From 0367d0a29427d5916b98cf31dfc85a8293540614 Mon Sep 17 00:00:00 2001 From: "Nikita V. Shirokov" Date: Tue, 17 Apr 2018 21:42:22 -0700 Subject: bpf: adding tests for bpf_xdp_adjust_tail adding selftests for bpf_xdp_adjust_tail helper. in this synthetic test we are testing that 1) if data_end < data helper will return EINVAL 2) for normal use case packet's length would be reduced. Signed-off-by: Nikita V. Shirokov Signed-off-by: Daniel Borkmann --- tools/include/uapi/linux/bpf.h | 10 +++++++- tools/testing/selftests/bpf/Makefile | 2 +- tools/testing/selftests/bpf/bpf_helpers.h | 3 +++ tools/testing/selftests/bpf/test_adjust_tail.c | 30 ++++++++++++++++++++++++ tools/testing/selftests/bpf/test_progs.c | 32 ++++++++++++++++++++++++++ 5 files changed, 75 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/bpf/test_adjust_tail.c diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 9d07465..56bf493 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -755,6 +755,13 @@ union bpf_attr { * @addr: pointer to struct sockaddr to bind socket to * @addr_len: length of sockaddr structure * Return: 0 on success or negative error code + * + * int bpf_xdp_adjust_tail(xdp_md, delta) + * Adjust the xdp_md.data_end by delta. Only shrinking of packet's + * size is supported. + * @xdp_md: pointer to xdp_md + * @delta: A negative integer to be added to xdp_md.data_end + * Return: 0 on success or negative on error */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -821,7 +828,8 @@ union bpf_attr { FN(msg_apply_bytes), \ FN(msg_cork_bytes), \ FN(msg_pull_data), \ - FN(bind), + FN(bind), \ + FN(xdp_adjust_tail), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 0a315dd..3e819dc 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -31,7 +31,7 @@ TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test sockmap_verdict_prog.o dev_cgroup.o sample_ret0.o test_tracepoint.o \ test_l4lb_noinline.o test_xdp_noinline.o test_stacktrace_map.o \ sample_map_ret0.o test_tcpbpf_kern.o test_stacktrace_build_id.o \ - sockmap_tcp_msg_prog.o connect4_prog.o connect6_prog.o + sockmap_tcp_msg_prog.o connect4_prog.o connect6_prog.o test_adjust_tail.o # Order correspond to 'make run_tests' order TEST_PROGS := test_kmod.sh \ diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h index d8223d9..50c6070 100644 --- a/tools/testing/selftests/bpf/bpf_helpers.h +++ b/tools/testing/selftests/bpf/bpf_helpers.h @@ -96,6 +96,9 @@ static int (*bpf_msg_pull_data)(void *ctx, int start, int end, int flags) = (void *) BPF_FUNC_msg_pull_data; static int (*bpf_bind)(void *ctx, void *addr, int addr_len) = (void *) BPF_FUNC_bind; +static int (*bpf_xdp_adjust_tail)(void *ctx, int offset) = + (void *) BPF_FUNC_xdp_adjust_tail; + /* llvm builtin functions that eBPF C program may use to * emit BPF_LD_ABS and BPF_LD_IND instructions diff --git a/tools/testing/selftests/bpf/test_adjust_tail.c b/tools/testing/selftests/bpf/test_adjust_tail.c new file mode 100644 index 0000000..4cd5e86 --- /dev/null +++ b/tools/testing/selftests/bpf/test_adjust_tail.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 +#include +#include "bpf_helpers.h" + +int _version SEC("version") = 1; + +SEC("xdp_adjust_tail") +int _xdp_adjust_tail(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) + offset = 256; + else + offset = 20; + if (bpf_xdp_adjust_tail(xdp, 0 - offset)) + return XDP_DROP; + return XDP_TX; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c index faadbe2..eedda98 100644 --- a/tools/testing/selftests/bpf/test_progs.c +++ b/tools/testing/selftests/bpf/test_progs.c @@ -166,6 +166,37 @@ out: bpf_object__close(obj); } +static void test_xdp_adjust_tail(void) +{ + const char *file = "./test_adjust_tail.o"; + struct bpf_object *obj; + char buf[128]; + __u32 duration, retval, size; + int err, prog_fd; + + err = bpf_prog_load(file, BPF_PROG_TYPE_XDP, &obj, &prog_fd); + if (err) { + error_cnt++; + return; + } + + err = bpf_prog_test_run(prog_fd, 1, &pkt_v4, sizeof(pkt_v4), + buf, &size, &retval, &duration); + + CHECK(err || errno || retval != XDP_DROP, + "ipv4", "err %d errno %d retval %d size %d\n", + err, errno, retval, size); + + err = bpf_prog_test_run(prog_fd, 1, &pkt_v6, sizeof(pkt_v6), + buf, &size, &retval, &duration); + CHECK(err || errno || retval != XDP_TX || size != 54, + "ipv6", "err %d errno %d retval %d size %d\n", + err, errno, retval, size); + bpf_object__close(obj); +} + + + #define MAGIC_VAL 0x1234 #define NUM_ITER 100000 #define VIP_NUM 5 @@ -1177,6 +1208,7 @@ int main(void) { test_pkt_access(); test_xdp(); + test_xdp_adjust_tail(); test_l4lb_all(); test_xdp_noinline(); test_tcp_estats(); -- cgit v1.1