xref: /linux/tools/testing/selftests/bpf/prog_tests/fib_lookup.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
3 
4 #include <linux/rtnetlink.h>
5 #include <sys/types.h>
6 #include <net/if.h>
7 
8 #include "test_progs.h"
9 #include "network_helpers.h"
10 #include "fib_lookup.skel.h"
11 
12 #define NS_TEST			"fib_lookup_ns"
13 #define IPV6_IFACE_ADDR		"face::face"
14 #define IPV6_IFACE_ADDR_SEC	"cafe::cafe"
15 #define IPV6_ADDR_DST		"face::3"
16 #define IPV6_NUD_FAILED_ADDR	"face::1"
17 #define IPV6_NUD_STALE_ADDR	"face::2"
18 #define IPV4_IFACE_ADDR		"10.0.0.254"
19 #define IPV4_IFACE_ADDR_SEC	"10.1.0.254"
20 #define IPV4_ADDR_DST		"10.2.0.254"
21 #define IPV4_NUD_FAILED_ADDR	"10.0.0.1"
22 #define IPV4_NUD_STALE_ADDR	"10.0.0.2"
23 #define IPV4_TBID_ADDR		"172.0.0.254"
24 #define IPV4_TBID_NET		"172.0.0.0"
25 #define IPV4_TBID_DST		"172.0.0.2"
26 #define IPV6_TBID_ADDR		"fd00::FFFF"
27 #define IPV6_TBID_NET		"fd00::"
28 #define IPV6_TBID_DST		"fd00::2"
29 #define MARK_NO_POLICY		33
30 #define MARK			42
31 #define MARK_TABLE		"200"
32 #define IPV4_REMOTE_DST		"1.2.3.4"
33 #define IPV4_LOCAL		"10.4.0.3"
34 #define IPV4_GW1		"10.4.0.1"
35 #define IPV4_GW2		"10.4.0.2"
36 #define IPV6_REMOTE_DST		"be:ef::b0:10"
37 #define IPV6_LOCAL		"fd01::3"
38 #define IPV6_GW1		"fd01::1"
39 #define IPV6_GW2		"fd01::2"
40 #define DMAC			"11:11:11:11:11:11"
41 #define DMAC_INIT { 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, }
42 #define DMAC2			"01:01:01:01:01:01"
43 #define DMAC_INIT2 { 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, }
44 
45 struct fib_lookup_test {
46 	const char *desc;
47 	const char *daddr;
48 	int expected_ret;
49 	const char *expected_src;
50 	const char *expected_dst;
51 	int lookup_flags;
52 	__u32 tbid;
53 	__u8 dmac[6];
54 	__u32 mark;
55 };
56 
57 static const struct fib_lookup_test tests[] = {
58 	{ .desc = "IPv6 failed neigh",
59 	  .daddr = IPV6_NUD_FAILED_ADDR, .expected_ret = BPF_FIB_LKUP_RET_NO_NEIGH, },
60 	{ .desc = "IPv6 stale neigh",
61 	  .daddr = IPV6_NUD_STALE_ADDR, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
62 	  .dmac = DMAC_INIT, },
63 	{ .desc = "IPv6 skip neigh",
64 	  .daddr = IPV6_NUD_FAILED_ADDR, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
65 	  .lookup_flags = BPF_FIB_LOOKUP_SKIP_NEIGH, },
66 	{ .desc = "IPv4 failed neigh",
67 	  .daddr = IPV4_NUD_FAILED_ADDR, .expected_ret = BPF_FIB_LKUP_RET_NO_NEIGH, },
68 	{ .desc = "IPv4 stale neigh",
69 	  .daddr = IPV4_NUD_STALE_ADDR, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
70 	  .dmac = DMAC_INIT, },
71 	{ .desc = "IPv4 skip neigh",
72 	  .daddr = IPV4_NUD_FAILED_ADDR, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
73 	  .lookup_flags = BPF_FIB_LOOKUP_SKIP_NEIGH, },
74 	{ .desc = "IPv4 TBID lookup failure",
75 	  .daddr = IPV4_TBID_DST, .expected_ret = BPF_FIB_LKUP_RET_NOT_FWDED,
76 	  .lookup_flags = BPF_FIB_LOOKUP_DIRECT | BPF_FIB_LOOKUP_TBID,
77 	  .tbid = RT_TABLE_MAIN, },
78 	{ .desc = "IPv4 TBID lookup success",
79 	  .daddr = IPV4_TBID_DST, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
80 	  .lookup_flags = BPF_FIB_LOOKUP_DIRECT | BPF_FIB_LOOKUP_TBID, .tbid = 100,
81 	  .dmac = DMAC_INIT2, },
82 	{ .desc = "IPv6 TBID lookup failure",
83 	  .daddr = IPV6_TBID_DST, .expected_ret = BPF_FIB_LKUP_RET_NOT_FWDED,
84 	  .lookup_flags = BPF_FIB_LOOKUP_DIRECT | BPF_FIB_LOOKUP_TBID,
85 	  .tbid = RT_TABLE_MAIN, },
86 	{ .desc = "IPv6 TBID lookup success",
87 	  .daddr = IPV6_TBID_DST, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
88 	  .lookup_flags = BPF_FIB_LOOKUP_DIRECT | BPF_FIB_LOOKUP_TBID, .tbid = 100,
89 	  .dmac = DMAC_INIT2, },
90 	{ .desc = "IPv4 set src addr from netdev",
91 	  .daddr = IPV4_NUD_FAILED_ADDR, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
92 	  .expected_src = IPV4_IFACE_ADDR,
93 	  .lookup_flags = BPF_FIB_LOOKUP_SRC | BPF_FIB_LOOKUP_SKIP_NEIGH, },
94 	{ .desc = "IPv6 set src addr from netdev",
95 	  .daddr = IPV6_NUD_FAILED_ADDR, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
96 	  .expected_src = IPV6_IFACE_ADDR,
97 	  .lookup_flags = BPF_FIB_LOOKUP_SRC | BPF_FIB_LOOKUP_SKIP_NEIGH, },
98 	{ .desc = "IPv4 set prefsrc addr from route",
99 	  .daddr = IPV4_ADDR_DST, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
100 	  .expected_src = IPV4_IFACE_ADDR_SEC,
101 	  .lookup_flags = BPF_FIB_LOOKUP_SRC | BPF_FIB_LOOKUP_SKIP_NEIGH, },
102 	{ .desc = "IPv6 set prefsrc addr route",
103 	  .daddr = IPV6_ADDR_DST, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
104 	  .expected_src = IPV6_IFACE_ADDR_SEC,
105 	  .lookup_flags = BPF_FIB_LOOKUP_SRC | BPF_FIB_LOOKUP_SKIP_NEIGH, },
106 	/* policy routing */
107 	{ .desc = "IPv4 policy routing, default",
108 	  .daddr = IPV4_REMOTE_DST, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
109 	  .expected_dst = IPV4_GW1,
110 	  .lookup_flags = BPF_FIB_LOOKUP_MARK | BPF_FIB_LOOKUP_SKIP_NEIGH, },
111 	{ .desc = "IPv4 policy routing, mark doesn't point to a policy",
112 	  .daddr = IPV4_REMOTE_DST, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
113 	  .expected_dst = IPV4_GW1,
114 	  .lookup_flags = BPF_FIB_LOOKUP_MARK | BPF_FIB_LOOKUP_SKIP_NEIGH,
115 	  .mark = MARK_NO_POLICY, },
116 	{ .desc = "IPv4 policy routing, mark points to a policy",
117 	  .daddr = IPV4_REMOTE_DST, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
118 	  .expected_dst = IPV4_GW2,
119 	  .lookup_flags = BPF_FIB_LOOKUP_MARK | BPF_FIB_LOOKUP_SKIP_NEIGH,
120 	  .mark = MARK, },
121 	{ .desc = "IPv4 policy routing, mark points to a policy, but no flag",
122 	  .daddr = IPV4_REMOTE_DST, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
123 	  .expected_dst = IPV4_GW1,
124 	  .lookup_flags = BPF_FIB_LOOKUP_SKIP_NEIGH,
125 	  .mark = MARK, },
126 	{ .desc = "IPv6 policy routing, default",
127 	  .daddr = IPV6_REMOTE_DST, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
128 	  .expected_dst = IPV6_GW1,
129 	  .lookup_flags = BPF_FIB_LOOKUP_MARK | BPF_FIB_LOOKUP_SKIP_NEIGH, },
130 	{ .desc = "IPv6 policy routing, mark doesn't point to a policy",
131 	  .daddr = IPV6_REMOTE_DST, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
132 	  .expected_dst = IPV6_GW1,
133 	  .lookup_flags = BPF_FIB_LOOKUP_MARK | BPF_FIB_LOOKUP_SKIP_NEIGH,
134 	  .mark = MARK_NO_POLICY, },
135 	{ .desc = "IPv6 policy routing, mark points to a policy",
136 	  .daddr = IPV6_REMOTE_DST, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
137 	  .expected_dst = IPV6_GW2,
138 	  .lookup_flags = BPF_FIB_LOOKUP_MARK | BPF_FIB_LOOKUP_SKIP_NEIGH,
139 	  .mark = MARK, },
140 	{ .desc = "IPv6 policy routing, mark points to a policy, but no flag",
141 	  .daddr = IPV6_REMOTE_DST, .expected_ret = BPF_FIB_LKUP_RET_SUCCESS,
142 	  .expected_dst = IPV6_GW1,
143 	  .lookup_flags = BPF_FIB_LOOKUP_SKIP_NEIGH,
144 	  .mark = MARK, },
145 };
146 
147 static int setup_netns(void)
148 {
149 	int err;
150 
151 	SYS(fail, "ip link add veth1 type veth peer name veth2");
152 	SYS(fail, "ip link set dev veth1 up");
153 	SYS(fail, "ip link set dev veth2 up");
154 
155 	err = write_sysctl("/proc/sys/net/ipv4/neigh/veth1/gc_stale_time", "900");
156 	if (!ASSERT_OK(err, "write_sysctl(net.ipv4.neigh.veth1.gc_stale_time)"))
157 		goto fail;
158 
159 	err = write_sysctl("/proc/sys/net/ipv6/neigh/veth1/gc_stale_time", "900");
160 	if (!ASSERT_OK(err, "write_sysctl(net.ipv6.neigh.veth1.gc_stale_time)"))
161 		goto fail;
162 
163 	SYS(fail, "ip addr add %s/64 dev veth1 nodad", IPV6_IFACE_ADDR);
164 	SYS(fail, "ip neigh add %s dev veth1 nud failed", IPV6_NUD_FAILED_ADDR);
165 	SYS(fail, "ip neigh add %s dev veth1 lladdr %s nud stale", IPV6_NUD_STALE_ADDR, DMAC);
166 
167 	SYS(fail, "ip addr add %s/24 dev veth1", IPV4_IFACE_ADDR);
168 	SYS(fail, "ip neigh add %s dev veth1 nud failed", IPV4_NUD_FAILED_ADDR);
169 	SYS(fail, "ip neigh add %s dev veth1 lladdr %s nud stale", IPV4_NUD_STALE_ADDR, DMAC);
170 
171 	/* Setup for prefsrc IP addr selection */
172 	SYS(fail, "ip addr add %s/24 dev veth1", IPV4_IFACE_ADDR_SEC);
173 	SYS(fail, "ip route add %s/32 dev veth1 src %s", IPV4_ADDR_DST, IPV4_IFACE_ADDR_SEC);
174 
175 	SYS(fail, "ip addr add %s/64 dev veth1 nodad", IPV6_IFACE_ADDR_SEC);
176 	SYS(fail, "ip route add %s/128 dev veth1 src %s", IPV6_ADDR_DST, IPV6_IFACE_ADDR_SEC);
177 
178 	/* Setup for tbid lookup tests */
179 	SYS(fail, "ip addr add %s/24 dev veth2", IPV4_TBID_ADDR);
180 	SYS(fail, "ip route del %s/24 dev veth2", IPV4_TBID_NET);
181 	SYS(fail, "ip route add table 100 %s/24 dev veth2", IPV4_TBID_NET);
182 	SYS(fail, "ip neigh add %s dev veth2 lladdr %s nud stale", IPV4_TBID_DST, DMAC2);
183 
184 	SYS(fail, "ip addr add %s/64 dev veth2", IPV6_TBID_ADDR);
185 	SYS(fail, "ip -6 route del %s/64 dev veth2", IPV6_TBID_NET);
186 	SYS(fail, "ip -6 route add table 100 %s/64 dev veth2", IPV6_TBID_NET);
187 	SYS(fail, "ip neigh add %s dev veth2 lladdr %s nud stale", IPV6_TBID_DST, DMAC2);
188 
189 	err = write_sysctl("/proc/sys/net/ipv4/conf/veth1/forwarding", "1");
190 	if (!ASSERT_OK(err, "write_sysctl(net.ipv4.conf.veth1.forwarding)"))
191 		goto fail;
192 
193 	err = write_sysctl("/proc/sys/net/ipv6/conf/veth1/forwarding", "1");
194 	if (!ASSERT_OK(err, "write_sysctl(net.ipv6.conf.veth1.forwarding)"))
195 		goto fail;
196 
197 	/* Setup for policy routing tests */
198 	SYS(fail, "ip addr add %s/24 dev veth1", IPV4_LOCAL);
199 	SYS(fail, "ip addr add %s/64 dev veth1 nodad", IPV6_LOCAL);
200 	SYS(fail, "ip route add %s/32 via %s", IPV4_REMOTE_DST, IPV4_GW1);
201 	SYS(fail, "ip route add %s/32 via %s table %s", IPV4_REMOTE_DST, IPV4_GW2, MARK_TABLE);
202 	SYS(fail, "ip -6 route add %s/128 via %s", IPV6_REMOTE_DST, IPV6_GW1);
203 	SYS(fail, "ip -6 route add %s/128 via %s table %s", IPV6_REMOTE_DST, IPV6_GW2, MARK_TABLE);
204 	SYS(fail, "ip rule add prio 2 fwmark %d lookup %s", MARK, MARK_TABLE);
205 	SYS(fail, "ip -6 rule add prio 2 fwmark %d lookup %s", MARK, MARK_TABLE);
206 
207 	return 0;
208 fail:
209 	return -1;
210 }
211 
212 static int set_lookup_params(struct bpf_fib_lookup *params,
213 			     const struct fib_lookup_test *test,
214 			     int ifindex)
215 {
216 	int ret;
217 
218 	memset(params, 0, sizeof(*params));
219 
220 	params->l4_protocol = IPPROTO_TCP;
221 	params->ifindex = ifindex;
222 	params->tbid = test->tbid;
223 	params->mark = test->mark;
224 
225 	if (inet_pton(AF_INET6, test->daddr, params->ipv6_dst) == 1) {
226 		params->family = AF_INET6;
227 		if (!(test->lookup_flags & BPF_FIB_LOOKUP_SRC)) {
228 			ret = inet_pton(AF_INET6, IPV6_IFACE_ADDR, params->ipv6_src);
229 			if (!ASSERT_EQ(ret, 1, "inet_pton(IPV6_IFACE_ADDR)"))
230 				return -1;
231 		}
232 
233 		return 0;
234 	}
235 
236 	ret = inet_pton(AF_INET, test->daddr, &params->ipv4_dst);
237 	if (!ASSERT_EQ(ret, 1, "convert IP[46] address"))
238 		return -1;
239 	params->family = AF_INET;
240 
241 	if (!(test->lookup_flags & BPF_FIB_LOOKUP_SRC)) {
242 		ret = inet_pton(AF_INET, IPV4_IFACE_ADDR, &params->ipv4_src);
243 		if (!ASSERT_EQ(ret, 1, "inet_pton(IPV4_IFACE_ADDR)"))
244 			return -1;
245 	}
246 
247 	return 0;
248 }
249 
250 static void mac_str(char *b, const __u8 *mac)
251 {
252 	sprintf(b, "%02X:%02X:%02X:%02X:%02X:%02X",
253 		mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
254 }
255 
256 static void assert_ip_address(int family, void *addr, const char *expected_str)
257 {
258 	char str[INET6_ADDRSTRLEN];
259 	u8 expected_addr[16];
260 	int addr_len = 0;
261 	int ret;
262 
263 	switch (family) {
264 	case AF_INET6:
265 		ret = inet_pton(AF_INET6, expected_str, expected_addr);
266 		ASSERT_EQ(ret, 1, "inet_pton(AF_INET6, expected_str)");
267 		addr_len = 16;
268 		break;
269 	case AF_INET:
270 		ret = inet_pton(AF_INET, expected_str, expected_addr);
271 		ASSERT_EQ(ret, 1, "inet_pton(AF_INET, expected_str)");
272 		addr_len = 4;
273 		break;
274 	default:
275 		PRINT_FAIL("invalid address family: %d", family);
276 		break;
277 	}
278 
279 	if (memcmp(addr, expected_addr, addr_len)) {
280 		inet_ntop(family, addr, str, sizeof(str));
281 		PRINT_FAIL("expected %s actual %s ", expected_str, str);
282 	}
283 }
284 
285 static void assert_src_ip(struct bpf_fib_lookup *params, const char *expected)
286 {
287 	assert_ip_address(params->family, params->ipv6_src, expected);
288 }
289 
290 static void assert_dst_ip(struct bpf_fib_lookup *params, const char *expected)
291 {
292 	assert_ip_address(params->family, params->ipv6_dst, expected);
293 }
294 
295 void test_fib_lookup(void)
296 {
297 	struct bpf_fib_lookup *fib_params;
298 	struct nstoken *nstoken = NULL;
299 	struct __sk_buff skb = { };
300 	struct fib_lookup *skel;
301 	int prog_fd, err, ret, i;
302 
303 	/* The test does not use the skb->data, so
304 	 * use pkt_v6 for both v6 and v4 test.
305 	 */
306 	LIBBPF_OPTS(bpf_test_run_opts, run_opts,
307 		    .data_in = &pkt_v6,
308 		    .data_size_in = sizeof(pkt_v6),
309 		    .ctx_in = &skb,
310 		    .ctx_size_in = sizeof(skb),
311 	);
312 
313 	skel = fib_lookup__open_and_load();
314 	if (!ASSERT_OK_PTR(skel, "skel open_and_load"))
315 		return;
316 	prog_fd = bpf_program__fd(skel->progs.fib_lookup);
317 
318 	SYS(fail, "ip netns add %s", NS_TEST);
319 
320 	nstoken = open_netns(NS_TEST);
321 	if (!ASSERT_OK_PTR(nstoken, "open_netns"))
322 		goto fail;
323 
324 	if (setup_netns())
325 		goto fail;
326 
327 	skb.ifindex = if_nametoindex("veth1");
328 	if (!ASSERT_NEQ(skb.ifindex, 0, "if_nametoindex(veth1)"))
329 		goto fail;
330 
331 	fib_params = &skel->bss->fib_params;
332 
333 	for (i = 0; i < ARRAY_SIZE(tests); i++) {
334 		printf("Testing %s ", tests[i].desc);
335 
336 		if (set_lookup_params(fib_params, &tests[i], skb.ifindex))
337 			continue;
338 
339 		skel->bss->fib_lookup_ret = -1;
340 		skel->bss->lookup_flags = tests[i].lookup_flags;
341 
342 		err = bpf_prog_test_run_opts(prog_fd, &run_opts);
343 		if (!ASSERT_OK(err, "bpf_prog_test_run_opts"))
344 			continue;
345 
346 		ASSERT_EQ(skel->bss->fib_lookup_ret, tests[i].expected_ret,
347 			  "fib_lookup_ret");
348 
349 		if (tests[i].expected_src)
350 			assert_src_ip(fib_params, tests[i].expected_src);
351 
352 		if (tests[i].expected_dst)
353 			assert_dst_ip(fib_params, tests[i].expected_dst);
354 
355 		ret = memcmp(tests[i].dmac, fib_params->dmac, sizeof(tests[i].dmac));
356 		if (!ASSERT_EQ(ret, 0, "dmac not match")) {
357 			char expected[18], actual[18];
358 
359 			mac_str(expected, tests[i].dmac);
360 			mac_str(actual, fib_params->dmac);
361 			printf("dmac expected %s actual %s ", expected, actual);
362 		}
363 
364 		// ensure tbid is zero'd out after fib lookup.
365 		if (tests[i].lookup_flags & BPF_FIB_LOOKUP_DIRECT) {
366 			if (!ASSERT_EQ(skel->bss->fib_params.tbid, 0,
367 					"expected fib_params.tbid to be zero"))
368 				goto fail;
369 		}
370 	}
371 
372 fail:
373 	if (nstoken)
374 		close_netns(nstoken);
375 	SYS_NOFAIL("ip netns del " NS_TEST);
376 	fib_lookup__destroy(skel);
377 }
378