *options) +{ + tor_assert(mgr); + tor_assert(options); + tor_assert(mgr->frozen); + struct_check_magic(options, &mgr->toplevel_magic); + + config_suite_t **suitep = config_mgr_get_suite_ptr(mgr, (void*)options); + if (suitep == NULL) { + tor_assert(smartlist_len(mgr->subconfigs) == 0); + return; + } + + tor_assert(smartlist_len((*suitep)->configs) == + smartlist_len(mgr->subconfigs)); + SMARTLIST_FOREACH_BEGIN(mgr->subconfigs, const config_format_t *, fmt) { + void *obj = smartlist_get((*suitep)->configs, fmt_sl_idx); + tor_assert(obj); + struct_check_magic(obj, &fmt->magic); + } SMARTLIST_FOREACH_END(fmt); +} + +/** Macro: assert that <b>cfg</b> has the right magic field for + * <b>mgr</b>. */ +#define CONFIG_CHECK(mgr, cfg) STMT_BEGIN \ + config_mgr_assert_magic_ok((mgr), (cfg)); \ + STMT_END + +/** Allocate an empty configuration object of a given format type. */ +void * +config_new(const config_mgr_t *mgr) +{ + tor_assert(mgr->frozen); + void *opts = tor_malloc_zero(mgr->toplevel->size); + struct_set_magic(opts, &mgr->toplevel_magic); + config_suite_t **suitep = config_mgr_get_suite_ptr(mgr, opts); + if (suitep) { + *suitep = config_suite_new(); + SMARTLIST_FOREACH_BEGIN(mgr->subconfigs, const config_format_t *, fmt) { + void *obj = tor_malloc_zero(fmt->size); + struct_set_magic(obj, &fmt->magic); + smartlist_add((*suitep)->configs, obj); + } SMARTLIST_FOREACH_END(fmt); + } + CONFIG_CHECK(mgr, opts); + return opts; +} + +/* + * Functions to parse config options + */ + +/** If <b>option</b> is an official abbreviation for a longer option, + * return the longer option. Otherwise return <b>option</b>. + * If <b>command_line</b> is set, apply all abbreviations. Otherwise, only + * apply abbreviations that work for the config file and the command line. + * If <b>warn_obsolete</b> is set, warn about deprecated names. */ +const char * +config_expand_abbrev(const config_mgr_t *mgr, const char *option, + int command_line, int warn_obsolete) +{ + SMARTLIST_FOREACH_BEGIN(mgr->all_abbrevs, const config_abbrev_t *, abbrev) { + /* Abbreviations are case insensitive. */ + if (!strcasecmp(option, abbrev->abbreviated) && + (command_line || !abbrev->commandline_only)) { + if (warn_obsolete && abbrev->warn) { + log_warn(LD_CONFIG, + "The configuration option '%s' is deprecated; " + "use '%s' instead.", + abbrev->abbreviated, + abbrev->full); + } + /* Keep going through the list in case we want to rewrite it more. + * (We could imagine recursing here, but I don't want to get the + * user into an infinite loop if we craft our list wrong.) */ + option = abbrev->full; + } + } SMARTLIST_FOREACH_END(abbrev); + return option; +} + +/** If <b>key</b> is a deprecated configuration option, return the message + * explaining why it is deprecated (which may be an empty string). Return NULL + * if it is not deprecated. The <b>key</b> field must be fully expanded. */ +const char * +config_find_deprecation(const config_mgr_t *mgr, const char *key) +{ + if (BUG(mgr == NULL) || BUG(key == NULL)) + return NULL; // LCOV_EXCL_LINE + + SMARTLIST_FOREACH_BEGIN(mgr->all_deprecations, const config_deprecation_t *, + d) { + if (!strcasecmp(d->name, key)) { + return d->why_deprecated ? d->why_deprecated : ""; + } + } SMARTLIST_FOREACH_END(d); + return NULL; +} + +/** + * Find the managed_var_t object for a variable whose name is <b>name</b> + * according to <b>mgr</b>. Return that object, or NULL if none exists. + * + * If <b>allow_truncated</b> is true, then accept any variable whose + * name begins with <b>name</b>. + * + * If <b>idx_out</b> is not NULL, set *<b>idx_out</b> to the position of + * that variable within mgr->all_vars, or to -1 if the variable is + * not found. + */ +static const managed_var_t * +config_mgr_find_var(const config_mgr_t *mgr, + const char *key, + bool allow_truncated, int *idx_out) +{ + const size_t keylen = strlen(key); + if (idx_out) + *idx_out = -1; + + if (!keylen) + return NULL; /* if they say "--" on the command line, it's not an option */ + + /* First, check for an exact (case-insensitive) match */ + SMARTLIST_FOREACH_BEGIN(mgr->all_vars, const managed_var_t *, mv) { + if (!strcasecmp(mv->cvar->member.name, key)) { + if (idx_out) + *idx_out = mv_sl_idx; + return mv; + } + } SMARTLIST_FOREACH_END(mv); + + if (!allow_truncated) + return NULL; + + /* If none, check for an abbreviated match */ + SMARTLIST_FOREACH_BEGIN(mgr->all_vars, const managed_var_t *, mv) { + if (!strncasecmp(key, mv->cvar->member.name, keylen)) { + log_warn(LD_CONFIG, "The abbreviation '%s' is deprecated. " + "Please use '%s' instead", + key, mv->cvar->member.name); + if (idx_out) + *idx_out = mv_sl_idx; + return mv; + } + } SMARTLIST_FOREACH_END(mv); + + /* Okay, unrecognized option */ + return NULL; +} + +/** + * If <b>key</b> is a name or an abbreviation configuration option, return + * the corresponding canonical name for it. Warn if the abbreviation is + * non-standard. Return NULL if the option does not exist. + */ +const char * +config_find_option_name(const config_mgr_t *mgr, const char *key) +{ + key = config_expand_abbrev(mgr, key, 0, 0); + const managed_var_t *mv = config_mgr_find_var(mgr, key, true, NULL); + if (mv) + return mv->cvar->member.name; + else + return NULL; +} + +/** Return the number of option entries in <b>fmt</b>. */ +static int +config_count_options(const config_mgr_t *mgr) +{ + return smartlist_len(mgr->all_vars); +} + +/** + * Return true iff at least one bit from <b>flag</b> is set on <b>var</b>, + * either in <b>var</b>'s flags, or on the flags of its type. + **/ +static bool +config_var_has_flag(const config_var_t *var, uint32_t flag) +{ + uint32_t have_flags = var->flags | struct_var_get_flags(&var->member); + + return (have_flags & flag) != 0; +} + +/** + * Return true if assigning a value to <b>var</b> replaces the previous + * value. Return false if assigning a value to <b>var</b> appends + * to the previous value. + **/ +static bool +config_var_is_replaced_on_set(const config_var_t *var) +{ + return ! config_var_has_flag(var, CFLG_NOREPLACE); +} + +/** + * Return true iff <b>var</b> may be assigned by name (e.g., via the + * CLI, the configuration files, or the controller API). + **/ +bool +config_var_is_settable(const config_var_t *var) +{ + return ! config_var_has_flag(var, CFLG_NOSET); +} + +/** + * Return true iff the controller is allowed to fetch the value of + * <b>var</b>. + **/ +static bool +config_var_is_gettable(const config_var_t *var) +{ + /* Arguably, invisible or obsolete options should not be gettable. However, + * they have been gettable for a long time, and making them ungettable could + * have compatibility effects. For now, let's leave them alone. + */ + + // return ! config_var_has_flag(var, CVFLAG_OBSOLETE|CFGLAGS_INVISIBLE); + (void)var; + return true; +} + +/** + * Return true iff we need to check <b>var</b> for changes when we are + * comparing config options for changes. + * + * A false result might mean that the variable is a derived variable, and that + * comparing the variable it derives from compares this one too-- or it might + * mean that there is no data to compare. + **/ +static bool +config_var_should_list_changes(const config_var_t *var) +{ + return ! config_var_has_flag(var, CFLG_NOCMP); +} + +/** + * Return true iff we need to copy the data for <b>var</b> when we are + * copying a config option. + * + * A false option might mean that the variable is a derived variable, and that + * copying the variable it derives from copies it-- or it might mean that + * there is no data to copy. + **/ +static bool +config_var_needs_copy(const config_var_t *var) +{ + return ! config_var_has_flag(var, CFLG_NOCOPY); +} + +/** + * Return true iff variable <b>var</b> should appear on list of variable + * names given to the controller or the CLI. + * + * (Note that this option is imperfectly obeyed. The + * --list-torrc-options command looks at the "settable" flag, whereas + * "GETINFO config/defaults" and "list_deprecated_*()" do not filter + * their results. It would be good for consistency to try to converge + * these behaviors in the future.) + **/ +bool +config_var_is_listable(const config_var_t *var) +{ + return ! config_var_has_flag(var, CFLG_NOLIST); +} + +/** + * Return true iff variable <b>var</b> should be written out when we + * are writing our configuration to disk, to a controller, or via the + * --dump-config command. + * + * This option may be set because a variable is hidden, or because it is + * derived from another variable which will already be written out. + **/ +static bool +config_var_is_dumpable(const config_var_t *var) +{ + return ! config_var_has_flag(var, CFLG_NODUMP); +} + +/* + * Functions to assign config options. + */ + +/** <b>c</b>-\>key is known to be a real key. Update <b>options</b> + * with <b>c</b>-\>value and return 0, or return -1 if bad value. + * + * Called from config_assign_line() and option_reset(). + */ +static int +config_assign_value(const config_mgr_t *mgr, void *options, + config_line_t *c, char **msg) +{ + const managed_var_t *var; + + CONFIG_CHECK(mgr, options); + + var = config_mgr_find_var(mgr, c->key, true, NULL); + tor_assert(var); + tor_assert(!strcmp(c->key, var->cvar->member.name)); + void *object = config_mgr_get_obj_mutable(mgr, options, var->object_idx); + + if (config_var_has_flag(var->cvar, CFLG_WARN_OBSOLETE)) { + log_warn(LD_GENERAL, "Skipping obsolete configuration option \"%s\".", + var->cvar->member.name); + } else if (config_var_has_flag(var->cvar, CFLG_WARN_DISABLED)) { + log_warn(LD_GENERAL, "This copy of Tor was built without support for " + "the option \"%s\". Skipping.", var->cvar->member.name); + } + + return struct_var_kvassign(object, c, msg, &var->cvar->member); +} + +/** Mark every linelist in <b>options</b> "fragile", so that fresh assignments + * to it will replace old ones. */ +static void +config_mark_lists_fragile(const config_mgr_t *mgr, void *options) +{ + tor_assert(mgr); + tor_assert(options); + + SMARTLIST_FOREACH_BEGIN(mgr->all_vars, const managed_var_t *, mv) { + void *object = config_mgr_get_obj_mutable(mgr, options, mv->object_idx); + struct_var_mark_fragile(object, &mv->cvar->member); + } SMARTLIST_FOREACH_END(mv); +} + +/** + * Log a warning that declaring that the option called <b>what</b> + * is deprecated because of the reason in <b>why</b>. + * + * (Both arguments must be non-NULL.) + **/ +void +warn_deprecated_option(const char *what, const char *why) +{ + const char *space = (why && strlen(why)) ? " " : ""; + log_warn(LD_CONFIG, "The %s option is deprecated, and will most likely " + "be removed in a future version of Tor.%s%s (If you think this is " + "a mistake, please let us know!)", + what, space, why); +} + +/** If <b>c</b> is a syntactically valid configuration line, update + * <b>options</b> with its value and return 0. Otherwise return -1 for bad + * key, -2 for bad value. + * + * If <b>clear_first</b> is set, clear the value first. Then if + * <b>use_defaults</b> is set, set the value to the default. + * + * Called from config_assign(). + */ +static int +config_assign_line(const config_mgr_t *mgr, void *options, + config_line_t *c, unsigned flags, + bitarray_t *options_seen, char **msg) +{ + const unsigned use_defaults = flags & CAL_USE_DEFAULTS; + const unsigned clear_first = flags & CAL_CLEAR_FIRST; + const unsigned warn_deprecations = flags & CAL_WARN_DEPRECATIONS; + const managed_var_t *mvar; + + CONFIG_CHECK(mgr, options); + + int var_index = -1; + mvar = config_mgr_find_var(mgr, c->key, true, &var_index); + if (!mvar) { + const config_format_t *fmt = mgr->toplevel; + if (fmt->extra) { + void *lvalue = STRUCT_VAR_P(options, fmt->extra->offset); + log_info(LD_CONFIG, + "Found unrecognized option '%s'; saving it.", c->key); + config_line_append((config_line_t**)lvalue, c->key, c->value); + return 0; + } else { + tor_asprintf(msg, + "Unknown option '%s'. Failing.", c->key); + return -1; + } + } + + const config_var_t *cvar = mvar->cvar; + tor_assert(cvar); + + /* Put keyword into canonical case. */ + if (strcmp(cvar->member.name, c->key)) { + tor_free(c->key); + c->key = tor_strdup(cvar->member.name); + } + + const char *deprecation_msg; + if (warn_deprecations && + (deprecation_msg = config_find_deprecation(mgr, cvar->member.name))) { + warn_deprecated_option(cvar->member.name, deprecation_msg); + } + + if (!strlen(c->value)) { + /* reset or clear it, then return */ + if (!clear_first) { + if (! config_var_is_replaced_on_set(cvar) && + c->command != CONFIG_LINE_CLEAR) { + /* We got an empty linelist from the torrc or command line. + As a special case, call this an error. Warn and ignore. */ + log_warn(LD_CONFIG, + "Linelist option '%s' has no value. Skipping.", c->key); + } else { /* not already cleared */ + config_reset(mgr, options, mvar, use_defaults); + } + } + return 0; + } else if (c->command == CONFIG_LINE_CLEAR && !clear_first) { + // This block is unreachable, since a CLEAR line always has an + // empty value, and so will trigger be handled by the previous + // "if (!strlen(c->value))" block. + + // LCOV_EXCL_START + tor_assert_nonfatal_unreached(); + config_reset(mgr, options, mvar, use_defaults); + // LCOV_EXCL_STOP + } + + if (options_seen && config_var_is_replaced_on_set(cvar)) { + /* We're tracking which options we've seen, and this option is not + * supposed to occur more than once. */ + tor_assert(var_index >= 0); + if (bitarray_is_set(options_seen, var_index)) { + log_warn(LD_CONFIG, "Option '%s' used more than once; all but the last " + "value will be ignored.", cvar->member.name); + } + bitarray_set(options_seen, var_index); + } + + if (config_assign_value(mgr, options, c, msg) < 0) + return -2; + return 0; +} + +/** Restore the option named <b>key</b> in options to its default value. + * Called from config_assign(). */ +STATIC void +config_reset_line(const config_mgr_t *mgr, void *options, + const char *key, int use_defaults) +{ + const managed_var_t *var; + + CONFIG_CHECK(mgr, options); + + var = config_mgr_find_var(mgr, key, true, NULL); + if (!var) + return; /* give error on next pass. */ + + config_reset(mgr, options, var, use_defaults); +} + +/** Return true iff value needs to be quoted and escaped to be used in + * a configuration file. */ +static int +config_value_needs_escape(const char *value) +{ + if (*value == '\"') + return 1; + while (*value) { + switch (*value) + { + case '\r': + case '\n': + case '#': + /* Note: quotes and backspaces need special handling when we are using + * quotes, not otherwise, so they don't trigger escaping on their + * own. */ + return 1; + default: + if (!TOR_ISPRINT(*value)) + return 1; + } + ++value; + } + return 0; +} + +/** Return newly allocated line or lines corresponding to <b>key</b> in the + * configuration <b>options</b>. If <b>escape_val</b> is true and a + * value needs to be quoted before it's put in a config file, quote and + * escape that value. Return NULL if no such key exists. */ +config_line_t * +config_get_assigned_option(const config_mgr_t *mgr, const void *options, + const char *key, int escape_val) +{ + const managed_var_t *var; + config_line_t *result; + + tor_assert(options && key); + + CONFIG_CHECK(mgr, options); + + var = config_mgr_find_var(mgr, key, true, NULL); + if (!var) { + log_warn(LD_CONFIG, "Unknown option '%s'. Failing.", key); + return NULL; + } + if (! config_var_is_gettable(var->cvar)) { + log_warn(LD_CONFIG, "Option '%s' is obsolete or unfetchable. Failing.", + key); + return NULL; + } + const void *object = config_mgr_get_obj(mgr, options, var->object_idx); + + result = struct_var_kvencode(object, &var->cvar->member); + + if (escape_val) { + config_line_t *line; + for (line = result; line; line = line->next) { + if (line->value && config_value_needs_escape(line->value)) { + char *newval = esc_for_log(line->value); + tor_free(line->value); + line->value = newval; + } + } + } + + return result; +} +/** Iterate through the linked list of requested options <b>list</b>. + * For each item, convert as appropriate and assign to <b>options</b>. + * If an item is unrecognized, set *msg and return -1 immediately, + * else return 0 for success. + * + * If <b>clear_first</b>, interpret config options as replacing (not + * extending) their previous values. If <b>clear_first</b> is set, + * then <b>use_defaults</b> to decide if you set to defaults after + * clearing, or make the value 0 or NULL. + * + * Here are the use cases: + * 1. A non-empty AllowInvalid line in your torrc. Appends to current + * if linelist, replaces current if csv. + * 2. An empty AllowInvalid line in your torrc. Should clear it. + * 3. "RESETCONF AllowInvalid" sets it to default. + * 4. "SETCONF AllowInvalid" makes it NULL. + * 5. "SETCONF AllowInvalid=foo" clears it and sets it to "foo". + * + * Use_defaults Clear_first + * 0 0 "append" + * 1 0 undefined, don't use + * 0 1 "set to null first" + * 1 1 "set to defaults first" + * Return 0 on success, -1 on bad key, -2 on bad value. + * + * As an additional special case, if a LINELIST config option has + * no value and clear_first is 0, then warn and ignore it. + */ + +/* +There are three call cases for config_assign() currently. + +Case one: Torrc entry +options_init_from_torrc() calls config_assign(0, 0) + calls config_assign_line(0, 0). + if value is empty, calls config_reset(0) and returns. + calls config_assign_value(), appends. + +Case two: setconf +options_trial_assign() calls config_assign(0, 1) + calls config_reset_line(0) + calls config_reset(0) + calls option_clear(). + calls config_assign_line(0, 1). + if value is empty, returns. + calls config_assign_value(), appends. + +Case three: resetconf +options_trial_assign() calls config_assign(1, 1) + calls config_reset_line(1) + calls config_reset(1) + calls option_clear(). + calls config_assign_value(default) + calls config_assign_line(1, 1). + returns. +*/ +int +config_assign(const config_mgr_t *mgr, void *options, config_line_t *list, + unsigned config_assign_flags, char **msg) +{ + config_line_t *p; + bitarray_t *options_seen; + const int n_options = config_count_options(mgr); + const unsigned clear_first = config_assign_flags & CAL_CLEAR_FIRST; + const unsigned use_defaults = config_assign_flags & CAL_USE_DEFAULTS; + + CONFIG_CHECK(mgr, options); + + /* pass 1: normalize keys */ + for (p = list; p; p = p->next) { + const char *full = config_expand_abbrev(mgr, p->key, 0, 1); + if (strcmp(full,p->key)) { + tor_free(p->key); + p->key = tor_strdup(full); + } + } + + /* pass 2: if we're reading from a resetting source, clear all + * mentioned config options, and maybe set to their defaults. */ + if (clear_first) { + for (p = list; p; p = p->next) + config_reset_line(mgr, options, p->key, use_defaults); + } + + options_seen = bitarray_init_zero(n_options); + /* pass 3: assign. */ + while (list) { + int r; + if ((r=config_assign_line(mgr, options, list, config_assign_flags, + options_seen, msg))) { + bitarray_free(options_seen); + return r; + } + list = list->next; + } + bitarray_free(options_seen); + + /** Now we're done assigning a group of options to the configuration. + * Subsequent group assignments should _replace_ linelists, not extend + * them. */ + config_mark_lists_fragile(mgr, options); + + return 0; +} + +/** Reset config option <b>var</b> to 0, 0.0, NULL, or the equivalent. + * Called from config_reset() and config_free(). */ +static void +config_clear(const config_mgr_t *mgr, void *options, const managed_var_t *var) +{ + void *object = config_mgr_get_obj_mutable(mgr, options, var->object_idx); + struct_var_free(object, &var->cvar->member); +} + +/** Clear the option indexed by <b>var</b> in <b>options</b>. Then if + * <b>use_defaults</b>, set it to its default value. + * Called by config_init() and option_reset_line() and option_assign_line(). */ +static void +config_reset(const config_mgr_t *mgr, void *options, + const managed_var_t *var, int use_defaults) +{ + config_line_t *c; + char *msg = NULL; + CONFIG_CHECK(mgr, options); + config_clear(mgr, options, var); /* clear it first */ + + if (!use_defaults) + return; /* all done */ + + if (var->cvar->initvalue) { + c = tor_malloc_zero(sizeof(config_line_t)); + c->key = tor_strdup(var->cvar->member.name); + c->value = tor_strdup(var->cvar->initvalue); + if (config_assign_value(mgr, options, c, &msg) < 0) { + // LCOV_EXCL_START + log_warn(LD_BUG, "Failed to assign default: %s", msg); + tor_free(msg); /* if this happens it's a bug */ + // LCOV_EXCL_STOP + } + config_free_lines(c); + } +} + +/** Release storage held by <b>options</b>. */ +void +config_free_(const config_mgr_t *mgr, void *options) +{ + if (!options) + return; + + tor_assert(mgr); + + if (mgr->toplevel->clear_fn) { + mgr->toplevel->clear_fn(mgr, options); + } + config_suite_t **suitep = config_mgr_get_suite_ptr(mgr, options); + if (suitep) { + tor_assert(smartlist_len((*suitep)->configs) == + smartlist_len(mgr->subconfigs)); + SMARTLIST_FOREACH_BEGIN(mgr->subconfigs, const config_format_t *, fmt) { + void *obj = smartlist_get((*suitep)->configs, fmt_sl_idx); + if (fmt->clear_fn) { + fmt->clear_fn(mgr, obj); + } + } SMARTLIST_FOREACH_END(fmt); + } + + SMARTLIST_FOREACH_BEGIN(mgr->all_vars, const managed_var_t *, mv) { + config_clear(mgr, options, mv); + } SMARTLIST_FOREACH_END(mv); + + if (mgr->toplevel->extra) { + config_line_t **linep = STRUCT_VAR_P(options, + mgr->toplevel->extra->offset); + config_free_lines(*linep); + *linep = NULL; + } + + if (suitep) { + SMARTLIST_FOREACH((*suitep)->configs, void *, obj, tor_free(obj)); + config_suite_free(*suitep); + } + + tor_free(options); +} + +/** Return true iff the option <b>name</b> has the same value in <b>o1</b> + * and <b>o2</b>. Must not be called for LINELIST_S or OBSOLETE options. + */ +int +config_is_same(const config_mgr_t *mgr, + const void *o1, const void *o2, + const char *name) +{ + CONFIG_CHECK(mgr, o1); + CONFIG_CHECK(mgr, o2); + + const managed_var_t *var = config_mgr_find_var(mgr, name, true, NULL); + if (!var) { + return true; + } + const void *obj1 = config_mgr_get_obj(mgr, o1, var->object_idx); + const void *obj2 = config_mgr_get_obj(mgr, o2, var->object_idx); + + return struct_var_eq(obj1, obj2, &var->cvar->member); +} + +/** + * Return a list of the options which have changed between <b>options1</b> and + * <b>options2</b>. If an option has reverted to its default value, it has a + * value entry of NULL. + * + * <b>options1</b> and <b>options2</b> must be top-level configuration objects + * of the type managed by <b>mgr</b>. + **/ +config_line_t * +config_get_changes(const config_mgr_t *mgr, + const void *options1, const void *options2) +{ + config_line_t *result = NULL; + config_line_t **next = &result; + SMARTLIST_FOREACH_BEGIN(mgr->all_vars, managed_var_t *, mv) { + if (! config_var_should_list_changes(mv->cvar)) { + /* something else will check this var, or it doesn't need checking */ + continue; + } + const void *obj1 = config_mgr_get_obj(mgr, options1, mv->object_idx); + const void *obj2 = config_mgr_get_obj(mgr, options2, mv->object_idx); + + if (struct_var_eq(obj1, obj2, &mv->cvar->member)) { + continue; + } + + const char *varname = mv->cvar->member.name; + config_line_t *line = + config_get_assigned_option(mgr, options2, varname, 1); + + if (line) { + *next = line; + } else { + *next = tor_malloc_zero(sizeof(config_line_t)); + (*next)->key = tor_strdup(varname); + } + while (*next) + next = &(*next)->next; + } SMARTLIST_FOREACH_END(mv); + + return result; +} + +/** Copy storage held by <b>old</b> into a new or_options_t and return it. */ +void * +config_dup(const config_mgr_t *mgr, const void *old) +{ + void *newopts; + + newopts = config_new(mgr); + SMARTLIST_FOREACH_BEGIN(mgr->all_vars, managed_var_t *, mv) { + if (! config_var_needs_copy(mv->cvar)) { + // Something else will copy this option, or it doesn't need copying. + continue; + } + const void *oldobj = config_mgr_get_obj(mgr, old, mv->object_idx); + void *newobj = config_mgr_get_obj_mutable(mgr, newopts, mv->object_idx); + if (struct_var_copy(newobj, oldobj, &mv->cvar->member) < 0) { + // LCOV_EXCL_START + log_err(LD_BUG, "Unable to copy value for %s.", + mv->cvar->member.name); + tor_assert_unreached(); + // LCOV_EXCL_STOP + } + } SMARTLIST_FOREACH_END(mv); + + return newopts; +} +/** Set all vars in the configuration object <b>options</b> to their default + * values. */ +void +config_init(const config_mgr_t *mgr, void *options) +{ + CONFIG_CHECK(mgr, options); + + SMARTLIST_FOREACH_BEGIN(mgr->all_vars, const managed_var_t *, mv) { + if (!mv->cvar->initvalue) + continue; /* defaults to NULL or 0 */ + config_reset(mgr, options, mv, 1); + } SMARTLIST_FOREACH_END(mv); +} + +/** + * Helper for config_validate_single: see whether any immutable option + * has changed between old_options and new_options. + * + * On success return 0; on failure set *msg_out to a newly allocated + * string explaining what is wrong, and return -1. + */ +static int +config_check_immutable_flags(const config_format_t *fmt, + const void *old_options, + const void *new_options, + char **msg_out) +{ + tor_assert(fmt); + tor_assert(new_options); + if (BUG(! old_options)) + return 0; + + unsigned i; + for (i = 0; fmt->vars[i].member.name; ++i) { + const config_var_t *v = &fmt->vars[i]; + if (! config_var_has_flag(v, CFLG_IMMUTABLE)) + continue; + + if (! struct_var_eq(old_options, new_options, &v->member)) { + tor_asprintf(msg_out, + "While Tor is running, changing %s is not allowed", + v->member.name); + return -1; + } + } + + return 0; +} + +/** + * Normalize and validate a single object `options` within a configuration + * suite, according to its format. `options` may be modified as appropriate + * in order to set ancillary data. If `old_options` is provided, make sure + * that the transition from `old_options` to `options` is permitted. + * + * On success return VSTAT_OK; on failure set *msg_out to a newly allocated + * string explaining what is wrong, and return a different validation_status_t + * to describe which step failed. + **/ +static validation_status_t +config_validate_single(const config_format_t *fmt, + const void *old_options, void *options, + char **msg_out) +{ + tor_assert(fmt); + tor_assert(options); + + if (fmt->pre_normalize_fn) { + if (fmt->pre_normalize_fn(options, msg_out) < 0) { + return VSTAT_PRE_NORMALIZE_ERR; + } + } + + if (fmt->legacy_validate_fn) { + if (fmt->legacy_validate_fn(old_options, options, msg_out) < 0) { + return VSTAT_LEGACY_ERR; + } + } + + if (fmt->validate_fn) { + if (fmt->validate_fn(options, msg_out) < 0) { + return VSTAT_VALIDATE_ERR; + } + } + + if (old_options) { + if (config_check_immutable_flags(fmt, old_options, options, msg_out) < 0) { + return VSTAT_TRANSITION_ERR; + } + + if (fmt->check_transition_fn) { + if (fmt->check_transition_fn(old_options, options, msg_out) < 0) { + return VSTAT_TRANSITION_ERR; + } + } + } + + if (fmt->post_normalize_fn) { + if (fmt->post_normalize_fn(options, msg_out) < 0) { + return VSTAT_POST_NORMALIZE_ERR; + } + } + + return VSTAT_OK; +} + +/** + * Normalize and validate all the options in configuration object `options` + * and its sub-objects. `options` may be modified as appropriate in order to + * set ancillary data. If `old_options` is provided, make sure that the + * transition from `old_options` to `options` is permitted. + * + * On success return VSTAT_OK; on failure set *msg_out to a newly allocated + * string explaining what is wrong, and return a different validation_status_t + * to describe which step failed. + **/ +validation_status_t +config_validate(const config_mgr_t *mgr, + const void *old_options, void *options, + char **msg_out) +{ + validation_status_t rv; + CONFIG_CHECK(mgr, options); + if (old_options) { + CONFIG_CHECK(mgr, old_options); + } + + config_suite_t **suitep_new = config_mgr_get_suite_ptr(mgr, options); + config_suite_t **suitep_old = NULL; + if (old_options) + suitep_old = config_mgr_get_suite_ptr(mgr, (void*) old_options); + + /* Validate the sub-objects */ + if (suitep_new) { + SMARTLIST_FOREACH_BEGIN(mgr->subconfigs, const config_format_t *, fmt) { + void *obj = smartlist_get((*suitep_new)->configs, fmt_sl_idx); + const void *obj_old=NULL; + if (suitep_old) + obj_old = smartlist_get((*suitep_old)->configs, fmt_sl_idx); + + rv = config_validate_single(fmt, obj_old, obj, msg_out); + if (rv < 0) + return rv; + } SMARTLIST_FOREACH_END(fmt); + } + + /* Validate the top-level object. */ + rv = config_validate_single(mgr->toplevel, old_options, options, msg_out); + if (rv < 0) + return rv; + + return VSTAT_OK; +} + +/** Allocate and return a new string holding the written-out values of the vars + * in 'options'. If 'minimal', do not write out any default-valued vars. + * Else, if comment_defaults, write default values as comments. + */ +char * +config_dump(const config_mgr_t *mgr, const void *default_options, + const void *options, int minimal, + int comment_defaults) +{ + const config_format_t *fmt = mgr->toplevel; + smartlist_t *elements; + const void *defaults = default_options; + void *defaults_tmp = NULL; + config_line_t *line, *assigned; + char *result; + char *msg = NULL; + + if (defaults == NULL) { + defaults = defaults_tmp = config_new(mgr); + config_init(mgr, defaults_tmp); + } + + /* XXX use a 1 here so we don't add a new log line while dumping */ + if (default_options == NULL) { + if (config_validate(mgr, NULL, defaults_tmp, &msg) < 0) { + // LCOV_EXCL_START + log_err(LD_BUG, "Failed to validate default config: %s", msg); + tor_free(msg); + tor_assert(0); + // LCOV_EXCL_STOP + } + } + + elements = smartlist_new(); + SMARTLIST_FOREACH_BEGIN(mgr->all_vars, managed_var_t *, mv) { + int comment_option = 0; + /* Don't save 'hidden' control variables. */ + if (! config_var_is_dumpable(mv->cvar)) + continue; + const char *name = mv->cvar->member.name; + if (minimal && config_is_same(mgr, options, defaults, name)) + continue; + else if (comment_defaults && + config_is_same(mgr, options, defaults, name)) + comment_option = 1; + + line = assigned = + config_get_assigned_option(mgr, options, name, 1); + + for (; line; line = line->next) { + if (!strcmpstart(line->key, "__")) { + /* This check detects "hidden" variables inside LINELIST_V structures. + */ + continue; + } + int value_exists = line->value && *(line->value); + smartlist_add_asprintf(elements, "%s%s%s%s\n", + comment_option ? "# " : "", + line->key, value_exists ? " " : "", line->value); + } + config_free_lines(assigned); + } SMARTLIST_FOREACH_END(mv); + + if (fmt->extra) { + line = *(config_line_t**)STRUCT_VAR_P(options, fmt->extra->offset); + for (; line; line = line->next) { + int value_exists = line->value && *(line->value); + smartlist_add_asprintf(elements, "%s%s%s\n", + line->key, value_exists ? " " : "", line->value); + } + } + + result = smartlist_join_strings(elements, "", 0, NULL); + SMARTLIST_FOREACH(elements, char *, cp, tor_free(cp)); + smartlist_free(elements); + config_free(mgr, defaults_tmp); + return result; +} + +/** + * Return true if every member of <b>options</b> is in-range and well-formed. + * Return false otherwise. Log errors at level <b>severity</b>. + */ +bool +config_check_ok(const config_mgr_t *mgr, const void *options, int severity) +{ + bool all_ok = true; + + SMARTLIST_FOREACH_BEGIN(mgr->all_vars, const managed_var_t *, mv) { + if (!struct_var_ok(options, &mv->cvar->member)) { + log_fn(severity, LD_BUG, "Invalid value for %s", + mv->cvar->member.name); + all_ok = false; + } + } SMARTLIST_FOREACH_END(mv); + + return all_ok; +} |