1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2023 Isovalent */
3 #include <uapi/linux/if_link.h>
4 #include <test_progs.h>
5 
6 #include <netinet/tcp.h>
7 #include <netinet/udp.h>
8 
9 #include "network_helpers.h"
10 #include "test_assign_reuse.skel.h"
11 
12 #define NS_TEST "assign_reuse"
13 #define LOOPBACK 1
14 #define PORT 4443
15 
attach_reuseport(int sock_fd,int prog_fd)16 static int attach_reuseport(int sock_fd, int prog_fd)
17 {
18 	return setsockopt(sock_fd, SOL_SOCKET, SO_ATTACH_REUSEPORT_EBPF,
19 			  &prog_fd, sizeof(prog_fd));
20 }
21 
cookie(int fd)22 static __u64 cookie(int fd)
23 {
24 	__u64 cookie = 0;
25 	socklen_t cookie_len = sizeof(cookie);
26 	int ret;
27 
28 	ret = getsockopt(fd, SOL_SOCKET, SO_COOKIE, &cookie, &cookie_len);
29 	ASSERT_OK(ret, "cookie");
30 	ASSERT_GT(cookie, 0, "cookie_invalid");
31 
32 	return cookie;
33 }
34 
echo_test_udp(int fd_sv)35 static int echo_test_udp(int fd_sv)
36 {
37 	struct sockaddr_storage addr = {};
38 	socklen_t len = sizeof(addr);
39 	char buff[1] = {};
40 	int fd_cl = -1, ret;
41 
42 	fd_cl = connect_to_fd(fd_sv, 100);
43 	ASSERT_GT(fd_cl, 0, "create_client");
44 	ASSERT_EQ(getsockname(fd_cl, (void *)&addr, &len), 0, "getsockname");
45 
46 	ASSERT_EQ(send(fd_cl, buff, sizeof(buff), 0), 1, "send_client");
47 
48 	ret = recv(fd_sv, buff, sizeof(buff), 0);
49 	if (ret < 0) {
50 		close(fd_cl);
51 		return errno;
52 	}
53 
54 	ASSERT_EQ(ret, 1, "recv_server");
55 	ASSERT_EQ(sendto(fd_sv, buff, sizeof(buff), 0, (void *)&addr, len), 1, "send_server");
56 	ASSERT_EQ(recv(fd_cl, buff, sizeof(buff), 0), 1, "recv_client");
57 	close(fd_cl);
58 	return 0;
59 }
60 
echo_test_tcp(int fd_sv)61 static int echo_test_tcp(int fd_sv)
62 {
63 	char buff[1] = {};
64 	int fd_cl = -1, fd_sv_cl = -1;
65 
66 	fd_cl = connect_to_fd(fd_sv, 100);
67 	if (fd_cl < 0)
68 		return errno;
69 
70 	fd_sv_cl = accept(fd_sv, NULL, NULL);
71 	ASSERT_GE(fd_sv_cl, 0, "accept_fd");
72 
73 	ASSERT_EQ(send(fd_cl, buff, sizeof(buff), 0), 1, "send_client");
74 	ASSERT_EQ(recv(fd_sv_cl, buff, sizeof(buff), 0), 1, "recv_server");
75 	ASSERT_EQ(send(fd_sv_cl, buff, sizeof(buff), 0), 1, "send_server");
76 	ASSERT_EQ(recv(fd_cl, buff, sizeof(buff), 0), 1, "recv_client");
77 	close(fd_sv_cl);
78 	close(fd_cl);
79 	return 0;
80 }
81 
run_assign_reuse(int family,int sotype,const char * ip,__u16 port)82 void run_assign_reuse(int family, int sotype, const char *ip, __u16 port)
83 {
84 	DECLARE_LIBBPF_OPTS(bpf_tc_hook, tc_hook,
85 		.ifindex = LOOPBACK,
86 		.attach_point = BPF_TC_INGRESS,
87 	);
88 	DECLARE_LIBBPF_OPTS(bpf_tc_opts, tc_opts,
89 		.handle = 1,
90 		.priority = 1,
91 	);
92 	bool hook_created = false, tc_attached = false;
93 	int ret, fd_tc, fd_accept, fd_drop, fd_map;
94 	int *fd_sv = NULL;
95 	__u64 fd_val;
96 	struct test_assign_reuse *skel;
97 	const int zero = 0;
98 
99 	skel = test_assign_reuse__open();
100 	if (!ASSERT_OK_PTR(skel, "skel_open"))
101 		goto cleanup;
102 
103 	skel->rodata->dest_port = port;
104 
105 	ret = test_assign_reuse__load(skel);
106 	if (!ASSERT_OK(ret, "skel_load"))
107 		goto cleanup;
108 
109 	ASSERT_EQ(skel->bss->sk_cookie_seen, 0, "cookie_init");
110 
111 	fd_tc = bpf_program__fd(skel->progs.tc_main);
112 	fd_accept = bpf_program__fd(skel->progs.reuse_accept);
113 	fd_drop = bpf_program__fd(skel->progs.reuse_drop);
114 	fd_map = bpf_map__fd(skel->maps.sk_map);
115 
116 	fd_sv = start_reuseport_server(family, sotype, ip, port, 100, 1);
117 	if (!ASSERT_NEQ(fd_sv, NULL, "start_reuseport_server"))
118 		goto cleanup;
119 
120 	ret = attach_reuseport(*fd_sv, fd_drop);
121 	if (!ASSERT_OK(ret, "attach_reuseport"))
122 		goto cleanup;
123 
124 	fd_val = *fd_sv;
125 	ret = bpf_map_update_elem(fd_map, &zero, &fd_val, BPF_NOEXIST);
126 	if (!ASSERT_OK(ret, "bpf_sk_map"))
127 		goto cleanup;
128 
129 	ret = bpf_tc_hook_create(&tc_hook);
130 	if (ret == 0)
131 		hook_created = true;
132 	ret = ret == -EEXIST ? 0 : ret;
133 	if (!ASSERT_OK(ret, "bpf_tc_hook_create"))
134 		goto cleanup;
135 
136 	tc_opts.prog_fd = fd_tc;
137 	ret = bpf_tc_attach(&tc_hook, &tc_opts);
138 	if (!ASSERT_OK(ret, "bpf_tc_attach"))
139 		goto cleanup;
140 	tc_attached = true;
141 
142 	if (sotype == SOCK_STREAM)
143 		ASSERT_EQ(echo_test_tcp(*fd_sv), ECONNREFUSED, "drop_tcp");
144 	else
145 		ASSERT_EQ(echo_test_udp(*fd_sv), EAGAIN, "drop_udp");
146 	ASSERT_EQ(skel->bss->reuseport_executed, 1, "program executed once");
147 
148 	skel->bss->sk_cookie_seen = 0;
149 	skel->bss->reuseport_executed = 0;
150 	ASSERT_OK(attach_reuseport(*fd_sv, fd_accept), "attach_reuseport(accept)");
151 
152 	if (sotype == SOCK_STREAM)
153 		ASSERT_EQ(echo_test_tcp(*fd_sv), 0, "echo_tcp");
154 	else
155 		ASSERT_EQ(echo_test_udp(*fd_sv), 0, "echo_udp");
156 
157 	ASSERT_EQ(skel->bss->sk_cookie_seen, cookie(*fd_sv),
158 		  "cookie_mismatch");
159 	ASSERT_EQ(skel->bss->reuseport_executed, 1, "program executed once");
160 cleanup:
161 	if (tc_attached) {
162 		tc_opts.flags = tc_opts.prog_fd = tc_opts.prog_id = 0;
163 		ret = bpf_tc_detach(&tc_hook, &tc_opts);
164 		ASSERT_OK(ret, "bpf_tc_detach");
165 	}
166 	if (hook_created) {
167 		tc_hook.attach_point = BPF_TC_INGRESS | BPF_TC_EGRESS;
168 		bpf_tc_hook_destroy(&tc_hook);
169 	}
170 	test_assign_reuse__destroy(skel);
171 	free_fds(fd_sv, 1);
172 }
173 
test_assign_reuse(void)174 void test_assign_reuse(void)
175 {
176 	struct nstoken *tok = NULL;
177 
178 	SYS(out, "ip netns add %s", NS_TEST);
179 	SYS(cleanup, "ip -net %s link set dev lo up", NS_TEST);
180 
181 	tok = open_netns(NS_TEST);
182 	if (!ASSERT_OK_PTR(tok, "netns token"))
183 		return;
184 
185 	if (test__start_subtest("tcpv4"))
186 		run_assign_reuse(AF_INET, SOCK_STREAM, "127.0.0.1", PORT);
187 	if (test__start_subtest("tcpv6"))
188 		run_assign_reuse(AF_INET6, SOCK_STREAM, "::1", PORT);
189 	if (test__start_subtest("udpv4"))
190 		run_assign_reuse(AF_INET, SOCK_DGRAM, "127.0.0.1", PORT);
191 	if (test__start_subtest("udpv6"))
192 		run_assign_reuse(AF_INET6, SOCK_DGRAM, "::1", PORT);
193 
194 cleanup:
195 	close_netns(tok);
196 	SYS_NOFAIL("ip netns delete %s", NS_TEST);
197 out:
198 	return;
199 }
200