xref: /openbmc/google-ipmi-sys/cable.cpp (revision 444b5ea4)
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 
23 #include <cstdint>
24 #include <cstring>
25 #include <span>
26 #include <string>
27 #include <vector>
28 
29 namespace google
30 {
31 namespace ipmi
32 {
33 
34 struct CableRequest
35 {
36     uint8_t ifNameLength;
37 } __attribute__((packed));
38 
39 Resp cableCheck(std::span<const uint8_t> data, const HandlerInterface* handler)
40 {
41     // There is an IPMI LAN channel statistics command which could be used for
42     // this type of check, however, we're not able to wait for the OpenBMC
43     // implementation to stabilize related to the network management.
44     //
45     // There is a link status file, but it is "unknown" to start with...
46     // The path we're checking: /sys/class/net/eth1/statistics/rx_packets
47 
48     // This command is expecting: [0x00][len][ifName]
49     // data should have [len][ifName]
50     if (data.size() < sizeof(struct CableRequest))
51     {
52         std::fprintf(stderr, "Invalid command length: %u\n",
53                      static_cast<uint32_t>(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         std::fprintf(stderr, "Invalid string length: %d\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         std::fprintf(stderr, "*dataLen too small: %u\n",
72                      static_cast<uint32_t>(data.size()));
73         return ::ipmi::responseReqDataLenInvalid();
74     }
75 
76     // Maximum length one can specify, plus null terminator.
77     char nameBuf[256] = {};
78     // Copy the string out of the request buffer.
79     std::memcpy(&nameBuf[0], request + 1, request->ifNameLength);
80     std::string name = nameBuf;
81     int64_t count;
82 
83     try
84     {
85         count = handler->getRxPackets(name);
86     }
87     catch (const IpmiException& e)
88     {
89         return ::ipmi::response(e.getIpmiError());
90     }
91 
92     // If we have received packets then there is a cable present.
93     std::uint8_t value = (count > 0) ? 1 : 0;
94 
95     return ::ipmi::responseSuccess(SysOEMCommands::SysCableCheck,
96                                    std::vector<std::uint8_t>{value});
97 }
98 
99 } // namespace ipmi
100 } // namespace google
101