diff --git a/Tethering/jni/android_net_util_TetheringUtils.cpp b/Tethering/jni/android_net_util_TetheringUtils.cpp
index 27c84cf..2e76501 100644
--- a/Tethering/jni/android_net_util_TetheringUtils.cpp
+++ b/Tethering/jni/android_net_util_TetheringUtils.cpp
@@ -34,6 +34,10 @@
 static const uint32_t kIPv6PayloadStart = sizeof(ip6_hdr);
 static const uint32_t kICMPv6TypeOffset = kIPv6PayloadStart + offsetof(icmp6_hdr, icmp6_type);
 
+static void throwSocketException(JNIEnv *env, const char* msg, int error) {
+    jniThrowExceptionFmt(env, "java/net/SocketException", "%s: %s", msg, strerror(error));
+}
+
 static void android_net_util_setupIcmpFilter(JNIEnv *env, jobject javaFd, uint32_t type) {
     sock_filter filter_code[] = {
         // Check header is ICMPv6.
@@ -56,8 +60,7 @@
 
     int fd = netjniutils::GetNativeFileDescriptor(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));
+        throwSocketException(env, "setsockopt(SO_ATTACH_FILTER)", errno);
     }
 }
 
@@ -84,8 +87,7 @@
     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));
+        throwSocketException(env, "setsockopt(ICMP6_FILTER)", errno);
         return;
     }
 
@@ -97,8 +99,7 @@
     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));
+        throwSocketException(env, "setsockopt(IPV6_MULTICAST_HOPS)", errno);
         return;
     }
 
@@ -106,8 +107,7 @@
     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));
+        throwSocketException(env, "setsockopt(IPV6_UNICAST_HOPS)", errno);
         return;
     }
 
@@ -115,16 +115,14 @@
     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));
+        throwSocketException(env, "setsockopt(IPV6_MULTICAST_LOOP)", 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));
+        throwSocketException(env, "setsockopt(IPV6_MULTICAST_IF)", errno);
         return;
     }
 
@@ -144,8 +142,7 @@
     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));
+        throwSocketException(env, "bind(IN6ADDR_ANY)", errno);
         return;
     }
 
@@ -156,8 +153,7 @@
     };
     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));
+        throwSocketException(env, "setsockopt(IPV6_JOIN_GROUP)", errno);
         return;
     }
 }
diff --git a/Tethering/jni/com_android_networkstack_tethering_BpfMap.cpp b/Tethering/jni/com_android_networkstack_tethering_BpfMap.cpp
index eadc210..7970a23 100644
--- a/Tethering/jni/com_android_networkstack_tethering_BpfMap.cpp
+++ b/Tethering/jni/com_android_networkstack_tethering_BpfMap.cpp
@@ -27,40 +27,11 @@
 
 namespace android {
 
-static jclass sErrnoExceptionClass;
-static jmethodID sErrnoExceptionCtor2;
-static jmethodID sErrnoExceptionCtor3;
-
-static void throwErrnoException(JNIEnv* env, const char* functionName, int error) {
-    if (sErrnoExceptionClass == nullptr || sErrnoExceptionClass == nullptr) return;
-
-    jthrowable cause = nullptr;
-    if (env->ExceptionCheck()) {
-        cause = env->ExceptionOccurred();
-        env->ExceptionClear();
-    }
-
-    ScopedLocalRef<jstring> msg(env, env->NewStringUTF(functionName));
-
-    // Not really much we can do here if msg is null, let's try to stumble on...
-    if (msg.get() == nullptr) env->ExceptionClear();
-
-    jobject errnoException;
-    if (cause != nullptr) {
-        errnoException = env->NewObject(sErrnoExceptionClass, sErrnoExceptionCtor3, msg.get(),
-                error, cause);
-    } else {
-        errnoException = env->NewObject(sErrnoExceptionClass, sErrnoExceptionCtor2, msg.get(),
-                error);
-    }
-    env->Throw(static_cast<jthrowable>(errnoException));
-}
-
 static jint com_android_networkstack_tethering_BpfMap_closeMap(JNIEnv *env, jobject clazz,
         jint fd) {
     int ret = close(fd);
 
-    if (ret) throwErrnoException(env, "closeMap", errno);
+    if (ret) jniThrowErrnoException(env, "closeMap", errno);
 
     return ret;
 }
@@ -82,13 +53,13 @@
     int ret = bpf::writeToMapEntry(static_cast<int>(fd), keyRO.get(), valueRO.get(),
             static_cast<int>(flags));
 
-    if (ret) throwErrnoException(env, "writeToMapEntry", errno);
+    if (ret) jniThrowErrnoException(env, "writeToMapEntry", errno);
 }
 
 static jboolean throwIfNotEnoent(JNIEnv *env, const char* functionName, int ret, int err) {
     if (ret == 0) return true;
 
-    if (err != ENOENT) throwErrnoException(env, functionName, err);
+    if (err != ENOENT) jniThrowErrnoException(env, functionName, err);
     return false;
 }
 
@@ -155,18 +126,6 @@
 };
 
 int register_com_android_networkstack_tethering_BpfMap(JNIEnv* env) {
-    sErrnoExceptionClass = static_cast<jclass>(env->NewGlobalRef(
-            env->FindClass("android/system/ErrnoException")));
-    if (sErrnoExceptionClass == nullptr) return JNI_ERR;
-
-    sErrnoExceptionCtor2 = env->GetMethodID(sErrnoExceptionClass, "<init>",
-            "(Ljava/lang/String;I)V");
-    if (sErrnoExceptionCtor2 == nullptr) return JNI_ERR;
-
-    sErrnoExceptionCtor3 = env->GetMethodID(sErrnoExceptionClass, "<init>",
-            "(Ljava/lang/String;ILjava/lang/Throwable;)V");
-    if (sErrnoExceptionCtor3 == nullptr) return JNI_ERR;
-
     return jniRegisterNativeMethods(env,
             "com/android/networkstack/tethering/BpfMap",
             gMethods, NELEM(gMethods));
diff --git a/Tethering/jni/com_android_networkstack_tethering_BpfUtils.cpp b/Tethering/jni/com_android_networkstack_tethering_BpfUtils.cpp
index 2fb5985..2d679a8 100644
--- a/Tethering/jni/com_android_networkstack_tethering_BpfUtils.cpp
+++ b/Tethering/jni/com_android_networkstack_tethering_BpfUtils.cpp
@@ -44,37 +44,36 @@
 const uint16_t NETLINK_REQUEST_FLAGS = NLM_F_REQUEST | NLM_F_ACK;
 const sockaddr_nl KERNEL_NLADDR = {AF_NETLINK, 0, 0, 0};
 
+static void throwIOException(JNIEnv *env, const char* msg, int error) {
+    jniThrowExceptionFmt(env, "java/io/IOException", "%s: %s", msg, strerror(error));
+}
+
 // TODO: move to frameworks/libs/net/common/native for sharing with
 // system/netd/server/OffloadUtils.{c, h}.
 static void sendAndProcessNetlinkResponse(JNIEnv* env, const void* req, int len) {
     int fd = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE);  // TODO: use unique_fd
     if (fd == -1) {
-        jniThrowExceptionFmt(env, "java/io/IOException",
-                             "socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE): %s",
-                             strerror(errno));
+        throwIOException(env, "socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE)", errno);
         return;
     }
 
     static constexpr int on = 1;
     if (setsockopt(fd, SOL_NETLINK, NETLINK_CAP_ACK, &on, sizeof(on))) {
-        jniThrowExceptionFmt(env, "java/io/IOException",
-                             "setsockopt(fd, SOL_NETLINK, NETLINK_CAP_ACK, %d)", on);
+        throwIOException(env, "setsockopt(fd, SOL_NETLINK, NETLINK_CAP_ACK, 1)", errno);
         close(fd);
         return;
     }
 
     // this is needed to get valid strace netlink parsing, it allocates the pid
     if (bind(fd, (const struct sockaddr*)&KERNEL_NLADDR, sizeof(KERNEL_NLADDR))) {
-        jniThrowExceptionFmt(env, "java/io/IOException", "bind(fd, {AF_NETLINK, 0, 0}): %s",
-                             strerror(errno));
+        throwIOException(env, "bind(fd, {AF_NETLINK, 0, 0})", errno);
         close(fd);
         return;
     }
 
     // we do not want to receive messages from anyone besides the kernel
     if (connect(fd, (const struct sockaddr*)&KERNEL_NLADDR, sizeof(KERNEL_NLADDR))) {
-        jniThrowExceptionFmt(env, "java/io/IOException", "connect(fd, {AF_NETLINK, 0, 0}): %s",
-                             strerror(errno));
+        throwIOException(env, "connect(fd, {AF_NETLINK, 0, 0})", errno);
         close(fd);
         return;
     }
@@ -82,15 +81,13 @@
     int rv = send(fd, req, len, 0);
 
     if (rv == -1) {
-        jniThrowExceptionFmt(env, "java/io/IOException", "send(fd, req, len, 0): %s",
-                             strerror(errno));
+        throwIOException(env, "send(fd, req, len, 0)", errno);
         close(fd);
         return;
     }
 
     if (rv != len) {
-        jniThrowExceptionFmt(env, "java/io/IOException", "send(fd, req, len, 0): %s",
-                             strerror(EMSGSIZE));
+        throwIOException(env, "send(fd, req, len, 0)", EMSGSIZE);
         close(fd);
         return;
     }
@@ -104,7 +101,7 @@
     rv = recv(fd, &resp, sizeof(resp), MSG_TRUNC);
 
     if (rv == -1) {
-        jniThrowExceptionFmt(env, "java/io/IOException", "recv() failed: %s", strerror(errno));
+        throwIOException(env, "recv() failed", errno);
         close(fd);
         return;
     }
@@ -131,8 +128,7 @@
     }
 
     if (resp.e.error) {  // returns 0 on success
-        jniThrowExceptionFmt(env, "java/io/IOException", "NLMSG_ERROR message return error: %s",
-                             strerror(-resp.e.error));
+        throwIOException(env, "NLMSG_ERROR message return error", -resp.e.error);
     }
     close(fd);
     return;
@@ -198,8 +194,7 @@
 
     const int bpfFd = bpf::retrieveProgram(pathname.c_str());
     if (bpfFd == -1) {
-        jniThrowExceptionFmt(env, "java/io/IOException", "retrieveProgram failed %s",
-                             strerror(errno));
+        throwIOException(env, "retrieveProgram failed", errno);
         return;
     }