Hi Syam,
> Dynamic PSM choosen by the kernel should bound to either BDADDR_ANY
> or the same adapter address(not both) for a particular adapter.
>
> The problem here is by giving PSM 0, the kernel should return the first
> available PSM in the non-reserverd space, but since we reuse the same
> code to do the matching it end up given both Obexd and HDP the same
> PSM.
>
> Provid a helper function to handle the dymanic PSM auto selection.
>
> Signed-off-by: Syam Sidhardhan <s.syam@xxxxxxxxxxx>
> ---
> net/bluetooth/l2cap_core.c | 55 ++++++++++++++++++++++++++++++++++++--------
> 1 file changed, 46 insertions(+), 9 deletions(-)
>
> diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> index d42cdb1..33b5d34 100644
> --- a/net/bluetooth/l2cap_core.c
> +++ b/net/bluetooth/l2cap_core.c
> @@ -119,6 +119,43 @@ static struct l2cap_chan *__l2cap_global_chan_by_addr(__le16 psm, bdaddr_t *src)
> return NULL;
> }
>
> +/* Returns free dynamic PSM */
> +static u16 __l2cap_global_get_dyna_chan_by_addr(bdaddr_t *src)
> +{
this is a bad name. No idea what kind of meaning "dyna" has.
And btw. there is no such thing as dynamic PSM. It has nothing dynamic
about it. It is an auto-selected PSM. And in the end, it just selects
the next free one.
> + struct l2cap_chan *c;
> + u16 p;
> + bool found;
> +
> + for (p = 0x1001; p < 0x1100; p += 2) {
> + found = false;
> +
> + list_for_each_entry(c, &chan_list, global_l) {
> + if (c->sport != p)
> + continue;
> +
> + /* PSM match found */
> + found = true;
> +
> + /* Exact match */
> + if (!bacmp(&bt_sk(c->sk)->src, src))
> + break;
> +
> + /* BDADDR_ANY match */
> + if (!bacmp(&bt_sk(c->sk)->src, BDADDR_ANY) ||
> + !bacmp(src, BDADDR_ANY))
> + break;
> +
> + /* Match found only for other adapter address */
> + return p;
> + }
> +
> + if (!found)
> + return p;
> + }
> +
> + return 0;
> +}
> +
This code needs a comment on how it is suppose to work and why it is
correct.
> int l2cap_add_psm(struct l2cap_chan *chan, bdaddr_t *src, __le16 psm)
> {
> int err;
> @@ -135,16 +172,16 @@ int l2cap_add_psm(struct l2cap_chan *chan, bdaddr_t *src, __le16 psm)
> chan->sport = psm;
> err = 0;
> } else {
> - u16 p;
> -
> + /* No PSM given by user space */
> + u16 dpsm;
> err = -EINVAL;
> - for (p = 0x1001; p < 0x1100; p += 2)
> - if (!__l2cap_global_chan_by_addr(cpu_to_le16(p), src)) {
> - chan->psm = cpu_to_le16(p);
> - chan->sport = cpu_to_le16(p);
> - err = 0;
> - break;
> - }
> +
> + dpsm = __l2cap_global_get_dyna_chan_by_addr(src);
> + if (dpsm) {
> + chan->psm = dpsm;
> + chan->sport = dpsm;
> + err = 0;
> + }
> }
>
> done:
Regards
Marcel
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