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Avoid the use of low-numbered file descriptors for sockets.

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This commit is contained in:
levlam 2023-03-21 13:54:43 +03:00
parent 28362c1879
commit b5fe088574
1 changed files with 16 additions and 0 deletions
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16
tdutils/td/utils/port/SocketFd.cpp
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@ -637,6 +637,22 @@ Result<SocketFd> SocketFd::open(const IPAddress &address) {
if (!native_fd) {
return OS_SOCKET_ERROR("Failed to create a socket");
}
#if TD_PORT_POSIX
// Avoid the use of low-numbered file descriptors, which can be used directly by some other functions
constexpr int MINIMUM_FILE_DESCRIPTOR = 3;
while (native_fd.socket() < MINIMUM_FILE_DESCRIPTOR) {
native_fd.close();
LOG(ERROR) << "Receive " << native_fd << " as a file descriptor";
int dummy_fd = detail::skip_eintr([&] { return ::open("/dev/null", O_RDONLY, 0); });
if (dummy_fd < 0) {
return OS_ERROR("Can't open /dev/null");
}
native_fd = NativeFd{socket(address.get_address_family(), SOCK_STREAM, IPPROTO_TCP)};
if (!native_fd) {
return OS_SOCKET_ERROR("Failed to create a socket");
}
}
#endif
TRY_STATUS(detail::init_socket_options(native_fd));
#if TD_PORT_POSIX