systemctl: split up humungous systemctl.c file

This is just some refactoring: shifting around of code, not change in
codeflow.

This splits up the way too huge systemctl.c in multiple more easily
digestable files. It roughly follows the rule that each family of verbs
gets its own .c/.h file pair, and so do all the compat executable names
we support. Plus three extra files for sysv compat (which existed before
already, but I renamed slightly, to get the systemctl- prefix lik
everything else), a -util file with generic stuff everything uses, and a
-logind file with everything that talks directly to logind instead of
PID1.

systemctl is still a bit too complex for my taste, but I think this way
itc omes in a more digestable bits at least.

No change of behaviour, just reshuffling of some code.

1 files changed, 284 insertions, 0 deletions

diff --git a/src/systemctl/systemctl-enable.c b/src/systemctl/systemctl-enable.c
new file mode 100644
index 0000000000..c9daeb15ba
--- /dev/null
+++ b/src/systemctl/systemctl-enable.c
@@ -0,0 +1,284 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include "bus-error.h"
+#include "bus-locator.h"
+#include "locale-util.h"
+#include "path-util.h"
+#include "systemctl-daemon-reload.h"
+#include "systemctl-enable.h"
+#include "systemctl-start-unit.h"
+#include "systemctl-sysv-compat.h"
+#include "systemctl-util.h"
+#include "systemctl.h"
+
+static int normalize_filenames(char **names) {
+        char **u;
+        int r;
+
+        STRV_FOREACH(u, names)
+                if (!path_is_absolute(*u)) {
+                        char* normalized_path;
+
+                        if (!isempty(arg_root))
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "Non-absolute paths are not allowed when --root is used: %s",
+                                                       *u);
+
+                        if (!strchr(*u,'/'))
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "Link argument does contain at least one directory separator: %s",
+                                                       *u);
+
+                        r = path_make_absolute_cwd(*u, &normalized_path);
+                        if (r < 0)
+                                return r;
+
+                        free_and_replace(*u, normalized_path);
+                }
+
+        return 0;
+}
+
+static int normalize_names(char **names, bool warn_if_path) {
+        char **u;
+        bool was_path = false;
+
+        STRV_FOREACH(u, names) {
+                int r;
+
+                if (!is_path(*u))
+                        continue;
+
+                r = free_and_strdup(u, basename(*u));
+                if (r < 0)
+                        return log_error_errno(r, "Failed to normalize unit file path: %m");
+
+                was_path = true;
+        }
+
+        if (warn_if_path && was_path)
+                log_warning("Warning: Can't execute disable on the unit file path. Proceeding with the unit name.");
+
+        return 0;
+}
+
+int enable_unit(int argc, char *argv[], void *userdata) {
+        _cleanup_strv_free_ char **names = NULL;
+        const char *verb = argv[0];
+        UnitFileChange *changes = NULL;
+        size_t n_changes = 0;
+        int carries_install_info = -1;
+        bool ignore_carries_install_info = arg_quiet;
+        int r;
+
+        if (!argv[1])
+                return 0;
+
+        r = mangle_names("to enable", strv_skip(argv, 1), &names);
+        if (r < 0)
+                return r;
+
+        r = enable_sysv_units(verb, names);
+        if (r < 0)
+                return r;
+
+        /* If the operation was fully executed by the SysV compat, let's finish early */
+        if (strv_isempty(names)) {
+                if (arg_no_reload || install_client_side())
+                        return 0;
+                return daemon_reload(argc, argv, userdata);
+        }
+
+        if (streq(verb, "disable")) {
+                r = normalize_names(names, true);
+                if (r < 0)
+                        return r;
+        }
+
+        if (streq(verb, "link")) {
+                r = normalize_filenames(names);
+                if (r < 0)
+                        return r;
+        }
+
+        if (install_client_side()) {
+                UnitFileFlags flags;
+
+                flags = unit_file_flags_from_args();
+                if (streq(verb, "enable")) {
+                        r = unit_file_enable(arg_scope, flags, arg_root, names, &changes, &n_changes);
+                        carries_install_info = r;
+                } else if (streq(verb, "disable"))
+                        r = unit_file_disable(arg_scope, flags, arg_root, names, &changes, &n_changes);
+                else if (streq(verb, "reenable")) {
+                        r = unit_file_reenable(arg_scope, flags, arg_root, names, &changes, &n_changes);
+                        carries_install_info = r;
+                } else if (streq(verb, "link"))
+                        r = unit_file_link(arg_scope, flags, arg_root, names, &changes, &n_changes);
+                else if (streq(verb, "preset")) {
+                        r = unit_file_preset(arg_scope, flags, arg_root, names, arg_preset_mode, &changes, &n_changes);
+                } else if (streq(verb, "mask"))
+                        r = unit_file_mask(arg_scope, flags, arg_root, names, &changes, &n_changes);
+                else if (streq(verb, "unmask"))
+                        r = unit_file_unmask(arg_scope, flags, arg_root, names, &changes, &n_changes);
+                else if (streq(verb, "revert"))
+                        r = unit_file_revert(arg_scope, arg_root, names, &changes, &n_changes);
+                else
+                        assert_not_reached("Unknown verb");
+
+                unit_file_dump_changes(r, verb, changes, n_changes, arg_quiet);
+                if (r < 0)
+                        goto finish;
+                r = 0;
+        } else {
+                _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL, *m = NULL;
+                _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+                bool expect_carries_install_info = false;
+                bool send_runtime = true, send_force = true, send_preset_mode = false;
+                const char *method;
+                sd_bus *bus;
+
+                if (STR_IN_SET(verb, "mask", "unmask")) {
+                        char **name;
+                        _cleanup_(lookup_paths_free) LookupPaths lp = {};
+
+                        r = lookup_paths_init(&lp, arg_scope, 0, arg_root);
+                        if (r < 0)
+                                return r;
+
+                        STRV_FOREACH(name, names) {
+                                r = unit_exists(&lp, *name);
+                                if (r < 0)
+                                        return r;
+                                if (r == 0)
+                                        log_notice("Unit %s does not exist, proceeding anyway.", *name);
+                        }
+                }
+
+                r = acquire_bus(BUS_MANAGER, &bus);
+                if (r < 0)
+                        return r;
+
+                polkit_agent_open_maybe();
+
+                if (streq(verb, "enable")) {
+                        method = "EnableUnitFiles";
+                        expect_carries_install_info = true;
+                } else if (streq(verb, "disable")) {
+                        method = "DisableUnitFiles";
+                        send_force = false;
+                } else if (streq(verb, "reenable")) {
+                        method = "ReenableUnitFiles";
+                        expect_carries_install_info = true;
+                } else if (streq(verb, "link"))
+                        method = "LinkUnitFiles";
+                else if (streq(verb, "preset")) {
+
+                        if (arg_preset_mode != UNIT_FILE_PRESET_FULL) {
+                                method = "PresetUnitFilesWithMode";
+                                send_preset_mode = true;
+                        } else
+                                method = "PresetUnitFiles";
+
+                        expect_carries_install_info = true;
+                        ignore_carries_install_info = true;
+                } else if (streq(verb, "mask"))
+                        method = "MaskUnitFiles";
+                else if (streq(verb, "unmask")) {
+                        method = "UnmaskUnitFiles";
+                        send_force = false;
+                } else if (streq(verb, "revert")) {
+                        method = "RevertUnitFiles";
+                        send_runtime = send_force = false;
+                } else
+                        assert_not_reached("Unknown verb");
+
+                r = bus_message_new_method_call(bus, &m, bus_systemd_mgr, method);
+                if (r < 0)
+                        return bus_log_create_error(r);
+
+                r = sd_bus_message_append_strv(m, names);
+                if (r < 0)
+                        return bus_log_create_error(r);
+
+                if (send_preset_mode) {
+                        r = sd_bus_message_append(m, "s", unit_file_preset_mode_to_string(arg_preset_mode));
+                        if (r < 0)
+                                return bus_log_create_error(r);
+                }
+
+                if (send_runtime) {
+                        r = sd_bus_message_append(m, "b", arg_runtime);
+                        if (r < 0)
+                                return bus_log_create_error(r);
+                }
+
+                if (send_force) {
+                        r = sd_bus_message_append(m, "b", arg_force);
+                        if (r < 0)
+                                return bus_log_create_error(r);
+                }
+
+                r = sd_bus_call(bus, m, 0, &error, &reply);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to %s unit: %s", verb, bus_error_message(&error, r));
+
+                if (expect_carries_install_info) {
+                        r = sd_bus_message_read(reply, "b", &carries_install_info);
+                        if (r < 0)
+                                return bus_log_parse_error(r);
+                }
+
+                r = bus_deserialize_and_dump_unit_file_changes(reply, arg_quiet, &changes, &n_changes);
+                if (r < 0)
+                        goto finish;
+
+                /* Try to reload if enabled */
+                if (!arg_no_reload)
+                        r = daemon_reload(argc, argv, userdata);
+                else
+                        r = 0;
+        }
+
+        if (carries_install_info == 0 && !ignore_carries_install_info)
+                log_notice("The unit files have no installation config (WantedBy=, RequiredBy=, Also=,\n"
+                           "Alias= settings in the [Install] section, and DefaultInstance= for template\n"
+                           "units). This means they are not meant to be enabled using systemctl.\n"
+                           " \n" /* trick: the space is needed so that the line does not get stripped from output */
+                           "Possible reasons for having this kind of units are:\n"
+                           "%1$s A unit may be statically enabled by being symlinked from another unit's\n"
+                           "  .wants/ or .requires/ directory.\n"
+                           "%1$s A unit's purpose may be to act as a helper for some other unit which has\n"
+                           "  a requirement dependency on it.\n"
+                           "%1$s A unit may be started when needed via activation (socket, path, timer,\n"
+                           "  D-Bus, udev, scripted systemctl call, ...).\n"
+                           "%1$s In case of template units, the unit is meant to be enabled with some\n"
+                           "  instance name specified.",
+                           special_glyph(SPECIAL_GLYPH_BULLET));
+
+        if (arg_now && STR_IN_SET(argv[0], "enable", "disable", "mask")) {
+                sd_bus *bus;
+                size_t len, i;
+
+                r = acquire_bus(BUS_MANAGER, &bus);
+                if (r < 0)
+                        goto finish;
+
+                len = strv_length(names);
+                {
+                        char *new_args[len + 2];
+
+                        new_args[0] = (char*) (streq(argv[0], "enable") ? "start" : "stop");
+                        for (i = 0; i < len; i++)
+                                new_args[i + 1] = basename(names[i]);
+                        new_args[i + 1] = NULL;
+
+                        r = start_unit(len + 1, new_args, userdata);
+                }
+        }
+
+finish:
+        unit_file_changes_free(changes, n_changes);
+
+        return r;
+}