xref: /openbmc/google-ipmi-sys/cable.cpp (revision c5b55232)
1 // Copyright 2021 Google LLC
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 //      http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 
15 #include "cable.hpp"
16 
17 #include "commands.hpp"
18 #include "errors.hpp"
19 #include "handler.hpp"
20 
21 #include <ipmid/api-types.hpp>
22 #include <stdplus/print.hpp>
23 
24 #include <cstdint>
25 #include <cstring>
26 #include <span>
27 #include <string>
28 #include <vector>
29 
30 namespace google
31 {
32 namespace ipmi
33 {
34 
35 struct CableRequest
36 {
37     uint8_t ifNameLength;
38 } __attribute__((packed));
39 
40 Resp cableCheck(std::span<const uint8_t> data, const HandlerInterface* handler)
41 {
42     // There is an IPMI LAN channel statistics command which could be used for
43     // this type of check, however, we're not able to wait for the OpenBMC
44     // implementation to stabilize related to the network management.
45     //
46     // There is a link status file, but it is "unknown" to start with...
47     // The path we're checking: /sys/class/net/eth1/statistics/rx_packets
48 
49     // This command is expecting: [0x00][len][ifName]
50     // data should have [len][ifName]
51     if (data.size() < sizeof(struct CableRequest))
52     {
53         stdplus::print(stderr, "Invalid command length: {}\n", data.size());
54         return ::ipmi::responseReqDataLenInvalid();
55     }
56 
57     const auto request =
58         reinterpret_cast<const struct CableRequest*>(data.data());
59 
60     // Sanity check the object contents.
61     if (request->ifNameLength == 0)
62     {
63         stdplus::print(stderr, "Invalid string length: {}\n",
64                        request->ifNameLength);
65         return ::ipmi::responseReqDataLenInvalid();
66     }
67 
68     // Verify the request buffer contains the object and the string.
69     if (data.size() < (sizeof(struct CableRequest) + request->ifNameLength))
70     {
71         stdplus::print(stderr, "*dataLen too small: {}\n", data.size());
72         return ::ipmi::responseReqDataLenInvalid();
73     }
74 
75     // Maximum length one can specify, plus null terminator.
76     char nameBuf[256] = {};
77     // Copy the string out of the request buffer.
78     std::memcpy(&nameBuf[0], request + 1, request->ifNameLength);
79     std::string name = nameBuf;
80     int64_t count;
81 
82     try
83     {
84         count = handler->getRxPackets(name);
85     }
86     catch (const IpmiException& e)
87     {
88         return ::ipmi::response(e.getIpmiError());
89     }
90 
91     // If we have received packets then there is a cable present.
92     std::uint8_t value = (count > 0) ? 1 : 0;
93 
94     return ::ipmi::responseSuccess(SysOEMCommands::SysCableCheck,
95                                    std::vector<std::uint8_t>{value});
96 }
97 
98 } // namespace ipmi
99 } // namespace google
100