Bluetooth: A2MP: Process A2MP messages

Implement basic processing for AMP Manager Protocol (A2MP).

Example below shows processing unrecognized command.
...
> ACL data: handle 11 flags 0x02 dlen 12
    A2MP: code 0x00 ident 3 len 0
< ACL data: handle 11 flags 0x00 dlen 14
    A2MP: Command Reject: reason (0) - Command not recognized
...

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

diff --git a/net/bluetooth/a2mp.c b/net/bluetooth/a2mp.c
index f7c710c..0726c9f 100644 (file)
--- a/net/bluetooth/a2mp.c
+++ b/net/bluetooth/a2mp.c
@@ -63,6 +63,70 @@ static void a2mp_send(struct amp_mgr *mgr, u8 code, u8 ident, u16 len,
        kfree(cmd);
 }
 
+/* Handle A2MP signalling */
+static int a2mp_chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
+{
+       struct a2mp_cmd *hdr = (void *) skb->data;
+       struct amp_mgr *mgr = chan->data;
+       int err = 0;
+
+       amp_mgr_get(mgr);
+
+       while (skb->len >= sizeof(*hdr)) {
+               struct a2mp_cmd *hdr = (void *) skb->data;
+               u16 len = le16_to_cpu(hdr->len);
+
+               BT_DBG("code 0x%02x id %d len %d", hdr->code, hdr->ident, len);
+
+               skb_pull(skb, sizeof(*hdr));
+
+               if (len > skb->len || !hdr->ident) {
+                       err = -EINVAL;
+                       break;
+               }
+
+               mgr->ident = hdr->ident;
+
+               switch (hdr->code) {
+               case A2MP_COMMAND_REJ:
+               case A2MP_DISCOVER_REQ:
+               case A2MP_CHANGE_NOTIFY:
+               case A2MP_GETINFO_REQ:
+               case A2MP_GETAMPASSOC_REQ:
+               case A2MP_CREATEPHYSLINK_REQ:
+               case A2MP_DISCONNPHYSLINK_REQ:
+               case A2MP_CHANGE_RSP:
+               case A2MP_DISCOVER_RSP:
+               case A2MP_GETINFO_RSP:
+               case A2MP_GETAMPASSOC_RSP:
+               case A2MP_CREATEPHYSLINK_RSP:
+               case A2MP_DISCONNPHYSLINK_RSP:
+               default:
+                       BT_ERR("Unknown A2MP sig cmd 0x%2.2x", hdr->code);
+                       err = -EINVAL;
+                       break;
+               }
+       }
+
+       if (err) {
+               struct a2mp_cmd_rej rej;
+               rej.reason = __constant_cpu_to_le16(0);
+
+               BT_DBG("Send A2MP Rej: cmd 0x%2.2x err %d", hdr->code, err);
+
+               a2mp_send(mgr, A2MP_COMMAND_REJ, hdr->ident, sizeof(rej),
+                         &rej);
+       }
+
+       /* Always free skb and return success error code to prevent
+          from sending L2CAP Disconnect over A2MP channel */
+       kfree_skb(skb);
+
+       amp_mgr_put(mgr);
+
+       return 0;
+}
+
 static void a2mp_chan_close_cb(struct l2cap_chan *chan)
 {
        l2cap_chan_destroy(chan);
@@ -112,6 +176,7 @@ static void a2mp_chan_no_ready(struct l2cap_chan *chan)
 
 static struct l2cap_ops a2mp_chan_ops = {
        .name = "L2CAP A2MP channel",
+       .recv = a2mp_chan_recv_cb,
        .close = a2mp_chan_close_cb,
        .state_change = a2mp_chan_state_change_cb,
        .alloc_skb = a2mp_chan_alloc_skb_cb,