reqwest_wasm/async_impl/
multipart.rs

1//! multipart/form-data
2use std::borrow::Cow;
3use std::fmt;
4use std::pin::Pin;
5
6use bytes::Bytes;
7use http::HeaderMap;
8use mime_guess::Mime;
9use percent_encoding::{self, AsciiSet, NON_ALPHANUMERIC};
10
11use futures_core::Stream;
12use futures_util::{future, stream, StreamExt};
13
14use super::Body;
15
16/// An async multipart/form-data request.
17pub struct Form {
18    inner: FormParts<Part>,
19}
20
21/// A field in a multipart form.
22pub struct Part {
23    meta: PartMetadata,
24    value: Body,
25    body_length: Option<u64>,
26}
27
28pub(crate) struct FormParts<P> {
29    pub(crate) boundary: String,
30    pub(crate) computed_headers: Vec<Vec<u8>>,
31    pub(crate) fields: Vec<(Cow<'static, str>, P)>,
32    pub(crate) percent_encoding: PercentEncoding,
33}
34
35pub(crate) struct PartMetadata {
36    mime: Option<Mime>,
37    file_name: Option<Cow<'static, str>>,
38    pub(crate) headers: HeaderMap,
39}
40
41pub(crate) trait PartProps {
42    fn value_len(&self) -> Option<u64>;
43    fn metadata(&self) -> &PartMetadata;
44}
45
46// ===== impl Form =====
47
48impl Default for Form {
49    fn default() -> Self {
50        Self::new()
51    }
52}
53
54impl Form {
55    /// Creates a new async Form without any content.
56    pub fn new() -> Form {
57        Form {
58            inner: FormParts::new(),
59        }
60    }
61
62    /// Get the boundary that this form will use.
63    #[inline]
64    pub fn boundary(&self) -> &str {
65        self.inner.boundary()
66    }
67
68    /// Add a data field with supplied name and value.
69    ///
70    /// # Examples
71    ///
72    /// ```
73    /// let form = reqwest::multipart::Form::new()
74    ///     .text("username", "seanmonstar")
75    ///     .text("password", "secret");
76    /// ```
77    pub fn text<T, U>(self, name: T, value: U) -> Form
78    where
79        T: Into<Cow<'static, str>>,
80        U: Into<Cow<'static, str>>,
81    {
82        self.part(name, Part::text(value))
83    }
84
85    /// Adds a customized Part.
86    pub fn part<T>(self, name: T, part: Part) -> Form
87    where
88        T: Into<Cow<'static, str>>,
89    {
90        self.with_inner(move |inner| inner.part(name, part))
91    }
92
93    /// Configure this `Form` to percent-encode using the `path-segment` rules.
94    pub fn percent_encode_path_segment(self) -> Form {
95        self.with_inner(|inner| inner.percent_encode_path_segment())
96    }
97
98    /// Configure this `Form` to percent-encode using the `attr-char` rules.
99    pub fn percent_encode_attr_chars(self) -> Form {
100        self.with_inner(|inner| inner.percent_encode_attr_chars())
101    }
102
103    /// Configure this `Form` to skip percent-encoding
104    pub fn percent_encode_noop(self) -> Form {
105        self.with_inner(|inner| inner.percent_encode_noop())
106    }
107
108    /// Consume this instance and transform into an instance of Body for use in a request.
109    pub(crate) fn stream(mut self) -> Body {
110        if self.inner.fields.is_empty() {
111            return Body::empty();
112        }
113
114        // create initial part to init reduce chain
115        let (name, part) = self.inner.fields.remove(0);
116        let start = Box::pin(self.part_stream(name, part))
117            as Pin<Box<dyn Stream<Item = crate::Result<Bytes>> + Send + Sync>>;
118
119        let fields = self.inner.take_fields();
120        // for each field, chain an additional stream
121        let stream = fields.into_iter().fold(start, |memo, (name, part)| {
122            let part_stream = self.part_stream(name, part);
123            Box::pin(memo.chain(part_stream))
124                as Pin<Box<dyn Stream<Item = crate::Result<Bytes>> + Send + Sync>>
125        });
126        // append special ending boundary
127        let last = stream::once(future::ready(Ok(
128            format!("--{}--\r\n", self.boundary()).into()
129        )));
130        Body::stream(stream.chain(last))
131    }
132
133    /// Generate a hyper::Body stream for a single Part instance of a Form request.
134    pub(crate) fn part_stream<T>(
135        &mut self,
136        name: T,
137        part: Part,
138    ) -> impl Stream<Item = Result<Bytes, crate::Error>>
139    where
140        T: Into<Cow<'static, str>>,
141    {
142        // start with boundary
143        let boundary = stream::once(future::ready(Ok(
144            format!("--{}\r\n", self.boundary()).into()
145        )));
146        // append headers
147        let header = stream::once(future::ready(Ok({
148            let mut h = self
149                .inner
150                .percent_encoding
151                .encode_headers(&name.into(), &part.meta);
152            h.extend_from_slice(b"\r\n\r\n");
153            h.into()
154        })));
155        // then append form data followed by terminating CRLF
156        boundary
157            .chain(header)
158            .chain(part.value.into_stream())
159            .chain(stream::once(future::ready(Ok("\r\n".into()))))
160    }
161
162    pub(crate) fn compute_length(&mut self) -> Option<u64> {
163        self.inner.compute_length()
164    }
165
166    fn with_inner<F>(self, func: F) -> Self
167    where
168        F: FnOnce(FormParts<Part>) -> FormParts<Part>,
169    {
170        Form {
171            inner: func(self.inner),
172        }
173    }
174}
175
176impl fmt::Debug for Form {
177    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
178        self.inner.fmt_fields("Form", f)
179    }
180}
181
182// ===== impl Part =====
183
184impl Part {
185    /// Makes a text parameter.
186    pub fn text<T>(value: T) -> Part
187    where
188        T: Into<Cow<'static, str>>,
189    {
190        let body = match value.into() {
191            Cow::Borrowed(slice) => Body::from(slice),
192            Cow::Owned(string) => Body::from(string),
193        };
194        Part::new(body, None)
195    }
196
197    /// Makes a new parameter from arbitrary bytes.
198    pub fn bytes<T>(value: T) -> Part
199    where
200        T: Into<Cow<'static, [u8]>>,
201    {
202        let body = match value.into() {
203            Cow::Borrowed(slice) => Body::from(slice),
204            Cow::Owned(vec) => Body::from(vec),
205        };
206        Part::new(body, None)
207    }
208
209    /// Makes a new parameter from an arbitrary stream.
210    pub fn stream<T: Into<Body>>(value: T) -> Part {
211        Part::new(value.into(), None)
212    }
213
214    /// Makes a new parameter from an arbitrary stream with a known length. This is particularly
215    /// useful when adding something like file contents as a stream, where you can know the content
216    /// length beforehand.
217    pub fn stream_with_length<T: Into<Body>>(value: T, length: u64) -> Part {
218        Part::new(value.into(), Some(length))
219    }
220
221    fn new(value: Body, body_length: Option<u64>) -> Part {
222        Part {
223            meta: PartMetadata::new(),
224            value,
225            body_length,
226        }
227    }
228
229    /// Tries to set the mime of this part.
230    pub fn mime_str(self, mime: &str) -> crate::Result<Part> {
231        Ok(self.mime(mime.parse().map_err(crate::error::builder)?))
232    }
233
234    // Re-export when mime 0.4 is available, with split MediaType/MediaRange.
235    fn mime(self, mime: Mime) -> Part {
236        self.with_inner(move |inner| inner.mime(mime))
237    }
238
239    /// Sets the filename, builder style.
240    pub fn file_name<T>(self, filename: T) -> Part
241    where
242        T: Into<Cow<'static, str>>,
243    {
244        self.with_inner(move |inner| inner.file_name(filename))
245    }
246
247    fn with_inner<F>(self, func: F) -> Self
248    where
249        F: FnOnce(PartMetadata) -> PartMetadata,
250    {
251        Part {
252            meta: func(self.meta),
253            ..self
254        }
255    }
256}
257
258impl fmt::Debug for Part {
259    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
260        let mut dbg = f.debug_struct("Part");
261        dbg.field("value", &self.value);
262        self.meta.fmt_fields(&mut dbg);
263        dbg.finish()
264    }
265}
266
267impl PartProps for Part {
268    fn value_len(&self) -> Option<u64> {
269        if self.body_length.is_some() {
270            self.body_length
271        } else {
272            self.value.content_length()
273        }
274    }
275
276    fn metadata(&self) -> &PartMetadata {
277        &self.meta
278    }
279}
280
281// ===== impl FormParts =====
282
283impl<P: PartProps> FormParts<P> {
284    pub(crate) fn new() -> Self {
285        FormParts {
286            boundary: gen_boundary(),
287            computed_headers: Vec::new(),
288            fields: Vec::new(),
289            percent_encoding: PercentEncoding::PathSegment,
290        }
291    }
292
293    pub(crate) fn boundary(&self) -> &str {
294        &self.boundary
295    }
296
297    /// Adds a customized Part.
298    pub(crate) fn part<T>(mut self, name: T, part: P) -> Self
299    where
300        T: Into<Cow<'static, str>>,
301    {
302        self.fields.push((name.into(), part));
303        self
304    }
305
306    /// Configure this `Form` to percent-encode using the `path-segment` rules.
307    pub(crate) fn percent_encode_path_segment(mut self) -> Self {
308        self.percent_encoding = PercentEncoding::PathSegment;
309        self
310    }
311
312    /// Configure this `Form` to percent-encode using the `attr-char` rules.
313    pub(crate) fn percent_encode_attr_chars(mut self) -> Self {
314        self.percent_encoding = PercentEncoding::AttrChar;
315        self
316    }
317
318    /// Configure this `Form` to skip percent-encoding
319    pub(crate) fn percent_encode_noop(mut self) -> Self {
320        self.percent_encoding = PercentEncoding::NoOp;
321        self
322    }
323
324    // If predictable, computes the length the request will have
325    // The length should be preditable if only String and file fields have been added,
326    // but not if a generic reader has been added;
327    pub(crate) fn compute_length(&mut self) -> Option<u64> {
328        let mut length = 0u64;
329        for &(ref name, ref field) in self.fields.iter() {
330            match field.value_len() {
331                Some(value_length) => {
332                    // We are constructing the header just to get its length. To not have to
333                    // construct it again when the request is sent we cache these headers.
334                    let header = self.percent_encoding.encode_headers(name, field.metadata());
335                    let header_length = header.len();
336                    self.computed_headers.push(header);
337                    // The additions mimic the format string out of which the field is constructed
338                    // in Reader. Not the cleanest solution because if that format string is
339                    // ever changed then this formula needs to be changed too which is not an
340                    // obvious dependency in the code.
341                    length += 2
342                        + self.boundary().len() as u64
343                        + 2
344                        + header_length as u64
345                        + 4
346                        + value_length
347                        + 2
348                }
349                _ => return None,
350            }
351        }
352        // If there is a at least one field there is a special boundary for the very last field.
353        if !self.fields.is_empty() {
354            length += 2 + self.boundary().len() as u64 + 4
355        }
356        Some(length)
357    }
358
359    /// Take the fields vector of this instance, replacing with an empty vector.
360    fn take_fields(&mut self) -> Vec<(Cow<'static, str>, P)> {
361        std::mem::replace(&mut self.fields, Vec::new())
362    }
363}
364
365impl<P: fmt::Debug> FormParts<P> {
366    pub(crate) fn fmt_fields(&self, ty_name: &'static str, f: &mut fmt::Formatter) -> fmt::Result {
367        f.debug_struct(ty_name)
368            .field("boundary", &self.boundary)
369            .field("parts", &self.fields)
370            .finish()
371    }
372}
373
374// ===== impl PartMetadata =====
375
376impl PartMetadata {
377    pub(crate) fn new() -> Self {
378        PartMetadata {
379            mime: None,
380            file_name: None,
381            headers: HeaderMap::default(),
382        }
383    }
384
385    pub(crate) fn mime(mut self, mime: Mime) -> Self {
386        self.mime = Some(mime);
387        self
388    }
389
390    pub(crate) fn file_name<T>(mut self, filename: T) -> Self
391    where
392        T: Into<Cow<'static, str>>,
393    {
394        self.file_name = Some(filename.into());
395        self
396    }
397}
398
399impl PartMetadata {
400    pub(crate) fn fmt_fields<'f, 'fa, 'fb>(
401        &self,
402        debug_struct: &'f mut fmt::DebugStruct<'fa, 'fb>,
403    ) -> &'f mut fmt::DebugStruct<'fa, 'fb> {
404        debug_struct
405            .field("mime", &self.mime)
406            .field("file_name", &self.file_name)
407            .field("headers", &self.headers)
408    }
409}
410
411// https://url.spec.whatwg.org/#fragment-percent-encode-set
412const FRAGMENT_ENCODE_SET: &AsciiSet = &percent_encoding::CONTROLS
413    .add(b' ')
414    .add(b'"')
415    .add(b'<')
416    .add(b'>')
417    .add(b'`');
418
419// https://url.spec.whatwg.org/#path-percent-encode-set
420const PATH_ENCODE_SET: &AsciiSet = &FRAGMENT_ENCODE_SET.add(b'#').add(b'?').add(b'{').add(b'}');
421
422const PATH_SEGMENT_ENCODE_SET: &AsciiSet = &PATH_ENCODE_SET.add(b'/').add(b'%');
423
424// https://tools.ietf.org/html/rfc8187#section-3.2.1
425const ATTR_CHAR_ENCODE_SET: &AsciiSet = &NON_ALPHANUMERIC
426    .remove(b'!')
427    .remove(b'#')
428    .remove(b'$')
429    .remove(b'&')
430    .remove(b'+')
431    .remove(b'-')
432    .remove(b'.')
433    .remove(b'^')
434    .remove(b'_')
435    .remove(b'`')
436    .remove(b'|')
437    .remove(b'~');
438
439pub(crate) enum PercentEncoding {
440    PathSegment,
441    AttrChar,
442    NoOp,
443}
444
445impl PercentEncoding {
446    pub(crate) fn encode_headers(&self, name: &str, field: &PartMetadata) -> Vec<u8> {
447        let s = format!(
448            "Content-Disposition: form-data; {}{}{}",
449            self.format_parameter("name", name),
450            match field.file_name {
451                Some(ref file_name) => format!("; {}", self.format_filename(file_name)),
452                None => String::new(),
453            },
454            match field.mime {
455                Some(ref mime) => format!("\r\nContent-Type: {}", mime),
456                None => "".to_string(),
457            },
458        );
459        field
460            .headers
461            .iter()
462            .fold(s.into_bytes(), |mut header, (k, v)| {
463                header.extend_from_slice(b"\r\n");
464                header.extend_from_slice(k.as_str().as_bytes());
465                header.extend_from_slice(b": ");
466                header.extend_from_slice(v.as_bytes());
467                header
468            })
469    }
470
471    // According to RFC7578 Section 4.2, `filename*=` syntax is invalid.
472    // See https://github.com/seanmonstar/reqwest/issues/419.
473    fn format_filename(&self, filename: &str) -> String {
474        let legal_filename = filename
475            .replace("\\", "\\\\")
476            .replace("\"", "\\\"")
477            .replace("\r", "\\\r")
478            .replace("\n", "\\\n");
479        format!("filename=\"{}\"", legal_filename)
480    }
481
482    fn format_parameter(&self, name: &str, value: &str) -> String {
483        let legal_value = match *self {
484            PercentEncoding::PathSegment => {
485                percent_encoding::utf8_percent_encode(value, PATH_SEGMENT_ENCODE_SET).to_string()
486            }
487            PercentEncoding::AttrChar => {
488                percent_encoding::utf8_percent_encode(value, ATTR_CHAR_ENCODE_SET).to_string()
489            }
490            PercentEncoding::NoOp => value.to_string(),
491        };
492        if value.len() == legal_value.len() {
493            // nothing has been percent encoded
494            format!("{}=\"{}\"", name, value)
495        } else {
496            // something has been percent encoded
497            format!("{}*=utf-8''{}", name, legal_value)
498        }
499    }
500}
501
502fn gen_boundary() -> String {
503    use crate::util::fast_random as random;
504
505    let a = random();
506    let b = random();
507    let c = random();
508    let d = random();
509
510    format!("{:016x}-{:016x}-{:016x}-{:016x}", a, b, c, d)
511}
512
513#[cfg(test)]
514mod tests {
515    use super::*;
516    use futures_util::TryStreamExt;
517    use futures_util::{future, stream};
518    use tokio::{self, runtime};
519
520    #[test]
521    fn form_empty() {
522        let form = Form::new();
523
524        let rt = runtime::Builder::new_current_thread()
525            .enable_all()
526            .build()
527            .expect("new rt");
528        let body = form.stream().into_stream();
529        let s = body.map_ok(|try_c| try_c.to_vec()).try_concat();
530
531        let out = rt.block_on(s);
532        assert!(out.unwrap().is_empty());
533    }
534
535    #[test]
536    fn stream_to_end() {
537        let mut form = Form::new()
538            .part(
539                "reader1",
540                Part::stream(Body::stream(stream::once(future::ready::<
541                    Result<String, crate::Error>,
542                >(Ok(
543                    "part1".to_owned()
544                ))))),
545            )
546            .part("key1", Part::text("value1"))
547            .part("key2", Part::text("value2").mime(mime::IMAGE_BMP))
548            .part(
549                "reader2",
550                Part::stream(Body::stream(stream::once(future::ready::<
551                    Result<String, crate::Error>,
552                >(Ok(
553                    "part2".to_owned()
554                ))))),
555            )
556            .part("key3", Part::text("value3").file_name("filename"));
557        form.inner.boundary = "boundary".to_string();
558        let expected = "--boundary\r\n\
559             Content-Disposition: form-data; name=\"reader1\"\r\n\r\n\
560             part1\r\n\
561             --boundary\r\n\
562             Content-Disposition: form-data; name=\"key1\"\r\n\r\n\
563             value1\r\n\
564             --boundary\r\n\
565             Content-Disposition: form-data; name=\"key2\"\r\n\
566             Content-Type: image/bmp\r\n\r\n\
567             value2\r\n\
568             --boundary\r\n\
569             Content-Disposition: form-data; name=\"reader2\"\r\n\r\n\
570             part2\r\n\
571             --boundary\r\n\
572             Content-Disposition: form-data; name=\"key3\"; filename=\"filename\"\r\n\r\n\
573             value3\r\n--boundary--\r\n";
574        let rt = runtime::Builder::new_current_thread()
575            .enable_all()
576            .build()
577            .expect("new rt");
578        let body = form.stream().into_stream();
579        let s = body.map(|try_c| try_c.map(|r| r.to_vec())).try_concat();
580
581        let out = rt.block_on(s).unwrap();
582        // These prints are for debug purposes in case the test fails
583        println!(
584            "START REAL\n{}\nEND REAL",
585            std::str::from_utf8(&out).unwrap()
586        );
587        println!("START EXPECTED\n{}\nEND EXPECTED", expected);
588        assert_eq!(std::str::from_utf8(&out).unwrap(), expected);
589    }
590
591    #[test]
592    fn stream_to_end_with_header() {
593        let mut part = Part::text("value2").mime(mime::IMAGE_BMP);
594        part.meta.headers.insert("Hdr3", "/a/b/c".parse().unwrap());
595        let mut form = Form::new().part("key2", part);
596        form.inner.boundary = "boundary".to_string();
597        let expected = "--boundary\r\n\
598                        Content-Disposition: form-data; name=\"key2\"\r\n\
599                        Content-Type: image/bmp\r\n\
600                        hdr3: /a/b/c\r\n\
601                        \r\n\
602                        value2\r\n\
603                        --boundary--\r\n";
604        let rt = runtime::Builder::new_current_thread()
605            .enable_all()
606            .build()
607            .expect("new rt");
608        let body = form.stream().into_stream();
609        let s = body.map(|try_c| try_c.map(|r| r.to_vec())).try_concat();
610
611        let out = rt.block_on(s).unwrap();
612        // These prints are for debug purposes in case the test fails
613        println!(
614            "START REAL\n{}\nEND REAL",
615            std::str::from_utf8(&out).unwrap()
616        );
617        println!("START EXPECTED\n{}\nEND EXPECTED", expected);
618        assert_eq!(std::str::from_utf8(&out).unwrap(), expected);
619    }
620
621    #[test]
622    fn correct_content_length() {
623        // Setup an arbitrary data stream
624        let stream_data = b"just some stream data";
625        let stream_len = stream_data.len();
626        let stream_data = stream_data
627            .chunks(3)
628            .map(|c| Ok::<_, std::io::Error>(Bytes::from(c)));
629        let the_stream = futures_util::stream::iter(stream_data);
630
631        let bytes_data = b"some bytes data".to_vec();
632        let bytes_len = bytes_data.len();
633
634        let stream_part = Part::stream_with_length(Body::stream(the_stream), stream_len as u64);
635        let body_part = Part::bytes(bytes_data);
636
637        // A simple check to make sure we get the configured body length
638        assert_eq!(stream_part.value_len().unwrap(), stream_len as u64);
639
640        // Make sure it delegates to the underlying body if length is not specified
641        assert_eq!(body_part.value_len().unwrap(), bytes_len as u64);
642    }
643
644    #[test]
645    fn header_percent_encoding() {
646        let name = "start%'\"\r\nßend";
647        let field = Part::text("");
648
649        assert_eq!(
650            PercentEncoding::PathSegment.encode_headers(name, &field.meta),
651            &b"Content-Disposition: form-data; name*=utf-8''start%25'%22%0D%0A%C3%9Fend"[..]
652        );
653
654        assert_eq!(
655            PercentEncoding::AttrChar.encode_headers(name, &field.meta),
656            &b"Content-Disposition: form-data; name*=utf-8''start%25%27%22%0D%0A%C3%9Fend"[..]
657        );
658    }
659}
reqwest_wasm/async_impl/multipart.rs

reqwest_wasm/async_impl/
multipart.rs
