Basic IPv6 Router Advertisement daemon
Bug: 9580643
Change-Id: Iebd4d1f694699ffd4daf7d71e9b9d8f49e9b632f
diff --git a/core/java/android/net/NetworkUtils.java b/core/java/android/net/NetworkUtils.java
index 141af3d..35e3065 100644
--- a/core/java/android/net/NetworkUtils.java
+++ b/core/java/android/net/NetworkUtils.java
@@ -45,13 +45,20 @@
public native static void attachDhcpFilter(FileDescriptor fd) throws SocketException;
/**
- * Attaches a socket filter that accepts ICMP6 router advertisement packets to the given socket.
+ * Attaches a socket filter that accepts ICMPv6 router advertisements to the given socket.
* @param fd the socket's {@link FileDescriptor}.
* @param packetType the hardware address type, one of ARPHRD_*.
*/
public native static void attachRaFilter(FileDescriptor fd, int packetType) throws SocketException;
/**
+ * Configures a socket for receiving ICMPv6 router solicitations and sending advertisements.
+ * @param fd the socket's {@link FileDescriptor}.
+ * @param ifIndex the interface index.
+ */
+ public native static void setupRaSocket(FileDescriptor fd, int ifIndex) throws SocketException;
+
+ /**
* Binds the current process to the network designated by {@code netId}. All sockets created
* in the future (and not explicitly bound via a bound {@link SocketFactory} (see
* {@link Network#getSocketFactory}) will be bound to this network. Note that if this
diff --git a/core/jni/android_net_NetUtils.cpp b/core/jni/android_net_NetUtils.cpp
index 2364787..679e882 100644
--- a/core/jni/android_net_NetUtils.cpp
+++ b/core/jni/android_net_NetUtils.cpp
@@ -125,6 +125,99 @@
}
}
+static void android_net_utils_setupRaSocket(JNIEnv *env, jobject clazz, jobject javaFd,
+ jint ifIndex)
+{
+ static const int kLinkLocalHopLimit = 255;
+
+ int fd = jniGetFDFromFileDescriptor(env, javaFd);
+
+ // Set an ICMPv6 filter that only passes Router Solicitations.
+ struct icmp6_filter rs_only;
+ ICMP6_FILTER_SETBLOCKALL(&rs_only);
+ ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &rs_only);
+ socklen_t len = sizeof(rs_only);
+ if (setsockopt(fd, IPPROTO_ICMPV6, ICMP6_FILTER, &rs_only, len) != 0) {
+ jniThrowExceptionFmt(env, "java/net/SocketException",
+ "setsockopt(ICMP6_FILTER): %s", strerror(errno));
+ return;
+ }
+
+ // Most/all of the rest of these options can be set via Java code, but
+ // because we're here on account of setting an icmp6_filter go ahead
+ // and do it all natively for now.
+ //
+ // TODO: Consider moving these out to Java.
+
+ // Set the multicast hoplimit to 255 (link-local only).
+ int hops = kLinkLocalHopLimit;
+ len = sizeof(hops);
+ if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &hops, len) != 0) {
+ jniThrowExceptionFmt(env, "java/net/SocketException",
+ "setsockopt(IPV6_MULTICAST_HOPS): %s", strerror(errno));
+ return;
+ }
+
+ // Set the unicast hoplimit to 255 (link-local only).
+ hops = kLinkLocalHopLimit;
+ len = sizeof(hops);
+ if (setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &hops, len) != 0) {
+ jniThrowExceptionFmt(env, "java/net/SocketException",
+ "setsockopt(IPV6_UNICAST_HOPS): %s", strerror(errno));
+ return;
+ }
+
+ // Explicitly disable multicast loopback.
+ int off = 0;
+ len = sizeof(off);
+ if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &off, len) != 0) {
+ jniThrowExceptionFmt(env, "java/net/SocketException",
+ "setsockopt(IPV6_MULTICAST_LOOP): %s", strerror(errno));
+ return;
+ }
+
+ // Specify the IPv6 interface to use for outbound multicast.
+ len = sizeof(ifIndex);
+ if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &ifIndex, len) != 0) {
+ jniThrowExceptionFmt(env, "java/net/SocketException",
+ "setsockopt(IPV6_MULTICAST_IF): %s", strerror(errno));
+ return;
+ }
+
+ // Additional options to be considered:
+ // - IPV6_TCLASS
+ // - IPV6_RECVPKTINFO
+ // - IPV6_RECVHOPLIMIT
+
+ // Bind to [::].
+ const struct sockaddr_in6 sin6 = {
+ .sin6_family = AF_INET6,
+ .sin6_port = 0,
+ .sin6_flowinfo = 0,
+ .sin6_addr = IN6ADDR_ANY_INIT,
+ .sin6_scope_id = 0,
+ };
+ auto sa = reinterpret_cast<const struct sockaddr *>(&sin6);
+ len = sizeof(sin6);
+ if (bind(fd, sa, len) != 0) {
+ jniThrowExceptionFmt(env, "java/net/SocketException",
+ "bind(IN6ADDR_ANY): %s", strerror(errno));
+ return;
+ }
+
+ // Join the all-routers multicast group, ff02::2%index.
+ struct ipv6_mreq all_rtrs = {
+ .ipv6mr_multiaddr = {{{0xff,2,0,0,0,0,0,0,0,0,0,0,0,0,0,2}}},
+ .ipv6mr_interface = ifIndex,
+ };
+ len = sizeof(all_rtrs);
+ if (setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &all_rtrs, len) != 0) {
+ jniThrowExceptionFmt(env, "java/net/SocketException",
+ "setsockopt(IPV6_JOIN_GROUP): %s", strerror(errno));
+ return;
+ }
+}
+
static jboolean android_net_utils_bindProcessToNetwork(JNIEnv *env, jobject thiz, jint netId)
{
return (jboolean) !setNetworkForProcess(netId);
@@ -173,6 +266,7 @@
{ "queryUserAccess", "(II)Z", (void*)android_net_utils_queryUserAccess },
{ "attachDhcpFilter", "(Ljava/io/FileDescriptor;)V", (void*) android_net_utils_attachDhcpFilter },
{ "attachRaFilter", "(Ljava/io/FileDescriptor;I)V", (void*) android_net_utils_attachRaFilter },
+ { "setupRaSocket", "(Ljava/io/FileDescriptor;I)V", (void*) android_net_utils_setupRaSocket },
};
int register_android_net_NetworkUtils(JNIEnv* env)