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)
+{
+ 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;
+}
+
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:
--
1.7.9.5
--
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