machinectl: Add plumbing for a --force flag for file copy

machine: Add APIs CopyTo[Machine]WithFlags + CopyFrom[Machine]WithFlags
- Same API to those without `WithFlags` (except this can take flags)
- Initially, only a flag to allow replacing a file if it already exists

src/machine/machine-dbus.c

@@ -928,6 +928,20 @@ int bus_machine_method_copy(sd_bus_message *message, void *userdata, sd_bus_erro
         if (r < 0)
                 return r;
 
+        if (endswith(sd_bus_message_get_member(message), "WithFlags")) {
+                uint64_t raw_flags;
+
+                r = sd_bus_message_read(message, "t", &raw_flags);
+                if (r < 0)
+                        return r;
+
+                if ((raw_flags & ~_MACHINE_COPY_FLAGS_MASK_PUBLIC) != 0)
+                        return -EINVAL;
+
+                if (raw_flags & MACHINE_COPY_REPLACE)
+                        copy_flags |= COPY_REPLACE;
+        }
+
         if (!path_is_absolute(src))
                 return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "Source path must be absolute.");
 
@@ -1328,6 +1342,16 @@ static const sd_bus_vtable machine_vtable[] = {
                                 SD_BUS_NO_RESULT,
                                 bus_machine_method_copy,
                                 SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD_WITH_ARGS("CopyFromWithFlags",
+                                SD_BUS_ARGS("s", source, "s", destination, "t", flags),
+                                SD_BUS_NO_RESULT,
+                                bus_machine_method_copy,
+                                SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD_WITH_ARGS("CopyToWithFlags",
+                                SD_BUS_ARGS("s", source, "s", destination, "t", flags),
+                                SD_BUS_NO_RESULT,
+                                bus_machine_method_copy,
+                                SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD_WITH_ARGS("OpenRootDirectory",
                                 SD_BUS_NO_ARGS,
                                 SD_BUS_RESULT("h", fd),

src/machine/machine-dbus.h

@@ -6,6 +6,11 @@
 #include "bus-util.h"
 #include "machine.h"
 
+typedef enum {
+        MACHINE_COPY_REPLACE = 1 << 0, /* Public API via DBUS, do not change */
+        _MACHINE_COPY_FLAGS_MASK_PUBLIC = MACHINE_COPY_REPLACE,
+} MachineCopyFlags;
+
 extern const BusObjectImplementation machine_object;
 
 char *machine_bus_path(Machine *s);

src/machine/machinectl.c

@@ -34,6 +34,7 @@
 #include "locale-util.h"
 #include "log.h"
 #include "logs-show.h"
+#include "machine-dbus.h"
 #include "macro.h"
 #include "main-func.h"
 #include "mkdir.h"
@@ -1093,6 +1094,13 @@ static int terminate_machine(int argc, char *argv[], void *userdata) {
         return 0;
 }
 
+static const char *select_copy_method(bool copy_from, bool force) {
+        if (force)
+                return copy_from ? "CopyFromMachineWithFlags" : "CopyToMachineWithFlags";
+        else
+                return copy_from ? "CopyFromMachine" : "CopyToMachine";
+}
+
 static int copy_files(int argc, char *argv[], void *userdata) {
         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
         _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;
@@ -1123,7 +1131,7 @@ static int copy_files(int argc, char *argv[], void *userdata) {
                         bus,
                         &m,
                         bus_machine_mgr,
-                        copy_from ? "CopyFromMachine" : "CopyToMachine");
+                        select_copy_method(copy_from, arg_force));
         if (r < 0)
                 return bus_log_create_error(r);
 
@@ -1136,6 +1144,12 @@ static int copy_files(int argc, char *argv[], void *userdata) {
         if (r < 0)
                 return bus_log_create_error(r);
 
+        if (arg_force) {
+                r = sd_bus_message_append(m, "t", MACHINE_COPY_REPLACE);
+                if (r < 0)
+                        return bus_log_create_error(r);
+        }
+
         /* This is a slow operation, hence turn off any method call timeouts */
         r = sd_bus_call(bus, m, USEC_INFINITY, &error, NULL);
         if (r < 0)

src/machine/machined-dbus.c

@@ -1110,6 +1110,16 @@ const sd_bus_vtable manager_vtable[] = {
                                 SD_BUS_NO_RESULT,
                                 method_copy_machine,
                                 SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD_WITH_ARGS("CopyFromMachineWithFlags",
+                                SD_BUS_ARGS("s", name, "s", source, "s", destination, "t", flags),
+                                SD_BUS_NO_RESULT,
+                                method_copy_machine,
+                                SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD_WITH_ARGS("CopyToMachineWithFlags",
+                                SD_BUS_ARGS("s", name, "s", source, "s", destination, "t", flags),
+                                SD_BUS_NO_RESULT,
+                                method_copy_machine,
+                                SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD_WITH_ARGS("OpenMachineRootDirectory",
                                 SD_BUS_ARGS("s", name),
                                 SD_BUS_RESULT("h", fd),