/rust/registry/src/index.crates.io-1949cf8c6b5b557f/url-2.5.7/src/host.rs

Source
// Copyright 2013-2016 The rust-url developers.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use crate::net::{Ipv4Addr, Ipv6Addr};
use alloc::borrow::Cow;
use alloc::borrow::ToOwned;
use alloc::string::String;
use alloc::vec::Vec;
use core::cmp;
use core::fmt::{self, Formatter};

use percent_encoding::{percent_decode, utf8_percent_encode, CONTROLS};
#[cfg(feature = "serde")]
use serde::{Deserialize, Serialize};

use crate::parser::{ParseError, ParseResult};

#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
pub(crate) enum HostInternal {
    None,
    Domain,
    Ipv4(Ipv4Addr),
    Ipv6(Ipv6Addr),
}

impl From<Host<Cow<'_, str>>> for HostInternal {
    fn from(host: Host<Cow<'_, str>>) -> Self {
        match host {
            Host::Domain(ref s) if s.is_empty() => Self::None,
            Host::Domain(_) => Self::Domain,
            Host::Ipv4(address) => Self::Ipv4(address),
            Host::Ipv6(address) => Self::Ipv6(address),
        }
    }
}

/// The host name of an URL.
#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
#[derive(Clone, Debug, Eq, Ord, PartialOrd, Hash)]
pub enum Host<S = String> {
    /// A DNS domain name, as '.' dot-separated labels.
    /// Non-ASCII labels are encoded in punycode per IDNA if this is the host of
    /// a special URL, or percent encoded for non-special URLs. Hosts for
    /// non-special URLs are also called opaque hosts.
    Domain(S),

    /// An IPv4 address.
    /// `Url::host_str` returns the serialization of this address,
    /// as four decimal integers separated by `.` dots.
    Ipv4(Ipv4Addr),

    /// An IPv6 address.
    /// `Url::host_str` returns the serialization of that address between `[` and `]` brackets,
    /// in the format per [RFC 5952 *A Recommendation
    /// for IPv6 Address Text Representation*](https://tools.ietf.org/html/rfc5952):
    /// lowercase hexadecimal with maximal `::` compression.
    Ipv6(Ipv6Addr),
}

impl Host<&str> {
    /// Return a copy of `self` that owns an allocated `String` but does not borrow an `&Url`.
    pub fn to_owned(&self) -> Host<String> {
        match *self {
            Host::Domain(domain) => Host::Domain(domain.to_owned()),
            Host::Ipv4(address) => Host::Ipv4(address),
            Host::Ipv6(address) => Host::Ipv6(address),
        }
    }
}

impl Host<String> {
    /// Parse a host: either an IPv6 address in [] square brackets, or a domain.
    ///
    /// <https://url.spec.whatwg.org/#host-parsing>
    pub fn parse(input: &str) -> Result<Self, ParseError> {
        Host::<Cow<str>>::parse_cow(input.into()).map(|i| i.into_owned())
    }

    /// <https://url.spec.whatwg.org/#concept-opaque-host-parser>
    pub fn parse_opaque(input: &str) -> Result<Self, ParseError> {
        Host::<Cow<str>>::parse_opaque_cow(input.into()).map(|i| i.into_owned())
    }
}

impl<'a> Host<Cow<'a, str>> {
    pub(crate) fn parse_cow(input: Cow<'a, str>) -> Result<Self, ParseError> {
        if input.starts_with('[') {
            if !input.ends_with(']') {
                return Err(ParseError::InvalidIpv6Address);
            }
            return parse_ipv6addr(&input[1..input.len() - 1]).map(Host::Ipv6);
        }
        let domain: Cow<'_, [u8]> = percent_decode(input.as_bytes()).into();
        let domain: Cow<'a, [u8]> = match domain {
            Cow::Owned(v) => Cow::Owned(v),
            // if borrowed then we can use the original cow
            Cow::Borrowed(_) => match input {
                Cow::Borrowed(input) => Cow::Borrowed(input.as_bytes()),
                Cow::Owned(input) => Cow::Owned(input.into_bytes()),
            },
        };

        let domain = idna::domain_to_ascii_from_cow(domain, idna::AsciiDenyList::URL)?;

        if domain.is_empty() {
            return Err(ParseError::EmptyHost);
        }

        if ends_in_a_number(&domain) {
            let address = parse_ipv4addr(&domain)?;
            Ok(Host::Ipv4(address))
        } else {
            Ok(Host::Domain(domain))
        }
    }

    pub(crate) fn parse_opaque_cow(input: Cow<'a, str>) -> Result<Self, ParseError> {
        if input.starts_with('[') {
            if !input.ends_with(']') {
                return Err(ParseError::InvalidIpv6Address);
            }
            return parse_ipv6addr(&input[1..input.len() - 1]).map(Host::Ipv6);
        }

        let is_invalid_host_char = |c| {
            matches!(
                c,
                '\0' | '\t'
                    | '\n'
                    | '\r'
                    | ' '
                    | '#'
                    | '/'
                    | ':'
                    | '<'
                    | '>'
                    | '?'
                    | '@'
                    | '['
                    | '\\'
                    | ']'
                    | '^'
                    | '|'
            )
        };

        if input.find(is_invalid_host_char).is_some() {
            Err(ParseError::InvalidDomainCharacter)
        } else {
            Ok(Host::Domain(
                match utf8_percent_encode(&input, CONTROLS).into() {
                    Cow::Owned(v) => Cow::Owned(v),
                    // if we're borrowing, then we can return the original Cow
                    Cow::Borrowed(_) => input,
                },
            ))
        }
    }

    pub(crate) fn into_owned(self) -> Host<String> {
        match self {
            Host::Domain(s) => Host::Domain(s.into_owned()),
            Host::Ipv4(ip) => Host::Ipv4(ip),
            Host::Ipv6(ip) => Host::Ipv6(ip),
        }
    }
}

impl<S: AsRef<str>> fmt::Display for Host<S> {
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
        match *self {
            Self::Domain(ref domain) => domain.as_ref().fmt(f),
            Self::Ipv4(ref addr) => addr.fmt(f),
            Self::Ipv6(ref addr) => {
                f.write_str("[")?;
                write_ipv6(addr, f)?;
                f.write_str("]")
            }
        }
    }
}

impl<S, T> PartialEq<Host<T>> for Host<S>
where
    S: PartialEq<T>,
{
    fn eq(&self, other: &Host<T>) -> bool {
        match (self, other) {
            (Self::Domain(a), Host::Domain(b)) => a == b,
            (Self::Ipv4(a), Host::Ipv4(b)) => a == b,
            (Self::Ipv6(a), Host::Ipv6(b)) => a == b,
            (_, _) => false,
        }
    }
}

fn write_ipv6(addr: &Ipv6Addr, f: &mut Formatter<'_>) -> fmt::Result {
    let segments = addr.segments();
    let (compress_start, compress_end) = longest_zero_sequence(&segments);
    let mut i = 0;
    while i < 8 {
        if i == compress_start {
            f.write_str(":")?;
            if i == 0 {
                f.write_str(":")?;
            }
            if compress_end < 8 {
                i = compress_end;
            } else {
                break;
            }
        }
        write!(f, "{:x}", segments[i as usize])?;
        if i < 7 {
            f.write_str(":")?;
        }
        i += 1;
    }
    Ok(())
}

// https://url.spec.whatwg.org/#concept-ipv6-serializer step 2 and 3
fn longest_zero_sequence(pieces: &[u16; 8]) -> (isize, isize) {
    let mut longest = -1;
    let mut longest_length = -1;
    let mut start = -1;
    macro_rules! finish_sequence(
        ($end: expr) => {
            if start >= 0 {
                let length = $end - start;
                if length > longest_length {
                    longest = start;
                    longest_length = length;
                }
            }
        };
    );
    for i in 0..8 {
        if pieces[i as usize] == 0 {
            if start < 0 {
                start = i;
            }
        } else {
            finish_sequence!(i);
            start = -1;
        }
    }
    finish_sequence!(8);
    // https://url.spec.whatwg.org/#concept-ipv6-serializer
    // step 3: ignore lone zeroes
    if longest_length < 2 {
        (-1, -2)
    } else {
        (longest, longest + longest_length)
    }
}

/// <https://url.spec.whatwg.org/#ends-in-a-number-checker>
fn ends_in_a_number(input: &str) -> bool {
    let mut parts = input.rsplit('.');
    let last = parts.next().unwrap();
    let last = if last.is_empty() {
        if let Some(last) = parts.next() {
            last
        } else {
            return false;
        }
    } else {
        last
    };
    if !last.is_empty() && last.as_bytes().iter().all(|c| c.is_ascii_digit()) {
        return true;
    }

    parse_ipv4number(last).is_ok()
}

/// <https://url.spec.whatwg.org/#ipv4-number-parser>
/// Ok(None) means the input is a valid number, but it overflows a `u32`.
fn parse_ipv4number(mut input: &str) -> Result<Option<u32>, ()> {
    if input.is_empty() {
        return Err(());
    }

    let mut r = 10;
    if input.starts_with("0x") || input.starts_with("0X") {
        input = &input[2..];
        r = 16;
    } else if input.len() >= 2 && input.starts_with('0') {
        input = &input[1..];
        r = 8;
    }

    if input.is_empty() {
        return Ok(Some(0));
    }

    let valid_number = match r {
        8 => input.as_bytes().iter().all(|c| (b'0'..=b'7').contains(c)),
        10 => input.as_bytes().iter().all(|c| c.is_ascii_digit()),
        16 => input.as_bytes().iter().all(|c| c.is_ascii_hexdigit()),
        _ => false,
    };
    if !valid_number {
        return Err(());
    }

    match u32::from_str_radix(input, r) {
        Ok(num) => Ok(Some(num)),
        Err(_) => Ok(None), // The only possible error kind here is an integer overflow.
                            // The validity of the chars in the input is checked above.
    }
}

/// <https://url.spec.whatwg.org/#concept-ipv4-parser>
fn parse_ipv4addr(input: &str) -> ParseResult<Ipv4Addr> {
    let mut parts: Vec<&str> = input.split('.').collect();
    if parts.last() == Some(&"") {
        parts.pop();
    }
    if parts.len() > 4 {
        return Err(ParseError::InvalidIpv4Address);
    }
    let mut numbers: Vec<u32> = Vec::new();
    for part in parts {
        match parse_ipv4number(part) {
            Ok(Some(n)) => numbers.push(n),
            Ok(None) => return Err(ParseError::InvalidIpv4Address), // u32 overflow
            Err(()) => return Err(ParseError::InvalidIpv4Address),
        };
    }
    let mut ipv4 = numbers.pop().expect("a non-empty list of numbers");
    // Equivalent to: ipv4 >= 256 ** (4 − numbers.len())
    if ipv4 > u32::MAX >> (8 * numbers.len() as u32) {
        return Err(ParseError::InvalidIpv4Address);
    }
    if numbers.iter().any(|x| *x > 255) {
        return Err(ParseError::InvalidIpv4Address);
    }
    for (counter, n) in numbers.iter().enumerate() {
        ipv4 += n << (8 * (3 - counter as u32))
    }
    Ok(Ipv4Addr::from(ipv4))
}

/// <https://url.spec.whatwg.org/#concept-ipv6-parser>
fn parse_ipv6addr(input: &str) -> ParseResult<Ipv6Addr> {
    let input = input.as_bytes();
    let len = input.len();
    let mut is_ip_v4 = false;
    let mut pieces = [0, 0, 0, 0, 0, 0, 0, 0];
    let mut piece_pointer = 0;
    let mut compress_pointer = None;
    let mut i = 0;

    if len < 2 {
        return Err(ParseError::InvalidIpv6Address);
    }

    if input[0] == b':' {
        if input[1] != b':' {
            return Err(ParseError::InvalidIpv6Address);
        }
        i = 2;
        piece_pointer = 1;
        compress_pointer = Some(1);
    }

    while i < len {
        if piece_pointer == 8 {
            return Err(ParseError::InvalidIpv6Address);
        }
        if input[i] == b':' {
            if compress_pointer.is_some() {
                return Err(ParseError::InvalidIpv6Address);
            }
            i += 1;
            piece_pointer += 1;
            compress_pointer = Some(piece_pointer);
            continue;
        }
        let start = i;
        let end = cmp::min(len, start + 4);
        let mut value = 0u16;
        while i < end {
            match (input[i] as char).to_digit(16) {
                Some(digit) => {
                    value = value * 0x10 + digit as u16;
                    i += 1;
                }
                None => break,
            }
        }
        if i < len {
            match input[i] {
                b'.' => {
                    if i == start {
                        return Err(ParseError::InvalidIpv6Address);
                    }
                    i = start;
                    if piece_pointer > 6 {
                        return Err(ParseError::InvalidIpv6Address);
                    }
                    is_ip_v4 = true;
                }
                b':' => {
                    i += 1;
                    if i == len {
                        return Err(ParseError::InvalidIpv6Address);
                    }
                }
                _ => return Err(ParseError::InvalidIpv6Address),
            }
        }
        if is_ip_v4 {
            break;
        }
        pieces[piece_pointer] = value;
        piece_pointer += 1;
    }

    if is_ip_v4 {
        if piece_pointer > 6 {
            return Err(ParseError::InvalidIpv6Address);
        }
        let mut numbers_seen = 0;
        while i < len {
            if numbers_seen > 0 {
                if numbers_seen < 4 && (i < len && input[i] == b'.') {
                    i += 1
                } else {
                    return Err(ParseError::InvalidIpv6Address);
                }
            }

            let mut ipv4_piece = None;
            while i < len {
                let digit = match input[i] {
                    c @ b'0'..=b'9' => c - b'0',
                    _ => break,
                };
                match ipv4_piece {
                    None => ipv4_piece = Some(digit as u16),
                    Some(0) => return Err(ParseError::InvalidIpv6Address), // No leading zero
                    Some(ref mut v) => {
                        *v = *v * 10 + digit as u16;
                        if *v > 255 {
                            return Err(ParseError::InvalidIpv6Address);
                        }
                    }
                }
                i += 1;
            }

            pieces[piece_pointer] = if let Some(v) = ipv4_piece {
                pieces[piece_pointer] * 0x100 + v
            } else {
                return Err(ParseError::InvalidIpv6Address);
            };
            numbers_seen += 1;

            if numbers_seen == 2 || numbers_seen == 4 {
                piece_pointer += 1;
            }
        }

        if numbers_seen != 4 {
            return Err(ParseError::InvalidIpv6Address);
        }
    }

    if i < len {
        return Err(ParseError::InvalidIpv6Address);
    }

    match compress_pointer {
        Some(compress_pointer) => {
            let mut swaps = piece_pointer - compress_pointer;
            piece_pointer = 7;
            while swaps > 0 {
                pieces.swap(piece_pointer, compress_pointer + swaps - 1);
                swaps -= 1;
                piece_pointer -= 1;
            }
        }
        _ => {
            if piece_pointer != 8 {
                return Err(ParseError::InvalidIpv6Address);
            }
        }
    }
    Ok(Ipv6Addr::new(
        pieces[0], pieces[1], pieces[2], pieces[3], pieces[4], pieces[5], pieces[6], pieces[7],
    ))
}

Coverage Report

Created: 2025-10-13 06:09

Line	Count	Source
1		// Copyright 2013-2016 The rust-url developers.
2		//
3		// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
4		// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
5		// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
6		// option. This file may not be copied, modified, or distributed
7		// except according to those terms.
8
9		use crate::net::{Ipv4Addr, Ipv6Addr};
10		use alloc::borrow::Cow;
11		use alloc::borrow::ToOwned;
12		use alloc::string::String;
13		use alloc::vec::Vec;
14		use core::cmp;
15		use core::fmt::{self, Formatter};
16
17		use percent_encoding::{percent_decode, utf8_percent_encode, CONTROLS};
18		#[cfg(feature = "serde")]
19		use serde::{Deserialize, Serialize};
20
21		use crate::parser::{ParseError, ParseResult};
22
23		#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
24		#[derive(Copy, Clone, Debug, Eq, PartialEq)]
25		pub(crate) enum HostInternal {
26		None,
27		Domain,
28		Ipv4(Ipv4Addr),
29		Ipv6(Ipv6Addr),
30		}
31
32		impl From<Host<Cow<'_, str>>> for HostInternal {
33	0	fn from(host: Host<Cow<'_, str>>) -> Self {
34	0	match host {
35	0	Host::Domain(ref s) if s.is_empty() => Self::None,
36	0	Host::Domain(_) => Self::Domain,
37	0	Host::Ipv4(address) => Self::Ipv4(address),
38	0	Host::Ipv6(address) => Self::Ipv6(address),
39		}
40	0	}
41		}
42
43		/// The host name of an URL.
44		#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
45		#[derive(Clone, Debug, Eq, Ord, PartialOrd, Hash)]
46		pub enum Host<S = String> {
47		/// A DNS domain name, as '.' dot-separated labels.
48		/// Non-ASCII labels are encoded in punycode per IDNA if this is the host of
49		/// a special URL, or percent encoded for non-special URLs. Hosts for
50		/// non-special URLs are also called opaque hosts.
51		Domain(S),
52
53		/// An IPv4 address.
54		/// `Url::host_str` returns the serialization of this address,
55		/// as four decimal integers separated by `.` dots.
56		Ipv4(Ipv4Addr),
57
58		/// An IPv6 address.
59		/// `Url::host_str` returns the serialization of that address between `[` and `]` brackets,
60		/// in the format per [RFC 5952 *A Recommendation
61		/// for IPv6 Address Text Representation*](https://tools.ietf.org/html/rfc5952):
62		/// lowercase hexadecimal with maximal `::` compression.
63		Ipv6(Ipv6Addr),
64		}
65
66		impl Host<&str> {
67		/// Return a copy of `self` that owns an allocated `String` but does not borrow an `&Url`.
68	0	pub fn to_owned(&self) -> Host<String> {
69	0	match *self {
70	0	Host::Domain(domain) => Host::Domain(domain.to_owned()),
71	0	Host::Ipv4(address) => Host::Ipv4(address),
72	0	Host::Ipv6(address) => Host::Ipv6(address),
73		}
74	0	}
75		}
76
77		impl Host<String> {
78		/// Parse a host: either an IPv6 address in [] square brackets, or a domain.
79		///
80		/// <https://url.spec.whatwg.org/#host-parsing>
81	0	pub fn parse(input: &str) -> Result<Self, ParseError> {
82	0	Host::<Cow<str>>::parse_cow(input.into()).map(\|i\| i.into_owned())
83	0	}
84
85		/// <https://url.spec.whatwg.org/#concept-opaque-host-parser>
86	0	pub fn parse_opaque(input: &str) -> Result<Self, ParseError> {
87	0	Host::<Cow<str>>::parse_opaque_cow(input.into()).map(\|i\| i.into_owned())
88	0	}
89		}
90
91		impl<'a> Host<Cow<'a, str>> {
92	0	pub(crate) fn parse_cow(input: Cow<'a, str>) -> Result<Self, ParseError> {
93	0	if input.starts_with('[') {
94	0	if !input.ends_with(']') {
95	0	return Err(ParseError::InvalidIpv6Address);
96	0	}
97	0	return parse_ipv6addr(&input[1..input.len() - 1]).map(Host::Ipv6);
98	0	}
99	0	let domain: Cow<'_, [u8]> = percent_decode(input.as_bytes()).into();
100	0	let domain: Cow<'a, [u8]> = match domain {
101	0	Cow::Owned(v) => Cow::Owned(v),
102		// if borrowed then we can use the original cow
103	0	Cow::Borrowed(_) => match input {
104	0	Cow::Borrowed(input) => Cow::Borrowed(input.as_bytes()),
105	0	Cow::Owned(input) => Cow::Owned(input.into_bytes()),
106		},
107		};
108
109	0	let domain = idna::domain_to_ascii_from_cow(domain, idna::AsciiDenyList::URL)?;
110
111	0	if domain.is_empty() {
112	0	return Err(ParseError::EmptyHost);
113	0	}
114
115	0	if ends_in_a_number(&domain) {
116	0	let address = parse_ipv4addr(&domain)?;
117	0	Ok(Host::Ipv4(address))
118		} else {
119	0	Ok(Host::Domain(domain))
120		}
121	0	}
122
123	0	pub(crate) fn parse_opaque_cow(input: Cow<'a, str>) -> Result<Self, ParseError> {
124	0	if input.starts_with('[') {
125	0	if !input.ends_with(']') {
126	0	return Err(ParseError::InvalidIpv6Address);
127	0	}
128	0	return parse_ipv6addr(&input[1..input.len() - 1]).map(Host::Ipv6);
129	0	}
130
131	0	let is_invalid_host_char = \|c\| {
132	0	matches!(
133	0	c,
134		'\0' \| '\t'
135		\| '\n'
136		\| '\r'
137		\| ' '
138		\| '#'
139		\| '/'
140		\| ':'
141		\| '<'
142		\| '>'
143		\| '?'
144		\| '@'
145		\| '['
146		\| '\\'
147		\| ']'
148		\| '^'
149		\| '\|'
150		)
151	0	};
152
153	0	if input.find(is_invalid_host_char).is_some() {
154	0	Err(ParseError::InvalidDomainCharacter)
155		} else {
156		Ok(Host::Domain(
157	0	match utf8_percent_encode(&input, CONTROLS).into() {
158	0	Cow::Owned(v) => Cow::Owned(v),
159		// if we're borrowing, then we can return the original Cow
160	0	Cow::Borrowed(_) => input,
161		},
162		))
163		}
164	0	}
165
166	0	pub(crate) fn into_owned(self) -> Host<String> {
167	0	match self {
168	0	Host::Domain(s) => Host::Domain(s.into_owned()),
169	0	Host::Ipv4(ip) => Host::Ipv4(ip),
170	0	Host::Ipv6(ip) => Host::Ipv6(ip),
171		}
172	0	}
173		}
174
175		impl<S: AsRef<str>> fmt::Display for Host<S> {
176	0	fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
177	0	match *self {
178	0	Self::Domain(ref domain) => domain.as_ref().fmt(f),
179	0	Self::Ipv4(ref addr) => addr.fmt(f),
180	0	Self::Ipv6(ref addr) => {
181	0	f.write_str("[")?;
182	0	write_ipv6(addr, f)?;
183	0	f.write_str("]")
184		}
185		}
186	0	} Unexecuted instantiation: <url::host::Host<alloc::borrow::Cow<str>> as core::fmt::Display>::fmt Unexecuted instantiation: <url::host::Host as core::fmt::Display>::fmt
187		}
188
189		impl<S, T> PartialEq<Host<T>> for Host<S>
190		where
191		S: PartialEq<T>,
192		{
193	0	fn eq(&self, other: &Host<T>) -> bool {
194	0	match (self, other) {
195	0	(Self::Domain(a), Host::Domain(b)) => a == b,
196	0	(Self::Ipv4(a), Host::Ipv4(b)) => a == b,
197	0	(Self::Ipv6(a), Host::Ipv6(b)) => a == b,
198	0	(_, _) => false,
199		}
200	0	} Unexecuted instantiation: <url::host::Host<alloc::borrow::Cow<str>> as core::cmp::PartialEq<url::host::Host>>::eq Unexecuted instantiation: <url::host::Host<&str> as core::cmp::PartialEq>::eq
201		}
202
203	0	fn write_ipv6(addr: &Ipv6Addr, f: &mut Formatter<'_>) -> fmt::Result {
204	0	let segments = addr.segments();
205	0	let (compress_start, compress_end) = longest_zero_sequence(&segments);
206	0	let mut i = 0;
207	0	while i < 8 {
208	0	if i == compress_start {
209	0	f.write_str(":")?;
210	0	if i == 0 {
211	0	f.write_str(":")?;
212	0	}
213	0	if compress_end < 8 {
214	0	i = compress_end;
215	0	} else {
216	0	break;
217		}
218	0	}
219	0	write!(f, "{:x}", segments[i as usize])?;
220	0	if i < 7 {
221	0	f.write_str(":")?;
222	0	}
223	0	i += 1;
224		}
225	0	Ok(())
226	0	}
227
228		// https://url.spec.whatwg.org/#concept-ipv6-serializer step 2 and 3
229	0	fn longest_zero_sequence(pieces: &[u16; 8]) -> (isize, isize) {
230	0	let mut longest = -1;
231	0	let mut longest_length = -1;
232	0	let mut start = -1;
233		macro_rules! finish_sequence(
234		($end: expr) => {
235		if start >= 0 {
236		let length = $end - start;
237		if length > longest_length {
238		longest = start;
239		longest_length = length;
240		}
241		}
242		};
243		);
244	0	for i in 0..8 {
245	0	if pieces[i as usize] == 0 {
246	0	if start < 0 {
247	0	start = i;
248	0	}
249		} else {
250	0	finish_sequence!(i);
251	0	start = -1;
252		}
253		}
254	0	finish_sequence!(8);
255		// https://url.spec.whatwg.org/#concept-ipv6-serializer
256		// step 3: ignore lone zeroes
257	0	if longest_length < 2 {
258	0	(-1, -2)
259		} else {
260	0	(longest, longest + longest_length)
261		}
262	0	}
263
264		/// <https://url.spec.whatwg.org/#ends-in-a-number-checker>
265	0	fn ends_in_a_number(input: &str) -> bool {
266	0	let mut parts = input.rsplit('.');
267	0	let last = parts.next().unwrap();
268	0	let last = if last.is_empty() {
269	0	if let Some(last) = parts.next() {
270	0	last
271		} else {
272	0	return false;
273		}
274		} else {
275	0	last
276		};
277	0	if !last.is_empty() && last.as_bytes().iter().all(\|c\| c.is_ascii_digit()) {
278	0	return true;
279	0	}
280
281	0	parse_ipv4number(last).is_ok()
282	0	}
283
284		/// <https://url.spec.whatwg.org/#ipv4-number-parser>
285		/// Ok(None) means the input is a valid number, but it overflows a `u32`.
286	0	fn parse_ipv4number(mut input: &str) -> Result<Option<u32>, ()> {
287	0	if input.is_empty() {
288	0	return Err(());
289	0	}
290
291	0	let mut r = 10;
292	0	if input.starts_with("0x") \|\| input.starts_with("0X") {
293	0	input = &input[2..];
294	0	r = 16;
295	0	} else if input.len() >= 2 && input.starts_with('0') {
296	0	input = &input[1..];
297	0	r = 8;
298	0	}
299
300	0	if input.is_empty() {
301	0	return Ok(Some(0));
302	0	}
303
304	0	let valid_number = match r {
305	0	8 => input.as_bytes().iter().all(\|c\| (b'0'..=b'7').contains(c)),
306	0	10 => input.as_bytes().iter().all(\|c\| c.is_ascii_digit()),
307	0	16 => input.as_bytes().iter().all(\|c\| c.is_ascii_hexdigit()),
308	0	_ => false,
309		};
310	0	if !valid_number {
311	0	return Err(());
312	0	}
313
314	0	match u32::from_str_radix(input, r) {
315	0	Ok(num) => Ok(Some(num)),
316	0	Err(_) => Ok(None), // The only possible error kind here is an integer overflow.
317		// The validity of the chars in the input is checked above.
318		}
319	0	}
320
321		/// <https://url.spec.whatwg.org/#concept-ipv4-parser>
322	0	fn parse_ipv4addr(input: &str) -> ParseResult<Ipv4Addr> {
323	0	let mut parts: Vec<&str> = input.split('.').collect();
324	0	if parts.last() == Some(&"") {
325	0	parts.pop();
326	0	}
327	0	if parts.len() > 4 {
328	0	return Err(ParseError::InvalidIpv4Address);
329	0	}
330	0	let mut numbers: Vec<u32> = Vec::new();
331	0	for part in parts {
332	0	match parse_ipv4number(part) {
333	0	Ok(Some(n)) => numbers.push(n),
334	0	Ok(None) => return Err(ParseError::InvalidIpv4Address), // u32 overflow
335	0	Err(()) => return Err(ParseError::InvalidIpv4Address),
336		};
337		}
338	0	let mut ipv4 = numbers.pop().expect("a non-empty list of numbers");
339		// Equivalent to: ipv4 >= 256 ** (4 − numbers.len())
340	0	if ipv4 > u32::MAX >> (8 * numbers.len() as u32) {
341	0	return Err(ParseError::InvalidIpv4Address);
342	0	}
343	0	if numbers.iter().any(\|x\| *x > 255) {
344	0	return Err(ParseError::InvalidIpv4Address);
345	0	}
346	0	for (counter, n) in numbers.iter().enumerate() {
347	0	ipv4 += n << (8 * (3 - counter as u32))
348		}
349	0	Ok(Ipv4Addr::from(ipv4))
350	0	}
351
352		/// <https://url.spec.whatwg.org/#concept-ipv6-parser>
353	0	fn parse_ipv6addr(input: &str) -> ParseResult<Ipv6Addr> {
354	0	let input = input.as_bytes();
355	0	let len = input.len();
356	0	let mut is_ip_v4 = false;
357	0	let mut pieces = [0, 0, 0, 0, 0, 0, 0, 0];
358	0	let mut piece_pointer = 0;
359	0	let mut compress_pointer = None;
360	0	let mut i = 0;
361
362	0	if len < 2 {
363	0	return Err(ParseError::InvalidIpv6Address);
364	0	}
365
366	0	if input[0] == b':' {
367	0	if input[1] != b':' {
368	0	return Err(ParseError::InvalidIpv6Address);
369	0	}
370	0	i = 2;
371	0	piece_pointer = 1;
372	0	compress_pointer = Some(1);
373	0	}
374
375	0	while i < len {
376	0	if piece_pointer == 8 {
377	0	return Err(ParseError::InvalidIpv6Address);
378	0	}
379	0	if input[i] == b':' {
380	0	if compress_pointer.is_some() {
381	0	return Err(ParseError::InvalidIpv6Address);
382	0	}
383	0	i += 1;
384	0	piece_pointer += 1;
385	0	compress_pointer = Some(piece_pointer);
386	0	continue;
387	0	}
388	0	let start = i;
389	0	let end = cmp::min(len, start + 4);
390	0	let mut value = 0u16;
391	0	while i < end {
392	0	match (input[i] as char).to_digit(16) {
393	0	Some(digit) => {
394	0	value = value * 0x10 + digit as u16;
395	0	i += 1;
396	0	}
397	0	None => break,
398		}
399		}
400	0	if i < len {
401	0	match input[i] {
402		b'.' => {
403	0	if i == start {
404	0	return Err(ParseError::InvalidIpv6Address);
405	0	}
406	0	i = start;
407	0	if piece_pointer > 6 {
408	0	return Err(ParseError::InvalidIpv6Address);
409	0	}
410	0	is_ip_v4 = true;
411		}
412		b':' => {
413	0	i += 1;
414	0	if i == len {
415	0	return Err(ParseError::InvalidIpv6Address);
416	0	}
417		}
418	0	_ => return Err(ParseError::InvalidIpv6Address),
419		}
420	0	}
421	0	if is_ip_v4 {
422	0	break;
423	0	}
424	0	pieces[piece_pointer] = value;
425	0	piece_pointer += 1;
426		}
427
428	0	if is_ip_v4 {
429	0	if piece_pointer > 6 {
430	0	return Err(ParseError::InvalidIpv6Address);
431	0	}
432	0	let mut numbers_seen = 0;
433	0	while i < len {
434	0	if numbers_seen > 0 {
435	0	if numbers_seen < 4 && (i < len && input[i] == b'.') {
436	0	i += 1
437		} else {
438	0	return Err(ParseError::InvalidIpv6Address);
439		}
440	0	}
441
442	0	let mut ipv4_piece = None;
443	0	while i < len {
444	0	let digit = match input[i] {
445	0	c @ b'0'..=b'9' => c - b'0',
446	0	_ => break,
447		};
448	0	match ipv4_piece {
449	0	None => ipv4_piece = Some(digit as u16),
450	0	Some(0) => return Err(ParseError::InvalidIpv6Address), // No leading zero
451	0	Some(ref mut v) => {
452	0	v = v * 10 + digit as u16;
453	0	if *v > 255 {
454	0	return Err(ParseError::InvalidIpv6Address);
455	0	}
456		}
457		}
458	0	i += 1;
459		}
460
461	0	pieces[piece_pointer] = if let Some(v) = ipv4_piece {
462	0	pieces[piece_pointer] * 0x100 + v
463		} else {
464	0	return Err(ParseError::InvalidIpv6Address);
465		};
466	0	numbers_seen += 1;
467
468	0	if numbers_seen == 2 \|\| numbers_seen == 4 {
469	0	piece_pointer += 1;
470	0	}
471		}
472
473	0	if numbers_seen != 4 {
474	0	return Err(ParseError::InvalidIpv6Address);
475	0	}
476	0	}
477
478	0	if i < len {
479	0	return Err(ParseError::InvalidIpv6Address);
480	0	}
481
482	0	match compress_pointer {
483	0	Some(compress_pointer) => {
484	0	let mut swaps = piece_pointer - compress_pointer;
485	0	piece_pointer = 7;
486	0	while swaps > 0 {
487	0	pieces.swap(piece_pointer, compress_pointer + swaps - 1);
488	0	swaps -= 1;
489	0	piece_pointer -= 1;
490	0	}
491		}
492		_ => {
493	0	if piece_pointer != 8 {
494	0	return Err(ParseError::InvalidIpv6Address);
495	0	}
496		}
497		}
498	0	Ok(Ipv6Addr::new(
499	0	pieces[0], pieces[1], pieces[2], pieces[3], pieces[4], pieces[5], pieces[6], pieces[7],
500	0	))
501	0	}