http: return more than data from server app

Server app could return headers in front of body/data buffer.
Offers apis for building and serialization of headers section.
HTTP layer now only add Date, Server and Content-Lengths headers,
rest is up to app. Well known header names are predefined.

Type: improvement

Change-Id: If778bdfc9acf6b0d11a48f0a745a3a56c96c2436
Signed-off-by: Matus Fabian <matfabia@cisco.com>

4 files changed, 97 insertions, 26 deletions

diff --git a/src/plugins/http_static/builtinurl/json_urls.c b/src/plugins/http_static/builtinurl/json_urls.c
index 8578be147f3..19c5245e4b2 100644
--- a/src/plugins/http_static/builtinurl/json_urls.c
+++ b/src/plugins/http_static/builtinurl/json_urls.c
@@ -45,6 +45,7 @@ handle_get_version (hss_url_handler_args_t *args)
 
   args->data = s;
   args->data_len = vec_len (s);
+  args->ct = HTTP_CONTENT_APP_JSON;
   args->free_vec_data = 1;
   return HSS_URL_HANDLER_OK;
 }
@@ -117,6 +118,7 @@ handle_get_interface_stats (hss_url_handler_args_t *args)
 out:
   args->data = s;
   args->data_len = vec_len (s);
+  args->ct = HTTP_CONTENT_APP_JSON;
   args->free_vec_data = 1;
   vec_free (sw_if_indices);
   vec_free (stats);
@@ -157,6 +159,7 @@ handle_get_interface_list (hss_url_handler_args_t *args)
 
   args->data = s;
   args->data_len = vec_len (s);
+  args->ct = HTTP_CONTENT_APP_JSON;
   args->free_vec_data = 1;
   return HSS_URL_HANDLER_OK;
 }
diff --git a/src/plugins/http_static/http_cache.c b/src/plugins/http_static/http_cache.c
index 8b9751b7f78..7a069dace00 100644
--- a/src/plugins/http_static/http_cache.c
+++ b/src/plugins/http_static/http_cache.c
@@ -421,19 +421,19 @@ format_hss_cache (u8 *s, va_list *args)
     {
       s = format (s, "cache size %lld bytes, limit %lld bytes, evictions %lld",
 		  hc->cache_size, hc->cache_limit, hc->cache_evictions);
-      return 0;
+      return s;
     }
 
   vm = vlib_get_main ();
   now = vlib_time_now (vm);
 
-  s = format (s, "%U", format_hss_cache_entry, 0 /* header */, now);
+  s = format (s, "%U\n", format_hss_cache_entry, 0 /* header */, now);
 
   for (index = hc->first_index; index != ~0;)
     {
       ce = pool_elt_at_index (hc->cache_pool, index);
       index = ce->next_index;
-      s = format (s, "%U", format_hss_cache_entry, ce, now);
+      s = format (s, "%U\n", format_hss_cache_entry, ce, now);
     }
 
   s = format (s, "%40s%12lld", "Total Size", hc->cache_size);
diff --git a/src/plugins/http_static/http_static.h b/src/plugins/http_static/http_static.h
index 8f336e83d58..4c22e1d7ed7 100644
--- a/src/plugins/http_static/http_static.h
+++ b/src/plugins/http_static/http_static.h
@@ -50,8 +50,10 @@ typedef struct
   int free_data;
   /** File cache pool index */
   u32 cache_pool_index;
-  /** Content type, e.g. text, text/javascript, etc. */
-  http_content_type_t content_type;
+  /** Response header list */
+  http_header_t *resp_headers;
+  /** Serialized headers to send */
+  u8 *headers_buf;
 } hss_session_t;
 
 typedef struct hss_session_handle_
@@ -91,6 +93,7 @@ typedef struct hss_url_handler_args_
       uword data_len;
       u8 free_vec_data;
       http_status_code_t sc;
+      http_content_type_t ct;
     };
   };
 } hss_url_handler_args_t;
diff --git a/src/plugins/http_static/static_server.c b/src/plugins/http_static/static_server.c
index 26224989332..bc18875626e 100644
--- a/src/plugins/http_static/static_server.c
+++ b/src/plugins/http_static/static_server.c
@@ -19,6 +19,9 @@
 #include <sys/stat.h>
 #include <unistd.h>
 
+#include <http/http_header_names.h>
+#include <http/http_content_types.h>
+
 /** @file static_server.c
  *  Static http server, sufficient to serve .html / .css / .js content.
  */
@@ -83,34 +86,65 @@ start_send_data (hss_session_t *hs, http_status_code_t status)
 {
   http_msg_t msg;
   session_t *ts;
+  u8 *headers_buf = 0;
   int rv;
 
   ts = session_get (hs->vpp_session_index, hs->thread_index);
 
+  if (vec_len (hs->resp_headers))
+    {
+      headers_buf = http_serialize_headers (hs->resp_headers);
+      vec_free (hs->resp_headers);
+      msg.data.headers_offset = 0;
+      msg.data.headers_len = vec_len (headers_buf);
+    }
+  else
+    {
+      msg.data.headers_offset = 0;
+      msg.data.headers_len = 0;
+    }
+
   msg.type = HTTP_MSG_REPLY;
   msg.code = status;
-  msg.content_type = hs->content_type;
-  msg.data.len = hs->data_len;
+  msg.data.body_len = hs->data_len;
+  msg.data.len = msg.data.body_len + msg.data.headers_len;
 
-  if (hs->data_len > hss_main.use_ptr_thresh)
+  if (msg.data.len > hss_main.use_ptr_thresh)
     {
       msg.data.type = HTTP_MSG_DATA_PTR;
       rv = svm_fifo_enqueue (ts->tx_fifo, sizeof (msg), (u8 *) &msg);
       ASSERT (rv == sizeof (msg));
 
+      if (msg.data.headers_len)
+	{
+	  hs->headers_buf = headers_buf;
+	  uword headers = pointer_to_uword (hs->headers_buf);
+	  rv =
+	    svm_fifo_enqueue (ts->tx_fifo, sizeof (headers), (u8 *) &headers);
+	  ASSERT (rv == sizeof (headers));
+	}
+
       uword data = pointer_to_uword (hs->data);
       rv = svm_fifo_enqueue (ts->tx_fifo, sizeof (data), (u8 *) &data);
-      ASSERT (rv == sizeof (sizeof (data)));
+      ASSERT (rv == sizeof (data));
 
       goto done;
     }
 
   msg.data.type = HTTP_MSG_DATA_INLINE;
+  msg.data.body_offset = msg.data.headers_len;
 
   rv = svm_fifo_enqueue (ts->tx_fifo, sizeof (msg), (u8 *) &msg);
   ASSERT (rv == sizeof (msg));
 
-  if (!msg.data.len)
+  if (msg.data.headers_len)
+    {
+      rv = svm_fifo_enqueue (ts->tx_fifo, vec_len (headers_buf), headers_buf);
+      ASSERT (rv == msg.data.headers_len);
+      vec_free (headers_buf);
+    }
+
+  if (!msg.data.body_len)
     goto done;
 
   rv = svm_fifo_enqueue (ts->tx_fifo, hs->data_len, hs->data);
@@ -142,6 +176,15 @@ hss_session_send_data (hss_url_handler_args_t *args)
   hs->data = args->data;
   hs->data_len = args->data_len;
   hs->free_data = args->free_vec_data;
+
+  /* Set content type only if we have some response data */
+  if (hs->data_len)
+    {
+      http_add_header (&hs->resp_headers,
+		       http_header_name_token (HTTP_HEADER_CONTENT_TYPE),
+		       http_content_type_token (args->ct));
+    }
+
   start_send_data (hs, args->sc);
 }
 
@@ -217,7 +260,6 @@ try_url_handler (hss_main_t *hsm, hss_session_t *hs, http_req_method_t rt,
   http_status_code_t sc = HTTP_STATUS_OK;
   hss_url_handler_args_t args = {};
   uword *p, *url_table;
-  http_content_type_t type;
   int rv;
 
   if (!hsm->enable_url_handlers || !target_path)
@@ -229,8 +271,6 @@ try_url_handler (hss_main_t *hsm, hss_session_t *hs, http_req_method_t rt,
       target_path = format (target_path, "index.html");
     }
 
-  type = content_type_from_request (target_path);
-
   /* Look for built-in GET / POST handlers */
   url_table =
     (rt == HTTP_REQ_GET) ? hsm->get_url_handlers : hsm->post_url_handlers;
@@ -263,17 +303,24 @@ try_url_handler (hss_main_t *hsm, hss_session_t *hs, http_req_method_t rt,
     {
       clib_warning ("builtin handler %llx hit on %s '%s' but failed!", p[0],
 		    (rt == HTTP_REQ_GET) ? "GET" : "POST", target_path);
-      sc = HTTP_STATUS_NOT_FOUND;
+      sc = HTTP_STATUS_BAD_GATEWAY;
     }
 
   hs->data = args.data;
   hs->data_len = args.data_len;
   hs->free_data = args.free_vec_data;
-  hs->content_type = type;
+
+  /* Set content type only if we have some response data */
+  if (hs->data_len)
+    {
+      http_add_header (&hs->resp_headers,
+		       http_header_name_token (HTTP_HEADER_CONTENT_TYPE),
+		       http_content_type_token (args.ct));
+    }
 
   start_send_data (hs, sc);
 
-  if (!hs->data)
+  if (!hs->data_len)
     hss_session_disconnect_transport (hs);
 
   return 0;
@@ -337,18 +384,20 @@ try_index_file (hss_main_t *hsm, hss_session_t *hs, u8 *path)
     }
 
   redirect =
-    format (0,
-	    "Location: http%s://%U%s%s\r\n\r\n",
-	    proto == TRANSPORT_PROTO_TLS ? "s" : "", format_ip46_address,
-	    &endpt.ip, endpt.is_ip4, print_port ? port_str : (u8 *) "", path);
+    format (0, "http%s://%U%s%s", proto == TRANSPORT_PROTO_TLS ? "s" : "",
+	    format_ip46_address, &endpt.ip, endpt.is_ip4,
+	    print_port ? port_str : (u8 *) "", path);
 
   if (hsm->debug_level > 0)
     clib_warning ("redirect: %s", redirect);
 
   vec_free (port_str);
 
-  hs->data = redirect;
-  hs->data_len = vec_len (redirect);
+  http_add_header (&hs->resp_headers,
+		   http_header_name_token (HTTP_HEADER_LOCATION),
+		   (const char *) redirect, vec_len (redirect));
+  hs->data = redirect; /* TODO: find better way  */
+  hs->data_len = 0;
   hs->free_data = 1;
 
   return HTTP_STATUS_MOVED;
@@ -367,8 +416,6 @@ try_file_handler (hss_main_t *hsm, hss_session_t *hs, http_req_method_t rt,
   if (!hsm->www_root)
     return -1;
 
-  type = content_type_from_request (target);
-
   /* Remove dot segments to prevent path traversal */
   sanitized_path = http_path_remove_dot_segments (target);
 
@@ -420,11 +467,23 @@ try_file_handler (hss_main_t *hsm, hss_session_t *hs, http_req_method_t rt,
   hs->path = path;
   hs->cache_pool_index = ce_index;
 
+  /* Set following headers only for happy path:
+   * Content-Type
+   * Cache-Control max-age
+   */
+  type = content_type_from_request (target);
+  http_add_header (&hs->resp_headers,
+		   http_header_name_token (HTTP_HEADER_CONTENT_TYPE),
+		   http_content_type_token (type));
+  /* TODO configurable max-age value */
+  http_add_header (&hs->resp_headers,
+		   http_header_name_token (HTTP_HEADER_CACHE_CONTROL),
+		   http_token_lit ("max-age=600"));
+
 done:
   vec_free (sanitized_path);
-  hs->content_type = type;
   start_send_data (hs, sc);
-  if (!hs->data)
+  if (!hs->data_len)
     hss_session_disconnect_transport (hs);
 
   return 0;
@@ -459,6 +518,8 @@ hss_ts_rx_callback (session_t *ts)
   if (hs->free_data)
     vec_free (hs->data);
   hs->data = 0;
+  hs->resp_headers = 0;
+  vec_free (hs->headers_buf);
 
   /* Read the http message header */
   rv = svm_fifo_dequeue (ts->rx_fifo, sizeof (msg), (u8 *) &msg);
@@ -467,6 +528,9 @@ hss_ts_rx_callback (session_t *ts)
   if (msg.type != HTTP_MSG_REQUEST ||
       (msg.method_type != HTTP_REQ_GET && msg.method_type != HTTP_REQ_POST))
     {
+      http_add_header (&hs->resp_headers,
+		       http_header_name_token (HTTP_HEADER_ALLOW),
+		       http_token_lit ("GET, POST"));
       start_send_data (hs, HTTP_STATUS_METHOD_NOT_ALLOWED);
       goto done;
     }
@@ -648,6 +712,7 @@ hss_ts_cleanup (session_t *s, session_cleanup_ntf_t ntf)
   hs->data = 0;
   hs->data_offset = 0;
   hs->free_data = 0;
+  vec_free (hs->headers_buf);
   vec_free (hs->path);
 
   hss_session_free (hs);