1 /*
2  * Copyright (C) 2014 Linux Test Project, Inc.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of version 2 of the GNU General Public
6  * License as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it would be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
11  *
12  * Further, this software is distributed without any warranty that it
13  * is free of the rightful claim of any third person regarding
14  * infringement or the like.  Any license provided herein, whether
15  * implied or otherwise, applies only to this software file.  Patent
16  * licenses, if any, provided herein do not apply to combinations of
17  * this program with other software, or any other product whatsoever.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write the Free Software Foundation, Inc.
21  */
22 
23 #include <sys/types.h>
24 #include <sys/socket.h>
25 #include <netinet/in.h>
26 
27 #include "test.h"
28 
29 unsigned short tst_get_unused_port(void (cleanup_fn)(void),
30 	unsigned short family, int type)
31 {
32 	int sock;
33 	socklen_t slen;
34 	struct sockaddr_storage _addr;
35 	struct sockaddr *addr = (struct sockaddr *)&_addr;
36 	struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
37 	struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
38 
39 	switch (family) {
40 	case AF_INET:
41 		addr4->sin_family = AF_INET;
42 		addr4->sin_port = 0;
43 		addr4->sin_addr.s_addr = INADDR_ANY;
44 		slen = sizeof(*addr4);
45 		break;
46 
47 	case AF_INET6:
48 		addr6->sin6_family = AF_INET6;
49 		addr6->sin6_port = 0;
50 		addr6->sin6_addr = in6addr_any;
51 		slen = sizeof(*addr6);
52 		break;
53 
54 	default:
55 		tst_brkm(TBROK, cleanup_fn,
56 			"tst_get_unused_port unknown family");
57 		return -1;
58 	}
59 
60 	sock = socket(addr->sa_family, type, 0);
61 	if (sock < 0) {
62 		tst_brkm(TBROK | TERRNO, cleanup_fn, "socket failed");
63 		return -1;
64 	}
65 
66 	if (bind(sock, addr, slen) < 0) {
67 		tst_brkm(TBROK | TERRNO, cleanup_fn, "bind failed");
68 		return -1;
69 	}
70 
71 	if (getsockname(sock, addr, &slen) == -1) {
72 		tst_brkm(TBROK | TERRNO, cleanup_fn, "getsockname failed");
73 		return -1;
74 	}
75 
76 	if (close(sock) == -1) {
77 		tst_brkm(TBROK | TERRNO, cleanup_fn, "close failed");
78 		return -1;
79 	}
80 
81 	switch (family) {
82 	case AF_INET:
83 		return addr4->sin_port;
84 	case AF_INET6:
85 		return addr6->sin6_port;
86 	default:
87 		return -1;
88 	}
89 }
90