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// Copyright 2015 The Rust Project Developers.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! Utilities for creating and using sockets.
//!
//! The goal of this crate is to create and use a socket using advanced
//! configuration options (those that are not available in the types in the
//! standard library) without using any unsafe code.
//!
//! This crate provides as direct as possible access to the system's
//! functionality for sockets, this means little effort to provide
//! cross-platform utilities. It is up to the user to know how to use sockets
//! when using this crate. *If you don't know how to create a socket using
//! libc/system calls then this crate is not for you*. Most, if not all,
//! functions directly relate to the equivalent system call with no error
//! handling applied, so no handling errors such as [`EINTR`]. As a result using
//! this crate can be a little wordy, but it should give you maximal flexibility
//! over configuration of sockets.
//!
//! [`EINTR`]: std::io::ErrorKind::Interrupted
//!
//! # Examples
//!
//! ```no_run
//! # fn main() -> std::io::Result<()> {
//! use std::net::{SocketAddr, TcpListener};
//! use socket2::{Socket, Domain, Type};
//!
//! // Create a TCP listener bound to two addresses.
//! let socket = Socket::new(Domain::IPV6, Type::STREAM, None)?;
//!
//! socket.set_only_v6(false)?;
//! let address: SocketAddr = "[::1]:12345".parse().unwrap();
//! socket.bind(&address.into())?;
//! socket.listen(128)?;
//!
//! let listener: TcpListener = socket.into();
//! // ...
//! # drop(listener);
//! # Ok(()) }
//! ```
//!
//! ## Features
//!
//! This crate has a single feature `all`, which enables all functions even ones
//! that are not available on all OSs.
#![deny(missing_docs, missing_debug_implementations, rust_2018_idioms)]
// Show required OS/features on docs.rs.
#![cfg_attr(docsrs, feature(doc_cfg))]
// Disallow warnings when running tests.
#![cfg_attr(test, deny(warnings))]
// Disallow warnings in examples.
#![doc(test(attr(deny(warnings))))]
use std::fmt;
use std::mem::MaybeUninit;
use std::net::SocketAddr;
use std::ops::{Deref, DerefMut};
use std::time::Duration;
/// Macro to implement `fmt::Debug` for a type, printing the constant names
/// rather than a number.
///
/// Note this is used in the `sys` module and thus must be defined before
/// defining the modules.
macro_rules! impl_debug {
(
// Type name for which to implement `fmt::Debug`.
$type: path,
$(
$(#[$target: meta])*
// The flag(s) to check.
// Need to specific the libc crate because Windows doesn't use
// `libc` but `winapi`.
$libc: ident :: $flag: ident
),+ $(,)*
) => {
impl std::fmt::Debug for $type {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
let string = match self.0 {
$(
$(#[$target])*
$libc :: $flag => stringify!($flag),
)+
n => return write!(f, "{}", n),
};
f.write_str(string)
}
}
};
}
/// Macro to convert from one network type to another.
macro_rules! from {
($from: ty, $for: ty) => {
impl From<$from> for $for {
fn from(socket: $from) -> $for {
#[cfg(unix)]
unsafe {
<$for>::from_raw_fd(socket.into_raw_fd())
}
#[cfg(windows)]
unsafe {
<$for>::from_raw_socket(socket.into_raw_socket())
}
}
}
};
}
mod sockaddr;
mod socket;
mod sockref;
#[cfg_attr(unix, path = "sys/unix.rs")]
#[cfg_attr(windows, path = "sys/windows.rs")]
mod sys;
#[cfg(not(any(windows, unix)))]
compile_error!("Socket2 doesn't support the compile target");
use sys::c_int;
pub use sockaddr::SockAddr;
pub use socket::Socket;
pub use sockref::SockRef;
#[cfg(not(any(
target_os = "haiku",
target_os = "illumos",
target_os = "netbsd",
target_os = "redox",
target_os = "solaris",
)))]
pub use socket::InterfaceIndexOrAddress;
/// Specification of the communication domain for a socket.
///
/// This is a newtype wrapper around an integer which provides a nicer API in
/// addition to an injection point for documentation. Convenience constants such
/// as [`Domain::IPV4`], [`Domain::IPV6`], etc, are provided to avoid reaching
/// into libc for various constants.
///
/// This type is freely interconvertible with C's `int` type, however, if a raw
/// value needs to be provided.
#[derive(Copy, Clone, Eq, PartialEq)]
pub struct Domain(c_int);
impl Domain {
/// Domain for IPv4 communication, corresponding to `AF_INET`.
pub const IPV4: Domain = Domain(sys::AF_INET);
/// Domain for IPv6 communication, corresponding to `AF_INET6`.
pub const IPV6: Domain = Domain(sys::AF_INET6);
/// Returns the correct domain for `address`.
pub const fn for_address(address: SocketAddr) -> Domain {
match address {
SocketAddr::V4(_) => Domain::IPV4,
SocketAddr::V6(_) => Domain::IPV6,
}
}
}
impl From<c_int> for Domain {
fn from(d: c_int) -> Domain {
Domain(d)
}
}
impl From<Domain> for c_int {
fn from(d: Domain) -> c_int {
d.0
}
}
/// Specification of communication semantics on a socket.
///
/// This is a newtype wrapper around an integer which provides a nicer API in
/// addition to an injection point for documentation. Convenience constants such
/// as [`Type::STREAM`], [`Type::DGRAM`], etc, are provided to avoid reaching
/// into libc for various constants.
///
/// This type is freely interconvertible with C's `int` type, however, if a raw
/// value needs to be provided.
#[derive(Copy, Clone, Eq, PartialEq)]
pub struct Type(c_int);
impl Type {
/// Type corresponding to `SOCK_STREAM`.
///
/// Used for protocols such as TCP.
pub const STREAM: Type = Type(sys::SOCK_STREAM);
/// Type corresponding to `SOCK_DGRAM`.
///
/// Used for protocols such as UDP.
pub const DGRAM: Type = Type(sys::SOCK_DGRAM);
/// Type corresponding to `SOCK_SEQPACKET`.
#[cfg(feature = "all")]
#[cfg_attr(docsrs, doc(cfg(feature = "all")))]
pub const SEQPACKET: Type = Type(sys::SOCK_SEQPACKET);
/// Type corresponding to `SOCK_RAW`.
#[cfg(all(feature = "all", not(target_os = "redox")))]
#[cfg_attr(docsrs, doc(cfg(all(feature = "all", not(target_os = "redox")))))]
pub const RAW: Type = Type(sys::SOCK_RAW);
}
impl From<c_int> for Type {
fn from(t: c_int) -> Type {
Type(t)
}
}
impl From<Type> for c_int {
fn from(t: Type) -> c_int {
t.0
}
}
/// Protocol specification used for creating sockets via `Socket::new`.
///
/// This is a newtype wrapper around an integer which provides a nicer API in
/// addition to an injection point for documentation.
///
/// This type is freely interconvertible with C's `int` type, however, if a raw
/// value needs to be provided.
#[derive(Copy, Clone, Eq, PartialEq)]
pub struct Protocol(c_int);
impl Protocol {
/// Protocol corresponding to `ICMPv4`.
pub const ICMPV4: Protocol = Protocol(sys::IPPROTO_ICMP);
/// Protocol corresponding to `ICMPv6`.
pub const ICMPV6: Protocol = Protocol(sys::IPPROTO_ICMPV6);
/// Protocol corresponding to `TCP`.
pub const TCP: Protocol = Protocol(sys::IPPROTO_TCP);
/// Protocol corresponding to `UDP`.
pub const UDP: Protocol = Protocol(sys::IPPROTO_UDP);
}
impl From<c_int> for Protocol {
fn from(p: c_int) -> Protocol {
Protocol(p)
}
}
impl From<Protocol> for c_int {
fn from(p: Protocol) -> c_int {
p.0
}
}
/// Flags for incoming messages.
///
/// Flags provide additional information about incoming messages.
#[cfg(not(target_os = "redox"))]
#[cfg_attr(docsrs, doc(cfg(not(target_os = "redox"))))]
#[derive(Copy, Clone, Eq, PartialEq)]
pub struct RecvFlags(c_int);
#[cfg(not(target_os = "redox"))]
impl RecvFlags {
/// Check if the message contains a truncated datagram.
///
/// This flag is only used for datagram-based sockets,
/// not for stream sockets.
///
/// On Unix this corresponds to the `MSG_TRUNC` flag.
/// On Windows this corresponds to the `WSAEMSGSIZE` error code.
pub const fn is_truncated(self) -> bool {
self.0 & sys::MSG_TRUNC != 0
}
}
/// A version of [`IoSliceMut`] that allows the buffer to be uninitialised.
///
/// [`IoSliceMut`]: std::io::IoSliceMut
#[repr(transparent)]
pub struct MaybeUninitSlice<'a>(sys::MaybeUninitSlice<'a>);
impl<'a> fmt::Debug for MaybeUninitSlice<'a> {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Debug::fmt(self.0.as_slice(), fmt)
}
}
impl<'a> MaybeUninitSlice<'a> {
/// Creates a new `MaybeUninitSlice` wrapping a byte slice.
///
/// # Panics
///
/// Panics on Windows if the slice is larger than 4GB.
pub fn new(buf: &'a mut [MaybeUninit<u8>]) -> MaybeUninitSlice<'a> {
MaybeUninitSlice(sys::MaybeUninitSlice::new(buf))
}
}
impl<'a> Deref for MaybeUninitSlice<'a> {
type Target = [MaybeUninit<u8>];
fn deref(&self) -> &[MaybeUninit<u8>] {
self.0.as_slice()
}
}
impl<'a> DerefMut for MaybeUninitSlice<'a> {
fn deref_mut(&mut self) -> &mut [MaybeUninit<u8>] {
self.0.as_mut_slice()
}
}
/// Configures a socket's TCP keepalive parameters.
///
/// See [`Socket::set_tcp_keepalive`].
#[derive(Debug, Clone)]
pub struct TcpKeepalive {
#[cfg_attr(target_os = "openbsd", allow(dead_code))]
time: Option<Duration>,
#[cfg(not(any(
target_os = "openbsd",
target_os = "redox",
target_os = "solaris",
target_os = "nto",
)))]
interval: Option<Duration>,
#[cfg(not(any(
target_os = "openbsd",
target_os = "redox",
target_os = "solaris",
target_os = "windows",
target_os = "nto",
)))]
retries: Option<u32>,
}
impl TcpKeepalive {
/// Returns a new, empty set of TCP keepalive parameters.
pub const fn new() -> TcpKeepalive {
TcpKeepalive {
time: None,
#[cfg(not(any(
target_os = "openbsd",
target_os = "redox",
target_os = "solaris",
target_os = "nto",
)))]
interval: None,
#[cfg(not(any(
target_os = "openbsd",
target_os = "redox",
target_os = "solaris",
target_os = "windows",
target_os = "nto",
)))]
retries: None,
}
}
/// Set the amount of time after which TCP keepalive probes will be sent on
/// idle connections.
///
/// This will set `TCP_KEEPALIVE` on macOS and iOS, and
/// `TCP_KEEPIDLE` on all other Unix operating systems, except
/// OpenBSD and Haiku which don't support any way to set this
/// option. On Windows, this sets the value of the `tcp_keepalive`
/// struct's `keepalivetime` field.
///
/// Some platforms specify this value in seconds, so sub-second
/// specifications may be omitted.
pub const fn with_time(self, time: Duration) -> Self {
Self {
time: Some(time),
..self
}
}
/// Set the value of the `TCP_KEEPINTVL` option. On Windows, this sets the
/// value of the `tcp_keepalive` struct's `keepaliveinterval` field.
///
/// Sets the time interval between TCP keepalive probes.
///
/// Some platforms specify this value in seconds, so sub-second
/// specifications may be omitted.
#[cfg(all(
feature = "all",
any(
target_os = "android",
target_os = "dragonfly",
target_os = "freebsd",
target_os = "fuchsia",
target_os = "illumos",
target_os = "linux",
target_os = "netbsd",
target_vendor = "apple",
windows,
)
))]
#[cfg_attr(
docsrs,
doc(cfg(all(
feature = "all",
any(
target_os = "android",
target_os = "dragonfly",
target_os = "freebsd",
target_os = "fuchsia",
target_os = "illumos",
target_os = "linux",
target_os = "netbsd",
target_vendor = "apple",
windows,
)
)))
)]
pub const fn with_interval(self, interval: Duration) -> Self {
Self {
interval: Some(interval),
..self
}
}
/// Set the value of the `TCP_KEEPCNT` option.
///
/// Set the maximum number of TCP keepalive probes that will be sent before
/// dropping a connection, if TCP keepalive is enabled on this socket.
#[cfg(all(
feature = "all",
any(
doc,
target_os = "android",
target_os = "dragonfly",
target_os = "freebsd",
target_os = "fuchsia",
target_os = "illumos",
target_os = "linux",
target_os = "netbsd",
target_vendor = "apple",
)
))]
#[cfg_attr(
docsrs,
doc(cfg(all(
feature = "all",
any(
target_os = "android",
target_os = "dragonfly",
target_os = "freebsd",
target_os = "fuchsia",
target_os = "illumos",
target_os = "linux",
target_os = "netbsd",
target_vendor = "apple",
)
)))
)]
pub const fn with_retries(self, retries: u32) -> Self {
Self {
retries: Some(retries),
..self
}
}
}