bitswap/httpnet: do not follow redirects (#878)

* bitswap/httpnet: do not follow redirects

Avoid following redirects. We treat them as an incorrect provider record.  We
don't want to be coerced into opening new connections to new hosts and we
prefer provider records to be up to date rather than them relying in redirects
being followed. There are also problems with potential loops etc.

#862

* bitswap/httpnet: close response bodies

"The default HTTP client's Transport may not reuse HTTP/1.x "keep-alive" TCP connections if the Body is not read to completion and closed."

Author: hsanjuan

bitswap/network/httpnet/httpnet.go

@@ -267,6 +267,12 @@ func New(host host.Host, opts ...Option) network.BitSwapNetwork {
 
 	c := &http.Client{
 		Transport: t,
+		CheckRedirect: func(req *http.Request, via []*http.Request) error {
+			// we do not follow redirects. Providers should keep
+			// announcements up to
+			// date. https://github.com/boxo/issues/862.
+			return http.ErrUseLastResponse
+		},
 	}
 	htnet.client = c
 

bitswap/network/httpnet/msg_sender.go

@@ -247,6 +247,7 @@ func (sender *httpMsgSender) tryURL(ctx context.Context, u *senderURL, entry bsm
 
 		return nil, serr
 	}
+	defer resp.Body.Close()
 
 	// Record request size
 	var buf bytes.Buffer
@@ -302,7 +303,12 @@ func (sender *httpMsgSender) tryURL(ctx context.Context, u *senderURL, entry bsm
 	case http.StatusNotFound,
 		http.StatusGone,
 		http.StatusForbidden,
-		http.StatusUnavailableForLegalReasons:
+		http.StatusUnavailableForLegalReasons,
+		http.StatusMovedPermanently,
+		http.StatusFound,
+		http.StatusSeeOther,
+		http.StatusTemporaryRedirect,
+		http.StatusPermanentRedirect:
 
 		err := fmt.Errorf("%s %q -> %d: %q", req.Method, req.URL, statusCode, string(body))
 		log.Debug(err)