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 #[allow(non_camel_case_types)]
15 pub enum PartName { m, d, Other }
18 pub fn process_component<'b>(warnings: &mut Warnings,
19 after_leader: &'b [u8], expected: PartName)
20 -> Option<Component<'b>> {
21 let rhs = after_leader;
23 if let Some(rhs) = rhs.strip_prefix(b"\r\n") { rhs }
24 else if let Some(_ ) = rhs.strip_prefix(b"--" ) { return None }
25 else if let Some(rhs) = rhs.strip_prefix(b"\n" ) { rhs }
26 else { throw!(anyhow!("invalid multipart delimiter")) };
28 let mut part_name = None;
31 // RHS points to the start of a header line
32 let nl = memchr::memchr(b'\n', rhs)
33 .ok_or_else(|| anyhow!("part headers truncated"))?;
34 let l = &rhs[0..nl]; rhs = &rhs[nl+1..];
35 if l == b"\r" || l == b"" { break } // end of headers
36 if l.starts_with(b"--") { throw!(anyhow!("boundary in part headers")) }
39 let l = str::from_utf8(l).context("interpret part headers as utf-8")?;
41 let (_, disposition) = if let Some(y) =
42 regex_captures!(r#"^Content-Disposition[ \t]*:[ \t]*(.*)$"#i, l) { y }
43 else { return Ok(()) };
45 let disposition = disposition.trim_end();
46 if disposition.len() >= 100 { throw!(anyhow!(
47 "Content-Disposition value implausibly long"
49 // This let's us pretend it's a mime type, so we can use mime::Mime
50 let disposition = format!("dummy/{}", disposition);
52 let disposition: mime::Mime = disposition.parse()
53 .context("parse Content-Disposition")?;
54 let name = disposition.get_param("name")
55 .ok_or_else(|| anyhow!(r#"find "name" in Content-Disposition"#))?;
57 let name = match name.as_ref() {
63 if let Some(_) = mem::replace(&mut part_name, Some(name)) {
64 throw!(anyhow!(r#"multiple "name"s in Content-Disposition(s)"#))
68 Err(e) => warnings.add(&e)?,
73 Some(Component { name: part_name.unwrap_or(expected), payload_start: rhs })