1 // SPDX-License-Identifier: LGPL-2.1 OR BSD-2-Clause
2 /* Copyright (c) 2022, NVIDIA CORPORATION & AFFILIATES. All rights reserved. */
3 
4 #define _GNU_SOURCE
5 #include <test_progs.h>
6 #include <network_helpers.h>
7 #include <ctype.h>
8 
9 #define CMD_OUT_BUF_SIZE 1023
10 
11 #define SYS_OUT(cmd, ...) ({ \
12 	char buf[1024]; \
13 	snprintf(buf, sizeof(buf), (cmd), ##__VA_ARGS__); \
14 	FILE *f = popen(buf, "r"); \
15 	if (!ASSERT_OK_PTR(f, buf)) \
16 		goto out; \
17 	f; \
18 })
19 
20 /* out must be at least `size * 4 + 1` bytes long */
escape_str(char * out,const char * in,size_t size)21 static void escape_str(char *out, const char *in, size_t size)
22 {
23 	static const char *hex = "0123456789ABCDEF";
24 	size_t i;
25 
26 	for (i = 0; i < size; i++) {
27 		if (isprint(in[i]) && in[i] != '\\' && in[i] != '\'') {
28 			*out++ = in[i];
29 		} else {
30 			*out++ = '\\';
31 			*out++ = 'x';
32 			*out++ = hex[(in[i] >> 4) & 0xf];
33 			*out++ = hex[in[i] & 0xf];
34 		}
35 	}
36 	*out++ = '\0';
37 }
38 
expect_str(char * buf,size_t size,const char * str,const char * name)39 static bool expect_str(char *buf, size_t size, const char *str, const char *name)
40 {
41 	static char escbuf_expected[CMD_OUT_BUF_SIZE * 4];
42 	static char escbuf_actual[CMD_OUT_BUF_SIZE * 4];
43 	static int duration = 0;
44 	bool ok;
45 
46 	ok = size == strlen(str) && !memcmp(buf, str, size);
47 
48 	if (!ok) {
49 		escape_str(escbuf_expected, str, strlen(str));
50 		escape_str(escbuf_actual, buf, size);
51 	}
52 	CHECK(!ok, name, "unexpected %s: actual '%s' != expected '%s'\n",
53 	      name, escbuf_actual, escbuf_expected);
54 
55 	return ok;
56 }
57 
test_synproxy(bool xdp)58 static void test_synproxy(bool xdp)
59 {
60 	int server_fd = -1, client_fd = -1, accept_fd = -1;
61 	char *prog_id = NULL, *prog_id_end;
62 	struct nstoken *ns = NULL;
63 	FILE *ctrl_file = NULL;
64 	char buf[CMD_OUT_BUF_SIZE];
65 	size_t size;
66 
67 	SYS(out, "ip netns add synproxy");
68 
69 	SYS(out, "ip link add tmp0 type veth peer name tmp1");
70 	SYS(out, "ip link set tmp1 netns synproxy");
71 	SYS(out, "ip link set tmp0 up");
72 	SYS(out, "ip addr replace 198.18.0.1/24 dev tmp0");
73 
74 	/* When checksum offload is enabled, the XDP program sees wrong
75 	 * checksums and drops packets.
76 	 */
77 	SYS(out, "ethtool -K tmp0 tx off");
78 	if (xdp)
79 		/* Workaround required for veth. */
80 		SYS(out, "ip link set tmp0 xdp object xdp_dummy.bpf.o section xdp 2> /dev/null");
81 
82 	ns = open_netns("synproxy");
83 	if (!ASSERT_OK_PTR(ns, "setns"))
84 		goto out;
85 
86 	SYS(out, "ip link set lo up");
87 	SYS(out, "ip link set tmp1 up");
88 	SYS(out, "ip addr replace 198.18.0.2/24 dev tmp1");
89 	SYS(out, "sysctl -w net.ipv4.tcp_syncookies=2");
90 	SYS(out, "sysctl -w net.ipv4.tcp_timestamps=1");
91 	SYS(out, "sysctl -w net.netfilter.nf_conntrack_tcp_loose=0");
92 	SYS(out, "iptables-legacy -t raw -I PREROUTING \
93 	    -i tmp1 -p tcp -m tcp --syn --dport 8080 -j CT --notrack");
94 	SYS(out, "iptables-legacy -t filter -A INPUT \
95 	    -i tmp1 -p tcp -m tcp --dport 8080 -m state --state INVALID,UNTRACKED \
96 	    -j SYNPROXY --sack-perm --timestamp --wscale 7 --mss 1460");
97 	SYS(out, "iptables-legacy -t filter -A INPUT \
98 	    -i tmp1 -m state --state INVALID -j DROP");
99 
100 	ctrl_file = SYS_OUT("./xdp_synproxy --iface tmp1 --ports 8080 \
101 			    --single --mss4 1460 --mss6 1440 \
102 			    --wscale 7 --ttl 64%s", xdp ? "" : " --tc");
103 	size = fread(buf, 1, sizeof(buf), ctrl_file);
104 	pclose(ctrl_file);
105 	if (!expect_str(buf, size, "Total SYNACKs generated: 0\n",
106 			"initial SYNACKs"))
107 		goto out;
108 
109 	if (!xdp) {
110 		ctrl_file = SYS_OUT("tc filter show dev tmp1 ingress");
111 		size = fread(buf, 1, sizeof(buf), ctrl_file);
112 		pclose(ctrl_file);
113 		prog_id = memmem(buf, size, " id ", 4);
114 		if (!ASSERT_OK_PTR(prog_id, "find prog id"))
115 			goto out;
116 		prog_id += 4;
117 		if (!ASSERT_LT(prog_id, buf + size, "find prog id begin"))
118 			goto out;
119 		prog_id_end = prog_id;
120 		while (prog_id_end < buf + size && *prog_id_end >= '0' &&
121 		       *prog_id_end <= '9')
122 			prog_id_end++;
123 		if (!ASSERT_LT(prog_id_end, buf + size, "find prog id end"))
124 			goto out;
125 		*prog_id_end = '\0';
126 	}
127 
128 	server_fd = start_server(AF_INET, SOCK_STREAM, "198.18.0.2", 8080, 0);
129 	if (!ASSERT_GE(server_fd, 0, "start_server"))
130 		goto out;
131 
132 	close_netns(ns);
133 	ns = NULL;
134 
135 	client_fd = connect_to_fd(server_fd, 10000);
136 	if (!ASSERT_GE(client_fd, 0, "connect_to_fd"))
137 		goto out;
138 
139 	accept_fd = accept(server_fd, NULL, NULL);
140 	if (!ASSERT_GE(accept_fd, 0, "accept"))
141 		goto out;
142 
143 	ns = open_netns("synproxy");
144 	if (!ASSERT_OK_PTR(ns, "setns"))
145 		goto out;
146 
147 	if (xdp)
148 		ctrl_file = SYS_OUT("./xdp_synproxy --iface tmp1 --single");
149 	else
150 		ctrl_file = SYS_OUT("./xdp_synproxy --prog %s --single",
151 				    prog_id);
152 	size = fread(buf, 1, sizeof(buf), ctrl_file);
153 	pclose(ctrl_file);
154 	if (!expect_str(buf, size, "Total SYNACKs generated: 1\n",
155 			"SYNACKs after connection"))
156 		goto out;
157 
158 out:
159 	if (accept_fd >= 0)
160 		close(accept_fd);
161 	if (client_fd >= 0)
162 		close(client_fd);
163 	if (server_fd >= 0)
164 		close(server_fd);
165 	if (ns)
166 		close_netns(ns);
167 
168 	SYS_NOFAIL("ip link del tmp0");
169 	SYS_NOFAIL("ip netns del synproxy");
170 }
171 
test_xdp_synproxy(void)172 void test_xdp_synproxy(void)
173 {
174 	if (test__start_subtest("xdp"))
175 		test_synproxy(true);
176 	if (test__start_subtest("tc"))
177 		test_synproxy(false);
178 }
179