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 if (ss.ss_family == AF_UNIX) {
65        const sockaddr_un& sun = reinterpret_cast<const sockaddr_un&>(ss);
66        rawAddress = &sun.sun_path;
67        addressLength = strlen(sun.sun_path);
68    } else {
69        // We can't throw SocketException. We aren't meant to see bad addresses, so seeing one
70        // really does imply an internal error.
71        jniThrowExceptionFmt(env, "java/lang/IllegalArgumentException",
72                             "sockaddrToInetAddress unsupported ss_family: %i", ss.ss_family);
73        return NULL;
74    }
75    if (port != NULL) {
76        *port = sin_port;
77    }
78
79    ScopedLocalRef<jbyteArray> byteArray(env, env->NewByteArray(addressLength));
80    if (byteArray.get() == NULL) {
81        return NULL;
82    }
83    env->SetByteArrayRegion(byteArray.get(), 0, addressLength,
84            reinterpret_cast<const jbyte*>(rawAddress));
85
86    if (ss.ss_family == AF_UNIX) {
87        // Note that we get here for AF_UNIX sockets on accept(2). The unix(7) man page claims
88        // that the peer's sun_path will contain the path, but in practice it doesn't, and the
89        // peer length is returned as 2 (meaning only the sun_family field was set).
90        static jmethodID ctor = env->GetMethodID(JniConstants::inetUnixAddressClass, "<init>", "([B)V");
91        return env->NewObject(JniConstants::inetUnixAddressClass, ctor, byteArray.get());
92    }
93
94    static jmethodID getByAddressMethod = env->GetStaticMethodID(JniConstants::inetAddressClass,
95            "getByAddress", "(Ljava/lang/String;[BI)Ljava/net/InetAddress;");
96    if (getByAddressMethod == NULL) {
97        return NULL;
98    }
99    return env->CallStaticObjectMethod(JniConstants::inetAddressClass, getByAddressMethod,
100            NULL, byteArray.get(), scope_id);
101}
102
103static bool inetAddressToSockaddr(JNIEnv* env, jobject inetAddress, int port, sockaddr_storage& ss, socklen_t& sa_len, bool map) {
104    memset(&ss, 0, sizeof(ss));
105    sa_len = 0;
106
107    if (inetAddress == NULL) {
108        jniThrowNullPointerException(env, NULL);
109        return false;
110    }
111
112    // Get the address family.
113    static jfieldID familyFid = env->GetFieldID(JniConstants::inetAddressClass, "family", "I");
114    ss.ss_family = env->GetIntField(inetAddress, familyFid);
115    if (ss.ss_family == AF_UNSPEC) {
116        sa_len = sizeof(ss.ss_family);
117        return true; // Job done!
118    }
119
120    // Check this is an address family we support.
121    if (ss.ss_family != AF_INET && ss.ss_family != AF_INET6 && ss.ss_family != AF_UNIX) {
122        jniThrowExceptionFmt(env, "java/lang/IllegalArgumentException",
123                "inetAddressToSockaddr bad family: %i", ss.ss_family);
124        return false;
125    }
126
127    // Get the byte array that stores the IP address bytes in the InetAddress.
128    static jfieldID bytesFid = env->GetFieldID(JniConstants::inetAddressClass, "ipaddress", "[B");
129    ScopedLocalRef<jbyteArray> addressBytes(env, reinterpret_cast<jbyteArray>(env->GetObjectField(inetAddress, bytesFid)));
130    if (addressBytes.get() == NULL) {
131        jniThrowNullPointerException(env, NULL);
132        return false;
133    }
134
135    // Handle the AF_UNIX special case.
136    if (ss.ss_family == AF_UNIX) {
137        sockaddr_un& sun = reinterpret_cast<sockaddr_un&>(ss);
138
139        size_t path_length = env->GetArrayLength(addressBytes.get());
140        if (path_length >= sizeof(sun.sun_path)) {
141            jniThrowExceptionFmt(env, "java/lang/IllegalArgumentException",
142                                 "inetAddressToSockaddr path too long for AF_UNIX: %i", path_length);
143            return false;
144        }
145
146        // Copy the bytes...
147        jbyte* dst = reinterpret_cast<jbyte*>(&sun.sun_path);
148        memset(dst, 0, sizeof(sun.sun_path));
149        env->GetByteArrayRegion(addressBytes.get(), 0, path_length, dst);
150        sa_len = sizeof(sun.sun_path);
151        return true;
152    }
153
154    // TODO: bionic's getnameinfo(3) seems to want its length parameter to be exactly
155    // sizeof(sockaddr_in) for an IPv4 address and sizeof (sockaddr_in6) for an
156    // IPv6 address. Fix getnameinfo so it accepts sizeof(sockaddr_storage), and
157    // then unconditionally set sa_len to sizeof(sockaddr_storage) instead of having
158    // to deal with this case by case.
159
160    // We use AF_INET6 sockets, so we want an IPv6 address (which may be a IPv4-mapped address).
161    sockaddr_in6& sin6 = reinterpret_cast<sockaddr_in6&>(ss);
162    sin6.sin6_port = htons(port);
163    if (ss.ss_family == AF_INET6) {
164        // IPv6 address. Copy the bytes...
165        jbyte* dst = reinterpret_cast<jbyte*>(&sin6.sin6_addr.s6_addr);
166        env->GetByteArrayRegion(addressBytes.get(), 0, 16, dst);
167        // ...and set the scope id...
168        static jfieldID scopeFid = env->GetFieldID(JniConstants::inet6AddressClass, "scope_id", "I");
169        sin6.sin6_scope_id = env->GetIntField(inetAddress, scopeFid);
170        sa_len = sizeof(sockaddr_in6);
171        return true;
172    }
173
174    // Deal with Inet4Address instances.
175    if (map) {
176        // We should represent this Inet4Address as an IPv4-mapped IPv6 sockaddr_in6.
177        // Change the family...
178        sin6.sin6_family = AF_INET6;
179        // Copy the bytes...
180        jbyte* dst = reinterpret_cast<jbyte*>(&sin6.sin6_addr.s6_addr[12]);
181        env->GetByteArrayRegion(addressBytes.get(), 0, 4, dst);
182        // INADDR_ANY and in6addr_any are both all-zeros...
183        if (!IN6_IS_ADDR_UNSPECIFIED(&sin6.sin6_addr)) {
184            // ...but all other IPv4-mapped addresses are ::ffff:a.b.c.d, so insert the ffff...
185            memset(&(sin6.sin6_addr.s6_addr[10]), 0xff, 2);
186        }
187        sa_len = sizeof(sockaddr_in6);
188    } else {
189        // We should represent this Inet4Address as an IPv4 sockaddr_in.
190        sockaddr_in& sin = reinterpret_cast<sockaddr_in&>(ss);
191        sin.sin_port = htons(port);
192        jbyte* dst = reinterpret_cast<jbyte*>(&sin.sin_addr.s_addr);
193        env->GetByteArrayRegion(addressBytes.get(), 0, 4, dst);
194        sa_len = sizeof(sockaddr_in);
195    }
196    return true;
197}
198
199bool inetAddressToSockaddrVerbatim(JNIEnv* env, jobject inetAddress, int port, sockaddr_storage& ss, socklen_t& sa_len) {
200    return inetAddressToSockaddr(env, inetAddress, port, ss, sa_len, false);
201}
202
203bool inetAddressToSockaddr(JNIEnv* env, jobject inetAddress, int port, sockaddr_storage& ss, socklen_t& sa_len) {
204    return inetAddressToSockaddr(env, inetAddress, port, ss, sa_len, true);
205}
206
207bool setBlocking(int fd, bool blocking) {
208    int flags = fcntl(fd, F_GETFL);
209    if (flags == -1) {
210        return false;
211    }
212
213    if (!blocking) {
214        flags |= O_NONBLOCK;
215    } else {
216        flags &= ~O_NONBLOCK;
217    }
218
219    int rc = fcntl(fd, F_SETFL, flags);
220    return (rc != -1);
221}
222