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-rw-r--r--vendor/github.com/gorilla/handlers/canonical.go71
1 files changed, 71 insertions, 0 deletions
diff --git a/vendor/github.com/gorilla/handlers/canonical.go b/vendor/github.com/gorilla/handlers/canonical.go
new file mode 100644
index 000000000..3961695c4
--- /dev/null
+++ b/vendor/github.com/gorilla/handlers/canonical.go
@@ -0,0 +1,71 @@
+package handlers
+
+import (
+ "net/http"
+ "net/url"
+ "strings"
+)
+
+type canonical struct {
+ h http.Handler
+ domain string
+ code int
+}
+
+// CanonicalHost is HTTP middleware that re-directs requests to the canonical
+// domain. It accepts a domain and a status code (e.g. 301 or 302) and
+// re-directs clients to this domain. The existing request path is maintained.
+//
+// Note: If the provided domain is considered invalid by url.Parse or otherwise
+// returns an empty scheme or host, clients are not re-directed.
+// not re-directed.
+//
+// Example:
+//
+// r := mux.NewRouter()
+// canonical := handlers.CanonicalHost("http://www.gorillatoolkit.org", 302)
+// r.HandleFunc("/route", YourHandler)
+//
+// log.Fatal(http.ListenAndServe(":7000", canonical(r)))
+//
+func CanonicalHost(domain string, code int) func(h http.Handler) http.Handler {
+ fn := func(h http.Handler) http.Handler {
+ return canonical{h, domain, code}
+ }
+
+ return fn
+}
+
+func (c canonical) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+ dest, err := url.Parse(c.domain)
+ if err != nil {
+ // Call the next handler if the provided domain fails to parse.
+ c.h.ServeHTTP(w, r)
+ return
+ }
+
+ if dest.Scheme == "" || dest.Host == "" {
+ // Call the next handler if the scheme or host are empty.
+ // Note that url.Parse won't fail on in this case.
+ c.h.ServeHTTP(w, r)
+ return
+ }
+
+ if !strings.EqualFold(cleanHost(r.Host), dest.Host) {
+ // Re-build the destination URL
+ dest := dest.Scheme + "://" + dest.Host + r.URL.Path
+ http.Redirect(w, r, dest, c.code)
+ }
+
+ c.h.ServeHTTP(w, r)
+}
+
+// cleanHost cleans invalid Host headers by stripping anything after '/' or ' '.
+// This is backported from Go 1.5 (in response to issue #11206) and attempts to
+// mitigate malformed Host headers that do not match the format in RFC7230.
+func cleanHost(in string) string {
+ if i := strings.IndexAny(in, " /"); i != -1 {
+ return in[:i]
+ }
+ return in
+}