out_tcp: check connection first (fluent#6208)

compose_payload allocates memory when 'format' is not 'msgpack'. It is not released when no connection is available and it causes issue fluent#6208. This patch is to change flush flow. 1. Check connection 2. Invoke compose_payload Signed-off-by: Takahiro Yamashita <[email protected]> Signed-off-by: root <[email protected]>
sumitd2 · Feb 8, 2023 · 26d8d5c · 26d8d5c
1 parent 8bee4e5
commit 26d8d5c
Showing 1 changed file with 7 additions and 6 deletions.
diff --git a/plugins/out_tcp/tcp.c b/plugins/out_tcp/tcp.c
@@ -94,12 +94,6 @@ static void cb_tcp_flush(struct flb_event_chunk *event_chunk,
     size_t out_size = 0;
     (void) i_ins;
 
-    ret = compose_payload(ctx, event_chunk->data, event_chunk->size,
-                          &out_payload, &out_size);
-    if (ret != FLB_OK) {
-        return FLB_OUTPUT_RETURN(ret);
-    }
-
     /* Get upstream context and connection */
     u = ctx->u;
     u_conn = flb_upstream_conn_get(u);
@@ -109,6 +103,13 @@ static void cb_tcp_flush(struct flb_event_chunk *event_chunk,
         FLB_OUTPUT_RETURN(FLB_RETRY);
     }
 
+    ret = compose_payload(ctx, event_chunk->data, event_chunk->size,
+                          &out_payload, &out_size);
+    if (ret != FLB_OK) {
+        flb_upstream_conn_release(u_conn);
+        return FLB_OUTPUT_RETURN(ret);
+    }
+
     if (ctx->out_format == FLB_PACK_JSON_FORMAT_NONE) {
         ret = flb_io_net_write(u_conn,
                                event_chunk->data, event_chunk->size,