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 
29 #include <netinet/in.h>
30 
31 #include <errno.h>
32 #include <netdb.h>
33 #include <sys/types.h>
34 #include <sys/socket.h>
35 #include <string.h>
36 #include <unistd.h>
37 
38 constexpr int START_PORT = 600;
39 constexpr int END_PORT = IPPORT_RESERVED;
40 constexpr int NUM_PORTS = (END_PORT - START_PORT);
41 
bindresvport(int sd,struct sockaddr_in * sin)42 int bindresvport(int sd, struct sockaddr_in* sin) {
43   sockaddr_in sin0;
44   if (sin == nullptr) {
45     memset(&sin0, 0, sizeof(sin0));
46     sin = &sin0;
47     sin->sin_family = AF_INET;
48   }
49 
50   if (sin->sin_family != AF_INET) {
51     errno = EPFNOSUPPORT;
52     return -1;
53   }
54 
55   // TODO: thread safety!
56   static short port;
57   if (port == 0) {
58     port = START_PORT + (getpid() % NUM_PORTS);
59   }
60 
61   for (size_t i = NUM_PORTS; i > 0; i--, port++) {
62     if (port == END_PORT) port = START_PORT;
63     sin->sin_port = htons(port);
64     int rc = TEMP_FAILURE_RETRY(bind(sd, reinterpret_cast<sockaddr*>(sin), sizeof(*sin)));
65     if (rc >= 0) return rc;
66   }
67   return -1;
68 }
69 
70 const in6_addr in6addr_any = IN6ADDR_ANY_INIT;
71 const in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
72