diff options
Diffstat (limited to '')
-rw-r--r-- | tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_shrink.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_shrink.c b/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_shrink.c new file mode 100644 index 000000000..22065a9cf --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_shrink.c @@ -0,0 +1,30 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2018 Facebook + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + */ +#include <linux/bpf.h> +#include <linux/if_ether.h> +#include <bpf/bpf_helpers.h> + +int _version SEC("version") = 1; + +SEC("xdp_adjust_tail_shrink") +int _xdp_adjust_tail_shrink(struct xdp_md *xdp) +{ + void *data_end = (void *)(long)xdp->data_end; + void *data = (void *)(long)xdp->data; + int offset = 0; + + if (data_end - data == 54) /* sizeof(pkt_v4) */ + offset = 256; /* shrink too much */ + else + offset = 20; + if (bpf_xdp_adjust_tail(xdp, 0 - offset)) + return XDP_DROP; + return XDP_TX; +} + +char _license[] SEC("license") = "GPL"; |