xref: /freebsd/crypto/krb5/src/lib/rpc/bindresvport.c (revision 24e4dcf4ba5e9dedcf89efd358ea3e1fe5867020)
1 /* lib/rpc/bindresvport.c */
2 /*
3  * Copyright (c) 2010, Oracle America, Inc.
4  *
5  * 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 are met:
9  *
10  *     * Redistributions of source code must retain the above copyright
11  *       notice, this list of conditions and the following disclaimer.
12  *
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *
18  *     * Neither the name of the "Oracle America, Inc." nor the names of
19  *       its contributors may be used to endorse or promote products
20  *       derived from this software without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
23  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
24  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
25  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
26  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
28  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
29  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
30  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
31  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
32  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 #include <string.h>
36 #include <stdlib.h>
37 #include <stdint.h>
38 #include <unistd.h>
39 #include <sys/types.h>
40 #include <sys/errno.h>
41 #include <sys/socket.h>
42 #include <netinet/in.h>
43 #include <gssrpc/rpc.h>
44 #include <errno.h>
45 #include "socket-utils.h"
46 
47 /*
48  * Bind a socket to a privileged IP port
49  */
50 int
51 bindresvport_sa(int sd, struct sockaddr *sa)
52 {
53 	int res;
54 	static short port;
55 	struct sockaddr_storage myaddr;
56 	socklen_t salen;
57 	int i;
58 
59 #define STARTPORT 600
60 #define ENDPORT (IPPORT_RESERVED - 1)
61 #define NPORTS	(ENDPORT - STARTPORT + 1)
62 	if (sa == NULL) {
63 		salen = sizeof(myaddr);
64 		sa = ss2sa(&myaddr);
65 		res = getsockname(sd, sa, &salen);
66 		if (res < 0)
67 			return (-1);
68 	}
69 	if (!sa_is_inet(sa)) {
70 		errno = EPFNOSUPPORT;
71 		return (-1);
72 	}
73 	if (port == 0) {
74 		port = (getpid() % NPORTS) + STARTPORT;
75 	}
76 	res = -1;
77 	errno = EADDRINUSE;
78 	for (i = 0; i < NPORTS && res < 0 && errno == EADDRINUSE; i++) {
79 		sa_setport(sa, port++);
80 		if (port > ENDPORT) {
81 			port = STARTPORT;
82 		}
83 		res = bind(sd, sa, sa_socklen(sa));
84 	}
85 	return (res);
86 }
87 
88 int
89 bindresvport(int sd, struct sockaddr_in *sockin)
90 {
91 	return (bindresvport_sa(sd, (struct sockaddr *)sockin));
92 }
93