system: refuse sysupgrade with backup if it's unsupported

Don't allow it if validation methods marked firmware as not supporting a
backup.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

diff --git a/system.c b/system.c
index 98fcb661f4f0a5b1c643cbf4160f1321395847de..2a5d5bcbaf4fa204cc1332b7f5a059bc20d21d41 100644 (file)
--- a/system.c
+++ b/system.c
@@ -515,15 +515,17 @@ static int sysupgrade(struct ubus_context *ctx, struct ubus_object *obj,
        enum {
                VALIDATION_VALID,
                VALIDATION_FORCEABLE,
+               VALIDATION_ALLOW_BACKUP,
                __VALIDATION_MAX
        };
        static const struct blobmsg_policy validation_policy[__VALIDATION_MAX] = {
                [VALIDATION_VALID] = { .name = "valid", .type = BLOBMSG_TYPE_BOOL },
                [VALIDATION_FORCEABLE] = { .name = "forceable", .type = BLOBMSG_TYPE_BOOL },
+               [VALIDATION_ALLOW_BACKUP] = { .name = "allow_backup", .type = BLOBMSG_TYPE_BOOL },
        };
        struct blob_attr *validation[__VALIDATION_MAX];
        struct blob_attr *tb[__SYSUPGRADE_MAX];
-       bool valid, forceable;
+       bool valid, forceable, allow_backup;
 
        if (!msg)
                return UBUS_STATUS_INVALID_ARGUMENT;
@@ -539,6 +541,7 @@ static int sysupgrade(struct ubus_context *ctx, struct ubus_object *obj,
 
        valid = validation[VALIDATION_VALID] && blobmsg_get_bool(validation[VALIDATION_VALID]);
        forceable = validation[VALIDATION_FORCEABLE] && blobmsg_get_bool(validation[VALIDATION_FORCEABLE]);
+       allow_backup = validation[VALIDATION_ALLOW_BACKUP] && blobmsg_get_bool(validation[VALIDATION_ALLOW_BACKUP]);
 
        if (!valid) {
                if (!forceable) {
@@ -548,6 +551,9 @@ static int sysupgrade(struct ubus_context *ctx, struct ubus_object *obj,
                        fprintf(stderr, "Firmware image is invalid\n");
                        return UBUS_STATUS_NOT_SUPPORTED;
                }
+       } else if (!allow_backup && tb[SYSUPGRADE_BACKUP]) {
+               fprintf(stderr, "Firmware image doesn't allow preserving a backup\n");
+               return UBUS_STATUS_NOT_SUPPORTED;
        }
 
        sysupgrade_exec_upgraded(blobmsg_get_string(tb[SYSUPGRADE_PREFIX]),