diff options
Diffstat (limited to '3rdparty/asio/src/examples/cpp11/local/fd_passing_stream_client.cpp')
-rw-r--r-- | 3rdparty/asio/src/examples/cpp11/local/fd_passing_stream_client.cpp | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/3rdparty/asio/src/examples/cpp11/local/fd_passing_stream_client.cpp b/3rdparty/asio/src/examples/cpp11/local/fd_passing_stream_client.cpp new file mode 100644 index 00000000000..229509f1c14 --- /dev/null +++ b/3rdparty/asio/src/examples/cpp11/local/fd_passing_stream_client.cpp @@ -0,0 +1,102 @@ +// +// fd_passing_stream_client.cpp +// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +// +// Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com) +// Copyright (c) 2021 Heiko Hund (heiko at openvpn dot net) +// +// Distributed under the Boost Software License, Version 1.0. (See accompanying +// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) +// + +// Demonstrates how to pass file descriptors between processes with Asio. +// The client send a file name (destfile) to the server. The server opens +// the file and the associated file descriptor back to the client. + +#include <cstdlib> +#include <cstring> +#include <iostream> +#include "asio.hpp" + +#if defined(ASIO_HAS_LOCAL_SOCKETS) + +#include <sys/types.h> +#include <sys/socket.h> + +using asio::local::stream_protocol; + +constexpr std::size_t max_length = 1024; + +int main(int argc, char* argv[]) +{ + try + { + if (argc != 2) + { + std::cerr << "Usage: fd_passing_stream_client <serversocket>\n"; + return 1; + } + + asio::io_context io_context; + + stream_protocol::socket s(io_context); + s.connect(stream_protocol::endpoint(argv[1])); + + std::cout << "Enter path to write to: "; + char request[max_length]; + std::cin.getline(request, max_length); + size_t request_length = std::strlen(request); + asio::write(s, asio::buffer(request, request_length)); + + char reply[max_length]; + struct msghdr msg = {}; + struct iovec iov = { reply, sizeof(reply) }; + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + + union + { + struct cmsghdr align; + char buf[CMSG_SPACE(sizeof(int))]; + } cmsgu; + msg.msg_control = cmsgu.buf; + msg.msg_controllen = sizeof(cmsgu.buf); + + ::recvmsg(s.native_handle(), &msg, 0); + + int fd = -1; + struct cmsghdr* cmsg = CMSG_FIRSTHDR(&msg); + while (cmsg != NULL) + { + if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) + { + std::memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd)); + break; + } + cmsg = CMSG_NXTHDR(&msg, cmsg); + } + + if (fd != -1) + { + std::cout << "File descriptor received is: " << fd << "\n"; + FILE* f(::fdopen(fd, "w+")); + if (f) + { + ::fprintf(f, "stream_client writing to received fd #%d\n", fd); + ::fclose(f); + } + else + ::close(fd); + } + } + catch (std::exception& e) + { + std::cerr << "Exception: " << e.what() << "\n"; + } + + return 0; +} + +#else // defined(ASIO_HAS_LOCAL_SOCKETS) +# error Local sockets not available on this platform. +#endif // defined(ASIO_HAS_LOCAL_SOCKETS) |