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Added TODOs for specific bugs (and impl related ideas for how to go about preventing/warning in the event of `mode-memfd` system OOM) ; moved some RawFd-related functions into a submodule

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Fortune for collect's current commit: Small curse − 小凶
safe-memfd
Avril 2 years ago
parent 8dd7ddaed8
commit 0262ca88d9
Signed by: flanchan
GPG Key ID: 284488987C31F630
2 changed files with 230 additions and 280 deletions
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470
src/main.rs
Unescape View File

@ -5,8 +5,8 @@
#[cfg(feature="memfile")]
#[macro_use] extern crate lazy_static;
#[cfg(feature="memfile")]
#[macro_use] extern crate stackalloc;
#[cfg(feature="memfile")]
extern crate stackalloc;
/// Run this statement only if `tracing` is enabled
macro_rules! if_trace {
@ -65,6 +65,12 @@ macro_rules! function {
}}
}
mod sys;
use sys::{
try_get_size,
tell_file,
};
mod buffers;
use buffers::prelude::*;
@ -76,111 +82,6 @@ use bytes::{
BufMut,
};
/* TODO: XXX: For colouring buffer::Perc
#[derive(Debug)]
struct StackStr<const MAXLEN: usize>(usize, std::mem::MaybeUninit<[u8; MAXLEN]>);
impl<const SZ: usize> StackStr<SZ>
{
#[inline]
pub const fn new() -> Self
{
Self(0, std::mem::MaybeUninit::uninit())
}
#[inline(always)]
pub const unsafe fn slice_mut(&mut self) -> &mut [u8]
{
&mut self.1[self.0..]
}
#[inline]
pub const fn slice(&self) -> &[u8]
{
&self.1[self.0..]
}
#[inline]
pub const unsafe fn as_str_unchecked(&self) -> &str
{
std::str::from_utf8_unchecked(&self.1[self.0..])
}
#[inline]
pub const unsafe fn as_mut_str_unchecked(&mut self) -> &mut str
{
std::str::from_utf8_unchecked_mut(&mut self.1[..self.0])
}
#[inline]
#[cfg_attr(feature="logging", instrument(level="debug"))]
pub fn as_str(&self) -> &str
{
std::str::from_utf8(self.slice()).expect("Invalid string")
}
#[inline(always)]
const fn left(&self) -> usize {
SZ - self.0
}
#[inline(always)]
pub fn write_bytes(&mut self, s: &[u8]) -> usize {
let b = &s[..std::cmp::min(match self.left() {
0 => return 0,
x => x,
}, s.len())];
unsafe { &mut self.slice_mut() [self.0..] }.copy_from_slice(b);
let v = b.len();
self.0 += v;
v
}
}
impl<const SZ: usize> std::fmt::Write for StackStr<SZ>
{
#[inline]
fn write_str(&mut self, s: &str) -> std::fmt::Result {
self.write_bytes(s.as_bytes());
Ok(())
}
#[inline]
fn write_char(&mut self, c: char) -> std::fmt::Result {
let l = c.len_utf8();
if l > self.left() {
return Ok(())
}
self.write_bytes(c.encode_utf8(unsafe { &mut self.slice_mut() [self.0..] }));
self.0 += l;
Ok(())
}
}
*/
#[cfg_attr(feature="logging", instrument(level="info", skip(reader), fields(reader = ?std::any::type_name::<R>())))]
fn try_get_size<R: ?Sized>(reader: &R) -> Option<NonZeroUsize>
where R: AsRawFd
{
let fd = reader.as_raw_fd();
use libc::{
fstat64,
stat64,
};
if fd < 0 {
return None;
}
let mut st: MaybeUninit<stat64> = MaybeUninit::uninit();
unsafe {
match fstat64(fd, st.as_mut_ptr()) {
0 => {
NonZeroUsize::new(st.assume_init().st_size as usize)
},
_ => None,
}
}
}
fn init() -> eyre::Result<()>
{
cfg_if!{ if #[cfg(feature="logging")] {
@ -221,210 +122,219 @@ fn init() -> eyre::Result<()>
}
#[cfg_attr(feature="logging", instrument(err))]
#[inline]
fn non_map_work() -> eyre::Result<()>
#[inline]
fn feature_check() -> eyre::Result<()>
{
if_trace!(trace!("strategy: allocated buffer"));
let (bytes, read) = {
let stdin = io::stdin();
let mut bytes: buffers::DefaultMut = try_get_size(&stdin).create_buffer();
let read = io::copy(&mut stdin.lock(), &mut (&mut bytes).writer())
.with_section(|| bytes.len().header("Buffer size is"))
.with_section(|| bytes.capacity().header("Buffer cap is"))
.with_section(|| format!("{:?}", bytes).header("Buffer is"))
.wrap_err("Failed to read into buffer")?;
(bytes.freeze(), read as usize)
};
if_trace!(info!("collected {read} from stdin. starting write."));
let written =
io::copy(&mut (&bytes[..read]).reader() , &mut io::stdout().lock())
.with_section(|| read.header("Bytes read"))
.with_section(|| bytes.len().header("Buffer length (frozen)"))
.with_section(|| format!("{:?}", &bytes[..read]).header("Read Buffer"))
.with_section(|| format!("{:?}", bytes).header("Full Buffer"))
.wrap_err("Failed to write from buffer")?;
if_trace!(info!("written {written} to stdout."));
if read != written as usize {
return Err(io::Error::new(io::ErrorKind::BrokenPipe, format!("read {read} bytes, but only wrote {written}")))
.wrap_err("Writing failed: size mismatch");
if cfg!(feature="memfile") && cfg!(feature="mode-buffered") {
if_trace!(warn!("This is an incorrectly compiled binary! Compiled with `mode: buffered` and the `memfile` feature; `memfile` stragery will be used and the mode selection will be ignored."));
}
Ok(())
}
#[cfg_attr(feature="logging", instrument(err))]
#[inline]
#[cfg(feature="memfile")]
fn map_work() -> eyre::Result<()>
{
const DEFAULT_BUFFER_SIZE: fn () -> Option<std::num::NonZeroUsize> = || {
cfg_if!{
if #[cfg(feature="memfile-preallocate")] {
extern "C" {
fn getpagesize() -> libc::c_int;
}
unsafe { std::num::NonZeroUsize::new(getpagesize() as usize * 8) }
} else {
std::num::NonZeroUsize::new(0)
}
}
};
if_trace!(trace!("strategy: mapped memory file"));
use std::borrow::Borrow;
#[inline(always)]
fn tell_file<T>(file: &mut T) -> io::Result<u64>
where T: io::Seek + ?Sized
mod work {
use super::*;
#[cfg_attr(feature="logging", instrument(err))]
#[inline]
pub(super) fn buffered() -> eyre::Result<()>
{
file.stream_position()
if_trace!(trace!("strategy: allocated buffer"));
let (bytes, read) = {
let stdin = io::stdin();
let mut bytes: buffers::DefaultMut = try_get_size(&stdin).create_buffer();
let read = io::copy(&mut stdin.lock(), &mut (&mut bytes).writer())
.with_section(|| bytes.len().header("Buffer size is"))
.with_section(|| bytes.capacity().header("Buffer cap is"))
.with_section(|| format!("{:?}", bytes).header("Buffer is"))
.wrap_err("Failed to read into buffer")?;
(bytes.freeze(), read as usize)
};
if_trace!(info!("collected {read} from stdin. starting write."));
let written =
io::copy(&mut (&bytes[..read]).reader() , &mut io::stdout().lock())
.with_section(|| read.header("Bytes read"))
.with_section(|| bytes.len().header("Buffer length (frozen)"))
.with_section(|| format!("{:?}", &bytes[..read]).header("Read Buffer"))
.with_section(|| format!("{:?}", bytes).header("Full Buffer"))
.wrap_err("Failed to write from buffer")?;
if_trace!(info!("written {written} to stdout."));
if read != written as usize {
return Err(io::Error::new(io::ErrorKind::BrokenPipe, format!("read {read} bytes, but only wrote {written}")))
.wrap_err("Writing failed: size mismatch");
}
Ok(())
}
#[inline(always)]
fn unwrap_int_string<T, E>(i: impl Borrow<Result<T, E>>) -> String
where T: std::fmt::Display,
E: std::fmt::Display
#[cfg_attr(feature="logging", instrument(err))]
#[inline]
#[cfg(feature="memfile")]
//TODO: We should establish a max memory threshold for this to prevent full system OOM: Output a warning message if it exceeeds, say, 70-80% of free memory (not including used by this program (TODO: How do we calculate this efficiently?)), and fail with an error if it exceeds 90% of memory... Or, instead of using free memory as basis of the requirement levels on the max size of the memory file, use max memory? Or just total free memory at the start of program? Or check free memory each time (slow!! probably not this one...). Umm... I think basing it off total memory would be best; perhaps make the percentage levels user-configurable at compile time (and allow the user to set the memory value as opposed to using the total system memory at runtime.) or runtime (compile-time preffered; use that crate that lets us use TOML config files at comptime (find it pretty easy by looking through ~/work's rust projects, I've used it before.))
pub(super) fn memfd() -> eyre::Result<()>
{
i.borrow().as_ref().map(ToString::to_string)
.unwrap_or_else(|e| format!("<unknown: {e}>"))
}
const DEFAULT_BUFFER_SIZE: fn () -> Option<std::num::NonZeroUsize> = || {
cfg_if!{
if #[cfg(feature="memfile-preallocate")] {
extern "C" {
fn getpagesize() -> libc::c_int;
}
unsafe { std::num::NonZeroUsize::new(getpagesize() as usize * 8) }
} else {
std::num::NonZeroUsize::new(0)
}
}
};
if_trace!(trace!("strategy: mapped memory file"));
let (mut file, read) = {
let stdin = io::stdin();
use std::borrow::Borrow;
let buffsz = try_get_size(&stdin);
if_trace!(debug!("Attempted determining input size: {:?}", buffsz));
let buffsz = buffsz.or_else(DEFAULT_BUFFER_SIZE);
if_trace!(if let Some(buf) = buffsz.as_ref() {
trace!("Failed to determine input size: preallocating to {}", buf);
} else {
trace!("Failed to determine input size: alllocating on-the-fly (no preallocation)");
});
let mut file = memfile::create_memfile(Some("collect-buffer"),
buffsz.map(|x| x.get()).unwrap_or(0))
.with_section(|| format!("{:?}", buffsz).header("Deduced input buffer size"))
.wrap_err(eyre!("Failed to create in-memory buffer"))?;
#[inline(always)]
fn unwrap_int_string<T, E>(i: impl Borrow<Result<T, E>>) -> String
where T: std::fmt::Display,
E: std::fmt::Display
{
i.borrow().as_ref().map(ToString::to_string)
.unwrap_or_else(|e| format!("<unknown: {e}>"))
}
let read = io::copy(&mut stdin.lock(), &mut file)
.with_section(|| format!("{:?}", file).header("Memory buffer file"))?;
let read = {
use io::*;
use std::borrow::Cow;
let (mut file, read) = {
let stdin = io::stdin();
let (read, sp, sl) = if cfg!(any(feature="memfile-preallocate", debug_assertions)) {
let sp = file.stream_position();
let sl = memfile::stream_len(&file);
if_trace!(trace!("Stream position after read: {:?}", sp));
if_trace!(trace!("Stream length after read: {:?}", sp));
let read = match sp.as_ref() {
Ok(&v) if v != read => {
if_trace!(warn!("Reported read value not equal to memfile stream position: expected from `io::copy()`: {v}, got {read}"));
v
},
Ok(&x) => {
if_trace!(trace!("Reported memfile stream position and copy result equal: {x} == {}", read));
x
},
Err(e) => {
if_trace!(error!("Could not report memfile stream position, ignoring check on {read}: {e}"));
read
},
};
let buffsz = try_get_size(&stdin);
if_trace!(debug!("Attempted determining input size: {:?}", buffsz));
let buffsz = buffsz.or_else(DEFAULT_BUFFER_SIZE);
if_trace!(if let Some(buf) = buffsz.as_ref() {
trace!("Failed to determine input size: preallocating to {}", buf);
} else {
trace!("Failed to determine input size: alllocating on-the-fly (no preallocation)");
});
let mut file = memfile::create_memfile(Some("collect-buffer"),
buffsz.map(|x| x.get()).unwrap_or(0))
.with_section(|| format!("{:?}", buffsz).header("Deduced input buffer size"))
.wrap_err(eyre!("Failed to create in-memory buffer"))?;
let truncate_stream = |bad: u64, good: u64| {
use std::num::NonZeroU64;
file.set_len(good)
.map(|_| good)
.with_section(|| match NonZeroU64::new(bad) {Some (b) => Cow::Owned(b.get().to_string()), None => Cow::Borrowed("<unknown>") }.header("Original (bad) length"))
.with_section(|| good.header("New (correct) length"))
.wrap_err(eyre!("Failed to truncate stream to correct length")
.with_section(|| format!("{:?}", file).header("Memory buffer file")))
};
let read = match sl.as_ref() {
Ok(&v) if v != read => {
if_trace!(warn!("Reported read value not equal to memfile stream length: expected from `io::copy()`: {read}, got {v}"));
if_trace!(debug!("Attempting to correct memfile stream length from {v} to {read}"));
truncate_stream(v, read)?
},
Ok(&v) => {
if_trace!(trace!("Reported memfile stream length and copy result equal: {v} == {}", read));
v
},
Err(e) => {
if_trace!(error!("Could not report memfile stream length, ignoring check on {read}: {e}"));
if_trace!(warn!("Attempting to correct memfile stream length anyway"));
if let Err(e) = truncate_stream(0, read) {
if_trace!(error!("Truncate failed: {e}"));
let read = io::copy(&mut stdin.lock(), &mut file)
.with_section(|| format!("{:?}", file).header("Memory buffer file"))?;
let read = {
use io::*;
use std::borrow::Cow;
let (read, sp, sl) = if cfg!(any(feature="memfile-preallocate", debug_assertions)) {
let sp = file.stream_position(); //TODO: XXX: Is this really needed?
let sl = memfile::stream_len(&file);
if_trace!(trace!("Stream position after read: {:?}", sp));
if_trace!(trace!("Stream length after read: {:?}", sp));
let read = match sp.as_ref() {
Ok(&v) if v != read => {
if_trace!(warn!("Reported read value not equal to memfile stream position: expected from `io::copy()`: {v}, got {read}"));
v
},
Ok(&x) => {
if_trace!(trace!("Reported memfile stream position and copy result equal: {x} == {}", read));
x
},
Err(e) => {
if_trace!(error!("Could not report memfile stream position, ignoring check on {read}: {e}"));
read
},
};
let truncate_stream = |bad: u64, good: u64| {
use std::num::NonZeroU64;
file.set_len(good)
.map(|_| good)
.with_section(|| match NonZeroU64::new(bad) {Some (b) => Cow::Owned(b.get().to_string()), None => Cow::Borrowed("<unknown>") }.header("Original (bad) length"))
.with_section(|| good.header("New (correct) length"))
.wrap_err(eyre!("Failed to truncate stream to correct length")
.with_section(|| format!("{:?}", file).header("Memory buffer file")))
};
let read = match sl.as_ref() {
Ok(&v) if v != read => {
if_trace!(warn!("Reported read value not equal to memfile stream length: expected from `io::copy()`: {read}, got {v}"));
if_trace!(debug!("Attempting to correct memfile stream length from {v} to {read}"));
truncate_stream(v, read)?
},
Ok(&v) => {
if_trace!(trace!("Reported memfile stream length and copy result equal: {v} == {}", read));
v
},
Err(e) => {
if_trace!(error!("Could not report memfile stream length, ignoring check on {read}: {e}"));
if_trace!(warn!("Attempting to correct memfile stream length anyway"));
if let Err(e) = truncate_stream(0, read) {
if_trace!(error!("Truncate failed: {e}"));
}
read
}
read
}
};
(read, Some(sp), Some(sl))
} else {
(read, None, None)
};
(read, Some(sp), Some(sl))
} else {
(read, None, None)
};
file.seek(SeekFrom::Start(0))
.with_section(|| read.header("Actual read bytes"))
.wrap_err(eyre!("Failed to seek back to start of memory buffer file for output")
.with_section(move || if let Some(sp) = sp { Cow::Owned(unwrap_int_string(sp)) }
else { Cow::Borrowed("<unknown>") }.header("Memfile position"))
.with_section(move || if let Some(sp) = sl { Cow::Owned(unwrap_int_string(sp)) }
else { Cow::Borrowed("<unknown>") }.header("Memfile full length"))
/*.with_section(|| file.stream_len().map(|x| x.to_string())
.unwrap_or_else(|e| format!("<unknown: {e}>")).header("Memfile full length"))*/)?;
file.seek(SeekFrom::Start(0))
.with_section(|| read.header("Actual read bytes"))
.wrap_err(eyre!("Failed to seek back to start of memory buffer file for output")
.with_section(move || if let Some(sp) = sp { Cow::Owned(unwrap_int_string(sp)) }
else { Cow::Borrowed("<unknown>") }.header("Memfile position"))
.with_section(move || if let Some(sp) = sl { Cow::Owned(unwrap_int_string(sp)) }
else { Cow::Borrowed("<unknown>") }.header("Memfile full length"))
/*.with_section(|| file.stream_len().map(|x| x.to_string())
.unwrap_or_else(|e| format!("<unknown: {e}>")).header("Memfile full length"))*/)?;
read
};
read
(file, usize::try_from(read)
.wrap_err(eyre!("Failed to convert read bytes to `usize`")
.with_section(|| read.header("Number of bytes was"))
.with_section(|| u128::abs_diff(read.into(), usize::MAX as u128).header("Difference between `read` and `usize::MAX` is"))
.with_suggestion(|| "It is likely you are running on a 32-bit ptr width machine and this input exceeds that of the maximum 32-bit unsigned integer value")
.with_note(|| usize::MAX.header("Maximum value of `usize`")))?)
};
if_trace!(info!("collected {} from stdin. starting write.", read));
let written =
io::copy(&mut file, &mut io::stdout().lock())
.with_section(|| read.header("Bytes read from stdin"))
.with_section(|| unwrap_int_string(tell_file(&mut file)).header("Current buffer position"))
.wrap_err("Failed to write buffer to stdout")?;
if_trace!(info!("written {written} to stdout."));
if read != written as usize {
return Err(io::Error::new(io::ErrorKind::BrokenPipe, format!("read {read} bytes, but only wrote {written}")))
.wrap_err("Writing failed: size mismatch");
}
(file, usize::try_from(read)
.wrap_err(eyre!("Failed to convert read bytes to `usize`")
.with_section(|| read.header("Number of bytes was"))
.with_section(|| u128::abs_diff(read.into(), usize::MAX as u128).header("Difference between `read` and `usize::MAX` is"))
.with_suggestion(|| "It is likely you are running on a 32-bit ptr width machine and this input exceeds that of the maximum 32-bit unsigned integer value")
.with_note(|| usize::MAX.header("Maximum value of `usize`")))?)
};
if_trace!(info!("collected {} from stdin. starting write.", read));
let written =
io::copy(&mut file, &mut io::stdout().lock())
.with_section(|| read.header("Bytes read from stdin"))
.with_section(|| unwrap_int_string(tell_file(&mut file)).header("Current buffer position"))
.wrap_err("Failed to write buffer to stdout")?;
if_trace!(info!("written {written} to stdout."));
if read != written as usize {
return Err(io::Error::new(io::ErrorKind::BrokenPipe, format!("read {read} bytes, but only wrote {written}")))
.wrap_err("Writing failed: size mismatch");
Ok(())
}
Ok(())
}
#[cfg_attr(feature="logging", instrument(err))]
fn main() -> eyre::Result<()> {
init()?;
feature_check()?;
if_trace!(debug!("initialised"));
cfg_if!{
if #[cfg(feature="memfile")] {
map_work()
.wrap_err(eyre!("Operation failed").with_note(|| "With mapped memfd algorithm"))?;
work::memfd()
.wrap_err("Operation failed").with_note(|| "Stragery was `memfd`")?;
} else {
non_map_work()
.wrap_err(eyre!("Operation failed").with_note(|| "With alloc-buf (non-mapped) algorithm"))?;
work::buffered()
.wrap_err("Operation failed").with_note(|| "Strategy was `buffered`")?;
}
}

40
src/sys.rs
Unescape View File

@ -0,0 +1,40 @@
//! System interactions
//!
//! Basic system interactions.
use super::*;
/// Attempt to get the size of any stream that is backed by a file-descriptor.
///
/// If one cannot be determined (or the fd is unsized), `None` is returned.
#[cfg_attr(feature="logging", instrument(level="info", skip(reader), ret, fields(reader = std::any::type_name::<R>())))]
#[inline]
//TODO: XXX: What if the size of `reader` really *is* 0. We shouldn't use `NonZeroUsize` here, we should just use `usize`. I think `st_size` can be `-1` if `fstat64()` fails to find a size...
pub fn try_get_size<R: ?Sized>(reader: &R) -> Option<NonZeroUsize>
where R: AsRawFd
{
let fd = reader.as_raw_fd();
use libc::{
fstat64,
stat64,
};
if fd < 0 {
return None;
}
let mut st: MaybeUninit<stat64> = MaybeUninit::uninit();
unsafe {
match fstat64(fd, st.as_mut_ptr()) {
0 => {
NonZeroUsize::new(st.assume_init().st_size as usize)
},
_ => None,
}
}
}
/// Get the current stream position of any seekable stream.
#[inline(always)]
pub fn tell_file<T>(file: &mut T) -> io::Result<u64>
where T: io::Seek + ?Sized
{
file.stream_position()
}
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