1package http
 2
 3import (
 4	"context"
 5	"fmt"
 6	"github.com/aws/smithy-go/middleware"
 7	"strings"
 8)
 9
10// MinimumProtocolError is an error type indicating that the established connection did not meet the expected minimum
11// HTTP protocol version.
12type MinimumProtocolError struct {
13	proto              string
14	expectedProtoMajor int
15	expectedProtoMinor int
16}
17
18// Error returns the error message.
19func (m *MinimumProtocolError) Error() string {
20	return fmt.Sprintf("operation requires minimum HTTP protocol of HTTP/%d.%d, but was %s",
21		m.expectedProtoMajor, m.expectedProtoMinor, m.proto)
22}
23
24// RequireMinimumProtocol is a deserialization middleware that asserts that the established HTTP connection
25// meets the minimum major ad minor version.
26type RequireMinimumProtocol struct {
27	ProtoMajor int
28	ProtoMinor int
29}
30
31// AddRequireMinimumProtocol adds the RequireMinimumProtocol middleware to the stack using the provided minimum
32// protocol major and minor version.
33func AddRequireMinimumProtocol(stack *middleware.Stack, major, minor int) error {
34	return stack.Deserialize.Insert(&RequireMinimumProtocol{
35		ProtoMajor: major,
36		ProtoMinor: minor,
37	}, "OperationDeserializer", middleware.Before)
38}
39
40// ID returns the middleware identifier string.
41func (r *RequireMinimumProtocol) ID() string {
42	return "RequireMinimumProtocol"
43}
44
45// HandleDeserialize asserts that the established connection is a HTTP connection with the minimum major and minor
46// protocol version.
47func (r *RequireMinimumProtocol) HandleDeserialize(
48	ctx context.Context, in middleware.DeserializeInput, next middleware.DeserializeHandler,
49) (
50	out middleware.DeserializeOutput, metadata middleware.Metadata, err error,
51) {
52	out, metadata, err = next.HandleDeserialize(ctx, in)
53	if err != nil {
54		return out, metadata, err
55	}
56
57	response, ok := out.RawResponse.(*Response)
58	if !ok {
59		return out, metadata, fmt.Errorf("unknown transport type: %T", out.RawResponse)
60	}
61
62	if !strings.HasPrefix(response.Proto, "HTTP") {
63		return out, metadata, &MinimumProtocolError{
64			proto:              response.Proto,
65			expectedProtoMajor: r.ProtoMajor,
66			expectedProtoMinor: r.ProtoMinor,
67		}
68	}
69
70	if response.ProtoMajor < r.ProtoMajor || response.ProtoMinor < r.ProtoMinor {
71		return out, metadata, &MinimumProtocolError{
72			proto:              response.Proto,
73			expectedProtoMajor: r.ProtoMajor,
74			expectedProtoMinor: r.ProtoMinor,
75		}
76	}
77
78	return out, metadata, err
79}