Add support for network-specific host name resolution.

For now all such support is hidden.

Change-Id: I932f73158a8f6e3ccc36c319d138180dff2aa070

8 files changed, 109 insertions, 35 deletions

diff --git a/luni/src/main/java/android/system/Os.java b/luni/src/main/java/android/system/Os.java
index beb785f..0b80b52 100644
--- a/luni/src/main/java/android/system/Os.java
+++ b/luni/src/main/java/android/system/Os.java
@@ -61,6 +61,8 @@ public final class Os {
    */
   public static boolean access(String path, int mode) throws ErrnoException { return Libcore.os.access(path, mode); }
 
+  /** @hide */ public static InetAddress[] android_getaddrinfo(String node, StructAddrinfo hints, int netId) throws GaiException { return Libcore.os.android_getaddrinfo(node, hints, netId); }
+
   /**
    * See <a href="http://man7.org/linux/man-pages/man2/bind.2.html">bind(2)</a>.
    */
@@ -155,8 +157,6 @@ public final class Os {
    */
   public static String gai_strerror(int error) { return Libcore.os.gai_strerror(error); }
 
-  /** @hide */ public static InetAddress[] getaddrinfo(String node, StructAddrinfo hints) throws GaiException { return Libcore.os.getaddrinfo(node, hints); }
-
   /**
    * See <a href="http://man7.org/linux/man-pages/man2/getegid.2.html">getegid(2)</a>.
    */
diff --git a/luni/src/main/java/java/net/AddressCache.java b/luni/src/main/java/java/net/AddressCache.java
index 194761a..2aba78b 100644
--- a/luni/src/main/java/java/net/AddressCache.java
+++ b/luni/src/main/java/java/net/AddressCache.java
@@ -37,8 +37,36 @@ class AddressCache {
     private static final long TTL_NANOS = 2 * 1000000000L;
 
     // The actual cache.
-    private final BasicLruCache<String, AddressCacheEntry> cache
-            = new BasicLruCache<String, AddressCacheEntry>(MAX_ENTRIES);
+    private final BasicLruCache<AddressCacheKey, AddressCacheEntry> cache
+            = new BasicLruCache<AddressCacheKey, AddressCacheEntry>(MAX_ENTRIES);
+
+    static class AddressCacheKey {
+        private final String mHostname;
+        private final int mNetId;
+
+        AddressCacheKey(String hostname, int netId) {
+            mHostname = hostname;
+            mNetId = netId;
+        }
+
+        @Override public boolean equals(Object o) {
+            if (this == o) {
+                return true;
+            }
+            if (!(o instanceof AddressCacheKey)) {
+                return false;
+            }
+            AddressCacheKey lhs = (AddressCacheKey) o;
+            return mHostname.equals(lhs.mHostname) && mNetId == lhs.mNetId;
+        }
+
+        @Override public int hashCode() {
+            int result = 17;
+            result = 31 * result + mNetId;
+            result = 31 * result + mHostname.hashCode();
+            return result;
+        }
+    }
 
     static class AddressCacheEntry {
         // Either an InetAddress[] for a positive entry,
@@ -67,12 +95,12 @@ class AddressCache {
     }
 
     /**
-     * Returns the cached InetAddress[] associated with 'hostname'. Returns null if nothing is known
-     * about 'hostname'. Returns a String suitable for use as an UnknownHostException detail
-     * message if 'hostname' is known not to exist.
+     * Returns the cached InetAddress[] for 'hostname' on network 'netId'. Returns null
+     * if nothing is known about 'hostname'. Returns a String suitable for use as an
+     * UnknownHostException detail message if 'hostname' is known not to exist.
      */
-    public Object get(String hostname) {
-        AddressCacheEntry entry = cache.get(hostname);
+    public Object get(String hostname, int netId) {
+        AddressCacheEntry entry = cache.get(new AddressCacheKey(hostname, netId));
         // Do we have a valid cache entry?
         if (entry != null && entry.expiryNanos >= System.nanoTime()) {
             return entry.value;
@@ -86,15 +114,15 @@ class AddressCache {
      * Associates the given 'addresses' with 'hostname'. The association will expire after a
      * certain length of time.
      */
-    public void put(String hostname, InetAddress[] addresses) {
-        cache.put(hostname, new AddressCacheEntry(addresses));
+    public void put(String hostname, int netId, InetAddress[] addresses) {
+        cache.put(new AddressCacheKey(hostname, netId), new AddressCacheEntry(addresses));
     }
 
     /**
      * Records that 'hostname' is known not to have any associated addresses. (I.e. insert a
      * negative cache entry.)
      */
-    public void putUnknownHost(String hostname, String detailMessage) {
-        cache.put(hostname, new AddressCacheEntry(detailMessage));
+    public void putUnknownHost(String hostname, int netId, String detailMessage) {
+        cache.put(new AddressCacheKey(hostname, netId), new AddressCacheEntry(detailMessage));
     }
 }
diff --git a/luni/src/main/java/java/net/InetAddress.java b/luni/src/main/java/java/net/InetAddress.java
index e31b4c3..5cfa15a 100644
--- a/luni/src/main/java/java/net/InetAddress.java
+++ b/luni/src/main/java/java/net/InetAddress.java
@@ -127,6 +127,9 @@ public class InetAddress implements Serializable {
 
     private static final long serialVersionUID = 3286316764910316507L;
 
+    /** Using NetID of NETID_UNSET indicates resolution should be done on default network. */
+    private static final int NETID_UNSET = 0;
+
     private int family;
 
     byte[] ipaddress;
@@ -209,14 +212,29 @@ public class InetAddress implements Serializable {
      * @throws UnknownHostException if the address lookup fails.
      */
     public static InetAddress[] getAllByName(String host) throws UnknownHostException {
-        return getAllByNameImpl(host).clone();
+        return getAllByNameImpl(host, NETID_UNSET).clone();
     }
 
     /**
-     * Returns the InetAddresses for {@code host}. The returned array is shared
-     * and must be cloned before it is returned to application code.
+     * Operates identically to {@code getAllByName} except host resolution is
+     * performed on the network designated by {@code netId}.
+     *
+     * @param host the hostname or literal IP string to be resolved.
+     * @param netId the network to use for host resolution.
+     * @return the array of addresses associated with the specified host.
+     * @throws UnknownHostException if the address lookup fails.
+     * @hide internal use only
      */
-    private static InetAddress[] getAllByNameImpl(String host) throws UnknownHostException {
+    public static InetAddress[] getAllByNameOnNet(String host, int netId) throws UnknownHostException {
+        return getAllByNameImpl(host, netId).clone();
+    }
+
+    /**
+     * Returns the InetAddresses for {@code host} on network {@code netId}. The
+     * returned array is shared and must be cloned before it is returned to
+     * application code.
+     */
+    private static InetAddress[] getAllByNameImpl(String host, int netId) throws UnknownHostException {
         if (host == null || host.isEmpty()) {
             return loopbackAddresses();
         }
@@ -231,7 +249,7 @@ public class InetAddress implements Serializable {
             return new InetAddress[] { result };
         }
 
-        return lookupHostByName(host).clone();
+        return lookupHostByName(host, netId).clone();
     }
 
     private static InetAddress makeInetAddress(byte[] bytes, String hostName) throws UnknownHostException {
@@ -264,7 +282,7 @@ public class InetAddress implements Serializable {
         hints.ai_flags = AI_NUMERICHOST;
         InetAddress[] addresses = null;
         try {
-            addresses = Libcore.os.getaddrinfo(address, hints);
+            addresses = Libcore.os.android_getaddrinfo(address, hints, NETID_UNSET);
         } catch (GaiException ignored) {
         }
         return (addresses != null) ? addresses[0] : null;
@@ -284,7 +302,22 @@ public class InetAddress implements Serializable {
      *             if the address lookup fails.
      */
     public static InetAddress getByName(String host) throws UnknownHostException {
-        return getAllByNameImpl(host)[0];
+        return getAllByNameImpl(host, NETID_UNSET)[0];
+    }
+
+    /**
+     * Operates identically to {@code getByName} except host resolution is
+     * performed on the network designated by {@code netId}.
+     *
+     * @param host
+     *            the hostName to be resolved to an address or {@code null}.
+     * @param netId the network to use for host resolution.
+     * @return the {@code InetAddress} instance representing the host.
+     * @throws UnknownHostException if the address lookup fails.
+     * @hide internal use only
+     */
+    public static InetAddress getByNameOnNet(String host, int netId) throws UnknownHostException {
+        return getAllByNameImpl(host, netId)[0];
     }
 
     /**
@@ -360,7 +393,7 @@ public class InetAddress implements Serializable {
      */
     public static InetAddress getLocalHost() throws UnknownHostException {
         String host = Libcore.os.uname().nodename;
-        return lookupHostByName(host)[0];
+        return lookupHostByName(host, NETID_UNSET)[0];
     }
 
     /**
@@ -377,12 +410,14 @@ public class InetAddress implements Serializable {
      * Resolves a hostname to its IP addresses using a cache.
      *
      * @param host the hostname to resolve.
+     * @param netId the network to perform resolution upon.
      * @return the IP addresses of the host.
      */
-    private static InetAddress[] lookupHostByName(String host) throws UnknownHostException {
+    private static InetAddress[] lookupHostByName(String host, int netId)
+            throws UnknownHostException {
         BlockGuard.getThreadPolicy().onNetwork();
         // Do we have a result cached?
-        Object cachedResult = addressCache.get(host);
+        Object cachedResult = addressCache.get(host, netId);
         if (cachedResult != null) {
             if (cachedResult instanceof InetAddress[]) {
                 // A cached positive result.
@@ -400,12 +435,12 @@ public class InetAddress implements Serializable {
             // for SOCK_STREAM and one for SOCK_DGRAM. Since we do not return the family
             // anyway, just pick one.
             hints.ai_socktype = SOCK_STREAM;
-            InetAddress[] addresses = Libcore.os.getaddrinfo(host, hints);
+            InetAddress[] addresses = Libcore.os.android_getaddrinfo(host, hints, netId);
             // TODO: should getaddrinfo set the hostname of the InetAddresses it returns?
             for (InetAddress address : addresses) {
                 address.hostName = host;
             }
-            addressCache.put(host, addresses);
+            addressCache.put(host, netId, addresses);
             return addresses;
         } catch (GaiException gaiException) {
             // If the failure appears to have been a lack of INTERNET permission, throw a clear
@@ -418,7 +453,7 @@ public class InetAddress implements Serializable {
             }
             // Otherwise, throw an UnknownHostException.
             String detailMessage = "Unable to resolve host \"" + host + "\": " + Libcore.os.gai_strerror(gaiException.error);
-            addressCache.putUnknownHost(host, detailMessage);
+            addressCache.putUnknownHost(host, netId, detailMessage);
             throw gaiException.rethrowAsUnknownHostException(detailMessage);
         }
     }
diff --git a/luni/src/main/java/libcore/io/ForwardingOs.java b/luni/src/main/java/libcore/io/ForwardingOs.java
index d09e442..bf4b448 100644
--- a/luni/src/main/java/libcore/io/ForwardingOs.java
+++ b/luni/src/main/java/libcore/io/ForwardingOs.java
@@ -52,6 +52,7 @@ public class ForwardingOs implements Os {
 
     public FileDescriptor accept(FileDescriptor fd, InetSocketAddress peerAddress) throws ErrnoException, SocketException { return os.accept(fd, peerAddress); }
     public boolean access(String path, int mode) throws ErrnoException { return os.access(path, mode); }
+    public InetAddress[] android_getaddrinfo(String node, StructAddrinfo hints, int netId) throws GaiException { return os.android_getaddrinfo(node, hints, netId); }
     public void bind(FileDescriptor fd, InetAddress address, int port) throws ErrnoException, SocketException { os.bind(fd, address, port); }
     public void chmod(String path, int mode) throws ErrnoException { os.chmod(path, mode); }
     public void chown(String path, int uid, int gid) throws ErrnoException { os.chown(path, uid, gid); }
@@ -73,7 +74,6 @@ public class ForwardingOs implements Os {
     public void fsync(FileDescriptor fd) throws ErrnoException { os.fsync(fd); }
     public void ftruncate(FileDescriptor fd, long length) throws ErrnoException { os.ftruncate(fd, length); }
     public String gai_strerror(int error) { return os.gai_strerror(error); }
-    public InetAddress[] getaddrinfo(String node, StructAddrinfo hints) throws GaiException { return os.getaddrinfo(node, hints); }
     public int getegid() { return os.getegid(); }
     public int geteuid() { return os.geteuid(); }
     public int getgid() { return os.getgid(); }
diff --git a/luni/src/main/java/libcore/io/Os.java b/luni/src/main/java/libcore/io/Os.java
index a537aeb..511bb27 100644
--- a/luni/src/main/java/libcore/io/Os.java
+++ b/luni/src/main/java/libcore/io/Os.java
@@ -43,6 +43,7 @@ import java.nio.ByteBuffer;
 public interface Os {
     public FileDescriptor accept(FileDescriptor fd, InetSocketAddress peerAddress) throws ErrnoException, SocketException;
     public boolean access(String path, int mode) throws ErrnoException;
+    public InetAddress[] android_getaddrinfo(String node, StructAddrinfo hints, int netId) throws GaiException;
     public void bind(FileDescriptor fd, InetAddress address, int port) throws ErrnoException, SocketException;
     public void chmod(String path, int mode) throws ErrnoException;
     public void chown(String path, int uid, int gid) throws ErrnoException;
@@ -64,7 +65,6 @@ public interface Os {
     public void fsync(FileDescriptor fd) throws ErrnoException;
     public void ftruncate(FileDescriptor fd, long length) throws ErrnoException;
     public String gai_strerror(int error);
-    public InetAddress[] getaddrinfo(String node, StructAddrinfo hints) throws GaiException;
     public int getegid();
     public int geteuid();
     public int getgid();
diff --git a/luni/src/main/java/libcore/io/Posix.java b/luni/src/main/java/libcore/io/Posix.java
index 7551190..f5eaaa3 100644
--- a/luni/src/main/java/libcore/io/Posix.java
+++ b/luni/src/main/java/libcore/io/Posix.java
@@ -46,6 +46,7 @@ public final class Posix implements Os {
 
     public native FileDescriptor accept(FileDescriptor fd, InetSocketAddress peerAddress) throws ErrnoException, SocketException;
     public native boolean access(String path, int mode) throws ErrnoException;
+    public native InetAddress[] android_getaddrinfo(String node, StructAddrinfo hints, int netId) throws GaiException;
     public native void bind(FileDescriptor fd, InetAddress address, int port) throws ErrnoException, SocketException;
     public native void chmod(String path, int mode) throws ErrnoException;
     public native void chown(String path, int uid, int gid) throws ErrnoException;
@@ -67,7 +68,6 @@ public final class Posix implements Os {
     public native void fsync(FileDescriptor fd) throws ErrnoException;
     public native void ftruncate(FileDescriptor fd, long length) throws ErrnoException;
     public native String gai_strerror(int error);
-    public native InetAddress[] getaddrinfo(String node, StructAddrinfo hints) throws GaiException;
     public native int getegid();
     public native int geteuid();
     public native int getgid();
diff --git a/luni/src/main/native/Portability.h b/luni/src/main/native/Portability.h
index 60b7062..3c8384d 100644
--- a/luni/src/main/native/Portability.h
+++ b/luni/src/main/native/Portability.h
@@ -74,6 +74,15 @@ static inline int mincore(void* addr, size_t length, unsigned char* vec) {
 #include <sys/sendfile.h>
 #include <sys/statvfs.h>
 
+#if !defined(__BIONIC__)
+#include <netdb.h>
+#include "../../bionic/libc/dns/include/resolv_netid.h"
+inline int android_getaddrinfofornet(const char *hostname, const char *servname,
+    const struct addrinfo *hints, unsigned /*netid*/, unsigned /*mark*/, struct addrinfo **res) {
+  return getaddrinfo(hostname, servname, hints, res);
+}
+#endif
+
 #endif
 
 #endif  // PORTABILITY_H_included
diff --git a/luni/src/main/native/libcore_io_Posix.cpp b/luni/src/main/native/libcore_io_Posix.cpp
index b1217c0..6eee7f0 100644
--- a/luni/src/main/native/libcore_io_Posix.cpp
+++ b/luni/src/main/native/libcore_io_Posix.cpp
@@ -25,6 +25,7 @@
 #include "NetworkUtilities.h"
 #include "Portability.h"
 #include "readlink.h"
+#include "../../bionic/libc/dns/include/resolv_netid.h"  // For android_getaddrinfofornet.
 #include "ScopedBytes.h"
 #include "ScopedLocalRef.h"
 #include "ScopedPrimitiveArray.h"
@@ -645,7 +646,8 @@ static jstring Posix_gai_strerror(JNIEnv* env, jobject, jint error) {
     return env->NewStringUTF(gai_strerror(error));
 }
 
-static jobjectArray Posix_getaddrinfo(JNIEnv* env, jobject, jstring javaNode, jobject javaHints) {
+static jobjectArray Posix_android_getaddrinfo(JNIEnv* env, jobject, jstring javaNode,
+        jobject javaHints, jint netId) {
     ScopedUtfChars node(env, javaNode);
     if (node.c_str() == NULL) {
         return NULL;
@@ -665,10 +667,10 @@ static jobjectArray Posix_getaddrinfo(JNIEnv* env, jobject, jstring javaNode, jo
 
     addrinfo* addressList = NULL;
     errno = 0;
-    int rc = getaddrinfo(node.c_str(), NULL, &hints, &addressList);
+    int rc = android_getaddrinfofornet(node.c_str(), NULL, &hints, netId, 0, &addressList);
     UniquePtr<addrinfo, addrinfo_deleter> addressListDeleter(addressList);
     if (rc != 0) {
-        throwGaiException(env, "getaddrinfo", rc);
+        throwGaiException(env, "android_getaddrinfo", rc);
         return NULL;
     }
 
@@ -678,7 +680,7 @@ static jobjectArray Posix_getaddrinfo(JNIEnv* env, jobject, jstring javaNode, jo
         if (ai->ai_family == AF_INET || ai->ai_family == AF_INET6) {
             ++addressCount;
         } else {
-            ALOGE("getaddrinfo unexpected ai_family %i", ai->ai_family);
+            ALOGE("android_getaddrinfo unexpected ai_family %i", ai->ai_family);
         }
     }
     if (addressCount == 0) {
@@ -696,7 +698,7 @@ static jobjectArray Posix_getaddrinfo(JNIEnv* env, jobject, jstring javaNode, jo
     for (addrinfo* ai = addressList; ai != NULL; ai = ai->ai_next) {
         if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) {
             // Unknown address family. Skip this address.
-            ALOGE("getaddrinfo unexpected ai_family %i", ai->ai_family);
+            ALOGE("android_getaddrinfo unexpected ai_family %i", ai->ai_family);
             continue;
         }
 
@@ -1499,6 +1501,7 @@ static jint Posix_writev(JNIEnv* env, jobject, jobject javaFd, jobjectArray buff
 static JNINativeMethod gMethods[] = {
     NATIVE_METHOD(Posix, accept, "(Ljava/io/FileDescriptor;Ljava/net/InetSocketAddress;)Ljava/io/FileDescriptor;"),
     NATIVE_METHOD(Posix, access, "(Ljava/lang/String;I)Z"),
+    NATIVE_METHOD(Posix, android_getaddrinfo, "(Ljava/lang/String;Landroid/system/StructAddrinfo;I)[Ljava/net/InetAddress;"),
     NATIVE_METHOD(Posix, bind, "(Ljava/io/FileDescriptor;Ljava/net/InetAddress;I)V"),
     NATIVE_METHOD(Posix, chmod, "(Ljava/lang/String;I)V"),
     NATIVE_METHOD(Posix, chown, "(Ljava/lang/String;II)V"),
@@ -1520,7 +1523,6 @@ static JNINativeMethod gMethods[] = {
     NATIVE_METHOD(Posix, fsync, "(Ljava/io/FileDescriptor;)V"),
     NATIVE_METHOD(Posix, ftruncate, "(Ljava/io/FileDescriptor;J)V"),
     NATIVE_METHOD(Posix, gai_strerror, "(I)Ljava/lang/String;"),
-    NATIVE_METHOD(Posix, getaddrinfo, "(Ljava/lang/String;Landroid/system/StructAddrinfo;)[Ljava/net/InetAddress;"),
     NATIVE_METHOD(Posix, getegid, "()I"),
     NATIVE_METHOD(Posix, geteuid, "()I"),
     NATIVE_METHOD(Posix, getgid, "()I"),