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Diffstat (limited to 'library/core/src/net/parser.rs')
| -rw-r--r-- | library/core/src/net/parser.rs | 498 |
1 files changed, 498 insertions, 0 deletions
diff --git a/library/core/src/net/parser.rs b/library/core/src/net/parser.rs new file mode 100644 index 000000000..a08d2792d --- /dev/null +++ b/library/core/src/net/parser.rs @@ -0,0 +1,498 @@ +//! 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::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6}; +use crate::str::FromStr; + +trait ReadNumberHelper: crate::marker::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::net::{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::net::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::net::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::net::{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::net::{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::net::{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::net::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::net::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", + } + } +} |