summaryrefslogtreecommitdiff
path: root/tools/testing/selftests/bpf/progs/bind4_prog.c
blob: 474c6a62078a12f71ada300f1601c72de55c5c9a (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
// SPDX-License-Identifier: GPL-2.0

#include <string.h>

#include <linux/stddef.h>
#include <linux/bpf.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <sys/socket.h>
#include <netinet/tcp.h>
#include <linux/if.h>
#include <errno.h>

#include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>

#define SERV4_IP		0xc0a801feU /* 192.168.1.254 */
#define SERV4_PORT		4040
#define SERV4_REWRITE_IP	0x7f000001U /* 127.0.0.1 */
#define SERV4_REWRITE_PORT	4444

#ifndef IFNAMSIZ
#define IFNAMSIZ 16
#endif

static __inline int bind_to_device(struct bpf_sock_addr *ctx)
{
	char veth1[IFNAMSIZ] = "test_sock_addr1";
	char veth2[IFNAMSIZ] = "test_sock_addr2";
	char missing[IFNAMSIZ] = "nonexistent_dev";
	char del_bind[IFNAMSIZ] = "";
	int veth1_idx, veth2_idx;

	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
			   &veth1, sizeof(veth1)))
		return 1;
	if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
			   &veth1_idx, sizeof(veth1_idx)) || !veth1_idx)
		return 1;
	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
			   &veth2, sizeof(veth2)))
		return 1;
	if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
			   &veth2_idx, sizeof(veth2_idx)) || !veth2_idx ||
	    veth1_idx == veth2_idx)
		return 1;
	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
			   &missing, sizeof(missing)) != -ENODEV)
		return 1;
	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
			   &veth1_idx, sizeof(veth1_idx)))
		return 1;
	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
			   &del_bind, sizeof(del_bind)))
		return 1;

	return 0;
}

static __inline int bind_reuseport(struct bpf_sock_addr *ctx)
{
	int val = 1;

	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_REUSEPORT,
			   &val, sizeof(val)))
		return 1;
	if (bpf_getsockopt(ctx, SOL_SOCKET, SO_REUSEPORT,
			   &val, sizeof(val)) || !val)
		return 1;
	val = 0;
	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_REUSEPORT,
			   &val, sizeof(val)))
		return 1;
	if (bpf_getsockopt(ctx, SOL_SOCKET, SO_REUSEPORT,
			   &val, sizeof(val)) || val)
		return 1;

	return 0;
}

static __inline int misc_opts(struct bpf_sock_addr *ctx, int opt)
{
	int old, tmp, new = 0xeb9f;

	/* Socket in test case has guarantee that old never equals to new. */
	if (bpf_getsockopt(ctx, SOL_SOCKET, opt, &old, sizeof(old)) ||
	    old == new)
		return 1;
	if (bpf_setsockopt(ctx, SOL_SOCKET, opt, &new, sizeof(new)))
		return 1;
	if (bpf_getsockopt(ctx, SOL_SOCKET, opt, &tmp, sizeof(tmp)) ||
	    tmp != new)
		return 1;
	if (bpf_setsockopt(ctx, SOL_SOCKET, opt, &old, sizeof(old)))
		return 1;

	return 0;
}

SEC("cgroup/bind4")
int bind_v4_prog(struct bpf_sock_addr *ctx)
{
	struct bpf_sock *sk;
	__u32 user_ip4;
	__u16 user_port;

	sk = ctx->sk;
	if (!sk)
		return 0;

	if (sk->family != AF_INET)
		return 0;

	if (ctx->type != SOCK_STREAM && ctx->type != SOCK_DGRAM)
		return 0;

	if (ctx->user_ip4 != bpf_htonl(SERV4_IP) ||
	    ctx->user_port != bpf_htons(SERV4_PORT))
		return 0;

	// u8 narrow loads:
	user_ip4 = 0;
	user_ip4 |= ((volatile __u8 *)&ctx->user_ip4)[0] << 0;
	user_ip4 |= ((volatile __u8 *)&ctx->user_ip4)[1] << 8;
	user_ip4 |= ((volatile __u8 *)&ctx->user_ip4)[2] << 16;
	user_ip4 |= ((volatile __u8 *)&ctx->user_ip4)[3] << 24;
	if (ctx->user_ip4 != user_ip4)
		return 0;

	user_port = 0;
	user_port |= ((volatile __u8 *)&ctx->user_port)[0] << 0;
	user_port |= ((volatile __u8 *)&ctx->user_port)[1] << 8;
	if (ctx->user_port != user_port)
		return 0;

	// u16 narrow loads:
	user_ip4 = 0;
	user_ip4 |= ((volatile __u16 *)&ctx->user_ip4)[0] << 0;
	user_ip4 |= ((volatile __u16 *)&ctx->user_ip4)[1] << 16;
	if (ctx->user_ip4 != user_ip4)
		return 0;

	/* Bind to device and unbind it. */
	if (bind_to_device(ctx))
		return 0;

	/* Test for misc socket options. */
	if (misc_opts(ctx, SO_MARK) || misc_opts(ctx, SO_PRIORITY))
		return 0;

	/* Set reuseport and unset */
	if (bind_reuseport(ctx))
		return 0;

	ctx->user_ip4 = bpf_htonl(SERV4_REWRITE_IP);
	ctx->user_port = bpf_htons(SERV4_REWRITE_PORT);

	return 1;
}

char _license[] SEC("license") = "GPL";