1 /*
2 * Copyright (C) 2019 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <libnetdevice/libnetdevice.h>
18
19 #include "NetlinkRequest.h"
20 #include "NetlinkSocket.h"
21 #include "common.h"
22
23 #include <android-base/logging.h>
24 #include <android-base/unique_fd.h>
25
26 #include <linux/can.h>
27 #include <linux/can/error.h>
28 #include <linux/can/netlink.h>
29 #include <linux/can/raw.h>
30
31 namespace android::netdevice::can {
32
33 static constexpr can_err_mask_t kErrMask = CAN_ERR_MASK;
34
socket(const std::string & ifname)35 base::unique_fd socket(const std::string& ifname) {
36 struct sockaddr_can addr = {};
37 addr.can_family = AF_CAN;
38 addr.can_ifindex = nametoindex(ifname);
39 if (addr.can_ifindex == 0) {
40 LOG(ERROR) << "Interface " << ifname << " doesn't exists";
41 return {};
42 }
43
44 base::unique_fd sock(::socket(PF_CAN, SOCK_RAW, CAN_RAW));
45 if (!sock.ok()) {
46 LOG(ERROR) << "Failed to create CAN socket";
47 return {};
48 }
49
50 if (setsockopt(sock.get(), SOL_CAN_RAW, CAN_RAW_ERR_FILTER, &kErrMask, sizeof(kErrMask)) < 0) {
51 PLOG(ERROR) << "Can't receive error frames, CAN setsockpt failed";
52 return {};
53 }
54
55 if (0 != fcntl(sock.get(), F_SETFL, O_RDWR | O_NONBLOCK)) {
56 LOG(ERROR) << "Couldn't put CAN socket in non-blocking mode";
57 return {};
58 }
59
60 if (0 != bind(sock.get(), reinterpret_cast<struct sockaddr*>(&addr), sizeof(addr))) {
61 LOG(ERROR) << "Can't bind to CAN interface " << ifname;
62 return {};
63 }
64
65 return sock;
66 }
67
setBitrate(std::string ifname,uint32_t bitrate)68 bool setBitrate(std::string ifname, uint32_t bitrate) {
69 struct can_bittiming bt = {};
70 bt.bitrate = bitrate;
71
72 NetlinkRequest<struct ifinfomsg> req(RTM_NEWLINK, NLM_F_REQUEST);
73
74 const auto ifidx = nametoindex(ifname);
75 if (ifidx == 0) {
76 LOG(ERROR) << "Can't find interface " << ifname;
77 return false;
78 }
79 req.data().ifi_index = ifidx;
80
81 {
82 auto linkinfo = req.nest(IFLA_LINKINFO);
83 req.addattr(IFLA_INFO_KIND, "can");
84 {
85 auto infodata = req.nest(IFLA_INFO_DATA);
86 /* For CAN FD, it would require to add IFLA_CAN_DATA_BITTIMING
87 * and IFLA_CAN_CTRLMODE as well. */
88 req.addattr(IFLA_CAN_BITTIMING, bt);
89 }
90 }
91
92 NetlinkSocket sock(NETLINK_ROUTE);
93 return sock.send(req) && sock.receiveAck();
94 }
95
96 } // namespace android::netdevice::can
97