systemctl: add add-wants and add-requires verbs

9 files changed, 303 insertions, 40 deletions

diff --git a/TODO b/TODO
index 10baa1cec3..b437166273 100644
--- a/TODO
+++ b/TODO
@@ -461,7 +461,6 @@ Features:
   - "systemctl mask" should find all names by which a unit is accessible
     (i.e. by scanning for symlinks to it) and link them all to /dev/null
   - systemctl list-unit-files should list generated files (and probably with a new state "generated" for them, or so)
-  - systemctl: maybe add "systemctl add-wants" or so...
 
 * timer units:
   - timer units should get the ability to trigger when:
diff --git a/man/systemctl.xml b/man/systemctl.xml
index b28a3b7e8a..b2aa17f22b 100644
--- a/man/systemctl.xml
+++ b/man/systemctl.xml
@@ -1098,6 +1098,25 @@ kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service
         </varlistentry>
 
         <varlistentry>
+          <term><command>add-wants <replaceable>TARGET</replaceable>
+          <replaceable>NAME</replaceable>...</command></term>
+          <term><command>add-requires <replaceable>TARGET</replaceable>
+          <replaceable>NAME</replaceable>...</command></term>
+
+          <listitem>
+            <para>Adds <literal>Wants=</literal> resp. <literal>Requires=</literal>
+            dependency to the specified <replaceable>TARGET</replaceable> for
+            one or more units. </para>
+
+            <para>This command honors <option>--system</option>,
+            <option>--user</option>, <option>--runtime</option> and
+            <option>--global</option> in a similar way as
+            <command>enable</command>.</para>
+
+          </listitem>
+        </varlistentry>
+
+        <varlistentry>
           <term><command>link <replaceable>FILENAME</replaceable>...</command></term>
 
           <listitem>
diff --git a/src/core/dbus-manager.c b/src/core/dbus-manager.c
index 533ce439a7..57db1c9f6a 100644
--- a/src/core/dbus-manager.c
+++ b/src/core/dbus-manager.c
@@ -1562,9 +1562,6 @@ static int method_enable_unit_files_generic(
                 sd_bus_error *error) {
 
         _cleanup_strv_free_ char **l = NULL;
-#ifdef HAVE_SELINUX
-        char **i;
-#endif
         UnitFileChange *changes = NULL;
         unsigned n_changes = 0;
         UnitFileScope scope;
@@ -1588,18 +1585,9 @@ static int method_enable_unit_files_generic(
         if (r < 0)
                 return r;
 
-#ifdef HAVE_SELINUX
-        STRV_FOREACH(i, l) {
-                Unit *u;
-
-                u = manager_get_unit(m, *i);
-                if (u) {
-                        r = selinux_unit_access_check(u, message, verb, error);
-                        if (r < 0)
-                                return r;
-                }
-        }
-#endif
+        r = selinux_unit_access_check_strv(l, message, m, verb, error);
+        if (r < 0)
+                return r;
 
         scope = m->running_as == SYSTEMD_SYSTEM ? UNIT_FILE_SYSTEM : UNIT_FILE_USER;
 
@@ -1637,9 +1625,6 @@ static int method_mask_unit_files(sd_bus *bus, sd_bus_message *message, void *us
 static int method_preset_unit_files_with_mode(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
 
         _cleanup_strv_free_ char **l = NULL;
-#ifdef HAVE_SELINUX
-        char **i;
-#endif
         UnitFileChange *changes = NULL;
         unsigned n_changes = 0;
         Manager *m = userdata;
@@ -1674,18 +1659,9 @@ static int method_preset_unit_files_with_mode(sd_bus *bus, sd_bus_message *messa
                         return -EINVAL;
         }
 
-#ifdef HAVE_SELINUX
-        STRV_FOREACH(i, l) {
-                Unit *u;
-
-                u = manager_get_unit(m, *i);
-                if (u) {
-                        r = selinux_unit_access_check(u, message, "enable", error);
-                        if (r < 0)
-                                return r;
-                }
-        }
-#endif
+        r = selinux_unit_access_check_strv(l, message, m, "enable", error);
+        if (r < 0)
+                return r;
 
         scope = m->running_as == SYSTEMD_SYSTEM ? UNIT_FILE_SYSTEM : UNIT_FILE_USER;
 
@@ -1828,6 +1804,52 @@ static int method_preset_all_unit_files(sd_bus *bus, sd_bus_message *message, vo
         return reply_unit_file_changes_and_free(m, bus, message, -1, changes, n_changes);
 }
 
+static int method_add_dependency_unit_files(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
+        _cleanup_strv_free_ char **l = NULL;
+        Manager *m = userdata;
+        UnitFileChange *changes = NULL;
+        unsigned n_changes = 0;
+        UnitFileScope scope;
+        int runtime, force, r;
+        char *target;
+        char *type;
+        UnitDependency dep;
+
+        assert(bus);
+        assert(message);
+        assert(m);
+
+        r = bus_verify_manage_unit_files_async(m, message, error);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return 1; /* No authorization for now, but the async polkit stuff will call us again when it has it */
+
+        r = sd_bus_message_read_strv(message, &l);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_read(message, "ssbb", &target, &type, &runtime, &force);
+        if (r < 0)
+                return r;
+
+        dep = unit_dependency_from_string(type);
+        if (dep < 0)
+                return -EINVAL;
+
+        r = selinux_unit_access_check_strv(l, message, m, "enable", error);
+        if (r < 0)
+                return r;
+
+        scope = m->running_as == SYSTEMD_SYSTEM ? UNIT_FILE_SYSTEM : UNIT_FILE_USER;
+
+        r = unit_file_add_dependency(scope, runtime, NULL, l, target, dep, force, &changes, &n_changes);
+        if (r < 0)
+                return r;
+
+        return reply_unit_file_changes_and_free(m, bus, message, -1, changes, n_changes);
+}
+
 const sd_bus_vtable bus_manager_vtable[] = {
         SD_BUS_VTABLE_START(0),
 
@@ -1918,6 +1940,7 @@ const sd_bus_vtable bus_manager_vtable[] = {
         SD_BUS_METHOD("SetDefaultTarget", "sb", "a(sss)", method_set_default_target, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("GetDefaultTarget", NULL, "s", method_get_default_target, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("PresetAllUnitFiles", "sbb", "a(sss)", method_preset_all_unit_files, SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD("AddDependencyUnitFiles", "asssbb", "a(sss)", method_add_dependency_unit_files, SD_BUS_VTABLE_UNPRIVILEGED),
 
         SD_BUS_SIGNAL("UnitNew", "so", 0),
         SD_BUS_SIGNAL("UnitRemoved", "so", 0),
diff --git a/src/core/org.freedesktop.systemd1.conf b/src/core/org.freedesktop.systemd1.conf
index 3e1382524a..6a7a37ee92 100644
--- a/src/core/org.freedesktop.systemd1.conf
+++ b/src/core/org.freedesktop.systemd1.conf
@@ -199,6 +199,10 @@
                        send_member="PresetAllUnitFiles"/>
 
                 <allow send_destination="org.freedesktop.systemd1"
+                       send_interface="org.freedesktop.systemd1.Manager"
+                       send_member="AddDependencyUnitFiles"/>
+
+                <allow send_destination="org.freedesktop.systemd1"
                        send_interface="org.freedesktop.systemd1.Job"
                        send_member="Cancel"/>
 
diff --git a/src/core/selinux-access.c b/src/core/selinux-access.c
index cdbfb83a1a..184f202c1e 100644
--- a/src/core/selinux-access.c
+++ b/src/core/selinux-access.c
@@ -250,6 +250,27 @@ finish:
         return r;
 }
 
+int selinux_unit_access_check_strv(char **units,
+                                sd_bus_message *message,
+                                Manager *m,
+                                const char *permission,
+                                sd_bus_error *error) {
+        char **i;
+        Unit *u;
+        int r;
+
+        STRV_FOREACH(i, units) {
+                u = manager_get_unit(m, *i);
+                if (u) {
+                        r = selinux_unit_access_check(u, message, permission, error);
+                        if (r < 0)
+                                return r;
+                }
+        }
+
+        return 0;
+}
+
 #else
 
 int selinux_generic_access_check(
@@ -264,4 +285,12 @@ int selinux_generic_access_check(
 void selinux_access_free(void) {
 }
 
+int selinux_unit_access_check_strv(char **units,
+                                sd_bus_message *message,
+                                Manager *m,
+                                const char *permission,
+                                sd_bus_error *error) {
+        return 0;
+}
+
 #endif
diff --git a/src/core/selinux-access.h b/src/core/selinux-access.h
index 27d9e14591..6a4362a73c 100644
--- a/src/core/selinux-access.h
+++ b/src/core/selinux-access.h
@@ -24,11 +24,14 @@
 #include "sd-bus.h"
 #include "bus-error.h"
 #include "bus-util.h"
+#include "manager.h"
 
 void selinux_access_free(void);
 
 int selinux_generic_access_check(sd_bus_message *message, const char *path, const char *permission, sd_bus_error *error);
 
+int selinux_unit_access_check_strv(char **units, sd_bus_message *message, Manager *m, const char *permission, sd_bus_error *error);
+
 #ifdef HAVE_SELINUX
 
 #define selinux_access_check(message, permission, error) \
diff --git a/src/shared/install.c b/src/shared/install.c
index 945bb2748d..ff5dcbac15 100644
--- a/src/shared/install.c
+++ b/src/shared/install.c
@@ -1042,7 +1042,8 @@ static int unit_file_load(
                 InstallInfo *info,
                 const char *path,
                 const char *root_dir,
-                bool allow_symlink) {
+                bool allow_symlink,
+                bool load) {
 
         const ConfigTableItem items[] = {
                 { "Install", "Alias",           config_parse_strv,             0, &info->aliases           },
@@ -1064,6 +1065,11 @@ static int unit_file_load(
         if (!isempty(root_dir))
                 path = strappenda(root_dir, "/", path);
 
+        if (!load) {
+                r = access(path, F_OK) ? -errno : 0;
+                return r;
+        }
+
         fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|(allow_symlink ? 0 : O_NOFOLLOW));
         if (fd < 0)
                 return -errno;
@@ -1092,7 +1098,8 @@ static int unit_file_search(
                 InstallInfo *info,
                 LookupPaths *paths,
                 const char *root_dir,
-                bool allow_symlink) {
+                bool allow_symlink,
+                bool load) {
 
         char **p;
         int r;
@@ -1102,7 +1109,7 @@ static int unit_file_search(
         assert(paths);
 
         if (info->path)
-                return unit_file_load(c, info, info->path, root_dir, allow_symlink);
+                return unit_file_load(c, info, info->path, root_dir, allow_symlink, load);
 
         assert(info->name);
 
@@ -1113,7 +1120,7 @@ static int unit_file_search(
                 if (!path)
                         return -ENOMEM;
 
-                r = unit_file_load(c, info, path, root_dir, allow_symlink);
+                r = unit_file_load(c, info, path, root_dir, allow_symlink, load);
                 if (r >= 0) {
                         info->path = path;
                         path = NULL;
@@ -1142,7 +1149,7 @@ static int unit_file_search(
                         if (!path)
                                 return -ENOMEM;
 
-                        r = unit_file_load(c, info, path, root_dir, allow_symlink);
+                        r = unit_file_load(c, info, path, root_dir, allow_symlink, load);
                         if (r >= 0) {
                                 info->path = path;
                                 path = NULL;
@@ -1175,7 +1182,7 @@ static int unit_file_can_install(
 
         assert_se(i = hashmap_first(c.will_install));
 
-        r = unit_file_search(&c, i, paths, root_dir, allow_symlink);
+        r = unit_file_search(&c, i, paths, root_dir, allow_symlink, true);
 
         if (r >= 0)
                 r =
@@ -1402,7 +1409,7 @@ static int install_context_apply(
 
                 assert_se(hashmap_move_one(c->have_installed, c->will_install, i->name) == 0);
 
-                q = unit_file_search(c, i, paths, root_dir, false);
+                q = unit_file_search(c, i, paths, root_dir, false, true);
                 if (q < 0) {
                         if (r >= 0)
                                 r = q;
@@ -1443,7 +1450,7 @@ static int install_context_mark_for_removal(
 
                 assert_se(hashmap_move_one(c->have_installed, c->will_install, i->name) == 0);
 
-                q = unit_file_search(c, i, paths, root_dir, false);
+                q = unit_file_search(c, i, paths, root_dir, false, true);
                 if (q == -ENOENT) {
                         /* do nothing */
                 } else if (q < 0) {
@@ -1489,6 +1496,83 @@ static int install_context_mark_for_removal(
         return r;
 }
 
+int unit_file_add_dependency(
+                UnitFileScope scope,
+                bool runtime,
+                const char *root_dir,
+                char **files,
+                char *target,
+                UnitDependency dep,
+                bool force,
+                UnitFileChange **changes,
+                unsigned *n_changes) {
+
+        _cleanup_lookup_paths_free_ LookupPaths paths = {};
+        _cleanup_(install_context_done) InstallContext c = {};
+        _cleanup_free_ char *config_path = NULL;
+        char **i;
+        int r;
+        InstallInfo *info;
+
+        assert(scope >= 0);
+        assert(scope < _UNIT_FILE_SCOPE_MAX);
+
+        r = lookup_paths_init_from_scope(&paths, scope, root_dir);
+        if (r < 0)
+                return r;
+
+        r = get_config_path(scope, runtime, root_dir, &config_path);
+        if (r < 0)
+                return r;
+
+        STRV_FOREACH(i, files) {
+                UnitFileState state;
+
+                state = unit_file_get_state(scope, root_dir, *i);
+                if (state < 0) {
+                        log_error("Failed to get unit file state for %s: %s", *i, strerror(-state));
+                        return state;
+                }
+
+                if (state == UNIT_FILE_MASKED || state == UNIT_FILE_MASKED_RUNTIME) {
+                        log_error("Failed to enable unit: Unit %s is masked", *i);
+                        return -ENOTSUP;
+                }
+
+                r = install_info_add_auto(&c, *i);
+                if (r < 0)
+                        return r;
+        }
+
+        while ((info = hashmap_first(c.will_install))) {
+                r = hashmap_ensure_allocated(&c.have_installed, &string_hash_ops);
+                if (r < 0)
+                        return r;
+
+                assert_se(hashmap_move_one(c.have_installed, c.will_install, info->name) == 0);
+
+                r = unit_file_search(&c, info, &paths, root_dir, false, false);
+                if (r < 0)
+                        return r;
+
+                if (dep == UNIT_WANTS)
+                        r = strv_extend(&info->wanted_by, target);
+                else if (dep == UNIT_REQUIRES)
+                        r = strv_extend(&info->required_by, target);
+                else
+                        r = -EINVAL;
+
+                if (r < 0)
+                        return r;
+
+                r = install_info_apply(info, &paths, config_path, root_dir, force, changes, n_changes);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
 int unit_file_enable(
                 UnitFileScope scope,
                 bool runtime,
@@ -1638,7 +1722,7 @@ int unit_file_set_default(
 
         assert_se(i = hashmap_first(c.will_install));
 
-        r = unit_file_search(&c, i, &paths, root_dir, false);
+        r = unit_file_search(&c, i, &paths, root_dir, false, true);
         if (r < 0)
                 return r;
 
diff --git a/src/shared/install.h b/src/shared/install.h
index ff16d9f681..c0b4df69d5 100644
--- a/src/shared/install.h
+++ b/src/shared/install.h
@@ -22,6 +22,7 @@
 ***/
 
 #include "hashmap.h"
+#include "unit-name.h"
 
 typedef enum UnitFileScope {
         UNIT_FILE_SYSTEM,
@@ -93,6 +94,7 @@ int unit_file_mask(UnitFileScope scope, bool runtime, const char *root_dir, char
 int unit_file_unmask(UnitFileScope scope, bool runtime, const char *root_dir, char **files, UnitFileChange **changes, unsigned *n_changes);
 int unit_file_set_default(UnitFileScope scope, const char *root_dir, const char *file, bool force, UnitFileChange **changes, unsigned *n_changes);
 int unit_file_get_default(UnitFileScope scope, const char *root_dir, char **name);
+int unit_file_add_dependency(UnitFileScope scope, bool runtime, const char *root_dir, char **files, char *target, UnitDependency dep, bool force, UnitFileChange **changes, unsigned *n_changes);
 
 UnitFileState unit_file_get_state(UnitFileScope scope, const char *root_dir, const char *filename);
 
diff --git a/src/systemctl/systemctl.c b/src/systemctl/systemctl.c
index 1c6fef484e..12175923e9 100644
--- a/src/systemctl/systemctl.c
+++ b/src/systemctl/systemctl.c
@@ -5288,6 +5288,100 @@ finish:
         return r;
 }
 
+static int add_dependency(sd_bus *bus, char **args) {
+        _cleanup_strv_free_ char **names = NULL;
+        _cleanup_free_ char *target = NULL;
+        const char *verb = args[0];
+        UnitDependency dep;
+        int r = 0;
+
+        if (!args[1])
+                return 0;
+
+        target = unit_name_mangle_with_suffix(args[1], MANGLE_NOGLOB, ".target");
+        if (!target)
+                return log_oom();
+
+        r = mangle_names(args+2, &names);
+        if (r < 0)
+                return r;
+
+        if (streq(verb, "add-wants"))
+                dep = UNIT_WANTS;
+        else if (streq(verb, "add-requires"))
+                dep = UNIT_REQUIRES;
+        else
+                assert_not_reached("Unknown verb");
+
+        if (!bus || avoid_bus()) {
+                UnitFileChange *changes = NULL;
+                unsigned n_changes = 0;
+
+                r = unit_file_add_dependency(arg_scope, arg_runtime, arg_root, names, target, dep, arg_force, &changes, &n_changes);
+
+                if (r < 0) {
+                        log_error("Can't add dependency: %s", strerror(-r));
+                        return r;
+                }
+
+                if (!arg_quiet)
+                        dump_unit_file_changes(changes, n_changes);
+
+                unit_file_changes_free(changes, n_changes);
+
+        } else {
+                _cleanup_bus_message_unref_ sd_bus_message *reply = NULL, *m = NULL;
+                _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+
+                r = sd_bus_message_new_method_call(
+                                bus,
+                                &m,
+                                "org.freedesktop.systemd1",
+                                "/org/freedesktop/systemd1",
+                                "org.freedesktop.systemd1.Manager",
+                                "AddDependencyUnitFiles");
+                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);
+
+                r = sd_bus_message_append(m, "s", target);
+                if (r < 0)
+                        return bus_log_create_error(r);
+
+                r = sd_bus_message_append(m, "s", unit_dependency_to_string(dep));
+                if (r < 0)
+                        return bus_log_create_error(r);
+
+                r = sd_bus_message_append(m, "b", arg_runtime);
+                if (r < 0)
+                        return bus_log_create_error(r);
+
+                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) {
+                        log_error("Failed to execute operation: %s", bus_error_message(&error, r));
+                        return r;
+                }
+
+                r = deserialize_and_dump_unit_file_changes(reply);
+                if (r < 0)
+                        return r;
+
+                if (!arg_no_reload)
+                        r = daemon_reload(bus, args);
+                else
+                        r = 0;
+        }
+
+        return r;
+}
+
 static int preset_all(sd_bus *bus, char **args) {
         UnitFileChange *changes = NULL;
         unsigned n_changes = 0;
@@ -5533,6 +5627,10 @@ static void systemctl_help(void) {
                "  unmask NAME...                  Unmask one or more units\n"
                "  link PATH...                    Link one or more units files into\n"
                "                                  the search path\n"
+               "  add-wants TARGET NAME...        Add 'Wants' dependency for the target\n"
+               "                                  on specified one or more units\n"
+               "  add-requires TARGET NAME...     Add 'Requires' dependency for the target\n"
+               "                                  on specified one or more units\n"
                "  get-default                     Get the name of the default target\n"
                "  set-default NAME                Set the default target\n\n"
                "Machine Commands:\n"
@@ -6543,6 +6641,8 @@ static int systemctl_main(sd_bus *bus, int argc, char *argv[], int bus_error) {
                 { "get-default",           EQUAL, 1, get_default,      NOBUS },
                 { "set-property",          MORE,  3, set_property      },
                 { "is-system-running",     EQUAL, 1, is_system_running },
+                { "add-wants",             MORE,  3, add_dependency,        NOBUS },
+                { "add-requires",          MORE,  3, add_dependency,        NOBUS },
                 {}
         }, *verb = verbs;