[RFCv4 18/30] Bluetooth: A2MP: Process A2MP Discover Request

Andrei Emeltchenko
2012-03-15T12:30:09Z

Process A2MP Discover Request, code makes sure that first
controller in the list is BREDR one. Trace is shown below:
...
> ACL data: handle 11 flags 0x02 dlen 16
A2MP: Discover req: mtu/mps 670 mask: 0x0000
< ACL data: handle 11 flags 0x00 dlen 19
A2MP: Discover rsp: mtu/mps 670 mask: 0x0000
Controller list:
id 0, type 0, status 0x01 (Bluetooth only)
...

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
---
include/net/bluetooth/a2mp.h | 2 +
net/bluetooth/a2mp.c | 55 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 57 insertions(+), 0 deletions(-)

diff --git a/include/net/bluetooth/a2mp.h b/include/net/bluetooth/a2mp.h
index c99c375..a748ab0 100644
--- a/include/net/bluetooth/a2mp.h
+++ b/include/net/bluetooth/a2mp.h
@@ -15,6 +15,8 @@
#ifndef __A2MP_H
#define __A2MP_H

+#define A2MP_FEAT_EXT 0x8000
+
struct amp_mgr {
struct list_head list;
struct l2cap_conn *l2cap_conn;
diff --git a/net/bluetooth/a2mp.c b/net/bluetooth/a2mp.c
index ac5084c..612df03 100644
--- a/net/bluetooth/a2mp.c
+++ b/net/bluetooth/a2mp.c
@@ -111,6 +111,58 @@ static inline int a2mp_command_rej(struct amp_mgr *mgr, struct sk_buff *skb,
return 0;
}

+static inline int a2mp_discover_req(struct amp_mgr *mgr, struct sk_buff *skb,
+ struct a2mp_cmd *hdr)
+{
+ struct a2mp_discov_req *req = (struct a2mp_discov_req *)skb->data;
+ struct a2mp_discov_rsp *rsp;
+ u16 ext_feat;
+ size_t len;
+ u8 num_ctrl;
+
+ if (le16_to_cpu(hdr->len) < sizeof(*req))
+ return -EINVAL;
+
+ skb_pull(skb, sizeof(*req));
+
+ BT_DBG("mtu %d efm 0x%4.4x", le16_to_cpu(req->mtu),
+ le16_to_cpu(req->ext_feat));
+
+ ext_feat = le16_to_cpu(req->ext_feat);
+
+ /* check that packet is not broken for now */
+ while (ext_feat & A2MP_FEAT_EXT) {
+ if (skb->len < sizeof(ext_feat))
+ return -EINVAL;
+
+ ext_feat = get_unaligned_le16(skb->data);
+ BT_DBG("ext_feat 0x%4.4x", le16_to_cpu(req->ext_feat));
+ skb_pull(skb, sizeof(ext_feat));
+ }
+
+ read_lock(&hci_dev_list_lock);
+
+ num_ctrl = __hci_num_ctrl();
+ len = num_ctrl * sizeof(struct a2mp_cl) + sizeof(*rsp);
+ rsp = kmalloc(len, GFP_ATOMIC);
+ if (!rsp) {
+ read_unlock(&hci_dev_list_lock);
+ return -ENOMEM;
+ }
+
+ rsp->mtu = cpu_to_le16(L2CAP_A2MP_DEFAULT_MTU);
+ rsp->ext_feat = 0;
+
+ __a2mp_add_cl(mgr, rsp->cl, num_ctrl);
+
+ read_unlock(&hci_dev_list_lock);
+
+ a2mp_send(mgr, A2MP_DISCOVER_RSP, hdr->ident, len, rsp);
+
+ kfree(rsp);
+ return 0;
+}
+
/* Handle A2MP signalling */
static int a2mp_chan_recv_cb(void *data, struct sk_buff *skb)
{
@@ -141,6 +193,9 @@ static int a2mp_chan_recv_cb(void *data, struct sk_buff *skb)
break;

case A2MP_DISCOVER_REQ:
+ err = a2mp_discover_req(mgr, skb, hdr);
+ break;
+
case A2MP_CHANGE_NOTIFY:
case A2MP_GETINFO_REQ:
case A2MP_GETAMPASSOC_REQ:
--
1.7.9.1