1 /*
2  * Copyright (c) 2009, 2020, Oracle and/or its affiliates. All rights reserved.
3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4  *
5  * This code is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License version 2 only, as
7  * published by the Free Software Foundation.  Oracle designates this
8  * particular file as subject to the "Classpath" exception as provided
9  * by Oracle in the LICENSE file that accompanied this code.
10  *
11  * This code is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14  * version 2 for more details (a copy is included in the LICENSE file that
15  * accompanied this code).
16  *
17  * You should have received a copy of the GNU General Public License version
18  * 2 along with this work; if not, write to the Free Software Foundation,
19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20  *
21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22  * or visit www.oracle.com if you need additional information or have any
23  * questions.
24  */
25 
26 #include <sys/types.h>
27 #include <sys/socket.h>
28 #include <errno.h>
29 
30 #if defined(__linux__)
31   #if !defined(AF_INET_SDP)
32     #define AF_INET_SDP     27
33   #endif
34 #endif
35 
36 #include "jni.h"
37 #include "jni_util.h"
38 #include "net_util.h"
39 
40 #define RESTARTABLE(_cmd, _result) do { \
41   do { \
42     _result = _cmd; \
43   } while((_result == -1) && (errno == EINTR)); \
44 } while(0)
45 
46 
47 /**
48  * Creates a SDP socket.
49  */
create(JNIEnv * env)50 static int create(JNIEnv* env)
51 {
52     int s;
53 
54 #if defined(__linux__)
55     /**
56      * IPv6 not supported by SDP on Linux
57      */
58     if (ipv6_available()) {
59         JNU_ThrowIOException(env, "IPv6 not supported");
60         return -1;
61     }
62     s = socket(AF_INET_SDP, SOCK_STREAM, 0);
63 #else
64     /* not supported on other platforms at this time */
65     s = -1;
66     errno = EPROTONOSUPPORT;
67 #endif
68 
69     if (s < 0)
70         JNU_ThrowIOExceptionWithLastError(env, "socket");
71     return s;
72 }
73 
74 /**
75  * Creates a SDP socket, returning file descriptor referencing the socket.
76  */
77 JNIEXPORT jint JNICALL
Java_sun_net_sdp_SdpSupport_create0(JNIEnv * env,jclass cls)78 Java_sun_net_sdp_SdpSupport_create0(JNIEnv *env, jclass cls)
79 {
80     return create(env);
81 }
82 
83 /**
84  * Converts an existing file descriptor, that references an unbound TCP socket,
85  * to SDP.
86  */
87 JNIEXPORT void JNICALL
Java_sun_net_sdp_SdpSupport_convert0(JNIEnv * env,jclass cls,int fd)88 Java_sun_net_sdp_SdpSupport_convert0(JNIEnv *env, jclass cls, int fd)
89 {
90     int s = create(env);
91     if (s >= 0) {
92         socklen_t len;
93         int arg, res;
94         struct linger linger;
95 
96         /* copy socket options that are relevant to SDP */
97         len = sizeof(arg);
98         if (getsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char*)&arg, &len) == 0)
99             setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char*)&arg, len);
100 #ifdef SO_REUSEPORT
101         len = sizeof(arg);
102         if (getsockopt(fd, SOL_SOCKET, SO_REUSEPORT, (char*)&arg, &len) == 0)
103             setsockopt(s, SOL_SOCKET, SO_REUSEPORT, (char*)&arg, len);
104 #endif
105         len = sizeof(arg);
106         if (getsockopt(fd, SOL_SOCKET, SO_OOBINLINE, (char*)&arg, &len) == 0)
107             setsockopt(s, SOL_SOCKET, SO_OOBINLINE, (char*)&arg, len);
108         len = sizeof(linger);
109         if (getsockopt(fd, SOL_SOCKET, SO_LINGER, (void*)&linger, &len) == 0)
110             setsockopt(s, SOL_SOCKET, SO_LINGER, (char*)&linger, len);
111 
112         RESTARTABLE(dup2(s, fd), res);
113         if (res < 0)
114             JNU_ThrowIOExceptionWithLastError(env, "dup2");
115         res = close(s);
116         if (res < 0 && !(*env)->ExceptionOccurred(env))
117             JNU_ThrowIOExceptionWithLastError(env, "close");
118     }
119 }
120