MEDIUM: htx: Add a flag on a HTX message when no more data are expected

The HTX_FL_EOI flag must now be set on a HTX message when no more data are
expected. Most of time, it must be set before adding the EOM block. Thus, if
there is no space for the EOM, there is still an information to know all data
were received and pushed in the HTX message. There is only an exception for the
HTTP replies (deny, return...). For these messages, the flag is set after all
blocks are pushed in the message, including the EOM block, because, on error,
we remove all inserted data.

include/haproxy/htx-t.h

@@ -145,7 +145,9 @@
 #define HTX_FL_PROCESSING_ERROR  0x00000002 /* Set when a processing error occurred */
 #define HTX_FL_UPGRADE           0x00000004 /* Set when an upgrade is in progress */
 #define HTX_FL_PROXY_RESP        0x00000008 /* Set when the response was generated by HAProxy */
-
+#define HTX_FL_EOI               0x00000010 /* Set when end-of-input is reached from the HTX point of view
+					     * (at worst, on the EOM block is missing)
+					     */
 
 /* HTX block's type (max 15). */
 enum htx_blk_type {

include/haproxy/htx.h

@@ -585,6 +585,15 @@ static inline int htx_is_not_empty(const struct htx *htx)
 	return (htx->head != -1);
 }
 
+/* Returns 1 if no more data are expected for the message <htx>. Otherwise it
+ * returns 0. Note that it is illegal to call this with htx == NULL. Note also
+ * the EOM block may be missing.
+ */
+static inline int htx_expect_more(const struct htx *htx)
+{
+	return !(htx->flags & HTX_FL_EOI);
+}
+
 /* Copy an HTX message stored in the buffer <msg> to <htx>. We take care to
  * not overwrite existing data. All the message is copied or nothing. It returns
  * 1 on success and 0 on error.

src/cache.c

@@ -926,6 +926,7 @@ static void http_cache_io_handler(struct appctx *appctx)
 	}
 
 	if (appctx->st0 == HTX_CACHE_EOM) {
+		res_htx->flags |= HTX_FL_EOI; /* no more data are expected. Only EOM remains to add now */
 		if (!htx_add_endof(res_htx, HTX_BLK_EOM)) {
 			si_rx_room_blk(si);
 			goto out;

src/h1_htx.c

@@ -616,6 +616,8 @@ int h1_parse_msg_eom(struct h1m *h1m, struct htx *dsthtx, size_t max)
 		dsthtx->flags |= HTX_FL_PARSING_ERROR;
 		return 0;
 	}
+
+	dsthtx->flags |= HTX_FL_EOI; /* no more data are expected. Only EOM remains to add now */
 	if (max < sizeof(struct htx_blk) + 1 || !htx_add_endof(dsthtx, HTX_BLK_EOM))
 		return 0;
 

src/hlua.c

@@ -4582,6 +4582,7 @@ __LJMP static int hlua_applet_http_send_response(lua_State *L)
 	}
 
 	/* Finalize headers. */
+	htx->flags |= HTX_FL_EOI; /* no more data are expected. Only EOM remains to add now */
 	if (!htx_add_endof(htx, HTX_BLK_EOH)) {
 		hlua_pusherror(L, "Lua applet http '%s': Failed create the response.\n",
 			       appctx->appctx->rule->arg.hlua_rule->fcn.name);

src/http_ana.c

@@ -4577,6 +4577,7 @@ int http_forward_proxy_resp(struct stream *s, int final)
 		channel_auto_close(res);
 		channel_shutr_now(res);
 		res->flags |= CF_EOI; /* The response is terminated, add EOI */
+		htxbuf(&res->buf)->flags |= HTX_FL_EOI; /* no more data are expected */
 	}
 	else {
 		/* Send ASAP informational messages. Rely on CF_EOI for final

src/mux_h2.c

@@ -4452,6 +4452,7 @@ next_frame:
 
 	if ((h2c->dff & H2_F_HEADERS_END_STREAM)) {
 		/* Mark the end of message using EOM */
+		htx->flags |= HTX_FL_EOI; /* no more data are expected. Only EOM remains to add now */
 		if (!htx_add_endof(htx, HTX_BLK_EOM)) {
 			TRACE_STATE("failed to append HTX EOM block into rxbuf", H2_EV_RX_FRAME|H2_EV_RX_HDR|H2_EV_H2S_ERR, h2c->conn);
 			goto fail;
@@ -4587,6 +4588,7 @@ try_again:
 	 */
 
 	if (h2c->dff & H2_F_DATA_END_STREAM) {
+		htx->flags |= HTX_FL_EOI; /* no more data are expected. Only EOM remains to add now */
 		if (!htx_add_endof(htx, HTX_BLK_EOM)) {
 			TRACE_STATE("h2s rxbuf is full, failed to add EOM", H2_EV_RX_FRAME|H2_EV_RX_DATA|H2_EV_H2S_BLK, h2c->conn, h2s);
 			h2c->flags |= H2_CF_DEM_SFULL;
@@ -5778,6 +5780,8 @@ static size_t h2_rcv_buf(struct conn_stream *cs, struct buffer *buf, size_t coun
 		if (htx_is_empty(buf_htx))
 			cs->flags |= CS_FL_EOI;
 	}
+	else if (htx_is_empty(h2s_htx))
+		buf_htx->flags |= (h2s_htx->flags & HTX_FL_EOI);
 
 	buf_htx->extra = (h2s_htx->extra ? (h2s_htx->data + h2s_htx->extra) : 0);
 	htx_to_buf(buf_htx, buf);

src/stats.c

@@ -3339,6 +3339,7 @@ static void http_stats_io_handler(struct appctx *appctx)
 
 	if (appctx->st0 == STAT_HTTP_DONE) {
 		/* Don't add TLR because mux-h1 will take care of it */
+		res_htx->flags |= HTX_FL_EOI; /* no more data are expected. Only EOM remains to add now */
 		if (!htx_add_endof(res_htx, HTX_BLK_EOM)) {
 			si_rx_room_blk(si);
 			goto out;

src/tcpcheck.c

@@ -1335,8 +1335,11 @@ enum tcpcheck_eval_ret tcpcheck_eval_send(struct check *check, struct tcpcheck_r
 
 
 		if (!htx_add_endof(htx, HTX_BLK_EOH) ||
-		    (istlen(body) && !htx_add_data_atonce(htx, body)) ||
-		    !htx_add_endof(htx, HTX_BLK_EOM))
+		    (istlen(body) && !htx_add_data_atonce(htx, body)))
+			goto error_htx;
+
+		htx->flags |= HTX_FL_EOI; /* no more data are expected. Only EOM remains to add now */
+		if (!htx_add_endof(htx, HTX_BLK_EOM))
 			goto error_htx;
 
 		htx_to_buf(htx, &check->bo);