On 19 October 2018 at 04:22, Jason Wang <jasow...@redhat.com> wrote:
> From: Zhang Chen <zhangc...@gmail.com>
>
> We add almost full TCP state machine in filter-rewriter, except
> TCPS_LISTEN and some simplify in VM active close FIN states.
> The reason for this simplify job is because guest kernel will track
> the TCP status and wait 2MSL time too, if client resend the FIN packet,
> guest will resend the last ACK, so we needn't wait 2MSL time in
> filter-rewriter.
>
> After a net connection is closed, we didn't clear its related resources
> in connection_track_table, which will lead to memory leak.
>
> Let's track the state of net connection, if it is closed, its related
> resources will be cleared up.
Hi. Coverity (CID 1396477) points out that here:
> + /*
> + * Active close step 2.
> + */
> + if (conn->tcp_state == TCPS_FIN_WAIT_1) {
> + conn->tcp_state = TCPS_TIME_WAIT;
...this assignment to conn->tcp_state has no effect, because...
> + /*
> + * For simplify implementation, we needn't wait 2MSL time
> + * in filter rewriter. Because guest kernel will track the
> + * TCP status and wait 2MSL time, if client resend the FIN
> + * packet, guest will apply the last ACK too.
> + */
> + conn->tcp_state = TCPS_CLOSED;
...we immediately overwrite it with a different value.
> + g_hash_table_remove(rf->connection_track_table, key);
> + }
> }
What was the intention of the code here?
thanks
-- PMM
