diff options
Diffstat (limited to 'src/userdb')
| -rw-r--r-- | src/userdb/meson.build | 11 | ||||
| -rw-r--r-- | src/userdb/userdbd-manager.c | 302 | ||||
| -rw-r--r-- | src/userdb/userdbd-manager.h | 34 | ||||
| -rw-r--r-- | src/userdb/userdbd.c | 56 | ||||
| -rw-r--r-- | src/userdb/userwork.c | 778 |
5 files changed, 1181 insertions, 0 deletions
diff --git a/src/userdb/meson.build b/src/userdb/meson.build new file mode 100644 index 0000000000..72d2f7da08 --- /dev/null +++ b/src/userdb/meson.build @@ -0,0 +1,11 @@ +# SPDX-License-Identifier: LGPL-2.1+ + +systemd_userwork_sources = files(''' + userwork.c +'''.split()) + +systemd_userdbd_sources = files(''' + userdbd-manager.c + userdbd-manager.h + userdbd.c +'''.split()) diff --git a/src/userdb/userdbd-manager.c b/src/userdb/userdbd-manager.c new file mode 100644 index 0000000000..2836ca0409 --- /dev/null +++ b/src/userdb/userdbd-manager.c @@ -0,0 +1,302 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ + +#include <sys/wait.h> + +#include "sd-daemon.h" + +#include "fd-util.h" +#include "fs-util.h" +#include "mkdir.h" +#include "process-util.h" +#include "set.h" +#include "signal-util.h" +#include "socket-util.h" +#include "stdio-util.h" +#include "umask-util.h" +#include "userdbd-manager.h" + +#define LISTEN_TIMEOUT_USEC (25 * USEC_PER_SEC) + +static int start_workers(Manager *m, bool explicit_request); + +static int on_sigchld(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) { + Manager *m = userdata; + + assert(s); + assert(m); + + for (;;) { + siginfo_t siginfo = {}; + bool removed = false; + + if (waitid(P_ALL, 0, &siginfo, WNOHANG|WEXITED) < 0) { + if (errno == ECHILD) + break; + + log_warning_errno(errno, "Failed to invoke waitid(): %m"); + break; + } + if (siginfo.si_pid == 0) + break; + + if (set_remove(m->workers_dynamic, PID_TO_PTR(siginfo.si_pid))) + removed = true; + if (set_remove(m->workers_fixed, PID_TO_PTR(siginfo.si_pid))) + removed = true; + + if (!removed) { + log_warning("Weird, got SIGCHLD for unknown child " PID_FMT ", ignoring.", siginfo.si_pid); + continue; + } + + if (siginfo.si_code == CLD_EXITED) { + if (siginfo.si_status == EXIT_SUCCESS) + log_debug("Worker " PID_FMT " exited successfully.", siginfo.si_pid); + else + log_warning("Worker " PID_FMT " died with a failure exit status %i, ignoring.", siginfo.si_pid, siginfo.si_status); + } else if (siginfo.si_code == CLD_KILLED) + log_warning("Worker " PID_FMT " was killed by signal %s, ignoring.", siginfo.si_pid, signal_to_string(siginfo.si_status)); + else if (siginfo.si_code == CLD_DUMPED) + log_warning("Worker " PID_FMT " dumped core by signal %s, ignoring.", siginfo.si_pid, signal_to_string(siginfo.si_status)); + else + log_warning("Can't handle SIGCHLD of this type"); + } + + (void) start_workers(m, false); /* Fill up workers again if we fell below the low watermark */ + return 0; +} + +static int on_sigusr2(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) { + Manager *m = userdata; + + assert(s); + assert(m); + + (void) start_workers(m, true); /* Workers told us there's more work, let's add one more worker as long as we are below the high watermark */ + return 0; +} + +int manager_new(Manager **ret) { + Manager *m; + int r; + + m = new(Manager, 1); + if (!m) + return -ENOMEM; + + *m = (Manager) { + .listen_fd = -1, + .worker_ratelimit = { + .interval = 5 * USEC_PER_SEC, + .burst = 50, + }, + }; + + r = sd_event_new(&m->event); + if (r < 0) + return r; + + r = sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL); + if (r < 0) + return r; + + r = sd_event_add_signal(m->event, NULL, SIGTERM, NULL, NULL); + if (r < 0) + return r; + + (void) sd_event_set_watchdog(m->event, true); + + m->workers_fixed = set_new(NULL); + m->workers_dynamic = set_new(NULL); + + if (!m->workers_fixed || !m->workers_dynamic) + return -ENOMEM; + + r = sd_event_add_signal(m->event, &m->sigusr2_event_source, SIGUSR2, on_sigusr2, m); + if (r < 0) + return r; + + r = sd_event_add_signal(m->event, &m->sigchld_event_source, SIGCHLD, on_sigchld, m); + if (r < 0) + return r; + + *ret = TAKE_PTR(m); + return 0; +} + +Manager* manager_free(Manager *m) { + if (!m) + return NULL; + + set_free(m->workers_fixed); + set_free(m->workers_dynamic); + + sd_event_source_disable_unref(m->sigusr2_event_source); + sd_event_source_disable_unref(m->sigchld_event_source); + + sd_event_unref(m->event); + + return mfree(m); +} + +static size_t manager_current_workers(Manager *m) { + assert(m); + + return set_size(m->workers_fixed) + set_size(m->workers_dynamic); +} + +static int start_one_worker(Manager *m) { + bool fixed; + pid_t pid; + int r; + + assert(m); + + fixed = set_size(m->workers_fixed) < USERDB_WORKERS_MIN; + + r = safe_fork("(sd-worker)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_LOG, &pid); + if (r < 0) + return log_error_errno(r, "Failed to fork new worker child: %m"); + if (r == 0) { + char pids[DECIMAL_STR_MAX(pid_t)]; + /* Child */ + + log_close(); + + r = close_all_fds(&m->listen_fd, 1); + if (r < 0) { + log_error_errno(r, "Failed to close fds in child: %m"); + _exit(EXIT_FAILURE); + } + + log_open(); + + if (m->listen_fd == 3) { + r = fd_cloexec(3, false); + if (r < 0) { + log_error_errno(r, "Failed to turn off O_CLOEXEC for fd 3: %m"); + _exit(EXIT_FAILURE); + } + } else { + if (dup2(m->listen_fd, 3) < 0) { /* dup2() creates with O_CLOEXEC off */ + log_error_errno(errno, "Failed to move listen fd to 3: %m"); + _exit(EXIT_FAILURE); + } + + safe_close(m->listen_fd); + } + + xsprintf(pids, PID_FMT, pid); + if (setenv("LISTEN_PID", pids, 1) < 0) { + log_error_errno(errno, "Failed to set $LISTEN_PID: %m"); + _exit(EXIT_FAILURE); + } + + if (setenv("LISTEN_FDS", "1", 1) < 0) { + log_error_errno(errno, "Failed to set $LISTEN_FDS: %m"); + _exit(EXIT_FAILURE); + } + + + if (setenv("USERDB_FIXED_WORKER", one_zero(fixed), 1) < 0) { + log_error_errno(errno, "Failed to set $USERDB_FIXED_WORKER: %m"); + _exit(EXIT_FAILURE); + } + + /* execl("/home/lennart/projects/systemd/build/systemd-userwork", "systemd-userwork", "xxxxxxxxxxxxxxxx", NULL); /\* With some extra space rename_process() can make use of *\/ */ + /* execl("/usr/bin/valgrind", "valgrind", "/home/lennart/projects/systemd/build/systemd-userwork", "systemd-userwork", "xxxxxxxxxxxxxxxx", NULL); /\* With some extra space rename_process() can make use of *\/ */ + + execl(SYSTEMD_USERWORK_PATH, "systemd-userwork", "xxxxxxxxxxxxxxxx", NULL); /* With some extra space rename_process() can make use of */ + log_error_errno(errno, "Failed start worker process: %m"); + _exit(EXIT_FAILURE); + } + + if (fixed) + r = set_put(m->workers_fixed, PID_TO_PTR(pid)); + else + r = set_put(m->workers_dynamic, PID_TO_PTR(pid)); + if (r < 0) + return log_error_errno(r, "Failed to add child process to set: %m"); + + return 0; +} + +static int start_workers(Manager *m, bool explicit_request) { + int r; + + assert(m); + + for (;;) { + size_t n; + + n = manager_current_workers(m); + if (n >= USERDB_WORKERS_MIN && (!explicit_request || n >= USERDB_WORKERS_MAX)) + break; + + if (!ratelimit_below(&m->worker_ratelimit)) { + /* If we keep starting workers too often, let's fail the whole daemon, something is wrong */ + sd_event_exit(m->event, EXIT_FAILURE); + + return log_error_errno(SYNTHETIC_ERRNO(EUCLEAN), "Worker threads requested too frequently, something is wrong."); + } + + r = start_one_worker(m); + if (r < 0) + return r; + + explicit_request = false; + } + + return 0; +} + +int manager_startup(Manager *m) { + struct timeval ts; + int n, r; + + assert(m); + assert(m->listen_fd < 0); + + n = sd_listen_fds(false); + if (n < 0) + return log_error_errno(n, "Failed to determine number of passed file descriptors: %m"); + if (n > 1) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Expected one listening fd, got %i.", n); + if (n == 1) + m->listen_fd = SD_LISTEN_FDS_START; + else { + union sockaddr_union sockaddr; + + r = sockaddr_un_set_path(&sockaddr.un, "/run/systemd/userdb/io.systemd.NameServiceSwitch"); + if (r < 0) + return log_error_errno(r, "Cannot assign socket path to socket address: %m"); + + r = mkdir_p("/run/systemd/userdb", 0755); + if (r < 0) + return log_error_errno(r, "Failed to create /run/systemd/userdb: %m"); + + m->listen_fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0); + if (m->listen_fd < 0) + return log_error_errno(errno, "Failed to bind on socket: %m"); + + (void) sockaddr_un_unlink(&sockaddr.un); + + RUN_WITH_UMASK(0000) + if (bind(m->listen_fd, &sockaddr.sa, SOCKADDR_UN_LEN(sockaddr.un)) < 0) + return log_error_errno(errno, "Failed to bind socket: %m"); + + r = symlink_idempotent("io.systemd.NameServiceSwitch", "/run/systemd/userdb/io.systemd.Multiplexer", false); + if (r < 0) + return log_error_errno(r, "Failed to bind io.systemd.Multiplexer: %m"); + + if (listen(m->listen_fd, SOMAXCONN) < 0) + return log_error_errno(errno, "Failed to listen on socket: %m"); + } + + /* Let's make sure every accept() call on this socket times out after 25s. This allows workers to be + * GC'ed on idle */ + if (setsockopt(m->listen_fd, SOL_SOCKET, SO_RCVTIMEO, timeval_store(&ts, LISTEN_TIMEOUT_USEC), sizeof(ts)) < 0) + return log_error_errno(errno, "Failed to se SO_RCVTIMEO: %m"); + + return start_workers(m, false); +} diff --git a/src/userdb/userdbd-manager.h b/src/userdb/userdbd-manager.h new file mode 100644 index 0000000000..0bf67fe55b --- /dev/null +++ b/src/userdb/userdbd-manager.h @@ -0,0 +1,34 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ +#pragma once + +#include "sd-bus.h" +#include "sd-event.h" + +typedef struct Manager Manager; + +#include "hashmap.h" +#include "varlink.h" +#include "ratelimit.h" + +#define USERDB_WORKERS_MIN 3 +#define USERDB_WORKERS_MAX 4096 + +struct Manager { + sd_event *event; + + Set *workers_fixed; /* Workers 0…USERDB_WORKERS_MIN */ + Set *workers_dynamic; /* Workers USERD_WORKERS_MIN+1…USERDB_WORKERS_MAX */ + + sd_event_source *sigusr2_event_source; + sd_event_source *sigchld_event_source; + + int listen_fd; + + RateLimit worker_ratelimit; +}; + +int manager_new(Manager **ret); +Manager* manager_free(Manager *m); +DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_free); + +int manager_startup(Manager *m); diff --git a/src/userdb/userdbd.c b/src/userdb/userdbd.c new file mode 100644 index 0000000000..978fd1d788 --- /dev/null +++ b/src/userdb/userdbd.c @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ + +#include <sys/stat.h> +#include <sys/types.h> + +#include "daemon-util.h" +#include "userdbd-manager.h" +#include "log.h" +#include "main-func.h" +#include "signal-util.h" + +/* This service offers two Varlink services, both implementing io.systemd.UserDatabase: + * + * → io.systemd.NameServiceSwitch: this is a compatibility interface for glibc NSS: it response to + * name lookups by checking the classic NSS interfaces and responding that. + * + * → io.systemd.Multiplexer: this multiplexes lookup requests to all Varlink services that have a + * socket in /run/systemd/userdb/. It's supposed to simplify clients that don't want to implement + * the full iterative logic on their own. + */ + +static int run(int argc, char *argv[]) { + _cleanup_(notify_on_cleanup) const char *notify_stop = NULL; + _cleanup_(manager_freep) Manager *m = NULL; + int r; + + log_setup_service(); + + umask(0022); + + if (argc != 1) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "This program takes no arguments."); + + if (setenv("SYSTEMD_BYPASS_USERDB", "io.systemd.NameServiceSwitch:io.systemd.Multiplexer", 1) < 0) + return log_error_errno(errno, "Failed to se $SYSTEMD_BYPASS_USERDB: %m"); + + assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGCHLD, SIGTERM, SIGINT, SIGUSR2, -1) >= 0); + + r = manager_new(&m); + if (r < 0) + return log_error_errno(r, "Could not create manager: %m"); + + r = manager_startup(m); + if (r < 0) + return log_error_errno(r, "Failed to start up daemon: %m"); + + notify_stop = notify_start(NOTIFY_READY, NOTIFY_STOPPING); + + r = sd_event_loop(m->event); + if (r < 0) + return log_error_errno(r, "Event loop failed: %m"); + + return 0; +} + +DEFINE_MAIN_FUNCTION(run); diff --git a/src/userdb/userwork.c b/src/userdb/userwork.c new file mode 100644 index 0000000000..df11b5b984 --- /dev/null +++ b/src/userdb/userwork.c @@ -0,0 +1,778 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ + +#include <poll.h> +#include <sys/wait.h> + +#include "sd-daemon.h" + +#include "env-util.h" +#include "fd-util.h" +#include "group-record-nss.h" +#include "group-record.h" +#include "main-func.h" +#include "process-util.h" +#include "strv.h" +#include "time-util.h" +#include "user-record-nss.h" +#include "user-record.h" +#include "user-util.h" +#include "userdb.h" +#include "varlink.h" + +#define ITERATIONS_MAX 64U +#define RUNTIME_MAX_USEC (5 * USEC_PER_MINUTE) +#define PRESSURE_SLEEP_TIME_USEC (50 * USEC_PER_MSEC) +#define CONNECTION_IDLE_USEC (15 * USEC_PER_SEC) +#define LISTEN_IDLE_USEC (90 * USEC_PER_SEC) + +typedef struct LookupParameters { + const char *user_name; + const char *group_name; + union { + uid_t uid; + gid_t gid; + }; + const char *service; +} LookupParameters; + +static int add_nss_service(JsonVariant **v) { + _cleanup_(json_variant_unrefp) JsonVariant *status = NULL, *z = NULL; + char buf[SD_ID128_STRING_MAX]; + sd_id128_t mid; + int r; + + assert(v); + + /* Patch in service field if it's missing. The assumption here is that this field is unset only for + * NSS records */ + + if (json_variant_by_key(*v, "service")) + return 0; + + r = sd_id128_get_machine(&mid); + if (r < 0) + return r; + + status = json_variant_ref(json_variant_by_key(*v, "status")); + z = json_variant_ref(json_variant_by_key(status, sd_id128_to_string(mid, buf))); + + if (json_variant_by_key(z, "service")) + return 0; + + r = json_variant_set_field_string(&z, "service", "io.systemd.NameServiceSwitch"); + if (r < 0) + return r; + + r = json_variant_set_field(&status, buf, z); + if (r < 0) + return r; + + return json_variant_set_field(v, "status", status); +} + +static int build_user_json(Varlink *link, UserRecord *ur, JsonVariant **ret) { + _cleanup_(user_record_unrefp) UserRecord *stripped = NULL; + _cleanup_(json_variant_unrefp) JsonVariant *v = NULL; + UserRecordLoadFlags flags; + uid_t peer_uid; + bool trusted; + int r; + + assert(ur); + assert(ret); + + r = varlink_get_peer_uid(link, &peer_uid); + if (r < 0) { + log_debug_errno(r, "Unable to query peer UID, ignoring: %m"); + trusted = false; + } else + trusted = peer_uid == 0 || peer_uid == ur->uid; + + flags = USER_RECORD_REQUIRE_REGULAR|USER_RECORD_ALLOW_PER_MACHINE|USER_RECORD_ALLOW_BINDING|USER_RECORD_STRIP_SECRET|USER_RECORD_ALLOW_STATUS|USER_RECORD_ALLOW_SIGNATURE; + if (trusted) + flags |= USER_RECORD_ALLOW_PRIVILEGED; + else + flags |= USER_RECORD_STRIP_PRIVILEGED; + + r = user_record_clone(ur, flags, &stripped); + if (r < 0) + return r; + + stripped->incomplete = + ur->incomplete || + (FLAGS_SET(ur->mask, USER_RECORD_PRIVILEGED) && + !FLAGS_SET(stripped->mask, USER_RECORD_PRIVILEGED)); + + v = json_variant_ref(stripped->json); + r = add_nss_service(&v); + if (r < 0) + return r; + + return json_build(ret, JSON_BUILD_OBJECT( + JSON_BUILD_PAIR("record", JSON_BUILD_VARIANT(v)), + JSON_BUILD_PAIR("incomplete", JSON_BUILD_BOOLEAN(stripped->incomplete)))); +} + +static int vl_method_get_user_record(Varlink *link, JsonVariant *parameters, VarlinkMethodFlags flags, void *userdata) { + + static const JsonDispatch dispatch_table[] = { + { "uid", JSON_VARIANT_UNSIGNED, json_dispatch_uid_gid, offsetof(LookupParameters, uid), 0 }, + { "userName", JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, user_name), 0 }, + { "service", JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, service), 0 }, + {} + }; + + _cleanup_(json_variant_unrefp) JsonVariant *v = NULL; + _cleanup_(user_record_unrefp) UserRecord *hr = NULL; + LookupParameters p = { + .uid = UID_INVALID, + }; + int r; + + assert(parameters); + + r = json_dispatch(parameters, dispatch_table, NULL, 0, &p); + if (r < 0) + return r; + + if (streq_ptr(p.service, "io.systemd.NameServiceSwitch")) { + if (uid_is_valid(p.uid)) + r = nss_user_record_by_uid(p.uid, &hr); + else if (p.user_name) + r = nss_user_record_by_name(p.user_name, &hr); + else { + _cleanup_(json_variant_unrefp) JsonVariant *last = NULL; + + setpwent(); + + for (;;) { + _cleanup_(user_record_unrefp) UserRecord *z = NULL; + _cleanup_free_ char *sbuf = NULL; + struct passwd *pw; + struct spwd spwd; + + errno = 0; + pw = getpwent(); + if (!pw) { + if (errno != 0) + log_debug_errno(errno, "Failure while iterating through NSS user database, ignoring: %m"); + + break; + } + + r = nss_spwd_for_passwd(pw, &spwd, &sbuf); + if (r < 0) + log_debug_errno(r, "Failed to acquire shadow entry for user %s, ignoring: %m", pw->pw_name); + + r = nss_passwd_to_user_record(pw, NULL, &z); + if (r < 0) { + endpwent(); + return r; + } + + if (last) { + r = varlink_notify(link, last); + if (r < 0) { + endpwent(); + return r; + } + + last = json_variant_unref(last); + } + + r = build_user_json(link, z, &last); + if (r < 0) { + endpwent(); + return r; + } + } + + endpwent(); + + if (!last) + return varlink_error(link, "io.systemd.UserDatabase.NoRecordFound", NULL); + + return varlink_reply(link, last); + } + + } else if (streq_ptr(p.service, "io.systemd.Multiplexer")) { + + if (uid_is_valid(p.uid)) + r = userdb_by_uid(p.uid, USERDB_AVOID_MULTIPLEXER, &hr); + else if (p.user_name) + r = userdb_by_name(p.user_name, USERDB_AVOID_MULTIPLEXER, &hr); + else { + _cleanup_(userdb_iterator_freep) UserDBIterator *iterator = NULL; + _cleanup_(json_variant_unrefp) JsonVariant *last = NULL; + + r = userdb_all(USERDB_AVOID_MULTIPLEXER, &iterator); + if (r < 0) + return r; + + for (;;) { + _cleanup_(user_record_unrefp) UserRecord *z = NULL; + + r = userdb_iterator_get(iterator, &z); + if (r == -ESRCH) + break; + if (r < 0) + return r; + + if (last) { + r = varlink_notify(link, last); + if (r < 0) + return r; + + last = json_variant_unref(last); + } + + r = build_user_json(link, z, &last); + if (r < 0) + return r; + } + + if (!last) + return varlink_error(link, "io.systemd.UserDatabase.NoRecordFound", NULL); + + return varlink_reply(link, last); + } + } else + return varlink_error(link, "io.systemd.UserDatabase.BadService", NULL); + if (r == -ESRCH) + return varlink_error(link, "io.systemd.UserDatabase.NoRecordFound", NULL); + if (r < 0) { + log_debug_errno(r, "User lookup failed abnormally: %m"); + return varlink_error(link, "io.systemd.UserDatabase.ServiceNotAvailable", NULL); + } + + if ((uid_is_valid(p.uid) && hr->uid != p.uid) || + (p.user_name && !streq(hr->user_name, p.user_name))) + return varlink_error(link, "io.systemd.UserDatabase.ConflictingRecordFound", NULL); + + r = build_user_json(link, hr, &v); + if (r < 0) + return r; + + return varlink_reply(link, v); +} + +static int build_group_json(Varlink *link, GroupRecord *gr, JsonVariant **ret) { + _cleanup_(group_record_unrefp) GroupRecord *stripped = NULL; + _cleanup_(json_variant_unrefp) JsonVariant *v = NULL; + UserRecordLoadFlags flags; + uid_t peer_uid; + bool trusted; + int r; + + assert(gr); + assert(ret); + + r = varlink_get_peer_uid(link, &peer_uid); + if (r < 0) { + log_debug_errno(r, "Unable to query peer UID, ignoring: %m"); + trusted = false; + } else + trusted = peer_uid == 0; + + flags = USER_RECORD_REQUIRE_REGULAR|USER_RECORD_ALLOW_PER_MACHINE|USER_RECORD_ALLOW_BINDING|USER_RECORD_STRIP_SECRET|USER_RECORD_ALLOW_STATUS|USER_RECORD_ALLOW_SIGNATURE; + if (trusted) + flags |= USER_RECORD_ALLOW_PRIVILEGED; + else + flags |= USER_RECORD_STRIP_PRIVILEGED; + + r = group_record_clone(gr, flags, &stripped); + if (r < 0) + return r; + + stripped->incomplete = + gr->incomplete || + (FLAGS_SET(gr->mask, USER_RECORD_PRIVILEGED) && + !FLAGS_SET(stripped->mask, USER_RECORD_PRIVILEGED)); + + v = json_variant_ref(gr->json); + r = add_nss_service(&v); + if (r < 0) + return r; + + return json_build(ret, JSON_BUILD_OBJECT( + JSON_BUILD_PAIR("record", JSON_BUILD_VARIANT(v)), + JSON_BUILD_PAIR("incomplete", JSON_BUILD_BOOLEAN(stripped->incomplete)))); +} + +static int vl_method_get_group_record(Varlink *link, JsonVariant *parameters, VarlinkMethodFlags flags, void *userdata) { + + static const JsonDispatch dispatch_table[] = { + { "gid", JSON_VARIANT_UNSIGNED, json_dispatch_uid_gid, offsetof(LookupParameters, gid), 0 }, + { "groupName", JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, group_name), 0 }, + { "service", JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, service), 0 }, + {} + }; + + _cleanup_(json_variant_unrefp) JsonVariant *v = NULL; + _cleanup_(group_record_unrefp) GroupRecord *g = NULL; + LookupParameters p = { + .gid = GID_INVALID, + }; + int r; + + assert(parameters); + + r = json_dispatch(parameters, dispatch_table, NULL, 0, &p); + if (r < 0) + return r; + + if (streq_ptr(p.service, "io.systemd.NameServiceSwitch")) { + + if (gid_is_valid(p.gid)) + r = nss_group_record_by_gid(p.gid, &g); + else if (p.group_name) + r = nss_group_record_by_name(p.group_name, &g); + else { + _cleanup_(json_variant_unrefp) JsonVariant *last = NULL; + + setgrent(); + + for (;;) { + _cleanup_(group_record_unrefp) GroupRecord *z = NULL; + _cleanup_free_ char *sbuf = NULL; + struct group *grp; + struct sgrp sgrp; + + errno = 0; + grp = getgrent(); + if (!grp) { + if (errno != 0) + log_debug_errno(errno, "Failure while iterating through NSS group database, ignoring: %m"); + + break; + } + + r = nss_sgrp_for_group(grp, &sgrp, &sbuf); + if (r < 0) + log_debug_errno(r, "Failed to acquire shadow entry for group %s, ignoring: %m", grp->gr_name); + + r = nss_group_to_group_record(grp, r >= 0 ? &sgrp : NULL, &z); + if (r < 0) { + endgrent(); + return r; + } + + if (last) { + r = varlink_notify(link, last); + if (r < 0) { + endgrent(); + return r; + } + + last = json_variant_unref(last); + } + + r = build_group_json(link, z, &last); + if (r < 0) { + endgrent(); + return r; + } + } + + endgrent(); + + if (!last) + return varlink_error(link, "io.systemd.UserDatabase.NoRecordFound", NULL); + + return varlink_reply(link, last); + } + + } else if (streq_ptr(p.service, "io.systemd.Multiplexer")) { + + if (gid_is_valid(p.gid)) + r = groupdb_by_gid(p.gid, USERDB_AVOID_MULTIPLEXER, &g); + else if (p.group_name) + r = groupdb_by_name(p.group_name, USERDB_AVOID_MULTIPLEXER, &g); + else { + _cleanup_(userdb_iterator_freep) UserDBIterator *iterator = NULL; + _cleanup_(json_variant_unrefp) JsonVariant *last = NULL; + + r = groupdb_all(USERDB_AVOID_MULTIPLEXER, &iterator); + if (r < 0) + return r; + + for (;;) { + _cleanup_(group_record_unrefp) GroupRecord *z = NULL; + + r = groupdb_iterator_get(iterator, &z); + if (r == -ESRCH) + break; + if (r < 0) + return r; + + if (last) { + r = varlink_notify(link, last); + if (r < 0) + return r; + + last = json_variant_unref(last); + } + + r = build_group_json(link, z, &last); + if (r < 0) + return r; + } + + if (!last) + return varlink_error(link, "io.systemd.UserDatabase.NoRecordFound", NULL); + + return varlink_reply(link, last); + } + } else + return varlink_error(link, "io.systemd.UserDatabase.BadService", NULL); + if (r == -ESRCH) + return varlink_error(link, "io.systemd.UserDatabase.NoRecordFound", NULL); + if (r < 0) { + log_debug_errno(r, "Group lookup failed abnormally: %m"); + return varlink_error(link, "io.systemd.UserDatabase.ServiceNotAvailable", NULL); + } + + if ((uid_is_valid(p.gid) && g->gid != p.gid) || + (p.group_name && !streq(g->group_name, p.group_name))) + return varlink_error(link, "io.systemd.UserDatabase.ConflictingRecordFound", NULL); + + r = build_group_json(link, g, &v); + if (r < 0) + return r; + + return varlink_reply(link, v); +} + +static int vl_method_get_memberships(Varlink *link, JsonVariant *parameters, VarlinkMethodFlags flags, void *userdata) { + static const JsonDispatch dispatch_table[] = { + { "userName", JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, user_name), 0 }, + { "groupName", JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, group_name), 0 }, + { "service", JSON_VARIANT_STRING, json_dispatch_const_string, offsetof(LookupParameters, service), 0 }, + {} + }; + + LookupParameters p = {}; + int r; + + assert(parameters); + + r = json_dispatch(parameters, dispatch_table, NULL, 0, &p); + if (r < 0) + return r; + + if (streq_ptr(p.service, "io.systemd.NameServiceSwitch")) { + + if (p.group_name) { + _cleanup_(group_record_unrefp) GroupRecord *g = NULL; + const char *last = NULL; + char **i; + + r = nss_group_record_by_name(p.group_name, &g); + if (r == -ESRCH) + return varlink_error(link, "io.systemd.UserDatabase.NoRecordFound", NULL); + if (r < 0) + return r; + + STRV_FOREACH(i, g->members) { + + if (p.user_name && !streq_ptr(p.user_name, *i)) + continue; + + if (last) { + r = varlink_notifyb(link, JSON_BUILD_OBJECT( + JSON_BUILD_PAIR("userName", JSON_BUILD_STRING(last)), + JSON_BUILD_PAIR("groupName", JSON_BUILD_STRING(g->group_name)))); + if (r < 0) + return r; + } + + last = *i; + } + + if (!last) + return varlink_error(link, "io.systemd.UserDatabase.NoRecordFound", NULL); + + return varlink_replyb(link, JSON_BUILD_OBJECT( + JSON_BUILD_PAIR("userName", JSON_BUILD_STRING(last)), + JSON_BUILD_PAIR("groupName", JSON_BUILD_STRING(g->group_name)))); + } else { + _cleanup_free_ char *last_user_name = NULL, *last_group_name = NULL; + + setgrent(); + + for (;;) { + struct group *grp; + const char* two[2], **users, **i; + + errno = 0; + grp = getgrent(); + if (!grp) { + if (errno != 0) + log_debug_errno(errno, "Failure while iterating through NSS group database, ignoring: %m"); + + break; + } + + if (p.user_name) { + if (!strv_contains(grp->gr_mem, p.user_name)) + continue; + + two[0] = p.user_name; + two[1] = NULL; + + users = two; + } else + users = (const char**) grp->gr_mem; + + STRV_FOREACH(i, users) { + + if (last_user_name) { + assert(last_group_name); + + r = varlink_notifyb(link, JSON_BUILD_OBJECT( + JSON_BUILD_PAIR("userName", JSON_BUILD_STRING(last_user_name)), + JSON_BUILD_PAIR("groupName", JSON_BUILD_STRING(last_group_name)))); + if (r < 0) { + endgrent(); + return r; + } + + free(last_user_name); + free(last_group_name); + } + + last_user_name = strdup(*i); + last_group_name = strdup(grp->gr_name); + if (!last_user_name || !last_group_name) { + endgrent(); + return -ENOMEM; + } + } + } + + endgrent(); + + if (!last_user_name) { + assert(!last_group_name); + return varlink_error(link, "io.systemd.UserDatabase.NoRecordFound", NULL); + } + + assert(last_group_name); + + return varlink_replyb(link, JSON_BUILD_OBJECT( + JSON_BUILD_PAIR("userName", JSON_BUILD_STRING(last_user_name)), + JSON_BUILD_PAIR("groupName", JSON_BUILD_STRING(last_group_name)))); + } + + } else if (streq_ptr(p.service, "io.systemd.Multiplexer")) { + + _cleanup_free_ char *last_user_name = NULL, *last_group_name = NULL; + _cleanup_(userdb_iterator_freep) UserDBIterator *iterator = NULL; + + if (p.group_name) + r = membershipdb_by_group(p.group_name, USERDB_AVOID_MULTIPLEXER, &iterator); + else if (p.user_name) + r = membershipdb_by_user(p.user_name, USERDB_AVOID_MULTIPLEXER, &iterator); + else + r = membershipdb_all(USERDB_AVOID_MULTIPLEXER, &iterator); + if (r < 0) + return r; + + for (;;) { + _cleanup_free_ char *user_name = NULL, *group_name = NULL; + + r = membershipdb_iterator_get(iterator, &user_name, &group_name); + if (r == -ESRCH) + break; + if (r < 0) + return r; + + /* If both group + user are specified do a-posteriori filtering */ + if (p.group_name && p.user_name && !streq(group_name, p.group_name)) + continue; + + if (last_user_name) { + assert(last_group_name); + + r = varlink_notifyb(link, JSON_BUILD_OBJECT( + JSON_BUILD_PAIR("userName", JSON_BUILD_STRING(last_user_name)), + JSON_BUILD_PAIR("groupName", JSON_BUILD_STRING(last_group_name)))); + if (r < 0) + return r; + + free(last_user_name); + free(last_group_name); + } + + last_user_name = TAKE_PTR(user_name); + last_group_name = TAKE_PTR(group_name); + } + + if (!last_user_name) { + assert(!last_group_name); + return varlink_error(link, "io.systemd.UserDatabase.NoRecordFound", NULL); + } + + assert(last_group_name); + + return varlink_replyb(link, JSON_BUILD_OBJECT( + JSON_BUILD_PAIR("userName", JSON_BUILD_STRING(last_user_name)), + JSON_BUILD_PAIR("groupName", JSON_BUILD_STRING(last_group_name)))); + } + + return varlink_error(link, "io.systemd.UserDatabase.BadService", NULL); +} + +static int process_connection(VarlinkServer *server, int fd) { + _cleanup_(varlink_close_unrefp) Varlink *vl = NULL; + int r; + + r = varlink_server_add_connection(server, fd, &vl); + if (r < 0) { + fd = safe_close(fd); + return log_error_errno(r, "Failed to add connection: %m"); + } + + vl = varlink_ref(vl); + + for (;;) { + r = varlink_process(vl); + if (r == -ENOTCONN) { + log_debug("Connection terminated."); + break; + } + if (r < 0) + return log_error_errno(r, "Failed to process connection: %m"); + if (r > 0) + continue; + + r = varlink_wait(vl, CONNECTION_IDLE_USEC); + if (r < 0) + return log_error_errno(r, "Failed to wait for connection events: %m"); + if (r == 0) + break; + } + + return 0; +} + +static int run(int argc, char *argv[]) { + usec_t start_time, listen_idle_usec, last_busy_usec = USEC_INFINITY; + _cleanup_(varlink_server_unrefp) VarlinkServer *server = NULL; + _cleanup_close_ int lock = -1; + unsigned n_iterations = 0; + int m, listen_fd, r; + + log_setup_service(); + + m = sd_listen_fds(false); + if (m < 0) + return log_error_errno(m, "Failed to determine number of listening fds: %m"); + if (m == 0) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "No socket to listen on received."); + if (m > 1) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Worker can only listen on a single socket at a time."); + + listen_fd = SD_LISTEN_FDS_START; + + r = fd_nonblock(listen_fd, false); + if (r < 0) + return log_error_errno(r, "Failed to turn off non-blocking mode for listening socket: %m"); + + r = varlink_server_new(&server, 0); + if (r < 0) + return log_error_errno(r, "Failed to allocate server: %m"); + + r = varlink_server_bind_method_many( + server, + "io.systemd.UserDatabase.GetUserRecord", vl_method_get_user_record, + "io.systemd.UserDatabase.GetGroupRecord", vl_method_get_group_record, + "io.systemd.UserDatabase.GetMemberships", vl_method_get_memberships); + if (r < 0) + return log_error_errno(r, "Failed to bind methods: %m"); + + r = getenv_bool("USERDB_FIXED_WORKER"); + if (r < 0) + return log_error_errno(r, "Failed to parse USERDB_FIXED_WORKER: %m"); + listen_idle_usec = r ? USEC_INFINITY : LISTEN_IDLE_USEC; + + lock = userdb_nss_compat_disable(); + if (lock < 0) + return log_error_errno(r, "Failed to disable userdb NSS compatibility: %m"); + + start_time = now(CLOCK_MONOTONIC); + + for (;;) { + _cleanup_close_ int fd = -1; + usec_t n; + + /* Exit the worker in regular intervals, to flush out all memory use */ + if (n_iterations++ > ITERATIONS_MAX) { + log_debug("Exiting worker, processed %u iterations, that's enough.", n_iterations); + break; + } + + n = now(CLOCK_MONOTONIC); + if (n >= usec_add(start_time, RUNTIME_MAX_USEC)) { + char buf[FORMAT_TIMESPAN_MAX]; + log_debug("Exiting worker, ran for %s, that's enough.", format_timespan(buf, sizeof(buf), usec_sub_unsigned(n, start_time), 0)); + break; + } + + if (last_busy_usec == USEC_INFINITY) + last_busy_usec = n; + else if (listen_idle_usec != USEC_INFINITY && n >= usec_add(last_busy_usec, listen_idle_usec)) { + char buf[FORMAT_TIMESPAN_MAX]; + log_debug("Exiting worker, been idle for %s, .", format_timespan(buf, sizeof(buf), usec_sub_unsigned(n, last_busy_usec), 0)); + break; + } + + (void) rename_process("systemd-userwork: waiting..."); + + fd = accept4(listen_fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC); + if (fd < 0) + fd = -errno; + + (void) rename_process("systemd-userwork: processing..."); + + if (fd == -EAGAIN) + continue; /* The listening socket as SO_RECVTIMEO set, hence a time-out is expected + * after a while, let's check if it's time to exit though. */ + if (fd == -EINTR) + continue; /* Might be that somebody attached via strace, let's just continue in that + * case */ + if (fd < 0) + return log_error_errno(fd, "Failed to accept() from listening socket: %m"); + + if (now(CLOCK_MONOTONIC) <= usec_add(n, PRESSURE_SLEEP_TIME_USEC)) { + struct pollfd pfd = { + .fd = listen_fd, + .events = POLLIN, + }; + + /* We only slept a very short time? If so, let's see if there are more sockets + * pending, and if so, let's ask our parent for more workers */ + + if (poll(&pfd, 1, 0) < 0) + return log_error_errno(errno, "Failed to test for POLLIN on listening socket: %m"); + + if (FLAGS_SET(pfd.revents, POLLIN)) { + pid_t parent; + + parent = getppid(); + if (parent <= 1) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Parent already died?"); + + if (kill(parent, SIGUSR1) < 0) + return log_error_errno(errno, "Failed to kill our own parent."); + } + } + + (void) process_connection(server, TAKE_FD(fd)); + last_busy_usec = USEC_INFINITY; + } + + return 0; +} + +DEFINE_MAIN_FUNCTION(run); |