| /* |
| * Copyright 2008, The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #define LOG_TAG "NetUtils" |
| |
| #include "jni.h" |
| #include <nativehelper/JNIHelp.h> |
| #include "NetdClient.h" |
| #include <utils/misc.h> |
| #include <android_runtime/AndroidRuntime.h> |
| #include <utils/Log.h> |
| #include <arpa/inet.h> |
| #include <net/if.h> |
| #include <linux/filter.h> |
| #include <linux/if_arp.h> |
| #include <netinet/ether.h> |
| #include <netinet/icmp6.h> |
| #include <netinet/ip.h> |
| #include <netinet/ip6.h> |
| #include <netinet/udp.h> |
| #include <cutils/properties.h> |
| |
| #include "core_jni_helpers.h" |
| |
| extern "C" { |
| int ifc_enable(const char *ifname); |
| int ifc_disable(const char *ifname); |
| } |
| |
| #define NETUTILS_PKG_NAME "android/net/NetworkUtils" |
| |
| namespace android { |
| |
| static const uint32_t kEtherTypeOffset = offsetof(ether_header, ether_type); |
| static const uint32_t kEtherHeaderLen = sizeof(ether_header); |
| static const uint32_t kIPv4Protocol = kEtherHeaderLen + offsetof(iphdr, protocol); |
| static const uint32_t kIPv4FlagsOffset = kEtherHeaderLen + offsetof(iphdr, frag_off); |
| static const uint32_t kIPv6NextHeader = kEtherHeaderLen + offsetof(ip6_hdr, ip6_nxt); |
| static const uint32_t kIPv6PayloadStart = kEtherHeaderLen + sizeof(ip6_hdr); |
| static const uint32_t kICMPv6TypeOffset = kIPv6PayloadStart + offsetof(icmp6_hdr, icmp6_type); |
| static const uint32_t kUDPSrcPortIndirectOffset = kEtherHeaderLen + offsetof(udphdr, source); |
| static const uint32_t kUDPDstPortIndirectOffset = kEtherHeaderLen + offsetof(udphdr, dest); |
| static const uint16_t kDhcpClientPort = 68; |
| |
| static void android_net_utils_attachDhcpFilter(JNIEnv *env, jobject clazz, jobject javaFd) |
| { |
| struct sock_filter filter_code[] = { |
| // Check the protocol is UDP. |
| BPF_STMT(BPF_LD | BPF_B | BPF_ABS, kIPv4Protocol), |
| BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, IPPROTO_UDP, 0, 6), |
| |
| // Check this is not a fragment. |
| BPF_STMT(BPF_LD | BPF_H | BPF_ABS, kIPv4FlagsOffset), |
| BPF_JUMP(BPF_JMP | BPF_JSET | BPF_K, IP_OFFMASK, 4, 0), |
| |
| // Get the IP header length. |
| BPF_STMT(BPF_LDX | BPF_B | BPF_MSH, kEtherHeaderLen), |
| |
| // Check the destination port. |
| BPF_STMT(BPF_LD | BPF_H | BPF_IND, kUDPDstPortIndirectOffset), |
| BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, kDhcpClientPort, 0, 1), |
| |
| // Accept or reject. |
| BPF_STMT(BPF_RET | BPF_K, 0xffff), |
| BPF_STMT(BPF_RET | BPF_K, 0) |
| }; |
| struct sock_fprog filter = { |
| sizeof(filter_code) / sizeof(filter_code[0]), |
| filter_code, |
| }; |
| |
| int fd = jniGetFDFromFileDescriptor(env, javaFd); |
| if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)) != 0) { |
| jniThrowExceptionFmt(env, "java/net/SocketException", |
| "setsockopt(SO_ATTACH_FILTER): %s", strerror(errno)); |
| } |
| } |
| |
| static void android_net_utils_attachRaFilter(JNIEnv *env, jobject clazz, jobject javaFd, |
| jint hardwareAddressType) |
| { |
| if (hardwareAddressType != ARPHRD_ETHER) { |
| jniThrowExceptionFmt(env, "java/net/SocketException", |
| "attachRaFilter only supports ARPHRD_ETHER"); |
| return; |
| } |
| |
| struct sock_filter filter_code[] = { |
| // Check IPv6 Next Header is ICMPv6. |
| BPF_STMT(BPF_LD | BPF_B | BPF_ABS, kIPv6NextHeader), |
| BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, IPPROTO_ICMPV6, 0, 3), |
| |
| // Check ICMPv6 type is Router Advertisement. |
| BPF_STMT(BPF_LD | BPF_B | BPF_ABS, kICMPv6TypeOffset), |
| BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, ND_ROUTER_ADVERT, 0, 1), |
| |
| // Accept or reject. |
| BPF_STMT(BPF_RET | BPF_K, 0xffff), |
| BPF_STMT(BPF_RET | BPF_K, 0) |
| }; |
| struct sock_fprog filter = { |
| sizeof(filter_code) / sizeof(filter_code[0]), |
| filter_code, |
| }; |
| |
| int fd = jniGetFDFromFileDescriptor(env, javaFd); |
| if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)) != 0) { |
| jniThrowExceptionFmt(env, "java/net/SocketException", |
| "setsockopt(SO_ATTACH_FILTER): %s", strerror(errno)); |
| } |
| } |
| |
| // TODO: Move all this filter code into libnetutils. |
| static void android_net_utils_attachControlPacketFilter( |
| JNIEnv *env, jobject clazz, jobject javaFd, jint hardwareAddressType) { |
| if (hardwareAddressType != ARPHRD_ETHER) { |
| jniThrowExceptionFmt(env, "java/net/SocketException", |
| "attachControlPacketFilter only supports ARPHRD_ETHER"); |
| return; |
| } |
| |
| // Capture all: |
| // - ARPs |
| // - DHCPv4 packets |
| // - Router Advertisements & Solicitations |
| // - Neighbor Advertisements & Solicitations |
| // |
| // tcpdump: |
| // arp or |
| // '(ip and udp port 68)' or |
| // '(icmp6 and ip6[40] >= 133 and ip6[40] <= 136)' |
| struct sock_filter filter_code[] = { |
| // Load the link layer next payload field. |
| BPF_STMT(BPF_LD | BPF_H | BPF_ABS, kEtherTypeOffset), |
| |
| // Accept all ARP. |
| // TODO: Figure out how to better filter ARPs on noisy networks. |
| BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, ETHERTYPE_ARP, 16, 0), |
| |
| // If IPv4: |
| BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, ETHERTYPE_IP, 0, 9), |
| |
| // Check the protocol is UDP. |
| BPF_STMT(BPF_LD | BPF_B | BPF_ABS, kIPv4Protocol), |
| BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, IPPROTO_UDP, 0, 14), |
| |
| // Check this is not a fragment. |
| BPF_STMT(BPF_LD | BPF_H | BPF_ABS, kIPv4FlagsOffset), |
| BPF_JUMP(BPF_JMP | BPF_JSET | BPF_K, IP_OFFMASK, 12, 0), |
| |
| // Get the IP header length. |
| BPF_STMT(BPF_LDX | BPF_B | BPF_MSH, kEtherHeaderLen), |
| |
| // Check the source port. |
| BPF_STMT(BPF_LD | BPF_H | BPF_IND, kUDPSrcPortIndirectOffset), |
| BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, kDhcpClientPort, 8, 0), |
| |
| // Check the destination port. |
| BPF_STMT(BPF_LD | BPF_H | BPF_IND, kUDPDstPortIndirectOffset), |
| BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, kDhcpClientPort, 6, 7), |
| |
| // IPv6 ... |
| BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, ETHERTYPE_IPV6, 0, 6), |
| // ... check IPv6 Next Header is ICMPv6 (ignore fragments), ... |
| BPF_STMT(BPF_LD | BPF_B | BPF_ABS, kIPv6NextHeader), |
| BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, IPPROTO_ICMPV6, 0, 4), |
| // ... and check the ICMPv6 type is one of RS/RA/NS/NA. |
| BPF_STMT(BPF_LD | BPF_B | BPF_ABS, kICMPv6TypeOffset), |
| BPF_JUMP(BPF_JMP | BPF_JGE | BPF_K, ND_ROUTER_SOLICIT, 0, 2), |
| BPF_JUMP(BPF_JMP | BPF_JGT | BPF_K, ND_NEIGHBOR_ADVERT, 1, 0), |
| |
| // Accept or reject. |
| BPF_STMT(BPF_RET | BPF_K, 0xffff), |
| BPF_STMT(BPF_RET | BPF_K, 0) |
| }; |
| struct sock_fprog filter = { |
| sizeof(filter_code) / sizeof(filter_code[0]), |
| filter_code, |
| }; |
| |
| int fd = jniGetFDFromFileDescriptor(env, javaFd); |
| if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)) != 0) { |
| jniThrowExceptionFmt(env, "java/net/SocketException", |
| "setsockopt(SO_ATTACH_FILTER): %s", strerror(errno)); |
| } |
| } |
| |
| 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); |
| } |
| |
| static jint android_net_utils_getBoundNetworkForProcess(JNIEnv *env, jobject thiz) |
| { |
| return getNetworkForProcess(); |
| } |
| |
| static jboolean android_net_utils_bindProcessToNetworkForHostResolution(JNIEnv *env, jobject thiz, |
| jint netId) |
| { |
| return (jboolean) !setNetworkForResolv(netId); |
| } |
| |
| static jint android_net_utils_bindSocketToNetwork(JNIEnv *env, jobject thiz, jint socket, |
| jint netId) |
| { |
| return setNetworkForSocket(netId, socket); |
| } |
| |
| static jboolean android_net_utils_protectFromVpn(JNIEnv *env, jobject thiz, jint socket) |
| { |
| return (jboolean) !protectFromVpn(socket); |
| } |
| |
| static jboolean android_net_utils_queryUserAccess(JNIEnv *env, jobject thiz, jint uid, jint netId) |
| { |
| return (jboolean) !queryUserAccess(uid, netId); |
| } |
| |
| |
| // ---------------------------------------------------------------------------- |
| |
| /* |
| * JNI registration. |
| */ |
| static const JNINativeMethod gNetworkUtilMethods[] = { |
| /* name, signature, funcPtr */ |
| { "bindProcessToNetwork", "(I)Z", (void*) android_net_utils_bindProcessToNetwork }, |
| { "getBoundNetworkForProcess", "()I", (void*) android_net_utils_getBoundNetworkForProcess }, |
| { "bindProcessToNetworkForHostResolution", "(I)Z", (void*) android_net_utils_bindProcessToNetworkForHostResolution }, |
| { "bindSocketToNetwork", "(II)I", (void*) android_net_utils_bindSocketToNetwork }, |
| { "protectFromVpn", "(I)Z", (void*)android_net_utils_protectFromVpn }, |
| { "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 }, |
| { "attachControlPacketFilter", "(Ljava/io/FileDescriptor;I)V", (void*) android_net_utils_attachControlPacketFilter }, |
| { "setupRaSocket", "(Ljava/io/FileDescriptor;I)V", (void*) android_net_utils_setupRaSocket }, |
| }; |
| |
| int register_android_net_NetworkUtils(JNIEnv* env) |
| { |
| return RegisterMethodsOrDie(env, NETUTILS_PKG_NAME, gNetworkUtilMethods, |
| NELEM(gNetworkUtilMethods)); |
| } |
| |
| }; // namespace android |