commit 7bb76b24cf755799b7950ef078ac5ccf4d6e3a8a Author: Nick Mathewson nickm@torproject.org Date: Thu Nov 1 11:51:33 2018 -0400
Code to manage the list of subsystems. --- src/app/main/main.c | 6 ++ src/app/main/subsysmgr.c | 130 ++++++++++++++++++++++++++++++++++++++++++ src/app/main/subsysmgr.h | 20 +++++++ src/app/main/subsystem_list.c | 20 +++++++ src/core/include.am | 3 + src/lib/subsys/subsys.h | 5 ++ 6 files changed, 184 insertions(+)
diff --git a/src/app/main/main.c b/src/app/main/main.c index ae87add67..444d6ea7e 100644 --- a/src/app/main/main.c +++ b/src/app/main/main.c @@ -15,6 +15,7 @@ #include "app/config/statefile.h" #include "app/main/main.h" #include "app/main/ntmain.h" +#include "app/main/subsysmgr.h" #include "core/mainloop/connection.h" #include "core/mainloop/cpuworker.h" #include "core/mainloop/mainloop.h" @@ -813,6 +814,9 @@ tor_free_all(int postfork) release_lockfile(); } tor_libevent_free_all(); + + subsystems_shutdown(); + /* Stuff in util.c and address.c*/ if (!postfork) { escaped(NULL); @@ -1426,6 +1430,8 @@ tor_run_main(const tor_main_configuration_t *tor_cfg) event_set_mem_functions(tor_malloc_, tor_realloc_, tor_free_); #endif
+ subsystems_init(); + init_protocol_warning_severity_level();
update_approx_time(time(NULL)); diff --git a/src/app/main/subsysmgr.c b/src/app/main/subsysmgr.c new file mode 100644 index 000000000..7974f2d23 --- /dev/null +++ b/src/app/main/subsysmgr.c @@ -0,0 +1,130 @@ +/* Copyright (c) 2003-2004, Roger Dingledine + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2018, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +#include "orconfig.h" +#include "app/main/subsysmgr.h" +#include "lib/err/torerr.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; + +/** + * 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 bool sys_initialized[128]; + +/** + * 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_initialized) >= n_tor_subsystems); + memset(sys_initialized, 0, sizeof(sys_initialized)); + + 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"); + } + 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_initialized[i]) + continue; + int r = 0; + if (sys->initialize) + 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_initialized[i] = true; + } + + return 0; +} + +/** + * 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_initialized[i]) + continue; + if (sys->shutdown) + sys->shutdown(); + sys_initialized[i] = false; + } +} diff --git a/src/app/main/subsysmgr.h b/src/app/main/subsysmgr.h new file mode 100644 index 000000000..c9b892eee --- /dev/null +++ b/src/app/main/subsysmgr.h @@ -0,0 +1,20 @@ +/* Copyright (c) 2003-2004, Roger Dingledine + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2018, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +#ifndef TOR_SUBSYSMGR_T +#define TOR_SUBSYSMGR_T + +#include "lib/subsys/subsys.h" + +extern const struct subsys_fns_t *tor_subsystems[]; +extern const unsigned n_tor_subsystems; + +int subsystems_init(void); +int subsystems_init_upto(int level); + +void subsystems_shutdown(void); +void subsystems_shutdown_downto(int level); + +#endif diff --git a/src/app/main/subsystem_list.c b/src/app/main/subsystem_list.c new file mode 100644 index 000000000..fc1249e1c --- /dev/null +++ b/src/app/main/subsystem_list.c @@ -0,0 +1,20 @@ +/* Copyright (c) 2003-2004, Roger Dingledine + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2018, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +#include "orconfig.h" +#include "app/main/subsysmgr.h" +#include "lib/cc/compat_compiler.h" +#include "lib/cc/torint.h" + +#include <stddef.h> + +/** + * Global list of the subsystems in Tor, in the order of their initialization. + **/ +const subsys_fns_t *tor_subsystems[] = { + NULL // placeholder. +}; + +const unsigned n_tor_subsystems = ARRAY_LENGTH(tor_subsystems); diff --git a/src/core/include.am b/src/core/include.am index 1b8ef2ac5..d3fce5428 100644 --- a/src/core/include.am +++ b/src/core/include.am @@ -11,6 +11,8 @@ LIBTOR_APP_A_SOURCES = \ src/app/config/confparse.c \ src/app/config/statefile.c \ src/app/main/main.c \ + src/app/main/subsystem_list.c \ + src/app/main/subsysmgr.c \ src/core/crypto/hs_ntor.c \ src/core/crypto/onion_crypto.c \ src/core/crypto/onion_fast.c \ @@ -191,6 +193,7 @@ noinst_HEADERS += \ src/app/config/statefile.h \ src/app/main/main.h \ src/app/main/ntmain.h \ + src/app/main/subsysmgr.h \ src/core/crypto/hs_ntor.h \ src/core/crypto/onion_crypto.h \ src/core/crypto/onion_fast.h \ diff --git a/src/lib/subsys/subsys.h b/src/lib/subsys/subsys.h index 7e4fe5363..012b218da 100644 --- a/src/lib/subsys/subsys.h +++ b/src/lib/subsys/subsys.h @@ -43,6 +43,8 @@ typedef struct subsys_fns_t { * * This function MUST NOT rely on any runtime configuration information; * it is only for global state or pre-configuration state. + * + * This function MUST NOT have any parts that can fail. **/ int (*initialize)(void);
@@ -60,4 +62,7 @@ typedef struct subsys_fns_t {
} subsys_fns_t;
+#define MIN_SUBSYS_LEVEL -100 +#define MAX_SUBSYS_LEVEL 100 + #endif