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Diffstat (limited to 'src/app/main/subsysmgr.c')
| -rw-r--r-- | src/app/main/subsysmgr.c | 464 |
1 files changed, 464 insertions, 0 deletions
diff --git a/src/app/main/subsysmgr.c b/src/app/main/subsysmgr.c new file mode 100644 index 0000000000..5807cbbaa4 --- /dev/null +++ b/src/app/main/subsysmgr.c @@ -0,0 +1,464 @@ +/* Copyright (c) 2003-2004, Roger Dingledine + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2020, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * @file subsysmgr.c + * @brief Manager for Tor's subsystems. + * + * This code is responsible for initializing, configuring, and shutting + * down all of Tor's individual subsystems. + **/ + +#include "orconfig.h" +#include "app/main/subsysmgr.h" + +#include "lib/confmgt/confmgt.h" +#include "lib/dispatch/dispatch_naming.h" +#include "lib/dispatch/msgtypes.h" +#include "lib/err/torerr.h" +#include "lib/log/log.h" +#include "lib/log/util_bug.h" +#include "lib/malloc/malloc.h" +#include "lib/pubsub/pubsub_build.h" +#include "lib/pubsub/pubsub_connect.h" + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +/** + * True iff we have checked tor_subsystems for consistency. + **/ +static bool subsystem_array_validated = false; + +/** Index value indicating that a subsystem has no options/state object, and + * so that object does not have an index. */ +#define IDX_NONE (-1) + +/** + * Runtime status of a single subsystem. + **/ +typedef struct subsys_status_t { + /** True if the given subsystem is initialized. */ + bool initialized; + /** Index for this subsystem's options object, or IDX_NONE for none. */ + int options_idx; + /** Index for this subsystem's state object, or IDX_NONE for none. */ + int state_idx; +} subsys_status_t; + +/** An overestimate of the number of subsystems. */ +#define N_SYS_STATUS 128 +/** + * True if a given subsystem is initialized. Expand this array if there + * are more than this number of subsystems. (We'd rather not + * dynamically allocate in this module.) + **/ +static subsys_status_t sys_status[N_SYS_STATUS]; + +/** Set <b>status</b> to a default (not set-up) state. */ +static void +subsys_status_clear(subsys_status_t *status) +{ + if (!status) + return; + memset(status, 0, sizeof(*status)); + status->initialized = false; + status->state_idx = IDX_NONE; + status->options_idx = IDX_NONE; +} + +/** + * Exit with a raw assertion if the subsystems list is inconsistent; + * initialize the subsystem_initialized array. + **/ +static void +check_and_setup(void) +{ + if (subsystem_array_validated) + return; + + raw_assert(ARRAY_LENGTH(sys_status) >= n_tor_subsystems); + memset(sys_status, 0, sizeof(sys_status)); + + int last_level = MIN_SUBSYS_LEVEL; + + for (unsigned i = 0; i < n_tor_subsystems; ++i) { + const subsys_fns_t *sys = tor_subsystems[i]; + if (sys->level < MIN_SUBSYS_LEVEL || sys->level > MAX_SUBSYS_LEVEL) { + fprintf(stderr, "BUG: Subsystem %s (at %u) has an invalid level %d. " + "It is supposed to be between %d and %d (inclusive).\n", + sys->name, i, sys->level, MIN_SUBSYS_LEVEL, MAX_SUBSYS_LEVEL); + raw_assert_unreached_msg("There is a bug in subsystem_list.c"); + } + if (sys->level < last_level) { + fprintf(stderr, "BUG: Subsystem %s (at #%u) is in the wrong position. " + "Its level is %d; but the previous subsystem's level was %d.\n", + sys->name, i, sys->level, last_level); + raw_assert_unreached_msg("There is a bug in subsystem_list.c"); + } + subsys_status_clear(&sys_status[i]); + + last_level = sys->level; + } + + subsystem_array_validated = true; +} + +/** + * Initialize all the subsystems; exit on failure. + **/ +int +subsystems_init(void) +{ + return subsystems_init_upto(MAX_SUBSYS_LEVEL); +} + +/** + * Initialize all the subsystems whose level is less than or equal to + * <b>target_level</b>; exit on failure. + **/ +int +subsystems_init_upto(int target_level) +{ + check_and_setup(); + + for (unsigned i = 0; i < n_tor_subsystems; ++i) { + const subsys_fns_t *sys = tor_subsystems[i]; + if (!sys->supported) + continue; + if (sys->level > target_level) + break; + if (sys_status[i].initialized) + continue; + int r = 0; + if (sys->initialize) { + // Note that the logging subsystem is designed so that it does no harm + // to log a message in an uninitialized state. These messages will be + // discarded for now, however. + log_debug(LD_GENERAL, "Initializing %s", sys->name); + r = sys->initialize(); + } + if (r < 0) { + fprintf(stderr, "BUG: subsystem %s (at %u) initialization failed.\n", + sys->name, i); + raw_assert_unreached_msg("A subsystem couldn't be initialized."); + } + sys_status[i].initialized = true; + } + + return 0; +} + +/** + * Add publish/subscribe relationships to <b>builder</b> for all + * initialized subsystems of level no more than <b>target_level</b>. + **/ +int +subsystems_add_pubsub_upto(pubsub_builder_t *builder, + int target_level) +{ + for (unsigned i = 0; i < n_tor_subsystems; ++i) { + const subsys_fns_t *sys = tor_subsystems[i]; + if (!sys->supported) + continue; + if (sys->level > target_level) + break; + if (! sys_status[i].initialized) + continue; + int r = 0; + if (sys->add_pubsub) { + subsys_id_t sysid = get_subsys_id(sys->name); + raw_assert(sysid != ERROR_ID); + pubsub_connector_t *connector; + connector = pubsub_connector_for_subsystem(builder, sysid); + r = sys->add_pubsub(connector); + pubsub_connector_free(connector); + } + if (r < 0) { + fprintf(stderr, "BUG: subsystem %s (at %u) could not connect to " + "publish/subscribe system.", sys->name, sys->level); + raw_assert_unreached_msg("A subsystem couldn't be connected."); + } + } + + return 0; +} + +/** + * Add publish/subscribe relationships to <b>builder</b> for all + * initialized subsystems. + **/ +int +subsystems_add_pubsub(pubsub_builder_t *builder) +{ + return subsystems_add_pubsub_upto(builder, MAX_SUBSYS_LEVEL); +} + +/** + * Shut down all the subsystems. + **/ +void +subsystems_shutdown(void) +{ + subsystems_shutdown_downto(MIN_SUBSYS_LEVEL - 1); +} + +/** + * Shut down all the subsystems whose level is above <b>target_level</b>. + **/ +void +subsystems_shutdown_downto(int target_level) +{ + check_and_setup(); + + for (int i = (int)n_tor_subsystems - 1; i >= 0; --i) { + const subsys_fns_t *sys = tor_subsystems[i]; + if (!sys->supported) + continue; + if (sys->level <= target_level) + break; + if (! sys_status[i].initialized) + continue; + if (sys->shutdown) { + log_debug(LD_GENERAL, "Shutting down %s", sys->name); + sys->shutdown(); + } + subsys_status_clear(&sys_status[i]); + } +} + +/** + * Run pre-fork code on all subsystems that declare any + **/ +void +subsystems_prefork(void) +{ + check_and_setup(); + + for (int i = (int)n_tor_subsystems - 1; i >= 0; --i) { + const subsys_fns_t *sys = tor_subsystems[i]; + if (!sys->supported) + continue; + if (! sys_status[i].initialized) + continue; + if (sys->prefork) { + log_debug(LD_GENERAL, "Pre-fork: %s", sys->name); + sys->prefork(); + } + } +} + +/** + * Run post-fork code on all subsystems that declare any + **/ +void +subsystems_postfork(void) +{ + check_and_setup(); + + for (unsigned i = 0; i < n_tor_subsystems; ++i) { + const subsys_fns_t *sys = tor_subsystems[i]; + if (!sys->supported) + continue; + if (! sys_status[i].initialized) + continue; + if (sys->postfork) { + log_debug(LD_GENERAL, "Post-fork: %s", sys->name); + sys->postfork(); + } + } +} + +/** + * Run thread-cleanup code on all subsystems that declare any + **/ +void +subsystems_thread_cleanup(void) +{ + check_and_setup(); + + for (int i = (int)n_tor_subsystems - 1; i >= 0; --i) { + const subsys_fns_t *sys = tor_subsystems[i]; + if (!sys->supported) + continue; + if (! sys_status[i].initialized) + continue; + if (sys->thread_cleanup) { + log_debug(LD_GENERAL, "Thread cleanup: %s", sys->name); + sys->thread_cleanup(); + } + } +} + +/** + * Register all subsystem-declared options formats in <b>mgr</b>. + * + * Return 0 on success, -1 on failure. + **/ +int +subsystems_register_options_formats(config_mgr_t *mgr) +{ + tor_assert(mgr); + check_and_setup(); + + for (unsigned i = 0; i < n_tor_subsystems; ++i) { + const subsys_fns_t *sys = tor_subsystems[i]; + if (sys->options_format) { + int options_idx = config_mgr_add_format(mgr, sys->options_format); + sys_status[i].options_idx = options_idx; + log_debug(LD_CONFIG, "Added options format for %s with index %d", + sys->name, options_idx); + } + } + return 0; +} + +/** + * Register all subsystem-declared state formats in <b>mgr</b>. + * + * Return 0 on success, -1 on failure. + **/ +int +subsystems_register_state_formats(config_mgr_t *mgr) +{ + tor_assert(mgr); + check_and_setup(); + + for (unsigned i = 0; i < n_tor_subsystems; ++i) { + const subsys_fns_t *sys = tor_subsystems[i]; + if (sys->state_format) { + int state_idx = config_mgr_add_format(mgr, sys->state_format); + sys_status[i].state_idx = state_idx; + log_debug(LD_CONFIG, "Added state format for %s with index %d", + sys->name, state_idx); + } + } + return 0; +} + +#ifdef TOR_UNIT_TESTS +/** + * Helper: look up the index for <b>sys</b>. Return -1 if the subsystem + * is not recognized. + **/ +static int +subsys_get_idx(const subsys_fns_t *sys) +{ + for (unsigned i = 0; i < n_tor_subsystems; ++i) { + if (sys == tor_subsystems[i]) + return (int)i; + } + return -1; +} + +/** + * Return the current state-manager's index for any state held by the + * subsystem <b>sys</b>. If <b>sys</b> has no options, return -1. + * + * Using raw indices can be error-prone: only do this from the unit + * tests. If you need a way to access another subsystem's configuration, + * that subsystem should provide access functions. + **/ +int +subsystems_get_options_idx(const subsys_fns_t *sys) +{ + int i = subsys_get_idx(sys); + tor_assert(i >= 0); + return sys_status[i].options_idx; +} + +/** + * Return the current state-manager's index for any state held by the + * subsystem <b>sys</b>. If <b>sys</b> has no state, return -1. + * + * Using raw indices can be error-prone: only do this from the unit + * tests. If you need a way to access another subsystem's state + * that subsystem should provide access functions. + **/ +int +subsystems_get_state_idx(const subsys_fns_t *sys) +{ + int i = subsys_get_idx(sys); + tor_assert(i >= 0); + return sys_status[i].state_idx; +} +#endif /* defined(TOR_UNIT_TESTS) */ + +/** + * Call all appropriate set_options() methods to tell the various subsystems + * about a new set of torrc options. Return 0 on success, -1 on + * nonrecoverable failure. + **/ +int +subsystems_set_options(const config_mgr_t *mgr, struct or_options_t *options) +{ + /* XXXX This does not yet handle reversible option assignment; I'll + * do that later in this branch. */ + + for (unsigned i = 0; i < n_tor_subsystems; ++i) { + const subsys_fns_t *sys = tor_subsystems[i]; + if (sys_status[i].options_idx >= 0 && sys->set_options) { + void *obj = config_mgr_get_obj_mutable(mgr, options, + sys_status[i].options_idx); + int rv = sys->set_options(obj); + if (rv < 0) { + log_err(LD_CONFIG, "Error when handling option for %s; " + "cannot proceed.", sys->name); + return -1; + } + } + } + return 0; +} + +/** + * Call all appropriate set_state() methods to tell the various subsystems + * about an initial DataDir/state file. Return 0 on success, -1 on + * nonrecoverable failure. + **/ +int +subsystems_set_state(const config_mgr_t *mgr, struct or_state_t *state) +{ + for (unsigned i = 0; i < n_tor_subsystems; ++i) { + const subsys_fns_t *sys = tor_subsystems[i]; + if (sys_status[i].state_idx >= 0 && sys->set_state) { + void *obj = config_mgr_get_obj_mutable(mgr, state, + sys_status[i].state_idx); + int rv = sys->set_state(obj); + if (rv < 0) { + log_err(LD_CONFIG, "Error when handling state for %s; " + "cannot proceed.", sys->name); + return -1; + } + } + } + return 0; +} + +/** + * Call all appropriate flush_state() methods to tell the various subsystems + * to update the state objects in <b>state</b>. Return 0 on success, + * -1 on failure. + **/ +int +subsystems_flush_state(const config_mgr_t *mgr, struct or_state_t *state) +{ + int result = 0; + for (unsigned i = 0; i < n_tor_subsystems; ++i) { + const subsys_fns_t *sys = tor_subsystems[i]; + if (sys_status[i].state_idx >= 0 && sys->flush_state) { + void *obj = config_mgr_get_obj_mutable(mgr, state, + sys_status[i].state_idx); + int rv = sys->flush_state(obj); + if (rv < 0) { + log_warn(LD_CONFIG, "Error when flushing state to state object for %s", + sys->name); + result = -1; + } + } + } + return result; +} |