[CLATJ#18] libclat: move clat tc and bpf utilis from netd
Move native functions from ClatdController and TcUtils to libclat
for jni ClatdCoordinator.
Bug: 212345928
Test: atest libclat_test
Change-Id: Ia4b344b07537d57c3e4ff1285b0e7b17e0c63c3e
diff --git a/service/native/libs/libclat/TcUtils.cpp b/service/native/libs/libclat/TcUtils.cpp
new file mode 100644
index 0000000..cdfb763
--- /dev/null
+++ b/service/native/libs/libclat/TcUtils.cpp
@@ -0,0 +1,390 @@
+/*
+ * 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.
+ */
+
+#define LOG_TAG "TcUtils"
+
+#include "libclat/TcUtils.h"
+
+#include <arpa/inet.h>
+#include <linux/if.h>
+#include <linux/if_arp.h>
+#include <linux/netlink.h>
+#include <linux/pkt_cls.h>
+#include <linux/pkt_sched.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <log/log.h>
+
+#include "android-base/unique_fd.h"
+
+namespace android {
+namespace net {
+
+using std::max;
+
+// Sync from system/netd/server/NetlinkCommands.h
+const sockaddr_nl KERNEL_NLADDR = {AF_NETLINK, 0, 0, 0};
+const uint16_t NETLINK_REQUEST_FLAGS = NLM_F_REQUEST | NLM_F_ACK;
+
+static int doSIOCGIF(const std::string& interface, int opt) {
+ base::unique_fd ufd(socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0));
+
+ if (ufd < 0) {
+ const int err = errno;
+ ALOGE("socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0)");
+ return -err;
+ };
+
+ struct ifreq ifr = {};
+ // We use strncpy() instead of strlcpy() since kernel has to be able
+ // to handle non-zero terminated junk passed in by userspace anyway,
+ // and this way too long interface names (more than IFNAMSIZ-1 = 15
+ // characters plus terminating NULL) will not get truncated to 15
+ // characters and zero-terminated and thus potentially erroneously
+ // match a truncated interface if one were to exist.
+ strncpy(ifr.ifr_name, interface.c_str(), sizeof(ifr.ifr_name));
+
+ if (ioctl(ufd, opt, &ifr, sizeof(ifr))) return -errno;
+
+ if (opt == SIOCGIFHWADDR) return ifr.ifr_hwaddr.sa_family;
+ if (opt == SIOCGIFMTU) return ifr.ifr_mtu;
+ return -EINVAL;
+}
+
+int hardwareAddressType(const std::string& interface) {
+ return doSIOCGIF(interface, SIOCGIFHWADDR);
+}
+
+int deviceMTU(const std::string& interface) {
+ return doSIOCGIF(interface, SIOCGIFMTU);
+}
+
+base::Result<bool> isEthernet(const std::string& interface) {
+ int rv = hardwareAddressType(interface);
+ if (rv < 0) {
+ errno = -rv;
+ return ErrnoErrorf("Get hardware address type of interface {} failed", interface);
+ }
+
+ switch (rv) {
+ case ARPHRD_ETHER:
+ return true;
+ case ARPHRD_NONE:
+ case ARPHRD_RAWIP: // in Linux 4.14+ rmnet support was upstreamed and this is 519
+ case 530: // this is ARPHRD_RAWIP on some Android 4.9 kernels with rmnet
+ return false;
+ default:
+ errno = EAFNOSUPPORT; // Address family not supported
+ return ErrnoErrorf("Unknown hardware address type {} on interface {}", rv, interface);
+ }
+}
+
+// TODO: use //system/netd/server/NetlinkCommands.cpp:openNetlinkSocket(protocol)
+// and //system/netd/server/SockDiag.cpp:checkError(fd)
+static int sendAndProcessNetlinkResponse(const void* req, int len) {
+ base::unique_fd fd(socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE));
+ if (fd == -1) {
+ const int err = errno;
+ ALOGE("socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, NETLINK_ROUTE)");
+ return -err;
+ }
+
+ static constexpr int on = 1;
+ int rv = setsockopt(fd, SOL_NETLINK, NETLINK_CAP_ACK, &on, sizeof(on));
+ if (rv) ALOGE("setsockopt(fd, SOL_NETLINK, NETLINK_CAP_ACK, %d)", on);
+
+ // this is needed to get sane strace netlink parsing, it allocates the pid
+ rv = bind(fd, (const struct sockaddr*)&KERNEL_NLADDR, sizeof(KERNEL_NLADDR));
+ if (rv) {
+ const int err = errno;
+ ALOGE("bind(fd, {AF_NETLINK, 0, 0})");
+ return -err;
+ }
+
+ // we do not want to receive messages from anyone besides the kernel
+ rv = connect(fd, (const struct sockaddr*)&KERNEL_NLADDR, sizeof(KERNEL_NLADDR));
+ if (rv) {
+ const int err = errno;
+ ALOGE("connect(fd, {AF_NETLINK, 0, 0})");
+ return -err;
+ }
+
+ rv = send(fd, req, len, 0);
+ if (rv == -1) return -errno;
+ if (rv != len) return -EMSGSIZE;
+
+ struct {
+ nlmsghdr h;
+ nlmsgerr e;
+ char buf[256];
+ } resp = {};
+
+ rv = recv(fd, &resp, sizeof(resp), MSG_TRUNC);
+
+ if (rv == -1) {
+ const int err = errno;
+ ALOGE("recv() failed");
+ return -err;
+ }
+
+ if (rv < (int)NLMSG_SPACE(sizeof(struct nlmsgerr))) {
+ ALOGE("recv() returned short packet: %d", rv);
+ return -EMSGSIZE;
+ }
+
+ if (resp.h.nlmsg_len != (unsigned)rv) {
+ ALOGE("recv() returned invalid header length: %d != %d", resp.h.nlmsg_len, rv);
+ return -EBADMSG;
+ }
+
+ if (resp.h.nlmsg_type != NLMSG_ERROR) {
+ ALOGE("recv() did not return NLMSG_ERROR message: %d", resp.h.nlmsg_type);
+ return -EBADMSG;
+ }
+
+ return resp.e.error; // returns 0 on success
+}
+
+// ADD: nlMsgType=RTM_NEWQDISC nlMsgFlags=NLM_F_EXCL|NLM_F_CREATE
+// REPLACE: nlMsgType=RTM_NEWQDISC nlMsgFlags=NLM_F_CREATE|NLM_F_REPLACE
+// DEL: nlMsgType=RTM_DELQDISC nlMsgFlags=0
+int doTcQdiscClsact(int ifIndex, uint16_t nlMsgType, uint16_t nlMsgFlags) {
+ // This is the name of the qdisc we are attaching.
+ // Some hoop jumping to make this compile time constant with known size,
+ // so that the structure declaration is well defined at compile time.
+#define CLSACT "clsact"
+ // sizeof() includes the terminating NULL
+ static constexpr size_t ASCIIZ_LEN_CLSACT = sizeof(CLSACT);
+
+ const struct {
+ nlmsghdr n;
+ tcmsg t;
+ struct {
+ nlattr attr;
+ char str[NLMSG_ALIGN(ASCIIZ_LEN_CLSACT)];
+ } kind;
+ } req = {
+ .n =
+ {
+ .nlmsg_len = sizeof(req),
+ .nlmsg_type = nlMsgType,
+ .nlmsg_flags = static_cast<__u16>(NETLINK_REQUEST_FLAGS | nlMsgFlags),
+ },
+ .t =
+ {
+ .tcm_family = AF_UNSPEC,
+ .tcm_ifindex = ifIndex,
+ .tcm_handle = TC_H_MAKE(TC_H_CLSACT, 0),
+ .tcm_parent = TC_H_CLSACT,
+ },
+ .kind =
+ {
+ .attr =
+ {
+ .nla_len = NLA_HDRLEN + ASCIIZ_LEN_CLSACT,
+ .nla_type = TCA_KIND,
+ },
+ .str = CLSACT,
+ },
+ };
+#undef CLSACT
+
+ return sendAndProcessNetlinkResponse(&req, sizeof(req));
+}
+
+// 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) {
+ // This is the name of the filter we're attaching (ie. this is the 'bpf'
+ // packet classifier enabled by kernel config option CONFIG_NET_CLS_BPF.
+ //
+ // We go through some hoops in order to make this compile time constants
+ // so that we can define the struct further down the function with the
+ // field for this sized correctly already during the build.
+#define BPF "bpf"
+ // sizeof() includes the terminating NULL
+ static constexpr size_t ASCIIZ_LEN_BPF = sizeof(BPF);
+
+ // This is to replicate program name suffix used by 'tc' Linux cli
+ // when it attaches programs.
+#define FSOBJ_SUFFIX ":[*fsobj]"
+
+ // This macro expands (from header files) to:
+ // prog_clatd_schedcls_ingress6_clat_rawip:[*fsobj]
+ // and is the name of the pinned ingress ebpf program for ARPHRD_RAWIP interfaces.
+ // (also compatible with anything that has 0 size L2 header)
+ static constexpr char name_clat_rx_rawip[] = CLAT_INGRESS6_PROG_RAWIP_NAME FSOBJ_SUFFIX;
+
+ // This macro expands (from header files) to:
+ // prog_clatd_schedcls_ingress6_clat_ether:[*fsobj]
+ // and is the name of the pinned ingress ebpf program for ARPHRD_ETHER interfaces.
+ // (also compatible with anything that has standard ethernet header)
+ static constexpr char name_clat_rx_ether[] = CLAT_INGRESS6_PROG_ETHER_NAME FSOBJ_SUFFIX;
+
+ // This macro expands (from header files) to:
+ // prog_clatd_schedcls_egress4_clat_rawip:[*fsobj]
+ // and is the name of the pinned egress ebpf program for ARPHRD_RAWIP interfaces.
+ // (also compatible with anything that has 0 size L2 header)
+ static constexpr char name_clat_tx_rawip[] = CLAT_EGRESS4_PROG_RAWIP_NAME FSOBJ_SUFFIX;
+
+ // This macro expands (from header files) to:
+ // prog_clatd_schedcls_egress4_clat_ether:[*fsobj]
+ // and is the name of the pinned egress ebpf program for ARPHRD_ETHER interfaces.
+ // (also compatible with anything that has standard ethernet header)
+ static constexpr char name_clat_tx_ether[] = CLAT_EGRESS4_PROG_ETHER_NAME FSOBJ_SUFFIX;
+
+#undef FSOBJ_SUFFIX
+
+ // The actual name we'll use is determined at run time via 'ethernet' and 'ingress'
+ // booleans. We need to compile time allocate enough space in the struct
+ // hence this macro magic to make sure we have enough space for either
+ // possibility. In practice some of these are actually the same size.
+ static constexpr size_t ASCIIZ_MAXLEN_NAME = max({
+ sizeof(name_clat_rx_rawip),
+ sizeof(name_clat_rx_ether),
+ sizeof(name_clat_tx_rawip),
+ sizeof(name_clat_tx_ether),
+ });
+
+ // These are not compile time constants: 'name' is used in strncpy below
+ const char* const name_clat_rx = ethernet ? name_clat_rx_ether : name_clat_rx_rawip;
+ const char* const name_clat_tx = ethernet ? name_clat_tx_ether : name_clat_tx_rawip;
+ const char* const name = ingress ? name_clat_rx : name_clat_tx;
+
+ struct {
+ nlmsghdr n;
+ tcmsg t;
+ struct {
+ nlattr attr;
+ char str[NLMSG_ALIGN(ASCIIZ_LEN_BPF)];
+ } kind;
+ struct {
+ nlattr attr;
+ struct {
+ nlattr attr;
+ __u32 u32;
+ } fd;
+ struct {
+ nlattr attr;
+ char str[NLMSG_ALIGN(ASCIIZ_MAXLEN_NAME)];
+ } name;
+ struct {
+ nlattr attr;
+ __u32 u32;
+ } flags;
+ } options;
+ } req = {
+ .n =
+ {
+ .nlmsg_len = sizeof(req),
+ .nlmsg_type = RTM_NEWTFILTER,
+ .nlmsg_flags = NETLINK_REQUEST_FLAGS | NLM_F_EXCL | NLM_F_CREATE,
+ },
+ .t =
+ {
+ .tcm_family = AF_UNSPEC,
+ .tcm_ifindex = ifIndex,
+ .tcm_handle = TC_H_UNSPEC,
+ .tcm_parent = TC_H_MAKE(TC_H_CLSACT,
+ ingress ? TC_H_MIN_INGRESS : TC_H_MIN_EGRESS),
+ .tcm_info = static_cast<__u32>((PRIO_CLAT << 16) | htons(proto)),
+ },
+ .kind =
+ {
+ .attr =
+ {
+ .nla_len = sizeof(req.kind),
+ .nla_type = TCA_KIND,
+ },
+ .str = BPF,
+ },
+ .options =
+ {
+ .attr =
+ {
+ .nla_len = sizeof(req.options),
+ .nla_type = NLA_F_NESTED | TCA_OPTIONS,
+ },
+ .fd =
+ {
+ .attr =
+ {
+ .nla_len = sizeof(req.options.fd),
+ .nla_type = TCA_BPF_FD,
+ },
+ .u32 = static_cast<__u32>(bpfFd),
+ },
+ .name =
+ {
+ .attr =
+ {
+ .nla_len = sizeof(req.options.name),
+ .nla_type = TCA_BPF_NAME,
+ },
+ // Visible via 'tc filter show', but
+ // is overwritten by strncpy below
+ .str = "placeholder",
+ },
+ .flags =
+ {
+ .attr =
+ {
+ .nla_len = sizeof(req.options.flags),
+ .nla_type = TCA_BPF_FLAGS,
+ },
+ .u32 = TCA_BPF_FLAG_ACT_DIRECT,
+ },
+ },
+ };
+#undef BPF
+
+ strncpy(req.options.name.str, name, sizeof(req.options.name.str));
+
+ return sendAndProcessNetlinkResponse(&req, sizeof(req));
+}
+
+// tc filter del dev .. in/egress prio 4 protocol ..
+int tcFilterDelDev(int ifIndex, bool ingress, uint16_t prio, uint16_t proto) {
+ const struct {
+ nlmsghdr n;
+ tcmsg t;
+ } req = {
+ .n =
+ {
+ .nlmsg_len = sizeof(req),
+ .nlmsg_type = RTM_DELTFILTER,
+ .nlmsg_flags = NETLINK_REQUEST_FLAGS,
+ },
+ .t =
+ {
+ .tcm_family = AF_UNSPEC,
+ .tcm_ifindex = ifIndex,
+ .tcm_handle = TC_H_UNSPEC,
+ .tcm_parent = TC_H_MAKE(TC_H_CLSACT,
+ ingress ? TC_H_MIN_INGRESS : TC_H_MIN_EGRESS),
+ .tcm_info = (static_cast<uint32_t>(prio) << 16) |
+ static_cast<uint32_t>(htons(proto)),
+ },
+ };
+
+ return sendAndProcessNetlinkResponse(&req, sizeof(req));
+}
+
+} // namespace net
+} // namespace android