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
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
|
// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
#include "cgroup_helpers.h"
#include <linux/tcp.h>
#include "sockopt_sk.skel.h"
#ifndef SOL_TCP
#define SOL_TCP IPPROTO_TCP
#endif
#define SOL_CUSTOM 0xdeadbeef
static int getsetsockopt(void)
{
int fd, err;
union {
char u8[4];
__u32 u32;
char cc[16]; /* TCP_CA_NAME_MAX */
struct tcp_zerocopy_receive zc;
} buf = {};
socklen_t optlen;
char *big_buf = NULL;
fd = socket(AF_INET, SOCK_STREAM, 0);
if (fd < 0) {
log_err("Failed to create socket");
return -1;
}
/* IP_TOS - BPF bypass */
optlen = getpagesize() * 2;
big_buf = calloc(1, optlen);
if (!big_buf) {
log_err("Couldn't allocate two pages");
goto err;
}
*(int *)big_buf = 0x08;
err = setsockopt(fd, SOL_IP, IP_TOS, big_buf, optlen);
if (err) {
log_err("Failed to call setsockopt(IP_TOS)");
goto err;
}
memset(big_buf, 0, optlen);
optlen = 1;
err = getsockopt(fd, SOL_IP, IP_TOS, big_buf, &optlen);
if (err) {
log_err("Failed to call getsockopt(IP_TOS)");
goto err;
}
if (*big_buf != 0x08) {
log_err("Unexpected getsockopt(IP_TOS) optval 0x%x != 0x08",
(int)*big_buf);
goto err;
}
/* IP_TTL - EPERM */
buf.u8[0] = 1;
err = setsockopt(fd, SOL_IP, IP_TTL, &buf, 1);
if (!err || errno != EPERM) {
log_err("Unexpected success from setsockopt(IP_TTL)");
goto err;
}
/* SOL_CUSTOM - handled by BPF */
buf.u8[0] = 0x01;
err = setsockopt(fd, SOL_CUSTOM, 0, &buf, 1);
if (err) {
log_err("Failed to call setsockopt");
goto err;
}
buf.u32 = 0x00;
optlen = 4;
err = getsockopt(fd, SOL_CUSTOM, 0, &buf, &optlen);
if (err) {
log_err("Failed to call getsockopt");
goto err;
}
if (optlen != 1) {
log_err("Unexpected optlen %d != 1", optlen);
goto err;
}
if (buf.u8[0] != 0x01) {
log_err("Unexpected buf[0] 0x%02x != 0x01", buf.u8[0]);
goto err;
}
/* IP_FREEBIND - BPF can't access optval past PAGE_SIZE */
optlen = getpagesize() * 2;
memset(big_buf, 0, optlen);
err = setsockopt(fd, SOL_IP, IP_FREEBIND, big_buf, optlen);
if (err != 0) {
log_err("Failed to call setsockopt, ret=%d", err);
goto err;
}
err = getsockopt(fd, SOL_IP, IP_FREEBIND, big_buf, &optlen);
if (err != 0) {
log_err("Failed to call getsockopt, ret=%d", err);
goto err;
}
if (optlen != 1 || *(__u8 *)big_buf != 0x55) {
log_err("Unexpected IP_FREEBIND getsockopt, optlen=%d, optval=0x%x",
optlen, *(__u8 *)big_buf);
}
/* SO_SNDBUF is overwritten */
buf.u32 = 0x01010101;
err = setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &buf, 4);
if (err) {
log_err("Failed to call setsockopt(SO_SNDBUF)");
goto err;
}
buf.u32 = 0x00;
optlen = 4;
err = getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &buf, &optlen);
if (err) {
log_err("Failed to call getsockopt(SO_SNDBUF)");
goto err;
}
if (buf.u32 != 0x55AA*2) {
log_err("Unexpected getsockopt(SO_SNDBUF) 0x%x != 0x55AA*2",
buf.u32);
goto err;
}
/* TCP_CONGESTION can extend the string */
strcpy(buf.cc, "nv");
err = setsockopt(fd, SOL_TCP, TCP_CONGESTION, &buf, strlen("nv"));
if (err) {
log_err("Failed to call setsockopt(TCP_CONGESTION)");
goto err;
}
optlen = sizeof(buf.cc);
err = getsockopt(fd, SOL_TCP, TCP_CONGESTION, &buf, &optlen);
if (err) {
log_err("Failed to call getsockopt(TCP_CONGESTION)");
goto err;
}
if (strcmp(buf.cc, "cubic") != 0) {
log_err("Unexpected getsockopt(TCP_CONGESTION) %s != %s",
buf.cc, "cubic");
goto err;
}
/* TCP_ZEROCOPY_RECEIVE triggers */
memset(&buf, 0, sizeof(buf));
optlen = sizeof(buf.zc);
err = getsockopt(fd, SOL_TCP, TCP_ZEROCOPY_RECEIVE, &buf, &optlen);
if (err) {
log_err("Unexpected getsockopt(TCP_ZEROCOPY_RECEIVE) err=%d errno=%d",
err, errno);
goto err;
}
memset(&buf, 0, sizeof(buf));
buf.zc.address = 12345; /* rejected by BPF */
optlen = sizeof(buf.zc);
errno = 0;
err = getsockopt(fd, SOL_TCP, TCP_ZEROCOPY_RECEIVE, &buf, &optlen);
if (errno != EPERM) {
log_err("Unexpected getsockopt(TCP_ZEROCOPY_RECEIVE) err=%d errno=%d",
err, errno);
goto err;
}
free(big_buf);
close(fd);
return 0;
err:
free(big_buf);
close(fd);
return -1;
}
static void run_test(int cgroup_fd)
{
struct sockopt_sk *skel;
skel = sockopt_sk__open_and_load();
if (!ASSERT_OK_PTR(skel, "skel_load"))
goto cleanup;
skel->links._setsockopt =
bpf_program__attach_cgroup(skel->progs._setsockopt, cgroup_fd);
if (!ASSERT_OK_PTR(skel->links._setsockopt, "setsockopt_link"))
goto cleanup;
skel->links._getsockopt =
bpf_program__attach_cgroup(skel->progs._getsockopt, cgroup_fd);
if (!ASSERT_OK_PTR(skel->links._getsockopt, "getsockopt_link"))
goto cleanup;
ASSERT_OK(getsetsockopt(), "getsetsockopt");
cleanup:
sockopt_sk__destroy(skel);
}
void test_sockopt_sk(void)
{
int cgroup_fd;
cgroup_fd = test__join_cgroup("/sockopt_sk");
if (CHECK_FAIL(cgroup_fd < 0))
return;
run_test(cgroup_fd);
close(cgroup_fd);
}
|
