1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
|
package headers
import (
"net/http"
"strings"
"github.com/caddyserver/caddy"
"github.com/caddyserver/caddy/modules/caddyhttp"
)
func init() {
caddy.RegisterModule(caddy.Module{
Name: "http.middleware.headers",
New: func() interface{} { return new(Headers) },
})
}
// Headers is a middleware which can mutate HTTP headers.
type Headers struct {
Request *HeaderOps `json:"request,omitempty"`
Response *RespHeaderOps `json:"response,omitempty"`
}
// HeaderOps defines some operations to
// perform on HTTP headers.
type HeaderOps struct {
Add http.Header `json:"add,omitempty"`
Set http.Header `json:"set,omitempty"`
Delete []string `json:"delete,omitempty"`
}
// RespHeaderOps is like HeaderOps, but
// optionally deferred until response time.
type RespHeaderOps struct {
*HeaderOps
Require *caddyhttp.ResponseMatcher `json:"require,omitempty"`
Deferred bool `json:"deferred,omitempty"`
}
func (h Headers) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyhttp.Handler) error {
repl := r.Context().Value(caddy.ReplacerCtxKey).(caddy.Replacer)
apply(h.Request, r.Header, repl)
if h.Response.Deferred || h.Response.Require != nil {
w = &responseWriterWrapper{
ResponseWriterWrapper: &caddyhttp.ResponseWriterWrapper{ResponseWriter: w},
replacer: repl,
require: h.Response.Require,
headerOps: h.Response.HeaderOps,
}
} else {
apply(h.Response.HeaderOps, w.Header(), repl)
}
return next.ServeHTTP(w, r)
}
func apply(ops *HeaderOps, hdr http.Header, repl caddy.Replacer) {
for fieldName, vals := range ops.Add {
fieldName = repl.ReplaceAll(fieldName, "")
for _, v := range vals {
hdr.Add(fieldName, repl.ReplaceAll(v, ""))
}
}
for fieldName, vals := range ops.Set {
fieldName = repl.ReplaceAll(fieldName, "")
for i := range vals {
vals[i] = repl.ReplaceAll(vals[i], "")
}
hdr.Set(fieldName, strings.Join(vals, ","))
}
for _, fieldName := range ops.Delete {
hdr.Del(repl.ReplaceAll(fieldName, ""))
}
}
// responseWriterWrapper defers response header
// operations until WriteHeader is called.
type responseWriterWrapper struct {
*caddyhttp.ResponseWriterWrapper
replacer caddy.Replacer
require *caddyhttp.ResponseMatcher
headerOps *HeaderOps
wroteHeader bool
}
func (rww *responseWriterWrapper) WriteHeader(status int) {
if rww.wroteHeader {
return
}
rww.wroteHeader = true
if rww.require == nil || rww.require.Match(status, rww.ResponseWriterWrapper.Header()) {
apply(rww.headerOps, rww.ResponseWriterWrapper.Header(), rww.replacer)
}
rww.ResponseWriterWrapper.WriteHeader(status)
}
func (rww *responseWriterWrapper) Write(d []byte) (int, error) {
if !rww.wroteHeader {
rww.WriteHeader(http.StatusOK)
}
return rww.ResponseWriterWrapper.Write(d)
}
// Interface guards
var (
_ caddyhttp.MiddlewareHandler = (*Headers)(nil)
_ caddyhttp.HTTPInterfaces = (*responseWriterWrapper)(nil)
)
|
