Bluetooth: Move channel response

The move response command includes a result code indicating
"pending", "success", or "failure" status.  A pending result is
received when the remote address is still setting up a physical link,
and will be followed by success or failure.  On success, logical link
setup will proceed.  On failure, the move is stopped.  The receiver of
a move channel response must always follow up by sending a move
channel confirm command.

Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

1 files changed, 168 insertions, 15 deletions

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index fef0394add18..2277ed504283 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -129,6 +129,20 @@ static struct l2cap_chan *__l2cap_get_chan_by_ident(struct l2cap_conn *conn,
         return NULL;
 }
 
+static struct l2cap_chan *l2cap_get_chan_by_ident(struct l2cap_conn *conn,
+                                                  u8 ident)
+{
+        struct l2cap_chan *c;
+
+        mutex_lock(&conn->chan_lock);
+        c = __l2cap_get_chan_by_ident(conn, ident);
+        if (c)
+                l2cap_chan_lock(c);
+        mutex_unlock(&conn->chan_lock);
+
+        return c;
+}
+
 static struct l2cap_chan *__l2cap_global_chan_by_addr(__le16 psm, bdaddr_t *src)
 {
         struct l2cap_chan *c;
@@ -4185,23 +4199,34 @@ static void l2cap_send_move_chan_rsp(struct l2cap_conn *conn, u8 ident,
         l2cap_send_cmd(conn, ident, L2CAP_MOVE_CHAN_RSP, sizeof(rsp), &rsp);
 }
 
-static void l2cap_send_move_chan_cfm(struct l2cap_conn *conn,
-                                     struct l2cap_chan *chan,
-                                     u16 icid, u16 result)
+static void l2cap_send_move_chan_cfm(struct l2cap_chan *chan, u16 result)
 {
         struct l2cap_move_chan_cfm cfm;
-        u8 ident;
 
-        BT_DBG("icid 0x%4.4x, result 0x%4.4x", icid, result);
+        BT_DBG("chan %p, result 0x%4.4x", chan, result);
 
-        ident = l2cap_get_ident(conn);
-        if (chan)
-                chan->ident = ident;
+        chan->ident = l2cap_get_ident(chan->conn);
 
-        cfm.icid = cpu_to_le16(icid);
+        cfm.icid = cpu_to_le16(chan->scid);
         cfm.result = cpu_to_le16(result);
 
-        l2cap_send_cmd(conn, ident, L2CAP_MOVE_CHAN_CFM, sizeof(cfm), &cfm);
+        l2cap_send_cmd(chan->conn, chan->ident, L2CAP_MOVE_CHAN_CFM,
+                       sizeof(cfm), &cfm);
+
+        __set_chan_timer(chan, L2CAP_MOVE_TIMEOUT);
+}
+
+static void l2cap_send_move_chan_cfm_icid(struct l2cap_conn *conn, u16 icid)
+{
+        struct l2cap_move_chan_cfm cfm;
+
+        BT_DBG("conn %p, icid 0x%4.4x", conn, icid);
+
+        cfm.icid = cpu_to_le16(icid);
+        cfm.result = __constant_cpu_to_le16(L2CAP_MC_UNCONFIRMED);
+
+        l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_MOVE_CHAN_CFM,
+                       sizeof(cfm), &cfm);
 }
 
 static void l2cap_send_move_chan_cfm_rsp(struct l2cap_conn *conn, u8 ident,
@@ -4223,6 +4248,13 @@ static void __release_logical_link(struct l2cap_chan *chan)
         /* Placeholder - release the logical link */
 }
 
+static void l2cap_logical_cfm(struct l2cap_chan *chan, struct hci_chan *hchan,
+                              u8 status)
+{
+        /* Placeholder */
+        return;
+}
+
 static inline int l2cap_move_channel_req(struct l2cap_conn *conn,
                                          struct l2cap_cmd_hdr *cmd,
                                          u16 cmd_len, void *data)
@@ -4317,9 +4349,128 @@ send_move_response:
         return 0;
 }
 
-static inline int l2cap_move_channel_rsp(struct l2cap_conn *conn,
-                                         struct l2cap_cmd_hdr *cmd,
-                                         u16 cmd_len, void *data)
+static void l2cap_move_continue(struct l2cap_conn *conn, u16 icid, u16 result)
+{
+        struct l2cap_chan *chan;
+        struct hci_chan *hchan = NULL;
+
+        chan = l2cap_get_chan_by_scid(conn, icid);
+        if (!chan) {
+                l2cap_send_move_chan_cfm_icid(conn, icid);
+                return;
+        }
+
+        __clear_chan_timer(chan);
+        if (result == L2CAP_MR_PEND)
+                __set_chan_timer(chan, L2CAP_MOVE_ERTX_TIMEOUT);
+
+        switch (chan->move_state) {
+        case L2CAP_MOVE_WAIT_LOGICAL_COMP:
+                /* Move confirm will be sent when logical link
+                 * is complete.
+                 */
+                chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM;
+                break;
+        case L2CAP_MOVE_WAIT_RSP_SUCCESS:
+                if (result == L2CAP_MR_PEND) {
+                        break;
+                } else if (test_bit(CONN_LOCAL_BUSY,
+                                    &chan->conn_state)) {
+                        chan->move_state = L2CAP_MOVE_WAIT_LOCAL_BUSY;
+                } else {
+                        /* Logical link is up or moving to BR/EDR,
+                         * proceed with move
+                         */
+                        chan->move_state = L2CAP_MOVE_WAIT_CONFIRM_RSP;
+                        l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED);
+                }
+                break;
+        case L2CAP_MOVE_WAIT_RSP:
+                /* Moving to AMP */
+                if (result == L2CAP_MR_SUCCESS) {
+                        /* Remote is ready, send confirm immediately
+                         * after logical link is ready
+                         */
+                        chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM;
+                } else {
+                        /* Both logical link and move success
+                         * are required to confirm
+                         */
+                        chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_COMP;
+                }
+
+                /* Placeholder - get hci_chan for logical link */
+                if (!hchan) {
+                        /* Logical link not available */
+                        l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
+                        break;
+                }
+
+                /* If the logical link is not yet connected, do not
+                 * send confirmation.
+                 */
+                if (hchan->state != BT_CONNECTED)
+                        break;
+
+                /* Logical link is already ready to go */
+
+                chan->hs_hcon = hchan->conn;
+                chan->hs_hcon->l2cap_data = chan->conn;
+
+                if (result == L2CAP_MR_SUCCESS) {
+                        /* Can confirm now */
+                        l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED);
+                } else {
+                        /* Now only need move success
+                         * to confirm
+                         */
+                        chan->move_state = L2CAP_MOVE_WAIT_RSP_SUCCESS;
+                }
+
+                l2cap_logical_cfm(chan, hchan, L2CAP_MR_SUCCESS);
+                break;
+        default:
+                /* Any other amp move state means the move failed. */
+                chan->move_id = chan->local_amp_id;
+                l2cap_move_done(chan);
+                l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
+        }
+
+        l2cap_chan_unlock(chan);
+}
+
+static void l2cap_move_fail(struct l2cap_conn *conn, u8 ident, u16 icid,
+                            u16 result)
+{
+        struct l2cap_chan *chan;
+
+        chan = l2cap_get_chan_by_ident(conn, ident);
+        if (!chan) {
+                /* Could not locate channel, icid is best guess */
+                l2cap_send_move_chan_cfm_icid(conn, icid);
+                return;
+        }
+
+        __clear_chan_timer(chan);
+
+        if (chan->move_role == L2CAP_MOVE_ROLE_INITIATOR) {
+                if (result == L2CAP_MR_COLLISION) {
+                        chan->move_role = L2CAP_MOVE_ROLE_RESPONDER;
+                } else {
+                        /* Cleanup - cancel move */
+                        chan->move_id = chan->local_amp_id;
+                        l2cap_move_done(chan);
+                }
+        }
+
+        l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
+
+        l2cap_chan_unlock(chan);
+}
+
+static int l2cap_move_channel_rsp(struct l2cap_conn *conn,
+                                  struct l2cap_cmd_hdr *cmd,
+                                  u16 cmd_len, void *data)
 {
         struct l2cap_move_chan_rsp *rsp = data;
         u16 icid, result;
@@ -4332,8 +4483,10 @@ static inline int l2cap_move_channel_rsp(struct l2cap_conn *conn,
 
         BT_DBG("icid 0x%4.4x, result 0x%4.4x", icid, result);
 
-        /* Placeholder: Always unconfirmed */
-        l2cap_send_move_chan_cfm(conn, NULL, icid, L2CAP_MC_UNCONFIRMED);
+        if (result == L2CAP_MR_SUCCESS || result == L2CAP_MR_PEND)
+                l2cap_move_continue(conn, icid, result);
+        else
+                l2cap_move_fail(conn, cmd->ident, icid, result);
 
         return 0;
 }