pub struct Constraints { /* private fields */ }
Expand description

Represents some rules to be applied on the stream and field’s content size to prevent DoS attacks.

It’s recommended to add some rules on field (specially text field) size to avoid potential DoS attacks from attackers running the server out of memory. This type provides some API to apply constraints on very granular level to make multipart/form-data safe. By default, it does not apply any constraint.

Examples

use multer::{Multipart, Constraints, SizeLimit};

// Create some constraints to be applied to the fields to prevent DoS attack.
let constraints = Constraints::new()
     // We only accept `my_text_field` and `my_file_field` fields,
     // For any unknown field, we will throw an error.
     .allowed_fields(vec!["my_text_field", "my_file_field"])
     .size_limit(
         SizeLimit::new()
             // Set 15mb as size limit for the whole stream body.
             .whole_stream(15 * 1024 * 1024)
             // Set 10mb as size limit for all fields.
             .per_field(10 * 1024 * 1024)
             // Set 30kb as size limit for our text field only.
             .for_field("my_text_field", 30 * 1024),
     );

// Create a `Multipart` instance from a stream and the constraints.
let mut multipart = Multipart::with_constraints(some_stream, "X-BOUNDARY", constraints);

while let Some(field) = multipart.next_field().await.unwrap() {
    let content = field.text().await.unwrap();
    assert_eq!(content, "abcd");
}

Implementations

Creates a set of rules with default behaviour.

Applies rules on field’s content length.

Specify which fields should be allowed, for any unknown field, the next_field will throw an error.

Trait Implementations

Formats the value using the given formatter. Read more

Returns the “default value” for a type. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.