1 | /* |
2 | * Copyright (c) 2010, Oracle America, Inc. |
3 | * |
4 | * Redistribution and use in source and binary forms, with or without |
5 | * modification, are permitted provided that the following conditions are |
6 | * met: |
7 | * |
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 |
11 | * copyright notice, this list of conditions and the following |
12 | * disclaimer in the documentation and/or other materials |
13 | * provided with the distribution. |
14 | * * Neither the name of the "Oracle America, Inc." nor the names of its |
15 | * contributors may be used to endorse or promote products derived |
16 | * from this software without specific prior written permission. |
17 | * |
18 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
19 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
20 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
21 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
22 | * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, |
23 | * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
24 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE |
25 | * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
27 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
28 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
29 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
30 | */ |
31 | |
32 | #include <errno.h> |
33 | #include <unistd.h> |
34 | #include <string.h> |
35 | #include <sys/types.h> |
36 | #include <sys/socket.h> |
37 | #include <netinet/in.h> |
38 | #include <libc-lock.h> |
39 | |
40 | /* |
41 | * Locks the static variables in this file. |
42 | */ |
43 | __libc_lock_define_initialized (static, lock); |
44 | |
45 | /* |
46 | * Bind a socket to a privileged IP port |
47 | */ |
48 | int |
49 | bindresvport (int sd, struct sockaddr_in *sin) |
50 | { |
51 | static short port; |
52 | struct sockaddr_in myaddr; |
53 | int i; |
54 | |
55 | #define STARTPORT 600 |
56 | #define LOWPORT 512 |
57 | #define ENDPORT (IPPORT_RESERVED - 1) |
58 | #define NPORTS (ENDPORT - STARTPORT + 1) |
59 | static short startport = STARTPORT; |
60 | |
61 | if (sin == (struct sockaddr_in *) 0) |
62 | { |
63 | sin = &myaddr; |
64 | __bzero (sin, sizeof (*sin)); |
65 | sin->sin_family = AF_INET; |
66 | } |
67 | else if (sin->sin_family != AF_INET) |
68 | { |
69 | __set_errno (EAFNOSUPPORT); |
70 | return -1; |
71 | } |
72 | |
73 | if (port == 0) |
74 | { |
75 | port = (__getpid () % NPORTS) + STARTPORT; |
76 | } |
77 | |
78 | /* Initialize to make gcc happy. */ |
79 | int res = -1; |
80 | |
81 | int nports = ENDPORT - startport + 1; |
82 | int endport = ENDPORT; |
83 | |
84 | __libc_lock_lock (lock); |
85 | |
86 | again: |
87 | for (i = 0; i < nports; ++i) |
88 | { |
89 | sin->sin_port = htons (port++); |
90 | if (port > endport) |
91 | port = startport; |
92 | res = __bind (sd, sin, sizeof (struct sockaddr_in)); |
93 | if (res >= 0 || errno != EADDRINUSE) |
94 | break; |
95 | } |
96 | |
97 | if (i == nports && startport != LOWPORT) |
98 | { |
99 | startport = LOWPORT; |
100 | endport = STARTPORT - 1; |
101 | nports = STARTPORT - LOWPORT; |
102 | port = LOWPORT + port % (STARTPORT - LOWPORT); |
103 | goto again; |
104 | } |
105 | |
106 | __libc_lock_unlock (lock); |
107 | |
108 | return res; |
109 | } |
110 | libc_hidden_def (bindresvport) |
111 | |