alecmocatta / palaver

Cross-platform polyfills.

palaver

Docs

Cross-platform polyfills.

This library attempts to provide reliable polyfills for functionality that isn't implemented on all platforms.

palaver = "Platform Abstraction Layer" + pa·lav·er n. prolonged and tedious fuss.

Functionality

Threading	Description	Linux	macOS	Windows	FreeBSD	NetBSD	iOS	Android
gettid()	Get thread ID	✓	✓	✓	✓	✓	✓	✓
count()	Number of threads in current process	✓	✓				✓	✓
Files	Description	Linux	macOS	Windows	FreeBSD	NetBSD	iOS	Android
seal_fd()	Make a file descriptor read-only	✓	✓		✓	✓	✓	✓
dup_fd()	Duplicate a file descriptor	✓	✓		✓	✓	✓	✓
copy_fd()	Copy a file descriptor to a specific offset	✓	✓	–	✓	✓	✓	✓
move_fd()	Move a file descriptor to a specific offset	✓	✓	–	✓	✓	✓	✓
move_fds()	Move file descriptors to specific offsets	✓	✓	–	✓	✓	✓	✓
fd_dir()	Get a path to the file descriptor directory	✓	✓	–	✓	✓	✓	✓
fd_path()	Get a path to a file descriptor	✓	✓	–	✓	✓	✓	✓
FdIter	Iterate all open file descriptors	✓	✓		✓	✓	✓	✓
memfd_create()	Create an anonymous file	✓	✓		✓	✓	✓	✓
fexecve()	Execute program specified via file descriptor	✓	✓		✓	✓	✓	✓
copy()	Copy by looping io::copy	✓	✓	✓	✓	✓	✓	✓
copy_sendfile()	Copy using sendfile	✓	✓		✓		✓	✓
copy_splice()	Copy using splice	✓						✓
pipe()	Create a pipe	✓	✓		✓	✓	✓	✓
Socket	Description	Linux	macOS	Windows	FreeBSD	NetBSD	iOS	Android
socket()	Create a socket	✓	✓		✓	✓	✓	✓
accept()	Accept a connection on a socket	✓	✓		✓	✓	✓	✓
is_connected()	Get whether a pending connection is connected	✓	✓		✓	✓	✓	✓
unreceived()	Get number of bytes readable	✓	✓		✓	✓	✓	✓
unsent()	Get number of bytes that have yet to be acknowledged	✓	✓		✓	✓	✓	✓
Env	Description	Linux	macOS	Windows	FreeBSD	NetBSD	iOS	Android
exe()	Opens the current running executable	✓	✓	✓	✓	✓	✓	✓
exe_path()	Get a path to the current running executable	✓	✓	✓	✓	✓	✓	✓
args()	Get command line arguments	✓	✓	✓	✓	✓	✓	✓
vars()	Get environment variables	✓	✓	✓	✓	✓	✓	✓
Process	Description	Linux	macOS	Windows	FreeBSD	NetBSD	iOS	Android
count()	Count the processes visible to the current process	✓	✓	–	✓	✓	✓	✓
count_threads()	Count the threads visible to the current process	✓	✓	–	✓	✓	✓	✓
fork()	Fork a process, using process descriptors where available	✓	✓	–	✓	✓	✓	✓
Valgrind	Description	Linux	macOS	Windows	FreeBSD	NetBSD	iOS	Android
is()	Check if running under Valgrind	✓	✓	✓	✓	✓	✓	✓
start_fd()	Get Valgrind's file descriptor range	✓	✓	–	✓	✓	✓	✓

License

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE.txt or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT.txt or http://opensource.org/licenses/MIT)

at your option.

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

palaver's Issues

Prefer getrandom/getentropy to /dev/urandom

e.g. in

palaver/src/file.rs

Lines 293 to 298 in 60f5e88

	let rand = nix::fcntl::open(
	"/dev/urandom",
	OFlag::O_RDONLY,
	nix::sys::stat::Mode::empty(),
	)
	.expect("Couldn't open /dev/urandom");

currently the /dev/ based RNG is used, which can be problematic with various kinds of sandboxing. This crate looks like the best cross-platform API to get randomness without depending on the filesystem.

Add optional ftruncate to memfd_create

Add closefrom

Noticed this example in the documentation:

/// // Close all file descriptors except std{in,out,err}.
/// # #[cfg(unix)]
/// for fd in FdIter::new().unwrap() {
///     if fd > 2 {
///         nix::unistd::close(fd).unwrap();
///     }
/// }

the closefrom libc function for doing exactly this (via an efficient syscall/fcntl/whatever) has been a thing since Solaris 9, FreeBSD 8.0, DragonFly 1.2, OpenBSD 3.5, and NetBSD whatever-but-also-ages-ago. Would make sense to have a wrapper that uses it and falls back to the above code.

Android buid fails on MacOS

When I run cargo ndk -t arm64-v8a build --release

On MacOS it does not build.

With latest HEAD, I get:

   Compiling as-slice v0.1.5
error[E0433]: failed to resolve: could not find `linux` in `os`
  --> /Users/domenukk/.cargo/registry/src/github.com-1ecc6299db9ec823/procfs-0.8.1/src/process/mod.rs:62:14
   |
62 | use std::os::linux::fs::MetadataExt;
   |              ^^^^^ could not find `linux` in `os`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0433`.
error: could not compile `procfs`

With v0.2.8, I get:

   Compiling palaver v0.2.8 (/Users/domenukk/tmp/palaver)
error[E0432]: unresolved import `nix::sys::memfd`
   --> src/file.rs:185:8
    |
185 |             use nix::sys::memfd;
    |                 ^^^^^^^^^^^^^^^ no `memfd` in `sys`

error[E0425]: cannot find function `shm_open` in module `mman`
   --> src/file.rs:213:9
    |
213 |         mman::shm_open(
    |               ^^^^^^^^ not found in `mman`

error[E0425]: cannot find function `shm_unlink` in module `mman`
   --> src/file.rs:226:10
    |
226 |             mman::shm_unlink(name).unwrap();
    |                   ^^^^^^^^^^ not found in `mman`

warning: ignoring -C extra-filename flag due to -o flag

error: aborting due to 3 previous errors; 1 warning emitted

Some errors have detailed explanations: E0425, E0432.
For more information about an error, try `rustc --explain E0425`.
error: could not compile `palaver`

To learn more, run the command again with --verbose.

Both seem to somehow assume I'm building Android on Linux (I guess?), which is not the case.

Fix Android build

The procinfo dependency is failing to build. TODO: investigate.

Broken CI, Update deps

It looks like CI is not running correctly anymore and therefore the dependabot PR's are not passing. Would you be interested in a PR changing to GH ci?

thread::count() panics on i686-unknown-linux

Due to the procinfo crate capping the size of /proc/self/stat fields at "usize" (as documented) i.e. u32; except that i686 can still run on x86_64 where it's u64.

Support for stable rust?

Hi,

Are there any plans for this crate to support stable rust? Right now, valgrind_request, which is a dep, uses nightly only features.

FdIter not guaranteed to work properly on FreeBSD

fdescfs, which would populate /dev/fd/ with stuff other than 0/1/2, is an optional mount on FreeBSD, so the current FdIter which goes over fd_dir is not guaranteed to work properly.

There is work on fdwalk but that hasn't landed yet. So I guess there should be a safe fallback that iterates over all the descriptors. Plus #33 for the common closefrom case.

palaver with latest version of heapless crate

There is an issue with heapless crate v0.5.6. Is it possible to release new version of palaver crate with latest heapless version in dependency?