core: simplify drop-in writing logic a bit

let's make use of some format string magic!

5 files changed, 85 insertions, 49 deletions

diff --git a/src/core/dbus-cgroup.c b/src/core/dbus-cgroup.c
index 27b54f95c6..8ad3d118c5 100644
--- a/src/core/dbus-cgroup.c
+++ b/src/core/dbus-cgroup.c
@@ -162,7 +162,7 @@ int bus_cgroup_set_property(
                         dbus_message_iter_get_basic(i, &b);
 
                         c->cpu_accounting = b;
-                        unit_write_drop_in_private_section(u, mode, name, b ? "CPUAccounting=yes" : "CPUAccounting=no");
+                        unit_write_drop_in_private(u, mode, name, b ? "CPUAccounting=yes" : "CPUAccounting=no");
                 }
 
                 return 1;
@@ -181,11 +181,8 @@ int bus_cgroup_set_property(
                         return -EINVAL;
 
                 if (mode != UNIT_CHECK) {
-                        char buf[sizeof("CPUShares=") + DECIMAL_STR_MAX(ul)];
                         c->cpu_shares = ul;
-
-                        sprintf(buf, "CPUShares=%lu", ul);
-                        unit_write_drop_in_private_section(u, mode, name, buf);
+                        unit_write_drop_in_private_format(u, mode, name, "CPUShares=%lu", ul);
                 }
 
                 return 1;
@@ -200,7 +197,7 @@ int bus_cgroup_set_property(
                         dbus_message_iter_get_basic(i, &b);
 
                         c->blockio_accounting = b;
-                        unit_write_drop_in_private_section(u, mode, name, b ? "BlockIOAccounting=yes" : "BlockIOAccounting=no");
+                        unit_write_drop_in_private(u, mode, name, b ? "BlockIOAccounting=yes" : "BlockIOAccounting=no");
                 }
 
                 return 1;
@@ -219,11 +216,8 @@ int bus_cgroup_set_property(
                         return -EINVAL;
 
                 if (mode != UNIT_CHECK) {
-                        char buf[sizeof("BlockIOWeight=") + DECIMAL_STR_MAX(ul)];
                         c->cpu_shares = ul;
-
-                        sprintf(buf, "BlockIOWeight=%lu", ul);
-                        unit_write_drop_in_private_section(u, mode, name, buf);
+                        unit_write_drop_in_private_format(u, mode, name, "BlockIOWeight=%lu", ul);
                 }
 
                 return 1;
@@ -238,7 +232,7 @@ int bus_cgroup_set_property(
                         dbus_message_iter_get_basic(i, &b);
 
                         c->memory_accounting = b;
-                        unit_write_drop_in_private_section(u, mode, name, b ? "MemoryAccounting=yes" : "MemoryAccounting=no");
+                        unit_write_drop_in_private(u, mode, name, b ? "MemoryAccounting=yes" : "MemoryAccounting=no");
                 }
 
                 return 1;
@@ -250,19 +244,15 @@ int bus_cgroup_set_property(
 
                 if (mode != UNIT_CHECK) {
                         uint64_t limit;
-                        char buf[sizeof("MemorySoftLimit=") + DECIMAL_STR_MAX(limit)];
 
                         dbus_message_iter_get_basic(i, &limit);
 
-                        if (streq(name, "MemoryLimit")) {
+                        if (streq(name, "MemoryLimit"))
                                 c->memory_limit = limit;
-                                sprintf(buf, "MemoryLimit=%" PRIu64, limit);
-                                unit_write_drop_in_private_section(u, mode, name, buf);
-                        } else {
+                        else
                                 c->memory_soft_limit = limit;
-                                sprintf(buf, "MemorySoftLimit=%" PRIu64, limit);
-                                unit_write_drop_in_private_section(u, mode, name, buf);
-                        }
+
+                        unit_write_drop_in_private_format(u, mode, name, "%s=%" PRIu64, name, limit);
                 }
 
                 return 1;
@@ -285,7 +275,7 @@ int bus_cgroup_set_property(
                         c->device_policy = p;
 
                         buf = strappenda("DevicePolicy=", policy);
-                        unit_write_drop_in_private_section(u, mode, name, buf);
+                        unit_write_drop_in_private(u, mode, name, buf);
                 }
 
                 return 1;
@@ -365,7 +355,7 @@ int bus_cgroup_set_property(
                                 fprintf(f, "DeviceAllow=%s %s%s%s\n", a->path, a->r ? "r" : "", a->w ? "w" : "", a->m ? "m" : "");
 
                         fflush(f);
-                        unit_write_drop_in_private_section(u, mode, name, buf);
+                        unit_write_drop_in_private(u, mode, name, buf);
                 }
 
                 return 1;
diff --git a/src/core/dbus-service.c b/src/core/dbus-service.c
index d63ca01c4f..8b157b5f3c 100644
--- a/src/core/dbus-service.c
+++ b/src/core/dbus-service.c
@@ -276,7 +276,7 @@ static int bus_service_set_transient_property(
                         }
 
                         fflush(f);
-                        unit_write_drop_in_private_section(UNIT(s), mode, name, buf);
+                        unit_write_drop_in_private(UNIT(s), mode, name, buf);
                 }
 
                 return 1;
diff --git a/src/core/dbus-unit.c b/src/core/dbus-unit.c
index 5814971b8c..ba4d42652e 100644
--- a/src/core/dbus-unit.c
+++ b/src/core/dbus-unit.c
@@ -794,7 +794,6 @@ static int bus_unit_set_transient_property(
                         return -EINVAL;
 
                 if (mode != UNIT_CHECK) {
-                        _cleanup_free_ char *contents = NULL;
                         const char *description;
 
                         dbus_message_iter_get_basic(i, &description);
@@ -803,18 +802,13 @@ static int bus_unit_set_transient_property(
                         if (r < 0)
                                 return r;
 
-                        contents = strjoin("[Unit]\nDescription=", description, "\n", NULL);
-                        if (!contents)
-                                return -ENOMEM;
-
-                        unit_write_drop_in(u, mode, name, contents);
+                        unit_write_drop_in_format(u, mode, name, "[Unit]\nDescription=%s\n", description);
                 }
 
                 return 1;
 
         } else if (streq(name, "Slice") && unit_get_cgroup_context(u)) {
                 const char *s;
-                Unit *slice;
 
                 if (dbus_message_iter_get_arg_type(i) != DBUS_TYPE_STRING)
                         return -EINVAL;
@@ -822,10 +816,12 @@ static int bus_unit_set_transient_property(
                 dbus_message_iter_get_basic(i, &s);
 
                 if (isempty(s)) {
-                        if (mode != UNIT_CHECK)
+                        if (mode != UNIT_CHECK) {
                                 unit_ref_unset(&u->slice);
+                                unit_remove_drop_in(u, mode, name);
+                        }
                 } else {
-                        _cleanup_free_ char *contents = NULL;
+                        Unit *slice;
 
                         r = manager_load_unit(u->manager, s, NULL, error, &slice);
                         if (r < 0)
@@ -834,15 +830,12 @@ static int bus_unit_set_transient_property(
                         if (slice->type != UNIT_SLICE)
                                 return -EINVAL;
 
-                        if (mode != UNIT_CHECK)
+                        if (mode != UNIT_CHECK) {
                                 unit_ref_set(&u->slice, slice);
-
-                        contents = strjoin("[", UNIT_VTABLE(u)->private_section, "]\nSlice=", s, NULL);
-                        if (!contents)
-                                return -ENOMEM;
-
-                        unit_write_drop_in(u, mode, name, contents);
+                                unit_write_drop_in_private_format(u, mode, name, "Slice=%s\n", s);
+                        }
                 }
+
                 return 1;
 
         } else if (streq(name, "Requires") ||
@@ -880,7 +873,7 @@ static int bus_unit_set_transient_property(
                                 return -EINVAL;
 
                         if (mode != UNIT_CHECK) {
-                                _cleanup_free_ char *label = NULL, *contents = NULL;
+                                _cleanup_free_ char *label = NULL;
 
                                 r = unit_add_dependency_by_name(u, d, other, NULL, true);
                                 if (r < 0)
@@ -890,11 +883,7 @@ static int bus_unit_set_transient_property(
                                 if (!label)
                                         return -ENOMEM;
 
-                                contents = strjoin("[Unit]\n", name, "=", other, "\n", NULL);
-                                if (!contents)
-                                        return -ENOMEM;
-
-                                unit_write_drop_in(u, mode, label, contents);
+                                unit_write_drop_in_format(u, mode, label, "[Unit]\n%s=%s\n", name, other);
                         }
 
                         dbus_message_iter_next(&sub);
@@ -1048,10 +1037,11 @@ const BusProperty bus_unit_properties[] = {
         { "ConditionResult",      bus_property_append_bool,           "b", offsetof(Unit, condition_result)                   },
         { "LoadError",            bus_unit_append_load_error,      "(ss)", 0 },
         { "Transient",            bus_property_append_bool,           "b", offsetof(Unit, transient)                          },
-        { NULL, }
+        {}
 };
 
 const BusProperty bus_unit_cgroup_properties[] = {
         { "Slice",                bus_unit_append_slice,              "s", 0 },
         { "ControlGroup",         bus_property_append_string,         "s", offsetof(Unit, cgroup_path),                                true },
+        {}
 };
diff --git a/src/core/unit.c b/src/core/unit.c
index 86452859bc..dd08011ff4 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -2733,6 +2733,7 @@ CGroupContext *unit_get_cgroup_context(Unit *u) {
 }
 
 static int drop_in_file(Unit *u, UnitSetPropertiesMode mode, const char *name, char **_p, char **_q) {
+        _cleanup_free_ char *b = NULL;
         char *p, *q;
         int r;
 
@@ -2742,7 +2743,11 @@ static int drop_in_file(Unit *u, UnitSetPropertiesMode mode, const char *name, c
         assert(_q);
         assert(mode & (UNIT_PERSISTENT|UNIT_RUNTIME));
 
-        if (!filename_is_safe(name))
+        b = xescape(name, "/.");
+        if (!b)
+                return -ENOMEM;
+
+        if (!filename_is_safe(b))
                 return -EINVAL;
 
         if (u->manager->running_as == SYSTEMD_USER) {
@@ -2762,7 +2767,7 @@ static int drop_in_file(Unit *u, UnitSetPropertiesMode mode, const char *name, c
         if (!p)
                 return -ENOMEM;
 
-        q = strjoin(p, "/90-", name, ".conf", NULL);
+        q = strjoin(p, "/90-", b, ".conf", NULL);
         if (!q) {
                 free(p);
                 return -ENOMEM;
@@ -2792,7 +2797,29 @@ int unit_write_drop_in(Unit *u, UnitSetPropertiesMode mode, const char *name, co
         return write_string_file_atomic_label(q, data);
 }
 
-int unit_write_drop_in_private_section(Unit *u, UnitSetPropertiesMode mode, const char *name, const char *data) {
+int unit_write_drop_in_format(Unit *u, UnitSetPropertiesMode mode, const char *name, const char *format, ...) {
+        _cleanup_free_ char *p = NULL;
+        va_list ap;
+        int r;
+
+        assert(u);
+        assert(name);
+        assert(format);
+
+        if (!(mode & (UNIT_PERSISTENT|UNIT_RUNTIME)))
+                return 0;
+
+        va_start(ap, format);
+        r = vasprintf(&p, format, ap);
+        va_end(ap);
+
+        if (r < 0)
+                return -ENOMEM;
+
+        return unit_write_drop_in(u, mode, name, p);
+}
+
+int unit_write_drop_in_private(Unit *u, UnitSetPropertiesMode mode, const char *name, const char *data) {
         _cleanup_free_ char *ndata = NULL;
 
         assert(u);
@@ -2802,6 +2829,9 @@ int unit_write_drop_in_private_section(Unit *u, UnitSetPropertiesMode mode, cons
         if (!UNIT_VTABLE(u)->private_section)
                 return -EINVAL;
 
+        if (!(mode & (UNIT_PERSISTENT|UNIT_RUNTIME)))
+                return 0;
+
         ndata = strjoin("[", UNIT_VTABLE(u)->private_section, "]\n", data, NULL);
         if (!ndata)
                 return -ENOMEM;
@@ -2809,6 +2839,28 @@ int unit_write_drop_in_private_section(Unit *u, UnitSetPropertiesMode mode, cons
         return unit_write_drop_in(u, mode, name, ndata);
 }
 
+int unit_write_drop_in_private_format(Unit *u, UnitSetPropertiesMode mode, const char *name, const char *format, ...) {
+        _cleanup_free_ char *p = NULL;
+        va_list ap;
+        int r;
+
+        assert(u);
+        assert(name);
+        assert(format);
+
+        if (!(mode & (UNIT_PERSISTENT|UNIT_RUNTIME)))
+                return 0;
+
+        va_start(ap, format);
+        r = vasprintf(&p, format, ap);
+        va_end(ap);
+
+        if (r < 0)
+                return -ENOMEM;
+
+        return unit_write_drop_in_private(u, mode, name, p);
+}
+
 int unit_remove_drop_in(Unit *u, UnitSetPropertiesMode mode, const char *name) {
         _cleanup_free_ char *p = NULL, *q = NULL;
         int r;
diff --git a/src/core/unit.h b/src/core/unit.h
index ed4df18246..0caea183c4 100644
--- a/src/core/unit.h
+++ b/src/core/unit.h
@@ -598,7 +598,11 @@ ExecContext *unit_get_exec_context(Unit *u) _pure_;
 CGroupContext *unit_get_cgroup_context(Unit *u) _pure_;
 
 int unit_write_drop_in(Unit *u, UnitSetPropertiesMode mode, const char *name, const char *data);
-int unit_write_drop_in_private_section(Unit *u, UnitSetPropertiesMode mode, const char *name, const char *data);
+int unit_write_drop_in_format(Unit *u, UnitSetPropertiesMode mode, const char *name, const char *format, ...) _printf_attr_(4,5);
+
+int unit_write_drop_in_private(Unit *u, UnitSetPropertiesMode mode, const char *name, const char *data);
+int unit_write_drop_in_private_format(Unit *u, UnitSetPropertiesMode mode, const char *name, const char *format, ...) _printf_attr_(4,5);
+
 int unit_remove_drop_in(Unit *u, UnitSetPropertiesMode mode, const char *name);
 
 int unit_kill_context(Unit *u, KillContext *c, bool sigkill, pid_t main_pid, pid_t control_pid, bool main_pid_alien);