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.
This commit is contained in:
Nick Mathewson 2019-07-22 13:53:36 -04:00
parent e8dc513bd0
commit 769fe81717

View File

@ -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;
}
@ -124,18 +225,66 @@ 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;
}
/**
* 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.
*/
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;
}
@ -147,39 +296,18 @@ config_find_deprecation(const config_mgr_t *mgr, const char *key)
const config_var_t *
config_find_option(const config_mgr_t *mgr, const char *key)
{
const config_format_t *fmt = mgr->toplevel;
int i;
size_t keylen = strlen(key);
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];
}
}
/* 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)) {
log_warn(LD_CONFIG, "The abbreviation '%s' is deprecated. "
"Please use '%s' instead",
key, fmt->vars[i].member.name);
return &fmt->vars[i];
}
}
/* Okay, unrecognized option */
return NULL;
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;
}