1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28 #include <errno.h>
29 #include <sys/types.h>
30 #include <sys/socket.h>
31 #include <netinet/in.h>
32 #include <string.h>
33 #include <unistd.h>
34
35 #define START_PORT 600
36 #define END_PORT IPPORT_RESERVED
37 #define NUM_PORTS (END_PORT - START_PORT)
38
bindresvport(int sd,struct sockaddr_in * sin)39 int bindresvport(int sd, struct sockaddr_in *sin)
40 {
41 static short port;
42 struct sockaddr_in sin0;
43 int nn, ret;
44
45 if (sin == NULL) {
46 sin = &sin0;
47 memset( sin, 0, sizeof *sin );
48 sin->sin_family = AF_INET;
49 } else if (sin->sin_family != AF_INET) {
50 errno = EPFNOSUPPORT;
51 return -1;
52 }
53
54 if (port == 0) {
55 port = START_PORT + (getpid() % NUM_PORTS);
56 }
57
58 for (nn = NUM_PORTS; nn > 0; nn--, port++)
59 {
60 if (port == END_PORT)
61 port = START_PORT;
62
63 sin->sin_port = htons(port);
64 do {
65 ret = bind(sd, (struct sockaddr*)sin, sizeof(*sin));
66 } while (ret < 0 && errno == EINTR);
67
68 if (!ret)
69 break;
70 }
71 return ret;
72 }
73