Bluetooth: EWS: extended window size option support

Adds support for extended window size (EWS) config option. We enable EWS
feature in L2CAP Info RSP when hs enabled. EWS option is included in L2CAP
Config Req if tx_win (which is set via socket) bigger then standard default
value (63) && hs enabled && remote side supports EWS feature.

Using EWS selects extended control field in L2CAP.

Code partly based on Qualcomm and Atheros patches sent upstream a year ago.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>

diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index 08ad40b..51998ff 100644 (file)
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -32,6 +32,7 @@
 #define L2CAP_DEFAULT_MIN_MTU          48
 #define L2CAP_DEFAULT_FLUSH_TO         0xffff
 #define L2CAP_DEFAULT_TX_WINDOW                63
+#define L2CAP_DEFAULT_EXT_WINDOW       0x3FFF
 #define L2CAP_DEFAULT_MAX_TX           3
 #define L2CAP_DEFAULT_RETRANS_TO       2000    /* 2 seconds */
 #define L2CAP_DEFAULT_MONITOR_TO       12000   /* 12 seconds */
@@ -233,6 +234,7 @@ struct l2cap_conf_opt {
 #define L2CAP_CONF_QOS         0x03
 #define L2CAP_CONF_RFC         0x04
 #define L2CAP_CONF_FCS         0x05
+#define L2CAP_CONF_EWS         0x07
 
 #define L2CAP_CONF_MAX_SIZE    22
 
@@ -333,7 +335,7 @@ struct l2cap_chan {
 
        __u8            fcs;
 
-       __u8            tx_win;
+       __u16           tx_win;
        __u8            max_tx;
        __u16           retrans_timeout;
        __u16           monitor_timeout;
@@ -357,7 +359,7 @@ struct l2cap_chan {
        struct sk_buff  *sdu;
        struct sk_buff  *sdu_last_frag;
 
-       __u8            remote_tx_win;
+       __u16           remote_tx_win;
        __u8            remote_max_tx;
        __u16           remote_mps;
 
@@ -442,6 +444,7 @@ enum {
        CONF_CONNECT_PEND,
        CONF_NO_FCS_RECV,
        CONF_STATE2_DEVICE,
+       CONF_EWS_RECV,
 };
 
 #define L2CAP_CONF_MAX_CONF_REQ 2
@@ -465,6 +468,7 @@ enum {
        FLAG_FORCE_ACTIVE,
        FLAG_FORCE_RELIABLE,
        FLAG_FLUSHABLE,
+       FLAG_EXT_CTRL,
 };
 
 #define __set_chan_timer(c, t) l2cap_set_timer(c, &c->chan_timer, (t))

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 18a08c5..6e34312 100644 (file)
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -1898,6 +1898,22 @@ static inline __u8 l2cap_select_mode(__u8 mode, __u16 remote_feat_mask)
        }
 }
 
+static inline bool __l2cap_ews_supported(struct l2cap_chan *chan)
+{
+       return enable_hs && chan->conn->feat_mask & L2CAP_FEAT_EXT_WINDOW;
+}
+
+static inline void l2cap_txwin_setup(struct l2cap_chan *chan)
+{
+       if (chan->tx_win > L2CAP_DEFAULT_TX_WINDOW &&
+                                               __l2cap_ews_supported(chan))
+               /* use extended control field */
+               set_bit(FLAG_EXT_CTRL, &chan->flags);
+       else
+               chan->tx_win = min_t(u16, chan->tx_win,
+                                               L2CAP_DEFAULT_TX_WINDOW);
+}
+
 static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data)
 {
        struct l2cap_conf_req *req = data;
@@ -1944,7 +1960,6 @@ done:
 
        case L2CAP_MODE_ERTM:
                rfc.mode            = L2CAP_MODE_ERTM;
-               rfc.txwin_size      = chan->tx_win;
                rfc.max_transmit    = chan->max_tx;
                rfc.retrans_timeout = 0;
                rfc.monitor_timeout = 0;
@@ -1952,6 +1967,11 @@ done:
                if (L2CAP_DEFAULT_MAX_PDU_SIZE > chan->conn->mtu - 10)
                        rfc.max_pdu_size = cpu_to_le16(chan->conn->mtu - 10);
 
+               l2cap_txwin_setup(chan);
+
+               rfc.txwin_size = min_t(u16, chan->tx_win,
+                                               L2CAP_DEFAULT_TX_WINDOW);
+
                l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
                                                        (unsigned long) &rfc);
 
@@ -1963,6 +1983,10 @@ done:
                        chan->fcs = L2CAP_FCS_NONE;
                        l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1, chan->fcs);
                }
+
+               if (test_bit(FLAG_EXT_CTRL, &chan->flags))
+                       l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS, 2,
+                                                               chan->tx_win);
                break;
 
        case L2CAP_MODE_STREAMING:
@@ -2038,6 +2062,15 @@ static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data)
 
                        break;
 
+               case L2CAP_CONF_EWS:
+                       if (!enable_hs)
+                               return -ECONNREFUSED;
+
+                       set_bit(FLAG_EXT_CTRL, &chan->flags);
+                       set_bit(CONF_EWS_RECV, &chan->conf_state);
+                       chan->remote_tx_win = val;
+                       break;
+
                default:
                        if (hint)
                                break;
@@ -2098,7 +2131,11 @@ done:
                        break;
 
                case L2CAP_MODE_ERTM:
-                       chan->remote_tx_win = rfc.txwin_size;
+                       if (!test_bit(CONF_EWS_RECV, &chan->conf_state))
+                               chan->remote_tx_win = rfc.txwin_size;
+                       else
+                               rfc.txwin_size = L2CAP_DEFAULT_TX_WINDOW;
+
                        chan->remote_max_tx = rfc.max_transmit;
 
                        if (le16_to_cpu(rfc.max_pdu_size) > chan->conn->mtu - 10)
@@ -2190,6 +2227,13 @@ static int l2cap_parse_conf_rsp(struct l2cap_chan *chan, void *rsp, int len, voi
                        l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC,
                                        sizeof(rfc), (unsigned long) &rfc);
                        break;
+
+               case L2CAP_CONF_EWS:
+                       chan->tx_win = min_t(u16, val,
+                                               L2CAP_DEFAULT_EXT_WINDOW);
+                       l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS,
+                                                       2, chan->tx_win);
+                       break;
                }
        }
 
@@ -2785,7 +2829,8 @@ static inline int l2cap_information_req(struct l2cap_conn *conn, struct l2cap_cm
                        feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING
                                                         | L2CAP_FEAT_FCS;
                if (enable_hs)
-                       feat_mask |= L2CAP_FEAT_EXT_FLOW;
+                       feat_mask |= L2CAP_FEAT_EXT_FLOW
+                                               | L2CAP_FEAT_EXT_WINDOW;
 
                put_unaligned_le32(feat_mask, rsp->data);
                l2cap_send_cmd(conn, cmd->ident,

diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index 48ad8ba..836d12e 100644 (file)
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -331,7 +331,7 @@ static int l2cap_sock_getsockopt_old(struct socket *sock, int optname, char __us
                opts.mode     = chan->mode;
                opts.fcs      = chan->fcs;
                opts.max_tx   = chan->max_tx;
-               opts.txwin_size = (__u16)chan->tx_win;
+               opts.txwin_size = chan->tx_win;
 
                len = min_t(unsigned int, len, sizeof(opts));
                if (copy_to_user(optval, (char *) &opts, len))
@@ -501,7 +501,7 @@ static int l2cap_sock_setsockopt_old(struct socket *sock, int optname, char __us
                opts.mode     = chan->mode;
                opts.fcs      = chan->fcs;
                opts.max_tx   = chan->max_tx;
-               opts.txwin_size = (__u16)chan->tx_win;
+               opts.txwin_size = chan->tx_win;
 
                len = min_t(unsigned int, sizeof(opts), optlen);
                if (copy_from_user((char *) &opts, optval, len)) {
@@ -509,7 +509,7 @@ static int l2cap_sock_setsockopt_old(struct socket *sock, int optname, char __us
                        break;
                }
 
-               if (opts.txwin_size > L2CAP_DEFAULT_TX_WINDOW) {
+               if (opts.txwin_size > L2CAP_DEFAULT_EXT_WINDOW) {
                        err = -EINVAL;
                        break;
                }
@@ -533,7 +533,7 @@ static int l2cap_sock_setsockopt_old(struct socket *sock, int optname, char __us
                chan->omtu = opts.omtu;
                chan->fcs  = opts.fcs;
                chan->max_tx = opts.max_tx;
-               chan->tx_win = (__u8)opts.txwin_size;
+               chan->tx_win = opts.txwin_size;
                break;
 
        case L2CAP_LM: