[tor-commits] [tor/master] Start teaching config_mgr_t to handle sub-objects and sub-formats

commit 769fe817174d238c2c4a615872d6df9a0379dfc6 Author: Nick Mathewson nickm@torproject.org Date: Mon Jul 22 13:53:36 2019 -0400

Start teaching config_mgr_t to handle sub-objects and sub-formats

The eventual design here will be that multiple config_format_t objects get registered with a single config_mgr_t. That config_mgr_t manages a "top-level" object, which has a pointer to the other objects.

I had earlier thought of a different design, where there would be no top-level object, and config_mgr_t would deal with a container instead. But this would require a bunch of invasive refactoring that I don't think we should do just yet. --- src/app/config/confparse.c | 363 +++++++++++++++++++++++++++++++-------------- 1 file changed, 248 insertions(+), 115 deletions(-)

diff --git a/src/app/config/confparse.c b/src/app/config/confparse.c index 9c4c6a277..0964321ad 100644 --- a/src/app/config/confparse.c +++ b/src/app/config/confparse.c @@ -37,8 +37,38 @@ #include "lib/string/printf.h" #include "lib/string/util_string.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 config_var_t *var, int use_defaults); + 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_mgr_t { /** The 'top-level' configuration format. This one is used for legacy @@ -48,8 +78,17 @@ struct config_mgr_t { * contains. A subsequent commit will add more. XXXX) */ const config_format_t *toplevel; + /** A smartlist of managed_var_t objects for all configuration formats. */ + smartlist_t *all_vars; + /** A smartlist of config_abbrev_t objects for all abbreviations. These + * objects are */ + smartlist_t *all_abbrevs; + /** A smartlist of config_deprecation_t for all configuration formats. */ + smartlist_t *all_deprecations; };

+#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 * @@ -57,15 +96,81 @@ config_mgr_new(const config_format_t *toplevel_fmt) { config_mgr_t *mgr = tor_malloc_zero(sizeof(config_mgr_t)); mgr->toplevel = toplevel_fmt; + mgr->all_vars = smartlist_new(); + mgr->all_abbrevs = smartlist_new(); + mgr->all_deprecations = smartlist_new(); + + config_mgr_register_fmt(mgr, toplevel_fmt, IDX_TOPLEVEL); 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; + + /* 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); + } + } +} + +/** + * 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 modules. + */ +static void * +config_mgr_get_obj_mutable(const config_mgr_t *mgr, void *toplevel, int idx) +{ + (void)mgr; + tor_assert(idx == IDX_TOPLEVEL); // nothing else is implemented yet XXXX + tor_assert(toplevel); + return toplevel; +} + +/** As config_mgr_get_obj_mutable(), but return a const pointer. */ +static 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); +} + /** 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); memset(mgr, 0, sizeof(*mgr)); tor_free(mgr); } @@ -94,27 +199,23 @@ const char * config_expand_abbrev(const config_mgr_t *mgr, const char *option, int command_line, int warn_obsolete) { - const config_format_t *fmt = mgr->toplevel; - int i; - if (! fmt->abbrevs) - return option; - for (i=0; fmt->abbrevs[i].abbreviated; ++i) { + SMARTLIST_FOREACH_BEGIN(mgr->all_abbrevs, const config_abbrev_t *, abbrev) { /* Abbreviations are case insensitive. */ - if (!strcasecmp(option,fmt->abbrevs[i].abbreviated) && - (command_line || !fmt->abbrevs[i].commandline_only)) { - if (warn_obsolete && fmt->abbrevs[i].warn) { + 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.", - fmt->abbrevs[i].abbreviated, - fmt->abbrevs[i].full); + 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 = fmt->abbrevs[i].full; + option = abbrev->full; } - } + } SMARTLIST_FOREACH_END(abbrev); return option; }

@@ -124,62 +225,89 @@ config_expand_abbrev(const config_mgr_t *mgr, const char *option, const char * config_find_deprecation(const config_mgr_t *mgr, const char *key) { - const config_format_t *fmt = mgr->toplevel; - if (BUG(fmt == NULL) || BUG(key == NULL)) + if (BUG(mgr == NULL) || BUG(key == NULL)) return NULL; // LCOV_EXCL_LINE - if (fmt->deprecations == NULL) - return NULL;

- const config_deprecation_t *d; - for (d = fmt->deprecations; d->name; ++d) { + 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; }

-/** If <b>key</b> is a configuration option, return the corresponding const - * config_var_t. Otherwise, if <b>key</b> is a non-standard abbreviation, - * warn, and return the corresponding const config_var_t. Otherwise 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-&gt;all_vars, or to -1 if the variable is + * not found. */ -const config_var_t * -config_find_option(const config_mgr_t *mgr, const char *key) +static const managed_var_t * +config_mgr_find_var(const config_mgr_t *mgr, + const char *key, + bool allow_truncated, int *idx_out) { - const config_format_t *fmt = mgr->toplevel; - int i; - size_t keylen = strlen(key); + 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 */ - for (i=0; fmt->vars[i].member.name; ++i) { - if (!strcasecmp(key, fmt->vars[i].member.name)) { - return &fmt->vars[i]; + 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 */ - for (i=0; fmt->vars[i].member.name; ++i) { - if (!strncasecmp(key, fmt->vars[i].member.name, keylen)) { + 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, fmt->vars[i].member.name); - return &fmt->vars[i]; + 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 configuration option, return the corresponding const + * config_var_t. Otherwise, if <b>key</b> is a non-standard abbreviation, + * warn, and return the corresponding const config_var_t. Otherwise return + * NULL. + */ +const config_var_t * +config_find_option(const config_mgr_t *mgr, const char *key) +{ + const managed_var_t *mv = config_mgr_find_var(mgr, key, true, NULL); + if (mv) + return mv->cvar; + else + return NULL; +} + /** Return the number of option entries in <b>fmt</b>. */ static int config_count_options(const config_mgr_t *mgr) { - const config_format_t *fmt = mgr->toplevel; - int i; - for (i=0; fmt->vars[i].member.name; ++i) - ; - return i; + return smartlist_len(mgr->all_vars); }

bool @@ -213,16 +341,17 @@ static int config_assign_value(const config_mgr_t *mgr, void *options, config_line_t *c, char **msg) { - const config_var_t *var; + const managed_var_t *var; const config_format_t *fmt = mgr->toplevel;

CONFIG_CHECK(fmt, options);

- var = config_find_option(mgr, c->key); + var = config_mgr_find_var(mgr, c->key, true, NULL); tor_assert(var); - tor_assert(!strcmp(c->key, var->member.name)); + tor_assert(!strcmp(c->key, var->cvar->member.name)); + void *object = config_mgr_get_obj_mutable(mgr, options, var->object_idx);

- return struct_var_kvassign(options, c, msg, &var->member); + return struct_var_kvassign(object, c, msg, &var->cvar->member); }

/** Mark every linelist in <b>options</b> "fragile", so that fresh assignments @@ -230,16 +359,13 @@ config_assign_value(const config_mgr_t *mgr, void *options, static void config_mark_lists_fragile(const config_mgr_t *mgr, void *options) { - int i; - const config_format_t *fmt = mgr->toplevel; - - tor_assert(fmt); + tor_assert(mgr); tor_assert(options);

- for (i = 0; fmt->vars[i].member.name; ++i) { - const config_var_t *var = &fmt->vars[i]; - struct_var_mark_fragile(options, &var->member); - } + 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); }

void @@ -270,12 +396,13 @@ config_assign_line(const config_mgr_t *mgr, void *options, 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 config_var_t *var; + const managed_var_t *mvar;

CONFIG_CHECK(fmt, options);

- var = config_find_option(mgr, c->key); - if (!var) { + int var_index = -1; + mvar = config_mgr_find_var(mgr, c->key, true, &var_index); + if (!mvar) { if (fmt->extra) { void *lvalue = STRUCT_VAR_P(options, fmt->extra->offset); log_info(LD_CONFIG, @@ -289,44 +416,47 @@ config_assign_line(const config_mgr_t *mgr, void *options, } }

+ const config_var_t *cvar = mvar->cvar; + tor_assert(cvar); + /* Put keyword into canonical case. */ - if (strcmp(var->member.name, c->key)) { + if (strcmp(cvar->member.name, c->key)) { tor_free(c->key); - c->key = tor_strdup(var->member.name); + c->key = tor_strdup(cvar->member.name); }

const char *deprecation_msg; if (warn_deprecations && - (deprecation_msg = config_find_deprecation(mgr, var->member.name))) { - warn_deprecated_option(var->member.name, deprecation_msg); + (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_cumulative(var) && c->command != CONFIG_LINE_CLEAR) { + if (config_var_is_cumulative(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, var, use_defaults); + config_reset(mgr, options, mvar, use_defaults); } } return 0; } else if (c->command == CONFIG_LINE_CLEAR && !clear_first) { // XXXX This is unreachable, since a CLEAR line always has an // XXXX empty value. - config_reset(mgr, options, var, use_defaults); // LCOV_EXCL_LINE + config_reset(mgr, options, mvar, use_defaults); // LCOV_EXCL_LINE }

- if (options_seen && ! config_var_is_cumulative(var)) { + if (options_seen && ! config_var_is_cumulative(cvar)) { /* We're tracking which options we've seen, and this option is not * supposed to occur more than once. */ - int var_index = (int)(var - fmt->vars); + 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.", var->member.name); + "value will be ignored.", cvar->member.name); } bitarray_set(options_seen, var_index); } @@ -343,11 +473,11 @@ config_reset_line(const config_mgr_t *mgr, void *options, const char *key, int use_defaults) { const config_format_t *fmt = mgr->toplevel; - const config_var_t *var; + const managed_var_t *var;

CONFIG_CHECK(fmt, options);

- var = config_find_option(mgr, key); + var = config_mgr_find_var(mgr, key, true, NULL); if (!var) return; /* give error on next pass. */

@@ -388,7 +518,7 @@ config_line_t * config_get_assigned_option(const config_mgr_t *mgr, const void *options, const char *key, int escape_val) { - const config_var_t *var; + const managed_var_t *var; config_line_t *result; const config_format_t *fmt = mgr->toplevel;

@@ -396,13 +526,14 @@ config_get_assigned_option(const config_mgr_t *mgr, const void *options,

CONFIG_CHECK(fmt, options);

- var = config_find_option(mgr, key); + var = config_mgr_find_var(mgr, key, true, NULL); if (!var) { log_warn(LD_CONFIG, "Unknown option '%s'. Failing.", key); return NULL; } + const void *object = config_mgr_get_obj(mgr, options, var->object_idx);

- result = struct_var_kvencode(options, &var->member); + result = struct_var_kvencode(object, &var->cvar->member);

if (escape_val) { config_line_t *line; @@ -526,10 +657,10 @@ config_assign(const config_mgr_t *mgr, void *options, config_line_t *list, /** 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(void *options, - const config_var_t *var) +config_clear(const config_mgr_t *mgr, void *options, const managed_var_t *var) { - struct_var_free(options, &var->member); + 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 @@ -537,19 +668,21 @@ config_clear(void *options, * Called by config_init() and option_reset_line() and option_assign_line(). */ static void config_reset(const config_mgr_t *mgr, void *options, - const config_var_t *var, int use_defaults) + const managed_var_t *var, int use_defaults) { const config_format_t *fmt = mgr->toplevel; config_line_t *c; char *msg = NULL; CONFIG_CHECK(fmt, options); - config_clear(options, var); /* clear it first */ + config_clear(mgr, options, var); /* clear it first */ + if (!use_defaults) return; /* all done */ - if (var->initvalue) { + + if (var->cvar->initvalue) { c = tor_malloc_zero(sizeof(config_line_t)); - c->key = tor_strdup(var->member.name); - c->value = tor_strdup(var->initvalue); + 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); @@ -564,7 +697,6 @@ config_reset(const config_mgr_t *mgr, void *options, void config_free_(const config_mgr_t *mgr, void *options) { - int i; const config_format_t *fmt = mgr->toplevel;

if (!options) @@ -572,8 +704,9 @@ config_free_(const config_mgr_t *mgr, void *options)

tor_assert(fmt);

- for (i=0; fmt->vars[i].member.name; ++i) - config_clear(options, &(fmt->vars[i])); + SMARTLIST_FOREACH_BEGIN(mgr->all_vars, const managed_var_t *, mv) { + config_clear(mgr, options, mv); + } SMARTLIST_FOREACH_END(mv);

if (fmt->extra) { config_line_t **linep = STRUCT_VAR_P(options, fmt->extra->offset); @@ -595,36 +728,39 @@ config_is_same(const config_mgr_t *mgr, CONFIG_CHECK(fmt, o1); CONFIG_CHECK(fmt, o2);

- const config_var_t *var = config_find_option(mgr, name); + 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(o1, o2, &var->member); + return struct_var_eq(obj1, obj2, &var->cvar->member); }

/** 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) { - const config_format_t *fmt = mgr->toplevel; void *newopts; - int i;

newopts = config_new(mgr); - for (i=0; fmt->vars[i].member.name; ++i) { - if (config_var_is_contained(&fmt->vars[i])) { + SMARTLIST_FOREACH_BEGIN(mgr->all_vars, managed_var_t *, mv) { + if (config_var_is_contained(mv->cvar)) { // Something else will copy this option, or it doesn't need copying. continue; } - if (struct_var_copy(newopts, old, &fmt->vars[i].member) < 0) { + 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.", - fmt->vars[i].member.name); + 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 @@ -632,17 +768,14 @@ config_dup(const config_mgr_t *mgr, const void *old) void config_init(const config_mgr_t *mgr, void *options) { - int i; const config_format_t *fmt = mgr->toplevel; - const config_var_t *var; CONFIG_CHECK(fmt, options);

- for (i=0; fmt->vars[i].member.name; ++i) { - var = &fmt->vars[i]; - if (!var->initvalue) + 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, var, 1); - } + config_reset(mgr, options, mv, 1); + } SMARTLIST_FOREACH_END(mv); }

/** Allocate and return a new string holding the written-out values of the vars @@ -654,13 +787,12 @@ config_dump(const config_mgr_t *mgr, const void *default_options, const void *options, int minimal, int comment_defaults) { - smartlist_t *elements; 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; - int i; char *msg = NULL;

if (defaults == NULL) { @@ -680,24 +812,24 @@ config_dump(const config_mgr_t *mgr, const void *default_options, }

elements = smartlist_new(); - for (i=0; fmt->vars[i].member.name; ++i) { + SMARTLIST_FOREACH_BEGIN(mgr->all_vars, managed_var_t *, mv) { int comment_option = 0; - if (config_var_is_contained(&fmt->vars[i])) { + if (config_var_is_contained(mv->cvar)) { // Something else will dump this option, or it doesn't need dumping. continue; } /* Don't save 'hidden' control variables. */ - if (fmt->vars[i].flags & CVFLAG_NODUMP) + if (mv->cvar->flags & CVFLAG_NODUMP) continue; - if (minimal && config_is_same(mgr, options, defaults, - fmt->vars[i].member.name)) + 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, fmt->vars[i].member.name)) + config_is_same(mgr, options, defaults, name)) comment_option = 1;

line = assigned = - config_get_assigned_option(mgr, options, fmt->vars[i].member.name, 1); + config_get_assigned_option(mgr, options, name, 1);

for (; line; line = line->next) { if (!strcmpstart(line->key, "__")) { @@ -710,7 +842,7 @@ config_dump(const config_mgr_t *mgr, const void *default_options, line->key, line->value); } config_free_lines(assigned); - } + } SMARTLIST_FOREACH_END(mv);

if (fmt->extra) { line = *(config_line_t**)STRUCT_VAR_P(options, fmt->extra->offset); @@ -735,14 +867,15 @@ config_dump(const config_mgr_t *mgr, const void *default_options, bool config_check_ok(const config_mgr_t *mgr, const void *options, int severity) { - const config_format_t *fmt = mgr->toplevel; bool all_ok = true; - for (int i=0; fmt->vars[i].member.name; ++i) { - if (!struct_var_ok(options, &fmt->vars[i].member)) { + + 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", - fmt->vars[i].member.name); + mv->cvar->member.name); all_ok = false; } - } + } SMARTLIST_FOREACH_END(mv); + return all_ok; }