Files
sub2api/backend/internal/service/upstream_response_limit.go

39 lines
958 B
Go

package service
import (
"errors"
"fmt"
"io"
"github.com/Wei-Shaw/sub2api/internal/config"
)
var ErrUpstreamResponseBodyTooLarge = errors.New("upstream response body too large")
const defaultUpstreamResponseReadMaxBytes int64 = 8 * 1024 * 1024
func resolveUpstreamResponseReadLimit(cfg *config.Config) int64 {
if cfg != nil && cfg.Gateway.UpstreamResponseReadMaxBytes > 0 {
return cfg.Gateway.UpstreamResponseReadMaxBytes
}
return defaultUpstreamResponseReadMaxBytes
}
func readUpstreamResponseBodyLimited(reader io.Reader, maxBytes int64) ([]byte, error) {
if reader == nil {
return nil, errors.New("response body is nil")
}
if maxBytes <= 0 {
maxBytes = defaultUpstreamResponseReadMaxBytes
}
body, err := io.ReadAll(io.LimitReader(reader, maxBytes+1))
if err != nil {
return nil, err
}
if int64(len(body)) > maxBytes {
return nil, fmt.Errorf("%w: limit=%d", ErrUpstreamResponseBodyTooLarge, maxBytes)
}
return body, nil
}