From: Florin Coras <fcoras@cisco.com>
Date: Mon, 14 Apr 2025 02:50:51 +0000 (-0400)
Subject: tcp: remove erroneous exception seg check assert
X-Git-Tag: v25.10-rc0~94
X-Git-Url: https://gerrit.fd.io/r/gitweb?a=commitdiff_plain;h=f1db04c543bbf1ba5acbe76bae1e848b6b610e62;p=vpp.git

tcp: remove erroneous exception seg check assert

Type: fix

Change-Id: Ic3ae960e8f4a28f96b9964f6a3bd60379dd3795f
Signed-off-by: Florin Coras <fcoras@cisco.com>
---

diff --git a/src/vnet/tcp/tcp_input.c b/src/vnet/tcp/tcp_input.c
index 2d43cf0f01f..7977a6c0a6e 100644
--- a/src/vnet/tcp/tcp_input.c
+++ b/src/vnet/tcp/tcp_input.c
@@ -1361,10 +1361,9 @@ tcp_established_trace_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
 always_inline int
 tcp_segment_is_exception (tcp_connection_t *tc, tcp_header_t *th)
 {
-  /* TODO(fcoras): tcp-input should not allow segments without one of ack, rst,
-   * syn flags, so we shouldn't be checking for their presence. Leave the check
-   * in for now, remove in due time */
-  ASSERT (th->flags & (TCP_FLAG_ACK | TCP_FLAG_RST | TCP_FLAG_SYN));
+  /* tcp-input allows through segments without ack, e.g., fin without ack,
+   * which have to be handled as exception in nodes like established. So
+   * flags must be checked */
   return !tc || tc->state == TCP_STATE_CLOSED ||
 	 !(th->flags & (TCP_FLAG_ACK | TCP_FLAG_RST | TCP_FLAG_SYN));
 }