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-rw-r--r--src/initctl/initctl.c355
-rw-r--r--src/initctl/meson.build9
2 files changed, 364 insertions, 0 deletions
diff --git a/src/initctl/initctl.c b/src/initctl/initctl.c
new file mode 100644
index 0000000..d1b7c30
--- /dev/null
+++ b/src/initctl/initctl.c
@@ -0,0 +1,355 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <ctype.h>
+#include <errno.h>
+#include <stdio.h>
+#include <sys/epoll.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "sd-bus.h"
+#include "sd-daemon.h"
+
+#include "alloc-util.h"
+#include "bus-error.h"
+#include "bus-locator.h"
+#include "bus-util.h"
+#include "constants.h"
+#include "daemon-util.h"
+#include "fd-util.h"
+#include "format-util.h"
+#include "initreq.h"
+#include "list.h"
+#include "log.h"
+#include "main-func.h"
+#include "memory-util.h"
+#include "process-util.h"
+#include "reboot-util.h"
+#include "special.h"
+
+#define SERVER_FD_MAX 16
+#define TIMEOUT_MSEC ((int) (DEFAULT_EXIT_USEC/USEC_PER_MSEC))
+
+typedef struct Fifo Fifo;
+
+typedef struct Server {
+ int epoll_fd;
+
+ LIST_HEAD(Fifo, fifos);
+ unsigned n_fifos;
+
+ sd_bus *bus;
+
+ bool quit;
+} Server;
+
+struct Fifo {
+ Server *server;
+
+ int fd;
+
+ struct init_request buffer;
+ size_t bytes_read;
+
+ LIST_FIELDS(Fifo, fifo);
+};
+
+static const char *translate_runlevel(int runlevel, bool *isolate) {
+ static const struct {
+ const int runlevel;
+ const char *special;
+ bool isolate;
+ } table[] = {
+ { '0', SPECIAL_POWEROFF_TARGET, false },
+ { '1', SPECIAL_RESCUE_TARGET, true },
+ { 's', SPECIAL_RESCUE_TARGET, true },
+ { 'S', SPECIAL_RESCUE_TARGET, true },
+ { '2', SPECIAL_MULTI_USER_TARGET, true },
+ { '3', SPECIAL_MULTI_USER_TARGET, true },
+ { '4', SPECIAL_MULTI_USER_TARGET, true },
+ { '5', SPECIAL_GRAPHICAL_TARGET, true },
+ { '6', SPECIAL_REBOOT_TARGET, false },
+ };
+
+ assert(isolate);
+
+ for (size_t i = 0; i < ELEMENTSOF(table); i++)
+ if (table[i].runlevel == runlevel) {
+ *isolate = table[i].isolate;
+ if (runlevel == '6' && kexec_loaded())
+ return SPECIAL_KEXEC_TARGET;
+ return table[i].special;
+ }
+
+ return NULL;
+}
+
+static int change_runlevel(Server *s, int runlevel) {
+ const char *target;
+ _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+ const char *mode;
+ bool isolate = false;
+ int r;
+
+ assert(s);
+
+ target = translate_runlevel(runlevel, &isolate);
+ if (!target) {
+ log_warning("Got request for unknown runlevel %c, ignoring.", runlevel);
+ return 0;
+ }
+
+ if (isolate)
+ mode = "isolate";
+ else
+ mode = "replace-irreversibly";
+
+ log_debug("Requesting %s/start/%s", target, mode);
+
+ r = bus_call_method(s->bus, bus_systemd_mgr, "StartUnit", &error, NULL, "ss", target, mode);
+ if (r < 0)
+ return log_error_errno(r, "Failed to change runlevel: %s", bus_error_message(&error, r));
+
+ return 0;
+}
+
+static void request_process(Server *s, const struct init_request *req) {
+ assert(s);
+ assert(req);
+
+ if (req->magic != INIT_MAGIC) {
+ log_error("Got initctl request with invalid magic. Ignoring.");
+ return;
+ }
+
+ switch (req->cmd) {
+
+ case INIT_CMD_RUNLVL:
+ if (!isprint(req->runlevel))
+ log_error("Got invalid runlevel. Ignoring.");
+ else
+ switch (req->runlevel) {
+
+ /* we are async anyway, so just use kill for reexec/reload */
+ case 'u':
+ case 'U':
+ if (kill(1, SIGTERM) < 0)
+ log_error_errno(errno, "kill() failed: %m");
+
+ /* The bus connection will be
+ * terminated if PID 1 is reexecuted,
+ * hence let's just exit here, and
+ * rely on that we'll be restarted on
+ * the next request */
+ s->quit = true;
+ break;
+
+ case 'q':
+ case 'Q':
+ if (kill(1, SIGHUP) < 0)
+ log_error_errno(errno, "kill() failed: %m");
+ break;
+
+ default:
+ (void) change_runlevel(s, req->runlevel);
+ }
+ return;
+
+ case INIT_CMD_POWERFAIL:
+ case INIT_CMD_POWERFAILNOW:
+ case INIT_CMD_POWEROK:
+ log_warning("Received UPS/power initctl request. This is not implemented in systemd. Upgrade your UPS daemon!");
+ return;
+
+ case INIT_CMD_CHANGECONS:
+ log_warning("Received console change initctl request. This is not implemented in systemd.");
+ return;
+
+ case INIT_CMD_SETENV:
+ case INIT_CMD_UNSETENV:
+ log_warning("Received environment initctl request. This is not implemented in systemd.");
+ return;
+
+ default:
+ log_warning("Received unknown initctl request. Ignoring.");
+ return;
+ }
+}
+
+static int fifo_process(Fifo *f) {
+ ssize_t l;
+
+ assert(f);
+
+ errno = EIO;
+ l = read(f->fd,
+ ((uint8_t*) &f->buffer) + f->bytes_read,
+ sizeof(f->buffer) - f->bytes_read);
+ if (l <= 0) {
+ if (errno == EAGAIN)
+ return 0;
+
+ return log_warning_errno(errno, "Failed to read from fifo: %m");
+ }
+
+ f->bytes_read += l;
+ assert(f->bytes_read <= sizeof(f->buffer));
+
+ if (f->bytes_read == sizeof(f->buffer)) {
+ request_process(f->server, &f->buffer);
+ f->bytes_read = 0;
+ }
+
+ return 0;
+}
+
+static Fifo* fifo_free(Fifo *f) {
+ if (!f)
+ return NULL;
+
+ if (f->server) {
+ assert(f->server->n_fifos > 0);
+ f->server->n_fifos--;
+ LIST_REMOVE(fifo, f->server->fifos, f);
+ }
+
+ if (f->fd >= 0) {
+ if (f->server)
+ (void) epoll_ctl(f->server->epoll_fd, EPOLL_CTL_DEL, f->fd, NULL);
+
+ safe_close(f->fd);
+ }
+
+ return mfree(f);
+}
+DEFINE_TRIVIAL_CLEANUP_FUNC(Fifo*, fifo_free);
+
+static void server_done(Server *s) {
+ assert(s);
+
+ while (s->fifos)
+ fifo_free(s->fifos);
+
+ s->epoll_fd = safe_close(s->epoll_fd);
+ s->bus = sd_bus_flush_close_unref(s->bus);
+}
+
+static int server_init(Server *s, unsigned n_sockets) {
+ int r;
+
+ /* This function will leave s partially initialized on failure. Caller needs to clean up. */
+
+ assert(s);
+ assert(n_sockets > 0);
+
+ s->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
+ if (s->epoll_fd < 0)
+ return log_error_errno(errno, "Failed to create epoll object: %m");
+
+ for (unsigned i = 0; i < n_sockets; i++) {
+ _cleanup_(fifo_freep) Fifo *f = NULL;
+ int fd = SD_LISTEN_FDS_START + i;
+
+ r = sd_is_fifo(fd, NULL);
+ if (r < 0)
+ return log_error_errno(r, "Failed to determine file descriptor type: %m");
+ if (!r)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Wrong file descriptor type.");
+
+ f = new0(Fifo, 1);
+ if (!f)
+ return log_oom();
+
+ struct epoll_event ev = {
+ .events = EPOLLIN,
+ .data.ptr = f,
+ };
+
+ if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0)
+ return log_error_errno(errno, "Failed to add fifo fd to epoll object: %m");
+
+ f->fd = fd;
+ f->server = s;
+ LIST_PREPEND(fifo, s->fifos, TAKE_PTR(f));
+ s->n_fifos++;
+ }
+
+ r = bus_connect_system_systemd(&s->bus);
+ if (r < 0)
+ return log_error_errno(r, "Failed to get D-Bus connection: %m");
+
+ return 0;
+}
+
+static int process_event(Server *s, struct epoll_event *ev) {
+ int r;
+ _cleanup_(fifo_freep) Fifo *f = NULL;
+
+ assert(s);
+ assert(ev);
+
+ if (!(ev->events & EPOLLIN))
+ return log_info_errno(SYNTHETIC_ERRNO(EIO),
+ "Got invalid event from epoll. (3)");
+
+ f = (Fifo*) ev->data.ptr;
+ r = fifo_process(f);
+ if (r < 0)
+ return log_info_errno(r, "Got error on fifo: %m");
+
+ TAKE_PTR(f);
+
+ return 0;
+}
+
+static int run(int argc, char *argv[]) {
+ _cleanup_(server_done) Server server = { .epoll_fd = -EBADF };
+ _unused_ _cleanup_(notify_on_cleanup) const char *notify_stop = NULL;
+ int r, n;
+
+ if (argc > 1)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "This program does not take arguments.");
+
+ log_setup();
+
+ umask(0022);
+
+ n = sd_listen_fds(true);
+ if (n < 0)
+ return log_error_errno(errno,
+ "Failed to read listening file descriptors from environment: %m");
+
+ if (n <= 0 || n > SERVER_FD_MAX)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "No or too many file descriptors passed.");
+
+ r = server_init(&server, (unsigned) n);
+ if (r < 0)
+ return r;
+
+ notify_stop = notify_start(NOTIFY_READY, NOTIFY_STOPPING);
+
+ while (!server.quit) {
+ struct epoll_event event;
+ int k;
+
+ k = epoll_wait(server.epoll_fd, &event, 1, TIMEOUT_MSEC);
+ if (k < 0) {
+ if (errno == EINTR)
+ continue;
+ return log_error_errno(errno, "epoll_wait() failed: %m");
+ }
+ if (k == 0)
+ break;
+
+ r = process_event(&server, &event);
+ if (r < 0)
+ return r;
+ }
+
+ return 0;
+}
+
+DEFINE_MAIN_FUNCTION(run);
diff --git a/src/initctl/meson.build b/src/initctl/meson.build
new file mode 100644
index 0000000..c9fddc9
--- /dev/null
+++ b/src/initctl/meson.build
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+executables += [
+ libexec_template + {
+ 'name' : 'systemd-initctl',
+ 'conditions' : ['HAVE_SYSV_COMPAT'],
+ 'sources' : files('initctl.c'),
+ },
+]
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-27 21:54:17 +0000