relay_read_http: strip out Content-Length if we strip the body too

We should not forward Content-Length if the body is not also forwarded.

diff --git a/usr.sbin/relayd/relay_http.c b/usr.sbin/relayd/relay_http.c
index 0216de0..e62ece3 100644 (file)
--- a/usr.sbin/relayd/relay_http.c
+++ b/usr.sbin/relayd/relay_http.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: relay_http.c,v 1.86 2023/11/29 15:35:07 millert Exp $ */
+/*     $OpenBSD: relay_http.c,v 1.87 2023/12/01 16:48:40 millert Exp $ */
 
 /*
  * Copyright (c) 2006 - 2016 Reyk Floeter <reyk@openbsd.org>
@@ -413,24 +413,41 @@ relay_read_http(struct bufferevent *bev, void *arg)
 
                        if (desc->http_method != HTTP_METHOD_NONE &&
                            strcasecmp("Content-Length", key) == 0) {
-                               /*
-                                * These methods should not have a body
-                                * and thus no Content-Length header.
-                                */
-                               if (desc->http_method == HTTP_METHOD_TRACE ||
-                                   desc->http_method == HTTP_METHOD_CONNECT) {
+                               switch (desc->http_method) {
+                               case HTTP_METHOD_TRACE:
+                               case HTTP_METHOD_CONNECT:
+                                       /*
+                                        * These methods should not have a body
+                                        * and thus no Content-Length header.
+                                        */
                                        relay_abort_http(con, 400, "malformed",
                                            0);
                                        goto abort;
-                               }
-                               /*
-                                * HEAD responses may provide a Content-Length
-                                * header, but if so it should just be ignored,
-                                * since there is no actual payload in the
-                                * response.
-                                */
-                               if (desc->http_method != HTTP_METHOD_RESPONSE
-                                   || request_method != HTTP_METHOD_HEAD) {
+                               case HTTP_METHOD_GET:
+                               case HTTP_METHOD_HEAD:
+                               case HTTP_METHOD_COPY:
+                               case HTTP_METHOD_MOVE:
+                                       /*
+                                        * We strip the body (if present) from
+                                        * the GET, HEAD, COPY and MOVE methods
+                                        * so strip Content-Length too.
+                                        */
+                                       kv_delete(&desc->http_headers,
+                                           desc->http_lastheader);
+                                       break;
+                               case HTTP_METHOD_RESPONSE:
+                                       /*
+                                        * Strip Content-Length header from
+                                        * HEAD responses since there is no
+                                        * actual payload in the response.
+                                        */
+                                       if (request_method == HTTP_METHOD_HEAD) {
+                                               kv_delete(&desc->http_headers,
+                                                   desc->http_lastheader);
+                                               break;
+                                       }
+                                       /* FALLTHROUGH */
+                               default:
                                        /*
                                         * Need to read data from the client
                                         * after the HTTP header.
@@ -450,6 +467,7 @@ relay_read_http(struct bufferevent *bev, void *arg)
                                                    errstr, 0);
                                                goto abort;
                                        }
+                                       break;
                                }
                                /*
                                 * Response with a status code of 1xx