xref: /illumos-gate/usr/src/lib/libsocket/socket/socket.c (revision 9b9d39d2a32ff806d2431dbcc50968ef1e6d46b2)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 1990, 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 
25 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
26 /*	  All Rights Reserved   */
27 
28 /*
29  * University Copyright- Copyright (c) 1982, 1986, 1988
30  * The Regents of the University of California
31  * All Rights Reserved
32  *
33  * University Acknowledgment- Portions of this document are derived from
34  * software developed by the University of California, Berkeley, and its
35  * contributors.
36  */
37 
38 #include <sys/types.h>
39 #include <sys/socket.h>
40 #include <sys/stropts.h>
41 #include <sys/stream.h>
42 #include <sys/socketvar.h>
43 #include <errno.h>
44 #include <unistd.h>
45 #include <stdlib.h>
46 
47 extern int _so_socket();
48 extern int _s_netconfig_path();
49 extern int _setsockopt();
50 
51 int _socket_create(int, int, int, int);
52 
53 #pragma weak socket = _socket
54 
55 int
56 _socket(int family, int type, int protocol)
57 {
58 	return (_socket_create(family, type, protocol, SOV_DEFAULT));
59 }
60 
61 /*
62  * Used by the BCP library.
63  */
64 int
65 _socket_bsd(int family, int type, int protocol)
66 {
67 	return (_socket_create(family, type, protocol, SOV_SOCKBSD));
68 }
69 
70 int
71 _socket_svr4(int family, int type, int protocol)
72 {
73 	return (_socket_create(family, type, protocol, SOV_SOCKSTREAM));
74 }
75 
76 int
77 __xnet_socket(int family, int type, int protocol)
78 {
79 	return (_socket_create(family, type, protocol, SOV_XPG4_2));
80 }
81 
82 /*
83  * Create a socket endpoint for socket() and socketpair().
84  * In SunOS 4.X and in SunOS 5.X prior to XPG 4.2 the only error
85  * that could be returned due to invalid <family, type, protocol>
86  * was EPROTONOSUPPORT. (While the SunOS 4.X source contains EPROTOTYPE
87  * error as well that error can only be generated if the kernel is
88  * incorrectly configured.)
89  * For backwards compatibility only applications that request XPG 4.2
90  * (through c89 or XOPEN_SOURCE) will get EPROTOTYPE or EAFNOSUPPORT errors.
91  */
92 int
93 _socket_create(int family, int type, int protocol, int version)
94 {
95 	int fd;
96 
97 	/*
98 	 * Try creating without knowing the device assuming that
99 	 * the transport provider is registered in /etc/sock2path.d.
100 	 * If none found fall back to using /etc/netconfig to look
101 	 * up the name of the transport device name. This provides
102 	 * backwards compatibility for transport providers that have not
103 	 * yet been converted to using /etc/sock2path.d.
104 	 * XXX When all transport providers use /etc/sock2path.d. this
105 	 * part of the code can be removed.
106 	 */
107 	fd = _so_socket(family, type, protocol, NULL, version);
108 	if (fd == -1) {
109 		char *devpath;
110 		int saved_errno = errno;
111 		int prototype = 0;
112 
113 		switch (saved_errno) {
114 		case EAFNOSUPPORT:
115 		case EPROTOTYPE:
116 			if (version != SOV_XPG4_2)
117 				saved_errno = EPROTONOSUPPORT;
118 			break;
119 		case EPROTONOSUPPORT:
120 			break;
121 
122 		default:
123 			errno = saved_errno;
124 			return (-1);
125 		}
126 		if (_s_netconfig_path(family, type, protocol,
127 		    &devpath, &prototype) == -1) {
128 			errno = saved_errno;
129 			return (-1);
130 		}
131 		fd = _so_socket(family, type, protocol, devpath, version);
132 		free(devpath);
133 		if (fd == -1) {
134 			errno = saved_errno;
135 			return (-1);
136 		}
137 		if (prototype != 0) {
138 			if (_setsockopt(fd, SOL_SOCKET, SO_PROTOTYPE,
139 			    (caddr_t)&prototype, (int)sizeof (prototype)) < 0) {
140 				(void) close(fd);
141 				/*
142 				 * setsockopt often fails with ENOPROTOOPT
143 				 * but socket() should fail with
144 				 * EPROTONOSUPPORT.
145 				 */
146 				errno = EPROTONOSUPPORT;
147 				return (-1);
148 			}
149 		}
150 	}
151 	return (fd);
152 }
153