1
2
3
4#include <linux/if_link.h>
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 1
13
14static __u32 duration;
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;
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_obj_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 const char *prog_name = bpf_program__name(prog);
83 int retval_expect = XDP_PASS;
84 __u32 mtu_result = 0;
85 char buf[256] = {};
86 int err;
87 struct bpf_prog_test_run_attr tattr = {
88 .repeat = 1,
89 .data_in = &pkt_v4,
90 .data_size_in = sizeof(pkt_v4),
91 .data_out = buf,
92 .data_size_out = sizeof(buf),
93 .prog_fd = bpf_program__fd(prog),
94 };
95
96 err = bpf_prog_test_run_xattr(&tattr);
97 CHECK_ATTR(err != 0, "bpf_prog_test_run",
98 "prog_name:%s (err %d errno %d retval %d)\n",
99 prog_name, err, errno, tattr.retval);
100
101 CHECK(tattr.retval != retval_expect, "retval",
102 "progname:%s unexpected retval=%d expected=%d\n",
103 prog_name, tattr.retval, retval_expect);
104
105
106 mtu_result = skel->bss->global_bpf_mtu_xdp;
107 ASSERT_EQ(mtu_result, mtu_expect, "MTU-compare-user");
108}
109
110
111static void test_check_mtu_xdp(__u32 mtu, __u32 ifindex)
112{
113 struct test_check_mtu *skel;
114 int err;
115
116 skel = test_check_mtu__open();
117 if (CHECK(!skel, "skel_open", "failed"))
118 return;
119
120
121 skel->rodata->GLOBAL_USER_MTU = mtu;
122 skel->rodata->GLOBAL_USER_IFINDEX = ifindex;
123
124 err = test_check_mtu__load(skel);
125 if (CHECK(err, "skel_load", "failed: %d\n", err))
126 goto cleanup;
127
128 test_check_mtu_run_xdp(skel, skel->progs.xdp_use_helper, mtu);
129 test_check_mtu_run_xdp(skel, skel->progs.xdp_exceed_mtu, mtu);
130 test_check_mtu_run_xdp(skel, skel->progs.xdp_minus_delta, mtu);
131 test_check_mtu_run_xdp(skel, skel->progs.xdp_input_len, mtu);
132 test_check_mtu_run_xdp(skel, skel->progs.xdp_input_len_exceed, mtu);
133
134cleanup:
135 test_check_mtu__destroy(skel);
136}
137
138static void test_check_mtu_run_tc(struct test_check_mtu *skel,
139 struct bpf_program *prog,
140 __u32 mtu_expect)
141{
142 const char *prog_name = bpf_program__name(prog);
143 int retval_expect = BPF_OK;
144 __u32 mtu_result = 0;
145 char buf[256] = {};
146 int err;
147 struct bpf_prog_test_run_attr tattr = {
148 .repeat = 1,
149 .data_in = &pkt_v4,
150 .data_size_in = sizeof(pkt_v4),
151 .data_out = buf,
152 .data_size_out = sizeof(buf),
153 .prog_fd = bpf_program__fd(prog),
154 };
155
156 err = bpf_prog_test_run_xattr(&tattr);
157 CHECK_ATTR(err != 0, "bpf_prog_test_run",
158 "prog_name:%s (err %d errno %d retval %d)\n",
159 prog_name, err, errno, tattr.retval);
160
161 CHECK(tattr.retval != retval_expect, "retval",
162 "progname:%s unexpected retval=%d expected=%d\n",
163 prog_name, tattr.retval, retval_expect);
164
165
166 mtu_result = skel->bss->global_bpf_mtu_tc;
167 ASSERT_EQ(mtu_result, mtu_expect, "MTU-compare-user");
168}
169
170
171static void test_check_mtu_tc(__u32 mtu, __u32 ifindex)
172{
173 struct test_check_mtu *skel;
174 int err;
175
176 skel = test_check_mtu__open();
177 if (CHECK(!skel, "skel_open", "failed"))
178 return;
179
180
181 skel->rodata->GLOBAL_USER_MTU = mtu;
182 skel->rodata->GLOBAL_USER_IFINDEX = ifindex;
183
184 err = test_check_mtu__load(skel);
185 if (CHECK(err, "skel_load", "failed: %d\n", err))
186 goto cleanup;
187
188 test_check_mtu_run_tc(skel, skel->progs.tc_use_helper, mtu);
189 test_check_mtu_run_tc(skel, skel->progs.tc_exceed_mtu, mtu);
190 test_check_mtu_run_tc(skel, skel->progs.tc_exceed_mtu_da, mtu);
191 test_check_mtu_run_tc(skel, skel->progs.tc_minus_delta, mtu);
192 test_check_mtu_run_tc(skel, skel->progs.tc_input_len, mtu);
193 test_check_mtu_run_tc(skel, skel->progs.tc_input_len_exceed, mtu);
194cleanup:
195 test_check_mtu__destroy(skel);
196}
197
198void test_check_mtu(void)
199{
200 __u32 mtu_lo;
201
202 if (test__start_subtest("bpf_check_mtu XDP-attach"))
203 test_check_mtu_xdp_attach();
204
205 mtu_lo = read_mtu_device_lo();
206 if (CHECK(mtu_lo < 0, "reading MTU value", "failed (err:%d)", mtu_lo))
207 return;
208
209 if (test__start_subtest("bpf_check_mtu XDP-run"))
210 test_check_mtu_xdp(mtu_lo, 0);
211
212 if (test__start_subtest("bpf_check_mtu XDP-run ifindex-lookup"))
213 test_check_mtu_xdp(mtu_lo, IFINDEX_LO);
214
215 if (test__start_subtest("bpf_check_mtu TC-run"))
216 test_check_mtu_tc(mtu_lo, 0);
217
218 if (test__start_subtest("bpf_check_mtu TC-run ifindex-lookup"))
219 test_check_mtu_tc(mtu_lo, IFINDEX_LO);
220}
221
