xref: /aosp_15_r20/hardware/interfaces/automotive/can/1.0/default/CanController.cpp (revision 4d7e907c777eeecc4c5bd7cf640a754fac206ff7)
1*4d7e907cSAndroid Build Coastguard Worker /*
2*4d7e907cSAndroid Build Coastguard Worker  * Copyright (C) 2019 The Android Open Source Project
3*4d7e907cSAndroid Build Coastguard Worker  *
4*4d7e907cSAndroid Build Coastguard Worker  * Licensed under the Apache License, Version 2.0 (the "License");
5*4d7e907cSAndroid Build Coastguard Worker  * you may not use this file except in compliance with the License.
6*4d7e907cSAndroid Build Coastguard Worker  * You may obtain a copy of the License at
7*4d7e907cSAndroid Build Coastguard Worker  *
8*4d7e907cSAndroid Build Coastguard Worker  *      http://www.apache.org/licenses/LICENSE-2.0
9*4d7e907cSAndroid Build Coastguard Worker  *
10*4d7e907cSAndroid Build Coastguard Worker  * Unless required by applicable law or agreed to in writing, software
11*4d7e907cSAndroid Build Coastguard Worker  * distributed under the License is distributed on an "AS IS" BASIS,
12*4d7e907cSAndroid Build Coastguard Worker  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13*4d7e907cSAndroid Build Coastguard Worker  * See the License for the specific language governing permissions and
14*4d7e907cSAndroid Build Coastguard Worker  * limitations under the License.
15*4d7e907cSAndroid Build Coastguard Worker  */
16*4d7e907cSAndroid Build Coastguard Worker 
17*4d7e907cSAndroid Build Coastguard Worker #include "CanController.h"
18*4d7e907cSAndroid Build Coastguard Worker 
19*4d7e907cSAndroid Build Coastguard Worker #include "CanBusNative.h"
20*4d7e907cSAndroid Build Coastguard Worker #include "CanBusSlcan.h"
21*4d7e907cSAndroid Build Coastguard Worker #include "CanBusVirtual.h"
22*4d7e907cSAndroid Build Coastguard Worker 
23*4d7e907cSAndroid Build Coastguard Worker #include <android-base/logging.h>
24*4d7e907cSAndroid Build Coastguard Worker #include <android/hidl/manager/1.2/IServiceManager.h>
25*4d7e907cSAndroid Build Coastguard Worker 
26*4d7e907cSAndroid Build Coastguard Worker #include <filesystem>
27*4d7e907cSAndroid Build Coastguard Worker #include <fstream>
28*4d7e907cSAndroid Build Coastguard Worker #include <regex>
29*4d7e907cSAndroid Build Coastguard Worker 
30*4d7e907cSAndroid Build Coastguard Worker namespace android::hardware::automotive::can::V1_0::implementation {
31*4d7e907cSAndroid Build Coastguard Worker 
32*4d7e907cSAndroid Build Coastguard Worker using IfId = ICanController::BusConfig::InterfaceId;
33*4d7e907cSAndroid Build Coastguard Worker using IfIdDisc = ICanController::BusConfig::InterfaceId::hidl_discriminator;
34*4d7e907cSAndroid Build Coastguard Worker namespace fs = ::std::filesystem;
35*4d7e907cSAndroid Build Coastguard Worker 
36*4d7e907cSAndroid Build Coastguard Worker namespace fsErrors {
37*4d7e907cSAndroid Build Coastguard Worker static const std::error_code ok;
38*4d7e907cSAndroid Build Coastguard Worker static const std::error_code eperm(EPERM, std::generic_category());
39*4d7e907cSAndroid Build Coastguard Worker static const std::error_code enoent(ENOENT, std::generic_category());
40*4d7e907cSAndroid Build Coastguard Worker static const std::error_code eacces(EACCES, std::generic_category());
41*4d7e907cSAndroid Build Coastguard Worker }  // namespace fsErrors
42*4d7e907cSAndroid Build Coastguard Worker 
43*4d7e907cSAndroid Build Coastguard Worker /* In the /sys/devices tree, there are files called "serial", which contain the serial numbers
44*4d7e907cSAndroid Build Coastguard Worker  * for various devices. The exact location inside of this directory is dependent upon the
45*4d7e907cSAndroid Build Coastguard Worker  * hardware we are running on, so we have to start from /sys/devices and work our way down. */
46*4d7e907cSAndroid Build Coastguard Worker static const fs::path kDevPath("/sys/devices/");
47*4d7e907cSAndroid Build Coastguard Worker static const std::regex kTtyRe("^tty[A-Z]+[0-9]+$");
48*4d7e907cSAndroid Build Coastguard Worker static constexpr auto kOpts = ~(fs::directory_options::follow_directory_symlink |
49*4d7e907cSAndroid Build Coastguard Worker                                 fs::directory_options::skip_permission_denied);
50*4d7e907cSAndroid Build Coastguard Worker 
51*4d7e907cSAndroid Build Coastguard Worker /**
52*4d7e907cSAndroid Build Coastguard Worker  * A helper object to associate the interface name and type of a USB to CAN adapter.
53*4d7e907cSAndroid Build Coastguard Worker  */
54*4d7e907cSAndroid Build Coastguard Worker struct UsbCanIface {
55*4d7e907cSAndroid Build Coastguard Worker     ICanController::InterfaceType iftype;
56*4d7e907cSAndroid Build Coastguard Worker     std::string ifaceName;
57*4d7e907cSAndroid Build Coastguard Worker };
58*4d7e907cSAndroid Build Coastguard Worker 
getSupportedInterfaceTypes(getSupportedInterfaceTypes_cb _hidl_cb)59*4d7e907cSAndroid Build Coastguard Worker Return<void> CanController::getSupportedInterfaceTypes(getSupportedInterfaceTypes_cb _hidl_cb) {
60*4d7e907cSAndroid Build Coastguard Worker     _hidl_cb({ICanController::InterfaceType::VIRTUAL, ICanController::InterfaceType::SOCKETCAN,
61*4d7e907cSAndroid Build Coastguard Worker               ICanController::InterfaceType::SLCAN});
62*4d7e907cSAndroid Build Coastguard Worker     return {};
63*4d7e907cSAndroid Build Coastguard Worker }
64*4d7e907cSAndroid Build Coastguard Worker 
isValidName(const std::string & name)65*4d7e907cSAndroid Build Coastguard Worker static bool isValidName(const std::string& name) {
66*4d7e907cSAndroid Build Coastguard Worker     static const std::regex nameRE("^[a-zA-Z0-9_]{1,32}$");
67*4d7e907cSAndroid Build Coastguard Worker     return std::regex_match(name, nameRE);
68*4d7e907cSAndroid Build Coastguard Worker }
69*4d7e907cSAndroid Build Coastguard Worker 
70*4d7e907cSAndroid Build Coastguard Worker /**
71*4d7e907cSAndroid Build Coastguard Worker  * Given a UsbCanIface object, get the ifaceName given the serialPath.
72*4d7e907cSAndroid Build Coastguard Worker  *
73*4d7e907cSAndroid Build Coastguard Worker  * \param serialPath - Absolute path to a "serial" file for a given device in /sys.
74*4d7e907cSAndroid Build Coastguard Worker  * \return A populated UsbCanIface. On failure, nullopt is returned.
75*4d7e907cSAndroid Build Coastguard Worker  */
getIfaceName(fs::path serialPath)76*4d7e907cSAndroid Build Coastguard Worker static std::optional<UsbCanIface> getIfaceName(fs::path serialPath) {
77*4d7e907cSAndroid Build Coastguard Worker     std::error_code fsStatus;
78*4d7e907cSAndroid Build Coastguard Worker     // Since the path is to a file called "serial", we need to search its parent directory.
79*4d7e907cSAndroid Build Coastguard Worker     fs::recursive_directory_iterator fsItr(serialPath.parent_path(), kOpts, fsStatus);
80*4d7e907cSAndroid Build Coastguard Worker     if (fsStatus != fsErrors::ok) {
81*4d7e907cSAndroid Build Coastguard Worker         LOG(ERROR) << "Failed to open " << serialPath.parent_path();
82*4d7e907cSAndroid Build Coastguard Worker         return std::nullopt;
83*4d7e907cSAndroid Build Coastguard Worker     }
84*4d7e907cSAndroid Build Coastguard Worker 
85*4d7e907cSAndroid Build Coastguard Worker     for (; fsStatus == fsErrors::ok && fsItr != fs::recursive_directory_iterator();
86*4d7e907cSAndroid Build Coastguard Worker          fsItr.increment(fsStatus)) {
87*4d7e907cSAndroid Build Coastguard Worker         /* We want either a directory called "net" or a directory that looks like tty<something>, so
88*4d7e907cSAndroid Build Coastguard Worker          * skip files. */
89*4d7e907cSAndroid Build Coastguard Worker         bool isDir = fsItr->is_directory(fsStatus);
90*4d7e907cSAndroid Build Coastguard Worker         if (fsStatus != fsErrors::ok || !isDir) continue;
91*4d7e907cSAndroid Build Coastguard Worker 
92*4d7e907cSAndroid Build Coastguard Worker         /* path() returns an iterator that steps through directories from / to the leaf.
93*4d7e907cSAndroid Build Coastguard Worker          * end() returns one past the leaf of the path, but we want the leaf. Decrementing the
94*4d7e907cSAndroid Build Coastguard Worker          * path gives us a pointer to the leaf, which we then dereference.*/
95*4d7e907cSAndroid Build Coastguard Worker         std::string currentDir = *(--(fsItr->path().end()));
96*4d7e907cSAndroid Build Coastguard Worker         if (currentDir == "net") {
97*4d7e907cSAndroid Build Coastguard Worker             /* This device is a SocketCAN device. The iface name is the only directory under
98*4d7e907cSAndroid Build Coastguard Worker              * net/. Multiple directories under net/ is an error.*/
99*4d7e907cSAndroid Build Coastguard Worker             fs::directory_iterator netItr(fsItr->path(), kOpts, fsStatus);
100*4d7e907cSAndroid Build Coastguard Worker             if (fsStatus != fsErrors::ok) {
101*4d7e907cSAndroid Build Coastguard Worker                 LOG(ERROR) << "Failed to open " << fsItr->path() << " to get net name!";
102*4d7e907cSAndroid Build Coastguard Worker                 return std::nullopt;
103*4d7e907cSAndroid Build Coastguard Worker             }
104*4d7e907cSAndroid Build Coastguard Worker 
105*4d7e907cSAndroid Build Coastguard Worker             // Get the leaf of the path. This is the interface name, assuming it's the only leaf.
106*4d7e907cSAndroid Build Coastguard Worker             std::string netName = *(--(netItr->path().end()));
107*4d7e907cSAndroid Build Coastguard Worker 
108*4d7e907cSAndroid Build Coastguard Worker             // Check if there is more than one item in net/
109*4d7e907cSAndroid Build Coastguard Worker             netItr.increment(fsStatus);
110*4d7e907cSAndroid Build Coastguard Worker             if (fsStatus != fsErrors::ok) {
111*4d7e907cSAndroid Build Coastguard Worker                 // It's possible we have a valid net name, but this is most likely an error.
112*4d7e907cSAndroid Build Coastguard Worker                 LOG(ERROR) << "Failed to verify " << fsItr->path() << " has valid net name!";
113*4d7e907cSAndroid Build Coastguard Worker                 return std::nullopt;
114*4d7e907cSAndroid Build Coastguard Worker             }
115*4d7e907cSAndroid Build Coastguard Worker             if (netItr != fs::directory_iterator()) {
116*4d7e907cSAndroid Build Coastguard Worker                 // There should never be more than one name under net/
117*4d7e907cSAndroid Build Coastguard Worker                 LOG(ERROR) << "Found more than one net name in " << fsItr->path() << "!";
118*4d7e907cSAndroid Build Coastguard Worker                 return std::nullopt;
119*4d7e907cSAndroid Build Coastguard Worker             }
120*4d7e907cSAndroid Build Coastguard Worker             return {{ICanController::InterfaceType::SOCKETCAN, netName}};
121*4d7e907cSAndroid Build Coastguard Worker         } else if (std::regex_match(currentDir, kTtyRe)) {
122*4d7e907cSAndroid Build Coastguard Worker             // This device is a USB serial device, and currentDir is the tty name.
123*4d7e907cSAndroid Build Coastguard Worker             return {{ICanController::InterfaceType::SLCAN, "/dev/" + currentDir}};
124*4d7e907cSAndroid Build Coastguard Worker         }
125*4d7e907cSAndroid Build Coastguard Worker     }
126*4d7e907cSAndroid Build Coastguard Worker 
127*4d7e907cSAndroid Build Coastguard Worker     // check if the loop above exited due to a c++fs error.
128*4d7e907cSAndroid Build Coastguard Worker     if (fsStatus != fsErrors::ok) {
129*4d7e907cSAndroid Build Coastguard Worker         LOG(ERROR) << "Failed search filesystem: " << fsStatus;
130*4d7e907cSAndroid Build Coastguard Worker     }
131*4d7e907cSAndroid Build Coastguard Worker     return std::nullopt;
132*4d7e907cSAndroid Build Coastguard Worker }
133*4d7e907cSAndroid Build Coastguard Worker 
134*4d7e907cSAndroid Build Coastguard Worker /**
135*4d7e907cSAndroid Build Coastguard Worker  * A helper function to read the serial number from a "serial" file in /sys/devices/
136*4d7e907cSAndroid Build Coastguard Worker  *
137*4d7e907cSAndroid Build Coastguard Worker  * \param serialnoPath - path to the file to read.
138*4d7e907cSAndroid Build Coastguard Worker  * \return the serial number, or nullopt on failure.
139*4d7e907cSAndroid Build Coastguard Worker  */
readSerialNo(const std::string & serialnoPath)140*4d7e907cSAndroid Build Coastguard Worker static std::optional<std::string> readSerialNo(const std::string& serialnoPath) {
141*4d7e907cSAndroid Build Coastguard Worker     std::ifstream serialnoStream(serialnoPath);
142*4d7e907cSAndroid Build Coastguard Worker     std::string serialno;
143*4d7e907cSAndroid Build Coastguard Worker     if (!serialnoStream.good()) {
144*4d7e907cSAndroid Build Coastguard Worker         LOG(ERROR) << "Failed to read serial number from " << serialnoPath;
145*4d7e907cSAndroid Build Coastguard Worker         return std::nullopt;
146*4d7e907cSAndroid Build Coastguard Worker     }
147*4d7e907cSAndroid Build Coastguard Worker     std::getline(serialnoStream, serialno);
148*4d7e907cSAndroid Build Coastguard Worker     return serialno;
149*4d7e907cSAndroid Build Coastguard Worker }
150*4d7e907cSAndroid Build Coastguard Worker 
151*4d7e907cSAndroid Build Coastguard Worker /**
152*4d7e907cSAndroid Build Coastguard Worker  * Searches for USB devices found in /sys/devices/, and attempts to find a device matching the
153*4d7e907cSAndroid Build Coastguard Worker  * provided list of serial numbers.
154*4d7e907cSAndroid Build Coastguard Worker  *
155*4d7e907cSAndroid Build Coastguard Worker  * \param configSerialnos - a list of serial number (suffixes) from the HAL config.
156*4d7e907cSAndroid Build Coastguard Worker  * \param iftype - the type of the interface to be located.
157*4d7e907cSAndroid Build Coastguard Worker  * \return a matching USB device. On failure, std::nullopt is returned.
158*4d7e907cSAndroid Build Coastguard Worker  */
findUsbDevice(const hidl_vec<hidl_string> & configSerialnos)159*4d7e907cSAndroid Build Coastguard Worker static std::optional<UsbCanIface> findUsbDevice(const hidl_vec<hidl_string>& configSerialnos) {
160*4d7e907cSAndroid Build Coastguard Worker     std::error_code fsStatus;
161*4d7e907cSAndroid Build Coastguard Worker     fs::recursive_directory_iterator fsItr(kDevPath, kOpts, fsStatus);
162*4d7e907cSAndroid Build Coastguard Worker     if (fsStatus != fsErrors::ok) {
163*4d7e907cSAndroid Build Coastguard Worker         LOG(ERROR) << "Failed to open " << kDevPath;
164*4d7e907cSAndroid Build Coastguard Worker         return std::nullopt;
165*4d7e907cSAndroid Build Coastguard Worker     }
166*4d7e907cSAndroid Build Coastguard Worker 
167*4d7e907cSAndroid Build Coastguard Worker     for (; fsStatus == fsErrors::ok && fsItr != fs::recursive_directory_iterator();
168*4d7e907cSAndroid Build Coastguard Worker          fsItr.increment(fsStatus)) {
169*4d7e907cSAndroid Build Coastguard Worker         // We want to find a file called "serial", which is in a directory somewhere. Skip files.
170*4d7e907cSAndroid Build Coastguard Worker         bool isDir = fsItr->is_directory(fsStatus);
171*4d7e907cSAndroid Build Coastguard Worker         if (fsStatus != fsErrors::ok) {
172*4d7e907cSAndroid Build Coastguard Worker             LOG(ERROR) << "Failed check if " << fsStatus;
173*4d7e907cSAndroid Build Coastguard Worker             return std::nullopt;
174*4d7e907cSAndroid Build Coastguard Worker         }
175*4d7e907cSAndroid Build Coastguard Worker         if (!isDir) continue;
176*4d7e907cSAndroid Build Coastguard Worker 
177*4d7e907cSAndroid Build Coastguard Worker         auto serialnoPath = fsItr->path() / "serial";
178*4d7e907cSAndroid Build Coastguard Worker         bool isReg = fs::is_regular_file(serialnoPath, fsStatus);
179*4d7e907cSAndroid Build Coastguard Worker 
180*4d7e907cSAndroid Build Coastguard Worker         /* Make sure we have permissions to this directory, ignore enoent, since the file
181*4d7e907cSAndroid Build Coastguard Worker          * "serial" may not exist, which is ok. */
182*4d7e907cSAndroid Build Coastguard Worker         if (fsStatus == fsErrors::eperm || fsStatus == fsErrors::eacces) {
183*4d7e907cSAndroid Build Coastguard Worker             /* This means we  don't have access to this directory. If we recurse into it, this
184*4d7e907cSAndroid Build Coastguard Worker              * will cause the iterator to loose its state and we'll crash. */
185*4d7e907cSAndroid Build Coastguard Worker             fsItr.disable_recursion_pending();
186*4d7e907cSAndroid Build Coastguard Worker             continue;
187*4d7e907cSAndroid Build Coastguard Worker         }
188*4d7e907cSAndroid Build Coastguard Worker         if (fsStatus == fsErrors::enoent) continue;
189*4d7e907cSAndroid Build Coastguard Worker         if (fsStatus != fsErrors::ok) {
190*4d7e907cSAndroid Build Coastguard Worker             LOG(WARNING) << "An unexpected error occurred while checking for serialno: "
191*4d7e907cSAndroid Build Coastguard Worker                          << fsStatus;
192*4d7e907cSAndroid Build Coastguard Worker             continue;
193*4d7e907cSAndroid Build Coastguard Worker         }
194*4d7e907cSAndroid Build Coastguard Worker         if (!isReg) continue;
195*4d7e907cSAndroid Build Coastguard Worker 
196*4d7e907cSAndroid Build Coastguard Worker         // we found a serial number
197*4d7e907cSAndroid Build Coastguard Worker         auto serialno = readSerialNo(serialnoPath);
198*4d7e907cSAndroid Build Coastguard Worker         if (!serialno.has_value()) continue;
199*4d7e907cSAndroid Build Coastguard Worker 
200*4d7e907cSAndroid Build Coastguard Worker         // see if the serial number exists in the config
201*4d7e907cSAndroid Build Coastguard Worker         for (auto&& cfgSn : configSerialnos) {
202*4d7e907cSAndroid Build Coastguard Worker             if (serialno->ends_with(std::string(cfgSn))) {
203*4d7e907cSAndroid Build Coastguard Worker                 auto ifaceInfo = getIfaceName(serialnoPath);
204*4d7e907cSAndroid Build Coastguard Worker                 if (!ifaceInfo.has_value()) break;
205*4d7e907cSAndroid Build Coastguard Worker                 return ifaceInfo;
206*4d7e907cSAndroid Build Coastguard Worker             }
207*4d7e907cSAndroid Build Coastguard Worker         }
208*4d7e907cSAndroid Build Coastguard Worker     }
209*4d7e907cSAndroid Build Coastguard Worker     if (fsStatus != fsErrors::ok) {
210*4d7e907cSAndroid Build Coastguard Worker         LOG(ERROR) << "Error searching filesystem: " << fsStatus;
211*4d7e907cSAndroid Build Coastguard Worker         return std::nullopt;
212*4d7e907cSAndroid Build Coastguard Worker     }
213*4d7e907cSAndroid Build Coastguard Worker     return std::nullopt;
214*4d7e907cSAndroid Build Coastguard Worker }
215*4d7e907cSAndroid Build Coastguard Worker 
upInterface(const ICanController::BusConfig & config)216*4d7e907cSAndroid Build Coastguard Worker Return<ICanController::Result> CanController::upInterface(const ICanController::BusConfig& config) {
217*4d7e907cSAndroid Build Coastguard Worker     LOG(VERBOSE) << "Attempting to bring interface up: " << toString(config);
218*4d7e907cSAndroid Build Coastguard Worker 
219*4d7e907cSAndroid Build Coastguard Worker     std::lock_guard<std::mutex> lck(mCanBusesGuard);
220*4d7e907cSAndroid Build Coastguard Worker 
221*4d7e907cSAndroid Build Coastguard Worker     if (!isValidName(config.name)) {
222*4d7e907cSAndroid Build Coastguard Worker         LOG(ERROR) << "Bus name " << config.name << " is invalid";
223*4d7e907cSAndroid Build Coastguard Worker         return ICanController::Result::BAD_SERVICE_NAME;
224*4d7e907cSAndroid Build Coastguard Worker     }
225*4d7e907cSAndroid Build Coastguard Worker 
226*4d7e907cSAndroid Build Coastguard Worker     if (mCanBuses.find(config.name) != mCanBuses.end()) {
227*4d7e907cSAndroid Build Coastguard Worker         LOG(ERROR) << "Bus " << config.name << " is already up";
228*4d7e907cSAndroid Build Coastguard Worker         return ICanController::Result::INVALID_STATE;
229*4d7e907cSAndroid Build Coastguard Worker     }
230*4d7e907cSAndroid Build Coastguard Worker 
231*4d7e907cSAndroid Build Coastguard Worker     sp<CanBus> busService;
232*4d7e907cSAndroid Build Coastguard Worker 
233*4d7e907cSAndroid Build Coastguard Worker     // SocketCAN native type interface.
234*4d7e907cSAndroid Build Coastguard Worker     if (config.interfaceId.getDiscriminator() == IfIdDisc::socketcan) {
235*4d7e907cSAndroid Build Coastguard Worker         auto& socketcan = config.interfaceId.socketcan();
236*4d7e907cSAndroid Build Coastguard Worker         std::string ifaceName;
237*4d7e907cSAndroid Build Coastguard Worker         if (socketcan.getDiscriminator() == IfId::Socketcan::hidl_discriminator::serialno) {
238*4d7e907cSAndroid Build Coastguard Worker             // Configure by serial number.
239*4d7e907cSAndroid Build Coastguard Worker             auto selectedDevice = findUsbDevice(socketcan.serialno());
240*4d7e907cSAndroid Build Coastguard Worker             // verify the returned device is the correct one
241*4d7e907cSAndroid Build Coastguard Worker             if (!selectedDevice.has_value() ||
242*4d7e907cSAndroid Build Coastguard Worker                 selectedDevice->iftype != ICanController::InterfaceType::SOCKETCAN) {
243*4d7e907cSAndroid Build Coastguard Worker                 return ICanController::Result::BAD_INTERFACE_ID;
244*4d7e907cSAndroid Build Coastguard Worker             }
245*4d7e907cSAndroid Build Coastguard Worker             ifaceName = selectedDevice->ifaceName;
246*4d7e907cSAndroid Build Coastguard Worker         } else {
247*4d7e907cSAndroid Build Coastguard Worker             // configure by iface name.
248*4d7e907cSAndroid Build Coastguard Worker             ifaceName = socketcan.ifname();
249*4d7e907cSAndroid Build Coastguard Worker         }
250*4d7e907cSAndroid Build Coastguard Worker         busService = new CanBusNative(ifaceName, config.bitrate);
251*4d7e907cSAndroid Build Coastguard Worker     }
252*4d7e907cSAndroid Build Coastguard Worker     // Virtual interface.
253*4d7e907cSAndroid Build Coastguard Worker     else if (config.interfaceId.getDiscriminator() == IfIdDisc::virtualif) {
254*4d7e907cSAndroid Build Coastguard Worker         busService = new CanBusVirtual(config.interfaceId.virtualif().ifname);
255*4d7e907cSAndroid Build Coastguard Worker     }
256*4d7e907cSAndroid Build Coastguard Worker     // SLCAN interface.
257*4d7e907cSAndroid Build Coastguard Worker     else if (config.interfaceId.getDiscriminator() == IfIdDisc::slcan) {
258*4d7e907cSAndroid Build Coastguard Worker         auto& slcan = config.interfaceId.slcan();
259*4d7e907cSAndroid Build Coastguard Worker         std::string ttyName;
260*4d7e907cSAndroid Build Coastguard Worker         if (slcan.getDiscriminator() == IfId::Slcan::hidl_discriminator::serialno) {
261*4d7e907cSAndroid Build Coastguard Worker             // Configure by serial number.
262*4d7e907cSAndroid Build Coastguard Worker             auto selectedDevice = findUsbDevice(slcan.serialno());
263*4d7e907cSAndroid Build Coastguard Worker             if (!selectedDevice.has_value() ||
264*4d7e907cSAndroid Build Coastguard Worker                 selectedDevice->iftype != ICanController::InterfaceType::SLCAN) {
265*4d7e907cSAndroid Build Coastguard Worker                 return ICanController::Result::BAD_INTERFACE_ID;
266*4d7e907cSAndroid Build Coastguard Worker             }
267*4d7e907cSAndroid Build Coastguard Worker             ttyName = selectedDevice->ifaceName;
268*4d7e907cSAndroid Build Coastguard Worker         } else {
269*4d7e907cSAndroid Build Coastguard Worker             // Configure by tty name.
270*4d7e907cSAndroid Build Coastguard Worker             ttyName = slcan.ttyname();
271*4d7e907cSAndroid Build Coastguard Worker         }
272*4d7e907cSAndroid Build Coastguard Worker         busService = new CanBusSlcan(ttyName, config.bitrate);
273*4d7e907cSAndroid Build Coastguard Worker     } else {
274*4d7e907cSAndroid Build Coastguard Worker         return ICanController::Result::NOT_SUPPORTED;
275*4d7e907cSAndroid Build Coastguard Worker     }
276*4d7e907cSAndroid Build Coastguard Worker 
277*4d7e907cSAndroid Build Coastguard Worker     busService->setErrorCallback([this, name = config.name]() { downInterface(name); });
278*4d7e907cSAndroid Build Coastguard Worker 
279*4d7e907cSAndroid Build Coastguard Worker     const auto result = busService->up();
280*4d7e907cSAndroid Build Coastguard Worker     if (result != ICanController::Result::OK) return result;
281*4d7e907cSAndroid Build Coastguard Worker 
282*4d7e907cSAndroid Build Coastguard Worker     if (busService->registerAsService(config.name) != OK) {
283*4d7e907cSAndroid Build Coastguard Worker         LOG(ERROR) << "Failed to register ICanBus/" << config.name;
284*4d7e907cSAndroid Build Coastguard Worker         if (!busService->down()) {
285*4d7e907cSAndroid Build Coastguard Worker             LOG(WARNING) << "Failed to bring down CAN bus that failed to register";
286*4d7e907cSAndroid Build Coastguard Worker         }
287*4d7e907cSAndroid Build Coastguard Worker         return ICanController::Result::BAD_SERVICE_NAME;
288*4d7e907cSAndroid Build Coastguard Worker     }
289*4d7e907cSAndroid Build Coastguard Worker 
290*4d7e907cSAndroid Build Coastguard Worker     mCanBuses[config.name] = busService;
291*4d7e907cSAndroid Build Coastguard Worker 
292*4d7e907cSAndroid Build Coastguard Worker     return ICanController::Result::OK;
293*4d7e907cSAndroid Build Coastguard Worker }
294*4d7e907cSAndroid Build Coastguard Worker 
downInterface(const hidl_string & name)295*4d7e907cSAndroid Build Coastguard Worker Return<bool> CanController::downInterface(const hidl_string& name) {
296*4d7e907cSAndroid Build Coastguard Worker     LOG(VERBOSE) << "Attempting to bring interface down: " << name;
297*4d7e907cSAndroid Build Coastguard Worker 
298*4d7e907cSAndroid Build Coastguard Worker     std::lock_guard<std::mutex> lck(mCanBusesGuard);
299*4d7e907cSAndroid Build Coastguard Worker 
300*4d7e907cSAndroid Build Coastguard Worker     auto busEntry = mCanBuses.extract(name);
301*4d7e907cSAndroid Build Coastguard Worker     if (!busEntry) {
302*4d7e907cSAndroid Build Coastguard Worker         LOG(WARNING) << "Interface " << name << " is not up";
303*4d7e907cSAndroid Build Coastguard Worker         return false;
304*4d7e907cSAndroid Build Coastguard Worker     }
305*4d7e907cSAndroid Build Coastguard Worker 
306*4d7e907cSAndroid Build Coastguard Worker     auto success = true;
307*4d7e907cSAndroid Build Coastguard Worker 
308*4d7e907cSAndroid Build Coastguard Worker     if (!busEntry.mapped()->down()) {
309*4d7e907cSAndroid Build Coastguard Worker         LOG(ERROR) << "Couldn't bring " << name << " down";
310*4d7e907cSAndroid Build Coastguard Worker         success = false;
311*4d7e907cSAndroid Build Coastguard Worker     }
312*4d7e907cSAndroid Build Coastguard Worker 
313*4d7e907cSAndroid Build Coastguard Worker     return success;
314*4d7e907cSAndroid Build Coastguard Worker }
315*4d7e907cSAndroid Build Coastguard Worker 
316*4d7e907cSAndroid Build Coastguard Worker }  // namespace android::hardware::automotive::can::V1_0::implementation
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