[thirdparty/systemd.git] / src / userdb / userdbd-manager.c

/* SPDX-License-Identifier: LGPL-2.1-or-later */

#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) {
        _cleanup_(manager_freep) Manager *m = NULL;
        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) {
        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 = {
                        .un.sun_family = AF_UNIX,
                        .un.sun_path = "/run/systemd/userdb/io.systemd.Multiplexer",
                };

                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.Multiplexer",
                                       "/run/systemd/userdb/io.systemd.NameServiceSwitch", false);
                if (r < 0)
                        return log_error_errno(r, "Failed to bind io.systemd.Multiplexer: %m");

                r = symlink_idempotent("io.systemd.Multiplexer",
                                       "/run/systemd/userdb/io.systemd.DropIn", 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(LISTEN_TIMEOUT_USEC), sizeof(struct timeval)) < 0)
                return log_error_errno(errno, "Failed to se SO_RCVTIMEO: %m");

        return start_workers(m, false);
}
Commit	Line	Data
db9ecf05	1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
d093b62c LP	2
	3	#include <sys/wait.h>
	4
	5	#include "sd-daemon.h"
	6
	7	#include "fd-util.h"
	8	#include "fs-util.h"
	9	#include "mkdir.h"
	10	#include "process-util.h"
	11	#include "set.h"
	12	#include "signal-util.h"
	13	#include "socket-util.h"
	14	#include "stdio-util.h"
	15	#include "umask-util.h"
	16	#include "userdbd-manager.h"
	17
	18	#define LISTEN_TIMEOUT_USEC (25 * USEC_PER_SEC)
	19
	20	static int start_workers(Manager *m, bool explicit_request);
	21
	22	static int on_sigchld(sd_event_source s, const struct signalfd_siginfo si, void *userdata) {
	23	Manager *m = userdata;
	24
	25	assert(s);
	26	assert(m);
	27
	28	for (;;) {
	29	siginfo_t siginfo = {};
	30	bool removed = false;
	31
	32	if (waitid(P_ALL, 0, &siginfo, WNOHANG\|WEXITED) < 0) {
	33	if (errno == ECHILD)
	34	break;
	35
	36	log_warning_errno(errno, "Failed to invoke waitid(): %m");
	37	break;
	38	}
	39	if (siginfo.si_pid == 0)
	40	break;
	41
	42	if (set_remove(m->workers_dynamic, PID_TO_PTR(siginfo.si_pid)))
	43	removed = true;
	44	if (set_remove(m->workers_fixed, PID_TO_PTR(siginfo.si_pid)))
	45	removed = true;
	46
	47	if (!removed) {
	48	log_warning("Weird, got SIGCHLD for unknown child " PID_FMT ", ignoring.", siginfo.si_pid);
	49	continue;
	50	}
	51
	52	if (siginfo.si_code == CLD_EXITED) {
	53	if (siginfo.si_status == EXIT_SUCCESS)
	54	log_debug("Worker " PID_FMT " exited successfully.", siginfo.si_pid);
	55	else
	56	log_warning("Worker " PID_FMT " died with a failure exit status %i, ignoring.", siginfo.si_pid, siginfo.si_status);
	57	} else if (siginfo.si_code == CLD_KILLED)
	58	log_warning("Worker " PID_FMT " was killed by signal %s, ignoring.", siginfo.si_pid, signal_to_string(siginfo.si_status));
	59	else if (siginfo.si_code == CLD_DUMPED)
	60	log_warning("Worker " PID_FMT " dumped core by signal %s, ignoring.", siginfo.si_pid, signal_to_string(siginfo.si_status));
	61	else
	62	log_warning("Can't handle SIGCHLD of this type");
	63	}
	64
	65	(void) start_workers(m, false); /* Fill up workers again if we fell below the low watermark */
66	return 0;
67	}
68
69	static int on_sigusr2(sd_event_source s, const struct signalfd_siginfo si, void *userdata) {
70	Manager *m = userdata;
71
72	assert(s);
73	assert(m);
74
75	(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 */
76	return 0;
77	}
78
79	int manager_new(Manager **ret) {
b44b735a	80	_cleanup_(manager_freep) Manager *m = NULL;
d093b62c LP	81	int r;
	82
	83	m = new(Manager, 1);
	84	if (!m)
	85	return -ENOMEM;
	86
	87	*m = (Manager) {
	88	.listen_fd = -1,
	89	.worker_ratelimit = {
	90	.interval = 5 * USEC_PER_SEC,
	91	.burst = 50,
	92	},
	93	};
	94
	95	r = sd_event_new(&m->event);
	96	if (r < 0)
	97	return r;
	98
	99	r = sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL);
	100	if (r < 0)
	101	return r;
	102
	103	r = sd_event_add_signal(m->event, NULL, SIGTERM, NULL, NULL);
	104	if (r < 0)
	105	return r;
	106
	107	(void) sd_event_set_watchdog(m->event, true);
	108
	109	m->workers_fixed = set_new(NULL);
	110	m->workers_dynamic = set_new(NULL);
	111
	112	if (!m->workers_fixed \|\| !m->workers_dynamic)
	113	return -ENOMEM;
	114
	115	r = sd_event_add_signal(m->event, &m->sigusr2_event_source, SIGUSR2, on_sigusr2, m);
	116	if (r < 0)
	117	return r;
	118
	119	r = sd_event_add_signal(m->event, &m->sigchld_event_source, SIGCHLD, on_sigchld, m);
	120	if (r < 0)
	121	return r;
	122
	123	*ret = TAKE_PTR(m);
	124	return 0;
	125	}
	126
	127	Manager* manager_free(Manager *m) {
	128	if (!m)
	129	return NULL;
	130
	131	set_free(m->workers_fixed);
	132	set_free(m->workers_dynamic);
	133
	134	sd_event_source_disable_unref(m->sigusr2_event_source);
	135	sd_event_source_disable_unref(m->sigchld_event_source);
	136
	137	sd_event_unref(m->event);
	138
	139	return mfree(m);
	140	}
	141
	142	static size_t manager_current_workers(Manager *m) {
	143	assert(m);
	144
145	return set_size(m->workers_fixed) + set_size(m->workers_dynamic);
146	}
147
148	static int start_one_worker(Manager *m) {
149	bool fixed;
150	pid_t pid;
151	int r;
152
153	assert(m);
154
155	fixed = set_size(m->workers_fixed) < USERDB_WORKERS_MIN;
156
157	r = safe_fork("(sd-worker)", FORK_RESET_SIGNALS\|FORK_DEATHSIG\|FORK_LOG, &pid);
158	if (r < 0)
159	return log_error_errno(r, "Failed to fork new worker child: %m");
160	if (r == 0) {
161	char pids[DECIMAL_STR_MAX(pid_t)];
162	/* Child */
163
164	log_close();
165
166	r = close_all_fds(&m->listen_fd, 1);
167	if (r < 0) {
168	log_error_errno(r, "Failed to close fds in child: %m");
169	_exit(EXIT_FAILURE);
170	}
171
172	log_open();
173
174	if (m->listen_fd == 3) {
175	r = fd_cloexec(3, false);
176	if (r < 0) {
177	log_error_errno(r, "Failed to turn off O_CLOEXEC for fd 3: %m");
178	_exit(EXIT_FAILURE);
179	}
180	} else {
181	if (dup2(m->listen_fd, 3) < 0) { /* dup2() creates with O_CLOEXEC off */
182	log_error_errno(errno, "Failed to move listen fd to 3: %m");
183	_exit(EXIT_FAILURE);
184	}
185
186	safe_close(m->listen_fd);
187	}
188
189	xsprintf(pids, PID_FMT, pid);
190	if (setenv("LISTEN_PID", pids, 1) < 0) {
191	log_error_errno(errno, "Failed to set $LISTEN_PID: %m");
192	_exit(EXIT_FAILURE);
193	}
194
195	if (setenv("LISTEN_FDS", "1", 1) < 0) {
196	log_error_errno(errno, "Failed to set $LISTEN_FDS: %m");
197	_exit(EXIT_FAILURE);
198	}
199
200
201	if (setenv("USERDB_FIXED_WORKER", one_zero(fixed), 1) < 0) {
202	log_error_errno(errno, "Failed to set $USERDB_FIXED_WORKER: %m");
203	_exit(EXIT_FAILURE);
204	}
205
206	/* execl("/home/lennart/projects/systemd/build/systemd-userwork", "systemd-userwork", "xxxxxxxxxxxxxxxx", NULL); /\* With some extra space rename_process() can make use of \/ /
207	/* 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 \/ /
208
209	execl(SYSTEMD_USERWORK_PATH, "systemd-userwork", "xxxxxxxxxxxxxxxx", NULL); /* With some extra space rename_process() can make use of */
210	log_error_errno(errno, "Failed start worker process: %m");
211	_exit(EXIT_FAILURE);
212	}
213
214	if (fixed)
215	r = set_put(m->workers_fixed, PID_TO_PTR(pid));
216	else
217	r = set_put(m->workers_dynamic, PID_TO_PTR(pid));
218	if (r < 0)
219	return log_error_errno(r, "Failed to add child process to set: %m");
220
221	return 0;
222	}
223
224	static int start_workers(Manager *m, bool explicit_request) {
225	int r;
226
227	assert(m);
228
229	for (;;) {
230	size_t n;
231
232	n = manager_current_workers(m);
233	if (n >= USERDB_WORKERS_MIN && (!explicit_request \|\| n >= USERDB_WORKERS_MAX))
234	break;
235
236	if (!ratelimit_below(&m->worker_ratelimit)) {
237	/* If we keep starting workers too often, let's fail the whole daemon, something is wrong */
238	sd_event_exit(m->event, EXIT_FAILURE);
239
240	return log_error_errno(SYNTHETIC_ERRNO(EUCLEAN), "Worker threads requested too frequently, something is wrong.");
241	}
242
243	r = start_one_worker(m);
244	if (r < 0)
245	return r;
246
247	explicit_request = false;
248	}
249
250	return 0;
251	}
252
253	int manager_startup(Manager *m) {
d093b62c LP	254	int n, r;
	255
	256	assert(m);
	257	assert(m->listen_fd < 0);
	258
	259	n = sd_listen_fds(false);
	260	if (n < 0)
	261	return log_error_errno(n, "Failed to determine number of passed file descriptors: %m");
	262	if (n > 1)
	263	return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Expected one listening fd, got %i.", n);
	264	if (n == 1)
	265	m->listen_fd = SD_LISTEN_FDS_START;
	266	else {
425d925f ZJS	267	union sockaddr_union sockaddr = {
425d925f ZJS	268	.un.sun_family = AF_UNIX,
bbfb8c87	269	.un.sun_path = "/run/systemd/userdb/io.systemd.Multiplexer",
425d925f	270	};
d093b62c LP	271
	272	r = mkdir_p("/run/systemd/userdb", 0755);
	273	if (r < 0)
	274	return log_error_errno(r, "Failed to create /run/systemd/userdb: %m");
	275
	276	m->listen_fd = socket(AF_UNIX, SOCK_STREAM\|SOCK_CLOEXEC, 0);
	277	if (m->listen_fd < 0)
	278	return log_error_errno(errno, "Failed to bind on socket: %m");
	279
	280	(void) sockaddr_un_unlink(&sockaddr.un);
	281
	282	RUN_WITH_UMASK(0000)
	283	if (bind(m->listen_fd, &sockaddr.sa, SOCKADDR_UN_LEN(sockaddr.un)) < 0)
	284	return log_error_errno(errno, "Failed to bind socket: %m");
	285
bbfb8c87 LP	286	r = symlink_idempotent("io.systemd.Multiplexer",
bbfb8c87 LP	287	"/run/systemd/userdb/io.systemd.NameServiceSwitch", false);
d093b62c LP	288	if (r < 0)
	289	return log_error_errno(r, "Failed to bind io.systemd.Multiplexer: %m");
	290
8fbb1941 LP	291	r = symlink_idempotent("io.systemd.Multiplexer",
	292	"/run/systemd/userdb/io.systemd.DropIn", false);
	293	if (r < 0)
	294	return log_error_errno(r, "Failed to bind io.systemd.Multiplexer: %m");
	295
d093b62c LP	296	if (listen(m->listen_fd, SOMAXCONN) < 0)
	297	return log_error_errno(errno, "Failed to listen on socket: %m");
	298	}
	299
	300	/* Let's make sure every accept() call on this socket times out after 25s. This allows workers to be
	301	* GC'ed on idle */
52bb308c	302	if (setsockopt(m->listen_fd, SOL_SOCKET, SO_RCVTIMEO, TIMEVAL_STORE(LISTEN_TIMEOUT_USEC), sizeof(struct timeval)) < 0)
d093b62c LP	303	return log_error_errno(errno, "Failed to se SO_RCVTIMEO: %m");
	304
	305	return start_workers(m, false);
	306	}