commit 20c24e72d92c2d15ef78d683d71b6e627ac66799 Author: Nick Mathewson nickm@torproject.org Date: Thu Nov 7 12:59:50 2019 -0500
options_act_reversible(): Extract more startup-only pieces.
These have to happen after opening listeners and before opening logs :/ --- src/app/config/config.c | 156 ++++++++++++++++++++++++++++++------------------ 1 file changed, 99 insertions(+), 57 deletions(-)
diff --git a/src/app/config/config.c b/src/app/config/config.c index 57835f95d..1ef23824d 100644 --- a/src/app/config/config.c +++ b/src/app/config/config.c @@ -1431,7 +1431,7 @@ options_act_once_on_startup(char **msg_out) return 0;
const or_options_t *options = get_options(); - int running_tor = options->command == CMD_RUN_TOR; + const bool running_tor = options->command == CMD_RUN_TOR;
if (!running_tor) return 0; @@ -1481,15 +1481,109 @@ options_act_once_on_startup(char **msg_out) return 0; }
+/** + * Change our user ID if we're configured to do so. + **/ +static int +options_switch_id(char **msg_out) +{ + const or_options_t *options = get_options(); + + /* Setuid/setgid as appropriate */ + if (options->User) { + tor_assert(have_low_ports != -1); + unsigned switch_id_flags = 0; + if (options->KeepBindCapabilities == 1) { + switch_id_flags |= SWITCH_ID_KEEP_BINDLOW; + switch_id_flags |= SWITCH_ID_WARN_IF_NO_CAPS; + } + if (options->KeepBindCapabilities == -1 && have_low_ports) { + switch_id_flags |= SWITCH_ID_KEEP_BINDLOW; + } + if (switch_id(options->User, switch_id_flags) != 0) { + /* No need to roll back, since you can't change the value. */ + *msg_out = tor_strdup("Problem with User value. See logs for details."); + return -1; + } + } + + return 0; +} + +/** + * Create our DataDirectory, CacheDirectory, and KeyDirectory, and + * set their permissions correctly. + */ +static int +options_create_directories(char **msg_out) +{ + const or_options_t *options = get_options(); + const bool running_tor = options->command == CMD_RUN_TOR; + + /* Ensure data directory is private; create if possible. */ + /* It's okay to do this in "options_act_reversible()" even though it isn't + * actually reversible, since you can't change the DataDirectory while + * Tor is running. */ + if (check_and_create_data_directory(running_tor /* create */, + options->DataDirectory, + options->DataDirectoryGroupReadable, + options->User, + msg_out) < 0) { + return -1; + } + if (check_and_create_data_directory(running_tor /* create */, + options->KeyDirectory, + options->KeyDirectoryGroupReadable, + options->User, + msg_out) < 0) { + return -1; + } + + /* We need to handle the group-readable flag for the cache directory + * specially, since the directory defaults to being the same as the + * DataDirectory. */ + int cache_dir_group_readable; + if (options->CacheDirectoryGroupReadable != -1) { + /* If the user specified a value, use their setting */ + cache_dir_group_readable = options->CacheDirectoryGroupReadable; + } else if (!strcmp(options->CacheDirectory, options->DataDirectory)) { + /* If the user left the value as "auto", and the cache is the same as the + * datadirectory, use the datadirectory setting. + */ + cache_dir_group_readable = options->DataDirectoryGroupReadable; + } else { + /* Otherwise, "auto" means "not group readable". */ + cache_dir_group_readable = 0; + } + if (check_and_create_data_directory(running_tor /* create */, + options->CacheDirectory, + cache_dir_group_readable, + options->User, + msg_out) < 0) { + return -1; + } + + return 0; +} + /** Fetch the active option list, and take actions based on it. All of the * things we do should survive being done repeatedly. If present, * <b>old_options</b> contains the previous value of the options. * + * This function is only truly "reversible" _after_ the first time it + * is run. The first time that it runs, it performs some irreversible + * tasks in the correct sequence between the reversible option changes. + * + * Option changes should only be marked as "reversible" if they cannot + * be validated before switching them, but they can be switched back if + * some other validateion fails. + * * Return 0 if all goes well, return -1 if things went badly. */ MOCK_IMPL(STATIC int, options_act_reversible,(const or_options_t *old_options, char **msg)) { + const bool first_time = ! have_set_startup_options; smartlist_t *new_listeners = smartlist_new(); or_options_t *options = get_options_mutable(); int running_tor = options->command == CMD_RUN_TOR; @@ -1561,66 +1655,14 @@ options_act_reversible,(const or_options_t *old_options, char **msg)) } #endif /* defined(HAVE_NET_IF_H) && defined(HAVE_NET_PFVAR_H) */
- /* Setuid/setgid as appropriate */ - if (options->User) { - tor_assert(have_low_ports != -1); - unsigned switch_id_flags = 0; - if (options->KeepBindCapabilities == 1) { - switch_id_flags |= SWITCH_ID_KEEP_BINDLOW; - switch_id_flags |= SWITCH_ID_WARN_IF_NO_CAPS; - } - if (options->KeepBindCapabilities == -1 && have_low_ports) { - switch_id_flags |= SWITCH_ID_KEEP_BINDLOW; - } - if (switch_id(options->User, switch_id_flags) != 0) { - /* No need to roll back, since you can't change the value. */ - *msg = tor_strdup("Problem with User value. See logs for details."); + if (first_time) { + if (options_switch_id(msg) < 0) goto done; - } - }
- /* Ensure data directory is private; create if possible. */ - /* It's okay to do this in "options_act_reversible()" even though it isn't - * actually reversible, since you can't change the DataDirectory while - * Tor is running. */ - if (check_and_create_data_directory(running_tor /* create */, - options->DataDirectory, - options->DataDirectoryGroupReadable, - options->User, - msg) < 0) { - goto done; - } - if (check_and_create_data_directory(running_tor /* create */, - options->KeyDirectory, - options->KeyDirectoryGroupReadable, - options->User, - msg) < 0) { - goto done; + if (options_create_directories(msg) < 0) + goto done; }
- /* We need to handle the group-readable flag for the cache directory - * specially, since the directory defaults to being the same as the - * DataDirectory. */ - int cache_dir_group_readable; - if (options->CacheDirectoryGroupReadable != -1) { - /* If the user specified a value, use their setting */ - cache_dir_group_readable = options->CacheDirectoryGroupReadable; - } else if (!strcmp(options->CacheDirectory, options->DataDirectory)) { - /* If the user left the value as "auto", and the cache is the same as the - * datadirectory, use the datadirectory setting. - */ - cache_dir_group_readable = options->DataDirectoryGroupReadable; - } else { - /* Otherwise, "auto" means "not group readable". */ - cache_dir_group_readable = 0; - } - if (check_and_create_data_directory(running_tor /* create */, - options->CacheDirectory, - cache_dir_group_readable, - options->User, - msg) < 0) { - goto done; - }
/* Bail out at this point if we're not going to be a client or server: * we don't run Tor itself. */