Adding upstream version 252.22.upstream/252.22

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 306 insertions, 0 deletions

diff --git a/src/userdb/userdbd-manager.c b/src/userdb/userdbd-manager.c
new file mode 100644
index 0000000..f0589ad
--- /dev/null
+++ b/src/userdb/userdbd-manager.c
@@ -0,0 +1,306 @@
+/* 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 = ASSERT_PTR(userdata);
+
+        assert(s);
+
+        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 = ASSERT_PTR(userdata);
+
+        assert(s);
+
+        (void) start_workers(m, /* explicit_request=*/ 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 = 2 * USEC_PER_SEC,
+                        .burst = 2500,
+                },
+        };
+
+        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);
+
+        safe_close(m->listen_fd);
+
+        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_DELUXE) < 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, /* explicit_request= */ false);
+}