summaryrefslogtreecommitdiff
path: root/tools/testing/selftests/bpf/prog_tests/xdp_synproxy.c
blob: 75550a40e029d2b1ebacb5ef79393b4ded734adc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
// SPDX-License-Identifier: LGPL-2.1 OR BSD-2-Clause
/* Copyright (c) 2022, NVIDIA CORPORATION & AFFILIATES. All rights reserved. */

#define _GNU_SOURCE
#include <test_progs.h>
#include <network_helpers.h>
#include <ctype.h>

#define CMD_OUT_BUF_SIZE 1023

#define SYS(cmd) ({ \
	if (!ASSERT_OK(system(cmd), (cmd))) \
		goto out; \
})

#define SYS_OUT(cmd, ...) ({ \
	char buf[1024]; \
	snprintf(buf, sizeof(buf), (cmd), ##__VA_ARGS__); \
	FILE *f = popen(buf, "r"); \
	if (!ASSERT_OK_PTR(f, buf)) \
		goto out; \
	f; \
})

/* out must be at least `size * 4 + 1` bytes long */
static void escape_str(char *out, const char *in, size_t size)
{
	static const char *hex = "0123456789ABCDEF";
	size_t i;

	for (i = 0; i < size; i++) {
		if (isprint(in[i]) && in[i] != '\\' && in[i] != '\'') {
			*out++ = in[i];
		} else {
			*out++ = '\\';
			*out++ = 'x';
			*out++ = hex[(in[i] >> 4) & 0xf];
			*out++ = hex[in[i] & 0xf];
		}
	}
	*out++ = '\0';
}

static bool expect_str(char *buf, size_t size, const char *str, const char *name)
{
	static char escbuf_expected[CMD_OUT_BUF_SIZE * 4];
	static char escbuf_actual[CMD_OUT_BUF_SIZE * 4];
	static int duration = 0;
	bool ok;

	ok = size == strlen(str) && !memcmp(buf, str, size);

	if (!ok) {
		escape_str(escbuf_expected, str, strlen(str));
		escape_str(escbuf_actual, buf, size);
	}
	CHECK(!ok, name, "unexpected %s: actual '%s' != expected '%s'\n",
	      name, escbuf_actual, escbuf_expected);

	return ok;
}

static void test_synproxy(bool xdp)
{
	int server_fd = -1, client_fd = -1, accept_fd = -1;
	char *prog_id = NULL, *prog_id_end;
	struct nstoken *ns = NULL;
	FILE *ctrl_file = NULL;
	char buf[CMD_OUT_BUF_SIZE];
	size_t size;

	SYS("ip netns add synproxy");

	SYS("ip link add tmp0 type veth peer name tmp1");
	SYS("ip link set tmp1 netns synproxy");
	SYS("ip link set tmp0 up");
	SYS("ip addr replace 198.18.0.1/24 dev tmp0");

	/* When checksum offload is enabled, the XDP program sees wrong
	 * checksums and drops packets.
	 */
	SYS("ethtool -K tmp0 tx off");
	if (xdp)
		/* Workaround required for veth. */
		SYS("ip link set tmp0 xdp object xdp_dummy.bpf.o section xdp 2> /dev/null");

	ns = open_netns("synproxy");
	if (!ASSERT_OK_PTR(ns, "setns"))
		goto out;

	SYS("ip link set lo up");
	SYS("ip link set tmp1 up");
	SYS("ip addr replace 198.18.0.2/24 dev tmp1");
	SYS("sysctl -w net.ipv4.tcp_syncookies=2");
	SYS("sysctl -w net.ipv4.tcp_timestamps=1");
	SYS("sysctl -w net.netfilter.nf_conntrack_tcp_loose=0");
	SYS("iptables -t raw -I PREROUTING \
	    -i tmp1 -p tcp -m tcp --syn --dport 8080 -j CT --notrack");
	SYS("iptables -t filter -A INPUT \
	    -i tmp1 -p tcp -m tcp --dport 8080 -m state --state INVALID,UNTRACKED \
	    -j SYNPROXY --sack-perm --timestamp --wscale 7 --mss 1460");
	SYS("iptables -t filter -A INPUT \
	    -i tmp1 -m state --state INVALID -j DROP");

	ctrl_file = SYS_OUT("./xdp_synproxy --iface tmp1 --ports 8080 \
			    --single --mss4 1460 --mss6 1440 \
			    --wscale 7 --ttl 64%s", xdp ? "" : " --tc");
	size = fread(buf, 1, sizeof(buf), ctrl_file);
	pclose(ctrl_file);
	if (!expect_str(buf, size, "Total SYNACKs generated: 0\n",
			"initial SYNACKs"))
		goto out;

	if (!xdp) {
		ctrl_file = SYS_OUT("tc filter show dev tmp1 ingress");
		size = fread(buf, 1, sizeof(buf), ctrl_file);
		pclose(ctrl_file);
		prog_id = memmem(buf, size, " id ", 4);
		if (!ASSERT_OK_PTR(prog_id, "find prog id"))
			goto out;
		prog_id += 4;
		if (!ASSERT_LT(prog_id, buf + size, "find prog id begin"))
			goto out;
		prog_id_end = prog_id;
		while (prog_id_end < buf + size && *prog_id_end >= '0' &&
		       *prog_id_end <= '9')
			prog_id_end++;
		if (!ASSERT_LT(prog_id_end, buf + size, "find prog id end"))
			goto out;
		*prog_id_end = '\0';
	}

	server_fd = start_server(AF_INET, SOCK_STREAM, "198.18.0.2", 8080, 0);
	if (!ASSERT_GE(server_fd, 0, "start_server"))
		goto out;

	close_netns(ns);
	ns = NULL;

	client_fd = connect_to_fd(server_fd, 10000);
	if (!ASSERT_GE(client_fd, 0, "connect_to_fd"))
		goto out;

	accept_fd = accept(server_fd, NULL, NULL);
	if (!ASSERT_GE(accept_fd, 0, "accept"))
		goto out;

	ns = open_netns("synproxy");
	if (!ASSERT_OK_PTR(ns, "setns"))
		goto out;

	if (xdp)
		ctrl_file = SYS_OUT("./xdp_synproxy --iface tmp1 --single");
	else
		ctrl_file = SYS_OUT("./xdp_synproxy --prog %s --single",
				    prog_id);
	size = fread(buf, 1, sizeof(buf), ctrl_file);
	pclose(ctrl_file);
	if (!expect_str(buf, size, "Total SYNACKs generated: 1\n",
			"SYNACKs after connection"))
		goto out;

out:
	if (accept_fd >= 0)
		close(accept_fd);
	if (client_fd >= 0)
		close(client_fd);
	if (server_fd >= 0)
		close(server_fd);
	if (ns)
		close_netns(ns);

	system("ip link del tmp0");
	system("ip netns del synproxy");
}

void test_xdp_synproxy(void)
{
	if (test__start_subtest("xdp"))
		test_synproxy(true);
	if (test__start_subtest("tc"))
		test_synproxy(false);
}