Merge "Create Cronet's CTS for CronetEngine APIs"
diff --git a/OWNERS_core_networking b/OWNERS_core_networking
index 172670e..6d17476 100644
--- a/OWNERS_core_networking
+++ b/OWNERS_core_networking
@@ -1,4 +1,3 @@
-chenbruce@google.com
 chiachangwang@google.com
 cken@google.com
 huangaaron@google.com
diff --git a/bpf_progs/bpf_net_helpers.h b/bpf_progs/bpf_net_helpers.h
index c39269e..b7ca3af 100644
--- a/bpf_progs/bpf_net_helpers.h
+++ b/bpf_progs/bpf_net_helpers.h
@@ -21,6 +21,18 @@
 #include <stdbool.h>
 #include <stdint.h>
 
+// bionic kernel uapi linux/udp.h header is munged...
+#define __kernel_udphdr udphdr
+#include <linux/udp.h>
+
+// Offsets from beginning of L4 (TCP/UDP) header
+#define TCP_OFFSET(field) offsetof(struct tcphdr, field)
+#define UDP_OFFSET(field) offsetof(struct udphdr, field)
+
+// Offsets from beginning of L3 (IPv4/IPv6) header
+#define IP4_OFFSET(field) offsetof(struct iphdr, field)
+#define IP6_OFFSET(field) offsetof(struct ipv6hdr, field)
+
 // this returns 0 iff skb->sk is NULL
 static uint64_t (*bpf_get_socket_cookie)(struct __sk_buff* skb) = (void*)BPF_FUNC_get_socket_cookie;
 
diff --git a/bpf_progs/netd.c b/bpf_progs/netd.c
index 1272f96..84da79d 100644
--- a/bpf_progs/netd.c
+++ b/bpf_progs/netd.c
@@ -46,8 +46,9 @@
 static const bool INGRESS = false;
 static const bool EGRESS = true;
 
-#define IP_PROTO_OFF offsetof(struct iphdr, protocol)
-#define IPV6_PROTO_OFF offsetof(struct ipv6hdr, nexthdr)
+// Used for 'bool enable_tracing'
+static const bool TRACE_ON = true;
+static const bool TRACE_OFF = false;
 
 // offsetof(struct iphdr, ihl) -- but that's a bitfield
 #define IPPROTO_IHL_OFF 0
@@ -99,6 +100,19 @@
 /* never actually used from ebpf */
 DEFINE_BPF_MAP_NO_NETD(iface_index_name_map, HASH, uint32_t, IfaceValue, IFACE_INDEX_NAME_MAP_SIZE)
 
+// A single-element configuration array, packet tracing is enabled when 'true'.
+DEFINE_BPF_MAP_EXT(packet_trace_enabled_map, ARRAY, uint32_t, bool, 1,
+                   AID_ROOT, AID_SYSTEM, 0060, "fs_bpf_net_shared", "", false,
+                   BPFLOADER_IGNORED_ON_VERSION, BPFLOADER_MAX_VER, /*ignore_on_eng*/false,
+                   /*ignore_on_user*/true, /*ignore_on_userdebug*/false)
+
+// A ring buffer on which packet information is pushed. This map will only be loaded
+// on eng and userdebug devices. User devices won't load this to save memory.
+DEFINE_BPF_RINGBUF_EXT(packet_trace_ringbuf, PacketTrace, PACKET_TRACE_BUF_SIZE,
+                       AID_ROOT, AID_SYSTEM, 0060, "fs_bpf_net_shared", "", false,
+                       BPFLOADER_IGNORED_ON_VERSION, BPFLOADER_MAX_VER, /*ignore_on_eng*/false,
+                       /*ignore_on_user*/true, /*ignore_on_userdebug*/false);
+
 // iptables xt_bpf programs need to be usable by both netd and netutils_wrappers
 // selinux contexts, because even non-xt_bpf iptables mutations are implemented as
 // a full table dump, followed by an update in userspace, and then a reload into the kernel,
@@ -226,12 +240,72 @@
         : bpf_skb_load_bytes(skb, L3_off, to, len);
 }
 
+static __always_inline inline void do_packet_tracing(
+        const struct __sk_buff* const skb, const bool egress, const uint32_t uid,
+        const uint32_t tag, const bool enable_tracing, const unsigned kver) {
+    if (!enable_tracing) return;
+    if (kver < KVER(5, 8, 0)) return;
+
+    uint32_t mapKey = 0;
+    bool* traceConfig = bpf_packet_trace_enabled_map_lookup_elem(&mapKey);
+    if (traceConfig == NULL) return;
+    if (*traceConfig == false) return;
+
+    PacketTrace* pkt = bpf_packet_trace_ringbuf_reserve();
+    if (pkt == NULL) return;
+
+    // Errors from bpf_skb_load_bytes_net are ignored to favor returning something
+    // over returning nothing. In the event of an error, the kernel will fill in
+    // zero for the destination memory. Do not change the default '= 0' below.
+
+    uint8_t proto = 0;
+    uint8_t L4_off = 0;
+    uint8_t ipVersion = 0;
+    if (skb->protocol == htons(ETH_P_IP)) {
+        (void)bpf_skb_load_bytes_net(skb, IP4_OFFSET(protocol), &proto, sizeof(proto), kver);
+        (void)bpf_skb_load_bytes_net(skb, IPPROTO_IHL_OFF, &L4_off, sizeof(L4_off), kver);
+        L4_off = (L4_off & 0x0F) * 4;  // IHL calculation.
+        ipVersion = 4;
+    } else if (skb->protocol == htons(ETH_P_IPV6)) {
+        (void)bpf_skb_load_bytes_net(skb, IP6_OFFSET(nexthdr), &proto, sizeof(proto), kver);
+        L4_off = sizeof(struct ipv6hdr);
+        ipVersion = 6;
+    }
+
+    uint8_t flags = 0;
+    __be16 sport = 0, dport = 0;
+    if (proto == IPPROTO_TCP && L4_off >= 20) {
+        (void)bpf_skb_load_bytes_net(skb, L4_off + TCP_FLAG32_OFF + 1, &flags, sizeof(flags), kver);
+        (void)bpf_skb_load_bytes_net(skb, L4_off + TCP_OFFSET(source), &sport, sizeof(sport), kver);
+        (void)bpf_skb_load_bytes_net(skb, L4_off + TCP_OFFSET(dest), &dport, sizeof(dport), kver);
+    } else if (proto == IPPROTO_UDP && L4_off >= 20) {
+        (void)bpf_skb_load_bytes_net(skb, L4_off + UDP_OFFSET(source), &sport, sizeof(sport), kver);
+        (void)bpf_skb_load_bytes_net(skb, L4_off + UDP_OFFSET(dest), &dport, sizeof(dport), kver);
+    }
+
+    pkt->timestampNs = bpf_ktime_get_boot_ns();
+    pkt->ifindex = skb->ifindex;
+    pkt->length = skb->len;
+
+    pkt->uid = uid;
+    pkt->tag = tag;
+    pkt->sport = sport;
+    pkt->dport = dport;
+
+    pkt->egress = egress;
+    pkt->ipProto = proto;
+    pkt->tcpFlags = flags;
+    pkt->ipVersion = ipVersion;
+
+    bpf_packet_trace_ringbuf_submit(pkt);
+}
+
 static __always_inline inline bool skip_owner_match(struct __sk_buff* skb, const unsigned kver) {
     uint32_t flag = 0;
     if (skb->protocol == htons(ETH_P_IP)) {
         uint8_t proto;
         // no need to check for success, proto will be zeroed if bpf_skb_load_bytes_net() fails
-        (void)bpf_skb_load_bytes_net(skb, IP_PROTO_OFF, &proto, sizeof(proto), kver);
+        (void)bpf_skb_load_bytes_net(skb, IP4_OFFSET(protocol), &proto, sizeof(proto), kver);
         if (proto == IPPROTO_ESP) return true;
         if (proto != IPPROTO_TCP) return false;  // handles read failure above
         uint8_t ihl;
@@ -247,7 +321,7 @@
     } else if (skb->protocol == htons(ETH_P_IPV6)) {
         uint8_t proto;
         // no need to check for success, proto will be zeroed if bpf_skb_load_bytes_net() fails
-        (void)bpf_skb_load_bytes_net(skb, IPV6_PROTO_OFF, &proto, sizeof(proto), kver);
+        (void)bpf_skb_load_bytes_net(skb, IP6_OFFSET(nexthdr), &proto, sizeof(proto), kver);
         if (proto == IPPROTO_ESP) return true;
         if (proto != IPPROTO_TCP) return false;  // handles read failure above
         // if the read below fails, we'll just assume no TCP flags are set, which is fine.
@@ -319,6 +393,7 @@
 }
 
 static __always_inline inline int bpf_traffic_account(struct __sk_buff* skb, bool egress,
+                                                      const bool enable_tracing,
                                                       const unsigned kver) {
     uint32_t sock_uid = bpf_get_socket_uid(skb);
     uint64_t cookie = bpf_get_socket_cookie(skb);
@@ -378,34 +453,51 @@
         key.tag = 0;
     }
 
+    do_packet_tracing(skb, egress, uid, tag, enable_tracing, kver);
     update_stats_with_config(skb, egress, &key, *selectedMap);
     update_app_uid_stats_map(skb, egress, &uid);
     asm("%0 &= 1" : "+r"(match));
     return match;
 }
 
+DEFINE_BPF_PROG_EXT("cgroupskb/ingress/stats$trace", AID_ROOT, AID_SYSTEM,
+                    bpf_cgroup_ingress_trace, KVER(5, 8, 0), KVER_INF,
+                    BPFLOADER_IGNORED_ON_VERSION, BPFLOADER_MAX_VER, false,
+                    "fs_bpf_netd_readonly", "", false, true, false)
+(struct __sk_buff* skb) {
+    return bpf_traffic_account(skb, INGRESS, TRACE_ON, KVER(5, 8, 0));
+}
+
 DEFINE_NETD_BPF_PROG_KVER_RANGE("cgroupskb/ingress/stats$4_19", AID_ROOT, AID_SYSTEM,
                                 bpf_cgroup_ingress_4_19, KVER(4, 19, 0), KVER_INF)
 (struct __sk_buff* skb) {
-    return bpf_traffic_account(skb, INGRESS, KVER(4, 19, 0));
+    return bpf_traffic_account(skb, INGRESS, TRACE_OFF, KVER(4, 19, 0));
 }
 
 DEFINE_NETD_BPF_PROG_KVER_RANGE("cgroupskb/ingress/stats$4_14", AID_ROOT, AID_SYSTEM,
                                 bpf_cgroup_ingress_4_14, KVER_NONE, KVER(4, 19, 0))
 (struct __sk_buff* skb) {
-    return bpf_traffic_account(skb, INGRESS, KVER_NONE);
+    return bpf_traffic_account(skb, INGRESS, TRACE_OFF, KVER_NONE);
+}
+
+DEFINE_BPF_PROG_EXT("cgroupskb/egress/stats$trace", AID_ROOT, AID_SYSTEM,
+                    bpf_cgroup_egress_trace, KVER(5, 8, 0), KVER_INF,
+                    BPFLOADER_IGNORED_ON_VERSION, BPFLOADER_MAX_VER, false,
+                    "fs_bpf_netd_readonly", "", false, true, false)
+(struct __sk_buff* skb) {
+    return bpf_traffic_account(skb, EGRESS, TRACE_ON, KVER(5, 8, 0));
 }
 
 DEFINE_NETD_BPF_PROG_KVER_RANGE("cgroupskb/egress/stats$4_19", AID_ROOT, AID_SYSTEM,
                                 bpf_cgroup_egress_4_19, KVER(4, 19, 0), KVER_INF)
 (struct __sk_buff* skb) {
-    return bpf_traffic_account(skb, EGRESS, KVER(4, 19, 0));
+    return bpf_traffic_account(skb, EGRESS, TRACE_OFF, KVER(4, 19, 0));
 }
 
 DEFINE_NETD_BPF_PROG_KVER_RANGE("cgroupskb/egress/stats$4_14", AID_ROOT, AID_SYSTEM,
                                 bpf_cgroup_egress_4_14, KVER_NONE, KVER(4, 19, 0))
 (struct __sk_buff* skb) {
-    return bpf_traffic_account(skb, EGRESS, KVER_NONE);
+    return bpf_traffic_account(skb, EGRESS, TRACE_OFF, KVER_NONE);
 }
 
 // WARNING: Android T's non-updatable netd depends on the name of this program.
diff --git a/bpf_progs/netd.h b/bpf_progs/netd.h
index cc88680..be604f9 100644
--- a/bpf_progs/netd.h
+++ b/bpf_progs/netd.h
@@ -69,6 +69,24 @@
     uint64_t tcpTxPackets;
 } Stats;
 
+typedef struct {
+  uint64_t timestampNs;
+  uint32_t ifindex;
+  uint32_t length;
+
+  uint32_t uid;
+  uint32_t tag;
+
+  __be16 sport;
+  __be16 dport;
+
+  bool egress;
+  uint8_t ipProto;
+  uint8_t tcpFlags;
+  uint8_t ipVersion; // 4=IPv4, 6=IPv6, 0=unknown
+} PacketTrace;
+STRUCT_SIZE(PacketTrace, 8+4+4 + 4+4 + 2+2 + 1+1+1+1);
+
 // Since we cannot garbage collect the stats map since device boot, we need to make these maps as
 // large as possible. The maximum size of number of map entries we can have is depend on the rlimit
 // of MEM_LOCK granted to netd. The memory space needed by each map can be calculated by the
@@ -87,7 +105,8 @@
 // dozable_uid_map:     key:  4 bytes, value:  1 bytes, cost:  145216 bytes    =   145Kbytes
 // standby_uid_map:     key:  4 bytes, value:  1 bytes, cost:  145216 bytes    =   145Kbytes
 // powersave_uid_map:   key:  4 bytes, value:  1 bytes, cost:  145216 bytes    =   145Kbytes
-// total:                                                                         4930Kbytes
+// packet_trace_ringbuf:key:  0 bytes, value: 24 bytes, cost:   32768 bytes    =    32Kbytes
+// total:                                                                         4962Kbytes
 // It takes maximum 4.9MB kernel memory space if all maps are full, which requires any devices
 // running this module to have a memlock rlimit to be larger then 5MB. In the old qtaguid module,
 // we don't have a total limit for data entries but only have limitation of tags each uid can have.
@@ -102,6 +121,7 @@
 static const int IFACE_STATS_MAP_SIZE = 1000;
 static const int CONFIGURATION_MAP_SIZE = 2;
 static const int UID_OWNER_MAP_SIZE = 4000;
+static const int PACKET_TRACE_BUF_SIZE = 32 * 1024;
 
 #ifdef __cplusplus
 
@@ -145,6 +165,8 @@
 #define CONFIGURATION_MAP_PATH BPF_NETD_PATH "map_netd_configuration_map"
 #define UID_OWNER_MAP_PATH BPF_NETD_PATH "map_netd_uid_owner_map"
 #define UID_PERMISSION_MAP_PATH BPF_NETD_PATH "map_netd_uid_permission_map"
+#define PACKET_TRACE_RINGBUF_PATH BPF_NETD_PATH "map_netd_packet_trace_ringbuf"
+#define PACKET_TRACE_ENABLED_MAP_PATH BPF_NETD_PATH "map_netd_packet_trace_enabled_map"
 
 #endif // __cplusplus
 
diff --git a/service-t/native/libs/libnetworkstats/Android.bp b/service-t/native/libs/libnetworkstats/Android.bp
index 5b3d314..5cb27e6 100644
--- a/service-t/native/libs/libnetworkstats/Android.bp
+++ b/service-t/native/libs/libnetworkstats/Android.bp
@@ -24,7 +24,8 @@
     host_supported: false,
     header_libs: ["bpf_connectivity_headers"],
     srcs: [
-        "BpfNetworkStats.cpp"
+        "BpfNetworkStats.cpp",
+        "NetworkTraceHandler.cpp",
     ],
     shared_libs: [
         "libbase",
@@ -54,6 +55,7 @@
     header_libs: ["bpf_connectivity_headers"],
     srcs: [
         "BpfNetworkStatsTest.cpp",
+        "NetworkTraceHandlerTest.cpp",
     ],
     cflags: [
         "-Wall",
@@ -68,6 +70,7 @@
     shared_libs: [
         "libbase",
         "liblog",
+        "libandroid_net",
     ],
     compile_multilib: "both",
     multilib: {
diff --git a/service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp b/service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp
new file mode 100644
index 0000000..c679357
--- /dev/null
+++ b/service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2023 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 "NetworkTrace"
+
+#include "netdbpf/NetworkTraceHandler.h"
+
+#include <bpf/BpfUtils.h>
+#include <log/log.h>
+
+namespace android {
+namespace bpf {
+
+bool NetworkTraceHandler::Start() {
+  ALOGD("Starting datasource");
+
+  auto status = mConfigurationMap.init(PACKET_TRACE_ENABLED_MAP_PATH);
+  if (!status.ok()) {
+    ALOGW("Failed to bind config map: %s", status.error().message().c_str());
+    return false;
+  }
+
+  auto rb = BpfRingbuf<PacketTrace>::Create(PACKET_TRACE_RINGBUF_PATH);
+  if (!rb.ok()) {
+    ALOGW("Failed to create ringbuf: %s", rb.error().message().c_str());
+    return false;
+  }
+
+  mRingBuffer = std::move(*rb);
+
+  auto res = mConfigurationMap.writeValue(0, true, BPF_ANY);
+  if (!res.ok()) {
+    ALOGW("Failed to enable tracing: %s", res.error().message().c_str());
+    return false;
+  }
+
+  return true;
+}
+
+bool NetworkTraceHandler::Stop() {
+  ALOGD("Stopping datasource");
+
+  auto res = mConfigurationMap.writeValue(0, false, BPF_ANY);
+  if (!res.ok()) {
+    ALOGW("Failed to disable tracing: %s", res.error().message().c_str());
+    return false;
+  }
+
+  mRingBuffer.reset();
+
+  return true;
+}
+
+bool NetworkTraceHandler::ConsumeAll() {
+  if (mRingBuffer == nullptr) {
+    ALOGW("Tracing is not active");
+    return false;
+  }
+
+  base::Result<int> ret = mRingBuffer->ConsumeAll(mCallback);
+  if (!ret.ok()) {
+    ALOGW("Failed to poll ringbuf: %s", ret.error().message().c_str());
+    return false;
+  }
+
+  return true;
+}
+
+}  // namespace bpf
+}  // namespace android
diff --git a/service-t/native/libs/libnetworkstats/NetworkTraceHandlerTest.cpp b/service-t/native/libs/libnetworkstats/NetworkTraceHandlerTest.cpp
new file mode 100644
index 0000000..760ae91
--- /dev/null
+++ b/service-t/native/libs/libnetworkstats/NetworkTraceHandlerTest.cpp
@@ -0,0 +1,198 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+#include <android-base/unique_fd.h>
+#include <android/multinetwork.h>
+#include <arpa/inet.h>
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+#include <inttypes.h>
+#include <net/if.h>
+#include <netinet/tcp.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <vector>
+
+#include "netdbpf/NetworkTraceHandler.h"
+
+using ::testing::AllOf;
+using ::testing::AnyOf;
+using ::testing::Each;
+using ::testing::Eq;
+using ::testing::Field;
+using ::testing::Test;
+
+namespace android {
+namespace bpf {
+
+__be16 bindAndListen(int s) {
+  sockaddr_in sin = {.sin_family = AF_INET};
+  socklen_t len = sizeof(sin);
+  if (bind(s, (sockaddr*)&sin, sizeof(sin))) return 0;
+  if (listen(s, 1)) return 0;
+  if (getsockname(s, (sockaddr*)&sin, &len)) return 0;
+  return sin.sin_port;
+}
+
+// This takes tcp flag constants from the standard library and makes them usable
+// with the flags we get from BPF. The standard library flags are big endian
+// whereas the BPF flags are reported in host byte order. BPF also trims the
+// flags down to the 8 single-bit flag bits (fin, syn, rst, etc).
+constexpr inline uint8_t FlagToHost(__be32 be_unix_flags) {
+  return ntohl(be_unix_flags) >> 16;
+}
+
+// Pretty prints all fields for a list of packets (useful for debugging).
+struct PacketPrinter {
+  const std::vector<PacketTrace>& data;
+  static constexpr char kTcpFlagNames[] = "FSRPAUEC";
+
+  friend std::ostream& operator<<(std::ostream& os, const PacketPrinter& d) {
+    os << "Packet count: " << d.data.size();
+    for (const PacketTrace& info : d.data) {
+      os << "\nifidx=" << info.ifindex;
+      os << ", len=" << info.length;
+      os << ", uid=" << info.uid;
+      os << ", tag=" << info.tag;
+      os << ", sport=" << info.sport;
+      os << ", dport=" << info.dport;
+      os << ", direction=" << (info.egress ? "egress" : "ingress");
+      os << ", proto=" << static_cast<int>(info.ipProto);
+      os << ", ip=" << static_cast<int>(info.ipVersion);
+      os << ", flags=";
+      for (int i = 0; i < 8; i++) {
+        os << ((info.tcpFlags & (1 << i)) ? kTcpFlagNames[i] : '.');
+      }
+    }
+    return os;
+  }
+};
+
+class NetworkTraceHandlerTest : public testing::Test {
+ protected:
+  void SetUp() {
+    if (access(PACKET_TRACE_RINGBUF_PATH, R_OK)) {
+      GTEST_SKIP() << "Network tracing is not enabled/loaded on this build";
+    }
+  }
+};
+
+TEST_F(NetworkTraceHandlerTest, PollWhileInactive) {
+  NetworkTraceHandler handler([&](const PacketTrace& pkt) {});
+
+  // One succeed after start and before stop.
+  EXPECT_FALSE(handler.ConsumeAll());
+  ASSERT_TRUE(handler.Start());
+  EXPECT_TRUE(handler.ConsumeAll());
+  ASSERT_TRUE(handler.Stop());
+  EXPECT_FALSE(handler.ConsumeAll());
+}
+
+TEST_F(NetworkTraceHandlerTest, TraceTcpSession) {
+  __be16 server_port = 0;
+  std::vector<PacketTrace> packets;
+
+  // Record all packets with the bound address and current uid. This callback is
+  // involked only within ConsumeAll, at which point the port should have
+  // already been filled in and all packets have been processed.
+  NetworkTraceHandler handler([&](const PacketTrace& pkt) {
+    if (pkt.sport != server_port && pkt.dport != server_port) return;
+    if (pkt.uid != getuid()) return;
+    packets.push_back(pkt);
+  });
+
+  ASSERT_TRUE(handler.Start());
+  const uint32_t kClientTag = 2468;
+  const uint32_t kServerTag = 1357;
+
+  // Go through a typical connection sequence between two v4 sockets using tcp.
+  // This covers connection handshake, shutdown, and one data packet.
+  {
+    android::base::unique_fd clientsocket(socket(AF_INET, SOCK_STREAM, 0));
+    ASSERT_NE(-1, clientsocket) << "Failed to open client socket";
+    ASSERT_EQ(android_tag_socket(clientsocket, kClientTag), 0);
+
+    android::base::unique_fd serversocket(socket(AF_INET, SOCK_STREAM, 0));
+    ASSERT_NE(-1, serversocket) << "Failed to open server socket";
+    ASSERT_EQ(android_tag_socket(serversocket, kServerTag), 0);
+
+    server_port = bindAndListen(serversocket);
+    ASSERT_NE(0, server_port) << "Can't bind to server port";
+
+    sockaddr_in addr = {.sin_family = AF_INET, .sin_port = server_port};
+    ASSERT_EQ(0, connect(clientsocket, (sockaddr*)&addr, sizeof(addr)))
+        << "connect to loopback failed: " << strerror(errno);
+
+    int accepted = accept(serversocket, nullptr, nullptr);
+    ASSERT_NE(-1, accepted) << "accept connection failed: " << strerror(errno);
+
+    const char data[] = "abcdefghijklmnopqrstuvwxyz";
+    EXPECT_EQ(send(clientsocket, data, sizeof(data), 0), sizeof(data))
+        << "failed to send message: " << strerror(errno);
+
+    char buff[100] = {};
+    EXPECT_EQ(recv(accepted, buff, sizeof(buff), 0), sizeof(data))
+        << "failed to receive message: " << strerror(errno);
+
+    EXPECT_EQ(std::string(data), std::string(buff));
+  }
+
+  ASSERT_TRUE(handler.ConsumeAll());
+  ASSERT_TRUE(handler.Stop());
+
+  // There are 12 packets in total (6 messages: each seen by client & server):
+  // 1. Client connects to server with syn
+  // 2. Server responds with syn ack
+  // 3. Client responds with ack
+  // 4. Client sends data with psh ack
+  // 5. Server acks the data packet
+  // 6. Client closes connection with fin ack
+  ASSERT_EQ(packets.size(), 12) << PacketPrinter{packets};
+
+  // All packets should be TCP packets.
+  EXPECT_THAT(packets, Each(Field(&PacketTrace::ipProto, Eq(IPPROTO_TCP))));
+
+  // Packet 1: client requests connection with server.
+  EXPECT_EQ(packets[0].egress, 1) << PacketPrinter{packets};
+  EXPECT_EQ(packets[0].dport, server_port) << PacketPrinter{packets};
+  EXPECT_EQ(packets[0].tag, kClientTag) << PacketPrinter{packets};
+  EXPECT_EQ(packets[0].tcpFlags, FlagToHost(TCP_FLAG_SYN))
+      << PacketPrinter{packets};
+
+  // Packet 2: server receives request from client.
+  EXPECT_EQ(packets[1].egress, 0) << PacketPrinter{packets};
+  EXPECT_EQ(packets[1].dport, server_port) << PacketPrinter{packets};
+  EXPECT_EQ(packets[1].tag, kServerTag) << PacketPrinter{packets};
+  EXPECT_EQ(packets[1].tcpFlags, FlagToHost(TCP_FLAG_SYN))
+      << PacketPrinter{packets};
+
+  // Packet 3: server replies back with syn ack.
+  EXPECT_EQ(packets[2].egress, 1) << PacketPrinter{packets};
+  EXPECT_EQ(packets[2].sport, server_port) << PacketPrinter{packets};
+  EXPECT_EQ(packets[2].tcpFlags, FlagToHost(TCP_FLAG_SYN | TCP_FLAG_ACK))
+      << PacketPrinter{packets};
+
+  // Packet 4: client receives the server's syn ack.
+  EXPECT_EQ(packets[3].egress, 0) << PacketPrinter{packets};
+  EXPECT_EQ(packets[3].sport, server_port) << PacketPrinter{packets};
+  EXPECT_EQ(packets[3].tcpFlags, FlagToHost(TCP_FLAG_SYN | TCP_FLAG_ACK))
+      << PacketPrinter{packets};
+}
+
+}  // namespace bpf
+}  // namespace android
diff --git a/service-t/native/libs/libnetworkstats/include/netdbpf/NetworkTraceHandler.h b/service-t/native/libs/libnetworkstats/include/netdbpf/NetworkTraceHandler.h
new file mode 100644
index 0000000..67fcf41
--- /dev/null
+++ b/service-t/native/libs/libnetworkstats/include/netdbpf/NetworkTraceHandler.h
@@ -0,0 +1,54 @@
+/**
+ * Copyright (c) 2023, 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.
+ */
+
+#pragma once
+
+#include <string>
+#include <unordered_map>
+
+#include "bpf/BpfMap.h"
+#include "bpf/BpfRingbuf.h"
+
+// For PacketTrace struct definition
+#include "netd.h"
+
+namespace android {
+namespace bpf {
+
+class NetworkTraceHandler {
+ public:
+  // Initialize with a callback capable of intercepting data.
+  NetworkTraceHandler(std::function<void(const PacketTrace&)> callback)
+      : mCallback(std::move(callback)) {}
+
+  // Standalone functions without perfetto dependency.
+  bool Start();
+  bool Stop();
+  bool ConsumeAll();
+
+ private:
+  // The function to process PacketTrace, typically a Perfetto sink.
+  std::function<void(const PacketTrace&)> mCallback;
+
+  // The BPF ring buffer handle.
+  std::unique_ptr<BpfRingbuf<PacketTrace>> mRingBuffer;
+
+  // The packet tracing config map (really a 1-element array).
+  BpfMap<uint32_t, bool> mConfigurationMap;
+};
+
+}  // namespace bpf
+}  // namespace android
diff --git a/service-t/src/com/android/server/NsdService.java b/service-t/src/com/android/server/NsdService.java
index b361720..5dcf860 100644
--- a/service-t/src/com/android/server/NsdService.java
+++ b/service-t/src/com/android/server/NsdService.java
@@ -919,6 +919,12 @@
                             // interfaces that do not have an associated Network.
                             break;
                         }
+                        if (foundNetId == INetd.DUMMY_NET_ID) {
+                            // Ignore services on the dummy0 interface: they are only seen when
+                            // discovering locally advertised services, and are not reachable
+                            // through that interface.
+                            break;
+                        }
                         setServiceNetworkForCallback(servInfo, info.netId, info.interfaceIdx);
                         clientInfo.onServiceFound(clientId, servInfo);
                         break;
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index b9d2760..f5c6fb7 100755
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -6245,9 +6245,7 @@
         if (mOemNetworkPreferences.getNetworkPreferences().size() > 0) {
             handleSetOemNetworkPreference(mOemNetworkPreferences, null);
         }
-        if (!mProfileNetworkPreferences.isEmpty()) {
-            updateProfileAllowedNetworks();
-        }
+        updateProfileAllowedNetworks();
     }
 
     private void onUserRemoved(@NonNull final UserHandle user) {
diff --git a/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java b/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java
index 61b597a..f596b79 100644
--- a/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java
+++ b/tests/cts/net/src/android/net/cts/ConnectivityManagerTest.java
@@ -96,6 +96,7 @@
 import static com.android.net.module.util.NetworkStackConstants.TEST_CAPTIVE_PORTAL_HTTP_URL;
 import static com.android.networkstack.apishim.ConstantsShim.BLOCKED_REASON_LOCKDOWN_VPN;
 import static com.android.networkstack.apishim.ConstantsShim.BLOCKED_REASON_NONE;
+import static com.android.networkstack.apishim.ConstantsShim.RECEIVER_EXPORTED;
 import static com.android.testutils.Cleanup.testAndCleanup;
 import static com.android.testutils.DevSdkIgnoreRuleKt.SC_V2;
 import static com.android.testutils.MiscAsserts.assertThrows;
@@ -1131,7 +1132,8 @@
 
         final ConnectivityActionReceiver receiver = new ConnectivityActionReceiver(
                 mCm, ConnectivityManager.TYPE_WIFI, NetworkInfo.State.CONNECTED);
-        mContext.registerReceiver(receiver, filter);
+        final int flags = SdkLevel.isAtLeastT() ? RECEIVER_EXPORTED : 0;
+        mContext.registerReceiver(receiver, filter, flags);
 
         // Create a broadcast PendingIntent for NETWORK_CALLBACK_ACTION.
         final Intent intent = new Intent(NETWORK_CALLBACK_ACTION)
@@ -1225,7 +1227,8 @@
                     networkFuture.complete(intent.getParcelableExtra(EXTRA_NETWORK));
                 }
             };
-            mContext.registerReceiver(receiver, filter);
+            final int flags = SdkLevel.isAtLeastT() ? RECEIVER_EXPORTED : 0;
+            mContext.registerReceiver(receiver, filter, flags);
 
             final Network wifiNetwork = mCtsNetUtils.ensureWifiConnected();
             try {
diff --git a/tests/unit/java/com/android/server/ConnectivityServiceTest.java b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
index 17e769c..c9783ba 100755
--- a/tests/unit/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
@@ -15760,6 +15760,39 @@
     }
 
     @Test
+    public void testProfileNetworkPreferenceBlocking_addUser() throws Exception {
+        final InOrder inOrder = inOrder(mMockNetd);
+        doReturn(asList(PRIMARY_USER_HANDLE)).when(mUserManager).getUserHandles(anyBoolean());
+
+        // Only one network
+        mCellAgent = new TestNetworkAgentWrapper(TRANSPORT_CELLULAR);
+        mCellAgent.connect(true);
+
+        // Verify uid ranges 0~99999 are allowed
+        final ArraySet<UidRange> allowedRanges = new ArraySet<>();
+        allowedRanges.add(PRIMARY_UIDRANGE);
+        final NativeUidRangeConfig config1User = new NativeUidRangeConfig(
+                mCellAgent.getNetwork().netId,
+                toUidRangeStableParcels(allowedRanges),
+                0 /* subPriority */);
+        inOrder.verify(mMockNetd).setNetworkAllowlist(new NativeUidRangeConfig[] { config1User });
+
+        doReturn(asList(PRIMARY_USER_HANDLE, SECONDARY_USER_HANDLE))
+                .when(mUserManager).getUserHandles(anyBoolean());
+        final Intent addedIntent = new Intent(ACTION_USER_ADDED);
+        addedIntent.putExtra(Intent.EXTRA_USER, UserHandle.of(SECONDARY_USER));
+        processBroadcast(addedIntent);
+
+        // Make sure the allow list has been updated.
+        allowedRanges.add(UidRange.createForUser(SECONDARY_USER_HANDLE));
+        final NativeUidRangeConfig config2Users = new NativeUidRangeConfig(
+                mCellAgent.getNetwork().netId,
+                toUidRangeStableParcels(allowedRanges),
+                0 /* subPriority */);
+        inOrder.verify(mMockNetd).setNetworkAllowlist(new NativeUidRangeConfig[] { config2Users });
+    }
+
+    @Test
     public void testProfileNetworkPreferenceBlocking_changePreference() throws Exception {
         final InOrder inOrder = inOrder(mMockNetd);
         final UserHandle testHandle = setupEnterpriseNetwork();
diff --git a/tests/unit/java/com/android/server/NsdServiceTest.java b/tests/unit/java/com/android/server/NsdServiceTest.java
index c7a6639..98a8ed2 100644
--- a/tests/unit/java/com/android/server/NsdServiceTest.java
+++ b/tests/unit/java/com/android/server/NsdServiceTest.java
@@ -413,6 +413,35 @@
     }
 
     @Test
+    public void testDiscoverOnBlackholeNetwork() throws Exception {
+        final NsdManager client = connectClient(mService);
+        final DiscoveryListener discListener = mock(DiscoveryListener.class);
+        client.discoverServices(SERVICE_TYPE, PROTOCOL, discListener);
+        waitForIdle();
+
+        final IMDnsEventListener eventListener = getEventListener();
+        final ArgumentCaptor<Integer> discIdCaptor = ArgumentCaptor.forClass(Integer.class);
+        verify(mMockMDnsM).discover(discIdCaptor.capture(), eq(SERVICE_TYPE),
+                eq(0) /* interfaceIdx */);
+        // NsdManager uses a separate HandlerThread to dispatch callbacks (on ServiceHandler), so
+        // this needs to use a timeout
+        verify(discListener, timeout(TIMEOUT_MS)).onDiscoveryStarted(SERVICE_TYPE);
+
+        final DiscoveryInfo discoveryInfo = new DiscoveryInfo(
+                discIdCaptor.getValue(),
+                IMDnsEventListener.SERVICE_FOUND,
+                SERVICE_NAME,
+                SERVICE_TYPE,
+                DOMAIN_NAME,
+                123 /* interfaceIdx */,
+                INetd.DUMMY_NET_ID); // netId of the blackhole network
+        eventListener.onServiceDiscoveryStatus(discoveryInfo);
+        waitForIdle();
+
+        verify(discListener, never()).onServiceFound(any());
+    }
+
+    @Test
     public void testServiceRegistrationSuccessfulAndFailed() throws Exception {
         final NsdManager client = connectClient(mService);
         final NsdServiceInfo request = new NsdServiceInfo(SERVICE_NAME, SERVICE_TYPE);