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 
sockaddrToInetAddress(JNIEnv * env,const sockaddr_storage & ss,jint * port)31 jobject 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 
inetAddressToSockaddr(JNIEnv * env,jobject inetAddress,int port,sockaddr_storage & ss,socklen_t & sa_len,bool map)91 static 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 holder6Fid = env->GetFieldID(JniConstants::inet6AddressClass,
144                                                      "holder6",
145                                                      "Ljava/net/Inet6Address$Inet6AddressHolder;");
146         ScopedLocalRef<jobject> holder6(env, env->GetObjectField(inetAddress, holder6Fid));
147         static jfieldID scopeFid = env->GetFieldID(JniConstants::inet6AddressHolderClass, "scope_id", "I");
148         sin6.sin6_scope_id = env->GetIntField(holder6.get(), scopeFid);
149         sa_len = sizeof(sockaddr_in6);
150         return true;
151     }
152 
153     // Deal with Inet4Address instances.
154     if (map) {
155         // We should represent this Inet4Address as an IPv4-mapped IPv6 sockaddr_in6.
156         // Change the family...
157         sin6.sin6_family = AF_INET6;
158         // Copy the bytes...
159         jbyte* dst = reinterpret_cast<jbyte*>(&sin6.sin6_addr.s6_addr[12]);
160         env->GetByteArrayRegion(addressBytes.get(), 0, 4, dst);
161         // INADDR_ANY and in6addr_any are both all-zeros...
162         if (!IN6_IS_ADDR_UNSPECIFIED(&sin6.sin6_addr)) {
163             // ...but all other IPv4-mapped addresses are ::ffff:a.b.c.d, so insert the ffff...
164             memset(&(sin6.sin6_addr.s6_addr[10]), 0xff, 2);
165         }
166         sa_len = sizeof(sockaddr_in6);
167     } else {
168         // We should represent this Inet4Address as an IPv4 sockaddr_in.
169         sockaddr_in& sin = reinterpret_cast<sockaddr_in&>(ss);
170         sin.sin_port = htons(port);
171         jbyte* dst = reinterpret_cast<jbyte*>(&sin.sin_addr.s_addr);
172         env->GetByteArrayRegion(addressBytes.get(), 0, 4, dst);
173         sa_len = sizeof(sockaddr_in);
174     }
175     return true;
176 }
177 
inetAddressToSockaddrVerbatim(JNIEnv * env,jobject inetAddress,int port,sockaddr_storage & ss,socklen_t & sa_len)178 bool inetAddressToSockaddrVerbatim(JNIEnv* env, jobject inetAddress, int port, sockaddr_storage& ss, socklen_t& sa_len) {
179     return inetAddressToSockaddr(env, inetAddress, port, ss, sa_len, false);
180 }
181 
inetAddressToSockaddr(JNIEnv * env,jobject inetAddress,int port,sockaddr_storage & ss,socklen_t & sa_len)182 bool inetAddressToSockaddr(JNIEnv* env, jobject inetAddress, int port, sockaddr_storage& ss, socklen_t& sa_len) {
183     return inetAddressToSockaddr(env, inetAddress, port, ss, sa_len, true);
184 }
185 
setBlocking(int fd,bool blocking)186 bool setBlocking(int fd, bool blocking) {
187     int flags = fcntl(fd, F_GETFL);
188     if (flags == -1) {
189         return false;
190     }
191 
192     if (!blocking) {
193         flags |= O_NONBLOCK;
194     } else {
195         flags &= ~O_NONBLOCK;
196     }
197 
198     int rc = fcntl(fd, F_SETFL, flags);
199     return (rc != -1);
200 }
201