1 /* $OpenBSD: rresvport.c,v 1.12 2019/06/28 13:32:42 deraadt Exp $ */
2 /*
3 * Copyright (c) 1995, 1996, 1998 Theo de Raadt. All rights reserved.
4 * Copyright (c) 1983, 1993, 1994
5 * The Regents of the University of California. 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 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/socket.h>
33 #include <sys/stat.h>
34
35 #include <netinet/in.h>
36 #include <arpa/inet.h>
37
38 #include <signal.h>
39 #include <fcntl.h>
40 #include <netdb.h>
41 #include <unistd.h>
42 #include <pwd.h>
43 #include <errno.h>
44 #include <stdio.h>
45 #include <ctype.h>
46 #include <string.h>
47 #include <syslog.h>
48 #include <stdlib.h>
49 #include <netgroup.h>
50
51 int
rresvport(int * alport)52 rresvport(int *alport)
53 {
54 return rresvport_af(alport, AF_INET);
55 }
56
57
58 int
rresvport_af(int * alport,int af)59 rresvport_af(int *alport, int af)
60 {
61 struct sockaddr_storage ss;
62 struct sockaddr *sa;
63 u_int16_t *portp;
64 int s;
65
66 bzero(&ss, sizeof ss);
67 sa = (struct sockaddr *)&ss;
68
69 switch (af) {
70 case AF_INET:
71 sa->sa_len = sizeof(struct sockaddr_in);
72 portp = &((struct sockaddr_in *)sa)->sin_port;
73 break;
74 case AF_INET6:
75 sa->sa_len = sizeof(struct sockaddr_in6);
76 portp = &((struct sockaddr_in6 *)sa)->sin6_port;
77 break;
78 default:
79 errno = EPFNOSUPPORT;
80 return (-1);
81 }
82 sa->sa_family = af;
83
84 s = socket(af, SOCK_STREAM, 0);
85 if (s == -1)
86 return (-1);
87
88 *portp = htons(*alport);
89 if (*alport < IPPORT_RESERVED - 1) {
90 if (bind(s, sa, sa->sa_len) != -1)
91 return (s);
92 if (errno != EADDRINUSE) {
93 (void)close(s);
94 return (-1);
95 }
96 }
97
98 *portp = 0;
99 sa->sa_family = af;
100 if (bindresvport_sa(s, sa) == -1) {
101 (void)close(s);
102 return (-1);
103 }
104 *alport = ntohs(*portp);
105 return (s);
106 }
107 DEF_WEAK(rresvport_af);
108