1 files changed, 117 insertions, 0 deletions
diff --git a/server/TcUtils.h b/server/TcUtils.h
new file mode 100644
index 000000000..ef80fb04e
--- /dev/null
+++ b/server/TcUtils.h
@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) 2019 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 <android-base/result.h>
+#include <errno.h>
+#include <linux/if_ether.h>
+#include <linux/if_link.h>
+#include <linux/rtnetlink.h>
+
+#include <string>
+
+#include "bpf/BpfUtils.h"
+#include "netdbpf/bpf_shared.h"
+
+namespace android {
+namespace net {
+
+// For better code clarity - do not change values - used for booleans like
+// with_ethernet_header or isEthernet.
+constexpr bool RAWIP = false;
+constexpr bool ETHER = true;
+
+// For better code clarity when used for 'bool ingress' parameter.
+constexpr bool EGRESS = false;
+constexpr bool INGRESS = true;
+
+// The priority of clat hook - must be after tethering.
+constexpr uint16_t PRIO_CLAT = 4;
+
+// this returns an ARPHRD_* constant or a -errno
+int hardwareAddressType(const std::string& interface);
+
+// return MTU or -errno
+int deviceMTU(const std::string& interface);
+
+base::Result<bool> isEthernet(const std::string& interface);
+
+inline int getClatEgress4MapFd(void) {
+    const int fd = bpf::mapRetrieveRW(CLAT_EGRESS4_MAP_PATH);
+    return (fd == -1) ? -errno : fd;
+}
+
+inline int getClatEgress4ProgFd(bool with_ethernet_header) {
+    const int fd = bpf::retrieveProgram(with_ethernet_header ? CLAT_EGRESS4_PROG_ETHER_PATH
+                                                             : CLAT_EGRESS4_PROG_RAWIP_PATH);
+    return (fd == -1) ? -errno : fd;
+}
+
+inline int getClatIngress6MapFd(void) {
+    const int fd = bpf::mapRetrieveRW(CLAT_INGRESS6_MAP_PATH);
+    return (fd == -1) ? -errno : fd;
+}
+
+inline int getClatIngress6ProgFd(bool with_ethernet_header) {
+    const int fd = bpf::retrieveProgram(with_ethernet_header ? CLAT_INGRESS6_PROG_ETHER_PATH
+                                                             : CLAT_INGRESS6_PROG_RAWIP_PATH);
+    return (fd == -1) ? -errno : fd;
+}
+
+int doTcQdiscClsact(int ifIndex, uint16_t nlMsgType, uint16_t nlMsgFlags);
+
+inline int tcQdiscAddDevClsact(int ifIndex) {
+    return doTcQdiscClsact(ifIndex, RTM_NEWQDISC, NLM_F_EXCL | NLM_F_CREATE);
+}
+
+inline int tcQdiscReplaceDevClsact(int ifIndex) {
+    return doTcQdiscClsact(ifIndex, RTM_NEWQDISC, NLM_F_CREATE | NLM_F_REPLACE);
+}
+
+inline int tcQdiscDelDevClsact(int ifIndex) {
+    return doTcQdiscClsact(ifIndex, RTM_DELQDISC, 0);
+}
+
+// tc filter add dev .. in/egress prio 4 protocol ipv6/ip bpf object-pinned /sys/fs/bpf/...
+// direct-action
+int tcFilterAddDevBpf(int ifIndex, bool ingress, uint16_t proto, int bpfFd, bool ethernet);
+
+// tc filter add dev .. ingress prio 4 protocol ipv6 bpf object-pinned /sys/fs/bpf/... direct-action
+inline int tcFilterAddDevIngressClatIpv6(int ifIndex, int bpfFd, bool ethernet) {
+    return tcFilterAddDevBpf(ifIndex, INGRESS, ETH_P_IPV6, bpfFd, ethernet);
+}
+
+// tc filter add dev .. egress prio 4 protocol ip bpf object-pinned /sys/fs/bpf/... direct-action
+inline int tcFilterAddDevEgressClatIpv4(int ifIndex, int bpfFd, bool ethernet) {
+    return tcFilterAddDevBpf(ifIndex, EGRESS, ETH_P_IP, bpfFd, ethernet);
+}
+
+// tc filter del dev .. in/egress prio .. protocol ..
+int tcFilterDelDev(int ifIndex, bool ingress, uint16_t prio, uint16_t proto);
+
+// tc filter del dev .. ingress prio 4 protocol ipv6
+inline int tcFilterDelDevIngressClatIpv6(int ifIndex) {
+    return tcFilterDelDev(ifIndex, INGRESS, PRIO_CLAT, ETH_P_IPV6);
+}
+
+// tc filter del dev .. egress prio 4 protocol ip
+inline int tcFilterDelDevEgressClatIpv4(int ifIndex) {
+    return tcFilterDelDev(ifIndex, EGRESS, PRIO_CLAT, ETH_P_IP);
+}
+
+}  // namespace net
+}  // namespace android