NetworkUtilities.cpp revision d8cec780b3b5177b5c1e500ea606f731a67fb53c 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#define LOG_TAG "NetworkUtilities"
18
19#include "NetworkUtilities.h"
20#include "JNIHelp.h"
21#include "JniConstants.h"
22#include "ScopedLocalRef.h"
23
24#include <arpa/inet.h>
25#include <fcntl.h>
26#include <stdio.h>
27#include <string.h>
28#include <sys/socket.h>
29
30jobject sockaddrToInetAddress(JNIEnv* env, const sockaddr_storage* ss, jint* port) {
31    // Convert IPv4-mapped IPv6 addresses to IPv4 addresses.
32    // The RI states "Java will never return an IPv4-mapped address".
33    sockaddr_storage tmp;
34    memset(&tmp, 0, sizeof(tmp));
35    const sockaddr_in6* sin6 = reinterpret_cast<const sockaddr_in6*>(ss);
36    if (ss->ss_family == AF_INET6 && IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
37        // Copy the IPv6 address into the temporary sockaddr_storage.
38        memcpy(&tmp, ss, sizeof(tmp));
39        // Unmap it into an IPv4 address.
40        sockaddr_in* sin = reinterpret_cast<sockaddr_in*>(&tmp);
41        sin->sin_family = AF_INET;
42        sin->sin_port = sin6->sin6_port;
43        memcpy(&sin->sin_addr.s_addr, &sin6->sin6_addr.s6_addr[12], 4);
44        // Fall through into the regular conversion using the unmapped address.
45        ss = &tmp;
46    }
47
48    const void* rawAddress;
49    size_t addressLength;
50    int sin_port;
51    int scope_id = 0;
52    if (ss->ss_family == AF_INET) {
53        const sockaddr_in* sin = reinterpret_cast<const sockaddr_in*>(ss);
54        rawAddress = &sin->sin_addr.s_addr;
55        addressLength = 4;
56        sin_port = ntohs(sin->sin_port);
57    } else if (ss->ss_family == AF_INET6) {
58        const sockaddr_in6* sin6 = reinterpret_cast<const sockaddr_in6*>(ss);
59        rawAddress = &sin6->sin6_addr.s6_addr;
60        addressLength = 16;
61        sin_port = ntohs(sin6->sin6_port);
62        scope_id = sin6->sin6_scope_id;
63    } else {
64        // We can't throw SocketException. We aren't meant to see bad addresses, so seeing one
65        // really does imply an internal error.
66        jniThrowExceptionFmt(env, "java/lang/IllegalArgumentException",
67                "sockaddrToInetAddress bad ss_family: %i", ss->ss_family);
68        return NULL;
69    }
70    if (port != NULL) {
71        *port = sin_port;
72    }
73
74    ScopedLocalRef<jbyteArray> byteArray(env, env->NewByteArray(addressLength));
75    if (byteArray.get() == NULL) {
76        return NULL;
77    }
78    env->SetByteArrayRegion(byteArray.get(), 0, addressLength,
79            reinterpret_cast<const jbyte*>(rawAddress));
80
81    static jmethodID getByAddressMethod = env->GetStaticMethodID(JniConstants::inetAddressClass,
82            "getByAddress", "(Ljava/lang/String;[BI)Ljava/net/InetAddress;");
83    if (getByAddressMethod == NULL) {
84        return NULL;
85    }
86    return env->CallStaticObjectMethod(JniConstants::inetAddressClass, getByAddressMethod,
87            NULL, byteArray.get(), scope_id);
88}
89
90static bool inetAddressToSockaddr(JNIEnv* env, jobject inetAddress, int port, sockaddr_storage* ss, bool map) {
91    memset(ss, 0, sizeof(*ss));
92
93    if (inetAddress == NULL) {
94        jniThrowNullPointerException(env, NULL);
95        return false;
96    }
97
98    // Get the address family.
99    static jfieldID familyFid = env->GetFieldID(JniConstants::inetAddressClass, "family", "I");
100    ss->ss_family = env->GetIntField(inetAddress, familyFid);
101    if (ss->ss_family == AF_UNSPEC) {
102        return true; // Job done!
103    }
104
105    // Check this is an address family we support.
106    if (ss->ss_family != AF_INET && ss->ss_family != AF_INET6) {
107        jniThrowExceptionFmt(env, "java/lang/IllegalArgumentException",
108                "inetAddressToSockaddr bad family: %i", ss->ss_family);
109        return false;
110    }
111
112    // Get the byte array that stores the IP address bytes in the InetAddress.
113    static jfieldID bytesFid = env->GetFieldID(JniConstants::inetAddressClass, "ipaddress", "[B");
114    ScopedLocalRef<jbyteArray> addressBytes(env, reinterpret_cast<jbyteArray>(env->GetObjectField(inetAddress, bytesFid)));
115    if (addressBytes.get() == NULL) {
116        jniThrowNullPointerException(env, NULL);
117        return false;
118    }
119
120    // We use AF_INET6 sockets, so we want an IPv6 address (which may be a IPv4-mapped address).
121    sockaddr_in6* sin6 = reinterpret_cast<sockaddr_in6*>(ss);
122    sin6->sin6_port = htons(port);
123    if (ss->ss_family == AF_INET6) {
124        // IPv6 address. Copy the bytes...
125        jbyte* dst = reinterpret_cast<jbyte*>(&sin6->sin6_addr.s6_addr);
126        env->GetByteArrayRegion(addressBytes.get(), 0, 16, dst);
127        // ...and set the scope id...
128        static jfieldID scopeFid = env->GetFieldID(JniConstants::inet6AddressClass, "scope_id", "I");
129        sin6->sin6_scope_id = env->GetIntField(inetAddress, scopeFid);
130        return true;
131    }
132
133    // Deal with Inet4Address instances.
134    if (map) {
135        // We should represent this Inet4Address as an IPv4-mapped IPv6 sockaddr_in6.
136        // Change the family...
137        sin6->sin6_family = AF_INET6;
138        // Copy the bytes...
139        jbyte* dst = reinterpret_cast<jbyte*>(&sin6->sin6_addr.s6_addr[12]);
140        env->GetByteArrayRegion(addressBytes.get(), 0, 4, dst);
141        // INADDR_ANY and in6addr_any are both all-zeros...
142        if (!IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
143            // ...but all other IPv4-mapped addresses are ::ffff:a.b.c.d, so insert the ffff...
144            memset(&(sin6->sin6_addr.s6_addr[10]), 0xff, 2);
145        }
146    } else {
147        // We should represent this Inet4Address as an IPv4 sockaddr_in.
148        sockaddr_in* sin = reinterpret_cast<sockaddr_in*>(ss);
149        sin->sin_port = htons(port);
150        jbyte* dst = reinterpret_cast<jbyte*>(&sin->sin_addr.s_addr);
151        env->GetByteArrayRegion(addressBytes.get(), 0, 4, dst);
152    }
153    return true;
154}
155
156bool inetAddressToSockaddrVerbatim(JNIEnv* env, jobject inetAddress, int port, sockaddr_storage* ss) {
157    return inetAddressToSockaddr(env, inetAddress, port, ss, false);
158}
159
160bool inetAddressToSockaddr(JNIEnv* env, jobject inetAddress, int port, sockaddr_storage* ss) {
161    return inetAddressToSockaddr(env, inetAddress, port, ss, true);
162}
163
164bool setBlocking(int fd, bool blocking) {
165    int flags = fcntl(fd, F_GETFL);
166    if (flags == -1) {
167        return false;
168    }
169
170    if (!blocking) {
171        flags |= O_NONBLOCK;
172    } else {
173        flags &= ~O_NONBLOCK;
174    }
175
176    int rc = fcntl(fd, F_SETFL, flags);
177    return (rc != -1);
178}
179