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v16
src/launch/main.c
1 808 строк
61 KB
David Herrmann
launch: move magic numbers to front
09 окт 2018, 11:42
09 окт 2018, 11:42
5d765ef
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/* * D-Bus Broker Launcher */ #include <c-macro.h> #include <c-rbtree.h> #include <c-string.h> #include <fcntl.h> #include <getopt.h> #include <glib.h> #include <grp.h> #include <pwd.h> #include <signal.h> #include <stdlib.h> #include <sys/prctl.h> #include <sys/socket.h> #include <sys/types.h> #include <sys/un.h> #include <sys/wait.h> #include <systemd/sd-bus.h> #include <systemd/sd-daemon.h> #include <systemd/sd-event.h> #include <systemd/sd-id128.h> #include <unistd.h> #include "launch/config.h" #include "launch/nss-cache.h" #include "launch/policy.h" #include "util/apparmor.h" #include "util/audit.h" #include "util/dirwatch.h" #include "util/error.h" #include "util/log.h" #include "util/misc.h" typedef struct Manager Manager; typedef struct Service Service; enum { _MAIN_SUCCESS, MAIN_EXIT, MAIN_FAILED, }; enum { _MANAGER_E_SUCCESS, MANAGER_E_INVALID_CONFIG, }; typedef enum { SERVICE_STATE_PENDING, SERVICE_STATE_CURRENT, SERVICE_STATE_DEFUNCT, } ServiceState; struct Service { Manager *manager; ServiceState state; sd_bus_slot *slot; CRBNode rb; CRBNode rb_by_name; char *name; char *unit; size_t argc; char **argv; char *user; uid_t uid; uint64_t instance; char id[]; }; struct Manager { sd_event *event; sd_bus *bus_controller; sd_bus *bus_regular; int fd_listen; Dirwatch *dirwatch; sd_event_source *dirwatch_src; CRBTree services; CRBTree services_by_name; uint64_t service_ids; uint32_t uid; uint32_t gid; uint64_t max_bytes; uint64_t max_fds; uint64_t max_matches; }; /* * These are the default limits used when spawning dbus-broker. They are * similar to the limits used by dbus-daemon(1) (specified here in parentheses) * but slightly lowered to avoid DoS. We should be fine, since dbus-broker * employs a dynamically adjusted quota-based share distribution of resources. */ static const uint64_t main_max_outgoing_bytes = 8 * 1024 * 1024; /* 127MiB */ static const uint64_t main_max_outgoing_unix_fds = 64; static const uint64_t main_max_connections_per_user = 64; /* 256 */ static const uint64_t main_max_match_rules_per_connection = 256; static bool main_arg_audit = false; static const char * main_arg_broker = BINDIR "/dbus-broker"; static const char * main_arg_configfile = NULL; static bool main_arg_user_scope = false; static Log main_log = LOG_NULL; static sd_bus *bus_close_unref(sd_bus *bus) { /* * It is not sufficient to simply call sd_bus_unref(), as messages * in the bus' queues may pin the bus itself. Also, * sd_bus_flush_close_unref() is not always appropriate as it would * block in poll waiting for messages to be flushed to the socket. * * In some cases all we really want to do is close the socket and * release all the memory, ignoring whether or not it has been * flushed to the kernel (typically in error paths). */ if (!bus) return NULL; sd_bus_close(bus); return sd_bus_unref(bus); } static int service_compare(CRBTree *t, void *k, CRBNode *n) { Service *service = c_container_of(n, Service, rb); return strcmp(k, service->id); } static int service_compare_by_name(CRBTree *t, void *k, CRBNode *n) { Service *service = c_container_of(n, Service, rb_by_name); return strcmp(k, service->name); } static Service *service_free(Service *service) { if (!service) return NULL; c_rbnode_unlink(&service->rb_by_name); c_rbnode_unlink(&service->rb); free(service->user); for (size_t i = 0; i < service->argc; ++i) free(service->argv[i]); free(service->argv); free(service->unit); free(service->name); sd_bus_slot_unref(service->slot); free(service); return NULL; } C_DEFINE_CLEANUP(Service *, service_free); static int service_update(Service *service, const char *unit, size_t argc, char **argv, const char *user, uid_t uid) { service->unit = c_free(service->unit); service->argc = 0; service->argv = c_free(service->argv); service->user = c_free(service->user); service->uid = uid; if (unit) { service->unit = strdup(unit); if (!service->unit) return error_origin(-ENOMEM); } if (argc > 0) { service->argv = calloc(1, argc * sizeof(char*)); if (!service->argv) return error_origin(-ENOMEM); service->argc = argc; for (size_t i = 0; i < argc; ++i) { service->argv[i] = strdup(argv[i]); if (!service->argv[i]) return error_origin(-ENOMEM); } } if (user) { service->user = strdup(user); if (!service->user) return error_origin(-ENOMEM); } return 0; } static int service_new(Service **servicep, Manager *manager, const char *name, CRBNode **slot_by_name, CRBNode *parent_by_name, const char *unit, size_t argc, char **argv, const char *user, uid_t uid) { _c_cleanup_(service_freep) Service *service = NULL; CRBNode **slot, *parent; int r; service = calloc(1, sizeof(*service) + C_DECIMAL_MAX(uint64_t) + 1); if (!service) return error_origin(-ENOMEM); service->manager = manager; service->rb = (CRBNode)C_RBNODE_INIT(service->rb); service->rb_by_name = (CRBNode)C_RBNODE_INIT(service->rb_by_name); sprintf(service->id, "%" PRIu64, ++manager->service_ids); service->name = strdup(name); if (!service->name) return error_origin(-ENOMEM); r = service_update(service, unit, argc, argv, user, uid); if (r) return error_trace(r); slot = c_rbtree_find_slot(&manager->services, service_compare, service->id, &parent); assert(slot); c_rbtree_add(&manager->services, parent, slot, &service->rb); c_rbtree_add(&manager->services_by_name, parent_by_name, slot_by_name, &service->rb_by_name); *servicep = service; service = NULL; return 0; } static Manager *manager_free(Manager *manager) { Service *service, *safe; if (!manager) return NULL; c_rbtree_for_each_entry_safe_postorder_unlink(service, safe, &manager->services, rb) service_free(service); assert(c_rbtree_is_empty(&manager->services_by_name)); sd_event_source_unref(manager->dirwatch_src); dirwatch_free(manager->dirwatch); c_close(manager->fd_listen); bus_close_unref(manager->bus_regular); bus_close_unref(manager->bus_controller); sd_event_unref(manager->event); free(manager); return NULL; } C_DEFINE_CLEANUP(Manager *, manager_free); static int manager_reload_config(Manager *manager); static int manager_on_sighup(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) { Manager *manager = userdata; int r; fprintf(stderr, "Caught SIGHUP\n"); r = manager_reload_config(manager); if (r) { if (r == MANAGER_E_INVALID_CONFIG) fprintf(stderr, "Invalid configuration, ignored.\n"); else return error_fold(r); } return 1; } static int manager_on_dirwatch(sd_event_source *s, int fd, uint32_t revents, void *userdata) { Manager *manager = userdata; int r; r = dirwatch_dispatch(manager->dirwatch); if (r != DIRWATCH_E_TRIGGERED) return error_fold(r); fprintf(stderr, "Noticed file-system modification, trigger reload\n"); r = manager_reload_config(manager); if (r) { if (r == MANAGER_E_INVALID_CONFIG) fprintf(stderr, "Invalid configuration, ignored.\n"); else return error_fold(r); } return 1; } static int manager_new(Manager **managerp) { _c_cleanup_(manager_freep) Manager *manager = NULL; int r; manager = calloc(1, sizeof(*manager)); if (!manager) return error_origin(-ENOMEM); manager->fd_listen = -1; manager->uid = -1; manager->gid = -1; r = sd_event_default(&manager->event); if (r < 0) return error_origin(r); r = sd_event_add_signal(manager->event, NULL, SIGTERM, NULL, NULL); if (r < 0) return error_origin(r); r = sd_event_add_signal(manager->event, NULL, SIGINT, NULL, NULL); if (r < 0) return error_origin(r); r = sd_event_add_signal(manager->event, NULL, SIGHUP, manager_on_sighup, manager); if (r < 0) return error_origin(r); r = sd_bus_new(&manager->bus_controller); if (r < 0) return error_origin(r); *managerp = manager; manager = NULL; return 0; } static int manager_listen_inherit(Manager *manager) { _c_cleanup_(c_closep) int s = -1; int r, n; assert(manager->fd_listen < 0); n = sd_listen_fds(true); if (n < 0) return error_origin(n); if (n == 0) { fprintf(stderr, "No listener socket inherited\n"); return MAIN_FAILED; } if (n > 1) { fprintf(stderr, "More than one listener socket passed\n"); return MAIN_FAILED; } s = SD_LISTEN_FDS_START; r = sd_is_socket(s, PF_UNIX, SOCK_STREAM, 1); if (r < 0) return error_origin(r); if (!r) { fprintf(stderr, "Non unix-domain-socket passed as listener\n"); return MAIN_FAILED; } r = fcntl(s, F_GETFL); if (r < 0) return error_origin(-errno); r = fcntl(s, F_SETFL, r | O_NONBLOCK); if (r < 0) return error_origin(-errno); manager->fd_listen = s; s = -1; return 0; } static noreturn void manager_run_child(Manager *manager, int fd_log, int fd_controller) { sd_id128_t machine_id; char str_log[C_DECIMAL_MAX(int) + 1], str_controller[C_DECIMAL_MAX(int) + 1], str_machine_id[33], str_max_bytes[C_DECIMAL_MAX(uint64_t)], str_max_fds[C_DECIMAL_MAX(uint64_t)], str_max_matches[C_DECIMAL_MAX(uint64_t)]; const char * const argv[] = { "dbus-broker", "--log", str_log, "--controller", str_controller, "--machine-id", str_machine_id, "--max-bytes", str_max_bytes, "--max-fds", str_max_fds, "--max-matches", str_max_matches, main_arg_audit ? "--audit" : NULL, /* note that this needs to be the last argument to work */ NULL, }; int r; if (manager->uid != (uint32_t)-1) { r = util_audit_drop_permissions(manager->uid, manager->gid); if (r) goto exit; } r = prctl(PR_SET_PDEATHSIG, SIGTERM); if (r) { r = error_origin(-errno); goto exit; } r = fcntl(fd_log, F_GETFD); if (r < 0) { r = error_origin(-errno); goto exit; } r = fcntl(fd_log, F_SETFD, r & ~FD_CLOEXEC); if (r < 0) { r = error_origin(-errno); goto exit; } r = fcntl(fd_controller, F_GETFD); if (r < 0) { r = error_origin(-errno); goto exit; } r = fcntl(fd_controller, F_SETFD, r & ~FD_CLOEXEC); if (r < 0) { r = error_origin(-errno); goto exit; } r = sd_id128_get_machine(&machine_id); if (r < 0) { r = error_origin(r); goto exit; } sd_id128_to_string(machine_id, str_machine_id); r = snprintf(str_log, sizeof(str_log), "%d", fd_log); assert(r < (ssize_t)sizeof(str_log)); r = snprintf(str_controller, sizeof(str_controller), "%d", fd_controller); assert(r < (ssize_t)sizeof(str_controller)); r = snprintf(str_max_bytes, sizeof(str_max_bytes), "%"PRIu64, manager->max_bytes); assert(r < (ssize_t)sizeof(str_max_bytes)); r = snprintf(str_max_fds, sizeof(str_max_fds), "%"PRIu64, manager->max_fds); assert(r < (ssize_t)sizeof(str_max_fds)); r = snprintf(str_max_matches, sizeof(str_max_matches), "%"PRIu64, manager->max_matches); assert(r < (ssize_t)sizeof(str_max_matches)); r = execve(main_arg_broker, (char * const *)argv, environ); r = error_origin(-errno); exit: _exit(1); } static int manager_on_child_exit(sd_event_source *source, const siginfo_t *si, void *userdata) { fprintf(stderr, "Caught SIGCHLD of broker\n"); return sd_event_exit(sd_event_source_get_event(source), (si->si_code == CLD_EXITED) ? si->si_status : EXIT_FAILURE); } static int manager_fork(Manager *manager, int fd_controller) { pid_t pid; int r; pid = fork(); if (pid < 0) return error_origin(-errno); if (!pid) manager_run_child(manager, log_get_fd(&main_log), fd_controller); r = sd_event_add_child(manager->event, NULL, pid, WEXITED, manager_on_child_exit, manager); if (r < 0) return error_origin(-errno); close(fd_controller); return 0; } static int manager_start_unit_handler(sd_bus_message *message, void *userdata, sd_bus_error *errorp) { _c_cleanup_(c_freep) char *object_path = NULL; const sd_bus_error *error; Service *service = userdata; int r; service->slot = sd_bus_slot_unref(service->slot); error = sd_bus_message_get_error(message); if (!error) /* unit started successfully */ return 1; fprintf(stderr, "Activation request for '%s' failed: %s\n", service->name, error->message); /* unit failed, so reset pending activation requsets in the broker */ r = asprintf(&object_path, "/org/bus1/DBus/Name/%s", service->id); if (r < 0) return error_origin(-errno); r = sd_bus_call_method(service->manager->bus_controller, NULL, object_path, "org.bus1.DBus.Name", "Reset", NULL, NULL, ""); if (r < 0) return error_origin(r); return 1; } static int manager_start_unit(Manager *manager, Service *service) { _c_cleanup_(sd_bus_message_unrefp) sd_bus_message *method_call = NULL; int r; service->slot = sd_bus_slot_unref(service->slot); r = sd_bus_message_new_method_call(manager->bus_regular, &method_call, "org.freedesktop.systemd1", "/org/freedesktop/systemd1", "org.freedesktop.systemd1.Manager", "StartUnit"); if (r < 0) return error_origin(r); r = sd_bus_message_append(method_call, "ss", service->unit, "replace"); if (r < 0) return error_origin(r); r = sd_bus_call_async(manager->bus_regular, &service->slot, method_call, manager_start_unit_handler, service, -1); if (r < 0) return error_origin(r); return 0; } static int manager_start_transient_unit(Manager *manager, Service *service) { _c_cleanup_(sd_bus_message_unrefp) sd_bus_message *method_call = NULL; _c_cleanup_(c_freep) char *unit = NULL; const char *unique_name; int r; service->slot = sd_bus_slot_unref(service->slot); r = sd_bus_get_unique_name(manager->bus_regular, &unique_name); if (r < 0) return error_origin(r); r = asprintf(&unit, "dbus-%s-%s@%"PRIu64".service", unique_name, service->name, service->instance++); if (r < 0) return error_origin(-errno); r = sd_bus_message_new_method_call(manager->bus_regular, &method_call, "org.freedesktop.systemd1", "/org/freedesktop/systemd1", "org.freedesktop.systemd1.Manager", "StartTransientUnit"); if (r < 0) return error_origin(r); r = sd_bus_message_append(method_call, "ss", unit, "replace"); if (r < 0) return error_origin(r); r = sd_bus_message_open_container(method_call, 'a', "(sv)"); if (r < 0) return error_origin(r); { r = sd_bus_message_open_container(method_call, 'r', "sv"); if (r < 0) return error_origin(r); { r = sd_bus_message_append(method_call, "s", "ExecStart"); if (r < 0) return error_origin(r); r = sd_bus_message_open_container(method_call, 'v', "a(sasb)"); if (r < 0) return error_origin(r); { r = sd_bus_message_open_container(method_call, 'a', "(sasb)"); if (r < 0) return error_origin(r); { r = sd_bus_message_open_container(method_call, 'r', "sasb"); if (r < 0) return error_origin(r); { r = sd_bus_message_append(method_call, "s", service->argv[0]); if (r < 0) return error_origin(r); r = sd_bus_message_open_container(method_call, 'a', "s"); if (r < 0) return error_origin(r); { for (size_t i = 0; i < service->argc; ++i) { r = sd_bus_message_append(method_call, "s", service->argv[i]); if (r < 0) return error_origin(r); } } r = sd_bus_message_close_container(method_call); if (r < 0) return error_origin(r); r = sd_bus_message_append(method_call, "b", true); if (r < 0) return error_origin(r); } r = sd_bus_message_close_container(method_call); if (r < 0) return error_origin(r); } r = sd_bus_message_close_container(method_call); if (r < 0) return error_origin(r); } r = sd_bus_message_close_container(method_call); if (r < 0) return error_origin(r); } r = sd_bus_message_close_container(method_call); if (r < 0) return error_origin(r); r = sd_bus_message_open_container(method_call, 'r', "sv"); if (r < 0) return error_origin(r); { r = sd_bus_message_append(method_call, "s", "KillMode"); if (r < 0) return error_origin(r); r = sd_bus_message_open_container(method_call, 'v', "s"); if (r < 0) return error_origin(r); { r = sd_bus_message_append(method_call, "s", "process"); if (r < 0) return error_origin(r); } r = sd_bus_message_close_container(method_call); if (r < 0) return error_origin(r); } r = sd_bus_message_close_container(method_call); if (r < 0) return error_origin(r); if (service->user) { /* * Ideally we would unconditionally pass the UID * we are accounting on to systemd to run the service * under. However, in the case of the user instance, * systemd fails to start a transient unit if a user * is provided due to lack of permission. In practice * this works out ok, as in this case we would have * provided our own UID, which is systemd's UID, so * it would ammount to a no-op. It would have been * better if systemd could detect this case and not * fail, but in practice this is perfectly fine. */ r = sd_bus_message_open_container(method_call, 'r', "sv"); if (r < 0) return error_origin(r); { r = sd_bus_message_append(method_call, "s", "User"); if (r < 0) return error_origin(r); r = sd_bus_message_open_container(method_call, 'v', "s"); if (r < 0) return error_origin(r); { _c_cleanup_(c_freep) char *uid = NULL; /* * Pass the UID we parsed, rather than the * original username. This should resolve * to the same, but out of an abundance of * caution, we try to avoid any * inconsistencies. */ r = asprintf(&uid, "%"PRIu32, service->uid); if (r < 0) return error_origin(-errno); r = sd_bus_message_append(method_call, "s", uid); if (r < 0) return error_origin(r); } r = sd_bus_message_close_container(method_call); if (r < 0) return error_origin(r); } r = sd_bus_message_close_container(method_call); if (r < 0) return error_origin(r); } } r = sd_bus_message_close_container(method_call); if (r < 0) return error_origin(r); r = sd_bus_message_append(method_call, "a(sa(sv))", 0); if (r < 0) return error_origin(r); r = sd_bus_call_async(manager->bus_regular, &service->slot, method_call, manager_start_unit_handler, service, -1); if (r < 0) return error_origin(r); return 0; } static int manager_on_name_activate(Manager *manager, sd_bus_message *m, const char *id) { Service *service; int r; service = c_rbtree_find_entry(&manager->services, service_compare, id, Service, rb); if (!service) { fprintf(stderr, "Activation request on unknown name '%s'\n", id); return 0; } else if (!strcmp(service->name, "org.freedesktop.systemd1")) { /* pid1 activation requests are silently ignored */ return 0; } if (service->unit) { r = manager_start_unit(manager, service); if (r) return error_trace(r); } else { r = manager_start_transient_unit(manager, service); if (r) return error_trace(r); } return 0; } static int manager_set_environment_handler(sd_bus_message *message, void *userdata, sd_bus_error *errorp) { const sd_bus_error *error; error = sd_bus_message_get_error(message); if (!error) /* environment set successfully */ return 1; fprintf(stderr, "Updating activation environment failed: %s\n", error->message); return 1; } static int manager_on_set_activation_environment(Manager *manager, sd_bus_message *m) { _c_cleanup_(sd_bus_message_unrefp) sd_bus_message *method_call = NULL; int r; r = sd_bus_message_new_method_call(manager->bus_regular, &method_call, "org.freedesktop.systemd1", "/org/freedesktop/systemd1", "org.freedesktop.systemd1.Manager", "SetEnvironment"); if (r < 0) return error_origin(r); r = sd_bus_message_enter_container(m, 'a', "{ss}"); if (r < 0) return error_origin(r); r = sd_bus_message_open_container(method_call, 'a', "s"); if (r < 0) return error_origin(r); while (!sd_bus_message_at_end(m, false)) { _c_cleanup_(c_freep) char *entry = NULL; const char *key, *value; r = sd_bus_message_read(m, "{ss}", &key, &value); if (r < 0) return error_origin(r); r = asprintf(&entry, "%s=%s", key, value); if (r < 0) return error_origin(-errno); r = sd_bus_message_append(method_call, "s", entry); if (r < 0) return error_origin(r); } r = sd_bus_message_close_container(method_call); if (r < 0) return error_origin(r); r = sd_bus_message_exit_container(m); if (r < 0) return error_origin(r); r = sd_bus_call_async(manager->bus_regular, NULL, method_call, manager_set_environment_handler, NULL, -1); if (r < 0) return error_origin(r); return 0; } static int manager_on_message(sd_bus_message *m, void *userdata, sd_bus_error *error) { Manager *manager = userdata; const char *path, *suffix; int r = 0; path = sd_bus_message_get_path(m); if (!path) return 0; suffix = c_string_prefix(path, "/org/bus1/DBus/Name/"); if (suffix) { if (sd_bus_message_is_signal(m, "org.bus1.DBus.Name", "Activate")) r = manager_on_name_activate(manager, m, suffix); } else if (strcmp(path, "/org/bus1/DBus/Broker") == 0) { if (sd_bus_message_is_signal(m, "org.bus1.DBus.Broker", "SetActivationEnvironment")) r = manager_on_set_activation_environment(manager, m); } return error_trace(r); } static int manager_load_service_file(Manager *manager, const char *path, NSSCache *nss_cache) { gchar *name = NULL, *user = NULL, *unit = NULL, *exec = NULL, **argv = NULL; gint argc = 0; _c_cleanup_(service_freep) Service *service = NULL; GKeyFile *f; CRBNode **slot, *parent; uid_t uid; int r; /* * There seems to be no trivial way to properly parse D-Bus service * files. Hence, we resort to glib GKeyFile to parse it as a Desktop * File compatible ini-file. * * Preferably, we'd not have the glib dependency here, but it does not * hurt much either. If anyone cares, feel free to provide `c-ini'. */ f = g_key_file_new(); if (!g_key_file_load_from_file(f, path, G_KEY_FILE_NONE, NULL)) { fprintf(stderr, "Cannot load service file '%s'\n", path); r = 0; goto exit; } name = g_key_file_get_string(f, "D-BUS Service", "Name", NULL); user = g_key_file_get_string(f, "D-BUS Service", "User", NULL); unit = g_key_file_get_string(f, "D-BUS Service", "SystemdService", NULL); exec = g_key_file_get_string(f, "D-BUS Service", "Exec", NULL); if (!name) { fprintf(stderr, "Missing name in service file '%s'\n", path); r = 0; goto exit; } if (!unit && !exec) { fprintf(stderr, "Missing exec or unit in service file '%s'\n", path); r = 0; goto exit; } if (exec) { GError *error = NULL; if (!g_shell_parse_argv(exec, &argc, &argv, &error)) { fprintf(stderr, "Invalid exec '%s' in service file '%s': %s\n", exec, path, error->message); g_error_free(error); r = 0; goto exit; } } if (user) { r = nss_cache_get_uid(nss_cache, &uid, NULL, user); if (r) { if (r == NSS_CACHE_E_INVALID_NAME) { fprintf(stderr, "Invalid user name '%s' in service file '%s'\n", user, path); r = 0; goto exit; } } } else { uid = getuid(); } slot = c_rbtree_find_slot(&manager->services_by_name, service_compare_by_name, name, &parent); if (slot) { r = service_new(&service, manager, name, slot, parent, unit, argc, argv, user, uid); if (r) { r = error_trace(r); goto exit; } } else { Service *old_service = c_container_of(parent, Service, rb_by_name); if (old_service->state == SERVICE_STATE_DEFUNCT) { old_service->state = SERVICE_STATE_CURRENT; r = service_update(old_service, unit, argc, argv, user, uid); if (r) r = error_trace(r); } else { fprintf(stderr, "Ignoring duplicate name '%s' in service file '%s'\n", name, path); r = 0; } goto exit; } service = NULL; r = 0; exit: g_free(unit); g_free(user); g_free(name); g_free(exec); g_strfreev(argv); g_key_file_free(f); return r; } static int manager_load_service_dir(Manager *manager, const char *dirpath, NSSCache *nss_cache) { const char suffix[] = ".service"; _c_cleanup_(c_closedirp) DIR *dir = NULL; struct dirent *de; char *path; size_t n; int r; dir = opendir(dirpath); if (!dir) { if (errno == ENOENT || errno == ENOTDIR) return 0; else return error_origin(-errno); } r = dirwatch_add(manager->dirwatch, dirpath); if (r) return error_fold(r); for (errno = 0, de = readdir(dir); de; errno = 0, de = readdir(dir)) { if (de->d_name[0] == '.') continue; n = strlen(de->d_name); if (n <= strlen(suffix)) continue; if (strcmp(de->d_name + n - strlen(suffix), suffix)) continue; r = asprintf(&path, "%s/%s", dirpath, de->d_name); if (r < 0) return error_origin(-ENOMEM); r = manager_load_service_file(manager, path, nss_cache); free(path); if (r) return error_trace(r); } if (errno > 0) return error_origin(-errno); return 0; } static int manager_add_services(Manager *manager) { Service *service; int r; c_rbtree_for_each_entry(service, &manager->services, rb) { _c_cleanup_(c_freep) char *object_path = NULL; if (service->state != SERVICE_STATE_PENDING) continue; r = asprintf(&object_path, "/org/bus1/DBus/Name/%s", service->id); if (r < 0) return error_origin(-ENOMEM); r = sd_bus_call_method(manager->bus_controller, NULL, "/org/bus1/DBus/Broker", "org.bus1.DBus.Broker", "AddName", NULL, NULL, "osu", object_path, service->name, service->uid); if (r < 0) return error_origin(r); service->state = SERVICE_STATE_CURRENT; } return 0; } static int manager_remove_services(Manager *manager) { Service *service, *service_safe; int r; c_rbtree_for_each_entry_safe(service, service_safe, &manager->services, rb) { _c_cleanup_(c_freep) char *object_path = NULL; if (service->state != SERVICE_STATE_DEFUNCT) continue; r = asprintf(&object_path, "/org/bus1/DBus/Name/%s", service->id); if (r < 0) return error_origin(-ENOMEM); r = sd_bus_call_method(manager->bus_controller, NULL, object_path, "org.bus1.DBus.Name", "Release", NULL, NULL, ""); if (r < 0) return error_origin(r); service_free(service); } return 0; } static int manager_load_standard_session_services(Manager *manager, NSSCache *nss_cache) { const char *suffix = "dbus-1/services"; int r; /* * $XDG_RUNTIME_DIR/dbus-1/services is used in user-scope to * load transient units. dbus-daemon(1) actually creates this * path, we don't. It is incompatible with socket-activation of * dbus-daemon(1), so you must already be able to deal with * creating the directory yourself. But if the directory is * there, we load units from it. */ { _c_cleanup_(c_freep) char *dirpath = NULL; const char *runtime_dir; runtime_dir = getenv("XDG_RUNTIME_DIR"); if (!runtime_dir) { fprintf(stderr, "Cannot figure out service runtime directory\n"); } else { r = asprintf(&dirpath, "%s/%s", runtime_dir, suffix); if (r < 0) return error_origin(-ENOMEM); r = manager_load_service_dir(manager, dirpath, nss_cache); if (r) return error_trace(r); } } /* * $HOME/.local/share/dbus-1/services is used for user buses * additionally to the above mentioned directories. Note that * it can be modified via the XDG_DATA_HOME env-variable. */ { _c_cleanup_(c_freep) char *data_home_dir = NULL; struct passwd *passwd; const char *dir; dir = getenv("XDG_DATA_HOME"); if (dir) { r = asprintf(&data_home_dir, "%s/%s", dir, suffix); if (r < 0) return error_origin(-ENOMEM); } else { passwd = getpwuid(getuid()); if (passwd && passwd->pw_dir) { r = asprintf(&data_home_dir, "%s/.local/share/%s", passwd->pw_dir, suffix); if (r < 0) return error_origin(-ENOMEM); } } if (!data_home_dir) { fprintf(stderr, "Cannot figure out service home directory\n"); } else { r = manager_load_service_dir(manager, data_home_dir, nss_cache); if (r) return error_trace(r); } } /* * As last step, XDG_DATA_DIRS (or its default) are searched for * service files. ./dbus-1/services/ is appended to each path found in * XDG_DATA_DIRS. */ { const char *data_dirs, *sep; size_t n; data_dirs = getenv("XDG_DATA_DIRS") ?: "/usr/local/share:/usr/share"; while (*data_dirs) { sep = strchr(data_dirs, ':'); n = sep ? (size_t)(sep - data_dirs) : strlen(data_dirs); if (n) { _c_cleanup_(c_freep) char *dirpath = NULL; r = asprintf(&dirpath, "%.*s/%s", (int)n, data_dirs, suffix); if (r < 0) return error_origin(-ENOMEM); r = manager_load_service_dir(manager, dirpath, nss_cache); if (r) return error_trace(r); } data_dirs += n + !!sep; } } return 0; } static int manager_load_standard_system_services(Manager *manager, NSSCache *nss_cache) { static const char *default_data_dirs[] = { "/usr/local/share", "/usr/share", "/lib", NULL, }; const char *suffix = "dbus-1/system-services"; size_t i; int r; /* * In system scope, the default data directories are used. They * cannot be modified via env-variables! * * dbus-daemon(1) also supports /lib, which we don't. If there * is need, add it later. * * The order in which the directories are parsed follows the order * of dbus-daemon(1). */ for (i = 0; default_data_dirs[i]; ++i) { _c_cleanup_(c_freep) char *dirpath = NULL; r = asprintf(&dirpath, "%s/%s", default_data_dirs[i], suffix); if (r < 0) return error_origin(-ENOMEM); r = manager_load_service_dir(manager, dirpath, nss_cache); if (r) return error_trace(r); } return 0; } static int manager_load_services(Manager *manager, ConfigRoot *config, NSSCache *nss_cache) { ConfigNode *cnode; int r; c_list_for_each_entry(cnode, &config->node_list, root_link) { switch (cnode->type) { case CONFIG_NODE_STANDARD_SESSION_SERVICEDIRS: r = manager_load_standard_session_services(manager, nss_cache); if (r) return error_trace(r); break; case CONFIG_NODE_STANDARD_SYSTEM_SERVICEDIRS: r = manager_load_standard_system_services(manager, nss_cache); if (r) return error_trace(r); break; case CONFIG_NODE_SERVICEDIR: r = manager_load_service_dir(manager, cnode->servicedir.path, nss_cache); if (r) return error_trace(r); break; default: /* ignored */ break; } } return 0; } static int manager_parse_config(Manager *manager, ConfigRoot **rootp, NSSCache *nss_cache) { _c_cleanup_(config_parser_deinit) ConfigParser parser = CONFIG_PARSER_NULL(parser); _c_cleanup_(dirwatch_freep) Dirwatch *dirwatch = NULL; uint64_t max_match_rules_per_connection = main_max_match_rules_per_connection; uint64_t max_connections_per_user = main_max_connections_per_user; uint64_t max_outgoing_unix_fds = main_max_outgoing_unix_fds; uint64_t max_outgoing_bytes = main_max_outgoing_bytes; const char *configfile; ConfigNode *cnode; int r; r = dirwatch_new(&dirwatch); if (r) return error_fold(r); if (main_arg_configfile) configfile = main_arg_configfile; else if (main_arg_user_scope) configfile = "/usr/share/dbus-1/session.conf"; else configfile = "/usr/share/dbus-1/system.conf"; config_parser_init(&parser); r = config_parser_read(&parser, rootp, configfile, nss_cache, dirwatch); if (r) { if (r == CONFIG_E_INVALID) return MANAGER_E_INVALID_CONFIG; return error_fold(r); } manager->dirwatch = dirwatch_free(manager->dirwatch); manager->dirwatch_src = sd_event_source_unref(manager->dirwatch_src); manager->dirwatch = dirwatch; dirwatch = NULL; r = sd_event_add_io(manager->event, &manager->dirwatch_src, dirwatch_get_fd(manager->dirwatch), EPOLLIN, manager_on_dirwatch, manager); if (r) return error_origin(r); c_list_for_each_entry(cnode, &(*rootp)->node_list, root_link) { switch (cnode->type) { case CONFIG_NODE_USER: if (cnode->user.valid) { manager->uid = cnode->user.uid; manager->gid = cnode->user.gid; } break; case CONFIG_NODE_LIMIT: switch (cnode->limit.name) { case CONFIG_LIMIT_MAX_OUTGOING_BYTES: max_outgoing_bytes = cnode->limit.value; break; case CONFIG_LIMIT_MAX_OUTGOING_UNIX_FDS: max_outgoing_unix_fds = cnode->limit.value; break; case CONFIG_LIMIT_MAX_CONNECTIONS_PER_USER: max_connections_per_user = cnode->limit.value; break; case CONFIG_LIMIT_MAX_MATCH_RULES_PER_CONNECTION: max_match_rules_per_connection = cnode->limit.value; break; } break; default: /* ignored */ break; } } /* Convert the per-connection limits into per-user limits. */ manager->max_bytes = util_umul64_saturating(max_connections_per_user, max_outgoing_bytes); manager->max_fds = util_umul64_saturating(max_connections_per_user, max_outgoing_unix_fds); manager->max_matches = util_umul64_saturating(max_connections_per_user, max_match_rules_per_connection); return 0; } static int manager_load_policy(Manager *manager, ConfigRoot *root, Policy *policy) { int r; r = policy_import(policy, root); if (r) return error_fold(r); policy_optimize(policy); return 0; } static int manager_add_listener(Manager *manager, Policy *policy, uint32_t *system_console_users, size_t n_system_console_users) { _c_cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL; int r; r = sd_bus_message_new_method_call(manager->bus_controller, &m, NULL, "/org/bus1/DBus/Broker", "org.bus1.DBus.Broker", "AddListener"); if (r < 0) return error_origin(r); r = sd_bus_message_append(m, "oh", "/org/bus1/DBus/Listener/0", manager->fd_listen); if (r < 0) return error_origin(r); r = policy_export(policy, m, system_console_users, n_system_console_users); if (r) return error_fold(r); r = sd_bus_call(manager->bus_controller, m, 0, NULL, NULL); if (r < 0) return error_origin(r); return 0; } static int manager_set_policy(Manager *manager, Policy *policy, uint32_t *system_console_users, size_t n_system_console_users) { _c_cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL; int r; r = sd_bus_message_new_method_call(manager->bus_controller, &m, NULL, "/org/bus1/DBus/Listener/0", "org.bus1.DBus.Listener", "SetPolicy"); if (r < 0) return error_origin(r); r = policy_export(policy, m, system_console_users, n_system_console_users); if (r) return error_fold(r); r = sd_bus_call(manager->bus_controller, m, 0, NULL, NULL); if (r < 0) return error_origin(r); return 0; } static int manager_reload_config(Manager *manager) { _c_cleanup_(config_root_freep) ConfigRoot *root = NULL; _c_cleanup_(policy_deinit) Policy policy = POLICY_INIT(policy); _c_cleanup_(nss_cache_deinit) NSSCache nss_cache = NSS_CACHE_INIT; _c_cleanup_(c_freep) uint32_t *system_console_users = NULL; size_t n_system_console_users; Service *service; int r, res; r = sd_notify(false, "RELOADING=1"); if (r < 0) return error_origin(r); c_rbtree_for_each_entry(service, &manager->services, rb) service->state = SERVICE_STATE_DEFUNCT; r = nss_cache_populate(&nss_cache); if (r) goto out; r = manager_parse_config(manager, &root, &nss_cache); if (r) goto out; r = nss_cache_resolve_system_console_users(&nss_cache, &system_console_users, &n_system_console_users); if (r) return error_trace(r); r = manager_load_services(manager, root, &nss_cache); if (r) goto out; r = manager_load_policy(manager, root, &policy); if (r) goto out; switch (policy.apparmor_mode) { case CONFIG_APPARMOR_ENABLED: { bool enabled; /* XXX: See comments in manager_run() */ r = bus_apparmor_is_enabled(&enabled); if (r) return error_fold(r); if (enabled) fprintf(stderr, "AppArmor enabled, but not supported. Ignoring.\n"); policy.apparmor_mode = CONFIG_APPARMOR_DISABLED; break; } case CONFIG_APPARMOR_REQUIRED: fprintf(stderr, "AppArmor required, but not supported. Exiting.\n"); r = sd_event_exit(manager->event, 0); if (r < 0) return error_fold(r); return 0; } r = manager_remove_services(manager); if (r) goto out; r = manager_set_policy(manager, &policy, system_console_users, n_system_console_users); if (r) goto out; r = manager_add_services(manager); if (r) goto out; out: res = sd_notify(false, "READY=1"); if (res < 0) return error_origin(res); return error_trace(r); } static int manager_connect(Manager *manager) { int r; assert(!manager->bus_regular); if (main_arg_user_scope) { r = sd_bus_open_user(&manager->bus_regular); if (r < 0) return error_origin(r); } else { r = sd_bus_open_system(&manager->bus_regular); if (r < 0) return error_origin(r); } return 0; } static int bus_method_reload_config(sd_bus_message *message, void *userdata, sd_bus_error *error) { Manager *manager = userdata; int r; r = manager_reload_config(manager); if (r) { if (r == MANAGER_E_INVALID_CONFIG) return sd_bus_reply_method_errorf(message, "org.bus1.DBus.Controller.Error.InvalidConfig", "Invalid configuration. Reload ignored."); else return error_fold(r); } return sd_bus_reply_method_return(message, NULL); } const sd_bus_vtable manager_vtable[] = { SD_BUS_VTABLE_START(0), SD_BUS_METHOD("ReloadConfig", NULL, NULL, bus_method_reload_config, 0), SD_BUS_VTABLE_END }; static int manager_run(Manager *manager) { _c_cleanup_(config_root_freep) ConfigRoot *root = NULL; _c_cleanup_(policy_deinit) Policy policy = POLICY_INIT(policy); _c_cleanup_(nss_cache_deinit) NSSCache nss_cache = NSS_CACHE_INIT; _c_cleanup_(c_freep) uint32_t *system_console_users = NULL; size_t n_system_console_users; int r, controller[2]; r = nss_cache_populate(&nss_cache); if (r) return error_fold(r); r = manager_parse_config(manager, &root, &nss_cache); if (r) return error_trace(r); r = nss_cache_resolve_system_console_users(&nss_cache, &system_console_users, &n_system_console_users); if (r) return error_trace(r); r = manager_load_services(manager, root, &nss_cache); if (r) return error_trace(r); r = sd_notify(false, "READY=1"); if (r < 0) return error_origin(r); r = manager_load_policy(manager, root, &policy); if (r) return error_trace(r); switch (policy.apparmor_mode) { case CONFIG_APPARMOR_ENABLED: { bool enabled; r = bus_apparmor_is_enabled(&enabled); if (r) return error_fold(r); if (enabled) fprintf(stderr, "AppArmor enabled, but not supported. Ignoring.\n"); /* XXX: once the broker supports AppArmor, set this to DISABLED if and only if * it is disabled in the kernel. */ policy.apparmor_mode = CONFIG_APPARMOR_DISABLED; break; } case CONFIG_APPARMOR_REQUIRED: fprintf(stderr, "AppArmor required, but not supported. Exiting.\n"); /* XXX: once the broker supports AppArmor, set this to enabled if and only * if it is enabled in the kernel, and exit the launcher otherwise. */ return 0; } assert(manager->fd_listen >= 0); r = socketpair(PF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0, controller); if (r < 0) return error_origin(-errno); /* consumes FD controller[0] */ r = sd_bus_set_fd(manager->bus_controller, controller[0], controller[0]); if (r < 0) { close(controller[0]); close(controller[1]); return error_origin(r); } /* consumes FD controller[1] */ r = manager_fork(manager, controller[1]); if (r) { close(controller[1]); return error_trace(r); } r = sd_bus_add_object_vtable(manager->bus_controller, NULL, "/org/bus1/DBus/Controller", "org.bus1.DBus.Controller", manager_vtable, manager); if (r < 0) return error_origin(r); r = sd_bus_add_filter(manager->bus_controller, NULL, manager_on_message, manager); if (r < 0) return error_origin(r); r = sd_bus_start(manager->bus_controller); if (r < 0) return error_origin(r); r = manager_add_services(manager); if (r) return error_trace(r); r = manager_add_listener(manager, &policy, system_console_users, n_system_console_users); if (r) return error_trace(r); r = manager_connect(manager); if (r) return error_trace(r); r = sd_bus_attach_event(manager->bus_controller, manager->event, SD_EVENT_PRIORITY_NORMAL); if (r < 0) return error_origin(r); r = sd_bus_attach_event(manager->bus_regular, manager->event, SD_EVENT_PRIORITY_NORMAL); if (r < 0) return error_origin(r); if (manager->uid != (uint32_t)-1) { r = util_drop_permissions(manager->uid, manager->gid); if (r) return error_fold(r); } r = sd_event_loop(manager->event); if (r < 0) return error_origin(r); else if (r > 0) return MAIN_FAILED; return 0; } static int open_log(void) { _c_cleanup_(c_closep) int fd = -1; struct sockaddr_un address = { .sun_family = AF_UNIX, .sun_path = "/run/systemd/journal/socket", }; int r; fd = socket(PF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC, 0); if (fd < 0) return error_origin(-errno); r = connect(fd, (struct sockaddr *)&address, offsetof(struct sockaddr_un, sun_path) + strlen(address.sun_path)); if (r < 0) return error_origin(-errno); log_init_journal_consume(&main_log, fd); fd = -1; return 0; } static void help(void) { printf("%s [GLOBALS...] ...\n\n" "Linux D-Bus Message Broker Launcher\n\n" " -h --help Show this help\n" " --version Show package version\n" " --audit Enable audit support\n" " --config-file PATH Specify path to configuration file\n" " --scope SCOPE Scope of message bus\n" , program_invocation_short_name); } static int parse_argv(int argc, char *argv[]) { enum { ARG_VERSION = 0x100, ARG_VERBOSE, ARG_AUDIT, ARG_CONFIG, ARG_SCOPE, }; static const struct option options[] = { { "help", no_argument, NULL, 'h' }, { "version", no_argument, NULL, ARG_VERSION }, { "verbose", no_argument, NULL, ARG_VERBOSE }, { "audit", no_argument, NULL, ARG_AUDIT }, { "config-file", required_argument, NULL, ARG_CONFIG, }, { "scope", required_argument, NULL, ARG_SCOPE }, {} }; int c; while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) { switch (c) { case 'h': help(); return MAIN_EXIT; case ARG_VERSION: printf("dbus-broker-launch %d\n", PACKAGE_VERSION); return MAIN_EXIT; /* noop for backward compatibility */ case ARG_VERBOSE: break; case ARG_AUDIT: main_arg_audit = true; break; case ARG_CONFIG: main_arg_configfile = optarg; break; case ARG_SCOPE: if (!strcmp(optarg, "system")) { main_arg_user_scope = false; } else if (!strcmp(optarg, "user")) { main_arg_user_scope = true; } else { fprintf(stderr, "%s: invalid message bus scope -- '%s'\n", program_invocation_name, optarg); return MAIN_FAILED; } break; case '?': /* getopt_long() prints warning */ return MAIN_FAILED; default: return error_origin(-EINVAL); } } if (optind != argc) { fprintf(stderr, "%s: invalid arguments -- '%s'\n", program_invocation_name, argv[optind]); return MAIN_FAILED; } return 0; } static int run(void) { _c_cleanup_(manager_freep) Manager *manager = NULL; int r; r = manager_new(&manager); if (r) return error_trace(r); r = manager_listen_inherit(manager); if (r) return error_trace(r); r = manager_run(manager); r = error_trace(r); return r; } int main(int argc, char **argv) { sigset_t mask_new, mask_old; int r; r = open_log(); if (r) goto exit; r = parse_argv(argc, argv); if (r) goto exit; sigemptyset(&mask_new); sigaddset(&mask_new, SIGCHLD); sigaddset(&mask_new, SIGTERM); sigaddset(&mask_new, SIGINT); sigaddset(&mask_new, SIGHUP); sigprocmask(SIG_BLOCK, &mask_new, &mask_old); r = run(); sigprocmask(SIG_SETMASK, &mask_old, NULL); exit: r = error_trace(r); if (r < 0) fprintf(stderr, "Exiting due to fatal error: %d\n", r); return (r == 0 || r == MAIN_EXIT) ? 0 : 1; }