1 // Copyright 2021 Ian Jackson and contributors to Hippotat
2 // SPDX-License-Identifier: GPL-3.0-or-later
3 // There is NO WARRANTY.
8 pub struct Component<'b> {
10 pub payload_start: &'b [u8],
14 #[derive(Eq,PartialEq,Ord,PartialOrd,Hash)]
15 #[allow(non_camel_case_types)]
16 pub enum PartName { m, d, Other }
18 pub type BoundaryFinder = memchr::memmem::Finder<'static>;
21 pub fn process_component<'b>(warnings: &mut Warnings,
22 after_leader: &'b [u8], expected: PartName)
23 -> Option<Component<'b>> {
24 let rhs = after_leader;
26 if let Some(rhs) = rhs.strip_prefix(b"\r\n") { rhs }
27 else if let Some(_ ) = rhs.strip_prefix(b"--" ) { return None }
28 else if let Some(rhs) = rhs.strip_prefix(b"\n" ) { rhs }
29 else { throw!(anyhow!("invalid multipart delimiter")) };
31 let mut part_name = None;
34 // RHS points to the start of a header line
35 let nl = memchr::memchr(b'\n', rhs)
36 .ok_or_else(|| anyhow!("part headers truncated"))?;
37 let l = &rhs[0..nl]; rhs = &rhs[nl+1..];
38 if l == b"\r" || l == b"" { break } // end of headers
39 if l.starts_with(b"--") { throw!(anyhow!("boundary in part headers")) }
42 let l = str::from_utf8(l).context("interpret part headers as utf-8")?;
44 let (_, disposition) = if let Some(y) =
45 regex_captures!(r#"^Content-Disposition[ \t]*:[ \t]*(.*)$"#i, l) { y }
46 else { return Ok(()) };
48 let disposition = disposition.trim_end();
49 if disposition.len() >= 100 { throw!(anyhow!(
50 "Content-Disposition value implausibly long"
52 // This let's us pretend it's a mime type, so we can use mime::Mime
53 let disposition = format!("dummy/{}", disposition);
55 let disposition: mime::Mime = disposition.parse()
56 .context("parse Content-Disposition")?;
57 let name = disposition.get_param("name")
58 .ok_or_else(|| anyhow!(r#"find "name" in Content-Disposition"#))?;
60 let name = match name.as_ref() {
66 if let Some(_) = mem::replace(&mut part_name, Some(name)) {
67 throw!(anyhow!(r#"multiple "name"s in Content-Disposition(s)"#))
71 Err(e) => warnings.add(&e)?,
76 Some(Component { name: part_name.unwrap_or(expected), payload_start: rhs })
79 pub struct MetadataFieldIterator<'b> {
82 iter: memchr::Memchr<'b>,
85 impl<'b> MetadataFieldIterator<'b> {
86 pub fn new(buf: &'b [u8]) -> Self { Self {
89 iter: memchr::Memchr::new(b'\n', buf),
93 pub fn need_next(&mut self) -> &'b str
95 self.next().ok_or_else(|| anyhow!("missing"))??
99 pub fn need_parse<T>(&mut self) -> T
103 self.parse()?.ok_or_else(|| anyhow!("missing"))?
107 pub fn parse<T>(&mut self) -> Option<T>
111 let s = if let Some(r) = self.next() { r? } else { return None };
115 pub fn remaining_bytes_len(&self) -> usize {
116 if let Some(last) = self.last {
117 self.buf.len() - last
124 impl<'b> Iterator for MetadataFieldIterator<'b> {
125 type Item = Result<&'b str, std::str::Utf8Error>;
126 fn next(&mut self) -> Option<Result<&'b str, std::str::Utf8Error>> {
127 let last = self.last?;
128 let (s, last) = match self.iter.next() {
129 Some(nl) => (&self.buf[last..nl], Some(nl+1)),
130 None => (&self.buf[last..], None),
133 let s = str::from_utf8(s).map(|s| s.trim());
137 impl<'b> std::iter::FusedIterator for MetadataFieldIterator<'b> { }