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#include <sys/un.h>
30
31jobject sockaddrToInetAddress(JNIEnv* env, const sockaddr_storage& ss, jint* port) {
32    // Convert IPv4-mapped IPv6 addresses to IPv4 addresses.
33    // The RI states "Java will never return an IPv4-mapped address".
34    const sockaddr_in6& sin6 = reinterpret_cast<const sockaddr_in6&>(ss);
35    if (ss.ss_family == AF_INET6 && IN6_IS_ADDR_V4MAPPED(&sin6.sin6_addr)) {
36        // Copy the IPv6 address into the temporary sockaddr_storage.
37        sockaddr_storage tmp;
38        memset(&tmp, 0, sizeof(tmp));
39        memcpy(&tmp, &ss, sizeof(sockaddr_in6));
40        // Unmap it into an IPv4 address.
41        sockaddr_in& sin = reinterpret_cast<sockaddr_in&>(tmp);
42        sin.sin_family = AF_INET;
43        sin.sin_port = sin6.sin6_port;
44        memcpy(&sin.sin_addr.s_addr, &sin6.sin6_addr.s6_addr[12], 4);
45        // Do the regular conversion using the unmapped address.
46        return sockaddrToInetAddress(env, tmp, port);
47    }
48
49    const void* rawAddress;
50    size_t addressLength;
51    int sin_port = 0;
52    int scope_id = 0;
53    if (ss.ss_family == AF_INET) {
54        const sockaddr_in& sin = reinterpret_cast<const sockaddr_in&>(ss);
55        rawAddress = &sin.sin_addr.s_addr;
56        addressLength = 4;
57        sin_port = ntohs(sin.sin_port);
58    } else if (ss.ss_family == AF_INET6) {
59        const sockaddr_in6& sin6 = reinterpret_cast<const sockaddr_in6&>(ss);
60        rawAddress = &sin6.sin6_addr.s6_addr;
61        addressLength = 16;
62        sin_port = ntohs(sin6.sin6_port);
63        scope_id = sin6.sin6_scope_id;
64    } else {
65        // We can't throw SocketException. We aren't meant to see bad addresses, so seeing one
66        // really does imply an internal error.
67        jniThrowExceptionFmt(env, "java/lang/IllegalArgumentException",
68                             "sockaddrToInetAddress unsupported ss_family: %i", ss.ss_family);
69        return NULL;
70    }
71    if (port != NULL) {
72        *port = sin_port;
73    }
74
75    ScopedLocalRef<jbyteArray> byteArray(env, env->NewByteArray(addressLength));
76    if (byteArray.get() == NULL) {
77        return NULL;
78    }
79    env->SetByteArrayRegion(byteArray.get(), 0, addressLength,
80            reinterpret_cast<const jbyte*>(rawAddress));
81
82    static jmethodID getByAddressMethod = env->GetStaticMethodID(JniConstants::inetAddressClass,
83            "getByAddress", "(Ljava/lang/String;[BI)Ljava/net/InetAddress;");
84    if (getByAddressMethod == NULL) {
85        return NULL;
86    }
87    return env->CallStaticObjectMethod(JniConstants::inetAddressClass, getByAddressMethod,
88            NULL, byteArray.get(), scope_id);
89}
90
91static bool inetAddressToSockaddr(JNIEnv* env, jobject inetAddress, int port, sockaddr_storage& ss, socklen_t& sa_len, bool map) {
92    memset(&ss, 0, sizeof(ss));
93    sa_len = 0;
94
95    if (inetAddress == NULL) {
96        jniThrowNullPointerException(env, NULL);
97        return false;
98    }
99
100    // Get holder.
101    static jfieldID holderFid = env->GetFieldID(JniConstants::inetAddressClass, "holder", "Ljava/net/InetAddress$InetAddressHolder;");
102    ScopedLocalRef<jobject> holder(env, env->GetObjectField(inetAddress, holderFid));
103    // Get the address family.
104    static jfieldID familyFid = env->GetFieldID(JniConstants::inetAddressHolderClass, "family", "I");
105    ss.ss_family = env->GetIntField(holder.get(), familyFid);
106    if (ss.ss_family == AF_UNSPEC) {
107        sa_len = sizeof(ss.ss_family);
108        return true; // Job done!
109    }
110
111    // Check this is an address family we support.
112    if (ss.ss_family != AF_INET && ss.ss_family != AF_INET6) {
113        jniThrowExceptionFmt(env, "java/lang/IllegalArgumentException",
114                "inetAddressToSockaddr bad family: %i", ss.ss_family);
115        return false;
116    }
117
118    // Get the byte array that stores the IP address bytes in the InetAddress.
119    static jmethodID bytesMid = env->GetMethodID(JniConstants::inetAddressClass, "getAddress", "()[B");
120    ScopedLocalRef<jbyteArray> addressBytes(env, reinterpret_cast<jbyteArray>(env->CallObjectMethod(inetAddress, bytesMid)));
121    if (env->ExceptionCheck()) {
122        return false;
123    }
124    if (addressBytes.get() == NULL) {
125        jniThrowNullPointerException(env, NULL);
126        return false;
127    }
128
129    // TODO: bionic's getnameinfo(3) seems to want its length parameter to be exactly
130    // sizeof(sockaddr_in) for an IPv4 address and sizeof (sockaddr_in6) for an
131    // IPv6 address. Fix getnameinfo so it accepts sizeof(sockaddr_storage), and
132    // then unconditionally set sa_len to sizeof(sockaddr_storage) instead of having
133    // to deal with this case by case.
134
135    // We use AF_INET6 sockets, so we want an IPv6 address (which may be a IPv4-mapped address).
136    sockaddr_in6& sin6 = reinterpret_cast<sockaddr_in6&>(ss);
137    sin6.sin6_port = htons(port);
138    if (ss.ss_family == AF_INET6) {
139        // IPv6 address. Copy the bytes...
140        jbyte* dst = reinterpret_cast<jbyte*>(&sin6.sin6_addr.s6_addr);
141        env->GetByteArrayRegion(addressBytes.get(), 0, 16, dst);
142        // ...and set the scope id...
143        static jfieldID scopeFid = env->GetFieldID(JniConstants::inet6AddressClass, "scope_id", "I");
144        sin6.sin6_scope_id = env->GetIntField(inetAddress, scopeFid);
145        sa_len = sizeof(sockaddr_in6);
146        return true;
147    }
148
149    // Deal with Inet4Address instances.
150    if (map) {
151        // We should represent this Inet4Address as an IPv4-mapped IPv6 sockaddr_in6.
152        // Change the family...
153        sin6.sin6_family = AF_INET6;
154        // Copy the bytes...
155        jbyte* dst = reinterpret_cast<jbyte*>(&sin6.sin6_addr.s6_addr[12]);
156        env->GetByteArrayRegion(addressBytes.get(), 0, 4, dst);
157        // INADDR_ANY and in6addr_any are both all-zeros...
158        if (!IN6_IS_ADDR_UNSPECIFIED(&sin6.sin6_addr)) {
159            // ...but all other IPv4-mapped addresses are ::ffff:a.b.c.d, so insert the ffff...
160            memset(&(sin6.sin6_addr.s6_addr[10]), 0xff, 2);
161        }
162        sa_len = sizeof(sockaddr_in6);
163    } else {
164        // We should represent this Inet4Address as an IPv4 sockaddr_in.
165        sockaddr_in& sin = reinterpret_cast<sockaddr_in&>(ss);
166        sin.sin_port = htons(port);
167        jbyte* dst = reinterpret_cast<jbyte*>(&sin.sin_addr.s_addr);
168        env->GetByteArrayRegion(addressBytes.get(), 0, 4, dst);
169        sa_len = sizeof(sockaddr_in);
170    }
171    return true;
172}
173
174bool inetAddressToSockaddrVerbatim(JNIEnv* env, jobject inetAddress, int port, sockaddr_storage& ss, socklen_t& sa_len) {
175    return inetAddressToSockaddr(env, inetAddress, port, ss, sa_len, false);
176}
177
178bool inetAddressToSockaddr(JNIEnv* env, jobject inetAddress, int port, sockaddr_storage& ss, socklen_t& sa_len) {
179    return inetAddressToSockaddr(env, inetAddress, port, ss, sa_len, true);
180}
181
182bool setBlocking(int fd, bool blocking) {
183    int flags = fcntl(fd, F_GETFL);
184    if (flags == -1) {
185        return false;
186    }
187
188    if (!blocking) {
189        flags |= O_NONBLOCK;
190    } else {
191        flags &= ~O_NONBLOCK;
192    }
193
194    int rc = fcntl(fd, F_SETFL, flags);
195    return (rc != -1);
196}
197