1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2018 Facebook
3 // Copyright (c) 2019 Cloudflare
4 // Copyright (c) 2020 Isovalent, Inc.
5 /*
6 * Test that the socket assign program is able to redirect traffic towards a
7 * socket, regardless of whether the port or address destination of the traffic
8 * matches the port.
9 */
10
11 #define _GNU_SOURCE
12 #include <fcntl.h>
13 #include <signal.h>
14 #include <stdlib.h>
15 #include <unistd.h>
16
17 #include "test_progs.h"
18
19 #define BIND_PORT 1234
20 #define CONNECT_PORT 4321
21 #define TEST_DADDR (0xC0A80203)
22 #define NS_SELF "/proc/self/ns/net"
23 #define SERVER_MAP_PATH "/sys/fs/bpf/tc/globals/server_map"
24
25 static const struct timeval timeo_sec = { .tv_sec = 3 };
26 static const size_t timeo_optlen = sizeof(timeo_sec);
27 static int stop, duration;
28
29 static bool
configure_stack(void)30 configure_stack(void)
31 {
32 char tc_version[128];
33 char tc_cmd[BUFSIZ];
34 char *prog;
35 FILE *tc;
36
37 /* Check whether tc is built with libbpf. */
38 tc = popen("tc -V", "r");
39 if (CHECK_FAIL(!tc))
40 return false;
41 if (CHECK_FAIL(!fgets(tc_version, sizeof(tc_version), tc)))
42 return false;
43 if (strstr(tc_version, ", libbpf "))
44 prog = "test_sk_assign_libbpf.bpf.o";
45 else
46 prog = "test_sk_assign.bpf.o";
47 if (CHECK_FAIL(pclose(tc)))
48 return false;
49
50 /* Move to a new networking namespace */
51 if (CHECK_FAIL(unshare(CLONE_NEWNET)))
52 return false;
53
54 /* Configure necessary links, routes */
55 if (CHECK_FAIL(system("ip link set dev lo up")))
56 return false;
57 if (CHECK_FAIL(system("ip route add local default dev lo")))
58 return false;
59 if (CHECK_FAIL(system("ip -6 route add local default dev lo")))
60 return false;
61
62 /* Load qdisc, BPF program */
63 if (CHECK_FAIL(system("tc qdisc add dev lo clsact")))
64 return false;
65 sprintf(tc_cmd, "%s %s %s %s %s", "tc filter add dev lo ingress bpf",
66 "direct-action object-file", prog,
67 "section tc",
68 (env.verbosity < VERBOSE_VERY) ? " 2>/dev/null" : "verbose");
69 if (CHECK(system(tc_cmd), "BPF load failed;",
70 "run with -vv for more info\n"))
71 return false;
72
73 return true;
74 }
75
76 static int
start_server(const struct sockaddr * addr,socklen_t len,int type)77 start_server(const struct sockaddr *addr, socklen_t len, int type)
78 {
79 int fd;
80
81 fd = socket(addr->sa_family, type, 0);
82 if (CHECK_FAIL(fd == -1))
83 goto out;
84 if (CHECK_FAIL(setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &timeo_sec,
85 timeo_optlen)))
86 goto close_out;
87 if (CHECK_FAIL(bind(fd, addr, len) == -1))
88 goto close_out;
89 if (type == SOCK_STREAM && CHECK_FAIL(listen(fd, 128) == -1))
90 goto close_out;
91
92 goto out;
93 close_out:
94 close(fd);
95 fd = -1;
96 out:
97 return fd;
98 }
99
100 static int
connect_to_server(const struct sockaddr * addr,socklen_t len,int type)101 connect_to_server(const struct sockaddr *addr, socklen_t len, int type)
102 {
103 int fd = -1;
104
105 fd = socket(addr->sa_family, type, 0);
106 if (CHECK_FAIL(fd == -1))
107 goto out;
108 if (CHECK_FAIL(setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &timeo_sec,
109 timeo_optlen)))
110 goto close_out;
111 if (CHECK_FAIL(connect(fd, addr, len)))
112 goto close_out;
113
114 goto out;
115 close_out:
116 close(fd);
117 fd = -1;
118 out:
119 return fd;
120 }
121
122 static in_port_t
get_port(int fd)123 get_port(int fd)
124 {
125 struct sockaddr_storage ss;
126 socklen_t slen = sizeof(ss);
127 in_port_t port = 0;
128
129 if (CHECK_FAIL(getsockname(fd, (struct sockaddr *)&ss, &slen)))
130 return port;
131
132 switch (ss.ss_family) {
133 case AF_INET:
134 port = ((struct sockaddr_in *)&ss)->sin_port;
135 break;
136 case AF_INET6:
137 port = ((struct sockaddr_in6 *)&ss)->sin6_port;
138 break;
139 default:
140 CHECK(1, "Invalid address family", "%d\n", ss.ss_family);
141 }
142 return port;
143 }
144
145 static ssize_t
rcv_msg(int srv_client,int type)146 rcv_msg(int srv_client, int type)
147 {
148 char buf[BUFSIZ];
149
150 if (type == SOCK_STREAM)
151 return read(srv_client, &buf, sizeof(buf));
152 else
153 return recvfrom(srv_client, &buf, sizeof(buf), 0, NULL, NULL);
154 }
155
156 static int
run_test(int server_fd,const struct sockaddr * addr,socklen_t len,int type)157 run_test(int server_fd, const struct sockaddr *addr, socklen_t len, int type)
158 {
159 int client = -1, srv_client = -1;
160 char buf[] = "testing";
161 in_port_t port;
162 int ret = 1;
163
164 client = connect_to_server(addr, len, type);
165 if (client == -1) {
166 perror("Cannot connect to server");
167 goto out;
168 }
169
170 if (type == SOCK_STREAM) {
171 srv_client = accept(server_fd, NULL, NULL);
172 if (CHECK_FAIL(srv_client == -1)) {
173 perror("Can't accept connection");
174 goto out;
175 }
176 } else {
177 srv_client = server_fd;
178 }
179 if (CHECK_FAIL(write(client, buf, sizeof(buf)) != sizeof(buf))) {
180 perror("Can't write on client");
181 goto out;
182 }
183 if (CHECK_FAIL(rcv_msg(srv_client, type) != sizeof(buf))) {
184 perror("Can't read on server");
185 goto out;
186 }
187
188 port = get_port(srv_client);
189 if (CHECK_FAIL(!port))
190 goto out;
191 /* SOCK_STREAM is connected via accept(), so the server's local address
192 * will be the CONNECT_PORT rather than the BIND port that corresponds
193 * to the listen socket. SOCK_DGRAM on the other hand is connectionless
194 * so we can't really do the same check there; the server doesn't ever
195 * create a socket with CONNECT_PORT.
196 */
197 if (type == SOCK_STREAM &&
198 CHECK(port != htons(CONNECT_PORT), "Expected", "port %u but got %u",
199 CONNECT_PORT, ntohs(port)))
200 goto out;
201 else if (type == SOCK_DGRAM &&
202 CHECK(port != htons(BIND_PORT), "Expected",
203 "port %u but got %u", BIND_PORT, ntohs(port)))
204 goto out;
205
206 ret = 0;
207 out:
208 close(client);
209 if (srv_client != server_fd)
210 close(srv_client);
211 if (ret)
212 WRITE_ONCE(stop, 1);
213 return ret;
214 }
215
216 static void
prepare_addr(struct sockaddr * addr,int family,__u16 port,bool rewrite_addr)217 prepare_addr(struct sockaddr *addr, int family, __u16 port, bool rewrite_addr)
218 {
219 struct sockaddr_in *addr4;
220 struct sockaddr_in6 *addr6;
221
222 switch (family) {
223 case AF_INET:
224 addr4 = (struct sockaddr_in *)addr;
225 memset(addr4, 0, sizeof(*addr4));
226 addr4->sin_family = family;
227 addr4->sin_port = htons(port);
228 if (rewrite_addr)
229 addr4->sin_addr.s_addr = htonl(TEST_DADDR);
230 else
231 addr4->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
232 break;
233 case AF_INET6:
234 addr6 = (struct sockaddr_in6 *)addr;
235 memset(addr6, 0, sizeof(*addr6));
236 addr6->sin6_family = family;
237 addr6->sin6_port = htons(port);
238 addr6->sin6_addr = in6addr_loopback;
239 if (rewrite_addr)
240 addr6->sin6_addr.s6_addr32[3] = htonl(TEST_DADDR);
241 break;
242 default:
243 fprintf(stderr, "Invalid family %d", family);
244 }
245 }
246
247 struct test_sk_cfg {
248 const char *name;
249 int family;
250 struct sockaddr *addr;
251 socklen_t len;
252 int type;
253 bool rewrite_addr;
254 };
255
256 #define TEST(NAME, FAMILY, TYPE, REWRITE) \
257 { \
258 .name = NAME, \
259 .family = FAMILY, \
260 .addr = (FAMILY == AF_INET) ? (struct sockaddr *)&addr4 \
261 : (struct sockaddr *)&addr6, \
262 .len = (FAMILY == AF_INET) ? sizeof(addr4) : sizeof(addr6), \
263 .type = TYPE, \
264 .rewrite_addr = REWRITE, \
265 }
266
test_sk_assign(void)267 void test_sk_assign(void)
268 {
269 struct sockaddr_in addr4;
270 struct sockaddr_in6 addr6;
271 struct test_sk_cfg tests[] = {
272 TEST("ipv4 tcp port redir", AF_INET, SOCK_STREAM, false),
273 TEST("ipv4 tcp addr redir", AF_INET, SOCK_STREAM, true),
274 TEST("ipv6 tcp port redir", AF_INET6, SOCK_STREAM, false),
275 TEST("ipv6 tcp addr redir", AF_INET6, SOCK_STREAM, true),
276 TEST("ipv4 udp port redir", AF_INET, SOCK_DGRAM, false),
277 TEST("ipv4 udp addr redir", AF_INET, SOCK_DGRAM, true),
278 TEST("ipv6 udp port redir", AF_INET6, SOCK_DGRAM, false),
279 TEST("ipv6 udp addr redir", AF_INET6, SOCK_DGRAM, true),
280 };
281 __s64 server = -1;
282 int server_map;
283 int self_net;
284 int i;
285
286 self_net = open(NS_SELF, O_RDONLY);
287 if (CHECK_FAIL(self_net < 0)) {
288 perror("Unable to open "NS_SELF);
289 return;
290 }
291
292 if (!configure_stack()) {
293 perror("configure_stack");
294 goto cleanup;
295 }
296
297 server_map = bpf_obj_get(SERVER_MAP_PATH);
298 if (CHECK_FAIL(server_map < 0)) {
299 perror("Unable to open " SERVER_MAP_PATH);
300 goto cleanup;
301 }
302
303 for (i = 0; i < ARRAY_SIZE(tests) && !READ_ONCE(stop); i++) {
304 struct test_sk_cfg *test = &tests[i];
305 const struct sockaddr *addr;
306 const int zero = 0;
307 int err;
308
309 if (!test__start_subtest(test->name))
310 continue;
311 prepare_addr(test->addr, test->family, BIND_PORT, false);
312 addr = (const struct sockaddr *)test->addr;
313 server = start_server(addr, test->len, test->type);
314 if (server == -1)
315 goto close;
316
317 err = bpf_map_update_elem(server_map, &zero, &server, BPF_ANY);
318 if (CHECK_FAIL(err)) {
319 perror("Unable to update server_map");
320 goto close;
321 }
322
323 /* connect to unbound ports */
324 prepare_addr(test->addr, test->family, CONNECT_PORT,
325 test->rewrite_addr);
326 if (run_test(server, addr, test->len, test->type))
327 goto close;
328
329 close(server);
330 server = -1;
331 }
332
333 close:
334 close(server);
335 close(server_map);
336 cleanup:
337 if (CHECK_FAIL(unlink(SERVER_MAP_PATH)))
338 perror("Unable to unlink " SERVER_MAP_PATH);
339 if (CHECK_FAIL(setns(self_net, CLONE_NEWNET)))
340 perror("Failed to setns("NS_SELF")");
341 close(self_net);
342 }
343