genetlink: load policy based on validation flags

Set the policy and maxattr pointers based on validation flags.
genl_family_rcv_msg_attrs_parse() will do nothing and return NULL
if maxattrs is zero, so no behavior change is expected.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index c662997..770726a 100644 (file)
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -204,8 +204,14 @@ genl_cmd_full_to_split(struct genl_split_ops *op,
                op->post_doit   = family->post_doit;
        }
 
-       op->policy              = full->policy;
-       op->maxattr             = full->maxattr;
+       if (flags & GENL_CMD_CAP_DUMP &&
+           full->validate & GENL_DONT_VALIDATE_DUMP) {
+               op->policy      = NULL;
+               op->maxattr     = 0;
+       } else {
+               op->policy      = full->policy;
+               op->maxattr     = full->maxattr;
+       }
 
        op->cmd                 = full->cmd;
        op->internal_flags      = full->internal_flags;
@@ -638,10 +644,8 @@ static int genl_start(struct netlink_callback *cb)
        int rc = 0;
 
        ops = ctx->ops;
-       if (ops->validate & GENL_DONT_VALIDATE_DUMP)
-               goto no_attrs;
-
-       if (ctx->nlh->nlmsg_len < nlmsg_msg_size(ctx->hdrlen))
+       if (!(ops->validate & GENL_DONT_VALIDATE_DUMP) &&
+           ctx->nlh->nlmsg_len < nlmsg_msg_size(ctx->hdrlen))
                return -EINVAL;
 
        attrs = genl_family_rcv_msg_attrs_parse(ctx->family, ctx->nlh, ctx->extack,
@@ -650,7 +654,6 @@ static int genl_start(struct netlink_callback *cb)
        if (IS_ERR(attrs))
                return PTR_ERR(attrs);
 
-no_attrs:
        info = genl_dumpit_info_alloc();
        if (!info) {
                genl_family_rcv_msg_attrs_free(attrs);