//! Validating parsers for non-trusted (possibly invalid) input.
mod authority;
mod path;
use crate::parser::char;
use crate::parser::str::{
find_split, find_split2_hole, find_split_hole, satisfy_chars_with_pct_encoded,
};
use crate::spec::Spec;
use crate::validate::Error;
use self::authority::validate_authority;
pub(crate) use self::authority::{validate_host, validate_userinfo};
pub(crate) use self::path::validate_path;
use self::path::{
validate_path_abempty, validate_path_absolute_authority_absent,
validate_path_relative_authority_absent,
};
/// Returns `Ok(_)` if the string matches `scheme`.
pub(crate) fn validate_scheme(i: &str) -> Result<(), Error> {
debug_assert!(!i.is_empty());
let bytes = i.as_bytes();
if bytes[0].is_ascii_alphabetic()
&& bytes[1..]
.iter()
.all(|&b| b.is_ascii() && char::is_ascii_scheme_continue(b))
{
Ok(())
} else {
Err(Error::new())
}
}
/// Returns `Ok(_)` if the string matches `query` or `iquery`.
pub(crate) fn validate_query<S: Spec>(i: &str) -> Result<(), Error> {
let is_valid =
satisfy_chars_with_pct_encoded(i, char::is_ascii_frag_query, char::is_nonascii_query::<S>);
if is_valid {
Ok(())
} else {
Err(Error::new())
}
}
/// Returns `Ok(_)` if the string matches `authority path-abempty` rule sequence.
fn validate_authority_path_abempty<S: Spec>(i: &str) -> Result<(), Error> {
let (maybe_authority, maybe_path) = match find_split(i, b'/') {
Some(v) => v,
None => (i, ""),
};
validate_authority::<S>(maybe_authority)?;
validate_path_abempty::<S>(maybe_path)
}
/// Returns `Ok(_)` if the string matches `URI`/`IRI` rules.
#[inline]
pub(crate) fn validate_uri<S: Spec>(i: &str) -> Result<(), Error> {
validate_uri_reference_common::<S>(i, UriReferenceRule::Absolute)
}
/// Returns `Ok(_)` if the string matches `URI-reference`/`IRI-reference` rules.
#[inline]
pub(crate) fn validate_uri_reference<S: Spec>(i: &str) -> Result<(), Error> {
validate_uri_reference_common::<S>(i, UriReferenceRule::Any)
}
/// Returns `Ok(_)` if the string matches `absolute-URI`/`absolute-IRI` rules.
#[inline]
pub(crate) fn validate_absolute_uri<S: Spec>(i: &str) -> Result<(), Error> {
validate_uri_reference_common::<S>(i, UriReferenceRule::AbsoluteWithoutFragment)
}
/// Syntax rule for URI/IRI references.
#[derive(Clone, Copy, PartialEq, Eq, Hash)]
enum UriReferenceRule {
/// `URI` and `IRI`.
///
/// This can have a fragment.
Absolute,
/// `absolute-URI` and `absolute-IRI`.
///
/// This cannot have a fragment.
AbsoluteWithoutFragment,
/// `URI-reference` and `IRI-reference`.
///
/// This can be relative.
Any,
}
impl UriReferenceRule {
/// Returns `true` is the relative reference is allowed.
#[inline]
#[must_use]
fn is_relative_allowed(self) -> bool {
self == Self::Any
}
/// Returns `true` is the fragment part is allowed.
#[inline]
#[must_use]
fn is_fragment_allowed(self) -> bool {
matches!(self, Self::Absolute | Self::Any)
}
}
/// Returns `Ok(_)` if the string matches `URI-reference`/`IRI-reference` rules.
fn validate_uri_reference_common<S: Spec>(
i: &str,
ref_rule: UriReferenceRule,
) -> Result<(), Error> {
// Validate `scheme ":"`.
let (i, _scheme) = match find_split_hole(i, b':') {
None => {
if ref_rule.is_relative_allowed() {
return validate_relative_ref::<S>(i);
} else {
return Err(Error::new());
}
}
Some(("", _)) => return Err(Error::new()),
Some((maybe_scheme, rest)) => {
if validate_scheme(maybe_scheme).is_err() {
// The string before the first colon is not a scheme.
// Falling back to `relative-ref` parsing.
if ref_rule.is_relative_allowed() {
return validate_relative_ref::<S>(i);
} else {
return Err(Error::new());
}
}
(rest, maybe_scheme)
}
};
// Validate `hier-part`.
let after_path = match i.strip_prefix("//") {
Some(i) => {
let (maybe_authority_path, after_path) = match find_split2_hole(i, b'?', b'#') {
Some((maybe_authority_path, c, rest)) => (maybe_authority_path, Some((c, rest))),
None => (i, None),
};
validate_authority_path_abempty::<S>(maybe_authority_path)?;
after_path
}
None => {
let (maybe_path, after_path) = match find_split2_hole(i, b'?', b'#') {
Some((maybe_path, c, rest)) => (maybe_path, Some((c, rest))),
None => (i, None),
};
// Authority is absent.
validate_path_absolute_authority_absent::<S>(maybe_path)?;
after_path
}
};
// Validate `[ "?" query ] [ "#" fragment ]`.
if let Some((first, rest)) = after_path {
validate_after_path::<S>(first, rest, ref_rule.is_fragment_allowed())?;
}
Ok(())
}
/// Returns `Ok(_)` if the string matches `relative-ref`/`irelative-ref` rules.
pub(crate) fn validate_relative_ref<S: Spec>(i: &str) -> Result<(), Error> {
// Validate `relative-part`.
let after_path = match i.strip_prefix("//") {
Some(i) => {
let (maybe_authority_path, after_path) = match find_split2_hole(i, b'?', b'#') {
Some((maybe_authority_path, c, rest)) => (maybe_authority_path, Some((c, rest))),
None => (i, None),
};
validate_authority_path_abempty::<S>(maybe_authority_path)?;
after_path
}
None => {
let (maybe_path, after_path) = match find_split2_hole(i, b'?', b'#') {
Some((maybe_path, c, rest)) => (maybe_path, Some((c, rest))),
None => (i, None),
};
// Authority is absent.
validate_path_relative_authority_absent::<S>(maybe_path)?;
after_path
}
};
// Validate `[ "?" query ] [ "#" fragment ]`.
if let Some((first, rest)) = after_path {
validate_after_path::<S>(first, rest, true)?;
}
Ok(())
}
/// Returns `Ok(_)` if the string matches `[ "?" query ] [ "#" fragment ]` (or IRI version).
fn validate_after_path<S: Spec>(first: u8, rest: &str, accept_fragment: bool) -> Result<(), Error> {
let (maybe_query, maybe_fragment) = if first == b'?' {
match find_split_hole(rest, b'#') {
Some(v) => v,
None => (rest, ""),
}
} else {
debug_assert_eq!(first, b'#');
("", rest)
};
validate_query::<S>(maybe_query)?;
if !accept_fragment && !maybe_fragment.is_empty() {
return Err(Error::new());
}
validate_fragment::<S>(maybe_fragment)
}
/// Returns `Ok(_)` if the string matches `fragment`/`ifragment` rules.
pub(crate) fn validate_fragment<S: Spec>(i: &str) -> Result<(), Error> {
let is_valid = satisfy_chars_with_pct_encoded(
i,
char::is_ascii_frag_query,
char::is_nonascii_fragment::<S>,
);
if is_valid {
Ok(())
} else {
Err(Error::new())
}
}
