xref: /aosp_15_r20/hardware/interfaces/automotive/can/1.0/default/libnetdevice/ifreqs.cpp (revision 4d7e907c777eeecc4c5bd7cf640a754fac206ff7)
1 /*
2  * Copyright (C) 2020 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 "ifreqs.h"
18 
19 #include "common.h"
20 
21 #include <android-base/logging.h>
22 #include <android-base/unique_fd.h>
23 
24 #include <sys/ioctl.h>
25 
26 #include <map>
27 
28 namespace android::netdevice::ifreqs {
29 
30 static constexpr int defaultSocketDomain = AF_INET;
31 std::atomic_int socketDomain = defaultSocketDomain;
32 
33 struct SocketParams {
34     int domain;
35     int type;
36     int protocol;
37 };
38 
39 static const std::map<int, SocketParams> socketParams = {
40         {AF_INET, {AF_INET, SOCK_DGRAM, 0}},
41         {AF_CAN, {AF_CAN, SOCK_RAW, CAN_RAW}},
42 };
43 
getSocketParams(int domain)44 static SocketParams getSocketParams(int domain) {
45     if (socketParams.count(domain)) return socketParams.find(domain)->second;
46 
47     auto params = socketParams.find(defaultSocketDomain)->second;
48     params.domain = domain;
49     return params;
50 }
51 
trySend(unsigned long request,struct ifreq & ifr)52 int trySend(unsigned long request, struct ifreq& ifr) {
53     const auto sp = getSocketParams(socketDomain);
54     base::unique_fd sock(socket(sp.domain, sp.type, sp.protocol));
55     if (!sock.ok()) {
56         LOG(ERROR) << "Can't create socket";
57         return false;
58     }
59 
60     if (ioctl(sock.get(), request, &ifr) < 0) return errno;
61     return 0;
62 }
63 
send(unsigned long request,struct ifreq & ifr)64 bool send(unsigned long request, struct ifreq& ifr) {
65     if (trySend(request, ifr) != 0) {
66         PLOG(ERROR) << "ioctl(" << std::hex << request << std::dec << ") failed";
67         return false;
68     }
69 
70     return true;
71 }
72 
fromName(std::string_view ifname)73 struct ifreq fromName(std::string_view ifname) {
74     struct ifreq ifr = {};
75     // memcpy: last \0 initialized with ifreq above
76     memcpy(ifr.ifr_name, ifname.data(),
77            std::min(ifname.size(), static_cast<size_t>(IF_NAMESIZE - 1)));
78     return ifr;
79 }
80 
81 }  // namespace android::netdevice::ifreqs
82