Hi Michal,
On Thu, 2020-01-09 at 22:00 +0100, Michał Lowas-Rzechonek wrote:
> Hi Inga,
>
> On 01/09, Inga Stotland wrote:
> > When responding with NetKey List Status, packed NetKey indices into
> > 3 octets per pair. If number of NetKeys is odd, append the last key
> > index as a 2-octet value.
> > ---
> > mesh/net.c | 36 ++++++++++++++++++++++++++++--------
> > 1 file changed, 28 insertions(+), 8 deletions(-)
> >
> > diff --git a/mesh/net.c b/mesh/net.c
> > index 0a4d2e72c..90ebdf496 100644
> > --- a/mesh/net.c
> > +++ b/mesh/net.c
> > @@ -1065,26 +1065,46 @@ bool mesh_net_get_key(struct mesh_net *net,
> > bool new_key, uint16_t idx,
> > bool mesh_net_key_list_get(struct mesh_net *net, uint8_t *buf,
> > uint16_t *size)
> > {
> > const struct l_queue_entry *entry;
> > - uint16_t n, buf_size;
> > + uint16_t num_keys, req_size, buf_size;
> > + struct mesh_subnet *subnet;
> >
> > if (!net || !buf || !size)
> > return false;
> >
> > buf_size = *size;
> > - if (buf_size < l_queue_length(net->subnets) * 2)
> > +
> > + num_keys = l_queue_length(net->subnets);
> > + req_size = (num_keys >> 1) * 3 + (num_keys % 2) * 2;
>
> Please don't use bit shifts for division.
Why?
>
> Also, I think it's clearer to write this as:
> req_size = num_keys * 3 - num_keys % 2
>
This is not how I read the spec. We need to pack 2 key indices in 3
octets.
For example, 4 keys are packed in 6 octets and 5 keys are packed in 8
octets.
> > +
> > + if (buf_size < req_size)
> > return false;
> >
> > - n = 0;
> > - entry = l_queue_get_entries(net->subnets);
> > + *size = req_size;
> > +
> > + /* Pack NetKey indices in 3 octets */
> > + for (entry = l_queue_get_entries(net->subnets); num_keys > 1;)
> > {
> > + uint32_t idx_pair;
> >
> > - for (; entry; entry = entry->next) {
> > - struct mesh_subnet *subnet = entry->data;
> > + subnet = entry->data;
> > + idx_pair = subnet->idx;
> > + idx_pair <<= 12;
> > +
> > + subnet = entry->next->data;
> > + idx_pair += subnet->idx;
> > +
> > + l_put_le32(idx_pair, buf);
> > + buf += 3;
> > +
> > + num_keys -= 2;
> > + entry = entry->next->next;
> > + }
> >
> > + /* If odd number of NetKeys, fill in the end of the buffer */
> > + if (num_keys % 2) {
> > + subnet = entry->data;
> > l_put_le16(subnet->idx, buf);
> > - n += 2;
> > }
> >
> > - *size = n;
> > return true;
> > }
>
> Tested-by: Michał Lowas-Rzechonek <
> michal.lowas-rzechonek@xxxxxxxxxxx
> >
>
>
