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Diffstat (limited to 'library/std/src/net/parser.rs')
| -rw-r--r-- | library/std/src/net/parser.rs | 474 |
1 files changed, 474 insertions, 0 deletions
diff --git a/library/std/src/net/parser.rs b/library/std/src/net/parser.rs new file mode 100644 index 00000000000..12d3baf6333 --- /dev/null +++ b/library/std/src/net/parser.rs @@ -0,0 +1,474 @@ +//! A private parser implementation of IPv4, IPv6, and socket addresses. +//! +//! This module is "publicly exported" through the `FromStr` implementations +//! below. + +use crate::error::Error; +use crate::fmt; +use crate::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6}; +use crate::str::FromStr; + +struct Parser<'a> { + // parsing as ASCII, so can use byte array + state: &'a [u8], +} + +impl<'a> Parser<'a> { + fn new(input: &'a str) -> Parser<'a> { + Parser { state: input.as_bytes() } + } + + fn is_eof(&self) -> bool { + self.state.is_empty() + } + + /// 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 read_till_eof<T, F>(&mut self, inner: F) -> Option<T> + where + F: FnOnce(&mut Parser<'_>) -> Option<T>, + { + inner(self).filter(|_| self.is_eof()) + } + + /// Same as read_till_eof, but returns a Result<AddrParseError> on failure + fn parse_with<T, F>(&mut self, inner: F) -> Result<T, AddrParseError> + where + F: FnOnce(&mut Parser<'_>) -> Option<T>, + { + self.read_till_eof(inner).ok_or(AddrParseError(())) + } + + /// Read the next character from the input + fn read_char(&mut self) -> Option<char> { + self.state.split_first().map(|(&b, tail)| { + self.state = tail; + b as char + }) + } + + /// Read the next character from the input if it matches the target + fn read_given_char(&mut self, target: char) -> Option<char> { + self.read_atomically(|p| p.read_char().filter(|&c| c == target)) + } + + /// 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 { + let _ = p.read_given_char(sep)?; + } + inner(p) + }) + } + + // Read a single digit in the given radix. For instance, 0-9 in radix 10; + // 0-9A-F in radix 16. + fn read_digit(&mut self, radix: u32) -> Option<u32> { + self.read_atomically(move |p| p.read_char()?.to_digit(radix)) + } + + // 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 the value is >= upto, or if there is no number. + fn read_number(&mut self, radix: u32, max_digits: u32, upto: u32) -> Option<u32> { + self.read_atomically(move |p| { + let mut result = 0; + let mut digit_count = 0; + + while let Some(digit) = p.read_digit(radix) { + result = (result * radix) + digit; + digit_count += 1; + if digit_count > max_digits || result >= upto { + return None; + } + } + + if digit_count == 0 { 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| p.read_number(10, 3, 0x100))? as u8; + } + + 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 octets = v4_addr.octets(); + groups[i + 0] = ((octets[0] as u16) << 8) | (octets[1] as u16); + groups[i + 1] = ((octets[2] as u16) << 8) | (octets[3] as u16); + return (i + 2, true); + } + } + + let group = p.read_separator(':', i, |p| p.read_number(16, 4, 0x10000)); + + match group { + Some(g) => *slot = g as u16, + 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 + let _ = p.read_given_char(':')?; + let _ = 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| { + let _ = p.read_given_char(':')?; + let port = p.read_number(10, 5, 0x10000)?; + Some(port as u16) + }) + } + + /// 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| { + let _ = p.read_given_char('[')?; + let ip = p.read_ipv6_addr()?; + let _ = p.read_given_char(']')?; + + let port = p.read_port()?; + Some(SocketAddrV6::new(ip, port, 0, 0)) + }) + } + + /// 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)) + } +} + +#[stable(feature = "ip_addr", since = "1.7.0")] +impl FromStr for IpAddr { + type Err = AddrParseError; + fn from_str(s: &str) -> Result<IpAddr, AddrParseError> { + Parser::new(s).parse_with(|p| p.read_ip_addr()) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl FromStr for Ipv4Addr { + type Err = AddrParseError; + fn from_str(s: &str) -> Result<Ipv4Addr, AddrParseError> { + Parser::new(s).parse_with(|p| p.read_ipv4_addr()) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl FromStr for Ipv6Addr { + type Err = AddrParseError; + fn from_str(s: &str) -> Result<Ipv6Addr, AddrParseError> { + Parser::new(s).parse_with(|p| p.read_ipv6_addr()) + } +} + +#[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> { + Parser::new(s).parse_with(|p| p.read_socket_addr_v4()) + } +} + +#[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> { + Parser::new(s).parse_with(|p| p.read_socket_addr_v6()) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl FromStr for SocketAddr { + type Err = AddrParseError; + fn from_str(s: &str) -> Result<SocketAddr, AddrParseError> { + Parser::new(s).parse_with(|p| p.read_socket_addr()) + } +} + +/// 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"); +/// ``` +/// +/// [`FromStr`]: ../../std/str/trait.FromStr.html +/// [`IpAddr`]: ../../std/net/enum.IpAddr.html +/// [`Ipv4Addr`]: ../../std/net/struct.Ipv4Addr.html +/// [`Ipv6Addr`]: ../../std/net/struct.Ipv6Addr.html +/// [`SocketAddr`]: ../../std/net/enum.SocketAddr.html +/// [`SocketAddrV4`]: ../../std/net/struct.SocketAddrV4.html +/// [`SocketAddrV6`]: ../../std/net/struct.SocketAddrV6.html +#[stable(feature = "rust1", since = "1.0.0")] +#[derive(Debug, Clone, PartialEq, Eq)] +pub struct AddrParseError(()); + +#[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 { + "invalid IP address syntax" + } +} + +#[cfg(test)] +mod tests { + // FIXME: These tests are all excellent candidates for AFL fuzz testing + use crate::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6}; + use crate::str::FromStr; + + const PORT: u16 = 8080; + + const IPV4: Ipv4Addr = Ipv4Addr::new(192, 168, 0, 1); + const IPV4_STR: &str = "192.168.0.1"; + const IPV4_STR_PORT: &str = "192.168.0.1:8080"; + + const IPV6: Ipv6Addr = Ipv6Addr::new(0x2001, 0xdb8, 0, 0, 0, 0, 0xc0a8, 0x1); + const IPV6_STR_FULL: &str = "2001:db8:0:0:0:0:c0a8:1"; + const IPV6_STR_COMPRESS: &str = "2001:db8::c0a8:1"; + const IPV6_STR_V4: &str = "2001:db8::192.168.0.1"; + const IPV6_STR_PORT: &str = "[2001:db8::c0a8:1]:8080"; + + #[test] + fn parse_ipv4() { + let result: Ipv4Addr = IPV4_STR.parse().unwrap(); + assert_eq!(result, IPV4); + + assert!(Ipv4Addr::from_str(IPV4_STR_PORT).is_err()); + assert!(Ipv4Addr::from_str(IPV6_STR_FULL).is_err()); + assert!(Ipv4Addr::from_str(IPV6_STR_COMPRESS).is_err()); + assert!(Ipv4Addr::from_str(IPV6_STR_V4).is_err()); + assert!(Ipv4Addr::from_str(IPV6_STR_PORT).is_err()); + } + + #[test] + fn parse_ipv6() { + let result: Ipv6Addr = IPV6_STR_FULL.parse().unwrap(); + assert_eq!(result, IPV6); + + let result: Ipv6Addr = IPV6_STR_COMPRESS.parse().unwrap(); + assert_eq!(result, IPV6); + + let result: Ipv6Addr = IPV6_STR_V4.parse().unwrap(); + assert_eq!(result, IPV6); + + assert!(Ipv6Addr::from_str(IPV4_STR).is_err()); + assert!(Ipv6Addr::from_str(IPV4_STR_PORT).is_err()); + assert!(Ipv6Addr::from_str(IPV6_STR_PORT).is_err()); + } + + #[test] + fn parse_ip() { + let result: IpAddr = IPV4_STR.parse().unwrap(); + assert_eq!(result, IpAddr::from(IPV4)); + + let result: IpAddr = IPV6_STR_FULL.parse().unwrap(); + assert_eq!(result, IpAddr::from(IPV6)); + + let result: IpAddr = IPV6_STR_COMPRESS.parse().unwrap(); + assert_eq!(result, IpAddr::from(IPV6)); + + let result: IpAddr = IPV6_STR_V4.parse().unwrap(); + assert_eq!(result, IpAddr::from(IPV6)); + + assert!(IpAddr::from_str(IPV4_STR_PORT).is_err()); + assert!(IpAddr::from_str(IPV6_STR_PORT).is_err()); + } + + #[test] + fn parse_socket_v4() { + let result: SocketAddrV4 = IPV4_STR_PORT.parse().unwrap(); + assert_eq!(result, SocketAddrV4::new(IPV4, PORT)); + + assert!(SocketAddrV4::from_str(IPV4_STR).is_err()); + assert!(SocketAddrV4::from_str(IPV6_STR_FULL).is_err()); + assert!(SocketAddrV4::from_str(IPV6_STR_COMPRESS).is_err()); + assert!(SocketAddrV4::from_str(IPV6_STR_V4).is_err()); + assert!(SocketAddrV4::from_str(IPV6_STR_PORT).is_err()); + } + + #[test] + fn parse_socket_v6() { + let result: SocketAddrV6 = IPV6_STR_PORT.parse().unwrap(); + assert_eq!(result, SocketAddrV6::new(IPV6, PORT, 0, 0)); + + assert!(SocketAddrV6::from_str(IPV4_STR).is_err()); + assert!(SocketAddrV6::from_str(IPV4_STR_PORT).is_err()); + assert!(SocketAddrV6::from_str(IPV6_STR_FULL).is_err()); + assert!(SocketAddrV6::from_str(IPV6_STR_COMPRESS).is_err()); + assert!(SocketAddrV6::from_str(IPV6_STR_V4).is_err()); + } + + #[test] + fn parse_socket() { + let result: SocketAddr = IPV4_STR_PORT.parse().unwrap(); + assert_eq!(result, SocketAddr::from((IPV4, PORT))); + + let result: SocketAddr = IPV6_STR_PORT.parse().unwrap(); + assert_eq!(result, SocketAddr::from((IPV6, PORT))); + + assert!(SocketAddr::from_str(IPV4_STR).is_err()); + assert!(SocketAddr::from_str(IPV6_STR_FULL).is_err()); + assert!(SocketAddr::from_str(IPV6_STR_COMPRESS).is_err()); + assert!(SocketAddr::from_str(IPV6_STR_V4).is_err()); + } + + #[test] + fn ipv6_corner_cases() { + let result: Ipv6Addr = "1::".parse().unwrap(); + assert_eq!(result, Ipv6Addr::new(1, 0, 0, 0, 0, 0, 0, 0)); + + let result: Ipv6Addr = "1:1::".parse().unwrap(); + assert_eq!(result, Ipv6Addr::new(1, 1, 0, 0, 0, 0, 0, 0)); + + let result: Ipv6Addr = "::1".parse().unwrap(); + assert_eq!(result, Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1)); + + let result: Ipv6Addr = "::1:1".parse().unwrap(); + assert_eq!(result, Ipv6Addr::new(0, 0, 0, 0, 0, 0, 1, 1)); + + let result: Ipv6Addr = "::".parse().unwrap(); + assert_eq!(result, Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 0)); + + let result: Ipv6Addr = "::192.168.0.1".parse().unwrap(); + assert_eq!(result, Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0xc0a8, 0x1)); + + let result: Ipv6Addr = "::1:192.168.0.1".parse().unwrap(); + assert_eq!(result, Ipv6Addr::new(0, 0, 0, 0, 0, 1, 0xc0a8, 0x1)); + + let result: Ipv6Addr = "1:1:1:1:1:1:192.168.0.1".parse().unwrap(); + assert_eq!(result, Ipv6Addr::new(1, 1, 1, 1, 1, 1, 0xc0a8, 0x1)); + } + + // Things that might not seem like failures but are + #[test] + fn ipv6_corner_failures() { + // No IP address before the :: + assert!(Ipv6Addr::from_str("1:192.168.0.1::").is_err()); + + // :: must have at least 1 set of zeroes + assert!(Ipv6Addr::from_str("1:1:1:1::1:1:1:1").is_err()); + + // Need brackets for a port + assert!(SocketAddrV6::from_str("1:1:1:1:1:1:1:1:8080").is_err()); + } +} |