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echo/middleware/body_limit.go
Alex Ungur 6d9e043284 Introduced Go module support as v4, removed obsolete CloseNotifier() mechanism
This reintroduces support for Go modules, as v4.

CloseNotifier() is removed as it has been obsoleted, see https://golang.org/doc/go1.11#net/http

It was already NOT working (not sending signals) as of 1.11 the functionality was gone, we merely
deleted the functions that exposed it. If anyone still relies on it they should migrate to using
`c.Request().Context().Done()` instead.

Closes #1268, #1255
2019-01-30 16:11:42 +02:00

118 lines
2.7 KiB
Go

package middleware
import (
"fmt"
"io"
"sync"
"github.com/labstack/echo/v4"
"github.com/labstack/gommon/bytes"
)
type (
// BodyLimitConfig defines the config for BodyLimit middleware.
BodyLimitConfig struct {
// Skipper defines a function to skip middleware.
Skipper Skipper
// Maximum allowed size for a request body, it can be specified
// as `4x` or `4xB`, where x is one of the multiple from K, M, G, T or P.
Limit string `yaml:"limit"`
limit int64
}
limitedReader struct {
BodyLimitConfig
reader io.ReadCloser
read int64
context echo.Context
}
)
var (
// DefaultBodyLimitConfig is the default BodyLimit middleware config.
DefaultBodyLimitConfig = BodyLimitConfig{
Skipper: DefaultSkipper,
}
)
// BodyLimit returns a BodyLimit middleware.
//
// BodyLimit middleware sets the maximum allowed size for a request body, if the
// size exceeds the configured limit, it sends "413 - Request Entity Too Large"
// response. The BodyLimit is determined based on both `Content-Length` request
// header and actual content read, which makes it super secure.
// Limit can be specified as `4x` or `4xB`, where x is one of the multiple from K, M,
// G, T or P.
func BodyLimit(limit string) echo.MiddlewareFunc {
c := DefaultBodyLimitConfig
c.Limit = limit
return BodyLimitWithConfig(c)
}
// BodyLimitWithConfig returns a BodyLimit middleware with config.
// See: `BodyLimit()`.
func BodyLimitWithConfig(config BodyLimitConfig) echo.MiddlewareFunc {
// Defaults
if config.Skipper == nil {
config.Skipper = DefaultBodyLimitConfig.Skipper
}
limit, err := bytes.Parse(config.Limit)
if err != nil {
panic(fmt.Errorf("echo: invalid body-limit=%s", config.Limit))
}
config.limit = limit
pool := limitedReaderPool(config)
return func(next echo.HandlerFunc) echo.HandlerFunc {
return func(c echo.Context) error {
if config.Skipper(c) {
return next(c)
}
req := c.Request()
// Based on content length
if req.ContentLength > config.limit {
return echo.ErrStatusRequestEntityTooLarge
}
// Based on content read
r := pool.Get().(*limitedReader)
r.Reset(req.Body, c)
defer pool.Put(r)
req.Body = r
return next(c)
}
}
}
func (r *limitedReader) Read(b []byte) (n int, err error) {
n, err = r.reader.Read(b)
r.read += int64(n)
if r.read > r.limit {
return n, echo.ErrStatusRequestEntityTooLarge
}
return
}
func (r *limitedReader) Close() error {
return r.reader.Close()
}
func (r *limitedReader) Reset(reader io.ReadCloser, context echo.Context) {
r.reader = reader
r.context = context
r.read = 0
}
func limitedReaderPool(c BodyLimitConfig) sync.Pool {
return sync.Pool{
New: func() interface{} {
return &limitedReader{BodyLimitConfig: c}
},
}
}