On Sat, 25 Jan 2025 15:16:47 -0500
Jon Maloy <jmaloy(a)redhat.com> wrote:
Bug #93 states that a connect() will hang if the
remote port of a
connection setup doesn't exist. The remote host will respond with
the (RST | SYN | ACK) flags set, but we only relay the RST flag back
to the local user. This causes the situation described above.
Thanks for looking into this.
We now add a check if the reset happens in the
connection state
TAP_SYN_RCVD, in which case we add the missing (SYN | ACK) flags.
This solves the problem.
I guess that, actually, this part of the problem (or the whole bug #93?
I'm not sure) was solved by commit db2c91ae86c7 ("tcp: Set ACK flag on
*all* RST segments, even for client in SYN-SENT state").
Signed-off-by: Jon Maloy <jmaloy(a)redhat.com>
---
tcp.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/tcp.c b/tcp.c
index c89f323..46df6bd 100644
--- a/tcp.c
+++ b/tcp.c
@@ -1199,9 +1199,14 @@ static int tcp_send_flag(const struct ctx *c, struct tcp_tap_conn
*conn,
*/
void tcp_rst_do(const struct ctx *c, struct tcp_tap_conn *conn)
{
+ int flags = RST;
+
if (conn->events == CLOSED)
return;
+ if (conn->events == TAP_SYN_RCVD)
+ flags |= SYN | ACK;
+
...flags is not used, though. Could it be that you tested this after
rebasing on top of db2c91ae86c7?
if (!tcp_send_flag(c, conn, RST))
conn_event(c, conn, CLOSED);
}
--
Stefano