207 lines · c
1// SPDX-License-Identifier: GPL-2.02/* Copyright (c) 2020 Jesper Dangaard Brouer */3 4#include <linux/if_link.h> /* before test_progs.h, avoid bpf_util.h redefines */5#include <test_progs.h>6#include "test_check_mtu.skel.h"7#include "network_helpers.h"8 9#include <stdlib.h>10#include <inttypes.h>11 12#define IFINDEX_LO 113 14static __u32 duration; /* Hint: needed for CHECK macro */15 16static int read_mtu_device_lo(void)17{18 const char *filename = "/sys/class/net/lo/mtu";19 char buf[11] = {};20 int value, n, fd;21 22 fd = open(filename, 0, O_RDONLY);23 if (fd == -1)24 return -1;25 26 n = read(fd, buf, sizeof(buf));27 close(fd);28 29 if (n == -1)30 return -2;31 32 value = strtoimax(buf, NULL, 10);33 if (errno == ERANGE)34 return -3;35 36 return value;37}38 39static void test_check_mtu_xdp_attach(void)40{41 struct bpf_link_info link_info;42 __u32 link_info_len = sizeof(link_info);43 struct test_check_mtu *skel;44 struct bpf_program *prog;45 struct bpf_link *link;46 int err = 0;47 int fd;48 49 skel = test_check_mtu__open_and_load();50 if (CHECK(!skel, "open and load skel", "failed"))51 return; /* Exit if e.g. helper unknown to kernel */52 53 prog = skel->progs.xdp_use_helper_basic;54 55 link = bpf_program__attach_xdp(prog, IFINDEX_LO);56 if (!ASSERT_OK_PTR(link, "link_attach"))57 goto out;58 skel->links.xdp_use_helper_basic = link;59 60 memset(&link_info, 0, sizeof(link_info));61 fd = bpf_link__fd(link);62 err = bpf_link_get_info_by_fd(fd, &link_info, &link_info_len);63 if (CHECK(err, "link_info", "failed: %d\n", err))64 goto out;65 66 CHECK(link_info.type != BPF_LINK_TYPE_XDP, "link_type",67 "got %u != exp %u\n", link_info.type, BPF_LINK_TYPE_XDP);68 CHECK(link_info.xdp.ifindex != IFINDEX_LO, "link_ifindex",69 "got %u != exp %u\n", link_info.xdp.ifindex, IFINDEX_LO);70 71 err = bpf_link__detach(link);72 CHECK(err, "link_detach", "failed %d\n", err);73 74out:75 test_check_mtu__destroy(skel);76}77 78static void test_check_mtu_run_xdp(struct test_check_mtu *skel,79 struct bpf_program *prog,80 __u32 mtu_expect)81{82 int retval_expect = XDP_PASS;83 __u32 mtu_result = 0;84 char buf[256] = {};85 int err, prog_fd = bpf_program__fd(prog);86 LIBBPF_OPTS(bpf_test_run_opts, topts,87 .repeat = 1,88 .data_in = &pkt_v4,89 .data_size_in = sizeof(pkt_v4),90 .data_out = buf,91 .data_size_out = sizeof(buf),92 );93 94 err = bpf_prog_test_run_opts(prog_fd, &topts);95 ASSERT_OK(err, "test_run");96 ASSERT_EQ(topts.retval, retval_expect, "retval");97 98 /* Extract MTU that BPF-prog got */99 mtu_result = skel->bss->global_bpf_mtu_xdp;100 ASSERT_EQ(mtu_result, mtu_expect, "MTU-compare-user");101}102 103 104static void test_check_mtu_xdp(__u32 mtu, __u32 ifindex)105{106 struct test_check_mtu *skel;107 int err;108 109 skel = test_check_mtu__open();110 if (CHECK(!skel, "skel_open", "failed"))111 return;112 113 /* Update "constants" in BPF-prog *BEFORE* libbpf load */114 skel->rodata->GLOBAL_USER_MTU = mtu;115 skel->rodata->GLOBAL_USER_IFINDEX = ifindex;116 117 err = test_check_mtu__load(skel);118 if (CHECK(err, "skel_load", "failed: %d\n", err))119 goto cleanup;120 121 test_check_mtu_run_xdp(skel, skel->progs.xdp_use_helper, mtu);122 test_check_mtu_run_xdp(skel, skel->progs.xdp_exceed_mtu, mtu);123 test_check_mtu_run_xdp(skel, skel->progs.xdp_minus_delta, mtu);124 test_check_mtu_run_xdp(skel, skel->progs.xdp_input_len, mtu);125 test_check_mtu_run_xdp(skel, skel->progs.xdp_input_len_exceed, mtu);126 127cleanup:128 test_check_mtu__destroy(skel);129}130 131static void test_check_mtu_run_tc(struct test_check_mtu *skel,132 struct bpf_program *prog,133 __u32 mtu_expect)134{135 int retval_expect = BPF_OK;136 __u32 mtu_result = 0;137 char buf[256] = {};138 int err, prog_fd = bpf_program__fd(prog);139 LIBBPF_OPTS(bpf_test_run_opts, topts,140 .data_in = &pkt_v4,141 .data_size_in = sizeof(pkt_v4),142 .data_out = buf,143 .data_size_out = sizeof(buf),144 .repeat = 1,145 );146 147 err = bpf_prog_test_run_opts(prog_fd, &topts);148 ASSERT_OK(err, "test_run");149 ASSERT_EQ(topts.retval, retval_expect, "retval");150 151 /* Extract MTU that BPF-prog got */152 mtu_result = skel->bss->global_bpf_mtu_tc;153 ASSERT_EQ(mtu_result, mtu_expect, "MTU-compare-user");154}155 156 157static void test_check_mtu_tc(__u32 mtu, __u32 ifindex)158{159 struct test_check_mtu *skel;160 int err;161 162 skel = test_check_mtu__open();163 if (CHECK(!skel, "skel_open", "failed"))164 return;165 166 /* Update "constants" in BPF-prog *BEFORE* libbpf load */167 skel->rodata->GLOBAL_USER_MTU = mtu;168 skel->rodata->GLOBAL_USER_IFINDEX = ifindex;169 170 err = test_check_mtu__load(skel);171 if (CHECK(err, "skel_load", "failed: %d\n", err))172 goto cleanup;173 174 test_check_mtu_run_tc(skel, skel->progs.tc_use_helper, mtu);175 test_check_mtu_run_tc(skel, skel->progs.tc_exceed_mtu, mtu);176 test_check_mtu_run_tc(skel, skel->progs.tc_exceed_mtu_da, mtu);177 test_check_mtu_run_tc(skel, skel->progs.tc_minus_delta, mtu);178 test_check_mtu_run_tc(skel, skel->progs.tc_input_len, mtu);179 test_check_mtu_run_tc(skel, skel->progs.tc_input_len_exceed, mtu);180cleanup:181 test_check_mtu__destroy(skel);182}183 184void serial_test_check_mtu(void)185{186 int mtu_lo;187 188 if (test__start_subtest("bpf_check_mtu XDP-attach"))189 test_check_mtu_xdp_attach();190 191 mtu_lo = read_mtu_device_lo();192 if (CHECK(mtu_lo < 0, "reading MTU value", "failed (err:%d)", mtu_lo))193 return;194 195 if (test__start_subtest("bpf_check_mtu XDP-run"))196 test_check_mtu_xdp(mtu_lo, 0);197 198 if (test__start_subtest("bpf_check_mtu XDP-run ifindex-lookup"))199 test_check_mtu_xdp(mtu_lo, IFINDEX_LO);200 201 if (test__start_subtest("bpf_check_mtu TC-run"))202 test_check_mtu_tc(mtu_lo, 0);203 204 if (test__start_subtest("bpf_check_mtu TC-run ifindex-lookup"))205 test_check_mtu_tc(mtu_lo, IFINDEX_LO);206}207