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
| | // SPDX-License-Identifier: GPL-2.0-or-later
/* udp-close-dup.c
*
* Verify that closing one dup() of a UDP socket won't stop other dups from
* receiving packets.
*
* Copyright Red Hat
* Author: David Gibson <david@gibson.dropbear.id.au>
*/
#include <arpa/inet.h>
#include <errno.h>
#include <fcntl.h>
#include <net/if.h>
#include <netinet/in.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "common.h"
#define DSTPORT 13257U
/* 127.0.0.1:DSTPORT */
static const struct sockaddr_in lo_dst = SOCKADDR_INIT(INADDR_LOOPBACK, DSTPORT);
enum dup_method {
DUP_DUP,
DUP_FCNTL,
NUM_METHODS,
};
static void test_close_dup(enum dup_method method)
{
long token;
int s1, s2, send_s;
ssize_t rc;
s1 = sock_reuseaddr();
if (bind(s1, (struct sockaddr *)&lo_dst, sizeof(lo_dst)) < 0)
die("bind(): %s\n", strerror(errno));
send_s = sock_reuseaddr();
if (connect(send_s, (struct sockaddr *)&lo_dst, sizeof(lo_dst)) < 0)
die("connect(): %s\n", strerror(errno));
/* Receive before duplicating */
token = random();
send_token(send_s, token);
recv_token(s1, token);
switch (method) {
case DUP_DUP:
/* NOLINTNEXTLINE(android-cloexec-dup) */
s2 = dup(s1);
if (s2 < 0)
die("dup(): %s\n", strerror(errno));
break;
case DUP_FCNTL:
s2 = fcntl(s1, F_DUPFD_CLOEXEC, 0);
if (s2 < 0)
die("F_DUPFD_CLOEXEC: %s\n", strerror(errno));
break;
default:
die("Bad method\n");
}
/* Receive via original handle */
token = random();
send_token(send_s, token);
recv_token(s1, token);
/* Receive via duplicated handle */
token = random();
send_token(send_s, token);
recv_token(s2, token);
/* Close duplicate */
rc = close(s2);
if (rc < 0)
die("close() dup: %s\n", strerror(errno));
/* Receive after closing duplicate */
token = random();
send_token(send_s, token);
recv_token(s1, token);
}
int main(int argc, char *argv[])
{
enum dup_method method;
(void)argc;
(void)argv;
for (method = 0; method < NUM_METHODS; method++)
test_close_dup(method);
printf("Closing dup()ed UDP sockets seems to work as expected\n");
exit(0);
}
|