//! A private parser implementation of IPv4, IPv6, and socket addresses.
//!
//! This module is "publicly exported" through the `FromStr` implementations
//! below.
use crate::convert::TryInto;
use crate::error::Error;
use crate::fmt;
use crate:🥅:{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6};
use crate::str::FromStr;
trait ReadNumberHelper: Sized {
const ZERO: Self;
fn checked_mul(&self, other: u32) -> Option<Self>;
fn checked_add(&self, other: u32) -> Option<Self>;
}
macro_rules! impl_helper {
($($t:ty)*) => ($(impl ReadNumberHelper for $t {
const ZERO: Self = 0;
#[inline]
fn checked_mul(&self, other: u32) -> Option<Self> {
Self::checked_mul(*self, other.try_into().ok()?)
}
#[inline]
fn checked_add(&self, other: u32) -> Option<Self> {
Self::checked_add(*self, other.try_into().ok()?)
}
})*)
}
impl_helper! { u8 u16 u32 }
struct Parser<'a> {
// Parsing as ASCII, so can use byte array.
state: &'a [u8],
}
impl<'a> Parser<'a> {
fn new(input: &'a [u8]) -> Parser<'a> {
Parser { state: input }
}
/// Run a parser, and restore the pre-parse state if it fails.
fn read_atomically<T, F>(&mut self, inner: F) -> Option<T>
where
F: FnOnce(&mut Parser<'_>) -> Option<T>,
{
let state = self.state;
let result = inner(self);
if result.is_none() {
self.state = state;
}
result
}
/// Run a parser, but fail if the entire input wasn't consumed.
/// Doesn't run atomically.
fn parse_with<T, F>(&mut self, inner: F, kind: AddrKind) -> Result<T, AddrParseError>
where
F: FnOnce(&mut Parser<'_>) -> Option<T>,
{
let result = inner(self);
if self.state.is_empty() { result } else { None }.ok_or(AddrParseError(kind))
}
/// Peek the next character from the input
fn peek_char(&self) -> Option<char> {
self.state.first().map(|&b| char::from(b))
}
/// Read the next character from the input
fn read_char(&mut self) -> Option<char> {
self.state.split_first().map(|(&b, tail)| {
self.state = tail;
char::from(b)
})
}
#[must_use]
/// Read the next character from the input if it matches the target.
fn read_given_char(&mut self, target: char) -> Option<()> {
self.read_atomically(|p| {
p.read_char().and_then(|c| if c == target { Some(()) } else { None })
})
}
/// Helper for reading separators in an indexed loop. Reads the separator
/// character iff index > 0, then runs the parser. When used in a loop,
/// the separator character will only be read on index > 0 (see
/// read_ipv4_addr for an example)
fn read_separator<T, F>(&mut self, sep: char, index: usize, inner: F) -> Option<T>
where
F: FnOnce(&mut Parser<'_>) -> Option<T>,
{
self.read_atomically(move |p| {
if index > 0 {
p.read_given_char(sep)?;
}
inner(p)
})
}
// Read a number off the front of the input in the given radix, stopping
// at the first non-digit character or eof. Fails if the number has more
// digits than max_digits or if there is no number.
fn read_number<T: ReadNumberHelper>(
&mut self,
radix: u32,
max_digits: Option<usize>,
allow_zero_prefix: bool,
) -> Option<T> {
self.read_atomically(move |p| {
let mut result = T::ZERO;
let mut digit_count = 0;
let has_leading_zero = p.peek_char() == Some('0');
while let Some(digit) = p.read_atomically(|p| p.read_char()?.to_digit(radix)) {
result = result.checked_mul(radix)?;
result = result.checked_add(digit)?;
digit_count += 1;
if let Some(max_digits) = max_digits {
if digit_count > max_digits {
return None;
}
}
}
if digit_count == 0 {
None
} else if !allow_zero_prefix && has_leading_zero && digit_count > 1 {
None
} else {
Some(result)
}
})
}
/// Read an IPv4 address.
fn read_ipv4_addr(&mut self) -> Option<Ipv4Addr> {
self.read_atomically(|p| {
let mut groups = [0; 4];
for (i, slot) in groups.iter_mut().enumerate() {
*slot = p.read_separator('.', i, |p| {
// Disallow octal number in IP string.
// https://tools.ietf.org/html/rfc6943#section-3.1.1
p.read_number(10, Some(3), false)
})?;
}
Some(groups.into())
})
}
/// Read an IPv6 Address.
fn read_ipv6_addr(&mut self) -> Option<Ipv6Addr> {
/// Read a chunk of an IPv6 address into `groups`. Returns the number
/// of groups read, along with a bool indicating if an embedded
/// trailing IPv4 address was read. Specifically, read a series of
/// colon-separated IPv6 groups (0x0000 - 0xFFFF), with an optional
/// trailing embedded IPv4 address.
fn read_groups(p: &mut Parser<'_>, groups: &mut [u16]) -> (usize, bool) {
let limit = groups.len();
for (i, slot) in groups.iter_mut().enumerate() {
// Try to read a trailing embedded IPv4 address. There must be
// at least two groups left.
if i < limit - 1 {
let ipv4 = p.read_separator(':', i, |p| p.read_ipv4_addr());
if let Some(v4_addr) = ipv4 {
let [one, two, three, four] = v4_addr.octets();
groups[i + 0] = u16::from_be_bytes([one, two]);
groups[i + 1] = u16::from_be_bytes([three, four]);
return (i + 2, true);
}
}
let group = p.read_separator(':', i, |p| p.read_number(16, Some(4), true));
match group {
Some(g) => *slot = g,
None => return (i, false),
}
}
(groups.len(), false)
}
self.read_atomically(|p| {
// Read the front part of the address; either the whole thing, or up
// to the first ::
let mut head = [0; 8];
let (head_size, head_ipv4) = read_groups(p, &mut head);
if head_size == 8 {
return Some(head.into());
}
// IPv4 part is not allowed before `::`
if head_ipv4 {
return None;
}
// Read `::` if previous code parsed less than 8 groups.
// `::` indicates one or more groups of 16 bits of zeros.
p.read_given_char(':')?;
p.read_given_char(':')?;
// Read the back part of the address. The :: must contain at least one
// set of zeroes, so our max length is 7.
let mut tail = [0; 7];
let limit = 8 - (head_size + 1);
let (tail_size, _) = read_groups(p, &mut tail[..limit]);
// Concat the head and tail of the IP address
head[(8 - tail_size)..8].copy_from_slice(&tail[..tail_size]);
Some(head.into())
})
}
/// Read an IP Address, either IPv4 or IPv6.
fn read_ip_addr(&mut self) -> Option<IpAddr> {
self.read_ipv4_addr().map(IpAddr::V4).or_else(move || self.read_ipv6_addr().map(IpAddr::V6))
}
/// Read a `:` followed by a port in base 10.
fn read_port(&mut self) -> Option<u16> {
self.read_atomically(|p| {
p.read_given_char(':')?;
p.read_number(10, None, true)
})
}
/// Read a `%` followed by a scope ID in base 10.
fn read_scope_id(&mut self) -> Option<u32> {
self.read_atomically(|p| {
p.read_given_char('%')?;
p.read_number(10, None, true)
})
}
/// Read an IPv4 address with a port.
fn read_socket_addr_v4(&mut self) -> Option<SocketAddrV4> {
self.read_atomically(|p| {
let ip = p.read_ipv4_addr()?;
let port = p.read_port()?;
Some(SocketAddrV4::new(ip, port))
})
}
/// Read an IPv6 address with a port.
fn read_socket_addr_v6(&mut self) -> Option<SocketAddrV6> {
self.read_atomically(|p| {
p.read_given_char('[')?;
let ip = p.read_ipv6_addr()?;
let scope_id = p.read_scope_id().unwrap_or(0);
p.read_given_char(']')?;
let port = p.read_port()?;
Some(SocketAddrV6::new(ip, port, 0, scope_id))
})
}
/// Read an IP address with a port
fn read_socket_addr(&mut self) -> Option<SocketAddr> {
self.read_socket_addr_v4()
.map(SocketAddr::V4)
.or_else(|| self.read_socket_addr_v6().map(SocketAddr::V6))
}
}
impl IpAddr {
/// Parse an IP address from a slice of bytes.
///
/// ```
/// #![feature(addr_parse_ascii)]
///
/// use std:🥅:{IpAddr, Ipv4Addr, Ipv6Addr};
///
/// let localhost_v4 = IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1));
/// let localhost_v6 = IpAddr::V6(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1));
///
/// assert_eq!(IpAddr::parse_ascii(b"127.0.0.1"), Ok(localhost_v4));
/// assert_eq!(IpAddr::parse_ascii(b"::1"), Ok(localhost_v6));
/// ```
#[unstable(feature = "addr_parse_ascii", issue = "101035")]
pub fn parse_ascii(b: &[u8]) -> Result<Self, AddrParseError> {
Parser::new(b).parse_with(|p| p.read_ip_addr(), AddrKind::Ip)
}
}
#[stable(feature = "ip_addr", since = "1.7.0")]
impl FromStr for IpAddr {
type Err = AddrParseError;
fn from_str(s: &str) -> Result<IpAddr, AddrParseError> {
Self::parse_ascii(s.as_bytes())
}
}
impl Ipv4Addr {
/// Parse an IPv4 address from a slice of bytes.
///
/// ```
/// #![feature(addr_parse_ascii)]
///
/// use std:🥅:Ipv4Addr;
///
/// let localhost = Ipv4Addr::new(127, 0, 0, 1);
///
/// assert_eq!(Ipv4Addr::parse_ascii(b"127.0.0.1"), Ok(localhost));
/// ```
#[unstable(feature = "addr_parse_ascii", issue = "101035")]
pub fn parse_ascii(b: &[u8]) -> Result<Self, AddrParseError> {
// don't try to parse if too long
if b.len() > 15 {
Err(AddrParseError(AddrKind::Ipv4))
} else {
Parser::new(b).parse_with(|p| p.read_ipv4_addr(), AddrKind::Ipv4)
}
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl FromStr for Ipv4Addr {
type Err = AddrParseError;
fn from_str(s: &str) -> Result<Ipv4Addr, AddrParseError> {
Self::parse_ascii(s.as_bytes())
}
}
impl Ipv6Addr {
/// Parse an IPv6 address from a slice of bytes.
///
/// ```
/// #![feature(addr_parse_ascii)]
///
/// use std:🥅:Ipv6Addr;
///
/// let localhost = Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1);
///
/// assert_eq!(Ipv6Addr::parse_ascii(b"::1"), Ok(localhost));
/// ```
#[unstable(feature = "addr_parse_ascii", issue = "101035")]
pub fn parse_ascii(b: &[u8]) -> Result<Self, AddrParseError> {
Parser::new(b).parse_with(|p| p.read_ipv6_addr(), AddrKind::Ipv6)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl FromStr for Ipv6Addr {
type Err = AddrParseError;
fn from_str(s: &str) -> Result<Ipv6Addr, AddrParseError> {
Self::parse_ascii(s.as_bytes())
}
}
impl SocketAddrV4 {
/// Parse an IPv4 socket address from a slice of bytes.
///
/// ```
/// #![feature(addr_parse_ascii)]
///
/// use std:🥅:{Ipv4Addr, SocketAddrV4};
///
/// let socket = SocketAddrV4::new(Ipv4Addr::new(127, 0, 0, 1), 8080);
///
/// assert_eq!(SocketAddrV4::parse_ascii(b"127.0.0.1:8080"), Ok(socket));
/// ```
#[unstable(feature = "addr_parse_ascii", issue = "101035")]
pub fn parse_ascii(b: &[u8]) -> Result<Self, AddrParseError> {
Parser::new(b).parse_with(|p| p.read_socket_addr_v4(), AddrKind::SocketV4)
}
}
#[stable(feature = "socket_addr_from_str", since = "1.5.0")]
impl FromStr for SocketAddrV4 {
type Err = AddrParseError;
fn from_str(s: &str) -> Result<SocketAddrV4, AddrParseError> {
Self::parse_ascii(s.as_bytes())
}
}
impl SocketAddrV6 {
/// Parse an IPv6 socket address from a slice of bytes.
///
/// ```
/// #![feature(addr_parse_ascii)]
///
/// use std:🥅:{Ipv6Addr, SocketAddrV6};
///
/// let socket = SocketAddrV6::new(Ipv6Addr::new(0x2001, 0xdb8, 0, 0, 0, 0, 0, 1), 8080, 0, 0);
///
/// assert_eq!(SocketAddrV6::parse_ascii(b"[2001:db8::1]:8080"), Ok(socket));
/// ```
#[unstable(feature = "addr_parse_ascii", issue = "101035")]
pub fn parse_ascii(b: &[u8]) -> Result<Self, AddrParseError> {
Parser::new(b).parse_with(|p| p.read_socket_addr_v6(), AddrKind::SocketV6)
}
}
#[stable(feature = "socket_addr_from_str", since = "1.5.0")]
impl FromStr for SocketAddrV6 {
type Err = AddrParseError;
fn from_str(s: &str) -> Result<SocketAddrV6, AddrParseError> {
Self::parse_ascii(s.as_bytes())
}
}
impl SocketAddr {
/// Parse a socket address from a slice of bytes.
///
/// ```
/// #![feature(addr_parse_ascii)]
///
/// use std:🥅:{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr};
///
/// let socket_v4 = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8080);
/// let socket_v6 = SocketAddr::new(IpAddr::V6(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1)), 8080);
///
/// assert_eq!(SocketAddr::parse_ascii(b"127.0.0.1:8080"), Ok(socket_v4));
/// assert_eq!(SocketAddr::parse_ascii(b"[::1]:8080"), Ok(socket_v6));
/// ```
#[unstable(feature = "addr_parse_ascii", issue = "101035")]
pub fn parse_ascii(b: &[u8]) -> Result<Self, AddrParseError> {
Parser::new(b).parse_with(|p| p.read_socket_addr(), AddrKind::Socket)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl FromStr for SocketAddr {
type Err = AddrParseError;
fn from_str(s: &str) -> Result<SocketAddr, AddrParseError> {
Self::parse_ascii(s.as_bytes())
}
}
#[derive(Debug, Clone, PartialEq, Eq)]
enum AddrKind {
Ip,
Ipv4,
Ipv6,
Socket,
SocketV4,
SocketV6,
}
/// An error which can be returned when parsing an IP address or a socket address.
///
/// This error is used as the error type for the [`FromStr`] implementation for
/// [`IpAddr`], [`Ipv4Addr`], [`Ipv6Addr`], [`SocketAddr`], [`SocketAddrV4`], and
/// [`SocketAddrV6`].
///
/// # Potential causes
///
/// `AddrParseError` may be thrown because the provided string does not parse as the given type,
/// often because it includes information only handled by a different address type.
///
/// ```should_panic
/// use std:🥅:IpAddr;
/// let _foo: IpAddr = "127.0.0.1:8080".parse().expect("Cannot handle the socket port");
/// ```
///
/// [`IpAddr`] doesn't handle the port. Use [`SocketAddr`] instead.
///
/// ```
/// use std:🥅:SocketAddr;
///
/// // No problem, the `panic!` message has disappeared.
/// let _foo: SocketAddr = "127.0.0.1:8080".parse().expect("unreachable panic");
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct AddrParseError(AddrKind);
#[stable(feature = "addr_parse_error_error", since = "1.4.0")]
impl fmt::Display for AddrParseError {
#[allow(deprecated, deprecated_in_future)]
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt.write_str(self.description())
}
}
#[stable(feature = "addr_parse_error_error", since = "1.4.0")]
impl Error for AddrParseError {
#[allow(deprecated)]
fn description(&self) -> &str {
match self.0 {
AddrKind::Ip => "invalid IP address syntax",
AddrKind::Ipv4 => "invalid IPv4 address syntax",
AddrKind::Ipv6 => "invalid IPv6 address syntax",
AddrKind::Socket => "invalid socket address syntax",
AddrKind::SocketV4 => "invalid IPv4 socket address syntax",
AddrKind::SocketV6 => "invalid IPv6 socket address syntax",
}
}
}
