summaryrefslogtreecommitdiff
path: root/tools/testing/selftests/bpf/test_select_reuseport_kern.c
blob: 5b54ec637adafa95c5524c8eb127e329b438772f (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
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2018 Facebook */

#include <stdlib.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/bpf.h>
#include <linux/types.h>
#include <linux/if_ether.h>

#include "bpf_endian.h"
#include "bpf_helpers.h"
#include "test_select_reuseport_common.h"

int _version SEC("version") = 1;

#ifndef offsetof
#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
#endif

struct bpf_map_def SEC("maps") outer_map = {
	.type = BPF_MAP_TYPE_ARRAY_OF_MAPS,
	.key_size = sizeof(__u32),
	.value_size = sizeof(__u32),
	.max_entries = 1,
};

struct bpf_map_def SEC("maps") result_map = {
	.type = BPF_MAP_TYPE_ARRAY,
	.key_size = sizeof(__u32),
	.value_size = sizeof(__u32),
	.max_entries = NR_RESULTS,
};

struct bpf_map_def SEC("maps") tmp_index_ovr_map = {
	.type = BPF_MAP_TYPE_ARRAY,
	.key_size = sizeof(__u32),
	.value_size = sizeof(int),
	.max_entries = 1,
};

struct bpf_map_def SEC("maps") linum_map = {
	.type = BPF_MAP_TYPE_ARRAY,
	.key_size = sizeof(__u32),
	.value_size = sizeof(__u32),
	.max_entries = 1,
};

struct bpf_map_def SEC("maps") data_check_map = {
	.type = BPF_MAP_TYPE_ARRAY,
	.key_size = sizeof(__u32),
	.value_size = sizeof(struct data_check),
	.max_entries = 1,
};

#define GOTO_DONE(_result) ({			\
	result = (_result);			\
	linum = __LINE__;			\
	goto done;				\
})

SEC("select_by_skb_data")
int _select_by_skb_data(struct sk_reuseport_md *reuse_md)
{
	__u32 linum, index = 0, flags = 0, index_zero = 0;
	__u32 *result_cnt, *linum_value;
	struct data_check data_check = {};
	struct cmd *cmd, cmd_copy;
	void *data, *data_end;
	void *reuseport_array;
	enum result result;
	int *index_ovr;
	int err;

	data = reuse_md->data;
	data_end = reuse_md->data_end;
	data_check.len = reuse_md->len;
	data_check.eth_protocol = reuse_md->eth_protocol;
	data_check.ip_protocol = reuse_md->ip_protocol;
	data_check.hash = reuse_md->hash;
	data_check.bind_inany = reuse_md->bind_inany;
	if (data_check.eth_protocol == bpf_htons(ETH_P_IP)) {
		if (bpf_skb_load_bytes_relative(reuse_md,
						offsetof(struct iphdr, saddr),
						data_check.skb_addrs, 8,
						BPF_HDR_START_NET))
			GOTO_DONE(DROP_MISC);
	} else {
		if (bpf_skb_load_bytes_relative(reuse_md,
						offsetof(struct ipv6hdr, saddr),
						data_check.skb_addrs, 32,
						BPF_HDR_START_NET))
			GOTO_DONE(DROP_MISC);
	}

	/*
	 * The ip_protocol could be a compile time decision
	 * if the bpf_prog.o is dedicated to either TCP or
	 * UDP.
	 *
	 * Otherwise, reuse_md->ip_protocol or
	 * the protocol field in the iphdr can be used.
	 */
	if (data_check.ip_protocol == IPPROTO_TCP) {
		struct tcphdr *th = data;

		if (th + 1 > data_end)
			GOTO_DONE(DROP_MISC);

		data_check.skb_ports[0] = th->source;
		data_check.skb_ports[1] = th->dest;

		if ((th->doff << 2) + sizeof(*cmd) > data_check.len)
			GOTO_DONE(DROP_ERR_SKB_DATA);
		if (bpf_skb_load_bytes(reuse_md, th->doff << 2, &cmd_copy,
				       sizeof(cmd_copy)))
			GOTO_DONE(DROP_MISC);
		cmd = &cmd_copy;
	} else if (data_check.ip_protocol == IPPROTO_UDP) {
		struct udphdr *uh = data;

		if (uh + 1 > data_end)
			GOTO_DONE(DROP_MISC);

		data_check.skb_ports[0] = uh->source;
		data_check.skb_ports[1] = uh->dest;

		if (sizeof(struct udphdr) + sizeof(*cmd) > data_check.len)
			GOTO_DONE(DROP_ERR_SKB_DATA);
		if (data + sizeof(struct udphdr) + sizeof(*cmd) > data_end) {
			if (bpf_skb_load_bytes(reuse_md, sizeof(struct udphdr),
					       &cmd_copy, sizeof(cmd_copy)))
				GOTO_DONE(DROP_MISC);
			cmd = &cmd_copy;
		} else {
			cmd = data + sizeof(struct udphdr);
		}
	} else {
		GOTO_DONE(DROP_MISC);
	}

	reuseport_array = bpf_map_lookup_elem(&outer_map, &index_zero);
	if (!reuseport_array)
		GOTO_DONE(DROP_ERR_INNER_MAP);

	index = cmd->reuseport_index;
	index_ovr = bpf_map_lookup_elem(&tmp_index_ovr_map, &index_zero);
	if (!index_ovr)
		GOTO_DONE(DROP_MISC);

	if (*index_ovr != -1) {
		index = *index_ovr;
		*index_ovr = -1;
	}
	err = bpf_sk_select_reuseport(reuse_md, reuseport_array, &index,
				      flags);
	if (!err)
		GOTO_DONE(PASS);

	if (cmd->pass_on_failure)
		GOTO_DONE(PASS_ERR_SK_SELECT_REUSEPORT);
	else
		GOTO_DONE(DROP_ERR_SK_SELECT_REUSEPORT);

done:
	result_cnt = bpf_map_lookup_elem(&result_map, &result);
	if (!result_cnt)
		return SK_DROP;

	bpf_map_update_elem(&linum_map, &index_zero, &linum, BPF_ANY);
	bpf_map_update_elem(&data_check_map, &index_zero, &data_check, BPF_ANY);

	(*result_cnt)++;
	return result < PASS ? SK_DROP : SK_PASS;
}

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