xref: /linux/tools/testing/selftests/net/reuseaddr_conflict.c (revision 9b4f41684b239eedac96913270db4a5669956671)
1 /*
2  * Test for the regression introduced by
3  *
4  * b9470c27607b ("inet: kill smallest_size and smallest_port")
5  *
6  * If we open an ipv4 socket on a port with reuseaddr we shouldn't reset the tb
7  * when we open the ipv6 conterpart, which is what was happening previously.
8  */
9 #include <errno.h>
10 #include <error.h>
11 #include <arpa/inet.h>
12 #include <netinet/in.h>
13 #include <stdbool.h>
14 #include <stdio.h>
15 #include <sys/socket.h>
16 #include <sys/types.h>
17 #include <unistd.h>
18 
19 #define PORT 9999
20 
21 int open_port(int ipv6, int any)
22 {
23 	int fd = -1;
24 	int reuseaddr = 1;
25 	int v6only = 1;
26 	int addrlen;
27 	int ret = -1;
28 	struct sockaddr *addr;
29 	int family = ipv6 ? AF_INET6 : AF_INET;
30 
31 	struct sockaddr_in6 addr6 = {
32 		.sin6_family = AF_INET6,
33 		.sin6_port = htons(PORT),
34 		.sin6_addr = in6addr_any
35 	};
36 	struct sockaddr_in addr4 = {
37 		.sin_family = AF_INET,
38 		.sin_port = htons(PORT),
39 		.sin_addr.s_addr = any ? htonl(INADDR_ANY) : inet_addr("127.0.0.1"),
40 	};
41 
42 
43 	if (ipv6) {
44 		addr = (struct sockaddr*)&addr6;
45 		addrlen = sizeof(addr6);
46 	} else {
47 		addr = (struct sockaddr*)&addr4;
48 		addrlen = sizeof(addr4);
49 	}
50 
51 	if ((fd = socket(family, SOCK_STREAM, IPPROTO_TCP)) < 0) {
52 		perror("socket");
53 		goto out;
54 	}
55 
56 	if (ipv6 && setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, (void*)&v6only,
57 			       sizeof(v6only)) < 0) {
58 		perror("setsockopt IPV6_V6ONLY");
59 		goto out;
60 	}
61 
62 	if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &reuseaddr,
63 		       sizeof(reuseaddr)) < 0) {
64 		perror("setsockopt SO_REUSEADDR");
65 		goto out;
66 	}
67 
68 	if (bind(fd, addr, addrlen) < 0) {
69 		perror("bind");
70 		goto out;
71 	}
72 
73 	if (any)
74 		return fd;
75 
76 	if (listen(fd, 1) < 0) {
77 		perror("listen");
78 		goto out;
79 	}
80 	return fd;
81 out:
82 	close(fd);
83 	return ret;
84 }
85 
86 int main(void)
87 {
88 	int listenfd;
89 	int fd1, fd2;
90 
91 	fprintf(stderr, "Opening 127.0.0.1:%d\n", PORT);
92 	listenfd = open_port(0, 0);
93 	if (listenfd < 0)
94 		error(1, errno, "Couldn't open listen socket");
95 	fprintf(stderr, "Opening INADDR_ANY:%d\n", PORT);
96 	fd1 = open_port(0, 1);
97 	if (fd1 >= 0)
98 		error(1, 0, "Was allowed to create an ipv4 reuseport on a already bound non-reuseport socket");
99 	fprintf(stderr, "Opening in6addr_any:%d\n", PORT);
100 	fd1 = open_port(1, 1);
101 	if (fd1 < 0)
102 		error(1, errno, "Couldn't open ipv6 reuseport");
103 	fprintf(stderr, "Opening INADDR_ANY:%d\n", PORT);
104 	fd2 = open_port(0, 1);
105 	if (fd2 >= 0)
106 		error(1, 0, "Was allowed to create an ipv4 reuseport on a already bound non-reuseport socket");
107 	close(fd1);
108 	fprintf(stderr, "Opening INADDR_ANY:%d after closing ipv6 socket\n", PORT);
109 	fd1 = open_port(0, 1);
110 	if (fd1 >= 0)
111 		error(1, 0, "Was allowed to create an ipv4 reuseport on an already bound non-reuseport socket with no ipv6");
112 	fprintf(stderr, "Success\n");
113 	return 0;
114 }
115