rocket/form/
parser.rs

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
use multer::Multipart;
use either::Either;

use crate::request::{Request, local_cache_once};
use crate::data::{Data, Limits, Outcome};
use crate::form::{SharedStack, prelude::*};
use crate::http::{RawStr, Status};

type Result<'r, T> = std::result::Result<T, Error<'r>>;

type Field<'r, 'i> = Either<ValueField<'r>, DataField<'r, 'i>>;

pub struct MultipartParser<'r, 'i> {
    request: &'r Request<'i>,
    buffer: &'r SharedStack<String>,
    source: Multipart<'r>,
    done: bool,
}

pub struct RawStrParser<'r> {
    buffer: &'r SharedStack<String>,
    source: &'r RawStr,
}

pub enum Parser<'r, 'i> {
    Multipart(MultipartParser<'r, 'i>),
    RawStr(RawStrParser<'r>),
}

impl<'r, 'i> Parser<'r, 'i> {
    pub async fn new(
        req: &'r Request<'i>,
        data: Data<'r>
    ) -> Outcome<'r, Parser<'r, 'i>, Errors<'r>> {
        let parser = match req.content_type() {
            Some(c) if c.is_form() => Self::from_form(req, data).await,
            Some(c) if c.is_form_data() => Self::from_multipart(req, data).await,
            _ => return Outcome::Forward((data, Status::UnsupportedMediaType)),
        };

        match parser {
            Ok(storage) => Outcome::Success(storage),
            Err(e) => Outcome::Error((e.status(), e.into()))
        }
    }

    async fn from_form(req: &'r Request<'i>, data: Data<'r>) -> Result<'r, Parser<'r, 'i>> {
        let limit = req.limits().get("form").unwrap_or(Limits::FORM);
        let string = data.open(limit).into_string().await?;
        if !string.is_complete() {
            Err((None, Some(limit.as_u64())))?;
        }

        Ok(Parser::RawStr(RawStrParser {
            buffer: local_cache_once!(req, SharedStack::new()),
            source: RawStr::new(local_cache_once!(req, string.into_inner())),
        }))
    }

    async fn from_multipart(req: &'r Request<'i>, data: Data<'r>) -> Result<'r, Parser<'r, 'i>> {
        let boundary = req.content_type()
            .ok_or(multer::Error::NoMultipart)?
            .param("boundary")
            .ok_or(multer::Error::NoBoundary)?;

        let form_limit = req.limits()
            .get("data-form")
            .unwrap_or(Limits::DATA_FORM);

        // Increase internal limit by 1 so multer can limit to `form_limit`.
        let stream = data.open(form_limit + 1);
        let constraints = multer::Constraints::new()
            .size_limit(multer::SizeLimit::new()
                .whole_stream(form_limit.into())
                .per_field(form_limit.into()));

        Ok(Parser::Multipart(MultipartParser {
            request: req,
            buffer: local_cache_once!(req, SharedStack::new()),
            source: Multipart::with_reader_with_constraints(stream, boundary, constraints),
            done: false,
        }))
    }

    pub async fn next(&mut self) -> Option<Result<'r, Field<'r, 'i>>> {
        match self {
            Parser::Multipart(ref mut p) => p.next().await,
            Parser::RawStr(ref mut p) => p.next().map(|f| Ok(Either::Left(f)))
        }
    }
}

impl<'r> RawStrParser<'r> {
    pub fn new(buffer: &'r SharedStack<String>, source: &'r RawStr) -> Self {
        RawStrParser { buffer, source }
    }
}

impl<'r> Iterator for RawStrParser<'r> {
    type Item = ValueField<'r>;

    fn next(&mut self) -> Option<Self::Item> {
        use std::borrow::Cow::*;

        let (name, value) = loop {
            if self.source.is_empty() {
                return None;
            }

            let (field_str, rest) = self.source.split_at_byte(b'&');
            self.source = rest;

            if !field_str.is_empty() {
                break field_str.split_at_byte(b'=');
            }
        };

        trace_!("url-encoded field: {:?}", (name, value));
        let name_val = match (name.url_decode_lossy(), value.url_decode_lossy()) {
            (Borrowed(name), Borrowed(val)) => (name, val),
            (Borrowed(name), Owned(v)) => (name, self.buffer.push(v)),
            (Owned(name), Borrowed(val)) => (self.buffer.push(name), val),
            (Owned(mut name), Owned(val)) => {
                let len = name.len();
                name.push_str(&val);
                self.buffer.push_split(name, len)
            }
        };

        Some(ValueField::from(name_val))
    }
}

#[cfg(test)]
mod raw_str_parse_tests {
    use crate::form::ValueField as Field;

    #[test]
    fn test_skips_empty() {
        let buffer = super::SharedStack::new();
        let fields: Vec<_> = super::RawStrParser::new(&buffer, "a&b=c&&&c".into()).collect();
        assert_eq!(fields, &[Field::parse("a"), Field::parse("b=c"), Field::parse("c")]);
    }

    #[test]
    fn test_decodes() {
        let buffer = super::SharedStack::new();
        let fields: Vec<_> = super::RawStrParser::new(&buffer, "a+b=c%20d&%26".into()).collect();
        assert_eq!(fields, &[Field::parse("a b=c d"), Field::parse("&")]);
    }
}

impl<'r, 'i> MultipartParser<'r, 'i> {
    /// Returns `None` when there are no further fields. Otherwise tries to
    /// parse the next multipart form field and returns the result.
    async fn next(&mut self) -> Option<Result<'r, Field<'r, 'i>>> {
        if self.done {
            return None;
        }

        let field = match self.source.next_field().await {
            Ok(Some(field)) => field,
            Ok(None) => return None,
            Err(e) => {
                self.done = true;
                return Some(Err(e.into()));
            }
        };

        // A field with a content-type is data; one without is "value".
        trace_!("multipart field: {:?}", field);
        let content_type = field.content_type().and_then(|m| m.as_ref().parse().ok());
        let field = if let Some(content_type) = content_type {
            let (name, file_name) = match (field.name(), field.file_name()) {
                (None, None) => ("", None),
                (None, Some(file_name)) => ("", Some(self.buffer.push(file_name))),
                (Some(name), None) => (self.buffer.push(name), None),
                (Some(a), Some(b)) => {
                    let (field_name, file_name) = self.buffer.push_two(a, b);
                    (field_name, Some(file_name))
                }
            };

            Either::Right(DataField {
                content_type,
                request: self.request,
                name: NameView::new(name),
                file_name: file_name.map(crate::fs::FileName::new),
                data: Data::from(field),
            })
        } else {
            let (mut buf, len) = match field.name() {
                Some(s) => (s.to_string(), s.len()),
                None => (String::new(), 0)
            };

            match field.text().await {
                Ok(text) => buf.push_str(&text),
                Err(e) => return Some(Err(e.into())),
            };

            let name_val = self.buffer.push_split(buf, len);
            Either::Left(ValueField::from(name_val))
        };

        Some(Ok(field))
    }
}