A recently reported podman bug shows transfer failures in podman custom rootless networks connected with pasta. Analysis suggests this is triggered by pasta generating a TCP packet without the ACK flag when it should have one. The exact symptoms seem to arise because of some odd kernel behaviour - rather than simply ignoring the packet, an RST is observed killing the connection. However, there are also packets seen after the RST which don't seem to make sense. While there are some mysteries which we still hope to track down here, in the meantime it definitely seems like pasta's ACK behaviour isn't correct, and appears to trigger the other problems. So, fix it. Link: https://github.com/containers/podman/issues/22146 Link: https://bugs.passt.top/show_bug.cgi?id=84 David Gibson (4): tcp: Split handling of DUP_ACK from ACK tcp: Rearrange logic for setting ACK flag in tcp_send_flag() tcp: Never automatically add the ACK flag to RST packets tcp: Unconditionally force ACK for all !SYN, !RST packets tcp.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) -- 2.44.0