1 |
|
|
/* $OpenBSD: bindresvport.c,v 1.18 2015/09/14 11:01:47 guenther Exp $ */ |
2 |
|
|
|
3 |
|
|
/* |
4 |
|
|
* Copyright 1996, Jason Downs. All rights reserved. |
5 |
|
|
* Copyright 1998, Theo de Raadt. All rights reserved. |
6 |
|
|
* |
7 |
|
|
* Redistribution and use in source and binary forms, with or without |
8 |
|
|
* modification, are permitted provided that the following conditions |
9 |
|
|
* are met: |
10 |
|
|
* 1. Redistributions of source code must retain the above copyright |
11 |
|
|
* notice, this list of conditions and the following disclaimer. |
12 |
|
|
* 2. Redistributions in binary form must reproduce the above copyright |
13 |
|
|
* notice, this list of conditions and the following disclaimer in the |
14 |
|
|
* documentation and/or other materials provided with the distribution. |
15 |
|
|
* |
16 |
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
17 |
|
|
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
18 |
|
|
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
19 |
|
|
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
20 |
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
21 |
|
|
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
22 |
|
|
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
23 |
|
|
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
24 |
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
25 |
|
|
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
26 |
|
|
*/ |
27 |
|
|
|
28 |
|
|
#include <errno.h> |
29 |
|
|
#include <string.h> |
30 |
|
|
#include <sys/types.h> |
31 |
|
|
#include <sys/socket.h> |
32 |
|
|
#include <netinet/in.h> |
33 |
|
|
|
34 |
|
|
/* |
35 |
|
|
* Bind a socket to a privileged IP port |
36 |
|
|
*/ |
37 |
|
|
int |
38 |
|
|
bindresvport(int sd, struct sockaddr_in *sin) |
39 |
|
|
{ |
40 |
|
|
return bindresvport_sa(sd, (struct sockaddr *)sin); |
41 |
|
|
} |
42 |
|
|
DEF_WEAK(bindresvport); |
43 |
|
|
|
44 |
|
|
/* |
45 |
|
|
* Bind a socket to a privileged port for whatever protocol. |
46 |
|
|
*/ |
47 |
|
|
int |
48 |
|
|
bindresvport_sa(int sd, struct sockaddr *sa) |
49 |
|
|
{ |
50 |
|
|
int old, error, af; |
51 |
|
|
struct sockaddr_storage myaddr; |
52 |
|
|
struct sockaddr_in *sin; |
53 |
|
|
struct sockaddr_in6 *sin6; |
54 |
|
|
int proto, portrange, portlow; |
55 |
|
|
u_int16_t port; |
56 |
|
|
socklen_t salen; |
57 |
|
|
|
58 |
|
|
if (sa == NULL) { |
59 |
|
|
salen = sizeof(myaddr); |
60 |
|
|
sa = (struct sockaddr *)&myaddr; |
61 |
|
|
|
62 |
|
|
if (getsockname(sd, sa, &salen) == -1) |
63 |
|
|
return -1; /* errno is correctly set */ |
64 |
|
|
|
65 |
|
|
af = sa->sa_family; |
66 |
|
|
memset(&myaddr, 0, salen); |
67 |
|
|
} else |
68 |
|
|
af = sa->sa_family; |
69 |
|
|
|
70 |
|
|
if (af == AF_INET) { |
71 |
|
|
proto = IPPROTO_IP; |
72 |
|
|
portrange = IP_PORTRANGE; |
73 |
|
|
portlow = IP_PORTRANGE_LOW; |
74 |
|
|
sin = (struct sockaddr_in *)sa; |
75 |
|
|
salen = sizeof(struct sockaddr_in); |
76 |
|
|
port = sin->sin_port; |
77 |
|
|
} else if (af == AF_INET6) { |
78 |
|
|
proto = IPPROTO_IPV6; |
79 |
|
|
portrange = IPV6_PORTRANGE; |
80 |
|
|
portlow = IPV6_PORTRANGE_LOW; |
81 |
|
|
sin6 = (struct sockaddr_in6 *)sa; |
82 |
|
|
salen = sizeof(struct sockaddr_in6); |
83 |
|
|
port = sin6->sin6_port; |
84 |
|
|
} else { |
85 |
|
|
errno = EPFNOSUPPORT; |
86 |
|
|
return (-1); |
87 |
|
|
} |
88 |
|
|
sa->sa_family = af; |
89 |
|
|
sa->sa_len = salen; |
90 |
|
|
|
91 |
|
|
if (port == 0) { |
92 |
|
|
socklen_t oldlen = sizeof(old); |
93 |
|
|
|
94 |
|
|
error = getsockopt(sd, proto, portrange, &old, &oldlen); |
95 |
|
|
if (error < 0) |
96 |
|
|
return (error); |
97 |
|
|
|
98 |
|
|
error = setsockopt(sd, proto, portrange, &portlow, |
99 |
|
|
sizeof(portlow)); |
100 |
|
|
if (error < 0) |
101 |
|
|
return (error); |
102 |
|
|
} |
103 |
|
|
|
104 |
|
|
error = bind(sd, sa, salen); |
105 |
|
|
|
106 |
|
|
if (port == 0) { |
107 |
|
|
int saved_errno = errno; |
108 |
|
|
|
109 |
|
|
if (error) { |
110 |
|
|
if (setsockopt(sd, proto, portrange, &old, |
111 |
|
|
sizeof(old)) < 0) |
112 |
|
|
errno = saved_errno; |
113 |
|
|
return (error); |
114 |
|
|
} |
115 |
|
|
|
116 |
|
|
if (sa != (struct sockaddr *)&myaddr) { |
117 |
|
|
/* Hmm, what did the kernel assign... */ |
118 |
|
|
if (getsockname(sd, sa, &salen) < 0) |
119 |
|
|
errno = saved_errno; |
120 |
|
|
return (error); |
121 |
|
|
} |
122 |
|
|
} |
123 |
|
|
return (error); |
124 |
|
|
} |
125 |
|
|
DEF_WEAK(bindresvport_sa); |