fetch: implement multipart/form-data parsing for Request::formData() (#42041)

Testing: More test passed in `fetch/api/abort/request.any.js.ini` fixes: #25106 --------- Signed-off-by: Taym Haddadi <haddadi.taym@gmail.com>
2026-04-25 17:15:48 +02:00 · 2026-02-04 00:31:41 +01:00
parent 42359b26a2
commit b18d119261
10 changed files with 263 additions and 68 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -803,6 +803,12 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4c7f02d4ea65f2c1853089ffd8d2787bdbc63de2f0d29dedbcf8ccdfa0ccd4cf"

+[[package]]
+name = "base64"
+version = "0.12.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3441f0f7b02788e948e47f457ca01f1d7e6d92c693bc132c22b087d3141c03ff"
+
 [[package]]
 name = "base64"
 version = "0.21.7"
@@ -1041,6 +1047,12 @@ dependencies = [
 "alloc-stdlib",
 ]

+[[package]]
+name = "buf-read-ext"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2e2c71c44e5bbc64de4ecfac946e05f9bba5cc296ea7bab4d3eda242a3ffa73c"
+
 [[package]]
 name = "build-parallel"
 version = "0.1.2"
@@ -3112,6 +3124,17 @@ dependencies = [
 "windows-link 0.2.1",
 ]

+[[package]]
+name = "getrandom"
+version = "0.1.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8fc3cb4d91f53b50155bdcfd23f6a4c39ae1969c2ae85982b135750cccaf5fce"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi 0.9.0+wasi-snapshot-preview1",
+]
+
 [[package]]
 name = "getrandom"
 version = "0.2.17"
@@ -3120,7 +3143,7 @@ checksum = "ff2abc00be7fca6ebc474524697ae276ad847ad0a6b3faa4bcb027e9a4614ad0"
 dependencies = [
 "cfg-if",
 "libc",
- "wasi",
+ "wasi 0.11.1+wasi-snapshot-preview1",
 ]

 [[package]]
@@ -5375,6 +5398,21 @@ version = "0.3.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6877bb514081ee2a7ff5ef9de3281f14a4dd4bceac4c09388074a6b5df8a139a"

+[[package]]
+name = "mime-multipart-hyper1"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bc819448803ee517eb413276ca59613c2850a95c4fdcd87ec82c5a6ce6cdab1a"
+dependencies = [
+ "buf-read-ext",
+ "http 1.4.0",
+ "httparse",
+ "log",
+ "mime",
+ "tempfile",
+ "textnonce",
+]
+
 [[package]]
 name = "mime_guess"
 version = "2.0.5"
@@ -5408,7 +5446,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a69bcab0ad47271a0234d9422b131806bf3968021e5dc9328caf2d4cd58557fc"
 dependencies = [
 "libc",
- "wasi",
+ "wasi 0.11.1+wasi-snapshot-preview1",
 "windows-sys 0.61.2",
 ]

@@ -7168,6 +7206,19 @@ version = "5.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "69cdb34c158ceb288df11e18b4bd39de994f6657d83847bdffdbd7f346754b0f"

+[[package]]
+name = "rand"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6a6b1679d49b24bbfe0c803429aa1874472f50d9b363131f0e89fc356b544d03"
+dependencies = [
+ "getrandom 0.1.16",
+ "libc",
+ "rand_chacha 0.2.2",
+ "rand_core 0.5.1",
+ "rand_hc",
+]
+
 [[package]]
 name = "rand"
 version = "0.8.5"
@@ -7189,6 +7240,16 @@ dependencies = [
 "rand_core 0.9.3",
 ]

+[[package]]
+name = "rand_chacha"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f4c8ed856279c9737206bf725bf36935d8666ead7aa69b52be55af369d193402"
+dependencies = [
+ "ppv-lite86",
+ "rand_core 0.5.1",
+]
+
 [[package]]
 name = "rand_chacha"
 version = "0.3.1"
@@ -7209,6 +7270,15 @@ dependencies = [
 "rand_core 0.9.3",
 ]

+[[package]]
+name = "rand_core"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19"
+dependencies = [
+ "getrandom 0.1.16",
+]
+
 [[package]]
 name = "rand_core"
 version = "0.6.4"
@@ -7227,6 +7297,15 @@ dependencies = [
 "getrandom 0.3.4",
 ]

+[[package]]
+name = "rand_hc"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ca3129af7b92a17112d59ad498c6f81eaf463253766b90396d39ea7a39d6613c"
+dependencies = [
+ "rand_core 0.5.1",
+]
+
 [[package]]
 name = "range-alloc"
 version = "0.1.4"
@@ -7762,6 +7841,7 @@ dependencies = [
 "media",
 "metrics",
 "mime",
+ "mime-multipart-hyper1",
 "mime_guess",
 "ml-dsa",
 "ml-kem",
@@ -9188,6 +9268,16 @@ dependencies = [
 "winapi-util",
 ]

+[[package]]
+name = "textnonce"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7743f8d70cd784ed1dc33106a18998d77758d281dc40dc3e6d050cf0f5286683"
+dependencies = [
+ "base64 0.12.3",
+ "rand 0.7.3",
+]
+
 [[package]]
 name = "thin-vec"
 version = "0.2.14"
@@ -10089,6 +10179,12 @@ dependencies = [
 "tracing",
 ]

+[[package]]
+name = "wasi"
+version = "0.9.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
+
 [[package]]
 name = "wasi"
 version = "0.11.1+wasi-snapshot-preview1"
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -111,6 +111,7 @@ malloc_size_of_derive = "0.1"
 markup5ever = "0.38"
 memmap2 = "0.9.9"
 mime = "0.3.13"
+mime-multipart-hyper1 = "0.10.0"
 mime_guess = "2.0.5"
 ml-dsa = "0.0.4"
 ml-kem = { version = "0.2", features = ["deterministic"] }
--- a/components/script/Cargo.toml
+++ b/components/script/Cargo.toml
@@ -98,6 +98,7 @@ markup5ever = { workspace = true }
 media = { path = "../media" }
 metrics = { path = "../metrics" }
 mime = { workspace = true }
+mime-multipart-hyper1 = { workspace = true }
 mime_guess = { workspace = true }
 ml-dsa = { workspace = true }
 ml-kem = { workspace = true }
--- a/components/script/body.rs
+++ b/components/script/body.rs
@@ -2,12 +2,15 @@
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */

+use std::io::Cursor;
 use std::rc::Rc;
-use std::{ptr, slice, str};
+use std::{fs, ptr, slice, str};

 use base::generic_channel::GenericSharedMemory;
 use constellation_traits::BlobImpl;
 use encoding_rs::{Encoding, UTF_8};
+use http::HeaderMap;
+use http::header::{CONTENT_DISPOSITION, CONTENT_TYPE};
 use ipc_channel::ipc::{self, IpcReceiver, IpcSender};
 use ipc_channel::router::ROUTER;
 use js::jsapi::{Heap, JS_ClearPendingException, JSObject, Value as JSValue};
@@ -17,6 +20,7 @@ use js::rust::HandleValue;
 use js::rust::wrappers::{JS_GetPendingException, JS_ParseJSON};
 use js::typedarray::{ArrayBufferU8, Uint8};
 use mime::{self, Mime};
+use mime_multipart_hyper1::{Node, read_multipart_body};
 use net_traits::request::{
    BodyChunkRequest, BodyChunkResponse, BodySource as NetBodySource, RequestBody,
 };
@@ -27,12 +31,14 @@ use crate::dom::bindings::codegen::Bindings::BlobBinding::Blob_Binding::BlobMeth
 use crate::dom::bindings::codegen::Bindings::FormDataBinding::FormDataMethods;
 use crate::dom::bindings::codegen::Bindings::XMLHttpRequestBinding::BodyInit;
 use crate::dom::bindings::error::{Error, Fallible};
+use crate::dom::bindings::inheritance::Castable;
 use crate::dom::bindings::refcounted::Trusted;
 use crate::dom::bindings::reflector::{DomGlobal, DomObject};
 use crate::dom::bindings::root::{Dom, DomRoot, MutNullableDom};
 use crate::dom::bindings::str::{DOMString, USVString};
 use crate::dom::bindings::trace::RootedTraceableBox;
 use crate::dom::blob::{Blob, normalize_type_string};
+use crate::dom::file::File;
 use crate::dom::formdata::FormData;
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::html::htmlformelement::{encode_multipart_form_data, generate_boundary};
@@ -904,6 +910,114 @@ fn run_blob_data_algorithm(
    Ok(FetchedData::BlobData(blob))
 }

+fn extract_name_from_content_disposition(headers: &HeaderMap) -> Option<String> {
+    let cd = headers.get(CONTENT_DISPOSITION)?.to_str().ok()?;
+
+    for part in cd.split(';').map(|s| s.trim()) {
+        if let Some(rest) = part.strip_prefix("name=") {
+            let v = rest.trim();
+            let v = v.strip_prefix('"').unwrap_or(v);
+            let v = v.strip_suffix('"').unwrap_or(v);
+            return Some(v.to_string());
+        }
+    }
+    None
+}
+
+fn extract_filename_from_content_disposition(headers: &HeaderMap) -> Option<String> {
+    let cd = headers.get(CONTENT_DISPOSITION)?.to_str().ok()?;
+    if let Some(index) = cd.find("filename=") {
+        let start = index + "filename=".len();
+        return Some(
+            cd.get(start..)
+                .unwrap_or_default()
+                .trim_matches('"')
+                .to_owned(),
+        );
+    }
+    if let Some(index) = cd.find("filename*=UTF-8''") {
+        let start = index + "filename*=UTF-8''".len();
+        return Some(
+            cd.get(start..)
+                .unwrap_or_default()
+                .trim_matches('"')
+                .to_owned(),
+        );
+    }
+    None
+}
+
+fn content_type_from_headers(headers: &HeaderMap) -> Result<String, Error> {
+    match headers.get(CONTENT_TYPE) {
+        Some(value) => Ok(value
+            .to_str()
+            .map_err(|_| Error::Type("Inappropriate MIME-type for Body".to_string()))?
+            .to_string()),
+        None => Ok("text/plain".to_string()),
+    }
+}
+
+fn append_form_data_entry_from_part(
+    root: &GlobalScope,
+    formdata: &FormData,
+    headers: &HeaderMap,
+    body: Vec<u8>,
+    can_gc: CanGc,
+) -> Fallible<()> {
+    let Some(name) = extract_name_from_content_disposition(headers) else {
+        return Ok(());
+    };
+    // A part whose `Content-Disposition` header contains a `name` parameter whose value is `_charset_` is parsed like any other part. It does not change the encoding.
+    let filename = extract_filename_from_content_disposition(headers);
+    if let Some(filename) = filename {
+        // Each part whose `Content-Disposition` header contains a `filename` parameter must be parsed into an entry whose value is a File object whose contents are the contents of the part.
+        //
+        // The name attribute of the File object must have the value of the `filename` parameter of the part.
+        //
+        // The type attribute of the File object must have the value of the `Content-Type` header of the part if the part has such header, and `text/plain` (the default defined by [RFC7578] section 4.4) otherwise.
+        let content_type = content_type_from_headers(headers)?;
+        let file = File::new(
+            root,
+            BlobImpl::new_from_bytes(body, normalize_type_string(&content_type)),
+            DOMString::from(filename),
+            None,
+            can_gc,
+        );
+        let blob = file.upcast::<Blob>();
+        formdata.Append_(USVString(name), blob, None);
+    } else {
+        // Each part whose `Content-Disposition` header does not contain a `filename` parameter must be parsed into an entry whose value is the UTF-8 decoded without BOM content of the part. This is done regardless of the presence or the value of a `Content-Type` header and regardless of the presence or the value of a `charset` parameter.
+
+        let (value, _) = UTF_8.decode_without_bom_handling(&body);
+        formdata.Append(USVString(name), USVString(value.to_string()));
+    }
+    Ok(())
+}
+
+fn append_multipart_nodes(
+    root: &GlobalScope,
+    formdata: &FormData,
+    nodes: Vec<Node>,
+    can_gc: CanGc,
+) -> Fallible<()> {
+    for node in nodes {
+        match node {
+            Node::Part(part) => {
+                append_form_data_entry_from_part(root, formdata, &part.headers, part.body, can_gc)?;
+            },
+            Node::File(file_part) => {
+                let body = fs::read(&file_part.path)
+                    .map_err(|_| Error::Type("file part could not be read".to_string()))?;
+                append_form_data_entry_from_part(root, formdata, &file_part.headers, body, can_gc)?;
+            },
+            Node::Multipart((_, inner)) => {
+                append_multipart_nodes(root, formdata, inner, can_gc)?;
+            },
+        }
+    }
+    Ok(())
+}
+
 /// <https://fetch.spec.whatwg.org/#ref-for-concept-body-consume-body%E2%91%A2>
 fn run_form_data_algorithm(
    root: &GlobalScope,
@@ -911,15 +1025,57 @@ fn run_form_data_algorithm(
    mime: &[u8],
    can_gc: CanGc,
 ) -> Fallible<FetchedData> {
+    // The formData() method steps are to return the result of running consume body
+    // with this and the following steps given a byte sequence bytes:
    let mime_str = str::from_utf8(mime).unwrap_or_default();
    let mime: Mime = mime_str
        .parse()
        .map_err(|_| Error::Type("Inappropriate MIME-type for Body".to_string()))?;

-    // TODO
-    // ... Parser for Mime(TopLevel::Multipart, SubLevel::FormData, _)
-    // ... is not fully determined yet.
+    // Let mimeType be the result of get the MIME type with this.
+    //
+    // If mimeType is non-null, then switch on mimeType’s essence and run the corresponding steps:
+    if mime.type_() == mime::MULTIPART && mime.subtype() == mime::FORM_DATA {
+        // "multipart/form-data"
+        // Parse bytes, using the value of the `boundary` parameter from mimeType,
+        // per the rules set forth in Returning Values from Forms: multipart/form-data. [RFC7578]
+        let mut headers = HeaderMap::new();
+        headers.insert(
+            CONTENT_TYPE,
+            mime_str
+                .parse()
+                .map_err(|_| Error::Type("Inappropriate MIME-type for Body".to_string()))?,
+        );
+
+        if let Some(boundary) = mime.get_param(mime::BOUNDARY) {
+            let closing_boundary = format!("--{}--", boundary.as_str()).into_bytes();
+            let trimmed_bytes = bytes.strip_suffix(b"\r\n").unwrap_or(&bytes);
+            if trimmed_bytes == closing_boundary {
+                let formdata = FormData::new(None, root, can_gc);
+                return Ok(FetchedData::FormData(formdata));
+            }
+        }
+
+        let mut cursor = Cursor::new(bytes);
+        // If that fails for some reason, then throw a TypeError.
+        let nodes = read_multipart_body(&mut cursor, &headers, false)
+            .map_err(|_| Error::Type("Inappropriate MIME-type for Body".to_string()))?;
+        // The above is a rough approximation of what is needed for `multipart/form-data`,
+        // a more detailed parsing specification is to be written. Volunteers welcome.
+
+        // Return a new FormData object, appending each entry, resulting from the parsing operation, to its entry list.
+        let formdata = FormData::new(None, root, can_gc);
+
+        append_multipart_nodes(root, &formdata, nodes, can_gc)?;
+
+        return Ok(FetchedData::FormData(formdata));
+    }
+
    if mime.type_() == mime::APPLICATION && mime.subtype() == mime::WWW_FORM_URLENCODED {
+        // "application/x-www-form-urlencoded"
+        // Let entries be the result of parsing bytes.
+        //
+        // Return a new FormData object whose entry list is entries.
        let entries = form_urlencoded::parse(&bytes);
        let formdata = FormData::new(None, root, can_gc);
        for (k, e) in entries {
@@ -928,6 +1084,7 @@ fn run_form_data_algorithm(
        return Ok(FetchedData::FormData(formdata));
    }

+    // Throw a TypeError.
    Err(Error::Type("Inappropriate MIME-type for Body".to_string()))
 }

--- a/deny.toml
+++ b/deny.toml
@@ -98,6 +98,8 @@ skip = [
    "bitflags",
    "cookie",
    "redox_syscall",
+    # Duplicated by getrandom 0.1 and getrandom 0.2
+    "wasi",

    # New versions of these dependencies is pulled in by GStreamer / GLib.
    "itertools",
--- a/tests/wpt/meta/fetch/api/abort/request.any.js.ini
+++ b/tests/wpt/meta/fetch/api/abort/request.any.js.ini
@@ -1,10 +1,4 @@
 [request.any.html]
-  [Calling formData() on an aborted request]
-    expected: FAIL
-
-  [Aborting a request after calling formData()]
-    expected: FAIL
-

 [request.any.serviceworker.html]
  expected: ERROR
@@ -13,8 +7,3 @@
  expected: ERROR

 [request.any.worker.html]
-  [Calling formData() on an aborted request]
-    expected: FAIL
-
-  [Aborting a request after calling formData()]
-    expected: FAIL
--- a/tests/wpt/meta/fetch/api/body/formdata.any.js.ini
+++ b/tests/wpt/meta/fetch/api/body/formdata.any.js.ini
@@ -1,20 +0,0 @@
-[formdata.any.worker.html]
-  [Consume empty response.formData() as FormData]
-    expected: FAIL
-
-  [Consume empty request.formData() as FormData]
-    expected: FAIL
-
-  [Consume multipart/form-data headers case-insensitively]
-    expected: FAIL
-
-
-[formdata.any.html]
-  [Consume empty response.formData() as FormData]
-    expected: FAIL
-
-  [Consume empty request.formData() as FormData]
-    expected: FAIL
-
-  [Consume multipart/form-data headers case-insensitively]
-    expected: FAIL
--- a/tests/wpt/meta/fetch/api/request/request-consume.any.js.ini
+++ b/tests/wpt/meta/fetch/api/request/request-consume.any.js.ini
@@ -1,13 +1,3 @@
-[request-consume.any.html]
-  [Consume FormData request's body as FormData]
-    expected: FAIL
-
-
-[request-consume.any.worker.html]
-  [Consume FormData request's body as FormData]
-    expected: FAIL
-
-
 [request-consume.any.serviceworker.html]
  expected: ERROR

--- a/tests/wpt/meta/fetch/api/response/response-consume.html.ini
+++ b/tests/wpt/meta/fetch/api/response/response-consume.html.ini
@@ -1,21 +1,3 @@
 [response-consume.html]
-  [Consume response's body: from text with correct multipart type to formData]
-    expected: FAIL
-
-  [Consume response's body: from text with correct multipart type to formData with BOM]
-    expected: FAIL
-
-  [Consume response's body: from blob with correct multipart type to formData]
-    expected: FAIL
-
-  [Consume response's body: from FormData to formData]
-    expected: FAIL
-
-  [Consume response's body: from stream with correct multipart type to formData]
-    expected: FAIL
-
-  [Consume response's body: from multipart form data blob to formData]
-    expected: FAIL
-
  [Consume response's body: from FormData to blob]
    expected: FAIL
--- a/tests/wpt/meta/fetch/content-type/multipart.window.js.ini
+++ b/tests/wpt/meta/fetch/content-type/multipart.window.js.ini
@@ -1,3 +0,0 @@
-[multipart.window.html]
-  [Ensure capital letters can be used in the boundary value.]
-    expected: FAIL