On Tue, Mar 11, 2025 at 11:22 PM Wentao Liang <vulab@xxxxxxxxxxx> wrote:
>
> In sctp_sf_do_asconf(), SCTP_DISPOSITION_NOMEM error code returned
> from sctp_sf_heartbeat() represent a failure of sent HEARTBEAT. The
> return value of sctp_sf_heartbeat() needs to be checked and propagates
> to caller function.
Returning this error to the caller will only result in the packet
being discarded, without reverting any changes already made in
sctp_sf_do_asconf().
Moreover, this error is not fatal. Instead, it serves as an
optimization to confirm the new destination as quickly as possible,
as introduced in:
commit 6af29ccc223b0feb6fc6112281c3fa3cdb1afddf
Author: Michio Honda <micchie@xxxxxxxxxxxxxx>
Date: Thu Jun 16 17:14:34 2011 +0900
sctp: Bundle HEAERTBEAT into ASCONF_ACK
Ignoring this error is entirely reasonable, especially considering
that running out of memory (nomem) is an unlikely scenario.
Thanks.
>
> Signed-off-by: Wentao Liang <vulab@xxxxxxxxxxx>
> ---
> net/sctp/sm_statefuns.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
> index a0524ba8d787..89100546670a 100644
> --- a/net/sctp/sm_statefuns.c
> +++ b/net/sctp/sm_statefuns.c
> @@ -3973,8 +3973,10 @@ enum sctp_disposition sctp_sf_do_asconf(struct net *net,
> asconf_ack->dest = chunk->source;
> sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
> if (asoc->new_transport) {
> - sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport, commands);
> - ((struct sctp_association *)asoc)->new_transport = NULL;
> + if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport, commands)) {
> + ((struct sctp_association *)asoc)->new_transport = NULL;
> + return SCTP_DISPOSITION_NOMEM;
> + }
> }
>
> return SCTP_DISPOSITION_CONSUME;
> --
> 2.42.0.windows.2
>
