RE: [PATCH BlueZ 5/6] mesh: Keep canceled SAR data for at least 10 sec

[Isak Westin <karl.westin@loytec.com>]

Hi Brian,

> Hi Isak,
>
> Have you run this patch through any runtime analysis (like valgrind
> etc) to ensure it has introduced no memory leaks?
>
> I am particularily concerned with any l_timeout_remove() calls that don't immediately set the freed timer pointer to NULL, and any new
> l_timeout_create() calls that are not preceded with a check that there is not already a valid pointer occupying the seg_timeout or msg_timeout members.
>

I tested it with valgrind and found no memory leaks. However, it is perhaps anyway a better practice to use l_timeout_modify() ?
If so, I will update the patch.

> On Thu, 2022-10-06 at 16:59 +0200, Isak Westin wrote:
> > When a SAR transmission has been completed or canceled, the recipent
> > should store the block authentication values for at least 10 seconds
> > and ignore new segments with the same values during this period. See
> > MshPRFv1.0.1 section 3.5.3.4.
> > ---
> >  mesh/net.c | 30 ++++++++++++++++++++++++++++--
> >  1 file changed, 28 insertions(+), 2 deletions(-)
> >
> > diff --git a/mesh/net.c b/mesh/net.c
> > index 379a6e250..e95ae5114 100644
> > --- a/mesh/net.c
> > +++ b/mesh/net.c
> > @@ -46,6 +46,7 @@
> >
> >  #define SEG_TO 2
> >  #define MSG_TO 60
> > +#define SAR_DEL        10
> >
> >  #define DEFAULT_TRANSMIT_COUNT         1
> >  #define DEFAULT_TRANSMIT_INTERVAL      100
> > @@ -166,6 +167,7 @@ struct mesh_sar {
> >         bool segmented;
> >         bool frnd;
> >         bool frnd_cred;
> > +       bool delete;
> >         uint8_t ttl;
> >         uint8_t last_seg;
> >         uint8_t key_aid;
> > @@ -1493,13 +1495,27 @@ static void inseg_to(struct l_timeout
> > *seg_timeout, void *user_data)  static void inmsg_to(struct l_timeout
> > *msg_timeout, void *user_data)  {
> >         struct mesh_net *net = user_data;
> > -       struct mesh_sar *sar = l_queue_remove_if(net->sar_in,
> > +       struct mesh_sar *sar = l_queue_find(net->sar_in,
> >                         match_msg_timeout, msg_timeout);
> >
> >         l_timeout_remove(msg_timeout);
> >         if (!sar)
> >                 return;
> >
> > +       if (!sar->delete) {
> > +               /*
> > +                * Incomplete timer expired, cancel SAR and start
> > +                * delete timer
> > +                */
> > +               sar->delete = true;
> > +               l_timeout_remove(sar->seg_timeout);
> > +               sar->seg_timeout = NULL;
> > +               sar->msg_timeout = l_timeout_create(SAR_DEL,
> > +                                       inmsg_to, net, NULL);
> > +               return;
> > +       }
> > +
> > +       l_queue_remove(net->sar_in, sar);
> >         sar->msg_timeout = NULL;
> >         mesh_sar_free(sar);
> >  }
> > @@ -1956,7 +1972,9 @@ static bool seg_rxed(struct mesh_net *net, bool
> > frnd, uint32_t iv_index,
> >                         /* Re-Send ACK for full msg */
> >                         send_net_ack(net, sar_in, expected);
> >                         return true;
> > -               }
> > +               } else if (sar_in->delete)
> > +                       /* Ignore canceled */
> > +                       return false;
> >         } else {
> >                 uint16_t len = MAX_SEG_TO_LEN(segN);
> >
> > @@ -1996,6 +2014,9 @@ static bool seg_rxed(struct mesh_net *net, bool
> > frnd, uint32_t iv_index,
> >                 sar_in->len = segN * MAX_SEG_LEN + size;
> >
> >         if (sar_in->flags == expected) {
> > +               /* Remove message incomplete timer */
> > +               l_timeout_remove(sar_in->msg_timeout);
> > +
> >                 /* Got it all */
> >                 send_net_ack(net, sar_in, expected);
> >
> > @@ -2006,6 +2027,11 @@ static bool seg_rxed(struct mesh_net *net, bool
> > frnd, uint32_t iv_index,
> >                 /* Kill Inter-Seg timeout */
> >                 l_timeout_remove(sar_in->seg_timeout);
> >                 sar_in->seg_timeout = NULL;
> > +
> > +               /* Start delete timer */
> > +               sar_in->delete = true;
> > +               sar_in->msg_timeout = l_timeout_create(SAR_DEL,
> > +                               inmsg_to, net, NULL);
> >                 return true;
> >         }
> >
>
>