1 // Copyright 2022 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 <fmt/format.h>
16 
17 #include <sdeventplus/event.hpp>
18 #include <sdeventplus/source/io.hpp>
19 #include <stdplus/fd/create.hpp>
20 #include <stdplus/fd/ops.hpp>
21 
22 // A privileged port that is reserved for querying BMC DHCP completion.
23 // This is well known by the clients querying the status.
24 constexpr uint16_t kListenPort = 23;
25 
26 stdplus::ManagedFd createListener()
27 {
28     using namespace stdplus::fd;
29     auto sock =
30         socket(SocketDomain::INet6, SocketType::Stream, SocketProto::TCP);
31     setFileFlags(sock, getFileFlags(sock).set(stdplus::fd::FileFlag::NonBlock));
32     sockaddr_in6 addr = {};
33     addr.sin6_family = AF_INET6;
34     addr.sin6_port = htons(kListenPort);
35     bind(sock, addr);
36     listen(sock, 10);
37     return sock;
38 }
39 
40 int main()
41 {
42     try
43     {
44         auto listener = createListener();
45         auto event = sdeventplus::Event::get_default();
46         sdeventplus::source::IO do_accept(
47             event, listener.get(), EPOLLIN | EPOLLET,
48             [&](sdeventplus::source::IO&, int, uint32_t) {
49                 while (stdplus::fd::accept(listener))
50                     ;
51             });
52         return event.loop();
53     }
54     catch (const std::exception& e)
55     {
56         fmt::print(stderr, "Failed: {}\n", e.what());
57         return 1;
58     }
59 }
60