Default implementation for CAN bus HAL
This implementation supports SocketCAN interfaces.
Bug: 135918744
Test: VTS (separate new change)
Change-Id: I12b93e37fa64e341bee2c64eaf130b39977fcef5
diff --git a/automotive/can/1.0/default/libnetdevice/libnetdevice.cpp b/automotive/can/1.0/default/libnetdevice/libnetdevice.cpp
new file mode 100644
index 0000000..fc2b193
--- /dev/null
+++ b/automotive/can/1.0/default/libnetdevice/libnetdevice.cpp
@@ -0,0 +1,100 @@
+/*
+ * 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.
+ */
+
+#include <libnetdevice/libnetdevice.h>
+
+#include "NetlinkRequest.h"
+#include "NetlinkSocket.h"
+#include "common.h"
+
+#include <android-base/logging.h>
+
+#include <linux/can.h>
+#include <net/if.h>
+
+namespace android {
+namespace netdevice {
+
+bool exists(std::string ifname) {
+ return nametoindex(ifname) != 0;
+}
+
+static bool sendIfreq(unsigned long request, struct ifreq& ifr) {
+ /* For general interfaces it would be socket(AF_INET, SOCK_DGRAM, 0),
+ * but SEPolicy forces us to limit our flexibility here. */
+ base::unique_fd sock(socket(PF_CAN, SOCK_RAW, CAN_RAW));
+ if (!sock.ok()) {
+ LOG(ERROR) << "Can't create socket";
+ return false;
+ }
+
+ if (ioctl(sock.get(), request, &ifr) < 0) {
+ LOG(ERROR) << "ioctl(" << std::hex << request << std::dec << ") failed: " << errno;
+ return false;
+ }
+
+ return true;
+}
+
+static struct ifreq ifreqFromName(const std::string& ifname) {
+ struct ifreq ifr = {};
+ strlcpy(ifr.ifr_name, ifname.c_str(), IF_NAMESIZE);
+ return ifr;
+}
+
+std::optional<bool> isUp(std::string ifname) {
+ struct ifreq ifr = ifreqFromName(ifname);
+ if (!sendIfreq(SIOCGIFFLAGS, ifr)) return std::nullopt;
+ return ifr.ifr_flags & IFF_UP;
+}
+
+bool up(std::string ifname) {
+ struct ifreq ifr = ifreqFromName(ifname);
+ if (!sendIfreq(SIOCGIFFLAGS, ifr)) return false;
+ ifr.ifr_flags |= IFF_UP;
+ return sendIfreq(SIOCSIFFLAGS, ifr);
+}
+
+bool down(std::string ifname) {
+ struct ifreq ifr = ifreqFromName(ifname);
+ if (!sendIfreq(SIOCGIFFLAGS, ifr)) return false;
+ ifr.ifr_flags &= ~IFF_UP;
+ return sendIfreq(SIOCSIFFLAGS, ifr);
+}
+
+bool add(std::string dev, std::string type) {
+ NetlinkRequest<struct ifinfomsg> req(RTM_NEWLINK, NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL);
+ req.addattr(IFLA_IFNAME, dev);
+
+ {
+ auto linkinfo = req.nest(IFLA_LINKINFO);
+ req.addattr(IFLA_INFO_KIND, type);
+ }
+
+ NetlinkSocket sock(NETLINK_ROUTE);
+ return sock.send(req) && sock.receiveAck();
+}
+
+bool del(std::string dev) {
+ NetlinkRequest<struct ifinfomsg> req(RTM_DELLINK, NLM_F_REQUEST);
+ req.addattr(IFLA_IFNAME, dev);
+
+ NetlinkSocket sock(NETLINK_ROUTE);
+ return sock.send(req) && sock.receiveAck();
+}
+
+} // namespace netdevice
+} // namespace android