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