1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2020 Facebook */
3
4 #define _GNU_SOURCE
5 #include <netinet/in.h>
6 #include <arpa/inet.h>
7 #include <unistd.h>
8 #include <stdlib.h>
9 #include <string.h>
10 #include <errno.h>
11 #include <sched.h>
12 #include <linux/compiler.h>
13 #include <bpf/libbpf.h>
14
15 #include "network_helpers.h"
16 #include "test_progs.h"
17 #include "test_btf_skc_cls_ingress.skel.h"
18
19 static struct test_btf_skc_cls_ingress *skel;
20 static struct sockaddr_in6 srv_sa6;
21 static __u32 duration;
22
23 #define PROG_PIN_FILE "/sys/fs/bpf/btf_skc_cls_ingress"
24
write_sysctl(const char * sysctl,const char * value)25 static int write_sysctl(const char *sysctl, const char *value)
26 {
27 int fd, err, len;
28
29 fd = open(sysctl, O_WRONLY);
30 if (CHECK(fd == -1, "open sysctl", "open(%s): %s (%d)\n",
31 sysctl, strerror(errno), errno))
32 return -1;
33
34 len = strlen(value);
35 err = write(fd, value, len);
36 close(fd);
37 if (CHECK(err != len, "write sysctl",
38 "write(%s, %s, %d): err:%d %s (%d)\n",
39 sysctl, value, len, err, strerror(errno), errno))
40 return -1;
41
42 return 0;
43 }
44
prepare_netns(void)45 static int prepare_netns(void)
46 {
47 if (CHECK(unshare(CLONE_NEWNET), "create netns",
48 "unshare(CLONE_NEWNET): %s (%d)",
49 strerror(errno), errno))
50 return -1;
51
52 if (CHECK(system("ip link set dev lo up"),
53 "ip link set dev lo up", "failed\n"))
54 return -1;
55
56 if (CHECK(system("tc qdisc add dev lo clsact"),
57 "tc qdisc add dev lo clsact", "failed\n"))
58 return -1;
59
60 if (CHECK(system("tc filter add dev lo ingress bpf direct-action object-pinned " PROG_PIN_FILE),
61 "install tc cls-prog at ingress", "failed\n"))
62 return -1;
63
64 /* Ensure 20 bytes options (i.e. in total 40 bytes tcp header) for the
65 * bpf_tcp_gen_syncookie() helper.
66 */
67 if (write_sysctl("/proc/sys/net/ipv4/tcp_window_scaling", "1") ||
68 write_sysctl("/proc/sys/net/ipv4/tcp_timestamps", "1") ||
69 write_sysctl("/proc/sys/net/ipv4/tcp_sack", "1"))
70 return -1;
71
72 return 0;
73 }
74
reset_test(void)75 static void reset_test(void)
76 {
77 memset(&skel->bss->srv_sa6, 0, sizeof(skel->bss->srv_sa6));
78 skel->bss->listen_tp_sport = 0;
79 skel->bss->req_sk_sport = 0;
80 skel->bss->recv_cookie = 0;
81 skel->bss->gen_cookie = 0;
82 skel->bss->linum = 0;
83 }
84
print_err_line(void)85 static void print_err_line(void)
86 {
87 if (skel->bss->linum)
88 printf("bpf prog error at line %u\n", skel->bss->linum);
89 }
90
test_conn(void)91 static void test_conn(void)
92 {
93 int listen_fd = -1, cli_fd = -1, err;
94 socklen_t addrlen = sizeof(srv_sa6);
95 int srv_port;
96
97 if (write_sysctl("/proc/sys/net/ipv4/tcp_syncookies", "1"))
98 return;
99
100 listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0);
101 if (CHECK_FAIL(listen_fd == -1))
102 return;
103
104 err = getsockname(listen_fd, (struct sockaddr *)&srv_sa6, &addrlen);
105 if (CHECK(err, "getsockname(listen_fd)", "err:%d errno:%d\n", err,
106 errno))
107 goto done;
108 memcpy(&skel->bss->srv_sa6, &srv_sa6, sizeof(srv_sa6));
109 srv_port = ntohs(srv_sa6.sin6_port);
110
111 cli_fd = connect_to_fd(listen_fd, 0);
112 if (CHECK_FAIL(cli_fd == -1))
113 goto done;
114
115 if (CHECK(skel->bss->listen_tp_sport != srv_port ||
116 skel->bss->req_sk_sport != srv_port,
117 "Unexpected sk src port",
118 "listen_tp_sport:%u req_sk_sport:%u expected:%u\n",
119 skel->bss->listen_tp_sport, skel->bss->req_sk_sport,
120 srv_port))
121 goto done;
122
123 if (CHECK(skel->bss->gen_cookie || skel->bss->recv_cookie,
124 "Unexpected syncookie states",
125 "gen_cookie:%u recv_cookie:%u\n",
126 skel->bss->gen_cookie, skel->bss->recv_cookie))
127 goto done;
128
129 CHECK(skel->bss->linum, "bpf prog detected error", "at line %u\n",
130 skel->bss->linum);
131
132 done:
133 if (listen_fd != -1)
134 close(listen_fd);
135 if (cli_fd != -1)
136 close(cli_fd);
137 }
138
test_syncookie(void)139 static void test_syncookie(void)
140 {
141 int listen_fd = -1, cli_fd = -1, err;
142 socklen_t addrlen = sizeof(srv_sa6);
143 int srv_port;
144
145 /* Enforce syncookie mode */
146 if (write_sysctl("/proc/sys/net/ipv4/tcp_syncookies", "2"))
147 return;
148
149 listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0);
150 if (CHECK_FAIL(listen_fd == -1))
151 return;
152
153 err = getsockname(listen_fd, (struct sockaddr *)&srv_sa6, &addrlen);
154 if (CHECK(err, "getsockname(listen_fd)", "err:%d errno:%d\n", err,
155 errno))
156 goto done;
157 memcpy(&skel->bss->srv_sa6, &srv_sa6, sizeof(srv_sa6));
158 srv_port = ntohs(srv_sa6.sin6_port);
159
160 cli_fd = connect_to_fd(listen_fd, 0);
161 if (CHECK_FAIL(cli_fd == -1))
162 goto done;
163
164 if (CHECK(skel->bss->listen_tp_sport != srv_port,
165 "Unexpected tp src port",
166 "listen_tp_sport:%u expected:%u\n",
167 skel->bss->listen_tp_sport, srv_port))
168 goto done;
169
170 if (CHECK(skel->bss->req_sk_sport,
171 "Unexpected req_sk src port",
172 "req_sk_sport:%u expected:0\n",
173 skel->bss->req_sk_sport))
174 goto done;
175
176 if (CHECK(!skel->bss->gen_cookie ||
177 skel->bss->gen_cookie != skel->bss->recv_cookie,
178 "Unexpected syncookie states",
179 "gen_cookie:%u recv_cookie:%u\n",
180 skel->bss->gen_cookie, skel->bss->recv_cookie))
181 goto done;
182
183 CHECK(skel->bss->linum, "bpf prog detected error", "at line %u\n",
184 skel->bss->linum);
185
186 done:
187 if (listen_fd != -1)
188 close(listen_fd);
189 if (cli_fd != -1)
190 close(cli_fd);
191 }
192
193 struct test {
194 const char *desc;
195 void (*run)(void);
196 };
197
198 #define DEF_TEST(name) { #name, test_##name }
199 static struct test tests[] = {
200 DEF_TEST(conn),
201 DEF_TEST(syncookie),
202 };
203
test_btf_skc_cls_ingress(void)204 void test_btf_skc_cls_ingress(void)
205 {
206 int i, err;
207
208 skel = test_btf_skc_cls_ingress__open_and_load();
209 if (CHECK(!skel, "test_btf_skc_cls_ingress__open_and_load", "failed\n"))
210 return;
211
212 err = bpf_program__pin(skel->progs.cls_ingress, PROG_PIN_FILE);
213 if (CHECK(err, "bpf_program__pin",
214 "cannot pin bpf prog to %s. err:%d\n", PROG_PIN_FILE, err)) {
215 test_btf_skc_cls_ingress__destroy(skel);
216 return;
217 }
218
219 for (i = 0; i < ARRAY_SIZE(tests); i++) {
220 if (!test__start_subtest(tests[i].desc))
221 continue;
222
223 if (prepare_netns())
224 break;
225
226 tests[i].run();
227
228 print_err_line();
229 reset_test();
230 }
231
232 bpf_program__unpin(skel->progs.cls_ingress, PROG_PIN_FILE);
233 test_btf_skc_cls_ingress__destroy(skel);
234 }
235