| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| // KIND, either express or implied. See the License for the |
| // specific language governing permissions and limitations |
| // under the License.. |
| |
| use crate::io::{self, IoSlice, IoSliceMut}; |
| use crate::sys::fd::FileDesc; |
| use crate::sys::{cvt_ocall, cvt_ocall_r}; |
| use alloc_crate::vec::Vec; |
| use core::mem; |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // Anonymous pipes |
| //////////////////////////////////////////////////////////////////////////////// |
| |
| pub struct AnonPipe(FileDesc); |
| |
| pub fn anon_pipe() -> io::Result<(AnonPipe, AnonPipe)> { |
| let mut fds = [0; 2]; |
| cvt_ocall(unsafe { libc::pipe2(&mut fds, libc::O_CLOEXEC) })?; |
| |
| let fd0 = FileDesc::new(fds[0]); |
| let fd1 = FileDesc::new(fds[1]); |
| Ok((AnonPipe(fd0), AnonPipe(fd1))) |
| } |
| |
| impl AnonPipe { |
| pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> { |
| self.0.read(buf) |
| } |
| |
| pub fn read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> { |
| self.0.read_vectored(bufs) |
| } |
| |
| pub fn write(&self, buf: &[u8]) -> io::Result<usize> { |
| self.0.write(buf) |
| } |
| |
| pub fn write_vectored(&self, bufs: &[IoSlice<'_>]) -> io::Result<usize> { |
| self.0.write_vectored(bufs) |
| } |
| |
| pub fn fd(&self) -> &FileDesc { |
| &self.0 |
| } |
| pub fn into_fd(self) -> FileDesc { |
| self.0 |
| } |
| } |
| |
| pub fn read2(p1: AnonPipe, v1: &mut Vec<u8>, p2: AnonPipe, v2: &mut Vec<u8>) -> io::Result<()> { |
| // Set both pipes into nonblocking mode as we're gonna be reading from both |
| // in the `select` loop below, and we wouldn't want one to block the other! |
| let p1 = p1.into_fd(); |
| let p2 = p2.into_fd(); |
| p1.set_nonblocking(true)?; |
| p2.set_nonblocking(true)?; |
| |
| let mut fds: [libc::pollfd; 2] = unsafe { mem::zeroed() }; |
| fds[0].fd = p1.raw(); |
| fds[0].events = libc::POLLIN; |
| fds[1].fd = p2.raw(); |
| fds[1].events = libc::POLLIN; |
| loop { |
| // wait for either pipe to become readable using `poll` |
| cvt_ocall_r(|| unsafe { libc::poll(&mut fds, -1) })?; |
| |
| if fds[0].revents != 0 && read(&p1, v1)? { |
| p2.set_nonblocking(false)?; |
| return p2.read_to_end(v2).map(drop); |
| } |
| if fds[1].revents != 0 && read(&p2, v2)? { |
| p1.set_nonblocking(false)?; |
| return p1.read_to_end(v1).map(drop); |
| } |
| } |
| |
| // Read as much as we can from each pipe, ignoring EWOULDBLOCK or |
| // EAGAIN. If we hit EOF, then this will happen because the underlying |
| // reader will return Ok(0), in which case we'll see `Ok` ourselves. In |
| // this case we flip the other fd back into blocking mode and read |
| // whatever's leftover on that file descriptor. |
| fn read(fd: &FileDesc, dst: &mut Vec<u8>) -> Result<bool, io::Error> { |
| match fd.read_to_end(dst) { |
| Ok(_) => Ok(true), |
| Err(e) => { |
| if e.raw_os_error() == Some(libc::EWOULDBLOCK) |
| || e.raw_os_error() == Some(libc::EAGAIN) |
| { |
| Ok(false) |
| } else { |
| Err(e) |
| } |
| } |
| } |
| } |
| } |
| |
| mod libc { |
| pub use sgx_trts::libc::ocall::{pipe2, poll}; |
| pub use sgx_trts::libc::*; |
| } |