diff options
Diffstat (limited to 'modules/caddyhttp/headers')
| -rw-r--r-- | modules/caddyhttp/headers/headers.go | 160 |
1 files changed, 137 insertions, 23 deletions
diff --git a/modules/caddyhttp/headers/headers.go b/modules/caddyhttp/headers/headers.go index ba9d89d..71e575d 100644 --- a/modules/caddyhttp/headers/headers.go +++ b/modules/caddyhttp/headers/headers.go @@ -15,7 +15,9 @@ package headers import ( + "fmt" "net/http" + "regexp" "strings" "github.com/caddyserver/caddy/v2" @@ -23,43 +25,61 @@ import ( ) func init() { - caddy.RegisterModule(Headers{}) + caddy.RegisterModule(Handler{}) } -// Headers is a middleware which can mutate HTTP headers. -type Headers struct { +// Handler is a middleware which can mutate HTTP headers. +type Handler struct { Request *HeaderOps `json:"request,omitempty"` Response *RespHeaderOps `json:"response,omitempty"` } // CaddyModule returns the Caddy module information. -func (Headers) CaddyModule() caddy.ModuleInfo { +func (Handler) CaddyModule() caddy.ModuleInfo { return caddy.ModuleInfo{ Name: "http.handlers.headers", - New: func() caddy.Module { return new(Headers) }, + New: func() caddy.Module { return new(Handler) }, } } -// 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"` +// Provision sets up h's configuration. +func (h *Handler) Provision(_ caddy.Context) error { + if h.Request != nil { + err := h.Request.provision() + if err != nil { + return err + } + } + if h.Response != nil { + err := h.Response.provision() + if err != nil { + return err + } + } + return nil } -// 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"` +// Validate ensures h's configuration is valid. +func (h Handler) Validate() error { + if h.Request != nil { + err := h.Request.validate() + if err != nil { + return err + } + } + if h.Response != nil { + err := h.Response.validate() + if err != nil { + return err + } + } + return nil } -func (h Headers) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyhttp.Handler) error { +func (h Handler) 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) + h.Request.applyTo(r.Header, repl) // request header's Host is handled specially by the // Go standard library, so if that header was changed, @@ -79,22 +99,79 @@ func (h Headers) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyhtt headerOps: h.Response.HeaderOps, } } else { - apply(h.Response.HeaderOps, w.Header(), repl) + h.Response.applyTo(w.Header(), repl) } } + return next.ServeHTTP(w, r) } -func apply(ops *HeaderOps, hdr http.Header, repl caddy.Replacer) { +// 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"` + Replace map[string][]Replacement `json:"replace,omitempty"` +} + +func (ops *HeaderOps) provision() error { + for fieldName, replacements := range ops.Replace { + for i, r := range replacements { + if r.SearchRegexp != "" { + re, err := regexp.Compile(r.SearchRegexp) + if err != nil { + return fmt.Errorf("replacement %d for header field '%s': %v", i, fieldName, err) + } + replacements[i].re = re + } + } + } + return nil +} + +func (ops HeaderOps) validate() error { + for fieldName, replacements := range ops.Replace { + for _, r := range replacements { + if r.Search != "" && r.SearchRegexp != "" { + return fmt.Errorf("cannot specify both a substring search and a regular expression search for field '%s'", fieldName) + } + } + } + return nil +} + +// Replacement describes a string replacement, +// either a simple and fast sugbstring search +// or a slower but more powerful regex search. +type Replacement struct { + Search string `json:"search,omitempty"` + SearchRegexp string `json:"search_regexp,omitempty"` + Replace string `json:"replace,omitempty"` + + re *regexp.Regexp +} + +// 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 (ops *HeaderOps) applyTo(hdr http.Header, repl caddy.Replacer) { if ops == nil { return } + 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 { @@ -102,9 +179,45 @@ func apply(ops *HeaderOps, hdr http.Header, repl caddy.Replacer) { } hdr.Set(fieldName, strings.Join(vals, ",")) } + for _, fieldName := range ops.Delete { hdr.Del(repl.ReplaceAll(fieldName, "")) } + + for fieldName, replacements := range ops.Replace { + fieldName = repl.ReplaceAll(fieldName, "") + + // perform replacements across all fields + if fieldName == "*" { + for _, r := range replacements { + search := repl.ReplaceAll(r.Search, "") + replace := repl.ReplaceAll(r.Replace, "") + for fieldName, vals := range hdr { + for i := range vals { + if r.re != nil { + hdr[fieldName][i] = r.re.ReplaceAllString(hdr[fieldName][i], replace) + } else { + hdr[fieldName][i] = strings.ReplaceAll(hdr[fieldName][i], search, replace) + } + } + } + } + continue + } + + // perform replacements only with the named field + for _, r := range replacements { + search := repl.ReplaceAll(r.Search, "") + replace := repl.ReplaceAll(r.Replace, "") + for i := range hdr[fieldName] { + if r.re != nil { + hdr[fieldName][i] = r.re.ReplaceAllString(hdr[fieldName][i], replace) + } else { + hdr[fieldName][i] = strings.ReplaceAll(hdr[fieldName][i], search, replace) + } + } + } + } } // responseWriterWrapper defers response header @@ -123,7 +236,7 @@ func (rww *responseWriterWrapper) WriteHeader(status int) { } rww.wroteHeader = true if rww.require == nil || rww.require.Match(status, rww.ResponseWriterWrapper.Header()) { - apply(rww.headerOps, rww.ResponseWriterWrapper.Header(), rww.replacer) + rww.headerOps.applyTo(rww.ResponseWriterWrapper.Header(), rww.replacer) } rww.ResponseWriterWrapper.WriteHeader(status) } @@ -137,6 +250,7 @@ func (rww *responseWriterWrapper) Write(d []byte) (int, error) { // Interface guards var ( - _ caddyhttp.MiddlewareHandler = (*Headers)(nil) + _ caddy.Provisioner = (*Handler)(nil) + _ caddyhttp.MiddlewareHandler = (*Handler)(nil) _ caddyhttp.HTTPInterfaces = (*responseWriterWrapper)(nil) ) |