core: add dbus-util.[ch] to simplify creating transient units

The functions and macros introduced by them will be used in later commits.

3 files changed, 392 insertions, 0 deletions

diff --git a/src/core/dbus-util.c b/src/core/dbus-util.c
new file mode 100644
index 000000000..a44f4fd0b
--- /dev/null
+++ b/src/core/dbus-util.c
@@ -0,0 +1,119 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+//#include "bus-util.h"
+//#include "dbus-util.h"
+//#include "parse-util.h"
+//#include "path-util.h"
+//#include "unit-printf.h"
+//#include "user-util.h"
+//#include "unit.h"
+
+BUS_DEFINE_SET_TRANSIENT(mode_t, "u", uint32_t, mode_t, "%040o");
+BUS_DEFINE_SET_TRANSIENT(unsigned, "u", uint32_t, unsigned, "%" PRIu32);
+BUS_DEFINE_SET_TRANSIENT_STRING_WITH_CHECK(user, valid_user_group_name_or_id);
+BUS_DEFINE_SET_TRANSIENT_STRING_WITH_CHECK(path, path_is_absolute);
+
+int bus_set_transient_string(
+                Unit *u,
+                const char *name,
+                char **p,
+                sd_bus_message *message,
+                UnitWriteFlags flags,
+                sd_bus_error *error) {
+
+        const char *v;
+        int r;
+
+        assert(p);
+
+        r = sd_bus_message_read(message, "s", &v);
+        if (r < 0)
+                return r;
+
+        if (!UNIT_WRITE_FLAGS_NOOP(flags)) {
+                r = free_and_strdup(p, empty_to_null(v));
+                if (r < 0)
+                        return r;
+
+                unit_write_settingf(u, flags|UNIT_ESCAPE_SPECIFIERS, name,
+                                    "%s=%s", name, strempty(v));
+        }
+
+        return 1;
+}
+
+int bus_set_transient_bool(
+                Unit *u,
+                const char *name,
+                bool *p,
+                sd_bus_message *message,
+                UnitWriteFlags flags,
+                sd_bus_error *error) {
+
+        int v, r;
+
+        assert(p);
+
+        r = sd_bus_message_read(message, "b", &v);
+        if (r < 0)
+                return r;
+
+        if (!UNIT_WRITE_FLAGS_NOOP(flags)) {
+                *p = v;
+                unit_write_settingf(u, flags, name, "%s=%s", name, yes_no(v));
+        }
+
+        return 1;
+}
+
+int bus_set_transient_usec_internal(
+                Unit *u,
+                const char *name,
+                usec_t *p,
+                bool fix_0,
+                sd_bus_message *message,
+                UnitWriteFlags flags,
+                sd_bus_error *error) {
+
+        usec_t v;
+        int r;
+
+        assert(p);
+
+        r = sd_bus_message_read(message, "u", &v);
+        if (r < 0)
+                return r;
+
+        if (!UNIT_WRITE_FLAGS_NOOP(flags)) {
+                char *n, ts[FORMAT_TIMESPAN_MAX];
+
+                if (fix_0)
+                        *p = v ?: USEC_INFINITY;
+                else
+                        *p = v;
+
+                n = strndupa(name, strlen(name) - 4);
+                unit_write_settingf(u, flags, name, "%sSec=%s", n,
+                                    format_timespan(ts, sizeof(ts), v, USEC_PER_MSEC));
+        }
+
+        return 1;
+}
diff --git a/src/core/dbus-util.h b/src/core/dbus-util.h
new file mode 100644
index 000000000..99b96bd00
--- /dev/null
+++ b/src/core/dbus-util.h
@@ -0,0 +1,271 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+//#include "sd-bus.h"
+//#include "unit.h"
+
+#define BUS_DEFINE_SET_TRANSIENT(function, bus_type, type, cast_type, fmt) \
+        int bus_set_transient_##function(                               \
+                        Unit *u,                                        \
+                        const char *name,                               \
+                        cast_type *p,                                   \
+                        sd_bus_message *message,                        \
+                        UnitWriteFlags flags,                           \
+                        sd_bus_error *error) {                          \
+                                                                        \
+                type v;                                                 \
+                int r;                                                  \
+                                                                        \
+                assert(p);                                              \
+                                                                        \
+                r = sd_bus_message_read(message, bus_type, &v);         \
+                if (r < 0)                                              \
+                        return r;                                       \
+                                                                        \
+                if (!UNIT_WRITE_FLAGS_NOOP(flags)) {                    \
+                        *p = (cast_type) v;                             \
+                        unit_write_settingf(u, flags, name,             \
+                                            "%s=" fmt, name, v);        \
+                }                                                       \
+                                                                        \
+                return 1;                                               \
+        }                                                               \
+        struct __useless_struct_to_allow_trailing_semicolon__
+
+#define BUS_DEFINE_SET_TRANSIENT_IS_VALID(function, bus_type, type, cast_type, fmt, check) \
+        int bus_set_transient_##function(                               \
+                        Unit *u,                                        \
+                        const char *name,                               \
+                        cast_type *p,                                   \
+                        sd_bus_message *message,                        \
+                        UnitWriteFlags flags,                           \
+                        sd_bus_error *error) {                          \
+                                                                        \
+                type v;                                                 \
+                int r;                                                  \
+                                                                        \
+                assert(p);                                              \
+                                                                        \
+                r = sd_bus_message_read(message, bus_type, &v);         \
+                if (r < 0)                                              \
+                        return r;                                       \
+                                                                        \
+                if (!check(v))                                          \
+                        return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, \
+                                                 "Invalid %s setting: " fmt, name, v); \
+                                                                        \
+                if (!UNIT_WRITE_FLAGS_NOOP(flags)) {                    \
+                        *p = (cast_type) v;                             \
+                        unit_write_settingf(u, flags, name,             \
+                                            "%s=" fmt, name, v);        \
+                }                                                       \
+                                                                        \
+                return 1;                                               \
+        }                                                               \
+        struct __useless_struct_to_allow_trailing_semicolon__
+
+#define BUS_DEFINE_SET_TRANSIENT_TO_STRING(function, bus_type, type, cast_type, fmt, to_string) \
+        int bus_set_transient_##function(                               \
+                        Unit *u,                                        \
+                        const char *name,                               \
+                        cast_type *p,                                   \
+                        sd_bus_message *message,                        \
+                        UnitWriteFlags flags,                           \
+                        sd_bus_error *error) {                          \
+                                                                        \
+                const char *s;                                          \
+                type v;                                                 \
+                int r;                                                  \
+                                                                        \
+                assert(p);                                              \
+                                                                        \
+                r = sd_bus_message_read(message, bus_type, &v);         \
+                if (r < 0)                                              \
+                        return r;                                       \
+                                                                        \
+                s = to_string(v);                                       \
+                if (!s)                                                 \
+                        return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, \
+                                                 "Invalid %s setting: " fmt, name, v); \
+                                                                        \
+                if (!UNIT_WRITE_FLAGS_NOOP(flags)) {                    \
+                        *p = (cast_type) v;                             \
+                        unit_write_settingf(u, flags, name,             \
+                                            "%s=%s", name, s);          \
+                }                                                       \
+                                                                        \
+                return 1;                                               \
+        }                                                               \
+        struct __useless_struct_to_allow_trailing_semicolon__
+
+#define BUS_DEFINE_SET_TRANSIENT_TO_STRING_ALLOC(function, bus_type, type, cast_type, fmt, to_string) \
+        int bus_set_transient_##function(                               \
+                        Unit *u,                                        \
+                        const char *name,                               \
+                        cast_type *p,                                   \
+                        sd_bus_message *message,                        \
+                        UnitWriteFlags flags,                           \
+                        sd_bus_error *error) {                          \
+                                                                        \
+                _cleanup_free_ char *s = NULL;                          \
+                type v;                                                 \
+                int r;                                                  \
+                                                                        \
+                assert(p);                                              \
+                                                                        \
+                r = sd_bus_message_read(message, bus_type, &v);         \
+                if (r < 0)                                              \
+                        return r;                                       \
+                                                                        \
+                r = to_string(v, &s);                                   \
+                if (r == -EINVAL)                                       \
+                        return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, \
+                                                 "Invalid %s setting: " fmt, name, v); \
+                if (r < 0)                                              \
+                        return r;                                       \
+                                                                        \
+                if (!UNIT_WRITE_FLAGS_NOOP(flags)) {                    \
+                        *p = (cast_type) v;                             \
+                        unit_write_settingf(u, flags, name,             \
+                                            "%s=%s", name, s);          \
+                }                                                       \
+                                                                        \
+                return 1;                                               \
+        }                                                               \
+        struct __useless_struct_to_allow_trailing_semicolon__
+
+#define BUS_DEFINE_SET_TRANSIENT_PARSE(function, type, parse)           \
+        int bus_set_transient_##function(                               \
+                        Unit *u,                                        \
+                        const char *name,                               \
+                        type *p,                                        \
+                        sd_bus_message *message,                        \
+                        UnitWriteFlags flags,                           \
+                        sd_bus_error *error) {                          \
+                                                                        \
+                const char *s;                                          \
+                type v;                                                 \
+                int r;                                                  \
+                                                                        \
+                assert(p);                                              \
+                                                                        \
+                r = sd_bus_message_read(message, "s", &s);              \
+                if (r < 0)                                              \
+                        return r;                                       \
+                                                                        \
+                v = parse(s);                                           \
+                if (v < 0)                                              \
+                        return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, \
+                                                 "Invalid %s setting: %s", name, s); \
+                                                                        \
+                if (!UNIT_WRITE_FLAGS_NOOP(flags)) {                    \
+                        *p = v;                                         \
+                        unit_write_settingf(u, flags, name,             \
+                                            "%s=%s", name, s);          \
+                }                                                       \
+                                                                        \
+                return 1;                                               \
+        }                                                               \
+        struct __useless_struct_to_allow_trailing_semicolon__
+
+#define BUS_DEFINE_SET_TRANSIENT_PARSE_PTR(function, type, parse)       \
+        int bus_set_transient_##function(                               \
+                        Unit *u,                                        \
+                        const char *name,                               \
+                        type *p,                                        \
+                        sd_bus_message *message,                        \
+                        UnitWriteFlags flags,                           \
+                        sd_bus_error *error) {                          \
+                                                                        \
+                const char *s;                                          \
+                type v;                                                 \
+                int r;                                                  \
+                                                                        \
+                assert(p);                                              \
+                                                                        \
+                r = sd_bus_message_read(message, "s", &s);              \
+                if (r < 0)                                              \
+                        return r;                                       \
+                                                                        \
+                r = parse(s, &v);                                       \
+                if (r < 0)                                              \
+                        return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, \
+                                                 "Invalid %s setting: %s", name, s); \
+                                                                        \
+                if (!UNIT_WRITE_FLAGS_NOOP(flags)) {                    \
+                        *p = v;                                         \
+                        unit_write_settingf(u, flags, name,             \
+                                            "%s=%s", name, strempty(s)); \
+                }                                                       \
+                                                                        \
+                return 1;                                               \
+        }                                                               \
+        struct __useless_struct_to_allow_trailing_semicolon__
+
+#define BUS_DEFINE_SET_TRANSIENT_STRING_WITH_CHECK(function, check)     \
+        int bus_set_transient_##function(                               \
+                        Unit *u,                                        \
+                        const char *name,                               \
+                        char **p,                                       \
+                        sd_bus_message *message,                        \
+                        UnitWriteFlags flags,                           \
+                        sd_bus_error *error) {                          \
+                                                                        \
+                const char *v;                                          \
+                int r;                                                  \
+                                                                        \
+                assert(p);                                              \
+                                                                        \
+                r = sd_bus_message_read(message, "s", &v);              \
+                if (r < 0)                                              \
+                        return r;                                       \
+                                                                        \
+                if (!isempty(v) && !check(v))                           \
+                        return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, \
+                                                 "Invalid %s setting: %s", name, v); \
+                                                                        \
+                if (!UNIT_WRITE_FLAGS_NOOP(flags)) {                    \
+                        r = free_and_strdup(p, empty_to_null(v));       \
+                        if (r < 0)                                      \
+                                return r;                               \
+                                                                        \
+                        unit_write_settingf(u, flags|UNIT_ESCAPE_SPECIFIERS, name, \
+                                            "%s=%s", name, strempty(v)); \
+                }                                                       \
+                                                                        \
+                return 1;                                               \
+        }                                                               \
+        struct __useless_struct_to_allow_trailing_semicolon__
+
+int bus_set_transient_mode_t(Unit *u, const char *name, mode_t *p, sd_bus_message *message, UnitWriteFlags flags, sd_bus_error *error);
+int bus_set_transient_unsigned(Unit *u, const char *name, unsigned *p, sd_bus_message *message, UnitWriteFlags flags, sd_bus_error *error);
+int bus_set_transient_user(Unit *u, const char *name, char **p, sd_bus_message *message, UnitWriteFlags flags, sd_bus_error *error);
+int bus_set_transient_path(Unit *u, const char *name, char **p, sd_bus_message *message, UnitWriteFlags flags, sd_bus_error *error);
+int bus_set_transient_string(Unit *u, const char *name, char **p, sd_bus_message *message, UnitWriteFlags flags, sd_bus_error *error);
+int bus_set_transient_bool(Unit *u, const char *name, bool *p, sd_bus_message *message, UnitWriteFlags flags, sd_bus_error *error);
+int bus_set_transient_usec_internal(Unit *u, const char *name, usec_t *p, bool fix_0, sd_bus_message *message, UnitWriteFlags flags, sd_bus_error *error);
+static inline int bus_set_transient_usec(Unit *u, const char *name, usec_t *p, sd_bus_message *message, UnitWriteFlags flags, sd_bus_error *error) {
+        return bus_set_transient_usec_internal(u, name, p, false, message, flags, error);
+}
+static inline int bus_set_transient_usec_fix_0(Unit *u, const char *name, usec_t *p, sd_bus_message *message, UnitWriteFlags flags, sd_bus_error *error) {
+        return bus_set_transient_usec_internal(u, name, p, true, message, flags, error);
+}
diff --git a/src/core/meson.build b/src/core/meson.build
index ce8c0f647..70831dd57 100644
--- a/src/core/meson.build
+++ b/src/core/meson.build
@@ -61,6 +61,8 @@
 #         dbus-timer.h
 #         dbus-unit.c
 #         dbus-unit.h
+#         dbus-util.c
+#         dbus-util.h
 #         dbus.c
 #         dbus.h
 #         device.c